2 * linux/kernel/posix-timers.c
5 * 2002-10-15 Posix Clocks & timers
6 * by George Anzinger george@mvista.com
8 * Copyright (C) 2002 2003 by MontaVista Software.
10 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
11 * Copyright (C) 2004 Boris Hu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA
30 /* These are all the functions necessary to implement
31 * POSIX clocks & timers
34 #include <linux/interrupt.h>
35 #include <linux/slab.h>
36 #include <linux/time.h>
37 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
40 #include <linux/list.h>
41 #include <linux/init.h>
42 #include <linux/compiler.h>
43 #include <linux/idr.h>
44 #include <linux/posix-clock.h>
45 #include <linux/posix-timers.h>
46 #include <linux/syscalls.h>
47 #include <linux/wait.h>
48 #include <linux/workqueue.h>
49 #include <linux/export.h>
52 * Management arrays for POSIX timers. Timers are kept in slab memory
53 * Timer ids are allocated by an external routine that keeps track of the
54 * id and the timer. The external interface is:
56 * void *idr_find(struct idr *idp, int id); to find timer_id <id>
57 * int idr_get_new(struct idr *idp, void *ptr); to get a new id and
59 * void idr_remove(struct idr *idp, int id); to release <id>
60 * void idr_init(struct idr *idp); to initialize <idp>
62 * The idr_get_new *may* call slab for more memory so it must not be
63 * called under a spin lock. Likewise idr_remore may release memory
64 * (but it may be ok to do this under a lock...).
65 * idr_find is just a memory look up and is quite fast. A -1 return
66 * indicates that the requested id does not exist.
70 * Lets keep our timers in a slab cache :-)
72 static struct kmem_cache
*posix_timers_cache
;
73 static struct idr posix_timers_id
;
74 static DEFINE_SPINLOCK(idr_lock
);
77 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
78 * SIGEV values. Here we put out an error if this assumption fails.
80 #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
81 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
82 #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
86 * parisc wants ENOTSUP instead of EOPNOTSUPP
89 # define ENANOSLEEP_NOTSUP EOPNOTSUPP
91 # define ENANOSLEEP_NOTSUP ENOTSUP
95 * The timer ID is turned into a timer address by idr_find().
96 * Verifying a valid ID consists of:
98 * a) checking that idr_find() returns other than -1.
99 * b) checking that the timer id matches the one in the timer itself.
100 * c) that the timer owner is in the callers thread group.
104 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
105 * to implement others. This structure defines the various
108 * RESOLUTION: Clock resolution is used to round up timer and interval
109 * times, NOT to report clock times, which are reported with as
110 * much resolution as the system can muster. In some cases this
111 * resolution may depend on the underlying clock hardware and
112 * may not be quantifiable until run time, and only then is the
113 * necessary code is written. The standard says we should say
114 * something about this issue in the documentation...
116 * FUNCTIONS: The CLOCKs structure defines possible functions to
117 * handle various clock functions.
119 * The standard POSIX timer management code assumes the
120 * following: 1.) The k_itimer struct (sched.h) is used for
121 * the timer. 2.) The list, it_lock, it_clock, it_id and
122 * it_pid fields are not modified by timer code.
124 * Permissions: It is assumed that the clock_settime() function defined
125 * for each clock will take care of permission checks. Some
126 * clocks may be set able by any user (i.e. local process
127 * clocks) others not. Currently the only set able clock we
128 * have is CLOCK_REALTIME and its high res counter part, both of
129 * which we beg off on and pass to do_sys_settimeofday().
132 static struct k_clock posix_clocks
[MAX_CLOCKS
];
135 * These ones are defined below.
