Merge tag 'v3.15' into next

Linux 3.15

1 files changed, 14 insertions, 9 deletions

diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index faf6f5b53e7..5cf6731b98e 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -71,18 +71,23 @@ void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 
 void debug_mutex_unlock(struct mutex *lock)
 {
-	if (unlikely(!debug_locks))
-		return;
+	if (likely(debug_locks)) {
+		DEBUG_LOCKS_WARN_ON(lock->magic != lock);
 
-	DEBUG_LOCKS_WARN_ON(lock->magic != lock);
+		if (!lock->owner)
+			DEBUG_LOCKS_WARN_ON(!lock->owner);
+		else
+			DEBUG_LOCKS_WARN_ON(lock->owner != current);
 
-	if (!lock->owner)
-		DEBUG_LOCKS_WARN_ON(!lock->owner);
-	else
-		DEBUG_LOCKS_WARN_ON(lock->owner != current);
+		DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
+		mutex_clear_owner(lock);
+	}
 
-	DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
-	mutex_clear_owner(lock);
+	/*
+	 * __mutex_slowpath_needs_to_unlock() is explicitly 0 for debug
+	 * mutexes so that we can do it here after we've verified state.
+	 */
+	atomic_set(&lock->count, 1);
 }
 
 void debug_mutex_init(struct mutex *lock, const char *name,