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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * 2002-10-15 Posix Clocks & timers
4 * by George Anzinger george@mvista.com
5 * Copyright (C) 2002 2003 by MontaVista Software.
6 *
7 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
8 * Copyright (C) 2004 Boris Hu
9 *
10 * These are all the functions necessary to implement POSIX clocks & timers
11 */
12#include <linux/mm.h>
13#include <linux/interrupt.h>
14#include <linux/slab.h>
15#include <linux/time.h>
16#include <linux/mutex.h>
17#include <linux/sched/task.h>
18
19#include <linux/uaccess.h>
20#include <linux/list.h>
21#include <linux/init.h>
22#include <linux/compiler.h>
23#include <linux/hash.h>
24#include <linux/posix-clock.h>
25#include <linux/posix-timers.h>
26#include <linux/syscalls.h>
27#include <linux/wait.h>
28#include <linux/workqueue.h>
29#include <linux/export.h>
30#include <linux/hashtable.h>
31#include <linux/compat.h>
32#include <linux/nospec.h>
33#include <linux/time_namespace.h>
34
35#include "timekeeping.h"
36#include "posix-timers.h"
37
38/*
39 * Management arrays for POSIX timers. Timers are now kept in static hash table
40 * with 512 entries.
41 * Timer ids are allocated by local routine, which selects proper hash head by
42 * key, constructed from current->signal address and per signal struct counter.
43 * This keeps timer ids unique per process, but now they can intersect between
44 * processes.
45 */
46
47/*
48 * Lets keep our timers in a slab cache :-)
49 */
50static struct kmem_cache *posix_timers_cache;
51
52static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
53static DEFINE_SPINLOCK(hash_lock);
54
55static const struct k_clock * const posix_clocks[];
56static const struct k_clock *clockid_to_kclock(const clockid_t id);
57static const struct k_clock clock_realtime, clock_monotonic;
58
59/*
60 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
61 * SIGEV values. Here we put out an error if this assumption fails.
62 */
63#if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
64 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
65#error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
66#endif
67
68/*
69 * The timer ID is turned into a timer address by idr_find().
70 * Verifying a valid ID consists of:
71 *
72 * a) checking that idr_find() returns other than -1.
73 * b) checking that the timer id matches the one in the timer itself.
74 * c) that the timer owner is in the callers thread group.
75 */
76
77/*
78 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
79 * to implement others. This structure defines the various
80 * clocks.
81 *
82 * RESOLUTION: Clock resolution is used to round up timer and interval
83 * times, NOT to report clock times, which are reported with as
84 * much resolution as the system can muster. In some cases this
85 * resolution may depend on the underlying clock hardware and
86 * may not be quantifiable until run time, and only then is the
87 * necessary code is written. The standard says we should say
88 * something about this issue in the documentation...
89 *
90 * FUNCTIONS: The CLOCKs structure defines possible functions to
91 * handle various clock functions.
92 *
93 * The standard POSIX timer management code assumes the
94 * following: 1.) The k_itimer struct (sched.h) is used for
95 * the timer. 2.) The list, it_lock, it_clock, it_id and
96 * it_pid fields are not modified by timer code.
97 *
98 * Permissions: It is assumed that the clock_settime() function defined
99 * for each clock will take care of permission checks. Some
100 * clocks may be set able by any user (i.e. local process
101 * clocks) others not. Currently the only set able clock we
102 * have is CLOCK_REALTIME and its high res counter part, both of
103 * which we beg off on and pass to do_sys_settimeofday().
