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-timers.h>
45 #include <linux/syscalls.h>
46 #include <linux/wait.h>
47 #include <linux/workqueue.h>
48 #include <linux/module.h>
51 * Management arrays for POSIX timers. Timers are kept in slab memory
52 * Timer ids are allocated by an external routine that keeps track of the
53 * id and the timer. The external interface is:
55 * void *idr_find(struct idr *idp, int id); to find timer_id <id>
56 * int idr_get_new(struct idr *idp, void *ptr); to get a new id and
58 * void idr_remove(struct idr *idp, int id); to release <id>
59 * void idr_init(struct idr *idp); to initialize <idp>
61 * The idr_get_new *may* call slab for more memory so it must not be
62 * called under a spin lock. Likewise idr_remore may release memory
63 * (but it may be ok to do this under a lock...).
64 * idr_find is just a memory look up and is quite fast. A -1 return
65 * indicates that the requested id does not exist.
69 * Lets keep our timers in a slab cache :-)
71 static struct kmem_cache *posix_timers_cache;
72 static struct idr posix_timers_id;
73 static DEFINE_SPINLOCK(idr_lock);
76 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
77 * SIGEV values. Here we put out an error if this assumption fails.
79 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
80 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
81 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
85 * parisc wants ENOTSUP instead of EOPNOTSUPP
88 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
90 # define ENANOSLEEP_NOTSUP ENOTSUP
94 * The timer ID is turned into a timer address by idr_find().
95 * Verifying a valid ID consists of:
97 * a) checking that idr_find() returns other than -1.
98 * b) checking that the timer id matches the one in the timer itself.
99 * c) that the timer owner is in the callers thread group.
103 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
104 * to implement others. This structure defines the various
105 * clocks and allows the possibility of adding others. We
106 * provide an interface to add clocks to the table and expect
107 * the "arch" code to add at least one clock that is high
108 * resolution. Here we define the standard CLOCK_REALTIME as a
109 * 1/HZ resolution clock.
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 handle
120 * various clock functions. For clocks that use the standard
121 * system timer code these entries should be NULL. This will
122 * allow dispatch without the overhead of indirect function
123 * calls. CLOCKS that depend on other sources (e.g. WWV or GPS)
124 * must supply functions here, even if the function just returns
125 * ENOSYS. The standard POSIX timer management code assumes the
126 * following: 1.) The k_itimer struct (sched.h) is used for the
127 * timer. 2.) The list, it_lock, it_clock, it_id and it_pid
128 * fields are not modified by timer code.
130 * At this time all functions EXCEPT clock_nanosleep can be
131 * redirected by the CLOCKS structure. Clock_nanosleep is in
132 * there, but the code ignores it.
134 * Permissions: It is assumed that the clock_settime() function defined
135 * for each clock will take care of permission checks. Some
136 * clocks may be set able by any user (i.e. local process
137 * clocks) others not. Currently the only set able clock we
138 * have is CLOCK_REALTIME and its high res counter part, both of
139 * which we beg off on and pass to do_sys_settimeofday().
142 static struct k_clock posix_clocks[MAX_CLOCKS];
145 * These ones are defined below.
147 static int common_nsleep(const clockid_t, int flags, struct timespec *t,
148 struct timespec __user *rmtp);
149 static int common_timer_create(struct k_itimer *new_timer);
150 static void common_timer_get(struct k_itimer *, struct itimerspec *);
151 static int common_timer_set(struct k_itimer *, int,
152 struct itimerspec *, struct itimerspec *);
153 static int common_timer_del(struct k_itimer *timer);
155 static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
157 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
159 #define lock_timer(tid, flags) \
160 ({ struct k_itimer *__timr; \
161 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
165 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
167 spin_unlock_irqrestore(&timr->it_lock, flags);
171 * Call the k_clock hook function if non-null, or the default function.
