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| author | Zqiang <qiang.zhang@windriver.com> | 2020-11-01 17:07:53 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-10 10:24:02 +0100 |
| commit | a1ffa0673dd172dcea574ef20ff49fd66d0fa220 (patch) | |
| tree | 39117dd27341386554c6ee402a2b36da213646d1 | |
| parent | 1332c71e576ffcb66697a672987ef297b8692c7c (diff) | |
| download | linux-stable-a1ffa0673dd172dcea574ef20ff49fd66d0fa220.tar.gz linux-stable-a1ffa0673dd172dcea574ef20ff49fd66d0fa220.tar.bz2 linux-stable-a1ffa0673dd172dcea574ef20ff49fd66d0fa220.zip | |
kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled
commit 6993d0fdbee0eb38bfac350aa016f65ad11ed3b1 upstream.
There is a small race window when a delayed work is being canceled and
the work still might be queued from the timer_fn:
CPU0 CPU1
kthread_cancel_delayed_work_sync()
__kthread_cancel_work_sync()
__kthread_cancel_work()
work->canceling++;
kthread_delayed_work_timer_fn()
kthread_insert_work();
BUG: kthread_insert_work() should not get called when work->canceling is
set.
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201014083030.16895-1-qiang.zhang@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/kthread.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c index fbc230e41969..60f54c5a07a4 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -828,7 +828,8 @@ void kthread_delayed_work_timer_fn(unsigned long __data) /* Move the work from worker->delayed_work_list. */ WARN_ON_ONCE(list_empty(&work->node)); list_del_init(&work->node); - kthread_insert_work(worker, work, &worker->work_list); + if (!work->canceling) + kthread_insert_work(worker, work, &worker->work_list); spin_unlock(&worker->lock); } |