Linux-libre 4.7.1-gnupck-4.7.1-gnu

11 files changed, 190 insertions, 49 deletions

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 78c1c0ee6..81f1a7107 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -45,6 +45,7 @@
 #include <linux/bitops.h>
 #include <linux/gfp.h>
 #include <linux/kmemcheck.h>
+#include <linux/random.h>
 
 #include <asm/sections.h>
 
@@ -708,7 +709,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
  * yet. Otherwise we look it up. We cache the result in the lock object
  * itself, so actual lookup of the hash should be once per lock object.
  */
-static inline struct lock_class *
+static struct lock_class *
 register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 {
 	struct lockdep_subclass_key *key;
@@ -3585,7 +3586,35 @@ static int __lock_is_held(struct lockdep_map *lock)
 	return 0;
 }
 
-static void __lock_pin_lock(struct lockdep_map *lock)
+static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock)
+{
+	struct pin_cookie cookie = NIL_COOKIE;
+	struct task_struct *curr = current;
+	int i;
+
+	if (unlikely(!debug_locks))
+		return cookie;
+
+	for (i = 0; i < curr->lockdep_depth; i++) {
+		struct held_lock *hlock = curr->held_locks + i;
+
+		if (match_held_lock(hlock, lock)) {
+			/*
+			 * Grab 16bits of randomness; this is sufficient to not
+			 * be guessable and still allows some pin nesting in
+			 * our u32 pin_count.
+			 */
+			cookie.val = 1 + (prandom_u32() >> 16);
+			hlock->pin_count += cookie.val;
+			return cookie;
+		}
+	}
+
+	WARN(1, "pinning an unheld lock\n");
+	return cookie;
+}
+
+static void __lock_repin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
 {
 	struct task_struct *curr = current;
 	int i;
@@ -3597,7 +3626,7 @@ static void __lock_pin_lock(struct lockdep_map *lock)
 		struct held_lock *hlock = curr->held_locks + i;
 
 		if (match_held_lock(hlock, lock)) {
-			hlock->pin_count++;
+			hlock->pin_count += cookie.val;
 			return;
 		}
 	}
@@ -3605,7 +3634,7 @@ static void __lock_pin_lock(struct lockdep_map *lock)
 	WARN(1, "pinning an unheld lock\n");
 }
 
-static void __lock_unpin_lock(struct lockdep_map *lock)
+static void __lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
 {
 	struct task_struct *curr = current;
 	int i;
@@ -3620,7 +3649,11 @@ static void __lock_unpin_lock(struct lockdep_map *lock)
 			if (WARN(!hlock->pin_count, "unpinning an unpinned lock\n"))
 				return;
 
-			hlock->pin_count--;
+			hlock->pin_count -= cookie.val;
+
+			if (WARN((int)hlock->pin_count < 0, "pin count corrupted\n"))
+				hlock->pin_count = 0;
+
 			return;
 		}
 	}
@@ -3751,24 +3784,44 @@ int lock_is_held(struct lockdep_map *lock)
 }
 EXPORT_SYMBOL_GPL(lock_is_held);
 
-void lock_pin_lock(struct lockdep_map *lock)
+struct pin_cookie lock_pin_lock(struct lockdep_map *lock)
 {
+	struct pin_cookie cookie = NIL_COOKIE;
 	unsigned long flags;
 
 	if (unlikely(current->lockdep_recursion))
-		return;
+		return cookie;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
 	current->lockdep_recursion = 1;
-	__lock_pin_lock(lock);
+	cookie = __lock_pin_lock(lock);
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
+
+	return cookie;
 }
 EXPORT_SYMBOL_GPL(lock_pin_lock);
 
-void lock_unpin_lock(struct lockdep_map *lock)
+void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
+{
+	unsigned long flags;
+
+	if (unlikely(current->lockdep_recursion))
+		return;
+
+	raw_local_irq_save(flags);
+	check_flags(flags);
+
+	current->lockdep_recursion = 1;
+	__lock_repin_lock(lock, cookie);
+	current->lockdep_recursion = 0;
+	raw_local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(lock_repin_lock);
+
+void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
 {
 	unsigned long flags;
 
@@ -3779,7 +3832,7 @@ void lock_unpin_lock(struct lockdep_map *lock)
 	check_flags(flags);
 
 	current->lockdep_recursion = 1;
-	__lock_unpin_lock(lock);
+	__lock_unpin_lock(lock, cookie);
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 8ef1919d6..f8c5af52a 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -75,12 +75,7 @@ struct lock_stress_stats {
 	long n_lock_acquired;
 };
 