173 #define CLOCK_DISPATCH(clock, call, arglist) \
174 ((clock) < 0 ? posix_cpu_##call arglist : \
175 (posix_clocks[clock].call != NULL \
176 ? (*posix_clocks[clock].call) arglist : common_##call arglist))
179 * Return nonzero if we know a priori this clockid_t value is bogus.
181 static inline int invalid_clockid(const clockid_t which_clock)
183 if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */
185 if ((unsigned) which_clock >= MAX_CLOCKS)
187 if (posix_clocks[which_clock].clock_getres != NULL)
192 /* Get clock_realtime */
193 static int posix_clock_realtime_get(clockid_t which_clock, struct timespec *tp)
195 ktime_get_real_ts(tp);
199 /* Set clock_realtime */
200 static int posix_clock_realtime_set(const clockid_t which_clock,
201 const struct timespec *tp)
203 return do_sys_settimeofday(tp, NULL);
207 * Get monotonic time for posix timers
209 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
216 * Get monotonic time for posix timers
218 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
225 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
227 *tp = current_kernel_time();
231 static int posix_get_monotonic_coarse(clockid_t which_clock,
234 *tp = get_monotonic_coarse();
238 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
240 *tp = ktime_to_timespec(KTIME_LOW_RES);
244 * Initialize everything, well, just everything in Posix clocks/timers ;)
246 static __init int init_posix_timers(void)
248 struct k_clock clock_realtime = {
249 .clock_getres = hrtimer_get_res,
250 .clock_get = posix_clock_realtime_get,
251 .clock_set = posix_clock_realtime_set,
252 .nsleep = common_nsleep,
253 .nsleep_restart = hrtimer_nanosleep_restart,
254 .timer_create = common_timer_create,
256 struct k_clock clock_monotonic = {
257 .clock_getres = hrtimer_get_res,
258 .clock_get = posix_ktime_get_ts,
259 .nsleep = common_nsleep,
260 .nsleep_restart = hrtimer_nanosleep_restart,
261 .timer_create = common_timer_create,
263 struct k_clock clock_monotonic_raw = {
264 .clock_getres = hrtimer_get_res,
265 .clock_get = posix_get_monotonic_raw,
267 struct k_clock clock_realtime_coarse = {
268 .clock_getres = posix_get_coarse_res,
269 .clock_get = posix_get_realtime_coarse,
271 struct k_clock clock_monotonic_coarse = {
272 .clock_getres = posix_get_coarse_res,
273 .clock_get = posix_get_monotonic_coarse,
276 register_posix_clock(CLOCK_REALTIME, &clock_realtime);
277 register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
278 register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
279 register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
280 register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
282 posix_timers_cache = kmem_cache_create("posix_timers_cache",
283 sizeof (struct k_itimer), 0, SLAB_PANIC,
285 idr_init(&posix_timers_id);
289 __initcall(init_posix_timers);
291 static void schedule_next_timer(struct k_itimer *timr)
293 struct hrtimer *timer = &timr->it.real.timer;
295 if (timr->it.real.interval.tv64 == 0)
298 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
299 timer->base->get_time(),
300 timr->it.real.interval);
302 timr->it_overrun_last = timr->it_overrun;
303 timr->it_overrun = -1;
304 ++timr->it_requeue_pending;
305 hrtimer_restart(timer);
309 * This function is exported for use by the signal deliver code. It is
310 * called just prior to the info block being released and passes that
311 * block to us. It's function is to update the overrun entry AND to
312 * restart the timer. It should only be called if the timer is to be
313 * restarted (i.e. we have flagged this in the sys_private entry of the
316 * To protect aginst the timer going away while the interrupt is queued,
317 * we require that the it_requeue_pending flag be set.
