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/module.h>
52 * Management arrays for POSIX timers. Timers are kept in slab memory
53 * Timer ids are allocated by an external routine that keeps track of the
54 * id and the timer. The external interface is:
56 * void *idr_find(struct idr *idp, int id); to find timer_id <id>
57 * int idr_get_new(struct idr *idp, void *ptr); to get a new id and
59 * void idr_remove(struct idr *idp, int id); to release <id>
60 * void idr_init(struct idr *idp); to initialize <idp>
62 * The idr_get_new *may* call slab for more memory so it must not be
63 * called under a spin lock. Likewise idr_remore may release memory
64 * (but it may be ok to do this under a lock...).
65 * idr_find is just a memory look up and is quite fast. A -1 return
66 * indicates that the requested id does not exist.
70 * Lets keep our timers in a slab cache :-)
72 static struct kmem_cache *posix_timers_cache;
73 static struct idr posix_timers_id;
74 static DEFINE_SPINLOCK(idr_lock);
77 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
78 * SIGEV values. Here we put out an error if this assumption fails.
80 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
81 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
82 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
86 * parisc wants ENOTSUP instead of EOPNOTSUPP
89 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
91 # define ENANOSLEEP_NOTSUP ENOTSUP
95 * The timer ID is turned into a timer address by idr_find().
96 * Verifying a valid ID consists of:
98 * a) checking that idr_find() returns other than -1.
99 * b) checking that the timer id matches the one in the timer itself.
100 * c) that the timer owner is in the callers thread group.
104 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
105 * to implement others. This structure defines the various
108 * RESOLUTION: Clock resolution is used to round up timer and interval
109 * times, NOT to report clock times, which are reported with as
110 * much resolution as the system can muster. In some cases this
111 * resolution may depend on the underlying clock hardware and
112 * may not be quantifiable until run time, and only then is the
113 * necessary code is written. The standard says we should say
114 * something about this issue in the documentation...
116 * FUNCTIONS: The CLOCKs structure defines possible functions to
117 * handle various clock functions.
119 * The standard POSIX timer management code assumes the
120 * following: 1.) The k_itimer struct (sched.h) is used for
121 * the timer. 2.) The list, it_lock, it_clock, it_id and
122 * it_pid fields are not modified by timer code.
124 * Permissions: It is assumed that the clock_settime() function defined
125 * for each clock will take care of permission checks. Some
126 * clocks may be set able by any user (i.e. local process
127 * clocks) others not. Currently the only set able clock we
128 * have is CLOCK_REALTIME and its high res counter part, both of
129 * which we beg off on and pass to do_sys_settimeofday().
132 static struct k_clock posix_clocks[MAX_CLOCKS];
135 * These ones are defined below.
137 static int common_nsleep(const clockid_t, int flags, struct timespec *t,
138 struct timespec __user *rmtp);
139 static int common_timer_create(struct k_itimer *new_timer);
140 static void common_timer_get(struct k_itimer *, struct itimerspec *);
141 static int common_timer_set(struct k_itimer *, int,
142 struct itimerspec *, struct itimerspec *);
143 static int common_timer_del(struct k_itimer *timer);
145 static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
147 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
149 #define lock_timer(tid, flags) \
150 ({ struct k_itimer *__timr; \
151 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
155 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
157 spin_unlock_irqrestore(&timr->it_lock, flags);
160 /* Get clock_realtime */
161 static int posix_clock_realtime_get(clockid_t which_clock, struct timespec *tp)
163 ktime_get_real_ts(tp);
167 /* Set clock_realtime */
168 static int posix_clock_realtime_set(const clockid_t which_clock,
