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>
38 #include <linux/sched/task.h>
40 #include <linux/uaccess.h>
41 #include <linux/list.h>
42 #include <linux/init.h>
43 #include <linux/compiler.h>
44 #include <linux/hash.h>
45 #include <linux/posix-clock.h>
46 #include <linux/posix-timers.h>
47 #include <linux/syscalls.h>
48 #include <linux/wait.h>
49 #include <linux/workqueue.h>
50 #include <linux/export.h>
51 #include <linux/hashtable.h>
52 #include <linux/compat.h>
53 #include <linux/nospec.h>
55 #include "timekeeping.h"
56 #include "posix-timers.h"
59 * Management arrays for POSIX timers. Timers are now kept in static hash table
61 * Timer ids are allocated by local routine, which selects proper hash head by
62 * key, constructed from current->signal address and per signal struct counter.
63 * This keeps timer ids unique per process, but now they can intersect between
68 * Lets keep our timers in a slab cache :-)
70 static struct kmem_cache
*posix_timers_cache
;
72 static DEFINE_HASHTABLE(posix_timers_hashtable
, 9);
73 static DEFINE_SPINLOCK(hash_lock
);
75 static const struct k_clock
* const posix_clocks
[];
76 static const struct k_clock
*clockid_to_kclock(const clockid_t id
);
77 static const struct k_clock clock_realtime
, clock_monotonic
;
80 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
81 * SIGEV values. Here we put out an error if this assumption fails.
83 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
84 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
85 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
89 * parisc wants ENOTSUP instead of EOPNOTSUPP
92 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
94 # define ENANOSLEEP_NOTSUP ENOTSUP
98 * The timer ID is turned into a timer address by idr_find().
99 * Verifying a valid ID consists of:
101 * a) checking that idr_find() returns other than -1.
102 * b) checking that the timer id matches the one in the timer itself.
103 * c) that the timer owner is in the callers thread group.
107 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
108 * to implement others. This structure defines the various
111 * RESOLUTION: Clock resolution is used to round up timer and interval
112 * times, NOT to report clock times, which are reported with as
113 * much resolution as the system can muster. In some cases this
114 * resolution may depend on the underlying clock hardware and
115 * may not be quantifiable until run time, and only then is the
116 * necessary code is written. The standard says we should say
117 * something about this issue in the documentation...
119 * FUNCTIONS: The CLOCKs structure defines possible functions to
120 * handle various clock functions.
122 * The standard POSIX timer management code assumes the
123 * following: 1.) The k_itimer struct (sched.h) is used for
124 * the timer. 2.) The list, it_lock, it_clock, it_id and
125 * it_pid fields are not modified by timer code.
127 * Permissions: It is assumed that the clock_settime() function defined
128 * for each clock will take care of permission checks. Some
129 * clocks may be set able by any user (i.e. local process
130 * clocks) others not. Currently the only set able clock we
131 * have is CLOCK_REALTIME and its high res counter part, both of
132 * which we beg off on and pass to do_sys_settimeofday().
134 static struct k_itimer
*__lock_timer(timer_t timer_id
, unsigned long *flags
);
136 #define lock_timer(tid, flags) \
137 ({ struct k_itimer *__timr; \
138 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
142 static int hash(struct signal_struct
*sig
, unsigned int nr
)
144 return hash_32(hash32_ptr(sig
) ^ nr
, HASH_BITS(posix_timers_hashtable
));
147 static struct k_itimer
*__posix_timers_find(struct hlist_head
*head
,
148 struct signal_struct
*sig
,
151 struct k_itimer
*timer
;
153 hlist_for_each_entry_rcu(timer
, head
, t_hash
) {
154 if ((timer
->it_signal
== sig
) && (timer
->it_id
== id
))
160 static struct k_itimer
*posix_timer_by_id(timer_t id
)
162 struct signal_struct
*sig
= current
->signal
;
163 struct hlist_head
*head
= &posix_timers_hashtable
[hash(sig
, id
)];
165 return __posix_timers_find(head
, sig
, id
);
168 static int posix_timer_add(struct k_itimer
*timer
)
170 struct signal_struct
*sig
= current
->signal
;
171 int first_free_id
= sig
->posix_timer_id
;
172 struct hlist_head
*head
;
176 spin_lock(&hash_lock
);
177 head
= &posix_timers_hashtable
[hash(sig
, sig
->posix_timer_id
)];
178 if (!__posix_timers_find(head
, sig
, sig
->posix_timer_id
)) {
179 hlist_add_head_rcu(&timer
->t_hash
, head
);
180 ret
= sig
->posix_timer_id
;