319 void do_schedule_next_timer(struct siginfo *info)
321 struct k_itimer *timr;
324 timr = lock_timer(info->si_tid, &flags);
326 if (timr && timr->it_requeue_pending == info->si_sys_private) {
327 if (timr->it_clock < 0)
328 posix_cpu_timer_schedule(timr);
330 schedule_next_timer(timr);
332 info->si_overrun += timr->it_overrun_last;
336 unlock_timer(timr, flags);
339 int posix_timer_event(struct k_itimer *timr, int si_private)
341 struct task_struct *task;
342 int shared, ret = -1;
344 * FIXME: if ->sigq is queued we can race with
345 * dequeue_signal()->do_schedule_next_timer().
347 * If dequeue_signal() sees the "right" value of
348 * si_sys_private it calls do_schedule_next_timer().
349 * We re-queue ->sigq and drop ->it_lock().
350 * do_schedule_next_timer() locks the timer
351 * and re-schedules it while ->sigq is pending.
352 * Not really bad, but not that we want.
354 timr->sigq->info.si_sys_private = si_private;
357 task = pid_task(timr->it_pid, PIDTYPE_PID);
359 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
360 ret = send_sigqueue(timr->sigq, task, shared);
363 /* If we failed to send the signal the timer stops. */
366 EXPORT_SYMBOL_GPL(posix_timer_event);
369 * This function gets called when a POSIX.1b interval timer expires. It
370 * is used as a callback from the kernel internal timer. The
371 * run_timer_list code ALWAYS calls with interrupts on.
373 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
375 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
377 struct k_itimer *timr;
380 enum hrtimer_restart ret = HRTIMER_NORESTART;
382 timr = container_of(timer, struct k_itimer, it.real.timer);
383 spin_lock_irqsave(&timr->it_lock, flags);
385 if (timr->it.real.interval.tv64 != 0)
386 si_private = ++timr->it_requeue_pending;
388 if (posix_timer_event(timr, si_private)) {
390 * signal was not sent because of sig_ignor
391 * we will not get a call back to restart it AND
392 * it should be restarted.
394 if (timr->it.real.interval.tv64 != 0) {
395 ktime_t now = hrtimer_cb_get_time(timer);
398 * FIXME: What we really want, is to stop this
399 * timer completely and restart it in case the
400 * SIG_IGN is removed. This is a non trivial
401 * change which involves sighand locking
402 * (sigh !), which we don't want to do late in
405 * For now we just let timers with an interval
406 * less than a jiffie expire every jiffie to
407 * avoid softirq starvation in case of SIG_IGN
408 * and a very small interval, which would put
409 * the timer right back on the softirq pending
410 * list. By moving now ahead of time we trick
411 * hrtimer_forward() to expire the timer
412 * later, while we still maintain the overrun
413 * accuracy, but have some inconsistency in
414 * the timer_gettime() case. This is at least
415 * better than a starved softirq. A more
416 * complex fix which solves also another related
417 * inconsistency is already in the pipeline.