169 const struct timespec *tp)
171 return do_sys_settimeofday(tp, NULL);
174 static int posix_clock_realtime_adj(const clockid_t which_clock,
177 return do_adjtimex(t);
181 * Get monotonic time for posix timers
183 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
190 * Get monotonic time for posix timers
192 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
199 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
201 *tp = current_kernel_time();
205 static int posix_get_monotonic_coarse(clockid_t which_clock,
208 *tp = get_monotonic_coarse();
212 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
214 *tp = ktime_to_timespec(KTIME_LOW_RES);
218 * Initialize everything, well, just everything in Posix clocks/timers ;)
220 static __init int init_posix_timers(void)
222 struct k_clock clock_realtime = {
223 .clock_getres = hrtimer_get_res,
224 .clock_get = posix_clock_realtime_get,
225 .clock_set = posix_clock_realtime_set,
226 .clock_adj = posix_clock_realtime_adj,
227 .nsleep = common_nsleep,
228 .nsleep_restart = hrtimer_nanosleep_restart,
229 .timer_create = common_timer_create,
230 .timer_set = common_timer_set,
231 .timer_get = common_timer_get,
232 .timer_del = common_timer_del,
234 struct k_clock clock_monotonic = {
235 .clock_getres = hrtimer_get_res,
236 .clock_get = posix_ktime_get_ts,
237 .nsleep = common_nsleep,
238 .nsleep_restart = hrtimer_nanosleep_restart,
239 .timer_create = common_timer_create,
240 .timer_set = common_timer_set,
241 .timer_get = common_timer_get,
242 .timer_del = common_timer_del,
244 struct k_clock clock_monotonic_raw = {
245 .clock_getres = hrtimer_get_res,
246 .clock_get = posix_get_monotonic_raw,
248 struct k_clock clock_realtime_coarse = {
249 .clock_getres = posix_get_coarse_res,
250 .clock_get = posix_get_realtime_coarse,
252 struct k_clock clock_monotonic_coarse = {
253 .clock_getres = posix_get_coarse_res,
254 .clock_get = posix_get_monotonic_coarse,
257 posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime);
258 posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic);
259 posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
260 posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
261 posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
263 posix_timers_cache = kmem_cache_create("posix_timers_cache",
264 sizeof (struct k_itimer), 0, SLAB_PANIC,
266 idr_init(&posix_timers_id);
270 __initcall(init_posix_timers);
272 static void schedule_next_timer(struct k_itimer *timr)
274 struct hrtimer *timer = &timr->it.real.timer;
276 if (timr->it.real.interval.tv64 == 0)
279 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
280 timer->base->get_time(),
281 timr->it.real.interval);
283 timr->it_overrun_last = timr->it_overrun;
284 timr->it_overrun = -1;
285 ++timr->it_requeue_pending;
286 hrtimer_restart(timer);
290 * This function is exported for use by the signal deliver code. It is
291 * called just prior to the info block being released and passes that
292 * block to us. It's function is to update the overrun entry AND to
293 * restart the timer. It should only be called if the timer is to be
294 * restarted (i.e. we have flagged this in the sys_private entry of the
297 * To protect aginst the timer going away while the interrupt is queued,
298 * we require that the it_requeue_pending flag be set.
300 void do_schedule_next_timer(struct siginfo *info)
302 struct k_itimer *timr;
305 timr = lock_timer(info->si_tid, &flags);
307 if (timr && timr->it_requeue_pending == info->si_sys_private) {
308 if (timr->it_clock < 0)
309 posix_cpu_timer_schedule(timr);
311 schedule_next_timer(timr);
313 info->si_overrun += timr->it_overrun_last;
317 unlock_timer(timr, flags);
320 int posix_timer_event(struct k_itimer *timr, int si_private)
322 struct task_struct *task;
323 int shared, ret = -1;
325 * FIXME: if ->sigq is queued we can race with
326 * dequeue_signal()->do_schedule_next_timer().
328 * If dequeue_signal() sees the "right" value of
329 * si_sys_private it calls do_schedule_next_timer().
330 * We re-queue ->sigq and drop ->it_lock().
331 * do_schedule_next_timer() locks the timer
332 * and re-schedules it while ->sigq is pending.
