Linux-libre 4.6.2-gnu

125 files changed, 6383 insertions, 2114 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 53abf008e..f0c40bf49 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -14,11 +14,21 @@ obj-y     = fork.o exec_domain.o panic.o \
 obj-$(CONFIG_MULTIUSER) += groups.o
 
 ifdef CONFIG_FUNCTION_TRACER
-# Do not trace debug files and internal ftrace files
-CFLAGS_REMOVE_cgroup-debug.o = $(CC_FLAGS_FTRACE)
+# Do not trace internal ftrace files
 CFLAGS_REMOVE_irq_work.o = $(CC_FLAGS_FTRACE)
 endif
 
+# Prevents flicker of uninteresting __do_softirq()/__local_bh_disable_ip()
+# in coverage traces.
+KCOV_INSTRUMENT_softirq.o := n
+# These are called from save_stack_trace() on slub debug path,
+# and produce insane amounts of uninteresting coverage.
+KCOV_INSTRUMENT_module.o := n
+KCOV_INSTRUMENT_extable.o := n
+# Don't self-instrument.
+KCOV_INSTRUMENT_kcov.o := n
+KASAN_SANITIZE_kcov.o := n
+
 # cond_syscall is currently not LTO compatible
 CFLAGS_sys_ni.o = $(DISABLE_LTO)
 
@@ -69,6 +79,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
 obj-$(CONFIG_AUDIT_WATCH) += audit_watch.o audit_fsnotify.o
 obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
 obj-$(CONFIG_GCOV_KERNEL) += gcov/
+obj-$(CONFIG_KCOV) += kcov.o
 obj-$(CONFIG_KPROBES) += kprobes.o
 obj-$(CONFIG_KGDB) += debug/
 obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
diff --git a/kernel/audit.c b/kernel/audit.c
index 3a3e5deed..678c3f000 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -809,6 +809,16 @@ static int audit_set_feature(struct sk_buff *skb)
 	return 0;
 }
 
+static int audit_replace(pid_t pid)
+{
+	struct sk_buff *skb = audit_make_reply(0, 0, AUDIT_REPLACE, 0, 0,
+					       &pid, sizeof(pid));
+
+	if (!skb)
+		return -ENOMEM;
+	return netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
+}
+
 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
 	u32			seq;
@@ -870,9 +880,17 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		}
 		if (s.mask & AUDIT_STATUS_PID) {
 			int new_pid = s.pid;
+			pid_t requesting_pid = task_tgid_vnr(current);
 
-			if ((!new_pid) && (task_tgid_vnr(current) != audit_pid))
+			if ((!new_pid) && (requesting_pid != audit_pid)) {
+				audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
 				return -EACCES;
+			}
+			if (audit_pid && new_pid &&
+			    audit_replace(requesting_pid) != -ECONNREFUSED) {
+				audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
+				return -EEXIST;
+			}
 			if (audit_enabled != AUDIT_OFF)
 				audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
 			audit_pid = new_pid;
@@ -920,7 +938,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		if (err == 1) { /* match or error */
 			err = 0;
 			if (msg_type == AUDIT_USER_TTY) {
-				err = tty_audit_push_current();
+				err = tty_audit_push();
 				if (err)
 					break;
 			}
@@ -1030,20 +1048,19 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	case AUDIT_TTY_GET: {
 		struct audit_tty_status s;
-		struct task_struct *tsk = current;
+		unsigned int t;
 
-		spin_lock(&tsk->sighand->siglock);
-		s.enabled = tsk->signal->audit_tty;
-		s.log_passwd = tsk->signal->audit_tty_log_passwd;
-		spin_unlock(&tsk->sighand->siglock);
+		t = READ_ONCE(current->signal->audit_tty);
+		s.enabled = t & AUDIT_TTY_ENABLE;
+		s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
 
 		audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
 		break;
 	}
 	case AUDIT_TTY_SET: {
 		struct audit_tty_status s, old;
-		struct task_struct *tsk = current;
 		struct audit_buffer	*ab;
+		unsigned int t;
 
 		memset(&s, 0, sizeof(s));
 		/* guard against past and future API changes */
@@ -1053,14 +1070,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		    (s.log_passwd != 0 && s.log_passwd != 1))
 			err = -EINVAL;
 
-		spin_lock(&tsk->sighand->siglock);
-		old.enabled = tsk->signal->audit_tty;
-		old.log_passwd = tsk->signal->audit_tty_log_passwd;
-		if (!err) {
-			tsk->signal->audit_tty = s.enabled;
-			tsk->signal->audit_tty_log_passwd = s.log_passwd;
+		if (err)
+			t = READ_ONCE(current->signal->audit_tty);
+		else {
+			t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
+			t = xchg(&current->signal->audit_tty, t);
 		}
-		spin_unlock(&tsk->sighand->siglock);
+		old.enabled = t & AUDIT_TTY_ENABLE;
+		old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
 
 		audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
 		audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 9f194aad0..3cf1c5978 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -185,7 +185,7 @@ static struct audit_watch *audit_init_watch(char *path)
 	return watch;
 }
 
-/* Translate a watch string to kernel respresentation. */
+/* Translate a watch string to kernel representation. */
 int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op)
 {
 	struct audit_watch *watch;
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b8ff9e193..94ca7b1e5 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -158,7 +158,7 @@ char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 	return str;
 }
 
-/* Translate an inode field to kernel respresentation. */
+/* Translate an inode field to kernel representation. */
 static inline int audit_to_inode(struct audit_krule *krule,
 				 struct audit_field *f)
 {
@@ -415,7 +415,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 	return 0;
 }
 
-/* Translate struct audit_rule_data to kernel's rule respresentation. */
+/* Translate struct audit_rule_data to kernel's rule representation. */
 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 					       size_t datasz)
 {
@@ -593,7 +593,7 @@ static inline size_t audit_pack_string(void **bufp, const char *str)
 	return len;
 }
 
-/* Translate kernel rule respresentation to struct audit_rule_data. */
+/* Translate kernel rule representation to struct audit_rule_data. */
 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 {
 	struct audit_rule_data *data;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 195ffaee5..7d0e3cf8a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2412,8 +2412,8 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
 		return;
 	audit_log_task(ab);
 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
-			 signr, syscall_get_arch(), syscall, is_compat_task(),
-			 KSTK_EIP(current), code);
+			 signr, syscall_get_arch(), syscall,
+			 in_compat_syscall(), KSTK_EIP(current), code);
 	audit_log_end(ab);
 }
 
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 13272582e..eed911d09 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -1,4 +1,7 @@
 obj-y := core.o
 
 obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o
-obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o
+obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o
+ifeq ($(CONFIG_PERF_EVENTS),y)
+obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
+endif
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 89ebbc4d1..76d5a794e 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -17,15 +17,43 @@
 #include <linux/filter.h>
 #include <linux/perf_event.h>
 
+static void bpf_array_free_percpu(struct bpf_array *array)
+{
+	int i;
+
+	for (i = 0; i < array->map.max_entries; i++)
+		free_percpu(array->pptrs[i]);
+}
+
+static int bpf_array_alloc_percpu(struct bpf_array *array)
+{
+	void __percpu *ptr;
+	int i;
+
+	for (i = 0; i < array->map.max_entries; i++) {
+		ptr = __alloc_percpu_gfp(array->elem_size, 8,
+					 GFP_USER | __GFP_NOWARN);
+		if (!ptr) {
+			bpf_array_free_percpu(array);
+			return -ENOMEM;
+		}
+		array->pptrs[i] = ptr;
+	}
+
+	return 0;
+}
+
 /* Called from syscall */
 static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 {
+	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
 	struct bpf_array *array;
-	u32 elem_size, array_size;
+	u64 array_size;
+	u32 elem_size;
 
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size == 0)
+	    attr->value_size == 0 || attr->map_flags)
 		return ERR_PTR(-EINVAL);
 
 	if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1))
@@ -36,12 +64,16 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 
 	elem_size = round_up(attr->value_size, 8);
 
-	/* check round_up into zero and u32 overflow */
-	if (elem_size == 0 ||
-	    attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size)
+	array_size = sizeof(*array);
+	if (percpu)
+		array_size += (u64) attr->max_entries * sizeof(void *);
+	else
+		array_size += (u64) attr->max_entries * elem_size;
+
+	/* make sure there is no u32 overflow later in round_up() */
+	if (array_size >= U32_MAX - PAGE_SIZE)
 		return ERR_PTR(-ENOMEM);
 
-	array_size = sizeof(*array) + attr->max_entries * elem_size;
 
 	/* allocate all map elements and zero-initialize them */
 	array = kzalloc(array_size, GFP_USER | __GFP_NOWARN);
@@ -52,12 +84,25 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 	}
 
 	/* copy mandatory map attributes */
+	array->map.map_type = attr->map_type;
 	array->map.key_size = attr->key_size;
 	array->map.value_size = attr->value_size;
 	array->map.max_entries = attr->max_entries;
-	array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT;
 	array->elem_size = elem_size;
 
+	if (!percpu)
+		goto out;
+
+	array_size += (u64) attr->max_entries * elem_size * num_possible_cpus();
+
+	if (array_size >= U32_MAX - PAGE_SIZE ||
+	    elem_size > PCPU_MIN_UNIT_SIZE || bpf_array_alloc_percpu(array)) {
+		kvfree(array);
+		return ERR_PTR(-ENOMEM);
+	}
+out:
+	array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT;
+
 	return &array->map;
 }
 
@@ -67,12 +112,50 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key)
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
 	u32 index = *(u32 *)key;
 
-	if (index >= array->map.max_entries)
+	if (unlikely(index >= array->map.max_entries))
 		return NULL;
 
 	return array->value + array->elem_size * index;
 }
 
+/* Called from eBPF program */
+static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+
+	if (unlikely(index >= array->map.max_entries))
+		return NULL;
+
+	return this_cpu_ptr(array->pptrs[index]);
+}
+
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	void __percpu *pptr;
+	int cpu, off = 0;
+	u32 size;
+
+	if (unlikely(index >= array->map.max_entries))
+		return -ENOENT;
+
+	/* per_cpu areas are zero-filled and bpf programs can only
+	 * access 'value_size' of them, so copying rounded areas
+	 * will not leak any kernel data
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	pptr = array->pptrs[index];
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
+		off += size;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
 /* Called from syscall */
 static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 {
@@ -99,19 +182,62 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
 	u32 index = *(u32 *)key;
 
-	if (map_flags > BPF_EXIST)
+	if (unlikely(map_flags > BPF_EXIST))
 		/* unknown flags */
 		return -EINVAL;
 
-	if (index >= array->map.max_entries)
+	if (unlikely(index >= array->map.max_entries))
 		/* all elements were pre-allocated, cannot insert a new one */
 		return -E2BIG;
 
-	if (map_flags == BPF_NOEXIST)
+	if (unlikely(map_flags == BPF_NOEXIST))
 		/* all elements already exist */
 		return -EEXIST;
 
-	memcpy(array->value + array->elem_size * index, value, map->value_size);
+	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		memcpy(this_cpu_ptr(array->pptrs[index]),
+		       value, map->value_size);
+	else
+		memcpy(array->value + array->elem_size * index,
+		       value, map->value_size);
+	return 0;
+}
+
+int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
+			    u64 map_flags)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	void __percpu *pptr;
+	int cpu, off = 0;
+	u32 size;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	if (unlikely(index >= array->map.max_entries))
+		/* all elements were pre-allocated, cannot insert a new one */
+		return -E2BIG;
+
+	if (unlikely(map_flags == BPF_NOEXIST))
+		/* all elements already exist */
+		return -EEXIST;
+
+	/* the user space will provide round_up(value_size, 8) bytes that
+	 * will be copied into per-cpu area. bpf programs can only access
+	 * value_size of it. During lookup the same extra bytes will be
+	 * returned or zeros which were zero-filled by percpu_alloc,
+	 * so no kernel data leaks possible
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	pptr = array->pptrs[index];
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
+		off += size;
+	}
+	rcu_read_unlock();
 	return 0;
 }
 
@@ -133,6 +259,9 @@ static void array_map_free(struct bpf_map *map)
 	 */
 	synchronize_rcu();
 
+	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		bpf_array_free_percpu(array);
+
 	kvfree(array);
 }
 
@@ -150,9 +279,24 @@ static struct bpf_map_type_list array_type __read_mostly = {
 	.type = BPF_MAP_TYPE_ARRAY,
 };
 
+static const struct bpf_map_ops percpu_array_ops = {
+	.map_alloc = array_map_alloc,
+	.map_free = array_map_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = percpu_array_map_lookup_elem,
+	.map_update_elem = array_map_update_elem,
+	.map_delete_elem = array_map_delete_elem,
+};
+
+static struct bpf_map_type_list percpu_array_type __read_mostly = {
+	.ops = &percpu_array_ops,
+	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
+};
+
 static int __init register_array_map(void)
 {
 	bpf_register_map_type(&array_type);
+	bpf_register_map_type(&percpu_array_type);
 	return 0;
 }
 late_initcall(register_array_map);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 972d9a8e4..be0abf669 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -27,6 +27,7 @@
 #include <linux/random.h>
 #include <linux/moduleloader.h>
 #include <linux/bpf.h>
+#include <linux/frame.h>
 
 #include <asm/unaligned.h>
 
@@ -649,6 +650,7 @@ load_byte:
 		WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
 		return 0;
 }
+STACK_FRAME_NON_STANDARD(__bpf_prog_run); /* jump table */
 
 bool bpf_prog_array_compatible(struct bpf_array *array,
 			       const struct bpf_prog *fp)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index c5b30fd8a..fff3650d5 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1,4 +1,5 @@
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
@@ -13,6 +14,7 @@
 #include <linux/jhash.h>
 #include <linux/filter.h>
 #include <linux/vmalloc.h>
+#include "percpu_freelist.h"
 
 struct bucket {
 	struct hlist_head head;
@@ -22,6 +24,8 @@ struct bucket {
 struct bpf_htab {
 	struct bpf_map map;
 	struct bucket *buckets;
+	void *elems;
+	struct pcpu_freelist freelist;
 	atomic_t count;	/* number of elements in this hashtable */
 	u32 n_buckets;	/* number of hash buckets */
 	u32 elem_size;	/* size of each element in bytes */
@@ -29,26 +33,108 @@ struct bpf_htab {
 
 /* each htab element is struct htab_elem + key + value */
 struct htab_elem {
-	struct hlist_node hash_node;
+	union {
+		struct hlist_node hash_node;
+		struct bpf_htab *htab;
+		struct pcpu_freelist_node fnode;
+	};
 	struct rcu_head rcu;
 	u32 hash;
 	char key[0] __aligned(8);
 };
 
+static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
+				     void __percpu *pptr)
+{
+	*(void __percpu **)(l->key + key_size) = pptr;
+}
+
+static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
+{
+	return *(void __percpu **)(l->key + key_size);
+}
+
+static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
+{
+	return (struct htab_elem *) (htab->elems + i * htab->elem_size);
+}
+
+static void htab_free_elems(struct bpf_htab *htab)
+{
+	int i;
+
+	if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
+		goto free_elems;
+
+	for (i = 0; i < htab->map.max_entries; i++) {
+		void __percpu *pptr;
+
+		pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
+					 htab->map.key_size);
+		free_percpu(pptr);
+	}
+free_elems:
+	vfree(htab->elems);
+}
+
+static int prealloc_elems_and_freelist(struct bpf_htab *htab)
+{
+	int err = -ENOMEM, i;
+
+	htab->elems = vzalloc(htab->elem_size * htab->map.max_entries);
+	if (!htab->elems)
+		return -ENOMEM;
+
+	if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
+		goto skip_percpu_elems;
+
+	for (i = 0; i < htab->map.max_entries; i++) {
+		u32 size = round_up(htab->map.value_size, 8);
+		void __percpu *pptr;
+
+		pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
+		if (!pptr)
+			goto free_elems;
+		htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
+				  pptr);
+	}
+
+skip_percpu_elems:
+	err = pcpu_freelist_init(&htab->freelist);
+	if (err)
+		goto free_elems;
+
+	pcpu_freelist_populate(&htab->freelist, htab->elems, htab->elem_size,
+			       htab->map.max_entries);
+	return 0;
+
+free_elems:
+	htab_free_elems(htab);
+	return err;
+}
+
 /* Called from syscall */
 static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 {
+	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_HASH;
 	struct bpf_htab *htab;
 	int err, i;
+	u64 cost;
+
+	if (attr->map_flags & ~BPF_F_NO_PREALLOC)
+		/* reserved bits should not be used */
+		return ERR_PTR(-EINVAL);
 
 	htab = kzalloc(sizeof(*htab), GFP_USER);
 	if (!htab)
 		return ERR_PTR(-ENOMEM);
 
 	/* mandatory map attributes */
+	htab->map.map_type = attr->map_type;
 	htab->map.key_size = attr->key_size;
 	htab->map.value_size = attr->value_size;
 	htab->map.max_entries = attr->max_entries;
+	htab->map.map_flags = attr->map_flags;
 
 	/* check sanity of attributes.
 	 * value_size == 0 may be allowed in the future to use map as a set
@@ -77,24 +163,39 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 		 */
 		goto free_htab;
 
+	if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE)
+		/* make sure the size for pcpu_alloc() is reasonable */
+		goto free_htab;
+
 	htab->elem_size = sizeof(struct htab_elem) +
-			  round_up(htab->map.key_size, 8) +
-			  htab->map.value_size;
+			  round_up(htab->map.key_size, 8);
+	if (percpu)
+		htab->elem_size += sizeof(void *);
+	else
+		htab->elem_size += round_up(htab->map.value_size, 8);
 
 	/* prevent zero size kmalloc and check for u32 overflow */
 	if (htab->n_buckets == 0 ||
 	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
 		goto free_htab;
 
-	if ((u64) htab->n_buckets * sizeof(struct bucket) +
-	    (u64) htab->elem_size * htab->map.max_entries >=
-	    U32_MAX - PAGE_SIZE)
+	cost = (u64) htab->n_buckets * sizeof(struct bucket) +
+	       (u64) htab->elem_size * htab->map.max_entries;
+
+	if (percpu)
+		cost += (u64) round_up(htab->map.value_size, 8) *
+			num_possible_cpus() * htab->map.max_entries;
+
+	if (cost >= U32_MAX - PAGE_SIZE)
 		/* make sure page count doesn't overflow */
 		goto free_htab;
 
-	htab->map.pages = round_up(htab->n_buckets * sizeof(struct bucket) +
-				   htab->elem_size * htab->map.max_entries,
-				   PAGE_SIZE) >> PAGE_SHIFT;
+	htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+	/* if map size is larger than memlock limit, reject it early */
+	err = bpf_map_precharge_memlock(htab->map.pages);
+	if (err)
+		goto free_htab;
 
 	err = -ENOMEM;
 	htab->buckets = kmalloc_array(htab->n_buckets, sizeof(struct bucket),
@@ -111,10 +212,16 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 		raw_spin_lock_init(&htab->buckets[i].lock);
 	}
 
-	atomic_set(&htab->count, 0);
+	if (!(attr->map_flags & BPF_F_NO_PREALLOC)) {
+		err = prealloc_elems_and_freelist(htab);
+		if (err)
+			goto free_buckets;
+	}
 
 	return &htab->map;
 
+free_buckets:
+	kvfree(htab->buckets);
 free_htab:
 	kfree(htab);
 	return ERR_PTR(err);
@@ -148,7 +255,7 @@ static struct htab_elem *lookup_elem_raw(struct hlist_head *head, u32 hash,
 }
 
 /* Called from syscall or from eBPF program */
-static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
+static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
 {
 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 	struct hlist_head *head;
@@ -166,6 +273,13 @@ static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
 
 	l = lookup_elem_raw(head, hash, key, key_size);
 
+	return l;
+}
+
+static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
 	if (l)
 		return l->key + round_up(map->key_size, 8);
 
@@ -226,86 +340,248 @@ find_first_elem:
 		}
 	}
 
-	/* itereated over all buckets and all elements */
+	/* iterated over all buckets and all elements */
 	return -ENOENT;
 }
 
+static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
+{
+	if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
+		free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
+	kfree(l);
+
+}
+
+static void htab_elem_free_rcu(struct rcu_head *head)
+{
+	struct htab_elem *l = container_of(head, struct htab_elem, rcu);
+	struct bpf_htab *htab = l->htab;
+
+	/* must increment bpf_prog_active to avoid kprobe+bpf triggering while
+	 * we're calling kfree, otherwise deadlock is possible if kprobes
+	 * are placed somewhere inside of slub
+	 */
+	preempt_disable();
+	__this_cpu_inc(bpf_prog_active);
+	htab_elem_free(htab, l);
+	__this_cpu_dec(bpf_prog_active);
+	preempt_enable();
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+	if (!(htab->map.map_flags & BPF_F_NO_PREALLOC)) {
+		pcpu_freelist_push(&htab->freelist, &l->fnode);
+	} else {
+		atomic_dec(&htab->count);
+		l->htab = htab;
+		call_rcu(&l->rcu, htab_elem_free_rcu);
+	}
+}
+
+static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
+					 void *value, u32 key_size, u32 hash,
+					 bool percpu, bool onallcpus)
+{
+	u32 size = htab->map.value_size;
+	bool prealloc = !(htab->map.map_flags & BPF_F_NO_PREALLOC);
+	struct htab_elem *l_new;
+	void __percpu *pptr;
+
+	if (prealloc) {
+		l_new = (struct htab_elem *)pcpu_freelist_pop(&htab->freelist);
+		if (!l_new)
+			return ERR_PTR(-E2BIG);
+	} else {
+		if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
+			atomic_dec(&htab->count);
+			return ERR_PTR(-E2BIG);
+		}
+		l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
+		if (!l_new)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	memcpy(l_new->key, key, key_size);
+	if (percpu) {
+		/* round up value_size to 8 bytes */
+		size = round_up(size, 8);
+
+		if (prealloc) {
+			pptr = htab_elem_get_ptr(l_new, key_size);
+		} else {
+			/* alloc_percpu zero-fills */
+			pptr = __alloc_percpu_gfp(size, 8,
+						  GFP_ATOMIC | __GFP_NOWARN);
+			if (!pptr) {
+				kfree(l_new);
+				return ERR_PTR(-ENOMEM);
+			}
+		}
+
+		if (!onallcpus) {
+			/* copy true value_size bytes */
+			memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
+		} else {
+			int off = 0, cpu;
+
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
+						value + off, size);
+				off += size;
+			}
+		}
+		if (!prealloc)
+			htab_elem_set_ptr(l_new, key_size, pptr);
+	} else {
+		memcpy(l_new->key + round_up(key_size, 8), value, size);
+	}
+
+	l_new->hash = hash;
+	return l_new;
+}
+
+static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
+		       u64 map_flags)
+{
+	if (l_old && map_flags == BPF_NOEXIST)
+		/* elem already exists */
+		return -EEXIST;
+
+	if (!l_old && map_flags == BPF_EXIST)
+		/* elem doesn't exist, cannot update it */
+		return -ENOENT;
+
+	return 0;
+}
+
 /* Called from syscall or from eBPF program */
 static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 				u64 map_flags)
 {
 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
-	struct htab_elem *l_new, *l_old;
+	struct htab_elem *l_new = NULL, *l_old;
 	struct hlist_head *head;
-	struct bucket *b;
 	unsigned long flags;
-	u32 key_size;
+	struct bucket *b;
+	u32 key_size, hash;
 	int ret;
 
-	if (map_flags > BPF_EXIST)
+	if (unlikely(map_flags > BPF_EXIST))
 		/* unknown flags */
 		return -EINVAL;
 
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
-	/* allocate new element outside of lock */
-	l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
-	if (!l_new)
-		return -ENOMEM;
-
 	key_size = map->key_size;
 
-	memcpy(l_new->key, key, key_size);
-	memcpy(l_new->key + round_up(key_size, 8), value, map->value_size);
+	hash = htab_map_hash(key, key_size);
 
-	l_new->hash = htab_map_hash(l_new->key, key_size);
-	b = __select_bucket(htab, l_new->hash);
+	b = __select_bucket(htab, hash);
 	head = &b->head;
 
 	/* bpf_map_update_elem() can be called in_irq() */
 	raw_spin_lock_irqsave(&b->lock, flags);
 
-	l_old = lookup_elem_raw(head, l_new->hash, key, key_size);
+	l_old = lookup_elem_raw(head, hash, key, key_size);
 
-	if (!l_old && unlikely(atomic_read(&htab->count) >= map->max_entries)) {
-		/* if elem with this 'key' doesn't exist and we've reached
-		 * max_entries limit, fail insertion of new elem
-		 */
-		ret = -E2BIG;
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
 		goto err;
-	}
 
-	if (l_old && map_flags == BPF_NOEXIST) {
-		/* elem already exists */
-		ret = -EEXIST;
+	l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false);
+	if (IS_ERR(l_new)) {
+		/* all pre-allocated elements are in use or memory exhausted */
+		ret = PTR_ERR(l_new);
 		goto err;
 	}
 
-	if (!l_old && map_flags == BPF_EXIST) {
-		/* elem doesn't exist, cannot update it */
-		ret = -ENOENT;
-		goto err;
-	}
-
-	/* add new element to the head of the list, so that concurrent
-	 * search will find it before old elem
+	/* add new element to the head of the list, so that
+	 * concurrent search will find it before old elem
 	 */
 	hlist_add_head_rcu(&l_new->hash_node, head);
 	if (l_old) {
 		hlist_del_rcu(&l_old->hash_node);
-		kfree_rcu(l_old, rcu);
-	} else {
-		atomic_inc(&htab->count);
+		free_htab_elem(htab, l_old);
 	}
+	ret = 0;
+err:
 	raw_spin_unlock_irqrestore(&b->lock, flags);
+	return ret;
+}
 
-	return 0;
+static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+					 void *value, u64 map_flags,
+					 bool onallcpus)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct htab_elem *l_new = NULL, *l_old;
+	struct hlist_head *head;
+	unsigned long flags;
+	struct bucket *b;
+	u32 key_size, hash;
+	int ret;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size);
+
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	/* bpf_map_update_elem() can be called in_irq() */
+	raw_spin_lock_irqsave(&b->lock, flags);
+
+	l_old = lookup_elem_raw(head, hash, key, key_size);
+
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
+		goto err;
+
+	if (l_old) {
+		void __percpu *pptr = htab_elem_get_ptr(l_old, key_size);
+		u32 size = htab->map.value_size;
+
+		/* per-cpu hash map can update value in-place */
+		if (!onallcpus) {
+			memcpy(this_cpu_ptr(pptr), value, size);
+		} else {
+			int off = 0, cpu;
+
+			size = round_up(size, 8);
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
+						value + off, size);
+				off += size;
+			}
+		}
+	} else {
+		l_new = alloc_htab_elem(htab, key, value, key_size,
+					hash, true, onallcpus);
+		if (IS_ERR(l_new)) {
+			ret = PTR_ERR(l_new);
+			goto err;
+		}
+		hlist_add_head_rcu(&l_new->hash_node, head);
+	}
+	ret = 0;
 err:
 	raw_spin_unlock_irqrestore(&b->lock, flags);
-	kfree(l_new);
 	return ret;
 }
 
+static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+				       void *value, u64 map_flags)
+{
+	return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
+}
+
 /* Called from syscall or from eBPF program */
 static int htab_map_delete_elem(struct bpf_map *map, void *key)
 {
@@ -331,8 +607,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
 
 	if (l) {
 		hlist_del_rcu(&l->hash_node);
-		atomic_dec(&htab->count);
-		kfree_rcu(l, rcu);
+		free_htab_elem(htab, l);
 		ret = 0;
 	}
 
@@ -351,12 +626,10 @@ static void delete_all_elements(struct bpf_htab *htab)
 
 		hlist_for_each_entry_safe(l, n, head, hash_node) {
 			hlist_del_rcu(&l->hash_node);
-			atomic_dec(&htab->count);
-			kfree(l);
+			htab_elem_free(htab, l);
 		}
 	}
 }
-
 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */
 static void htab_map_free(struct bpf_map *map)
 {
@@ -369,10 +642,16 @@ static void htab_map_free(struct bpf_map *map)
 	 */
 	synchronize_rcu();
 
-	/* some of kfree_rcu() callbacks for elements of this map may not have
-	 * executed. It's ok. Proceed to free residual elements and map itself
+	/* some of free_htab_elem() callbacks for elements of this map may
+	 * not have executed. Wait for them.
 	 */
-	delete_all_elements(htab);
+	rcu_barrier();
+	if (htab->map.map_flags & BPF_F_NO_PREALLOC) {
+		delete_all_elements(htab);
+	} else {
+		htab_free_elems(htab);
+		pcpu_freelist_destroy(&htab->freelist);
+	}
 	kvfree(htab->buckets);
 	kfree(htab);
 }
@@ -391,9 +670,76 @@ static struct bpf_map_type_list htab_type __read_mostly = {
 	.type = BPF_MAP_TYPE_HASH,
 };
 
+/* Called from eBPF program */
+static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+	if (l)
+		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
+	else
+		return NULL;
+}
+
+int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct htab_elem *l;
+	void __percpu *pptr;
+	int ret = -ENOENT;
+	int cpu, off = 0;
+	u32 size;
+
+	/* per_cpu areas are zero-filled and bpf programs can only
+	 * access 'value_size' of them, so copying rounded areas
+	 * will not leak any kernel data
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	l = __htab_map_lookup_elem(map, key);
+	if (!l)
+		goto out;
+	pptr = htab_elem_get_ptr(l, map->key_size);
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(value + off,
+				per_cpu_ptr(pptr, cpu), size);
+		off += size;
+	}
+	ret = 0;
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
+			   u64 map_flags)
+{
+	int ret;
+
+	rcu_read_lock();
+	ret = __htab_percpu_map_update_elem(map, key, value, map_flags, true);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static const struct bpf_map_ops htab_percpu_ops = {
+	.map_alloc = htab_map_alloc,
+	.map_free = htab_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_percpu_map_lookup_elem,
+	.map_update_elem = htab_percpu_map_update_elem,
+	.map_delete_elem = htab_map_delete_elem,
+};
+
+static struct bpf_map_type_list htab_percpu_type __read_mostly = {
+	.ops = &htab_percpu_ops,
+	.type = BPF_MAP_TYPE_PERCPU_HASH,
+};
+
 static int __init register_htab_map(void)
 {
 	bpf_register_map_type(&htab_type);
+	bpf_register_map_type(&htab_percpu_type);
 	return 0;
 }
 late_initcall(register_htab_map);
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index f2ece3c17..8f94ca186 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -31,10 +31,10 @@ static void *bpf_any_get(void *raw, enum bpf_type type)
 {
 	switch (type) {
 	case BPF_TYPE_PROG:
-		atomic_inc(&((struct bpf_prog *)raw)->aux->refcnt);
+		raw = bpf_prog_inc(raw);
 		break;
 	case BPF_TYPE_MAP:
-		bpf_map_inc(raw, true);
+		raw = bpf_map_inc(raw, true);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -297,7 +297,8 @@ static void *bpf_obj_do_get(const struct filename *pathname,
 		goto out;
 
 	raw = bpf_any_get(inode->i_private, *type);
-	touch_atime(&path);
+	if (!IS_ERR(raw))
+		touch_atime(&path);
 
 	path_put(&path);
 	return raw;
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
new file mode 100644
index 000000000..5c51d1985
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.c
@@ -0,0 +1,100 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "percpu_freelist.h"
+
+int pcpu_freelist_init(struct pcpu_freelist *s)
+{
+	int cpu;
+
+	s->freelist = alloc_percpu(struct pcpu_freelist_head);
+	if (!s->freelist)
+		return -ENOMEM;
+
+	for_each_possible_cpu(cpu) {
+		struct pcpu_freelist_head *head = per_cpu_ptr(s->freelist, cpu);
+
+		raw_spin_lock_init(&head->lock);
+		head->first = NULL;
+	}
+	return 0;
+}
+
+void pcpu_freelist_destroy(struct pcpu_freelist *s)
+{
+	free_percpu(s->freelist);
+}
+
+static inline void __pcpu_freelist_push(struct pcpu_freelist_head *head,
+					struct pcpu_freelist_node *node)
+{
+	raw_spin_lock(&head->lock);
+	node->next = head->first;
+	head->first = node;
+	raw_spin_unlock(&head->lock);
+}
+
+void pcpu_freelist_push(struct pcpu_freelist *s,
+			struct pcpu_freelist_node *node)
+{
+	struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
+
+	__pcpu_freelist_push(head, node);
+}
+
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+			    u32 nr_elems)
+{
+	struct pcpu_freelist_head *head;
+	unsigned long flags;
+	int i, cpu, pcpu_entries;
+
+	pcpu_entries = nr_elems / num_possible_cpus() + 1;
+	i = 0;
+
+	/* disable irq to workaround lockdep false positive
+	 * in bpf usage pcpu_freelist_populate() will never race
+	 * with pcpu_freelist_push()
+	 */
+	local_irq_save(flags);
+	for_each_possible_cpu(cpu) {
+again:
+		head = per_cpu_ptr(s->freelist, cpu);
+		__pcpu_freelist_push(head, buf);
+		i++;
+		buf += elem_size;
+		if (i == nr_elems)
+			break;
+		if (i % pcpu_entries)
+			goto again;
+	}
+	local_irq_restore(flags);
+}
+
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+	struct pcpu_freelist_head *head;
+	struct pcpu_freelist_node *node;
+	int orig_cpu, cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		head = per_cpu_ptr(s->freelist, cpu);
+		raw_spin_lock(&head->lock);
+		node = head->first;
+		if (node) {
+			head->first = node->next;
+			raw_spin_unlock(&head->lock);
+			return node;
+		}
+		raw_spin_unlock(&head->lock);
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+		if (cpu == orig_cpu)
+			return NULL;
+	}
+}
diff --git a/kernel/bpf/percpu_freelist.h b/kernel/bpf/percpu_freelist.h
new file mode 100644
index 000000000..3049aae8e
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.h
@@ -0,0 +1,31 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#ifndef __PERCPU_FREELIST_H__
+#define __PERCPU_FREELIST_H__
+#include <linux/spinlock.h>
+#include <linux/percpu.h>
+
+struct pcpu_freelist_head {
+	struct pcpu_freelist_node *first;
+	raw_spinlock_t lock;
+};
+
+struct pcpu_freelist {
+	struct pcpu_freelist_head __percpu *freelist;
+};
+
+struct pcpu_freelist_node {
+	struct pcpu_freelist_node *next;
+};
+
+void pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *);
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+			    u32 nr_elems);
+int pcpu_freelist_init(struct pcpu_freelist *);
+void pcpu_freelist_destroy(struct pcpu_freelist *s);
+#endif
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
new file mode 100644
index 000000000..499d9e933
--- /dev/null
+++ b/kernel/bpf/stackmap.c
@@ -0,0 +1,290 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/jhash.h>
+#include <linux/filter.h>
+#include <linux/vmalloc.h>
+#include <linux/stacktrace.h>
+#include <linux/perf_event.h>
+#include "percpu_freelist.h"
+
+struct stack_map_bucket {
+	struct pcpu_freelist_node fnode;
+	u32 hash;
+	u32 nr;
+	u64 ip[];
+};
+
+struct bpf_stack_map {
+	struct bpf_map map;
+	void *elems;
+	struct pcpu_freelist freelist;
+	u32 n_buckets;
+	struct stack_map_bucket *buckets[];
+};
+
+static int prealloc_elems_and_freelist(struct bpf_stack_map *smap)
+{
+	u32 elem_size = sizeof(struct stack_map_bucket) + smap->map.value_size;
+	int err;
+
+	smap->elems = vzalloc(elem_size * smap->map.max_entries);
+	if (!smap->elems)
+		return -ENOMEM;
+
+	err = pcpu_freelist_init(&smap->freelist);
+	if (err)
+		goto free_elems;
+
+	pcpu_freelist_populate(&smap->freelist, smap->elems, elem_size,
+			       smap->map.max_entries);
+	return 0;
+
+free_elems:
+	vfree(smap->elems);
+	return err;
+}
+
+/* Called from syscall */
+static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
+{
+	u32 value_size = attr->value_size;
+	struct bpf_stack_map *smap;
+	u64 cost, n_buckets;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+
+	if (attr->map_flags)
+		return ERR_PTR(-EINVAL);
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 || attr->key_size != 4 ||
+	    value_size < 8 || value_size % 8 ||
+	    value_size / 8 > PERF_MAX_STACK_DEPTH)
+		return ERR_PTR(-EINVAL);
+
+	/* hash table size must be power of 2 */
+	n_buckets = roundup_pow_of_two(attr->max_entries);
+
+	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
+	if (cost >= U32_MAX - PAGE_SIZE)
+		return ERR_PTR(-E2BIG);
+
+	smap = kzalloc(cost, GFP_USER | __GFP_NOWARN);
+	if (!smap) {
+		smap = vzalloc(cost);
+		if (!smap)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	err = -E2BIG;
+	cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));
+	if (cost >= U32_MAX - PAGE_SIZE)
+		goto free_smap;
+
+	smap->map.map_type = attr->map_type;
+	smap->map.key_size = attr->key_size;
+	smap->map.value_size = value_size;
+	smap->map.max_entries = attr->max_entries;
+	smap->n_buckets = n_buckets;
+	smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+	err = bpf_map_precharge_memlock(smap->map.pages);
+	if (err)
+		goto free_smap;
+
+	err = get_callchain_buffers();
+	if (err)
+		goto free_smap;
+
+	err = prealloc_elems_and_freelist(smap);
+	if (err)
+		goto put_buffers;
+
+	return &smap->map;
+
+put_buffers:
+	put_callchain_buffers();
+free_smap:
+	kvfree(smap);
+	return ERR_PTR(err);
+}
+
+static u64 bpf_get_stackid(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5)
+{
+	struct pt_regs *regs = (struct pt_regs *) (long) r1;
+	struct bpf_map *map = (struct bpf_map *) (long) r2;
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct perf_callchain_entry *trace;
+	struct stack_map_bucket *bucket, *new_bucket, *old_bucket;
+	u32 max_depth = map->value_size / 8;
+	/* stack_map_alloc() checks that max_depth <= PERF_MAX_STACK_DEPTH */
+	u32 init_nr = PERF_MAX_STACK_DEPTH - max_depth;
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	u32 hash, id, trace_nr, trace_len;
+	bool user = flags & BPF_F_USER_STACK;
+	bool kernel = !user;
+	u64 *ips;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+		return -EINVAL;
+
+	trace = get_perf_callchain(regs, init_nr, kernel, user, false, false);
+
+	if (unlikely(!trace))
+		/* couldn't fetch the stack trace */
+		return -EFAULT;
+
+	/* get_perf_callchain() guarantees that trace->nr >= init_nr
+	 * and trace-nr <= PERF_MAX_STACK_DEPTH, so trace_nr <= max_depth
+	 */
+	trace_nr = trace->nr - init_nr;
+
+	if (trace_nr <= skip)
+		/* skipping more than usable stack trace */
+		return -EFAULT;
+
+	trace_nr -= skip;
+	trace_len = trace_nr * sizeof(u64);
+	ips = trace->ip + skip + init_nr;
+	hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0);
+	id = hash & (smap->n_buckets - 1);
+	bucket = READ_ONCE(smap->buckets[id]);
+
+	if (bucket && bucket->hash == hash) {
+		if (flags & BPF_F_FAST_STACK_CMP)
+			return id;
+		if (bucket->nr == trace_nr &&
+		    memcmp(bucket->ip, ips, trace_len) == 0)
+			return id;
+	}
+
+	/* this call stack is not in the map, try to add it */
+	if (bucket && !(flags & BPF_F_REUSE_STACKID))
+		return -EEXIST;
+
+	new_bucket = (struct stack_map_bucket *)
+		pcpu_freelist_pop(&smap->freelist);
+	if (unlikely(!new_bucket))
+		return -ENOMEM;
+
+	memcpy(new_bucket->ip, ips, trace_len);
+	new_bucket->hash = hash;
+	new_bucket->nr = trace_nr;
+
+	old_bucket = xchg(&smap->buckets[id], new_bucket);
+	if (old_bucket)
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+	return id;
+}
+
+const struct bpf_func_proto bpf_get_stackid_proto = {
+	.func		= bpf_get_stackid,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+/* Called from eBPF program */
+static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return NULL;
+}
+
+/* Called from syscall */
+int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct stack_map_bucket *bucket, *old_bucket;
+	u32 id = *(u32 *)key, trace_len;
+
+	if (unlikely(id >= smap->n_buckets))
+		return -ENOENT;
+
+	bucket = xchg(&smap->buckets[id], NULL);
+	if (!bucket)
+		return -ENOENT;
+
+	trace_len = bucket->nr * sizeof(u64);
+	memcpy(value, bucket->ip, trace_len);
+	memset(value + trace_len, 0, map->value_size - trace_len);
+
+	old_bucket = xchg(&smap->buckets[id], bucket);
+	if (old_bucket)
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+	return 0;
+}
+
+static int stack_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	return -EINVAL;
+}
+
+static int stack_map_update_elem(struct bpf_map *map, void *key, void *value,
+				 u64 map_flags)
+{
+	return -EINVAL;
+}
+
+/* Called from syscall or from eBPF program */
+static int stack_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct stack_map_bucket *old_bucket;
+	u32 id = *(u32 *)key;
+
+	if (unlikely(id >= smap->n_buckets))
+		return -E2BIG;
+
+	old_bucket = xchg(&smap->buckets[id], NULL);
+	if (old_bucket) {
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+		return 0;
+	} else {
+		return -ENOENT;
+	}
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void stack_map_free(struct bpf_map *map)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+
+	/* wait for bpf programs to complete before freeing stack map */
+	synchronize_rcu();
+
+	vfree(smap->elems);
+	pcpu_freelist_destroy(&smap->freelist);
+	kvfree(smap);
+	put_callchain_buffers();
+}
+
+static const struct bpf_map_ops stack_map_ops = {
+	.map_alloc = stack_map_alloc,
+	.map_free = stack_map_free,
+	.map_get_next_key = stack_map_get_next_key,
+	.map_lookup_elem = stack_map_lookup_elem,
+	.map_update_elem = stack_map_update_elem,
+	.map_delete_elem = stack_map_delete_elem,
+};
+
+static struct bpf_map_type_list stack_map_type __read_mostly = {
+	.ops = &stack_map_ops,
+	.type = BPF_MAP_TYPE_STACK_TRACE,
+};
+
+static int __init register_stack_map(void)
+{
+	bpf_register_map_type(&stack_map_type);
+	return 0;
+}
+late_initcall(register_stack_map);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 637397059..cf5e9f7ad 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -18,6 +18,8 @@
 #include <linux/filter.h>
 #include <linux/version.h>
 
+DEFINE_PER_CPU(int, bpf_prog_active);
+
 int sysctl_unprivileged_bpf_disabled __read_mostly;
 
 static LIST_HEAD(bpf_map_types);
@@ -46,6 +48,19 @@ void bpf_register_map_type(struct bpf_map_type_list *tl)
 	list_add(&tl->list_node, &bpf_map_types);
 }
 
+int bpf_map_precharge_memlock(u32 pages)
+{
+	struct user_struct *user = get_current_user();
+	unsigned long memlock_limit, cur;
+
+	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	cur = atomic_long_read(&user->locked_vm);
+	free_uid(user);
+	if (cur + pages > memlock_limit)
+		return -EPERM;
+	return 0;
+}
+
 static int bpf_map_charge_memlock(struct bpf_map *map)
 {
 	struct user_struct *user = get_current_user();
@@ -122,11 +137,13 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 		   "map_type:\t%u\n"
 		   "key_size:\t%u\n"
 		   "value_size:\t%u\n"
-		   "max_entries:\t%u\n",
+		   "max_entries:\t%u\n"
+		   "map_flags:\t%#x\n",
 		   map->map_type,
 		   map->key_size,
 		   map->value_size,
-		   map->max_entries);
+		   map->max_entries,
+		   map->map_flags);
 }
 #endif
 
@@ -151,7 +168,7 @@ int bpf_map_new_fd(struct bpf_map *map)
 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
 
-#define BPF_MAP_CREATE_LAST_FIELD max_entries
+#define BPF_MAP_CREATE_LAST_FIELD map_flags
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
@@ -201,11 +218,18 @@ struct bpf_map *__bpf_map_get(struct fd f)
 	return f.file->private_data;
 }
 
-void bpf_map_inc(struct bpf_map *map, bool uref)
+/* prog's and map's refcnt limit */
+#define BPF_MAX_REFCNT 32768
+
+struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
 {
-	atomic_inc(&map->refcnt);
+	if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
+		atomic_dec(&map->refcnt);
+		return ERR_PTR(-EBUSY);
+	}
 	if (uref)
 		atomic_inc(&map->usercnt);
+	return map;
 }
 
 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
@@ -217,7 +241,7 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 	if (IS_ERR(map))
 		return map;
 
-	bpf_map_inc(map, true);
+	map = bpf_map_inc(map, true);
 	fdput(f);
 
 	return map;
@@ -229,6 +253,11 @@ static void __user *u64_to_ptr(__u64 val)
 	return (void __user *) (unsigned long) val;
 }
 
+int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+	return -ENOTSUPP;
+}
+
 /* last field in 'union bpf_attr' used by this command */
 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
 
@@ -239,6 +268,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 	int ufd = attr->map_fd;
 	struct bpf_map *map;
 	void *key, *value, *ptr;
+	u32 value_size;
 	struct fd f;
 	int err;
 
@@ -259,23 +289,37 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (copy_from_user(key, ukey, map->key_size) != 0)
 		goto free_key;
 
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		value_size = round_up(map->value_size, 8) * num_possible_cpus();
+	else
+		value_size = map->value_size;
+
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
-	rcu_read_lock();
-	ptr = map->ops->map_lookup_elem(map, key);
-	if (ptr)
-		memcpy(value, ptr, map->value_size);
-	rcu_read_unlock();
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
+		err = bpf_percpu_hash_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
+		err = bpf_stackmap_copy(map, key, value);
+	} else {
+		rcu_read_lock();
+		ptr = map->ops->map_lookup_elem(map, key);
+		if (ptr)
+			memcpy(value, ptr, value_size);
+		rcu_read_unlock();
+		err = ptr ? 0 : -ENOENT;
+	}
 
-	err = -ENOENT;
-	if (!ptr)
+	if (err)
 		goto free_value;
 
 	err = -EFAULT;
-	if (copy_to_user(uvalue, value, map->value_size) != 0)
+	if (copy_to_user(uvalue, value, value_size) != 0)
 		goto free_value;
 
 	err = 0;
@@ -298,6 +342,7 @@ static int map_update_elem(union bpf_attr *attr)
 	int ufd = attr->map_fd;
 	struct bpf_map *map;
 	void *key, *value;
+	u32 value_size;
 	struct fd f;
 	int err;
 
@@ -318,21 +363,37 @@ static int map_update_elem(union bpf_attr *attr)
 	if (copy_from_user(key, ukey, map->key_size) != 0)
 		goto free_key;
 
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		value_size = round_up(map->value_size, 8) * num_possible_cpus();
+	else
+		value_size = map->value_size;
+
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
 	err = -EFAULT;
-	if (copy_from_user(value, uvalue, map->value_size) != 0)
+	if (copy_from_user(value, uvalue, value_size) != 0)
 		goto free_value;
 
-	/* eBPF program that use maps are running under rcu_read_lock(),
-	 * therefore all map accessors rely on this fact, so do the same here
+	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
+	 * inside bpf map update or delete otherwise deadlocks are possible
 	 */
-	rcu_read_lock();
-	err = map->ops->map_update_elem(map, key, value, attr->flags);
-	rcu_read_unlock();
+	preempt_disable();
+	__this_cpu_inc(bpf_prog_active);
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
+		err = bpf_percpu_hash_update(map, key, value, attr->flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_update(map, key, value, attr->flags);
+	} else {
+		rcu_read_lock();
+		err = map->ops->map_update_elem(map, key, value, attr->flags);
+		rcu_read_unlock();
+	}
+	__this_cpu_dec(bpf_prog_active);
+	preempt_enable();
 
 free_value:
 	kfree(value);
@@ -371,9 +432,13 @@ static int map_delete_elem(union bpf_attr *attr)
 	if (copy_from_user(key, ukey, map->key_size) != 0)
 		goto free_key;
 
+	preempt_disable();
+	__this_cpu_inc(bpf_prog_active);
 	rcu_read_lock();
 	err = map->ops->map_delete_elem(map, key);
 	rcu_read_unlock();
+	__this_cpu_dec(bpf_prog_active);
+	preempt_enable();
 
 free_key:
 	kfree(key);
@@ -600,6 +665,15 @@ static struct bpf_prog *__bpf_prog_get(struct fd f)
 	return f.file->private_data;
 }
 
+struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
+{
+	if (atomic_inc_return(&prog->aux->refcnt) > BPF_MAX_REFCNT) {
+		atomic_dec(&prog->aux->refcnt);
+		return ERR_PTR(-EBUSY);
+	}
+	return prog;
+}
+
 /* called by sockets/tracing/seccomp before attaching program to an event
  * pairs with bpf_prog_put()
  */
@@ -612,7 +686,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd)
 	if (IS_ERR(prog))
 		return prog;
 
-	atomic_inc(&prog->aux->refcnt);
+	prog = bpf_prog_inc(prog);
 	fdput(f);
 
 	return prog;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2e7f7ab73..c5c17a62f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -239,15 +239,6 @@ static const char * const reg_type_str[] = {
 	[CONST_IMM]		= "imm",
 };
 
-static const struct {
-	int map_type;
-	int func_id;
-} func_limit[] = {
-	{BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call},
-	{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read},
-	{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_output},
-};
-
 static void print_verifier_state(struct verifier_env *env)
 {
 	enum bpf_reg_type t;
@@ -778,15 +769,24 @@ static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
  * bytes from that pointer, make sure that it's within stack boundary
  * and all elements of stack are initialized
  */
-static int check_stack_boundary(struct verifier_env *env,
-				int regno, int access_size)
+static int check_stack_boundary(struct verifier_env *env, int regno,
+				int access_size, bool zero_size_allowed)
 {
 	struct verifier_state *state = &env->cur_state;
 	struct reg_state *regs = state->regs;
 	int off, i;
 
-	if (regs[regno].type != PTR_TO_STACK)
+	if (regs[regno].type != PTR_TO_STACK) {
+		if (zero_size_allowed && access_size == 0 &&
+		    regs[regno].type == CONST_IMM &&
+		    regs[regno].imm  == 0)
+			return 0;
+
+		verbose("R%d type=%s expected=%s\n", regno,
+			reg_type_str[regs[regno].type],
+			reg_type_str[PTR_TO_STACK]);
 		return -EACCES;
+	}
 
 	off = regs[regno].imm;
 	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
@@ -829,15 +829,24 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
 		return 0;
 	}
 
-	if (arg_type == ARG_PTR_TO_STACK || arg_type == ARG_PTR_TO_MAP_KEY ||
+	if (arg_type == ARG_PTR_TO_MAP_KEY ||
 	    arg_type == ARG_PTR_TO_MAP_VALUE) {
 		expected_type = PTR_TO_STACK;
-	} else if (arg_type == ARG_CONST_STACK_SIZE) {
+	} else if (arg_type == ARG_CONST_STACK_SIZE ||
+		   arg_type == ARG_CONST_STACK_SIZE_OR_ZERO) {
 		expected_type = CONST_IMM;
 	} else if (arg_type == ARG_CONST_MAP_PTR) {
 		expected_type = CONST_PTR_TO_MAP;
 	} else if (arg_type == ARG_PTR_TO_CTX) {
 		expected_type = PTR_TO_CTX;
+	} else if (arg_type == ARG_PTR_TO_STACK) {
+		expected_type = PTR_TO_STACK;
+		/* One exception here. In case function allows for NULL to be
+		 * passed in as argument, it's a CONST_IMM type. Final test
+		 * happens during stack boundary checking.
+		 */
+		if (reg->type == CONST_IMM && reg->imm == 0)
+			expected_type = CONST_IMM;
 	} else {
 		verbose("unsupported arg_type %d\n", arg_type);
 		return -EFAULT;
@@ -867,8 +876,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
 			verbose("invalid map_ptr to access map->key\n");
 			return -EACCES;
 		}
-		err = check_stack_boundary(env, regno, (*mapp)->key_size);
-
+		err = check_stack_boundary(env, regno, (*mapp)->key_size,
+					   false);
 	} else if (arg_type == ARG_PTR_TO_MAP_VALUE) {
 		/* bpf_map_xxx(..., map_ptr, ..., value) call:
 		 * check [value, value + map->value_size) validity
@@ -878,9 +887,12 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
 			verbose("invalid map_ptr to access map->value\n");
 			return -EACCES;
 		}
-		err = check_stack_boundary(env, regno, (*mapp)->value_size);
+		err = check_stack_boundary(env, regno, (*mapp)->value_size,
+					   false);
+	} else if (arg_type == ARG_CONST_STACK_SIZE ||
+		   arg_type == ARG_CONST_STACK_SIZE_OR_ZERO) {
+		bool zero_size_allowed = (arg_type == ARG_CONST_STACK_SIZE_OR_ZERO);
 
-	} else if (arg_type == ARG_CONST_STACK_SIZE) {
 		/* bpf_xxx(..., buf, len) call will access 'len' bytes
 		 * from stack pointer 'buf'. Check it
 		 * note: regno == len, regno - 1 == buf
@@ -890,7 +902,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
 			verbose("ARG_CONST_STACK_SIZE cannot be first argument\n");
 			return -EACCES;
 		}
-		err = check_stack_boundary(env, regno - 1, reg->imm);
+		err = check_stack_boundary(env, regno - 1, reg->imm,
+					   zero_size_allowed);
 	}
 
 	return err;
@@ -898,24 +911,52 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
 
 static int check_map_func_compatibility(struct bpf_map *map, int func_id)
 {
-	bool bool_map, bool_func;
-	int i;
-
 	if (!map)
 		return 0;
 
-	for (i = 0; i < ARRAY_SIZE(func_limit); i++) {
-		bool_map = (map->map_type == func_limit[i].map_type);
-		bool_func = (func_id == func_limit[i].func_id);
-		/* only when map & func pair match it can continue.
-		 * don't allow any other map type to be passed into
-		 * the special func;
-		 */
-		if (bool_func && bool_map != bool_func)
-			return -EINVAL;
+	/* We need a two way check, first is from map perspective ... */
+	switch (map->map_type) {
+	case BPF_MAP_TYPE_PROG_ARRAY:
+		if (func_id != BPF_FUNC_tail_call)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+		if (func_id != BPF_FUNC_perf_event_read &&
+		    func_id != BPF_FUNC_perf_event_output)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_STACK_TRACE:
+		if (func_id != BPF_FUNC_get_stackid)
+			goto error;
+		break;
+	default:
+		break;
+	}
+
+	/* ... and second from the function itself. */
+	switch (func_id) {
+	case BPF_FUNC_tail_call:
+		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
+			goto error;
+		break;
+	case BPF_FUNC_perf_event_read:
+	case BPF_FUNC_perf_event_output:
+		if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
+			goto error;
+		break;
+	case BPF_FUNC_get_stackid:
+		if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
+			goto error;
+		break;
+	default:
+		break;
 	}
 
 	return 0;
+error:
+	verbose("cannot pass map_type %d into func %d\n",
+		map->map_type, func_id);
+	return -EINVAL;
 }
 
 static int check_call(struct verifier_env *env, int func_id)
@@ -1348,6 +1389,7 @@ static int check_ld_abs(struct verifier_env *env, struct bpf_insn *insn)
 	}
 
 	if (insn->dst_reg != BPF_REG_0 || insn->off != 0 ||
+	    BPF_SIZE(insn->code) == BPF_DW ||
 	    (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) {
 		verbose("BPF_LD_ABS uses reserved fields\n");
 		return -EINVAL;
@@ -2003,7 +2045,6 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
 			if (IS_ERR(map)) {
 				verbose("fd %d is not pointing to valid bpf_map\n",
 					insn->imm);
-				fdput(f);
 				return PTR_ERR(map);
 			}
 
@@ -2023,15 +2064,18 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
 				return -E2BIG;
 			}
 
-			/* remember this map */
-			env->used_maps[env->used_map_cnt++] = map;
-
 			/* hold the map. If the program is rejected by verifier,
 			 * the map will be released by release_maps() or it
 			 * will be used by the valid program until it's unloaded
 			 * and all maps are released in free_bpf_prog_info()
 			 */
-			bpf_map_inc(map, false);
+			map = bpf_map_inc(map, false);
+			if (IS_ERR(map)) {
+				fdput(f);
+				return PTR_ERR(map);
+			}
+			env->used_maps[env->used_map_cnt++] = map;
+
 			fdput(f);
 next_insn:
 			insn++;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 355cd5f2b..86cb5c6e8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -59,6 +59,9 @@
 #include <linux/delay.h>
 #include <linux/atomic.h>
 #include <linux/cpuset.h>
+#include <linux/proc_ns.h>
+#include <linux/nsproxy.h>
+#include <linux/proc_ns.h>
 #include <net/sock.h>
 
 /*
@@ -178,10 +181,16 @@ EXPORT_SYMBOL_GPL(cgrp_dfl_root);
  * The default hierarchy always exists but is hidden until mounted for the
  * first time.  This is for backward compatibility.
  */
-static bool cgrp_dfl_root_visible;
+static bool cgrp_dfl_visible;
+
+/* Controllers blocked by the commandline in v1 */
+static u16 cgroup_no_v1_mask;
 
 /* some controllers are not supported in the default hierarchy */
-static unsigned long cgrp_dfl_root_inhibit_ss_mask;
+static u16 cgrp_dfl_inhibit_ss_mask;
+
+/* some controllers are implicitly enabled on the default hierarchy */
+static unsigned long cgrp_dfl_implicit_ss_mask;
 
 /* The list of hierarchy roots */
 
@@ -205,23 +214,34 @@ static u64 css_serial_nr_next = 1;
  * fork/exit handlers to call. This avoids us having to do extra work in the
  * fork/exit path to check which subsystems have fork/exit callbacks.
  */
-static unsigned long have_fork_callback __read_mostly;
-static unsigned long have_exit_callback __read_mostly;
-static unsigned long have_free_callback __read_mostly;
+static u16 have_fork_callback __read_mostly;
+static u16 have_exit_callback __read_mostly;
+static u16 have_free_callback __read_mostly;
+
+/* cgroup namespace for init task */
+struct cgroup_namespace init_cgroup_ns = {
+	.count		= { .counter = 2, },
+	.user_ns	= &init_user_ns,
+	.ns.ops		= &cgroupns_operations,
+	.ns.inum	= PROC_CGROUP_INIT_INO,
+	.root_cset	= &init_css_set,
+};
 
