| Message ID | 20201025225719.4xfmn%akpm@linux-foundation.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | +kthread_worker-prevent-queuing-delayed-work-from-timer_fn-when-it-is-being-canceled.patchadded to -mm tree | expand |
--- a/kernel/kthread.c~kthread_worker-prevent-queuing-delayed-work-from-timer_fn-when-it-is-being-canceled +++ a/kernel/kthread.c @@ -897,7 +897,8 @@ void kthread_delayed_work_timer_fn(struc /* 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); }
The patch titled Subject: kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled has been added to the -mm tree. Its filename is kthread_worker-prevent-queuing-delayed-work-from-timer_fn-when-it-is-being-canceled.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kthread_worker-prevent-queuing-delayed-work-from-timer_fn-when-it-is-being-canceled.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/kthread_worker-prevent-queuing-delayed-work-from-timer_fn-when-it-is-being-canceled.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Zqiang <qiang.zhang@windriver.com> 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. Link: https://lkml.kernel.org/r/20201014083030.16895-1-qiang.zhang@windriver.com Signed-off-by: Zqiang <qiang.zhang@windriver.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- kernel/kthread.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)