Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/sfc-next-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / posix-timers.c
blobe5498d7405c31ff8d9f5afd85b85ed8038ad691d
1 /*
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
33 #include <linux/mm.h>
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
58 * related it to <ptr>
59 * void idr_remove(struct idr *idp, int id); to release <id>
60 * void idr_init(struct idr *idp); to initialize <idp>
61 * which we supply.
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!"
83 #endif
86 * parisc wants ENOTSUP instead of EOPNOTSUPP
88 #ifndef ENOTSUP
89 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
90 #else
91 # define ENANOSLEEP_NOTSUP ENOTSUP
92 #endif
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
106 * clocks.
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)); \
152 __timr; \
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);
164 return 0;
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,
175 struct timex *t)
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)
185 ktime_get_ts(tp);
186 return 0;
190 * Get monotonic-raw time for posix timers
192 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
194 getrawmonotonic(tp);
195 return 0;
199 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
201 *tp = current_kernel_time();
202 return 0;
205 static int posix_get_monotonic_coarse(clockid_t which_clock,
206 struct timespec *tp)
208 *tp = get_monotonic_coarse();
209 return 0;
212 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
214 *tp = ktime_to_timespec(KTIME_LOW_RES);
215 return 0;
218 static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp)
220 get_monotonic_boottime(tp);
221 return 0;
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,
232 .clock_get = posix_clock_realtime_get,
233 .clock_set = posix_clock_realtime_set,
234 .clock_adj = posix_clock_realtime_adj,
235 .nsleep = common_nsleep,
236 .nsleep_restart = hrtimer_nanosleep_restart,
237 .timer_create = common_timer_create,
238 .timer_set = common_timer_set,
239 .timer_get = common_timer_get,
240 .timer_del = common_timer_del,
242 struct k_clock clock_monotonic = {
243 .clock_getres = hrtimer_get_res,
244 .clock_get = posix_ktime_get_ts,
245 .nsleep = common_nsleep,
246 .nsleep_restart = hrtimer_nanosleep_restart,
247 .timer_create = common_timer_create,
248 .timer_set = common_timer_set,
249 .timer_get = common_timer_get,
250 .timer_del = common_timer_del,
252 struct k_clock clock_monotonic_raw = {
253 .clock_getres = hrtimer_get_res,
254 .clock_get = posix_get_monotonic_raw,
256 struct k_clock clock_realtime_coarse = {
257 .clock_getres = posix_get_coarse_res,
258 .clock_get = posix_get_realtime_coarse,
260 struct k_clock clock_monotonic_coarse = {
261 .clock_getres = posix_get_coarse_res,
262 .clock_get = posix_get_monotonic_coarse,
264 struct k_clock clock_boottime = {
265 .clock_getres = hrtimer_get_res,
266 .clock_get = posix_get_boottime,
267 .nsleep = common_nsleep,
268 .nsleep_restart = hrtimer_nanosleep_restart,
269 .timer_create = common_timer_create,
270 .timer_set = common_timer_set,
271 .timer_get = common_timer_get,
272 .timer_del = common_timer_del,
275 posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime);
276 posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic);
277 posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
278 posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
279 posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
280 posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime);
282 posix_timers_cache = kmem_cache_create("posix_timers_cache",
283 sizeof (struct k_itimer), 0, SLAB_PANIC,
284 NULL);
285 idr_init(&posix_timers_id);
286 return 0;
289 __initcall(init_posix_timers);
291 static void schedule_next_timer(struct k_itimer *timr)
293 struct hrtimer *timer = &timr->it.real.timer;
295 if (timr->it.real.interval.tv64 == 0)
296 return;
298 timr->it_overrun += (unsigned int) hrtimer_forward(timer,
299 timer->base->get_time(),
300 timr->it.real.interval);
302 timr->it_overrun_last = timr->it_overrun;
303 timr->it_overrun = -1;
304 ++timr->it_requeue_pending;
305 hrtimer_restart(timer);
309 * This function is exported for use by the signal deliver code. It is
310 * called just prior to the info block being released and passes that
311 * block to us. It's function is to update the overrun entry AND to
312 * restart the timer. It should only be called if the timer is to be
313 * restarted (i.e. we have flagged this in the sys_private entry of the
314 * info block).