104 */
105static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
106
107#define lock_timer(tid, flags) \
108({ struct k_itimer *__timr; \
109 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
110 __timr; \
111})
112
113static int hash(struct signal_struct *sig, unsigned int nr)
114{
115 return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable));
116}
117
118static struct k_itimer *__posix_timers_find(struct hlist_head *head,
119 struct signal_struct *sig,
120 timer_t id)
121{
122 struct k_itimer *timer;
123
124 hlist_for_each_entry_rcu(timer, head, t_hash,
125 lockdep_is_held(&hash_lock)) {
126 if ((timer->it_signal == sig) && (timer->it_id == id))
127 return timer;
128 }
129 return NULL;
130}
131
132static struct k_itimer *posix_timer_by_id(timer_t id)
133{
134 struct signal_struct *sig = current->signal;
135 struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)];
136
137 return __posix_timers_find(head, sig, id);
138}
139
140static int posix_timer_add(struct k_itimer *timer)
141{
142 struct signal_struct *sig = current->signal;
143 int first_free_id = sig->posix_timer_id;
144 struct hlist_head *head;
145 int ret = -ENOENT;
146
147 do {
148 spin_lock(&hash_lock);
149 head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)];
150 if (!__posix_timers_find(head, sig, sig->posix_timer_id)) {
151 hlist_add_head_rcu(&timer->t_hash, head);
152 ret = sig->posix_timer_id;
153 }
154 if (++sig->posix_timer_id < 0)
155 sig->posix_timer_id = 0;
156 if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT))
157 /* Loop over all possible ids completed */
158 ret = -EAGAIN;
159 spin_unlock(&hash_lock);
160 } while (ret == -ENOENT);
161 return ret;
162}
163
164static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
165{
166 spin_unlock_irqrestore(&timr->it_lock, flags);
167}
168
169/* Get clock_realtime */
170static int posix_get_realtime_timespec(clockid_t which_clock, struct timespec64 *tp)
171{
172 ktime_get_real_ts64(tp);
173 return 0;
174}
175
176static ktime_t posix_get_realtime_ktime(clockid_t which_clock)
177{
178 return ktime_get_real();
179}
180
181/* Set clock_realtime */
182static int posix_clock_realtime_set(const clockid_t which_clock,
183 const struct timespec64 *tp)
184{
185 return do_sys_settimeofday64(tp, NULL);
186}
187
188static int posix_clock_realtime_adj(const clockid_t which_clock,
189 struct __kernel_timex *t)
190{
191 return do_adjtimex(t);
192}
193
194/*
195 * Get monotonic time for posix timers
196 */
197static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp)
198{
199 ktime_get_ts64(tp);
200 timens_add_monotonic(tp);
201 return 0;
202}
203
204static ktime_t posix_get_monotonic_ktime(clockid_t which_clock)
205{
206 return ktime_get();
207}
208
209/*
210 * Get monotonic-raw time for posix timers
211 */
212static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
213{
214 ktime_get_raw_ts64(tp);
215 timens_add_monotonic(tp);
216 return 0;
217}
218
219
220static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp)
221{
222 ktime_get_coarse_real_ts64(tp);
223 return 0;
224}
225
226static int posix_get_monotonic_coarse(clockid_t which_clock,
227 struct timespec64 *tp)
228{
229 ktime_get_coarse_ts64(tp);
230 timens_add_monotonic(tp);
231 return 0;
232}
233
234static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
235{
236 *tp = ktime_to_timespec64(KTIME_LOW_RES);
237 return 0;
238}
239
240static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
241{
242 ktime_get_boottime_ts64(tp);
243 timens_add_boottime(tp);
244 return 0;
245}
246
247static ktime_t posix_get_boottime_ktime(const clockid_t which_clock)
248{
249 return ktime_get_boottime();
250}
251
252static int posix_get_tai_timespec(clockid_t which_clock, struct timespec64 *tp)
253{
254 ktime_get_clocktai_ts64(tp);
255 return 0;
256}
257
258static ktime_t posix_get_tai_ktime(clockid_t which_clock)
259{
260 return ktime_get_clocktai();
261}
262
263static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
264{
265 tp->tv_sec = 0;
266 tp->tv_nsec = hrtimer_resolution;
267 return 0;
268}
269
270/*
271 * Initialize everything, well, just everything in Posix clocks/timers ;)
272 */
273static __init int init_posix_timers(void)
274{
275 posix_timers_cache = kmem_cache_create("posix_timers_cache",
276 sizeof(struct k_itimer), 0,
277 SLAB_PANIC | SLAB_ACCOUNT, NULL);
278 return 0;
279}
280__initcall(init_posix_timers);
281
282/*
283 * The siginfo si_overrun field and the return value of timer_getoverrun(2)
284 * are of type int. Clamp the overrun value to INT_MAX
285 */
286static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
287{
288 s64 sum = timr->it_overrun_last + (s64)baseval;
289
290 return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
291}
292
293static void common_hrtimer_rearm(struct k_itimer *timr)
294{
295 struct hrtimer *timer = &timr->it.real.timer;
296
297 timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
298 timr->it_interval);
299 hrtimer_restart(timer);
300}
301
302/*
303 * This function is exported for use by the signal deliver code. It is
304 * called just prior to the info block being released and passes that
305 * block to us. It's function is to update the overrun entry AND to
306 * restart the timer. It should only be called if the timer is to be
307 * restarted (i.e. we have flagged this in the sys_private entry of the
308 * info block).
