[PATCH 2/2] proc: switch inode number allocation to IDA
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / posix-timers.c
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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-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
57 * related it to <ptr>
58 * void idr_remove(struct idr *idp, int id); to release <id>
59 * void idr_init(struct idr *idp); to initialize <idp>
60 * which we supply.
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!"
82 #endif
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,
172 struct timespec *tp)
174 tp->tv_sec = 0;
175 tp->tv_nsec = posix_clocks[which_clock].res;
176 return 0;
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);
185 return 0;
188 static inline int common_clock_set(const clockid_t which_clock,
189 struct timespec *tp)
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);
197 return 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 */
206 return 0;
207 if ((unsigned) which_clock >= MAX_CLOCKS)
208 return 1;
209 if (posix_clocks[which_clock].clock_getres != NULL)
210 return 0;
211 if (posix_clocks[which_clock].res != 0)
212 return 0;
213 return 1;
217 * Get monotonic time for posix timers
219 static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
221 ktime_get_ts(tp);
222 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,
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,
244 NULL);
245 idr_init(&posix_timers_id);
246 return 0;
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)
256 return;
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
274 * info block).
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;
282 unsigned long flags;
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);
289 else
290 schedule_next_timer(timr);
292 info->si_overrun = timr->it_overrun_last;
295 if (timr)
296 unlock_timer(timr, flags);
299 int posix_timer_event(struct k_itimer *timr,int si_private)
301 memset(&timr->sigq->info, 0, sizeof(siginfo_t));
302 timr->sigq->info.si_sys_private = si_private;
303 /* Send signal to the process that owns this timer.*/
305 timr->sigq->info.si_signo = timr->it_sigev_signo;
306 timr->sigq->info.si_errno = 0;
307 timr->sigq->info.si_code = SI_TIMER;
308 timr->sigq->info.si_tid = timr->it_id;
309 timr->sigq->info.si_value = timr->it_sigev_value;
311 if (timr->it_sigev_notify & SIGEV_THREAD_ID) {
312 struct task_struct *leader;
313 int ret = send_sigqueue(timr->sigq, timr->it_process, 0);
315 if (likely(ret >= 0))
316 return ret;
318 timr->it_sigev_notify = SIGEV_SIGNAL;
319 leader = timr->it_process->group_leader;
320 put_task_struct(timr->it_process);
321 timr->it_process = leader;
324 return send_sigqueue(timr->sigq, timr->it_process, 1);
326 EXPORT_SYMBOL_GPL(posix_timer_event);
329 * This function gets called when a POSIX.1b interval timer expires. It
330 * is used as a callback from the kernel internal timer. The
331 * run_timer_list code ALWAYS calls with interrupts on.
333 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
335 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
337 struct k_itimer *timr;
338 unsigned long flags;
339 int si_private = 0;
340 enum hrtimer_restart ret = HRTIMER_NORESTART;
342 timr = container_of(timer, struct k_itimer, it.real.timer);
343 spin_lock_irqsave(&timr->it_lock, flags);
345 if (timr->it.real.interval.tv64 != 0)
346 si_private = ++timr->it_requeue_pending;
348 if (posix_timer_event(timr, si_private)) {
350 * signal was not sent because of sig_ignor
351 * we will not get a call back to restart it AND
352 * it should be restarted.
354 if (timr->it.real.interval.tv64 != 0) {
355 ktime_t now = hrtimer_cb_get_time(timer);
358 * FIXME: What we really want, is to stop this
359 * timer completely and restart it in case the
360 * SIG_IGN is removed. This is a non trivial
361 * change which involves sighand locking
362 * (sigh !), which we don't want to do late in
363 * the release cycle.
365 * For now we just let timers with an interval
366 * less than a jiffie expire every jiffie to
367 * avoid softirq starvation in case of SIG_IGN
368 * and a very small interval, which would put
369 * the timer right back on the softirq pending
370 * list. By moving now ahead of time we trick
371 * hrtimer_forward() to expire the timer
372 * later, while we still maintain the overrun
373 * accuracy, but have some inconsistency in
374 * the timer_gettime() case. This is at least
375 * better than a starved softirq. A more
376 * complex fix which solves also another related
377 * inconsistency is already in the pipeline.