 /* Ditto for the can_fork callback. */
-static unsigned long have_canfork_callback __read_mostly;
+static u16 have_canfork_callback __read_mostly;
 
 static struct file_system_type cgroup2_fs_type;
 static struct cftype cgroup_dfl_base_files[];
 static struct cftype cgroup_legacy_base_files[];
 
-static int rebind_subsystems(struct cgroup_root *dst_root,
-			     unsigned long ss_mask);
+static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);
+static void cgroup_lock_and_drain_offline(struct cgroup *cgrp);
+static int cgroup_apply_control(struct cgroup *cgrp);
+static void cgroup_finalize_control(struct cgroup *cgrp, int ret);
 static void css_task_iter_advance(struct css_task_iter *it);
 static int cgroup_destroy_locked(struct cgroup *cgrp);
-static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
-		      bool visible);
+static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
+					      struct cgroup_subsys *ss);
 static void css_release(struct percpu_ref *ref);
 static void kill_css(struct cgroup_subsys_state *css);
 static int cgroup_addrm_files(struct cgroup_subsys_state *css,
@@ -238,9 +258,17 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
  */
 static bool cgroup_ssid_enabled(int ssid)
 {
+	if (CGROUP_SUBSYS_COUNT == 0)
+		return false;
+
 	return static_key_enabled(cgroup_subsys_enabled_key[ssid]);
 }
 
+static bool cgroup_ssid_no_v1(int ssid)
+{
+	return cgroup_no_v1_mask & (1 << ssid);
+}
+
 /**
  * cgroup_on_dfl - test whether a cgroup is on the default hierarchy
  * @cgrp: the cgroup of interest
@@ -339,6 +367,32 @@ static struct cgroup *cgroup_parent(struct cgroup *cgrp)
 	return NULL;
 }
 
+/* subsystems visibly enabled on a cgroup */
+static u16 cgroup_control(struct cgroup *cgrp)
+{
+	struct cgroup *parent = cgroup_parent(cgrp);
+	u16 root_ss_mask = cgrp->root->subsys_mask;
+
+	if (parent)
+		return parent->subtree_control;
+
+	if (cgroup_on_dfl(cgrp))
+		root_ss_mask &= ~(cgrp_dfl_inhibit_ss_mask |
+				  cgrp_dfl_implicit_ss_mask);
+	return root_ss_mask;
+}
+
+/* subsystems enabled on a cgroup */
+static u16 cgroup_ss_mask(struct cgroup *cgrp)
+{
+	struct cgroup *parent = cgroup_parent(cgrp);
+
+	if (parent)
+		return parent->subtree_ss_mask;
+
+	return cgrp->root->subsys_mask;
+}
+
 /**
  * cgroup_css - obtain a cgroup's css for the specified subsystem
  * @cgrp: the cgroup of interest
@@ -378,16 +432,15 @@ static struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp,
 	if (!ss)
 		return &cgrp->self;
 
-	if (!(cgrp->root->subsys_mask & (1 << ss->id)))
-		return NULL;
-
 	/*
 	 * This function is used while updating css associations and thus
-	 * can't test the csses directly.  Use ->child_subsys_mask.
+	 * can't test the csses directly.  Test ss_mask.
 	 */
-	while (cgroup_parent(cgrp) &&
-	       !(cgroup_parent(cgrp)->child_subsys_mask & (1 << ss->id)))
+	while (!(cgroup_ss_mask(cgrp) & (1 << ss->id))) {
 		cgrp = cgroup_parent(cgrp);
+		if (!cgrp)
+			return NULL;
+	}
 
 	return cgroup_css(cgrp, ss);
 }
@@ -506,22 +559,28 @@ static int notify_on_release(const struct cgroup *cgrp)
 	     (((ss) = cgroup_subsys[ssid]) || true); (ssid)++)
 
 /**
- * for_each_subsys_which - filter for_each_subsys with a bitmask
+ * do_each_subsys_mask - filter for_each_subsys with a bitmask
  * @ss: the iteration cursor
  * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
- * @ss_maskp: a pointer to the bitmask
+ * @ss_mask: the bitmask
  *
  * The block will only run for cases where the ssid-th bit (1 << ssid) of
- * mask is set to 1.
+ * @ss_mask is set.
  */
-#define for_each_subsys_which(ss, ssid, ss_maskp)			\
-	if (!CGROUP_SUBSYS_COUNT) /* to avoid spurious gcc warning */	\
+#define do_each_subsys_mask(ss, ssid, ss_mask) do {			\
+	unsigned long __ss_mask = (ss_mask);				\
+	if (!CGROUP_SUBSYS_COUNT) { /* to avoid spurious gcc warning */	\
 		(ssid) = 0;						\
-	else								\
-		for_each_set_bit(ssid, ss_maskp, CGROUP_SUBSYS_COUNT)	\
-			if (((ss) = cgroup_subsys[ssid]) && false)	\
-				break;					\
-			else
+		break;							\
+	}								\
+	for_each_set_bit(ssid, &__ss_mask, CGROUP_SUBSYS_COUNT) {	\
+		(ss) = cgroup_subsys[ssid];				\
+		{
+
+#define while_each_subsys_mask()					\
+		}							\
+	}								\
+} while (false)
 
 /* iterate across the hierarchies */
 #define for_each_root(root)						\
@@ -535,6 +594,24 @@ static int notify_on_release(const struct cgroup *cgrp)
 			;						\
 		else
 
+/* walk live descendants in preorder */
+#define cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp)		\
+	css_for_each_descendant_pre((d_css), cgroup_css((cgrp), NULL))	\
+		if (({ lockdep_assert_held(&cgroup_mutex);		\
+		       (dsct) = (d_css)->cgroup;			\
+		       cgroup_is_dead(dsct); }))			\
+			;						\
+		else
+
+/* walk live descendants in postorder */
+#define cgroup_for_each_live_descendant_post(dsct, d_css, cgrp)		\
+	css_for_each_descendant_post((d_css), cgroup_css((cgrp), NULL))	\
+		if (({ lockdep_assert_held(&cgroup_mutex);		\
+		       (dsct) = (d_css)->cgroup;			\
+		       cgroup_is_dead(dsct); }))			\
+			;						\
+		else
+
 static void cgroup_release_agent(struct work_struct *work);
 static void check_for_release(struct cgroup *cgrp);
 
@@ -665,6 +742,9 @@ static void css_set_move_task(struct task_struct *task,
 {
 	lockdep_assert_held(&css_set_lock);
 
+	if (to_cset && !css_set_populated(to_cset))
+		css_set_update_populated(to_cset, true);
+
 	if (from_cset) {
 		struct css_task_iter *it, *pos;
 
@@ -698,8 +778,6 @@ static void css_set_move_task(struct task_struct *task,
 		 */
 		WARN_ON_ONCE(task->flags & PF_EXITING);
 
-		if (!css_set_populated(to_cset))
-			css_set_update_populated(to_cset, true);
 		rcu_assign_pointer(task->cgroups, to_cset);
 		list_add_tail(&task->cg_list, use_mg_tasks ? &to_cset->mg_tasks :
 							     &to_cset->tasks);
@@ -1102,13 +1180,13 @@ static void cgroup_destroy_root(struct cgroup_root *root)
 	struct cgroup *cgrp = &root->cgrp;
 	struct cgrp_cset_link *link, *tmp_link;
 
-	mutex_lock(&cgroup_mutex);
+	cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
 
 	BUG_ON(atomic_read(&root->nr_cgrps));
 	BUG_ON(!list_empty(&cgrp->self.children));
 
 	/* Rebind all subsystems back to the default hierarchy */
-	rebind_subsystems(&cgrp_dfl_root, root->subsys_mask);
+	WARN_ON(rebind_subsystems(&cgrp_dfl_root, root->subsys_mask));
 
 	/*
 	 * Release all the links from cset_links to this hierarchy's
@@ -1137,6 +1215,41 @@ static void cgroup_destroy_root(struct cgroup_root *root)
 	cgroup_free_root(root);
 }
 
+/*
+ * look up cgroup associated with current task's cgroup namespace on the
+ * specified hierarchy
+ */
+static struct cgroup *
+current_cgns_cgroup_from_root(struct cgroup_root *root)
+{
+	struct cgroup *res = NULL;
+	struct css_set *cset;
+
+	lockdep_assert_held(&css_set_lock);
+
+	rcu_read_lock();
+
+	cset = current->nsproxy->cgroup_ns->root_cset;
+	if (cset == &init_css_set) {
+		res = &root->cgrp;
+	} else {
+		struct cgrp_cset_link *link;
+
+		list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
+			struct cgroup *c = link->cgrp;
+
+			if (c->root == root) {
+				res = c;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	BUG_ON(!res);
+	return res;
+}
+
 /* look up cgroup associated with given css_set on the specified hierarchy */
 static struct cgroup *cset_cgroup_from_root(struct css_set *cset,
 					    struct cgroup_root *root)
@@ -1248,46 +1361,40 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
 }
 
 /**
- * cgroup_calc_child_subsys_mask - calculate child_subsys_mask
- * @cgrp: the target cgroup
+ * cgroup_calc_subtree_ss_mask - calculate subtree_ss_mask
  * @subtree_control: the new subtree_control mask to consider
+ * @this_ss_mask: available subsystems
  *
  * On the default hierarchy, a subsystem may request other subsystems to be
  * enabled together through its ->depends_on mask.  In such cases, more
  * subsystems than specified in "cgroup.subtree_control" may be enabled.
  *
  * This function calculates which subsystems need to be enabled if
- * @subtree_control is to be applied to @cgrp.  The returned mask is always
- * a superset of @subtree_control and follows the usual hierarchy rules.
+ * @subtree_control is to be applied while restricted to @this_ss_mask.
  */
-static unsigned long cgroup_calc_child_subsys_mask(struct cgroup *cgrp,
-						  unsigned long subtree_control)
+static u16 cgroup_calc_subtree_ss_mask(u16 subtree_control, u16 this_ss_mask)
 {
-	struct cgroup *parent = cgroup_parent(cgrp);
-	unsigned long cur_ss_mask = subtree_control;
+	u16 cur_ss_mask = subtree_control;
 	struct cgroup_subsys *ss;
 	int ssid;
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	if (!cgroup_on_dfl(cgrp))
-		return cur_ss_mask;
+	cur_ss_mask |= cgrp_dfl_implicit_ss_mask;
 
 	while (true) {
-		unsigned long new_ss_mask = cur_ss_mask;
+		u16 new_ss_mask = cur_ss_mask;
 
-		for_each_subsys_which(ss, ssid, &cur_ss_mask)
+		do_each_subsys_mask(ss, ssid, cur_ss_mask) {
 			new_ss_mask |= ss->depends_on;
+		} while_each_subsys_mask();
 
 		/*
 		 * Mask out subsystems which aren't available.  This can
 		 * happen only if some depended-upon subsystems were bound
 		 * to non-default hierarchies.
 		 */
-		if (parent)
-			new_ss_mask &= parent->child_subsys_mask;
-		else
-			new_ss_mask &= cgrp->root->subsys_mask;
+		new_ss_mask &= this_ss_mask;
 
 		if (new_ss_mask == cur_ss_mask)
 			break;
@@ -1298,19 +1405,6 @@ static unsigned long cgroup_calc_child_subsys_mask(struct cgroup *cgrp,
 }
 
 /**
- * cgroup_refresh_child_subsys_mask - update child_subsys_mask
- * @cgrp: the target cgroup
- *
- * Update @cgrp->child_subsys_mask according to the current
- * @cgrp->subtree_control using cgroup_calc_child_subsys_mask().
- */
-static void cgroup_refresh_child_subsys_mask(struct cgroup *cgrp)
-{
-	cgrp->child_subsys_mask =
-		cgroup_calc_child_subsys_mask(cgrp, cgrp->subtree_control);
-}
-
-/**
  * cgroup_kn_unlock - unlocking helper for cgroup kernfs methods
  * @kn: the kernfs_node being serviced
  *
@@ -1338,19 +1432,22 @@ static void cgroup_kn_unlock(struct kernfs_node *kn)
 /**
  * cgroup_kn_lock_live - locking helper for cgroup kernfs methods
  * @kn: the kernfs_node being serviced
+ * @drain_offline: perform offline draining on the cgroup
  *
  * This helper is to be used by a cgroup kernfs method currently servicing
  * @kn.  It breaks the active protection, performs cgroup locking and
  * verifies that the associated cgroup is alive.  Returns the cgroup if
  * alive; otherwise, %NULL.  A successful return should be undone by a
- * matching cgroup_kn_unlock() invocation.
+ * matching cgroup_kn_unlock() invocation.  If @drain_offline is %true, the
+ * cgroup is drained of offlining csses before return.
  *
  * Any cgroup kernfs method implementation which requires locking the
  * associated cgroup should use this helper.  It avoids nesting cgroup
  * locking under kernfs active protection and allows all kernfs operations
  * including self-removal.
  */
-static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn)
+static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn,
+					  bool drain_offline)
 {
 	struct cgroup *cgrp;
 
@@ -1369,7 +1466,10 @@ static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn)
 		return NULL;
 	kernfs_break_active_protection(kn);
 
-	mutex_lock(&cgroup_mutex);
+	if (drain_offline)
+		cgroup_lock_and_drain_offline(cgrp);
+	else
+		mutex_lock(&cgroup_mutex);
 
 	if (!cgroup_is_dead(cgrp))
 		return cgrp;
@@ -1399,14 +1499,17 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 /**
  * css_clear_dir - remove subsys files in a cgroup directory
  * @css: taget css
- * @cgrp_override: specify if target cgroup is different from css->cgroup
  */
-static void css_clear_dir(struct cgroup_subsys_state *css,
-			  struct cgroup *cgrp_override)
+static void css_clear_dir(struct cgroup_subsys_state *css)
 {
-	struct cgroup *cgrp = cgrp_override ?: css->cgroup;
+	struct cgroup *cgrp = css->cgroup;
 	struct cftype *cfts;
 
+	if (!(css->flags & CSS_VISIBLE))
+		return;
+
+	css->flags &= ~CSS_VISIBLE;
+
 	list_for_each_entry(cfts, &css->ss->cfts, node)
 		cgroup_addrm_files(css, cgrp, cfts, false);
 }
@@ -1414,17 +1517,18 @@ static void css_clear_dir(struct cgroup_subsys_state *css,
 /**
  * css_populate_dir - create subsys files in a cgroup directory
  * @css: target css
- * @cgrp_overried: specify if target cgroup is different from css->cgroup
  *
  * On failure, no file is added.
  */
-static int css_populate_dir(struct cgroup_subsys_state *css,
-			    struct cgroup *cgrp_override)
+static int css_populate_dir(struct cgroup_subsys_state *css)
 {
-	struct cgroup *cgrp = cgrp_override ?: css->cgroup;
+	struct cgroup *cgrp = css->cgroup;
 	struct cftype *cfts, *failed_cfts;
 	int ret;
 
+	if ((css->flags & CSS_VISIBLE) || !cgrp->kn)
+		return 0;
+
 	if (!css->ss) {
 		if (cgroup_on_dfl(cgrp))
 			cfts = cgroup_dfl_base_files;
@@ -1441,6 +1545,9 @@ static int css_populate_dir(struct cgroup_subsys_state *css,
 			goto err;
 		}
 	}
+
+	css->flags |= CSS_VISIBLE;
+
 	return 0;
 err:
 	list_for_each_entry(cfts, &css->ss->cfts, node) {
@@ -1451,67 +1558,30 @@ err:
 	return ret;
 }
 
-static int rebind_subsystems(struct cgroup_root *dst_root,
-			     unsigned long ss_mask)
+static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
 {
 	struct cgroup *dcgrp = &dst_root->cgrp;
 	struct cgroup_subsys *ss;
-	unsigned long tmp_ss_mask;
 	int ssid, i, ret;
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	for_each_subsys_which(ss, ssid, &ss_mask) {
-		/* if @ss has non-root csses attached to it, can't move */
-		if (css_next_child(NULL, cgroup_css(&ss->root->cgrp, ss)))
+	do_each_subsys_mask(ss, ssid, ss_mask) {
+		/*
+		 * If @ss has non-root csses attached to it, can't move.
+		 * If @ss is an implicit controller, it is exempt from this
+		 * rule and can be stolen.
+		 */
+		if (css_next_child(NULL, cgroup_css(&ss->root->cgrp, ss)) &&
+		    !ss->implicit_on_dfl)
 			return -EBUSY;
 
 		/* can't move between two non-dummy roots either */
 		if (ss->root != &cgrp_dfl_root && dst_root != &cgrp_dfl_root)
 			return -EBUSY;
-	}
-
-	/* skip creating root files on dfl_root for inhibited subsystems */
-	tmp_ss_mask = ss_mask;
-	if (dst_root == &cgrp_dfl_root)
-		tmp_ss_mask &= ~cgrp_dfl_root_inhibit_ss_mask;
+	} while_each_subsys_mask();
 
-	for_each_subsys_which(ss, ssid, &tmp_ss_mask) {
-		struct cgroup *scgrp = &ss->root->cgrp;
-		int tssid;
-
-		ret = css_populate_dir(cgroup_css(scgrp, ss), dcgrp);
-		if (!ret)
-			continue;
-
-		/*
-		 * Rebinding back to the default root is not allowed to
-		 * fail.  Using both default and non-default roots should
-		 * be rare.  Moving subsystems back and forth even more so.
-		 * Just warn about it and continue.
-		 */
-		if (dst_root == &cgrp_dfl_root) {
-			if (cgrp_dfl_root_visible) {
-				pr_warn("failed to create files (%d) while rebinding 0x%lx to default root\n",
-					ret, ss_mask);
-				pr_warn("you may retry by moving them to a different hierarchy and unbinding\n");
-			}
-			continue;
-		}
-
-		for_each_subsys_which(ss, tssid, &tmp_ss_mask) {
-			if (tssid == ssid)
-				break;
-			css_clear_dir(cgroup_css(scgrp, ss), dcgrp);
-		}
-		return ret;
-	}
-
-	/*
-	 * Nothing can fail from this point on.  Remove files for the
-	 * removed subsystems and rebind each subsystem.
-	 */
-	for_each_subsys_which(ss, ssid, &ss_mask) {
+	do_each_subsys_mask(ss, ssid, ss_mask) {
 		struct cgroup_root *src_root = ss->root;
 		struct cgroup *scgrp = &src_root->cgrp;
 		struct cgroup_subsys_state *css = cgroup_css(scgrp, ss);
@@ -1519,8 +1589,12 @@ static int rebind_subsystems(struct cgroup_root *dst_root,
 
 		WARN_ON(!css || cgroup_css(dcgrp, ss));
 
-		css_clear_dir(css, NULL);
+		/* disable from the source */
+		src_root->subsys_mask &= ~(1 << ssid);
+		WARN_ON(cgroup_apply_control(scgrp));
+		cgroup_finalize_control(scgrp, 0);
 
+		/* rebind */
 		RCU_INIT_POINTER(scgrp->subsys[ssid], NULL);
 		rcu_assign_pointer(dcgrp->subsys[ssid], css);
 		ss->root = dst_root;
@@ -1532,28 +1606,55 @@ static int rebind_subsystems(struct cgroup_root *dst_root,
 				       &dcgrp->e_csets[ss->id]);
 		spin_unlock_bh(&css_set_lock);
 
-		src_root->subsys_mask &= ~(1 << ssid);
-		scgrp->subtree_control &= ~(1 << ssid);
-		cgroup_refresh_child_subsys_mask(scgrp);
-
 		/* default hierarchy doesn't enable controllers by default */
 		dst_root->subsys_mask |= 1 << ssid;
 		if (dst_root == &cgrp_dfl_root) {
 			static_branch_enable(cgroup_subsys_on_dfl_key[ssid]);
 		} else {
 			dcgrp->subtree_control |= 1 << ssid;
-			cgroup_refresh_child_subsys_mask(dcgrp);
 			static_branch_disable(cgroup_subsys_on_dfl_key[ssid]);
 		}
 
+		ret = cgroup_apply_control(dcgrp);
+		if (ret)
+			pr_warn("partial failure to rebind %s controller (err=%d)\n",
+				ss->name, ret);
+
 		if (ss->bind)
 			ss->bind(css);
-	}
+	} while_each_subsys_mask();
 
 	kernfs_activate(dcgrp->kn);
 	return 0;
 }
 
+static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
+			    struct kernfs_root *kf_root)
+{
+	int len = 0;
+	char *buf = NULL;
+	struct cgroup_root *kf_cgroot = cgroup_root_from_kf(kf_root);
+	struct cgroup *ns_cgroup;
+
+	buf = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	spin_lock_bh(&css_set_lock);
+	ns_cgroup = current_cgns_cgroup_from_root(kf_cgroot);
+	len = kernfs_path_from_node(kf_node, ns_cgroup->kn, buf, PATH_MAX);
+	spin_unlock_bh(&css_set_lock);
+
+	if (len >= PATH_MAX)
+		len = -ERANGE;
+	else if (len > 0) {
+		seq_escape(sf, buf, " \t\n\\");
+		len = 0;
+	}
+	kfree(buf);
+	return len;
+}
+
 static int cgroup_show_options(struct seq_file *seq,
 			       struct kernfs_root *kf_root)
 {
@@ -1584,7 +1685,7 @@ static int cgroup_show_options(struct seq_file *seq,
 }
 
 struct cgroup_sb_opts {
-	unsigned long subsys_mask;
+	u16 subsys_mask;
 	unsigned int flags;
 	char *release_agent;
 	bool cpuset_clone_children;
@@ -1597,13 +1698,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 {
 	char *token, *o = data;
 	bool all_ss = false, one_ss = false;
-	unsigned long mask = -1UL;
+	u16 mask = U16_MAX;
 	struct cgroup_subsys *ss;
 	int nr_opts = 0;
 	int i;
 
 #ifdef CONFIG_CPUSETS
-	mask = ~(1U << cpuset_cgrp_id);
+	mask = ~((u16)1 << cpuset_cgrp_id);
 #endif
 
 	memset(opts, 0, sizeof(*opts));
@@ -1678,6 +1779,8 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 				continue;
 			if (!cgroup_ssid_enabled(i))
 				continue;
+			if (cgroup_ssid_no_v1(i))
+				continue;
 
 			/* Mutually exclusive option 'all' + subsystem name */
 			if (all_ss)
@@ -1698,7 +1801,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 	 */
 	if (all_ss || (!one_ss && !opts->none && !opts->name))
 		for_each_subsys(ss, i)
-			if (cgroup_ssid_enabled(i))
+			if (cgroup_ssid_enabled(i) && !cgroup_ssid_no_v1(i))
 				opts->subsys_mask |= (1 << i);
 
 	/*
@@ -1728,14 +1831,14 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
 	int ret = 0;
 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);
 	struct cgroup_sb_opts opts;
-	unsigned long added_mask, removed_mask;
+	u16 added_mask, removed_mask;
 
 	if (root == &cgrp_dfl_root) {
 		pr_err("remount is not allowed\n");
 		return -EINVAL;
 	}
 
-	mutex_lock(&cgroup_mutex);
+	cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
 
 	/* See what subsystems are wanted */
 	ret = parse_cgroupfs_options(data, &opts);
@@ -1768,7 +1871,7 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
 	if (ret)
 		goto out_unlock;
 
-	rebind_subsystems(&cgrp_dfl_root, removed_mask);
+	WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
 
 	if (opts.release_agent) {
 		spin_lock(&release_agent_path_lock);
@@ -1876,7 +1979,7 @@ static void init_cgroup_root(struct cgroup_root *root,
 		set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);
 }
 
-static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask)
+static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
 {
 	LIST_HEAD(tmp_links);
 	struct cgroup *root_cgrp = &root->cgrp;
@@ -1899,10 +2002,11 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask)
 	/*
 	 * We're accessing css_set_count without locking css_set_lock here,
 	 * but that's OK - it can only be increased by someone holding
-	 * cgroup_lock, and that's us. The worst that can happen is that we
-	 * have some link structures left over
+	 * cgroup_lock, and that's us.  Later rebinding may disable
+	 * controllers on the default hierarchy and thus create new csets,
+	 * which can't be more than the existing ones.  Allocate 2x.
 	 */
-	ret = allocate_cgrp_cset_links(css_set_count, &tmp_links);
+	ret = allocate_cgrp_cset_links(2 * css_set_count, &tmp_links);
 	if (ret)
 		goto cancel_ref;
 
@@ -1919,7 +2023,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask)
 	}
 	root_cgrp->kn = root->kf_root->kn;
 
-	ret = css_populate_dir(&root_cgrp->self, NULL);
+	ret = css_populate_dir(&root_cgrp->self);
 	if (ret)
 		goto destroy_root;
 
@@ -1972,6 +2076,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 {
 	bool is_v2 = fs_type == &cgroup2_fs_type;
 	struct super_block *pinned_sb = NULL;
+	struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
 	struct cgroup_subsys *ss;
 	struct cgroup_root *root;
 	struct cgroup_sb_opts opts;
@@ -1980,6 +2085,14 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 	int i;
 	bool new_sb;
 
+	get_cgroup_ns(ns);
+
+	/* Check if the caller has permission to mount. */
+	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) {
+		put_cgroup_ns(ns);
+		return ERR_PTR(-EPERM);
+	}
+
 	/*
 	 * The first time anyone tries to mount a cgroup, enable the list
 	 * linking each css_set to its tasks and fix up all existing tasks.
@@ -1990,15 +2103,16 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 	if (is_v2) {
 		if (data) {
 			pr_err("cgroup2: unknown option \"%s\"\n", (char *)data);
+			put_cgroup_ns(ns);
 			return ERR_PTR(-EINVAL);
 		}
-		cgrp_dfl_root_visible = true;
+		cgrp_dfl_visible = true;
 		root = &cgrp_dfl_root;
 		cgroup_get(&root->cgrp);
 		goto out_mount;
 	}
 
-	mutex_lock(&cgroup_mutex);
+	cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
 
 	/* First find the desired set of subsystems */
 	ret = parse_cgroupfs_options(data, &opts);
@@ -2095,6 +2209,16 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 		goto out_unlock;
 	}
 
+	/*
+	 * We know this subsystem has not yet been bound.  Users in a non-init
+	 * user namespace may only mount hierarchies with no bound subsystems,
+	 * i.e. 'none,name=user1'
+	 */
+	if (!opts.none && !capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
 	root = kzalloc(sizeof(*root), GFP_KERNEL);
 	if (!root) {
 		ret = -ENOMEM;
@@ -2113,12 +2237,37 @@ out_free:
 	kfree(opts.release_agent);
 	kfree(opts.name);
 
-	if (ret)
+	if (ret) {
+		put_cgroup_ns(ns);
 		return ERR_PTR(ret);
+	}
 out_mount:
 	dentry = kernfs_mount(fs_type, flags, root->kf_root,
 			      is_v2 ? CGROUP2_SUPER_MAGIC : CGROUP_SUPER_MAGIC,
 			      &new_sb);
+
+	/*
+	 * In non-init cgroup namespace, instead of root cgroup's
+	 * dentry, we return the dentry corresponding to the
+	 * cgroupns->root_cgrp.
+	 */
+	if (!IS_ERR(dentry) && ns != &init_cgroup_ns) {
+		struct dentry *nsdentry;
+		struct cgroup *cgrp;
+
+		mutex_lock(&cgroup_mutex);
+		spin_lock_bh(&css_set_lock);
+
+		cgrp = cset_cgroup_from_root(ns->root_cset, root);
+
+		spin_unlock_bh(&css_set_lock);
+		mutex_unlock(&cgroup_mutex);
+
+		nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb);
+		dput(dentry);
+		dentry = nsdentry;
+	}
+
 	if (IS_ERR(dentry) || !new_sb)
 		cgroup_put(&root->cgrp);
 
@@ -2131,6 +2280,7 @@ out_mount:
 		deactivate_super(pinned_sb);
 	}
 
+	put_cgroup_ns(ns);
 	return dentry;
 }
 
@@ -2159,14 +2309,45 @@ static struct file_system_type cgroup_fs_type = {
 	.name = "cgroup",
 	.mount = cgroup_mount,
 	.kill_sb = cgroup_kill_sb,
+	.fs_flags = FS_USERNS_MOUNT,
 };
 
 static struct file_system_type cgroup2_fs_type = {
 	.name = "cgroup2",
 	.mount = cgroup_mount,
 	.kill_sb = cgroup_kill_sb,
+	.fs_flags = FS_USERNS_MOUNT,
 };
 
+static char *cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
+				   struct cgroup_namespace *ns)
+{
+	struct cgroup *root = cset_cgroup_from_root(ns->root_cset, cgrp->root);
+	int ret;
+
+	ret = kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen);
+	if (ret < 0 || ret >= buflen)
+		return NULL;
+	return buf;
+}
+
+char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
+		     struct cgroup_namespace *ns)
+{
+	char *ret;
+
+	mutex_lock(&cgroup_mutex);
+	spin_lock_bh(&css_set_lock);
+
+	ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns);
+
+	spin_unlock_bh(&css_set_lock);
+	mutex_unlock(&cgroup_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cgroup_path_ns);
+
 /**
  * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy
  * @task: target task
@@ -2194,7 +2375,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
 
 	if (root) {
 		cgrp = task_cgroup_from_root(task, root);
-		path = cgroup_path(cgrp, buf, buflen);
+		path = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
 	} else {
 		/* if no hierarchy exists, everyone is in "/" */
 		if (strlcpy(buf, "/", buflen) < buflen)
@@ -2338,38 +2519,38 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
 }
 
 /**
- * cgroup_taskset_migrate - migrate a taskset to a cgroup
+ * cgroup_taskset_migrate - migrate a taskset
  * @tset: taget taskset
- * @dst_cgrp: destination cgroup
+ * @root: cgroup root the migration is taking place on
  *
- * Migrate tasks in @tset to @dst_cgrp.  This function fails iff one of the
- * ->can_attach callbacks fails and guarantees that either all or none of
- * the tasks in @tset are migrated.  @tset is consumed regardless of
- * success.
+ * Migrate tasks in @tset as setup by migration preparation functions.
+ * This function fails iff one of the ->can_attach callbacks fails and
+ * guarantees that either all or none of the tasks in @tset are migrated.
+ * @tset is consumed regardless of success.
  */
 static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
-				  struct cgroup *dst_cgrp)
+				  struct cgroup_root *root)
 {
-	struct cgroup_subsys_state *css, *failed_css = NULL;
+	struct cgroup_subsys *ss;
 	struct task_struct *task, *tmp_task;
 	struct css_set *cset, *tmp_cset;
-	int i, ret;
+	int ssid, failed_ssid, ret;
 
 	/* methods shouldn't be called if no task is actually migrating */
 	if (list_empty(&tset->src_csets))
 		return 0;
 
 	/* check that we can legitimately attach to the cgroup */
-	for_each_e_css(css, i, dst_cgrp) {
-		if (css->ss->can_attach) {
-			tset->ssid = i;
-			ret = css->ss->can_attach(tset);
+	do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+		if (ss->can_attach) {
+			tset->ssid = ssid;
+			ret = ss->can_attach(tset);
 			if (ret) {
-				failed_css = css;
+				failed_ssid = ssid;
 				goto out_cancel_attach;
 			}
 		}
-	}
+	} while_each_subsys_mask();
 
 	/*
 	 * Now that we're guaranteed success, proceed to move all tasks to
@@ -2396,25 +2577,25 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
 	 */
 	tset->csets = &tset->dst_csets;
 
-	for_each_e_css(css, i, dst_cgrp) {
-		if (css->ss->attach) {
-			tset->ssid = i;
-			css->ss->attach(tset);
+	do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+		if (ss->attach) {
+			tset->ssid = ssid;
+			ss->attach(tset);
 		}
-	}
+	} while_each_subsys_mask();
 
 	ret = 0;
 	goto out_release_tset;
 
 out_cancel_attach:
-	for_each_e_css(css, i, dst_cgrp) {
-		if (css == failed_css)
+	do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+		if (ssid == failed_ssid)
 			break;
-		if (css->ss->cancel_attach) {
-			tset->ssid = i;
-			css->ss->cancel_attach(tset);
+		if (ss->cancel_attach) {
+			tset->ssid = ssid;
+			ss->cancel_attach(tset);
 		}
-	}
+	} while_each_subsys_mask();
 out_release_tset:
 	spin_lock_bh(&css_set_lock);
 	list_splice_init(&tset->dst_csets, &tset->src_csets);
@@ -2427,6 +2608,20 @@ out_release_tset:
 }
 
 /**
+ * cgroup_may_migrate_to - verify whether a cgroup can be migration destination
+ * @dst_cgrp: destination cgroup to test
+ *
+ * On the default hierarchy, except for the root, subtree_control must be
+ * zero for migration destination cgroups with tasks so that child cgroups
+ * don't compete against tasks.
+ */
+static bool cgroup_may_migrate_to(struct cgroup *dst_cgrp)
+{
+	return !cgroup_on_dfl(dst_cgrp) || !cgroup_parent(dst_cgrp) ||
+		!dst_cgrp->subtree_control;
+}
+
+/**
  * cgroup_migrate_finish - cleanup after attach
  * @preloaded_csets: list of preloaded css_sets
  *
@@ -2442,6 +2637,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
 	spin_lock_bh(&css_set_lock);
 	list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {
 		cset->mg_src_cgrp = NULL;
+		cset->mg_dst_cgrp = NULL;
 		cset->mg_dst_cset = NULL;
 		list_del_init(&cset->mg_preload_node);
 		put_css_set_locked(cset);
@@ -2488,52 +2684,42 @@ static void cgroup_migrate_add_src(struct css_set *src_cset,
 		return;
 
 	WARN_ON(src_cset->mg_src_cgrp);
+	WARN_ON(src_cset->mg_dst_cgrp);
 	WARN_ON(!list_empty(&src_cset->mg_tasks));
 	WARN_ON(!list_empty(&src_cset->mg_node));
 
 	src_cset->mg_src_cgrp = src_cgrp;
+	src_cset->mg_dst_cgrp = dst_cgrp;
 	get_css_set(src_cset);
 	list_add(&src_cset->mg_preload_node, preloaded_csets);
 }
 
 /**
  * cgroup_migrate_prepare_dst - prepare destination css_sets for migration
- * @dst_cgrp: the destination cgroup (may be %NULL)
  * @preloaded_csets: list of preloaded source css_sets
  *
- * Tasks are about to be moved to @dst_cgrp and all the source css_sets
- * have been preloaded to @preloaded_csets.  This function looks up and
- * pins all destination css_sets, links each to its source, and append them
- * to @preloaded_csets.  If @dst_cgrp is %NULL, the destination of each
- * source css_set is assumed to be its cgroup on the default hierarchy.
+ * Tasks are about to be moved and all the source css_sets have been
+ * preloaded to @preloaded_csets.  This function looks up and pins all
+ * destination css_sets, links each to its source, and append them to
+ * @preloaded_csets.
  *
  * This function must be called after cgroup_migrate_add_src() has been
  * called on each migration source css_set.  After migration is performed
  * using cgroup_migrate(), cgroup_migrate_finish() must be called on
  * @preloaded_csets.
  */
-static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp,
-				      struct list_head *preloaded_csets)
+static int cgroup_migrate_prepare_dst(struct list_head *preloaded_csets)
 {
 	LIST_HEAD(csets);
 	struct css_set *src_cset, *tmp_cset;
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	/*
-	 * Except for the root, child_subsys_mask must be zero for a cgroup
-	 * with tasks so that child cgroups don't compete against tasks.
-	 */
-	if (dst_cgrp && cgroup_on_dfl(dst_cgrp) && cgroup_parent(dst_cgrp) &&
-	    dst_cgrp->child_subsys_mask)
-		return -EBUSY;
-
 	/* look up the dst cset for each src cset and link it to src */
 	list_for_each_entry_safe(src_cset, tmp_cset, preloaded_csets, mg_preload_node) {
 		struct css_set *dst_cset;
 
-		dst_cset = find_css_set(src_cset,
-					dst_cgrp ?: src_cset->dfl_cgrp);
+		dst_cset = find_css_set(src_cset, src_cset->mg_dst_cgrp);
 		if (!dst_cset)
 			goto err;
 
@@ -2546,6 +2732,7 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp,
 		 */
 		if (src_cset == dst_cset) {
 			src_cset->mg_src_cgrp = NULL;
+			src_cset->mg_dst_cgrp = NULL;
 			list_del_init(&src_cset->mg_preload_node);
 			put_css_set(src_cset);
 			put_css_set(dst_cset);
@@ -2571,11 +2758,11 @@ err:
  * cgroup_migrate - migrate a process or task to a cgroup
  * @leader: the leader of the process or the task to migrate
  * @threadgroup: whether @leader points to the whole process or a single task
- * @cgrp: the destination cgroup
+ * @root: cgroup root migration is taking place on
  *
- * Migrate a process or task denoted by @leader to @cgrp.  If migrating a
- * process, the caller must be holding cgroup_threadgroup_rwsem.  The
- * caller is also responsible for invoking cgroup_migrate_add_src() and
+ * Migrate a process or task denoted by @leader.  If migrating a process,
+ * the caller must be holding cgroup_threadgroup_rwsem.  The caller is also
+ * responsible for invoking cgroup_migrate_add_src() and
  * cgroup_migrate_prepare_dst() on the targets before invoking this
  * function and following up with cgroup_migrate_finish().
  *
@@ -2586,7 +2773,7 @@ err:
  * actually starting migrating.
  */
 static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
-			  struct cgroup *cgrp)
+			  struct cgroup_root *root)
 {
 	struct cgroup_taskset tset = CGROUP_TASKSET_INIT(tset);
 	struct task_struct *task;
@@ -2607,7 +2794,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
 	rcu_read_unlock();
 	spin_unlock_bh(&css_set_lock);
 
-	return cgroup_taskset_migrate(&tset, cgrp);
+	return cgroup_taskset_migrate(&tset, root);
 }
 
 /**
@@ -2625,6 +2812,9 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
 	struct task_struct *task;
 	int ret;
 
+	if (!cgroup_may_migrate_to(dst_cgrp))
+		return -EBUSY;
+
 	/* look up all src csets */
 	spin_lock_bh(&css_set_lock);
 	rcu_read_lock();
@@ -2639,9 +2829,9 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
 	spin_unlock_bh(&css_set_lock);
 
 	/* prepare dst csets and commit */
-	ret = cgroup_migrate_prepare_dst(dst_cgrp, &preloaded_csets);
+	ret = cgroup_migrate_prepare_dst(&preloaded_csets);
 	if (!ret)
-		ret = cgroup_migrate(leader, threadgroup, dst_cgrp);
+		ret = cgroup_migrate(leader, threadgroup, dst_cgrp->root);
 
 	cgroup_migrate_finish(&preloaded_csets);
 	return ret;
@@ -2705,7 +2895,7 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
 	if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
 		return -EINVAL;
 
-	cgrp = cgroup_kn_lock_live(of->kn);
+	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
 		return -ENODEV;
 
@@ -2805,7 +2995,7 @@ static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
 
 	BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
 
-	cgrp = cgroup_kn_lock_live(of->kn);
+	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
 		return -ENODEV;
 	spin_lock(&release_agent_path_lock);
@@ -2833,38 +3023,28 @@ static int cgroup_sane_behavior_show(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static void cgroup_print_ss_mask(struct seq_file *seq, unsigned long ss_mask)
+static void cgroup_print_ss_mask(struct seq_file *seq, u16 ss_mask)
 {
 	struct cgroup_subsys *ss;
 	bool printed = false;
 	int ssid;
 
-	for_each_subsys_which(ss, ssid, &ss_mask) {
+	do_each_subsys_mask(ss, ssid, ss_mask) {
 		if (printed)
 			seq_putc(seq, ' ');
 		seq_printf(seq, "%s", ss->name);
 		printed = true;
-	}
+	} while_each_subsys_mask();
 	if (printed)
 		seq_putc(seq, '\n');
 }
 
-/* show controllers which are currently attached to the default hierarchy */
-static int cgroup_root_controllers_show(struct seq_file *seq, void *v)
-{
-	struct cgroup *cgrp = seq_css(seq)->cgroup;
-
-	cgroup_print_ss_mask(seq, cgrp->root->subsys_mask &
-			     ~cgrp_dfl_root_inhibit_ss_mask);
-	return 0;
-}
-
 /* show controllers which are enabled from the parent */
 static int cgroup_controllers_show(struct seq_file *seq, void *v)
 {
 	struct cgroup *cgrp = seq_css(seq)->cgroup;
 
-	cgroup_print_ss_mask(seq, cgroup_parent(cgrp)->subtree_control);
+	cgroup_print_ss_mask(seq, cgroup_control(cgrp));
 	return 0;
 }
 
@@ -2881,16 +3061,17 @@ static int cgroup_subtree_control_show(struct seq_file *seq, void *v)
  * cgroup_update_dfl_csses - update css assoc of a subtree in default hierarchy
  * @cgrp: root of the subtree to update csses for
  *
- * @cgrp's child_subsys_mask has changed and its subtree's (self excluded)
- * css associations need to be updated accordingly.  This function looks up
- * all css_sets which are attached to the subtree, creates the matching
- * updated css_sets and migrates the tasks to the new ones.
+ * @cgrp's control masks have changed and its subtree's css associations
+ * need to be updated accordingly.  This function looks up all css_sets
+ * which are attached to the subtree, creates the matching updated css_sets
+ * and migrates the tasks to the new ones.
  */
 static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 {
 	LIST_HEAD(preloaded_csets);
 	struct cgroup_taskset tset = CGROUP_TASKSET_INIT(tset);
-	struct cgroup_subsys_state *css;
+	struct cgroup_subsys_state *d_css;
+	struct cgroup *dsct;
 	struct css_set *src_cset;
 	int ret;
 
@@ -2900,21 +3081,17 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 
 	/* look up all csses currently attached to @cgrp's subtree */
 	spin_lock_bh(&css_set_lock);
-	css_for_each_descendant_pre(css, cgroup_css(cgrp, NULL)) {
+	cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
 		struct cgrp_cset_link *link;
 
-		/* self is not affected by child_subsys_mask change */
-		if (css->cgroup == cgrp)
-			continue;
-
-		list_for_each_entry(link, &css->cgroup->cset_links, cset_link)
-			cgroup_migrate_add_src(link->cset, cgrp,
+		list_for_each_entry(link, &dsct->cset_links, cset_link)
+			cgroup_migrate_add_src(link->cset, dsct,
 					       &preloaded_csets);
 	}
 	spin_unlock_bh(&css_set_lock);
 
 	/* NULL dst indicates self on default hierarchy */
-	ret = cgroup_migrate_prepare_dst(NULL, &preloaded_csets);
+	ret = cgroup_migrate_prepare_dst(&preloaded_csets);
 	if (ret)
 		goto out_finish;
 
@@ -2932,20 +3109,272 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 	}
 	spin_unlock_bh(&css_set_lock);
 
-	ret = cgroup_taskset_migrate(&tset, cgrp);
+	ret = cgroup_taskset_migrate(&tset, cgrp->root);
 out_finish:
 	cgroup_migrate_finish(&preloaded_csets);
 	percpu_up_write(&cgroup_threadgroup_rwsem);
 	return ret;
 }
 
+/**
+ * cgroup_lock_and_drain_offline - lock cgroup_mutex and drain offlined csses
+ * @cgrp: root of the target subtree
+ *
+ * Because css offlining is asynchronous, userland may try to re-enable a
+ * controller while the previous css is still around.  This function grabs
+ * cgroup_mutex and drains the previous css instances of @cgrp's subtree.
+ */
+static void cgroup_lock_and_drain_offline(struct cgroup *cgrp)
+	__acquires(&cgroup_mutex)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+	struct cgroup_subsys *ss;
+	int ssid;
+
+restart:
+	mutex_lock(&cgroup_mutex);
+
+	cgroup_for_each_live_descendant_post(dsct, d_css, cgrp) {
+		for_each_subsys(ss, ssid) {
+			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);
+			DEFINE_WAIT(wait);
+
+			if (!css || !percpu_ref_is_dying(&css->refcnt))
+				continue;
+
+			cgroup_get(dsct);
+			prepare_to_wait(&dsct->offline_waitq, &wait,
+					TASK_UNINTERRUPTIBLE);
+
+			mutex_unlock(&cgroup_mutex);
+			schedule();
+			finish_wait(&dsct->offline_waitq, &wait);
+
+			cgroup_put(dsct);
+			goto restart;
+		}
+	}
+}
+
+/**
+ * cgroup_save_control - save control masks of a subtree
+ * @cgrp: root of the target subtree
+ *
+ * Save ->subtree_control and ->subtree_ss_mask to the respective old_
+ * prefixed fields for @cgrp's subtree including @cgrp itself.
+ */
+static void cgroup_save_control(struct cgroup *cgrp)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+
+	cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
+		dsct->old_subtree_control = dsct->subtree_control;
+		dsct->old_subtree_ss_mask = dsct->subtree_ss_mask;
+	}
+}
+
+/**
+ * cgroup_propagate_control - refresh control masks of a subtree
+ * @cgrp: root of the target subtree
+ *
+ * For @cgrp and its subtree, ensure ->subtree_ss_mask matches
+ * ->subtree_control and propagate controller availability through the
+ * subtree so that descendants don't have unavailable controllers enabled.
+ */
+static void cgroup_propagate_control(struct cgroup *cgrp)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+
+	cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
+		dsct->subtree_control &= cgroup_control(dsct);
+		dsct->subtree_ss_mask =
+			cgroup_calc_subtree_ss_mask(dsct->subtree_control,
+						    cgroup_ss_mask(dsct));
+	}
+}
+
+/**
+ * cgroup_restore_control - restore control masks of a subtree
+ * @cgrp: root of the target subtree
+ *
+ * Restore ->subtree_control and ->subtree_ss_mask from the respective old_
+ * prefixed fields for @cgrp's subtree including @cgrp itself.
+ */
+static void cgroup_restore_control(struct cgroup *cgrp)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+
+	cgroup_for_each_live_descendant_post(dsct, d_css, cgrp) {
+		dsct->subtree_control = dsct->old_subtree_control;
+		dsct->subtree_ss_mask = dsct->old_subtree_ss_mask;
+	}
+}
+
+static bool css_visible(struct cgroup_subsys_state *css)
+{
+	struct cgroup_subsys *ss = css->ss;
+	struct cgroup *cgrp = css->cgroup;
+
+	if (cgroup_control(cgrp) & (1 << ss->id))
+		return true;
+	if (!(cgroup_ss_mask(cgrp) & (1 << ss->id)))
+		return false;
+	return cgroup_on_dfl(cgrp) && ss->implicit_on_dfl;
+}
+
+/**
+ * cgroup_apply_control_enable - enable or show csses according to control
+ * @cgrp: root of the target subtree
+ *
+ * Walk @cgrp's subtree and create new csses or make the existing ones
+ * visible.  A css is created invisible if it's being implicitly enabled
+ * through dependency.  An invisible css is made visible when the userland
+ * explicitly enables it.
+ *
+ * Returns 0 on success, -errno on failure.  On failure, csses which have
+ * been processed already aren't cleaned up.  The caller is responsible for
+ * cleaning up with cgroup_apply_control_disble().
+ */
+static int cgroup_apply_control_enable(struct cgroup *cgrp)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+	struct cgroup_subsys *ss;
+	int ssid, ret;
+
+	cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
+		for_each_subsys(ss, ssid) {
+			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);
+
+			WARN_ON_ONCE(css && percpu_ref_is_dying(&css->refcnt));
+
+			if (!(cgroup_ss_mask(dsct) & (1 << ss->id)))
+				continue;
+
+			if (!css) {
+				css = css_create(dsct, ss);
+				if (IS_ERR(css))
+					return PTR_ERR(css);
+			}
+
+			if (css_visible(css)) {
+				ret = css_populate_dir(css);
+				if (ret)
+					return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * cgroup_apply_control_disable - kill or hide csses according to control
+ * @cgrp: root of the target subtree
+ *
+ * Walk @cgrp's subtree and kill and hide csses so that they match
+ * cgroup_ss_mask() and cgroup_visible_mask().
+ *
+ * A css is hidden when the userland requests it to be disabled while other
+ * subsystems are still depending on it.  The css must not actively control
+ * resources and be in the vanilla state if it's made visible again later.
+ * Controllers which may be depended upon should provide ->css_reset() for
+ * this purpose.
+ */
+static void cgroup_apply_control_disable(struct cgroup *cgrp)
+{
+	struct cgroup *dsct;
+	struct cgroup_subsys_state *d_css;
+	struct cgroup_subsys *ss;
+	int ssid;
+
+	cgroup_for_each_live_descendant_post(dsct, d_css, cgrp) {
+		for_each_subsys(ss, ssid) {
+			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);
+
+			WARN_ON_ONCE(css && percpu_ref_is_dying(&css->refcnt));
+
+			if (!css)
+				continue;
+
+			if (css->parent &&
+			    !(cgroup_ss_mask(dsct) & (1 << ss->id))) {
+				kill_css(css);
+			} else if (!css_visible(css)) {
+				css_clear_dir(css);
+				if (ss->css_reset)
+					ss->css_reset(css);
+			}
+		}
+	}
+}
+
+/**
+ * cgroup_apply_control - apply control mask updates to the subtree
+ * @cgrp: root of the target subtree
+ *
+ * subsystems can be enabled and disabled in a subtree using the following
+ * steps.
+ *
+ * 1. Call cgroup_save_control() to stash the current state.
+ * 2. Update ->subtree_control masks in the subtree as desired.
+ * 3. Call cgroup_apply_control() to apply the changes.
+ * 4. Optionally perform other related operations.
+ * 5. Call cgroup_finalize_control() to finish up.
+ *
+ * This function implements step 3 and propagates the mask changes
+ * throughout @cgrp's subtree, updates csses accordingly and perform
+ * process migrations.
+ */
+static int cgroup_apply_control(struct cgroup *cgrp)
+{
+	int ret;
+
+	cgroup_propagate_control(cgrp);
+
+	ret = cgroup_apply_control_enable(cgrp);
+	if (ret)
+		return ret;
+
+	/*
+	 * At this point, cgroup_e_css() results reflect the new csses
+	 * making the following cgroup_update_dfl_csses() properly update
+	 * css associations of all tasks in the subtree.
+	 */
+	ret = cgroup_update_dfl_csses(cgrp);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/**
+ * cgroup_finalize_control - finalize control mask update
+ * @cgrp: root of the target subtree
+ * @ret: the result of the update
+ *
+ * Finalize control mask update.  See cgroup_apply_control() for more info.
+ */
+static void cgroup_finalize_control(struct cgroup *cgrp, int ret)
+{
+	if (ret) {
+		cgroup_restore_control(cgrp);
+		cgroup_propagate_control(cgrp);
+	}
+
+	cgroup_apply_control_disable(cgrp);
+}
+
 /* change the enabled child controllers for a cgroup in the default hierarchy */
 static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 					    char *buf, size_t nbytes,
 					    loff_t off)
 {
-	unsigned long enable = 0, disable = 0;
-	unsigned long css_enable, css_disable, old_sc, new_sc, old_ss, new_ss;
+	u16 enable = 0, disable = 0;
 	struct cgroup *cgrp, *child;
 	struct cgroup_subsys *ss;
 	char *tok;
@@ -2957,11 +3386,9 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 	 */
 	buf = strstrip(buf);
 	while ((tok = strsep(&buf, " "))) {
-		unsigned long tmp_ss_mask = ~cgrp_dfl_root_inhibit_ss_mask;
-
 		if (tok[0] == '\0')
 			continue;
-		for_each_subsys_which(ss, ssid, &tmp_ss_mask) {
+		do_each_subsys_mask(ss, ssid, ~cgrp_dfl_inhibit_ss_mask) {
 			if (!cgroup_ssid_enabled(ssid) ||
 			    strcmp(tok + 1, ss->name))
 				continue;
@@ -2976,12 +3403,12 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 				return -EINVAL;
 			}
 			break;
-		}
+		} while_each_subsys_mask();
 		if (ssid == CGROUP_SUBSYS_COUNT)
 			return -EINVAL;
 	}
 
-	cgrp = cgroup_kn_lock_live(of->kn);
+	cgrp = cgroup_kn_lock_live(of->kn, true);
 	if (!cgrp)
 		return -ENODEV;
 
@@ -2992,10 +3419,7 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 				continue;
 			}
 
-			/* unavailable or not enabled on the parent? */
-			if (!(cgrp_dfl_root.subsys_mask & (1 << ssid)) ||
-			    (cgroup_parent(cgrp) &&
-			     !(cgroup_parent(cgrp)->subtree_control & (1 << ssid)))) {
+			if (!(cgroup_control(cgrp) & (1 << ssid))) {
 				ret = -ENOENT;
 				goto out_unlock;
 			}
@@ -3029,150 +3453,21 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 		goto out_unlock;
 	}
 
-	/*
-	 * Update subsys masks and calculate what needs to be done.  More
-	 * subsystems than specified may need to be enabled or disabled
-	 * depending on subsystem dependencies.
-	 */
-	old_sc = cgrp->subtree_control;
-	old_ss = cgrp->child_subsys_mask;
-	new_sc = (old_sc | enable) & ~disable;
-	new_ss = cgroup_calc_child_subsys_mask(cgrp, new_sc);
+	/* save and update control masks and prepare csses */
+	cgroup_save_control(cgrp);
 
-	css_enable = ~old_ss & new_ss;
-	css_disable = old_ss & ~new_ss;
-	enable |= css_enable;
-	disable |= css_disable;
-
-	/*
-	 * Because css offlining is asynchronous, userland might try to
-	 * re-enable the same controller while the previous instance is
-	 * still around.  In such cases, wait till it's gone using
-	 * offline_waitq.
-	 */
-	for_each_subsys_which(ss, ssid, &css_enable) {
-		cgroup_for_each_live_child(child, cgrp) {
-			DEFINE_WAIT(wait);
-
-			if (!cgroup_css(child, ss))
-				continue;
-
-			cgroup_get(child);
-			prepare_to_wait(&child->offline_waitq, &wait,
-					TASK_UNINTERRUPTIBLE);
-			cgroup_kn_unlock(of->kn);
-			schedule();
-			finish_wait(&child->offline_waitq, &wait);
-			cgroup_put(child);
-
-			return restart_syscall();
-		}
-	}
-
-	cgrp->subtree_control = new_sc;
-	cgrp->child_subsys_mask = new_ss;
-
-	/*
-	 * Create new csses or make the existing ones visible.  A css is
-	 * created invisible if it's being implicitly enabled through
-	 * dependency.  An invisible css is made visible when the userland
-	 * explicitly enables it.
-	 */
-	for_each_subsys(ss, ssid) {
-		if (!(enable & (1 << ssid)))
-			continue;
-
-		cgroup_for_each_live_child(child, cgrp) {
-			if (css_enable & (1 << ssid))
-				ret = create_css(child, ss,
-					cgrp->subtree_control & (1 << ssid));
-			else
-				ret = css_populate_dir(cgroup_css(child, ss),
-						       NULL);
-			if (ret)
-				goto err_undo_css;
-		}
-	}
-
-	/*
-	 * At this point, cgroup_e_css() results reflect the new csses
-	 * making the following cgroup_update_dfl_csses() properly update
-	 * css associations of all tasks in the subtree.
-	 */
-	ret = cgroup_update_dfl_csses(cgrp);
-	if (ret)
-		goto err_undo_css;
-
-	/*
-	 * All tasks are migrated out of disabled csses.  Kill or hide
-	 * them.  A css is hidden when the userland requests it to be
-	 * disabled while other subsystems are still depending on it.  The
-	 * css must not actively control resources and be in the vanilla
-	 * state if it's made visible again later.  Controllers which may
-	 * be depended upon should provide ->css_reset() for this purpose.
-	 */
-	for_each_subsys(ss, ssid) {
-		if (!(disable & (1 << ssid)))
-			continue;
-
-		cgroup_for_each_live_child(child, cgrp) {
-			struct cgroup_subsys_state *css = cgroup_css(child, ss);
-
-			if (css_disable & (1 << ssid)) {
-				kill_css(css);
-			} else {
-				css_clear_dir(css, NULL);
-				if (ss->css_reset)
-					ss->css_reset(css);
-			}
-		}
-	}
-
-	/*
-	 * The effective csses of all the descendants (excluding @cgrp) may
-	 * have changed.  Subsystems can optionally subscribe to this event
-	 * by implementing ->css_e_css_changed() which is invoked if any of
-	 * the effective csses seen from the css's cgroup may have changed.
-	 */
-	for_each_subsys(ss, ssid) {
-		struct cgroup_subsys_state *this_css = cgroup_css(cgrp, ss);
-		struct cgroup_subsys_state *css;
+	cgrp->subtree_control |= enable;
+	cgrp->subtree_control &= ~disable;
 
-		if (!ss->css_e_css_changed || !this_css)
-			continue;
+	ret = cgroup_apply_control(cgrp);
 
-		css_for_each_descendant_pre(css, this_css)
-			if (css != this_css)
-				ss->css_e_css_changed(css);
-	}
+	cgroup_finalize_control(cgrp, ret);
 
 	kernfs_activate(cgrp->kn);
 	ret = 0;
 out_unlock:
 	cgroup_kn_unlock(of->kn);
 	return ret ?: nbytes;
-
-err_undo_css:
-	cgrp->subtree_control = old_sc;
-	cgrp->child_subsys_mask = old_ss;
-
-	for_each_subsys(ss, ssid) {
-		if (!(enable & (1 << ssid)))
-			continue;
-
-		cgroup_for_each_live_child(child, cgrp) {
-			struct cgroup_subsys_state *css = cgroup_css(child, ss);
-
-			if (!css)
-				continue;
-
-			if (css_enable & (1 << ssid))
-				kill_css(css);
-			else
-				css_clear_dir(css, NULL);
-		}
-	}
-	goto out_unlock;
 }
 
 static int cgroup_events_show(struct seq_file *seq, void *v)
@@ -3370,7 +3665,7 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
 			      bool is_add)
 {
 	struct cftype *cft, *cft_end = NULL;
-	int ret;
+	int ret = 0;
 
 	lockdep_assert_held(&cgroup_mutex);
 
