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 * The timer ID is turned into a timer address by idr_find().
90 * Verifying a valid ID consists of:
92 * a) checking that idr_find() returns other than -1.
93 * b) checking that the timer id matches the one in the timer itself.
94 * c) that the timer owner is in the callers thread group.
98 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
99 * to implement others. This structure defines the various
102 * RESOLUTION: Clock resolution is used to round up timer and interval
103 * times, NOT to report clock times, which are reported with as
104 * much resolution as the system can muster. In some cases this
105 * resolution may depend on the underlying clock hardware and
106 * may not be quantifiable until run time, and only then is the
107 * necessary code is written. The standard says we should say
108 * something about this issue in the documentation...
110 * FUNCTIONS: The CLOCKs structure defines possible functions to
111 * handle various clock functions.
113 * The standard POSIX timer management code assumes the
114 * following: 1.) The k_itimer struct (sched.h) is used for
115 * the timer. 2.) The list, it_lock, it_clock, it_id and
116 * it_pid fields are not modified by timer code.
118 * Permissions: It is assumed that the clock_settime() function defined
119 * for each clock will take care of permission checks. Some
120 * clocks may be set able by any user (i.e. local process
121 * clocks) others not. Currently the only set able clock we
122 * have is CLOCK_REALTIME and its high res counter part, both of
123 * which we beg off on and pass to do_sys_settimeofday().
125 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
127 #define lock_timer(tid, flags) \
128 ({ struct k_itimer *__timr; \
129 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
133 static int hash(struct signal_struct *sig, unsigned int nr)
135 return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable));
138 static struct k_itimer *__posix_timers_find(struct hlist_head *head,
139 struct signal_struct *sig,
142 struct k_itimer *timer;
144 hlist_for_each_entry_rcu(timer, head, t_hash) {
145 if ((timer->it_signal == sig) && (timer->it_id == id))
151 static struct k_itimer *posix_timer_by_id(timer_t id)
153 struct signal_struct *sig = current->signal;
154 struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)];
156 return __posix_timers_find(head, sig, id);
159 static int posix_timer_add(struct k_itimer *timer)
161 struct signal_struct *sig = current->signal;
162 int first_free_id = sig->posix_timer_id;
163 struct hlist_head *head;
167 spin_lock(&hash_lock);
168 head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)];
169 if (!__posix_timers_find(head, sig, sig->posix_timer_id)) {
170 hlist_add_head_rcu(&timer->t_hash, head);
171 ret = sig->posix_timer_id;
173 if (++sig->posix_timer_id < 0)
174 sig->posix_timer_id = 0;
175 if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT))
176 /* Loop over all possible ids completed */
178 spin_unlock(&hash_lock);
179 } while (ret == -ENOENT);
183 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
185 spin_unlock_irqrestore(&timr->it_lock, flags);
188 /* Get clock_realtime */
189 static int posix_clock_realtime_get(clockid_t which_clock, struct timespec64 *tp)
191 ktime_get_real_ts64(tp);
195 /* Set clock_realtime */
196 static int posix_clock_realtime_set(const clockid_t which_clock,
197 const struct timespec64 *tp)
199 return do_sys_settimeofday64(tp, NULL);
202 static int posix_clock_realtime_adj(const clockid_t which_clock,
205 return do_adjtimex(t);
209 * Get monotonic time for posix timers
211 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec64 *tp)
218 * Get monotonic-raw time for posix timers
220 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
222 ktime_get_raw_ts64(tp);
227 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp)
229 ktime_get_coarse_real_ts64(tp);
233 static int posix_get_monotonic_coarse(clockid_t which_clock,
234 struct timespec64 *tp)
236 ktime_get_coarse_ts64(tp);
240 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
242 *tp = ktime_to_timespec64(KTIME_LOW_RES);
246 static int posix_get_boottime(const clockid_t which_clock, struct timespec64 *tp)
248 ktime_get_boottime_ts64(tp);
252 static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
254 ktime_get_clocktai_ts64(tp);
258 static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
261 tp->tv_nsec = hrtimer_resolution;
266 * Initialize everything, well, just everything in Posix clocks/timers ;)
268 static __init int init_posix_timers(void)
270 posix_timers_cache = kmem_cache_create("posix_timers_cache",
271 sizeof (struct k_itimer), 0, SLAB_PANIC,
275 __initcall(init_posix_timers);
278 * The siginfo si_overrun field and the return value of timer_getoverrun(2)
279 * are of type int. Clamp the overrun value to INT_MAX
281 static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
283 s64 sum = timr->it_overrun_last + (s64)baseval;
285 return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
288 static void common_hrtimer_rearm(struct k_itimer *timr)
290 struct hrtimer *timer = &timr->it.real.timer;
292 if (!timr->it_interval)
295 timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
297 hrtimer_restart(timer);
301 * This function is exported for use by the signal deliver code. It is
302 * called just prior to the info block being released and passes that
303 * block to us. It's function is to update the overrun entry AND to
304 * restart the timer. It should only be called if the timer is to be
305 * restarted (i.e. we have flagged this in the sys_private entry of the
308 * To protect against the timer going away while the interrupt is queued,
309 * we require that the it_requeue_pending flag be set.