137 static int common_nsleep(const clockid_t
, int flags
, struct timespec
*t
,
138 struct timespec __user
*rmtp
);
139 static int common_timer_create(struct k_itimer
*new_timer
);
140 static void common_timer_get(struct k_itimer
*, struct itimerspec
*);
141 static int common_timer_set(struct k_itimer
*, int,
142 struct itimerspec
*, struct itimerspec
*);
143 static int common_timer_del(struct k_itimer
*timer
);
145 static enum hrtimer_restart
posix_timer_fn(struct hrtimer
*data
);
147 static struct k_itimer
*__lock_timer(timer_t timer_id
, unsigned long *flags
);
149 #define lock_timer(tid, flags) \
150 ({ struct k_itimer *__timr; \
151 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
155 static inline void unlock_timer(struct k_itimer
*timr
, unsigned long flags
)
157 spin_unlock_irqrestore(&timr
->it_lock
, flags
);
160 /* Get clock_realtime */
161 static int posix_clock_realtime_get(clockid_t which_clock
, struct timespec
*tp
)
163 ktime_get_real_ts(tp
);
167 /* Set clock_realtime */
168 static int posix_clock_realtime_set(const clockid_t which_clock
,
169 const struct timespec
*tp
)
171 return do_sys_settimeofday(tp
, NULL
);
174 static int posix_clock_realtime_adj(const clockid_t which_clock
,
177 return do_adjtimex(t
);
181 * Get monotonic time for posix timers
183 static int posix_ktime_get_ts(clockid_t which_clock
, struct timespec
*tp
)
190 * Get monotonic-raw time for posix timers
192 static int posix_get_monotonic_raw(clockid_t which_clock
, struct timespec
*tp
)
199 static int posix_get_realtime_coarse(clockid_t which_clock
, struct timespec
*tp
)
201 *tp
= current_kernel_time();
205 static int posix_get_monotonic_coarse(clockid_t which_clock
,
208 *tp
= get_monotonic_coarse();
212 static int posix_get_coarse_res(const clockid_t which_clock
, struct timespec
*tp
)
214 *tp
= ktime_to_timespec(KTIME_LOW_RES
);
218 static int posix_get_boottime(const clockid_t which_clock
, struct timespec
*tp
)
220 get_monotonic_boottime(tp
);
224 static int posix_get_tai(clockid_t which_clock
, struct timespec
*tp
)
226 timekeeping_clocktai(tp
);
231 * Initialize everything, well, just everything in Posix clocks/timers ;)
233 static __init
int init_posix_timers(void)
235 struct k_clock clock_realtime
= {
236 .clock_getres
= hrtimer_get_res
,
237 .clock_get
= posix_clock_realtime_get
,
238 .clock_set
= posix_clock_realtime_set
,
239 .clock_adj
= posix_clock_realtime_adj
,
240 .nsleep
= common_nsleep
,
241 .nsleep_restart
= hrtimer_nanosleep_restart
,
242 .timer_create
= common_timer_create
,
243 .timer_set
= common_timer_set
,
244 .timer_get
= common_timer_get
,
245 .timer_del
= common_timer_del
,
247 struct k_clock clock_monotonic
= {
248 .clock_getres
= hrtimer_get_res
,
249 .clock_get
= posix_ktime_get_ts
,
250 .nsleep
= common_nsleep
,
251 .nsleep_restart
= hrtimer_nanosleep_restart
,
252 .timer_create
= common_timer_create
,
253 .timer_set
= common_timer_set
,
254 .timer_get
= common_timer_get
,
255 .timer_del
= common_timer_del
,
257 struct k_clock clock_monotonic_raw
= {
258 .clock_getres
= hrtimer_get_res
,
259 .clock_get
= posix_get_monotonic_raw
,
261 struct k_clock clock_realtime_coarse
= {
262 .clock_getres
= posix_get_coarse_res
,
263 .clock_get
= posix_get_realtime_coarse
,
265 struct k_clock clock_monotonic_coarse
= {
266 .clock_getres
= posix_get_coarse_res
,
267 .clock_get
= posix_get_monotonic_coarse
,
269 struct k_clock clock_tai
= {
270 .clock_getres
= hrtimer_get_res
,
271 .clock_get
= posix_get_tai
,
273 struct k_clock clock_boottime
= {
274 .clock_getres
= hrtimer_get_res
,
275 .clock_get
= posix_get_boottime
,
276 .nsleep
= common_nsleep
,
277 .nsleep_restart
= hrtimer_nanosleep_restart
,
278 .timer_create
= common_timer_create
,
279 .timer_set
