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!"
86 * The timer ID is turned into a timer address by idr_find().
87 * Verifying a valid ID consists of:
89 * a) checking that idr_find() returns other than -1.
90 * b) checking that the timer id matches the one in the timer itself.
91 * c) that the timer owner is in the callers thread group.
95 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
96 * to implement others. This structure defines the various
97 * clocks and allows the possibility of adding others. We
98 * provide an interface to add clocks to the table and expect
99 * the "arch" code to add at least one clock that is high
100 * resolution. Here we define the standard CLOCK_REALTIME as a
101 * 1/HZ resolution clock.
103 * RESOLUTION: Clock resolution is used to round up timer and interval
104 * times, NOT to report clock times, which are reported with as
105 * much resolution as the system can muster. In some cases this
106 * resolution may depend on the underlying clock hardware and
107 * may not be quantifiable until run time, and only then is the
108 * necessary code is written. The standard says we should say
109 * something about this issue in the documentation...
111 * FUNCTIONS: The CLOCKs structure defines possible functions to handle
112 * various clock functions. For clocks that use the standard
113 * system timer code these entries should be NULL. This will
114 * allow dispatch without the overhead of indirect function
115 * calls. CLOCKS that depend on other sources (e.g. WWV or GPS)
116 * must supply functions here, even if the function just returns
117 * ENOSYS. The standard POSIX timer management code assumes the
118 * following: 1.) The k_itimer struct (sched.h) is used for the
119 * timer. 2.) The list, it_lock, it_clock, it_id and it_pid
120 * fields are not modified by timer code.
122 * At this time all functions EXCEPT clock_nanosleep can be
123 * redirected by the CLOCKS structure. Clock_nanosleep is in
124 * there, but the code ignores it.
126 * Permissions: It is assumed that the clock_settime() function defined
127 * for each clock will take care of permission checks. Some
128 * clocks may be set able by any user (i.e. local process
129 * clocks) others not. Currently the only set able clock we
130 * have is CLOCK_REALTIME and its high res counter part, both of
131 * which we beg off on and pass to do_sys_settimeofday().
134 static struct k_clock posix_clocks[MAX_CLOCKS];
137 * These ones are defined below.
139 static int common_nsleep(const clockid_t, int flags, struct timespec *t,
140 struct timespec __user *rmtp);
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);
162 * Call the k_clock hook function if non-null, or the default function.
164 #define CLOCK_DISPATCH(clock, call, arglist) \
165 ((clock) < 0 ? posix_cpu_##call arglist : \
166 (posix_clocks[clock].call != NULL \
167 ? (*posix_clocks[clock].call) arglist : common_##call arglist))
170 * Default clock hook functions when the struct k_clock passed
171 * to register_posix_clock leaves a function pointer null.
173 * The function common_CALL is the default implementation for
174 * the function pointer CALL in struct k_clock.
177 static inline int common_clock_getres(const clockid_t which_clock,
181 tp->tv_nsec = posix_clocks[which_clock].res;
186 * Get real time for posix timers
188 static int common_clock_get(clockid_t which_clock, struct timespec *tp)
190 ktime_get_real_ts(tp);
194 static inline int common_clock_set(const clockid_t which_clock,
197 return do_sys_settimeofday(tp, NULL);
200 static int common_timer_create(struct k_itimer *new_timer)
202 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
206 static int no_timer_create(struct k_itimer *new_timer)
211 static int no_nsleep(const clockid_t which_clock, int flags,
212 struct timespec *tsave, struct timespec __user *rmtp)
218 * Return nonzero if we know a priori this clockid_t value is bogus.
