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_process
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 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
152 spin_unlock_irqrestore(&timr->it_lock, flags);
156 * Call the k_clock hook function if non-null, or the default function.
158 #define CLOCK_DISPATCH(clock, call, arglist) \
159 ((clock) < 0 ? posix_cpu_##call arglist : \
160 (posix_clocks[clock].call != NULL \
161 ? (*posix_clocks[clock].call) arglist : common_##call arglist))
164 * Default clock hook functions when the struct k_clock passed
165 * to register_posix_clock leaves a function pointer null.
167 * The function common_CALL is the default implementation for
168 * the function pointer CALL in struct k_clock.
171 static inline int common_clock_getres(const clockid_t which_clock,
175 tp->tv_nsec = posix_clocks[which_clock].res;
180 * Get real time for posix timers
182 static int common_clock_get(clockid_t which_clock, struct timespec *tp)
184 ktime_get_real_ts(tp);
188 static inline int common_clock_set(const clockid_t which_clock,
191 return do_sys_settimeofday(tp, NULL);
194 static int common_timer_create(struct k_itimer *new_timer)
196 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
201 * Return nonzero if we know a priori this clockid_t value is bogus.
203 static inline int invalid_clockid(const clockid_t which_clock)
205 if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */
207 if ((unsigned) which_clock >= MAX_CLOCKS)
209 if (posix_clocks[which_clock].clock_getres != NULL)
211 if (posix_clocks[which_clock].res != 0)
217 * Get monotonic time for posix timers
219 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
226 * Initialize everything, well, just everything in Posix clocks/timers ;)
228 static __init int init_posix_timers(void)
230 struct k_clock clock_realtime = {
231 .clock_getres = hrtimer_get_res,
233 struct k_clock clock_monotonic = {
234 .clock_getres = hrtimer_get_res,
235 .clock_get = posix_ktime_get_ts,
236 .clock_set = do_posix_clock_nosettime,
239 register_posix_clock(CLOCK_REALTIME, &clock_realtime);
240 register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
242 posix_timers_cache = kmem_cache_create("posix_timers_cache",
243 sizeof (struct k_itimer), 0, SLAB_PANIC,
245 idr_init(&posix_timers_id);
249 __initcall(init_posix_timers);
251 static void schedule_next_timer(struct k_itimer *timr)
253 struct hrtimer *timer = &timr->it.real.timer;
255 if (timr->it.real.interval.tv64 == 0)
258 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
259 timer->base->get_time(),
260 timr->it.real.interval);
262 timr->it_overrun_last = timr->it_overrun;
263 timr->it_overrun = -1;
264 ++timr->it_requeue_pending;
265 hrtimer_restart(timer);
269 * This function is exported for use by the signal deliver code. It is
270 * called just prior to the info block being released and passes that
271 * block to us. It's function is to update the overrun entry AND to
272 * restart the timer. It should only be called if the timer is to be
273 * restarted (i.e. we have flagged this in the sys_private entry of the
276 * To protect aginst the timer going away while the interrupt is queued,
277 * we require that the it_requeue_pending flag be set.
279 void do_schedule_next_timer(struct siginfo *info)
281 struct k_itimer *timr;
284 timr = lock_timer(info->si_tid, &flags);
286 if (timr && timr->it_requeue_pending == info->si_sys_private) {
287 if (timr->it_clock < 0)
288 posix_cpu_timer_schedule(timr);
290 schedule_next_timer(timr);
292 info->si_overrun += timr->it_overrun_last;
296 unlock_timer(timr, flags);
299 int posix_timer_event(struct k_itimer *timr, int si_private)
302 * FIXME: if ->sigq is queued we can race with
303 * dequeue_signal()->do_schedule_next_timer().
305 * If dequeue_signal() sees the "right" value of
306 * si_sys_private it calls do_schedule_next_timer().
307 * We re-queue ->sigq and drop ->it_lock().
308 * do_schedule_next_timer() locks the timer
309 * and re-schedules it while ->sigq is pending.
310 * Not really bad, but not that we want.