-#if defined(MODULE)
-#define LOCKTORTURE_RUNNABLE_INIT 1
-#else
-#define LOCKTORTURE_RUNNABLE_INIT 0
-#endif
-int torture_runnable = LOCKTORTURE_RUNNABLE_INIT;
+int torture_runnable = IS_ENABLED(MODULE);
 module_param(torture_runnable, int, 0444);
 MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init");
 
@@ -394,12 +389,12 @@ static void torture_rtmutex_boost(struct torture_random_state *trsp)
 
 	if (!rt_task(current)) {
 		/*
-		 * (1) Boost priority once every ~50k operations. When the
+		 * Boost priority once every ~50k operations. When the
 		 * task tries to take the lock, the rtmutex it will account
 		 * for the new priority, and do any corresponding pi-dance.
 		 */
-		if (!(torture_random(trsp) %
-		      (cxt.nrealwriters_stress * factor))) {
+		if (trsp && !(torture_random(trsp) %
+			      (cxt.nrealwriters_stress * factor))) {
 			policy = SCHED_FIFO;
 			param.sched_priority = MAX_RT_PRIO - 1;
 		} else /* common case, do nothing */
@@ -748,6 +743,15 @@ static void lock_torture_cleanup(void)
 	if (torture_cleanup_begin())
 		return;
 
+	/*
+	 * Indicates early cleanup, meaning that the test has not run,
+	 * such as when passing bogus args when loading the module. As
+	 * such, only perform the underlying torture-specific cleanups,
+	 * and avoid anything related to locktorture.
+	 */
+	if (!cxt.lwsa)
+		goto end;
+
 	if (writer_tasks) {
 		for (i = 0; i < cxt.nrealwriters_stress; i++)
 			torture_stop_kthread(lock_torture_writer,
@@ -776,6 +780,7 @@ static void lock_torture_cleanup(void)
 	else
 		lock_torture_print_module_parms(cxt.cur_ops,
 						"End of test: SUCCESS");
+end:
 	torture_cleanup_end();
 }
 
@@ -870,6 +875,7 @@ static int __init lock_torture_init(void)
 			VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
 			firsterr = -ENOMEM;
 			kfree(cxt.lwsa);
+			cxt.lwsa = NULL;
 			goto unwind;
 		}
 
@@ -878,6 +884,7 @@ static int __init lock_torture_init(void)
 			cxt.lrsa[i].n_lock_acquired = 0;
 		}
 	}
+
 	lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
 
 	/* Prepare torture context. */
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index 3ef373600..9c951fade 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -49,21 +49,21 @@ void debug_mutex_free_waiter(struct mutex_waiter *waiter)
 }
 
 void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
-			    struct thread_info *ti)
+			    struct task_struct *task)
 {
 	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
 
 	/* Mark the current thread as blocked on the lock: */
-	ti->task->blocked_on = waiter;
+	task->blocked_on = waiter;
 }
 
 void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
-			 struct thread_info *ti)
+			 struct task_struct *task)
 {
 	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
-	DEBUG_LOCKS_WARN_ON(waiter->task != ti->task);
-	DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter);
-	ti->task->blocked_on = NULL;
+	DEBUG_LOCKS_WARN_ON(waiter->task != task);
+	DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
+	task->blocked_on = NULL;
 
 	list_del_init(&waiter->list);
 	waiter->task = NULL;
diff --git a/kernel/locking/mutex-debug.h b/kernel/locking/mutex-debug.h
index 0799fd3e4..d06ae3bb4 100644
--- a/kernel/locking/mutex-debug.h
+++ b/kernel/locking/mutex-debug.h
@@ -20,9 +20,9 @@ extern void debug_mutex_wake_waiter(struct mutex *lock,
 extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
 extern void debug_mutex_add_waiter(struct mutex *lock,
 				   struct mutex_waiter *waiter,
-				   struct thread_info *ti);
+				   struct task_struct *task);
 extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
-				struct thread_info *ti);
+				struct task_struct *task);
 extern void debug_mutex_unlock(struct mutex *lock);
 extern void debug_mutex_init(struct mutex *lock, const char *name,
 			     struct lock_class_key *key);
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 79d2d765a..a70b90db3 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -537,7 +537,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		goto skip_wait;
 
 	debug_mutex_lock_common(lock, &waiter);
-	debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
+	debug_mutex_add_waiter(lock, &waiter, task);
 
 	/* add waiting tasks to the end of the waitqueue (FIFO): */
 	list_add_tail(&waiter.list, &lock->wait_list);
@@ -584,7 +584,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	}
 	__set_task_state(task, TASK_RUNNING);
 
