Commit 4c5cd058 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

posix-timers: Remove a few paranoid warnings 



Warnings about a non-initialized timer or non-existing callbacks are just
useful for implementing new posix clocks, but there a NULL pointer
dereference is expected anyway. :)

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20250308155623.765462334@linutronix.de
parent 6ad9c338

kernel/time/posix-timers.c

+8 −29
Original line number Diff line number Diff line
@@ -682,7 +682,6 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) 


static int do_timer_gettime(timer_t timer_id,  struct itimerspec64 *setting)

{

	const struct k_clock *kc;

	struct k_itimer *timr;

	unsigned long flags;

	int ret = 0;
@@ -692,11 +691,7 @@ static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting) 
		return -EINVAL;



	memset(setting, 0, sizeof(*setting));

	kc = timr->kclock;

	if (WARN_ON_ONCE(!kc || !kc->timer_get))

		ret = -EINVAL;

	else

		kc->timer_get(timr, setting);

	timr->kclock->timer_get(timr, setting);



	unlock_timer(timr, flags);

	return ret;
@@ -824,7 +819,6 @@ static void common_timer_wait_running(struct k_itimer *timer) 
static struct k_itimer *timer_wait_running(struct k_itimer *timer,

					   unsigned long *flags)

{

	const struct k_clock *kc = READ_ONCE(timer->kclock);

	timer_t timer_id = READ_ONCE(timer->it_id);



	/* Prevent kfree(timer) after dropping the lock */
@@ -835,8 +829,7 @@ static struct k_itimer *timer_wait_running(struct k_itimer *timer, 
	 * kc->timer_wait_running() might drop RCU lock. So @timer

	 * cannot be touched anymore after the function returns!

	 */

	if (!WARN_ON_ONCE(!kc->timer_wait_running))

		kc->timer_wait_running(timer);

	timer->kclock->timer_wait_running(timer);



	rcu_read_unlock();

	/* Relock the timer. It might be not longer hashed. */
@@ -899,7 +892,6 @@ static int do_timer_settime(timer_t timer_id, int tmr_flags, 
			    struct itimerspec64 *new_spec64,

			    struct itimerspec64 *old_spec64)

{

	const struct k_clock *kc;

	struct k_itimer *timr;

	unsigned long flags;

	int error;
@@ -922,11 +914,7 @@ static int do_timer_settime(timer_t timer_id, int tmr_flags, 
	/* Prevent signal delivery and rearming. */

	timr->it_signal_seq++;



	kc = timr->kclock;

	if (WARN_ON_ONCE(!kc || !kc->timer_set))

		error = -EINVAL;

	else

		error = kc->timer_set(timr, tmr_flags, new_spec64, old_spec64);

	error = timr->kclock->timer_set(timr, tmr_flags, new_spec64, old_spec64);



	if (error == TIMER_RETRY) {

		// We already got the old time...
@@ -1008,18 +996,6 @@ static inline void posix_timer_cleanup_ignored(struct k_itimer *tmr) 
	}

}



static inline int timer_delete_hook(struct k_itimer *timer)

{

	const struct k_clock *kc = timer->kclock;



	/* Prevent signal delivery and rearming. */

	timer->it_signal_seq++;



	if (WARN_ON_ONCE(!kc || !kc->timer_del))

		return -EINVAL;

	return kc->timer_del(timer);

}



/* Delete a POSIX.1b interval timer. */

SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)

{
@@ -1032,7 +1008,10 @@ SYSCALL_DEFINE1(timer_delete, timer_t, timer_id) 
	if (!timer)

		return -EINVAL;



	if (unlikely(timer_delete_hook(timer) == TIMER_RETRY)) {

	/* Prevent signal delivery and rearming. */

	timer->it_signal_seq++;



	if (unlikely(timer->kclock->timer_del(timer) == TIMER_RETRY)) {

		/* Unlocks and relocks the timer if it still exists */

		timer = timer_wait_running(timer, &flags);

		goto retry_delete;
@@ -1078,7 +1057,7 @@ static void itimer_delete(struct k_itimer *timer) 
	 * mechanism. Worse, that timer mechanism might run the expiry

	 * function concurrently.

	 */

	if (timer_delete_hook(timer) == TIMER_RETRY) {

	if (timer->kclock->timer_del(timer) == TIMER_RETRY) {

		/*

		 * Timer is expired concurrently, prevent livelocks

		 * and pointless spinning on RT.