Messages in this thread | | | Date | Tue, 11 Jul 2023 11:29:16 -1000 | From | Tejun Heo <> | Subject | Re: [syzbot] WARNING in kthread_bind_mask |
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Hello,
On Tue, Jul 11, 2023 at 12:01:48PM +0800, Z qiang wrote: > Full email path here: > https://lore.kernel.org/all/0000000000005ca92705d877448c@google.com/T/ > https://syzkaller.appspot.com/bug?extid=087b7effddeec0697c66 > > > static void __kthread_bind_mask(struct task_struct *p, const struct > cpumask *mask, unsigned int state) > { > unsigned long flags; > > if (!wait_task_inactive(p, state)) { > WARN_ON(1); <--------------------------trigger warning > return; > } > .... > } > > Inconsistent task state trigger WARN_ON().
The usage looks correct to me. The rescuer kthread was just created successfully and did complete(done) in kthread() and then should be either about to sleep or already sleeping in the subsequent schedule_preempt_disabled(). Either there's something buggy in wait_task_inactive() or task state transition itself, or there's something else which somehow ends up waking up the newly created task? My hunch is the latter but it's impossible to tell from the available information.
It'd be really great if syzbot can find a repro.
Thanks.
-- tejun
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