309 *
310 * To protect against the timer going away while the interrupt is queued,
311 * we require that the it_requeue_pending flag be set.
312 */
313void posixtimer_rearm(struct kernel_siginfo *info)
314{
315 struct k_itimer *timr;
316 unsigned long flags;
317
318 timr = lock_timer(info->si_tid, &flags);
319 if (!timr)
320 return;
321
322 if (timr->it_interval && timr->it_requeue_pending == info->si_sys_private) {
323 timr->kclock->timer_rearm(timr);
324
325 timr->it_active = 1;
326 timr->it_overrun_last = timr->it_overrun;
327 timr->it_overrun = -1LL;
328 ++timr->it_requeue_pending;
329
330 info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
331 }
332
333 unlock_timer(timr, flags);
334}
335
336int posix_timer_event(struct k_itimer *timr, int si_private)
337{
338 enum pid_type type;
339 int ret;
340 /*
341 * FIXME: if ->sigq is queued we can race with
342 * dequeue_signal()->posixtimer_rearm().
343 *
344 * If dequeue_signal() sees the "right" value of
345 * si_sys_private it calls posixtimer_rearm().
346 * We re-queue ->sigq and drop ->it_lock().
347 * posixtimer_rearm() locks the timer
348 * and re-schedules it while ->sigq is pending.
349 * Not really bad, but not that we want.
350 */
351 timr->sigq->info.si_sys_private = si_private;
352
353 type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID;
354 ret = send_sigqueue(timr->sigq, timr->it_pid, type);
355 /* If we failed to send the signal the timer stops. */
356 return ret > 0;
357}
358
359/*
360 * This function gets called when a POSIX.1b interval timer expires. It
361 * is used as a callback from the kernel internal timer. The
362 * run_timer_list code ALWAYS calls with interrupts on.
363
364 * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
365 */
366static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
367{
368 struct k_itimer *timr;
369 unsigned long flags;
370 int si_private = 0;
371 enum hrtimer_restart ret = HRTIMER_NORESTART;
372
373 timr = container_of(timer, struct k_itimer, it.real.timer);
374 spin_lock_irqsave(&timr->it_lock, flags);
375
376 timr->it_active = 0;
377 if (timr->it_interval != 0)
378 si_private = ++timr->it_requeue_pending;
379
380 if (posix_timer_event(timr, si_private)) {
381 /*
382 * signal was not sent because of sig_ignor
383 * we will not get a call back to restart it AND
384 * it should be restarted.
385 */
386 if (timr->it_interval != 0) {
387 ktime_t now = hrtimer_cb_get_time(timer);
388
389 /*
390 * FIXME: What we really want, is to stop this
391 * timer completely and restart it in case the
392 * SIG_IGN is removed. This is a non trivial
393 * change which involves sighand locking
394 * (sigh !), which we don't want to do late in
395 * the release cycle.
396 *
397 * For now we just let timers with an interval
398 * less than a jiffie expire every jiffie to
399 * avoid softirq starvation in case of SIG_IGN
400 * and a very small interval, which would put
401 * the timer right back on the softirq pending
402 * list. By moving now ahead of time we trick
403 * hrtimer_forward() to expire the timer
404 * later, while we still maintain the overrun
405 * accuracy, but have some inconsistency in
406 * the timer_gettime() case. This is at least
407 * better than a starved softirq. A more
408 * complex fix which solves also another related
409 * inconsistency is already in the pipeline.
