locking/mutex: Fix debug checks
OK, so commit:
1d8fe7dc8078 ("locking/mutexes: Unlock the mutex without the wait_lock")
generates this boot warning when CONFIG_DEBUG_MUTEXES=y:
WARNING: CPU: 0 PID: 139 at /usr/src/linux-2.6/kernel/locking/mutex-debug.c:82 debug_mutex_unlock+0x155/0x180() DEBUG_LOCKS_WARN_ON(lock->owner != current)
And that makes sense, because as soon as we release the lock a
new owner can come in...
One would think that !__mutex_slowpath_needs_to_unlock()
implementations suffer the same, but for DEBUG we fall back to
mutex-null.h which has an unconditional 1 for that.
The mutex debug code requires the mutex to be unlocked after
doing the debug checks, otherwise it can find inconsistent
Reported-by: Ingo Molnar <email@example.com>
Signed-off-by: Peter Zijlstra <firstname.lastname@example.org>
Signed-off-by: Ingo Molnar <email@example.com>
2 files changed