[PATCH] lockdep: debug_locks check after check_chain_key

In __lock_acquire check_chain_key can turn off debug_locks, so check is
needed to assure proper return code.

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 592c576d77a7..a08a17218dfa 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2228,6 +2228,10 @@ out_calc_hash:
 
         curr->lockdep_depth++;
         check_chain_key(curr);
+#ifdef CONFIG_DEBUG_LOCKDEP
+        if (unlikely(!debug_locks))
+                return 0;
+#endif
         if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
                 debug_locks_off();
                 printk("BUG: MAX_LOCK_DEPTH too low!\n");