2 * linux/kernel/posix-timers.c
5 * 2002-10-15 Posix Clocks & timers
6 * by George Anzinger george@mvista.com
8 * Copyright (C) 2002 2003 by MontaVista Software.
10 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
11 * Copyright (C) 2004 Boris Hu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA
30 /* These are all the functions necessary to implement
31 * POSIX clocks & timers
34 #include <linux/interrupt.h>
35 #include <linux/slab.h>
36 #include <linux/time.h>
37 #include <linux/mutex.h>
38 #include <linux/sched/task.h>
40 #include <linux/uaccess.h>
41 #include <linux/list.h>
42 #include <linux/init.h>
43 #include <linux/compiler.h>
44 #include <linux/hash.h>
45 #include <linux/posix-clock.h>
46 #include <linux/posix-timers.h>
47 #include <linux/syscalls.h>
48 #include <linux/wait.h>
49 #include <linux/workqueue.h>
50 #include <linux/export.h>
51 #include <linux/hashtable.h>
52 #include <linux/compat.h>
53 #include <linux/nospec.h>
55 #include "timekeeping.h"
56 #include "posix-timers.h"
59 * Management arrays for POSIX timers. Timers are now kept in static hash table
61 * Timer ids are allocated by local routine, which selects proper hash head by
62 * key, constructed from current->signal address and per signal struct counter.
63 * This keeps timer ids unique per process, but now they can intersect between
68 * Lets keep our timers in a slab cache :-)
70 static struct kmem_cache *posix_timers_cache;
72 static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
73 static DEFINE_SPINLOCK(hash_lock);
75 static const struct k_clock * const posix_clocks[];
76 static const struct k_clock *clockid_to_kclock(const clockid_t id);
77 static const struct k_clock clock_realtime, clock_monotonic;
80 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
81 * SIGEV values. Here we put out an error if this assumption fails.
83 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
84 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
85 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
89 * parisc wants ENOTSUP instead of EOPNOTSUPP
92 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
94 # define ENANOSLEEP_NOTSUP ENOTSUP
98 * The timer ID is turned into a timer address by idr_find().
99 * Verifying a valid ID consists of:
101 * a) checking that idr_find() returns other than -1.
102 * b) checking that the timer id matches the one in the timer itself.
103 * c) that the timer owner is in the callers thread group.
107 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
108 * to implement others. This structure defines the various
111 * RESOLUTION: Clock resolution is used to round up timer and interval
112 * times, NOT to report clock times, which are reported with as
113 * much resolution as the system can muster. In some cases this
114 * resolution may depend on the underlying clock hardware and
115 * may not be quantifiable until run time, and only then is the
116 * necessary code is written. The standard says we should say
117 * something about this issue in the documentation...
119 * FUNCTIONS: The CLOCKs structure defines possible functions to
120 * handle various clock functions.
122 * The standard POSIX timer management code assumes the
123 * following: 1.) The k_itimer struct (sched.h) is used for
124 * the timer. 2.) The list, it_lock, it_clock, it_id and
125 * it_pid fields are not modified by timer code.
127 * Permissions: It is assumed that the clock_settime() function defined
128 * for each clock will take care of permission checks. Some
129 * clocks may be set able by any user (i.e. local process
130 * clocks) others not. Currently the only set able clock we
131 * have is CLOCK_REALTIME and its high res counter part, both of
132 * which we beg off on and pass to do_sys_settimeofday().