410 */
411#ifdef CONFIG_HIGH_RES_TIMERS
412 {
413 ktime_t kj = NSEC_PER_SEC / HZ;
414
415 if (timr->it_interval < kj)
416 now = ktime_add(now, kj);
417 }
418#endif
419 timr->it_overrun += hrtimer_forward(timer, now,
420 timr->it_interval);
421 ret = HRTIMER_RESTART;
422 ++timr->it_requeue_pending;
423 timr->it_active = 1;
424 }
425 }
426
427 unlock_timer(timr, flags);
428 return ret;
429}
430
431static struct pid *good_sigevent(sigevent_t * event)
432{
433 struct pid *pid = task_tgid(current);
434 struct task_struct *rtn;
435
436 switch (event->sigev_notify) {
437 case SIGEV_SIGNAL | SIGEV_THREAD_ID:
438 pid = find_vpid(event->sigev_notify_thread_id);
439 rtn = pid_task(pid, PIDTYPE_PID);
440 if (!rtn || !same_thread_group(rtn, current))
441 return NULL;
442 fallthrough;
443 case SIGEV_SIGNAL:
444 case SIGEV_THREAD:
445 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
446 return NULL;
447 fallthrough;
448 case SIGEV_NONE:
449 return pid;
450 default:
451 return NULL;
452 }
453}
454
455static struct k_itimer * alloc_posix_timer(void)
456{
457 struct k_itimer *tmr;
458 tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
459 if (!tmr)
460 return tmr;
461 if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
462 kmem_cache_free(posix_timers_cache, tmr);
463 return NULL;
464 }
465 clear_siginfo(&tmr->sigq->info);
466 return tmr;
467}
468
469static void k_itimer_rcu_free(struct rcu_head *head)
470{
471 struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
472
473 kmem_cache_free(posix_timers_cache, tmr);
474}
475
476#define IT_ID_SET 1
477#define IT_ID_NOT_SET 0
478static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
479{
480 if (it_id_set) {
481 unsigned long flags;
482 spin_lock_irqsave(&hash_lock, flags);
483 hlist_del_rcu(&tmr->t_hash);
484 spin_unlock_irqrestore(&hash_lock, flags);
485 }
486 put_pid(tmr->it_pid);
487 sigqueue_free(tmr->sigq);
488 call_rcu(&tmr->rcu, k_itimer_rcu_free);
489}
490
491static int common_timer_create(struct k_itimer *new_timer)
492{
493 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
494 return 0;
495}
496
497/* Create a POSIX.1b interval timer. */
498static int do_timer_create(clockid_t which_clock, struct sigevent *event,
499 timer_t __user *created_timer_id)
500{
501 const struct k_clock *kc = clockid_to_kclock(which_clock);
502 struct k_itimer *new_timer;
503 int error, new_timer_id;
504 int it_id_set = IT_ID_NOT_SET;
505
506 if (!kc)
507 return -EINVAL;
508 if (!kc->timer_create)
509 return -EOPNOTSUPP;
510
511 new_timer = alloc_posix_timer();
512 if (unlikely(!new_timer))
513 return -EAGAIN;
514
515 spin_lock_init(&new_timer->it_lock);
516 new_timer_id = posix_timer_add(new_timer);
517 if (new_timer_id < 0) {
518 error = new_timer_id;
519 goto out;
520 }
521
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->kclock = kc;
526 new_timer->it_overrun = -1LL;
527
528 if (event) {
529 rcu_read_lock();
530 new_timer->it_pid = get_pid(good_sigevent(event));
531 rcu_read_unlock();
532 if (!new_timer->it_pid) {
533 error = -EINVAL;
534 goto out;
535 }
536 new_timer->it_sigev_notify = event->sigev_notify;
537 new_timer->sigq->info.si_signo = event->sigev_signo;
538 new_timer->sigq->info.si_value = event->sigev_value;
539 } else {
540 new_timer->it_sigev_notify = SIGEV_SIGNAL;
541 new_timer->sigq->info.si_signo = SIGALRM;
542 memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t));
543 new_timer->sigq->info.si_value.sival_int = new_timer->it_id;
544 new_timer->it_pid = get_pid(task_tgid(current));
545 }
546
547 new_timer->sigq->info.si_tid = new_timer->it_id;
548 new_timer->sigq->info.si_code = SI_TIMER;
549
550 if (copy_to_user(created_timer_id,
551 &new_timer_id, sizeof (new_timer_id))) {
552 error = -EFAULT;
553 goto out;
554 }
555
556 error = kc->timer_create(new_timer);
557 if (error)
558 goto out;
559
560 spin_lock_irq(¤t->sighand->siglock);
561 new_timer->it_signal = current->signal;
562 list_add(&new_timer->list, ¤t->signal->posix_timers);
563 spin_unlock_irq(¤t->sighand->siglock);
564
565 return 0;
566 /*
567 * In the case of the timer belonging to another task, after
568 * the task is unlocked, the timer is owned by the other task
569 * and may cease to exist at any time. Don't use or modify
570 * new_timer after the unlock call.
