diff options
| author | Chuansheng Liu <[email protected]> | 2013-12-04 13:58:13 +0800 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2013-12-17 15:35:10 +0100 |
| commit | 91f30a17024ff0d8345e11228af33ee938b13426 (patch) | |
| tree | 283bc22529ed94d7e5f4611609eb935a75032c98 | |
| parent | bb799d3b980eb803ca2da4a4eefbd9308f8d988a (diff) | |
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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Paul E. McKenney <[email protected]>
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 <[email protected]>
| -rw-r--r-- | kernel/locking/mutex-debug.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c index 7e3443fe1f48..faf6f5b53e77 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); } |