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| author | Peter Zijlstra <peterz@infradead.org> | 2014-09-24 10:18:46 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-10-28 10:55:08 +0100 |
| commit | 6f942a1f264e875c5f3ad6f505d7b500a3e7fa82 (patch) | |
| tree | 261e52ac048e38cba572b08c9707c36b7bbecc5f /kernel/locking | |
| parent | f4e9d94a5bf60193d45f92b136e3d166be3ec8d5 (diff) | |
| download | linux-6f942a1f264e875c5f3ad6f505d7b500a3e7fa82.tar.bz2 | |
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>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/mutex.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index dadbf88c22c4..454195194d4a 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -378,8 +378,14 @@ done: * reschedule now, before we try-lock the mutex. This avoids getting * scheduled out right after we obtained the mutex. */ - if (need_resched()) + if (need_resched()) { + /* + * We _should_ have TASK_RUNNING here, but just in case + * we do not, make it so, otherwise we might get stuck. + */ + __set_current_state(TASK_RUNNING); schedule_preempt_disabled(); + } return false; } |