2 * linux/kernel/posix-timers.c
5 * 2002-10-15 Posix Clocks & timers
6 * by George Anzinger george@mvista.com
8 * Copyright (C) 2002 2003 by MontaVista Software.
10 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
11 * Copyright (C) 2004 Boris Hu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA
30 /* These are all the functions necessary to implement
31 * POSIX clocks & timers
34 #include <linux/interrupt.h>
35 #include <linux/slab.h>
36 #include <linux/time.h>
37 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
40 #include <linux/list.h>
41 #include <linux/init.h>
42 #include <linux/compiler.h>
43 #include <linux/idr.h>
44 #include <linux/posix-clock.h>
45 #include <linux/posix-timers.h>
46 #include <linux/syscalls.h>
47 #include <linux/wait.h>
48 #include <linux/workqueue.h>
49 #include <linux/export.h>
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-raw 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 static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp)
220 get_monotonic_boottime(tp);
224 static int posix_get_tai(clockid_t which_clock, struct timespec *tp)
226 timekeeping_clocktai(tp);
231 * Initialize everything, well, just everything in Posix clocks/timers ;)
233 static __init int init_posix_timers(void)
235 struct k_clock clock_realtime = {
236 .clock_getres = hrtimer_get_res,
237 .clock_get = posix_clock_realtime_get,
238 .clock_set = posix_clock_realtime_set,
239 .clock_adj = posix_clock_realtime_adj,
240 .nsleep = common_nsleep,
241 .nsleep_restart = hrtimer_nanosleep_restart,
242 .timer_create = common_timer_create,
243 .timer_set = common_timer_set,
244 .timer_get = common_timer_get,
245 .timer_del = common_timer_del,
247 struct k_clock clock_monotonic = {
248 .clock_getres = hrtimer_get_res,
249 .clock_get = posix_ktime_get_ts,
250 .nsleep = common_nsleep,
251 .nsleep_restart = hrtimer_nanosleep_restart,
252 .timer_create = common_timer_create,
253 .timer_set = common_timer_set,
254 .timer_get = common_timer_get,
255 .timer_del = common_timer_del,
257 struct k_clock clock_monotonic_raw = {
258 .clock_getres = hrtimer_get_res,
259 .clock_get = posix_get_monotonic_raw,
261 struct k_clock clock_realtime_coarse = {
262 .clock_getres = posix_get_coarse_res,
263 .clock_get = posix_get_realtime_coarse,
265 struct k_clock clock_monotonic_coarse = {
266 .clock_getres = posix_get_coarse_res,
267 .clock_get = posix_get_monotonic_coarse,
269 struct k_clock clock_tai = {
270 .clock_getres = hrtimer_get_res,
271 .clock_get = posix_get_tai,
272 .nsleep = common_nsleep,
273 .nsleep_restart = hrtimer_nanosleep_restart,
274 .timer_create = common_timer_create,
275 .timer_set = common_timer_set,
276 .timer_get = common_timer_get,
277 .timer_del = common_timer_del,
279 struct k_clock clock_boottime = {
280 .clock_getres = hrtimer_get_res,
281 .clock_get = posix_get_boottime,
282 .nsleep = common_nsleep,
283 .nsleep_restart = hrtimer_nanosleep_restart,
284 .timer_create = common_timer_create,
285 .timer_set = common_timer_set,
286 .timer_get = common_timer_get,
287 .timer_del = common_timer_del,
290 posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime);
291 posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic);
292 posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
293 posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
294 posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
295 posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime);
296 posix_timers_register_clock(CLOCK_TAI, &clock_tai);
298 posix_timers_cache = kmem_cache_create("posix_timers_cache",
299 sizeof (struct k_itimer), 0, SLAB_PANIC,
301 idr_init(&posix_timers_id);
305 __initcall(init_posix_timers);
307 static void schedule_next_timer(struct k_itimer *timr)
309 struct hrtimer *timer = &timr->it.real.timer;
311 if (timr->it.real.interval.tv64 == 0)
314 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
315 timer->base->get_time(),
316 timr->it.real.interval);
318 timr->it_overrun_last = timr->it_overrun;
319 timr->it_overrun = -1;
320 ++timr->it_requeue_pending;
321 hrtimer_restart(timer);
325 * This function is exported for use by the signal deliver code. It is
326 * called just prior to the info block being released and passes that
327 * block to us. It's function is to update the overrun entry AND to
328 * restart the timer. It should only be called if the timer is to be
329 * restarted (i.e. we have flagged this in the sys_private entry of the
332 * To protect against the timer going away while the interrupt is queued,
333 * we require that the it_requeue_pending flag be set.
