Messages in this thread | | | Date | Fri, 25 Sep 2020 11:30:46 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH v2] kernel/kthread.c: kthread_worker: add work status check in timer_fn |
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On Fri 2020-09-25 13:07:59, qiang.zhang@windriver.com wrote: > From: Zqiang <qiang.zhang@windriver.com> > > When queue delayed work to worker, at some point after that the timer_fn > will be call, add work to worker's work_list, at this time, the work may > be cancel, so add "work->canceling" check current work status.
Great catch!
I was able to understand the problem from the description. Though I would still try to improve it a bit. I suggest:
<new_text> Subject: kthread_worker: Prevent queuing delayed work from timer_fn when it is being canceled
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. </new_text>
> Signed-off-by: Zqiang <qiang.zhang@windriver.com>
With the above subject and commit message:
Reviewed-by: Petr Mladek <pmladek@suse.com>
Best Regards, Petr
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