571 */
572out:
573 release_posix_timer(new_timer, it_id_set);
574 return error;
575}
576
577SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
578 struct sigevent __user *, timer_event_spec,
579 timer_t __user *, created_timer_id)
580{
581 if (timer_event_spec) {
582 sigevent_t event;
583
584 if (copy_from_user(&event, timer_event_spec, sizeof (event)))
585 return -EFAULT;
586 return do_timer_create(which_clock, &event, created_timer_id);
587 }
588 return do_timer_create(which_clock, NULL, created_timer_id);
589}
590
591#ifdef CONFIG_COMPAT
592COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
593 struct compat_sigevent __user *, timer_event_spec,
594 timer_t __user *, created_timer_id)
595{
596 if (timer_event_spec) {
597 sigevent_t event;
598
599 if (get_compat_sigevent(&event, timer_event_spec))
600 return -EFAULT;
601 return do_timer_create(which_clock, &event, created_timer_id);
602 }
603 return do_timer_create(which_clock, NULL, created_timer_id);
604}
605#endif
606
607/*
608 * Locking issues: We need to protect the result of the id look up until
609 * we get the timer locked down so it is not deleted under us. The
610 * removal is done under the idr spinlock so we use that here to bridge
611 * the find to the timer lock. To avoid a dead lock, the timer id MUST
612 * be release with out holding the timer lock.
613 */
614static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
615{
616 struct k_itimer *timr;
617
618 /*
619 * timer_t could be any type >= int and we want to make sure any
620 * @timer_id outside positive int range fails lookup.
621 */
622 if ((unsigned long long)timer_id > INT_MAX)
623 return NULL;
624
625 rcu_read_lock();
626 timr = posix_timer_by_id(timer_id);
627 if (timr) {
628 spin_lock_irqsave(&timr->it_lock, *flags);
629 if (timr->it_signal == current->signal) {
630 rcu_read_unlock();
631 return timr;
632 }
633 spin_unlock_irqrestore(&timr->it_lock, *flags);
634 }
635 rcu_read_unlock();
636
637 return NULL;
638}
639
640static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
641{
642 struct hrtimer *timer = &timr->it.real.timer;
643
644 return __hrtimer_expires_remaining_adjusted(timer, now);
645}
646
647static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
648{
649 struct hrtimer *timer = &timr->it.real.timer;
650
651 return hrtimer_forward(timer, now, timr->it_interval);
652}
653
654/*
655 * Get the time remaining on a POSIX.1b interval timer. This function
656 * is ALWAYS called with spin_lock_irq on the timer, thus it must not
657 * mess with irq.
658 *
659 * We have a couple of messes to clean up here. First there is the case
660 * of a timer that has a requeue pending. These timers should appear to
661 * be in the timer list with an expiry as if we were to requeue them
662 * now.
663 *
664 * The second issue is the SIGEV_NONE timer which may be active but is
665 * not really ever put in the timer list (to save system resources).