134 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
136 #define lock_timer(tid, flags) \
137 ({ struct k_itimer *__timr; \
138 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
142 static int hash(struct signal_struct *sig, unsigned int nr)
144 return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable));
147 static struct k_itimer *__posix_timers_find(struct hlist_head *head,
148 struct signal_struct *sig,
151 struct k_itimer *timer;
153 hlist_for_each_entry_rcu(timer, head, t_hash) {
154 if ((timer->it_signal == sig) && (timer->it_id == id))
160 static struct k_itimer *posix_timer_by_id(timer_t id)
162 struct signal_struct *sig = current->signal;
163 struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)];
165 return __posix_timers_find(head, sig, id);
168 static int posix_timer_add(struct k_itimer *timer)
170 struct signal_struct *sig = current->signal;
171 int first_free_id = sig->posix_timer_id;
172 struct hlist_head *head;
176 spin_lock(&hash_lock);
177 head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)];
178 if (!__posix_timers_find(head, sig, sig->posix_timer_id)) {
179 hlist_add_head_rcu(&timer->t_hash, head);
180 ret = sig->posix_timer_id;
182 if (++sig->posix_timer_id < 0)
183 sig->posix_timer_id = 0;
184 if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT))
185 /* Loop over all possible ids completed */
187 spin_unlock(&hash_lock);
188 } while (ret == -ENOENT);
192 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
194 spin_unlock_irqrestore(&timr->it_lock, flags);
197 /* Get clock_realtime */
198 static int posix_clock_realtime_get(clockid_t which_clock, struct timespec64 *tp)
200 ktime_get_real_ts64(tp);
204 /* Set clock_realtime */
205 static int posix_clock_realtime_set(const clockid_t which_clock,
206 const struct timespec64 *tp)
208 return do_sys_settimeofday64(tp, NULL);
211 static int posix_clock_realtime_adj(const clockid_t which_clock,
214 return do_adjtimex(t);
218 * Get monotonic time for posix timers
220 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec64 *tp)
227 * Get monotonic-raw time for posix timers
229 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
231 ktime_get_raw_ts64(tp);
236 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp)
238 ktime_get_coarse_real_ts64(tp);
242 static int posix_get_monotonic_coarse(clockid_t which_clock,
243 struct timespec64 *tp)
245 ktime_get_coarse_ts64(tp);
249 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
251 *tp = ktime_to_timespec64(KTIME_LOW_RES);
255 static int posix_get_boottime(const clockid_t which_clock, struct timespec64 *tp)
257 ktime_get_boottime_ts64(tp);
261 static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
263 ktime_get_clocktai_ts64(tp);
267 static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
270 tp->tv_nsec = hrtimer_resolution;
275 * Initialize everything, well, just everything in Posix clocks/timers ;)
277 static __init int init_posix_timers(void)
279 posix_timers_cache = kmem_cache_create("posix_timers_cache",
280 sizeof (struct k_itimer), 0, SLAB_PANIC,
284 __initcall(init_posix_timers);
287 * The siginfo si_overrun field and the return value of timer_getoverrun(2)
288 * are of type int. Clamp the overrun value to INT_MAX
290 static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
292 s64 sum = timr->it_overrun_last + (s64)baseval;
294 return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
297 static void common_hrtimer_rearm(struct k_itimer *timr)
299 struct hrtimer *timer = &timr->it.real.timer;
301 if (!timr->it_interval)
304 timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
306 hrtimer_restart(timer);
310 * This function is exported for use by the signal deliver code. It is
311 * called just prior to the info block being released and passes that
312 * block to us. It's function is to update the overrun entry AND to
313 * restart the timer. It should only be called if the timer is to be
314 * restarted (i.e. we have flagged this in the sys_private entry of the
317 * To protect against the timer going away while the interrupt is queued,
318 * we require that the it_requeue_pending flag be set.
320 void posixtimer_rearm(struct siginfo *info)
322 struct k_itimer *timr;
325 timr = lock_timer(info->si_tid, &flags);
329 if (timr->it_requeue_pending == info->si_sys_private) {
330 timr->kclock->timer_rearm(timr);
333 timr->it_overrun_last = timr->it_overrun;
334 timr->it_overrun = -1LL;
335 ++timr->it_requeue_pending;
337 info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
340 unlock_timer(timr, flags);
343 int posix_timer_event(struct k_itimer *timr, int si_private)
345 struct task_struct *task;
346 int shared, ret = -1;
348 * FIXME: if ->sigq is queued we can race with
349 * dequeue_signal()->posixtimer_rearm().
351 * If dequeue_signal() sees the "right" value of
352 * si_sys_private it calls posixtimer_rearm().
353 * We re-queue ->sigq and drop ->it_lock().
354 * posixtimer_rearm() locks the timer
355 * and re-schedules it while ->sigq is pending.
356 * Not really bad, but not that we want.
