2024-04-10 22:48:47

by Thomas Gleixner

Subject: [patch V2 11/50] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set()

Expired SIGEV_NONE oneshot timers must return 0 nsec for the expiry time in
timer_get(), but the posix CPU timer implementation returns 1 nsec.

Add the missing conditional.

This will be cleaned up in a follow up patch.

Signed-off-by: Thomas Gleixner <[email protected]>
---
V2: Split out into new patch to make review simpler - Frederic
---
kernel/time/posix-cpu-timers.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -706,7 +706,16 @@ static int posix_cpu_timer_set(struct k_
old_expires = exp - val;
old->it_value = ns_to_timespec64(old_expires);
} else {
- old->it_value.tv_nsec = 1;
+ /*
+ * A single shot SIGEV_NONE timer must return 0, when it is
+ * expired! Timers which have a real signal delivery mode
+ * must return a remaining time greater than 0 because the
+ * signal has not yet been delivered.
+ */
+ if (sigev_none)
+ old->it_value.tv_nsec = 0;
+ else
+ old->it_value.tv_nsec = 1;
old->it_value.tv_sec = 0;
}
}

2024-04-11 17:25:41

by Anna-Maria Behnsen

Subject: Re: [patch V2 11/50] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set()

Thomas Gleixner <[email protected]> writes:

> Expired SIGEV_NONE oneshot timers must return 0 nsec for the expiry time in
> timer_get(), but the posix CPU timer implementation returns 1 nsec.

copy paste error (get/set) ?

> Add the missing conditional.
>
> This will be cleaned up in a follow up patch.

I'm confused. Why do you want to cleanup the conditional in a follow up
patch?

Thanks,

Anna-Maria

2024-04-11 22:02:38

by Thomas Gleixner

Subject: Re: [patch V2 11/50] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set()

On Thu, Apr 11 2024 at 17:48, Anna-Maria Behnsen wrote:

> Thomas Gleixner <[email protected]> writes:
>
>> Expired SIGEV_NONE oneshot timers must return 0 nsec for the expiry time in
>> timer_get(), but the posix CPU timer implementation returns 1 nsec.
>
> copy paste error (get/set) ?

Yes.

>> Add the missing conditional.
>>
>> This will be cleaned up in a follow up patch.
>
> I'm confused. Why do you want to cleanup the conditional in a follow up
> patch?

This patch is to fix the issue. The next one consolidates the code, but
I can see why the "this will be ..." part of the changelog does not make
sense.

Thanks,

tglx

2024-04-17 23:04:20

by Frederic Weisbecker

Subject: Re: [patch V2 11/50] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set()

Le Fri, Apr 12, 2024 at 12:02:28AM +0200, Thomas Gleixner a ?crit :
> On Thu, Apr 11 2024 at 17:48, Anna-Maria Behnsen wrote:
>
> > Thomas Gleixner <[email protected]> writes:
> >
> >> Expired SIGEV_NONE oneshot timers must return 0 nsec for the expiry time in
> >> timer_get(), but the posix CPU timer implementation returns 1 nsec.
> >
> > copy paste error (get/set) ?
>
> Yes.
>
> >> Add the missing conditional.
> >>
> >> This will be cleaned up in a follow up patch.
> >
> > I'm confused. Why do you want to cleanup the conditional in a follow up
> > patch?
>
> This patch is to fix the issue. The next one consolidates the code, but
> I can see why the "this will be ..." part of the changelog does not make
> sense.

But please keep it cut that way. FWIW it's much easier to review than the
previous take. That way we aren't missing subtle changes.