@@ -3399,7 +3694,7 @@ restart:
 			cgroup_rm_file(cgrp, cft);
 		}
 	}
-	return 0;
+	return ret;
 }
 
 static int cgroup_apply_cftypes(struct cftype *cfts, bool is_add)
@@ -3416,7 +3711,7 @@ static int cgroup_apply_cftypes(struct cftype *cfts, bool is_add)
 	css_for_each_descendant_pre(css, cgroup_css(root, ss)) {
 		struct cgroup *cgrp = css->cgroup;
 
-		if (cgroup_is_dead(cgrp))
+		if (!(css->flags & CSS_VISIBLE))
 			continue;
 
 		ret = cgroup_addrm_files(css, cgrp, cfts, is_add);
@@ -4037,6 +4332,9 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 	struct task_struct *task;
 	int ret;
 
+	if (!cgroup_may_migrate_to(to))
+		return -EBUSY;
+
 	mutex_lock(&cgroup_mutex);
 
 	/* all tasks in @from are being moved, all csets are source */
@@ -4045,7 +4343,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 		cgroup_migrate_add_src(link->cset, to, &preloaded_csets);
 	spin_unlock_bh(&css_set_lock);
 
-	ret = cgroup_migrate_prepare_dst(to, &preloaded_csets);
+	ret = cgroup_migrate_prepare_dst(&preloaded_csets);
 	if (ret)
 		goto out_err;
 
@@ -4061,7 +4359,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 		css_task_iter_end(&it);
 
 		if (task) {
-			ret = cgroup_migrate(task, false, to);
+			ret = cgroup_migrate(task, false, to->root);
 			put_task_struct(task);
 		}
 	} while (task && !ret);
@@ -4568,12 +4866,6 @@ static struct cftype cgroup_dfl_base_files[] = {
 	},
 	{
 		.name = "cgroup.controllers",
-		.flags = CFTYPE_ONLY_ON_ROOT,
-		.seq_show = cgroup_root_controllers_show,
-	},
-	{
-		.name = "cgroup.controllers",
-		.flags = CFTYPE_NOT_ON_ROOT,
 		.seq_show = cgroup_controllers_show,
 	},
 	{
@@ -4742,7 +5034,9 @@ static void css_release_work_fn(struct work_struct *work)
 		 * Those are supported by RCU protecting clearing of
 		 * cgrp->kn->priv backpointer.
 		 */
-		RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL);
+		if (cgrp->kn)
+			RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv,
+					 NULL);
 	}
 
 	mutex_unlock(&cgroup_mutex);
@@ -4813,6 +5107,9 @@ static void offline_css(struct cgroup_subsys_state *css)
 	if (!(css->flags & CSS_ONLINE))
 		return;
 
+	if (ss->css_reset)
+		ss->css_reset(css);
+
 	if (ss->css_offline)
 		ss->css_offline(css);
 
@@ -4823,17 +5120,16 @@ static void offline_css(struct cgroup_subsys_state *css)
 }
 
 /**
- * create_css - create a cgroup_subsys_state
+ * css_create - create a cgroup_subsys_state
  * @cgrp: the cgroup new css will be associated with
  * @ss: the subsys of new css
- * @visible: whether to create control knobs for the new css or not
  *
  * Create a new css associated with @cgrp - @ss pair.  On success, the new
- * css is online and installed in @cgrp with all interface files created if
- * @visible.  Returns 0 on success, -errno on failure.
+ * css is online and installed in @cgrp.  This function doesn't create the
+ * interface files.  Returns 0 on success, -errno on failure.
  */
-static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
-		      bool visible)
+static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
+					      struct cgroup_subsys *ss)
 {
 	struct cgroup *parent = cgroup_parent(cgrp);
 	struct cgroup_subsys_state *parent_css = cgroup_css(parent, ss);
@@ -4844,7 +5140,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
 
 	css = ss->css_alloc(parent_css);
 	if (IS_ERR(css))
-		return PTR_ERR(css);
+		return css;
 
 	init_and_link_css(css, ss, cgrp);
 
@@ -4857,12 +5153,6 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
 		goto err_free_percpu_ref;
 	css->id = err;
 
-	if (visible) {
-		err = css_populate_dir(css, NULL);
-		if (err)
-			goto err_free_id;
-	}
-
 	/* @css is ready to be brought online now, make it visible */
 	list_add_tail_rcu(&css->sibling, &parent_css->children);
 	cgroup_idr_replace(&ss->css_idr, css, css->id);
@@ -4880,47 +5170,30 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
 		ss->warned_broken_hierarchy = true;
 	}
 
-	return 0;
+	return css;
 
 err_list_del:
 	list_del_rcu(&css->sibling);
-	css_clear_dir(css, NULL);
-err_free_id:
 	cgroup_idr_remove(&ss->css_idr, css->id);
 err_free_percpu_ref:
 	percpu_ref_exit(&css->refcnt);
 err_free_css:
 	call_rcu(&css->rcu_head, css_free_rcu_fn);
-	return err;
+	return ERR_PTR(err);
 }
 
-static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
-			umode_t mode)
+static struct cgroup *cgroup_create(struct cgroup *parent)
 {
-	struct cgroup *parent, *cgrp, *tcgrp;
-	struct cgroup_root *root;
-	struct cgroup_subsys *ss;
-	struct kernfs_node *kn;
-	int level, ssid, ret;
-
-	/* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
-	 */
-	if (strchr(name, '\n'))
-		return -EINVAL;
-
-	parent = cgroup_kn_lock_live(parent_kn);
-	if (!parent)
-		return -ENODEV;
-	root = parent->root;
-	level = parent->level + 1;
+	struct cgroup_root *root = parent->root;
+	struct cgroup *cgrp, *tcgrp;
+	int level = parent->level + 1;
+	int ret;
 
 	/* allocate the cgroup and its ID, 0 is reserved for the root */
 	cgrp = kzalloc(sizeof(*cgrp) +
 		       sizeof(cgrp->ancestor_ids[0]) * (level + 1), GFP_KERNEL);
-	if (!cgrp) {
-		ret = -ENOMEM;
-		goto out_unlock;
-	}
+	if (!cgrp)
+		return ERR_PTR(-ENOMEM);
 
 	ret = percpu_ref_init(&cgrp->self.refcnt, css_release, 0, GFP_KERNEL);
 	if (ret)
@@ -4951,20 +5224,6 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
 	if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &parent->flags))
 		set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
 
-	/* create the directory */
-	kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
-	if (IS_ERR(kn)) {
-		ret = PTR_ERR(kn);
-		goto out_free_id;
-	}
-	cgrp->kn = kn;
-
-	/*
-	 * This extra ref will be put in cgroup_free_fn() and guarantees
-	 * that @cgrp->kn is always accessible.
-	 */
-	kernfs_get(kn);
-
 	cgrp->self.serial_nr = css_serial_nr_next++;
 
 	/* allocation complete, commit to creation */
@@ -4978,51 +5237,90 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
 	 */
 	cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
 
-	ret = cgroup_kn_set_ugid(kn);
-	if (ret)
-		goto out_destroy;
+	/*
+	 * On the default hierarchy, a child doesn't automatically inherit
+	 * subtree_control from the parent.  Each is configured manually.
+	 */
+	if (!cgroup_on_dfl(cgrp))
+		cgrp->subtree_control = cgroup_control(cgrp);
 
-	ret = css_populate_dir(&cgrp->self, NULL);
+	cgroup_propagate_control(cgrp);
+
+	/* @cgrp doesn't have dir yet so the following will only create csses */
+	ret = cgroup_apply_control_enable(cgrp);
 	if (ret)
 		goto out_destroy;
 
-	/* let's create and online css's */
-	for_each_subsys(ss, ssid) {
-		if (parent->child_subsys_mask & (1 << ssid)) {
-			ret = create_css(cgrp, ss,
-					 parent->subtree_control & (1 << ssid));
-			if (ret)
-				goto out_destroy;
-		}
+	return cgrp;
+
+out_cancel_ref:
+	percpu_ref_exit(&cgrp->self.refcnt);
+out_free_cgrp:
+	kfree(cgrp);
+	return ERR_PTR(ret);
+out_destroy:
+	cgroup_destroy_locked(cgrp);
+	return ERR_PTR(ret);
+}
+
+static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+			umode_t mode)
+{
+	struct cgroup *parent, *cgrp;
+	struct kernfs_node *kn;
+	int ret;
+
+	/* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */
+	if (strchr(name, '\n'))
+		return -EINVAL;
+
+	parent = cgroup_kn_lock_live(parent_kn, false);
+	if (!parent)
+		return -ENODEV;
+
+	cgrp = cgroup_create(parent);
+	if (IS_ERR(cgrp)) {
+		ret = PTR_ERR(cgrp);
+		goto out_unlock;
 	}
 
+	/* create the directory */
+	kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
+	if (IS_ERR(kn)) {
+		ret = PTR_ERR(kn);
+		goto out_destroy;
+	}
+	cgrp->kn = kn;
+
 	/*
-	 * On the default hierarchy, a child doesn't automatically inherit
-	 * subtree_control from the parent.  Each is configured manually.
+	 * This extra ref will be put in cgroup_free_fn() and guarantees
+	 * that @cgrp->kn is always accessible.
 	 */
-	if (!cgroup_on_dfl(cgrp)) {
-		cgrp->subtree_control = parent->subtree_control;
-		cgroup_refresh_child_subsys_mask(cgrp);
-	}
+	kernfs_get(kn);
 
+	ret = cgroup_kn_set_ugid(kn);
+	if (ret)
+		goto out_destroy;
+
+	ret = css_populate_dir(&cgrp->self);
+	if (ret)
+		goto out_destroy;
+
+	ret = cgroup_apply_control_enable(cgrp);
+	if (ret)
+		goto out_destroy;
+
+	/* let's create and online css's */
 	kernfs_activate(kn);
 
 	ret = 0;
 	goto out_unlock;
 
-out_free_id:
-	cgroup_idr_remove(&root->cgroup_idr, cgrp->id);
-out_cancel_ref:
-	percpu_ref_exit(&cgrp->self.refcnt);
-out_free_cgrp:
-	kfree(cgrp);
+out_destroy:
+	cgroup_destroy_locked(cgrp);
 out_unlock:
 	cgroup_kn_unlock(parent_kn);
 	return ret;
-
-out_destroy:
-	cgroup_destroy_locked(cgrp);
-	goto out_unlock;
 }
 
 /*
@@ -5076,7 +5374,7 @@ static void kill_css(struct cgroup_subsys_state *css)
 	 * This must happen before css is disassociated with its cgroup.
 	 * See seq_css() for details.
 	 */
-	css_clear_dir(css, NULL);
+	css_clear_dir(css);
 
 	/*
 	 * Killing would put the base ref, but we need to keep it alive
@@ -5181,7 +5479,7 @@ static int cgroup_rmdir(struct kernfs_node *kn)
 	struct cgroup *cgrp;
 	int ret = 0;
 
-	cgrp = cgroup_kn_lock_live(kn);
+	cgrp = cgroup_kn_lock_live(kn, false);
 	if (!cgrp)
 		return 0;
 
@@ -5197,6 +5495,7 @@ static struct kernfs_syscall_ops cgroup_kf_syscall_ops = {
 	.mkdir			= cgroup_mkdir,
 	.rmdir			= cgroup_rmdir,
 	.rename			= cgroup_rename,
+	.show_path		= cgroup_show_path,
 };
 
 static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
@@ -5271,7 +5570,7 @@ int __init cgroup_init_early(void)
 
 	for_each_subsys(ss, i) {
 		WARN(!ss->css_alloc || !ss->css_free || ss->name || ss->id,
-		     "invalid cgroup_subsys %d:%s css_alloc=%p css_free=%p name:id=%d:%s\n",
+		     "invalid cgroup_subsys %d:%s css_alloc=%p css_free=%p id:name=%d:%s\n",
 		     i, cgroup_subsys_name[i], ss->css_alloc, ss->css_free,
 		     ss->id, ss->name);
 		WARN(strlen(cgroup_subsys_name[i]) > MAX_CGROUP_TYPE_NAMELEN,
@@ -5288,7 +5587,7 @@ int __init cgroup_init_early(void)
 	return 0;
 }
 
-static unsigned long cgroup_disable_mask __initdata;
+static u16 cgroup_disable_mask __initdata;
 
 /**
  * cgroup_init - cgroup initialization
@@ -5299,18 +5598,23 @@ static unsigned long cgroup_disable_mask __initdata;
 int __init cgroup_init(void)
 {
 	struct cgroup_subsys *ss;
-	unsigned long key;
 	int ssid;
 
+	BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16);
 	BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
 
+	get_user_ns(init_cgroup_ns.user_ns);
+
 	mutex_lock(&cgroup_mutex);
 
-	/* Add init_css_set to the hash table */
-	key = css_set_hash(init_css_set.subsys);
-	hash_add(css_set_table, &init_css_set.hlist, key);
+	/*
+	 * Add init_css_set to the hash table so that dfl_root can link to
+	 * it during init.
+	 */
+	hash_add(css_set_table, &init_css_set.hlist,
+		 css_set_hash(init_css_set.subsys));
 
 	BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0));
 
@@ -5343,10 +5647,16 @@ int __init cgroup_init(void)
 			continue;
 		}
 
+		if (cgroup_ssid_no_v1(ssid))
+			printk(KERN_INFO "Disabling %s control group subsystem in v1 mounts\n",
+			       ss->name);
+
 		cgrp_dfl_root.subsys_mask |= 1 << ss->id;
 
-		if (!ss->dfl_cftypes)
-			cgrp_dfl_root_inhibit_ss_mask |= 1 << ss->id;
+		if (ss->implicit_on_dfl)
+			cgrp_dfl_implicit_ss_mask |= 1 << ss->id;
+		else if (!ss->dfl_cftypes)
+			cgrp_dfl_inhibit_ss_mask |= 1 << ss->id;
 
 		if (ss->dfl_cftypes == ss->legacy_cftypes) {
 			WARN_ON(cgroup_add_cftypes(ss, ss->dfl_cftypes));
@@ -5359,6 +5669,11 @@ int __init cgroup_init(void)
 			ss->bind(init_css_set.subsys[ssid]);
 	}
 
+	/* init_css_set.subsys[] has been updated, re-hash */
+	hash_del(&init_css_set.hlist);
+	hash_add(css_set_table, &init_css_set.hlist,
+		 css_set_hash(init_css_set.subsys));
+
 	WARN_ON(sysfs_create_mount_point(fs_kobj, "cgroup"));
 	WARN_ON(register_filesystem(&cgroup_fs_type));
 	WARN_ON(register_filesystem(&cgroup2_fs_type));
@@ -5417,7 +5732,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
 		struct cgroup *cgrp;
 		int ssid, count = 0;
 
-		if (root == &cgrp_dfl_root && !cgrp_dfl_root_visible)
+		if (root == &cgrp_dfl_root && !cgrp_dfl_visible)
 			continue;
 
 		seq_printf(m, "%d:", root->hierarchy_id);
@@ -5443,7 +5758,8 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
 		 * " (deleted)" is appended to the cgroup path.
 		 */
 		if (cgroup_on_dfl(cgrp) || !(tsk->flags & PF_EXITING)) {
-			path = cgroup_path(cgrp, buf, PATH_MAX);
+			path = cgroup_path_ns_locked(cgrp, buf, PATH_MAX,
+						current->nsproxy->cgroup_ns);
 			if (!path) {
 				retval = -ENAMETOOLONG;
 				goto out_unlock;
@@ -5532,11 +5848,11 @@ int cgroup_can_fork(struct task_struct *child)
 	struct cgroup_subsys *ss;
 	int i, j, ret;
 
-	for_each_subsys_which(ss, i, &have_canfork_callback) {
+	do_each_subsys_mask(ss, i, have_canfork_callback) {
 		ret = ss->can_fork(child);
 		if (ret)
 			goto out_revert;
-	}
+	} while_each_subsys_mask();
 
 	return 0;
 
@@ -5621,8 +5937,9 @@ void cgroup_post_fork(struct task_struct *child)
 	 * css_set; otherwise, @child might change state between ->fork()
 	 * and addition to css_set.
 	 */
-	for_each_subsys_which(ss, i, &have_fork_callback)
+	do_each_subsys_mask(ss, i, have_fork_callback) {
 		ss->fork(child);
+	} while_each_subsys_mask();
 }
 
 /**
@@ -5665,8 +5982,9 @@ void cgroup_exit(struct task_struct *tsk)
 	}
 
 	/* see cgroup_post_fork() for details */
-	for_each_subsys_which(ss, i, &have_exit_callback)
+	do_each_subsys_mask(ss, i, have_exit_callback) {
 		ss->exit(tsk);
+	} while_each_subsys_mask();
 }
 
 void cgroup_free(struct task_struct *task)
@@ -5675,8 +5993,9 @@ void cgroup_free(struct task_struct *task)
 	struct cgroup_subsys *ss;
 	int ssid;
 
-	for_each_subsys_which(ss, ssid, &have_free_callback)
+	do_each_subsys_mask(ss, ssid, have_free_callback) {
 		ss->free(task);
+	} while_each_subsys_mask();
 
 	put_css_set(cset);
 }
@@ -5725,7 +6044,9 @@ static void cgroup_release_agent(struct work_struct *work)
 	if (!pathbuf || !agentbuf)
 		goto out;
 
-	path = cgroup_path(cgrp, pathbuf, PATH_MAX);
+	spin_lock_bh(&css_set_lock);
+	path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
+	spin_unlock_bh(&css_set_lock);
 	if (!path)
 		goto out;
 
@@ -5769,6 +6090,33 @@ static int __init cgroup_disable(char *str)
 }
 __setup("cgroup_disable=", cgroup_disable);
 
+static int __init cgroup_no_v1(char *str)
+{
+	struct cgroup_subsys *ss;
+	char *token;
+	int i;
+
+	while ((token = strsep(&str, ",")) != NULL) {
+		if (!*token)
+			continue;
+
+		if (!strcmp(token, "all")) {
+			cgroup_no_v1_mask = U16_MAX;
+			break;
+		}
+
+		for_each_subsys(ss, i) {
+			if (strcmp(token, ss->name) &&
+			    strcmp(token, ss->legacy_name))
+				continue;
+
+			cgroup_no_v1_mask |= 1 << i;
+		}
+	}
+	return 1;
+}
+__setup("cgroup_no_v1=", cgroup_no_v1);
+
 /**
  * css_tryget_online_from_dir - get corresponding css from a cgroup dentry
  * @dentry: directory dentry of interest
@@ -5782,12 +6130,13 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
 						       struct cgroup_subsys *ss)
 {
 	struct kernfs_node *kn = kernfs_node_from_dentry(dentry);
+	struct file_system_type *s_type = dentry->d_sb->s_type;
 	struct cgroup_subsys_state *css = NULL;
 	struct cgroup *cgrp;
 
 	/* is @dentry a cgroup dir? */
-	if (dentry->d_sb->s_type != &cgroup_fs_type || !kn ||
-	    kernfs_type(kn) != KERNFS_DIR)
+	if ((s_type != &cgroup_fs_type && s_type != &cgroup2_fs_type) ||
+	    !kn || kernfs_type(kn) != KERNFS_DIR)
 		return ERR_PTR(-EBADF);
 
 	rcu_read_lock();
@@ -5909,6 +6258,133 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd)
 
 #endif	/* CONFIG_SOCK_CGROUP_DATA */
 
+/* cgroup namespaces */
+
+static struct cgroup_namespace *alloc_cgroup_ns(void)
+{
+	struct cgroup_namespace *new_ns;
+	int ret;
+
+	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL);
+	if (!new_ns)
+		return ERR_PTR(-ENOMEM);
+	ret = ns_alloc_inum(&new_ns->ns);
+	if (ret) {
+		kfree(new_ns);
+		return ERR_PTR(ret);
+	}
+	atomic_set(&new_ns->count, 1);
+	new_ns->ns.ops = &cgroupns_operations;
+	return new_ns;
+}
+
+void free_cgroup_ns(struct cgroup_namespace *ns)
+{
+	put_css_set(ns->root_cset);
+	put_user_ns(ns->user_ns);
+	ns_free_inum(&ns->ns);
+	kfree(ns);
+}
+EXPORT_SYMBOL(free_cgroup_ns);
+
+struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
+					struct user_namespace *user_ns,
+					struct cgroup_namespace *old_ns)
+{
+	struct cgroup_namespace *new_ns;
+	struct css_set *cset;
+
+	BUG_ON(!old_ns);
+
+	if (!(flags & CLONE_NEWCGROUP)) {
+		get_cgroup_ns(old_ns);
+		return old_ns;
+	}
+
+	/* Allow only sysadmin to create cgroup namespace. */
+	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+
+	mutex_lock(&cgroup_mutex);
+	spin_lock_bh(&css_set_lock);
+
+	cset = task_css_set(current);
+	get_css_set(cset);
+
+	spin_unlock_bh(&css_set_lock);
+	mutex_unlock(&cgroup_mutex);
+
+	new_ns = alloc_cgroup_ns();
+	if (IS_ERR(new_ns)) {
+		put_css_set(cset);
+		return new_ns;
+	}
+
+	new_ns->user_ns = get_user_ns(user_ns);
+	new_ns->root_cset = cset;
+
+	return new_ns;
+}
+
+static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct cgroup_namespace, ns);
+}
+
+static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+{
+	struct cgroup_namespace *cgroup_ns = to_cg_ns(ns);
+
+	if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) ||
+	    !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* Don't need to do anything if we are attaching to our own cgroupns. */
+	if (cgroup_ns == nsproxy->cgroup_ns)
+		return 0;
+
+	get_cgroup_ns(cgroup_ns);
+	put_cgroup_ns(nsproxy->cgroup_ns);
+	nsproxy->cgroup_ns = cgroup_ns;
+
+	return 0;
+}
+
+static struct ns_common *cgroupns_get(struct task_struct *task)
+{
+	struct cgroup_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	task_lock(task);
+	nsproxy = task->nsproxy;
+	if (nsproxy) {
+		ns = nsproxy->cgroup_ns;
+		get_cgroup_ns(ns);
+	}
+	task_unlock(task);
+
+	return ns ? &ns->ns : NULL;
+}
+
+static void cgroupns_put(struct ns_common *ns)
+{
+	put_cgroup_ns(to_cg_ns(ns));
+}
+
+const struct proc_ns_operations cgroupns_operations = {
+	.name		= "cgroup",
+	.type		= CLONE_NEWCGROUP,
+	.get		= cgroupns_get,
+	.put		= cgroupns_put,
+	.install	= cgroupns_install,
+};
+
+static __init int cgroup_namespaces_init(void)
+{
+	return 0;
+}
+subsys_initcall(cgroup_namespaces_init);
+
 #ifdef CONFIG_CGROUP_DEBUG
 static struct cgroup_subsys_state *
 debug_css_alloc(struct cgroup_subsys_state *parent_css)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5b9d39633..3e3f6e49e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -22,13 +22,90 @@
 #include <linux/lockdep.h>
 #include <linux/tick.h>
 #include <linux/irq.h>
+#include <linux/smpboot.h>
+
 #include <trace/events/power.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/cpuhp.h>
 
 #include "smpboot.h"
 
+/**
+ * cpuhp_cpu_state - Per cpu hotplug state storage
+ * @state:	The current cpu state
+ * @target:	The target state
+ * @thread:	Pointer to the hotplug thread
+ * @should_run:	Thread should execute
+ * @rollback:	Perform a rollback
+ * @cb_stat:	The state for a single callback (install/uninstall)
+ * @cb:		Single callback function (install/uninstall)
+ * @result:	Result of the operation
+ * @done:	Signal completion to the issuer of the task
+ */
+struct cpuhp_cpu_state {
+	enum cpuhp_state	state;
+	enum cpuhp_state	target;
+#ifdef CONFIG_SMP
+	struct task_struct	*thread;
+	bool			should_run;
+	bool			rollback;
+	enum cpuhp_state	cb_state;
+	int			(*cb)(unsigned int cpu);
+	int			result;
+	struct completion	done;
+#endif
+};
+
+static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
+
+/**
+ * cpuhp_step - Hotplug state machine step
+ * @name:	Name of the step
+ * @startup:	Startup function of the step
+ * @teardown:	Teardown function of the step
+ * @skip_onerr:	Do not invoke the functions on error rollback
+ *		Will go away once the notifiers	are gone
+ * @cant_stop:	Bringup/teardown can't be stopped at this step
+ */
+struct cpuhp_step {
+	const char	*name;
+	int		(*startup)(unsigned int cpu);
+	int		(*teardown)(unsigned int cpu);
+	bool		skip_onerr;
+	bool		cant_stop;
+};
+
+static DEFINE_MUTEX(cpuhp_state_mutex);
+static struct cpuhp_step cpuhp_bp_states[];
+static struct cpuhp_step cpuhp_ap_states[];
+
+/**
+ * cpuhp_invoke_callback _ Invoke the callbacks for a given state
+ * @cpu:	The cpu for which the callback should be invoked
+ * @step:	The step in the state machine
+ * @cb:		The callback function to invoke
+ *
+ * Called from cpu hotplug and from the state register machinery
+ */
+static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step,
+				 int (*cb)(unsigned int))
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+	int ret = 0;
+
+	if (cb) {
+		trace_cpuhp_enter(cpu, st->target, step, cb);
+		ret = cb(cpu);
+		trace_cpuhp_exit(cpu, st->state, step, ret);
+	}
+	return ret;
+}
+
 #ifdef CONFIG_SMP
 /* Serializes the updates to cpu_online_mask, cpu_present_mask */
 static DEFINE_MUTEX(cpu_add_remove_lock);
+bool cpuhp_tasks_frozen;
+EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
 
 /*
  * The following two APIs (cpu_maps_update_begin/done) must be used when
@@ -207,31 +284,296 @@ int __register_cpu_notifier(struct notifier_block *nb)
 	return raw_notifier_chain_register(&cpu_chain, nb);
 }
 
-static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
 			int *nr_calls)
 {
+	unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
+	void *hcpu = (void *)(long)cpu;
+
 	int ret;
 
-	ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+	ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
 					nr_calls);
 
 	return notifier_to_errno(ret);
 }
 
-static int cpu_notify(unsigned long val, void *v)
+static int cpu_notify(unsigned long val, unsigned int cpu)
 {
-	return __cpu_notify(val, v, -1, NULL);
+	return __cpu_notify(val, cpu, -1, NULL);
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
+static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
+{
+	BUG_ON(cpu_notify(val, cpu));
+}
+
+/* Notifier wrappers for transitioning to state machine */
+static int notify_prepare(unsigned int cpu)
+{
+	int nr_calls = 0;
+	int ret;
+
+	ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
+	if (ret) {
+		nr_calls--;
+		printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
+				__func__, cpu);
+		__cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
+	}
+	return ret;
+}
+
+static int notify_online(unsigned int cpu)
+{
+	cpu_notify(CPU_ONLINE, cpu);
+	return 0;
+}
+
+static int notify_starting(unsigned int cpu)
+{
+	cpu_notify(CPU_STARTING, cpu);
+	return 0;
+}
+
+static int bringup_wait_for_ap(unsigned int cpu)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+	wait_for_completion(&st->done);
+	return st->result;
+}
+
+static int bringup_cpu(unsigned int cpu)
+{
+	struct task_struct *idle = idle_thread_get(cpu);
+	int ret;
+
+	/* Arch-specific enabling code. */
+	ret = __cpu_up(cpu, idle);
+	if (ret) {
+		cpu_notify(CPU_UP_CANCELED, cpu);
+		return ret;
+	}
+	ret = bringup_wait_for_ap(cpu);
+	BUG_ON(!cpu_online(cpu));
+	return ret;
+}
+
+/*
+ * Hotplug state machine related functions
+ */
+static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st,
+			  struct cpuhp_step *steps)
+{
+	for (st->state++; st->state < st->target; st->state++) {
+		struct cpuhp_step *step = steps + st->state;
+
+		if (!step->skip_onerr)
+			cpuhp_invoke_callback(cpu, st->state, step->startup);
+	}
+}
+
+static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
+				struct cpuhp_step *steps, enum cpuhp_state target)
+{
+	enum cpuhp_state prev_state = st->state;
+	int ret = 0;
+
+	for (; st->state > target; st->state--) {
+		struct cpuhp_step *step = steps + st->state;
+
+		ret = cpuhp_invoke_callback(cpu, st->state, step->teardown);
+		if (ret) {
+			st->target = prev_state;
+			undo_cpu_down(cpu, st, steps);
+			break;
+		}
+	}
+	return ret;
+}
+
+static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st,
+			struct cpuhp_step *steps)
+{
+	for (st->state--; st->state > st->target; st->state--) {
+		struct cpuhp_step *step = steps + st->state;
+
+		if (!step->skip_onerr)
+			cpuhp_invoke_callback(cpu, st->state, step->teardown);
+	}
+}
+
+static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
+			      struct cpuhp_step *steps, enum cpuhp_state target)
+{
+	enum cpuhp_state prev_state = st->state;
+	int ret = 0;
+
+	while (st->state < target) {
+		struct cpuhp_step *step;
+
+		st->state++;
+		step = steps + st->state;
+		ret = cpuhp_invoke_callback(cpu, st->state, step->startup);
+		if (ret) {
+			st->target = prev_state;
+			undo_cpu_up(cpu, st, steps);
+			break;
+		}
+	}
+	return ret;
+}
+
+/*
+ * The cpu hotplug threads manage the bringup and teardown of the cpus
+ */
+static void cpuhp_create(unsigned int cpu)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+	init_completion(&st->done);
+}
+
+static int cpuhp_should_run(unsigned int cpu)
+{
+	struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+
+	return st->should_run;
+}
+
+/* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */
+static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+	enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU);
+
+	return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target);
+}
+
+/* Execute the online startup callbacks. Used to be CPU_ONLINE */
+static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+	return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target);
+}
+
+/*
+ * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke
+ * callbacks when a state gets [un]installed at runtime.
+ */
+static void cpuhp_thread_fun(unsigned int cpu)
+{
+	struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+	int ret = 0;
+
+	/*
+	 * Paired with the mb() in cpuhp_kick_ap_work and
+	 * cpuhp_invoke_ap_callback, so the work set is consistent visible.
+	 */
+	smp_mb();
+	if (!st->should_run)
+		return;
+
+	st->should_run = false;
+
+	/* Single callback invocation for [un]install ? */
+	if (st->cb) {
+		if (st->cb_state < CPUHP_AP_ONLINE) {
+			local_irq_disable();
+			ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+			local_irq_enable();
+		} else {
+			ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+		}
+	} else if (st->rollback) {
+		BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
 
-static void cpu_notify_nofail(unsigned long val, void *v)
+		undo_cpu_down(cpu, st, cpuhp_ap_states);
+		/*
+		 * This is a momentary workaround to keep the notifier users
+		 * happy. Will go away once we got rid of the notifiers.
+		 */
+		cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
+		st->rollback = false;
+	} else {
+		/* Cannot happen .... */
+		BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
+
+		/* Regular hotplug work */
+		if (st->state < st->target)
+			ret = cpuhp_ap_online(cpu, st);
+		else if (st->state > st->target)
+			ret = cpuhp_ap_offline(cpu, st);
+	}
+	st->result = ret;
+	complete(&st->done);
+}
+
+/* Invoke a single callback on a remote cpu */
+static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state,
+				    int (*cb)(unsigned int))
 {
-	BUG_ON(cpu_notify(val, v));
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+	if (!cpu_online(cpu))
+		return 0;
+
+	st->cb_state = state;
+	st->cb = cb;
+	/*
+	 * Make sure the above stores are visible before should_run becomes
+	 * true. Paired with the mb() above in cpuhp_thread_fun()
+	 */
+	smp_mb();
+	st->should_run = true;
+	wake_up_process(st->thread);
+	wait_for_completion(&st->done);
+	return st->result;
+}
+
+/* Regular hotplug invocation of the AP hotplug thread */
+static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st)
+{
+	st->result = 0;
+	st->cb = NULL;
+	/*
+	 * Make sure the above stores are visible before should_run becomes
+	 * true. Paired with the mb() above in cpuhp_thread_fun()
+	 */
+	smp_mb();
+	st->should_run = true;
+	wake_up_process(st->thread);
 }
+
+static int cpuhp_kick_ap_work(unsigned int cpu)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+	enum cpuhp_state state = st->state;
+
+	trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work);
+	__cpuhp_kick_ap_work(st);
+	wait_for_completion(&st->done);
+	trace_cpuhp_exit(cpu, st->state, state, st->result);
+	return st->result;
+}
+
+static struct smp_hotplug_thread cpuhp_threads = {
+	.store			= &cpuhp_state.thread,
+	.create			= &cpuhp_create,
+	.thread_should_run	= cpuhp_should_run,
+	.thread_fn		= cpuhp_thread_fun,
+	.thread_comm		= "cpuhp/%u",
+	.selfparking		= true,
+};
+
+void __init cpuhp_threads_init(void)
+{
+	BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads));
+	kthread_unpark(this_cpu_read(cpuhp_state.thread));
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
 EXPORT_SYMBOL(register_cpu_notifier);
 EXPORT_SYMBOL(__register_cpu_notifier);
-
 void unregister_cpu_notifier(struct notifier_block *nb)
 {
 	cpu_maps_update_begin();
@@ -311,57 +653,55 @@ static inline void check_for_tasks(int dead_cpu)
 	read_unlock(&tasklist_lock);
 }
 
-struct take_cpu_down_param {
-	unsigned long mod;
-	void *hcpu;
-};
+static int notify_down_prepare(unsigned int cpu)
+{
+	int err, nr_calls = 0;
+
+	err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
+	if (err) {
+		nr_calls--;
+		__cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL);
+		pr_warn("%s: attempt to take down CPU %u failed\n",
+				__func__, cpu);
+	}
+	return err;
+}
+
+static int notify_dying(unsigned int cpu)
+{
+	cpu_notify(CPU_DYING, cpu);
+	return 0;
+}
 
 /* Take this CPU down. */
 static int take_cpu_down(void *_param)
 {
-	struct take_cpu_down_param *param = _param;
-	int err;
+	struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+	enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE);
+	int err, cpu = smp_processor_id();
 
 	/* Ensure this CPU doesn't handle any more interrupts. */
 	err = __cpu_disable();
 	if (err < 0)
 		return err;
 
-	cpu_notify(CPU_DYING | param->mod, param->hcpu);
+	/* Invoke the former CPU_DYING callbacks */
+	for (; st->state > target; st->state--) {
+		struct cpuhp_step *step = cpuhp_ap_states + st->state;
+
+		cpuhp_invoke_callback(cpu, st->state, step->teardown);
+	}
 	/* Give up timekeeping duties */
 	tick_handover_do_timer();
 	/* Park the stopper thread */
-	stop_machine_park((long)param->hcpu);
+	stop_machine_park(cpu);
 	return 0;
 }
 
-/* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu, int tasks_frozen)
+static int takedown_cpu(unsigned int cpu)
 {
-	int err, nr_calls = 0;
-	void *hcpu = (void *)(long)cpu;
-	unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
-	struct take_cpu_down_param tcd_param = {
-		.mod = mod,
-		.hcpu = hcpu,
-	};
-
-	if (num_online_cpus() == 1)
-		return -EBUSY;
-
-	if (!cpu_online(cpu))
-		return -EINVAL;
-
-	cpu_hotplug_begin();
-
-	err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
-	if (err) {
-		nr_calls--;
-		__cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
-		pr_warn("%s: attempt to take down CPU %u failed\n",
-			__func__, cpu);
-		goto out_release;
-	}
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+	int err;
 
 	/*
 	 * By now we've cleared cpu_active_mask, wait for all preempt-disabled
@@ -378,6 +718,8 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
 	else
 		synchronize_rcu();
 
+	/* Park the smpboot threads */
+	kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
 	smpboot_park_threads(cpu);
 
 	/*
@@ -389,12 +731,13 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
 	/*
 	 * So now all preempt/rcu users must observe !cpu_active().
 	 */
-	err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
+	err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
 	if (err) {
-		/* CPU didn't die: tell everyone.  Can't complain. */
-		cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
+		/* CPU refused to die */
 		irq_unlock_sparse();
-		goto out_release;
+		/* Unpark the hotplug thread so we can rollback there */
+		kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread);
+		return err;
 	}
 	BUG_ON(cpu_online(cpu));
 
@@ -405,10 +748,8 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
 	 *
 	 * Wait for the stop thread to go away.
 	 */
-	while (!per_cpu(cpu_dead_idle, cpu))
-		cpu_relax();
-	smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
-	per_cpu(cpu_dead_idle, cpu) = false;
+	wait_for_completion(&st->done);
+	BUG_ON(st->state != CPUHP_AP_IDLE_DEAD);
 
 	/* Interrupts are moved away from the dying cpu, reenable alloc/free */
 	irq_unlock_sparse();
@@ -417,20 +758,109 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
 	/* This actually kills the CPU. */
 	__cpu_die(cpu);
 
-	/* CPU is completely dead: tell everyone.  Too late to complain. */
 	tick_cleanup_dead_cpu(cpu);
-	cpu_notify_nofail(CPU_DEAD | mod, hcpu);
+	return 0;
+}
 
+static int notify_dead(unsigned int cpu)
+{
+	cpu_notify_nofail(CPU_DEAD, cpu);
 	check_for_tasks(cpu);
+	return 0;
+}
+
+static void cpuhp_complete_idle_dead(void *arg)
+{
+	struct cpuhp_cpu_state *st = arg;
+
+	complete(&st->done);
+}
+
+void cpuhp_report_idle_dead(void)
+{
+	struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+
+	BUG_ON(st->state != CPUHP_AP_OFFLINE);
+	rcu_report_dead(smp_processor_id());
+	st->state = CPUHP_AP_IDLE_DEAD;
+	/*
+	 * We cannot call complete after rcu_report_dead() so we delegate it
+	 * to an online cpu.
+	 */
+	smp_call_function_single(cpumask_first(cpu_online_mask),
+				 cpuhp_complete_idle_dead, st, 0);
+}
+
+#else
+#define notify_down_prepare	NULL
+#define takedown_cpu		NULL
+#define notify_dead		NULL
+#define notify_dying		NULL
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* Requires cpu_add_remove_lock to be held */
+static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
+			   enum cpuhp_state target)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+	int prev_state, ret = 0;
+	bool hasdied = false;
+
+	if (num_online_cpus() == 1)
+		return -EBUSY;
 
-out_release:
+	if (!cpu_present(cpu))
+		return -EINVAL;
+
+	cpu_hotplug_begin();
+
+	cpuhp_tasks_frozen = tasks_frozen;
+
+	prev_state = st->state;
+	st->target = target;
+	/*
+	 * If the current CPU state is in the range of the AP hotplug thread,
+	 * then we need to kick the thread.
+	 */
+	if (st->state > CPUHP_TEARDOWN_CPU) {
+		ret = cpuhp_kick_ap_work(cpu);
+		/*
+		 * The AP side has done the error rollback already. Just
+		 * return the error code..
+		 */
+		if (ret)
+			goto out;
+
+		/*
+		 * We might have stopped still in the range of the AP hotplug
+		 * thread. Nothing to do anymore.
+		 */
+		if (st->state > CPUHP_TEARDOWN_CPU)
+			goto out;
+	}
+	/*
+	 * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need
+	 * to do the further cleanups.
+	 */
+	ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target);
+	if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) {
+		st->target = prev_state;
+		st->rollback = true;
+		cpuhp_kick_ap_work(cpu);
+	}
+
+	hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
+out:
 	cpu_hotplug_done();
-	if (!err)
-		cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
-	return err;
+	/* This post dead nonsense must die */
+	if (!ret && hasdied)
+		cpu_notify_nofail(CPU_POST_DEAD, cpu);
+	return ret;
 }
 
-int cpu_down(unsigned int cpu)
+static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
 {
 	int err;
 
@@ -441,100 +871,131 @@ int cpu_down(unsigned int cpu)
 		goto out;
 	}
 
-	err = _cpu_down(cpu, 0);
+	err = _cpu_down(cpu, 0, target);
 
 out:
 	cpu_maps_update_done();
 	return err;
 }
+int cpu_down(unsigned int cpu)
+{
+	return do_cpu_down(cpu, CPUHP_OFFLINE);
+}
 EXPORT_SYMBOL(cpu_down);
 #endif /*CONFIG_HOTPLUG_CPU*/
 
-/*
- * Unpark per-CPU smpboot kthreads at CPU-online time.
+/**
+ * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * @cpu: cpu that just started
+ *
+ * This function calls the cpu_chain notifiers with CPU_STARTING.
+ * It must be called by the arch code on the new cpu, before the new cpu
+ * enables interrupts and before the "boot" cpu returns from __cpu_up().
  */
-static int smpboot_thread_call(struct notifier_block *nfb,
-			       unsigned long action, void *hcpu)
+void notify_cpu_starting(unsigned int cpu)
 {
-	int cpu = (long)hcpu;
-
-	switch (action & ~CPU_TASKS_FROZEN) {
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+	enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE);
 
-	case CPU_DOWN_FAILED:
-	case CPU_ONLINE:
-		smpboot_unpark_threads(cpu);
-		break;
+	while (st->state < target) {
+		struct cpuhp_step *step;
 
-	default:
-		break;
+		st->state++;
+		step = cpuhp_ap_states + st->state;
+		cpuhp_invoke_callback(cpu, st->state, step->startup);
 	}
-
-	return NOTIFY_OK;
 }
 
-static struct notifier_block smpboot_thread_notifier = {
-	.notifier_call = smpboot_thread_call,
-	.priority = CPU_PRI_SMPBOOT,
-};
-
-void smpboot_thread_init(void)
+/*
+ * Called from the idle task. We need to set active here, so we can kick off
+ * the stopper thread and unpark the smpboot threads. If the target state is
+ * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the
+ * cpu further.
+ */
+void cpuhp_online_idle(enum cpuhp_state state)
 {
-	register_cpu_notifier(&smpboot_thread_notifier);
+	struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+	unsigned int cpu = smp_processor_id();
+
+	/* Happens for the boot cpu */
+	if (state != CPUHP_AP_ONLINE_IDLE)
+		return;
+
+	st->state = CPUHP_AP_ONLINE_IDLE;
+
+	/* The cpu is marked online, set it active now */
+	set_cpu_active(cpu, true);
+	/* Unpark the stopper thread and the hotplug thread of this cpu */
+	stop_machine_unpark(cpu);
+	kthread_unpark(st->thread);
+
+	/* Should we go further up ? */
+	if (st->target > CPUHP_AP_ONLINE_IDLE)
+		__cpuhp_kick_ap_work(st);
+	else
+		complete(&st->done);
 }
 
 /* Requires cpu_add_remove_lock to be held */
-static int _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
 {
-	int ret, nr_calls = 0;
-	void *hcpu = (void *)(long)cpu;
-	unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
 	struct task_struct *idle;
+	int ret = 0;
 
 	cpu_hotplug_begin();
 
-	if (cpu_online(cpu) || !cpu_present(cpu)) {
+	if (!cpu_present(cpu)) {
 		ret = -EINVAL;
 		goto out;
 	}
 
-	idle = idle_thread_get(cpu);
-	if (IS_ERR(idle)) {
-		ret = PTR_ERR(idle);
-		goto out;
-	}
-
-	ret = smpboot_create_threads(cpu);
-	if (ret)
+	/*
+	 * The caller of do_cpu_up might have raced with another
+	 * caller. Ignore it for now.
+	 */
+	if (st->state >= target)
 		goto out;
 
-	ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
-	if (ret) {
-		nr_calls--;
-		pr_warn("%s: attempt to bring up CPU %u failed\n",
-			__func__, cpu);
-		goto out_notify;
+	if (st->state == CPUHP_OFFLINE) {
+		/* Let it fail before we try to bring the cpu up */
+		idle = idle_thread_get(cpu);
+		if (IS_ERR(idle)) {
+			ret = PTR_ERR(idle);
+			goto out;
+		}
 	}
 
-	/* Arch-specific enabling code. */
-	ret = __cpu_up(cpu, idle);
-
-	if (ret != 0)
-		goto out_notify;
-	BUG_ON(!cpu_online(cpu));
+	cpuhp_tasks_frozen = tasks_frozen;
 
-	/* Now call notifier in preparation. */
-	cpu_notify(CPU_ONLINE | mod, hcpu);
+	st->target = target;
+	/*
+	 * If the current CPU state is in the range of the AP hotplug thread,
+	 * then we need to kick the thread once more.
+	 */
+	if (st->state > CPUHP_BRINGUP_CPU) {
+		ret = cpuhp_kick_ap_work(cpu);
+		/*
+		 * The AP side has done the error rollback already. Just
+		 * return the error code..
+		 */
+		if (ret)
+			goto out;
+	}
 
-out_notify:
-	if (ret != 0)
-		__cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+	/*
+	 * Try to reach the target state. We max out on the BP at
+	 * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is
+	 * responsible for bringing it up to the target state.
+	 */
+	target = min((int)target, CPUHP_BRINGUP_CPU);
+	ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target);
 out:
 	cpu_hotplug_done();
-
 	return ret;
 }
 
-int cpu_up(unsigned int cpu)
+static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
 {
 	int err = 0;
 
@@ -558,12 +1019,16 @@ int cpu_up(unsigned int cpu)
 		goto out;
 	}
 
-	err = _cpu_up(cpu, 0);
-
+	err = _cpu_up(cpu, 0, target);
 out:
 	cpu_maps_update_done();
 	return err;
 }
+
+int cpu_up(unsigned int cpu)
+{
+	return do_cpu_up(cpu, CPUHP_ONLINE);
+}
 EXPORT_SYMBOL_GPL(cpu_up);
 
 #ifdef CONFIG_PM_SLEEP_SMP
@@ -586,7 +1051,7 @@ int disable_nonboot_cpus(void)
 		if (cpu == first_cpu)
 			continue;
 		trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
-		error = _cpu_down(cpu, 1);
+		error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
 		trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
 		if (!error)
 			cpumask_set_cpu(cpu, frozen_cpus);
@@ -636,7 +1101,7 @@ void enable_nonboot_cpus(void)
 
 	for_each_cpu(cpu, frozen_cpus) {
 		trace_suspend_resume(TPS("CPU_ON"), cpu, true);
-		error = _cpu_up(cpu, 1);
+		error = _cpu_up(cpu, 1, CPUHP_ONLINE);
 		trace_suspend_resume(TPS("CPU_ON"), cpu, false);
 		if (!error) {
 			pr_info("CPU%d is up\n", cpu);
@@ -709,26 +1174,464 @@ core_initcall(cpu_hotplug_pm_sync_init);
 
 #endif /* CONFIG_PM_SLEEP_SMP */
 
+#endif /* CONFIG_SMP */
+
+/* Boot processor state steps */
+static struct cpuhp_step cpuhp_bp_states[] = {
+	[CPUHP_OFFLINE] = {
+		.name			= "offline",
+		.startup		= NULL,
+		.teardown		= NULL,
+	},
+#ifdef CONFIG_SMP
+	[CPUHP_CREATE_THREADS]= {
+		.name			= "threads:create",
+		.startup		= smpboot_create_threads,
+		.teardown		= NULL,
+		.cant_stop		= true,
+	},
+	/*
+	 * Preparatory and dead notifiers. Will be replaced once the notifiers
+	 * are converted to states.
+	 */
+	[CPUHP_NOTIFY_PREPARE] = {
+		.name			= "notify:prepare",
+		.startup		= notify_prepare,
+		.teardown		= notify_dead,
+		.skip_onerr		= true,
+		.cant_stop		= true,
+	},
+	/* Kicks the plugged cpu into life */
+	[CPUHP_BRINGUP_CPU] = {
+		.name			= "cpu:bringup",
+		.startup		= bringup_cpu,
+		.teardown		= NULL,
+		.cant_stop		= true,
+	},
+	/*
+	 * Handled on controll processor until the plugged processor manages
+	 * this itself.
+	 */
+	[CPUHP_TEARDOWN_CPU] = {
+		.name			= "cpu:teardown",
+		.startup		= NULL,
+		.teardown		= takedown_cpu,
+		.cant_stop		= true,
+	},
+#endif
+};
+
+/* Application processor state steps */
+static struct cpuhp_step cpuhp_ap_states[] = {
+#ifdef CONFIG_SMP
+	/* Final state before CPU kills itself */
+	[CPUHP_AP_IDLE_DEAD] = {
+		.name			= "idle:dead",
+	},
+	/*
+	 * Last state before CPU enters the idle loop to die. Transient state
+	 * for synchronization.
+	 */
+	[CPUHP_AP_OFFLINE] = {
+		.name			= "ap:offline",
+		.cant_stop		= true,
+	},
+	/*
+	 * Low level startup/teardown notifiers. Run with interrupts
+	 * disabled. Will be removed once the notifiers are converted to
+	 * states.
+	 */
+	[CPUHP_AP_NOTIFY_STARTING] = {
+		.name			= "notify:starting",
+		.startup		= notify_starting,
+		.teardown		= notify_dying,
+		.skip_onerr		= true,
+		.cant_stop		= true,
+	},
+	/* Entry state on starting. Interrupts enabled from here on. Transient
+	 * state for synchronsization */
+	[CPUHP_AP_ONLINE] = {
+		.name			= "ap:online",
+	},
+	/* Handle smpboot threads park/unpark */
+	[CPUHP_AP_SMPBOOT_THREADS] = {
+		.name			= "smpboot:threads",
+		.startup		= smpboot_unpark_threads,
+		.teardown		= NULL,
+	},
+	/*
+	 * Online/down_prepare notifiers. Will be removed once the notifiers
+	 * are converted to states.
+	 */
+	[CPUHP_AP_NOTIFY_ONLINE] = {
+		.name			= "notify:online",
+		.startup		= notify_online,
+		.teardown		= notify_down_prepare,
+		.skip_onerr		= true,
+	},
+#endif
+	/*
+	 * The dynamically registered state space is here
+	 */
+
+	/* CPU is fully up and running. */
+	[CPUHP_ONLINE] = {
+		.name			= "online",
+		.startup		= NULL,
+		.teardown		= NULL,
+	},
+};
+
+/* Sanity check for callbacks */
+static int cpuhp_cb_check(enum cpuhp_state state)
+{
+	if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE)
+		return -EINVAL;
+	return 0;
+}
+
+static bool cpuhp_is_ap_state(enum cpuhp_state state)
+{
+	/*
+	 * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
+	 * purposes as that state is handled explicitely in cpu_down.
+	 */
+	return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
+}
+
+static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
+{
+	struct cpuhp_step *sp;
+
+	sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
+	return sp + state;
+}
+
+static void cpuhp_store_callbacks(enum cpuhp_state state,
+				  const char *name,
+				  int (*startup)(unsigned int cpu),
+				  int (*teardown)(unsigned int cpu))
+{
+	/* (Un)Install the callbacks for further cpu hotplug operations */
+	struct cpuhp_step *sp;
+
+	mutex_lock(&cpuhp_state_mutex);
+	sp = cpuhp_get_step(state);
+	sp->startup = startup;
+	sp->teardown = teardown;
+	sp->name = name;
+	mutex_unlock(&cpuhp_state_mutex);
+}
+
+static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
+{
+	return cpuhp_get_step(state)->teardown;
+}
+
+/*
+ * Call the startup/teardown function for a step either on the AP or
+ * on the current CPU.
+ */
+static int cpuhp_issue_call(int cpu, enum cpuhp_state state,
+			    int (*cb)(unsigned int), bool bringup)
+{
+	int ret;
+
+	if (!cb)
+		return 0;
+	/*
+	 * The non AP bound callbacks can fail on bringup. On teardown
+	 * e.g. module removal we crash for now.
+	 */
+#ifdef CONFIG_SMP
+	if (cpuhp_is_ap_state(state))
+		ret = cpuhp_invoke_ap_callback(cpu, state, cb);
+	else
+		ret = cpuhp_invoke_callback(cpu, state, cb);
+#else
+	ret = cpuhp_invoke_callback(cpu, state, cb);
+#endif
+	BUG_ON(ret && !bringup);
+	return ret;
+}
+
+/*
+ * Called from __cpuhp_setup_state on a recoverable failure.
+ *
+ * Note: The teardown callbacks for rollback are not allowed to fail!
+ */
+static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state,
+				   int (*teardown)(unsigned int cpu))
+{
+	int cpu;
+
+	if (!teardown)
+		return;
+
+	/* Roll back the already executed steps on the other cpus */
+	for_each_present_cpu(cpu) {
+		struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+		int cpustate = st->state;
+
+		if (cpu >= failedcpu)
+			break;
+
+		/* Did we invoke the startup call on that cpu ? */
+		if (cpustate >= state)
+			cpuhp_issue_call(cpu, state, teardown, false);
+	}
+}
+
+/*
+ * Returns a free for dynamic slot assignment of the Online state. The states
+ * are protected by the cpuhp_slot_states mutex and an empty slot is identified
+ * by having no name assigned.
+ */
+static int cpuhp_reserve_state(enum cpuhp_state state)
+{
+	enum cpuhp_state i;
+
+	mutex_lock(&cpuhp_state_mutex);
+	for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
+		if (cpuhp_ap_states[i].name)
+			continue;
+
+		cpuhp_ap_states[i].name = "Reserved";
+		mutex_unlock(&cpuhp_state_mutex);
+		return i;
+	}
+	mutex_unlock(&cpuhp_state_mutex);
+	WARN(1, "No more dynamic states available for CPU hotplug\n");
+	return -ENOSPC;
+}
+
 /**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
- * @cpu: cpu that just started
+ * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state
+ * @state:	The state to setup
+ * @invoke:	If true, the startup function is invoked for cpus where
+ *		cpu state >= @state
+ * @startup:	startup callback function
+ * @teardown:	teardown callback function
  *
- * This function calls the cpu_chain notifiers with CPU_STARTING.
- * It must be called by the arch code on the new cpu, before the new cpu
- * enables interrupts and before the "boot" cpu returns from __cpu_up().
+ * Returns 0 if successful, otherwise a proper error code
  */
-void notify_cpu_starting(unsigned int cpu)
+int __cpuhp_setup_state(enum cpuhp_state state,
+			const char *name, bool invoke,
+			int (*startup)(unsigned int cpu),
+			int (*teardown)(unsigned int cpu))
 {
-	unsigned long val = CPU_STARTING;
+	int cpu, ret = 0;
+	int dyn_state = 0;
 
-#ifdef CONFIG_PM_SLEEP_SMP
-	if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
-		val = CPU_STARTING_FROZEN;
-#endif /* CONFIG_PM_SLEEP_SMP */
-	cpu_notify(val, (void *)(long)cpu);
+	if (cpuhp_cb_check(state) || !name)
+		return -EINVAL;
+
+	get_online_cpus();
+
+	/* currently assignments for the ONLINE state are possible */
+	if (state == CPUHP_AP_ONLINE_DYN) {
+		dyn_state = 1;
+		ret = cpuhp_reserve_state(state);
+		if (ret < 0)
+			goto out;
+		state = ret;
+	}
+
+	cpuhp_store_callbacks(state, name, startup, teardown);
+
+	if (!invoke || !startup)
+		goto out;
+
+	/*
+	 * Try to call the startup callback for each present cpu
+	 * depending on the hotplug state of the cpu.
+	 */
+	for_each_present_cpu(cpu) {
+		struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+		int cpustate = st->state;
+
+		if (cpustate < state)
+			continue;
+
+		ret = cpuhp_issue_call(cpu, state, startup, true);
+		if (ret) {
+			cpuhp_rollback_install(cpu, state, teardown);
+			cpuhp_store_callbacks(state, NULL, NULL, NULL);
+			goto out;
+		}
+	}
+out:
+	put_online_cpus();
+	if (!ret && dyn_state)
+		return state;
+	return ret;
 }
+EXPORT_SYMBOL(__cpuhp_setup_state);
 
-#endif /* CONFIG_SMP */
+/**
+ * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state
+ * @state:	The state to remove
+ * @invoke:	If true, the teardown function is invoked for cpus where
+ *		cpu state >= @state
+ *
+ * The teardown callback is currently not allowed to fail. Think
+ * about module removal!
+ */
+void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
+{
+	int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state);
+	int cpu;
+
+	BUG_ON(cpuhp_cb_check(state));
+
+	get_online_cpus();
+
+	if (!invoke || !teardown)
+		goto remove;
+
+	/*
+	 * Call the teardown callback for each present cpu depending
+	 * on the hotplug state of the cpu. This function is not
+	 * allowed to fail currently!
+	 */
+	for_each_present_cpu(cpu) {
+		struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+		int cpustate = st->state;
+
+		if (cpustate >= state)
+			cpuhp_issue_call(cpu, state, teardown, false);
+	}
+remove:
+	cpuhp_store_callbacks(state, NULL, NULL, NULL);
+	put_online_cpus();
+}
+EXPORT_SYMBOL(__cpuhp_remove_state);
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
+static ssize_t show_cpuhp_state(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+
+	return sprintf(buf, "%d\n", st->state);
+}
+static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL);
+
+static ssize_t write_cpuhp_target(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+	struct cpuhp_step *sp;
+	int target, ret;
+
+	ret = kstrtoint(buf, 10, &target);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL
+	if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE)
+		return -EINVAL;
+#else
+	if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE)
+		return -EINVAL;
+#endif
+
+	ret = lock_device_hotplug_sysfs();
+	if (ret)
+		return ret;
+
+	mutex_lock(&cpuhp_state_mutex);
+	sp = cpuhp_get_step(target);
+	ret = !sp->name || sp->cant_stop ? -EINVAL : 0;
+	mutex_unlock(&cpuhp_state_mutex);
+	if (ret)
+		return ret;
+
+	if (st->state < target)
+		ret = do_cpu_up(dev->id, target);
+	else
+		ret = do_cpu_down(dev->id, target);
+
+	unlock_device_hotplug();
+	return ret ? ret : count;
+}
+
+static ssize_t show_cpuhp_target(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+
+	return sprintf(buf, "%d\n", st->target);
+}
+static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target);
+
+static struct attribute *cpuhp_cpu_attrs[] = {
+	&dev_attr_state.attr,
+	&dev_attr_target.attr,
+	NULL
+};
+
+static struct attribute_group cpuhp_cpu_attr_group = {
+	.attrs = cpuhp_cpu_attrs,
+	.name = "hotplug",
+	NULL
+};
+
+static ssize_t show_cpuhp_states(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	ssize_t cur, res = 0;
+	int i;
+
+	mutex_lock(&cpuhp_state_mutex);
+	for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) {
+		struct cpuhp_step *sp = cpuhp_get_step(i);
+
+		if (sp->name) {
+			cur = sprintf(buf, "%3d: %s\n", i, sp->name);
+			buf += cur;
+			res += cur;
+		}
+	}
+	mutex_unlock(&cpuhp_state_mutex);
+	return res;
+}
+static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL);
+
+static struct attribute *cpuhp_cpu_root_attrs[] = {
+	&dev_attr_states.attr,
+	NULL
+};
+
+static struct attribute_group cpuhp_cpu_root_attr_group = {
+	.attrs = cpuhp_cpu_root_attrs,
+	.name = "hotplug",
+	NULL
+};
+
+static int __init cpuhp_sysfs_init(void)
+{
+	int cpu, ret;
+
+	ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
+				 &cpuhp_cpu_root_attr_group);
+	if (ret)
+		return ret;
+
+	for_each_possible_cpu(cpu) {
+		struct device *dev = get_cpu_device(cpu);
+
+		if (!dev)
+			continue;
+		ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+device_initcall(cpuhp_sysfs_init);
+#endif
 