358 timr->sigq->info.si_sys_private = si_private;
361 task = pid_task(timr->it_pid, PIDTYPE_PID);
363 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
364 ret = send_sigqueue(timr->sigq, task, shared);
367 /* If we failed to send the signal the timer stops. */
372 * This function gets called when a POSIX.1b interval timer expires. It
373 * is used as a callback from the kernel internal timer. The
374 * run_timer_list code ALWAYS calls with interrupts on.
376 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
378 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
380 struct k_itimer *timr;
383 enum hrtimer_restart ret = HRTIMER_NORESTART;
385 timr = container_of(timer, struct k_itimer, it.real.timer);
386 spin_lock_irqsave(&timr->it_lock, flags);
389 if (timr->it_interval != 0)
390 si_private = ++timr->it_requeue_pending;
392 if (posix_timer_event(timr, si_private)) {
394 * signal was not sent because of sig_ignor
395 * we will not get a call back to restart it AND
396 * it should be restarted.
398 if (timr->it_interval != 0) {
399 ktime_t now = hrtimer_cb_get_time(timer);
402 * FIXME: What we really want, is to stop this
403 * timer completely and restart it in case the
404 * SIG_IGN is removed. This is a non trivial
405 * change which involves sighand locking
406 * (sigh !), which we don't want to do late in
409 * For now we just let timers with an interval
410 * less than a jiffie expire every jiffie to
411 * avoid softirq starvation in case of SIG_IGN
412 * and a very small interval, which would put
413 * the timer right back on the softirq pending
414 * list. By moving now ahead of time we trick
415 * hrtimer_forward() to expire the timer
416 * later, while we still maintain the overrun
417 * accuracy, but have some inconsistency in
418 * the timer_gettime() case. This is at least
419 * better than a starved softirq. A more
420 * complex fix which solves also another related
421 * inconsistency is already in the pipeline.
423 #ifdef CONFIG_HIGH_RES_TIMERS
425 ktime_t kj = NSEC_PER_SEC / HZ;
427 if (timr->it_interval < kj)
428 now = ktime_add(now, kj);
431 timr->it_overrun += hrtimer_forward(timer, now,
433 ret = HRTIMER_RESTART;
434 ++timr->it_requeue_pending;
439 unlock_timer(timr, flags);
443 static struct pid *good_sigevent(sigevent_t * event)
445 struct task_struct *rtn = current->group_leader;
447 switch (event->sigev_notify) {
448 case SIGEV_SIGNAL | SIGEV_THREAD_ID:
449 rtn = find_task_by_vpid(event->sigev_notify_thread_id);
450 if (!rtn || !same_thread_group(rtn, current))
455 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
459 return task_pid(rtn);
465 static struct k_itimer * alloc_posix_timer(void)
467 struct k_itimer *tmr;
468 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
471 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
472 kmem_cache_free(posix_timers_cache, tmr);
475 clear_siginfo(&tmr->sigq->info);
479 static void k_itimer_rcu_free(struct rcu_head *head)
481 struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
483 kmem_cache_free(posix_timers_cache, tmr);
487 #define IT_ID_NOT_SET 0
488 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
492 spin_lock_irqsave(&hash_lock, flags);
493 hlist_del_rcu(&tmr->t_hash);
494 spin_unlock_irqrestore(&hash_lock, flags);
496 put_pid(tmr->it_pid);
497 sigqueue_free(tmr->sigq);
498 call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
501 static int common_timer_create(struct k_itimer *new_timer)
503 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
507 /* Create a POSIX.1b interval timer. */
508 static int do_timer_create(clockid_t which_clock, struct sigevent *event,
509 timer_t __user *created_timer_id)
511 const struct k_clock *kc = clockid_to_kclock(which_clock);
512 struct k_itimer *new_timer;
513 int error, new_timer_id;
514 int it_id_set = IT_ID_NOT_SET;
518 if (!kc->timer_create)
521 new_timer = alloc_posix_timer();
522 if (unlikely(!new_timer))
