2 * linux/kernel/posix-timers.c
5 * 2002-10-15 Posix Clocks & timers
6 * by George Anzinger george@mvista.com
8 * Copyright (C) 2002 2003 by MontaVista Software.
10 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
11 * Copyright (C) 2004 Boris Hu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA
30 /* These are all the functions necessary to implement
31 * POSIX clocks & timers
34 #include <linux/interrupt.h>
35 #include <linux/slab.h>
36 #include <linux/time.h>
37 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
40 #include <linux/list.h>
41 #include <linux/init.h>
42 #include <linux/compiler.h>
43 #include <linux/idr.h>
44 #include <linux/posix-timers.h>
45 #include <linux/syscalls.h>
46 #include <linux/wait.h>
47 #include <linux/workqueue.h>
48 #include <linux/module.h>
51 * Management arrays for POSIX timers. Timers are kept in slab memory
52 * Timer ids are allocated by an external routine that keeps track of the
53 * id and the timer. The external interface is:
55 * void *idr_find(struct idr *idp, int id); to find timer_id <id>
56 * int idr_get_new(struct idr *idp, void *ptr); to get a new id and
58 * void idr_remove(struct idr *idp, int id); to release <id>
59 * void idr_init(struct idr *idp); to initialize <idp>
61 * The idr_get_new *may* call slab for more memory so it must not be
62 * called under a spin lock. Likewise idr_remore may release memory
63 * (but it may be ok to do this under a lock...).
64 * idr_find is just a memory look up and is quite fast. A -1 return
65 * indicates that the requested id does not exist.
69 * Lets keep our timers in a slab cache :-)
71 static struct kmem_cache
*posix_timers_cache
;
72 static struct idr posix_timers_id
;
73 static DEFINE_SPINLOCK(idr_lock
);
76 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
77 * SIGEV values. Here we put out an error if this assumption fails.
79 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
80 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
81 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
86 * The timer ID is turned into a timer address by idr_find().
87 * Verifying a valid ID consists of:
89 * a) checking that idr_find() returns other than -1.
90 * b) checking that the timer id matches the one in the timer itself.
91 * c) that the timer owner is in the callers thread group.
95 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
96 * to implement others. This structure defines the various
97 * clocks and allows the possibility of adding others. We
98 * provide an interface to add clocks to the table and expect
99 * the "arch" code to add at least one clock that is high
100 * resolution. Here we define the standard CLOCK_REALTIME as a
101 * 1/HZ resolution clock.
103 * RESOLUTION: Clock resolution is used to round up timer and interval
104 * times, NOT to report clock times, which are reported with as
105 * much resolution as the system can muster. In some cases this
106 * resolution may depend on the underlying clock hardware and
107 * may not be quantifiable until run time, and only then is the
108 * necessary code is written. The standard says we should say
109 * something about this issue in the documentation...
111 * FUNCTIONS: The CLOCKs structure defines possible functions to handle
112 * various clock functions. For clocks that use the standard
113 * system timer code these entries should be NULL. This will
114 * allow dispatch without the overhead of indirect function
115 * calls. CLOCKS that depend on other sources (e.g. WWV or GPS)
116 * must supply functions here, even if the function just returns
117 * ENOSYS. The standard POSIX timer management code assumes the
118 * following: 1.) The k_itimer struct (sched.h) is used for the
119 * timer. 2.) The list, it_lock, it_clock, it_id and it_process
120 * fields are not modified by timer code.
122 * At this time all functions EXCEPT clock_nanosleep can be
123 * redirected by the CLOCKS structure. Clock_nanosleep is in
124 * there, but the code ignores it.
126 * Permissions: It is assumed that the clock_settime() function defined
127 * for each clock will take care of permission checks. Some
128 * clocks may be set able by any user (i.e. local process
129 * clocks) others not. Currently the only set able clock we
130 * have is CLOCK_REALTIME and its high res counter part, both of
131 * which we beg off on and pass to do_sys_settimeofday().