379 #ifdef CONFIG_HIGH_RES_TIMERS
381 ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
383 if (timr->it.real.interval.tv64 < kj.tv64)
384 now = ktime_add(now, kj);
386 #endif
387 timr->it_overrun += (unsigned int)
388 hrtimer_forward(timer, now,
389 timr->it.real.interval);
390 ret = HRTIMER_RESTART;
391 ++timr->it_requeue_pending;
395 unlock_timer(timr, flags);
396 return ret;
399 static struct task_struct * good_sigevent(sigevent_t * event)
401 struct task_struct *rtn = current->group_leader;
403 if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
404 (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
405 !same_thread_group(rtn, current) ||
406 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
407 return NULL;
409 if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
410 ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
411 return NULL;
413 return rtn;
416 void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
418 if ((unsigned) clock_id >= MAX_CLOCKS) {
419 printk("POSIX clock register failed for clock_id %d\n",
420 clock_id);
421 return;
424 posix_clocks[clock_id] = *new_clock;
426 EXPORT_SYMBOL_GPL(register_posix_clock);
428 static struct k_itimer * alloc_posix_timer(void)
430 struct k_itimer *tmr;
431 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
432 if (!tmr)
433 return tmr;
434 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
435 kmem_cache_free(posix_timers_cache, tmr);
436 tmr = NULL;
438 return tmr;
441 #define IT_ID_SET 1
442 #define IT_ID_NOT_SET 0
443 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
445 if (it_id_set) {
446 unsigned long flags;
447 spin_lock_irqsave(&idr_lock, flags);
448 idr_remove(&posix_timers_id, tmr->it_id);
449 spin_unlock_irqrestore(&idr_lock, flags);
451 sigqueue_free(tmr->sigq);
452 kmem_cache_free(posix_timers_cache, tmr);
455 /* Create a POSIX.1b interval timer. */
457 asmlinkage long
458 sys_timer_create(const clockid_t which_clock,
459 struct sigevent __user *timer_event_spec,
460 timer_t __user * created_timer_id)
462 int error = 0;
463 struct k_itimer *new_timer = NULL;
464 int new_timer_id;
465 struct task_struct *process = NULL;
466 unsigned long flags;
467 sigevent_t event;
468 int it_id_set = IT_ID_NOT_SET;
470 if (invalid_clockid(which_clock))
471 return -EINVAL;
473 new_timer = alloc_posix_timer();
474 if (unlikely(!new_timer))
475 return -EAGAIN;
477 spin_lock_init(&new_timer->it_lock);
478 retry:
479 if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
480 error = -EAGAIN;
481 goto out;
483 spin_lock_irq(&idr_lock);
484 error = idr_get_new(&posix_timers_id, (void *) new_timer,
485 &new_timer_id);
486 spin_unlock_irq(&idr_lock);
487 if (error == -EAGAIN)
488 goto retry;
489 else if (error) {
491 * Weird looking, but we return EAGAIN if the IDR is
492 * full (proper POSIX return value for this)
494 error = -EAGAIN;
495 goto out;
498 it_id_set = IT_ID_SET;
499 new_timer->it_id = (timer_t) new_timer_id;
500 new_timer->it_clock = which_clock;
501 new_timer->it_overrun = -1;
502 error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
503 if (error)
504 goto out;
507 * return the timer_id now. The next step is hard to
508 * back out if there is an error.
510 if (copy_to_user(created_timer_id,
511 &new_timer_id, sizeof (new_timer_id))) {
512 error = -EFAULT;
513 goto out;
515 if (timer_event_spec) {
516 if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
517 error = -EFAULT;
518 goto out;
520 new_timer->it_sigev_notify = event.sigev_notify;
521 new_timer->it_sigev_signo = event.sigev_signo;
522 new_timer->it_sigev_value = event.sigev_value;
524 read_lock(&tasklist_lock);
525 if ((process = good_sigevent(&event))) {
527 * We may be setting up this process for another
528 * thread. It may be exiting. To catch this
529 * case the we check the PF_EXITING flag. If
530 * the flag is not set, the siglock will catch
531 * him before it is too late (in exit_itimers).