182 if (++sig
->posix_timer_id
< 0)
183 sig
->posix_timer_id
= 0;
184 if ((sig
->posix_timer_id
== first_free_id
) && (ret
== -ENOENT
))
185 /* Loop over all possible ids completed */
187 spin_unlock(&hash_lock
);
188 } while (ret
== -ENOENT
);
192 static inline void unlock_timer(struct k_itimer
*timr
, unsigned long flags
)
194 spin_unlock_irqrestore(&timr
->it_lock
, flags
);
197 /* Get clock_realtime */
198 static int posix_clock_realtime_get(clockid_t which_clock
, struct timespec64
*tp
)
200 ktime_get_real_ts64(tp
);
204 /* Set clock_realtime */
205 static int posix_clock_realtime_set(const clockid_t which_clock
,
206 const struct timespec64
*tp
)
208 return do_sys_settimeofday64(tp
, NULL
);
211 static int posix_clock_realtime_adj(const clockid_t which_clock
,
214 return do_adjtimex(t
);
218 * Get monotonic time for posix timers
220 static int posix_ktime_get_ts(clockid_t which_clock
, struct timespec64
*tp
)
227 * Get monotonic-raw time for posix timers
229 static int posix_get_monotonic_raw(clockid_t which_clock
, struct timespec64
*tp
)
231 getrawmonotonic64(tp
);
236 static int posix_get_realtime_coarse(clockid_t which_clock
, struct timespec64
*tp
)
238 *tp
= current_kernel_time64();
242 static int posix_get_monotonic_coarse(clockid_t which_clock
,
243 struct timespec64
*tp
)
245 *tp
= get_monotonic_coarse64();
249 static int posix_get_coarse_res(const clockid_t which_clock
, struct timespec64
*tp
)
251 *tp
= ktime_to_timespec64(KTIME_LOW_RES
);
255 static int posix_get_boottime(const clockid_t which_clock
, struct timespec64
*tp
)
257 get_monotonic_boottime64(tp
);
261 static int posix_get_tai(clockid_t which_clock
, struct timespec64
*tp
)
263 timekeeping_clocktai64(tp
);
267 static int posix_get_hrtimer_res(clockid_t which_clock
, struct timespec64
*tp
)
270 tp
->tv_nsec
= hrtimer_resolution
;
275 * Initialize everything, well, just everything in Posix clocks/timers ;)
277 static __init
int init_posix_timers(void)
279 posix_timers_cache
= kmem_cache_create("posix_timers_cache",
280 sizeof (struct k_itimer
), 0, SLAB_PANIC
,
284 __initcall(init_posix_timers
);
287 * The siginfo si_overrun field and the return value of timer_getoverrun(2)
288 * are of type int. Clamp the overrun value to INT_MAX
290 static inline int timer_overrun_to_int(struct k_itimer
*timr
, int baseval
)
292 s64 sum
= timr
->it_overrun_last
+ (s64
)baseval
;
294 return sum
> (s64
)INT_MAX
? INT_MAX
: (int)sum
;
297 static void common_hrtimer_rearm(struct k_itimer
*timr
)
299 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
301 if (!timr
->it_interval
)
304 timr
->it_overrun
+= hrtimer_forward(timer
, timer
->base
->get_time(),
306 hrtimer_restart(timer
);
310 * This function is exported for use by the signal deliver code. It is
311 * called just prior to the info block being released and passes that
312 * block to us. It's function is to update the overrun entry AND to
313 * restart the timer. It should only be called if the timer is to be
314 * restarted (i.e. we have flagged this in the sys_private entry of the
317 * To protect against the timer going away while the interrupt is queued,
318 * we require that the it_requeue_pending flag be set.
320 void posixtimer_rearm(struct siginfo
*info
)
322 struct k_itimer
*timr
;
325 timr
= lock_timer(info
->si_tid
, &flags
);
329 if (timr
->it_requeue_pending
== info
->si_sys_private
) {
330 timr
->kclock
->timer_rearm(timr
);
333 timr
->it_overrun_last
= timr
->it_overrun
;
334 timr
->it_overrun
= -1LL;
335 ++timr
->it_requeue_pending
;
337 info
->si_overrun
= timer_overrun_to_int(timr
, info
->si_overrun
);
340 unlock_timer(timr
, flags
);
343 int posix_timer_event(struct k_itimer
*timr
, int si_private
)
345 struct task_struct
*task
;
346 int shared
, ret
= -1;
348 * FIXME: if ->sigq is queued we can race with
349 * dequeue_signal()->posixtimer_rearm().
351 * If dequeue_signal() sees the "right" value of
352 * si_sys_private it calls posixtimer_rearm().
353 * We re-queue ->sigq and drop ->it_lock().
354 * posixtimer_rearm() locks the timer
355 * and re-schedules it while ->sigq is pending.
356 * Not really bad, but not that we want.
358 timr
->sigq
->info
.si_sys_private
= si_private
;
361 task
= pid_task(timr
->it_pid
, PIDTYPE_PID
);
363 shared
= !(timr
->it_sigev_notify
& SIGEV_THREAD_ID
);
364 ret
= send_sigqueue(timr
->sigq
, task
, shared
);
367 /* If we failed to send the signal the timer stops. */
372 * This function gets called when a POSIX.1b interval timer expires. It
373 * is used as a callback from the kernel internal timer. The
374 * run_timer_list code ALWAYS calls with interrupts on.
