Re: [patch V2 08/17] posix-timers: Rework timer removal

[Thomas Gleixner]

On Sat, Mar 08 2025 at 23:48, Frederic Weisbecker wrote:
> Le Sat, Mar 08, 2025 at 09:34:06AM +0100, Thomas Gleixner a écrit :
>> >> --- a/kernel/time/posix-timers.c
>> >> +++ b/kernel/time/posix-timers.c
>> >> @@ -279,7 +279,7 @@ static bool __posixtimer_deliver_signal(
>> >>  	 * since the signal was queued. In either case, don't rearm and
>> >>  	 * drop the signal.
>> >>  	 */
>> >> -	if (timr->it_signal_seq != timr->it_sigqueue_seq || WARN_ON_ONCE(!timr->it_signal))
>> >> +	if (timr->it_signal_seq != timr->it_sigqueue_seq || !posixtimer_valid(timr))
>> >
>> > Hmm, should it still warn here? ie: WARN_ON_ONCE(!posixtimer_valid(timr)) ?
>> 
>> No, because the timer is invalidated early now.
>
> But the signal can only be queued before posix_timer_delete(). So
> if the bit 0 of it_signal has been reset, it_signal_seq must have been
> incremented along, right?
>
> And if so then timr->it_signal_seq == timr->it_sigqueue_seq must imply
> posixtimer_valid(). And if not we should warn. Or am I missing something?

You're just missing the fact, that I managed to confuse myself :)