= common_timer_set
,
280 .timer_get
= common_timer_get
,
281 .timer_del
= common_timer_del
,
284 posix_timers_register_clock(CLOCK_REALTIME
, &clock_realtime
);
285 posix_timers_register_clock(CLOCK_MONOTONIC
, &clock_monotonic
);
286 posix_timers_register_clock(CLOCK_MONOTONIC_RAW
, &clock_monotonic_raw
);
287 posix_timers_register_clock(CLOCK_REALTIME_COARSE
, &clock_realtime_coarse
);
288 posix_timers_register_clock(CLOCK_MONOTONIC_COARSE
, &clock_monotonic_coarse
);
289 posix_timers_register_clock(CLOCK_BOOTTIME
, &clock_boottime
);
290 posix_timers_register_clock(CLOCK_TAI
, &clock_tai
);
292 posix_timers_cache
= kmem_cache_create("posix_timers_cache",
293 sizeof (struct k_itimer
), 0, SLAB_PANIC
,
295 idr_init(&posix_timers_id
);
299 __initcall(init_posix_timers
);
301 static void schedule_next_timer(struct k_itimer
*timr
)
303 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
305 if (timr
->it
.real
.interval
.tv64
== 0)
308 timr
->it_overrun
+= (unsigned int) hrtimer_forward(timer
,
309 timer
->base
->get_time(),
310 timr
->it
.real
.interval
);
312 timr
->it_overrun_last
= timr
->it_overrun
;
313 timr
->it_overrun
= -1;
314 ++timr
->it_requeue_pending
;
315 hrtimer_restart(timer
);
319 * This function is exported for use by the signal deliver code. It is
320 * called just prior to the info block being released and passes that
321 * block to us. It's function is to update the overrun entry AND to
322 * restart the timer. It should only be called if the timer is to be
323 * restarted (i.e. we have flagged this in the sys_private entry of the
326 * To protect against the timer going away while the interrupt is queued,
327 * we require that the it_requeue_pending flag be set.
329 void do_schedule_next_timer(struct siginfo
*info
)
331 struct k_itimer
*timr
;
334 timr
= lock_timer(info
->si_tid
, &flags
);
336 if (timr
&& timr
->it_requeue_pending
== info
->si_sys_private
) {
337 if (timr
->it_clock
< 0)
338 posix_cpu_timer_schedule(timr
);
340 schedule_next_timer(timr
);
342 info
->si_overrun
+= timr
->it_overrun_last
;
346 unlock_timer(timr
, flags
);
349 int posix_timer_event(struct k_itimer
*timr
, int si_private
)
351 struct task_struct
*task
;
352 int shared
, ret
= -1;
354 * FIXME: if ->sigq is queued we can race with
355 * dequeue_signal()->do_schedule_next_timer().
357 * If dequeue_signal() sees the "right" value of
358 * si_sys_private it calls do_schedule_next_timer().
359 * We re-queue ->sigq and drop ->it_lock().
360 * do_schedule_next_timer() locks the timer
361 * and re-schedules it while ->sigq is pending.
362 * Not really bad, but not that we want.
364 timr
->sigq
->info
.si_sys_private
= si_private
;
367 task
= pid_task(timr
->it_pid
, PIDTYPE_PID
);
369 shared
= !(timr
->it_sigev_notify
& SIGEV_THREAD_ID
);
370 ret
= send_sigqueue(timr
->sigq
, task
, shared
);
373 /* If we failed to send the signal the timer stops. */
376 EXPORT_SYMBOL_GPL(posix_timer_event
);
379 * This function gets called when a POSIX.1b interval timer expires. It
380 * is used as a callback from the kernel internal timer. The
381 * run_timer_list code ALWAYS calls with interrupts on.
383 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
385 static enum hrtimer_restart
posix_timer_fn(struct hrtimer
*timer
)
387 struct k_itimer
*timr
;
390 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
392 timr
= container_of(timer
, struct k_itimer
, it
.real
.timer
);
393 spin_lock_irqsave(&timr
->it_lock
, flags
);
395 if (timr
->it
.real
.interval
.tv64
!= 0)
396 si_private
= ++timr
->it_requeue_pending
;
398 if (posix_timer_event(timr
, si_private
)) {
400 * signal was not sent because of sig_ignor
401 * we will not get a call back to restart it AND
402 * it should be restarted.