419 #ifdef CONFIG_HIGH_RES_TIMERS
421 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
423 if (timr->it.real.interval.tv64 < kj.tv64)
424 now = ktime_add(now, kj);
427 timr->it_overrun += (unsigned int)
428 hrtimer_forward(timer, now,
429 timr->it.real.interval);
430 ret = HRTIMER_RESTART;
431 ++timr->it_requeue_pending;
435 unlock_timer(timr, flags);
439 static struct pid *good_sigevent(sigevent_t * event)
441 struct task_struct *rtn = current->group_leader;
443 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
444 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
445 !same_thread_group(rtn, current) ||
446 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
449 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
450 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
453 return task_pid(rtn);
456 void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
458 if ((unsigned) clock_id >= MAX_CLOCKS) {
459 printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
464 if (!new_clock->clock_get) {
465 printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
469 if (!new_clock->clock_getres) {
470 printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
475 posix_clocks[clock_id] = *new_clock;
477 EXPORT_SYMBOL_GPL(register_posix_clock);
479 static struct k_itimer * alloc_posix_timer(void)
481 struct k_itimer *tmr;
482 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
485 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
486 kmem_cache_free(posix_timers_cache, tmr);
489 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
494 #define IT_ID_NOT_SET 0
495 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
499 spin_lock_irqsave(&idr_lock, flags);
500 idr_remove(&posix_timers_id, tmr->it_id);
501 spin_unlock_irqrestore(&idr_lock, flags);
503 put_pid(tmr->it_pid);
504 sigqueue_free(tmr->sigq);
505 kmem_cache_free(posix_timers_cache, tmr);
508 static struct k_clock *clockid_to_kclock(const clockid_t id)
511 return &clock_posix_cpu;
513 if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
515 return &posix_clocks[id];
518 static int common_timer_create(struct k_itimer *new_timer)
520 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
524 /* Create a POSIX.1b interval timer. */
526 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
527 struct sigevent __user *, timer_event_spec,
528 timer_t __user *, created_timer_id)
530 struct k_clock *kc = clockid_to_kclock(which_clock);
531 struct k_itimer *new_timer;
532 int error, new_timer_id;
534 int it_id_set = IT_ID_NOT_SET;
538 if (!kc->timer_create)
541 new_timer = alloc_posix_timer();
542 if (unlikely(!new_timer))
545 spin_lock_init(&new_timer->it_lock);
547 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
551 spin_lock_irq(&idr_lock);
552 error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
553 spin_unlock_irq(&idr_lock);
555 if (error == -EAGAIN)
558 * Weird looking, but we return EAGAIN if the IDR is
559 * full (proper POSIX return value for this)
565 it_id_set = IT_ID_SET;
566 new_timer->it_id = (timer_t) new_timer_id;
567 new_timer->it_clock = which_clock;
568 new_timer->it_overrun = -1;
570 if (timer_event_spec) {
571 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
576 new_timer->it_pid = get_pid(good_sigevent(&event));
578 if (!new_timer->it_pid) {
583 event.sigev_notify = SIGEV_SIGNAL;
584 event.sigev_signo = SIGALRM;
585 event.sigev_value.sival_int = new_timer->it_id;
586 new_timer->it_pid = get_pid(task_tgid(current));
589 new_timer->it_sigev_notify = event.sigev_notify;
590 new_timer->sigq->info.si_signo = event.sigev_signo;
591 new_timer->sigq->info.si_value = event.sigev_value;
592 new_timer->sigq->info.si_tid = new_timer->it_id;
593 new_timer->sigq->info.si_code = SI_TIMER;
595 if (copy_to_user(created_timer_id,
596 &new_timer_id, sizeof (new_timer_id))) {
601 error = kc->timer_create(new_timer);
605 spin_lock_irq(¤t->sighand->siglock);
606 new_timer->it_signal = current->signal;
607 list_add(&new_timer->list, ¤t->signal->posix_timers);
608 spin_unlock_irq(¤t->sighand->siglock);
612 * In the case of the timer belonging to another task, after
613 * the task is unlocked, the timer is owned by the other task
614 * and may cease to exist at any time. Don't use or modify
615 * new_timer after the unlock call.
618 release_posix_timer(new_timer, it_id_set);
623 * Locking issues: We need to protect the result of the id look up until
624 * we get the timer locked down so it is not deleted under us. The
625 * removal is done under the idr spinlock so we use that here to bridge
626 * the find to the timer lock. To avoid a dead lock, the timer id MUST
627 * be release with out holding the timer lock.
629 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
631 struct k_itimer *timr;
633 * Watch out here. We do a irqsave on the idr_lock and pass the
634 * flags part over to the timer lock. Must not let interrupts in
635 * while we are moving the lock.
