diff options
Diffstat (limited to 'kernel')
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(¤t->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(¤t->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 = ¤t->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(¤t->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(¤t->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(¤t->tick_dep_mask) || + atomic_read(¤t->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 */ |