134 static struct k_clock posix_clocks
[MAX_CLOCKS
];
137 * These ones are defined below.
139 static int common_nsleep(const clockid_t
, int flags
, struct timespec
*t
,
140 struct timespec __user
*rmtp
);
141 static void common_timer_get(struct k_itimer
*, struct itimerspec
*);
142 static int common_timer_set(struct k_itimer
*, int,
143 struct itimerspec
*, struct itimerspec
*);
144 static int common_timer_del(struct k_itimer
*timer
);
146 static enum hrtimer_restart
posix_timer_fn(struct hrtimer
*data
);
148 static struct k_itimer
*lock_timer(timer_t timer_id
, unsigned long *flags
);
150 static inline void unlock_timer(struct k_itimer
*timr
, unsigned long flags
)
152 spin_unlock_irqrestore(&timr
->it_lock
, flags
);
156 * Call the k_clock hook function if non-null, or the default function.
158 #define CLOCK_DISPATCH(clock, call, arglist) \
159 ((clock) < 0 ? posix_cpu_##call arglist : \
160 (posix_clocks[clock].call != NULL \
161 ? (*posix_clocks[clock].call) arglist : common_##call arglist))
164 * Default clock hook functions when the struct k_clock passed
165 * to register_posix_clock leaves a function pointer null.
167 * The function common_CALL is the default implementation for
168 * the function pointer CALL in struct k_clock.
171 static inline int common_clock_getres(const clockid_t which_clock
,
175 tp
->tv_nsec
= posix_clocks
[which_clock
].res
;
180 * Get real time for posix timers
182 static int common_clock_get(clockid_t which_clock
, struct timespec
*tp
)
184 ktime_get_real_ts(tp
);
188 static inline int common_clock_set(const clockid_t which_clock
,
191 return do_sys_settimeofday(tp
, NULL
);
194 static int common_timer_create(struct k_itimer
*new_timer
)
196 hrtimer_init(&new_timer
->it
.real
.timer
, new_timer
->it_clock
, 0);
201 * Return nonzero if we know a priori this clockid_t value is bogus.
203 static inline int invalid_clockid(const clockid_t which_clock
)
205 if (which_clock
< 0) /* CPU clock, posix_cpu_* will check it */
207 if ((unsigned) which_clock
>= MAX_CLOCKS
)
209 if (posix_clocks
[which_clock
].clock_getres
!= NULL
)
211 if (posix_clocks
[which_clock
].res
!= 0)
217 * Get monotonic time for posix timers
219 static int posix_ktime_get_ts(clockid_t which_clock
, struct timespec
*tp
)
226 * Get monotonic time for posix timers
228 static int posix_get_monotonic_raw(clockid_t which_clock
, struct timespec
*tp
)
235 * Initialize everything, well, just everything in Posix clocks/timers ;)
237 static __init
int init_posix_timers(void)
239 struct k_clock clock_realtime
= {
240 .clock_getres
= hrtimer_get_res
,
242 struct k_clock clock_monotonic
= {
243 .clock_getres
= hrtimer_get_res
,
244 .clock_get
= posix_ktime_get_ts
,
245 .clock_set
= do_posix_clock_nosettime
,
247 struct k_clock clock_monotonic_raw
= {
248 .clock_getres
= hrtimer_get_res
,
249 .clock_get
= posix_get_monotonic_raw
,
250 .clock_set
= do_posix_clock_nosettime
,
253 register_posix_clock(CLOCK_REALTIME
, &clock_realtime
);
254 register_posix_clock(CLOCK_MONOTONIC
, &clock_monotonic
);
255 register_posix_clock(CLOCK_MONOTONIC_RAW
, &clock_monotonic_raw
);
257 posix_timers_cache
= kmem_cache_create("posix_timers_cache",
258 sizeof (struct k_itimer
), 0, SLAB_PANIC
,
260 idr_init(&posix_timers_id
);
264 __initcall(init_posix_timers
);
266 static void schedule_next_timer(struct k_itimer
*timr
)
268 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
270 if (timr
->it
.real
.interval
.tv64
== 0)
273 timr
->it_overrun
+= (unsigned int) hrtimer_forward(timer
,
274 timer
->base
->get_time(),
275 timr
->it
.real
.interval
);
277 timr
->it_overrun_last
= timr
->it_overrun
;
278 timr
->it_overrun
= -1;
279 ++timr
->it_requeue_pending
;
280 hrtimer_restart(timer
);
284 * This function is exported for use by the signal deliver code. It is
285 * called just prior to the info block being released and passes that
286 * block to us. It's function is to update the overrun entry AND to
287 * restart the timer. It should only be called if the timer is to be
288 * restarted (i.e. we have flagged this in the sys_private entry of the
291 * To protect aginst the timer going away while the interrupt is queued,
292 * we require that the it_requeue_pending flag be set.