637 spin_lock_irqsave(&idr_lock, *flags);
638 timr = idr_find(&posix_timers_id, (int)timer_id);
640 spin_lock(&timr->it_lock);
641 if (timr->it_signal == current->signal) {
642 spin_unlock(&idr_lock);
645 spin_unlock(&timr->it_lock);
647 spin_unlock_irqrestore(&idr_lock, *flags);
653 * Get the time remaining on a POSIX.1b interval timer. This function
654 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
657 * We have a couple of messes to clean up here. First there is the case
658 * of a timer that has a requeue pending. These timers should appear to
659 * be in the timer list with an expiry as if we were to requeue them
662 * The second issue is the SIGEV_NONE timer which may be active but is
663 * not really ever put in the timer list (to save system resources).
664 * This timer may be expired, and if so, we will do it here. Otherwise
665 * it is the same as a requeue pending timer WRT to what we should
669 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
671 ktime_t now, remaining, iv;
672 struct hrtimer *timer = &timr->it.real.timer;
674 memset(cur_setting, 0, sizeof(struct itimerspec));
676 iv = timr->it.real.interval;
678 /* interval timer ? */
680 cur_setting->it_interval = ktime_to_timespec(iv);
681 else if (!hrtimer_active(timer) &&
682 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
685 now = timer->base->get_time();
688 * When a requeue is pending or this is a SIGEV_NONE
689 * timer move the expiry time forward by intervals, so
692 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
693 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
694 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
696 remaining = ktime_sub(hrtimer_get_expires(timer), now);
697 /* Return 0 only, when the timer is expired and not pending */
698 if (remaining.tv64 <= 0) {
700 * A single shot SIGEV_NONE timer must return 0, when
703 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
704 cur_setting->it_value.tv_nsec = 1;
706 cur_setting->it_value = ktime_to_timespec(remaining);
709 /* Get the time remaining on a POSIX.1b interval timer. */
710 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
711 struct itimerspec __user *, setting)
713 struct k_itimer *timr;
714 struct itimerspec cur_setting;
717 timr = lock_timer(timer_id, &flags);
721 CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting));
723 unlock_timer(timr, flags);
725 if (copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
732 * Get the number of overruns of a POSIX.1b interval timer. This is to
733 * be the overrun of the timer last delivered. At the same time we are
734 * accumulating overruns on the next timer. The overrun is frozen when
735 * the signal is delivered, either at the notify time (if the info block
736 * is not queued) or at the actual delivery time (as we are informed by
737 * the call back to do_schedule_next_timer(). So all we need to do is
738 * to pick up the frozen overrun.
740 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
742 struct k_itimer *timr;
746 timr = lock_timer(timer_id, &flags);
750 overrun = timr->it_overrun_last;
751 unlock_timer(timr, flags);
756 /* Set a POSIX.1b interval timer. */
757 /* timr->it_lock is taken. */
759 common_timer_set(struct k_itimer *timr, int flags,
760 struct itimerspec *new_setting, struct itimerspec *old_setting)
762 struct hrtimer *timer = &timr->it.real.timer;
763 enum hrtimer_mode mode;
766 common_timer_get(timr, old_setting);
768 /* disable the timer */
769 timr->it.real.interval.tv64 = 0;
771 * careful here. If smp we could be in the "fire" routine which will
772 * be spinning as we hold the lock. But this is ONLY an SMP issue.
774 if (hrtimer_try_to_cancel(timer) < 0)
777 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
779 timr->it_overrun_last = 0;
781 /* switch off the timer when it_value is zero */
782 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
785 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
786 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
787 timr->it.real.timer.function = posix_timer_fn;
789 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
791 /* Convert interval */
792 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
794 /* SIGEV_NONE timers are not queued ! See common_timer_get */
795 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
796 /* Setup correct expiry time for relative timers */
797 if (mode == HRTIMER_MODE_REL) {
798 hrtimer_add_expires(timer, timer->base->get_time());
803 hrtimer_start_expires(timer, mode);
807 /* Set a POSIX.1b interval timer */
808 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
809 const struct itimerspec __user *, new_setting,
810 struct itimerspec __user *, old_setting)
812 struct k_itimer *timr;
813 struct itimerspec new_spec, old_spec;
816 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
821 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
824 if (!timespec_valid(&new_spec.it_interval) ||
825 !timespec_valid(&new_spec.it_value))
828 timr = lock_timer(timer_id, &flag);
832 error = CLOCK_DISPATCH(timr->it_clock, timer_set,
833 (timr, flags, &new_spec, rtn));
835 unlock_timer(timr, flag);
836 if (error == TIMER_RETRY) {
837 rtn = NULL; // We already got the old time...
