Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix wrong assumption in match_held_lock

kernel/lockdep.c

@@ -3111,7 +3111,13 @@ static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
 		if (!class)
 			class = look_up_lock_class(lock, 0);
 
-		if (DEBUG_LOCKS_WARN_ON(!class))
+		/*
+		 * If look_up_lock_class() failed to find a class, we're trying
+		 * to test if we hold a lock that has never yet been acquired.
+		 * Clearly if the lock hasn't been acquired _ever_, we're not
+		 * holding it either, so report failure.
+		 */
+		if (!class)
 			return 0;
 
 		if (DEBUG_LOCKS_WARN_ON(!hlock->nest_lock))