525 spin_lock_init(&new_timer->it_lock);
526 new_timer_id = posix_timer_add(new_timer);
527 if (new_timer_id < 0) {
528 error = new_timer_id;
532 it_id_set = IT_ID_SET;
533 new_timer->it_id = (timer_t) new_timer_id;
534 new_timer->it_clock = which_clock;
535 new_timer->kclock = kc;
536 new_timer->it_overrun = -1LL;
540 new_timer->it_pid = get_pid(good_sigevent(event));
542 if (!new_timer->it_pid) {
546 new_timer->it_sigev_notify = event->sigev_notify;
547 new_timer->sigq->info.si_signo = event->sigev_signo;
548 new_timer->sigq->info.si_value = event->sigev_value;
550 new_timer->it_sigev_notify = SIGEV_SIGNAL;
551 new_timer->sigq->info.si_signo = SIGALRM;
552 memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t));
553 new_timer->sigq->info.si_value.sival_int = new_timer->it_id;
554 new_timer->it_pid = get_pid(task_tgid(current));
557 new_timer->sigq->info.si_tid = new_timer->it_id;
558 new_timer->sigq->info.si_code = SI_TIMER;
560 if (copy_to_user(created_timer_id,
561 &new_timer_id, sizeof (new_timer_id))) {
566 error = kc->timer_create(new_timer);
570 spin_lock_irq(¤t->sighand->siglock);
571 new_timer->it_signal = current->signal;
572 list_add(&new_timer->list, ¤t->signal->posix_timers);
573 spin_unlock_irq(¤t->sighand->siglock);
577 * In the case of the timer belonging to another task, after
578 * the task is unlocked, the timer is owned by the other task
579 * and may cease to exist at any time. Don't use or modify
580 * new_timer after the unlock call.
583 release_posix_timer(new_timer, it_id_set);
587 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
588 struct sigevent __user *, timer_event_spec,
589 timer_t __user *, created_timer_id)
591 if (timer_event_spec) {
594 if (copy_from_user(&event, timer_event_spec, sizeof (event)))
596 return do_timer_create(which_clock, &event, created_timer_id);
598 return do_timer_create(which_clock, NULL, created_timer_id);
602 COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
603 struct compat_sigevent __user *, timer_event_spec,
604 timer_t __user *, created_timer_id)
606 if (timer_event_spec) {
609 if (get_compat_sigevent(&event, timer_event_spec))
611 return do_timer_create(which_clock, &event, created_timer_id);
613 return do_timer_create(which_clock, NULL, created_timer_id);
618 * Locking issues: We need to protect the result of the id look up until
619 * we get the timer locked down so it is not deleted under us. The
620 * removal is done under the idr spinlock so we use that here to bridge
621 * the find to the timer lock. To avoid a dead lock, the timer id MUST
622 * be release with out holding the timer lock.
624 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
626 struct k_itimer *timr;
629 * timer_t could be any type >= int and we want to make sure any
630 * @timer_id outside positive int range fails lookup.
632 if ((unsigned long long)timer_id > INT_MAX)
636 timr = posix_timer_by_id(timer_id);
638 spin_lock_irqsave(&timr->it_lock, *flags);
639 if (timr->it_signal == current->signal) {
643 spin_unlock_irqrestore(&timr->it_lock, *flags);
650 static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
652 struct hrtimer *timer = &timr->it.real.timer;
654 return __hrtimer_expires_remaining_adjusted(timer, now);
657 static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
659 struct hrtimer *timer = &timr->it.real.timer;
661 return hrtimer_forward(timer, now, timr->it_interval);
665 * Get the time remaining on a POSIX.1b interval timer. This function
666 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
669 * We have a couple of messes to clean up here. First there is the case
670 * of a timer that has a requeue pending. These timers should appear to
671 * be in the timer list with an expiry as if we were to requeue them
674 * The second issue is the SIGEV_NONE timer which may be active but is
675 * not really ever put in the timer list (to save system resources).