316 * To protect against the timer going away while the interrupt is queued,
317 * we require that the it_requeue_pending flag be set.
319 void do_schedule_next_timer(struct siginfo *info)
321 struct k_itimer *timr;
322 unsigned long flags;
324 timr = lock_timer(info->si_tid, &flags);
326 if (timr && timr->it_requeue_pending == info->si_sys_private) {
327 if (timr->it_clock < 0)
328 posix_cpu_timer_schedule(timr);
329 else
330 schedule_next_timer(timr);
332 info->si_overrun += timr->it_overrun_last;
335 if (timr)
336 unlock_timer(timr, flags);
339 int posix_timer_event(struct k_itimer *timr, int si_private)
341 struct task_struct *task;
342 int shared, ret = -1;
344 * FIXME: if ->sigq is queued we can race with
345 * dequeue_signal()->do_schedule_next_timer().
347 * If dequeue_signal() sees the "right" value of
348 * si_sys_private it calls do_schedule_next_timer().
349 * We re-queue ->sigq and drop ->it_lock().
350 * do_schedule_next_timer() locks the timer
351 * and re-schedules it while ->sigq is pending.
352 * Not really bad, but not that we want.
354 timr->sigq->info.si_sys_private = si_private;
356 rcu_read_lock();
357 task = pid_task(timr->it_pid, PIDTYPE_PID);
358 if (task) {
359 shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
360 ret = send_sigqueue(timr->sigq, task, shared);
362 rcu_read_unlock();
363 /* If we failed to send the signal the timer stops. */
364 return ret > 0;
366 EXPORT_SYMBOL_GPL(posix_timer_event);
369 * This function gets called when a POSIX.1b interval timer expires. It
370 * is used as a callback from the kernel internal timer. The
371 * run_timer_list code ALWAYS calls with interrupts on.
373 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
375 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
377 struct k_itimer *timr;
378 unsigned long flags;
379 int si_private = 0;
380 enum hrtimer_restart ret = HRTIMER_NORESTART;
382 timr = container_of(timer, struct k_itimer, it.real.timer);
383 spin_lock_irqsave(&timr->it_lock, flags);
385 if (timr->it.real.interval.tv64 != 0)
386 si_private = ++timr->it_requeue_pending;
388 if (posix_timer_event(timr, si_private)) {
390 * signal was not sent because of sig_ignor
391 * we will not get a call back to restart it AND
392 * it should be restarted.
394 if (timr->it.real.interval.tv64 != 0) {
395 ktime_t now = hrtimer_cb_get_time(timer);
398 * FIXME: What we really want, is to stop this
399 * timer completely and restart it in case the
400 * SIG_IGN is removed. This is a non trivial
401 * change which involves sighand locking
402 * (sigh !), which we don't want to do late in
403 * the release cycle.
405 * For now we just let timers with an interval
406 * less than a jiffie expire every jiffie to
407 * avoid softirq starvation in case of SIG_IGN
408 * and a very small interval, which would put
409 * the timer right back on the softirq pending
410 * list. By moving now ahead of time we trick
411 * hrtimer_forward() to expire the timer
412 * later, while we still maintain the overrun
413 * accuracy, but have some inconsistency in
414 * the timer_gettime() case. This is at least
415 * better than a starved softirq. A more
416 * complex fix which solves also another related
417 * inconsistency is already in the pipeline.