666 * This timer may be expired, and if so, we will do it here. Otherwise
667 * it is the same as a requeue pending timer WRT to what we should
668 * report.
669 */
670void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
671{
672 const struct k_clock *kc = timr->kclock;
673 ktime_t now, remaining, iv;
674 bool sig_none;
675
676 sig_none = timr->it_sigev_notify == SIGEV_NONE;
677 iv = timr->it_interval;
678
679 /* interval timer ? */
680 if (iv) {
681 cur_setting->it_interval = ktime_to_timespec64(iv);
682 } else if (!timr->it_active) {
683 /*
684 * SIGEV_NONE oneshot timers are never queued. Check them
685 * below.
686 */
687 if (!sig_none)
688 return;
689 }
690
691 now = kc->clock_get_ktime(timr->it_clock);
692
693 /*
694 * When a requeue is pending or this is a SIGEV_NONE timer move the
695 * expiry time forward by intervals, so expiry is > now.
696 */
697 if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
698 timr->it_overrun += kc->timer_forward(timr, now);
699
700 remaining = kc->timer_remaining(timr, now);
701 /* Return 0 only, when the timer is expired and not pending */
702 if (remaining <= 0) {
703 /*
704 * A single shot SIGEV_NONE timer must return 0, when
705 * it is expired !
706 */
707 if (!sig_none)
708 cur_setting->it_value.tv_nsec = 1;
709 } else {
710 cur_setting->it_value = ktime_to_timespec64(remaining);
711 }
712}
713
714/* Get the time remaining on a POSIX.1b interval timer. */
715static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting)
716{
717 struct k_itimer *timr;
718 const struct k_clock *kc;
719 unsigned long flags;
720 int ret = 0;
721
722 timr = lock_timer(timer_id, &flags);
723 if (!timr)
724 return -EINVAL;
725
726 memset(setting, 0, sizeof(*setting));
727 kc = timr->kclock;
728 if (WARN_ON_ONCE(!kc || !kc->timer_get))
729 ret = -EINVAL;
730 else
731 kc->timer_get(timr, setting);
732
733 unlock_timer(timr, flags);
734 return ret;
735}
736
737/* Get the time remaining on a POSIX.1b interval timer. */
738SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
739 struct __kernel_itimerspec __user *, setting)
740{
741 struct itimerspec64 cur_setting;
742
743 int ret = do_timer_gettime(timer_id, &cur_setting);
744 if (!ret) {
745 if (put_itimerspec64(&cur_setting, setting))
746 ret = -EFAULT;
747 }
748 return ret;
749}
750
751#ifdef CONFIG_COMPAT_32BIT_TIME
752
753SYSCALL_DEFINE2(timer_gettime32, timer_t, timer_id,
754 struct old_itimerspec32 __user *, setting)
755{
756 struct itimerspec64 cur_setting;
757
758 int ret = do_timer_gettime(timer_id, &cur_setting);
759 if (!ret) {
760 if (put_old_itimerspec32(&cur_setting, setting))
761 ret = -EFAULT;
762 }
763 return ret;
764}
765
766#endif
767
768/*
769 * Get the number of overruns of a POSIX.1b interval timer. This is to
770 * be the overrun of the timer last delivered. At the same time we are
771 * accumulating overruns on the next timer. The overrun is frozen when
772 * the signal is delivered, either at the notify time (if the info block
773 * is not queued) or at the actual delivery time (as we are informed by
774 * the call back to posixtimer_rearm(). So all we need to do is
775 * to pick up the frozen overrun.
776 */
777SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
778{
779 struct k_itimer *timr;
780 int overrun;
781 unsigned long flags;
782
783 timr = lock_timer(timer_id, &flags);
784 if (!timr)
785 return -EINVAL;
786
787 overrun = timer_overrun_to_int(timr, 0);
788 unlock_timer(timr, flags);
789
790 return overrun;
791}
792
793static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
794 bool absolute, bool sigev_none)
795{
796 struct hrtimer *timer = &timr->it.real.timer;
797 enum hrtimer_mode mode;
798
799 mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
800 /*
801 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
802 * clock modifications, so they become CLOCK_MONOTONIC based under the
803 * hood. See hrtimer_init(). Update timr->kclock, so the generic
804 * functions which use timr->kclock->clock_get_*() work.