676 * This timer may be expired, and if so, we will do it here. Otherwise
677 * it is the same as a requeue pending timer WRT to what we should
680 void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
682 const struct k_clock *kc = timr->kclock;
683 ktime_t now, remaining, iv;
684 struct timespec64 ts64;
687 sig_none = timr->it_sigev_notify == SIGEV_NONE;
688 iv = timr->it_interval;
690 /* interval timer ? */
692 cur_setting->it_interval = ktime_to_timespec64(iv);
693 } else if (!timr->it_active) {
695 * SIGEV_NONE oneshot timers are never queued. Check them
703 * The timespec64 based conversion is suboptimal, but it's not
704 * worth to implement yet another callback.
706 kc->clock_get(timr->it_clock, &ts64);
707 now = timespec64_to_ktime(ts64);
710 * When a requeue is pending or this is a SIGEV_NONE timer move the
711 * expiry time forward by intervals, so expiry is > now.
713 if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
714 timr->it_overrun += kc->timer_forward(timr, now);
716 remaining = kc->timer_remaining(timr, now);
717 /* Return 0 only, when the timer is expired and not pending */
718 if (remaining <= 0) {
720 * A single shot SIGEV_NONE timer must return 0, when
724 cur_setting->it_value.tv_nsec = 1;
726 cur_setting->it_value = ktime_to_timespec64(remaining);
730 /* Get the time remaining on a POSIX.1b interval timer. */
731 static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting)
733 struct k_itimer *timr;
734 const struct k_clock *kc;
738 timr = lock_timer(timer_id, &flags);
742 memset(setting, 0, sizeof(*setting));
744 if (WARN_ON_ONCE(!kc || !kc->timer_get))
747 kc->timer_get(timr, setting);
749 unlock_timer(timr, flags);
753 /* Get the time remaining on a POSIX.1b interval timer. */
754 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
755 struct __kernel_itimerspec __user *, setting)
757 struct itimerspec64 cur_setting;
759 int ret = do_timer_gettime(timer_id, &cur_setting);
761 if (put_itimerspec64(&cur_setting, setting))
767 #ifdef CONFIG_COMPAT_32BIT_TIME
769 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
770 struct compat_itimerspec __user *, setting)
772 struct itimerspec64 cur_setting;
774 int ret = do_timer_gettime(timer_id, &cur_setting);
776 if (put_compat_itimerspec64(&cur_setting, setting))
785 * Get the number of overruns of a POSIX.1b interval timer. This is to
786 * be the overrun of the timer last delivered. At the same time we are
787 * accumulating overruns on the next timer. The overrun is frozen when
788 * the signal is delivered, either at the notify time (if the info block
789 * is not queued) or at the actual delivery time (as we are informed by
790 * the call back to posixtimer_rearm(). So all we need to do is
791 * to pick up the frozen overrun.
793 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
795 struct k_itimer *timr;
799 timr = lock_timer(timer_id, &flags);
803 overrun = timer_overrun_to_int(timr, 0);
804 unlock_timer(timr, flags);
809 static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
810 bool absolute, bool sigev_none)
812 struct hrtimer *timer = &timr->it.real.timer;
813 enum hrtimer_mode mode;
815 mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
817 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
818 * clock modifications, so they become CLOCK_MONOTONIC based under the
819 * hood. See hrtimer_init(). Update timr->kclock, so the generic
820 * functions which use timr->kclock->clock_get() work.
822 * Note: it_clock stays unmodified, because the next timer_set() might
823 * use ABSTIME, so it needs to switch back.
825 if (timr->it_clock == CLOCK_REALTIME)
826 timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
828 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
829 timr->it.real.timer.function = posix_timer_fn;
832 expires = ktime_add_safe(expires, timer->base->get_time());
833 hrtimer_set_expires(timer, expires);
836 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
839 static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
841 return hrtimer_try_to_cancel(&timr->it.real.timer);
844 /* Set a POSIX.1b interval timer. */
845 int common_timer_set(struct k_itimer *timr, int flags,
846 struct itimerspec64 *new_setting,
847 struct itimerspec64 *old_setting)
849 const struct k_clock *kc = timr->kclock;
854 common_timer_get(timr, old_setting);
856 /* Prevent rearming by clearing the interval */
857 timr->it_interval = 0;
859 * Careful here. On SMP systems the timer expiry function could be
860 * active and spinning on timr->it_lock.