312 timr->sigq->info.si_sys_private = si_private;
314 timr->sigq->info.si_signo = timr->it_sigev_signo;
315 timr->sigq->info.si_code = SI_TIMER;
316 timr->sigq->info.si_tid = timr->it_id;
317 timr->sigq->info.si_value = timr->it_sigev_value;
319 if (timr->it_sigev_notify & SIGEV_THREAD_ID) {
320 struct task_struct *leader;
321 int ret = send_sigqueue(timr->sigq, timr->it_process, 0);
323 if (likely(ret >= 0))
326 timr->it_sigev_notify = SIGEV_SIGNAL;
327 leader = timr->it_process->group_leader;
328 put_task_struct(timr->it_process);
329 timr->it_process = leader;
332 return send_sigqueue(timr->sigq, timr->it_process, 1);
334 EXPORT_SYMBOL_GPL(posix_timer_event);
337 * This function gets called when a POSIX.1b interval timer expires. It
338 * is used as a callback from the kernel internal timer. The
339 * run_timer_list code ALWAYS calls with interrupts on.
341 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
343 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
345 struct k_itimer *timr;
348 enum hrtimer_restart ret = HRTIMER_NORESTART;
350 timr = container_of(timer, struct k_itimer, it.real.timer);
351 spin_lock_irqsave(&timr->it_lock, flags);
353 if (timr->it.real.interval.tv64 != 0)
354 si_private = ++timr->it_requeue_pending;
356 if (posix_timer_event(timr, si_private)) {
358 * signal was not sent because of sig_ignor
359 * we will not get a call back to restart it AND
360 * it should be restarted.
362 if (timr->it.real.interval.tv64 != 0) {
363 ktime_t now = hrtimer_cb_get_time(timer);
366 * FIXME: What we really want, is to stop this
367 * timer completely and restart it in case the
368 * SIG_IGN is removed. This is a non trivial
369 * change which involves sighand locking
370 * (sigh !), which we don't want to do late in
373 * For now we just let timers with an interval
374 * less than a jiffie expire every jiffie to
375 * avoid softirq starvation in case of SIG_IGN
376 * and a very small interval, which would put
377 * the timer right back on the softirq pending
378 * list. By moving now ahead of time we trick
379 * hrtimer_forward() to expire the timer
380 * later, while we still maintain the overrun
381 * accuracy, but have some inconsistency in
382 * the timer_gettime() case. This is at least
383 * better than a starved softirq. A more
384 * complex fix which solves also another related
385 * inconsistency is already in the pipeline.
387 #ifdef CONFIG_HIGH_RES_TIMERS
389 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
391 if (timr->it.real.interval.tv64 < kj.tv64)
392 now = ktime_add(now, kj);
395 timr->it_overrun += (unsigned int)
396 hrtimer_forward(timer, now,
397 timr->it.real.interval);
398 ret = HRTIMER_RESTART;
399 ++timr->it_requeue_pending;
403 unlock_timer(timr, flags);
407 static struct task_struct * good_sigevent(sigevent_t * event)
409 struct task_struct *rtn = current->group_leader;
411 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
412 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
413 !same_thread_group(rtn, current) ||
414 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
417 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
418 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
424 void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
426 if ((unsigned) clock_id >= MAX_CLOCKS) {
427 printk("POSIX clock register failed for clock_id %d\n",
432 posix_clocks[clock_id] = *new_clock;
434 EXPORT_SYMBOL_GPL(register_posix_clock);
436 static struct k_itimer * alloc_posix_timer(void)
438 struct k_itimer *tmr;
439 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
442 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
443 kmem_cache_free(posix_timers_cache, tmr);
446 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
451 #define IT_ID_NOT_SET 0
452 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
456 spin_lock_irqsave(&idr_lock, flags);
457 idr_remove(&posix_timers_id, tmr->it_id);
458 spin_unlock_irqrestore(&idr_lock, flags);
460 sigqueue_free(tmr->sigq);
461 kmem_cache_free(posix_timers_cache, tmr);
464 /* Create a POSIX.1b interval timer. */
467 sys_timer_create(const clockid_t which_clock,
468 struct sigevent __user *timer_event_spec,
469 timer_t __user * created_timer_id)
472 struct k_itimer *new_timer = NULL;
474 struct task_struct *process = NULL;
477 int it_id_set = IT_ID_NOT_SET;
479 if (invalid_clockid(which_clock))
482 new_timer = alloc_posix_timer();
483 if (unlikely(!new_timer))
486 spin_lock_init(&new_timer->it_lock);
488 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
492 spin_lock_irq(&idr_lock);
493 error = idr_get_new(&posix_timers_id, (void *) new_timer,
495 spin_unlock_irq(&idr_lock);
496 if (error == -EAGAIN)
500 * Weird looking, but we return EAGAIN if the IDR is
501 * full (proper POSIX return value for this)
507 it_id_set = IT_ID_SET;
508 new_timer->it_id = (timer_t) new_timer_id;
509 new_timer->it_clock = which_clock;
510 new_timer->it_overrun = -1;
511 error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
516 * return the timer_id now. The next step is hard to
517 * back out if there is an error.