841 if (old_setting && !error &&
842 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
848 static inline int common_timer_del(struct k_itimer *timer)
850 timer->it.real.interval.tv64 = 0;
852 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
857 static inline int timer_delete_hook(struct k_itimer *timer)
859 return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer));
862 /* Delete a POSIX.1b interval timer. */
863 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
865 struct k_itimer *timer;
869 timer = lock_timer(timer_id, &flags);
873 if (timer_delete_hook(timer) == TIMER_RETRY) {
874 unlock_timer(timer, flags);
878 spin_lock(¤t->sighand->siglock);
879 list_del(&timer->list);
880 spin_unlock(¤t->sighand->siglock);
882 * This keeps any tasks waiting on the spin lock from thinking
883 * they got something (see the lock code above).
885 timer->it_signal = NULL;
887 unlock_timer(timer, flags);
888 release_posix_timer(timer, IT_ID_SET);
893 * return timer owned by the process, used by exit_itimers
895 static void itimer_delete(struct k_itimer *timer)
900 spin_lock_irqsave(&timer->it_lock, flags);
902 if (timer_delete_hook(timer) == TIMER_RETRY) {
903 unlock_timer(timer, flags);
906 list_del(&timer->list);
908 * This keeps any tasks waiting on the spin lock from thinking
909 * they got something (see the lock code above).
911 timer->it_signal = NULL;
913 unlock_timer(timer, flags);
914 release_posix_timer(timer, IT_ID_SET);
918 * This is called by do_exit or de_thread, only when there are no more
919 * references to the shared signal_struct.
921 void exit_itimers(struct signal_struct *sig)
923 struct k_itimer *tmr;
925 while (!list_empty(&sig->posix_timers)) {
926 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
931 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
932 const struct timespec __user *, tp)
934 struct k_clock *kc = clockid_to_kclock(which_clock);
935 struct timespec new_tp;
937 if (!kc || !kc->clock_set)
940 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
943 return kc->clock_set(which_clock, &new_tp);
946 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
947 struct timespec __user *,tp)
949 struct k_clock *kc = clockid_to_kclock(which_clock);
950 struct timespec kernel_tp;
956 error = kc->clock_get(which_clock, &kernel_tp);
958 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
964 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
965 struct timespec __user *, tp)
967 struct k_clock *kc = clockid_to_kclock(which_clock);
968 struct timespec rtn_tp;
974 error = kc->clock_getres(which_clock, &rtn_tp);
976 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
983 * nanosleep for monotonic and realtime clocks
985 static int common_nsleep(const clockid_t which_clock, int flags,
986 struct timespec *tsave, struct timespec __user *rmtp)
988 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
989 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
993 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
994 const struct timespec __user *, rqtp,
995 struct timespec __user *, rmtp)
997 struct k_clock *kc = clockid_to_kclock(which_clock);
1003 return -ENANOSLEEP_NOTSUP;
1005 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1008 if (!timespec_valid(&t))
1011 return kc->nsleep(which_clock, flags, &t, rmtp);
1015 * This will restart clock_nanosleep. This is required only by
1016 * compat_clock_nanosleep_restart for now.
1018 long clock_nanosleep_restart(struct restart_block *restart_block)
1020 clockid_t which_clock = restart_block->nanosleep.index;
1021 struct k_clock *kc = clockid_to_kclock(which_clock);
1023 if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
1026 return kc->nsleep_restart(restart_block);