335 void do_schedule_next_timer(struct siginfo *info)
337 struct k_itimer *timr;
340 timr = lock_timer(info->si_tid, &flags);
342 if (timr && timr->it_requeue_pending == info->si_sys_private) {
343 if (timr->it_clock < 0)
344 posix_cpu_timer_schedule(timr);
346 schedule_next_timer(timr);
348 info->si_overrun += timr->it_overrun_last;
352 unlock_timer(timr, flags);
355 int posix_timer_event(struct k_itimer *timr, int si_private)
357 struct task_struct *task;
358 int shared, ret = -1;
360 * FIXME: if ->sigq is queued we can race with
361 * dequeue_signal()->do_schedule_next_timer().
363 * If dequeue_signal() sees the "right" value of
364 * si_sys_private it calls do_schedule_next_timer().
365 * We re-queue ->sigq and drop ->it_lock().
366 * do_schedule_next_timer() locks the timer
367 * and re-schedules it while ->sigq is pending.
368 * Not really bad, but not that we want.
370 timr->sigq->info.si_sys_private = si_private;
373 task = pid_task(timr->it_pid, PIDTYPE_PID);
375 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
376 ret = send_sigqueue(timr->sigq, task, shared);
379 /* If we failed to send the signal the timer stops. */
382 EXPORT_SYMBOL_GPL(posix_timer_event);
385 * This function gets called when a POSIX.1b interval timer expires. It
386 * is used as a callback from the kernel internal timer. The
387 * run_timer_list code ALWAYS calls with interrupts on.
389 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
391 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
393 struct k_itimer *timr;
396 enum hrtimer_restart ret = HRTIMER_NORESTART;
398 timr = container_of(timer, struct k_itimer, it.real.timer);
399 spin_lock_irqsave(&timr->it_lock, flags);
401 if (timr->it.real.interval.tv64 != 0)
402 si_private = ++timr->it_requeue_pending;
404 if (posix_timer_event(timr, si_private)) {
406 * signal was not sent because of sig_ignor
407 * we will not get a call back to restart it AND
408 * it should be restarted.
410 if (timr->it.real.interval.tv64 != 0) {
411 ktime_t now = hrtimer_cb_get_time(timer);
414 * FIXME: What we really want, is to stop this
415 * timer completely and restart it in case the
416 * SIG_IGN is removed. This is a non trivial
417 * change which involves sighand locking
418 * (sigh !), which we don't want to do late in
421 * For now we just let timers with an interval
422 * less than a jiffie expire every jiffie to
423 * avoid softirq starvation in case of SIG_IGN
424 * and a very small interval, which would put
425 * the timer right back on the softirq pending
426 * list. By moving now ahead of time we trick
427 * hrtimer_forward() to expire the timer
428 * later, while we still maintain the overrun
429 * accuracy, but have some inconsistency in
430 * the timer_gettime() case. This is at least
431 * better than a starved softirq. A more
432 * complex fix which solves also another related
433 * inconsistency is already in the pipeline.