311 void posixtimer_rearm(struct siginfo *info)
313 struct k_itimer *timr;
316 timr = lock_timer(info->si_tid, &flags);
320 if (timr->it_requeue_pending == info->si_sys_private) {
321 timr->kclock->timer_rearm(timr);
324 timr->it_overrun_last = timr->it_overrun;
325 timr->it_overrun = -1LL;
326 ++timr->it_requeue_pending;
328 info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
331 unlock_timer(timr, flags);
334 int posix_timer_event(struct k_itimer *timr, int si_private)
336 struct task_struct *task;
337 int shared, ret = -1;
339 * FIXME: if ->sigq is queued we can race with
340 * dequeue_signal()->posixtimer_rearm().
342 * If dequeue_signal() sees the "right" value of
343 * si_sys_private it calls posixtimer_rearm().
344 * We re-queue ->sigq and drop ->it_lock().
345 * posixtimer_rearm() locks the timer
346 * and re-schedules it while ->sigq is pending.
347 * Not really bad, but not that we want.
349 timr->sigq->info.si_sys_private = si_private;
352 task = pid_task(timr->it_pid, PIDTYPE_PID);
354 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
355 ret = send_sigqueue(timr->sigq, task, shared);
358 /* If we failed to send the signal the timer stops. */
363 * This function gets called when a POSIX.1b interval timer expires. It
364 * is used as a callback from the kernel internal timer. The
365 * run_timer_list code ALWAYS calls with interrupts on.
367 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
369 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
371 struct k_itimer *timr;
374 enum hrtimer_restart ret = HRTIMER_NORESTART;
376 timr = container_of(timer, struct k_itimer, it.real.timer);
377 spin_lock_irqsave(&timr->it_lock, flags);
380 if (timr->it_interval != 0)
381 si_private = ++timr->it_requeue_pending;
383 if (posix_timer_event(timr, si_private)) {
385 * signal was not sent because of sig_ignor
386 * we will not get a call back to restart it AND
387 * it should be restarted.
389 if (timr->it_interval != 0) {
390 ktime_t now = hrtimer_cb_get_time(timer);
393 * FIXME: What we really want, is to stop this
394 * timer completely and restart it in case the
395 * SIG_IGN is removed. This is a non trivial
396 * change which involves sighand locking
397 * (sigh !), which we don't want to do late in
400 * For now we just let timers with an interval
401 * less than a jiffie expire every jiffie to
402 * avoid softirq starvation in case of SIG_IGN
403 * and a very small interval, which would put
404 * the timer right back on the softirq pending
405 * list. By moving now ahead of time we trick
406 * hrtimer_forward() to expire the timer
407 * later, while we still maintain the overrun
408 * accuracy, but have some inconsistency in
409 * the timer_gettime() case. This is at least
410 * better than a starved softirq. A more
411 * complex fix which solves also another related
412 * inconsistency is already in the pipeline.