 /*
  * cpu_bit_bitmap[] is a special, "compressed" data structure that
@@ -789,3 +1692,25 @@ void init_cpu_online(const struct cpumask *src)
 {
 	cpumask_copy(&__cpu_online_mask, src);
 }
+
+/*
+ * Activate the first processor.
+ */
+void __init boot_cpu_init(void)
+{
+	int cpu = smp_processor_id();
+
+	/* Mark the boot cpu "present", "online" etc for SMP and UP case */
+	set_cpu_online(cpu, true);
+	set_cpu_active(cpu, true);
+	set_cpu_present(cpu, true);
+	set_cpu_possible(cpu, true);
+}
+
+/*
+ * Must be called _AFTER_ setting up the per_cpu areas
+ */
+void __init boot_cpu_state_init(void)
+{
+	per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
+}
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index df16d0c93..1902956ba 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2089,7 +2089,7 @@ struct cgroup_subsys cpuset_cgrp_subsys = {
 	.post_attach	= cpuset_post_attach,
 	.bind		= cpuset_bind,
 	.legacy_cftypes	= files,
-	.early_init	= 1,
+	.early_init	= true,
 };
 
 /**
@@ -2714,10 +2714,10 @@ int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
 		goto out;
 
 	retval = -ENAMETOOLONG;
-	rcu_read_lock();
-	css = task_css(tsk, cpuset_cgrp_id);
-	p = cgroup_path(css->cgroup, buf, PATH_MAX);
-	rcu_read_unlock();
+	css = task_get_css(tsk, cpuset_cgrp_id);
+	p = cgroup_path_ns(css->cgroup, buf, PATH_MAX,
+			   current->nsproxy->cgroup_ns);
+	css_put(css);
 	if (!p)
 		goto out_free;
 	seq_puts(m, p);
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index e1dbf4a2c..90ff129c8 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -153,13 +153,11 @@ static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
 	} else {
 		kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
 			   __func__, bp->bp_addr);
-#ifdef CONFIG_DEBUG_RODATA
 		if (!bp->bp_type) {
 			kdb_printf("Software breakpoints are unavailable.\n"
-				   "  Change the kernel CONFIG_DEBUG_RODATA=n\n"
+				   "  Boot the kernel with rodata=off\n"
 				   "  OR use hw breaks: help bph\n");
 		}
-#endif
 		return 1;
 	}
 	return 0;
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 9c418002b..343c22f5e 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -159,15 +159,24 @@ put_callchain_entry(int rctx)
 struct perf_callchain_entry *
 perf_callchain(struct perf_event *event, struct pt_regs *regs)
 {
-	int rctx;
-	struct perf_callchain_entry *entry;
-
-	int kernel = !event->attr.exclude_callchain_kernel;
-	int user   = !event->attr.exclude_callchain_user;
+	bool kernel = !event->attr.exclude_callchain_kernel;
+	bool user   = !event->attr.exclude_callchain_user;
+	/* Disallow cross-task user callchains. */
+	bool crosstask = event->ctx->task && event->ctx->task != current;
 
 	if (!kernel && !user)
 		return NULL;
 
+	return get_perf_callchain(regs, 0, kernel, user, crosstask, true);
+}
+
+struct perf_callchain_entry *
+get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
+		   bool crosstask, bool add_mark)
+{
+	struct perf_callchain_entry *entry;
+	int rctx;
+
 	entry = get_callchain_entry(&rctx);
 	if (rctx == -1)
 		return NULL;
@@ -175,10 +184,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
 	if (!entry)
 		goto exit_put;
 
-	entry->nr = 0;
+	entry->nr = init_nr;
 
 	if (kernel && !user_mode(regs)) {
-		perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
+		if (add_mark)
+			perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
 		perf_callchain_kernel(entry, regs);
 	}
 
@@ -191,13 +201,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
 		}
 
 		if (regs) {
-			/*
-			 * Disallow cross-task user callchains.
-			 */
-			if (event->ctx->task && event->ctx->task != current)
+			if (crosstask)
 				goto exit_put;
 
-			perf_callchain_store(entry, PERF_CONTEXT_USER);
+			if (add_mark)
+				perf_callchain_store(entry, PERF_CONTEXT_USER);
 			perf_callchain_user(entry, regs);
 		}
 	}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a0ef98b25..c0ded2416 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -351,7 +351,7 @@ static struct srcu_struct pmus_srcu;
  *   1 - disallow cpu events for unpriv
  *   2 - disallow kernel profiling for unpriv
  */
-int sysctl_perf_event_paranoid __read_mostly = 1;
+int sysctl_perf_event_paranoid __read_mostly = 2;
 
 /* Minimum for 512 kiB + 1 user control page */
 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
@@ -376,8 +376,11 @@ static void update_perf_cpu_limits(void)
 	u64 tmp = perf_sample_period_ns;
 
 	tmp *= sysctl_perf_cpu_time_max_percent;
-	do_div(tmp, 100);
-	ACCESS_ONCE(perf_sample_allowed_ns) = tmp;
+	tmp = div_u64(tmp, 100);
+	if (!tmp)
+		tmp = 1;
+
+	WRITE_ONCE(perf_sample_allowed_ns, tmp);
 }
 
 static int perf_rotate_context(struct perf_cpu_context *cpuctx);
@@ -409,7 +412,14 @@ int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
 	if (ret || !write)
 		return ret;
 
-	update_perf_cpu_limits();
+	if (sysctl_perf_cpu_time_max_percent == 100 ||
+	    sysctl_perf_cpu_time_max_percent == 0) {
+		printk(KERN_WARNING
+		       "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
+		WRITE_ONCE(perf_sample_allowed_ns, 0);
+	} else {
+		update_perf_cpu_limits();
+	}
 
 	return 0;
 }
@@ -423,62 +433,68 @@ int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
 #define NR_ACCUMULATED_SAMPLES 128
 static DEFINE_PER_CPU(u64, running_sample_length);
 
+static u64 __report_avg;
+static u64 __report_allowed;
+
 static void perf_duration_warn(struct irq_work *w)
 {
-	u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
-	u64 avg_local_sample_len;
-	u64 local_samples_len;
-
-	local_samples_len = __this_cpu_read(running_sample_length);
-	avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
-
 	printk_ratelimited(KERN_WARNING
-			"perf interrupt took too long (%lld > %lld), lowering "
-			"kernel.perf_event_max_sample_rate to %d\n",
-			avg_local_sample_len, allowed_ns >> 1,
-			sysctl_perf_event_sample_rate);
+		"perf: interrupt took too long (%lld > %lld), lowering "
+		"kernel.perf_event_max_sample_rate to %d\n",
+		__report_avg, __report_allowed,
+		sysctl_perf_event_sample_rate);
 }
 
 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
 
 void perf_sample_event_took(u64 sample_len_ns)
 {
-	u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
-	u64 avg_local_sample_len;
-	u64 local_samples_len;
+	u64 max_len = READ_ONCE(perf_sample_allowed_ns);
+	u64 running_len;
+	u64 avg_len;
+	u32 max;
 
-	if (allowed_ns == 0)
+	if (max_len == 0)
 		return;
 
-	/* decay the counter by 1 average sample */
-	local_samples_len = __this_cpu_read(running_sample_length);
-	local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES;
-	local_samples_len += sample_len_ns;
-	__this_cpu_write(running_sample_length, local_samples_len);
+	/* Decay the counter by 1 average sample. */
+	running_len = __this_cpu_read(running_sample_length);
+	running_len -= running_len/NR_ACCUMULATED_SAMPLES;
+	running_len += sample_len_ns;
+	__this_cpu_write(running_sample_length, running_len);
 
 	/*
-	 * note: this will be biased artifically low until we have
-	 * seen NR_ACCUMULATED_SAMPLES.  Doing it this way keeps us
+	 * Note: this will be biased artifically low until we have
+	 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
 	 * from having to maintain a count.
 	 */
-	avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
-
-	if (avg_local_sample_len <= allowed_ns)
+	avg_len = running_len/NR_ACCUMULATED_SAMPLES;
+	if (avg_len <= max_len)
 		return;
 
-	if (max_samples_per_tick <= 1)
-		return;
+	__report_avg = avg_len;
+	__report_allowed = max_len;
 
-	max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2);
-	sysctl_perf_event_sample_rate = max_samples_per_tick * HZ;
-	perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
+	/*
+	 * Compute a throttle threshold 25% below the current duration.
+	 */
+	avg_len += avg_len / 4;
+	max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
+	if (avg_len < max)
+		max /= (u32)avg_len;
+	else
+		max = 1;
 
-	update_perf_cpu_limits();
+	WRITE_ONCE(perf_sample_allowed_ns, avg_len);
+	WRITE_ONCE(max_samples_per_tick, max);
+
+	sysctl_perf_event_sample_rate = max * HZ;
+	perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
 
 	if (!irq_work_queue(&perf_duration_work)) {
-		early_printk("perf interrupt took too long (%lld > %lld), lowering "
+		early_printk("perf: interrupt took too long (%lld > %lld), lowering "
 			     "kernel.perf_event_max_sample_rate to %d\n",
-			     avg_local_sample_len, allowed_ns >> 1,
+			     __report_avg, __report_allowed,
 			     sysctl_perf_event_sample_rate);
 	}
 }
@@ -1090,6 +1106,7 @@ static void put_ctx(struct perf_event_context *ctx)
  * function.
  *
  * Lock order:
+ *    cred_guard_mutex
  *	task_struct::perf_event_mutex
  *	  perf_event_context::mutex
  *	    perf_event::child_mutex;
@@ -3122,17 +3139,6 @@ done:
 	return rotate;
 }
 
-#ifdef CONFIG_NO_HZ_FULL
-bool perf_event_can_stop_tick(void)
-{
-	if (atomic_read(&nr_freq_events) ||
-	    __this_cpu_read(perf_throttled_count))
-		return false;
-	else
-		return true;
-}
-#endif
-
 void perf_event_task_tick(void)
 {
 	struct list_head *head = this_cpu_ptr(&active_ctx_list);
@@ -3143,6 +3149,7 @@ void perf_event_task_tick(void)
 
 	__this_cpu_inc(perf_throttled_seq);
 	throttled = __this_cpu_xchg(perf_throttled_count, 0);
+	tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
 
 	list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
 		perf_adjust_freq_unthr_context(ctx, throttled);
@@ -3415,7 +3422,6 @@ static struct task_struct *
 find_lively_task_by_vpid(pid_t vpid)
 {
 	struct task_struct *task;
-	int err;
 
 	rcu_read_lock();
 	if (!vpid)
@@ -3429,16 +3435,7 @@ find_lively_task_by_vpid(pid_t vpid)
 	if (!task)
 		return ERR_PTR(-ESRCH);
 
-	/* Reuse ptrace permission checks for now. */
-	err = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
-		goto errout;
-
 	return task;
-errout:
-	put_task_struct(task);
-	return ERR_PTR(err);
-
 }
 
 /*
@@ -3574,6 +3571,28 @@ static void unaccount_event_cpu(struct perf_event *event, int cpu)
 		atomic_dec(&per_cpu(perf_cgroup_events, cpu));
 }
 
+#ifdef CONFIG_NO_HZ_FULL
+static DEFINE_SPINLOCK(nr_freq_lock);
+#endif
+
+static void unaccount_freq_event_nohz(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+	spin_lock(&nr_freq_lock);
+	if (atomic_dec_and_test(&nr_freq_events))
+		tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
+	spin_unlock(&nr_freq_lock);
+#endif
+}
+
+static void unaccount_freq_event(void)
+{
+	if (tick_nohz_full_enabled())
+		unaccount_freq_event_nohz();
+	else
+		atomic_dec(&nr_freq_events);
+}
+
 static void unaccount_event(struct perf_event *event)
 {
 	bool dec = false;
@@ -3590,7 +3609,7 @@ static void unaccount_event(struct perf_event *event)
 	if (event->attr.task)
 		atomic_dec(&nr_task_events);
 	if (event->attr.freq)
-		atomic_dec(&nr_freq_events);
+		unaccount_freq_event();
 	if (event->attr.context_switch) {
 		dec = true;
 		atomic_dec(&nr_switch_events);
@@ -4208,6 +4227,14 @@ static void __perf_event_period(struct perf_event *event,
 	active = (event->state == PERF_EVENT_STATE_ACTIVE);
 	if (active) {
 		perf_pmu_disable(ctx->pmu);
+		/*
+		 * We could be throttled; unthrottle now to avoid the tick
+		 * trying to unthrottle while we already re-started the event.
+		 */
+		if (event->hw.interrupts == MAX_INTERRUPTS) {
+			event->hw.interrupts = 0;
+			perf_log_throttle(event, 1);
+		}
 		event->pmu->stop(event, PERF_EF_UPDATE);
 	}
 
@@ -6434,9 +6461,9 @@ static int __perf_event_overflow(struct perf_event *event,
 		if (unlikely(throttle
 			     && hwc->interrupts >= max_samples_per_tick)) {
 			__this_cpu_inc(perf_throttled_count);
+			tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
 			hwc->interrupts = MAX_INTERRUPTS;
 			perf_log_throttle(event, 0);
-			tick_nohz_full_kick();
 			ret = 1;
 		}
 	}
@@ -6795,7 +6822,7 @@ static void swevent_hlist_release(struct swevent_htable *swhash)
 	kfree_rcu(hlist, rcu_head);
 }
 
-static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
+static void swevent_hlist_put_cpu(int cpu)
 {
 	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
 
@@ -6807,15 +6834,15 @@ static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
 	mutex_unlock(&swhash->hlist_mutex);
 }
 
-static void swevent_hlist_put(struct perf_event *event)
+static void swevent_hlist_put(void)
 {
 	int cpu;
 
 	for_each_possible_cpu(cpu)
-		swevent_hlist_put_cpu(event, cpu);
+		swevent_hlist_put_cpu(cpu);
 }
 
-static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
+static int swevent_hlist_get_cpu(int cpu)
 {
 	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
 	int err = 0;
@@ -6838,14 +6865,13 @@ exit:
 	return err;
 }
 
-static int swevent_hlist_get(struct perf_event *event)
+static int swevent_hlist_get(void)
 {
-	int err;
-	int cpu, failed_cpu;
+	int err, cpu, failed_cpu;
 
 	get_online_cpus();
 	for_each_possible_cpu(cpu) {
-		err = swevent_hlist_get_cpu(event, cpu);
+		err = swevent_hlist_get_cpu(cpu);
 		if (err) {
 			failed_cpu = cpu;
 			goto fail;
@@ -6858,7 +6884,7 @@ fail:
 	for_each_possible_cpu(cpu) {
 		if (cpu == failed_cpu)
 			break;
-		swevent_hlist_put_cpu(event, cpu);
+		swevent_hlist_put_cpu(cpu);
 	}
 
 	put_online_cpus();
@@ -6874,7 +6900,7 @@ static void sw_perf_event_destroy(struct perf_event *event)
 	WARN_ON(event->parent);
 
 	static_key_slow_dec(&perf_swevent_enabled[event_id]);
-	swevent_hlist_put(event);
+	swevent_hlist_put();
 }
 
 static int perf_swevent_init(struct perf_event *event)
@@ -6905,7 +6931,7 @@ static int perf_swevent_init(struct perf_event *event)
 	if (!event->parent) {
 		int err;
 
-		err = swevent_hlist_get(event);
+		err = swevent_hlist_get();
 		if (err)
 			return err;
 
@@ -7826,6 +7852,27 @@ static void account_event_cpu(struct perf_event *event, int cpu)
 		atomic_inc(&per_cpu(perf_cgroup_events, cpu));
 }
 
+/* Freq events need the tick to stay alive (see perf_event_task_tick). */
+static void account_freq_event_nohz(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+	/* Lock so we don't race with concurrent unaccount */
+	spin_lock(&nr_freq_lock);
+	if (atomic_inc_return(&nr_freq_events) == 1)
+		tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
+	spin_unlock(&nr_freq_lock);
+#endif
+}
+
+static void account_freq_event(void)
+{
+	if (tick_nohz_full_enabled())
+		account_freq_event_nohz();
+	else
+		atomic_inc(&nr_freq_events);
+}
+
+
 static void account_event(struct perf_event *event)
 {
 	bool inc = false;
@@ -7841,10 +7888,8 @@ static void account_event(struct perf_event *event)
 		atomic_inc(&nr_comm_events);
 	if (event->attr.task)
 		atomic_inc(&nr_task_events);
-	if (event->attr.freq) {
-		if (atomic_inc_return(&nr_freq_events) == 1)
-			tick_nohz_full_kick_all();
-	}
+	if (event->attr.freq)
+		account_freq_event();
 	if (event->attr.context_switch) {
 		atomic_inc(&nr_switch_events);
 		inc = true;
@@ -8360,6 +8405,24 @@ SYSCALL_DEFINE5(perf_event_open,
 
 	get_online_cpus();
 
+	if (task) {
+		err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
+		if (err)
+			goto err_cpus;
+
+		/*
+		 * Reuse ptrace permission checks for now.
+		 *
+		 * We must hold cred_guard_mutex across this and any potential
+		 * perf_install_in_context() call for this new event to
+		 * serialize against exec() altering our credentials (and the
+		 * perf_event_exit_task() that could imply).
+		 */
+		err = -EACCES;
+		if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
+			goto err_cred;
+	}
+
 	if (flags & PERF_FLAG_PID_CGROUP)
 		cgroup_fd = pid;
 
@@ -8367,7 +8430,7 @@ SYSCALL_DEFINE5(perf_event_open,
 				 NULL, NULL, cgroup_fd);
 	if (IS_ERR(event)) {
 		err = PTR_ERR(event);
-		goto err_cpus;
+		goto err_cred;
 	}
 
 	if (is_sampling_event(event)) {
@@ -8426,11 +8489,6 @@ SYSCALL_DEFINE5(perf_event_open,
 		goto err_context;
 	}
 
-	if (task) {
-		put_task_struct(task);
-		task = NULL;
-	}
-
 	/*
 	 * Look up the group leader (we will attach this event to it):
 	 */
@@ -8528,6 +8586,11 @@ SYSCALL_DEFINE5(perf_event_open,
 
 	WARN_ON_ONCE(ctx->parent_ctx);
 
+	/*
+	 * This is the point on no return; we cannot fail hereafter. This is
+	 * where we start modifying current state.
+	 */
+
 	if (move_group) {
 		/*
 		 * See perf_event_ctx_lock() for comments on the details
@@ -8599,6 +8662,11 @@ SYSCALL_DEFINE5(perf_event_open,
 		mutex_unlock(&gctx->mutex);
 	mutex_unlock(&ctx->mutex);
 
+	if (task) {
+		mutex_unlock(&task->signal->cred_guard_mutex);
+		put_task_struct(task);
+	}
+
 	put_online_cpus();
 
 	mutex_lock(&current->perf_event_mutex);
@@ -8631,6 +8699,9 @@ err_alloc:
 	 */
 	if (!event_file)
 		free_event(event);
+err_cred:
+	if (task)
+		mutex_unlock(&task->signal->cred_guard_mutex);
 err_cpus:
 	put_online_cpus();
 err_task:
@@ -8915,6 +8986,9 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
 
 /*
  * When a child task exits, feed back event values to parent events.
+ *
+ * Can be called with cred_guard_mutex held when called from
+ * install_exec_creds().
  */
 void perf_event_exit_task(struct task_struct *child)
 {
@@ -9407,10 +9481,29 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
 	switch (action & ~CPU_TASKS_FROZEN) {
 
 	case CPU_UP_PREPARE:
+		/*
+		 * This must be done before the CPU comes alive, because the
+		 * moment we can run tasks we can encounter (software) events.
+		 *
+		 * Specifically, someone can have inherited events on kthreadd
+		 * or a pre-existing worker thread that gets re-bound.
+		 */
 		perf_event_init_cpu(cpu);
 		break;
 
 	case CPU_DOWN_PREPARE:
+		/*
+		 * This must be done before the CPU dies because after that an
+		 * active event might want to IPI the CPU and that'll not work
+		 * so great for dead CPUs.
+		 *
+		 * XXX smp_call_function_single() return -ENXIO without a warn
+		 * so we could possibly deal with this.
+		 *
+		 * This is safe against new events arriving because
+		 * sys_perf_event_open() serializes against hotplug using
+		 * get_online_cpus().
+		 */
 		perf_event_exit_cpu(cpu);
 		break;
 	default:
@@ -9457,6 +9550,7 @@ ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
 
 static int __init perf_event_sysfs_init(void)
 {
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 2bbad9c12..4199b6d19 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -182,8 +182,6 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 /* Callchain handling */
 extern struct perf_callchain_entry *
 perf_callchain(struct perf_event *event, struct pt_regs *regs);
-extern int get_callchain_buffers(void);
-extern void put_callchain_buffers(void);
 
 static inline int get_recursion_context(int *recursion)
 {
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 1faad2cfd..7611d0f66 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -347,6 +347,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
 			 bool truncated)
 {
 	struct ring_buffer *rb = handle->rb;
+	bool wakeup = truncated;
 	unsigned long aux_head;
 	u64 flags = 0;
 
@@ -375,9 +376,16 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
 	aux_head = rb->user_page->aux_head = local_read(&rb->aux_head);
 
 	if (aux_head - local_read(&rb->aux_wakeup) >= rb->aux_watermark) {
-		perf_output_wakeup(handle);
+		wakeup = true;
 		local_add(rb->aux_watermark, &rb->aux_wakeup);
 	}
+
+	if (wakeup) {
+		if (truncated)
+			handle->event->pending_disable = 1;
+		perf_output_wakeup(handle);
+	}
+
 	handle->event = NULL;
 
 	local_set(&rb->aux_nest, 0);
@@ -746,8 +754,10 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 
 	rb->user_page = all_buf;
 	rb->data_pages[0] = all_buf + PAGE_SIZE;
-	rb->page_order = ilog2(nr_pages);
-	rb->nr_pages = !!nr_pages;
+	if (nr_pages) {
+		rb->nr_pages = 1;
+		rb->page_order = ilog2(nr_pages);
+	}
 
 	ring_buffer_init(rb, watermark, flags);
 
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 016767918..7edc95edf 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -299,7 +299,7 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
 
 retry:
 	/* Read the page with vaddr into memory */
-	ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
+	ret = get_user_pages_remote(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
 	if (ret <= 0)
 		return ret;
 
@@ -321,7 +321,7 @@ retry:
 	copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
 
 	ret = __replace_page(vma, vaddr, old_page, new_page);
-	page_cache_release(new_page);
+	put_page(new_page);
 put_old:
 	put_page(old_page);
 
@@ -539,14 +539,14 @@ static int __copy_insn(struct address_space *mapping, struct file *filp,
 	 * see uprobe_register().
 	 */
 	if (mapping->a_ops->readpage)
-		page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp);
+		page = read_mapping_page(mapping, offset >> PAGE_SHIFT, filp);
 	else
-		page = shmem_read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT);
+		page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
 	if (IS_ERR(page))
 		return PTR_ERR(page);
 
 	copy_from_page(page, offset, insn, nbytes);
-	page_cache_release(page);
+	put_page(page);
 
 	return 0;
 }
@@ -1178,6 +1178,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 		goto free_area;
 
 	area->xol_mapping.name = "[uprobes]";
+	area->xol_mapping.fault = NULL;
 	area->xol_mapping.pages = area->pages;
 	area->pages[0] = alloc_page(GFP_HIGHUSER);
 	if (!area->pages[0])
@@ -1700,7 +1701,13 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
 	if (likely(result == 0))
 		goto out;
 
-	result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
+	/*
+	 * The NULL 'tsk' here ensures that any faults that occur here
+	 * will not be accounted to the task.  'mm' *is* current->mm,
+	 * but we treat this as a 'remote' access since it is
+	 * essentially a kernel access to the memory.
+	 */
+	result = get_user_pages_remote(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
 	if (result < 0)
 		return result;
 
diff --git a/kernel/exit.c b/kernel/exit.c
index ac8f9b7d6..11c33c5e4 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -53,6 +53,7 @@
 #include <linux/oom.h>
 #include <linux/writeback.h>
 #include <linux/shm.h>
+#include <linux/kcov.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -434,7 +435,7 @@ static void exit_mm(struct task_struct *tsk)
 	mm_update_next_owner(mm);
 	mmput(mm);
 	if (test_thread_flag(TIF_MEMDIE))
-		exit_oom_victim();
+		exit_oom_victim(tsk);
 }
 
 static struct task_struct *find_alive_thread(struct task_struct *p)
@@ -655,6 +656,7 @@ void do_exit(long code)
 	TASKS_RCU(int tasks_rcu_i);
 
 	profile_task_exit(tsk);
+	kcov_task_exit(tsk);
 
 	WARN_ON(blk_needs_flush_plug(tsk));
 
@@ -916,17 +918,28 @@ static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
 		task_pid_type(p, wo->wo_type) == wo->wo_pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int
+eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
 {
 	if (!eligible_pid(wo, p))
 		return 0;
-	/* Wait for all children (clone and not) if __WALL is set;
-	 * otherwise, wait for clone children *only* if __WCLONE is
-	 * set; otherwise, wait for non-clone children *only*.  (Note:
-	 * A "clone" child here is one that reports to its parent
-	 * using a signal other than SIGCHLD.) */
-	if (((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
-	    && !(wo->wo_flags & __WALL))
+
+	/*
+	 * Wait for all children (clone and not) if __WALL is set or
+	 * if it is traced by us.
+	 */
+	if (ptrace || (wo->wo_flags & __WALL))
+		return 1;
+
+	/*
+	 * Otherwise, wait for clone children *only* if __WCLONE is set;
+	 * otherwise, wait for non-clone children *only*.
+	 *
+	 * Note: a "clone" child here is one that reports to its parent
+	 * using a signal other than SIGCHLD, or a non-leader thread which
+	 * we can only see if it is traced by us.
+	 */
+	if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
 		return 0;
 
 	return 1;
@@ -1298,7 +1311,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
 	if (unlikely(exit_state == EXIT_DEAD))
 		return 0;
 
-	ret = eligible_child(wo, p);
+	ret = eligible_child(wo, ptrace, p);
 	if (!ret)
 		return ret;
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 8fbec37c5..f809ba4ee 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -75,6 +75,7 @@
 #include <linux/aio.h>
 #include <linux/compiler.h>
 #include <linux/sysctl.h>
+#include <linux/kcov.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -164,12 +165,20 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
 	struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
 						  THREAD_SIZE_ORDER);
 
+	if (page)
+		memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
+					    1 << THREAD_SIZE_ORDER);
+
 	return page ? page_address(page) : NULL;
 }
 
 static inline void free_thread_info(struct thread_info *ti)
 {
-	free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+	struct page *page = virt_to_page(ti);
+
+	memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
+				    -(1 << THREAD_SIZE_ORDER));
+	__free_kmem_pages(page, THREAD_SIZE_ORDER);
 }
 # else
 static struct kmem_cache *thread_info_cache;
@@ -384,6 +393,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 
 	account_kernel_stack(ti, 1);
 
+	kcov_task_init(tsk);
+
 	return tsk;
 
 free_ti:
@@ -1884,7 +1895,7 @@ static int check_unshare_flags(unsigned long unshare_flags)
 	if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
 				CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
 				CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
-				CLONE_NEWUSER|CLONE_NEWPID))
+				CLONE_NEWUSER|CLONE_NEWPID|CLONE_NEWCGROUP))
 		return -EINVAL;
 	/*
 	 * Not implemented, but pretend it works if there is nothing
diff --git a/kernel/futex.c b/kernel/futex.c
index 11b502159..c20f06f38 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -124,16 +124,16 @@
  *   futex_wait(futex, val);
  *
  *   waiters++; (a)
- *   mb(); (A) <-- paired with -.
- *                              |
- *   lock(hash_bucket(futex));  |
- *                              |
- *   uval = *futex;             |
- *                              |        *futex = newval;
- *                              |        sys_futex(WAKE, futex);
- *                              |          futex_wake(futex);
- *                              |
- *                              `------->  mb(); (B)
+ *   smp_mb(); (A) <-- paired with -.
+ *                                  |
+ *   lock(hash_bucket(futex));      |
+ *                                  |
+ *   uval = *futex;                 |
+ *                                  |        *futex = newval;
+ *                                  |        sys_futex(WAKE, futex);
+ *                                  |          futex_wake(futex);
+ *                                  |
+ *                                  `--------> smp_mb(); (B)
  *   if (uval == val)
  *     queue();
  *     unlock(hash_bucket(futex));
@@ -334,7 +334,7 @@ static inline void futex_get_mm(union futex_key *key)
 	/*
 	 * Ensure futex_get_mm() implies a full barrier such that
 	 * get_futex_key() implies a full barrier. This is relied upon
-	 * as full barrier (B), see the ordering comment above.
+	 * as smp_mb(); (B), see the ordering comment above.
 	 */
 	smp_mb__after_atomic();
 }
@@ -407,10 +407,10 @@ static void get_futex_key_refs(union futex_key *key)
 
 	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
 	case FUT_OFF_INODE:
-		ihold(key->shared.inode); /* implies MB (B) */
+		ihold(key->shared.inode); /* implies smp_mb(); (B) */
 		break;
 	case FUT_OFF_MMSHARED:
-		futex_get_mm(key); /* implies MB (B) */
+		futex_get_mm(key); /* implies smp_mb(); (B) */
 		break;
 	default:
 		/*
@@ -418,7 +418,7 @@ static void get_futex_key_refs(union futex_key *key)
 		 * mm, therefore the only purpose of calling get_futex_key_refs
 		 * is because we need the barrier for the lockless waiter check.
 		 */
-		smp_mb(); /* explicit MB (B) */
+		smp_mb(); /* explicit smp_mb(); (B) */
 	}
 }
 
@@ -497,7 +497,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
 	if (!fshared) {
 		key->private.mm = mm;
 		key->private.address = address;
-		get_futex_key_refs(key);  /* implies MB (B) */
+		get_futex_key_refs(key);  /* implies smp_mb(); (B) */
 		return 0;
 	}
 
@@ -520,7 +520,20 @@ again:
 	else
 		err = 0;
 
-	lock_page(page);
+	/*
+	 * The treatment of mapping from this point on is critical. The page
+	 * lock protects many things but in this context the page lock
+	 * stabilizes mapping, prevents inode freeing in the shared
+	 * file-backed region case and guards against movement to swap cache.
+	 *
+	 * Strictly speaking the page lock is not needed in all cases being
+	 * considered here and page lock forces unnecessarily serialization
+	 * From this point on, mapping will be re-verified if necessary and
+	 * page lock will be acquired only if it is unavoidable
+	 */
+	page = compound_head(page);
+	mapping = READ_ONCE(page->mapping);
+
 	/*
 	 * If page->mapping is NULL, then it cannot be a PageAnon
 	 * page; but it might be the ZERO_PAGE or in the gate area or
@@ -536,19 +549,31 @@ again:
 	 * shmem_writepage move it from filecache to swapcache beneath us:
 	 * an unlikely race, but we do need to retry for page->mapping.
 	 */
-	mapping = compound_head(page)->mapping;
-	if (!mapping) {
-		int shmem_swizzled = PageSwapCache(page);
+	if (unlikely(!mapping)) {
+		int shmem_swizzled;
+
+		/*
+		 * Page lock is required to identify which special case above
+		 * applies. If this is really a shmem page then the page lock
+		 * will prevent unexpected transitions.
+		 */
+		lock_page(page);
+		shmem_swizzled = PageSwapCache(page) || page->mapping;
 		unlock_page(page);
 		put_page(page);
+
 		if (shmem_swizzled)
 			goto again;
+
 		return -EFAULT;
 	}
 
 	/*
 	 * Private mappings are handled in a simple way.
 	 *
+	 * If the futex key is stored on an anonymous page, then the associated
+	 * object is the mm which is implicitly pinned by the calling process.
+	 *
 	 * NOTE: When userspace waits on a MAP_SHARED mapping, even if
 	 * it's a read-only handle, it's expected that futexes attach to
 	 * the object not the particular process.
@@ -566,16 +591,74 @@ again:
 		key->both.offset |= FUT_OFF_MMSHARED; /* ref taken on mm */
 		key->private.mm = mm;
 		key->private.address = address;
+
+		get_futex_key_refs(key); /* implies smp_mb(); (B) */
+
 	} else {
+		struct inode *inode;
+
+		/*
+		 * The associated futex object in this case is the inode and
+		 * the page->mapping must be traversed. Ordinarily this should
+		 * be stabilised under page lock but it's not strictly
+		 * necessary in this case as we just want to pin the inode, not
+		 * update the radix tree or anything like that.
+		 *
+		 * The RCU read lock is taken as the inode is finally freed
+		 * under RCU. If the mapping still matches expectations then the
+		 * mapping->host can be safely accessed as being a valid inode.
+		 */
+		rcu_read_lock();
+
+		if (READ_ONCE(page->mapping) != mapping) {
+			rcu_read_unlock();
+			put_page(page);
+
+			goto again;
+		}
+
+		inode = READ_ONCE(mapping->host);
+		if (!inode) {
+			rcu_read_unlock();
+			put_page(page);
+
+			goto again;
+		}
+
+		/*
+		 * Take a reference unless it is about to be freed. Previously
+		 * this reference was taken by ihold under the page lock
+		 * pinning the inode in place so i_lock was unnecessary. The
+		 * only way for this check to fail is if the inode was
+		 * truncated in parallel so warn for now if this happens.
+		 *
+		 * We are not calling into get_futex_key_refs() in file-backed
+		 * cases, therefore a successful atomic_inc return below will
+		 * guarantee that get_futex_key() will still imply smp_mb(); (B).
+		 */
+		if (WARN_ON_ONCE(!atomic_inc_not_zero(&inode->i_count))) {
+			rcu_read_unlock();
+			put_page(page);
+
+			goto again;
+		}
+
+		/* Should be impossible but lets be paranoid for now */
+		if (WARN_ON_ONCE(inode->i_mapping != mapping)) {
+			err = -EFAULT;
+			rcu_read_unlock();
+			iput(inode);
+
+			goto out;
+		}
+
 		key->both.offset |= FUT_OFF_INODE; /* inode-based key */
-		key->shared.inode = mapping->host;
+		key->shared.inode = inode;
 		key->shared.pgoff = basepage_index(page);
+		rcu_read_unlock();
 	}
 
-	get_futex_key_refs(key); /* implies MB (B) */
-
 out:
-	unlock_page(page);
 	put_page(page);
 	return err;
 }
@@ -1874,7 +1957,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
 
 	q->lock_ptr = &hb->lock;
 
-	spin_lock(&hb->lock); /* implies MB (A) */
+	spin_lock(&hb->lock); /* implies smp_mb(); (A) */
 	return hb;
 }
 
@@ -1937,8 +2020,12 @@ static int unqueue_me(struct futex_q *q)
 
 	/* In the common case we don't take the spinlock, which is nice. */
 retry:
-	lock_ptr = q->lock_ptr;
-	barrier();
+	/*
+	 * q->lock_ptr can change between this read and the following spin_lock.
+	 * Use READ_ONCE to forbid the compiler from reloading q->lock_ptr and
+	 * optimizing lock_ptr out of the logic below.
+	 */
+	lock_ptr = READ_ONCE(q->lock_ptr);
 	if (lock_ptr != NULL) {
 		spin_lock(lock_ptr);
 		/*
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index e0f90c2b5..d23402280 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -185,10 +185,12 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
 	rcu_read_unlock();
 }
 
-static unsigned long timeout_jiffies(unsigned long timeout)
+static long hung_timeout_jiffies(unsigned long last_checked,
+				 unsigned long timeout)
 {
 	/* timeout of 0 will disable the watchdog */
-	return timeout ? timeout * HZ : MAX_SCHEDULE_TIMEOUT;
+	return timeout ? last_checked - jiffies + timeout * HZ :
+		MAX_SCHEDULE_TIMEOUT;
 }
 
 /*
@@ -224,18 +226,21 @@ EXPORT_SYMBOL_GPL(reset_hung_task_detector);
  */
 static int watchdog(void *dummy)
 {
+	unsigned long hung_last_checked = jiffies;
+
 	set_user_nice(current, 0);
 
 	for ( ; ; ) {
 		unsigned long timeout = sysctl_hung_task_timeout_secs;
+		long t = hung_timeout_jiffies(hung_last_checked, timeout);
 
-		while (schedule_timeout_interruptible(timeout_jiffies(timeout)))
-			timeout = sysctl_hung_task_timeout_secs;
-
-		if (atomic_xchg(&reset_hung_task, 0))
+		if (t <= 0) {
+			if (!atomic_xchg(&reset_hung_task, 0))
+				check_hung_uninterruptible_tasks(timeout);
+			hung_last_checked = jiffies;
 			continue;
-
-		check_hung_uninterruptible_tasks(timeout);
+		}
+		schedule_timeout_interruptible(t);
 	}
 
 	return 0;
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 3b48dab80..3bbfd6a9c 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -64,6 +64,10 @@ config IRQ_DOMAIN_HIERARCHY
 	bool
 	select IRQ_DOMAIN
 
+# Generic IRQ IPI support
+config GENERIC_IRQ_IPI
+	bool
+
 # Generic MSI interrupt support
 config GENERIC_MSI_IRQ
 	bool
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 2fc9cbdf3..2ee42e95a 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
 obj-$(CONFIG_GENERIC_IRQ_MIGRATION) += cpuhotplug.o
 obj-$(CONFIG_PM_SLEEP) += pm.o
 obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o
+obj-$(CONFIG_GENERIC_IRQ_IPI) += ipi.o
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 5797909f4..2f9f2b0e7 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -961,6 +961,7 @@ void irq_chip_mask_parent(struct irq_data *data)
 	data = data->parent_data;
 	data->chip->irq_mask(data);
 }
+EXPORT_SYMBOL_GPL(irq_chip_mask_parent);
 
 /**
  * irq_chip_unmask_parent - Unmask the parent interrupt
@@ -971,6 +972,7 @@ void irq_chip_unmask_parent(struct irq_data *data)
 	data = data->parent_data;
 	data->chip->irq_unmask(data);
 }
+EXPORT_SYMBOL_GPL(irq_chip_unmask_parent);
 
 /**
  * irq_chip_eoi_parent - Invoke EOI on the parent interrupt
@@ -981,6 +983,7 @@ void irq_chip_eoi_parent(struct irq_data *data)
 	data = data->parent_data;
 	data->chip->irq_eoi(data);
 }
+EXPORT_SYMBOL_GPL(irq_chip_eoi_parent);
 
 /**
  * irq_chip_set_affinity_parent - Set affinity on the parent interrupt
@@ -1016,6 +1019,7 @@ int irq_chip_set_type_parent(struct irq_data *data, unsigned int type)
 
 	return -ENOSYS;
 }
+EXPORT_SYMBOL_GPL(irq_chip_set_type_parent);
 
 /**
  * irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 57bff7857..a15b5485b 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -136,10 +136,9 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 {
 	irqreturn_t retval = IRQ_NONE;
 	unsigned int flags = 0, irq = desc->irq_data.irq;
-	struct irqaction *action = desc->action;
+	struct irqaction *action;
 
-	/* action might have become NULL since we dropped the lock */
-	while (action) {
+	for_each_action_of_desc(desc, action) {
 		irqreturn_t res;
 
 		trace_irq_handler_entry(irq, action);
@@ -173,7 +172,6 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 		}
 
 		retval |= res;
-		action = action->next;
 	}
 
 	add_interrupt_randomness(irq, flags);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index fcab63c66..09be2c903 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -131,6 +131,9 @@ static inline void chip_bus_sync_unlock(struct irq_desc *desc)
 #define IRQ_GET_DESC_CHECK_GLOBAL	(_IRQ_DESC_CHECK)
 #define IRQ_GET_DESC_CHECK_PERCPU	(_IRQ_DESC_CHECK | _IRQ_DESC_PERCPU)
 
+#define for_each_action_of_desc(desc, act)			\
+	for (act = desc->act; act; act = act->next)
+
 struct irq_desc *
 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 		    unsigned int check);
@@ -160,6 +163,8 @@ irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags)
 	__irq_put_desc_unlock(desc, flags, false);
 }
 
+#define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
+
 /*
  * Manipulation functions for irq_data.state
  */
@@ -188,6 +193,8 @@ static inline bool irqd_has_set(struct irq_data *d, unsigned int mask)
 	return __irqd_to_state(d) & mask;
 }
 
+#undef __irqd_to_state
+
 static inline void kstat_incr_irqs_this_cpu(struct irq_desc *desc)
 {
 	__this_cpu_inc(*desc->kstat_irqs);
diff --git a/kernel/irq/ipi.c b/kernel/irq/ipi.c
new file mode 100644
index 000000000..14777af8e
--- /dev/null
+++ b/kernel/irq/ipi.c
@@ -0,0 +1,327 @@
+/*
+ * linux/kernel/irq/ipi.c
+ *
+ * Copyright (C) 2015 Imagination Technologies Ltd
+ * Author: Qais Yousef <qais.yousef@imgtec.com>
+ *
+ * This file contains driver APIs to the IPI subsystem.
+ */
+
+#define pr_fmt(fmt) "genirq/ipi: " fmt
+
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+
+/**
+ * irq_reserve_ipi() - Setup an IPI to destination cpumask
+ * @domain:	IPI domain
+ * @dest:	cpumask of cpus which can receive the IPI
+ *
+ * Allocate a virq that can be used to send IPI to any CPU in dest mask.
+ *
+ * On success it'll return linux irq number and 0 on failure
+ */
+unsigned int irq_reserve_ipi(struct irq_domain *domain,
+			     const struct cpumask *dest)
+{
+	unsigned int nr_irqs, offset;
+	struct irq_data *data;
+	int virq, i;
+
+	if (!domain ||!irq_domain_is_ipi(domain)) {
+		pr_warn("Reservation on a non IPI domain\n");
+		return 0;
+	}
+
+	if (!cpumask_subset(dest, cpu_possible_mask)) {
+		pr_warn("Reservation is not in possible_cpu_mask\n");
+		return 0;
+	}
+
+	nr_irqs = cpumask_weight(dest);
+	if (!nr_irqs) {
+		pr_warn("Reservation for empty destination mask\n");
+		return 0;
+	}
+
+	if (irq_domain_is_ipi_single(domain)) {
+		/*
+		 * If the underlying implementation uses a single HW irq on
+		 * all cpus then we only need a single Linux irq number for
+		 * it. We have no restrictions vs. the destination mask. The
+		 * underlying implementation can deal with holes nicely.
+		 */
+		nr_irqs = 1;
+		offset = 0;
+	} else {
+		unsigned int next;
+
+		/*
+		 * The IPI requires a seperate HW irq on each CPU. We require
+		 * that the destination mask is consecutive. If an
+		 * implementation needs to support holes, it can reserve
+		 * several IPI ranges.
+		 */
+		offset = cpumask_first(dest);
+		/*
+		 * Find a hole and if found look for another set bit after the
+		 * hole. For now we don't support this scenario.
+		 */
+		next = cpumask_next_zero(offset, dest);
+		if (next < nr_cpu_ids)
+			next = cpumask_next(next, dest);
+		if (next < nr_cpu_ids) {
+			pr_warn("Destination mask has holes\n");
+			return 0;
+		}
+	}
+
+	virq = irq_domain_alloc_descs(-1, nr_irqs, 0, NUMA_NO_NODE);
+	if (virq <= 0) {
+		pr_warn("Can't reserve IPI, failed to alloc descs\n");
+		return 0;
+	}
+
+	virq = __irq_domain_alloc_irqs(domain, virq, nr_irqs, NUMA_NO_NODE,
+				       (void *) dest, true);
+
+	if (virq <= 0) {
+		pr_warn("Can't reserve IPI, failed to alloc hw irqs\n");
+		goto free_descs;
+	}
+
+	for (i = 0; i < nr_irqs; i++) {
+		data = irq_get_irq_data(virq + i);
+		cpumask_copy(data->common->affinity, dest);
+		data->common->ipi_offset = offset;
+		irq_set_status_flags(virq + i, IRQ_NO_BALANCING);
+	}
+	return virq;
+
+free_descs:
+	irq_free_descs(virq, nr_irqs);
+	return 0;
+}
+
+/**
+ * irq_destroy_ipi() - unreserve an IPI that was previously allocated
+ * @irq:	linux irq number to be destroyed
+ *
+ * Return the IPIs allocated with irq_reserve_ipi() to the system destroying
+ * all virqs associated with them.
+ */
+void irq_destroy_ipi(unsigned int irq)
+{
+	struct irq_data *data = irq_get_irq_data(irq);
+	struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+	struct irq_domain *domain;
+	unsigned int nr_irqs;
+
+	if (!irq || !data || !ipimask)
+		return;
+
+	domain = data->domain;
+	if (WARN_ON(domain == NULL))
+		return;
+
+	if (!irq_domain_is_ipi(domain)) {
+		pr_warn("Trying to destroy a non IPI domain!\n");
+		return;
+	}
+
+	if (irq_domain_is_ipi_per_cpu(domain))
+		nr_irqs = cpumask_weight(ipimask);
+	else
+		nr_irqs = 1;
+
+	irq_domain_free_irqs(irq, nr_irqs);
+}
+
+/**
+ * ipi_get_hwirq - Get the hwirq associated with an IPI to a cpu
+ * @irq:	linux irq number
+ * @cpu:	the target cpu
+ *
+ * When dealing with coprocessors IPI, we need to inform the coprocessor of
+ * the hwirq it needs to use to receive and send IPIs.
+ *
+ * Returns hwirq value on success and INVALID_HWIRQ on failure.
+ */
+irq_hw_number_t ipi_get_hwirq(unsigned int irq, unsigned int cpu)
+{
+	struct irq_data *data = irq_get_irq_data(irq);
+	struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+
+	if (!data || !ipimask || cpu > nr_cpu_ids)
+		return INVALID_HWIRQ;
+
+	if (!cpumask_test_cpu(cpu, ipimask))
+		return INVALID_HWIRQ;
+
+	/*
+	 * Get the real hardware irq number if the underlying implementation
+	 * uses a seperate irq per cpu. If the underlying implementation uses
+	 * a single hardware irq for all cpus then the IPI send mechanism
+	 * needs to take care of the cpu destinations.
+	 */
+	if (irq_domain_is_ipi_per_cpu(data->domain))
+		data = irq_get_irq_data(irq + cpu - data->common->ipi_offset);
+
+	return data ? irqd_to_hwirq(data) : INVALID_HWIRQ;
+}
+EXPORT_SYMBOL_GPL(ipi_get_hwirq);
+
+static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data,
+			   const struct cpumask *dest, unsigned int cpu)
+{
+	struct cpumask *ipimask = irq_data_get_affinity_mask(data);
+
+	if (!chip || !ipimask)
+		return -EINVAL;
+
+	if (!chip->ipi_send_single && !chip->ipi_send_mask)
+		return -EINVAL;
+
+	if (cpu > nr_cpu_ids)
+		return -EINVAL;
+
+	if (dest) {
+		if (!cpumask_subset(dest, ipimask))
+			return -EINVAL;
+	} else {
+		if (!cpumask_test_cpu(cpu, ipimask))
+			return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ * __ipi_send_single - send an IPI to a target Linux SMP CPU
+ * @desc:	pointer to irq_desc of the IRQ
+ * @cpu:	destination CPU, must in the destination mask passed to
+ *		irq_reserve_ipi()
+ *
+ * This function is for architecture or core code to speed up IPI sending. Not
+ * usable from driver code.
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int __ipi_send_single(struct irq_desc *desc, unsigned int cpu)
+{
+	struct irq_data *data = irq_desc_get_irq_data(desc);
+	struct irq_chip *chip = irq_data_get_irq_chip(data);
+
+#ifdef DEBUG
+	/*
+	 * Minimise the overhead by omitting the checks for Linux SMP IPIs.
+	 * Since the callers should be arch or core code which is generally
+	 * trusted, only check for errors when debugging.
+	 */
+	if (WARN_ON_ONCE(ipi_send_verify(chip, data, NULL, cpu)))
+		return -EINVAL;
+#endif
+	if (!chip->ipi_send_single) {
+		chip->ipi_send_mask(data, cpumask_of(cpu));
+		return 0;
+	}
+
+	/* FIXME: Store this information in irqdata flags */
+	if (irq_domain_is_ipi_per_cpu(data->domain) &&
+	    cpu != data->common->ipi_offset) {
+		/* use the correct data for that cpu */
+		unsigned irq = data->irq + cpu - data->common->ipi_offset;
+
+		data = irq_get_irq_data(irq);
+	}
+	chip->ipi_send_single(data, cpu);
+	return 0;
+}
+
+/**
+ * ipi_send_mask - send an IPI to target Linux SMP CPU(s)
+ * @desc:	pointer to irq_desc of the IRQ
+ * @dest:	dest CPU(s), must be a subset of the mask passed to
+ *		irq_reserve_ipi()
+ *
+ * This function is for architecture or core code to speed up IPI sending. Not
+ * usable from driver code.
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int __ipi_send_mask(struct irq_desc *desc, const struct cpumask *dest)
+{
+	struct irq_data *data = irq_desc_get_irq_data(desc);
+	struct irq_chip *chip = irq_data_get_irq_chip(data);
+	unsigned int cpu;
+
+#ifdef DEBUG
+	/*
+	 * Minimise the overhead by omitting the checks for Linux SMP IPIs.
+	 * Since the callers should be arch or core code which is generally
+	 * trusted, only check for errors when debugging.
+	 */
+	if (WARN_ON_ONCE(ipi_send_verify(chip, data, dest, 0)))
+		return -EINVAL;
+#endif
+	if (chip->ipi_send_mask) {
+		chip->ipi_send_mask(data, dest);
+		return 0;
+	}
+
+	if (irq_domain_is_ipi_per_cpu(data->domain)) {
+		unsigned int base = data->irq;
+
+		for_each_cpu(cpu, dest) {
+			unsigned irq = base + cpu - data->common->ipi_offset;
+
+			data = irq_get_irq_data(irq);
+			chip->ipi_send_single(data, cpu);
+		}
+	} else {
+		for_each_cpu(cpu, dest)
+			chip->ipi_send_single(data, cpu);
+	}
+	return 0;
+}
+
+/**
+ * ipi_send_single - Send an IPI to a single CPU
+ * @virq:	linux irq number from irq_reserve_ipi()
+ * @cpu:	destination CPU, must in the destination mask passed to
+ *		irq_reserve_ipi()
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int ipi_send_single(unsigned int virq, unsigned int cpu)
+{
+	struct irq_desc *desc = irq_to_desc(virq);
+	struct irq_data *data = desc ? irq_desc_get_irq_data(desc) : NULL;
+	struct irq_chip *chip = data ? irq_data_get_irq_chip(data) : NULL;
+
+	if (WARN_ON_ONCE(ipi_send_verify(chip, data, NULL, cpu)))
+		return -EINVAL;
+
+	return __ipi_send_single(desc, cpu);
+}
+EXPORT_SYMBOL_GPL(ipi_send_single);
+
+/**
+ * ipi_send_mask - Send an IPI to target CPU(s)
+ * @virq:	linux irq number from irq_reserve_ipi()
+ * @dest:	dest CPU(s), must be a subset of the mask passed to
+ *		irq_reserve_ipi()
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int ipi_send_mask(unsigned int virq, const struct cpumask *dest)
+{
+	struct irq_desc *desc = irq_to_desc(virq);
+	struct irq_data *data = desc ? irq_desc_get_irq_data(desc) : NULL;
+	struct irq_chip *chip = data ? irq_data_get_irq_chip(data) : NULL;
+
+	if (WARN_ON_ONCE(ipi_send_verify(chip, data, dest, 0)))
+		return -EINVAL;
+
+	return __ipi_send_mask(desc, dest);
+}
+EXPORT_SYMBOL_GPL(ipi_send_mask);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0409da0bc..0ccd02881 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -24,10 +24,27 @@
 static struct lock_class_key irq_desc_lock_class;
 
 #if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+	zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+	cpulist_parse(str, irq_default_affinity);
+	/*
+	 * Set at least the boot cpu. We don't want to end up with
+	 * bugreports caused by random comandline masks
+	 */
+	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+	return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
 static void __init init_irq_default_affinity(void)
 {
-	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
-	cpumask_setall(irq_default_affinity);
+#ifdef CONFIG_CPUMASK_OFFSTACK
+	if (!irq_default_affinity)
+		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+#endif
+	if (cpumask_empty(irq_default_affinity))
+		cpumask_setall(irq_default_affinity);
 }
 #else
 static void __init init_irq_default_affinity(void)
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3e56d2f03..3a519a011 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -23,8 +23,6 @@ static DEFINE_MUTEX(irq_domain_mutex);
 static DEFINE_MUTEX(revmap_trees_mutex);
 static struct irq_domain *irq_default_domain;
 
-static int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
-				  irq_hw_number_t hwirq, int node);
 static void irq_domain_check_hierarchy(struct irq_domain *domain);
 
 struct irqchip_fwid {
@@ -840,8 +838,8 @@ const struct irq_domain_ops irq_domain_simple_ops = {
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
 
-static int irq_domain_alloc_descs(int virq, unsigned int cnt,
-				  irq_hw_number_t hwirq, int node)
+int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
+			   int node)
 {
 	unsigned int hint;
 
@@ -895,6 +893,7 @@ struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
 
 	return domain;
 }
+EXPORT_SYMBOL_GPL(irq_domain_create_hierarchy);
 
 static void irq_domain_insert_irq(int virq)
 {
@@ -1045,6 +1044,7 @@ int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(irq_domain_set_hwirq_and_chip);
 
 /**
  * irq_domain_set_info - Set the complete data for a @virq in @domain
@@ -1078,6 +1078,7 @@ void irq_domain_reset_irq_data(struct irq_data *irq_data)
 	irq_data->chip = &no_irq_chip;
 	irq_data->chip_data = NULL;
 }
+EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
 
 /**
  * irq_domain_free_irqs_common - Clear irq_data and free the parent
@@ -1275,6 +1276,7 @@ int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
 						       nr_irqs, arg);
 	return -ENOSYS;
 }
+EXPORT_SYMBOL_GPL(irq_domain_alloc_irqs_parent);
 
 /**
  * irq_domain_free_irqs_parent - Free interrupts from parent domain
@@ -1292,6 +1294,7 @@ void irq_domain_free_irqs_parent(struct irq_domain *domain,
 		irq_domain_free_irqs_recursive(domain->parent, irq_base,
 					       nr_irqs);
 }
+EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent);
 
 /**
  * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 841187239..cc1cc641d 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -144,13 +144,11 @@ int irq_can_set_affinity(unsigned int irq)
  */
 void irq_set_thread_affinity(struct irq_desc *desc)
 {
-	struct irqaction *action = desc->action;
+	struct irqaction *action;
 
-	while (action) {
+	for_each_action_of_desc(desc, action)
 		if (action->thread)
 			set_bit(IRQTF_AFFINITY, &action->thread_flags);
-		action = action->next;
-	}
 }
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
@@ -994,7 +992,7 @@ void irq_wake_thread(unsigned int irq, void *dev_id)
 		return;
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	for (action = desc->action; action; action = action->next) {
+	for_each_action_of_desc(desc, action) {
 		if (action->dev_id == dev_id) {
 			if (action->thread)
 				__irq_wake_thread(desc, action);
@@ -1324,8 +1322,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
 		if (nmsk != omsk)
 			/* hope the handler works with current  trigger mode */
-			pr_warning("irq %d uses trigger mode %u; requested %u\n",
-				   irq, nmsk, omsk);
+			pr_warn("irq %d uses trigger mode %u; requested %u\n",
+				irq, nmsk, omsk);
 	}
 
 	*old_ptr = new;
@@ -1609,6 +1607,9 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
 	struct irq_desc *desc;
 	int retval;
 
+	if (irq == IRQ_NOTCONNECTED)
+		return -ENOTCONN;
+
 	/*
 	 * Sanity-check: shared interrupts must pass in a real dev-ID,
 	 * otherwise we'll have trouble later trying to figure out
@@ -1699,9 +1700,13 @@ EXPORT_SYMBOL(request_threaded_irq);
 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
 			    unsigned long flags, const char *name, void *dev_id)
 {
-	struct irq_desc *desc = irq_to_desc(irq);
+	struct irq_desc *desc;
 	int ret;
 
+	if (irq == IRQ_NOTCONNECTED)
+		return -ENOTCONN;
+
+	desc = irq_to_desc(irq);
 	if (!desc)
 		return -EINVAL;
 
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index a2c02fd5d..4e1b94726 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -291,7 +291,7 @@ static int name_unique(unsigned int irq, struct irqaction *new_action)
 	int ret = 1;
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	for (action = desc->action ; action; action = action->next) {
+	for_each_action_of_desc(desc, action) {
 		if ((action != new_action) && action->name &&
 				!strcmp(new_action->name, action->name)) {
 			ret = 0;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 321441754..5707f97a3 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -211,14 +211,12 @@ static void __report_bad_irq(struct irq_desc *desc, irqreturn_t action_ret)
 	 * desc->lock here. See synchronize_irq().
 	 */
 	raw_spin_lock_irqsave(&desc->lock, flags);
-	action = desc->action;
-	while (action) {
+	for_each_action_of_desc(desc, action) {
 		printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler);
 		if (action->thread_fn)
 			printk(KERN_CONT " threaded [<%p>] %pf",
 					action->thread_fn, action->thread_fn);
 		printk(KERN_CONT "\n");
-		action = action->next;
 	}
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 5c5987f10..fafd1a3ef 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -38,6 +38,7 @@
  * during the second link stage.
  */
 extern const unsigned long kallsyms_addresses[] __weak;
+extern const int kallsyms_offsets[] __weak;
 extern const u8 kallsyms_names[] __weak;
 