435 #ifdef CONFIG_HIGH_RES_TIMERS
437 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
439 if (timr->it.real.interval.tv64 < kj.tv64)
440 now = ktime_add(now, kj);
443 timr->it_overrun += (unsigned int)
444 hrtimer_forward(timer, now,
445 timr->it.real.interval);
446 ret = HRTIMER_RESTART;
447 ++timr->it_requeue_pending;
451 unlock_timer(timr, flags);
455 static struct pid *good_sigevent(sigevent_t * event)
457 struct task_struct *rtn = current->group_leader;
459 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
460 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
461 !same_thread_group(rtn, current) ||
462 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
465 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
466 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
469 return task_pid(rtn);
472 void posix_timers_register_clock(const clockid_t clock_id,
473 struct k_clock *new_clock)
475 if ((unsigned) clock_id >= MAX_CLOCKS) {
476 printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
481 if (!new_clock->clock_get) {
482 printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
486 if (!new_clock->clock_getres) {
487 printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
492 posix_clocks[clock_id] = *new_clock;
494 EXPORT_SYMBOL_GPL(posix_timers_register_clock);
496 static struct k_itimer * alloc_posix_timer(void)
498 struct k_itimer *tmr;
499 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
502 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
503 kmem_cache_free(posix_timers_cache, tmr);
506 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
510 static void k_itimer_rcu_free(struct rcu_head *head)
512 struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
514 kmem_cache_free(posix_timers_cache, tmr);
518 #define IT_ID_NOT_SET 0
519 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
523 spin_lock_irqsave(&idr_lock, flags);
524 idr_remove(&posix_timers_id, tmr->it_id);
525 spin_unlock_irqrestore(&idr_lock, flags);
527 put_pid(tmr->it_pid);
528 sigqueue_free(tmr->sigq);
529 call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
532 static struct k_clock *clockid_to_kclock(const clockid_t id)
535 return (id & CLOCKFD_MASK) == CLOCKFD ?
536 &clock_posix_dynamic : &clock_posix_cpu;
538 if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
540 return &posix_clocks[id];
543 static int common_timer_create(struct k_itimer *new_timer)
545 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
549 /* Create a POSIX.1b interval timer. */
551 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
552 struct sigevent __user *, timer_event_spec,
553 timer_t __user *, created_timer_id)
555 struct k_clock *kc = clockid_to_kclock(which_clock);
556 struct k_itimer *new_timer;
557 int error, new_timer_id;
559 int it_id_set = IT_ID_NOT_SET;
563 if (!kc->timer_create)
566 new_timer = alloc_posix_timer();
567 if (unlikely(!new_timer))
570 spin_lock_init(&new_timer->it_lock);
572 idr_preload(GFP_KERNEL);
573 spin_lock_irq(&idr_lock);
574 error = idr_alloc(&posix_timers_id, new_timer, 0, 0, GFP_NOWAIT);
575 spin_unlock_irq(&idr_lock);
579 * Weird looking, but we return EAGAIN if the IDR is
580 * full (proper POSIX return value for this)
582 if (error == -ENOSPC)
586 new_timer_id = error;
588 it_id_set = IT_ID_SET;
589 new_timer->it_id = (timer_t) new_timer_id;
590 new_timer->it_clock = which_clock;
591 new_timer->it_overrun = -1;
593 if (timer_event_spec) {
594 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
599 new_timer->it_pid = get_pid(good_sigevent(&event));
601 if (!new_timer->it_pid) {
606 event.sigev_notify = SIGEV_SIGNAL;
607 event.sigev_signo = SIGALRM;
608 event.sigev_value.sival_int = new_timer->it_id;
609 new_timer->it_pid = get_pid(task_tgid(current));
612 new_timer->it_sigev_notify = event.sigev_notify;
613 new_timer->sigq->info.si_signo = event.sigev_signo;
614 new_timer->sigq->info.si_value = event.sigev_value;
615 new_timer->sigq->info.si_tid = new_timer->it_id;
616 new_timer->sigq->info.si_code = SI_TIMER;
618 if (copy_to_user(created_timer_id,
619 &new_timer_id, sizeof (new_timer_id))) {
624 error = kc->timer_create(new_timer);
628 spin_lock_irq(¤t->sighand->siglock);
629 new_timer->it_signal = current->signal;
630 list_add(&new_timer->list, ¤t->signal->posix_timers);
631 spin_unlock_irq(¤t->sighand->siglock);
635 * In the case of the timer belonging to another task, after
636 * the task is unlocked, the timer is owned by the other task
637 * and may cease to exist at any time. Don't use or modify
638 * new_timer after the unlock call.
641 release_posix_timer(new_timer, it_id_set);
646 * Locking issues: We need to protect the result of the id look up until
647 * we get the timer locked down so it is not deleted under us. The
648 * removal is done under the idr spinlock so we use that here to bridge
649 * the find to the timer lock. To avoid a dead lock, the timer id MUST
650 * be release with out holding the timer lock.
652 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
654 struct k_itimer *timr;
657 * timer_t could be any type >= int and we want to make sure any
658 * @timer_id outside positive int range fails lookup.