404 if (timr
->it
.real
.interval
.tv64
!= 0) {
405 ktime_t now
= hrtimer_cb_get_time(timer
);
408 * FIXME: What we really want, is to stop this
409 * timer completely and restart it in case the
410 * SIG_IGN is removed. This is a non trivial
411 * change which involves sighand locking
412 * (sigh !), which we don't want to do late in
415 * For now we just let timers with an interval
416 * less than a jiffie expire every jiffie to
417 * avoid softirq starvation in case of SIG_IGN
418 * and a very small interval, which would put
419 * the timer right back on the softirq pending
420 * list. By moving now ahead of time we trick
421 * hrtimer_forward() to expire the timer
422 * later, while we still maintain the overrun
423 * accuracy, but have some inconsistency in
424 * the timer_gettime() case. This is at least
425 * better than a starved softirq. A more
426 * complex fix which solves also another related
427 * inconsistency is already in the pipeline.
429 #ifdef CONFIG_HIGH_RES_TIMERS
431 ktime_t kj
= ktime_set(0, NSEC_PER_SEC
/ HZ
);
433 if (timr
->it
.real
.interval
.tv64
< kj
.tv64
)
434 now
= ktime_add(now
, kj
);
437 timr
->it_overrun
+= (unsigned int)
438 hrtimer_forward(timer
, now
,
439 timr
->it
.real
.interval
);
440 ret
= HRTIMER_RESTART
;
441 ++timr
->it_requeue_pending
;
445 unlock_timer(timr
, flags
);
449 static struct pid
*good_sigevent(sigevent_t
* event
)
451 struct task_struct
*rtn
= current
->group_leader
;
453 if ((event
->sigev_notify
& SIGEV_THREAD_ID
) &&
454 (!(rtn
= find_task_by_vpid(event
->sigev_notify_thread_id
)) ||
455 !same_thread_group(rtn
, current
) ||
456 (event
->sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_SIGNAL
))
459 if (((event
->sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
) &&
460 ((event
->sigev_signo
<= 0) || (event
->sigev_signo
> SIGRTMAX
)))
463 return task_pid(rtn
);
466 void posix_timers_register_clock(const clockid_t clock_id
,
467 struct k_clock
*new_clock
)
469 if ((unsigned) clock_id
>= MAX_CLOCKS
) {
470 printk(KERN_WARNING
"POSIX clock register failed for clock_id %d\n",
475 if (!new_clock
->clock_get
) {
476 printk(KERN_WARNING
"POSIX clock id %d lacks clock_get()\n",
480 if (!new_clock
->clock_getres
) {
481 printk(KERN_WARNING
"POSIX clock id %d lacks clock_getres()\n",
486 posix_clocks
[clock_id
] = *new_clock
;
488 EXPORT_SYMBOL_GPL(posix_timers_register_clock
);
490 static struct k_itimer
* alloc_posix_timer(void)
492 struct k_itimer
*tmr
;
493 tmr
= kmem_cache_zalloc(posix_timers_cache
, GFP_KERNEL
);
496 if (unlikely(!(tmr
->sigq
= sigqueue_alloc()))) {
497 kmem_cache_free(posix_timers_cache
, tmr
);
500 memset(&tmr
->sigq
->info
, 0, sizeof(siginfo_t
));
504 static void k_itimer_rcu_free(struct rcu_head
*head
)
506 struct k_itimer
*tmr
= container_of(head
, struct k_itimer
, it
.rcu
);
508 kmem_cache_free(posix_timers_cache
, tmr
);
512 #define IT_ID_NOT_SET 0
513 static void release_posix_timer(struct k_itimer
*tmr
, int it_id_set
)
517 spin_lock_irqsave(&idr_lock
, flags
);
518 idr_remove(&posix_timers_id
, tmr
->it_id
);
519 spin_unlock_irqrestore(&idr_lock
, flags
);
521 put_pid(tmr
->it_pid
);
522 sigqueue_free(tmr
->sigq
);
523 call_rcu(&tmr
->it
.rcu
, k_itimer_rcu_free
);
526 static struct k_clock
*clockid_to_kclock(const clockid_t id
)
529 return (id
& CLOCKFD_MASK
) == CLOCKFD
?
