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posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set()

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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 <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Thomas Gleixner 2024-06-23 13:16:02 +02:00 committed by Frederic Weisbecker
parent d786b8ba9f
commit 5f9d4a1065
1 changed files with 11 additions and 1 deletions
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12
kernel/time/posix-cpu-timers.c
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@ -623,6 +623,7 @@ static void cpu_timer_fire(struct k_itimer *timer)
static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
struct itimerspec64 *new, struct itimerspec64 *old)
{
bool sigev_none = timer->it_sigev_notify == SIGEV_NONE;
clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
u64 old_expires, new_expires, old_incr, val;
struct cpu_timer *ctmr = &timer->it.cpu;
@ -706,7 +707,16 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
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;
}
}