 /*
@@ -47,6 +48,9 @@ extern const u8 kallsyms_names[] __weak;
 extern const unsigned long kallsyms_num_syms
 __attribute__((weak, section(".rodata")));
 
+extern const unsigned long kallsyms_relative_base
+__attribute__((weak, section(".rodata")));
+
 extern const u8 kallsyms_token_table[] __weak;
 extern const u16 kallsyms_token_index[] __weak;
 
@@ -176,6 +180,23 @@ static unsigned int get_symbol_offset(unsigned long pos)
 	return name - kallsyms_names;
 }
 
+static unsigned long kallsyms_sym_address(int idx)
+{
+	if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
+		return kallsyms_addresses[idx];
+
+	/* values are unsigned offsets if --absolute-percpu is not in effect */
+	if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
+		return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
+
+	/* ...otherwise, positive offsets are absolute values */
+	if (kallsyms_offsets[idx] >= 0)
+		return kallsyms_offsets[idx];
+
+	/* ...and negative offsets are relative to kallsyms_relative_base - 1 */
+	return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
+}
+
 /* Lookup the address for this symbol. Returns 0 if not found. */
 unsigned long kallsyms_lookup_name(const char *name)
 {
@@ -187,7 +208,7 @@ unsigned long kallsyms_lookup_name(const char *name)
 		off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
 
 		if (strcmp(namebuf, name) == 0)
-			return kallsyms_addresses[i];
+			return kallsyms_sym_address(i);
 	}
 	return module_kallsyms_lookup_name(name);
 }
@@ -204,7 +225,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
 
 	for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
 		off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
-		ret = fn(data, namebuf, NULL, kallsyms_addresses[i]);
+		ret = fn(data, namebuf, NULL, kallsyms_sym_address(i));
 		if (ret != 0)
 			return ret;
 	}
@@ -220,7 +241,10 @@ static unsigned long get_symbol_pos(unsigned long addr,
 	unsigned long i, low, high, mid;
 
 	/* This kernel should never had been booted. */
-	BUG_ON(!kallsyms_addresses);
+	if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
+		BUG_ON(!kallsyms_addresses);
+	else
+		BUG_ON(!kallsyms_offsets);
 
 	/* Do a binary search on the sorted kallsyms_addresses array. */
 	low = 0;
@@ -228,7 +252,7 @@ static unsigned long get_symbol_pos(unsigned long addr,
 
 	while (high - low > 1) {
 		mid = low + (high - low) / 2;
-		if (kallsyms_addresses[mid] <= addr)
+		if (kallsyms_sym_address(mid) <= addr)
 			low = mid;
 		else
 			high = mid;
@@ -238,15 +262,15 @@ static unsigned long get_symbol_pos(unsigned long addr,
 	 * Search for the first aliased symbol. Aliased
 	 * symbols are symbols with the same address.
 	 */
-	while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low])
+	while (low && kallsyms_sym_address(low-1) == kallsyms_sym_address(low))
 		--low;
 
-	symbol_start = kallsyms_addresses[low];
+	symbol_start = kallsyms_sym_address(low);
 
 	/* Search for next non-aliased symbol. */
 	for (i = low + 1; i < kallsyms_num_syms; i++) {
-		if (kallsyms_addresses[i] > symbol_start) {
-			symbol_end = kallsyms_addresses[i];
+		if (kallsyms_sym_address(i) > symbol_start) {
+			symbol_end = kallsyms_sym_address(i);
 			break;
 		}
 	}
@@ -470,7 +494,7 @@ static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
 	unsigned off = iter->nameoff;
 
 	iter->module_name[0] = '\0';
-	iter->value = kallsyms_addresses[iter->pos];
+	iter->value = kallsyms_sym_address(iter->pos);
 
 	iter->type = kallsyms_get_symbol_type(off);
 
diff --git a/kernel/kcov.c b/kernel/kcov.c
new file mode 100644
index 000000000..a02f2dddd
--- /dev/null
+++ b/kernel/kcov.c
@@ -0,0 +1,274 @@
+#define pr_fmt(fmt) "kcov: " fmt
+
+#define DISABLE_BRANCH_PROFILING
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/kcov.h>
+
+/*
+ * kcov descriptor (one per opened debugfs file).
+ * State transitions of the descriptor:
+ *  - initial state after open()
+ *  - then there must be a single ioctl(KCOV_INIT_TRACE) call
+ *  - then, mmap() call (several calls are allowed but not useful)
+ *  - then, repeated enable/disable for a task (only one task a time allowed)
+ */
+struct kcov {
+	/*
+	 * Reference counter. We keep one for:
+	 *  - opened file descriptor
+	 *  - task with enabled coverage (we can't unwire it from another task)
+	 */
+	atomic_t		refcount;
+	/* The lock protects mode, size, area and t. */
+	spinlock_t		lock;
+	enum kcov_mode		mode;
+	/* Size of arena (in long's for KCOV_MODE_TRACE). */
+	unsigned		size;
+	/* Coverage buffer shared with user space. */
+	void			*area;
+	/* Task for which we collect coverage, or NULL. */
+	struct task_struct	*t;
+};
+
+/*
+ * Entry point from instrumented code.
+ * This is called once per basic-block/edge.
+ */
+void notrace __sanitizer_cov_trace_pc(void)
+{
+	struct task_struct *t;
+	enum kcov_mode mode;
+
+	t = current;
+	/*
+	 * We are interested in code coverage as a function of a syscall inputs,
+	 * so we ignore code executed in interrupts.
+	 */
+	if (!t || in_interrupt())
+		return;
+	mode = READ_ONCE(t->kcov_mode);
+	if (mode == KCOV_MODE_TRACE) {
+		unsigned long *area;
+		unsigned long pos;
+
+		/*
+		 * There is some code that runs in interrupts but for which
+		 * in_interrupt() returns false (e.g. preempt_schedule_irq()).
+		 * READ_ONCE()/barrier() effectively provides load-acquire wrt
+		 * interrupts, there are paired barrier()/WRITE_ONCE() in
+		 * kcov_ioctl_locked().
+		 */
+		barrier();
+		area = t->kcov_area;
+		/* The first word is number of subsequent PCs. */
+		pos = READ_ONCE(area[0]) + 1;
+		if (likely(pos < t->kcov_size)) {
+			area[pos] = _RET_IP_;
+			WRITE_ONCE(area[0], pos);
+		}
+	}
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_pc);
+
+static void kcov_get(struct kcov *kcov)
+{
+	atomic_inc(&kcov->refcount);
+}
+
+static void kcov_put(struct kcov *kcov)
+{
+	if (atomic_dec_and_test(&kcov->refcount)) {
+		vfree(kcov->area);
+		kfree(kcov);
+	}
+}
+
+void kcov_task_init(struct task_struct *t)
+{
+	t->kcov_mode = KCOV_MODE_DISABLED;
+	t->kcov_size = 0;
+	t->kcov_area = NULL;
+	t->kcov = NULL;
+}
+
+void kcov_task_exit(struct task_struct *t)
+{
+	struct kcov *kcov;
+
+	kcov = t->kcov;
+	if (kcov == NULL)
+		return;
+	spin_lock(&kcov->lock);
+	if (WARN_ON(kcov->t != t)) {
+		spin_unlock(&kcov->lock);
+		return;
+	}
+	/* Just to not leave dangling references behind. */
+	kcov_task_init(t);
+	kcov->t = NULL;
+	spin_unlock(&kcov->lock);
+	kcov_put(kcov);
+}
+
+static int kcov_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+	int res = 0;
+	void *area;
+	struct kcov *kcov = vma->vm_file->private_data;
+	unsigned long size, off;
+	struct page *page;
+
+	area = vmalloc_user(vma->vm_end - vma->vm_start);
+	if (!area)
+		return -ENOMEM;
+
+	spin_lock(&kcov->lock);
+	size = kcov->size * sizeof(unsigned long);
+	if (kcov->mode == KCOV_MODE_DISABLED || vma->vm_pgoff != 0 ||
+	    vma->vm_end - vma->vm_start != size) {
+		res = -EINVAL;
+		goto exit;
+	}
+	if (!kcov->area) {
+		kcov->area = area;
+		vma->vm_flags |= VM_DONTEXPAND;
+		spin_unlock(&kcov->lock);
+		for (off = 0; off < size; off += PAGE_SIZE) {
+			page = vmalloc_to_page(kcov->area + off);
+			if (vm_insert_page(vma, vma->vm_start + off, page))
+				WARN_ONCE(1, "vm_insert_page() failed");
+		}
+		return 0;
+	}
+exit:
+	spin_unlock(&kcov->lock);
+	vfree(area);
+	return res;
+}
+
+static int kcov_open(struct inode *inode, struct file *filep)
+{
+	struct kcov *kcov;
+
+	kcov = kzalloc(sizeof(*kcov), GFP_KERNEL);
+	if (!kcov)
+		return -ENOMEM;
+	atomic_set(&kcov->refcount, 1);
+	spin_lock_init(&kcov->lock);
+	filep->private_data = kcov;
+	return nonseekable_open(inode, filep);
+}
+
+static int kcov_close(struct inode *inode, struct file *filep)
+{
+	kcov_put(filep->private_data);
+	return 0;
+}
+
+static int kcov_ioctl_locked(struct kcov *kcov, unsigned int cmd,
+			     unsigned long arg)
+{
+	struct task_struct *t;
+	unsigned long size, unused;
+
+	switch (cmd) {
+	case KCOV_INIT_TRACE:
+		/*
+		 * Enable kcov in trace mode and setup buffer size.
+		 * Must happen before anything else.
+		 */
+		if (kcov->mode != KCOV_MODE_DISABLED)
+			return -EBUSY;
+		/*
+		 * Size must be at least 2 to hold current position and one PC.
+		 * Later we allocate size * sizeof(unsigned long) memory,
+		 * that must not overflow.
+		 */
+		size = arg;
+		if (size < 2 || size > INT_MAX / sizeof(unsigned long))
+			return -EINVAL;
+		kcov->size = size;
+		kcov->mode = KCOV_MODE_TRACE;
+		return 0;
+	case KCOV_ENABLE:
+		/*
+		 * Enable coverage for the current task.
+		 * At this point user must have been enabled trace mode,
+		 * and mmapped the file. Coverage collection is disabled only
+		 * at task exit or voluntary by KCOV_DISABLE. After that it can
+		 * be enabled for another task.
+		 */
+		unused = arg;
+		if (unused != 0 || kcov->mode == KCOV_MODE_DISABLED ||
+		    kcov->area == NULL)
+			return -EINVAL;
+		if (kcov->t != NULL)
+			return -EBUSY;
+		t = current;
+		/* Cache in task struct for performance. */
+		t->kcov_size = kcov->size;
+		t->kcov_area = kcov->area;
+		/* See comment in __sanitizer_cov_trace_pc(). */
+		barrier();
+		WRITE_ONCE(t->kcov_mode, kcov->mode);
+		t->kcov = kcov;
+		kcov->t = t;
+		/* This is put either in kcov_task_exit() or in KCOV_DISABLE. */
+		kcov_get(kcov);
+		return 0;
+	case KCOV_DISABLE:
+		/* Disable coverage for the current task. */
+		unused = arg;
+		if (unused != 0 || current->kcov != kcov)
+			return -EINVAL;
+		t = current;
+		if (WARN_ON(kcov->t != t))
+			return -EINVAL;
+		kcov_task_init(t);
+		kcov->t = NULL;
+		kcov_put(kcov);
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+}
+
+static long kcov_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+	struct kcov *kcov;
+	int res;
+
+	kcov = filep->private_data;
+	spin_lock(&kcov->lock);
+	res = kcov_ioctl_locked(kcov, cmd, arg);
+	spin_unlock(&kcov->lock);
+	return res;
+}
+
+static const struct file_operations kcov_fops = {
+	.open		= kcov_open,
+	.unlocked_ioctl	= kcov_ioctl,
+	.mmap		= kcov_mmap,
+	.release        = kcov_close,
+};
+
+static int __init kcov_init(void)
+{
+	if (!debugfs_create_file("kcov", 0600, NULL, NULL, &kcov_fops)) {
+		pr_err("failed to create kcov in debugfs\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+device_initcall(kcov_init);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 8dc659144..1391d3ee3 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -66,13 +66,15 @@ struct resource crashk_res = {
 	.name  = "Crash kernel",
 	.start = 0,
 	.end   = 0,
-	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
+	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+	.desc  = IORES_DESC_CRASH_KERNEL
 };
 struct resource crashk_low_res = {
 	.name  = "Crash kernel",
 	.start = 0,
 	.end   = 0,
-	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
+	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+	.desc  = IORES_DESC_CRASH_KERNEL
 };
 
 int kexec_should_crash(struct task_struct *p)
@@ -959,7 +961,7 @@ int crash_shrink_memory(unsigned long new_size)
 
 	ram_res->start = end;
 	ram_res->end = crashk_res.end;
-	ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+	ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
 	ram_res->name = "System RAM";
 
 	crashk_res.end = end - 1;
@@ -1413,6 +1415,9 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_OFFSET(page, lru);
 	VMCOREINFO_OFFSET(page, _mapcount);
 	VMCOREINFO_OFFSET(page, private);
+	VMCOREINFO_OFFSET(page, compound_dtor);
+	VMCOREINFO_OFFSET(page, compound_order);
+	VMCOREINFO_OFFSET(page, compound_head);
 	VMCOREINFO_OFFSET(pglist_data, node_zones);
 	VMCOREINFO_OFFSET(pglist_data, nr_zones);
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -1445,8 +1450,8 @@ static int __init crash_save_vmcoreinfo_init(void)
 #ifdef CONFIG_X86
 	VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
 #endif
-#ifdef CONFIG_HUGETLBFS
-	VMCOREINFO_SYMBOL(free_huge_page);
+#ifdef CONFIG_HUGETLB_PAGE
+	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 #endif
 
 	arch_crash_save_vmcoreinfo();
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 007b791f6..c72d2ff58 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -18,6 +18,7 @@
 #include <linux/kexec.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
+#include <linux/fs.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
 #include <linux/syscalls.h>
@@ -33,65 +34,6 @@ size_t __weak kexec_purgatory_size = 0;
 
 static int kexec_calculate_store_digests(struct kimage *image);
 
-static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
-{
-	struct fd f = fdget(fd);
-	int ret;
-	struct kstat stat;
-	loff_t pos;
-	ssize_t bytes = 0;
-
-	if (!f.file)
-		return -EBADF;
-
-	ret = vfs_getattr(&f.file->f_path, &stat);
-	if (ret)
-		goto out;
-
-	if (stat.size > INT_MAX) {
-		ret = -EFBIG;
-		goto out;
-	}
-
-	/* Don't hand 0 to vmalloc, it whines. */
-	if (stat.size == 0) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	*buf = vmalloc(stat.size);
-	if (!*buf) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	pos = 0;
-	while (pos < stat.size) {
-		bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
-				    stat.size - pos);
-		if (bytes < 0) {
-			vfree(*buf);
-			ret = bytes;
-			goto out;
-		}
-
-		if (bytes == 0)
-			break;
-		pos += bytes;
-	}
-
-	if (pos != stat.size) {
-		ret = -EBADF;
-		vfree(*buf);
-		goto out;
-	}
-
-	*buf_len = pos;
-out:
-	fdput(f);
-	return ret;
-}
-
 /* Architectures can provide this probe function */
 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 					 unsigned long buf_len)
@@ -182,16 +124,17 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 {
 	int ret = 0;
 	void *ldata;
+	loff_t size;
 
-	ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
-				&image->kernel_buf_len);
+	ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
+				       &size, INT_MAX, READING_KEXEC_IMAGE);
 	if (ret)
 		return ret;
+	image->kernel_buf_len = size;
 
 	/* Call arch image probe handlers */
 	ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
 					    image->kernel_buf_len);
-
 	if (ret)
 		goto out;
 
@@ -206,10 +149,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 #endif
 	/* It is possible that there no initramfs is being loaded */
 	if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
-		ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
-					&image->initrd_buf_len);
+		ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
+					       &size, INT_MAX,
+					       READING_KEXEC_INITRAMFS);
 		if (ret)
 			goto out;
+		image->initrd_buf_len = size;
 	}
 
 	if (cmdline_len) {
@@ -524,10 +469,10 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
 	if (image->type == KEXEC_TYPE_CRASH)
-		ret = walk_iomem_res("Crash kernel",
-				     IORESOURCE_MEM | IORESOURCE_BUSY,
-				     crashk_res.start, crashk_res.end, kbuf,
-				     locate_mem_hole_callback);
+		ret = walk_iomem_res_desc(crashk_res.desc,
+				IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+				crashk_res.start, crashk_res.end, kbuf,
+				locate_mem_hole_callback);
 	else
 		ret = walk_system_ram_res(0, -1, kbuf,
 					  locate_mem_hole_callback);
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index bc2c85c06..d68fbf63b 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -99,12 +99,12 @@ static void klp_find_object_module(struct klp_object *obj)
 	/*
 	 * We do not want to block removal of patched modules and therefore
 	 * we do not take a reference here. The patches are removed by
-	 * a going module handler instead.
+	 * klp_module_going() instead.
 	 */
 	mod = find_module(obj->name);
 	/*
-	 * Do not mess work of the module coming and going notifiers.
-	 * Note that the patch might still be needed before the going handler
+	 * Do not mess work of klp_module_coming() and klp_module_going().
+	 * Note that the patch might still be needed before klp_module_going()
 	 * is called. Module functions can be called even in the GOING state
 	 * until mod->exit() finishes. This is especially important for
 	 * patches that modify semantic of the functions.
@@ -190,8 +190,8 @@ static int klp_find_object_symbol(const char *objname, const char *name,
 	if (args.addr == 0)
 		pr_err("symbol '%s' not found in symbol table\n", name);
 	else if (args.count > 1 && sympos == 0) {
-		pr_err("unresolvable ambiguity (%lu matches) on symbol '%s' in object '%s'\n",
-		       args.count, name, objname);
+		pr_err("unresolvable ambiguity for symbol '%s' in object '%s'\n",
+		       name, objname);
 	} else if (sympos != args.count && sympos > 0) {
 		pr_err("symbol position %lu for symbol '%s' in object '%s' not found\n",
 		       sympos, name, objname ? objname : "vmlinux");
@@ -866,103 +866,108 @@ int klp_register_patch(struct klp_patch *patch)
 }
 EXPORT_SYMBOL_GPL(klp_register_patch);
 
-static int klp_module_notify_coming(struct klp_patch *patch,
-				     struct klp_object *obj)
+int klp_module_coming(struct module *mod)
 {
-	struct module *pmod = patch->mod;
-	struct module *mod = obj->mod;
 	int ret;
+	struct klp_patch *patch;
+	struct klp_object *obj;
 
-	ret = klp_init_object_loaded(patch, obj);
-	if (ret) {
-		pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",
-			pmod->name, mod->name, ret);
-		return ret;
-	}
+	if (WARN_ON(mod->state != MODULE_STATE_COMING))
+		return -EINVAL;
 
-	if (patch->state == KLP_DISABLED)
-		return 0;
+	mutex_lock(&klp_mutex);
+	/*
+	 * Each module has to know that klp_module_coming()
+	 * has been called. We never know what module will
+	 * get patched by a new patch.
+	 */
+	mod->klp_alive = true;
 
-	pr_notice("applying patch '%s' to loading module '%s'\n",
-		  pmod->name, mod->name);
+	list_for_each_entry(patch, &klp_patches, list) {
+		klp_for_each_object(patch, obj) {
+			if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
+				continue;
 
-	ret = klp_enable_object(obj);
-	if (ret)
-		pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
-			pmod->name, mod->name, ret);
-	return ret;
-}
+			obj->mod = mod;
 
-static void klp_module_notify_going(struct klp_patch *patch,
-				    struct klp_object *obj)
-{
-	struct module *pmod = patch->mod;
-	struct module *mod = obj->mod;
+			ret = klp_init_object_loaded(patch, obj);
+			if (ret) {
+				pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",
+					patch->mod->name, obj->mod->name, ret);
+				goto err;
+			}
 
-	if (patch->state == KLP_DISABLED)
-		goto disabled;
+			if (patch->state == KLP_DISABLED)
+				break;
+
+			pr_notice("applying patch '%s' to loading module '%s'\n",
+				  patch->mod->name, obj->mod->name);
+
+			ret = klp_enable_object(obj);
+			if (ret) {
+				pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
+					patch->mod->name, obj->mod->name, ret);
+				goto err;
+			}
+
+			break;
+		}
+	}
 
-	pr_notice("reverting patch '%s' on unloading module '%s'\n",
-		  pmod->name, mod->name);
+	mutex_unlock(&klp_mutex);
 
-	klp_disable_object(obj);
+	return 0;
 
-disabled:
+err:
+	/*
+	 * If a patch is unsuccessfully applied, return
+	 * error to the module loader.
+	 */
+	pr_warn("patch '%s' failed for module '%s', refusing to load module '%s'\n",
+		patch->mod->name, obj->mod->name, obj->mod->name);
+	mod->klp_alive = false;
 	klp_free_object_loaded(obj);
+	mutex_unlock(&klp_mutex);
+
+	return ret;
 }
 
-static int klp_module_notify(struct notifier_block *nb, unsigned long action,
-			     void *data)
+void klp_module_going(struct module *mod)
 {
-	int ret;
-	struct module *mod = data;
 	struct klp_patch *patch;
 	struct klp_object *obj;
 
-	if (action != MODULE_STATE_COMING && action != MODULE_STATE_GOING)
-		return 0;
+	if (WARN_ON(mod->state != MODULE_STATE_GOING &&
+		    mod->state != MODULE_STATE_COMING))
+		return;
 
 	mutex_lock(&klp_mutex);
-
 	/*
-	 * Each module has to know that the notifier has been called.
-	 * We never know what module will get patched by a new patch.
+	 * Each module has to know that klp_module_going()
+	 * has been called. We never know what module will
+	 * get patched by a new patch.
 	 */
-	if (action == MODULE_STATE_COMING)
-		mod->klp_alive = true;
-	else /* MODULE_STATE_GOING */
-		mod->klp_alive = false;
+	mod->klp_alive = false;
 
 	list_for_each_entry(patch, &klp_patches, list) {
 		klp_for_each_object(patch, obj) {
 			if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
 				continue;
 
-			if (action == MODULE_STATE_COMING) {
-				obj->mod = mod;
-				ret = klp_module_notify_coming(patch, obj);
-				if (ret) {
-					obj->mod = NULL;
-					pr_warn("patch '%s' is in an inconsistent state!\n",
-						patch->mod->name);
-				}
-			} else /* MODULE_STATE_GOING */
-				klp_module_notify_going(patch, obj);
+			if (patch->state != KLP_DISABLED) {
+				pr_notice("reverting patch '%s' on unloading module '%s'\n",
+					  patch->mod->name, obj->mod->name);
+				klp_disable_object(obj);
+			}
 
+			klp_free_object_loaded(obj);
 			break;
 		}
 	}
 
 	mutex_unlock(&klp_mutex);
-
-	return 0;
 }
 
-static struct notifier_block klp_module_nb = {
-	.notifier_call = klp_module_notify,
-	.priority = INT_MIN+1, /* called late but before ftrace notifier */
-};
-
 static int __init klp_init(void)
 {
 	int ret;
@@ -973,21 +978,11 @@ static int __init klp_init(void)
 		return -EINVAL;
 	}
 
-	ret = register_module_notifier(&klp_module_nb);
-	if (ret)
-		return ret;
-
 	klp_root_kobj = kobject_create_and_add("livepatch", kernel_kobj);
-	if (!klp_root_kobj) {
-		ret = -ENOMEM;
-		goto unregister;
-	}
+	if (!klp_root_kobj)
+		return -ENOMEM;
 
 	return 0;
-
-unregister:
-	unregister_module_notifier(&klp_module_nb);
-	return ret;
 }
 
 module_init(klp_init);
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 8e96f6cc2..31322a427 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -1,3 +1,6 @@
+# Any varying coverage in these files is non-deterministic
+# and is generally not a function of system call inputs.
+KCOV_INSTRUMENT		:= n
 
 obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
 
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 716547fdb..78c1c0ee6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -123,8 +123,6 @@ static inline int debug_locks_off_graph_unlock(void)
 	return ret;
 }
 
-static int lockdep_initialized;
-
 unsigned long nr_list_entries;
 static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
 
@@ -150,8 +148,7 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 }
 
 #ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
-		      cpu_lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats);
 
 static inline u64 lockstat_clock(void)
 {
@@ -434,19 +431,6 @@ unsigned int max_lockdep_depth;
 
 #ifdef CONFIG_DEBUG_LOCKDEP
 /*
- * We cannot printk in early bootup code. Not even early_printk()
- * might work. So we mark any initialization errors and printk
- * about it later on, in lockdep_info().
- */
-static int lockdep_init_error;
-static const char *lock_init_error;
-static unsigned long lockdep_init_trace_data[20];
-static struct stack_trace lockdep_init_trace = {
-	.max_entries = ARRAY_SIZE(lockdep_init_trace_data),
-	.entries = lockdep_init_trace_data,
-};
-
-/*
  * Various lockdep statistics:
  */
 DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
@@ -669,20 +653,6 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	struct hlist_head *hash_head;
 	struct lock_class *class;
 
-#ifdef CONFIG_DEBUG_LOCKDEP
-	/*
-	 * If the architecture calls into lockdep before initializing
-	 * the hashes then we'll warn about it later. (we cannot printk
-	 * right now)
-	 */
-	if (unlikely(!lockdep_initialized)) {
-		lockdep_init();
-		lockdep_init_error = 1;
-		lock_init_error = lock->name;
-		save_stack_trace(&lockdep_init_trace);
-	}
-#endif
-
 	if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
 		debug_locks_off();
 		printk(KERN_ERR
@@ -2011,6 +1981,130 @@ struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
 }
 
 /*
+ * Returns the index of the first held_lock of the current chain
+ */
+static inline int get_first_held_lock(struct task_struct *curr,
+					struct held_lock *hlock)
+{
+	int i;
+	struct held_lock *hlock_curr;
+
+	for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+		hlock_curr = curr->held_locks + i;
+		if (hlock_curr->irq_context != hlock->irq_context)
+			break;
+
+	}
+
+	return ++i;
+}
+
+#ifdef CONFIG_DEBUG_LOCKDEP
+/*
+ * Returns the next chain_key iteration
+ */
+static u64 print_chain_key_iteration(int class_idx, u64 chain_key)
+{
+	u64 new_chain_key = iterate_chain_key(chain_key, class_idx);
+
+	printk(" class_idx:%d -> chain_key:%016Lx",
+		class_idx,
+		(unsigned long long)new_chain_key);
+	return new_chain_key;
+}
+
+static void
+print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next)
+{
+	struct held_lock *hlock;
+	u64 chain_key = 0;
+	int depth = curr->lockdep_depth;
+	int i;
+
+	printk("depth: %u\n", depth + 1);
+	for (i = get_first_held_lock(curr, hlock_next); i < depth; i++) {
+		hlock = curr->held_locks + i;
+		chain_key = print_chain_key_iteration(hlock->class_idx, chain_key);
+
+		print_lock(hlock);
+	}
+
+	print_chain_key_iteration(hlock_next->class_idx, chain_key);
+	print_lock(hlock_next);
+}
+
+static void print_chain_keys_chain(struct lock_chain *chain)
+{
+	int i;
+	u64 chain_key = 0;
+	int class_id;
+
+	printk("depth: %u\n", chain->depth);
+	for (i = 0; i < chain->depth; i++) {
+		class_id = chain_hlocks[chain->base + i];
+		chain_key = print_chain_key_iteration(class_id + 1, chain_key);
+
+		print_lock_name(lock_classes + class_id);
+		printk("\n");
+	}
+}
+
+static void print_collision(struct task_struct *curr,
+			struct held_lock *hlock_next,
+			struct lock_chain *chain)
+{
+	printk("\n");
+	printk("======================\n");
+	printk("[chain_key collision ]\n");
+	print_kernel_ident();
+	printk("----------------------\n");
+	printk("%s/%d: ", current->comm, task_pid_nr(current));
+	printk("Hash chain already cached but the contents don't match!\n");
+
+	printk("Held locks:");
+	print_chain_keys_held_locks(curr, hlock_next);
+
+	printk("Locks in cached chain:");
+	print_chain_keys_chain(chain);
+
+	printk("\nstack backtrace:\n");
+	dump_stack();
+}
+#endif
+
+/*
+ * Checks whether the chain and the current held locks are consistent
+ * in depth and also in content. If they are not it most likely means
+ * that there was a collision during the calculation of the chain_key.
+ * Returns: 0 not passed, 1 passed
+ */
+static int check_no_collision(struct task_struct *curr,
+			struct held_lock *hlock,
+			struct lock_chain *chain)
+{
+#ifdef CONFIG_DEBUG_LOCKDEP
+	int i, j, id;
+
+	i = get_first_held_lock(curr, hlock);
+
+	if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) {
+		print_collision(curr, hlock, chain);
+		return 0;
+	}
+
+	for (j = 0; j < chain->depth - 1; j++, i++) {
+		id = curr->held_locks[i].class_idx - 1;
+
+		if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {
+			print_collision(curr, hlock, chain);
+			return 0;
+		}
+	}
+#endif
+	return 1;
+}
+
+/*
  * Look up a dependency chain. If the key is not present yet then
  * add it and return 1 - in this case the new dependency chain is
  * validated. If the key is already hashed, return 0.
@@ -2023,7 +2117,6 @@ static inline int lookup_chain_cache(struct task_struct *curr,
 	struct lock_class *class = hlock_class(hlock);
 	struct hlist_head *hash_head = chainhashentry(chain_key);
 	struct lock_chain *chain;
-	struct held_lock *hlock_curr;
 	int i, j;
 
 	/*
@@ -2041,6 +2134,9 @@ static inline int lookup_chain_cache(struct task_struct *curr,
 		if (chain->chain_key == chain_key) {
 cache_hit:
 			debug_atomic_inc(chain_lookup_hits);
+			if (!check_no_collision(curr, hlock, chain))
+				return 0;
+
 			if (very_verbose(class))
 				printk("\nhash chain already cached, key: "
 					"%016Lx tail class: [%p] %s\n",
@@ -2078,23 +2174,39 @@ cache_hit:
 	chain = lock_chains + nr_lock_chains++;
 	chain->chain_key = chain_key;
 	chain->irq_context = hlock->irq_context;
-	/* Find the first held_lock of current chain */
-	for (i = curr->lockdep_depth - 1; i >= 0; i--) {
-		hlock_curr = curr->held_locks + i;
-		if (hlock_curr->irq_context != hlock->irq_context)
-			break;
-	}
-	i++;
+	i = get_first_held_lock(curr, hlock);
 	chain->depth = curr->lockdep_depth + 1 - i;
+
+	BUILD_BUG_ON((1UL << 24) <= ARRAY_SIZE(chain_hlocks));
+	BUILD_BUG_ON((1UL << 6)  <= ARRAY_SIZE(curr->held_locks));
+	BUILD_BUG_ON((1UL << 8*sizeof(chain_hlocks[0])) <= ARRAY_SIZE(lock_classes));
+
 	if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
 		chain->base = nr_chain_hlocks;
-		nr_chain_hlocks += chain->depth;
 		for (j = 0; j < chain->depth - 1; j++, i++) {
 			int lock_id = curr->held_locks[i].class_idx - 1;
 			chain_hlocks[chain->base + j] = lock_id;
 		}
 		chain_hlocks[chain->base + j] = class - lock_classes;
 	}
+
+	if (nr_chain_hlocks < MAX_LOCKDEP_CHAIN_HLOCKS)
+		nr_chain_hlocks += chain->depth;
+
+#ifdef CONFIG_DEBUG_LOCKDEP
+	/*
+	 * Important for check_no_collision().
+	 */
+	if (unlikely(nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)) {
+		if (debug_locks_off_graph_unlock())
+			return 0;
+
+		print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!");
+		dump_stack();
+		return 0;
+	}
+#endif
+
 	hlist_add_head_rcu(&chain->entry, hash_head);
 	debug_atomic_inc(chain_lookup_misses);
 	inc_chains();
@@ -2172,7 +2284,7 @@ static void check_chain_key(struct task_struct *curr)
 {
 #ifdef CONFIG_DEBUG_LOCKDEP
 	struct held_lock *hlock, *prev_hlock = NULL;
-	unsigned int i, id;
+	unsigned int i;
 	u64 chain_key = 0;
 
 	for (i = 0; i < curr->lockdep_depth; i++) {
@@ -2189,17 +2301,16 @@ static void check_chain_key(struct task_struct *curr)
 				(unsigned long long)hlock->prev_chain_key);
 			return;
 		}
-		id = hlock->class_idx - 1;
 		/*
 		 * Whoops ran out of static storage again?
 		 */
-		if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+		if (DEBUG_LOCKS_WARN_ON(hlock->class_idx > MAX_LOCKDEP_KEYS))
 			return;
 
 		if (prev_hlock && (prev_hlock->irq_context !=
 							hlock->irq_context))
 			chain_key = 0;
-		chain_key = iterate_chain_key(chain_key, id);
+		chain_key = iterate_chain_key(chain_key, hlock->class_idx);
 		prev_hlock = hlock;
 	}
 	if (chain_key != curr->curr_chain_key) {
@@ -2843,6 +2954,11 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
 	return 1;
 }
 
+static inline unsigned int task_irq_context(struct task_struct *task)
+{
+	return 2 * !!task->hardirq_context + !!task->softirq_context;
+}
+
 static int separate_irq_context(struct task_struct *curr,
 		struct held_lock *hlock)
 {
@@ -2851,8 +2967,6 @@ static int separate_irq_context(struct task_struct *curr,
 	/*
 	 * Keep track of points where we cross into an interrupt context:
 	 */
-	hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) +
-				curr->softirq_context;
 	if (depth) {
 		struct held_lock *prev_hlock;
 
@@ -2884,6 +2998,11 @@ static inline int mark_irqflags(struct task_struct *curr,
 	return 1;
 }
 
+static inline unsigned int task_irq_context(struct task_struct *task)
+{
+	return 0;
+}
+
 static inline int separate_irq_context(struct task_struct *curr,
 		struct held_lock *hlock)
 {
@@ -3077,7 +3196,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	struct task_struct *curr = current;
 	struct lock_class *class = NULL;
 	struct held_lock *hlock;
-	unsigned int depth, id;
+	unsigned int depth;
 	int chain_head = 0;
 	int class_idx;
 	u64 chain_key;
@@ -3152,6 +3271,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	hlock->acquire_ip = ip;
 	hlock->instance = lock;
 	hlock->nest_lock = nest_lock;
+	hlock->irq_context = task_irq_context(curr);
 	hlock->trylock = trylock;
 	hlock->read = read;
 	hlock->check = check;
@@ -3180,11 +3300,10 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	 * The 'key ID' is what is the most compact key value to drive
 	 * the hash, not class->key.
 	 */
-	id = class - lock_classes;
 	/*
 	 * Whoops, we did it again.. ran straight out of our static allocation.
 	 */
-	if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+	if (DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS))
 		return 0;
 
 	chain_key = curr->curr_chain_key;
@@ -3202,7 +3321,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 		chain_key = 0;
 		chain_head = 1;
 	}
-	chain_key = iterate_chain_key(chain_key, id);
+	chain_key = iterate_chain_key(chain_key, class_idx);
 
 	if (nest_lock && !__lock_is_held(nest_lock))
 		return print_lock_nested_lock_not_held(curr, hlock, ip);
@@ -4013,28 +4132,6 @@ out_restore:
 	raw_local_irq_restore(flags);
 }
 
-void lockdep_init(void)
-{
-	int i;
-
-	/*
-	 * Some architectures have their own start_kernel()
-	 * code which calls lockdep_init(), while we also
-	 * call lockdep_init() from the start_kernel() itself,
-	 * and we want to initialize the hashes only once:
-	 */
-	if (lockdep_initialized)
-		return;
-
-	for (i = 0; i < CLASSHASH_SIZE; i++)
-		INIT_HLIST_HEAD(classhash_table + i);
-
-	for (i = 0; i < CHAINHASH_SIZE; i++)
-		INIT_HLIST_HEAD(chainhash_table + i);
-
-	lockdep_initialized = 1;
-}
-
 void __init lockdep_info(void)
 {
 	printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
@@ -4061,14 +4158,6 @@ void __init lockdep_info(void)
 
 	printk(" per task-struct memory footprint: %lu bytes\n",
 		sizeof(struct held_lock) * MAX_LOCK_DEPTH);
-
-#ifdef CONFIG_DEBUG_LOCKDEP
-	if (lockdep_init_error) {
-		printk("WARNING: lockdep init error: lock '%s' was acquired before lockdep_init().\n", lock_init_error);
-		printk("Call stack leading to lockdep invocation was:\n");
-		print_stack_trace(&lockdep_init_trace, 0);
-	}
-#endif
 }
 
 static void
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index dbb61a302..a0f61effa 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -141,6 +141,8 @@ static int lc_show(struct seq_file *m, void *v)
 	int i;
 
 	if (v == SEQ_START_TOKEN) {
+		if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)
+			seq_printf(m, "(buggered) ");
 		seq_printf(m, "all lock chains:\n");
 		return 0;
 	}
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 0551c219c..e364b424b 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -716,6 +716,7 @@ static inline void
 __mutex_unlock_common_slowpath(struct mutex *lock, int nested)
 {
 	unsigned long flags;
+	WAKE_Q(wake_q);
 
 	/*
 	 * As a performance measurement, release the lock before doing other
@@ -743,11 +744,11 @@ __mutex_unlock_common_slowpath(struct mutex *lock, int nested)
 					   struct mutex_waiter, list);
 
 		debug_mutex_wake_waiter(lock, waiter);
-
-		wake_up_process(waiter->task);
+		wake_q_add(&wake_q, waiter->task);
 	}
 
 	spin_unlock_mutex(&lock->wait_lock, flags);
+	wake_up_q(&wake_q);
 }
 
 /*
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 393d1874b..ce2f75e32 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -358,8 +358,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
 	 * sequentiality; this is because not all clear_pending_set_locked()
 	 * implementations imply full barriers.
 	 */
-	while ((val = smp_load_acquire(&lock->val.counter)) & _Q_LOCKED_MASK)
-		cpu_relax();
+	smp_cond_acquire(!(atomic_read(&lock->val) & _Q_LOCKED_MASK));
 
 	/*
 	 * take ownership and clear the pending bit.
@@ -435,7 +434,7 @@ queue:
 	 *
 	 * The PV pv_wait_head_or_lock function, if active, will acquire
 	 * the lock and return a non-zero value. So we have to skip the
-	 * smp_load_acquire() call. As the next PV queue head hasn't been
+	 * smp_cond_acquire() call. As the next PV queue head hasn't been
 	 * designated yet, there is no way for the locked value to become
 	 * _Q_SLOW_VAL. So both the set_locked() and the
 	 * atomic_cmpxchg_relaxed() calls will be safe.
@@ -466,7 +465,7 @@ locked:
 			break;
 		}
 		/*
-		 * The smp_load_acquire() call above has provided the necessary
+		 * The smp_cond_acquire() call above has provided the necessary
 		 * acquire semantics required for locking. At most two
 		 * iterations of this loop may be ran.
 		 */
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 87bb235c3..21ede57f6 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -55,6 +55,11 @@ struct pv_node {
 };
 
 /*
+ * Include queued spinlock statistics code
+ */
+#include "qspinlock_stat.h"
+
+/*
  * By replacing the regular queued_spin_trylock() with the function below,
  * it will be called once when a lock waiter enter the PV slowpath before
  * being queued. By allowing one lock stealing attempt here when the pending
@@ -65,9 +70,11 @@ struct pv_node {
 static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock)
 {
 	struct __qspinlock *l = (void *)lock;
+	int ret = !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) &&
+		   (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0);
 
-	return !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) &&
-		(cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0);
+	qstat_inc(qstat_pv_lock_stealing, ret);
+	return ret;
 }
 
 /*
@@ -138,11 +145,6 @@ static __always_inline int trylock_clear_pending(struct qspinlock *lock)
 #endif /* _Q_PENDING_BITS == 8 */
 
 /*
- * Include queued spinlock statistics code
- */
-#include "qspinlock_stat.h"
-
-/*
  * Lock and MCS node addresses hash table for fast lookup
  *
  * Hashing is done on a per-cacheline basis to minimize the need to access
@@ -398,6 +400,11 @@ pv_wait_head_or_lock(struct qspinlock *lock, struct mcs_spinlock *node)
 	if (READ_ONCE(pn->state) == vcpu_hashed)
 		lp = (struct qspinlock **)1;
 
+	/*
+	 * Tracking # of slowpath locking operations
+	 */
+	qstat_inc(qstat_pv_lock_slowpath, true);
+
 	for (;; waitcnt++) {
 		/*
 		 * Set correct vCPU state to be used by queue node wait-early
diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 640dcecdd..d734b7502 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -22,6 +22,7 @@
  *   pv_kick_wake	- # of vCPU kicks used for computing pv_latency_wake
  *   pv_latency_kick	- average latency (ns) of vCPU kick operation
  *   pv_latency_wake	- average latency (ns) from vCPU kick to wakeup
+ *   pv_lock_slowpath	- # of locking operations via the slowpath
  *   pv_lock_stealing	- # of lock stealing operations
  *   pv_spurious_wakeup	- # of spurious wakeups
  *   pv_wait_again	- # of vCPU wait's that happened after a vCPU kick
@@ -45,6 +46,7 @@ enum qlock_stats {
 	qstat_pv_kick_wake,
 	qstat_pv_latency_kick,
 	qstat_pv_latency_wake,
+	qstat_pv_lock_slowpath,
 	qstat_pv_lock_stealing,
 	qstat_pv_spurious_wakeup,
 	qstat_pv_wait_again,
@@ -70,6 +72,7 @@ static const char * const qstat_names[qstat_num + 1] = {
 	[qstat_pv_spurious_wakeup] = "pv_spurious_wakeup",
 	[qstat_pv_latency_kick]	   = "pv_latency_kick",
 	[qstat_pv_latency_wake]    = "pv_latency_wake",
+	[qstat_pv_lock_slowpath]   = "pv_lock_slowpath",
 	[qstat_pv_lock_stealing]   = "pv_lock_stealing",
 	[qstat_pv_wait_again]      = "pv_wait_again",
 	[qstat_pv_wait_early]      = "pv_wait_early",
@@ -133,10 +136,12 @@ static ssize_t qstat_read(struct file *file, char __user *user_buf,
 	}
 
 	if (counter == qstat_pv_hash_hops) {
-		u64 frac;
+		u64 frac = 0;
 
-		frac = 100ULL * do_div(stat, kicks);
-		frac = DIV_ROUND_CLOSEST_ULL(frac, kicks);
+		if (kicks) {
+			frac = 100ULL * do_div(stat, kicks);
+			frac = DIV_ROUND_CLOSEST_ULL(frac, kicks);
+		}
 
 		/*
 		 * Return a X.XX decimal number
@@ -279,19 +284,6 @@ static inline void __pv_wait(u8 *ptr, u8 val)
 #define pv_kick(c)	__pv_kick(c)
 #define pv_wait(p, v)	__pv_wait(p, v)
 
-/*
- * PV unfair trylock count tracking function
- */
-static inline int qstat_spin_steal_lock(struct qspinlock *lock)
-{
-	int ret = pv_queued_spin_steal_lock(lock);
-
-	qstat_inc(qstat_pv_lock_stealing, ret);
-	return ret;
-}
-#undef  queued_spin_trylock
-#define queued_spin_trylock(l)	qstat_spin_steal_lock(l)
-
 #else /* CONFIG_QUEUED_LOCK_STAT */
 
 static inline void qstat_inc(enum qlock_stats stat, bool cond)	{ }
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 6cf54615a..a6d382312 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -41,13 +41,15 @@ static void *try_ram_remap(resource_size_t offset, size_t size)
  * memremap() - remap an iomem_resource as cacheable memory
  * @offset: iomem resource start address
  * @size: size of remap
- * @flags: either MEMREMAP_WB or MEMREMAP_WT
+ * @flags: any of MEMREMAP_WB, MEMREMAP_WT and MEMREMAP_WC
  *
  * memremap() is "ioremap" for cases where it is known that the resource
  * being mapped does not have i/o side effects and the __iomem
- * annotation is not applicable.
+ * annotation is not applicable. In the case of multiple flags, the different
+ * mapping types will be attempted in the order listed below until one of
+ * them succeeds.
  *
- * MEMREMAP_WB - matches the default mapping for "System RAM" on
+ * MEMREMAP_WB - matches the default mapping for System RAM on
  * the architecture.  This is usually a read-allocate write-back cache.
  * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
  * memremap() will bypass establishing a new mapping and instead return
@@ -56,13 +58,21 @@ static void *try_ram_remap(resource_size_t offset, size_t size)
  * MEMREMAP_WT - establish a mapping whereby writes either bypass the
  * cache or are written through to memory and never exist in a
  * cache-dirty state with respect to program visibility.  Attempts to
- * map "System RAM" with this mapping type will fail.
+ * map System RAM with this mapping type will fail.
+ *
+ * MEMREMAP_WC - establish a writecombine mapping, whereby writes may
+ * be coalesced together (e.g. in the CPU's write buffers), but is otherwise
+ * uncached. Attempts to map System RAM with this mapping type will fail.
  */
 void *memremap(resource_size_t offset, size_t size, unsigned long flags)
 {
-	int is_ram = region_intersects(offset, size, "System RAM");
+	int is_ram = region_intersects(offset, size,
+				       IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
 	void *addr = NULL;
 
+	if (!flags)
+		return NULL;
+
 	if (is_ram == REGION_MIXED) {
 		WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
 				&offset, (unsigned long) size);
@@ -71,12 +81,11 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
 
 	/* Try all mapping types requested until one returns non-NULL */
 	if (flags & MEMREMAP_WB) {
-		flags &= ~MEMREMAP_WB;
 		/*
 		 * MEMREMAP_WB is special in that it can be satisifed
 		 * from the direct map.  Some archs depend on the
 		 * capability of memremap() to autodetect cases where
-		 * the requested range is potentially in "System RAM"
+		 * the requested range is potentially in System RAM.
 		 */
 		if (is_ram == REGION_INTERSECTS)
 			addr = try_ram_remap(offset, size);
@@ -85,21 +94,22 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
 	}
 
 	/*
-	 * If we don't have a mapping yet and more request flags are
-	 * pending then we will be attempting to establish a new virtual
+	 * If we don't have a mapping yet and other request flags are
+	 * present then we will be attempting to establish a new virtual
 	 * address mapping.  Enforce that this mapping is not aliasing
-	 * "System RAM"
+	 * System RAM.
 	 */
-	if (!addr && is_ram == REGION_INTERSECTS && flags) {
+	if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) {
 		WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
 				&offset, (unsigned long) size);
 		return NULL;
 	}
 
-	if (!addr && (flags & MEMREMAP_WT)) {
-		flags &= ~MEMREMAP_WT;
+	if (!addr && (flags & MEMREMAP_WT))
 		addr = ioremap_wt(offset, size);
-	}
+
+	if (!addr && (flags & MEMREMAP_WC))
+		addr = ioremap_wc(offset, size);
 
 	return addr;
 }
@@ -279,7 +289,8 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
 	align_start = res->start & ~(SECTION_SIZE - 1);
 	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
 		- align_start;
-	is_ram = region_intersects(align_start, align_size, "System RAM");
+	is_ram = region_intersects(align_start, align_size,
+		IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
 
 	if (is_ram == REGION_MIXED) {
 		WARN_ONCE(1, "%s attempted on mixed region %pr\n",
@@ -389,7 +400,7 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
 	/*
 	 * 'memmap_start' is the virtual address for the first "struct
 	 * page" in this range of the vmemmap array.  In the case of
-	 * CONFIG_SPARSE_VMEMMAP a page_to_pfn conversion is simple
+	 * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple
 	 * pointer arithmetic, so we can perform this to_vmem_altmap()
 	 * conversion without concern for the initialization state of
 	 * the struct page fields.
@@ -398,7 +409,7 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
 	struct dev_pagemap *pgmap;
 
 	/*
-	 * Uncoditionally retrieve a dev_pagemap associated with the
+	 * Unconditionally retrieve a dev_pagemap associated with the
 	 * given physical address, this is only for use in the
 	 * arch_{add|remove}_memory() for setting up and tearing down
 	 * the memmap.
diff --git a/kernel/module.c b/kernel/module.c
index 794ebe8e8..041200ca4 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -53,6 +53,7 @@
 #include <asm/sections.h>
 #include <linux/tracepoint.h>
 #include <linux/ftrace.h>
+#include <linux/livepatch.h>
 #include <linux/async.h>
 #include <linux/percpu.h>
 #include <linux/kmemleak.h>
@@ -984,6 +985,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 		mod->exit();
 	blocking_notifier_call_chain(&module_notify_list,
 				     MODULE_STATE_GOING, mod);
+	klp_module_going(mod);
 	ftrace_release_mod(mod);
 
 	async_synchronize_full();
@@ -2675,7 +2677,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
 	if (info->len < sizeof(*(info->hdr)))
 		return -ENOEXEC;
 
-	err = security_kernel_module_from_file(NULL);
+	err = security_kernel_read_file(NULL, READING_MODULE);
 	if (err)
 		return err;
 
@@ -2693,63 +2695,6 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
 	return 0;
 }
 
-/* Sets info->hdr and info->len. */
-static int copy_module_from_fd(int fd, struct load_info *info)
-{
-	struct fd f = fdget(fd);
-	int err;
-	struct kstat stat;
-	loff_t pos;
-	ssize_t bytes = 0;
-
-	if (!f.file)
-		return -ENOEXEC;
-
-	err = security_kernel_module_from_file(f.file);
-	if (err)
-		goto out;
-
-	err = vfs_getattr(&f.file->f_path, &stat);
-	if (err)
-		goto out;
-
-	if (stat.size > INT_MAX) {
-		err = -EFBIG;
-		goto out;
-	}
-
-	/* Don't hand 0 to vmalloc, it whines. */
-	if (stat.size == 0) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	info->hdr = vmalloc(stat.size);
-	if (!info->hdr) {
-		err = -ENOMEM;
-		goto out;
-	}
-
-	pos = 0;
-	while (pos < stat.size) {
-		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
-				    stat.size - pos);
-		if (bytes < 0) {
-			vfree(info->hdr);
-			err = bytes;
-			goto out;
-		}
-		if (bytes == 0)
-			break;
-		pos += bytes;
-	}
-	info->len = pos;
-
-out:
-	fdput(f);
-	return err;
-}
-
 static void free_copy(struct load_info *info)
 {
 	vfree(info->hdr);
@@ -3315,6 +3260,7 @@ fail:
 	module_put(mod);
 	blocking_notifier_call_chain(&module_notify_list,
 				     MODULE_STATE_GOING, mod);
+	klp_module_going(mod);
 	ftrace_release_mod(mod);
 	free_module(mod);
 	wake_up_all(&module_wq);
@@ -3392,9 +3338,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
 	mod->state = MODULE_STATE_COMING;
 	mutex_unlock(&module_mutex);
 
-	ftrace_module_enable(mod);
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_COMING, mod);
 	return 0;
 
 out:
@@ -3402,6 +3345,20 @@ out:
 	return err;
 }
 
+static int prepare_coming_module(struct module *mod)
+{
+	int err;
+
+	ftrace_module_enable(mod);
+	err = klp_module_coming(mod);
+	if (err)
+		return err;
+
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_COMING, mod);
+	return 0;
+}
+
 static int unknown_module_param_cb(char *param, char *val, const char *modname,
 				   void *arg)
 {
@@ -3516,13 +3473,17 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	if (err)
 		goto ddebug_cleanup;
 
+	err = prepare_coming_module(mod);
+	if (err)
+		goto bug_cleanup;
+
 	/* Module is ready to execute: parsing args may do that. */
 	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
 				  -32768, 32767, mod,
 				  unknown_module_param_cb);
 	if (IS_ERR(after_dashes)) {
 		err = PTR_ERR(after_dashes);
-		goto bug_cleanup;
+		goto coming_cleanup;
 	} else if (after_dashes) {
 		pr_warn("%s: parameters '%s' after `--' ignored\n",
 		       mod->name, after_dashes);
@@ -3531,7 +3492,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	/* Link in to syfs. */
 	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
 	if (err < 0)
-		goto bug_cleanup;
+		goto coming_cleanup;
 
 	/* Get rid of temporary copy. */
 	free_copy(info);
@@ -3541,15 +3502,17 @@ static int load_module(struct load_info *info, const char __user *uargs,
 
 	return do_init_module(mod);
 
+ coming_cleanup:
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_GOING, mod);
+	klp_module_going(mod);
+
  bug_cleanup:
 	/* module_bug_cleanup needs module_mutex protection */
 	mutex_lock(&module_mutex);
 	module_bug_cleanup(mod);
 	mutex_unlock(&module_mutex);
 
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_GOING, mod);
-
 	/* we can't deallocate the module until we clear memory protection */
 	module_disable_ro(mod);
 	module_disable_nx(mod);
@@ -3611,8 +3574,10 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
 
 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 {
-	int err;
 	struct load_info info = { };
+	loff_t size;
+	void *hdr;
+	int err;
 
 	err = may_init_module();
 	if (err)
@@ -3624,9 +3589,12 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 		      |MODULE_INIT_IGNORE_VERMAGIC))
 		return -EINVAL;
 
-	err = copy_module_from_fd(fd, &info);
+	err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
+				       READING_MODULE);
 	if (err)
 		return err;
+	info.hdr = hdr;
+	info.len = size;
 
 	return load_module(&info, uargs, flags);
 }
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index 6528a79d9..64b9dead4 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -11,10 +11,17 @@
 
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/string.h>
 #include <keys/system_keyring.h>
 #include <crypto/public_key.h>
 #include "module-internal.h"
 
+enum pkey_id_type {
+	PKEY_ID_PGP,		/* OpenPGP generated key ID */
+	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
+	PKEY_ID_PKCS7,		/* Signature in PKCS#7 message */
+};
+
 /*
  * Module signature information block.
  *
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 49746c81a..782102e59 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -25,6 +25,7 @@
 #include <linux/proc_ns.h>
 #include <linux/file.h>
 #include <linux/syscalls.h>
+#include <linux/cgroup.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -39,6 +40,9 @@ struct nsproxy init_nsproxy = {
 #ifdef CONFIG_NET
 	.net_ns			= &init_net,
 #endif
+#ifdef CONFIG_CGROUPS
+	.cgroup_ns		= &init_cgroup_ns,
+#endif
 };
 
 static inline struct nsproxy *create_nsproxy(void)
@@ -92,6 +96,13 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
 		goto out_pid;
 	}
 
+	new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns,
+					    tsk->nsproxy->cgroup_ns);
+	if (IS_ERR(new_nsp->cgroup_ns)) {
+		err = PTR_ERR(new_nsp->cgroup_ns);
+		goto out_cgroup;
+	}
+
 	new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
 	if (IS_ERR(new_nsp->net_ns)) {
 		err = PTR_ERR(new_nsp->net_ns);
@@ -101,6 +112,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
 	return new_nsp;
 
 out_net:
+	put_cgroup_ns(new_nsp->cgroup_ns);
+out_cgroup:
 	if (new_nsp->pid_ns_for_children)
 		put_pid_ns(new_nsp->pid_ns_for_children);
 out_pid:
@@ -128,7 +141,8 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 	struct nsproxy *new_ns;
 
 	if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
-			      CLONE_NEWPID | CLONE_NEWNET)))) {
+			      CLONE_NEWPID | CLONE_NEWNET |
+			      CLONE_NEWCGROUP)))) {
 		get_nsproxy(old_ns);
 		return 0;
 	}
@@ -165,6 +179,7 @@ void free_nsproxy(struct nsproxy *ns)
 		put_ipc_ns(ns->ipc_ns);
 	if (ns->pid_ns_for_children)
 		put_pid_ns(ns->pid_ns_for_children);
+	put_cgroup_ns(ns->cgroup_ns);
 	put_net(ns->net_ns);
 	kmem_cache_free(nsproxy_cachep, ns);
 }
@@ -180,7 +195,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 	int err = 0;
 
 	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
-			       CLONE_NEWNET | CLONE_NEWPID)))
+			       CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP)))
 		return 0;
 
 	user_ns = new_cred ? new_cred->user_ns : current_user_ns();
diff --git a/kernel/panic.c b/kernel/panic.c
index d96469de7..535c96510 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -24,6 +24,7 @@
 #include <linux/init.h>
 #include <linux/nmi.h>
 #include <linux/console.h>
+#include <linux/bug.h>
 
 #define PANIC_TIMER_STEP 100
 #define PANIC_BLINK_SPD 18
@@ -72,6 +73,26 @@ void __weak nmi_panic_self_stop(struct pt_regs *regs)
 
 atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
 
+/*
+ * A variant of panic() called from NMI context. We return if we've already
+ * panicked on this CPU. If another CPU already panicked, loop in
+ * nmi_panic_self_stop() which can provide architecture dependent code such
+ * as saving register state for crash dump.
+ */
+void nmi_panic(struct pt_regs *regs, const char *msg)
+{
+	int old_cpu, cpu;
+
+	cpu = raw_smp_processor_id();
+	old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
+
+	if (old_cpu == PANIC_CPU_INVALID)
+		panic("%s", msg);
+	else if (old_cpu != cpu)
+		nmi_panic_self_stop(regs);
+}
+EXPORT_SYMBOL(nmi_panic);
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -449,20 +470,25 @@ void oops_exit(void)
 	kmsg_dump(KMSG_DUMP_OOPS);
 }
 
-#ifdef WANT_WARN_ON_SLOWPATH
-struct slowpath_args {
+struct warn_args {
 	const char *fmt;
 	va_list args;
 };
 
