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

1 files changed, 7 insertions, 1 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 8c24294e477f..91d67ce3a8d5 100644
--- a/kernel/lockdep.c
+++ b/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))