376 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
378 static enum hrtimer_restart
posix_timer_fn(struct hrtimer
*timer
)
380 struct k_itimer
*timr
;
383 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
385 timr
= container_of(timer
, struct k_itimer
, it
.real
.timer
);
386 spin_lock_irqsave(&timr
->it_lock
, flags
);
389 if (timr
->it_interval
!= 0)
390 si_private
= ++timr
->it_requeue_pending
;
392 if (posix_timer_event(timr
, si_private
)) {
394 * signal was not sent because of sig_ignor
395 * we will not get a call back to restart it AND
396 * it should be restarted.
398 if (timr
->it_interval
!= 0) {
399 ktime_t now
= hrtimer_cb_get_time(timer
);
402 * FIXME: What we really want, is to stop this
403 * timer completely and restart it in case the
404 * SIG_IGN is removed. This is a non trivial
405 * change which involves sighand locking
406 * (sigh !), which we don't want to do late in
409 * For now we just let timers with an interval
410 * less than a jiffie expire every jiffie to
411 * avoid softirq starvation in case of SIG_IGN
412 * and a very small interval, which would put
413 * the timer right back on the softirq pending
414 * list. By moving now ahead of time we trick
415 * hrtimer_forward() to expire the timer
416 * later, while we still maintain the overrun
417 * accuracy, but have some inconsistency in
418 * the timer_gettime() case. This is at least
419 * better than a starved softirq. A more
420 * complex fix which solves also another related
421 * inconsistency is already in the pipeline.
423 #ifdef CONFIG_HIGH_RES_TIMERS
425 ktime_t kj
= NSEC_PER_SEC
/ HZ
;
427 if (timr
->it_interval
< kj
)
428 now
= ktime_add(now
, kj
);
431 timr
->it_overrun
+= hrtimer_forward(timer
, now
,
433 ret
= HRTIMER_RESTART
;
434 ++timr
->it_requeue_pending
;
439 unlock_timer(timr
, flags
);
443 static struct pid
*good_sigevent(sigevent_t
* event
)
445 struct task_struct
*rtn
= current
->group_leader
;
447 switch (event
->sigev_notify
) {
448 case SIGEV_SIGNAL
| SIGEV_THREAD_ID
:
449 rtn
= find_task_by_vpid(event
->sigev_notify_thread_id
);
450 if (!rtn
|| !same_thread_group(rtn
, current
))
455 if (event
->sigev_signo
<= 0 || event
->sigev_signo
> SIGRTMAX
)
459 return task_pid(rtn
);
465 static struct k_itimer
* alloc_posix_timer(void)
467 struct k_itimer
*tmr
;
468 tmr
= kmem_cache_zalloc(posix_timers_cache
, GFP_KERNEL
);
471 if (unlikely(!(tmr
->sigq
= sigqueue_alloc()))) {
472 kmem_cache_free(posix_timers_cache
, tmr
);
475 memset(&tmr
->sigq
->info
, 0, sizeof(siginfo_t
));
479 static void k_itimer_rcu_free(struct rcu_head
*head
)
481 struct k_itimer
*tmr
= container_of(head
, struct k_itimer
, it
.rcu
);
483 kmem_cache_free(posix_timers_cache
, tmr
);
487 #define IT_ID_NOT_SET 0
488 static void release_posix_timer(struct k_itimer
*tmr
, int it_id_set
)
492 spin_lock_irqsave(&hash_lock
, flags
);
493 hlist_del_rcu(&tmr
->t_hash
);
494 spin_unlock_irqrestore(&hash_lock
, flags
);
496 put_pid(tmr
->it_pid
);
497 sigqueue_free(tmr
->sigq
);
498 call_rcu(&tmr
->it
.rcu
, k_itimer_rcu_free
);
501 static int common_timer_create(struct k_itimer
*new_timer
)
503 hrtimer_init(&new_timer
->it
.real
.timer
, new_timer
->it_clock
, 0);
507 /* Create a POSIX.1b interval timer. */
508 static int do_timer_create(clockid_t which_clock
, struct sigevent
*event
,
509 timer_t __user
*created_timer_id
)
511 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
512 struct k_itimer
*new_timer
;
513 int error
, new_timer_id
;
514 int it_id_set
= IT_ID_NOT_SET
;
518 if (!kc
->timer_create
)
521 new_timer
= alloc_posix_timer();
522 if (unlikely(!new_timer
))
525 spin_lock_init(&new_timer
->it_lock
);
526 new_timer_id
= posix_timer_add(new_timer
);
527 if (new_timer_id
< 0) {
528 error
= new_timer_id
;
532 it_id_set
= IT_ID_SET
;
533 new_timer
->it_id
= (timer_t
) new_timer_id
;
534 new_timer
->it_clock
= which_clock
;
535 new_timer
->kclock
= kc
;
536 new_timer
->it_overrun
= -1LL;
540 new_timer
->it_pid
= get_pid(good_sigevent(event
));
542 if (!new_timer
->it_pid
) {
546 new_timer
->it_sigev_notify
= event
->sigev_notify
;
547 new_timer
->sigq
->info
.si_signo
= event
->sigev_signo
;
548 new_timer
->sigq
->info
.si_value
= event
->sigev_value
;
550 new_timer
->it_sigev_notify
= SIGEV_SIGNAL
;
551 new_timer
->sigq
->info
.si_signo
= SIGALRM
;
552 memset(&new_timer
->sigq
->info
.si_value
, 0, sizeof(sigval_t
));
553 new_timer
->sigq
->info
.si_value
.sival_int
= new_timer
->it_id
;
554 new_timer
->it_pid
= get_pid(task_tgid(current
));
557 new_timer
->sigq
->info
.si_tid
= new_timer
->it_id
;
558 new_timer
->sigq
->info
.si_code
= SI_TIMER
;
560 if (copy_to_user(created_timer_id
,
561 &new_timer_id
, sizeof (new_timer_id
))) {
566 error
= kc
->timer_create(new_timer
);
570 spin_lock_irq(¤t
->sighand
->siglock
);
571 new_timer
->it_signal
= current
->signal
;
572 list_add(&new_timer
->list
, ¤t
->signal
->posix_timers
);
573 spin_unlock_irq(¤t
->sighand
->siglock
);
577 * In the case of the timer belonging to another task, after
578 * the task is unlocked, the timer is owned by the other task
579 * and may cease to exist at any time. Don't use or modify
580 * new_timer after the unlock call.