519 if (copy_to_user(created_timer_id,
520 &new_timer_id, sizeof (new_timer_id))) {
524 if (timer_event_spec) {
525 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
529 new_timer->it_sigev_notify = event.sigev_notify;
530 new_timer->it_sigev_signo = event.sigev_signo;
531 new_timer->it_sigev_value = event.sigev_value;
533 read_lock(&tasklist_lock);
534 if ((process = good_sigevent(&event))) {
536 * We may be setting up this process for another
537 * thread. It may be exiting. To catch this
538 * case the we check the PF_EXITING flag. If
539 * the flag is not set, the siglock will catch
540 * him before it is too late (in exit_itimers).
542 * The exec case is a bit more invloved but easy
543 * to code. If the process is in our thread
544 * group (and it must be or we would not allow
545 * it here) and is doing an exec, it will cause
546 * us to be killed. In this case it will wait
547 * for us to die which means we can finish this
548 * linkage with our last gasp. I.e. no code :)
550 spin_lock_irqsave(&process->sighand->siglock, flags);
551 if (!(process->flags & PF_EXITING)) {
552 new_timer->it_process = process;
553 list_add(&new_timer->list,
554 &process->signal->posix_timers);
555 if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
556 get_task_struct(process);
557 spin_unlock_irqrestore(&process->sighand->siglock, flags);
559 spin_unlock_irqrestore(&process->sighand->siglock, flags);
563 read_unlock(&tasklist_lock);
569 new_timer->it_sigev_notify = SIGEV_SIGNAL;
570 new_timer->it_sigev_signo = SIGALRM;
571 new_timer->it_sigev_value.sival_int = new_timer->it_id;
572 process = current->group_leader;
573 spin_lock_irqsave(&process->sighand->siglock, flags);
574 new_timer->it_process = process;
575 list_add(&new_timer->list, &process->signal->posix_timers);
576 spin_unlock_irqrestore(&process->sighand->siglock, flags);
580 * In the case of the timer belonging to another task, after
581 * the task is unlocked, the timer is owned by the other task
582 * and may cease to exist at any time. Don't use or modify
583 * new_timer after the unlock call.
588 release_posix_timer(new_timer, it_id_set);
594 * Locking issues: We need to protect the result of the id look up until
595 * we get the timer locked down so it is not deleted under us. The
596 * removal is done under the idr spinlock so we use that here to bridge
597 * the find to the timer lock. To avoid a dead lock, the timer id MUST
598 * be release with out holding the timer lock.
600 static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags)
602 struct k_itimer *timr;
604 * Watch out here. We do a irqsave on the idr_lock and pass the
605 * flags part over to the timer lock. Must not let interrupts in
606 * while we are moving the lock.
609 spin_lock_irqsave(&idr_lock, *flags);
610 timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id);
612 spin_lock(&timr->it_lock);
614 if ((timr->it_id != timer_id) || !(timr->it_process) ||
615 !same_thread_group(timr->it_process, current)) {
616 spin_unlock(&timr->it_lock);
617 spin_unlock_irqrestore(&idr_lock, *flags);
620 spin_unlock(&idr_lock);
622 spin_unlock_irqrestore(&idr_lock, *flags);
628 * Get the time remaining on a POSIX.1b interval timer. This function
629 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
632 * We have a couple of messes to clean up here. First there is the case
633 * of a timer that has a requeue pending. These timers should appear to
634 * be in the timer list with an expiry as if we were to requeue them
637 * The second issue is the SIGEV_NONE timer which may be active but is
638 * not really ever put in the timer list (to save system resources).