294 void do_schedule_next_timer(struct siginfo
*info
)
296 struct k_itimer
*timr
;
299 timr
= lock_timer(info
->si_tid
, &flags
);
301 if (timr
&& timr
->it_requeue_pending
== info
->si_sys_private
) {
302 if (timr
->it_clock
< 0)
303 posix_cpu_timer_schedule(timr
);
305 schedule_next_timer(timr
);
307 info
->si_overrun
+= timr
->it_overrun_last
;
311 unlock_timer(timr
, flags
);
314 int posix_timer_event(struct k_itimer
*timr
, int si_private
)
317 * FIXME: if ->sigq is queued we can race with
318 * dequeue_signal()->do_schedule_next_timer().
320 * If dequeue_signal() sees the "right" value of
321 * si_sys_private it calls do_schedule_next_timer().
322 * We re-queue ->sigq and drop ->it_lock().
323 * do_schedule_next_timer() locks the timer
324 * and re-schedules it while ->sigq is pending.
325 * Not really bad, but not that we want.
327 timr
->sigq
->info
.si_sys_private
= si_private
;
329 timr
->sigq
->info
.si_signo
= timr
->it_sigev_signo
;
330 timr
->sigq
->info
.si_code
= SI_TIMER
;
331 timr
->sigq
->info
.si_tid
= timr
->it_id
;
332 timr
->sigq
->info
.si_value
= timr
->it_sigev_value
;
334 if (timr
->it_sigev_notify
& SIGEV_THREAD_ID
) {
335 struct task_struct
*leader
;
336 int ret
= send_sigqueue(timr
->sigq
, timr
->it_process
, 0);
338 if (likely(ret
>= 0))
341 timr
->it_sigev_notify
= SIGEV_SIGNAL
;
342 leader
= timr
->it_process
->group_leader
;
343 put_task_struct(timr
->it_process
);
344 timr
->it_process
= leader
;
347 return send_sigqueue(timr
->sigq
, timr
->it_process
, 1);
349 EXPORT_SYMBOL_GPL(posix_timer_event
);
352 * This function gets called when a POSIX.1b interval timer expires. It
353 * is used as a callback from the kernel internal timer. The
354 * run_timer_list code ALWAYS calls with interrupts on.
356 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
358 static enum hrtimer_restart
posix_timer_fn(struct hrtimer
*timer
)
360 struct k_itimer
*timr
;
363 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
365 timr
= container_of(timer
, struct k_itimer
, it
.real
.timer
);
366 spin_lock_irqsave(&timr
->it_lock
, flags
);
368 if (timr
->it
.real
.interval
.tv64
!= 0)
369 si_private
= ++timr
->it_requeue_pending
;
371 if (posix_timer_event(timr
, si_private
)) {
373 * signal was not sent because of sig_ignor
374 * we will not get a call back to restart it AND
375 * it should be restarted.
