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locking/lockdep: Apply crossrelease to completions

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Although wait_for_completion() and its family can cause deadlock, the
lock correctness validator could not be applied to them until now,
because things like complete() are usually called in a different context
from the waiting context, which violates lockdep's assumption.

Thanks to CONFIG_LOCKDEP_CROSSRELEASE, we can now apply the lockdep
detector to those completion operations. Applied it.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: boqun.feng@gmail.com
Cc: kernel-team@lge.com
Cc: kirill@shutemov.name
Cc: npiggin@gmail.com
Cc: walken@google.com
Cc: willy@infradead.org
Link: http://lkml.kernel.org/r/1502089981-21272-10-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Byungchul Park
2017-08-07 16:12:56 +09:00
committed by Ingo Molnar
parent 383a4bc888
commit cd8084f91c
3 changed files with 64 additions and 1 deletions
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11
kernel/sched/completion.c
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@@ -32,6 +32,12 @@ void complete(struct completion *x)
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
/*
* Perform commit of crossrelease here.
*/
complete_release_commit(x);
if (x->done != UINT_MAX)
x->done++;
__wake_up_locked(&x->wait, TASK_NORMAL, 1);
@@ -92,9 +98,14 @@ __wait_for_common(struct completion *x,
{
might_sleep();
complete_acquire(x);
spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
spin_unlock_irq(&x->wait.lock);
complete_release(x);
return timeout;
}