The following commit has been merged into the timers/core branch of tip:
Commit-ID: d786b8ba9f01b361817033d06766b2dadf619c60
Gitweb: https://git.kernel.org/tip/d786b8ba9f01b361817033d06766b2dadf619c60
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 10 Jun 2024 18:42:17 +02:00
Committer: Frederic Weisbecker <frederic@xxxxxxxxxx>
CommitterDate: Mon, 29 Jul 2024 21:57:34 +02:00
posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_get()
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@xxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/time/posix-cpu-timers.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 92222ca..d70879d 100644
--- 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_itimer *timer, int timer_flags,
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 k_itimer *timer, struct itimerspec64 *i
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;
}
}
|