414 #ifdef CONFIG_HIGH_RES_TIMERS
416 ktime_t kj = NSEC_PER_SEC / HZ;
418 if (timr->it_interval < kj)
419 now = ktime_add(now, kj);
422 timr->it_overrun += hrtimer_forward(timer, now,
424 ret = HRTIMER_RESTART;
425 ++timr->it_requeue_pending;
430 unlock_timer(timr, flags);
434 static struct pid *good_sigevent(sigevent_t * event)
436 struct task_struct *rtn = current->group_leader;
438 switch (event->sigev_notify) {
439 case SIGEV_SIGNAL | SIGEV_THREAD_ID:
440 rtn = find_task_by_vpid(event->sigev_notify_thread_id);
441 if (!rtn || !same_thread_group(rtn, current))
446 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
450 return task_pid(rtn);
456 static struct k_itimer * alloc_posix_timer(void)
458 struct k_itimer *tmr;
459 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
462 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
463 kmem_cache_free(posix_timers_cache, tmr);
466 clear_siginfo(&tmr->sigq->info);
470 static void k_itimer_rcu_free(struct rcu_head *head)
472 struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
474 kmem_cache_free(posix_timers_cache, tmr);
478 #define IT_ID_NOT_SET 0
479 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
483 spin_lock_irqsave(&hash_lock, flags);
484 hlist_del_rcu(&tmr->t_hash);
485 spin_unlock_irqrestore(&hash_lock, flags);
487 put_pid(tmr->it_pid);
488 sigqueue_free(tmr->sigq);
489 call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
492 static int common_timer_create(struct k_itimer *new_timer)
494 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
498 /* Create a POSIX.1b interval timer. */
499 static int do_timer_create(clockid_t which_clock, struct sigevent *event,
500 timer_t __user *created_timer_id)
502 const struct k_clock *kc = clockid_to_kclock(which_clock);
503 struct k_itimer *new_timer;
504 int error, new_timer_id;
505 int it_id_set = IT_ID_NOT_SET;
509 if (!kc->timer_create)
512 new_timer = alloc_posix_timer();
513 if (unlikely(!new_timer))
516 spin_lock_init(&new_timer->it_lock);
517 new_timer_id = posix_timer_add(new_timer);
518 if (new_timer_id < 0) {
519 error = new_timer_id;
523 it_id_set = IT_ID_SET;
524 new_timer->it_id = (timer_t) new_timer_id;
525 new_timer->it_clock = which_clock;
526 new_timer->kclock = kc;
527 new_timer->it_overrun = -1LL;
531 new_timer->it_pid = get_pid(good_sigevent(event));
533 if (!new_timer->it_pid) {
537 new_timer->it_sigev_notify = event->sigev_notify;
538 new_timer->sigq->info.si_signo = event->sigev_signo;
539 new_timer->sigq->info.si_value = event->sigev_value;
541 new_timer->it_sigev_notify = SIGEV_SIGNAL;
542 new_timer->sigq->info.si_signo = SIGALRM;
543 memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t));
544 new_timer->sigq->info.si_value.sival_int = new_timer->it_id;
545 new_timer->it_pid = get_pid(task_tgid(current));
548 new_timer->sigq->info.si_tid = new_timer->it_id;
549 new_timer->sigq->info.si_code = SI_TIMER;
551 if (copy_to_user(created_timer_id,
552 &new_timer_id, sizeof (new_timer_id))) {
557 error = kc->timer_create(new_timer);
561 spin_lock_irq(¤t->sighand->siglock);
562 new_timer->it_signal = current->signal;
563 list_add(&new_timer->list, ¤t->signal->posix_timers);
564 spin_unlock_irq(¤t->sighand->siglock);
568 * In the case of the timer belonging to another task, after
569 * the task is unlocked, the timer is owned by the other task
570 * and may cease to exist at any time. Don't use or modify
571 * new_timer after the unlock call.
574 release_posix_timer(new_timer, it_id_set);
578 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
579 struct sigevent __user *, timer_event_spec,
580 timer_t __user *, created_timer_id)
582 if (timer_event_spec) {
585 if (copy_from_user(&event, timer_event_spec, sizeof (event)))
587 return do_timer_create(which_clock, &event, created_timer_id);
589 return do_timer_create(which_clock, NULL, created_timer_id);
593 COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
594 struct compat_sigevent __user *, timer_event_spec,
595 timer_t __user *, created_timer_id)
597 if (timer_event_spec) {
600 if (get_compat_sigevent(&event, timer_event_spec))
602 return do_timer_create(which_clock, &event, created_timer_id);
604 return do_timer_create(which_clock, NULL, created_timer_id);
609 * Locking issues: We need to protect the result of the id look up until
610 * we get the timer locked down so it is not deleted under us. The
611 * removal is done under the idr spinlock so we use that here to bridge
612 * the find to the timer lock. To avoid a dead lock, the timer id MUST
613 * be release with out holding the timer lock.
615 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
617 struct k_itimer *timr;
620 * timer_t could be any type >= int and we want to make sure any
621 * @timer_id outside positive int range fails lookup.
623 if ((unsigned long long)timer_id > INT_MAX)
627 timr = posix_timer_by_id(timer_id);
629 spin_lock_irqsave(&timr->it_lock, *flags);
630 if (timr->it_signal == current->signal) {
634 spin_unlock_irqrestore(&timr->it_lock, *flags);
641 static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
643 struct hrtimer *timer = &timr->it.real.timer;
645 return __hrtimer_expires_remaining_adjusted(timer, now);
648 static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
650 struct hrtimer *timer = &timr->it.real.timer;
652 return hrtimer_forward(timer, now, timr->it_interval);
656 * Get the time remaining on a POSIX.1b interval timer. This function
657 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
660 * We have a couple of messes to clean up here. First there is the case
661 * of a timer that has a requeue pending. These timers should appear to
662 * be in the timer list with an expiry as if we were to requeue them
665 * The second issue is the SIGEV_NONE timer which may be active but is
666 * not really ever put in the timer list (to save system resources).
667 * This timer may be expired, and if so, we will do it here. Otherwise
668 * it is the same as a requeue pending timer WRT to what we should
671 void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
673 const struct k_clock *kc = timr->kclock;
674 ktime_t now, remaining, iv;
675 struct timespec64 ts64;
678 sig_none = timr->it_sigev_notify == SIGEV_NONE;
679 iv = timr->it_interval;
681 /* interval timer ? */
683 cur_setting->it_interval = ktime_to_timespec64(iv);
684 } else if (!timr->it_active) {
686 * SIGEV_NONE oneshot timers are never queued. Check them
694 * The timespec64 based conversion is suboptimal, but it's not
695 * worth to implement yet another callback.
697 kc->clock_get(timr->it_clock, &ts64);
698 now = timespec64_to_ktime(ts64);
701 * When a requeue is pending or this is a SIGEV_NONE timer move the
702 * expiry time forward by intervals, so expiry is > now.
704 if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
705 timr->it_overrun += kc->timer_forward(timr, now);
707 remaining = kc->timer_remaining(timr, now);
708 /* Return 0 only, when the timer is expired and not pending */
709 if (remaining <= 0) {
711 * A single shot SIGEV_NONE timer must return 0, when
715 cur_setting->it_value.tv_nsec = 1;
717 cur_setting->it_value = ktime_to_timespec64(remaining);
721 /* Get the time remaining on a POSIX.1b interval timer. */
722 static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting)
724 struct k_itimer *timr;
725 const struct k_clock *kc;
729 timr = lock_timer(timer_id, &flags);
733 memset(setting, 0, sizeof(*setting));
735 if (WARN_ON_ONCE(!kc || !kc->timer_get))
738 kc->timer_get(timr, setting);
740 unlock_timer(timr, flags);
744 /* Get the time remaining on a POSIX.1b interval timer. */
745 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
746 struct __kernel_itimerspec __user *, setting)
748 struct itimerspec64 cur_setting;
750 int ret = do_timer_gettime(timer_id, &cur_setting);
752 if (put_itimerspec64(&cur_setting, setting))
758 #ifdef CONFIG_COMPAT_32BIT_TIME
760 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
761 struct compat_itimerspec __user *, setting)
763 struct itimerspec64 cur_setting;
765 int ret = do_timer_gettime(timer_id, &cur_setting);
767 if (put_compat_itimerspec64(&cur_setting, setting))
776 * Get the number of overruns of a POSIX.1b interval timer. This is to
777 * be the overrun of the timer last delivered. At the same time we are
778 * accumulating overruns on the next timer. The overrun is frozen when
779 * the signal is delivered, either at the notify time (if the info block
780 * is not queued) or at the actual delivery time (as we are informed by
781 * the call back to posixtimer_rearm(). So all we need to do is
782 * to pick up the frozen overrun.
784 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
786 struct k_itimer *timr;
790 timr = lock_timer(timer_id, &flags);
794 overrun = timer_overrun_to_int(timr, 0);
795 unlock_timer(timr, flags);
800 static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
801 bool absolute, bool sigev_none)
803 struct hrtimer *timer = &timr->it.real.timer;
804 enum hrtimer_mode mode;
806 mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
808 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
809 * clock modifications, so they become CLOCK_MONOTONIC based under the
810 * hood. See hrtimer_init(). Update timr->kclock, so the generic
811 * functions which use timr->kclock->clock_get() work.
813 * Note: it_clock stays unmodified, because the next timer_set() might
814 * use ABSTIME, so it needs to switch back.
816 if (timr->it_clock == CLOCK_REALTIME)
817 timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
819 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
820 timr->it.real.timer.function = posix_timer_fn;
823 expires = ktime_add_safe(expires, timer->base->get_time());
824 hrtimer_set_expires(timer, expires);
827 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
830 static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
832 return hrtimer_try_to_cancel(&timr->it.real.timer);
835 /* Set a POSIX.1b interval timer. */
836 int common_timer_set(struct k_itimer *timr, int flags,
837 struct itimerspec64 *new_setting,
838 struct itimerspec64 *old_setting)
840 const struct k_clock *kc = timr->kclock;
845 common_timer_get(timr, old_setting);
847 /* Prevent rearming by clearing the interval */
848 timr->it_interval = 0;
850 * Careful here. On SMP systems the timer expiry function could be
851 * active and spinning on timr->it_lock.
853 if (kc->timer_try_to_cancel(timr) < 0)
857 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
859 timr->it_overrun_last = 0;
861 /* Switch off the timer when it_value is zero */
862 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
865 timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
866 expires = timespec64_to_ktime(new_setting->it_value);
867 sigev_none = timr->it_sigev_notify == SIGEV_NONE;
869 kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
870 timr->it_active = !sigev_none;
874 static int do_timer_settime(timer_t timer_id, int flags,
875 struct itimerspec64 *new_spec64,
876 struct itimerspec64 *old_spec64)
878 const struct k_clock *kc;
879 struct k_itimer *timr;
883 if (!timespec64_valid(&new_spec64->it_interval) ||
884 !timespec64_valid(&new_spec64->it_value))
888 memset(old_spec64, 0, sizeof(*old_spec64));
890 timr = lock_timer(timer_id, &flag);
895 if (WARN_ON_ONCE(!kc || !kc->timer_set))
898 error = kc->timer_set(timr, flags, new_spec64, old_spec64);
900 unlock_timer(timr, flag);
901 if (error == TIMER_RETRY) {
902 old_spec64 = NULL; // We already got the old time...
909 /* Set a POSIX.1b interval timer */
910 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
911 const struct __kernel_itimerspec __user *, new_setting,
912 struct __kernel_itimerspec __user *, old_setting)
914 struct itimerspec64 new_spec, old_spec;
915 struct itimerspec64 *rtn = old_setting ? &old_spec : NULL;
921 if (get_itimerspec64(&new_spec, new_setting))
924 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
925 if (!error && old_setting) {
926 if (put_itimerspec64(&old_spec, old_setting))
932 #ifdef CONFIG_COMPAT_32BIT_TIME
933 COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
934 struct compat_itimerspec __user *, new,
935 struct compat_itimerspec __user *, old)
937 struct itimerspec64 new_spec, old_spec;
938 struct itimerspec64 *rtn = old ? &old_spec : NULL;
943 if (get_compat_itimerspec64(&new_spec, new))
946 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
948 if (put_compat_itimerspec64(&old_spec, old))
955 int common_timer_del(struct k_itimer *timer)
957 const struct k_clock *kc = timer->kclock;
959 timer->it_interval = 0;
960 if (kc->timer_try_to_cancel(timer) < 0)
962 timer->it_active = 0;
966 static inline int timer_delete_hook(struct k_itimer *timer)
968 const struct k_clock *kc = timer->kclock;
970 if (WARN_ON_ONCE(!kc || !kc->timer_del))
972 return kc->timer_del(timer);
975 /* Delete a POSIX.1b interval timer. */
976 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
978 struct k_itimer *timer;
982 timer = lock_timer(timer_id, &flags);
986 if (timer_delete_hook(timer) == TIMER_RETRY) {
987 unlock_timer(timer, flags);
991 spin_lock(¤t->sighand->siglock);
992 list_del(&timer->list);
993 spin_unlock(¤t->sighand->siglock);
995 * This keeps any tasks waiting on the spin lock from thinking
996 * they got something (see the lock code above).
998 timer->it_signal = NULL;
1000 unlock_timer(timer, flags);
1001 release_posix_timer(timer, IT_ID_SET);
1006 * return timer owned by the process, used by exit_itimers
1008 static void itimer_delete(struct k_itimer *timer)
1010 unsigned long flags;
1013 spin_lock_irqsave(&timer->it_lock, flags);
1015 if (timer_delete_hook(timer) == TIMER_RETRY) {
1016 unlock_timer(timer, flags);
1019 list_del(&timer->list);
1021 * This keeps any tasks waiting on the spin lock from thinking
1022 * they got something (see the lock code above).
1024 timer->it_signal = NULL;
1026 unlock_timer(timer, flags);
1027 release_posix_timer(timer, IT_ID_SET);
1031 * This is called by do_exit or de_thread, only when there are no more
1032 * references to the shared signal_struct.
1034 void exit_itimers(struct signal_struct *sig)
1036 struct k_itimer *tmr;
1038 while (!list_empty(&sig->posix_timers)) {
1039 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
1044 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
1045 const struct __kernel_timespec __user *, tp)
1047 const struct k_clock *kc = clockid_to_kclock(which_clock);
1048 struct timespec64 new_tp;
1050 if (!kc || !kc->clock_set)
1053 if (get_timespec64(&new_tp, tp))
1056 return kc->clock_set(which_clock, &new_tp);
1059 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
1060 struct __kernel_timespec __user *, tp)
1062 const struct k_clock *kc = clockid_to_kclock(which_clock);
1063 struct timespec64 kernel_tp;
1069 error = kc->clock_get(which_clock, &kernel_tp);
1071 if (!error && put_timespec64(&kernel_tp, tp))
1077 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1078 struct timex __user *, utx)
1080 const struct k_clock *kc = clockid_to_kclock(which_clock);
1089 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1092 err = kc->clock_adj(which_clock, &ktx);
1094 if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1100 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1101 struct __kernel_timespec __user *, tp)
1103 const struct k_clock *kc = clockid_to_kclock(which_clock);
1104 struct timespec64 rtn_tp;
1110 error = kc->clock_getres(which_clock, &rtn_tp);
1112 if (!error && tp && put_timespec64(&rtn_tp, tp))
1118 #ifdef CONFIG_COMPAT_32BIT_TIME
1120 COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
1121 struct compat_timespec __user *, tp)
1123 const struct k_clock *kc = clockid_to_kclock(which_clock);
1124 struct timespec64 ts;
1126 if (!kc || !kc->clock_set)
1129 if (compat_get_timespec64(&ts, tp))
1132 return kc->clock_set(which_clock, &ts);
1135 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
1136 struct compat_timespec __user *, tp)
1138 const struct k_clock *kc = clockid_to_kclock(which_clock);
1139 struct timespec64 ts;
1145 err = kc->clock_get(which_clock, &ts);
1147 if (!err && compat_put_timespec64(&ts, tp))
1155 #ifdef CONFIG_COMPAT
1157 COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
1158 struct compat_timex __user *, utp)
1160 const struct k_clock *kc = clockid_to_kclock(which_clock);
1169 err = compat_get_timex(&ktx, utp);
1173 err = kc->clock_adj(which_clock, &ktx);
1176 err = compat_put_timex(utp, &ktx);
1183 #ifdef CONFIG_COMPAT_32BIT_TIME
1185 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
1186 struct compat_timespec __user *, tp)
1188 const struct k_clock *kc = clockid_to_kclock(which_clock);
1189 struct timespec64 ts;
1195 err = kc->clock_getres(which_clock, &ts);
1196 if (!err && tp && compat_put_timespec64(&ts, tp))
1205 * nanosleep for monotonic and realtime clocks
1207 static int common_nsleep(const clockid_t which_clock, int flags,
1208 const struct timespec64 *rqtp)
1210 return hrtimer_nanosleep(rqtp, flags & TIMER_ABSTIME ?
1211 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1215 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1216 const struct __kernel_timespec __user *, rqtp,
1217 struct __kernel_timespec __user *, rmtp)
1219 const struct k_clock *kc = clockid_to_kclock(which_clock);
1220 struct timespec64 t;
1227 if (get_timespec64(&t, rqtp))
1230 if (!timespec64_valid(&t))
1232 if (flags & TIMER_ABSTIME)
1234 current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
1235 current->restart_block.nanosleep.rmtp = rmtp;
1237 return kc->nsleep(which_clock, flags, &t);
1240 #ifdef CONFIG_COMPAT_32BIT_TIME
1242 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
1243 struct compat_timespec __user *, rqtp,
1244 struct compat_timespec __user *, rmtp)
1246 const struct k_clock *kc = clockid_to_kclock(which_clock);
1247 struct timespec64 t;
1254 if (compat_get_timespec64(&t, rqtp))
1257 if (!timespec64_valid(&t))
1259 if (flags & TIMER_ABSTIME)
1261 current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
1262 current->restart_block.nanosleep.compat_rmtp = rmtp;
1264 return kc->nsleep(which_clock, flags, &t);
1269 static const struct k_clock clock_realtime = {
1270 .clock_getres = posix_get_hrtimer_res,
1271 .clock_get = posix_clock_realtime_get,
1272 .clock_set = posix_clock_realtime_set,
1273 .clock_adj = posix_clock_realtime_adj,
1274 .nsleep = common_nsleep,
1275 .timer_create = common_timer_create,
1276 .timer_set = common_timer_set,
1277 .timer_get = common_timer_get,
1278 .timer_del = common_timer_del,
1279 .timer_rearm = common_hrtimer_rearm,
1280 .timer_forward = common_hrtimer_forward,
1281 .timer_remaining = common_hrtimer_remaining,
1282 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1283 .timer_arm = common_hrtimer_arm,
1286 static const struct k_clock clock_monotonic = {
1287 .clock_getres = posix_get_hrtimer_res,
1288 .clock_get = posix_ktime_get_ts,
1289 .nsleep = common_nsleep,
1290 .timer_create = common_timer_create,
1291 .timer_set = common_timer_set,
1292 .timer_get = common_timer_get,
1293 .timer_del = common_timer_del,
1294 .timer_rearm = common_hrtimer_rearm,
1295 .timer_forward = common_hrtimer_forward,
1296 .timer_remaining = common_hrtimer_remaining,
1297 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1298 .timer_arm = common_hrtimer_arm,
1301 static const struct k_clock clock_monotonic_raw = {
1302 .clock_getres = posix_get_hrtimer_res,
1303 .clock_get = posix_get_monotonic_raw,
1306 static const struct k_clock clock_realtime_coarse = {
1307 .clock_getres = posix_get_coarse_res,
1308 .clock_get = posix_get_realtime_coarse,
1311 static const struct k_clock clock_monotonic_coarse = {
1312 .clock_getres = posix_get_coarse_res,
1313 .clock_get = posix_get_monotonic_coarse,
1316 static const struct k_clock clock_tai = {
1317 .clock_getres = posix_get_hrtimer_res,
1318 .clock_get = posix_get_tai,
1319 .nsleep = common_nsleep,
1320 .timer_create = common_timer_create,
1321 .timer_set = common_timer_set,
1322 .timer_get = common_timer_get,
1323 .timer_del = common_timer_del,
1324 .timer_rearm = common_hrtimer_rearm,
1325 .timer_forward = common_hrtimer_forward,
1326 .timer_remaining = common_hrtimer_remaining,
1327 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1328 .timer_arm = common_hrtimer_arm,
1331 static const struct k_clock clock_boottime = {
1332 .clock_getres = posix_get_hrtimer_res,
1333 .clock_get = posix_get_boottime,
1334 .nsleep = common_nsleep,
1335 .timer_create = common_timer_create,
1336 .timer_set = common_timer_set,
1337 .timer_get = common_timer_get,
1338 .timer_del = common_timer_del,
1339 .timer_rearm = common_hrtimer_rearm,
1340 .timer_forward = common_hrtimer_forward,
1341 .timer_remaining = common_hrtimer_remaining,
1342 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1343 .timer_arm = common_hrtimer_arm,
1346 static const struct k_clock * const posix_clocks[] = {
1347 [CLOCK_REALTIME] = &clock_realtime,
1348 [CLOCK_MONOTONIC] = &clock_monotonic,
1349 [CLOCK_PROCESS_CPUTIME_ID] = &clock_process,
1350 [CLOCK_THREAD_CPUTIME_ID] = &clock_thread,
1351 [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw,
1352 [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse,
1353 [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse,
1354 [CLOCK_BOOTTIME] = &clock_boottime,
1355 [CLOCK_REALTIME_ALARM] = &alarm_clock,
1356 [CLOCK_BOOTTIME_ALARM] = &alarm_clock,
1357 [CLOCK_TAI] = &clock_tai,
1360 static const struct k_clock *clockid_to_kclock(const clockid_t id)
1365 return (id & CLOCKFD_MASK) == CLOCKFD ?
1366 &clock_posix_dynamic : &clock_posix_cpu;
1369 if (id >= ARRAY_SIZE(posix_clocks))
1372 return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];