-	mutex_remove_waiter(lock, &waiter, current_thread_info());
+	mutex_remove_waiter(lock, &waiter, task);
 	/* set it to 0 if there are no waiters left: */
 	if (likely(list_empty(&lock->wait_list)))
 		atomic_set(&lock->count, 0);
@@ -605,7 +605,7 @@ skip_wait:
 	return 0;
 
 err:
-	mutex_remove_waiter(lock, &waiter, task_thread_info(task));
+	mutex_remove_waiter(lock, &waiter, task);
 	spin_unlock_mutex(&lock->wait_lock, flags);
 	debug_mutex_free_waiter(&waiter);
 	mutex_release(&lock->dep_map, 1, ip);
diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h
index 5cda39760..a68bae5e8 100644
--- a/kernel/locking/mutex.h
+++ b/kernel/locking/mutex.h
@@ -13,7 +13,7 @@
 		do { spin_lock(lock); (void)(flags); } while (0)
 #define spin_unlock_mutex(lock, flags) \
 		do { spin_unlock(lock); (void)(flags); } while (0)
-#define mutex_remove_waiter(lock, waiter, ti) \
+#define mutex_remove_waiter(lock, waiter, task) \
 		__list_del((waiter)->list.prev, (waiter)->list.next)
 
 #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c
index f231e0bb3..bec0b647f 100644
--- a/kernel/locking/percpu-rwsem.c
+++ b/kernel/locking/percpu-rwsem.c
@@ -37,6 +37,7 @@ void percpu_free_rwsem(struct percpu_rw_semaphore *brw)
 	free_percpu(brw->fast_read_ctr);
 	brw->fast_read_ctr = NULL; /* catch use after free bugs */
 }
+EXPORT_SYMBOL_GPL(percpu_free_rwsem);
 
 /*
  * This is the fast-path for down_read/up_read. If it succeeds we rely
diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index d734b7502..22e025309 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -191,8 +191,6 @@ static ssize_t qstat_write(struct file *file, const char __user *user_buf,
 
 		for (i = 0 ; i < qstat_num; i++)
 			WRITE_ONCE(ptr[i], 0);
-		for (i = 0 ; i < qstat_num; i++)
-			WRITE_ONCE(ptr[i], 0);
 	}
 	return count;
 }
@@ -214,10 +212,8 @@ static int __init init_qspinlock_stat(void)
 	struct dentry *d_qstat = debugfs_create_dir("qlockstat", NULL);
 	int i;
 
-	if (!d_qstat) {
-		pr_warn("Could not create 'qlockstat' debugfs directory\n");
-		return 0;
-	}
+	if (!d_qstat)
+		goto out;
 
 	/*
 	 * Create the debugfs files
@@ -227,12 +223,20 @@ static int __init init_qspinlock_stat(void)
 	 * performance.
 	 */
 	for (i = 0; i < qstat_num; i++)
-		debugfs_create_file(qstat_names[i], 0400, d_qstat,
-				   (void *)(long)i, &fops_qstat);
+		if (!debugfs_create_file(qstat_names[i], 0400, d_qstat,
+					 (void *)(long)i, &fops_qstat))
+			goto fail_undo;
+
+	if (!debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
+				 (void *)(long)qstat_reset_cnts, &fops_qstat))
+		goto fail_undo;
 
-	debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
-			   (void *)(long)qstat_reset_cnts, &fops_qstat);
 	return 0;
+fail_undo:
+	debugfs_remove_recursive(d_qstat);
+out:
+	pr_warn("Could not create 'qlockstat' debugfs entries\n");
+	return -ENOMEM;
 }
 fs_initcall(init_qspinlock_stat);
 
diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c
index 3a5048572..1591f6b35 100644
--- a/kernel/locking/rwsem-spinlock.c
+++ b/kernel/locking/rwsem-spinlock.c
@@ -191,11 +191,12 @@ int __down_read_trylock(struct rw_semaphore *sem)
 /*
  * get a write lock on the semaphore
  */
-void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
+int __sched __down_write_common(struct rw_semaphore *sem, int state)
 {
 	struct rwsem_waiter waiter;
 	struct task_struct *tsk;
 	unsigned long flags;
+	int ret = 0;
 
 	raw_spin_lock_irqsave(&sem->wait_lock, flags);
 
@@ -215,21 +216,33 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
 		 */
 		if (sem->count == 0)
 			break;
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+		if (signal_pending_state(state, current)) {
+			ret = -EINTR;
+			goto out;
+		}
+		set_task_state(tsk, state);
 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
 		schedule();
 		raw_spin_lock_irqsave(&sem->wait_lock, flags);
 	}
 	/* got the lock */
 	sem->count = -1;
+out:
 	list_del(&waiter.list);
 