533 * The exec case is a bit more invloved but easy
534 * to code. If the process is in our thread
535 * group (and it must be or we would not allow
536 * it here) and is doing an exec, it will cause
537 * us to be killed. In this case it will wait
538 * for us to die which means we can finish this
539 * linkage with our last gasp. I.e. no code :)
541 spin_lock_irqsave(&process->sighand->siglock, flags);
542 if (!(process->flags & PF_EXITING)) {
543 new_timer->it_process = process;
544 list_add(&new_timer->list,
545 &process->signal->posix_timers);
546 if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
547 get_task_struct(process);
548 spin_unlock_irqrestore(&process->sighand->siglock, flags);
549 } else {
550 spin_unlock_irqrestore(&process->sighand->siglock, flags);
551 process = NULL;
554 read_unlock(&tasklist_lock);
555 if (!process) {
556 error = -EINVAL;
557 goto out;
559 } else {
560 new_timer->it_sigev_notify = SIGEV_SIGNAL;
561 new_timer->it_sigev_signo = SIGALRM;
562 new_timer->it_sigev_value.sival_int = new_timer->it_id;
563 process = current->group_leader;
564 spin_lock_irqsave(&process->sighand->siglock, flags);
565 new_timer->it_process = process;
566 list_add(&new_timer->list, &process->signal->posix_timers);
567 spin_unlock_irqrestore(&process->sighand->siglock, flags);
571 * In the case of the timer belonging to another task, after
572 * the task is unlocked, the timer is owned by the other task
573 * and may cease to exist at any time. Don't use or modify
574 * new_timer after the unlock call.
577 out:
578 if (error)
579 release_posix_timer(new_timer, it_id_set);
581 return error;
585 * Locking issues: We need to protect the result of the id look up until
586 * we get the timer locked down so it is not deleted under us. The
587 * removal is done under the idr spinlock so we use that here to bridge
588 * the find to the timer lock. To avoid a dead lock, the timer id MUST
589 * be release with out holding the timer lock.
591 static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags)
593 struct k_itimer *timr;
595 * Watch out here. We do a irqsave on the idr_lock and pass the
596 * flags part over to the timer lock. Must not let interrupts in
597 * while we are moving the lock.
600 spin_lock_irqsave(&idr_lock, *flags);
601 timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id);
602 if (timr) {
603 spin_lock(&timr->it_lock);
605 if ((timr->it_id != timer_id) || !(timr->it_process) ||
606 !same_thread_group(timr->it_process, current)) {
607 spin_unlock(&timr->it_lock);
608 spin_unlock_irqrestore(&idr_lock, *flags);
609 timr = NULL;
610 } else
611 spin_unlock(&idr_lock);
612 } else
613 spin_unlock_irqrestore(&idr_lock, *flags);
615 return timr;
619 * Get the time remaining on a POSIX.1b interval timer. This function
620 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
621 * mess with irq.
623 * We have a couple of messes to clean up here. First there is the case
624 * of a timer that has a requeue pending. These timers should appear to
625 * be in the timer list with an expiry as if we were to requeue them
626 * now.
628 * The second issue is the SIGEV_NONE timer which may be active but is
629 * not really ever put in the timer list (to save system resources).
630 * This timer may be expired, and if so, we will do it here. Otherwise
631 * it is the same as a requeue pending timer WRT to what we should
632 * report.
634 static void
635 common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
637 ktime_t now, remaining, iv;
638 struct hrtimer *timer = &timr->it.real.timer;
640 memset(cur_setting, 0, sizeof(struct itimerspec));
642 iv = timr->it.real.interval;
644 /* interval timer ? */
645 if (iv.tv64)
646 cur_setting->it_interval = ktime_to_timespec(iv);
647 else if (!hrtimer_active(timer) &&
648 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
649 return;
651 now = timer->base->get_time();
654 * When a requeue is pending or this is a SIGEV_NONE
655 * timer move the expiry time forward by intervals, so
656 * expiry is > now.
658 if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
659 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
660 timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
662 remaining = ktime_sub(timer->expires, now);
663 /* Return 0 only, when the timer is expired and not pending */
664 if (remaining.tv64 <= 0) {
666 * A single shot SIGEV_NONE timer must return 0, when
667 * it is expired !
