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@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 92222ca89f499eeed2642cbda5bff7f0e6b4178f..d70879d502f909f050cf20962925741e11505eab 100644 (file)
--- 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;
        }
 }