530 &clock_posix_dynamic
: &clock_posix_cpu
;
532 if (id
>= MAX_CLOCKS
|| !posix_clocks
[id
].clock_getres
)
534 return &posix_clocks
[id
];
537 static int common_timer_create(struct k_itimer
*new_timer
)
539 hrtimer_init(&new_timer
->it
.real
.timer
, new_timer
->it_clock
, 0);
543 /* Create a POSIX.1b interval timer. */
545 SYSCALL_DEFINE3(timer_create
, const clockid_t
, which_clock
,
546 struct sigevent __user
*, timer_event_spec
,
547 timer_t __user
*, created_timer_id
)
549 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
550 struct k_itimer
*new_timer
;
551 int error
, new_timer_id
;
553 int it_id_set
= IT_ID_NOT_SET
;
557 if (!kc
->timer_create
)
560 new_timer
= alloc_posix_timer();
561 if (unlikely(!new_timer
))
564 spin_lock_init(&new_timer
->it_lock
);
566 idr_preload(GFP_KERNEL
);
567 spin_lock_irq(&idr_lock
);
568 error
= idr_alloc(&posix_timers_id
, new_timer
, 0, 0, GFP_NOWAIT
);
569 spin_unlock_irq(&idr_lock
);
573 * Weird looking, but we return EAGAIN if the IDR is
574 * full (proper POSIX return value for this)
576 if (error
== -ENOSPC
)
580 new_timer_id
= error
;
582 it_id_set
= IT_ID_SET
;
583 new_timer
->it_id
= (timer_t
) new_timer_id
;
584 new_timer
->it_clock
= which_clock
;
585 new_timer
->it_overrun
= -1;
587 if (timer_event_spec
) {
588 if (copy_from_user(&event
, timer_event_spec
, sizeof (event
))) {
593 new_timer
->it_pid
= get_pid(good_sigevent(&event
));
595 if (!new_timer
->it_pid
) {
600 event
.sigev_notify
= SIGEV_SIGNAL
;
601 event
.sigev_signo
= SIGALRM
;
602 event
.sigev_value
.sival_int
= new_timer
->it_id
;
603 new_timer
->it_pid
= get_pid(task_tgid(current
));
606 new_timer
->it_sigev_notify
= event
.sigev_notify
;
607 new_timer
->sigq
->info
.si_signo
= event
.sigev_signo
;
608 new_timer
->sigq
->info
.si_value
= event
.sigev_value
;
609 new_timer
->sigq
->info
.si_tid
= new_timer
->it_id
;
610 new_timer
->sigq
->info
.si_code
= SI_TIMER
;
612 if (copy_to_user(created_timer_id
,
613 &new_timer_id
, sizeof (new_timer_id
))) {
618 error
= kc
->timer_create(new_timer
);
622 spin_lock_irq(¤t
->sighand
->siglock
);
623 new_timer
->it_signal
= current
->signal
;
624 list_add(&new_timer
->list
, ¤t
->signal
->posix_timers
);
625 spin_unlock_irq(¤t
->sighand
->siglock
);
629 * In the case of the timer belonging to another task, after
630 * the task is unlocked, the timer is owned by the other task
631 * and may cease to exist at any time. Don't use or modify
632 * new_timer after the unlock call.
635 release_posix_timer(new_timer
, it_id_set
);
640 * Locking issues: We need to protect the result of the id look up until
641 * we get the timer locked down so it is not deleted under us. The
642 * removal is done under the idr spinlock so we use that here to bridge
643 * the find to the timer lock. To avoid a dead lock, the timer id MUST
644 * be release with out holding the timer lock.
