| From | Thomas Gleixner <> | Subject | [patch V2 10/50] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_get() | Date | Thu, 11 Apr 2024 00:46:29 +0200 (CEST) |
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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.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- V2: Split out into new patch to make review simpler - Frederic --- kernel/time/posix-cpu-timers.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
--- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -787,15 +787,17 @@ static int posix_cpu_timer_set(struct k_ static void __posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp, u64 now) { + bool sigev_none = timer->it_sigev_notify == SIGEV_NONE; u64 expires, iv = timer->it_interval; /* * Make sure that interval timers are moved forward for the * following cases: + * - SIGEV_NONE timers which are never armed * - Timers which expired, but the signal has not yet been * delivered */ - if (iv && (timer->it_requeue_pending & REQUEUE_PENDING)) + if (iv && ((timer->it_requeue_pending & REQUEUE_PENDING) || sigev_none)) expires = bump_cpu_timer(timer, now); else expires = cpu_timer_getexpires(&timer->it.cpu); @@ -809,11 +811,13 @@ static void __posix_cpu_timer_get(struct itp->it_value = ns_to_timespec64(expires - now); } else { /* - * The timer should have expired already, but the firing - * hasn't taken place yet. Say it's just about to expire. + * 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. */ - itp->it_value.tv_nsec = 1; - itp->it_value.tv_sec = 0; + if (!sigev_none) + itp->it_value.tv_nsec = 1; } }
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