583 release_posix_timer(new_timer
, it_id_set
);
587 SYSCALL_DEFINE3(timer_create
, const clockid_t
, which_clock
,
588 struct sigevent __user
*, timer_event_spec
,
589 timer_t __user
*, created_timer_id
)
591 if (timer_event_spec
) {
594 if (copy_from_user(&event
, timer_event_spec
, sizeof (event
)))
596 return do_timer_create(which_clock
, &event
, created_timer_id
);
598 return do_timer_create(which_clock
, NULL
, created_timer_id
);
602 COMPAT_SYSCALL_DEFINE3(timer_create
, clockid_t
, which_clock
,
603 struct compat_sigevent __user
*, timer_event_spec
,
604 timer_t __user
*, created_timer_id
)
606 if (timer_event_spec
) {
609 if (get_compat_sigevent(&event
, timer_event_spec
))
611 return do_timer_create(which_clock
, &event
, created_timer_id
);
613 return do_timer_create(which_clock
, NULL
, created_timer_id
);
618 * Locking issues: We need to protect the result of the id look up until
619 * we get the timer locked down so it is not deleted under us. The
620 * removal is done under the idr spinlock so we use that here to bridge
621 * the find to the timer lock. To avoid a dead lock, the timer id MUST
622 * be release with out holding the timer lock.
624 static struct k_itimer
*__lock_timer(timer_t timer_id
, unsigned long *flags
)
626 struct k_itimer
*timr
;
629 * timer_t could be any type >= int and we want to make sure any
630 * @timer_id outside positive int range fails lookup.
632 if ((unsigned long long)timer_id
> INT_MAX
)
636 timr
= posix_timer_by_id(timer_id
);
638 spin_lock_irqsave(&timr
->it_lock
, *flags
);
639 if (timr
->it_signal
== current
->signal
) {
643 spin_unlock_irqrestore(&timr
->it_lock
, *flags
);
650 static ktime_t
common_hrtimer_remaining(struct k_itimer
*timr
, ktime_t now
)
652 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
654 return __hrtimer_expires_remaining_adjusted(timer
, now
);
657 static int common_hrtimer_forward(struct k_itimer
*timr
, ktime_t now
)
659 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
661 return (int)hrtimer_forward(timer
, now
, timr
->it_interval
);
665 * Get the time remaining on a POSIX.1b interval timer. This function
666 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
669 * We have a couple of messes to clean up here. First there is the case
670 * of a timer that has a requeue pending. These timers should appear to
671 * be in the timer list with an expiry as if we were to requeue them
674 * The second issue is the SIGEV_NONE timer which may be active but is
675 * not really ever put in the timer list (to save system resources).
676 * This timer may be expired, and if so, we will do it here. Otherwise
677 * it is the same as a requeue pending timer WRT to what we should
680 void common_timer_get(struct k_itimer
*timr
, struct itimerspec64
*cur_setting
)
682 const struct k_clock
*kc
= timr
->kclock
;
683 ktime_t now
, remaining
, iv
;
684 struct timespec64 ts64
;
687 sig_none
= timr
->it_sigev_notify
== SIGEV_NONE
;
688 iv
= timr
->it_interval
;
690 /* interval timer ? */
692 cur_setting
->it_interval
= ktime_to_timespec64(iv
);
693 } else if (!timr
->it_active
) {
695 * SIGEV_NONE oneshot timers are never queued. Check them
703 * The timespec64 based conversion is suboptimal, but it's not
704 * worth to implement yet another callback.