669 if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
670 cur_setting->it_value.tv_nsec = 1;
671 } else
672 cur_setting->it_value = ktime_to_timespec(remaining);
675 /* Get the time remaining on a POSIX.1b interval timer. */
676 asmlinkage long
677 sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting)
679 struct k_itimer *timr;
680 struct itimerspec cur_setting;
681 unsigned long flags;
683 timr = lock_timer(timer_id, &flags);
684 if (!timr)
685 return -EINVAL;
687 CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting));
689 unlock_timer(timr, flags);
691 if (copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
692 return -EFAULT;
694 return 0;
698 * Get the number of overruns of a POSIX.1b interval timer. This is to
699 * be the overrun of the timer last delivered. At the same time we are
700 * accumulating overruns on the next timer. The overrun is frozen when
701 * the signal is delivered, either at the notify time (if the info block
702 * is not queued) or at the actual delivery time (as we are informed by
703 * the call back to do_schedule_next_timer(). So all we need to do is
704 * to pick up the frozen overrun.
706 asmlinkage long
707 sys_timer_getoverrun(timer_t timer_id)
709 struct k_itimer *timr;
710 int overrun;
711 unsigned long flags;
713 timr = lock_timer(timer_id, &flags);
714 if (!timr)
715 return -EINVAL;
717 overrun = timr->it_overrun_last;
718 unlock_timer(timr, flags);
720 return overrun;
723 /* Set a POSIX.1b interval timer. */
724 /* timr->it_lock is taken. */
725 static int
726 common_timer_set(struct k_itimer *timr, int flags,
727 struct itimerspec *new_setting, struct itimerspec *old_setting)
729 struct hrtimer *timer = &timr->it.real.timer;
730 enum hrtimer_mode mode;
732 if (old_setting)
733 common_timer_get(timr, old_setting);
735 /* disable the timer */
736 timr->it.real.interval.tv64 = 0;
738 * careful here. If smp we could be in the "fire" routine which will
739 * be spinning as we hold the lock. But this is ONLY an SMP issue.
741 if (hrtimer_try_to_cancel(timer) < 0)
742 return TIMER_RETRY;
744 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
745 ~REQUEUE_PENDING;
746 timr->it_overrun_last = 0;
748 /* switch off the timer when it_value is zero */
749 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
750 return 0;
752 mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
753 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
754 timr->it.real.timer.function = posix_timer_fn;
756 timer->expires = timespec_to_ktime(new_setting->it_value);
758 /* Convert interval */
759 timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
761 /* SIGEV_NONE timers are not queued ! See common_timer_get */
762 if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
763 /* Setup correct expiry time for relative timers */
764 if (mode == HRTIMER_MODE_REL) {
765 timer->expires =
766 ktime_add_safe(timer->expires,
767 timer->base->get_time());
769 return 0;
772 hrtimer_start(timer, timer->expires, mode);
773 return 0;
776 /* Set a POSIX.1b interval timer */
777 asmlinkage long
778 sys_timer_settime(timer_t timer_id, int flags,
779 const struct itimerspec __user *new_setting,
780 struct itimerspec __user *old_setting)
782 struct k_itimer *timr;
783 struct itimerspec new_spec, old_spec;
784 int error = 0;
785 unsigned long flag;
786 struct itimerspec *rtn = old_setting ? &old_spec : NULL;
788 if (!new_setting)
789 return -EINVAL;
791 if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
792 return -EFAULT;
794 if (!timespec_valid(&new_spec.it_interval) ||
795 !timespec_valid(&new_spec.it_value))
796 return -EINVAL;
797 retry:
798 timr = lock_timer(timer_id, &flag);
799 if (!timr)
800 return -EINVAL;
802 error = CLOCK_DISPATCH(timr->it_clock, timer_set,
803 (timr, flags, &new_spec, rtn));
805 unlock_timer(timr, flag);
806 if (error == TIMER_RETRY) {
807 rtn = NULL; // We already got the old time...
808 goto retry;
811 if (old_setting && !error &&
812 copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
813 error = -EFAULT;
815 return error;
818 static inline int common_timer_del(struct k_itimer *timer)
820 timer->it.real.interval.tv64 = 0;
822 if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
823 return TIMER_RETRY;
824 return 0;
827 static inline int timer_delete_hook(struct k_itimer *timer)
829 return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer));
832 /* Delete a POSIX.1b interval timer. */
833 asmlinkage long
834 sys_timer_delete(timer_t timer_id)
836 struct k_itimer *timer;
837 unsigned long flags;
839 retry_delete:
840 timer = lock_timer(timer_id, &flags);
841 if (!timer)
842 return -EINVAL;
844 if (timer_delete_hook(timer) == TIMER_RETRY) {
845 unlock_timer(timer, flags);
846 goto retry_delete;
849 spin_lock(&current->sighand->siglock);
850 list_del(&timer->list);
851 spin_unlock(&current->sighand->siglock);
853 * This keeps any tasks waiting on the spin lock from thinking
854 * they got something (see the lock code above).
