locking/mutex: Don't assume TASK_RUNNING
authorPeter Zijlstra <peterz@infradead.org>
Wed, 24 Sep 2014 08:18:46 +0000 (10:18 +0200)
committerIngo Molnar <mingo@kernel.org>
Tue, 28 Oct 2014 09:55:08 +0000 (10:55 +0100)
commit6f942a1f264e875c5f3ad6f505d7b500a3e7fa82
tree261e52ac048e38cba572b08c9707c36b7bbecc5f
parentf4e9d94a5bf60193d45f92b136e3d166be3ec8d5
locking/mutex: Don't assume TASK_RUNNING

We're going to make might_sleep() test for TASK_RUNNING, because
blocking without TASK_RUNNING will destroy the task state by setting
it to TASK_RUNNING.

There are a few occasions where its 'valid' to call blocking
primitives (and mutex_lock in particular) and not have TASK_RUNNING,
typically such cases are right before we set TASK_RUNNING anyhow.

Robustify the code by not assuming this; this has the beneficial side
effect of allowing optional code emission for fixing the above
might_sleep() false positives.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: tglx@linutronix.de
Cc: ilya.dryomov@inktank.com
Cc: umgwanakikbuti@gmail.com
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140924082241.988560063@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/locking/mutex.c