Messages in this thread Patch in this message | | | From | Zqiang <> | Subject | [PATCH v4] kthread_worker: Prevent queuing delayed work from timer_fn when it is being canceled | Date | Wed, 14 Oct 2020 15:50:48 +0800 |
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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.
Cc: <stable@vger.kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Zqiang <qiang.zhang@windriver.com> --- v1->v2->v3: Change the description of the problem and add 'Reviewed-by' tags. v3->v4: Add 'stable' and 'Acked-by' tags.
kernel/kthread.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/kthread.c b/kernel/kthread.c index 3edaa380dc7b..85a2c9b32049 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -897,7 +897,8 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) /* 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); raw_spin_unlock_irqrestore(&worker->lock, flags); } -- 2.17.1
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