646 static struct k_itimer
*__lock_timer(timer_t timer_id
, unsigned long *flags
)
648 struct k_itimer
*timr
;
651 * timer_t could be any type >= int and we want to make sure any
652 * @timer_id outside positive int range fails lookup.
654 if ((unsigned long long)timer_id
> INT_MAX
)
658 timr
= idr_find(&posix_timers_id
, (int)timer_id
);
660 spin_lock_irqsave(&timr
->it_lock
, *flags
);
661 if (timr
->it_signal
== current
->signal
) {
665 spin_unlock_irqrestore(&timr
->it_lock
, *flags
);
673 * Get the time remaining on a POSIX.1b interval timer. This function
674 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
677 * We have a couple of messes to clean up here. First there is the case
678 * of a timer that has a requeue pending. These timers should appear to
679 * be in the timer list with an expiry as if we were to requeue them
682 * The second issue is the SIGEV_NONE timer which may be active but is
683 * not really ever put in the timer list (to save system resources).
684 * This timer may be expired, and if so, we will do it here. Otherwise
685 * it is the same as a requeue pending timer WRT to what we should
689 common_timer_get(struct k_itimer
*timr
, struct itimerspec
*cur_setting
)
691 ktime_t now
, remaining
, iv
;
692 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
694 memset(cur_setting
, 0, sizeof(struct itimerspec
));
696 iv
= timr
->it
.real
.interval
;
698 /* interval timer ? */
700 cur_setting
->it_interval
= ktime_to_timespec(iv
);
701 else if (!hrtimer_active(timer
) &&
702 (timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
)
705 now
= timer
->base
->get_time();
708 * When a requeue is pending or this is a SIGEV_NONE
709 * timer move the expiry time forward by intervals, so
712 if (iv
.tv64
&& (timr
->it_requeue_pending
& REQUEUE_PENDING
||
713 (timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) == SIGEV_NONE
))
714 timr
->it_overrun
+= (unsigned int) hrtimer_forward(timer
, now
, iv
);
716 remaining
= ktime_sub(hrtimer_get_expires(timer
), now
);
717 /* Return 0 only, when the timer is expired and not pending */
718 if (remaining
.tv64
<= 0) {
720 * A single shot SIGEV_NONE timer must return 0, when
723 if ((timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) != SIGEV_NONE
)
724 cur_setting
->it_value
.tv_nsec
= 1;
726 cur_setting
->it_value
= ktime_to_timespec(remaining
);
729 /* Get the time remaining on a POSIX.1b interval timer. */
730 SYSCALL_DEFINE2(timer_gettime
, timer_t
, timer_id
,
731 struct itimerspec __user
*, setting
)
733 struct itimerspec cur_setting
;
734 struct k_itimer
*timr
;
739 timr
= lock_timer(timer_id
, &flags
);
743 kc
= clockid_to_kclock(timr
->it_clock
);
744 if (WARN_ON_ONCE(!kc
|| !kc
->timer_get
))
747 kc
->timer_get(timr
, &cur_setting
);
749 unlock_timer(timr
, flags
);
751 if (!ret
&& copy_to_user(setting
, &cur_setting
, sizeof (cur_setting
)))
758 * Get the number of overruns of a POSIX.1b interval timer. This is to
759 * be the overrun of the timer last delivered. At the same time we are
760 * accumulating overruns on the next timer. The overrun is frozen when
761 * the signal is delivered, either at the notify time (if the info block
762 * is not queued) or at the actual delivery time (as we are informed by
763 * the call back to do_schedule_next_timer(). So all we need to do is
764 * to pick up the frozen overrun.
766 SYSCALL_DEFINE1(timer_getoverrun
, timer_t
, timer_id
)
768 struct k_itimer
*timr
;
772 timr
= lock_timer(timer_id
, &flags
);
776 overrun
= timr
->it_overrun_last
;
777 unlock_timer(timr
, flags
);
782 /* Set a POSIX.1b interval timer. */
783 /* timr->it_lock is taken. */
785 common_timer_set(struct k_itimer
*timr
, int flags
,
786 struct itimerspec
*new_setting
, struct itimerspec
*old_setting
)
788 struct hrtimer
*timer
= &timr
->it
.real
.timer
;
789 enum hrtimer_mode mode
;
792 common_timer_get(timr
, old_setting
);
794 /* disable the timer */
795 timr
->it
.real
.interval
.tv64
= 0;
797 * careful here. If smp we could be in the "fire" routine which will
798 * be spinning as we hold the lock. But this is ONLY an SMP issue.
