diff options
Diffstat (limited to 'kernel/time/posix-timers.c')
| -rw-r--r-- | kernel/time/posix-timers.c | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 5a01c4fdbfef..a5ec421e3437 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -463,7 +463,7 @@ static struct k_itimer * alloc_posix_timer(void) static void k_itimer_rcu_free(struct rcu_head *head) { - struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu); + struct k_itimer *tmr = container_of(head, struct k_itimer, rcu); kmem_cache_free(posix_timers_cache, tmr); } @@ -480,7 +480,7 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); - call_rcu(&tmr->it.rcu, k_itimer_rcu_free); + call_rcu(&tmr->rcu, k_itimer_rcu_free); } static int common_timer_create(struct k_itimer *new_timer) @@ -821,6 +821,22 @@ static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires, hrtimer_start_expires(timer, HRTIMER_MODE_ABS); } +/* + * Protected by RCU! + */ +static void timer_wait_for_callback(const struct k_clock *kc, struct k_itimer *timr) +{ +#ifdef CONFIG_PREEMPT_RT_FULL + if (kc->timer_arm == common_hrtimer_arm) + hrtimer_wait_for_timer(&timr->it.real.timer); + else if (kc == &alarm_clock) + hrtimer_wait_for_timer(&timr->it.alarm.alarmtimer.timer); + else + /* FIXME: Whacky hack for posix-cpu-timers */ + schedule_timeout(1); +#endif +} + static int common_hrtimer_try_to_cancel(struct k_itimer *timr) { return hrtimer_try_to_cancel(&timr->it.real.timer); @@ -885,6 +901,7 @@ retry: if (!timr) return -EINVAL; + rcu_read_lock(); kc = timr->kclock; if (WARN_ON_ONCE(!kc || !kc->timer_set)) error = -EINVAL; @@ -893,9 +910,12 @@ retry: unlock_timer(timr, flag); if (error == TIMER_RETRY) { + timer_wait_for_callback(kc, timr); old_spec64 = NULL; // We already got the old time... + rcu_read_unlock(); goto retry; } + rcu_read_unlock(); return error; } @@ -977,10 +997,15 @@ retry_delete: if (!timer) return -EINVAL; + rcu_read_lock(); if (timer_delete_hook(timer) == TIMER_RETRY) { unlock_timer(timer, flags); + timer_wait_for_callback(clockid_to_kclock(timer->it_clock), + timer); + rcu_read_unlock(); goto retry_delete; } + rcu_read_unlock(); spin_lock(¤t->sighand->siglock); list_del(&timer->list); @@ -1006,8 +1031,18 @@ static void itimer_delete(struct k_itimer *timer) retry_delete: spin_lock_irqsave(&timer->it_lock, flags); + /* On RT we can race with a deletion */ + if (!timer->it_signal) { + unlock_timer(timer, flags); + return; + } + if (timer_delete_hook(timer) == TIMER_RETRY) { + rcu_read_lock(); unlock_timer(timer, flags); + timer_wait_for_callback(clockid_to_kclock(timer->it_clock), + timer); + rcu_read_unlock(); goto retry_delete; } list_del(&timer->list); |