660 if ((unsigned long long)timer_id > INT_MAX)
664 timr = idr_find(&posix_timers_id, (int)timer_id);
666 spin_lock_irqsave(&timr->it_lock, *flags);
667 if (timr->it_signal == current->signal) {
671 spin_unlock_irqrestore(&timr->it_lock, *flags);
679 * Get the time remaining on a POSIX.1b interval timer. This function
680 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
683 * We have a couple of messes to clean up here. First there is the case
684 * of a timer that has a requeue pending. These timers should appear to
685 * be in the timer list with an expiry as if we were to requeue them
688 * The second issue is the SIGEV_NONE timer which may be active but is
689 * not really ever put in the timer list (to save system resources).
690 * This timer may be expired, and if so, we will do it here. Otherwise
691 * it is the same as a requeue pending timer WRT to what we should
695 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
697 ktime_t now, remaining, iv;
698 struct hrtimer *timer = &timr->it.real.timer;
700 memset(cur_setting, 0, sizeof(struct itimerspec));
702 iv = timr->it.real.interval;
704 /* interval timer ? */
706 cur_setting->it_interval = ktime_to_timespec(iv);
707 else if (!hrtimer_active(timer) &&
708 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
711 now = timer->base->get_time();
714 * When a requeue is pending or this is a SIGEV_NONE
715 * timer move the expiry time forward by intervals, so
718 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
719 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
720 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
722 remaining = ktime_sub(hrtimer_get_expires(timer), now);
723 /* Return 0 only, when the timer is expired and not pending */
724 if (remaining.tv64 <= 0) {
726 * A single shot SIGEV_NONE timer must return 0, when
729 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
730 cur_setting->it_value.tv_nsec = 1;
732 cur_setting->it_value = ktime_to_timespec(remaining);
735 /* Get the time remaining on a POSIX.1b interval timer. */
736 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
737 struct itimerspec __user *, setting)
739 struct itimerspec cur_setting;
740 struct k_itimer *timr;
745 timr = lock_timer(timer_id, &flags);
749 kc = clockid_to_kclock(timr->it_clock);
750 if (WARN_ON_ONCE(!kc || !kc->timer_get))
753 kc->timer_get(timr, &cur_setting);
755 unlock_timer(timr, flags);
757 if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
764 * Get the number of overruns of a POSIX.1b interval timer. This is to
765 * be the overrun of the timer last delivered. At the same time we are
766 * accumulating overruns on the next timer. The overrun is frozen when
767 * the signal is delivered, either at the notify time (if the info block
768 * is not queued) or at the actual delivery time (as we are informed by
769 * the call back to do_schedule_next_timer(). So all we need to do is
770 * to pick up the frozen overrun.
772 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
774 struct k_itimer *timr;
778 timr = lock_timer(timer_id, &flags);
782 overrun = timr->it_overrun_last;
783 unlock_timer(timr, flags);
788 /* Set a POSIX.1b interval timer. */
789 /* timr->it_lock is taken. */
791 common_timer_set(struct k_itimer *timr, int flags,
792 struct itimerspec *new_setting, struct itimerspec *old_setting)
794 struct hrtimer *timer = &timr->it.real.timer;
795 enum hrtimer_mode mode;
798 common_timer_get(timr, old_setting);
800 /* disable the timer */
801 timr->it.real.interval.tv64 = 0;
803 * careful here. If smp we could be in the "fire" routine which will
804 * be spinning as we hold the lock. But this is ONLY an SMP issue.
806 if (hrtimer_try_to_cancel(timer) < 0)
809 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
811 timr->it_overrun_last = 0;
813 /* switch off the timer when it_value is zero */
814 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
817 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
818 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
819 timr->it.real.timer.function = posix_timer_fn;
821 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
823 /* Convert interval */
824 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
826 /* SIGEV_NONE timers are not queued ! See common_timer_get */
827 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
828 /* Setup correct expiry time for relative timers */
829 if (mode == HRTIMER_MODE_REL) {
830 hrtimer_add_expires(timer, timer->base->get_time());
835 hrtimer_start_expires(timer, mode);
839 /* Set a POSIX.1b interval timer */
840 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
841 const struct itimerspec __user *, new_setting,
842 struct itimerspec __user *, old_setting)
844 struct k_itimer *timr;
845 struct itimerspec new_spec, old_spec;
848 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
854 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
857 if (!timespec_valid(&new_spec.it_interval) ||
858 !timespec_valid(&new_spec.it_value))
861 timr = lock_timer(timer_id, &flag);
865 kc = clockid_to_kclock(timr->it_clock);
866 if (WARN_ON_ONCE(!kc || !kc->timer_set))
869 error = kc->timer_set(timr, flags, &new_spec, rtn);
871 unlock_timer(timr, flag);
872 if (error == TIMER_RETRY) {
873 rtn = NULL; // We already got the old time...
