Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Three patches to fix memory ordering issues on ALPHA and a comment to
  clarify the usage scope of a mutex internal function"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs
  locking/xchg/alpha: Clean up barrier usage by using smp_mb() in place of __ASM__MB
  locking/xchg/alpha: Add unconditional memory barrier to cmpxchg()
  locking/mutex: Add comment to __mutex_owner() to deter usage

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f25c13423bd4..cb3bbed4e633 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -66,6 +66,11 @@ struct mutex {
 #endif
 };
 
+/*
+ * Internal helper function; C doesn't allow us to hide it :/
+ *
+ * DO NOT USE (outside of mutex code).
+ */
 static inline struct task_struct *__mutex_owner(struct mutex *lock)
 {
 	return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);