-static void warn_slowpath_common(const char *file, int line, void *caller,
-				 unsigned taint, struct slowpath_args *args)
+void __warn(const char *file, int line, void *caller, unsigned taint,
+	    struct pt_regs *regs, struct warn_args *args)
 {
 	disable_trace_on_warning();
 
 	pr_warn("------------[ cut here ]------------\n");
-	pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS()\n",
-		raw_smp_processor_id(), current->pid, file, line, caller);
+
+	if (file)
+		pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
+			raw_smp_processor_id(), current->pid, file, line,
+			caller);
+	else
+		pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
+			raw_smp_processor_id(), current->pid, caller);
 
 	if (args)
 		vprintk(args->fmt, args->args);
@@ -479,20 +505,27 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
 	}
 
 	print_modules();
-	dump_stack();
+
+	if (regs)
+		show_regs(regs);
+	else
+		dump_stack();
+
 	print_oops_end_marker();
+
 	/* Just a warning, don't kill lockdep. */
 	add_taint(taint, LOCKDEP_STILL_OK);
 }
 
+#ifdef WANT_WARN_ON_SLOWPATH
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
 {
-	struct slowpath_args args;
+	struct warn_args args;
 
 	args.fmt = fmt;
 	va_start(args.args, fmt);
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     TAINT_WARN, &args);
+	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL,
+	       &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
@@ -500,20 +533,18 @@ EXPORT_SYMBOL(warn_slowpath_fmt);
 void warn_slowpath_fmt_taint(const char *file, int line,
 			     unsigned taint, const char *fmt, ...)
 {
-	struct slowpath_args args;
+	struct warn_args args;
 
 	args.fmt = fmt;
 	va_start(args.args, fmt);
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     taint, &args);
+	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt_taint);
 
 void warn_slowpath_null(const char *file, int line)
 {
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     TAINT_WARN, NULL);
+	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
 }
 EXPORT_SYMBOL(warn_slowpath_null);
 #endif
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index ba2dda520..31b665ba1 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1171,6 +1171,22 @@ static int __init kaslr_nohibernate_setup(char *str)
 	return nohibernate_setup(str);
 }
 
+static int __init page_poison_nohibernate_setup(char *str)
+{
+#ifdef CONFIG_PAGE_POISONING_ZERO
+	/*
+	 * The zeroing option for page poison skips the checks on alloc.
+	 * since hibernation doesn't save free pages there's no way to
+	 * guarantee the pages will still be zeroed.
+	 */
+	if (!strcmp(str, "on")) {
+		pr_info("Disabling hibernation due to page poisoning\n");
+		return nohibernate_setup(str);
+	}
+#endif
+	return 1;
+}
+
 __setup("noresume", noresume_setup);
 __setup("resume_offset=", resume_offset_setup);
 __setup("resume=", resume_setup);
@@ -1179,3 +1195,4 @@ __setup("resumewait", resumewait_setup);
 __setup("resumedelay=", resumedelay_setup);
 __setup("nohibernate", nohibernate_setup);
 __setup("kaslr", kaslr_nohibernate_setup);
+__setup("page_poison=", page_poison_nohibernate_setup);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 564f786df..df058bed5 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -30,13 +30,12 @@ static int try_to_freeze_tasks(bool user_only)
 	unsigned long end_time;
 	unsigned int todo;
 	bool wq_busy = false;
-	struct timeval start, end;
-	u64 elapsed_msecs64;
+	ktime_t start, end, elapsed;
 	unsigned int elapsed_msecs;
 	bool wakeup = false;
 	int sleep_usecs = USEC_PER_MSEC;
 
-	do_gettimeofday(&start);
+	start = ktime_get_boottime();
 
 	end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
 
@@ -78,10 +77,9 @@ static int try_to_freeze_tasks(bool user_only)
 			sleep_usecs *= 2;
 	}
 
-	do_gettimeofday(&end);
-	elapsed_msecs64 = timeval_to_ns(&end) - timeval_to_ns(&start);
-	do_div(elapsed_msecs64, NSEC_PER_MSEC);
-	elapsed_msecs = elapsed_msecs64;
+	end = ktime_get_boottime();
+	elapsed = ktime_sub(end, start);
+	elapsed_msecs = ktime_to_ms(elapsed);
 
 	if (todo) {
 		pr_cont("\n");
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index f9fe133c1..5b70d64b8 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -248,7 +248,7 @@ static int suspend_test(int level)
 {
 #ifdef CONFIG_PM_DEBUG
 	if (pm_test_level == level) {
-		printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
+		pr_info("suspend debug: Waiting for %d second(s).\n",
 				pm_test_delay);
 		mdelay(pm_test_delay * 1000);
 		return 1;
@@ -320,7 +320,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_late(PMSG_SUSPEND);
 	if (error) {
-		printk(KERN_ERR "PM: late suspend of devices failed\n");
+		pr_err("PM: late suspend of devices failed\n");
 		goto Platform_finish;
 	}
 	error = platform_suspend_prepare_late(state);
@@ -329,7 +329,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
-		printk(KERN_ERR "PM: noirq suspend of devices failed\n");
+		pr_err("PM: noirq suspend of devices failed\n");
 		goto Platform_early_resume;
 	}
 	error = platform_suspend_prepare_noirq(state);
@@ -473,8 +473,7 @@ static int enter_state(suspend_state_t state)
 	if (state == PM_SUSPEND_FREEZE) {
 #ifdef CONFIG_PM_DEBUG
 		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
-			pr_warning("PM: Unsupported test mode for suspend to idle,"
-				   "please choose none/freezer/devices/platform.\n");
+			pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
 			return -EAGAIN;
 		}
 #endif
diff --git a/kernel/power/tuxonice_highlevel.c b/kernel/power/tuxonice_highlevel.c
index 1ef1f22b7..13bb93811 100644
--- a/kernel/power/tuxonice_highlevel.c
+++ b/kernel/power/tuxonice_highlevel.c
@@ -161,7 +161,6 @@ void toi_finish_anything(int hibernate_or_resume)
                 toi_alloc_print_debug_stats();
                 atomic_inc(&snapshot_device_available);
                 unlock_system_sleep();
-                release_super_lock();
         }
 
         set_fs(oldfs);
@@ -186,7 +185,6 @@ int toi_start_anything(int hibernate_or_resume)
         toi_trace_index = 0;
 
         if (hibernate_or_resume) {
-            take_super_lock();
             lock_system_sleep();
 
                 if (!atomic_add_unless(&snapshot_device_available, -1, 0))
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 464c10ac4..637070dc5 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -382,16 +382,20 @@ static int logbuf_has_space(u32 msg_size, bool empty)
 
 static int log_make_free_space(u32 msg_size)
 {
-	while (log_first_seq < log_next_seq) {
-		if (logbuf_has_space(msg_size, false))
-			return 0;
+	while (log_first_seq < log_next_seq &&
+	       !logbuf_has_space(msg_size, false)) {
 		/* drop old messages until we have enough contiguous space */
 		log_first_idx = log_next(log_first_idx);
 		log_first_seq++;
 	}
 
+	if (clear_seq < log_first_seq) {
+		clear_seq = log_first_seq;
+		clear_idx = log_first_idx;
+	}
+
 	/* sequence numbers are equal, so the log buffer is empty */
-	if (logbuf_has_space(msg_size, true))
+	if (logbuf_has_space(msg_size, log_first_seq == log_next_seq))
 		return 0;
 
 	return -ENOMEM;
@@ -869,6 +873,7 @@ void log_buf_kexec_setup(void)
 	VMCOREINFO_SYMBOL(log_buf);
 	VMCOREINFO_SYMBOL(log_buf_len);
 	VMCOREINFO_SYMBOL(log_first_idx);
+	VMCOREINFO_SYMBOL(clear_idx);
 	VMCOREINFO_SYMBOL(log_next_idx);
 	/*
 	 * Export struct printk_log size and field offsets. User space tools can
@@ -1231,12 +1236,6 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u32 idx;
 		enum log_flags prev;
 
-		if (clear_seq < log_first_seq) {
-			/* messages are gone, move to first available one */
-			clear_seq = log_first_seq;
-			clear_idx = log_first_idx;
-		}
-
 		/*
 		 * Find first record that fits, including all following records,
 		 * into the user-provided buffer for this dump.
@@ -1498,58 +1497,6 @@ static void zap_locks(void)
 	sema_init(&console_sem, 1);
 }
 
-/*
- * Check if we have any console that is capable of printing while cpu is
- * booting or shutting down. Requires console_sem.
- */
-static int have_callable_console(void)
-{
-	struct console *con;
-
-	for_each_console(con)
-		if (con->flags & CON_ANYTIME)
-			return 1;
-
-	return 0;
-}
-
-/*
- * Can we actually use the console at this time on this cpu?
- *
- * Console drivers may assume that per-cpu resources have been allocated. So
- * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't
- * call them until this CPU is officially up.
- */
-static inline int can_use_console(unsigned int cpu)
-{
-	return cpu_online(cpu) || have_callable_console();
-}
-
-/*
- * Try to get console ownership to actually show the kernel
- * messages from a 'printk'. Return true (and with the
- * console_lock held, and 'console_locked' set) if it
- * is successful, false otherwise.
- */
-static int console_trylock_for_printk(void)
-{
-	unsigned int cpu = smp_processor_id();
-
-	if (!console_trylock())
-		return 0;
-	/*
-	 * If we can't use the console, we need to release the console
-	 * semaphore by hand to avoid flushing the buffer. We need to hold the
-	 * console semaphore in order to do this test safely.
-	 */
-	if (!can_use_console(cpu)) {
-		console_locked = 0;
-		up_console_sem();
-		return 0;
-	}
-	return 1;
-}
-
 int printk_delay_msec __read_mostly;
 
 static inline void printk_delay(void)
@@ -1696,7 +1643,6 @@ asmlinkage int vprintk_emit(int facility, int level,
 	boot_delay_msec(level);
 	printk_delay();
 
-	/* This stops the holder of console_sem just where we want him */
 	local_irq_save(flags);
 	this_cpu = smp_processor_id();
 
@@ -1720,6 +1666,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	}
 
 	lockdep_off();
+	/* This stops the holder of console_sem just where we want him */
 	raw_spin_lock(&logbuf_lock);
 	logbuf_cpu = this_cpu;
 
@@ -1825,20 +1772,12 @@ asmlinkage int vprintk_emit(int facility, int level,
 	if (!in_sched) {
 		lockdep_off();
 		/*
-		 * Disable preemption to avoid being preempted while holding
-		 * console_sem which would prevent anyone from printing to
-		 * console
-		 */
-		preempt_disable();
-
-		/*
 		 * Try to acquire and then immediately release the console
 		 * semaphore.  The release will print out buffers and wake up
 		 * /dev/kmsg and syslog() users.
 		 */
-		if (console_trylock_for_printk())
+		if (console_trylock())
 			console_unlock();
-		preempt_enable();
 		lockdep_on();
 	}
 
@@ -2189,7 +2128,20 @@ int console_trylock(void)
 		return 0;
 	}
 	console_locked = 1;
-	console_may_schedule = 0;
+	/*
+	 * When PREEMPT_COUNT disabled we can't reliably detect if it's
+	 * safe to schedule (e.g. calling printk while holding a spin_lock),
+	 * because preempt_disable()/preempt_enable() are just barriers there
+	 * and preempt_count() is always 0.
+	 *
+	 * RCU read sections have a separate preemption counter when
+	 * PREEMPT_RCU enabled thus we must take extra care and check
+	 * rcu_preempt_depth(), otherwise RCU read sections modify
+	 * preempt_count().
+	 */
+	console_may_schedule = !oops_in_progress &&
+			preemptible() &&
+			!rcu_preempt_depth();
 	return 1;
 }
 EXPORT_SYMBOL(console_trylock);
@@ -2199,6 +2151,34 @@ int is_console_locked(void)
 	return console_locked;
 }
 
+/*
+ * Check if we have any console that is capable of printing while cpu is
+ * booting or shutting down. Requires console_sem.
+ */
+static int have_callable_console(void)
+{
+	struct console *con;
+
+	for_each_console(con)
+		if ((con->flags & CON_ENABLED) &&
+				(con->flags & CON_ANYTIME))
+			return 1;
+
+	return 0;
+}
+
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have been allocated. So
+ * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't
+ * call them until this CPU is officially up.
+ */
+static inline int can_use_console(void)
+{
+	return cpu_online(raw_smp_processor_id()) || have_callable_console();
+}
+
 static void console_cont_flush(char *text, size_t size)
 {
 	unsigned long flags;
@@ -2269,9 +2249,21 @@ void console_unlock(void)
 	do_cond_resched = console_may_schedule;
 	console_may_schedule = 0;
 
+again:
+	/*
+	 * We released the console_sem lock, so we need to recheck if
+	 * cpu is online and (if not) is there at least one CON_ANYTIME
+	 * console.
+	 */
+	if (!can_use_console()) {
+		console_locked = 0;
+		up_console_sem();
+		return;
+	}
+
 	/* flush buffered message fragment immediately to console */
 	console_cont_flush(text, sizeof(text));
-again:
+
 	for (;;) {
 		struct printk_log *msg;
 		size_t ext_len = 0;
diff --git a/kernel/profile.c b/kernel/profile.c
index 513696974..c2199e990 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -44,7 +44,7 @@ int prof_on __read_mostly;
 EXPORT_SYMBOL_GPL(prof_on);
 
 static cpumask_var_t prof_cpu_mask;
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
 static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
 static DEFINE_PER_CPU(int, cpu_profile_flip);
 static DEFINE_MUTEX(profile_flip_mutex);
@@ -202,7 +202,7 @@ int profile_event_unregister(enum profile_type type, struct notifier_block *n)
 }
 EXPORT_SYMBOL_GPL(profile_event_unregister);
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
 /*
  * Each cpu has a pair of open-addressed hashtables for pending
  * profile hits. read_profile() IPI's all cpus to request them
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 2341efe7f..d49bfa1e5 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -73,12 +73,11 @@ void __ptrace_unlink(struct task_struct *child)
 {
 	BUG_ON(!child->ptrace);
 
-	child->ptrace = 0;
 	child->parent = child->real_parent;
 	list_del_init(&child->ptrace_entry);
 
 	spin_lock(&child->sighand->siglock);
-
+	child->ptrace = 0;
 	/*
 	 * Clear all pending traps and TRAPPING.  TRAPPING should be
 	 * cleared regardless of JOBCTL_STOP_PENDING.  Do it explicitly.
@@ -681,7 +680,7 @@ static int ptrace_peek_siginfo(struct task_struct *child,
 			break;
 
 #ifdef CONFIG_COMPAT
-		if (unlikely(is_compat_task())) {
+		if (unlikely(in_compat_syscall())) {
 			compat_siginfo_t __user *uinfo = compat_ptr(data);
 
 			if (copy_siginfo_to_user32(uinfo, &info) ||
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
index 61a16569f..032b2c015 100644
--- a/kernel/rcu/Makefile
+++ b/kernel/rcu/Makefile
@@ -1,3 +1,7 @@
+# Any varying coverage in these files is non-deterministic
+# and is generally not a function of system call inputs.
+KCOV_INSTRUMENT := n
+
 obj-y += update.o sync.o
 obj-$(CONFIG_SRCU) += srcu.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d2988d047..250ea67c1 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -130,10 +130,8 @@ static struct rcu_torture __rcu *rcu_torture_current;
 static unsigned long rcu_torture_current_version;
 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
 static DEFINE_SPINLOCK(rcu_torture_lock);
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
-		      rcu_torture_count) = { 0 };
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
-		      rcu_torture_batch) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = { 0 };
 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
 static atomic_t n_rcu_torture_alloc;
 static atomic_t n_rcu_torture_alloc_fail;
@@ -932,12 +930,14 @@ rcu_torture_writer(void *arg)
 	int nsynctypes = 0;
 
 	VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
-	pr_alert("%s" TORTURE_FLAG
-		 " Grace periods expedited from boot/sysfs for %s,\n",
-		 torture_type, cur_ops->name);
-	pr_alert("%s" TORTURE_FLAG
-		 " Testing of dynamic grace-period expediting diabled.\n",
-		 torture_type);
+	if (!can_expedite) {
+		pr_alert("%s" TORTURE_FLAG
+			 " Grace periods expedited from boot/sysfs for %s,\n",
+			 torture_type, cur_ops->name);
+		pr_alert("%s" TORTURE_FLAG
+			 " Disabled dynamic grace-period expediting.\n",
+			 torture_type);
+	}
 
 	/* Initialize synctype[] array.  If none set, take default. */
 	if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
diff --git a/kernel/rcu/tiny_plugin.h b/kernel/rcu/tiny_plugin.h
index e492a5253..196f0302e 100644
--- a/kernel/rcu/tiny_plugin.h
+++ b/kernel/rcu/tiny_plugin.h
@@ -23,7 +23,7 @@
  */
 
 #include <linux/kthread.h>
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 
@@ -122,18 +122,7 @@ free_out:
 	debugfs_remove_recursive(rcudir);
 	return 1;
 }
-
-static void __exit rcutiny_trace_cleanup(void)
-{
-	debugfs_remove_recursive(rcudir);
-}
-
-module_init(rcutiny_trace_init);
-module_exit(rcutiny_trace_cleanup);
-
-MODULE_AUTHOR("Paul E. McKenney");
-MODULE_DESCRIPTION("Read-Copy Update tracing for tiny implementation");
-MODULE_LICENSE("GPL");
+device_initcall(rcutiny_trace_init);
 
 static void check_cpu_stall(struct rcu_ctrlblk *rcp)
 {
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9fd5b628a..9a535a86e 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -108,7 +108,6 @@ RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
 RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
 
 static struct rcu_state *const rcu_state_p;
-static struct rcu_data __percpu *const rcu_data_p;
 LIST_HEAD(rcu_struct_flavors);
 
 /* Dump rcu_node combining tree at boot to verify correct setup. */
@@ -1083,13 +1082,12 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp,
 	rcu_sysidle_check_cpu(rdp, isidle, maxj);
 	if ((rdp->dynticks_snap & 0x1) == 0) {
 		trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
-		return 1;
-	} else {
 		if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4,
 				 rdp->mynode->gpnum))
 			WRITE_ONCE(rdp->gpwrap, true);
-		return 0;
+		return 1;
 	}
+	return 0;
 }
 
 /*
@@ -1173,15 +1171,16 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
 			smp_mb(); /* ->cond_resched_completed before *rcrmp. */
 			WRITE_ONCE(*rcrmp,
 				   READ_ONCE(*rcrmp) + rdp->rsp->flavor_mask);
-			resched_cpu(rdp->cpu);  /* Force CPU into scheduler. */
-			rdp->rsp->jiffies_resched += 5; /* Enable beating. */
-		} else if (ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
-			/* Time to beat on that CPU again! */
-			resched_cpu(rdp->cpu);  /* Force CPU into scheduler. */
-			rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
 		}
+		rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
 	}
 
+	/* And if it has been a really long time, kick the CPU as well. */
+	if (ULONG_CMP_GE(jiffies,
+			 rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) ||
+	    ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs))
+		resched_cpu(rdp->cpu);  /* Force CPU into scheduler. */
+
 	return 0;
 }
 
@@ -1246,7 +1245,7 @@ static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
 				if (rnp->qsmask & (1UL << cpu))
 					dump_cpu_task(rnp->grplo + cpu);
 		}
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
 }
 
@@ -1266,12 +1265,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	delta = jiffies - READ_ONCE(rsp->jiffies_stall);
 	if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;
 	}
 	WRITE_ONCE(rsp->jiffies_stall,
 		   jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 	/*
 	 * OK, time to rat on our buddy...
@@ -1292,7 +1291,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
 					ndetected++;
 				}
 		}
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
 
 	print_cpu_stall_info_end();
@@ -1357,7 +1356,7 @@ static void print_cpu_stall(struct rcu_state *rsp)
 	if (ULONG_CMP_GE(jiffies, READ_ONCE(rsp->jiffies_stall)))
 		WRITE_ONCE(rsp->jiffies_stall,
 			   jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 	/*
 	 * Attempt to revive the RCU machinery by forcing a context switch.
@@ -1595,7 +1594,7 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp,
 	}
 unlock_out:
 	if (rnp != rnp_root)
-		raw_spin_unlock(&rnp_root->lock);
+		raw_spin_unlock_rcu_node(rnp_root);
 out:
 	if (c_out != NULL)
 		*c_out = c;
@@ -1814,7 +1813,7 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
 		return;
 	}
 	needwake = __note_gp_changes(rsp, rnp, rdp);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	if (needwake)
 		rcu_gp_kthread_wake(rsp);
 }
@@ -1839,7 +1838,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 	raw_spin_lock_irq_rcu_node(rnp);
 	if (!READ_ONCE(rsp->gp_flags)) {
 		/* Spurious wakeup, tell caller to go back to sleep.  */
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 		return false;
 	}
 	WRITE_ONCE(rsp->gp_flags, 0); /* Clear all flags: New grace period. */
@@ -1849,7 +1848,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 		 * Grace period already in progress, don't start another.
 		 * Not supposed to be able to happen.
 		 */
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 		return false;
 	}
 
@@ -1858,7 +1857,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 	/* Record GP times before starting GP, hence smp_store_release(). */
 	smp_store_release(&rsp->gpnum, rsp->gpnum + 1);
 	trace_rcu_grace_period(rsp->name, rsp->gpnum, TPS("start"));
-	raw_spin_unlock_irq(&rnp->lock);
+	raw_spin_unlock_irq_rcu_node(rnp);
 
 	/*
 	 * Apply per-leaf buffered online and offline operations to the
@@ -1872,7 +1871,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 		if (rnp->qsmaskinit == rnp->qsmaskinitnext &&
 		    !rnp->wait_blkd_tasks) {
 			/* Nothing to do on this leaf rcu_node structure. */
-			raw_spin_unlock_irq(&rnp->lock);
+			raw_spin_unlock_irq_rcu_node(rnp);
 			continue;
 		}
 
@@ -1906,7 +1905,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 			rcu_cleanup_dead_rnp(rnp);
 		}
 
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 	}
 
 	/*
@@ -1937,7 +1936,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
 		trace_rcu_grace_period_init(rsp->name, rnp->gpnum,
 					    rnp->level, rnp->grplo,
 					    rnp->grphi, rnp->qsmask);
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 		cond_resched_rcu_qs();
 		WRITE_ONCE(rsp->gp_activity, jiffies);
 	}
@@ -1995,7 +1994,7 @@ static void rcu_gp_fqs(struct rcu_state *rsp, bool first_time)
 		raw_spin_lock_irq_rcu_node(rnp);
 		WRITE_ONCE(rsp->gp_flags,
 			   READ_ONCE(rsp->gp_flags) & ~RCU_GP_FLAG_FQS);
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 	}
 }
 
@@ -2025,7 +2024,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
 	 * safe for us to drop the lock in order to mark the grace
 	 * period as completed in all of the rcu_node structures.
 	 */
-	raw_spin_unlock_irq(&rnp->lock);
+	raw_spin_unlock_irq_rcu_node(rnp);
 
 	/*
 	 * Propagate new ->completed value to rcu_node structures so
@@ -2047,7 +2046,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
 		/* smp_mb() provided by prior unlock-lock pair. */
 		nocb += rcu_future_gp_cleanup(rsp, rnp);
 		sq = rcu_nocb_gp_get(rnp);
-		raw_spin_unlock_irq(&rnp->lock);
+		raw_spin_unlock_irq_rcu_node(rnp);
 		rcu_nocb_gp_cleanup(sq);
 		cond_resched_rcu_qs();
 		WRITE_ONCE(rsp->gp_activity, jiffies);
@@ -2070,7 +2069,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
 				       READ_ONCE(rsp->gpnum),
 				       TPS("newreq"));
 	}
-	raw_spin_unlock_irq(&rnp->lock);
+	raw_spin_unlock_irq_rcu_node(rnp);
 }
 
 /*
@@ -2236,18 +2235,20 @@ static bool rcu_start_gp(struct rcu_state *rsp)
 }
 
 /*
- * Report a full set of quiescent states to the specified rcu_state
- * data structure.  This involves cleaning up after the prior grace
- * period and letting rcu_start_gp() start up the next grace period
- * if one is needed.  Note that the caller must hold rnp->lock, which
- * is released before return.
+ * Report a full set of quiescent states to the specified rcu_state data
+ * structure.  Invoke rcu_gp_kthread_wake() to awaken the grace-period
+ * kthread if another grace period is required.  Whether we wake
+ * the grace-period kthread or it awakens itself for the next round
+ * of quiescent-state forcing, that kthread will clean up after the
+ * just-completed grace period.  Note that the caller must hold rnp->lock,
+ * which is released before return.
  */
 static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
 	__releases(rcu_get_root(rsp)->lock)
 {
 	WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
 	WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
-	raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags);
 	swake_up(&rsp->gp_wq);  /* Memory barrier implied by swake_up() path. */
 }
 
@@ -2277,7 +2278,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
 			 * Our bit has already been cleared, or the
 			 * relevant grace period is already over, so done.
 			 */
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			return;
 		}
 		WARN_ON_ONCE(oldmask); /* Any child must be all zeroed! */
@@ -2289,7 +2290,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
 		if (rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) {
 
 			/* Other bits still set at this level, so done. */
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			return;
 		}
 		mask = rnp->grpmask;
@@ -2299,7 +2300,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
 
 			break;
 		}
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		rnp_c = rnp;
 		rnp = rnp->parent;
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
@@ -2331,7 +2332,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp,
 
 	if (rcu_state_p == &rcu_sched_state || rsp != rcu_state_p ||
 	    rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;  /* Still need more quiescent states! */
 	}
 
@@ -2348,19 +2349,14 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp,
 	/* Report up the rest of the hierarchy, tracking current ->gpnum. */
 	gps = rnp->gpnum;
 	mask = rnp->grpmask;
-	raw_spin_unlock(&rnp->lock);	/* irqs remain disabled. */
+	raw_spin_unlock_rcu_node(rnp);	/* irqs remain disabled. */
 	raw_spin_lock_rcu_node(rnp_p);	/* irqs already disabled. */
 	rcu_report_qs_rnp(mask, rsp, rnp_p, gps, flags);
 }
 
 /*
  * Record a quiescent state for the specified CPU to that CPU's rcu_data
- * structure.  This must be either called from the specified CPU, or
- * called when the specified CPU is known to be offline (and when it is
- * also known that no other CPU is concurrently trying to help the offline
- * CPU).  The lastcomp argument is used to make sure we are still in the
- * grace period of interest.  We don't want to end the current grace period
- * based on quiescent states detected in an earlier grace period!
+ * structure.  This must be called from the specified CPU.
  */
 static void
 rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
@@ -2385,14 +2381,14 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
 		 */
 		rdp->cpu_no_qs.b.norm = true;	/* need qs for new gp. */
 		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;
 	}
 	mask = rdp->grpmask;
 	if ((rnp->qsmask & mask) == 0) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	} else {
-		rdp->core_needs_qs = 0;
+		rdp->core_needs_qs = false;
 
 		/*
 		 * This GP can't end until cpu checks in, so all of our
@@ -2601,36 +2597,15 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf)
 		rnp->qsmaskinit &= ~mask;
 		rnp->qsmask &= ~mask;
 		if (rnp->qsmaskinit) {
-			raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+			raw_spin_unlock_rcu_node(rnp);
+			/* irqs remain disabled. */
 			return;
 		}
-		raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+		raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
 	}
 }
 
 /*
- * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
- * function.  We now remove it from the rcu_node tree's ->qsmaskinit
- * bit masks.
- */
-static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
-{
-	unsigned long flags;
-	unsigned long mask;
-	struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
-	struct rcu_node *rnp = rdp->mynode;  /* Outgoing CPU's rdp & rnp. */
-
-	if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
-		return;
-
-	/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
-	mask = rdp->grpmask;
-	raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
-	rnp->qsmaskinitnext &= ~mask;
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
-}
-
-/*
  * The CPU has been completely removed, and some other CPU is reporting
  * this fact from process context.  Do the remainder of the cleanup,
  * including orphaning the outgoing CPU's RCU callbacks, and also
@@ -2861,7 +2836,7 @@ static void force_qs_rnp(struct rcu_state *rsp,
 			rcu_report_qs_rnp(mask, rsp, rnp, rnp->gpnum, flags);
 		} else {
 			/* Nothing to do here, so just drop the lock. */
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		}
 	}
 }
@@ -2897,11 +2872,11 @@ static void force_quiescent_state(struct rcu_state *rsp)
 	raw_spin_unlock(&rnp_old->fqslock);
 	if (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
 		rsp->n_force_qs_lh++;
-		raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
 		return;  /* Someone beat us to it. */
 	}
 	WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
-	raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
 	swake_up(&rsp->gp_wq); /* Memory barrier implied by swake_up() path. */
 }
 
@@ -2927,7 +2902,7 @@ __rcu_process_callbacks(struct rcu_state *rsp)
 	if (cpu_needs_another_gp(rsp, rdp)) {
 		raw_spin_lock_rcu_node(rcu_get_root(rsp)); /* irqs disabled. */
 		needwake = rcu_start_gp(rsp);
-		raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags);
 		if (needwake)
 			rcu_gp_kthread_wake(rsp);
 	} else {
@@ -3018,7 +2993,7 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
 
 			raw_spin_lock_rcu_node(rnp_root);
 			needwake = rcu_start_gp(rsp);
-			raw_spin_unlock(&rnp_root->lock);
+			raw_spin_unlock_rcu_node(rnp_root);
 			if (needwake)
 				rcu_gp_kthread_wake(rsp);
 		} else {
@@ -3438,14 +3413,14 @@ static void sync_exp_reset_tree_hotplug(struct rcu_state *rsp)
 	rcu_for_each_leaf_node(rsp, rnp) {
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 		if (rnp->expmaskinit == rnp->expmaskinitnext) {
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			continue;  /* No new CPUs, nothing to do. */
 		}
 
 		/* Update this node's mask, track old value for propagation. */
 		oldmask = rnp->expmaskinit;
 		rnp->expmaskinit = rnp->expmaskinitnext;
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 		/* If was already nonzero, nothing to propagate. */
 		if (oldmask)
@@ -3460,7 +3435,7 @@ static void sync_exp_reset_tree_hotplug(struct rcu_state *rsp)
 			if (rnp_up->expmaskinit)
 				done = true;
 			rnp_up->expmaskinit |= mask;
-			raw_spin_unlock_irqrestore(&rnp_up->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp_up, flags);
 			if (done)
 				break;
 			mask = rnp_up->grpmask;
@@ -3483,7 +3458,7 @@ static void __maybe_unused sync_exp_reset_tree(struct rcu_state *rsp)
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 		WARN_ON_ONCE(rnp->expmask);
 		rnp->expmask = rnp->expmaskinit;
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
 }
 
@@ -3524,11 +3499,11 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
 			if (!rnp->expmask)
 				rcu_initiate_boost(rnp, flags);
 			else
-				raw_spin_unlock_irqrestore(&rnp->lock, flags);
+				raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			break;
 		}
 		if (rnp->parent == NULL) {
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			if (wake) {
 				smp_mb(); /* EGP done before wake_up(). */
 				swake_up(&rsp->expedited_wq);
@@ -3536,7 +3511,7 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
 			break;
 		}
 		mask = rnp->grpmask;
-		raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
+		raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled */
 		rnp = rnp->parent;
 		raw_spin_lock_rcu_node(rnp); /* irqs already disabled */
 		WARN_ON_ONCE(!(rnp->expmask & mask));
@@ -3571,7 +3546,7 @@ static void rcu_report_exp_cpu_mult(struct rcu_state *rsp, struct rcu_node *rnp,
 
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	if (!(rnp->expmask & mask)) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;
 	}
 	rnp->expmask &= ~mask;
@@ -3732,7 +3707,7 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
 		 */
 		if (rcu_preempt_has_tasks(rnp))
 			rnp->exp_tasks = rnp->blkd_tasks.next;
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 		/* IPI the remaining CPUs for expedited quiescent state. */
 		mask = 1;
@@ -3749,7 +3724,7 @@ retry_ipi:
 			raw_spin_lock_irqsave_rcu_node(rnp, flags);
 			if (cpu_online(cpu) &&
 			    (rnp->expmask & mask)) {
-				raw_spin_unlock_irqrestore(&rnp->lock, flags);
+				raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 				schedule_timeout_uninterruptible(1);
 				if (cpu_online(cpu) &&
 				    (rnp->expmask & mask))
@@ -3758,7 +3733,7 @@ retry_ipi:
 			}
 			if (!(rnp->expmask & mask))
 				mask_ofl_ipi &= ~mask;
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		}
 		/* Report quiescent states for those that went offline. */
 		mask_ofl_test |= mask_ofl_ipi;
@@ -4165,7 +4140,7 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
 			return;
 		raw_spin_lock_rcu_node(rnp); /* Interrupts already disabled. */
 		rnp->qsmaskinit |= mask;
-		raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */
+		raw_spin_unlock_rcu_node(rnp); /* Interrupts remain disabled. */
 	}
 }
 
@@ -4189,7 +4164,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->rsp = rsp;
 	mutex_init(&rdp->exp_funnel_mutex);
 	rcu_boot_init_nocb_percpu_data(rdp);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
 /*
@@ -4217,7 +4192,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rcu_sysidle_init_percpu_data(rdp->dynticks);
 	atomic_set(&rdp->dynticks->dynticks,
 		   (atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1);
-	raw_spin_unlock(&rnp->lock);		/* irqs remain disabled. */
+	raw_spin_unlock_rcu_node(rnp);		/* irqs remain disabled. */
 
 	/*
 	 * Add CPU to leaf rcu_node pending-online bitmask.  Any needed
@@ -4238,7 +4213,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu);
 	rdp->core_needs_qs = false;
 	trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
 static void rcu_prepare_cpu(int cpu)
@@ -4249,6 +4224,46 @@ static void rcu_prepare_cpu(int cpu)
 		rcu_init_percpu_data(cpu, rsp);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
+ * function.  We now remove it from the rcu_node tree's ->qsmaskinit
+ * bit masks.
+ * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
+ * function.  We now remove it from the rcu_node tree's ->qsmaskinit
+ * bit masks.
+ */
+static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
+{
+	unsigned long flags;
+	unsigned long mask;
+	struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
+	struct rcu_node *rnp = rdp->mynode;  /* Outgoing CPU's rdp & rnp. */
+
+	if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
+		return;
+
+	/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
+	mask = rdp->grpmask;
+	raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
+	rnp->qsmaskinitnext &= ~mask;
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+}
+
+void rcu_report_dead(unsigned int cpu)
+{
+	struct rcu_state *rsp;
+
+	/* QS for any half-done expedited RCU-sched GP. */
+	preempt_disable();
+	rcu_report_exp_rdp(&rcu_sched_state,
+			   this_cpu_ptr(rcu_sched_state.rda), true);
+	preempt_enable();
+	for_each_rcu_flavor(rsp)
+		rcu_cleanup_dying_idle_cpu(cpu, rsp);
+}
+#endif
+
 /*
  * Handle CPU online/offline notification events.
  */
@@ -4280,17 +4295,6 @@ int rcu_cpu_notify(struct notifier_block *self,
 		for_each_rcu_flavor(rsp)
 			rcu_cleanup_dying_cpu(rsp);
 		break;
-	case CPU_DYING_IDLE:
-		/* QS for any half-done expedited RCU-sched GP. */
-		preempt_disable();
-		rcu_report_exp_rdp(&rcu_sched_state,
-				   this_cpu_ptr(rcu_sched_state.rda), true);
-		preempt_enable();
-
-		for_each_rcu_flavor(rsp) {
-			rcu_cleanup_dying_idle_cpu(cpu, rsp);
-		}
-		break;
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
 	case CPU_UP_CANCELED:
@@ -4360,7 +4364,7 @@ static int __init rcu_spawn_gp_kthread(void)
 			sp.sched_priority = kthread_prio;
 			sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
 		}
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		wake_up_process(t);
 	}
 	rcu_spawn_nocb_kthreads();
@@ -4451,8 +4455,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
 		cpustride *= levelspread[i];
 		rnp = rsp->level[i];
 		for (j = 0; j < levelcnt[i]; j++, rnp++) {
-			raw_spin_lock_init(&rnp->lock);
-			lockdep_set_class_and_name(&rnp->lock,
+			raw_spin_lock_init(&ACCESS_PRIVATE(rnp, lock));
+			lockdep_set_class_and_name(&ACCESS_PRIVATE(rnp, lock),
 						   &rcu_node_class[i], buf[i]);
 			raw_spin_lock_init(&rnp->fqslock);
 			lockdep_set_class_and_name(&rnp->fqslock,
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index bbd235d0e..df668c0f9 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -150,8 +150,9 @@ struct rcu_dynticks {
  * Definition for node within the RCU grace-period-detection hierarchy.
  */
 struct rcu_node {
-	raw_spinlock_t lock;	/* Root rcu_node's lock protects some */
-				/*  rcu_state fields as well as following. */
+	raw_spinlock_t __private lock;	/* Root rcu_node's lock protects */
+					/*  some rcu_state fields as well as */
+					/*  following. */
 	unsigned long gpnum;	/* Current grace period for this node. */
 				/*  This will either be equal to or one */
 				/*  behind the root rcu_node's gpnum. */
@@ -682,7 +683,7 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
 #endif /* #else #ifdef CONFIG_PPC */
 
 /*
- * Wrappers for the rcu_node::lock acquire.
+ * Wrappers for the rcu_node::lock acquire and release.
  *
  * Because the rcu_nodes form a tree, the tree traversal locking will observe
  * different lock values, this in turn means that an UNLOCK of one level
@@ -691,29 +692,48 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
  *
  * In order to restore full ordering between tree levels, augment the regular
  * lock acquire functions with smp_mb__after_unlock_lock().
+ *
+ * As ->lock of struct rcu_node is a __private field, therefore one should use
+ * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock.
  */
 static inline void raw_spin_lock_rcu_node(struct rcu_node *rnp)
 {
-	raw_spin_lock(&rnp->lock);
+	raw_spin_lock(&ACCESS_PRIVATE(rnp, lock));
 	smp_mb__after_unlock_lock();
 }
 
+static inline void raw_spin_unlock_rcu_node(struct rcu_node *rnp)
+{
+	raw_spin_unlock(&ACCESS_PRIVATE(rnp, lock));
+}
+
 static inline void raw_spin_lock_irq_rcu_node(struct rcu_node *rnp)
 {
-	raw_spin_lock_irq(&rnp->lock);
+	raw_spin_lock_irq(&ACCESS_PRIVATE(rnp, lock));
 	smp_mb__after_unlock_lock();
 }
 
-#define raw_spin_lock_irqsave_rcu_node(rnp, flags)	\
-do {							\
-	typecheck(unsigned long, flags);		\
-	raw_spin_lock_irqsave(&(rnp)->lock, flags);	\
-	smp_mb__after_unlock_lock();			\
+static inline void raw_spin_unlock_irq_rcu_node(struct rcu_node *rnp)
+{
+	raw_spin_unlock_irq(&ACCESS_PRIVATE(rnp, lock));
+}
+
+#define raw_spin_lock_irqsave_rcu_node(rnp, flags)			\
+do {									\
+	typecheck(unsigned long, flags);				\
+	raw_spin_lock_irqsave(&ACCESS_PRIVATE(rnp, lock), flags);	\
+	smp_mb__after_unlock_lock();					\
+} while (0)
+
+#define raw_spin_unlock_irqrestore_rcu_node(rnp, flags)			\
+do {									\
+	typecheck(unsigned long, flags);				\
+	raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(rnp, lock), flags);	\
 } while (0)
 
 static inline bool raw_spin_trylock_rcu_node(struct rcu_node *rnp)
 {
-	bool locked = raw_spin_trylock(&rnp->lock);
+	bool locked = raw_spin_trylock(&ACCESS_PRIVATE(rnp, lock));
 
 	if (locked)
 		smp_mb__after_unlock_lock();
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 080bd202d..efdf7b61c 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -235,7 +235,7 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
 		rnp->gp_tasks = &t->rcu_node_entry;
 	if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD))
 		rnp->exp_tasks = &t->rcu_node_entry;
-	raw_spin_unlock(&rnp->lock); /* rrupts remain disabled. */
+	raw_spin_unlock_rcu_node(rnp); /* interrupts remain disabled. */
 
 	/*
 	 * Report the quiescent state for the expedited GP.  This expedited
@@ -489,7 +489,7 @@ void rcu_read_unlock_special(struct task_struct *t)
 							 !!rnp->gp_tasks);
 			rcu_report_unblock_qs_rnp(rcu_state_p, rnp, flags);
 		} else {
-			raw_spin_unlock_irqrestore(&rnp->lock, flags);
+			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		}
 
 		/* Unboost if we were boosted. */
@@ -518,14 +518,14 @@ static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
 
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	if (!rcu_preempt_blocked_readers_cgp(rnp)) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;
 	}
 	t = list_entry(rnp->gp_tasks->prev,
 		       struct task_struct, rcu_node_entry);
 	list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry)
 		sched_show_task(t);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
 /*
@@ -807,7 +807,6 @@ void exit_rcu(void)
 #else /* #ifdef CONFIG_PREEMPT_RCU */
 
 static struct rcu_state *const rcu_state_p = &rcu_sched_state;
-static struct rcu_data __percpu *const rcu_data_p = &rcu_sched_data;
 
 /*
  * Tell them what RCU they are running.
@@ -991,7 +990,7 @@ static int rcu_boost(struct rcu_node *rnp)
 	 * might exit their RCU read-side critical sections on their own.
 	 */
 	if (rnp->exp_tasks == NULL && rnp->boost_tasks == NULL) {
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return 0;
 	}
 
@@ -1028,7 +1027,7 @@ static int rcu_boost(struct rcu_node *rnp)
 	 */
 	t = container_of(tb, struct task_struct, rcu_node_entry);
 	rt_mutex_init_proxy_locked(&rnp->boost_mtx, t);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	/* Lock only for side effect: boosts task t's priority. */
 	rt_mutex_lock(&rnp->boost_mtx);
 	rt_mutex_unlock(&rnp->boost_mtx);  /* Then keep lockdep happy. */
@@ -1088,7 +1087,7 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
 
 	if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) {
 		rnp->n_balk_exp_gp_tasks++;
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return;
 	}
 	if (rnp->exp_tasks != NULL ||
@@ -1098,13 +1097,13 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
 	     ULONG_CMP_GE(jiffies, rnp->boost_time))) {
 		if (rnp->exp_tasks == NULL)
 			rnp->boost_tasks = rnp->gp_tasks;
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		t = rnp->boost_kthread_task;
 		if (t)
 			rcu_wake_cond(t, rnp->boost_kthread_status);
 	} else {
 		rcu_initiate_boost_trace(rnp);
-		raw_spin_unlock_irqrestore(&rnp->lock, flags);
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
 }
 
@@ -1172,7 +1171,7 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 		return PTR_ERR(t);
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	rnp->boost_kthread_task = t;
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	sp.sched_priority = kthread_prio;
 	sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
 	wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
@@ -1308,7 +1307,7 @@ static void rcu_prepare_kthreads(int cpu)
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
 	__releases(rnp->lock)
 {
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
 static void invoke_rcu_callbacks_kthread(void)
@@ -1559,7 +1558,7 @@ static void rcu_prepare_for_idle(void)
 		rnp = rdp->mynode;
 		raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */
 		needwake = rcu_accelerate_cbs(rsp, rnp, rdp);
-		raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+		raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
 		if (needwake)
 			rcu_gp_kthread_wake(rsp);
 	}
@@ -2064,7 +2063,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
 
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	needwake = rcu_start_future_gp(rnp, rdp, &c);
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	if (needwake)
 		rcu_gp_kthread_wake(rdp->rsp);
 
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 76b94e194..ca828b41c 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -128,6 +128,7 @@ bool rcu_gp_is_normal(void)
 {
 	return READ_ONCE(rcu_normal);
 }
+EXPORT_SYMBOL_GPL(rcu_gp_is_normal);
 
 static atomic_t rcu_expedited_nesting =
 	ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0);
diff --git a/kernel/resource.c b/kernel/resource.c
index 3669d1bfc..9b5f04404 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -105,16 +105,25 @@ static int r_show(struct seq_file *m, void *v)
 {
 	struct resource *root = m->private;
 	struct resource *r = v, *p;
+	unsigned long long start, end;
 	int width = root->end < 0x10000 ? 4 : 8;
 	int depth;
 
 	for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
 		if (p->parent == root)
 			break;
+
+	if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
+		start = r->start;
+		end = r->end;
+	} else {
+		start = end = 0;
+	}
+
 	seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
 			depth * 2, "",
-			width, (unsigned long long) r->start,
-			width, (unsigned long long) r->end,
+			width, start,
+			width, end,
 			r->name ? r->name : "<BAD>");
 	return 0;
 }
@@ -233,9 +242,9 @@ static struct resource * __request_resource(struct resource *root, struct resour
 	}
 }
 
-static int __release_resource(struct resource *old)
+static int __release_resource(struct resource *old, bool release_child)
 {
-	struct resource *tmp, **p;
+	struct resource *tmp, **p, *chd;
 
 	p = &old->parent->child;
 	for (;;) {
@@ -243,7 +252,17 @@ static int __release_resource(struct resource *old)
 		if (!tmp)
 			break;
 		if (tmp == old) {
-			*p = tmp->sibling;
+			if (release_child || !(tmp->child)) {
+				*p = tmp->sibling;
+			} else {
+				for (chd = tmp->child;; chd = chd->sibling) {
+					chd->parent = tmp->parent;
+					if (!(chd->sibling))
+						break;
+				}
+				*p = tmp->child;
+				chd->sibling = tmp->sibling;
+			}
 			old->parent = NULL;
 			return 0;
 		}
@@ -325,7 +344,7 @@ int release_resource(struct resource *old)
 	int retval;
 
 	write_lock(&resource_lock);
-	retval = __release_resource(old);
+	retval = __release_resource(old, true);
 	write_unlock(&resource_lock);
 	return retval;
 }
@@ -333,13 +352,13 @@ int release_resource(struct resource *old)
 EXPORT_SYMBOL(release_resource);
 
 /*
- * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
- * the caller must specify res->start, res->end, res->flags and "name".
- * If found, returns 0, res is overwritten, if not found, returns -1.
- * This walks through whole tree and not just first level children
- * until and unless first_level_children_only is true.
+ * Finds the lowest iomem resource existing within [res->start.res->end).
+ * The caller must specify res->start, res->end, res->flags, and optionally
+ * desc.  If found, returns 0, res is overwritten, if not found, returns -1.
+ * This function walks the whole tree and not just first level children until
+ * and unless first_level_children_only is true.
  */
-static int find_next_iomem_res(struct resource *res, char *name,
+static int find_next_iomem_res(struct resource *res, unsigned long desc,
 			       bool first_level_children_only)
 {
 	resource_size_t start, end;
@@ -358,9 +377,9 @@ static int find_next_iomem_res(struct resource *res, char *name,
 	read_lock(&resource_lock);
 
 	for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
-		if (p->flags != res->flags)
+		if ((p->flags & res->flags) != res->flags)
 			continue;
-		if (name && strcmp(p->name, name))
+		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
 			continue;
 		if (p->start > end) {
 			p = NULL;
@@ -385,15 +404,18 @@ static int find_next_iomem_res(struct resource *res, char *name,
  * Walks through iomem resources and calls func() with matching resource
  * ranges. This walks through whole tree and not just first level children.
  * All the memory ranges which overlap start,end and also match flags and
- * name are valid candidates.
+ * desc are valid candidates.
  *
- * @name: name of resource
- * @flags: resource flags
+ * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
+ * @flags: I/O resource flags
  * @start: start addr
  * @end: end addr
+ *
+ * NOTE: For a new descriptor search, define a new IORES_DESC in
+ * <linux/ioport.h> and set it in 'desc' of a target resource entry.
  */
-int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
-		void *arg, int (*func)(u64, u64, void *))
+int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
+		u64 end, void *arg, int (*func)(u64, u64, void *))
 {
 	struct resource res;
 	u64 orig_end;
@@ -403,23 +425,27 @@ int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
 	res.end = end;
 	res.flags = flags;
 	orig_end = res.end;
+
 	while ((res.start < res.end) &&
-		(!find_next_iomem_res(&res, name, false))) {
+		(!find_next_iomem_res(&res, desc, false))) {
+
 		ret = (*func)(res.start, res.end, arg);
 		if (ret)
 			break;
+
 		res.start = res.end + 1;
 		res.end = orig_end;
 	}
+
 	return ret;
 }
 
 /*
- * This function calls callback against all memory range of "System RAM"
- * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
- * Now, this function is only for "System RAM". This function deals with
- * full ranges and not pfn. If resources are not pfn aligned, dealing
- * with pfn can truncate ranges.
+ * This function calls the @func callback against all memory ranges of type
+ * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
+ * Now, this function is only for System RAM, it deals with full ranges and
+ * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
+ * ranges.
  */
 int walk_system_ram_res(u64 start, u64 end, void *arg,
 				int (*func)(u64, u64, void *))
@@ -430,10 +456,10 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
 
 	res.start = start;
 	res.end = end;
-	res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 	orig_end = res.end;
 	while ((res.start < res.end) &&
-		(!find_next_iomem_res(&res, "System RAM", true))) {
+		(!find_next_iomem_res(&res, IORES_DESC_NONE, true))) {
 		ret = (*func)(res.start, res.end, arg);
 		if (ret)
 			break;
@@ -446,9 +472,9 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 
 /*
- * This function calls callback against all memory range of "System RAM"
- * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
- * Now, this function is only for "System RAM".
+ * This function calls the @func callback against all memory ranges of type
+ * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
+ * It is to be used only for System RAM.
  */
 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 		void *arg, int (*func)(unsigned long, unsigned long, void *))
@@ -460,10 +486,10 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 
 	res.start = (u64) start_pfn << PAGE_SHIFT;
 	res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
-	res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 	orig_end = res.end;
 	while ((res.start < res.end) &&
-		(find_next_iomem_res(&res, "System RAM", true) >= 0)) {
+		(find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
 		pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 		end_pfn = (res.end + 1) >> PAGE_SHIFT;
 		if (end_pfn > pfn)
@@ -484,7 +510,7 @@ static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 }
 /*
  * This generic page_is_ram() returns true if specified address is
- * registered as "System RAM" in iomem_resource list.
+ * registered as System RAM in iomem_resource list.
  */
 int __weak page_is_ram(unsigned long pfn)
 {
@@ -496,30 +522,34 @@ EXPORT_SYMBOL_GPL(page_is_ram);
  * region_intersects() - determine intersection of region with known resources
  * @start: region start address
  * @size: size of region
- * @name: name of resource (in iomem_resource)
+ * @flags: flags of resource (in iomem_resource)
+ * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
  *
  * Check if the specified region partially overlaps or fully eclipses a
- * resource identified by @name.  Return REGION_DISJOINT if the region
- * does not overlap @name, return REGION_MIXED if the region overlaps
- * @type and another resource, and return REGION_INTERSECTS if the
- * region overlaps @type and no other defined resource. Note, that
- * REGION_INTERSECTS is also returned in the case when the specified
- * region overlaps RAM and undefined memory holes.
+ * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
+ * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
+ * return REGION_MIXED if the region overlaps @flags/@desc and another
+ * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
+ * and no other defined resource. Note that REGION_INTERSECTS is also
+ * returned in the case when the specified region overlaps RAM and undefined
+ * memory holes.
  *
  * region_intersect() is used by memory remapping functions to ensure
  * the user is not remapping RAM and is a vast speed up over walking
  * through the resource table page by page.
  */
-int region_intersects(resource_size_t start, size_t size, const char *name)
+int region_intersects(resource_size_t start, size_t size, unsigned long flags,
+		      unsigned long desc)
 {
-	unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 	resource_size_t end = start + size - 1;
 	int type = 0; int other = 0;
 	struct resource *p;
 
 	read_lock(&resource_lock);
 	for (p = iomem_resource.child; p ; p = p->sibling) {
-		bool is_type = strcmp(p->name, name) == 0 && p->flags == flags;
+		bool is_type = (((p->flags & flags) == flags) &&
+				((desc == IORES_DESC_NONE) ||
+				 (desc == p->desc)));
 
 		if (start >= p->start && start <= p->end)
 			is_type ? type++ : other++;
@@ -538,6 +568,7 @@ int region_intersects(resource_size_t start, size_t size, const char *name)
 
 	return REGION_DISJOINT;
 }
+EXPORT_SYMBOL_GPL(region_intersects);
 
 void __weak arch_remove_reservations(struct resource *avail)
 {
@@ -667,7 +698,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
 		old->start = new.start;
 		old->end = new.end;
 	} else {
-		__release_resource(old);
+		__release_resource(old, true);
 		*old = new;
 		conflict = __request_resource(root, old);
 		BUG_ON(conflict);
@@ -813,6 +844,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
  * entirely fit within the range of the new resource, then the new
  * resource is inserted and the conflicting resources become children of
  * the new resource.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
  */
 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 {
@@ -830,6 +864,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour
  * @new: new resource to insert
  *
  * Returns 0 on success, -EBUSY if the resource can't be inserted.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
  */
 int insert_resource(struct resource *parent, struct resource *new)
 {
@@ -838,6 +875,7 @@ int insert_resource(struct resource *parent, struct resource *new)
 	conflict = insert_resource_conflict(parent, new);
 	return conflict ? -EBUSY : 0;
 }
+EXPORT_SYMBOL_GPL(insert_resource);
 
 /**
  * insert_resource_expand_to_fit - Insert a resource into the resource tree
@@ -873,6 +911,32 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 	write_unlock(&resource_lock);
 }
 
+/**
+ * remove_resource - Remove a resource in the resource tree
+ * @old: resource to remove
+ *
+ * Returns 0 on success, -EINVAL if the resource is not valid.
+ *
+ * This function removes a resource previously inserted by insert_resource()
+ * or insert_resource_conflict(), and moves the children (if any) up to
+ * where they were before.  insert_resource() and insert_resource_conflict()
+ * insert a new resource, and move any conflicting resources down to the
+ * children of the new resource.
+ *
+ * insert_resource(), insert_resource_conflict() and remove_resource() are
+ * intended for producers of resources, such as FW modules and bus drivers.
+ */
+int remove_resource(struct resource *old)
+{
+	int retval;
+
+	write_lock(&resource_lock);
+	retval = __release_resource(old, false);
+	write_unlock(&resource_lock);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(remove_resource);
+
 static int __adjust_resource(struct resource *res, resource_size_t start,
 				resource_size_t size)
 {
@@ -948,6 +1012,7 @@ static void __init __reserve_region_with_split(struct resource *root,
 	res->start = start;
 	res->end = end;
 	res->flags = IORESOURCE_BUSY;
+	res->desc = IORES_DESC_NONE;
 
 	while (1) {
 
@@ -982,6 +1047,7 @@ static void __init __reserve_region_with_split(struct resource *root,
 				next_res->start = conflict->end + 1;
 				next_res->end = end;
 				next_res->flags = IORESOURCE_BUSY;
+				next_res->desc = IORES_DESC_NONE;
 			}
 		} else {
 			res->start = conflict->end + 1;
@@ -1071,14 +1137,16 @@ struct resource * __request_region(struct resource *parent,
 	res->name = name;
 	res->start = start;
 	res->end = start + n - 1;
-	res->flags = resource_type(parent);
-	res->flags |= IORESOURCE_BUSY | flags;
 
 	write_lock(&resource_lock);
 
 	for (;;) {
 		struct resource *conflict;
 
+		res->flags = resource_type(parent) | resource_ext_type(parent);
+		res->flags |= IORESOURCE_BUSY | flags;
+		res->desc = parent->desc;
+
 		conflict = __request_resource(parent, res);
 		if (!conflict)
 			break;
@@ -1238,6 +1306,7 @@ int release_mem_region_adjustable(struct resource *parent,
 			new_res->start = end + 1;
 			new_res->end = res->end;
 			new_res->flags = res->flags;
+			new_res->desc = res->desc;
 			new_res->parent = res->parent;
 			new_res->sibling = res->sibling;
 			new_res->child = NULL;
@@ -1413,6 +1482,7 @@ static int __init reserve_setup(char *str)
 			res->start = io_start;
 			res->end = io_start + io_num - 1;
 			res->flags = IORESOURCE_BUSY;
+			res->desc = IORES_DESC_NONE;
 			res->child = NULL;
 			if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
 				reserved = x+1;
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 15e398808..97b0aaece 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -2,6 +2,10 @@ ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE)
 endif
 
+# These files are disabled because they produce non-interesting flaky coverage
+# that is not a function of syscall inputs. E.g. involuntary context switches.
+KCOV_INSTRUMENT := n
+
 ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
 # needed for x86 only.  Why this used to be enabled for all architectures is beyond
@@ -24,3 +28,4 @@ endif
 obj-y += wait.o swait.o completion.o idle.o
 obj-$(CONFIG_SMP) += cpupri.o
 obj-$(CONFIG_SCHEDSTATS) += stats.o
+obj-$(CONFIG_CPU_FREQ) += cpufreq.o
diff --git a/kernel/sched/bfs.c b/kernel/sched/bfs.c
index 698007a9f..280a75479 100644
--- a/kernel/sched/bfs.c
+++ b/kernel/sched/bfs.c
@@ -136,7 +136,7 @@
 
 void print_scheduler_version(void)
 {
-	printk(KERN_INFO "BFS CPU scheduler v0.469 by Con Kolivas.\n");
+	printk(KERN_INFO "BFS CPU scheduler v0.470 by Con Kolivas.\n");
 }
 
 /*
@@ -978,6 +978,7 @@ static void activate_task(struct task_struct *p, struct rq *rq)
 	p->on_rq = 1;
 	grq.nr_running++;
 	inc_qnr();
+	cpufreq_trigger(grq.niffies);
 }
 
 static inline void clear_sticky(struct task_struct *p);
@@ -994,6 +995,7 @@ static inline void deactivate_task(struct task_struct *p, struct rq *rq)
 	p->on_rq = 0;
 	grq.nr_running--;
 	clear_sticky(p);
+	cpufreq_trigger(grq.niffies);
 }
 
 #ifdef CONFIG_SMP
@@ -1593,7 +1595,8 @@ out_running:
 out_unlock:
 	task_grq_unlock(&flags);
 
-	ttwu_stat(p, cpu, wake_flags);
+	if (schedstat_enabled())
+		ttwu_stat(p, cpu, wake_flags);
 
 	put_cpu();
 