377 if (timr
->it
.real
.interval
.tv64
!= 0) {
378 ktime_t now
= hrtimer_cb_get_time(timer
);
381 * FIXME: What we really want, is to stop this
382 * timer completely and restart it in case the
383 * SIG_IGN is removed. This is a non trivial
384 * change which involves sighand locking
385 * (sigh !), which we don't want to do late in
388 * For now we just let timers with an interval
389 * less than a jiffie expire every jiffie to
390 * avoid softirq starvation in case of SIG_IGN
391 * and a very small interval, which would put
392 * the timer right back on the softirq pending
393 * list. By moving now ahead of time we trick
394 * hrtimer_forward() to expire the timer
395 * later, while we still maintain the overrun
396 * accuracy, but have some inconsistency in
397 * the timer_gettime() case. This is at least
398 * better than a starved softirq. A more
399 * complex fix which solves also another related
400 * inconsistency is already in the pipeline.
402 #ifdef CONFIG_HIGH_RES_TIMERS
404 ktime_t kj
= ktime_set(0, NSEC_PER_SEC
/ HZ
);
406 if (timr
->it
.real
.interval
.tv64
< kj
.tv64
)
407 now
= ktime_add(now
, kj
);
410 timr
->it_overrun
+= (unsigned int)
411 hrtimer_forward(timer
, now
,
412 timr
->it
.real
.interval
);
413 ret
= HRTIMER_RESTART
;
414 ++timr
->it_requeue_pending
;
418 unlock_timer(timr
, flags
);
422 static struct task_struct
* good_sigevent(sigevent_t
* event
)
424 struct task_struct
*rtn
= current
->group_leader
;
426 if ((event
->sigev_notify
& SIGEV_THREAD_ID
) &&
427 (!(rtn
= find_task_by_vpid(event
->sigev_notify_thread_id
)) ||
428 !same_thread_group(rtn
, current
) ||
429 (event
->sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_SIGNAL
))
432 if (((event
->sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
) &&
433 ((event
->sigev_signo
<= 0) || (event
->sigev_signo
> SIGRTMAX
)))
439 void register_posix_clock(const clockid_t clock_id
, struct k_clock
*new_clock
)
441 if ((unsigned) clock_id
>= MAX_CLOCKS
) {
442 printk("POSIX clock register failed for clock_id %d\n",
447 posix_clocks
[clock_id
] = *new_clock
;
449 EXPORT_SYMBOL_GPL(register_posix_clock
);
451 static struct k_itimer
* alloc_posix_timer(void)
453 struct k_itimer
*tmr
;
454 tmr
= kmem_cache_zalloc(posix_timers_cache
, GFP_KERNEL
);
457 if (unlikely(!(tmr
->sigq
= sigqueue_alloc()))) {
458 kmem_cache_free(posix_timers_cache
, tmr
);
461 memset(&tmr
->sigq
->info
, 0, sizeof(siginfo_t
));
466 #define IT_ID_NOT_SET 0
467 static void release_posix_timer(struct k_itimer
*tmr
, int it_id_set
)
471 spin_lock_irqsave(&idr_lock
, flags
);
472 idr_remove(&posix_timers_id
, tmr
->it_id
);
473 spin_unlock_irqrestore(&idr_lock
, flags
);
475 sigqueue_free(tmr
->sigq
);
476 kmem_cache_free(posix_timers_cache
, tmr
);
479 /* Create a POSIX.1b interval timer. */
482 sys_timer_create(const clockid_t which_clock
,
483 struct sigevent __user
*timer_event_spec
,
484 timer_t __user
* created_timer_id
)
487 struct k_itimer
*new_timer
= NULL
;
489 struct task_struct
*process
= NULL
;
492 int it_id_set
= IT_ID_NOT_SET
;
494 if (invalid_clockid(which_clock
))
497 new_timer
= alloc_posix_timer();
498 if (unlikely(!new_timer
))
501 spin_lock_init(&new_timer
->it_lock
);
503 if (unlikely(!idr_pre_get(&posix_timers_id
, GFP_KERNEL
))) {
507 spin_lock_irq(&idr_lock
);
508 error
= idr_get_new(&posix_timers_id
, (void *) new_timer
,
510 spin_unlock_irq(&idr_lock
);
511 if (error
== -EAGAIN
)
515 * Weird looking, but we return EAGAIN if the IDR is
516 * full (proper POSIX return value for this)
522 it_id_set
= IT_ID_SET
;
523 new_timer
->it_id
= (timer_t
) new_timer_id
;
524 new_timer
->it_clock
= which_clock
;
525 new_timer
->it_overrun
= -1;
526 error
= CLOCK_DISPATCH(which_clock
, timer_create
, (new_timer
));
531 * return the timer_id now. The next step is hard to
532 * back out if there is an error.