220 static inline int invalid_clockid(const clockid_t which_clock)
222 if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */
224 if ((unsigned) which_clock >= MAX_CLOCKS)
226 if (posix_clocks[which_clock].clock_getres != NULL)
228 if (posix_clocks[which_clock].res != 0)
234 * Get monotonic time for posix timers
236 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
243 * Get monotonic time for posix timers
245 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
252 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
254 *tp = current_kernel_time();
258 static int posix_get_monotonic_coarse(clockid_t which_clock,
261 *tp = get_monotonic_coarse();
265 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
267 *tp = ktime_to_timespec(KTIME_LOW_RES);
271 * Initialize everything, well, just everything in Posix clocks/timers ;)
273 static __init int init_posix_timers(void)
275 struct k_clock clock_realtime = {
276 .clock_getres = hrtimer_get_res,
278 struct k_clock clock_monotonic = {
279 .clock_getres = hrtimer_get_res,
280 .clock_get = posix_ktime_get_ts,
281 .clock_set = do_posix_clock_nosettime,
283 struct k_clock clock_monotonic_raw = {
284 .clock_getres = hrtimer_get_res,
285 .clock_get = posix_get_monotonic_raw,
286 .clock_set = do_posix_clock_nosettime,
287 .timer_create = no_timer_create,
290 struct k_clock clock_realtime_coarse = {
291 .clock_getres = posix_get_coarse_res,
292 .clock_get = posix_get_realtime_coarse,
293 .clock_set = do_posix_clock_nosettime,
294 .timer_create = no_timer_create,
297 struct k_clock clock_monotonic_coarse = {
298 .clock_getres = posix_get_coarse_res,
299 .clock_get = posix_get_monotonic_coarse,
300 .clock_set = do_posix_clock_nosettime,
301 .timer_create = no_timer_create,
305 register_posix_clock(CLOCK_REALTIME, &clock_realtime);
306 register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
307 register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
308 register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
309 register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
311 posix_timers_cache = kmem_cache_create("posix_timers_cache",
312 sizeof (struct k_itimer), 0, SLAB_PANIC,
314 idr_init(&posix_timers_id);
318 __initcall(init_posix_timers);
320 static void schedule_next_timer(struct k_itimer *timr)
322 struct hrtimer *timer = &timr->it.real.timer;
324 if (timr->it.real.interval.tv64 == 0)
327 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
328 timer->base->get_time(),
329 timr->it.real.interval);
331 timr->it_overrun_last = timr->it_overrun;
332 timr->it_overrun = -1;
333 ++timr->it_requeue_pending;
334 hrtimer_restart(timer);
338 * This function is exported for use by the signal deliver code. It is
339 * called just prior to the info block being released and passes that
340 * block to us. It's function is to update the overrun entry AND to
341 * restart the timer. It should only be called if the timer is to be
342 * restarted (i.e. we have flagged this in the sys_private entry of the
345 * To protect aginst the timer going away while the interrupt is queued,
346 * we require that the it_requeue_pending flag be set.
348 void do_schedule_next_timer(struct siginfo *info)
350 struct k_itimer *timr;
353 timr = lock_timer(info->si_tid, &flags);
355 if (timr && timr->it_requeue_pending == info->si_sys_private) {
356 if (timr->it_clock < 0)
357 posix_cpu_timer_schedule(timr);
359 schedule_next_timer(timr);
361 info->si_overrun += timr->it_overrun_last;
365 unlock_timer(timr, flags);
368 int posix_timer_event(struct k_itimer *timr, int si_private)
370 struct task_struct *task;
371 int shared, ret = -1;
373 * FIXME: if ->sigq is queued we can race with
374 * dequeue_signal()->do_schedule_next_timer().
376 * If dequeue_signal() sees the "right" value of
377 * si_sys_private it calls do_schedule_next_timer().
378 * We re-queue ->sigq and drop ->it_lock().
379 * do_schedule_next_timer() locks the timer
380 * and re-schedules it while ->sigq is pending.
381 * Not really bad, but not that we want.
383 timr->sigq->info.si_sys_private = si_private;
386 task = pid_task(timr->it_pid, PIDTYPE_PID);
388 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
389 ret = send_sigqueue(timr->sigq, task, shared);
392 /* If we failed to send the signal the timer stops. */
395 EXPORT_SYMBOL_GPL(posix_timer_event);
398 * This function gets called when a POSIX.1b interval timer expires. It
399 * is used as a callback from the kernel internal timer. The
400 * run_timer_list code ALWAYS calls with interrupts on.
402 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
404 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
406 struct k_itimer *timr;
409 enum hrtimer_restart ret = HRTIMER_NORESTART;
411 timr = container_of(timer, struct k_itimer, it.real.timer);
412 spin_lock_irqsave(&timr->it_lock, flags);
414 if (timr->it.real.interval.tv64 != 0)
415 si_private = ++timr->it_requeue_pending;
417 if (posix_timer_event(timr, si_private)) {
419 * signal was not sent because of sig_ignor
420 * we will not get a call back to restart it AND
421 * it should be restarted.