862 if (kc->timer_try_to_cancel(timr) < 0)
866 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
868 timr->it_overrun_last = 0;
870 /* Switch off the timer when it_value is zero */
871 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
874 timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
875 expires = timespec64_to_ktime(new_setting->it_value);
876 sigev_none = timr->it_sigev_notify == SIGEV_NONE;
878 kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
879 timr->it_active = !sigev_none;
883 static int do_timer_settime(timer_t timer_id, int flags,
884 struct itimerspec64 *new_spec64,
885 struct itimerspec64 *old_spec64)
887 const struct k_clock *kc;
888 struct k_itimer *timr;
892 if (!timespec64_valid(&new_spec64->it_interval) ||
893 !timespec64_valid(&new_spec64->it_value))
897 memset(old_spec64, 0, sizeof(*old_spec64));
899 timr = lock_timer(timer_id, &flag);
904 if (WARN_ON_ONCE(!kc || !kc->timer_set))
907 error = kc->timer_set(timr, flags, new_spec64, old_spec64);
909 unlock_timer(timr, flag);
910 if (error == TIMER_RETRY) {
911 old_spec64 = NULL; // We already got the old time...
918 /* Set a POSIX.1b interval timer */
919 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
920 const struct __kernel_itimerspec __user *, new_setting,
921 struct __kernel_itimerspec __user *, old_setting)
923 struct itimerspec64 new_spec, old_spec;
924 struct itimerspec64 *rtn = old_setting ? &old_spec : NULL;
930 if (get_itimerspec64(&new_spec, new_setting))
933 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
934 if (!error && old_setting) {
935 if (put_itimerspec64(&old_spec, old_setting))
941 #ifdef CONFIG_COMPAT_32BIT_TIME
942 COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
943 struct compat_itimerspec __user *, new,
944 struct compat_itimerspec __user *, old)
946 struct itimerspec64 new_spec, old_spec;
947 struct itimerspec64 *rtn = old ? &old_spec : NULL;
952 if (get_compat_itimerspec64(&new_spec, new))
955 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
957 if (put_compat_itimerspec64(&old_spec, old))
964 int common_timer_del(struct k_itimer *timer)
966 const struct k_clock *kc = timer->kclock;
968 timer->it_interval = 0;
969 if (kc->timer_try_to_cancel(timer) < 0)
971 timer->it_active = 0;
975 static inline int timer_delete_hook(struct k_itimer *timer)
977 const struct k_clock *kc = timer->kclock;
979 if (WARN_ON_ONCE(!kc || !kc->timer_del))
981 return kc->timer_del(timer);
984 /* Delete a POSIX.1b interval timer. */
985 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
987 struct k_itimer *timer;
991 timer = lock_timer(timer_id, &flags);
995 if (timer_delete_hook(timer) == TIMER_RETRY) {
996 unlock_timer(timer, flags);
1000 spin_lock(¤t->sighand->siglock);
1001 list_del(&timer->list);
1002 spin_unlock(¤t->sighand->siglock);
1004 * This keeps any tasks waiting on the spin lock from thinking
1005 * they got something (see the lock code above).
1007 timer->it_signal = NULL;
1009 unlock_timer(timer, flags);
1010 release_posix_timer(timer, IT_ID_SET);
1015 * return timer owned by the process, used by exit_itimers
1017 static void itimer_delete(struct k_itimer *timer)
1019 unsigned long flags;
1022 spin_lock_irqsave(&timer->it_lock, flags);
1024 if (timer_delete_hook(timer) == TIMER_RETRY) {
1025 unlock_timer(timer, flags);
1028 list_del(&timer->list);
1030 * This keeps any tasks waiting on the spin lock from thinking
1031 * they got something (see the lock code above).
1033 timer->it_signal = NULL;
1035 unlock_timer(timer, flags);
1036 release_posix_timer(timer, IT_ID_SET);
1040 * This is called by do_exit or de_thread, only when there are no more
1041 * references to the shared signal_struct.
