From 60e114d1134555d1813e20a8cd86304331da05c7 Mon Sep 17 00:00:00 2001
From: Jarek Poplawski <jarkao2@o2.pl>
Date: Tue, 20 Feb 2007 13:58:00 -0800
Subject: [PATCH] [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>
---
 kernel/lockdep.c | 4 ++++
 1 file changed, 4 insertions(+)

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 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 
 	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");