From 5f9d4a1065949a64c107f93a89dc2b62f806c833 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 23 Jun 2024 13:16:02 +0200 Subject: 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 Signed-off-by: Frederic Weisbecker Acked-by: Peter Zijlstra (Intel) --- kernel/time/posix-cpu-timers.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/time') diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index d70879d502f9..cf8904423cba 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -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; } } -- cgit v1.2.3