333 * Not really bad, but not that we want.
335 timr->sigq->info.si_sys_private = si_private;
338 task = pid_task(timr->it_pid, PIDTYPE_PID);
340 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
341 ret = send_sigqueue(timr->sigq, task, shared);
344 /* If we failed to send the signal the timer stops. */
347 EXPORT_SYMBOL_GPL(posix_timer_event);
350 * This function gets called when a POSIX.1b interval timer expires. It
351 * is used as a callback from the kernel internal timer. The
352 * run_timer_list code ALWAYS calls with interrupts on.
354 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
356 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
358 struct k_itimer *timr;
361 enum hrtimer_restart ret = HRTIMER_NORESTART;
363 timr = container_of(timer, struct k_itimer, it.real.timer);
364 spin_lock_irqsave(&timr->it_lock, flags);
366 if (timr->it.real.interval.tv64 != 0)
367 si_private = ++timr->it_requeue_pending;
369 if (posix_timer_event(timr, si_private)) {
371 * signal was not sent because of sig_ignor
372 * we will not get a call back to restart it AND
373 * it should be restarted.
375 if (timr->it.real.interval.tv64 != 0) {
376 ktime_t now = hrtimer_cb_get_time(timer);
379 * FIXME: What we really want, is to stop this
380 * timer completely and restart it in case the
381 * SIG_IGN is removed. This is a non trivial
382 * change which involves sighand locking
383 * (sigh !), which we don't want to do late in
386 * For now we just let timers with an interval
387 * less than a jiffie expire every jiffie to
388 * avoid softirq starvation in case of SIG_IGN
389 * and a very small interval, which would put
390 * the timer right back on the softirq pending
391 * list. By moving now ahead of time we trick
392 * hrtimer_forward() to expire the timer
393 * later, while we still maintain the overrun
394 * accuracy, but have some inconsistency in
395 * the timer_gettime() case. This is at least
396 * better than a starved softirq. A more
397 * complex fix which solves also another related
398 * inconsistency is already in the pipeline.
400 #ifdef CONFIG_HIGH_RES_TIMERS
402 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
404 if (timr->it.real.interval.tv64 < kj.tv64)
405 now = ktime_add(now, kj);
408 timr->it_overrun += (unsigned int)
409 hrtimer_forward(timer, now,
410 timr->it.real.interval);
411 ret = HRTIMER_RESTART;
412 ++timr->it_requeue_pending;
416 unlock_timer(timr, flags);
420 static struct pid *good_sigevent(sigevent_t * event)
422 struct task_struct *rtn = current->group_leader;
424 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
425 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
426 !same_thread_group(rtn, current) ||
427 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
430 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
431 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
434 return task_pid(rtn);
437 void posix_timers_register_clock(const clockid_t clock_id,
438 struct k_clock *new_clock)
440 if ((unsigned) clock_id >= MAX_CLOCKS) {
441 printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
446 if (!new_clock->clock_get) {
447 printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
451 if (!new_clock->clock_getres) {
452 printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
457 posix_clocks[clock_id] = *new_clock;
459 EXPORT_SYMBOL_GPL(posix_timers_register_clock);
461 static struct k_itimer * alloc_posix_timer(void)
463 struct k_itimer *tmr;
464 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
467 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
468 kmem_cache_free(posix_timers_cache, tmr);
471 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
476 #define IT_ID_NOT_SET 0
477 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
481 spin_lock_irqsave(&idr_lock, flags);
482 idr_remove(&posix_timers_id, tmr->it_id);
483 spin_unlock_irqrestore(&idr_lock, flags);
485 put_pid(tmr->it_pid);
486 sigqueue_free(tmr->sigq);
487 kmem_cache_free(posix_timers_cache, tmr);
490 static struct k_clock *clockid_to_kclock(const clockid_t id)
493 return (id & CLOCKFD_MASK) == CLOCKFD ?