419 #ifdef CONFIG_HIGH_RES_TIMERS
421 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
423 if (timr->it.real.interval.tv64 < kj.tv64)
424 now = ktime_add(now, kj);
426 #endif
427 timr->it_overrun += (unsigned int)
428 hrtimer_forward(timer, now,
429 timr->it.real.interval);
430 ret = HRTIMER_RESTART;
431 ++timr->it_requeue_pending;
435 unlock_timer(timr, flags);
436 return ret;
439 static struct pid *good_sigevent(sigevent_t * event)
441 struct task_struct *rtn = current->group_leader;
443 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
444 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
445 !same_thread_group(rtn, current) ||
446 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
447 return NULL;
449 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
450 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
451 return NULL;
453 return task_pid(rtn);
456 void posix_timers_register_clock(const clockid_t clock_id,
457 struct k_clock *new_clock)
459 if ((unsigned) clock_id >= MAX_CLOCKS) {
460 printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
461 clock_id);
462 return;
465 if (!new_clock->clock_get) {
466 printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
467 clock_id);
468 return;
470 if (!new_clock->clock_getres) {
471 printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
472 clock_id);
473 return;
476 posix_clocks[clock_id] = *new_clock;
478 EXPORT_SYMBOL_GPL(posix_timers_register_clock);
480 static struct k_itimer * alloc_posix_timer(void)
482 struct k_itimer *tmr;
483 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
484 if (!tmr)
485 return tmr;
486 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
487 kmem_cache_free(posix_timers_cache, tmr);
488 return NULL;
490 memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
491 return tmr;
494 #define IT_ID_SET 1
495 #define IT_ID_NOT_SET 0
496 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
498 if (it_id_set) {
499 unsigned long flags;
500 spin_lock_irqsave(&idr_lock, flags);
501 idr_remove(&posix_timers_id, tmr->it_id);
502 spin_unlock_irqrestore(&idr_lock, flags);
504 put_pid(tmr->it_pid);
505 sigqueue_free(tmr->sigq);
506 kmem_cache_free(posix_timers_cache, tmr);
509 static struct k_clock *clockid_to_kclock(const clockid_t id)
511 if (id < 0)
512 return (id & CLOCKFD_MASK) == CLOCKFD ?
513 &clock_posix_dynamic : &clock_posix_cpu;
515 if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
516 return NULL;
517 return &posix_clocks[id];
520 static int common_timer_create(struct k_itimer *new_timer)
522 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
523 return 0;
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_clock *kc = clockid_to_kclock(which_clock);
533 struct k_itimer *new_timer;
534 int error, new_timer_id;
535 sigevent_t event;
536 int it_id_set = IT_ID_NOT_SET;
538 if (!kc)
539 return -EINVAL;
540 if (!kc->timer_create)
541 return -EOPNOTSUPP;
543 new_timer = alloc_posix_timer();
544 if (unlikely(!new_timer))
545 return -EAGAIN;
547 spin_lock_init(&new_timer->it_lock);
548 retry:
549 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
550 error = -EAGAIN;
551 goto out;
553 spin_lock_irq(&idr_lock);
554 error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
555 spin_unlock_irq(&idr_lock);
556 if (error) {
557 if (error == -EAGAIN)
558 goto retry;
560 * Weird looking, but we return EAGAIN if the IDR is
561 * full (proper POSIX return value for this)
563 error = -EAGAIN;
564 goto out;
567 it_id_set = IT_ID_SET;
568 new_timer->it_id = (timer_t) new_timer_id;
569 new_timer->it_clock = which_clock;
570 new_timer->it_overrun = -1;
572 if (timer_event_spec) {
573 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
574 error = -EFAULT;
575 goto out;
577 rcu_read_lock();
578 new_timer->it_pid = get_pid(good_sigevent(&event));
579 rcu_read_unlock();
580 if (!new_timer->it_pid) {
581 error = -EINVAL;
582 goto out;
584 } else {
585 event.sigev_notify = SIGEV_SIGNAL;
586 event.sigev_signo = SIGALRM;
587 event.sigev_value.sival_int = new_timer->it_id;
588 new_timer->it_pid = get_pid(task_tgid(current));
591 new_timer->it_sigev_notify = event.sigev_notify;
592 new_timer->sigq->info.si_signo = event.sigev_signo;
593 new_timer->sigq->info.si_value = event.sigev_value;
594 new_timer->sigq->info.si_tid = new_timer->it_id;
595 new_timer->sigq->info.si_code = SI_TIMER;
597 if (copy_to_user(created_timer_id,
598 &new_timer_id, sizeof (new_timer_id))) {
599 error = -EFAULT;
600 goto out;
603 error = kc->timer_create(new_timer);
604 if (error)
605 goto out;
607 spin_lock_irq(&current->sighand->siglock);
608 new_timer->it_signal = current->signal;
609 list_add(&new_timer->list, &current->signal->posix_timers);
610 spin_unlock_irq(&current->sighand->siglock);
612 return 0;
614 * In the case of the timer belonging to another task, after
615 * the task is unlocked, the timer is owned by the other task
616 * and may cease to exist at any time. Don't use or modify
617 * new_timer after the unlock call.