@@ -1626,7 +1629,8 @@ static void try_to_wake_up_local(struct task_struct *p)
 			schedstat_inc(rq, ttwu_local);
 		}
 		ttwu_activate(p, rq, false);
-		ttwu_stat(p, smp_processor_id(), 0);
+		if (schedstat_enabled())
+			ttwu_stat(p, smp_processor_id(), 0);
 		success = true;
 	}
 	ttwu_post_activation(p, rq, success);
@@ -1715,6 +1719,69 @@ int sched_fork(unsigned long __maybe_unused clone_flags, struct task_struct *p)
 	return 0;
 }
 
+DEFINE_STATIC_KEY_FALSE(sched_schedstats);
+
+#ifdef CONFIG_SCHEDSTATS
+static void set_schedstats(bool enabled)
+{
+	if (enabled)
+		static_branch_enable(&sched_schedstats);
+	else
+		static_branch_disable(&sched_schedstats);
+}
+
+void force_schedstat_enabled(void)
+{
+	if (!schedstat_enabled()) {
+		pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n");
+		static_branch_enable(&sched_schedstats);
+	}
+}
+
+static int __init setup_schedstats(char *str)
+{
+	int ret = 0;
+	if (!str)
+		goto out;
+
+	if (!strcmp(str, "enable")) {
+		set_schedstats(true);
+		ret = 1;
+	} else if (!strcmp(str, "disable")) {
+		set_schedstats(false);
+		ret = 1;
+	}
+out:
+	if (!ret)
+		pr_warn("Unable to parse schedstats=\n");
+
+	return ret;
+}
+__setup("schedstats=", setup_schedstats);
+
+#ifdef CONFIG_PROC_SYSCTL
+int sysctl_schedstats(struct ctl_table *table, int write,
+			 void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table t;
+	int err;
+	int state = static_branch_likely(&sched_schedstats);
+
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	t = *table;
+	t.data = &state;
+	err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
+	if (err < 0)
+		return err;
+	if (write)
+		set_schedstats(state);
+	return err;
+}
+#endif
+#endif
+
 /*
  * wake_up_new_task - wake up a newly created task for the first time.
  *
@@ -2007,7 +2074,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev)
 /*
  * context_switch - switch to the new MM and the new thread's register state.
  */
-static inline struct rq *
+static __always_inline struct rq *
 context_switch(struct rq *rq, struct task_struct *prev,
 	       struct task_struct *next)
 {
@@ -2980,16 +3047,6 @@ void scheduler_tick(void)
 	perf_event_task_tick();
 }
 
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
-	if (in_lock_functions(addr)) {
-		addr = CALLER_ADDR2;
-		if (in_lock_functions(addr))
-			addr = CALLER_ADDR3;
-	}
-	return addr;
-}
-
 #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
 				defined(CONFIG_PREEMPT_TRACER))
 void preempt_count_add(int val)
@@ -3010,7 +3067,7 @@ void preempt_count_add(int val)
 				PREEMPT_MASK - 10);
 #endif
 	if (preempt_count() == val) {
-		unsigned long ip = get_parent_ip(CALLER_ADDR1);
+		unsigned long ip = get_lock_parent_ip();
 #ifdef CONFIG_DEBUG_PREEMPT
 		current->preempt_disable_ip = ip;
 #endif
@@ -3037,7 +3094,7 @@ void preempt_count_sub(int val)
 #endif
 
 	if (preempt_count() == val)
-		trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+		trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
 	__preempt_count_sub(val);
 }
 EXPORT_SYMBOL(preempt_count_sub);
@@ -3484,7 +3541,7 @@ static void __sched notrace __schedule(bool preempt)
 			if (prev->flags & PF_WQ_WORKER) {
 				struct task_struct *to_wakeup;
 
-				to_wakeup = wq_worker_sleeping(prev, cpu);
+				to_wakeup = wq_worker_sleeping(prev);
 				if (to_wakeup) {
 					/* This shouldn't happen, but does */
 					if (unlikely(to_wakeup == prev))
@@ -5543,7 +5600,6 @@ void sched_set_stop_task(int cpu, struct task_struct *stop)
 	}
 }
 
-
 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
 
 static struct ctl_table sd_ctl_dir[] = {
@@ -5592,16 +5648,26 @@ static void sd_free_ctl_entry(struct ctl_table **tablep)
 	*tablep = NULL;
 }
 
+#define CPU_LOAD_IDX_MAX 5
+static int min_load_idx = 0;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
+
 static void
 set_table_entry(struct ctl_table *entry,
 		const char *procname, void *data, int maxlen,
-		mode_t mode, proc_handler *proc_handler)
+		umode_t mode, proc_handler *proc_handler,
+		bool load_idx)
 {
 	entry->procname = procname;
 	entry->data = data;
 	entry->maxlen = maxlen;
 	entry->mode = mode;
 	entry->proc_handler = proc_handler;
+
+	if (load_idx) {
+		entry->extra1 = &min_load_idx;
+		entry->extra2 = &max_load_idx;
+	}
 }
 
 static struct ctl_table *
@@ -5613,33 +5679,33 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
 		return NULL;
 
 	set_table_entry(&table[0], "min_interval", &sd->min_interval,
-		sizeof(long), 0644, proc_doulongvec_minmax);
+		sizeof(long), 0644, proc_doulongvec_minmax, false);
 	set_table_entry(&table[1], "max_interval", &sd->max_interval,
-		sizeof(long), 0644, proc_doulongvec_minmax);
+		sizeof(long), 0644, proc_doulongvec_minmax, false);
 	set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, true);
 	set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, true);
 	set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, true);
 	set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, true);
 	set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, true);
 	set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, false);
 	set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, false);
 	set_table_entry(&table[9], "cache_nice_tries",
 		&sd->cache_nice_tries,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, false);
 	set_table_entry(&table[10], "flags", &sd->flags,
-		sizeof(int), 0644, proc_dointvec_minmax);
+		sizeof(int), 0644, proc_dointvec_minmax, false);
 	set_table_entry(&table[11], "max_newidle_lb_cost",
 		&sd->max_newidle_lb_cost,
-		sizeof(long), 0644, proc_doulongvec_minmax);
+		sizeof(long), 0644, proc_doulongvec_minmax, false);
 	set_table_entry(&table[12], "name", sd->name,
-		CORENAME_MAX_SIZE, 0444, proc_dostring);
+		CORENAME_MAX_SIZE, 0444, proc_dostring, false);
 	/* &table[13] is terminator */
 
 	return table;
@@ -5671,7 +5737,7 @@ static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
 }
 
 static struct ctl_table_header *sd_sysctl_header;
-static void register_sched_domain_sysctl(void)
+void register_sched_domain_sysctl(void)
 {
 	int i, cpu_num = num_possible_cpus();
 	struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
@@ -5696,21 +5762,14 @@ static void register_sched_domain_sysctl(void)
 }
 
 /* may be called multiple times per register */
-static void unregister_sched_domain_sysctl(void)
+void unregister_sched_domain_sysctl(void)
 {
 	unregister_sysctl_table(sd_sysctl_header);
 	sd_sysctl_header = NULL;
 	if (sd_ctl_dir[0].child)
 		sd_free_ctl_entry(&sd_ctl_dir[0].child);
 }
-#else /* CONFIG_SCHED_DEBUG && CONFIG_SYSCTL */
-static void register_sched_domain_sysctl(void)
-{
-}
-static void unregister_sched_domain_sysctl(void)
-{
-}
-#endif /* CONFIG_SCHED_DEBUG && CONFIG_SYSCTL */
+#endif /* CONFIG_SYSCTL */
 
 static void set_rq_online(struct rq *rq)
 {
@@ -5802,15 +5861,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_STARTING:
 		return NOTIFY_OK;
-	case CPU_ONLINE:
-		/*
-		 * At this point a starting CPU has marked itself as online via
-		 * set_cpu_online(). But it might not yet have marked itself
-		 * as active, which is essential from here on.
-		 */
-		set_cpu_active(cpu, true);
-		stop_machine_unpark(cpu);
-		return NOTIFY_OK;
 
 	case CPU_DOWN_FAILED:
 		set_cpu_active(cpu, true);
@@ -6130,8 +6180,14 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 /* Setup the mask of cpus configured for isolated domains */
 static int __init isolated_cpu_setup(char *str)
 {
+	int ret;
+
 	alloc_bootmem_cpumask_var(&cpu_isolated_map);
-	cpulist_parse(str, cpu_isolated_map);
+	ret = cpulist_parse(str, cpu_isolated_map);
+	if (ret) {
+		pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids);
+		return 0;
+	}
 	return 1;
 }
 
diff --git a/kernel/sched/bfs_sched.h b/kernel/sched/bfs_sched.h
index 5d97f7919..95bf4dc9e 100644
--- a/kernel/sched/bfs_sched.h
+++ b/kernel/sched/bfs_sched.h
@@ -127,6 +127,7 @@ static inline u64 rq_clock_task(struct rq *rq)
 }
 
 extern struct mutex sched_domains_mutex;
+extern struct static_key_false sched_schedstats;
 
 #define rcu_dereference_check_sched_domain(p) \
 	rcu_dereference_check((p), \
@@ -142,6 +143,18 @@ extern struct mutex sched_domains_mutex;
 #define for_each_domain(cpu, __sd) \
 	for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
 
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
+void register_sched_domain_sysctl(void);
+void unregister_sched_domain_sysctl(void);
+#else
+static inline void register_sched_domain_sysctl(void)
+{
+}
+static inline void unregister_sched_domain_sysctl(void)
+{
+}
+#endif
+
 static inline void sched_ttwu_pending(void) { }
 
 static inline int task_on_rq_queued(struct task_struct *p)
@@ -178,4 +191,21 @@ static inline struct cpuidle_state *idle_get_state(struct rq *rq)
 	return NULL;
 }
 #endif
+
+#ifdef CONFIG_CPU_FREQ
+DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+static inline void cpufreq_trigger(u64 time)
+{
+       struct update_util_data *data;
+
+       data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
+       if (data)
+               data->func(data, time, ULONG_MAX, 0);
+}
+#else
+static inline void cpufreq_trigger(u64 __maybe_unused time)
+{
+}
+#endif /* CONFIG_CPU_FREQ */
 #endif /* BFS_SCHED_H */
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index bc54e8467..fedb967a9 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -61,6 +61,7 @@
 #include <linux/static_key.h>
 #include <linux/workqueue.h>
 #include <linux/compiler.h>
+#include <linux/tick.h>
 
 /*
  * Scheduler clock - returns current time in nanosec units.
@@ -89,6 +90,8 @@ static void __set_sched_clock_stable(void)
 {
 	if (!sched_clock_stable())
 		static_key_slow_inc(&__sched_clock_stable);
+
+	tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE);
 }
 
 void set_sched_clock_stable(void)
@@ -108,6 +111,8 @@ static void __clear_sched_clock_stable(struct work_struct *work)
 	/* XXX worry about clock continuity */
 	if (sched_clock_stable())
 		static_key_slow_dec(&__sched_clock_stable);
+
+	tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE);
 }
 
 static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5699f2dd2..d1f7149f8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -73,6 +73,7 @@
 #include <linux/init_task.h>
 #include <linux/context_tracking.h>
 #include <linux/compiler.h>
+#include <linux/frame.h>
 
 #include <asm/switch_to.h>
 #include <asm/tlb.h>
@@ -323,15 +324,19 @@ static inline void init_hrtick(void)
 /*
  * cmpxchg based fetch_or, macro so it works for different integer types
  */
-#define fetch_or(ptr, val)						\
-({	typeof(*(ptr)) __old, __val = *(ptr);				\
- 	for (;;) {							\
- 		__old = cmpxchg((ptr), __val, __val | (val));		\
- 		if (__old == __val)					\
- 			break;						\
- 		__val = __old;						\
- 	}								\
- 	__old;								\
+#define fetch_or(ptr, mask)						\
+	({								\
+		typeof(ptr) _ptr = (ptr);				\
+		typeof(mask) _mask = (mask);				\
+		typeof(*_ptr) _old, _val = *_ptr;			\
+									\
+		for (;;) {						\
+			_old = cmpxchg(_ptr, _val, _val | _mask);	\
+			if (_old == _val)				\
+				break;					\
+			_val = _old;					\
+		}							\
+	_old;								\
 })
 
 #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
@@ -582,31 +587,39 @@ static inline bool got_nohz_idle_kick(void)
 #endif /* CONFIG_NO_HZ_COMMON */
 
 #ifdef CONFIG_NO_HZ_FULL
-bool sched_can_stop_tick(void)
+bool sched_can_stop_tick(struct rq *rq)
 {
+	int fifo_nr_running;
+
+	/* Deadline tasks, even if single, need the tick */
+	if (rq->dl.dl_nr_running)
+		return false;
+
 	/*
-	 * FIFO realtime policy runs the highest priority task. Other runnable
-	 * tasks are of a lower priority. The scheduler tick does nothing.
+	 * If there are more than one RR tasks, we need the tick to effect the
+	 * actual RR behaviour.
 	 */
-	if (current->policy == SCHED_FIFO)
-		return true;
+	if (rq->rt.rr_nr_running) {
+		if (rq->rt.rr_nr_running == 1)
+			return true;
+		else
+			return false;
+	}
 
 	/*
-	 * Round-robin realtime tasks time slice with other tasks at the same
-	 * realtime priority. Is this task the only one at this priority?
+	 * If there's no RR tasks, but FIFO tasks, we can skip the tick, no
+	 * forced preemption between FIFO tasks.
 	 */
-	if (current->policy == SCHED_RR) {
-		struct sched_rt_entity *rt_se = &current->rt;
-
-		return list_is_singular(&rt_se->run_list);
-	}
+	fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+	if (fifo_nr_running)
+		return true;
 
 	/*
-	 * More than one running task need preemption.
-	 * nr_running update is assumed to be visible
-	 * after IPI is sent from wakers.
+	 * If there are no DL,RR/FIFO tasks, there must only be CFS tasks left;
+	 * if there's more than one we need the tick for involuntary
+	 * preemption.
 	 */
-	if (this_rq()->nr_running > 1)
+	if (rq->nr_running > 1)
 		return false;
 
 	return true;
@@ -2698,7 +2711,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev)
 /*
  * context_switch - switch to the new MM and the new thread's register state.
  */
-static inline struct rq *
+static __always_inline struct rq *
 context_switch(struct rq *rq, struct task_struct *prev,
 	       struct task_struct *next)
 {
@@ -3183,7 +3196,7 @@ static void __sched notrace __schedule(bool preempt)
 			if (prev->flags & PF_WQ_WORKER) {
 				struct task_struct *to_wakeup;
 
-				to_wakeup = wq_worker_sleeping(prev, cpu);
+				to_wakeup = wq_worker_sleeping(prev);
 				if (to_wakeup)
 					try_to_wake_up_local(to_wakeup);
 			}
@@ -3213,6 +3226,7 @@ static void __sched notrace __schedule(bool preempt)
 
 	balance_callback(rq);
 }
+STACK_FRAME_NON_STANDARD(__schedule); /* switch_to() */
 
 static inline void sched_submit_work(struct task_struct *tsk)
 {
@@ -5444,16 +5458,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
 		set_cpu_rq_start_time();
 		return NOTIFY_OK;
 
-	case CPU_ONLINE:
-		/*
-		 * At this point a starting CPU has marked itself as online via
-		 * set_cpu_online(). But it might not yet have marked itself
-		 * as active, which is essential from here on.
-		 */
-		set_cpu_active(cpu, true);
-		stop_machine_unpark(cpu);
-		return NOTIFY_OK;
-
 	case CPU_DOWN_FAILED:
 		set_cpu_active(cpu, true);
 		return NOTIFY_OK;
@@ -8454,7 +8458,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
 	.can_attach	= cpu_cgroup_can_attach,
 	.attach		= cpu_cgroup_attach,
 	.legacy_cftypes	= cpu_files,
-	.early_init	= 1,
+	.early_init	= true,
 };
 
 #endif	/* CONFIG_CGROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dd7cbb55b..4a811203c 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -145,13 +145,16 @@ static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
 }
 
 static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
-			  u64 reset)
+			  u64 val)
 {
 	struct cpuacct *ca = css_ca(css);
 	int err = 0;
 	int i;
 
-	if (reset) {
+	/*
+	 * Only allow '0' here to do a reset.
+	 */
+	if (val) {
 		err = -EINVAL;
 		goto out;
 	}
@@ -235,23 +238,10 @@ static struct cftype files[] = {
 void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 {
 	struct cpuacct *ca;
-	int cpu;
-
-	cpu = task_cpu(tsk);
 
 	rcu_read_lock();
-
-	ca = task_ca(tsk);
-
-	while (true) {
-		u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
-		*cpuusage += cputime;
-
-		ca = parent_ca(ca);
-		if (!ca)
-			break;
-	}
-
+	for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
+		*this_cpu_ptr(ca->cpuusage) += cputime;
 	rcu_read_unlock();
 }
 
@@ -260,18 +250,13 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime)
  *
  * Note: it's the caller that updates the account of the root cgroup.
  */
-void cpuacct_account_field(struct task_struct *p, int index, u64 val)
+void cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
 {
-	struct kernel_cpustat *kcpustat;
 	struct cpuacct *ca;
 
 	rcu_read_lock();
-	ca = task_ca(p);
-	while (ca != &root_cpuacct) {
-		kcpustat = this_cpu_ptr(ca->cpustat);
-		kcpustat->cpustat[index] += val;
-		ca = parent_ca(ca);
-	}
+	for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
+		this_cpu_ptr(ca->cpustat)->cpustat[index] += val;
 	rcu_read_unlock();
 }
 
@@ -279,5 +264,5 @@ struct cgroup_subsys cpuacct_cgrp_subsys = {
 	.css_alloc	= cpuacct_css_alloc,
 	.css_free	= cpuacct_css_free,
 	.legacy_cftypes	= files,
-	.early_init	= 1,
+	.early_init	= true,
 };
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index ed605624a..ba72807c7 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -1,7 +1,7 @@
 #ifdef CONFIG_CGROUP_CPUACCT
 
 extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
-extern void cpuacct_account_field(struct task_struct *p, int index, u64 val);
+extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
 
 #else
 
@@ -10,7 +10,7 @@ static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 }
 
 static inline void
-cpuacct_account_field(struct task_struct *p, int index, u64 val)
+cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
 {
 }
 
diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c
new file mode 100644
index 000000000..7bad2358c
--- /dev/null
+++ b/kernel/sched/cpufreq.c
@@ -0,0 +1,41 @@
+/*
+ * Scheduler code and data structures related to cpufreq.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifdef CONFIG_SCHED_BFS
+#include "bfs_sched.h"
+#else
+#include "sched.h"
+#endif
+
+DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_set_update_util_data - Populate the CPU's update_util_data pointer.
+ * @cpu: The CPU to set the pointer for.
+ * @data: New pointer value.
+ *
+ * Set and publish the update_util_data pointer for the given CPU.  That pointer
+ * points to a struct update_util_data object containing a callback function
+ * to call from cpufreq_update_util().  That function will be called from an RCU
+ * read-side critical section, so it must not sleep.
+ *
+ * Callers must use RCU-sched callbacks to free any memory that might be
+ * accessed via the old update_util_data pointer or invoke synchronize_sched()
+ * right after this function to avoid use-after-free.
+ */
+void cpufreq_set_update_util_data(int cpu, struct update_util_data *data)
+{
+	if (WARN_ON(data && !data->func))
+		return;
+
+	rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
+}
+EXPORT_SYMBOL_GPL(cpufreq_set_update_util_data);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index c7a036fac..686ec8adf 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -717,6 +717,10 @@ static void update_curr_dl(struct rq *rq)
 	if (!dl_task(curr) || !on_dl_rq(dl_se))
 		return;
 
+	/* Kick cpufreq (see the comment in linux/cpufreq.h). */
+	if (cpu_of(rq) == smp_processor_id())
+		cpufreq_trigger_update(rq_clock(rq));
+
 	/*
 	 * Consumed budget is computed considering the time as
 	 * observed by schedulable tasks (excluding time spent
@@ -1390,6 +1394,7 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq)
 				     !cpumask_test_cpu(later_rq->cpu,
 				                       &task->cpus_allowed) ||
 				     task_running(rq, task) ||
+				     !dl_task(task) ||
 				     !task_on_rq_queued(task))) {
 				double_unlock_balance(rq, later_rq);
 				later_rq = NULL;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ac7fb39c3..5518a9621 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2881,7 +2881,8 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
 {
 	struct cfs_rq *cfs_rq = cfs_rq_of(se);
 	u64 now = cfs_rq_clock_task(cfs_rq);
-	int cpu = cpu_of(rq_of(cfs_rq));
+	struct rq *rq = rq_of(cfs_rq);
+	int cpu = cpu_of(rq);
 
 	/*
 	 * Track task load average for carrying it to new CPU after migrated, and
@@ -2893,6 +2894,29 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
 
 	if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
 		update_tg_load_avg(cfs_rq, 0);
+
+	if (cpu == smp_processor_id() && &rq->cfs == cfs_rq) {
+		unsigned long max = rq->cpu_capacity_orig;
+
+		/*
+		 * There are a few boundary cases this might miss but it should
+		 * get called often enough that that should (hopefully) not be
+		 * a real problem -- added to that it only calls on the local
+		 * CPU, so if we enqueue remotely we'll miss an update, but
+		 * the next tick/schedule should update.
+		 *
+		 * It will not get called when we go idle, because the idle
+		 * thread is a different class (!fair), nor will the utilization
+		 * number include things like RT tasks.
+		 *
+		 * As is, the util number is not freq-invariant (we'd have to
+		 * implement arch_scale_freq_capacity() for that).
+		 *
+		 * See cpu_util().
+		 */
+		cpufreq_update_util(rq_clock(rq),
+				    min(cfs_rq->avg.util_avg, max), max);
+	}
 }
 
 static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -3031,7 +3055,14 @@ static int idle_balance(struct rq *this_rq);
 
 #else /* CONFIG_SMP */
 
-static inline void update_load_avg(struct sched_entity *se, int update_tg) {}
+static inline void update_load_avg(struct sched_entity *se, int not_used)
+{
+	struct cfs_rq *cfs_rq = cfs_rq_of(se);
+	struct rq *rq = rq_of(cfs_rq);
+
+	cpufreq_trigger_update(rq_clock(rq));
+}
+
 static inline void
 enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 static inline void
@@ -5072,7 +5103,19 @@ static int select_idle_sibling(struct task_struct *p, int target)
 		return i;
 
 	/*
-	 * Otherwise, iterate the domains and find an elegible idle cpu.
+	 * Otherwise, iterate the domains and find an eligible idle cpu.
+	 *
+	 * A completely idle sched group at higher domains is more
+	 * desirable than an idle group at a lower level, because lower
+	 * domains have smaller groups and usually share hardware
+	 * resources which causes tasks to contend on them, e.g. x86
+	 * hyperthread siblings in the lowest domain (SMT) can contend
+	 * on the shared cpu pipeline.
+	 *
+	 * However, while we prefer idle groups at higher domains
+	 * finding an idle cpu at the lowest domain is still better than
+	 * returning 'target', which we've already established, isn't
+	 * idle.
 	 */
 	sd = rcu_dereference(per_cpu(sd_llc, target));
 	for_each_lower_domain(sd) {
@@ -5082,11 +5125,16 @@ static int select_idle_sibling(struct task_struct *p, int target)
 						tsk_cpus_allowed(p)))
 				goto next;
 
+			/* Ensure the entire group is idle */
 			for_each_cpu(i, sched_group_cpus(sg)) {
 				if (i == target || !idle_cpu(i))
 					goto next;
 			}
 
+			/*
+			 * It doesn't matter which cpu we pick, the
+			 * whole group is idle.
+			 */
 			target = cpumask_first_and(sched_group_cpus(sg),
 					tsk_cpus_allowed(p));
 			goto done;
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index bbf813929..f9d1dbfbe 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -4,6 +4,7 @@
 #include <linux/sched.h>
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
+#include <linux/cpuhotplug.h>
 #include <linux/tick.h>
 #include <linux/mm.h>
 #include <linux/stackprotector.h>
@@ -197,8 +198,6 @@ exit_idle:
 	rcu_idle_exit();
 }
 
-DEFINE_PER_CPU(bool, cpu_dead_idle);
-
 /*
  * Generic idle loop implementation
  *
@@ -225,10 +224,7 @@ static void cpu_idle_loop(void)
 			rmb();
 
 			if (cpu_is_offline(smp_processor_id())) {
-				rcu_cpu_notify(NULL, CPU_DYING_IDLE,
-					       (void *)(long)smp_processor_id());
-				smp_mb(); /* all activity before dead. */
-				this_cpu_write(cpu_dead_idle, true);
+				cpuhp_report_idle_dead();
 				arch_cpu_idle_dead();
 			}
 
@@ -295,5 +291,6 @@ void cpu_startup_entry(enum cpuhp_state state)
 	boot_init_stack_canary();
 #endif
 	arch_cpu_idle_prepare();
+	cpuhp_online_idle(state);
 	cpu_idle_loop();
 }
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index ef7159012..b0b93fd33 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -99,10 +99,13 @@ long calc_load_fold_active(struct rq *this_rq)
 static unsigned long
 calc_load(unsigned long load, unsigned long exp, unsigned long active)
 {
-	load *= exp;
-	load += active * (FIXED_1 - exp);
-	load += 1UL << (FSHIFT - 1);
-	return load >> FSHIFT;
+	unsigned long newload;
+
+	newload = load * exp + active * (FIXED_1 - exp);
+	if (active >= load)
+		newload += FIXED_1-1;
+
+	return newload / FIXED_1;
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a774b4dbf..ec4f538d4 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -953,6 +953,10 @@ static void update_curr_rt(struct rq *rq)
 	if (curr->sched_class != &rt_sched_class)
 		return;
 
+	/* Kick cpufreq (see the comment in linux/cpufreq.h). */
+	if (cpu_of(rq) == smp_processor_id())
+		cpufreq_trigger_update(rq_clock(rq));
+
 	delta_exec = rq_clock_task(rq) - curr->se.exec_start;
 	if (unlikely((s64)delta_exec <= 0))
 		return;
@@ -1150,12 +1154,27 @@ unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
 }
 
 static inline
+unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
+{
+	struct rt_rq *group_rq = group_rt_rq(rt_se);
+	struct task_struct *tsk;
+
+	if (group_rq)
+		return group_rq->rr_nr_running;
+
+	tsk = rt_task_of(rt_se);
+
+	return (tsk->policy == SCHED_RR) ? 1 : 0;
+}
+
+static inline
 void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	int prio = rt_se_prio(rt_se);
 
 	WARN_ON(!rt_prio(prio));
 	rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
+	rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
 
 	inc_rt_prio(rt_rq, prio);
 	inc_rt_migration(rt_se, rt_rq);
@@ -1168,6 +1187,7 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 	WARN_ON(!rt_prio(rt_se_prio(rt_se)));
 	WARN_ON(!rt_rq->rt_nr_running);
 	rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
+	rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
 
 	dec_rt_prio(rt_rq, rt_se_prio(rt_se));
 	dec_rt_migration(rt_se, rt_rq);
@@ -1709,6 +1729,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
 				     !cpumask_test_cpu(lowest_rq->cpu,
 						       tsk_cpus_allowed(task)) ||
 				     task_running(rq, task) ||
+				     !rt_task(task) ||
 				     !task_on_rq_queued(task))) {
 
 				double_unlock_balance(rq, lowest_rq);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 60c5b6ba4..ec2e8d235 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -450,6 +450,7 @@ static inline int rt_bandwidth_enabled(void)
 struct rt_rq {
 	struct rt_prio_array active;
 	unsigned int rt_nr_running;
+	unsigned int rr_nr_running;
 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
 	struct {
 		int curr; /* highest queued rt task prio */
@@ -1313,6 +1314,35 @@ unsigned long to_ratio(u64 period, u64 runtime);
 
 extern void init_entity_runnable_average(struct sched_entity *se);
 
+#ifdef CONFIG_NO_HZ_FULL
+extern bool sched_can_stop_tick(struct rq *rq);
+
+/*
+ * Tick may be needed by tasks in the runqueue depending on their policy and
+ * requirements. If tick is needed, lets send the target an IPI to kick it out of
+ * nohz mode if necessary.
+ */
+static inline void sched_update_tick_dependency(struct rq *rq)
+{
+	int cpu;
+
+	if (!tick_nohz_full_enabled())
+		return;
+
+	cpu = cpu_of(rq);
+
+	if (!tick_nohz_full_cpu(cpu))
+		return;
+
+	if (sched_can_stop_tick(rq))
+		tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
+	else
+		tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
+}
+#else
+static inline void sched_update_tick_dependency(struct rq *rq) { }
+#endif
+
 static inline void add_nr_running(struct rq *rq, unsigned count)
 {
 	unsigned prev_nr = rq->nr_running;
@@ -1324,26 +1354,16 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
 		if (!rq->rd->overload)
 			rq->rd->overload = true;
 #endif
-
-#ifdef CONFIG_NO_HZ_FULL
-		if (tick_nohz_full_cpu(rq->cpu)) {
-			/*
-			 * Tick is needed if more than one task runs on a CPU.
-			 * Send the target an IPI to kick it out of nohz mode.
-			 *
-			 * We assume that IPI implies full memory barrier and the
-			 * new value of rq->nr_running is visible on reception
-			 * from the target.
-			 */
-			tick_nohz_full_kick_cpu(rq->cpu);
-		}
-#endif
 	}
+
+	sched_update_tick_dependency(rq);
 }
 
 static inline void sub_nr_running(struct rq *rq, unsigned count)
 {
 	rq->nr_running -= count;
+	/* Check if we still need preemption */
+	sched_update_tick_dependency(rq);
 }
 
 static inline void rq_last_tick_reset(struct rq *rq)
@@ -1774,6 +1794,54 @@ static inline u64 irq_time_read(int cpu)
 #endif /* CONFIG_64BIT */
 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
 
+#ifdef CONFIG_CPU_FREQ
+DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_update_util - Take a note about CPU utilization changes.
+ * @time: Current time.
+ * @util: Current utilization.
+ * @max: Utilization ceiling.
+ *
+ * This function is called by the scheduler on every invocation of
+ * update_load_avg() on the CPU whose utilization is being updated.
+ *
+ * It can only be called from RCU-sched read-side critical sections.
+ */
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
+{
+       struct update_util_data *data;
+
+       data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
+       if (data)
+               data->func(data, time, util, max);
+}
+
+/**
+ * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
+ * @time: Current time.
+ *
+ * The way cpufreq is currently arranged requires it to evaluate the CPU
+ * performance state (frequency/voltage) on a regular basis to prevent it from
+ * being stuck in a completely inadequate performance level for too long.
+ * That is not guaranteed to happen if the updates are only triggered from CFS,
+ * though, because they may not be coming in if RT or deadline tasks are active
+ * all the time (or there are RT and DL tasks only).
+ *
+ * As a workaround for that issue, this function is called by the RT and DL
+ * sched classes to trigger extra cpufreq updates to prevent it from stalling,
+ * but that really is a band-aid.  Going forward it should be replaced with
+ * solutions targeted more specifically at RT and DL tasks.
+ */
+static inline void cpufreq_trigger_update(u64 time)
+{
+	cpufreq_update_util(time, ULONG_MAX, 0);
+}
+#else
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
+static inline void cpufreq_trigger_update(u64 time) {}
+#endif /* CONFIG_CPU_FREQ */
+
 static inline void account_reset_rq(struct rq *rq)
 {
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 15a1795bb..e1e5a3548 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -395,7 +395,7 @@ seccomp_prepare_user_filter(const char __user *user_filter)
 	struct seccomp_filter *filter = ERR_PTR(-EFAULT);
 
 #ifdef CONFIG_COMPAT
-	if (is_compat_task()) {
+	if (in_compat_syscall()) {
 		struct compat_sock_fprog fprog32;
 		if (copy_from_user(&fprog32, user_filter, sizeof(fprog32)))
 			goto out;
@@ -529,7 +529,7 @@ static void __secure_computing_strict(int this_syscall)
 {
 	int *syscall_whitelist = mode1_syscalls;
 #ifdef CONFIG_COMPAT
-	if (is_compat_task())
+	if (in_compat_syscall())
 		syscall_whitelist = mode1_syscalls_32;
 #endif
 	do {
diff --git a/kernel/signal.c b/kernel/signal.c
index 0508544c8..aa9bf0074 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2709,6 +2709,10 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
 			err |= __put_user(from->si_upper, &to->si_upper);
 		}
 #endif
+#ifdef SEGV_PKUERR
+		if (from->si_signo == SIGSEGV && from->si_code == SEGV_PKUERR)
+			err |= __put_user(from->si_pkey, &to->si_pkey);
+#endif
 		break;
 	case __SI_CHLD:
 		err |= __put_user(from->si_pid, &to->si_pid);
@@ -3581,6 +3585,10 @@ __weak const char *arch_vma_name(struct vm_area_struct *vma)
 
 void __init signals_init(void)
 {
+	/* If this check fails, the __ARCH_SI_PREAMBLE_SIZE value is wrong! */
+	BUILD_BUG_ON(__ARCH_SI_PREAMBLE_SIZE
+		!= offsetof(struct siginfo, _sifields._pad));
+
 	sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
 }
 
diff --git a/kernel/smp.c b/kernel/smp.c
index d903c0222..74165443c 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -105,13 +105,12 @@ void __init call_function_init(void)
  * previous function call. For multi-cpu calls its even more interesting
  * as we'll have to ensure no other cpu is observing our csd.
  */
-static void csd_lock_wait(struct call_single_data *csd)
+static __always_inline void csd_lock_wait(struct call_single_data *csd)
 {
-	while (smp_load_acquire(&csd->flags) & CSD_FLAG_LOCK)
-		cpu_relax();
+	smp_cond_acquire(!(csd->flags & CSD_FLAG_LOCK));
 }
 
-static void csd_lock(struct call_single_data *csd)
+static __always_inline void csd_lock(struct call_single_data *csd)
 {
 	csd_lock_wait(csd);
 	csd->flags |= CSD_FLAG_LOCK;
@@ -124,7 +123,7 @@ static void csd_lock(struct call_single_data *csd)
 	smp_wmb();
 }
 
-static void csd_unlock(struct call_single_data *csd)
+static __always_inline void csd_unlock(struct call_single_data *csd)
 {
 	WARN_ON(!(csd->flags & CSD_FLAG_LOCK));
 
@@ -569,6 +568,7 @@ void __init smp_init(void)
 	unsigned int cpu;
 
 	idle_threads_init();
+	cpuhp_threads_init();
 
 	/* FIXME: This should be done in userspace --RR */
 	for_each_present_cpu(cpu) {
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 28c8e736d..ca4e5343a 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -226,7 +226,7 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp
 		kthread_unpark(tsk);
 }
 
-void smpboot_unpark_threads(unsigned int cpu)
+int smpboot_unpark_threads(unsigned int cpu)
 {
 	struct smp_hotplug_thread *cur;
 
@@ -235,6 +235,7 @@ void smpboot_unpark_threads(unsigned int cpu)
 		if (cpumask_test_cpu(cpu, cur->cpumask))
 			smpboot_unpark_thread(cur, cpu);
 	mutex_unlock(&smpboot_threads_lock);
+	return 0;
 }
 
 static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
@@ -245,7 +246,7 @@ static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
 		kthread_park(tsk);
 }
 
-void smpboot_park_threads(unsigned int cpu)
+int smpboot_park_threads(unsigned int cpu)
 {
 	struct smp_hotplug_thread *cur;
 
@@ -253,6 +254,7 @@ void smpboot_park_threads(unsigned int cpu)
 	list_for_each_entry_reverse(cur, &hotplug_threads, list)
 		smpboot_park_thread(cur, cpu);
 	mutex_unlock(&smpboot_threads_lock);
+	return 0;
 }
 
 static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 72415a0eb..485b81cfa 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -14,7 +14,9 @@ static inline void idle_threads_init(void) { }
 #endif
 
 int smpboot_create_threads(unsigned int cpu);
-void smpboot_park_threads(unsigned int cpu);
-void smpboot_unpark_threads(unsigned int cpu);
+int smpboot_park_threads(unsigned int cpu);
+int smpboot_unpark_threads(unsigned int cpu);
+
+void __init cpuhp_threads_init(void);
 
 #endif
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 8aae49dd7..17caf4b63 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -227,7 +227,7 @@ static inline bool lockdep_softirq_start(void) { return false; }
 static inline void lockdep_softirq_end(bool in_hardirq) { }
 #endif
 
-asmlinkage __visible void __do_softirq(void)
+asmlinkage __visible void __softirq_entry __do_softirq(void)
 {
 	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
 	unsigned long old_flags = current->flags;
diff --git a/kernel/sys.c b/kernel/sys.c
index 78947de6f..cf8ba545c 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2169,7 +2169,10 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		error = perf_event_task_enable();
 		break;
 	case PR_GET_TIMERSLACK:
-		error = current->timer_slack_ns;
+		if (current->timer_slack_ns > ULONG_MAX)
+			error = ULONG_MAX;
+		else
+			error = current->timer_slack_ns;
 		break;
 	case PR_SET_TIMERSLACK:
 		if (arg2 <= 0)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c4887773a..d81973099 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -125,12 +125,12 @@ static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
 static int __maybe_unused four = 4;
 static unsigned long one_ul = 1;
-static int __maybe_unused one_hundred = 100;
+static int __read_mostly one_hundred = 100;
+static int __read_mostly one_thousand = 1000;
 #ifdef CONFIG_SCHED_BFS
 extern int rr_interval;
 extern int sched_interactive;
 extern int sched_iso_cpu;
-static int __read_mostly one_thousand = 1000;
 #endif
 #ifdef CONFIG_PRINTK
 static int ten_thousand = 10000;
@@ -1441,6 +1441,15 @@ static struct ctl_table vm_table[] = {
 		.extra1		= &zero,
 	},
 	{
+		.procname	= "watermark_scale_factor",
+		.data		= &watermark_scale_factor,
+		.maxlen		= sizeof(watermark_scale_factor),
+		.mode		= 0644,
+		.proc_handler	= watermark_scale_factor_sysctl_handler,
+		.extra1		= &one,
+		.extra2		= &one_thousand,
+	},
+	{
 		.procname	= "percpu_pagelist_fraction",
 		.data		= &percpu_pagelist_fraction,
 		.maxlen		= sizeof(percpu_pagelist_fraction),
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 664de5392..56ece145a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -323,13 +323,42 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
 		/* cs is a watchdog. */
 		if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
 			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+	}
+	spin_unlock_irqrestore(&watchdog_lock, flags);
+}
+
+static void clocksource_select_watchdog(bool fallback)
+{
+	struct clocksource *cs, *old_wd;
+	unsigned long flags;
+
+	spin_lock_irqsave(&watchdog_lock, flags);
+	/* save current watchdog */
+	old_wd = watchdog;
+	if (fallback)
+		watchdog = NULL;
+
+	list_for_each_entry(cs, &clocksource_list, list) {
+		/* cs is a clocksource to be watched. */
+		if (cs->flags & CLOCK_SOURCE_MUST_VERIFY)
+			continue;
+
+		/* Skip current if we were requested for a fallback. */
+		if (fallback && cs == old_wd)
+			continue;
+
 		/* Pick the best watchdog. */
-		if (!watchdog || cs->rating > watchdog->rating) {
+		if (!watchdog || cs->rating > watchdog->rating)
 			watchdog = cs;
-			/* Reset watchdog cycles */
-			clocksource_reset_watchdog();
-		}
 	}
+	/* If we failed to find a fallback restore the old one. */
+	if (!watchdog)
+		watchdog = old_wd;
+
+	/* If we changed the watchdog we need to reset cycles. */
+	if (watchdog != old_wd)
+		clocksource_reset_watchdog();
+
 	/* Check if the watchdog timer needs to be started. */
 	clocksource_start_watchdog();
 	spin_unlock_irqrestore(&watchdog_lock, flags);
@@ -404,6 +433,7 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
 		cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
 }
 
+static void clocksource_select_watchdog(bool fallback) { }
 static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
 static inline void clocksource_resume_watchdog(void) { }
 static inline int __clocksource_watchdog_kthread(void) { return 0; }
@@ -736,6 +766,7 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
 	clocksource_enqueue(cs);
 	clocksource_enqueue_watchdog(cs);
 	clocksource_select();
+	clocksource_select_watchdog(false);
 	mutex_unlock(&clocksource_mutex);
 	return 0;
 }
@@ -758,6 +789,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
 	mutex_lock(&clocksource_mutex);
 	__clocksource_change_rating(cs, rating);
 	clocksource_select();
+	clocksource_select_watchdog(false);
 	mutex_unlock(&clocksource_mutex);
 }
 EXPORT_SYMBOL(clocksource_change_rating);
@@ -767,12 +799,12 @@ EXPORT_SYMBOL(clocksource_change_rating);
  */
 static int clocksource_unbind(struct clocksource *cs)
 {
-	/*
-	 * I really can't convince myself to support this on hardware
-	 * designed by lobotomized monkeys.
-	 */
-	if (clocksource_is_watchdog(cs))
-		return -EBUSY;
+	if (clocksource_is_watchdog(cs)) {
+		/* Select and try to install a replacement watchdog. */
+		clocksource_select_watchdog(true);
+		if (clocksource_is_watchdog(cs))
+			return -EBUSY;
+	}
 
 	if (cs == curr_clocksource) {
 		/* Select and try to install a replacement clock source */
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index fa909f9fd..fa0b98329 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -515,7 +515,7 @@ static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
 /*
  * High resolution timer enabled ?
  */
-static int hrtimer_hres_enabled __read_mostly  = 1;
+static bool hrtimer_hres_enabled __read_mostly  = true;
 unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC;
 EXPORT_SYMBOL_GPL(hrtimer_resolution);
 
@@ -524,13 +524,7 @@ EXPORT_SYMBOL_GPL(hrtimer_resolution);
  */
 static int __init setup_hrtimer_hres(char *str)
 {
-	if (!strcmp(str, "off"))
-		hrtimer_hres_enabled = 0;
-	else if (!strcmp(str, "on"))
-		hrtimer_hres_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return (kstrtobool(str, &hrtimer_hres_enabled) == 0);
 }
 
 __setup("highres=", setup_hrtimer_hres);
@@ -979,7 +973,7 @@ static inline ktime_t hrtimer_update_lowres(struct hrtimer *timer, ktime_t tim,
  *		relative (HRTIMER_MODE_REL)
  */
 void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
-			    unsigned long delta_ns, const enum hrtimer_mode mode)
+			    u64 delta_ns, const enum hrtimer_mode mode)
 {
 	struct hrtimer_clock_base *base, *new_base;
 	unsigned long flags;
@@ -1548,7 +1542,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
 	int ret = 0;
-	unsigned long slack;
+	u64 slack;
 
 	slack = current->timer_slack_ns;
 	if (dl_task(current) || rt_task(current))
@@ -1724,7 +1718,7 @@ void __init hrtimers_init(void)
  * @clock:	timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME
  */
 int __sched
-schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
+schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
 			       const enum hrtimer_mode mode, int clock)
 {
 	struct hrtimer_sleeper t;
@@ -1792,7 +1786,7 @@ schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
  *
  * Returns 0 when the timer has expired otherwise -EINTR
  */
-int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
+int __sched schedule_hrtimeout_range(ktime_t *expires, u64 delta,
 				     const enum hrtimer_mode mode)
 {
 	return schedule_hrtimeout_range_clock(expires, delta, mode,
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 347fecf86..555e21f7b 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -68,7 +68,7 @@ static struct clocksource clocksource_jiffies = {
 	.name		= "jiffies",
 	.rating		= 1, /* lowest valid rating*/
 	.read		= jiffies_read,
-	.mask		= 0xffffffff, /*32bits*/
+	.mask		= CLOCKSOURCE_MASK(32),
 	.mult		= NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
 	.shift		= JIFFIES_SHIFT,
 	.max_cycles	= 10,
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 7a48442ed..e284c2316 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -333,7 +333,6 @@ static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
 	return err;
 }
 
-
 /*
  * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
  * This is called from sys_timer_create() and do_cpu_nanosleep() with the
@@ -517,6 +516,10 @@ static void arm_timer(struct k_itimer *timer)
 				cputime_expires->sched_exp = exp;
 			break;
 		}
+		if (CPUCLOCK_PERTHREAD(timer->it_clock))
+			tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
+		else
+			tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
 	}
 }
 
@@ -582,39 +585,6 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
 	return 0;
 }
 
-#ifdef CONFIG_NO_HZ_FULL
-static void nohz_kick_work_fn(struct work_struct *work)
-{
-	tick_nohz_full_kick_all();
-}
-
-static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);
-
-/*
- * We need the IPIs to be sent from sane process context.
- * The posix cpu timers are always set with irqs disabled.
- */
-static void posix_cpu_timer_kick_nohz(void)
-{
-	if (context_tracking_is_enabled())
-		schedule_work(&nohz_kick_work);
-}
-
-bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
-{
-	if (!task_cputime_zero(&tsk->cputime_expires))
-		return false;
-
-	/* Check if cputimer is running. This is accessed without locking. */
-	if (READ_ONCE(tsk->signal->cputimer.running))
-		return false;
-
-	return true;
-}
-#else
-static inline void posix_cpu_timer_kick_nohz(void) { }
-#endif
-
 /*
  * Guts of sys_timer_settime for CPU timers.
  * This is called with the timer locked and interrupts disabled.
@@ -761,8 +731,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 		sample_to_timespec(timer->it_clock,
 				   old_incr, &old->it_interval);
 	}
-	if (!ret)
-		posix_cpu_timer_kick_nohz();
+
 	return ret;
 }
 
@@ -911,6 +880,8 @@ static void check_thread_timers(struct task_struct *tsk,
 			__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
 		}
 	}
+	if (task_cputime_zero(tsk_expires))
+		tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
 }
 
 static inline void stop_process_timers(struct signal_struct *sig)
@@ -919,6 +890,7 @@ static inline void stop_process_timers(struct signal_struct *sig)
 
 	/* Turn off cputimer->running. This is done without locking. */
 	WRITE_ONCE(cputimer->running, false);
+	tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
 }
 
 static u32 onecputick;
@@ -1095,8 +1067,6 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
 	arm_timer(timer);
 	unlock_task_sighand(p, &flags);
 
-	/* Kick full dynticks CPUs in case they need to tick on the new timer */
-	posix_cpu_timer_kick_nohz();
 out:
 	timer->it_overrun_last = timer->it_overrun;
 	timer->it_overrun = -1;
@@ -1270,7 +1240,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
 		}
 
 		if (!*newval)
-			goto out;
+			return;
 		*newval += now;
 	}
 
@@ -1288,8 +1258,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
 			tsk->signal->cputime_expires.virt_exp = *newval;
 		break;
 	}
-out:
-	posix_cpu_timer_kick_nohz();
+
+	tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
 }
 
 static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 0b1742434..58e3310c9 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -22,7 +22,6 @@
 #include <linux/module.h>
 #include <linux/irq_work.h>
 #include <linux/posix-timers.h>
-#include <linux/perf_event.h>
 #include <linux/context_tracking.h>
 
 #include <asm/irq_regs.h>
@@ -158,54 +157,61 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
 cpumask_var_t tick_nohz_full_mask;
 cpumask_var_t housekeeping_mask;
 bool tick_nohz_full_running;
+static atomic_t tick_dep_mask;
 
-static bool can_stop_full_tick(void)
+static bool check_tick_dependency(atomic_t *dep)
+{
+	int val = atomic_read(dep);
+
+	if (val & TICK_DEP_MASK_POSIX_TIMER) {
+		trace_tick_stop(0, TICK_DEP_MASK_POSIX_TIMER);
+		return true;
+	}
+
+	if (val & TICK_DEP_MASK_PERF_EVENTS) {
+		trace_tick_stop(0, TICK_DEP_MASK_PERF_EVENTS);
+		return true;
+	}
+
+	if (val & TICK_DEP_MASK_SCHED) {
+		trace_tick_stop(0, TICK_DEP_MASK_SCHED);
+		return true;
+	}
+
+	if (val & TICK_DEP_MASK_CLOCK_UNSTABLE) {
+		trace_tick_stop(0, TICK_DEP_MASK_CLOCK_UNSTABLE);
+		return true;
+	}
+
+	return false;
+}
+
+static bool can_stop_full_tick(struct tick_sched *ts)
 {
 	WARN_ON_ONCE(!irqs_disabled());
 
-	if (!sched_can_stop_tick()) {
-		trace_tick_stop(0, "more than 1 task in runqueue\n");
+	if (check_tick_dependency(&tick_dep_mask))
 		return false;
-	}
 
-	if (!posix_cpu_timers_can_stop_tick(current)) {
-		trace_tick_stop(0, "posix timers running\n");
+	if (check_tick_dependency(&ts->tick_dep_mask))
 		return false;
-	}
 
-	if (!perf_event_can_stop_tick()) {
-		trace_tick_stop(0, "perf events running\n");
+	if (check_tick_dependency(&current->tick_dep_mask))
 		return false;
-	}
 
-	/* sched_clock_tick() needs us? */
-#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-	/*
-	 * TODO: kick full dynticks CPUs when
-	 * sched_clock_stable is set.
-	 */
-	if (!sched_clock_stable()) {
-		trace_tick_stop(0, "unstable sched clock\n");
-		/*
-		 * Don't allow the user to think they can get
-		 * full NO_HZ with this machine.
-		 */
-		WARN_ONCE(tick_nohz_full_running,
-			  "NO_HZ FULL will not work with unstable sched clock");
+	if (check_tick_dependency(&current->signal->tick_dep_mask))
 		return false;
-	}
-#endif
 
 	return true;
 }
 
-static void nohz_full_kick_work_func(struct irq_work *work)
+static void nohz_full_kick_func(struct irq_work *work)
 {
 	/* Empty, the tick restart happens on tick_nohz_irq_exit() */
 }
 
 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
-	.func = nohz_full_kick_work_func,
+	.func = nohz_full_kick_func,
 };
 
 /*
@@ -214,7 +220,7 @@ static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
  * This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(),
  * is NMI safe.
  */
-void tick_nohz_full_kick(void)
+static void tick_nohz_full_kick(void)
 {
 	if (!tick_nohz_full_cpu(smp_processor_id()))
 		return;
@@ -234,27 +240,112 @@ void tick_nohz_full_kick_cpu(int cpu)
 	irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu);
 }
 
-static void nohz_full_kick_ipi(void *info)
-{
-	/* Empty, the tick restart happens on tick_nohz_irq_exit() */
-}
-
 /*
  * Kick all full dynticks CPUs in order to force these to re-evaluate
  * their dependency on the tick and restart it if necessary.
  */
-void tick_nohz_full_kick_all(void)
+static void tick_nohz_full_kick_all(void)
 {
+	int cpu;
+
 	if (!tick_nohz_full_running)
 		return;
 
 	preempt_disable();
-	smp_call_function_many(tick_nohz_full_mask,
-			       nohz_full_kick_ipi, NULL, false);
-	tick_nohz_full_kick();
+	for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask)
+		tick_nohz_full_kick_cpu(cpu);
 	preempt_enable();
 }
 
+static void tick_nohz_dep_set_all(atomic_t *dep,
+				  enum tick_dep_bits bit)
+{
+	int prev;
+
+	prev = atomic_fetch_or(dep, BIT(bit));
+	if (!prev)
+		tick_nohz_full_kick_all();
+}
+
+/*
+ * Set a global tick dependency. Used by perf events that rely on freq and
+ * by unstable clock.
+ */
+void tick_nohz_dep_set(enum tick_dep_bits bit)
+{
+	tick_nohz_dep_set_all(&tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear(enum tick_dep_bits bit)
+{
+	atomic_andnot(BIT(bit), &tick_dep_mask);
+}
+
+/*
+ * Set per-CPU tick dependency. Used by scheduler and perf events in order to
+ * manage events throttling.
+ */
+void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit)
+{
+	int prev;
+	struct tick_sched *ts;
+
+	ts = per_cpu_ptr(&tick_cpu_sched, cpu);
+
+	prev = atomic_fetch_or(&ts->tick_dep_mask, BIT(bit));
+	if (!prev) {
+		preempt_disable();
+		/* Perf needs local kick that is NMI safe */
+		if (cpu == smp_processor_id()) {
+			tick_nohz_full_kick();
+		} else {
+			/* Remote irq work not NMI-safe */
+			if (!WARN_ON_ONCE(in_nmi()))
+				tick_nohz_full_kick_cpu(cpu);
+		}
+		preempt_enable();
+	}
+}
+
+void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
+{
+	struct tick_sched *ts = per_cpu_ptr(&tick_cpu_sched, cpu);
+
+	atomic_andnot(BIT(bit), &ts->tick_dep_mask);
+}
+
+/*
+ * Set a per-task tick dependency. Posix CPU timers need this in order to elapse
+ * per task timers.
+ */
+void tick_nohz_dep_set_task(struct task_struct *tsk, enum tick_dep_bits bit)
+{
+	/*
+	 * We could optimize this with just kicking the target running the task
+	 * if that noise matters for nohz full users.
+	 */
+	tick_nohz_dep_set_all(&tsk->tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear_task(struct task_struct *tsk, enum tick_dep_bits bit)
+{
+	atomic_andnot(BIT(bit), &tsk->tick_dep_mask);
+}
+
+/*
+ * Set a per-taskgroup tick dependency. Posix CPU timers need this in order to elapse
+ * per process timers.
+ */
+void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits bit)
+{
+	tick_nohz_dep_set_all(&sig->tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bit)
+{
+	atomic_andnot(BIT(bit), &sig->tick_dep_mask);
+}
+
 /*
  * Re-evaluate the need for the tick as we switch the current task.
  * It might need the tick due to per task/process properties:
@@ -263,15 +354,20 @@ void tick_nohz_full_kick_all(void)
 void __tick_nohz_task_switch(void)
 {
 	unsigned long flags;
+	struct tick_sched *ts;
 
 	local_irq_save(flags);
 
 	if (!tick_nohz_full_cpu(smp_processor_id()))
 		goto out;
 
-	if (tick_nohz_tick_stopped() && !can_stop_full_tick())
-		tick_nohz_full_kick();
+	ts = this_cpu_ptr(&tick_cpu_sched);
 
+	if (ts->tick_stopped) {
+		if (atomic_read(&current->tick_dep_mask) ||
+		    atomic_read(&current->signal->tick_dep_mask))
+			tick_nohz_full_kick();
+	}
 out:
 	local_irq_restore(flags);
 }
@@ -281,7 +377,7 @@ static int __init tick_nohz_full_setup(char *str)
 {
 	alloc_bootmem_cpumask_var(&tick_nohz_full_mask);
 	if (cpulist_parse(str, tick_nohz_full_mask) < 0) {
-		pr_warning("NOHZ: Incorrect nohz_full cpumask\n");
+		pr_warn("NO_HZ: Incorrect nohz_full cpumask\n");
 		free_bootmem_cpumask_var(tick_nohz_full_mask);
 		return 1;
 	}
@@ -349,8 +445,7 @@ void __init tick_nohz_init(void)
 	 * interrupts to avoid circular dependency on the tick
 	 */
 	if (!arch_irq_work_has_interrupt()) {
-		pr_warning("NO_HZ: Can't run full dynticks because arch doesn't "
-			   "support irq work self-IPIs\n");
+		pr_warn("NO_HZ: Can't run full dynticks because arch doesn't support irq work self-IPIs\n");
 		cpumask_clear(tick_nohz_full_mask);
 		cpumask_copy(housekeeping_mask, cpu_possible_mask);
 		tick_nohz_full_running = false;
@@ -360,7 +455,8 @@ void __init tick_nohz_init(void)
 	cpu = smp_processor_id();
 
 	if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) {
-		pr_warning("NO_HZ: Clearing %d from nohz_full range for timekeeping\n", cpu);
+		pr_warn("NO_HZ: Clearing %d from nohz_full range for timekeeping\n",
+			cpu);
 		cpumask_clear_cpu(cpu, tick_nohz_full_mask);
 	}
 
@@ -389,20 +485,14 @@ void __init tick_nohz_init(void)
 /*
  * NO HZ enabled ?
  */
-int tick_nohz_enabled __read_mostly = 1;
+bool tick_nohz_enabled __read_mostly  = true;
 unsigned long tick_nohz_active  __read_mostly;
 /*
  * Enable / Disable tickless mode
  */
 static int __init setup_tick_nohz(char *str)
 {
-	if (!strcmp(str, "off"))
-		tick_nohz_enabled = 0;
-	else if (!strcmp(str, "on"))
-		tick_nohz_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return (kstrtobool(str, &tick_nohz_enabled) == 0);
 }
 
 __setup("nohz=", setup_tick_nohz);
@@ -689,7 +779,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 
 		ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
 		ts->tick_stopped = 1;
-		trace_tick_stop(1, " ");
+		trace_tick_stop(1, TICK_DEP_MASK_NONE);
 	}
 
 	/*
@@ -740,7 +830,7 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts)
 	if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
 		return;
 
-	if (can_stop_full_tick())
+	if (can_stop_full_tick(ts))
 		tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
 	else if (ts->tick_stopped)
 		tick_nohz_restart_sched_tick(ts, ktime_get(), 1);
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
index a4a8d4e9b..bf38226e5 100644
--- a/kernel/time/tick-sched.h
+++ b/kernel/time/tick-sched.h
@@ -60,6 +60,7 @@ struct tick_sched {
 	u64				next_timer;
 	ktime_t				idle_expires;
 	int				do_timer_last;
+	atomic_t			tick_dep_mask;
 };
 
 extern struct tick_sched *tick_get_tick_sched(int cpu);
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 86751c68e..be115b020 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -322,6 +322,13 @@ EXPORT_SYMBOL(timespec_trunc);
  * -year/100+year/400 terms, and add 10.]
  *
  * This algorithm was first published by Gauss (I think).
+ *
+ * A leap second can be indicated by calling this function with sec as
+ * 60 (allowable under ISO 8601).  The leap second is treated the same
+ * as the following second since they don't exist in UNIX time.
+ *
+ * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight
+ * tomorrow - (allowable under ISO 8601) is supported.
  */
 time64_t mktime64(const unsigned int year0, const unsigned int mon0,
 		const unsigned int day, const unsigned int hour,
@@ -338,7 +345,7 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0,
 	return ((((time64_t)
 		  (year/4 - year/100 + year/400 + 367*mon/12 + day) +
 		  year*365 - 719499
-	    )*24 + hour /* now have hours */
+	    )*24 + hour /* now have hours - midnight tomorrow handled here */
 	  )*60 + min /* now have minutes */
 	)*60 + sec; /* finally seconds */
 }
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 34b4cedfa..479d25cd3 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -131,7 +131,7 @@ static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
 		printk_deferred("         timekeeping: Your kernel is sick, but tries to cope by capping time updates\n");
 	} else {
 		if (offset > (max_cycles >> 1)) {
-			printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the the '%s' clock's 50%% safety margin (%lld)\n",
+			printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n",
 					offset, name, max_cycles >> 1);
 			printk_deferred("      timekeeping: Your kernel is still fine, but is feeling a bit nervous\n");
 		}
@@ -233,6 +233,7 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 	u64 tmp, ntpinterval;
 	struct clocksource *old_clock;
 