423 if (timr->it.real.interval.tv64 != 0) {
424 ktime_t now = hrtimer_cb_get_time(timer);
427 * FIXME: What we really want, is to stop this
428 * timer completely and restart it in case the
429 * SIG_IGN is removed. This is a non trivial
430 * change which involves sighand locking
431 * (sigh !), which we don't want to do late in
434 * For now we just let timers with an interval
435 * less than a jiffie expire every jiffie to
436 * avoid softirq starvation in case of SIG_IGN
437 * and a very small interval, which would put
438 * the timer right back on the softirq pending
439 * list. By moving now ahead of time we trick
440 * hrtimer_forward() to expire the timer
441 * later, while we still maintain the overrun
442 * accuracy, but have some inconsistency in
443 * the timer_gettime() case. This is at least
444 * better than a starved softirq. A more
445 * complex fix which solves also another related
446 * inconsistency is already in the pipeline.
448 #ifdef CONFIG_HIGH_RES_TIMERS
450 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
452 if (timr->it.real.interval.tv64 < kj.tv64)
453 now = ktime_add(now, kj);
456 timr->it_overrun += (unsigned int)
457 hrtimer_forward(timer, now,
458 timr->it.real.interval);
459 ret = HRTIMER_RESTART;
460 ++timr->it_requeue_pending;
464 unlock_timer(timr, flags);
468 static struct pid *good_sigevent(sigevent_t * event)
470 struct task_struct *rtn = current->group_leader;
472 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
473 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
474 !same_thread_group(rtn, current) ||
475 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
478 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
479 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
482 return task_pid(rtn);
485 void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
487 if ((unsigned) clock_id >= MAX_CLOCKS) {
488 printk("POSIX clock register failed for clock_id %d\n",
493 posix_clocks[clock_id] = *new_clock;
495 EXPORT_SYMBOL_GPL(register_posix_clock);
497 static struct k_itimer * alloc_posix_timer(void)
499 struct k_itimer *tmr;
500 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
503 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
504 kmem_cache_free(posix_timers_cache, tmr);
507 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
512 #define IT_ID_NOT_SET 0
513 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
517 spin_lock_irqsave(&idr_lock, flags);
518 idr_remove(&posix_timers_id, tmr->it_id);
519 spin_unlock_irqrestore(&idr_lock, flags);
521 put_pid(tmr->it_pid);
522 sigqueue_free(tmr->sigq);
523 kmem_cache_free(posix_timers_cache, tmr);
526 /* Create a POSIX.1b interval timer. */
528 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
529 struct sigevent __user *, timer_event_spec,
530 timer_t __user *, created_timer_id)
532 struct k_itimer *new_timer;
533 int error, new_timer_id;
535 int it_id_set = IT_ID_NOT_SET;
537 if (invalid_clockid(which_clock))
540 new_timer = alloc_posix_timer();
541 if (unlikely(!new_timer))
544 spin_lock_init(&new_timer->it_lock);
546 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
550 spin_lock_irq(&idr_lock);
551 error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
552 spin_unlock_irq(&idr_lock);
554 if (error == -EAGAIN)
557 * Weird looking, but we return EAGAIN if the IDR is
558 * full (proper POSIX return value for this)
564 it_id_set = IT_ID_SET;
565 new_timer->it_id = (timer_t) new_timer_id;
566 new_timer->it_clock = which_clock;
567 new_timer->it_overrun = -1;
569 if (timer_event_spec) {
570 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
575 new_timer->it_pid = get_pid(good_sigevent(&event));
577 if (!new_timer->it_pid) {
582 event.sigev_notify = SIGEV_SIGNAL;
583 event.sigev_signo = SIGALRM;
584 event.sigev_value.sival_int = new_timer->it_id;
585 new_timer->it_pid = get_pid(task_tgid(current));
588 new_timer->it_sigev_notify = event.sigev_notify;
589 new_timer->sigq->info.si_signo = event.sigev_signo;
590 new_timer->sigq->info.si_value = event.sigev_value;
591 new_timer->sigq->info.si_tid = new_timer->it_id;
592 new_timer->sigq->info.si_code = SI_TIMER;
594 if (copy_to_user(created_timer_id,
595 &new_timer_id, sizeof (new_timer_id))) {
600 error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
604 spin_lock_irq(¤t->sighand->siglock);
605 new_timer->it_signal = current->signal;
606 list_add(&new_timer->list, ¤t->signal->posix_timers);
607 spin_unlock_irq(¤t->sighand->siglock);
611 * In the case of the timer belonging to another task, after
612 * the task is unlocked, the timer is owned by the other task
613 * and may cease to exist at any time. Don't use or modify
614 * new_timer after the unlock call.
