Commit-ID: 91f30a17024ff0d8345e11228af33ee938b13426 Gitweb: http://git.kernel.org/tip/91f30a17024ff0d8345e11228af33ee938b13426 Author: Chuansheng Liu <chuansheng.liu@xxxxxxxxx> AuthorDate: Wed, 4 Dec 2013 13:58:13 +0800 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 17 Dec 2013 15:35:10 +0100 mutexes: Give more informative mutex warning in the !lock->owner case When mutex debugging is enabled and an imbalanced mutex_unlock() is called, we get the following, slightly confusing warning: [ 364.208284] DEBUG_LOCKS_WARN_ON(lock->owner != current) But in that case the warning is due to an imbalanced mutex_unlock() call, and the lock->owner is NULL - so the message is misleading. So improve the message by testing for this case specifically: DEBUG_LOCKS_WARN_ON(!lock->owner) Signed-off-by: Liu, Chuansheng <chuansheng.liu@xxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1386136693.3650.48.camel@cliu38-desktop-build [ Improved the changelog, changed the patch to use !lock->owner consistently. ] Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/locking/mutex-debug.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c index 7e3443f..faf6f5b 100644 --- a/kernel/locking/mutex-debug.c +++ b/kernel/locking/mutex-debug.c @@ -75,7 +75,12 @@ void debug_mutex_unlock(struct mutex *lock) return; DEBUG_LOCKS_WARN_ON(lock->magic != lock); - DEBUG_LOCKS_WARN_ON(lock->owner != current); + + if (!lock->owner) + DEBUG_LOCKS_WARN_ON(!lock->owner); + else + DEBUG_LOCKS_WARN_ON(lock->owner != current); + DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); mutex_clear_owner(lock); } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|