534 if (copy_to_user(created_timer_id
,
535 &new_timer_id
, sizeof (new_timer_id
))) {
539 if (timer_event_spec
) {
540 if (copy_from_user(&event
, timer_event_spec
, sizeof (event
))) {
544 new_timer
->it_sigev_notify
= event
.sigev_notify
;
545 new_timer
->it_sigev_signo
= event
.sigev_signo
;
546 new_timer
->it_sigev_value
= event
.sigev_value
;
548 read_lock(&tasklist_lock
);
549 if ((process
= good_sigevent(&event
))) {
551 * We may be setting up this process for another
552 * thread. It may be exiting. To catch this
553 * case the we check the PF_EXITING flag. If
554 * the flag is not set, the siglock will catch
555 * him before it is too late (in exit_itimers).
557 * The exec case is a bit more invloved but easy
558 * to code. If the process is in our thread
559 * group (and it must be or we would not allow
560 * it here) and is doing an exec, it will cause
561 * us to be killed. In this case it will wait
562 * for us to die which means we can finish this
563 * linkage with our last gasp. I.e. no code :)
565 spin_lock_irqsave(&process
->sighand
->siglock
, flags
);
566 if (!(process
->flags
& PF_EXITING
)) {
567 new_timer
->it_process
= process
;
568 list_add(&new_timer
->list
,
569 &process
->signal
->posix_timers
);
570 if (new_timer
->it_sigev_notify
== (SIGEV_SIGNAL
|SIGEV_THREAD_ID
))
571 get_task_struct(process
);
572 spin_unlock_irqrestore(&process
->sighand
->siglock
, flags
);
574 spin_unlock_irqrestore(&process
->sighand
->siglock
, flags
);
578 read_unlock(&tasklist_lock
);
584 new_timer
->it_sigev_notify
= SIGEV_SIGNAL
;
585 new_timer
->it_sigev_signo
= SIGALRM
;
586 new_timer
->it_sigev_value
.sival_int
= new_timer
->it_id
;
587 process
= current
->group_leader
;
588 spin_lock_irqsave(&process
->sighand
->siglock
, flags
);
589 new_timer
->it_process
= process
;
590 list_add(&new_timer
->list
, &process
->signal
->posix_timers
);
591 spin_unlock_irqrestore(&process
->sighand
->siglock
, flags
);
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.
603 release_posix_timer(new_timer
, it_id_set
);
609 * Locking issues: We need to protect the result of the id look up until
610 * we get the timer locked down so it is not deleted under us. The
611 * removal is done under the idr spinlock so we use that here to bridge
612 * the find to the timer lock. To avoid a dead lock, the timer id MUST
613 * be release with out holding the timer lock.
615 static struct k_itimer
* lock_timer(timer_t timer_id
, unsigned long *flags
)
617 struct k_itimer
*timr
;
619 * Watch out here. We do a irqsave on the idr_lock and pass the
620 * flags part over to the timer lock. Must not let interrupts in
621 * while we are moving the lock.
