[PATCH] mutex-debug: Check mutex magic before owner

From: Jeremy Kerr
Date: Wed Apr 23 2008 - 01:38:46 EST


Currently, the mutex debug code checks the lock->owner before
lock->magic, so a corrupt mutex will most likely result in
failing the owner check, rather than the magic check.

This change to debug_mutex_unlock does the magic check first, so
we have a better idea of what breaks.

Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>

---
kernel/mutex-debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 3aaa06c..1d94160 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -79,8 +79,8 @@ void debug_mutex_unlock(struct mutex *lock)
if (unlikely(!debug_locks))
return;

- DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
+ DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
}
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