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Groups > linux.kernel > #1400410
| From | Waiman Long <Waiman.Long@hpe.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v3 2/4] locking/rwsem: Don't wake up one's own task |
| Date | 2016-05-13 01:00 +0200 |
| Message-ID | <ry7Ki-7bF-15@gated-at.bofh.it> (permalink) |
| References | <ry7Kh-7bF-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
As rwsem_down_read_failed() will queue itself and potentially call __rwsem_do_wake(sem, RWSEM_WAKE_ANY), it is possible that a reader will try to wake up its own task. This patch adds a check to make sure that this won't happen. Signed-off-by: Waiman Long <Waiman.Long@hpe.com> --- kernel/locking/rwsem-xadd.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 7ccab5c..22f7d58 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -202,7 +202,8 @@ __rwsem_do_wake(struct rw_semaphore *sem, enum rwsem_wake_type wake_type) */ smp_mb(); waiter->task = NULL; - wake_up_process(tsk); + if (tsk != current) + wake_up_process(tsk); put_task_struct(tsk); } while (--loop); -- 1.7.1
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[PATCH v3 0/4] locking/rwsem: Add reader-owned state to the owner field Waiman Long <Waiman.Long@hpe.com> - 2016-05-13 01:00 +0200
[PATCH v3 2/4] locking/rwsem: Don't wake up one's own task Waiman Long <Waiman.Long@hpe.com> - 2016-05-13 01:00 +0200
Re: [PATCH v3 2/4] locking/rwsem: Don't wake up one's own task Peter Hurley <peter@hurleysoftware.com> - 2016-05-17 19:50 +0200
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