624 spin_lock_irqsave(&idr_lock
, *flags
);
625 timr
= (struct k_itimer
*) idr_find(&posix_timers_id
, (int) timer_id
);
627 spin_lock(&timr
->it_lock
);
629 if ((timr
->it_id
!= timer_id
) || !(timr
->it_process
) ||
630 !same_thread_group(timr
->it_process
, current
)) {
631 spin_unlock(&timr
->it_lock
);
632 spin_unlock_irqrestore(&idr_lock
, *flags
);
635 spin_unlock(&idr_lock
);
637 spin_unlock_irqrestore(&idr_lock
, *flags
);
643 * Get the time remaining on a POSIX.1b interval timer. This function
644 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
647 * We have a couple of messes to clean up here. First there is the case
648 * of a timer that has a requeue pending. These timers should appear to
649 * be in the timer list with an expiry as if we were to requeue them
652 * The second issue is the SIGEV_NONE timer which may be active but is
653 * not really ever put in the timer list (to save system resources).
654 * This timer may be expired, and if so, we will do it here. Otherwise
655 * it is the same as a requeue pending timer WRT to what we should
659 common_timer_get(struct k_itimer
*timr
, struct itimerspec
*cur_setting
)
661 ktime_t now
, remaining
, iv
;
662 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
664 memset(cur_setting
, 0, sizeof(struct itimerspec
));
666 iv
= timr
->it
.real
.interval
;
668 /* interval timer ? */
670 cur_setting
->it_interval
= ktime_to_timespec(iv
);
671 else if (!hrtimer_active(timer
) &&
672 (timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
)
675 now
= timer
->base
->get_time();
678 * When a requeue is pending or this is a SIGEV_NONE
679 * timer move the expiry time forward by intervals, so
682 if (iv
.tv64
&& (timr
->it_requeue_pending
& REQUEUE_PENDING
||
683 (timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) == SIGEV_NONE
))
684 timr
->it_overrun
+= (unsigned int) hrtimer_forward(timer
, now
, iv
);
686 remaining
= ktime_sub(timer
->expires
, now
);
687 /* Return 0 only, when the timer is expired and not pending */
688 if (remaining
.tv64
<= 0) {
690 * A single shot SIGEV_NONE timer must return 0, when
693 if ((timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
)
694 cur_setting
->it_value
.tv_nsec
= 1;
696 cur_setting
->it_value
= ktime_to_timespec(remaining
);
699 /* Get the time remaining on a POSIX.1b interval timer. */
701 sys_timer_gettime(timer_t timer_id
, struct itimerspec __user
*setting
)
703 struct k_itimer
*timr
;
704 struct itimerspec cur_setting
;
707 timr
= lock_timer(timer_id
, &flags
);
711 CLOCK_DISPATCH(timr
->it_clock
, timer_get
, (timr
, &cur_setting
));
713 unlock_timer(timr
, flags
);
715 if (copy_to_user(setting
, &cur_setting
, sizeof (cur_setting
)))
722 * Get the number of overruns of a POSIX.1b interval timer. This is to
723 * be the overrun of the timer last delivered. At the same time we are
724 * accumulating overruns on the next timer. The overrun is frozen when
725 * the signal is delivered, either at the notify time (if the info block
726 * is not queued) or at the actual delivery time (as we are informed by
727 * the call back to do_schedule_next_timer(). So all we need to do is
728 * to pick up the frozen overrun.
731 sys_timer_getoverrun(timer_t timer_id
)
733 struct k_itimer
*timr
;
737 timr
= lock_timer(timer_id
, &flags
);
741 overrun
= timr
->it_overrun_last
;
742 unlock_timer(timr
, flags
);
747 /* Set a POSIX.1b interval timer. */
748 /* timr->it_lock is taken. */
750 common_timer_set(struct k_itimer
*timr
, int flags
,
751 struct itimerspec
*new_setting
, struct itimerspec
*old_setting
)
753 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
754 enum hrtimer_mode mode
;
757 common_timer_get(timr
, old_setting
);
759 /* disable the timer */
760 timr
->it
.real
.interval
.tv64
= 0;
762 * careful here. If smp we could be in the "fire" routine which will
763 * be spinning as we hold the lock. But this is ONLY an SMP issue.