619 out:
620 release_posix_timer(new_timer, it_id_set);
621 return error;
625 * Locking issues: We need to protect the result of the id look up until
626 * we get the timer locked down so it is not deleted under us. The
627 * removal is done under the idr spinlock so we use that here to bridge
628 * the find to the timer lock. To avoid a dead lock, the timer id MUST
629 * be release with out holding the timer lock.
631 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
633 struct k_itimer *timr;
635 * Watch out here. We do a irqsave on the idr_lock and pass the
636 * flags part over to the timer lock. Must not let interrupts in
637 * while we are moving the lock.
639 spin_lock_irqsave(&idr_lock, *flags);
640 timr = idr_find(&posix_timers_id, (int)timer_id);
641 if (timr) {
642 spin_lock(&timr->it_lock);
643 if (timr->it_signal == current->signal) {
644 spin_unlock(&idr_lock);
645 return timr;
647 spin_unlock(&timr->it_lock);
649 spin_unlock_irqrestore(&idr_lock, *flags);
651 return NULL;
655 * Get the time remaining on a POSIX.1b interval timer. This function
656 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
657 * mess with irq.
659 * We have a couple of messes to clean up here. First there is the case
660 * of a timer that has a requeue pending. These timers should appear to
661 * be in the timer list with an expiry as if we were to requeue them
662 * now.
664 * The second issue is the SIGEV_NONE timer which may be active but is
665 * not really ever put in the timer list (to save system resources).
666 * This timer may be expired, and if so, we will do it here. Otherwise
667 * it is the same as a requeue pending timer WRT to what we should
668 * report.
670 static void
671 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
673 ktime_t now, remaining, iv;
674 struct hrtimer *timer = &timr->it.real.timer;
676 memset(cur_setting, 0, sizeof(struct itimerspec));
678 iv = timr->it.real.interval;
680 /* interval timer ? */
681 if (iv.tv64)
682 cur_setting->it_interval = ktime_to_timespec(iv);
683 else if (!hrtimer_active(timer) &&
684 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
685 return;
687 now = timer->base->get_time();
690 * When a requeue is pending or this is a SIGEV_NONE
691 * timer move the expiry time forward by intervals, so
692 * expiry is > now.
694 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
695 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
696 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
698 remaining = ktime_sub(hrtimer_get_expires(timer), now);
699 /* Return 0 only, when the timer is expired and not pending */
700 if (remaining.tv64 <= 0) {
702 * A single shot SIGEV_NONE timer must return 0, when
703 * it is expired !
705 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
706 cur_setting->it_value.tv_nsec = 1;
707 } else
708 cur_setting->it_value = ktime_to_timespec(remaining);
711 /* Get the time remaining on a POSIX.1b interval timer. */
712 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
713 struct itimerspec __user *, setting)
715 struct itimerspec cur_setting;
716 struct k_itimer *timr;
717 struct k_clock *kc;
718 unsigned long flags;
719 int ret = 0;
721 timr = lock_timer(timer_id, &flags);
722 if (!timr)
723 return -EINVAL;
725 kc = clockid_to_kclock(timr->it_clock);
726 if (WARN_ON_ONCE(!kc || !kc->timer_get))
727 ret = -EINVAL;
728 else
729 kc->timer_get(timr, &cur_setting);
731 unlock_timer(timr, flags);
733 if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
734 return -EFAULT;
736 return ret;
740 * Get the number of overruns of a POSIX.1b interval timer. This is to
741 * be the overrun of the timer last delivered. At the same time we are
742 * accumulating overruns on the next timer. The overrun is frozen when
743 * the signal is delivered, either at the notify time (if the info block
744 * is not queued) or at the actual delivery time (as we are informed by
745 * the call back to do_schedule_next_timer(). So all we need to do is
746 * to pick up the frozen overrun.