 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+	return ret;
 }
 
 void __sched __down_write(struct rw_semaphore *sem)
 {
-	__down_write_nested(sem, 0);
+	__down_write_common(sem, TASK_UNINTERRUPTIBLE);
+}
+
+int __sched __down_write_killable(struct rw_semaphore *sem)
+{
+	return __down_write_common(sem, TASK_KILLABLE);
 }
 
 /*
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index a4d4de05b..09e30c622 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -433,12 +433,13 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
 /*
  * Wait until we successfully acquire the write lock
  */
-__visible
-struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
+static inline struct rw_semaphore *
+__rwsem_down_write_failed_common(struct rw_semaphore *sem, int state)
 {
 	long count;
 	bool waiting = true; /* any queued threads before us */
 	struct rwsem_waiter waiter;
+	struct rw_semaphore *ret = sem;
 
 	/* undo write bias from down_write operation, stop active locking */
 	count = rwsem_atomic_update(-RWSEM_ACTIVE_WRITE_BIAS, sem);
@@ -478,7 +479,7 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
 		count = rwsem_atomic_update(RWSEM_WAITING_BIAS, sem);
 
 	/* wait until we successfully acquire the lock */
-	set_current_state(TASK_UNINTERRUPTIBLE);
+	set_current_state(state);
 	while (true) {
 		if (rwsem_try_write_lock(count, sem))
 			break;
@@ -486,21 +487,48 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
 
 		/* Block until there are no active lockers. */
 		do {
+			if (signal_pending_state(state, current))
+				goto out_nolock;
+
 			schedule();
-			set_current_state(TASK_UNINTERRUPTIBLE);
+			set_current_state(state);
 		} while ((count = sem->count) & RWSEM_ACTIVE_MASK);
 
 		raw_spin_lock_irq(&sem->wait_lock);
 	}
 	__set_current_state(TASK_RUNNING);
+	list_del(&waiter.list);
+	raw_spin_unlock_irq(&sem->wait_lock);
 
+	return ret;
+
+out_nolock:
+	__set_current_state(TASK_RUNNING);
+	raw_spin_lock_irq(&sem->wait_lock);
 	list_del(&waiter.list);
+	if (list_empty(&sem->wait_list))
+		rwsem_atomic_update(-RWSEM_WAITING_BIAS, sem);
+	else
+		__rwsem_do_wake(sem, RWSEM_WAKE_ANY);
 	raw_spin_unlock_irq(&sem->wait_lock);
 
-	return sem;
+	return ERR_PTR(-EINTR);
+}
+
+__visible struct rw_semaphore * __sched
+rwsem_down_write_failed(struct rw_semaphore *sem)
+{
+	return __rwsem_down_write_failed_common(sem, TASK_UNINTERRUPTIBLE);
 }
 EXPORT_SYMBOL(rwsem_down_write_failed);
 
+__visible struct rw_semaphore * __sched
+rwsem_down_write_failed_killable(struct rw_semaphore *sem)
+{
+	return __rwsem_down_write_failed_common(sem, TASK_KILLABLE);
+}
+EXPORT_SYMBOL(rwsem_down_write_failed_killable);
+
 /*
  * handle waking up a waiter on the semaphore
  * - up_read/up_write has decremented the active part of count if we come here
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 205be0ce3..2e853ad93 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -55,6 +55,25 @@ void __sched down_write(struct rw_semaphore *sem)
 EXPORT_SYMBOL(down_write);
 
 /*
+ * lock for writing
+ */
+int __sched down_write_killable(struct rw_semaphore *sem)
+{
+	might_sleep();
+	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+
+	if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) {
+		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		return -EINTR;
+	}
+
+	rwsem_set_owner(sem);
+	return 0;
+}
+
+EXPORT_SYMBOL(down_write_killable);
+
+/*
  * trylock for writing -- returns 1 if successful, 0 if contention
  */
 int down_write_trylock(struct rw_semaphore *sem)
@@ -154,6 +173,22 @@ void down_write_nested(struct rw_semaphore *sem, int subclass)
 
 EXPORT_SYMBOL(down_write_nested);
 
+int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass)
+{
+	might_sleep();
+	rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_);
+
+	if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) {
+		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		return -EINTR;
+	}
+
+	rwsem_set_owner(sem);
+	return 0;
+}
+
+EXPORT_SYMBOL(down_write_killable_nested);
+
 void up_read_non_owner(struct rw_semaphore *sem)
 {
 	__up_read(sem);