765 if (hrtimer_try_to_cancel(timer
) < 0)
768 timr
->it_requeue_pending
= (timr
->it_requeue_pending
+ 2) &
770 timr
->it_overrun_last
= 0;
772 /* switch off the timer when it_value is zero */
773 if (!new_setting
->it_value
.tv_sec
&& !new_setting
->it_value
.tv_nsec
)
776 mode
= flags
& TIMER_ABSTIME
? HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
;
777 hrtimer_init(&timr
->it
.real
.timer
, timr
->it_clock
, mode
);
778 timr
->it
.real
.timer
.function
= posix_timer_fn
;
780 timer
->expires
= timespec_to_ktime(new_setting
->it_value
);
782 /* Convert interval */
783 timr
->it
.real
.interval
= timespec_to_ktime(new_setting
->it_interval
);
785 /* SIGEV_NONE timers are not queued ! See common_timer_get */
786 if (((timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) == SIGEV_NONE
)) {
787 /* Setup correct expiry time for relative timers */
788 if (mode
== HRTIMER_MODE_REL
) {
790 ktime_add_safe(timer
->expires
,
791 timer
->base
->get_time());
796 hrtimer_start(timer
, timer
->expires
, mode
);
800 /* Set a POSIX.1b interval timer */
802 sys_timer_settime(timer_t timer_id
, int flags
,
803 const struct itimerspec __user
*new_setting
,
804 struct itimerspec __user
*old_setting
)
806 struct k_itimer
*timr
;
807 struct itimerspec new_spec
, old_spec
;
810 struct itimerspec
*rtn
= old_setting
? &old_spec
: NULL
;
815 if (copy_from_user(&new_spec
, new_setting
, sizeof (new_spec
)))
818 if (!timespec_valid(&new_spec
.it_interval
) ||
819 !timespec_valid(&new_spec
.it_value
))
822 timr
= lock_timer(timer_id
, &flag
);
826 error
= CLOCK_DISPATCH(timr
->it_clock
, timer_set
,
827 (timr
, flags
, &new_spec
, rtn
));
829 unlock_timer(timr
, flag
);
830 if (error
== TIMER_RETRY
) {
831 rtn
= NULL
; // We already got the old time...
835 if (old_setting
&& !error
&&
836 copy_to_user(old_setting
, &old_spec
, sizeof (old_spec
)))
842 static inline int common_timer_del(struct k_itimer
*timer
)
844 timer
->it
.real
.interval
.tv64
= 0;
846 if (hrtimer_try_to_cancel(&timer
->it
.real
.timer
) < 0)
851 static inline int timer_delete_hook(struct k_itimer
*timer
)
853 return CLOCK_DISPATCH(timer
->it_clock
, timer_del
, (timer
));
856 /* Delete a POSIX.1b interval timer. */
858 sys_timer_delete(timer_t timer_id
)
860 struct k_itimer
*timer
;
864 timer
= lock_timer(timer_id
, &flags
);
868 if (timer_delete_hook(timer
) == TIMER_RETRY
) {
869 unlock_timer(timer
, flags
);
873 spin_lock(¤t
->sighand
->siglock
);
874 list_del(&timer
->list
);
875 spin_unlock(¤t
->sighand
->siglock
);
877 * This keeps any tasks waiting on the spin lock from thinking
878 * they got something (see the lock code above).