494 &clock_posix_dynamic : &clock_posix_cpu;
496 if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
498 return &posix_clocks[id];
501 static int common_timer_create(struct k_itimer *new_timer)
503 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
507 /* Create a POSIX.1b interval timer. */
509 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
510 struct sigevent __user *, timer_event_spec,
511 timer_t __user *, created_timer_id)
513 struct k_clock *kc = clockid_to_kclock(which_clock);
514 struct k_itimer *new_timer;
515 int error, new_timer_id;
517 int it_id_set = IT_ID_NOT_SET;
521 if (!kc->timer_create)
524 new_timer = alloc_posix_timer();
525 if (unlikely(!new_timer))
528 spin_lock_init(&new_timer->it_lock);
530 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
534 spin_lock_irq(&idr_lock);
535 error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
536 spin_unlock_irq(&idr_lock);
538 if (error == -EAGAIN)
541 * Weird looking, but we return EAGAIN if the IDR is
542 * full (proper POSIX return value for this)
548 it_id_set = IT_ID_SET;
549 new_timer->it_id = (timer_t) new_timer_id;
550 new_timer->it_clock = which_clock;
551 new_timer->it_overrun = -1;
553 if (timer_event_spec) {
554 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
559 new_timer->it_pid = get_pid(good_sigevent(&event));
561 if (!new_timer->it_pid) {
566 event.sigev_notify = SIGEV_SIGNAL;
567 event.sigev_signo = SIGALRM;
568 event.sigev_value.sival_int = new_timer->it_id;
569 new_timer->it_pid = get_pid(task_tgid(current));
572 new_timer->it_sigev_notify = event.sigev_notify;
573 new_timer->sigq->info.si_signo = event.sigev_signo;
574 new_timer->sigq->info.si_value = event.sigev_value;
575 new_timer->sigq->info.si_tid = new_timer->it_id;
576 new_timer->sigq->info.si_code = SI_TIMER;
578 if (copy_to_user(created_timer_id,
579 &new_timer_id, sizeof (new_timer_id))) {
584 error = kc->timer_create(new_timer);
588 spin_lock_irq(¤t->sighand->siglock);
589 new_timer->it_signal = current->signal;
590 list_add(&new_timer->list, ¤t->signal->posix_timers);
591 spin_unlock_irq(¤t->sighand->siglock);
595 * In the case of the timer belonging to another task, after
596 * the task is unlocked, the timer is owned by the other task
597 * and may cease to exist at any time. Don't use or modify
598 * new_timer after the unlock call.
601 release_posix_timer(new_timer, it_id_set);
606 * Locking issues: We need to protect the result of the id look up until
607 * we get the timer locked down so it is not deleted under us. The
608 * removal is done under the idr spinlock so we use that here to bridge
609 * the find to the timer lock. To avoid a dead lock, the timer id MUST
610 * be release with out holding the timer lock.
612 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
614 struct k_itimer *timr;
616 * Watch out here. We do a irqsave on the idr_lock and pass the
617 * flags part over to the timer lock. Must not let interrupts in
618 * while we are moving the lock.
620 spin_lock_irqsave(&idr_lock, *flags);
621 timr = idr_find(&posix_timers_id, (int)timer_id);
623 spin_lock(&timr->it_lock);
624 if (timr->it_signal == current->signal) {
625 spin_unlock(&idr_lock);
628 spin_unlock(&timr->it_lock);
630 spin_unlock_irqrestore(&idr_lock, *flags);
636 * Get the time remaining on a POSIX.1b interval timer. This function
637 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
640 * We have a couple of messes to clean up here. First there is the case
641 * of a timer that has a requeue pending. These timers should appear to
642 * be in the timer list with an expiry as if we were to requeue them
645 * The second issue is the SIGEV_NONE timer which may be active but is
646 * not really ever put in the timer list (to save system resources).