+	++tk->cs_was_changed_seq;
 	old_clock = tk->tkr_mono.clock;
 	tk->tkr_mono.clock = clock;
 	tk->tkr_mono.read = clock->read;
@@ -298,17 +299,34 @@ u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
 static inline u32 arch_gettimeoffset(void) { return 0; }
 #endif
 
+static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
+					  cycle_t delta)
+{
+	s64 nsec;
+
+	nsec = delta * tkr->mult + tkr->xtime_nsec;
+	nsec >>= tkr->shift;
+
+	/* If arch requires, add in get_arch_timeoffset() */
+	return nsec + arch_gettimeoffset();
+}
+
 static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
 {
 	cycle_t delta;
-	s64 nsec;
 
 	delta = timekeeping_get_delta(tkr);
+	return timekeeping_delta_to_ns(tkr, delta);
+}
 
-	nsec = (delta * tkr->mult + tkr->xtime_nsec) >> tkr->shift;
+static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
+					    cycle_t cycles)
+{
+	cycle_t delta;
 
-	/* If arch requires, add in get_arch_timeoffset() */
-	return nsec + arch_gettimeoffset();
+	/* calculate the delta since the last update_wall_time */
+	delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask);
+	return timekeeping_delta_to_ns(tkr, delta);
 }
 
 /**
@@ -857,44 +875,262 @@ time64_t __ktime_get_real_seconds(void)
 	return tk->xtime_sec;
 }
 
+/**
+ * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter
+ * @systime_snapshot:	pointer to struct receiving the system time snapshot
+ */
+void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+	unsigned long seq;
+	ktime_t base_raw;
+	ktime_t base_real;
+	s64 nsec_raw;
+	s64 nsec_real;
+	cycle_t now;
 
-#ifdef CONFIG_NTP_PPS
+	WARN_ON_ONCE(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&tk_core.seq);
+
+		now = tk->tkr_mono.read(tk->tkr_mono.clock);
+		systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq;
+		systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq;
+		base_real = ktime_add(tk->tkr_mono.base,
+				      tk_core.timekeeper.offs_real);
+		base_raw = tk->tkr_raw.base;
+		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now);
+		nsec_raw  = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
+	} while (read_seqcount_retry(&tk_core.seq, seq));
+
+	systime_snapshot->cycles = now;
+	systime_snapshot->real = ktime_add_ns(base_real, nsec_real);
+	systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);
+}
+EXPORT_SYMBOL_GPL(ktime_get_snapshot);
+
+/* Scale base by mult/div checking for overflow */
+static int scale64_check_overflow(u64 mult, u64 div, u64 *base)
+{
+	u64 tmp, rem;
+
+	tmp = div64_u64_rem(*base, div, &rem);
+
+	if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) ||
+	    ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem)))
+		return -EOVERFLOW;
+	tmp *= mult;
+	rem *= mult;
+
+	do_div(rem, div);
+	*base = tmp + rem;
+	return 0;
+}
 
 /**
- * ktime_get_raw_and_real_ts64 - get day and raw monotonic time in timespec format
- * @ts_raw:	pointer to the timespec to be set to raw monotonic time
- * @ts_real:	pointer to the timespec to be set to the time of day
+ * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval
+ * @history:			Snapshot representing start of history
+ * @partial_history_cycles:	Cycle offset into history (fractional part)
+ * @total_history_cycles:	Total history length in cycles
+ * @discontinuity:		True indicates clock was set on history period
+ * @ts:				Cross timestamp that should be adjusted using
+ *	partial/total ratio
  *
- * This function reads both the time of day and raw monotonic time at the
- * same time atomically and stores the resulting timestamps in timespec
- * format.
+ * Helper function used by get_device_system_crosststamp() to correct the
+ * crosstimestamp corresponding to the start of the current interval to the
+ * system counter value (timestamp point) provided by the driver. The
+ * total_history_* quantities are the total history starting at the provided
+ * reference point and ending at the start of the current interval. The cycle
+ * count between the driver timestamp point and the start of the current
+ * interval is partial_history_cycles.
  */
-void ktime_get_raw_and_real_ts64(struct timespec64 *ts_raw, struct timespec64 *ts_real)
+static int adjust_historical_crosststamp(struct system_time_snapshot *history,
+					 cycle_t partial_history_cycles,
+					 cycle_t total_history_cycles,
+					 bool discontinuity,
+					 struct system_device_crosststamp *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long seq;
-	s64 nsecs_raw, nsecs_real;
+	u64 corr_raw, corr_real;
+	bool interp_forward;
+	int ret;
 
-	WARN_ON_ONCE(timekeeping_suspended);
+	if (total_history_cycles == 0 || partial_history_cycles == 0)
+		return 0;
+
+	/* Interpolate shortest distance from beginning or end of history */
+	interp_forward = partial_history_cycles > total_history_cycles/2 ?
+		true : false;
+	partial_history_cycles = interp_forward ?
+		total_history_cycles - partial_history_cycles :
+		partial_history_cycles;
+
+	/*
+	 * Scale the monotonic raw time delta by:
+	 *	partial_history_cycles / total_history_cycles
+	 */
+	corr_raw = (u64)ktime_to_ns(
+		ktime_sub(ts->sys_monoraw, history->raw));
+	ret = scale64_check_overflow(partial_history_cycles,
+				     total_history_cycles, &corr_raw);
+	if (ret)
+		return ret;
+
+	/*
+	 * If there is a discontinuity in the history, scale monotonic raw
+	 *	correction by:
+	 *	mult(real)/mult(raw) yielding the realtime correction
+	 * Otherwise, calculate the realtime correction similar to monotonic
+	 *	raw calculation
+	 */
+	if (discontinuity) {
+		corr_real = mul_u64_u32_div
+			(corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult);
+	} else {
+		corr_real = (u64)ktime_to_ns(
+			ktime_sub(ts->sys_realtime, history->real));
+		ret = scale64_check_overflow(partial_history_cycles,
+					     total_history_cycles, &corr_real);
+		if (ret)
+			return ret;
+	}
+
+	/* Fixup monotonic raw and real time time values */
+	if (interp_forward) {
+		ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw);
+		ts->sys_realtime = ktime_add_ns(history->real, corr_real);
+	} else {
+		ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw);
+		ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real);
+	}
+
+	return 0;
+}
+
+/*
+ * cycle_between - true if test occurs chronologically between before and after
+ */
+static bool cycle_between(cycle_t before, cycle_t test, cycle_t after)
+{
+	if (test > before && test < after)
+		return true;
+	if (test < before && before > after)
+		return true;
+	return false;
+}
+
+/**
+ * get_device_system_crosststamp - Synchronously capture system/device timestamp
+ * @get_time_fn:	Callback to get simultaneous device time and
+ *	system counter from the device driver
+ * @ctx:		Context passed to get_time_fn()
+ * @history_begin:	Historical reference point used to interpolate system
+ *	time when counter provided by the driver is before the current interval
+ * @xtstamp:		Receives simultaneously captured system and device time
+ *
+ * Reads a timestamp from a device and correlates it to system time
+ */
+int get_device_system_crosststamp(int (*get_time_fn)
+				  (ktime_t *device_time,
+				   struct system_counterval_t *sys_counterval,
+				   void *ctx),
+				  void *ctx,
+				  struct system_time_snapshot *history_begin,
+				  struct system_device_crosststamp *xtstamp)
+{
+	struct system_counterval_t system_counterval;
+	struct timekeeper *tk = &tk_core.timekeeper;
+	cycle_t cycles, now, interval_start;
+	unsigned int clock_was_set_seq = 0;
+	ktime_t base_real, base_raw;
+	s64 nsec_real, nsec_raw;
+	u8 cs_was_changed_seq;
+	unsigned long seq;
+	bool do_interp;
+	int ret;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
+		/*
+		 * Try to synchronously capture device time and a system
+		 * counter value calling back into the device driver
+		 */
+		ret = get_time_fn(&xtstamp->device, &system_counterval, ctx);
+		if (ret)
+			return ret;
+
+		/*
+		 * Verify that the clocksource associated with the captured
+		 * system counter value is the same as the currently installed
+		 * timekeeper clocksource
+		 */
+		if (tk->tkr_mono.clock != system_counterval.cs)
+			return -ENODEV;
+		cycles = system_counterval.cycles;
 
-		*ts_raw = tk->raw_time;
-		ts_real->tv_sec = tk->xtime_sec;
-		ts_real->tv_nsec = 0;
+		/*
+		 * Check whether the system counter value provided by the
+		 * device driver is on the current timekeeping interval.
+		 */
+		now = tk->tkr_mono.read(tk->tkr_mono.clock);
+		interval_start = tk->tkr_mono.cycle_last;
+		if (!cycle_between(interval_start, cycles, now)) {
+			clock_was_set_seq = tk->clock_was_set_seq;
+			cs_was_changed_seq = tk->cs_was_changed_seq;
+			cycles = interval_start;
+			do_interp = true;
+		} else {
+			do_interp = false;
+		}
 
-		nsecs_raw  = timekeeping_get_ns(&tk->tkr_raw);
-		nsecs_real = timekeeping_get_ns(&tk->tkr_mono);
+		base_real = ktime_add(tk->tkr_mono.base,
+				      tk_core.timekeeper.offs_real);
+		base_raw = tk->tkr_raw.base;
 
+		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono,
+						     system_counterval.cycles);
+		nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw,
+						    system_counterval.cycles);
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
-	timespec64_add_ns(ts_raw, nsecs_raw);
-	timespec64_add_ns(ts_real, nsecs_real);
-}
-EXPORT_SYMBOL(ktime_get_raw_and_real_ts64);
+	xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real);
+	xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw);
 
-#endif /* CONFIG_NTP_PPS */
+	/*
+	 * Interpolate if necessary, adjusting back from the start of the
+	 * current interval
+	 */
+	if (do_interp) {
+		cycle_t partial_history_cycles, total_history_cycles;
+		bool discontinuity;
+
+		/*
+		 * Check that the counter value occurs after the provided
+		 * history reference and that the history doesn't cross a
+		 * clocksource change
+		 */
+		if (!history_begin ||
+		    !cycle_between(history_begin->cycles,
+				   system_counterval.cycles, cycles) ||
+		    history_begin->cs_was_changed_seq != cs_was_changed_seq)
+			return -EINVAL;
+		partial_history_cycles = cycles - system_counterval.cycles;
+		total_history_cycles = cycles - history_begin->cycles;
+		discontinuity =
+			history_begin->clock_was_set_seq != clock_was_set_seq;
+
+		ret = adjust_historical_crosststamp(history_begin,
+						    partial_history_cycles,
+						    total_history_cycles,
+						    discontinuity, xtstamp);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(get_device_system_crosststamp);
 
 /**
  * do_gettimeofday - Returns the time of day in a timeval
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index bbc5d1114..73164c3aa 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1566,6 +1566,17 @@ signed long __sched schedule_timeout_uninterruptible(signed long timeout)
 }
 EXPORT_SYMBOL(schedule_timeout_uninterruptible);
 
+/*
+ * Like schedule_timeout_uninterruptible(), except this task will not contribute
+ * to load average.
+ */
+signed long __sched schedule_timeout_idle(signed long timeout)
+{
+	__set_current_state(TASK_IDLE);
+	return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_idle);
+
 #ifdef CONFIG_HOTPLUG_CPU
 static void migrate_timer_list(struct tvec_base *new_base, struct hlist_head *head)
 {
@@ -1698,10 +1709,10 @@ EXPORT_SYMBOL(msleep_interruptible);
 static void __sched do_usleep_range(unsigned long min, unsigned long max)
 {
 	ktime_t kmin;
-	unsigned long delta;
+	u64 delta;
 
 	kmin = ktime_set(0, min * NSEC_PER_USEC);
-	delta = (max - min) * NSEC_PER_USEC;
+	delta = (u64)(max - min) * NSEC_PER_USEC;
 	schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
 }
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 2aeb6ffc0..f94e7a21f 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1437,12 +1437,12 @@ static struct trace_event trace_blk_event = {
 static int __init init_blk_tracer(void)
 {
 	if (!register_trace_event(&trace_blk_event)) {
-		pr_warning("Warning: could not register block events\n");
+		pr_warn("Warning: could not register block events\n");
 		return 1;
 	}
 
 	if (register_tracer(&blk_tracer) != 0) {
-		pr_warning("Warning: could not register the block tracer\n");
+		pr_warn("Warning: could not register the block tracer\n");
 		unregister_trace_event(&trace_blk_event);
 		return 1;
 	}
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 326a75e88..3e4ffb3ac 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -13,8 +13,6 @@
 #include <linux/ctype.h>
 #include "trace.h"
 
-static DEFINE_PER_CPU(int, bpf_prog_active);
-
 /**
  * trace_call_bpf - invoke BPF program
  * @prog: BPF program
@@ -299,6 +297,8 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
 		return &bpf_perf_event_read_proto;
 	case BPF_FUNC_perf_event_output:
 		return &bpf_perf_event_output_proto;
+	case BPF_FUNC_get_stackid:
+		return &bpf_get_stackid_proto;
 	default:
 		return NULL;
 	}
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 57a6eea84..b1870fbd2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1030,8 +1030,7 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 	for_each_possible_cpu(cpu) {
 		stat = &per_cpu(ftrace_profile_stats, cpu);
 
-		/* allocate enough for function name + cpu number */
-		name = kmalloc(32, GFP_KERNEL);
+		name = kasprintf(GFP_KERNEL, "function%d", cpu);
 		if (!name) {
 			/*
 			 * The files created are permanent, if something happens
@@ -1043,7 +1042,6 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 			return;
 		}
 		stat->stat = function_stats;
-		snprintf(name, 32, "function%d", cpu);
 		stat->stat.name = name;
 		ret = register_stat_tracer(&stat->stat);
 		if (ret) {
@@ -1058,8 +1056,7 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 	entry = tracefs_create_file("function_profile_enabled", 0644,
 				    d_tracer, NULL, &ftrace_profile_fops);
 	if (!entry)
-		pr_warning("Could not create tracefs "
-			   "'function_profile_enabled' entry\n");
+		pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
 }
 
 #else /* CONFIG_FUNCTION_PROFILER */
@@ -1610,7 +1607,7 @@ static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
 	return  keep_regs;
 }
 
-static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
+static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
 				     int filter_hash,
 				     bool inc)
 {
@@ -1618,12 +1615,13 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 	struct ftrace_hash *other_hash;
 	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
+	bool update = false;
 	int count = 0;
 	int all = 0;
 
 	/* Only update if the ops has been registered */
 	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
-		return;
+		return false;
 
 	/*
 	 * In the filter_hash case:
@@ -1650,7 +1648,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 		 * then there's nothing to do.
 		 */
 		if (ftrace_hash_empty(hash))
-			return;
+			return false;
 	}
 
 	do_for_each_ftrace_rec(pg, rec) {
@@ -1694,7 +1692,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 		if (inc) {
 			rec->flags++;
 			if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
-				return;
+				return false;
 
 			/*
 			 * If there's only a single callback registered to a
@@ -1720,7 +1718,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 				rec->flags |= FTRACE_FL_REGS;
 		} else {
 			if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
-				return;
+				return false;
 			rec->flags--;
 
 			/*
@@ -1753,22 +1751,28 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 			 */
 		}
 		count++;
+
+		/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
+		update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
+
 		/* Shortcut, if we handled all records, we are done. */
 		if (!all && count == hash->count)
-			return;
+			return update;
 	} while_for_each_ftrace_rec();
+
+	return update;
 }
 
-static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
+static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
 				    int filter_hash)
 {
-	__ftrace_hash_rec_update(ops, filter_hash, 0);
+	return __ftrace_hash_rec_update(ops, filter_hash, 0);
 }
 
-static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
+static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
 				   int filter_hash)
 {
-	__ftrace_hash_rec_update(ops, filter_hash, 1);
+	return __ftrace_hash_rec_update(ops, filter_hash, 1);
 }
 
 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
@@ -2314,8 +2318,8 @@ unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
 	if (rec->flags & FTRACE_FL_TRAMP_EN) {
 		ops = ftrace_find_tramp_ops_curr(rec);
 		if (FTRACE_WARN_ON(!ops)) {
-			pr_warning("Bad trampoline accounting at: %p (%pS)\n",
-				    (void *)rec->ip, (void *)rec->ip);
+			pr_warn("Bad trampoline accounting at: %p (%pS)\n",
+				(void *)rec->ip, (void *)rec->ip);
 			/* Ftrace is shutting down, return anything */
 			return (unsigned long)FTRACE_ADDR;
 		}
@@ -2644,7 +2648,6 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
 		return ret;
 
 	ftrace_start_up++;
-	command |= FTRACE_UPDATE_CALLS;
 
 	/*
 	 * Note that ftrace probes uses this to start up
@@ -2665,7 +2668,8 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
 		return ret;
 	}
 
-	ftrace_hash_rec_enable(ops, 1);
+	if (ftrace_hash_rec_enable(ops, 1))
+		command |= FTRACE_UPDATE_CALLS;
 
 	ftrace_startup_enable(command);
 
@@ -2695,11 +2699,11 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 
 	/* Disabling ipmodify never fails */
 	ftrace_hash_ipmodify_disable(ops);
-	ftrace_hash_rec_disable(ops, 1);
 
-	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+	if (ftrace_hash_rec_disable(ops, 1))
+		command |= FTRACE_UPDATE_CALLS;
 
-	command |= FTRACE_UPDATE_CALLS;
+	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
 
 	if (saved_ftrace_func != ftrace_trace_function) {
 		saved_ftrace_func = ftrace_trace_function;
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
index eb4220a13..81b87451c 100644
--- a/kernel/trace/power-traces.c
+++ b/kernel/trace/power-traces.c
@@ -15,4 +15,5 @@
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(suspend_resume);
 EXPORT_TRACEPOINT_SYMBOL_GPL(cpu_idle);
+EXPORT_TRACEPOINT_SYMBOL_GPL(powernv_throttle);
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 95181e368..9c143739b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -437,7 +437,7 @@ struct ring_buffer_per_cpu {
 	raw_spinlock_t			reader_lock;	/* serialize readers */
 	arch_spinlock_t			lock;
 	struct lock_class_key		lock_key;
-	unsigned int			nr_pages;
+	unsigned long			nr_pages;
 	unsigned int			current_context;
 	struct list_head		*pages;
 	struct buffer_page		*head_page;	/* read from head */
@@ -458,7 +458,7 @@ struct ring_buffer_per_cpu {
 	u64				write_stamp;
 	u64				read_stamp;
 	/* ring buffer pages to update, > 0 to add, < 0 to remove */
-	int				nr_pages_to_update;
+	long				nr_pages_to_update;
 	struct list_head		new_pages; /* new pages to add */
 	struct work_struct		update_pages_work;
 	struct completion		update_done;
@@ -1128,10 +1128,10 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 	return 0;
 }
 
-static int __rb_allocate_pages(int nr_pages, struct list_head *pages, int cpu)
+static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu)
 {
-	int i;
 	struct buffer_page *bpage, *tmp;
+	long i;
 
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page;
@@ -1168,7 +1168,7 @@ free_pages:
 }
 
 static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
-			     unsigned nr_pages)
+			     unsigned long nr_pages)
 {
 	LIST_HEAD(pages);
 
@@ -1193,7 +1193,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static struct ring_buffer_per_cpu *
-rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu)
+rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
@@ -1293,8 +1293,9 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
 					struct lock_class_key *key)
 {
 	struct ring_buffer *buffer;
+	long nr_pages;
 	int bsize;
-	int cpu, nr_pages;
+	int cpu;
 
 	/* keep it in its own cache line */
 	buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()),
@@ -1420,12 +1421,12 @@ static inline unsigned long rb_page_write(struct buffer_page *bpage)
 }
 
 static int
-rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned int nr_pages)
+rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned long nr_pages)
 {
 	struct list_head *tail_page, *to_remove, *next_page;
 	struct buffer_page *to_remove_page, *tmp_iter_page;
 	struct buffer_page *last_page, *first_page;
-	unsigned int nr_removed;
+	unsigned long nr_removed;
 	unsigned long head_bit;
 	int page_entries;
 
@@ -1642,7 +1643,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 			int cpu_id)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	unsigned nr_pages;
+	unsigned long nr_pages;
 	int cpu, err = 0;
 
 	/*
@@ -1656,14 +1657,13 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 	    !cpumask_test_cpu(cpu_id, buffer->cpumask))
 		return size;
 
-	size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
-	size *= BUF_PAGE_SIZE;
+	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
 
 	/* we need a minimum of two pages */
-	if (size < BUF_PAGE_SIZE * 2)
-		size = BUF_PAGE_SIZE * 2;
+	if (nr_pages < 2)
+		nr_pages = 2;
 
-	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+	size = nr_pages * BUF_PAGE_SIZE;
 
 	/*
 	 * Don't succeed if resizing is disabled, as a reader might be
@@ -4640,8 +4640,9 @@ static int rb_cpu_notify(struct notifier_block *self,
 	struct ring_buffer *buffer =
 		container_of(self, struct ring_buffer, cpu_notify);
 	long cpu = (long)hcpu;
-	int cpu_i, nr_pages_same;
-	unsigned int nr_pages;
+	long nr_pages_same;
+	int cpu_i;
+	unsigned long nr_pages;
 
 	switch (action) {
 	case CPU_UP_PREPARE:
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8305cbb2d..a2f0b9f33 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -74,11 +74,6 @@ static struct tracer_opt dummy_tracer_opt[] = {
 	{ }
 };
 
-static struct tracer_flags dummy_tracer_flags = {
-	.val = 0,
-	.opts = dummy_tracer_opt
-};
-
 static int
 dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
@@ -1258,12 +1253,22 @@ int __init register_tracer(struct tracer *type)
 
 	if (!type->set_flag)
 		type->set_flag = &dummy_set_flag;
-	if (!type->flags)
-		type->flags = &dummy_tracer_flags;
-	else
+	if (!type->flags) {
+		/*allocate a dummy tracer_flags*/
+		type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL);
+		if (!type->flags) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		type->flags->val = 0;
+		type->flags->opts = dummy_tracer_opt;
+	} else
 		if (!type->flags->opts)
 			type->flags->opts = dummy_tracer_opt;
 
+	/* store the tracer for __set_tracer_option */
+	type->flags->trace = type;
+
 	ret = run_tracer_selftest(type);
 	if (ret < 0)
 		goto out;
@@ -1659,6 +1664,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 #else
 		TRACE_FLAG_IRQS_NOSUPPORT |
 #endif
+		((pc & NMI_MASK    ) ? TRACE_FLAG_NMI     : 0) |
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
 		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
 		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
@@ -2071,20 +2077,20 @@ void trace_printk_init_buffers(void)
 
 	/* trace_printk() is for debug use only. Don't use it in production. */
 
-	pr_warning("\n");
-	pr_warning("**********************************************************\n");
-	pr_warning("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
-	pr_warning("**                                                      **\n");
-	pr_warning("** trace_printk() being used. Allocating extra memory.  **\n");
-	pr_warning("**                                                      **\n");
-	pr_warning("** This means that this is a DEBUG kernel and it is     **\n");
-	pr_warning("** unsafe for production use.                           **\n");
-	pr_warning("**                                                      **\n");
-	pr_warning("** If you see this message and you are not debugging    **\n");
-	pr_warning("** the kernel, report this immediately to your vendor!  **\n");
-	pr_warning("**                                                      **\n");
-	pr_warning("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
-	pr_warning("**********************************************************\n");
+	pr_warn("\n");
+	pr_warn("**********************************************************\n");
+	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** trace_printk() being used. Allocating extra memory.  **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** This means that this is a DEBUG kernel and it is     **\n");
+	pr_warn("** unsafe for production use.                           **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** If you see this message and you are not debugging    **\n");
+	pr_warn("** the kernel, report this immediately to your vendor!  **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+	pr_warn("**********************************************************\n");
 
 	/* Expand the buffers to set size */
 	tracing_update_buffers();
@@ -3505,7 +3511,7 @@ static int __set_tracer_option(struct trace_array *tr,
 			       struct tracer_flags *tracer_flags,
 			       struct tracer_opt *opts, int neg)
 {
-	struct tracer *trace = tr->current_trace;
+	struct tracer *trace = tracer_flags->trace;
 	int ret;
 
 	ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
@@ -4101,7 +4107,7 @@ trace_insert_enum_map_file(struct module *mod, struct trace_enum_map **start,
 	 */
 	map_array = kmalloc(sizeof(*map_array) * (len + 2), GFP_KERNEL);
 	if (!map_array) {
-		pr_warning("Unable to allocate trace enum mapping\n");
+		pr_warn("Unable to allocate trace enum mapping\n");
 		return;
 	}
 
@@ -6134,7 +6140,7 @@ tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
 	snprintf(cpu_dir, 30, "cpu%ld", cpu);
 	d_cpu = tracefs_create_dir(cpu_dir, d_percpu);
 	if (!d_cpu) {
-		pr_warning("Could not create tracefs '%s' entry\n", cpu_dir);
+		pr_warn("Could not create tracefs '%s' entry\n", cpu_dir);
 		return;
 	}
 
@@ -6321,7 +6327,7 @@ struct dentry *trace_create_file(const char *name,
 
 	ret = tracefs_create_file(name, mode, parent, data, fops);
 	if (!ret)
-		pr_warning("Could not create tracefs '%s' entry\n", name);
+		pr_warn("Could not create tracefs '%s' entry\n", name);
 
 	return ret;
 }
@@ -6340,7 +6346,7 @@ static struct dentry *trace_options_init_dentry(struct trace_array *tr)
 
 	tr->options = tracefs_create_dir("options", d_tracer);
 	if (!tr->options) {
-		pr_warning("Could not create tracefs directory 'options'\n");
+		pr_warn("Could not create tracefs directory 'options'\n");
 		return NULL;
 	}
 
@@ -6394,11 +6400,8 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
 		return;
 
 	for (i = 0; i < tr->nr_topts; i++) {
-		/*
-		 * Check if these flags have already been added.
-		 * Some tracers share flags.
-		 */
-		if (tr->topts[i].tracer->flags == tracer->flags)
+		/* Make sure there's no duplicate flags. */
+		if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags))
 			return;
 	}
 
@@ -7251,8 +7254,8 @@ __init static int tracer_alloc_buffers(void)
 	if (trace_boot_clock) {
 		ret = tracing_set_clock(&global_trace, trace_boot_clock);
 		if (ret < 0)
-			pr_warning("Trace clock %s not defined, going back to default\n",
-				   trace_boot_clock);
+			pr_warn("Trace clock %s not defined, going back to default\n",
+				trace_boot_clock);
 	}
 
 	/*
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8414fa40b..3fff4adfd 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -125,6 +125,7 @@ enum trace_flag_type {
 	TRACE_FLAG_HARDIRQ		= 0x08,
 	TRACE_FLAG_SOFTIRQ		= 0x10,
 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
+	TRACE_FLAG_NMI			= 0x40,
 };
 
 #define TRACE_BUF_SIZE		1024
@@ -345,6 +346,7 @@ struct tracer_opt {
 struct tracer_flags {
 	u32			val;
 	struct tracer_opt	*opts;
+	struct tracer		*trace;
 };
 
 /* Makes more easy to define a tracer opt */
@@ -1111,6 +1113,18 @@ struct filter_pred {
 	unsigned short		right;
 };
 
+static inline bool is_string_field(struct ftrace_event_field *field)
+{
+	return field->filter_type == FILTER_DYN_STRING ||
+	       field->filter_type == FILTER_STATIC_STRING ||
+	       field->filter_type == FILTER_PTR_STRING;
+}
+
+static inline bool is_function_field(struct ftrace_event_field *field)
+{
+	return field->filter_type == FILTER_TRACE_FN;
+}
+
 extern enum regex_type
 filter_parse_regex(char *buff, int len, char **search, int *not);
 extern void print_event_filter(struct trace_event_file *file,
@@ -1159,9 +1173,24 @@ struct event_trigger_data {
 	struct event_filter __rcu	*filter;
 	char				*filter_str;
 	void				*private_data;
+	bool				paused;
 	struct list_head		list;
 };
 
+extern void trigger_data_free(struct event_trigger_data *data);
+extern int event_trigger_init(struct event_trigger_ops *ops,
+			      struct event_trigger_data *data);
+extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
+					      int trigger_enable);
+extern void update_cond_flag(struct trace_event_file *file);
+extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
+			       struct event_trigger_data *test,
+			       struct trace_event_file *file);
+extern int set_trigger_filter(char *filter_str,
+			      struct event_trigger_data *trigger_data,
+			      struct trace_event_file *file);
+extern int register_event_command(struct event_command *cmd);
+
 /**
  * struct event_trigger_ops - callbacks for trace event triggers
  *
@@ -1174,7 +1203,8 @@ struct event_trigger_data {
  * @func: The trigger 'probe' function called when the triggering
  *	event occurs.  The data passed into this callback is the data
  *	that was supplied to the event_command @reg() function that
- *	registered the trigger (see struct event_command).
+ *	registered the trigger (see struct event_command) along with
+ *	the trace record, rec.
  *
  * @init: An optional initialization function called for the trigger
  *	when the trigger is registered (via the event_command reg()
@@ -1199,7 +1229,8 @@ struct event_trigger_data {
  *	(see trace_event_triggers.c).
  */
 struct event_trigger_ops {
-	void			(*func)(struct event_trigger_data *data);
+	void			(*func)(struct event_trigger_data *data,
+					void *rec);
 	int			(*init)(struct event_trigger_ops *ops,
 					struct event_trigger_data *data);
 	void			(*free)(struct event_trigger_ops *ops,
@@ -1243,27 +1274,10 @@ struct event_trigger_ops {
  *	values are defined by adding new values to the trigger_type
  *	enum in include/linux/trace_events.h.
  *
- * @post_trigger: A flag that says whether or not this command needs
- *	to have its action delayed until after the current event has
- *	been closed.  Some triggers need to avoid being invoked while
- *	an event is currently in the process of being logged, since
- *	the trigger may itself log data into the trace buffer.  Thus
- *	we make sure the current event is committed before invoking
- *	those triggers.  To do that, the trigger invocation is split
- *	in two - the first part checks the filter using the current
- *	trace record; if a command has the @post_trigger flag set, it
- *	sets a bit for itself in the return value, otherwise it
- *	directly invokes the trigger.  Once all commands have been
- *	either invoked or set their return flag, the current record is
- *	either committed or discarded.  At that point, if any commands
- *	have deferred their triggers, those commands are finally
- *	invoked following the close of the current event.  In other
- *	words, if the event_trigger_ops @func() probe implementation
- *	itself logs to the trace buffer, this flag should be set,
- *	otherwise it can be left unspecified.
+ * @flags: See the enum event_command_flags below.
  *
- * All the methods below, except for @set_filter(), must be
- * implemented.
+ * All the methods below, except for @set_filter() and @unreg_all(),
+ * must be implemented.
  *
  * @func: The callback function responsible for parsing and
  *	registering the trigger written to the 'trigger' file by the
@@ -1288,6 +1302,10 @@ struct event_trigger_ops {
  *	This is usually implemented by the generic utility function
  *	@unregister_trigger() (see trace_event_triggers.c).
  *
+ * @unreg_all: An optional function called to remove all the triggers
+ *	from the list of triggers associated with the event.  Called
+ *	when a trigger file is opened in truncate mode.
+ *
  * @set_filter: An optional function called to parse and set a filter
  *	for the trigger.  If no @set_filter() method is set for the
  *	event command, filters set by the user for the command will be
@@ -1301,7 +1319,7 @@ struct event_command {
 	struct list_head	list;
 	char			*name;
 	enum event_trigger_type	trigger_type;
-	bool			post_trigger;
+	int			flags;
 	int			(*func)(struct event_command *cmd_ops,
 					struct trace_event_file *file,
 					char *glob, char *cmd, char *params);
@@ -1313,12 +1331,56 @@ struct event_command {
 					 struct event_trigger_ops *ops,
 					 struct event_trigger_data *data,
 					 struct trace_event_file *file);
+	void			(*unreg_all)(struct trace_event_file *file);
 	int			(*set_filter)(char *filter_str,
 					      struct event_trigger_data *data,
 					      struct trace_event_file *file);
 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
 };
 
+/**
+ * enum event_command_flags - flags for struct event_command
+ *
+ * @POST_TRIGGER: A flag that says whether or not this command needs
+ *	to have its action delayed until after the current event has
+ *	been closed.  Some triggers need to avoid being invoked while
+ *	an event is currently in the process of being logged, since
+ *	the trigger may itself log data into the trace buffer.  Thus
+ *	we make sure the current event is committed before invoking
+ *	those triggers.  To do that, the trigger invocation is split
+ *	in two - the first part checks the filter using the current
+ *	trace record; if a command has the @post_trigger flag set, it
+ *	sets a bit for itself in the return value, otherwise it
+ *	directly invokes the trigger.  Once all commands have been
+ *	either invoked or set their return flag, the current record is
+ *	either committed or discarded.  At that point, if any commands
+ *	have deferred their triggers, those commands are finally
+ *	invoked following the close of the current event.  In other
+ *	words, if the event_trigger_ops @func() probe implementation
+ *	itself logs to the trace buffer, this flag should be set,
+ *	otherwise it can be left unspecified.
+ *
+ * @NEEDS_REC: A flag that says whether or not this command needs
+ *	access to the trace record in order to perform its function,
+ *	regardless of whether or not it has a filter associated with
+ *	it (filters make a trigger require access to the trace record
+ *	but are not always present).
+ */
+enum event_command_flags {
+	EVENT_CMD_FL_POST_TRIGGER	= 1,
+	EVENT_CMD_FL_NEEDS_REC		= 2,
+};
+
+static inline bool event_command_post_trigger(struct event_command *cmd_ops)
+{
+	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
+}
+
+static inline bool event_command_needs_rec(struct event_command *cmd_ops)
+{
+	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
+}
+
 extern int trace_event_enable_disable(struct trace_event_file *file,
 				      int enable, int soft_disable);
 extern int tracing_alloc_snapshot(void);
@@ -1365,8 +1427,13 @@ int perf_ftrace_event_register(struct trace_event_call *call,
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 void init_ftrace_syscalls(void);
+const char *get_syscall_name(int syscall);
 #else
 static inline void init_ftrace_syscalls(void) { }
+static inline const char *get_syscall_name(int syscall)
+{
+	return NULL;
+}
 #endif
 
 #ifdef CONFIG_EVENT_TRACING
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 681630254..b3f5051cd 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -961,18 +961,6 @@ int filter_assign_type(const char *type)
 	return FILTER_OTHER;
 }
 
-static bool is_function_field(struct ftrace_event_field *field)
-{
-	return field->filter_type == FILTER_TRACE_FN;
-}
-
-static bool is_string_field(struct ftrace_event_field *field)
-{
-	return field->filter_type == FILTER_DYN_STRING ||
-	       field->filter_type == FILTER_STATIC_STRING ||
-	       field->filter_type == FILTER_PTR_STRING;
-}
-
 static bool is_legal_op(struct ftrace_event_field *field, int op)
 {
 	if (is_string_field(field) &&
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index b38f617b6..d67992f3b 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -28,8 +28,7 @@
 static LIST_HEAD(trigger_commands);
 static DEFINE_MUTEX(trigger_cmd_mutex);
 
-static void
-trigger_data_free(struct event_trigger_data *data)
+void trigger_data_free(struct event_trigger_data *data)
 {
 	if (data->cmd_ops->set_filter)
 		data->cmd_ops->set_filter(NULL, data, NULL);
@@ -73,18 +72,20 @@ event_triggers_call(struct trace_event_file *file, void *rec)
 		return tt;
 
 	list_for_each_entry_rcu(data, &file->triggers, list) {
+		if (data->paused)
+			continue;
 		if (!rec) {
-			data->ops->func(data);
+			data->ops->func(data, rec);
 			continue;
 		}
 		filter = rcu_dereference_sched(data->filter);
 		if (filter && !filter_match_preds(filter, rec))
 			continue;
-		if (data->cmd_ops->post_trigger) {
+		if (event_command_post_trigger(data->cmd_ops)) {
 			tt |= data->cmd_ops->trigger_type;
 			continue;
 		}
-		data->ops->func(data);
+		data->ops->func(data, rec);
 	}
 	return tt;
 }
@@ -94,6 +95,7 @@ EXPORT_SYMBOL_GPL(event_triggers_call);
  * event_triggers_post_call - Call 'post_triggers' for a trace event
  * @file: The trace_event_file associated with the event
  * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
+ * @rec: The trace entry for the event
  *
  * For each trigger associated with an event, invoke the trigger
  * function registered with the associated trigger command, if the
@@ -104,13 +106,16 @@ EXPORT_SYMBOL_GPL(event_triggers_call);
  */
 void
 event_triggers_post_call(struct trace_event_file *file,
-			 enum event_trigger_type tt)
+			 enum event_trigger_type tt,
+			 void *rec)
 {
 	struct event_trigger_data *data;
 
 	list_for_each_entry_rcu(data, &file->triggers, list) {
+		if (data->paused)
+			continue;
 		if (data->cmd_ops->trigger_type & tt)
-			data->ops->func(data);
+			data->ops->func(data, rec);
 	}
 }
 EXPORT_SYMBOL_GPL(event_triggers_post_call);
@@ -188,6 +193,19 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
 		return -ENODEV;
 	}
 
+	if ((file->f_mode & FMODE_WRITE) &&
+	    (file->f_flags & O_TRUNC)) {
+		struct trace_event_file *event_file;
+		struct event_command *p;
+
+		event_file = event_file_data(file);
+
+		list_for_each_entry(p, &trigger_commands, list) {
+			if (p->unreg_all)
+				p->unreg_all(event_file);
+		}
+	}
+
 	if (file->f_mode & FMODE_READ) {
 		ret = seq_open(file, &event_triggers_seq_ops);
 		if (!ret) {
@@ -306,7 +324,7 @@ const struct file_operations event_trigger_fops = {
  * Currently we only register event commands from __init, so mark this
  * __init too.
  */
-static __init int register_event_command(struct event_command *cmd)
+__init int register_event_command(struct event_command *cmd)
 {
 	struct event_command *p;
 	int ret = 0;
@@ -395,9 +413,8 @@ event_trigger_print(const char *name, struct seq_file *m,
  *
  * Return: 0 on success, errno otherwise
  */
-static int
-event_trigger_init(struct event_trigger_ops *ops,
-		   struct event_trigger_data *data)
+int event_trigger_init(struct event_trigger_ops *ops,
+		       struct event_trigger_data *data)
 {
 	data->ref++;
 	return 0;
@@ -425,8 +442,8 @@ event_trigger_free(struct event_trigger_ops *ops,
 		trigger_data_free(data);
 }
 
-static int trace_event_trigger_enable_disable(struct trace_event_file *file,
-					      int trigger_enable)
+int trace_event_trigger_enable_disable(struct trace_event_file *file,
+				       int trigger_enable)
 {
 	int ret = 0;
 
@@ -483,13 +500,14 @@ clear_event_triggers(struct trace_array *tr)
  * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
  * cleared.
  */
-static void update_cond_flag(struct trace_event_file *file)
+void update_cond_flag(struct trace_event_file *file)
 {
 	struct event_trigger_data *data;
 	bool set_cond = false;
 
 	list_for_each_entry_rcu(data, &file->triggers, list) {
-		if (data->filter || data->cmd_ops->post_trigger) {
+		if (data->filter || event_command_post_trigger(data->cmd_ops) ||
+		    event_command_needs_rec(data->cmd_ops)) {
 			set_cond = true;
 			break;
 		}
@@ -560,9 +578,9 @@ out:
  * Usually used directly as the @unreg method in event command
  * implementations.
  */
-static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
-			       struct event_trigger_data *test,
-			       struct trace_event_file *file)
+void unregister_trigger(char *glob, struct event_trigger_ops *ops,
+			struct event_trigger_data *test,
+			struct trace_event_file *file)
 {
 	struct event_trigger_data *data;
 	bool unregistered = false;
@@ -696,9 +714,9 @@ event_trigger_callback(struct event_command *cmd_ops,
  *
  * Return: 0 on success, errno otherwise
  */
-static int set_trigger_filter(char *filter_str,
-			      struct event_trigger_data *trigger_data,
-			      struct trace_event_file *file)
+int set_trigger_filter(char *filter_str,
+		       struct event_trigger_data *trigger_data,
+		       struct trace_event_file *file)
 {
 	struct event_trigger_data *data = trigger_data;
 	struct event_filter *filter = NULL, *tmp;
@@ -747,7 +765,7 @@ static int set_trigger_filter(char *filter_str,
 }
 
 static void
-traceon_trigger(struct event_trigger_data *data)
+traceon_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (tracing_is_on())
 		return;
@@ -756,7 +774,7 @@ traceon_trigger(struct event_trigger_data *data)
 }
 
 static void
-traceon_count_trigger(struct event_trigger_data *data)
+traceon_count_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (tracing_is_on())
 		return;
@@ -771,7 +789,7 @@ traceon_count_trigger(struct event_trigger_data *data)
 }
 
 static void
-traceoff_trigger(struct event_trigger_data *data)
+traceoff_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (!tracing_is_on())
 		return;
@@ -780,7 +798,7 @@ traceoff_trigger(struct event_trigger_data *data)
 }
 
 static void
-traceoff_count_trigger(struct event_trigger_data *data)
+traceoff_count_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (!tracing_is_on())
 		return;
@@ -876,13 +894,13 @@ static struct event_command trigger_traceoff_cmd = {
 
 #ifdef CONFIG_TRACER_SNAPSHOT
 static void
-snapshot_trigger(struct event_trigger_data *data)
+snapshot_trigger(struct event_trigger_data *data, void *rec)
 {
 	tracing_snapshot();
 }
 
 static void
-snapshot_count_trigger(struct event_trigger_data *data)
+snapshot_count_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (!data->count)
 		return;
@@ -890,7 +908,7 @@ snapshot_count_trigger(struct event_trigger_data *data)
 	if (data->count != -1)
 		(data->count)--;
 
-	snapshot_trigger(data);
+	snapshot_trigger(data, rec);
 }
 
 static int
@@ -969,13 +987,13 @@ static __init int register_trigger_snapshot_cmd(void) { return 0; }
 #define STACK_SKIP 3
 
 static void
-stacktrace_trigger(struct event_trigger_data *data)
+stacktrace_trigger(struct event_trigger_data *data, void *rec)
 {
 	trace_dump_stack(STACK_SKIP);
 }
 
 static void
-stacktrace_count_trigger(struct event_trigger_data *data)
+stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
 {
 	if (!data->count)
 		return;
@@ -983,7 +1001,7 @@ stacktrace_count_trigger(struct event_trigger_data *data)
 	if (data->count != -1)
 		(data->count)--;
 
-	stacktrace_trigger(data);
+	stacktrace_trigger(data, rec);
 }
 
 static int
@@ -1017,7 +1035,7 @@ stacktrace_get_trigger_ops(char *cmd, char *param)
 static struct event_command trigger_stacktrace_cmd = {
 	.name			= "stacktrace",
 	.trigger_type		= ETT_STACKTRACE,
-	.post_trigger		= true,
+	.flags			= EVENT_CMD_FL_POST_TRIGGER,
 	.func			= event_trigger_callback,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
@@ -1054,7 +1072,7 @@ struct enable_trigger_data {
 };
 
 static void
-event_enable_trigger(struct event_trigger_data *data)
+event_enable_trigger(struct event_trigger_data *data, void *rec)
 {
 	struct enable_trigger_data *enable_data = data->private_data;
 
@@ -1065,7 +1083,7 @@ event_enable_trigger(struct event_trigger_data *data)
 }
 
 static void
-event_enable_count_trigger(struct event_trigger_data *data)
+event_enable_count_trigger(struct event_trigger_data *data, void *rec)
 {
 	struct enable_trigger_data *enable_data = data->private_data;
 
@@ -1079,7 +1097,7 @@ event_enable_count_trigger(struct event_trigger_data *data)
 	if (data->count != -1)
 		(data->count)--;
 
-	event_enable_trigger(data);
+	event_enable_trigger(data, rec);
 }
 
 static int
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index fcd41a166..5a095c2e4 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -219,6 +219,8 @@ static void tracing_stop_function_trace(struct trace_array *tr)
 	unregister_ftrace_function(tr->ops);
 }
 
+static struct tracer function_trace;
+
 static int
 func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
@@ -228,6 +230,10 @@ func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 		if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
 			break;
 
+		/* We can change this flag when not running. */
+		if (tr->current_trace != &function_trace)
+			break;
+
 		unregister_ftrace_function(tr->ops);
 
 		if (set) {
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index a663cbb84..3a0244ff7 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -8,6 +8,7 @@
  */
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 
@@ -1350,7 +1351,7 @@ void graph_trace_open(struct trace_iterator *iter)
  out_err_free:
 	kfree(data);
  out_err:
-	pr_warning("function graph tracer: not enough memory\n");
+	pr_warn("function graph tracer: not enough memory\n");
 }
 
 void graph_trace_close(struct trace_iterator *iter)
@@ -1468,12 +1469,12 @@ static __init int init_graph_trace(void)
 	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
 
 	if (!register_trace_event(&graph_trace_entry_event)) {
-		pr_warning("Warning: could not register graph trace events\n");
+		pr_warn("Warning: could not register graph trace events\n");
 		return 1;
 	}
 
 	if (!register_trace_event(&graph_trace_ret_event)) {
-		pr_warning("Warning: could not register graph trace events\n");
+		pr_warn("Warning: could not register graph trace events\n");
 		return 1;
 	}
 
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index be3222b7d..03cdff84d 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -626,7 +626,6 @@ static int __irqsoff_tracer_init(struct trace_array *tr)
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();
-	tracing_reset_online_cpus(&tr->trace_buffer);
 
 	ftrace_init_array_ops(tr, irqsoff_tracer_call);
 
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c9956440d..919e0ddd8 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -30,7 +30,7 @@
 struct trace_kprobe {
 	struct list_head	list;
 	struct kretprobe	rp;	/* Use rp.kp for kprobe use */
-	unsigned long 		nhit;
+	unsigned long __percpu *nhit;
 	const char		*symbol;	/* symbol name */
 	struct trace_probe	tp;
 };
@@ -274,6 +274,10 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 	if (!tk)
 		return ERR_PTR(ret);
 
+	tk->nhit = alloc_percpu(unsigned long);
+	if (!tk->nhit)
+		goto error;
+
 	if (symbol) {
 		tk->symbol = kstrdup(symbol, GFP_KERNEL);
 		if (!tk->symbol)
@@ -313,6 +317,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 error:
 	kfree(tk->tp.call.name);
 	kfree(tk->symbol);
+	free_percpu(tk->nhit);
 	kfree(tk);
 	return ERR_PTR(ret);
 }
@@ -327,6 +332,7 @@ static void free_trace_kprobe(struct trace_kprobe *tk)
 	kfree(tk->tp.call.class->system);
 	kfree(tk->tp.call.name);
 	kfree(tk->symbol);
+	free_percpu(tk->nhit);
 	kfree(tk);
 }
 
@@ -453,16 +459,14 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
 	if (ret == 0)
 		tk->tp.flags |= TP_FLAG_REGISTERED;
 	else {
-		pr_warning("Could not insert probe at %s+%lu: %d\n",
-			   trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
+		pr_warn("Could not insert probe at %s+%lu: %d\n",
+			trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
 		if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
-			pr_warning("This probe might be able to register after"
-				   "target module is loaded. Continue.\n");
+			pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 			ret = 0;
 		} else if (ret == -EILSEQ) {
-			pr_warning("Probing address(0x%p) is not an "
-				   "instruction boundary.\n",
-				   tk->rp.kp.addr);
+			pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
+				tk->rp.kp.addr);
 			ret = -EINVAL;
 		}
 	}
@@ -523,7 +527,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
 	/* Register new event */
 	ret = register_kprobe_event(tk);
 	if (ret) {
-		pr_warning("Failed to register probe event(%d)\n", ret);
+		pr_warn("Failed to register probe event(%d)\n", ret);
 		goto end;
 	}
 
@@ -558,10 +562,9 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
 			__unregister_trace_kprobe(tk);
 			ret = __register_trace_kprobe(tk);
 			if (ret)
-				pr_warning("Failed to re-register probe %s on"
-					   "%s: %d\n",
-					   trace_event_name(&tk->tp.call),
-					   mod->name, ret);
+				pr_warn("Failed to re-register probe %s on %s: %d\n",
+					trace_event_name(&tk->tp.call),
+					mod->name, ret);
 		}
 	}
 	mutex_unlock(&probe_lock);
@@ -874,9 +877,14 @@ static const struct file_operations kprobe_events_ops = {
 static int probes_profile_seq_show(struct seq_file *m, void *v)
 {
 	struct trace_kprobe *tk = v;
+	unsigned long nhit = 0;
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		nhit += *per_cpu_ptr(tk->nhit, cpu);
 
 	seq_printf(m, "  %-44s %15lu %15lu\n",
-		   trace_event_name(&tk->tp.call), tk->nhit,
+		   trace_event_name(&tk->tp.call), nhit,
 		   tk->rp.kp.nmissed);
 
 	return 0;
@@ -1225,7 +1233,7 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
 {
 	struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
 
-	tk->nhit++;
+	raw_cpu_inc(*tk->nhit);
 
 	if (tk->tp.flags & TP_FLAG_TRACE)
 		kprobe_trace_func(tk, regs);
@@ -1242,7 +1250,7 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
 
-	tk->nhit++;
+	raw_cpu_inc(*tk->nhit);
 
 	if (tk->tp.flags & TP_FLAG_TRACE)
 		kretprobe_trace_func(tk, ri, regs);
@@ -1325,16 +1333,14 @@ static __init int init_kprobe_trace(void)
 
 	/* Event list interface */
 	if (!entry)
-		pr_warning("Could not create tracefs "
-			   "'kprobe_events' entry\n");
+		pr_warn("Could not create tracefs 'kprobe_events' entry\n");
 
 	/* Profile interface */
 	entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
 				    NULL, &kprobe_profile_ops);
 
 	if (!entry)
-		pr_warning("Could not create tracefs "
-			   "'kprobe_profile' entry\n");
+		pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
 	return 0;
 }
 fs_initcall(init_kprobe_trace);
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 2be8c4f24..68f376ca6 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -146,7 +146,7 @@ static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 		/* XXX: This is later than where events were lost. */
 		trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
 		if (!overrun_detected)
-			pr_warning("mmiotrace has lost events.\n");
+			pr_warn("mmiotrace has lost events\n");
 		overrun_detected = true;
 		goto print_out;
 	}
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 8bb207147..49f61fe96 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -56,7 +56,7 @@ static void nop_trace_reset(struct trace_array *tr)
 }
 
 /* It only serves as a signal handler and a callback to
- * accept or refuse tthe setting of a flag.
+ * accept or refuse the setting of a flag.
  * If you don't implement it, then the flag setting will be
  * automatically accepted.
  */
@@ -75,7 +75,7 @@ static int nop_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 
 	if (bit == TRACE_NOP_OPT_REFUSE) {
 		printk(KERN_DEBUG "nop_test_refuse flag set to %d: we refuse."
-			"Now cat trace_options to see the result\n",
+			" Now cat trace_options to see the result\n",
 			set);
 		return -EINVAL;
 	}
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 282982195..0bb9cf2d5 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -389,7 +389,9 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 	char irqs_off;
 	int hardirq;
 	int softirq;
+	int nmi;
 
+	nmi = entry->flags & TRACE_FLAG_NMI;
 	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 
@@ -415,10 +417,12 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 	}
 
 	hardsoft_irq =
+		(nmi && hardirq)     ? 'Z' :
+		nmi                  ? 'z' :
 		(hardirq && softirq) ? 'H' :
-		hardirq ? 'h' :
-		softirq ? 's' :
-		'.';
+		hardirq              ? 'h' :
+		softirq              ? 's' :
+		                       '.' ;
 
 	trace_seq_printf(s, "%c%c%c",
 			 irqs_off, need_resched, hardsoft_irq);
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 1769a81da..1d372fa6f 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -636,8 +636,8 @@ ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
 			*tmp = '\0';
 			size = tmp - kbuf + 1;
 		} else if (done + size < count) {
-			pr_warning("Line length is too long: "
-				   "Should be less than %d.", WRITE_BUFSIZE);
+			pr_warn("Line length is too long: Should be less than %d\n",
+				WRITE_BUFSIZE);
 			ret = -EINVAL;
 			goto out;
 		}
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 6cf935316..413ff108f 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -281,8 +281,7 @@ static int tracing_stat_init(void)
 
 	stat_dir = tracefs_create_dir("trace_stat", d_tracing);
 	if (!stat_dir)
-		pr_warning("Could not create tracefs "
-			   "'trace_stat' entry\n");
+		pr_warn("Could not create tracefs 'trace_stat' entry\n");
 	return 0;
 }
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 0655afbea..e78f364cc 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -106,6 +106,17 @@ static struct syscall_metadata *syscall_nr_to_meta(int nr)
 	return syscalls_metadata[nr];
 }
 
+const char *get_syscall_name(int syscall)
+{
+	struct syscall_metadata *entry;
+
+	entry = syscall_nr_to_meta(syscall);
+	if (!entry)
+		return NULL;
+
+	return entry->name;
+}
+
 static enum print_line_t
 print_syscall_enter(struct trace_iterator *iter, int flags,
 		    struct trace_event *event)
@@ -186,11 +197,11 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
 
 extern char *__bad_type_size(void);
 
-#define SYSCALL_FIELD(type, name)					\
-	sizeof(type) != sizeof(trace.name) ?				\
+#define SYSCALL_FIELD(type, field, name)				\
+	sizeof(type) != sizeof(trace.field) ?				\
 		__bad_type_size() :					\
-		#type, #name, offsetof(typeof(trace), name),		\
-		sizeof(trace.name), is_signed_type(type)
+		#type, #name, offsetof(typeof(trace), field),		\
+		sizeof(trace.field), is_signed_type(type)
 
 static int __init
 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
@@ -261,7 +272,8 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
 	int i;
 	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+				 FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -281,11 +293,12 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
 	struct syscall_trace_exit trace;
 	int ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+				 FILTER_OTHER);
 	if (ret)
 		return ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
+	ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret),
 				 FILTER_OTHER);
 
 	return ret;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index d2f6d0be3..7915142c8 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -334,7 +334,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
 
 	ret = register_uprobe_event(tu);
 	if (ret) {
-		pr_warning("Failed to register probe event(%d)\n", ret);
+		pr_warn("Failed to register probe event(%d)\n", ret);
 		goto end;
 	}
 
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index ecd536de6..d0639d917 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -491,7 +491,7 @@ static __init int init_tracepoints(void)
 
 	ret = register_module_notifier(&tracepoint_module_nb);
 	if (ret)
-		pr_warning("Failed to register tracepoint module enter notifier\n");
+		pr_warn("Failed to register tracepoint module enter notifier\n");
 
 	return ret;
 }
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 9e82d0450..5f5068e94 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -320,8 +320,7 @@ static bool wq_debug_force_rr_cpu = false;
 module_param_named(debug_force_rr_cpu, wq_debug_force_rr_cpu, bool, 0644);
 
 /* the per-cpu worker pools */
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],
-				     cpu_worker_pools);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS], cpu_worker_pools);
 
 static DEFINE_IDR(worker_pool_idr);	/* PR: idr of all pools */
 
@@ -887,7 +886,6 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
 /**
  * wq_worker_sleeping - a worker is going to sleep
  * @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
  *
  * This function is called during schedule() when a busy worker is
  * going to sleep.  Worker on the same cpu can be woken up by
@@ -899,7 +897,7 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
  * Return:
  * Worker task on @cpu to wake up, %NULL if none.
  */
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+struct task_struct *wq_worker_sleeping(struct task_struct *task)
 {
 	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
 	struct worker_pool *pool;
@@ -915,7 +913,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
 	pool = worker->pool;
 
 	/* this can only happen on the local cpu */
-	if (WARN_ON_ONCE(cpu != raw_smp_processor_id() || pool->cpu != cpu))
+	if (WARN_ON_ONCE(pool->cpu != raw_smp_processor_id()))
 		return NULL;
 
 	/*
@@ -4556,6 +4554,17 @@ static void rebind_workers(struct worker_pool *pool)
 						  pool->attrs->cpumask) < 0);
 
 	spin_lock_irq(&pool->lock);
+
+	/*
+	 * XXX: CPU hotplug notifiers are weird and can call DOWN_FAILED
+	 * w/o preceding DOWN_PREPARE.  Work around it.  CPU hotplug is
+	 * being reworked and this can go away in time.
+	 */
+	if (!(pool->flags & POOL_DISASSOCIATED)) {
+		spin_unlock_irq(&pool->lock);
+		return;
+	}
+
 	pool->flags &= ~POOL_DISASSOCIATED;
 
 	for_each_pool_worker(worker, pool) {
@@ -4725,7 +4734,7 @@ static void work_for_cpu_fn(struct work_struct *work)
 }
 
 /**
- * work_on_cpu - run a function in user context on a particular cpu
+ * work_on_cpu - run a function in thread context on a particular cpu
  * @cpu: the cpu to run on
  * @fn: the function to run
  * @arg: the function arg
@@ -5251,8 +5260,8 @@ int workqueue_sysfs_register(struct workqueue_struct *wq)
 
 	wq_dev->wq = wq;
 	wq_dev->dev.bus = &wq_subsys;
-	wq_dev->dev.init_name = wq->name;
 	wq_dev->dev.release = wq_device_release;
+	dev_set_name(&wq_dev->dev, "%s", wq->name);
 
 	/*
 	 * unbound_attrs are created separately.  Suppress uevent until
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index 45215870a..8635417c5 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -69,6 +69,6 @@ static inline struct worker *current_wq_worker(void)
  * sched/core.c and workqueue.c.
  */
 void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+struct task_struct *wq_worker_sleeping(struct task_struct *task);
 
 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */