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>
39 #include <asm/uaccess.h>
40 #include <linux/list.h>
41 #include <linux/init.h>
42 #include <linux/compiler.h>
43 #include <linux/idr.h>
44 #include <linux/posix-clock.h>
45 #include <linux/posix-timers.h>
46 #include <linux/syscalls.h>
47 #include <linux/wait.h>
48 #include <linux/workqueue.h>
49 #include <linux/export.h>
50 #include <linux/nospec.h>
53 * Management arrays for POSIX timers. Timers are kept in slab memory
54 * Timer ids are allocated by an external routine that keeps track of the
55 * id and the timer. The external interface is:
57 * void *idr_find(struct idr *idp, int id); to find timer_id <id>
58 * int idr_get_new(struct idr *idp, void *ptr); to get a new id and
60 * void idr_remove(struct idr *idp, int id); to release <id>
61 * void idr_init(struct idr *idp); to initialize <idp>
63 * The idr_get_new *may* call slab for more memory so it must not be
64 * called under a spin lock. Likewise idr_remore may release memory
65 * (but it may be ok to do this under a lock...).
66 * idr_find is just a memory look up and is quite fast. A -1 return
67 * indicates that the requested id does not exist.
71 * Lets keep our timers in a slab cache :-)
73 static struct kmem_cache *posix_timers_cache;
74 static struct idr posix_timers_id;
75 static DEFINE_SPINLOCK(idr_lock);
78 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
79 * SIGEV values. Here we put out an error if this assumption fails.
81 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
82 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
83 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
87 * parisc wants ENOTSUP instead of EOPNOTSUPP
90 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
92 # define ENANOSLEEP_NOTSUP ENOTSUP
96 * The timer ID is turned into a timer address by idr_find().
97 * Verifying a valid ID consists of:
99 * a) checking that idr_find() returns other than -1.
100 * b) checking that the timer id matches the one in the timer itself.
101 * c) that the timer owner is in the callers thread group.
105 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
106 * to implement others. This structure defines the various
109 * RESOLUTION: Clock resolution is used to round up timer and interval
110 * times, NOT to report clock times, which are reported with as
111 * much resolution as the system can muster. In some cases this
112 * resolution may depend on the underlying clock hardware and
113 * may not be quantifiable until run time, and only then is the
114 * necessary code is written. The standard says we should say
115 * something about this issue in the documentation...
117 * FUNCTIONS: The CLOCKs structure defines possible functions to
118 * handle various clock functions.
120 * The standard POSIX timer management code assumes the
121 * following: 1.) The k_itimer struct (sched.h) is used for
122 * the timer. 2.) The list, it_lock, it_clock, it_id and
123 * it_pid fields are not modified by timer code.
125 * Permissions: It is assumed that the clock_settime() function defined
126 * for each clock will take care of permission checks. Some
127 * clocks may be set able by any user (i.e. local process
128 * clocks) others not. Currently the only set able clock we
129 * have is CLOCK_REALTIME and its high res counter part, both of
130 * which we beg off on and pass to do_sys_settimeofday().
133 static struct k_clock posix_clocks[MAX_CLOCKS];
136 * These ones are defined below.
138 static int common_nsleep(const clockid_t, int flags, struct timespec *t,
139 struct timespec __user *rmtp);
140 static int common_timer_create(struct k_itimer *new_timer);
141 static void common_timer_get(struct k_itimer *, struct itimerspec *);
142 static int common_timer_set(struct k_itimer *, int,
143 struct itimerspec *, struct itimerspec *);
144 static int common_timer_del(struct k_itimer *timer);
146 static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
148 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
150 #define lock_timer(tid, flags) \
151 ({ struct k_itimer *__timr; \
152 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
156 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
158 spin_unlock_irqrestore(&timr->it_lock, flags);
161 /* Get clock_realtime */
162 static int posix_clock_realtime_get(clockid_t which_clock, struct timespec *tp)
164 ktime_get_real_ts(tp);
168 /* Set clock_realtime */
169 static int posix_clock_realtime_set(const clockid_t which_clock,
170 const struct timespec *tp)
172 return do_sys_settimeofday(tp, NULL);
175 static int posix_clock_realtime_adj(const clockid_t which_clock,
178 return do_adjtimex(t);
182 * Get monotonic time for posix timers
184 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
191 * Get monotonic-raw time for posix timers
193 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
200 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
202 *tp = current_kernel_time();
206 static int posix_get_monotonic_coarse(clockid_t which_clock,
209 *tp = get_monotonic_coarse();
213 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
215 *tp = ktime_to_timespec(KTIME_LOW_RES);
219 static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp)
221 get_monotonic_boottime(tp);
227 * Initialize everything, well, just everything in Posix clocks/timers ;)
229 static __init int init_posix_timers(void)
231 struct k_clock clock_realtime = {
232 .clock_getres = hrtimer_get_res,
233 .clock_get = posix_clock_realtime_get,
234 .clock_set = posix_clock_realtime_set,
235 .clock_adj = posix_clock_realtime_adj,
236 .nsleep = common_nsleep,
237 .nsleep_restart = hrtimer_nanosleep_restart,
238 .timer_create = common_timer_create,
239 .timer_set = common_timer_set,
240 .timer_get = common_timer_get,
241 .timer_del = common_timer_del,
243 struct k_clock clock_monotonic = {
244 .clock_getres = hrtimer_get_res,
245 .clock_get = posix_ktime_get_ts,
246 .nsleep = common_nsleep,
247 .nsleep_restart = hrtimer_nanosleep_restart,
248 .timer_create = common_timer_create,
249 .timer_set = common_timer_set,
250 .timer_get = common_timer_get,
251 .timer_del = common_timer_del,
253 struct k_clock clock_monotonic_raw = {
254 .clock_getres = hrtimer_get_res,
255 .clock_get = posix_get_monotonic_raw,
257 struct k_clock clock_realtime_coarse = {
258 .clock_getres = posix_get_coarse_res,
259 .clock_get = posix_get_realtime_coarse,
261 struct k_clock clock_monotonic_coarse = {
262 .clock_getres = posix_get_coarse_res,
263 .clock_get = posix_get_monotonic_coarse,
265 struct k_clock clock_boottime = {
266 .clock_getres = hrtimer_get_res,
267 .clock_get = posix_get_boottime,
268 .nsleep = common_nsleep,
269 .nsleep_restart = hrtimer_nanosleep_restart,
270 .timer_create = common_timer_create,
271 .timer_set = common_timer_set,
272 .timer_get = common_timer_get,
273 .timer_del = common_timer_del,
276 posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime);
277 posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic);
278 posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
279 posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
280 posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
281 posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime);
283 posix_timers_cache = kmem_cache_create("posix_timers_cache",
284 sizeof (struct k_itimer), 0, SLAB_PANIC,
286 idr_init(&posix_timers_id);
290 __initcall(init_posix_timers);
292 static void schedule_next_timer(struct k_itimer *timr)
294 struct hrtimer *timer = &timr->it.real.timer;
296 if (timr->it.real.interval.tv64 == 0)
299 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
300 timer->base->get_time(),
301 timr->it.real.interval);
303 timr->it_overrun_last = timr->it_overrun;
304 timr->it_overrun = -1;
305 ++timr->it_requeue_pending;
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 do_schedule_next_timer(struct siginfo *info)
322 struct k_itimer *timr;
325 timr = lock_timer(info->si_tid, &flags);
327 if (timr && timr->it_requeue_pending == info->si_sys_private) {
328 if (timr->it_clock < 0)
329 posix_cpu_timer_schedule(timr);
331 schedule_next_timer(timr);
333 info->si_overrun += timr->it_overrun_last;
337 unlock_timer(timr, flags);
340 int posix_timer_event(struct k_itimer *timr, int si_private)
342 struct task_struct *task;
343 int shared, ret = -1;
345 * FIXME: if ->sigq is queued we can race with
346 * dequeue_signal()->do_schedule_next_timer().
348 * If dequeue_signal() sees the "right" value of
349 * si_sys_private it calls do_schedule_next_timer().
350 * We re-queue ->sigq and drop ->it_lock().
351 * do_schedule_next_timer() locks the timer
352 * and re-schedules it while ->sigq is pending.
353 * Not really bad, but not that we want.
355 timr->sigq->info.si_sys_private = si_private;
358 task = pid_task(timr->it_pid, PIDTYPE_PID);
360 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
361 ret = send_sigqueue(timr->sigq, task, shared);
364 /* If we failed to send the signal the timer stops. */
367 EXPORT_SYMBOL_GPL(posix_timer_event);
370 * This function gets called when a POSIX.1b interval timer expires. It
371 * is used as a callback from the kernel internal timer. The
372 * run_timer_list code ALWAYS calls with interrupts on.
374 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
376 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
378 struct k_itimer *timr;
381 enum hrtimer_restart ret = HRTIMER_NORESTART;
383 timr = container_of(timer, struct k_itimer, it.real.timer);
384 spin_lock_irqsave(&timr->it_lock, flags);
386 if (timr->it.real.interval.tv64 != 0)
387 si_private = ++timr->it_requeue_pending;
389 if (posix_timer_event(timr, si_private)) {
391 * signal was not sent because of sig_ignor
392 * we will not get a call back to restart it AND
393 * it should be restarted.
395 if (timr->it.real.interval.tv64 != 0) {
396 ktime_t now = hrtimer_cb_get_time(timer);
399 * FIXME: What we really want, is to stop this
400 * timer completely and restart it in case the
401 * SIG_IGN is removed. This is a non trivial
402 * change which involves sighand locking
403 * (sigh !), which we don't want to do late in
406 * For now we just let timers with an interval
407 * less than a jiffie expire every jiffie to
408 * avoid softirq starvation in case of SIG_IGN
409 * and a very small interval, which would put
410 * the timer right back on the softirq pending
411 * list. By moving now ahead of time we trick
412 * hrtimer_forward() to expire the timer
413 * later, while we still maintain the overrun
414 * accuracy, but have some inconsistency in
415 * the timer_gettime() case. This is at least
416 * better than a starved softirq. A more
417 * complex fix which solves also another related
418 * inconsistency is already in the pipeline.
420 #ifdef CONFIG_HIGH_RES_TIMERS
422 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
424 if (timr->it.real.interval.tv64 < kj.tv64)
425 now = ktime_add(now, kj);
428 timr->it_overrun += (unsigned int)
429 hrtimer_forward(timer, now,
430 timr->it.real.interval);
431 ret = HRTIMER_RESTART;
432 ++timr->it_requeue_pending;
436 unlock_timer(timr, flags);
440 static struct pid *good_sigevent(sigevent_t * event)
442 struct task_struct *rtn = current->group_leader;
444 switch (event->sigev_notify) {
445 case SIGEV_SIGNAL | SIGEV_THREAD_ID:
446 rtn = find_task_by_vpid(event->sigev_notify_thread_id);
447 if (!rtn || !same_thread_group(rtn, current))
452 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
456 return task_pid(rtn);
462 void posix_timers_register_clock(const clockid_t clock_id,
463 struct k_clock *new_clock)
465 if ((unsigned) clock_id >= MAX_CLOCKS) {
466 printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
471 if (!new_clock->clock_get) {
472 printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
476 if (!new_clock->clock_getres) {
477 printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
482 posix_clocks[clock_id] = *new_clock;
484 EXPORT_SYMBOL_GPL(posix_timers_register_clock);
486 static struct k_itimer * alloc_posix_timer(void)
488 struct k_itimer *tmr;
489 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
492 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
493 kmem_cache_free(posix_timers_cache, tmr);
496 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
500 static void k_itimer_rcu_free(struct rcu_head *head)
502 struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
504 kmem_cache_free(posix_timers_cache, tmr);
508 #define IT_ID_NOT_SET 0
509 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
513 spin_lock_irqsave(&idr_lock, flags);
514 idr_remove(&posix_timers_id, tmr->it_id);
515 spin_unlock_irqrestore(&idr_lock, flags);
517 put_pid(tmr->it_pid);
518 sigqueue_free(tmr->sigq);
519 call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
522 static struct k_clock *clockid_to_kclock(const clockid_t id)
528 return (id & CLOCKFD_MASK) == CLOCKFD ?
529 &clock_posix_dynamic : &clock_posix_cpu;
532 if (id >= ARRAY_SIZE(posix_clocks))
535 kc = &posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];
536 if (!kc->clock_getres)
541 static int common_timer_create(struct k_itimer *new_timer)
543 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
547 /* Create a POSIX.1b interval timer. */
549 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
550 struct sigevent __user *, timer_event_spec,
551 timer_t __user *, created_timer_id)
553 struct k_clock *kc = clockid_to_kclock(which_clock);
554 struct k_itimer *new_timer;
555 int error, new_timer_id;
557 int it_id_set = IT_ID_NOT_SET;
561 if (!kc->timer_create)
564 new_timer = alloc_posix_timer();
565 if (unlikely(!new_timer))
568 spin_lock_init(&new_timer->it_lock);
570 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
574 spin_lock_irq(&idr_lock);
575 error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
576 spin_unlock_irq(&idr_lock);
578 if (error == -EAGAIN)
581 * Weird looking, but we return EAGAIN if the IDR is
582 * full (proper POSIX return value for this)
588 it_id_set = IT_ID_SET;
589 new_timer->it_id = (timer_t) new_timer_id;
590 new_timer->it_clock = which_clock;
591 new_timer->it_overrun = -1;
593 if (timer_event_spec) {
594 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
599 new_timer->it_pid = get_pid(good_sigevent(&event));
601 if (!new_timer->it_pid) {
606 memset(&event.sigev_value, 0, sizeof(event.sigev_value));
607 event.sigev_notify = SIGEV_SIGNAL;
608 event.sigev_signo = SIGALRM;
609 event.sigev_value.sival_int = new_timer->it_id;
610 new_timer->it_pid = get_pid(task_tgid(current));
613 new_timer->it_sigev_notify = event.sigev_notify;
614 new_timer->sigq->info.si_signo = event.sigev_signo;
615 new_timer->sigq->info.si_value = event.sigev_value;
616 new_timer->sigq->info.si_tid = new_timer->it_id;
617 new_timer->sigq->info.si_code = SI_TIMER;
619 if (copy_to_user(created_timer_id,
620 &new_timer_id, sizeof (new_timer_id))) {
625 error = kc->timer_create(new_timer);
629 spin_lock_irq(¤t->sighand->siglock);
630 new_timer->it_signal = current->signal;
631 list_add(&new_timer->list, ¤t->signal->posix_timers);
632 spin_unlock_irq(¤t->sighand->siglock);
636 * In the case of the timer belonging to another task, after
637 * the task is unlocked, the timer is owned by the other task
638 * and may cease to exist at any time. Don't use or modify
639 * new_timer after the unlock call.
642 release_posix_timer(new_timer, it_id_set);
647 * Locking issues: We need to protect the result of the id look up until
648 * we get the timer locked down so it is not deleted under us. The
649 * removal is done under the idr spinlock so we use that here to bridge
650 * the find to the timer lock. To avoid a dead lock, the timer id MUST
651 * be release with out holding the timer lock.
653 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
655 struct k_itimer *timr;
658 * timer_t could be any type >= int and we want to make sure any
659 * @timer_id outside positive int range fails lookup.
661 if ((unsigned long long)timer_id > INT_MAX)
665 timr = idr_find(&posix_timers_id, (int)timer_id);
667 spin_lock_irqsave(&timr->it_lock, *flags);
668 if (timr->it_signal == current->signal) {
672 spin_unlock_irqrestore(&timr->it_lock, *flags);
680 * Get the time remaining on a POSIX.1b interval timer. This function
681 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
684 * We have a couple of messes to clean up here. First there is the case
685 * of a timer that has a requeue pending. These timers should appear to
686 * be in the timer list with an expiry as if we were to requeue them
689 * The second issue is the SIGEV_NONE timer which may be active but is
690 * not really ever put in the timer list (to save system resources).
691 * This timer may be expired, and if so, we will do it here. Otherwise
692 * it is the same as a requeue pending timer WRT to what we should
696 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
698 ktime_t now, remaining, iv;
699 struct hrtimer *timer = &timr->it.real.timer;
702 memset(cur_setting, 0, sizeof(struct itimerspec));
704 sig_none = timr->it_sigev_notify == SIGEV_NONE;
705 iv = timr->it.real.interval;
707 /* interval timer ? */
709 cur_setting->it_interval = ktime_to_timespec(iv);
710 else if (!hrtimer_active(timer) && !sig_none)
713 now = timer->base->get_time();
716 * When a requeue is pending or this is a SIGEV_NONE
717 * timer move the expiry time forward by intervals, so
720 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
721 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
723 remaining = __hrtimer_expires_remaining_adjusted(timer, now);
724 /* Return 0 only, when the timer is expired and not pending */
725 if (remaining.tv64 <= 0) {
727 * A single shot SIGEV_NONE timer must return 0, when
731 cur_setting->it_value.tv_nsec = 1;
733 cur_setting->it_value = ktime_to_timespec(remaining);
736 /* Get the time remaining on a POSIX.1b interval timer. */
737 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
738 struct itimerspec __user *, setting)
740 struct itimerspec cur_setting;
741 struct k_itimer *timr;
746 timr = lock_timer(timer_id, &flags);
750 kc = clockid_to_kclock(timr->it_clock);
751 if (WARN_ON_ONCE(!kc || !kc->timer_get))
754 kc->timer_get(timr, &cur_setting);
756 unlock_timer(timr, flags);
758 if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
765 * Get the number of overruns of a POSIX.1b interval timer. This is to
766 * be the overrun of the timer last delivered. At the same time we are
767 * accumulating overruns on the next timer. The overrun is frozen when
768 * the signal is delivered, either at the notify time (if the info block
769 * is not queued) or at the actual delivery time (as we are informed by
770 * the call back to do_schedule_next_timer(). So all we need to do is
771 * to pick up the frozen overrun.
773 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
775 struct k_itimer *timr;
779 timr = lock_timer(timer_id, &flags);
783 overrun = timr->it_overrun_last;
784 unlock_timer(timr, flags);
789 /* Set a POSIX.1b interval timer. */
790 /* timr->it_lock is taken. */
792 common_timer_set(struct k_itimer *timr, int flags,
793 struct itimerspec *new_setting, struct itimerspec *old_setting)
795 struct hrtimer *timer = &timr->it.real.timer;
796 enum hrtimer_mode mode;
799 common_timer_get(timr, old_setting);
801 /* disable the timer */
802 timr->it.real.interval.tv64 = 0;
804 * careful here. If smp we could be in the "fire" routine which will
805 * be spinning as we hold the lock. But this is ONLY an SMP issue.
807 if (hrtimer_try_to_cancel(timer) < 0)
810 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
812 timr->it_overrun_last = 0;
814 /* switch off the timer when it_value is zero */
815 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
818 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
819 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
820 timr->it.real.timer.function = posix_timer_fn;
822 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
824 /* Convert interval */
825 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
827 /* SIGEV_NONE timers are not queued ! See common_timer_get */
828 if (timr->it_sigev_notify == SIGEV_NONE) {
829 /* Setup correct expiry time for relative timers */
830 if (mode == HRTIMER_MODE_REL) {
831 hrtimer_add_expires(timer, timer->base->get_time());
836 hrtimer_start_expires(timer, mode);
840 /* Set a POSIX.1b interval timer */
841 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
842 const struct itimerspec __user *, new_setting,
843 struct itimerspec __user *, old_setting)
845 struct k_itimer *timr;
846 struct itimerspec new_spec, old_spec;
849 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
855 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
858 if (!timespec_valid(&new_spec.it_interval) ||
859 !timespec_valid(&new_spec.it_value))
862 timr = lock_timer(timer_id, &flag);
866 kc = clockid_to_kclock(timr->it_clock);
867 if (WARN_ON_ONCE(!kc || !kc->timer_set))
870 error = kc->timer_set(timr, flags, &new_spec, rtn);
872 unlock_timer(timr, flag);
873 if (error == TIMER_RETRY) {
874 rtn = NULL; // We already got the old time...
878 if (old_setting && !error &&
879 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
885 static int common_timer_del(struct k_itimer *timer)
887 timer->it.real.interval.tv64 = 0;
889 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
894 static inline int timer_delete_hook(struct k_itimer *timer)
896 struct k_clock *kc = clockid_to_kclock(timer->it_clock);
898 if (WARN_ON_ONCE(!kc || !kc->timer_del))
900 return kc->timer_del(timer);
903 /* Delete a POSIX.1b interval timer. */
904 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
906 struct k_itimer *timer;
910 timer = lock_timer(timer_id, &flags);
914 if (timer_delete_hook(timer) == TIMER_RETRY) {
915 unlock_timer(timer, flags);
919 spin_lock(¤t->sighand->siglock);
920 list_del(&timer->list);
921 spin_unlock(¤t->sighand->siglock);
923 * This keeps any tasks waiting on the spin lock from thinking
924 * they got something (see the lock code above).
926 timer->it_signal = NULL;
928 unlock_timer(timer, flags);
929 release_posix_timer(timer, IT_ID_SET);
934 * return timer owned by the process, used by exit_itimers
936 static void itimer_delete(struct k_itimer *timer)
941 spin_lock_irqsave(&timer->it_lock, flags);
943 if (timer_delete_hook(timer) == TIMER_RETRY) {
944 unlock_timer(timer, flags);
947 list_del(&timer->list);
949 * This keeps any tasks waiting on the spin lock from thinking
950 * they got something (see the lock code above).
952 timer->it_signal = NULL;
954 unlock_timer(timer, flags);
955 release_posix_timer(timer, IT_ID_SET);
959 * This is called by do_exit or de_thread, only when there are no more
960 * references to the shared signal_struct.
962 void exit_itimers(struct signal_struct *sig)
964 struct k_itimer *tmr;
966 while (!list_empty(&sig->posix_timers)) {
967 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
972 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
973 const struct timespec __user *, tp)
975 struct k_clock *kc = clockid_to_kclock(which_clock);
976 struct timespec new_tp;
978 if (!kc || !kc->clock_set)
981 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
984 return kc->clock_set(which_clock, &new_tp);
987 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
988 struct timespec __user *,tp)
990 struct k_clock *kc = clockid_to_kclock(which_clock);
991 struct timespec kernel_tp;
997 error = kc->clock_get(which_clock, &kernel_tp);
999 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
1005 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1006 struct timex __user *, utx)
1008 struct k_clock *kc = clockid_to_kclock(which_clock);
1017 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1020 err = kc->clock_adj(which_clock, &ktx);
1022 if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
1028 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1029 struct timespec __user *, tp)
1031 struct k_clock *kc = clockid_to_kclock(which_clock);
1032 struct timespec rtn_tp;
1038 error = kc->clock_getres(which_clock, &rtn_tp);
1040 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
1047 * nanosleep for monotonic and realtime clocks
1049 static int common_nsleep(const clockid_t which_clock, int flags,
1050 struct timespec *tsave, struct timespec __user *rmtp)
1052 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
1053 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1057 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1058 const struct timespec __user *, rqtp,
1059 struct timespec __user *, rmtp)
1061 struct k_clock *kc = clockid_to_kclock(which_clock);
1067 return -ENANOSLEEP_NOTSUP;
1069 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1072 if (!timespec_valid(&t))
1075 return kc->nsleep(which_clock, flags, &t, rmtp);
1079 * This will restart clock_nanosleep. This is required only by
1080 * compat_clock_nanosleep_restart for now.
1082 long clock_nanosleep_restart(struct restart_block *restart_block)
1084 clockid_t which_clock = restart_block->nanosleep.clockid;
1085 struct k_clock *kc = clockid_to_kclock(which_clock);
1087 if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
1090 return kc->nsleep_restart(restart_block);