800 if (hrtimer_try_to_cancel(timer
) < 0)
803 timr
->it_requeue_pending
= (timr
->it_requeue_pending
+ 2) &
805 timr
->it_overrun_last
= 0;
807 /* switch off the timer when it_value is zero */
808 if (!new_setting
->it_value
.tv_sec
&& !new_setting
->it_value
.tv_nsec
)
811 mode
= flags
& TIMER_ABSTIME
? HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
;
812 hrtimer_init(&timr
->it
.real
.timer
, timr
->it_clock
, mode
);
813 timr
->it
.real
.timer
.function
= posix_timer_fn
;
815 hrtimer_set_expires(timer
, timespec_to_ktime(new_setting
->it_value
));
817 /* Convert interval */
818 timr
->it
.real
.interval
= timespec_to_ktime(new_setting
->it_interval
);
820 /* SIGEV_NONE timers are not queued ! See common_timer_get */
821 if (((timr
->it_sigev_notify
& ~SIGEV_THREAD_ID
) == SIGEV_NONE
)) {
822 /* Setup correct expiry time for relative timers */
823 if (mode
== HRTIMER_MODE_REL
) {
824 hrtimer_add_expires(timer
, timer
->base
->get_time());
829 hrtimer_start_expires(timer
, mode
);
833 /* Set a POSIX.1b interval timer */
834 SYSCALL_DEFINE4(timer_settime
, timer_t
, timer_id
, int, flags
,
835 const struct itimerspec __user
*, new_setting
,
836 struct itimerspec __user
*, old_setting
)
838 struct k_itimer
*timr
;
839 struct itimerspec new_spec
, old_spec
;
842 struct itimerspec
*rtn
= old_setting
? &old_spec
: NULL
;
848 if (copy_from_user(&new_spec
, new_setting
, sizeof (new_spec
)))
851 if (!timespec_valid(&new_spec
.it_interval
) ||
852 !timespec_valid(&new_spec
.it_value
))
855 timr
= lock_timer(timer_id
, &flag
);
859 kc
= clockid_to_kclock(timr
->it_clock
);
860 if (WARN_ON_ONCE(!kc
|| !kc
->timer_set
))
863 error
= kc
->timer_set(timr
, flags
, &new_spec
, rtn
);
865 unlock_timer(timr
, flag
);
866 if (error
== TIMER_RETRY
) {
867 rtn
= NULL
; // We already got the old time...
871 if (old_setting
&& !error
&&
872 copy_to_user(old_setting
, &old_spec
, sizeof (old_spec
)))
878 static int common_timer_del(struct k_itimer
*timer
)
880 timer
->it
.real
.interval
.tv64
= 0;
882 if (hrtimer_try_to_cancel(&timer
->it
.real
.timer
) < 0)
887 static inline int timer_delete_hook(struct k_itimer
*timer
)
889 struct k_clock
*kc
= clockid_to_kclock(timer
->it_clock
);
891 if (WARN_ON_ONCE(!kc
|| !kc
->timer_del
))
893 return kc
->timer_del(timer
);
896 /* Delete a POSIX.1b interval timer. */
897 SYSCALL_DEFINE1(timer_delete
, timer_t
, timer_id
)
899 struct k_itimer
*timer
;
903 timer
= lock_timer(timer_id
, &flags
);
907 if (timer_delete_hook(timer
) == TIMER_RETRY
) {
908 unlock_timer(timer
, flags
);
912 spin_lock(¤t
->sighand
->siglock
);
913 list_del(&timer
->list
);
914 spin_unlock(¤t
->sighand
->siglock
);
916 * This keeps any tasks waiting on the spin lock from thinking
917 * they got something (see the lock code above).