856 if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
857 put_task_struct(timer->it_process);
858 timer->it_process = NULL;
860 unlock_timer(timer, flags);
861 release_posix_timer(timer, IT_ID_SET);
862 return 0;
866 * return timer owned by the process, used by exit_itimers
868 static void itimer_delete(struct k_itimer *timer)
870 unsigned long flags;
872 retry_delete:
873 spin_lock_irqsave(&timer->it_lock, flags);
875 if (timer_delete_hook(timer) == TIMER_RETRY) {
876 unlock_timer(timer, flags);
877 goto retry_delete;
879 list_del(&timer->list);
881 * This keeps any tasks waiting on the spin lock from thinking
882 * they got something (see the lock code above).
884 if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
885 put_task_struct(timer->it_process);
886 timer->it_process = NULL;
888 unlock_timer(timer, flags);
889 release_posix_timer(timer, IT_ID_SET);
893 * This is called by do_exit or de_thread, only when there are no more
894 * references to the shared signal_struct.
896 void exit_itimers(struct signal_struct *sig)
898 struct k_itimer *tmr;
900 while (!list_empty(&sig->posix_timers)) {
901 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
902 itimer_delete(tmr);
906 /* Not available / possible... functions */
907 int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
909 return -EINVAL;
911 EXPORT_SYMBOL_GPL(do_posix_clock_nosettime);
913 int do_posix_clock_nonanosleep(const clockid_t clock, int flags,
914 struct timespec *t, struct timespec __user *r)
916 #ifndef ENOTSUP
917 return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */
918 #else /* parisc does define it separately. */
919 return -ENOTSUP;
920 #endif
922 EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep);
924 asmlinkage long sys_clock_settime(const clockid_t which_clock,
925 const struct timespec __user *tp)
927 struct timespec new_tp;
929 if (invalid_clockid(which_clock))
930 return -EINVAL;
931 if (copy_from_user(&new_tp, tp, sizeof (*tp)))
932 return -EFAULT;
934 return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp));
937 asmlinkage long
938 sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp)
940 struct timespec kernel_tp;
941 int error;
943 if (invalid_clockid(which_clock))
944 return -EINVAL;
945 error = CLOCK_DISPATCH(which_clock, clock_get,
946 (which_clock, &kernel_tp));
947 if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
948 error = -EFAULT;
950 return error;
954 asmlinkage long
955 sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
957 struct timespec rtn_tp;
958 int error;
960 if (invalid_clockid(which_clock))
961 return -EINVAL;
963 error = CLOCK_DISPATCH(which_clock, clock_getres,
964 (which_clock, &rtn_tp));
966 if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) {
967 error = -EFAULT;
970 return error;
974 * nanosleep for monotonic and realtime clocks
976 static int common_nsleep(const clockid_t which_clock, int flags,
977 struct timespec *tsave, struct timespec __user *rmtp)
979 return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
980 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
981 which_clock);
984 asmlinkage long
985 sys_clock_nanosleep(const clockid_t which_clock, int flags,
986 const struct timespec __user *rqtp,
987 struct timespec __user *rmtp)
989 struct timespec t;
991 if (invalid_clockid(which_clock))
992 return -EINVAL;
994 if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
995 return -EFAULT;
997 if (!timespec_valid(&t))
998 return -EINVAL;
1000 return CLOCK_DISPATCH(which_clock, nsleep,
1001 (which_clock, flags, &t, rmtp));
1005 * nanosleep_restart for monotonic and realtime clocks
1007 static int common_nsleep_restart(struct restart_block *restart_block)
1009 return hrtimer_nanosleep_restart(restart_block);
1013 * This will restart clock_nanosleep. This is required only by
1014 * compat_clock_nanosleep_restart for now.
1016 long
1017 clock_nanosleep_restart(struct restart_block *restart_block)
1019 clockid_t which_clock = restart_block->arg0;
1021 return CLOCK_DISPATCH(which_clock, nsleep_restart,
1022 (restart_block));