748 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
750 struct k_itimer *timr;
751 int overrun;
752 unsigned long flags;
754 timr = lock_timer(timer_id, &flags);
755 if (!timr)
756 return -EINVAL;
758 overrun = timr->it_overrun_last;
759 unlock_timer(timr, flags);
761 return overrun;
764 /* Set a POSIX.1b interval timer. */
765 /* timr->it_lock is taken. */
766 static int
767 common_timer_set(struct k_itimer *timr, int flags,
768 struct itimerspec *new_setting, struct itimerspec *old_setting)
770 struct hrtimer *timer = &timr->it.real.timer;
771 enum hrtimer_mode mode;
773 if (old_setting)
774 common_timer_get(timr, old_setting);
776 /* disable the timer */
777 timr->it.real.interval.tv64 = 0;
779 * careful here. If smp we could be in the "fire" routine which will
780 * be spinning as we hold the lock. But this is ONLY an SMP issue.
782 if (hrtimer_try_to_cancel(timer) < 0)
783 return TIMER_RETRY;
785 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
786 ~REQUEUE_PENDING;
787 timr->it_overrun_last = 0;
789 /* switch off the timer when it_value is zero */
790 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
791 return 0;
793 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
794 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
795 timr->it.real.timer.function = posix_timer_fn;
797 hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
799 /* Convert interval */
800 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
802 /* SIGEV_NONE timers are not queued ! See common_timer_get */
803 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
804 /* Setup correct expiry time for relative timers */
805 if (mode == HRTIMER_MODE_REL) {
806 hrtimer_add_expires(timer, timer->base->get_time());
808 return 0;
811 hrtimer_start_expires(timer, mode);
812 return 0;
815 /* Set a POSIX.1b interval timer */
816 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
817 const struct itimerspec __user *, new_setting,
818 struct itimerspec __user *, old_setting)
820 struct k_itimer *timr;
821 struct itimerspec new_spec, old_spec;
822 int error = 0;
823 unsigned long flag;
824 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
825 struct k_clock *kc;
827 if (!new_setting)
828 return -EINVAL;
830 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
831 return -EFAULT;
833 if (!timespec_valid(&new_spec.it_interval) ||
834 !timespec_valid(&new_spec.it_value))
835 return -EINVAL;
836 retry:
837 timr = lock_timer(timer_id, &flag);
838 if (!timr)
839 return -EINVAL;
841 kc = clockid_to_kclock(timr->it_clock);
842 if (WARN_ON_ONCE(!kc || !kc->timer_set))
843 error = -EINVAL;
844 else
845 error = kc->timer_set(timr, flags, &new_spec, rtn);
847 unlock_timer(timr, flag);
848 if (error == TIMER_RETRY) {
849 rtn = NULL; // We already got the old time...
850 goto retry;
853 if (old_setting && !error &&
854 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
855 error = -EFAULT;
857 return error;
860 static int common_timer_del(struct k_itimer *timer)
862 timer->it.real.interval.tv64 = 0;
864 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
865 return TIMER_RETRY;
866 return 0;
869 static inline int timer_delete_hook(struct k_itimer *timer)
871 struct k_clock *kc = clockid_to_kclock(timer->it_clock);
873 if (WARN_ON_ONCE(!kc || !kc->timer_del))
874 return -EINVAL;
875 return kc->timer_del(timer);
878 /* Delete a POSIX.1b interval timer. */
879 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
881 struct k_itimer *timer;
882 unsigned long flags;
884 retry_delete:
885 timer = lock_timer(timer_id, &flags);
886 if (!timer)
887 return -EINVAL;
889 if (timer_delete_hook(timer) == TIMER_RETRY) {
890 unlock_timer(timer, flags);
891 goto retry_delete;
894 spin_lock(&current->sighand->siglock);
895 list_del(&timer->list);
896 spin_unlock(&current->sighand->siglock);
898 * This keeps any tasks waiting on the spin lock from thinking
899 * they got something (see the lock code above).