706 kc
->clock_get(timr
->it_clock
, &ts64
);
707 now
= timespec64_to_ktime(ts64
);
710 * When a requeue is pending or this is a SIGEV_NONE timer move the
711 * expiry time forward by intervals, so expiry is > now.
713 if (iv
&& (timr
->it_requeue_pending
& REQUEUE_PENDING
|| sig_none
))
714 timr
->it_overrun
+= kc
->timer_forward(timr
, now
);
716 remaining
= kc
->timer_remaining(timr
, now
);
717 /* Return 0 only, when the timer is expired and not pending */
718 if (remaining
<= 0) {
720 * A single shot SIGEV_NONE timer must return 0, when
724 cur_setting
->it_value
.tv_nsec
= 1;
726 cur_setting
->it_value
= ktime_to_timespec64(remaining
);
730 /* Get the time remaining on a POSIX.1b interval timer. */
731 static int do_timer_gettime(timer_t timer_id
, struct itimerspec64
*setting
)
733 struct k_itimer
*timr
;
734 const struct k_clock
*kc
;
738 timr
= lock_timer(timer_id
, &flags
);
742 memset(setting
, 0, sizeof(*setting
));
744 if (WARN_ON_ONCE(!kc
|| !kc
->timer_get
))
747 kc
->timer_get(timr
, setting
);
749 unlock_timer(timr
, flags
);
753 /* Get the time remaining on a POSIX.1b interval timer. */
754 SYSCALL_DEFINE2(timer_gettime
, timer_t
, timer_id
,
755 struct itimerspec __user
*, setting
)
757 struct itimerspec64 cur_setting
;
759 int ret
= do_timer_gettime(timer_id
, &cur_setting
);
761 if (put_itimerspec64(&cur_setting
, setting
))
768 COMPAT_SYSCALL_DEFINE2(timer_gettime
, timer_t
, timer_id
,
769 struct compat_itimerspec __user
*, setting
)
771 struct itimerspec64 cur_setting
;
773 int ret
= do_timer_gettime(timer_id
, &cur_setting
);
775 if (put_compat_itimerspec64(&cur_setting
, setting
))
783 * Get the number of overruns of a POSIX.1b interval timer. This is to
784 * be the overrun of the timer last delivered. At the same time we are
785 * accumulating overruns on the next timer. The overrun is frozen when
786 * the signal is delivered, either at the notify time (if the info block
787 * is not queued) or at the actual delivery time (as we are informed by
788 * the call back to posixtimer_rearm(). So all we need to do is
789 * to pick up the frozen overrun.
791 SYSCALL_DEFINE1(timer_getoverrun
, timer_t
, timer_id
)
793 struct k_itimer
*timr
;
797 timr
= lock_timer(timer_id
, &flags
);
801 overrun
= timer_overrun_to_int(timr
, 0);
802 unlock_timer(timr
, flags
);
807 static void common_hrtimer_arm(struct k_itimer
*timr
, ktime_t expires
,
808 bool absolute
, bool sigev_none
)
810 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
811 enum hrtimer_mode mode
;
813 mode
= absolute
? HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
;
815 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
816 * clock modifications, so they become CLOCK_MONOTONIC based under the
817 * hood. See hrtimer_init(). Update timr->kclock, so the generic
818 * functions which use timr->kclock->clock_get() work.
820 * Note: it_clock stays unmodified, because the next timer_set() might
821 * use ABSTIME, so it needs to switch back.
823 if (timr
->it_clock
== CLOCK_REALTIME
)
824 timr
->kclock
= absolute
? &clock_realtime
: &clock_monotonic
;
826 hrtimer_init(&timr
->it
.real
.timer
, timr
->it_clock
, mode
);
827 timr
->it
.real
.timer
.function
= posix_timer_fn
;
830 expires
= ktime_add_safe(expires
, timer
->base
->get_time());
831 hrtimer_set_expires(timer
, expires
);
834 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS
);
837 static int common_hrtimer_try_to_cancel(struct k_itimer
*timr
)
839 return hrtimer_try_to_cancel(&timr
->it
.real
.timer
);
842 /* Set a POSIX.1b interval timer. */
843 int common_timer_set(struct k_itimer
*timr
, int flags
,
844 struct itimerspec64
*new_setting
,
845 struct itimerspec64
*old_setting
)
847 const struct k_clock
*kc
= timr
->kclock
;
852 common_timer_get(timr
, old_setting
);
854 /* Prevent rearming by clearing the interval */
855 timr
->it_interval
= 0;
857 * Careful here. On SMP systems the timer expiry function could be
858 * active and spinning on timr->it_lock.
860 if (kc
->timer_try_to_cancel(timr
) < 0)
864 timr
->it_requeue_pending
= (timr
->it_requeue_pending
+ 2) &
866 timr
->it_overrun_last
= 0;
868 /* Switch off the timer when it_value is zero */
869 if (!new_setting
->it_value
.tv_sec
&& !new_setting
->it_value
.tv_nsec
)
872 timr
->it_interval
= timespec64_to_ktime(new_setting
->it_interval
);
873 expires
= timespec64_to_ktime(new_setting
->it_value
);
874 sigev_none
= timr
->it_sigev_notify
== SIGEV_NONE
;
876 kc
->timer_arm(timr
, expires
, flags
& TIMER_ABSTIME
, sigev_none
);
877 timr
->it_active
= !sigev_none
;
881 static int do_timer_settime(timer_t timer_id
, int flags
,
882 struct itimerspec64
*new_spec64
,
883 struct itimerspec64
*old_spec64
)
885 const struct k_clock
*kc
;
886 struct k_itimer
*timr
;
890 if (!timespec64_valid(&new_spec64
->it_interval
) ||
891 !timespec64_valid(&new_spec64
->it_value
))
895 memset(old_spec64
, 0, sizeof(*old_spec64
));
897 timr
= lock_timer(timer_id
, &flag
);
902 if (WARN_ON_ONCE(!kc
|| !kc
->timer_set
))
905 error
= kc
->timer_set(timr
, flags
, new_spec64
, old_spec64
);
907 unlock_timer(timr
, flag
);
908 if (error
== TIMER_RETRY
) {
909 old_spec64
= NULL
; // We already got the old time...
916 /* Set a POSIX.1b interval timer */
917 SYSCALL_DEFINE4(timer_settime
, timer_t
, timer_id
, int, flags
,
918 const struct itimerspec __user
*, new_setting
,
919 struct itimerspec __user
*, old_setting
)
921 struct itimerspec64 new_spec
, old_spec
;
922 struct itimerspec64
*rtn
= old_setting
? &old_spec
: NULL
;
928 if (get_itimerspec64(&new_spec
, new_setting
))
931 error
= do_timer_settime(timer_id
, flags
, &new_spec
, rtn
);
932 if (!error
&& old_setting
) {
933 if (put_itimerspec64(&old_spec
, old_setting
))
940 COMPAT_SYSCALL_DEFINE4(timer_settime
, timer_t
, timer_id
, int, flags
,
941 struct compat_itimerspec __user
*, new,
942 struct compat_itimerspec __user
*, old
)
944 struct itimerspec64 new_spec
, old_spec
;
945 struct itimerspec64
*rtn
= old
? &old_spec
: NULL
;
950 if (get_compat_itimerspec64(&new_spec
, new))
953 error
= do_timer_settime(timer_id
, flags
, &new_spec
, rtn
);
955 if (put_compat_itimerspec64(&old_spec
, old
))
962 int common_timer_del(struct k_itimer
*timer
)
964 const struct k_clock
*kc
= timer
->kclock
;
966 timer
->it_interval
= 0;
967 if (kc
->timer_try_to_cancel(timer
) < 0)
969 timer
->it_active
= 0;
973 static inline int timer_delete_hook(struct k_itimer
*timer
)
975 const struct k_clock
*kc
= timer
->kclock
;
977 if (WARN_ON_ONCE(!kc
|| !kc
->timer_del
))
979 return kc
->timer_del(timer
);
982 /* Delete a POSIX.1b interval timer. */
983 SYSCALL_DEFINE1(timer_delete
, timer_t
, timer_id
)
985 struct k_itimer
*timer
;
989 timer
= lock_timer(timer_id
, &flags
);
993 if (timer_delete_hook(timer
) == TIMER_RETRY
) {
994 unlock_timer(timer
, flags
);
998 spin_lock(¤t
->sighand
->siglock
);
999 list_del(&timer
->list
);
1000 spin_unlock(¤t
->sighand
->siglock
);
1002 * This keeps any tasks waiting on the spin lock from thinking
1003 * they got something (see the lock code above).
1005 timer
->it_signal
= NULL
;
1007 unlock_timer(timer
, flags
);
1008 release_posix_timer(timer
, IT_ID_SET
);
1013 * return timer owned by the process, used by exit_itimers
1015 static void itimer_delete(struct k_itimer
*timer
)
1017 unsigned long flags
;
1020 spin_lock_irqsave(&timer
->it_lock
, flags
);
1022 if (timer_delete_hook(timer
) == TIMER_RETRY
) {
1023 unlock_timer(timer
, flags
);
1026 list_del(&timer
->list
);
1028 * This keeps any tasks waiting on the spin lock from thinking
1029 * they got something (see the lock code above).
1031 timer
->it_signal
= NULL
;
1033 unlock_timer(timer
, flags
);
1034 release_posix_timer(timer
, IT_ID_SET
);
1038 * This is called by do_exit or de_thread, only when there are no more
1039 * references to the shared signal_struct.