805 *
806 * Note: it_clock stays unmodified, because the next timer_set() might
807 * use ABSTIME, so it needs to switch back.
808 */
809 if (timr->it_clock == CLOCK_REALTIME)
810 timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
811
812 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
813 timr->it.real.timer.function = posix_timer_fn;
814
815 if (!absolute)
816 expires = ktime_add_safe(expires, timer->base->get_time());
817 hrtimer_set_expires(timer, expires);
818
819 if (!sigev_none)
820 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
821}
822
823static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
824{
825 return hrtimer_try_to_cancel(&timr->it.real.timer);
826}
827
828static void common_timer_wait_running(struct k_itimer *timer)
829{
830 hrtimer_cancel_wait_running(&timer->it.real.timer);
831}
832
833/*
834 * On PREEMPT_RT this prevent priority inversion against softirq kthread in
835 * case it gets preempted while executing a timer callback. See comments in
836 * hrtimer_cancel_wait_running. For PREEMPT_RT=n this just results in a
837 * cpu_relax().
838 */
839static struct k_itimer *timer_wait_running(struct k_itimer *timer,
840 unsigned long *flags)
841{
842 const struct k_clock *kc = READ_ONCE(timer->kclock);
843 timer_t timer_id = READ_ONCE(timer->it_id);
844
845 /* Prevent kfree(timer) after dropping the lock */
846 rcu_read_lock();
847 unlock_timer(timer, *flags);
848
849 if (!WARN_ON_ONCE(!kc->timer_wait_running))
850 kc->timer_wait_running(timer);
851
852 rcu_read_unlock();
853 /* Relock the timer. It might be not longer hashed. */
854 return lock_timer(timer_id, flags);
855}
856
857/* Set a POSIX.1b interval timer. */
858int common_timer_set(struct k_itimer *timr, int flags,
859 struct itimerspec64 *new_setting,
860 struct itimerspec64 *old_setting)
861{
862 const struct k_clock *kc = timr->kclock;
863 bool sigev_none;
864 ktime_t expires;
865
866 if (old_setting)
867 common_timer_get(timr, old_setting);
868
869 /* Prevent rearming by clearing the interval */
870 timr->it_interval = 0;
871 /*
872 * Careful here. On SMP systems the timer expiry function could be
873 * active and spinning on timr->it_lock.
874 */
875 if (kc->timer_try_to_cancel(timr) < 0)
876 return TIMER_RETRY;
877
878 timr->it_active = 0;
879 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
880 ~REQUEUE_PENDING;
881 timr->it_overrun_last = 0;
882
883 /* Switch off the timer when it_value is zero */
884 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
885 return 0;
886
887 timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
888 expires = timespec64_to_ktime(new_setting->it_value);
889 if (flags & TIMER_ABSTIME)
890 expires = timens_ktime_to_host(timr->it_clock, expires);
891 sigev_none = timr->it_sigev_notify == SIGEV_NONE;
892
893 kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
894 timr->it_active = !sigev_none;
895 return 0;
896}
897
898static int do_timer_settime(timer_t timer_id, int tmr_flags,
899 struct itimerspec64 *new_spec64,
900 struct itimerspec64 *old_spec64)
901{
902 const struct k_clock *kc;
903 struct k_itimer *timr;
904 unsigned long flags;
905 int error = 0;
906
907 if (!timespec64_valid(&new_spec64->it_interval) ||
908 !timespec64_valid(&new_spec64->it_value))
909 return -EINVAL;
910
911 if (old_spec64)
912 memset(old_spec64, 0, sizeof(*old_spec64));
913
914 timr = lock_timer(timer_id, &flags);
915retry:
916 if (!timr)
917 return -EINVAL;
918
919 kc = timr->kclock;
920 if (WARN_ON_ONCE(!kc || !kc->timer_set))
921 error = -EINVAL;
922 else
923 error = kc->timer_set(timr, tmr_flags, new_spec64, old_spec64);
924
925 if (error == TIMER_RETRY) {
926 // We already got the old time...