639 * This timer may be expired, and if so, we will do it here. Otherwise
640 * it is the same as a requeue pending timer WRT to what we should
644 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
646 ktime_t now, remaining, iv;
647 struct hrtimer *timer = &timr->it.real.timer;
649 memset(cur_setting, 0, sizeof(struct itimerspec));
651 iv = timr->it.real.interval;
653 /* interval timer ? */
655 cur_setting->it_interval = ktime_to_timespec(iv);
656 else if (!hrtimer_active(timer) &&
657 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
660 now = timer->base->get_time();
663 * When a requeue is pending or this is a SIGEV_NONE
664 * timer move the expiry time forward by intervals, so
667 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
668 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
669 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
671 remaining = ktime_sub(timer->expires, now);
672 /* Return 0 only, when the timer is expired and not pending */
673 if (remaining.tv64 <= 0) {
675 * A single shot SIGEV_NONE timer must return 0, when
678 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
679 cur_setting->it_value.tv_nsec = 1;
681 cur_setting->it_value = ktime_to_timespec(remaining);
684 /* Get the time remaining on a POSIX.1b interval timer. */
686 sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting)
688 struct k_itimer *timr;
689 struct itimerspec cur_setting;
692 timr = lock_timer(timer_id, &flags);
696 CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting));
698 unlock_timer(timr, flags);
700 if (copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
707 * Get the number of overruns of a POSIX.1b interval timer. This is to
708 * be the overrun of the timer last delivered. At the same time we are
709 * accumulating overruns on the next timer. The overrun is frozen when
710 * the signal is delivered, either at the notify time (if the info block
711 * is not queued) or at the actual delivery time (as we are informed by
712 * the call back to do_schedule_next_timer(). So all we need to do is
713 * to pick up the frozen overrun.
716 sys_timer_getoverrun(timer_t timer_id)
718 struct k_itimer *timr;
722 timr = lock_timer(timer_id, &flags);
726 overrun = timr->it_overrun_last;
727 unlock_timer(timr, flags);
732 /* Set a POSIX.1b interval timer. */
733 /* timr->it_lock is taken. */
735 common_timer_set(struct k_itimer *timr, int flags,
736 struct itimerspec *new_setting, struct itimerspec *old_setting)
738 struct hrtimer *timer = &timr->it.real.timer;
739 enum hrtimer_mode mode;
742 common_timer_get(timr, old_setting);
744 /* disable the timer */
745 timr->it.real.interval.tv64 = 0;
747 * careful here. If smp we could be in the "fire" routine which will
748 * be spinning as we hold the lock. But this is ONLY an SMP issue.
750 if (hrtimer_try_to_cancel(timer) < 0)
753 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
755 timr->it_overrun_last = 0;
757 /* switch off the timer when it_value is zero */
758 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
761 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
762 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
763 timr->it.real.timer.function = posix_timer_fn;
765 timer->expires = timespec_to_ktime(new_setting->it_value);
767 /* Convert interval */
768 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
770 /* SIGEV_NONE timers are not queued ! See common_timer_get */
771 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
772 /* Setup correct expiry time for relative timers */
773 if (mode == HRTIMER_MODE_REL) {
775 ktime_add_safe(timer->expires,
776 timer->base->get_time());
781 hrtimer_start(timer, timer->expires, mode);
785 /* Set a POSIX.1b interval timer */
787 sys_timer_settime(timer_t timer_id, int flags,
788 const struct itimerspec __user *new_setting,
789 struct itimerspec __user *old_setting)
791 struct k_itimer *timr;
792 struct itimerspec new_spec, old_spec;
795 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
800 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
803 if (!timespec_valid(&new_spec.it_interval) ||
804 !timespec_valid(&new_spec.it_value))
807 timr = lock_timer(timer_id, &flag);
811 error = CLOCK_DISPATCH(timr->it_clock, timer_set,
812 (timr, flags, &new_spec, rtn));
814 unlock_timer(timr, flag);
815 if (error == TIMER_RETRY) {
816 rtn = NULL; // We already got the old time...