919 timer
->it_signal
= NULL
;
921 unlock_timer(timer
, flags
);
922 release_posix_timer(timer
, IT_ID_SET
);
927 * return timer owned by the process, used by exit_itimers
929 static void itimer_delete(struct k_itimer
*timer
)
934 spin_lock_irqsave(&timer
->it_lock
, flags
);
936 if (timer_delete_hook(timer
) == TIMER_RETRY
) {
937 unlock_timer(timer
, flags
);
940 list_del(&timer
->list
);
942 * This keeps any tasks waiting on the spin lock from thinking
943 * they got something (see the lock code above).
945 timer
->it_signal
= NULL
;
947 unlock_timer(timer
, flags
);
948 release_posix_timer(timer
, IT_ID_SET
);
952 * This is called by do_exit or de_thread, only when there are no more
953 * references to the shared signal_struct.
955 void exit_itimers(struct signal_struct
*sig
)
957 struct k_itimer
*tmr
;
959 while (!list_empty(&sig
->posix_timers
)) {
960 tmr
= list_entry(sig
->posix_timers
.next
, struct k_itimer
, list
);
965 SYSCALL_DEFINE2(clock_settime
, const clockid_t
, which_clock
,
966 const struct timespec __user
*, tp
)
968 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
969 struct timespec new_tp
;
971 if (!kc
|| !kc
->clock_set
)
974 if (copy_from_user(&new_tp
, tp
, sizeof (*tp
)))
977 return kc
->clock_set(which_clock
, &new_tp
);
980 SYSCALL_DEFINE2(clock_gettime
, const clockid_t
, which_clock
,
981 struct timespec __user
*,tp
)
983 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
984 struct timespec kernel_tp
;
990 error
= kc
->clock_get(which_clock
, &kernel_tp
);
992 if (!error
&& copy_to_user(tp
, &kernel_tp
, sizeof (kernel_tp
)))
998 SYSCALL_DEFINE2(clock_adjtime
, const clockid_t
, which_clock
,
999 struct timex __user
*, utx
)
1001 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1010 if (copy_from_user(&ktx
, utx
, sizeof(ktx
)))
1013 err
= kc
->clock_adj(which_clock
, &ktx
);
1015 if (err
>= 0 && copy_to_user(utx
, &ktx
, sizeof(ktx
)))
1021 SYSCALL_DEFINE2(clock_getres
, const clockid_t
, which_clock
,
1022 struct timespec __user
*, tp
)
1024 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1025 struct timespec rtn_tp
;
1031 error
= kc
->clock_getres(which_clock
, &rtn_tp
);
1033 if (!error
&& tp
&& copy_to_user(tp
, &rtn_tp
, sizeof (rtn_tp
)))
1040 * nanosleep for monotonic and realtime clocks
1042 static int common_nsleep(const clockid_t which_clock
, int flags
,
1043 struct timespec
*tsave
, struct timespec __user
*rmtp
)
1045 return hrtimer_nanosleep(tsave
, rmtp
, flags
& TIMER_ABSTIME
?
1046 HRTIMER_MODE_ABS
: HRTIMER_MODE_REL
,
1050 SYSCALL_DEFINE4(clock_nanosleep
, const clockid_t
, which_clock
, int, flags
,
1051 const struct timespec __user
*, rqtp
,
1052 struct timespec __user
*, rmtp
)
1054 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1060 return -ENANOSLEEP_NOTSUP
;
1062 if (copy_from_user(&t
, rqtp
, sizeof (struct timespec
)))
1065 if (!timespec_valid(&t
))
1068 return kc
->nsleep(which_clock
, flags
, &t
, rmtp
);
1072 * This will restart clock_nanosleep. This is required only by
1073 * compat_clock_nanosleep_restart for now.
1075 long clock_nanosleep_restart(struct restart_block
*restart_block
)
1077 clockid_t which_clock
= restart_block
->nanosleep
.clockid
;
1078 struct k_clock
*kc
= clockid_to_kclock(which_clock
);
1080 if (WARN_ON_ONCE(!kc
|| !kc
->nsleep_restart
))
1083 return kc
->nsleep_restart(restart_block
);