647 * This timer may be expired, and if so, we will do it here. Otherwise
648 * it is the same as a requeue pending timer WRT to what we should
652 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
654 ktime_t now, remaining, iv;
655 struct hrtimer *timer = &timr->it.real.timer;
657 memset(cur_setting, 0, sizeof(struct itimerspec));
659 iv = timr->it.real.interval;
661 /* interval timer ? */
663 cur_setting->it_interval = ktime_to_timespec(iv);
664 else if (!hrtimer_active(timer) &&
665 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
668 now = timer->base->get_time();
671 * When a requeue is pending or this is a SIGEV_NONE
672 * timer move the expiry time forward by intervals, so
675 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
676 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
677 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
679 remaining = ktime_sub(hrtimer_get_expires(timer), now);
680 /* Return 0 only, when the timer is expired and not pending */
681 if (remaining.tv64 <= 0) {
683 * A single shot SIGEV_NONE timer must return 0, when
686 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
687 cur_setting->it_value.tv_nsec = 1;
689 cur_setting->it_value = ktime_to_timespec(remaining);
692 /* Get the time remaining on a POSIX.1b interval timer. */
693 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
694 struct itimerspec __user *, setting)
696 struct itimerspec cur_setting;
697 struct k_itimer *timr;
702 timr = lock_timer(timer_id, &flags);
706 kc = clockid_to_kclock(timr->it_clock);
707 if (WARN_ON_ONCE(!kc || !kc->timer_get))
710 kc->timer_get(timr, &cur_setting);
712 unlock_timer(timr, flags);
714 if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
721 * Get the number of overruns of a POSIX.1b interval timer. This is to
722 * be the overrun of the timer last delivered. At the same time we are
723 * accumulating overruns on the next timer. The overrun is frozen when
724 * the signal is delivered, either at the notify time (if the info block
725 * is not queued) or at the actual delivery time (as we are informed by
726 * the call back to do_schedule_next_timer(). So all we need to do is
727 * to pick up the frozen overrun.
729 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
731 struct k_itimer *timr;
735 timr = lock_timer(timer_id, &flags);
739 overrun = timr->it_overrun_last;
740 unlock_timer(timr, flags);
745 /* Set a POSIX.1b interval timer. */
746 /* timr->it_lock is taken. */
748 common_timer_set(struct k_itimer *timr, int flags,
749 struct itimerspec *new_setting, struct itimerspec *old_setting)
751 struct hrtimer *timer = &timr->it.real.timer;
752 enum hrtimer_mode mode;
755 common_timer_get(timr, old_setting);
757 /* disable the timer */
758 timr->it.real.interval.tv64 = 0;
760 * careful here. If smp we could be in the "fire" routine which will
761 * be spinning as we hold the lock. But this is ONLY an SMP issue.
763 if (hrtimer_try_to_cancel(timer) < 0)
766 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
768 timr->it_overrun_last = 0;
770 /* switch off the timer when it_value is zero */
771 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
774 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
775 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
776 timr->it.real.timer.function = posix_timer_fn;
778 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
780 /* Convert interval */
781 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
783 /* SIGEV_NONE timers are not queued ! See common_timer_get */
784 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
785 /* Setup correct expiry time for relative timers */
786 if (mode == HRTIMER_MODE_REL) {
787 hrtimer_add_expires(timer, timer->base->get_time());
792 hrtimer_start_expires(timer, mode);
796 /* Set a POSIX.1b interval timer */
797 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
798 const struct itimerspec __user *, new_setting,
799 struct itimerspec __user *, old_setting)
801 struct k_itimer *timr;
802 struct itimerspec new_spec, old_spec;
805 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
811 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
814 if (!timespec_valid(&new_spec.it_interval) ||
815 !timespec_valid(&new_spec.it_value))
818 timr = lock_timer(timer_id, &flag);
822 kc = clockid_to_kclock(timr->it_clock);
823 if (WARN_ON_ONCE(!kc || !kc->timer_set))
826 error = kc->timer_set(timr, flags, &new_spec, rtn);
828 unlock_timer(timr, flag);
829 if (error == TIMER_RETRY) {
830 rtn = NULL; // We already got the old time...