820 if (old_setting && !error &&
821 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
827 static inline int common_timer_del(struct k_itimer *timer)
829 timer->it.real.interval.tv64 = 0;
831 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
836 static inline int timer_delete_hook(struct k_itimer *timer)
838 return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer));
841 /* Delete a POSIX.1b interval timer. */
843 sys_timer_delete(timer_t timer_id)
845 struct k_itimer *timer;
849 timer = lock_timer(timer_id, &flags);
853 if (timer_delete_hook(timer) == TIMER_RETRY) {
854 unlock_timer(timer, flags);
858 spin_lock(¤t->sighand->siglock);
859 list_del(&timer->list);
860 spin_unlock(¤t->sighand->siglock);
862 * This keeps any tasks waiting on the spin lock from thinking
863 * they got something (see the lock code above).
865 if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
866 put_task_struct(timer->it_process);
867 timer->it_process = NULL;
869 unlock_timer(timer, flags);
870 release_posix_timer(timer, IT_ID_SET);
875 * return timer owned by the process, used by exit_itimers
877 static void itimer_delete(struct k_itimer *timer)
882 spin_lock_irqsave(&timer->it_lock, flags);
884 if (timer_delete_hook(timer) == TIMER_RETRY) {
885 unlock_timer(timer, flags);
888 list_del(&timer->list);
890 * This keeps any tasks waiting on the spin lock from thinking
891 * they got something (see the lock code above).
893 if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
894 put_task_struct(timer->it_process);
895 timer->it_process = NULL;
897 unlock_timer(timer, flags);
898 release_posix_timer(timer, IT_ID_SET);
902 * This is called by do_exit or de_thread, only when there are no more
903 * references to the shared signal_struct.
905 void exit_itimers(struct signal_struct *sig)
907 struct k_itimer *tmr;
909 while (!list_empty(&sig->posix_timers)) {
910 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
915 /* Not available / possible... functions */
916 int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
920 EXPORT_SYMBOL_GPL(do_posix_clock_nosettime);
922 int do_posix_clock_nonanosleep(const clockid_t clock, int flags,
923 struct timespec *t, struct timespec __user *r)
926 return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */
927 #else /* parisc does define it separately. */
931 EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep);
933 asmlinkage long sys_clock_settime(const clockid_t which_clock,
934 const struct timespec __user *tp)
936 struct timespec new_tp;
938 if (invalid_clockid(which_clock))
940 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
943 return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp));
947 sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp)
949 struct timespec kernel_tp;
952 if (invalid_clockid(which_clock))
954 error = CLOCK_DISPATCH(which_clock, clock_get,
955 (which_clock, &kernel_tp));
956 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
964 sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
966 struct timespec rtn_tp;
969 if (invalid_clockid(which_clock))
972 error = CLOCK_DISPATCH(which_clock, clock_getres,
973 (which_clock, &rtn_tp));
975 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,
994 sys_clock_nanosleep(const clockid_t which_clock, int flags,
995 const struct timespec __user *rqtp,
996 struct timespec __user *rmtp)
1000 if (invalid_clockid(which_clock))
1003 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1006 if (!timespec_valid(&t))
1009 return CLOCK_DISPATCH(which_clock, nsleep,
1010 (which_clock, flags, &t, rmtp));
1014 * nanosleep_restart for monotonic and realtime clocks
1016 static int common_nsleep_restart(struct restart_block *restart_block)
1018 return hrtimer_nanosleep_restart(restart_block);
1022 * This will restart clock_nanosleep. This is required only by
1023 * compat_clock_nanosleep_restart for now.
1026 clock_nanosleep_restart(struct restart_block *restart_block)
1028 clockid_t which_clock = restart_block->arg0;
1030 return CLOCK_DISPATCH(which_clock, nsleep_restart,