1041 void exit_itimers(struct signal_struct
*sig
)
1043 struct k_itimer
*tmr
;
1045 while (!list_empty(&sig
->posix_timers
)) {
1046 tmr
= list_entry(sig
->posix_timers
.next
, struct k_itimer
, list
);
1051 SYSCALL_DEFINE2(clock_settime
, const clockid_t
, which_clock
,
1052 const struct timespec __user
*, tp
)
1054 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1055 struct timespec64 new_tp
;
1057 if (!kc
|| !kc
->clock_set
)
1060 if (get_timespec64(&new_tp
, tp
))
1063 return kc
->clock_set(which_clock
, &new_tp
);
1066 SYSCALL_DEFINE2(clock_gettime
, const clockid_t
, which_clock
,
1067 struct timespec __user
*,tp
)
1069 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1070 struct timespec64 kernel_tp
;
1076 error
= kc
->clock_get(which_clock
, &kernel_tp
);
1078 if (!error
&& put_timespec64(&kernel_tp
, tp
))
1084 SYSCALL_DEFINE2(clock_adjtime
, const clockid_t
, which_clock
,
1085 struct timex __user
*, utx
)
1087 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1096 if (copy_from_user(&ktx
, utx
, sizeof(ktx
)))
1099 err
= kc
->clock_adj(which_clock
, &ktx
);
1101 if (err
>= 0 && copy_to_user(utx
, &ktx
, sizeof(ktx
)))
1107 SYSCALL_DEFINE2(clock_getres
, const clockid_t
, which_clock
,
1108 struct timespec __user
*, tp
)
1110 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1111 struct timespec64 rtn_tp
;
1117 error
= kc
->clock_getres(which_clock
, &rtn_tp
);
1119 if (!error
&& tp
&& put_timespec64(&rtn_tp
, tp
))
1125 #ifdef CONFIG_COMPAT
1127 COMPAT_SYSCALL_DEFINE2(clock_settime
, clockid_t
, which_clock
,
1128 struct compat_timespec __user
*, tp
)
1130 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1131 struct timespec64 ts
;
1133 if (!kc
|| !kc
->clock_set
)
1136 if (compat_get_timespec64(&ts
, tp
))
1139 return kc
->clock_set(which_clock
, &ts
);
1142 COMPAT_SYSCALL_DEFINE2(clock_gettime
, clockid_t
, which_clock
,
1143 struct compat_timespec __user
*, tp
)
1145 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1146 struct timespec64 ts
;
1152 err
= kc
->clock_get(which_clock
, &ts
);
1154 if (!err
&& compat_put_timespec64(&ts
, tp
))
1160 COMPAT_SYSCALL_DEFINE2(clock_adjtime
, clockid_t
, which_clock
,
1161 struct compat_timex __user
*, utp
)
1163 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1172 err
= compat_get_timex(&ktx
, utp
);
1176 err
= kc
->clock_adj(which_clock
, &ktx
);
1179 err
= compat_put_timex(utp
, &ktx
);
1184 COMPAT_SYSCALL_DEFINE2(clock_getres
, clockid_t
, which_clock
,
1185 struct compat_timespec __user
*, tp
)
1187 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1188 struct timespec64 ts
;
1194 err
= kc
->clock_getres(which_clock
, &ts
);
1195 if (!err
&& tp
&& compat_put_timespec64(&ts
, tp
))
1204 * nanosleep for monotonic and realtime clocks
1206 static int common_nsleep(const clockid_t which_clock
, int flags
,
1207 const struct timespec64
*rqtp
)
1209 return hrtimer_nanosleep(rqtp
, flags
& TIMER_ABSTIME
?
1210 HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
,
1214 SYSCALL_DEFINE4(clock_nanosleep
, const clockid_t
, which_clock
, int, flags
,
1215 const struct timespec __user
*, rqtp
,
1216 struct timespec __user
*, rmtp
)
1218 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1219 struct timespec64 t
;
1224 return -ENANOSLEEP_NOTSUP
;
1226 if (get_timespec64(&t
, rqtp
))
1229 if (!timespec64_valid(&t
))
1231 if (flags
& TIMER_ABSTIME
)
1233 current
->restart_block
.nanosleep
.type
= rmtp
? TT_NATIVE
: TT_NONE
;
1234 current
->restart_block
.nanosleep
.rmtp
= rmtp
;
1236 return kc
->nsleep(which_clock
, flags
, &t
);
1239 #ifdef CONFIG_COMPAT
1240 COMPAT_SYSCALL_DEFINE4(clock_nanosleep
, clockid_t
, which_clock
, int, flags
,
1241 struct compat_timespec __user
*, rqtp
,
1242 struct compat_timespec __user
*, rmtp
)
1244 const struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1245 struct timespec64 t
;
1250 return -ENANOSLEEP_NOTSUP
;
1252 if (compat_get_timespec64(&t