1043 void exit_itimers(struct signal_struct *sig)
1045 struct k_itimer *tmr;
1047 while (!list_empty(&sig->posix_timers)) {
1048 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
1053 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
1054 const struct __kernel_timespec __user *, tp)
1056 const struct k_clock *kc = clockid_to_kclock(which_clock);
1057 struct timespec64 new_tp;
1059 if (!kc || !kc->clock_set)
1062 if (get_timespec64(&new_tp, tp))
1065 return kc->clock_set(which_clock, &new_tp);
1068 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
1069 struct __kernel_timespec __user *, tp)
1071 const struct k_clock *kc = clockid_to_kclock(which_clock);
1072 struct timespec64 kernel_tp;
1078 error = kc->clock_get(which_clock, &kernel_tp);
1080 if (!error && put_timespec64(&kernel_tp, tp))
1086 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1087 struct timex __user *, utx)
1089 const struct k_clock *kc = clockid_to_kclock(which_clock);
1098 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1101 err = kc->clock_adj(which_clock, &ktx);
1103 if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1109 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1110 struct __kernel_timespec __user *, tp)
1112 const struct k_clock *kc = clockid_to_kclock(which_clock);
1113 struct timespec64 rtn_tp;
1119 error = kc->clock_getres(which_clock, &rtn_tp);
1121 if (!error && tp && put_timespec64(&rtn_tp, tp))
1127 #ifdef CONFIG_COMPAT_32BIT_TIME
1129 COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
1130 struct compat_timespec __user *, tp)
1132 const struct k_clock *kc = clockid_to_kclock(which_clock);
1133 struct timespec64 ts;
1135 if (!kc || !kc->clock_set)
1138 if (compat_get_timespec64(&ts, tp))
1141 return kc->clock_set(which_clock, &ts);
1144 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
1145 struct compat_timespec __user *, tp)
1147 const struct k_clock *kc = clockid_to_kclock(which_clock);
1148 struct timespec64 ts;
1154 err = kc->clock_get(which_clock, &ts);
1156 if (!err && compat_put_timespec64(&ts, tp))
1164 #ifdef CONFIG_COMPAT
1166 COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
1167 struct compat_timex __user *, utp)
1169 const struct k_clock *kc = clockid_to_kclock(which_clock);
1178 err = compat_get_timex(&ktx, utp);
1182 err = kc->clock_adj(which_clock, &ktx);
1185 err = compat_put_timex(utp, &ktx);
1192 #ifdef CONFIG_COMPAT_32BIT_TIME
1194 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
1195 struct compat_timespec __user *, tp)
1197 const struct k_clock *kc = clockid_to_kclock(which_clock);
1198 struct timespec64 ts;
1204 err = kc->clock_getres(which_clock, &ts);
1205 if (!err && tp && compat_put_timespec64(&ts, tp))
1214 * nanosleep for monotonic and realtime clocks
1216 static int common_nsleep(const clockid_t which_clock, int flags,
1217 const struct timespec64 *rqtp)
1219 return hrtimer_nanosleep(rqtp, flags & TIMER_ABSTIME ?
1220 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1224 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1225 const struct __kernel_timespec __user *, rqtp,
1226 struct __kernel_timespec __user *, rmtp)
1228 const struct k_clock *kc = clockid_to_kclock(which_clock);
1229 struct timespec64 t;
1234 return -ENANOSLEEP_NOTSUP;
1236 if (get_timespec64(&t, rqtp))
1239 if (!timespec64_valid(&t))
1241 if (flags & TIMER_ABSTIME)
1243 current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
1244 current->restart_block.nanosleep.rmtp = rmtp;
1246 return kc->nsleep(which_clock, flags, &t);
1249 #ifdef CONFIG_COMPAT_32BIT_TIME
1251 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
1252 struct compat_timespec __user *, rqtp,
1253 struct compat_timespec __user *, rmtp)
1255 const struct k_clock *kc = clockid_to_kclock(which_clock);
1256 struct timespec64 t;
1261 return -ENANOSLEEP_NOTSUP;