834 if (old_setting && !error &&
835 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
841 static int common_timer_del(struct k_itimer *timer)
843 timer->it.real.interval.tv64 = 0;
845 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
850 static inline int timer_delete_hook(struct k_itimer *timer)
852 struct k_clock *kc = clockid_to_kclock(timer->it_clock);
854 if (WARN_ON_ONCE(!kc || !kc->timer_del))
856 return kc->timer_del(timer);
859 /* Delete a POSIX.1b interval timer. */
860 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
862 struct k_itimer *timer;
866 timer = lock_timer(timer_id, &flags);
870 if (timer_delete_hook(timer) == TIMER_RETRY) {
871 unlock_timer(timer, flags);
875 spin_lock(¤t->sighand->siglock);
876 list_del(&timer->list);
877 spin_unlock(¤t->sighand->siglock);
879 * This keeps any tasks waiting on the spin lock from thinking
880 * they got something (see the lock code above).
882 timer->it_signal = NULL;
884 unlock_timer(timer, flags);
885 release_posix_timer(timer, IT_ID_SET);
890 * return timer owned by the process, used by exit_itimers
892 static void itimer_delete(struct k_itimer *timer)
897 spin_lock_irqsave(&timer->it_lock, flags);
899 if (timer_delete_hook(timer) == TIMER_RETRY) {
900 unlock_timer(timer, flags);
903 list_del(&timer->list);
905 * This keeps any tasks waiting on the spin lock from thinking
906 * they got something (see the lock code above).
908 timer->it_signal = NULL;
910 unlock_timer(timer, flags);
911 release_posix_timer(timer, IT_ID_SET);
915 * This is called by do_exit or de_thread, only when there are no more
916 * references to the shared signal_struct.
918 void exit_itimers(struct signal_struct *sig)
920 struct k_itimer *tmr;
922 while (!list_empty(&sig->posix_timers)) {
923 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
928 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
929 const struct timespec __user *, tp)
931 struct k_clock *kc = clockid_to_kclock(which_clock);
932 struct timespec new_tp;
934 if (!kc || !kc->clock_set)
937 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
940 return kc->clock_set(which_clock, &new_tp);
943 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
944 struct timespec __user *,tp)
946 struct k_clock *kc = clockid_to_kclock(which_clock);
947 struct timespec kernel_tp;
953 error = kc->clock_get(which_clock, &kernel_tp);
955 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
961 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
962 struct timex __user *, utx)
964 struct k_clock *kc = clockid_to_kclock(which_clock);
973 if (copy_from_user(&ktx, utx, sizeof(ktx)))
976 err = kc->clock_adj(which_clock, &ktx);
978 if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
984 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
985 struct timespec __user *, tp)
987 struct k_clock *kc = clockid_to_kclock(which_clock);
988 struct timespec rtn_tp;
994 error = kc->clock_getres(which_clock, &rtn_tp);
996 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
1003 * nanosleep for monotonic and realtime clocks
1005 static int common_nsleep(const clockid_t which_clock, int flags,
1006 struct timespec *tsave, struct timespec __user *rmtp)
1008 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
1009 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1013 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1014 const struct timespec __user *, rqtp,
1015 struct timespec __user *, rmtp)
1017 struct k_clock *kc = clockid_to_kclock(which_clock);
1023 return -ENANOSLEEP_NOTSUP;
1025 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1028 if (!timespec_valid(&t))
1031 return kc->nsleep(which_clock, flags, &t, rmtp);
1035 * This will restart clock_nanosleep. This is required only by
1036 * compat_clock_nanosleep_restart for now.
1038 long clock_nanosleep_restart(struct restart_block *restart_block)
1040 clockid_t which_clock = restart_block->nanosleep.index;
1041 struct k_clock *kc = clockid_to_kclock(which_clock);
1043 if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
1046 return kc->nsleep_restart(restart_block);