880 if (timer
->it_sigev_notify
== (SIGEV_SIGNAL
|SIGEV_THREAD_ID
))
881 put_task_struct(timer
->it_process
);
882 timer
->it_process
= 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 if (timer
->it_sigev_notify
== (SIGEV_SIGNAL
|SIGEV_THREAD_ID
))
909 put_task_struct(timer
->it_process
);
910 timer
->it_process
= NULL
;
912 unlock_timer(timer
, flags
);
913 release_posix_timer(timer
, IT_ID_SET
);
917 * This is called by do_exit or de_thread, only when there are no more
918 * references to the shared signal_struct.
920 void exit_itimers(struct signal_struct
*sig
)
922 struct k_itimer
*tmr
;
924 while (!list_empty(&sig
->posix_timers
)) {
925 tmr
= list_entry(sig
->posix_timers
.next
, struct k_itimer
, list
);
930 /* Not available / possible... functions */
931 int do_posix_clock_nosettime(const clockid_t clockid
, struct timespec
*tp
)
935 EXPORT_SYMBOL_GPL(do_posix_clock_nosettime
);
937 int do_posix_clock_nonanosleep(const clockid_t clock
, int flags
,
938 struct timespec
*t
, struct timespec __user
*r
)
941 return -EOPNOTSUPP
; /* aka ENOTSUP in userland for POSIX */
942 #else /* parisc does define it separately. */
946 EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep
);
948 asmlinkage
long sys_clock_settime(const clockid_t which_clock
,
949 const struct timespec __user
*tp
)
951 struct timespec new_tp
;
953 if (invalid_clockid(which_clock
))
955 if (copy_from_user(&new_tp
, tp
, sizeof (*tp
)))
958 return CLOCK_DISPATCH(which_clock
, clock_set
, (which_clock
, &new_tp
));
962 sys_clock_gettime(const clockid_t which_clock
, struct timespec __user
*tp
)
964 struct timespec kernel_tp
;
967 if (invalid_clockid(which_clock
))
969 error
= CLOCK_DISPATCH(which_clock
, clock_get
,
970 (which_clock
, &kernel_tp
));
971 if (!error
&& copy_to_user(tp
, &kernel_tp
, sizeof (kernel_tp
)))
979 sys_clock_getres(const clockid_t which_clock
, struct timespec __user
*tp
)
981 struct timespec rtn_tp
;
984 if (invalid_clockid(which_clock
))
987 error
= CLOCK_DISPATCH(which_clock
, clock_getres
,
988 (which_clock
, &rtn_tp
));
990 if (!error
&& tp
&& copy_to_user(tp
, &rtn_tp
, sizeof (rtn_tp
))) {
998 * nanosleep for monotonic and realtime clocks
1000 static int common_nsleep(const clockid_t which_clock
, int flags
,
1001 struct timespec
*tsave
, struct timespec __user
*rmtp
)
1003 return hrtimer_nanosleep(tsave
, rmtp
, flags
& TIMER_ABSTIME
?
1004 HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
,
1009 sys_clock_nanosleep(const clockid_t which_clock
, int flags
,
1010 const struct timespec __user
*rqtp
,
1011 struct timespec __user
*rmtp
)
1015 if (invalid_clockid(which_clock
))
1018 if (copy_from_user(&t
, rqtp
, sizeof (struct timespec
)))
1021 if (!timespec_valid(&t
))
1024 return CLOCK_DISPATCH(which_clock
, nsleep
,
1025 (which_clock
, flags
, &t
, rmtp
));
1029 * nanosleep_restart for monotonic and realtime clocks
1031 static int common_nsleep_restart(struct restart_block
*restart_block
)
1033 return hrtimer_nanosleep_restart(restart_block
);
1037 * This will restart clock_nanosleep. This is required only by
1038 * compat_clock_nanosleep_restart for now.
1041 clock_nanosleep_restart(struct restart_block
*restart_block
)
1043 clockid_t which_clock
= restart_block
->arg0
;
1045 return CLOCK_DISPATCH(which_clock
, nsleep_restart
,