1263 if (compat_get_timespec64(&t, rqtp))
1266 if (!timespec64_valid(&t))
1268 if (flags & TIMER_ABSTIME)
1270 current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
1271 current->restart_block.nanosleep.compat_rmtp = rmtp;
1273 return kc->nsleep(which_clock, flags, &t);
1278 static const struct k_clock clock_realtime = {
1279 .clock_getres = posix_get_hrtimer_res,
1280 .clock_get = posix_clock_realtime_get,
1281 .clock_set = posix_clock_realtime_set,
1282 .clock_adj = posix_clock_realtime_adj,
1283 .nsleep = common_nsleep,
1284 .timer_create = common_timer_create,
1285 .timer_set = common_timer_set,
1286 .timer_get = common_timer_get,
1287 .timer_del = common_timer_del,
1288 .timer_rearm = common_hrtimer_rearm,
1289 .timer_forward = common_hrtimer_forward,
1290 .timer_remaining = common_hrtimer_remaining,
1291 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1292 .timer_arm = common_hrtimer_arm,
1295 static const struct k_clock clock_monotonic = {
1296 .clock_getres = posix_get_hrtimer_res,
1297 .clock_get = posix_ktime_get_ts,
1298 .nsleep = common_nsleep,
1299 .timer_create = common_timer_create,
1300 .timer_set = common_timer_set,
1301 .timer_get = common_timer_get,
1302 .timer_del = common_timer_del,
1303 .timer_rearm = common_hrtimer_rearm,
1304 .timer_forward = common_hrtimer_forward,
1305 .timer_remaining = common_hrtimer_remaining,
1306 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1307 .timer_arm = common_hrtimer_arm,
1310 static const struct k_clock clock_monotonic_raw = {
1311 .clock_getres = posix_get_hrtimer_res,
1312 .clock_get = posix_get_monotonic_raw,
1315 static const struct k_clock clock_realtime_coarse = {
1316 .clock_getres = posix_get_coarse_res,
1317 .clock_get = posix_get_realtime_coarse,
1320 static const struct k_clock clock_monotonic_coarse = {
1321 .clock_getres = posix_get_coarse_res,
1322 .clock_get = posix_get_monotonic_coarse,
1325 static const struct k_clock clock_tai = {
1326 .clock_getres = posix_get_hrtimer_res,
1327 .clock_get = posix_get_tai,
1328 .nsleep = common_nsleep,
1329 .timer_create = common_timer_create,
1330 .timer_set = common_timer_set,
1331 .timer_get = common_timer_get,
1332 .timer_del = common_timer_del,
1333 .timer_rearm = common_hrtimer_rearm,
1334 .timer_forward = common_hrtimer_forward,
1335 .timer_remaining = common_hrtimer_remaining,
1336 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1337 .timer_arm = common_hrtimer_arm,
1340 static const struct k_clock clock_boottime = {
1341 .clock_getres = posix_get_hrtimer_res,
1342 .clock_get = posix_get_boottime,
1343 .nsleep = common_nsleep,
1344 .timer_create = common_timer_create,
1345 .timer_set = common_timer_set,
1346 .timer_get = common_timer_get,
1347 .timer_del = common_timer_del,
1348 .timer_rearm = common_hrtimer_rearm,
1349 .timer_forward = common_hrtimer_forward,
1350 .timer_remaining = common_hrtimer_remaining,
1351 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1352 .timer_arm = common_hrtimer_arm,
1355 static const struct k_clock * const posix_clocks[] = {
1356 [CLOCK_REALTIME] = &clock_realtime,
1357 [CLOCK_MONOTONIC] = &clock_monotonic,
1358 [CLOCK_PROCESS_CPUTIME_ID] = &clock_process,
1359 [CLOCK_THREAD_CPUTIME_ID] = &clock_thread,
1360 [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw,
1361 [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse,
1362 [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse,
1363 [CLOCK_BOOTTIME] = &clock_boottime,
1364 [CLOCK_REALTIME_ALARM] = &alarm_clock,
1365 [CLOCK_BOOTTIME_ALARM] = &alarm_clock,
1366 [CLOCK_TAI] = &clock_tai,
1369 static const struct k_clock *clockid_to_kclock(const clockid_t id)
1374 return (id & CLOCKFD_MASK) == CLOCKFD ?
1375 &clock_posix_dynamic : &clock_posix_cpu;
1378 if (id >= ARRAY_SIZE(posix_clocks))
1381 return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];