617 release_posix_timer(new_timer, it_id_set);
622 * Locking issues: We need to protect the result of the id look up until
623 * we get the timer locked down so it is not deleted under us. The
624 * removal is done under the idr spinlock so we use that here to bridge
625 * the find to the timer lock. To avoid a dead lock, the timer id MUST
626 * be release with out holding the timer lock.
628 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
630 struct k_itimer *timr;
632 * Watch out here. We do a irqsave on the idr_lock and pass the
633 * flags part over to the timer lock. Must not let interrupts in
634 * while we are moving the lock.
636 spin_lock_irqsave(&idr_lock, *flags);
637 timr = idr_find(&posix_timers_id, (int)timer_id);
639 spin_lock(&timr->it_lock);
640 if (timr->it_signal == current->signal) {
641 spin_unlock(&idr_lock);
644 spin_unlock(&timr->it_lock);
646 spin_unlock_irqrestore(&idr_lock, *flags);
652 * Get the time remaining on a POSIX.1b interval timer. This function
653 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
656 * We have a couple of messes to clean up here. First there is the case
657 * of a timer that has a requeue pending. These timers should appear to
658 * be in the timer list with an expiry as if we were to requeue them
661 * The second issue is the SIGEV_NONE timer which may be active but is
662 * not really ever put in the timer list (to save system resources).
663 * This timer may be expired, and if so, we will do it here. Otherwise
664 * it is the same as a requeue pending timer WRT to what we should
668 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
670 ktime_t now, remaining, iv;
671 struct hrtimer *timer = &timr->it.real.timer;
673 memset(cur_setting, 0, sizeof(struct itimerspec));
675 iv = timr->it.real.interval;
677 /* interval timer ? */
679 cur_setting->it_interval = ktime_to_timespec(iv);
680 else if (!hrtimer_active(timer) &&
681 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
684 now = timer->base->get_time();
687 * When a requeue is pending or this is a SIGEV_NONE
688 * timer move the expiry time forward by intervals, so
691 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
692 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
693 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
695 remaining = ktime_sub(hrtimer_get_expires(timer), now);
696 /* Return 0 only, when the timer is expired and not pending */
697 if (remaining.tv64 <= 0) {
699 * A single shot SIGEV_NONE timer must return 0, when
702 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
703 cur_setting->it_value.tv_nsec = 1;
705 cur_setting->it_value = ktime_to_timespec(remaining);
708 /* Get the time remaining on a POSIX.1b interval timer. */
709 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
710 struct itimerspec __user *, setting)
712 struct k_itimer *timr;
713 struct itimerspec cur_setting;
716 timr = lock_timer(timer_id, &flags);
720 CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting));
722 unlock_timer(timr, flags);
724 if (copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
731 * Get the number of overruns of a POSIX.1b interval timer. This is to
732 * be the overrun of the timer last delivered. At the same time we are
733 * accumulating overruns on the next timer. The overrun is frozen when
734 * the signal is delivered, either at the notify time (if the info block
735 * is not queued) or at the actual delivery time (as we are informed by
736 * the call back to do_schedule_next_timer(). So all we need to do is
737 * to pick up the frozen overrun.
739 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
741 struct k_itimer *timr;
745 timr = lock_timer(timer_id, &flags);
749 overrun = timr->it_overrun_last;
750 unlock_timer(timr, flags);
755 /* Set a POSIX.1b interval timer. */
756 /* timr->it_lock is taken. */
758 common_timer_set(struct k_itimer *timr, int flags,
759 struct itimerspec *new_setting, struct itimerspec *old_setting)
761 struct hrtimer *timer = &timr->it.real.timer;
762 enum hrtimer_mode mode;
765 common_timer_get(timr, old_setting);
767 /* disable the timer */
768 timr->it.real.interval.tv64 = 0;
770 * careful here. If smp we could be in the "fire" routine which will
771 * be spinning as we hold the lock. But this is ONLY an SMP issue.