901 timer->it_signal = NULL;
903 unlock_timer(timer, flags);
904 release_posix_timer(timer, IT_ID_SET);
905 return 0;
909 * return timer owned by the process, used by exit_itimers
911 static void itimer_delete(struct k_itimer *timer)
913 unsigned long flags;
915 retry_delete:
916 spin_lock_irqsave(&timer->it_lock, flags);
918 if (timer_delete_hook(timer) == TIMER_RETRY) {
919 unlock_timer(timer, flags);
920 goto retry_delete;
922 list_del(&timer->list);
924 * This keeps any tasks waiting on the spin lock from thinking
925 * they got something (see the lock code above).
927 timer->it_signal = NULL;
929 unlock_timer(timer, flags);
930 release_posix_timer(timer, IT_ID_SET);
934 * This is called by do_exit or de_thread, only when there are no more
935 * references to the shared signal_struct.
937 void exit_itimers(struct signal_struct *sig)
939 struct k_itimer *tmr;
941 while (!list_empty(&sig->posix_timers)) {
942 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
943 itimer_delete(tmr);
947 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
948 const struct timespec __user *, tp)
950 struct k_clock *kc = clockid_to_kclock(which_clock);
951 struct timespec new_tp;
953 if (!kc || !kc->clock_set)
954 return -EINVAL;
956 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
957 return -EFAULT;
959 return kc->clock_set(which_clock, &new_tp);
962 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
963 struct timespec __user *,tp)
965 struct k_clock *kc = clockid_to_kclock(which_clock);
966 struct timespec kernel_tp;
967 int error;
969 if (!kc)
970 return -EINVAL;
972 error = kc->clock_get(which_clock, &kernel_tp);
974 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
975 error = -EFAULT;
977 return error;
980 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
981 struct timex __user *, utx)
983 struct k_clock *kc = clockid_to_kclock(which_clock);
984 struct timex ktx;
985 int err;
987 if (!kc)
988 return -EINVAL;
989 if (!kc->clock_adj)
990 return -EOPNOTSUPP;
992 if (copy_from_user(&ktx, utx, sizeof(ktx)))
993 return -EFAULT;
995 err = kc->clock_adj(which_clock, &ktx);
997 if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
998 return -EFAULT;
1000 return err;
1003 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1004 struct timespec __user *, tp)
1006 struct k_clock *kc = clockid_to_kclock(which_clock);
1007 struct timespec rtn_tp;
1008 int error;
1010 if (!kc)
1011 return -EINVAL;
1013 error = kc->clock_getres(which_clock, &rtn_tp);
1015 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
1016 error = -EFAULT;
1018 return error;
1022 * nanosleep for monotonic and realtime clocks
1024 static int common_nsleep(const clockid_t which_clock, int flags,
1025 struct timespec *tsave, struct timespec __user *rmtp)
1027 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
1028 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1029 which_clock);
1032 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1033 const struct timespec __user *, rqtp,
1034 struct timespec __user *, rmtp)
1036 struct k_clock *kc = clockid_to_kclock(which_clock);
1037 struct timespec t;
1039 if (!kc)
1040 return -EINVAL;
1041 if (!kc->nsleep)
1042 return -ENANOSLEEP_NOTSUP;
1044 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
1045 return -EFAULT;
1047 if (!timespec_valid(&t))
1048 return -EINVAL;
1050 return kc->nsleep(which_clock, flags, &t, rmtp);
1054 * This will restart clock_nanosleep. This is required only by
1055 * compat_clock_nanosleep_restart for now.
1057 long clock_nanosleep_restart(struct restart_block *restart_block)
1059 clockid_t which_clock = restart_block->nanosleep.index;
1060 struct k_clock *kc = clockid_to_kclock(which_clock);
1062 if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
1063 return -EINVAL;
1065 return kc->nsleep_restart(restart_block);