, rqtp
))
1255 if (!timespec64_valid(&t
))
1257 if (flags
& TIMER_ABSTIME
)
1259 current
->restart_block
.nanosleep
.type
= rmtp
? TT_COMPAT
: TT_NONE
;
1260 current
->restart_block
.nanosleep
.compat_rmtp
= rmtp
;
1262 return kc
->nsleep(which_clock
, flags
, &t
);
1266 static const struct k_clock clock_realtime
= {
1267 .clock_getres
= posix_get_hrtimer_res
,
1268 .clock_get
= posix_clock_realtime_get
,
1269 .clock_set
= posix_clock_realtime_set
,
1270 .clock_adj
= posix_clock_realtime_adj
,
1271 .nsleep
= common_nsleep
,
1272 .timer_create
= common_timer_create
,
1273 .timer_set
= common_timer_set
,
1274 .timer_get
= common_timer_get
,
1275 .timer_del
= common_timer_del
,
1276 .timer_rearm
= common_hrtimer_rearm
,
1277 .timer_forward
= common_hrtimer_forward
,
1278 .timer_remaining
= common_hrtimer_remaining
,
1279 .timer_try_to_cancel
= common_hrtimer_try_to_cancel
,
1280 .timer_arm
= common_hrtimer_arm
,
1283 static const struct k_clock clock_monotonic
= {
1284 .clock_getres
= posix_get_hrtimer_res
,
1285 .clock_get
= posix_ktime_get_ts
,
1286 .nsleep
= common_nsleep
,
1287 .timer_create
= common_timer_create
,
1288 .timer_set
= common_timer_set
,
1289 .timer_get
= common_timer_get
,
1290 .timer_del
= common_timer_del
,
1291 .timer_rearm
= common_hrtimer_rearm
,
1292 .timer_forward
= common_hrtimer_forward
,
1293 .timer_remaining
= common_hrtimer_remaining
,
1294 .timer_try_to_cancel
= common_hrtimer_try_to_cancel
,
1295 .timer_arm
= common_hrtimer_arm
,
1298 static const struct k_clock clock_monotonic_raw
= {
1299 .clock_getres
= posix_get_hrtimer_res
,
1300 .clock_get
= posix_get_monotonic_raw
,
1303 static const struct k_clock clock_realtime_coarse
= {
1304 .clock_getres
= posix_get_coarse_res
,
1305 .clock_get
= posix_get_realtime_coarse
,
1308 static const struct k_clock clock_monotonic_coarse
= {
1309 .clock_getres
= posix_get_coarse_res
,
1310 .clock_get
= posix_get_monotonic_coarse
,
1313 static const struct k_clock clock_tai
= {
1314 .clock_getres
= posix_get_hrtimer_res
,
1315 .clock_get
= posix_get_tai
,
1316 .nsleep
= common_nsleep
,
1317 .timer_create
= common_timer_create
,
1318 .timer_set
= common_timer_set
,
1319 .timer_get
= common_timer_get
,
1320 .timer_del
= common_timer_del
,
1321 .timer_rearm
= common_hrtimer_rearm
,
1322 .timer_forward
= common_hrtimer_forward
,
1323 .timer_remaining
= common_hrtimer_remaining
,
1324 .timer_try_to_cancel
= common_hrtimer_try_to_cancel
,
1325 .timer_arm
= common_hrtimer_arm
,
1328 static const struct k_clock clock_boottime
= {
1329 .clock_getres
= posix_get_hrtimer_res
,
1330 .clock_get
= posix_get_boottime
,
1331 .nsleep
= common_nsleep
,
1332 .timer_create
= common_timer_create
,
1333 .timer_set
= common_timer_set
,
1334 .timer_get
= common_timer_get
,
1335 .timer_del
= common_timer_del
,
1336 .timer_rearm
= common_hrtimer_rearm
,
1337 .timer_forward
= common_hrtimer_forward
,
1338 .timer_remaining
= common_hrtimer_remaining
,
1339 .timer_try_to_cancel
= common_hrtimer_try_to_cancel
,
1340 .timer_arm
= common_hrtimer_arm
,
1343 static const struct k_clock
* const posix_clocks
[] = {
1344 [CLOCK_REALTIME
] = &clock_realtime
,
1345 [CLOCK_MONOTONIC
] = &clock_monotonic
,
1346 [CLOCK_PROCESS_CPUTIME_ID
] = &clock_process
,
1347 [CLOCK_THREAD_CPUTIME_ID
] = &clock_thread
,
1348 [CLOCK_MONOTONIC_RAW
] = &clock_monotonic_raw
,
1349 [CLOCK_REALTIME_COARSE
] = &clock_realtime_coarse
,
1350 [CLOCK_MONOTONIC_COARSE
] = &clock_monotonic_coarse
,
1351 [CLOCK_BOOTTIME
] = &clock_boottime
,
1352 [CLOCK_REALTIME_ALARM
] = &alarm_clock
,
1353 [CLOCK_BOOTTIME_ALARM
] = &alarm_clock
,
1354 [CLOCK_TAI
] = &clock_tai
,
1357 static const struct k_clock
*clockid_to_kclock(const clockid_t id
)
1362 return (id
& CLOCKFD_MASK
) == CLOCKFD
?
1363 &clock_posix_dynamic
: &clock_posix_cpu
;
1366 if (id
>= ARRAY_SIZE(posix_clocks
))
1369 return posix_clocks
[array_index_nospec(idx
, ARRAY_SIZE(posix_clocks
))];