773 if (hrtimer_try_to_cancel(timer) < 0)
776 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
778 timr->it_overrun_last = 0;
780 /* switch off the timer when it_value is zero */
781 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
784 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
785 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
786 timr->it.real.timer.function = posix_timer_fn;
788 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
790 /* Convert interval */
791 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
793 /* SIGEV_NONE timers are not queued ! See common_timer_get */
794 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
795 /* Setup correct expiry time for relative timers */
796 if (mode == HRTIMER_MODE_REL) {
797 hrtimer_add_expires(timer, timer->base->get_time());
802 hrtimer_start_expires(timer, mode);
806 /* Set a POSIX.1b interval timer */
807 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
808 const struct itimerspec __user *, new_setting,
809 struct itimerspec __user *, old_setting)
811 struct k_itimer *timr;
812 struct itimerspec new_spec, old_spec;
815 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
820 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
823 if (!timespec_valid(&new_spec.it_interval) ||
824 !timespec_valid(&new_spec.it_value))
827 timr = lock_timer(timer_id, &flag);
831 error = CLOCK_DISPATCH(timr->it_clock, timer_set,
832 (timr, flags, &new_spec, rtn));
834 unlock_timer(timr, flag);
835 if (error == TIMER_RETRY) {
836 rtn = NULL; // We already got the old time...
840 if (old_setting && !error &&
841 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
847 static inline int common_timer_del(struct k_itimer *timer)
849 timer->it.real.interval.tv64 = 0;
851 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
856 static inline int timer_delete_hook(struct k_itimer *timer)
858 return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer));
861 /* Delete a POSIX.1b interval timer. */
862 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
864 struct k_itimer *timer;
868 timer = lock_timer(timer_id, &flags);
872 if (timer_delete_hook(timer) == TIMER_RETRY) {
873 unlock_timer(timer, flags);
877 spin_lock(¤t->sighand->siglock);
878 list_del(&timer->list);
879 spin_unlock(¤t->sighand->siglock);
881 * This keeps any tasks waiting on the spin lock from thinking
882 * they got something (see the lock code above).
884 timer->it_signal = NULL;
886 unlock_timer(timer, flags);
887 release_posix_timer(timer, IT_ID_SET);
892 * return timer owned by the process, used by exit_itimers
894 static void itimer_delete(struct k_itimer *timer)
899 spin_lock_irqsave(&timer->it_lock, flags);
901 if (timer_delete_hook(timer) == TIMER_RETRY) {
902 unlock_timer(timer, flags);
905 list_del(&timer->list);
907 * This keeps any tasks waiting on the spin lock from thinking
908 * they got something (see the lock code above).
910 timer->it_signal = NULL;
912 unlock_timer(timer, flags);
913 release_posix_timer(timer, IT_ID_SET);
917 * This is called by do_exit or de_thread, only when there are no more
918 * references to the shared signal_struct.
920 void exit_itimers(struct signal_struct *sig)
922 struct k_itimer *tmr;
924 while (!list_empty(&sig->posix_timers)) {
925 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
930 /* Not available / possible... functions */
931 int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
935 EXPORT_SYMBOL_GPL(do_posix_clock_nosettime);
937 int do_posix_clock_nonanosleep(const clockid_t clock, int flags,
938 struct timespec *t, struct timespec __user *r)
941 return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */
942 #else /* parisc does define it separately. */
946 EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep);
948 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
949 const struct timespec __user *, tp)
951 struct timespec new_tp;
953 if (invalid_clockid(which_clock))
955 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
958 return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp));
961 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
962 struct timespec __user *,tp)
964 struct timespec kernel_tp;
967 if (invalid_clockid(which_clock))
969 error = CLOCK_DISPATCH(which_clock, clock_get,
970 (which_clock, &kernel_tp));
971 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
978 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
979 struct timespec __user *, tp)
981 struct timespec rtn_tp;
984 if (invalid_clockid(which_clock))
987 error = CLOCK_DISPATCH(which_clock, clock_getres,
988 (which_clock, &rtn_tp));
990 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) {
998 * nanosleep for monotonic and realtime clocks
1000 static int common_nsleep(const clockid_t which_clock, int flags,
1001 struct timespec *tsave, struct timespec __user *rmtp)
1003 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
1004 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1008 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1009 const struct timespec __user *, rqtp,
1010 struct timespec __user *, rmtp)
1014 if (invalid_clockid(which_clock))
1017 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1020 if (!timespec_valid(&t))
1023 return CLOCK_DISPATCH(which_clock, nsleep,
1024 (which_clock, flags, &t, rmtp));
1028 * nanosleep_restart for monotonic and realtime clocks
1030 static int common_nsleep_restart(struct restart_block *restart_block)
1032 return hrtimer_nanosleep_restart(restart_block);
1036 * This will restart clock_nanosleep. This is required only by
1037 * compat_clock_nanosleep_restart for now.
1040 clock_nanosleep_restart(struct restart_block *restart_block)
1042 clockid_t which_clock = restart_block->arg0;
1044 return CLOCK_DISPATCH(which_clock, nsleep_restart,