877 if (old_setting && !error &&
878 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
884 static int common_timer_del(struct k_itimer *timer)
886 timer->it.real.interval.tv64 = 0;
888 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
893 static inline int timer_delete_hook(struct k_itimer *timer)
895 struct k_clock *kc = clockid_to_kclock(timer->it_clock);
897 if (WARN_ON_ONCE(!kc || !kc->timer_del))
899 return kc->timer_del(timer);
902 /* Delete a POSIX.1b interval timer. */
903 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
905 struct k_itimer *timer;
909 timer = lock_timer(timer_id, &flags);
913 if (timer_delete_hook(timer) == TIMER_RETRY) {
914 unlock_timer(timer, flags);
918 spin_lock(¤t->sighand->siglock);
919 list_del(&timer->list);
920 spin_unlock(¤t->sighand->siglock);
922 * This keeps any tasks waiting on the spin lock from thinking
923 * they got something (see the lock code above).
925 timer->it_signal = NULL;
927 unlock_timer(timer, flags);
928 release_posix_timer(timer, IT_ID_SET);
933 * return timer owned by the process, used by exit_itimers
935 static void itimer_delete(struct k_itimer *timer)
940 spin_lock_irqsave(&timer->it_lock, flags);
942 if (timer_delete_hook(timer) == TIMER_RETRY) {
943 unlock_timer(timer, flags);
946 list_del(&timer->list);
948 * This keeps any tasks waiting on the spin lock from thinking
949 * they got something (see the lock code above).
951 timer->it_signal = NULL;
953 unlock_timer(timer, flags);
954 release_posix_timer(timer, IT_ID_SET);
958 * This is called by do_exit or de_thread, only when there are no more
959 * references to the shared signal_struct.
961 void exit_itimers(struct signal_struct *sig)
963 struct k_itimer *tmr;
965 while (!list_empty(&sig->posix_timers)) {
966 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
971 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
972 const struct timespec __user *, tp)
974 struct k_clock *kc = clockid_to_kclock(which_clock);
975 struct timespec new_tp;
977 if (!kc || !kc->clock_set)
980 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
983 return kc->clock_set(which_clock, &new_tp);
986 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
987 struct timespec __user *,tp)
989 struct k_clock *kc = clockid_to_kclock(which_clock);
990 struct timespec kernel_tp;
996 error = kc->clock_get(which_clock, &kernel_tp);
998 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
1004 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1005 struct timex __user *, utx)
1007 struct k_clock *kc = clockid_to_kclock(which_clock);
1016 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1019 err = kc->clock_adj(which_clock, &ktx);
1021 if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1027 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1028 struct timespec __user *, tp)
1030 struct k_clock *kc = clockid_to_kclock(which_clock);
1031 struct timespec rtn_tp;
1037 error = kc->clock_getres(which_clock, &rtn_tp);
1039 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
1046 * nanosleep for monotonic and realtime clocks
1048 static int common_nsleep(const clockid_t which_clock, int flags,
1049 struct timespec *tsave, struct timespec __user *rmtp)
1051 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
1052 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1056 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1057 const struct timespec __user *, rqtp,
1058 struct timespec __user *, rmtp)
1060 struct k_clock *kc = clockid_to_kclock(which_clock);
1066 return -ENANOSLEEP_NOTSUP;
1068 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1071 if (!timespec_valid(&t))
1074 return kc->nsleep(which_clock, flags, &t, rmtp);
1078 * This will restart clock_nanosleep. This is required only by
1079 * compat_clock_nanosleep_restart for now.
1081 long clock_nanosleep_restart(struct restart_block *restart_block)
1083 clockid_t which_clock = restart_block->nanosleep.clockid;
1084 struct k_clock *kc = clockid_to_kclock(which_clock);
1086 if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
1089 return kc->nsleep_restart(restart_block);