927 old_spec64 = NULL;
928 /* Unlocks and relocks the timer if it still exists */
929 timr = timer_wait_running(timr, &flags);
930 goto retry;
931 }
932 unlock_timer(timr, flags);
933
934 return error;
935}
936
937/* Set a POSIX.1b interval timer */
938SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
939 const struct __kernel_itimerspec __user *, new_setting,
940 struct __kernel_itimerspec __user *, old_setting)
941{
942 struct itimerspec64 new_spec, old_spec;
943 struct itimerspec64 *rtn = old_setting ? &old_spec : NULL;
944 int error = 0;
945
946 if (!new_setting)
947 return -EINVAL;
948
949 if (get_itimerspec64(&new_spec, new_setting))
950 return -EFAULT;
951
952 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
953 if (!error && old_setting) {
954 if (put_itimerspec64(&old_spec, old_setting))
955 error = -EFAULT;
956 }
957 return error;
958}
959
960#ifdef CONFIG_COMPAT_32BIT_TIME
961SYSCALL_DEFINE4(timer_settime32, timer_t, timer_id, int, flags,
962 struct old_itimerspec32 __user *, new,
963 struct old_itimerspec32 __user *, old)
964{
965 struct itimerspec64 new_spec, old_spec;
966 struct itimerspec64 *rtn = old ? &old_spec : NULL;
967 int error = 0;
968
969 if (!new)
970 return -EINVAL;
971 if (get_old_itimerspec32(&new_spec, new))
972 return -EFAULT;
973
974 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
975 if (!error && old) {
976 if (put_old_itimerspec32(&old_spec, old))
977 error = -EFAULT;
978 }
979 return error;
980}
981#endif
982
983int common_timer_del(struct k_itimer *timer)
984{
985 const struct k_clock *kc = timer->kclock;
986
987 timer->it_interval = 0;
988 if (kc->timer_try_to_cancel(timer) < 0)
989 return TIMER_RETRY;
990 timer->it_active = 0;
991 return 0;
992}
993
994static inline int timer_delete_hook(struct k_itimer *timer)
995{
996 const struct k_clock *kc = timer->kclock;
997
998 if (WARN_ON_ONCE(!kc || !kc->timer_del))
999 return -EINVAL;
1000 return kc->timer_del(timer);
1001}
1002
1003/* Delete a POSIX.1b interval timer. */
1004SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
1005{
1006 struct k_itimer *timer;
1007 unsigned long flags;
1008
1009 timer = lock_timer(timer_id, &flags);
1010
1011retry_delete:
1012 if (!timer)
1013 return -EINVAL;
1014
1015 if (unlikely(timer_delete_hook(timer) == TIMER_RETRY)) {
1016 /* Unlocks and relocks the timer if it still exists */
1017 timer = timer_wait_running(timer, &flags);
1018 goto retry_delete;
1019 }
1020
1021 spin_lock(¤t->sighand->siglock);
1022 list_del(&timer->list);
1023 spin_unlock(¤t->sighand->siglock);
1024 /*
1025 * This keeps any tasks waiting on the spin lock from thinking
1026 * they got something (see the lock code above).
1027 */
1028 timer->it_signal = NULL;
1029
1030 unlock_timer(timer, flags);
1031 release_posix_timer(timer, IT_ID_SET);
1032 return 0;
1033}
1034
1035/*
1036 * return timer owned by the process, used by exit_itimers
1037 */
1038static void itimer_delete(struct k_itimer *timer)
1039{
1040retry_delete:
1041 spin_lock_irq(&timer->it_lock);
1042
1043 if (timer_delete_hook(timer) == TIMER_RETRY) {
1044 spin_unlock_irq(&timer->it_lock);
1045 goto retry_delete;
1046 }
1047 list_del(&timer->list);
1048
1049 spin_unlock_irq(&timer->it_lock);
1050 release_posix_timer(timer, IT_ID_SET);
1051}
1052
1053/*
1054 * This is called by do_exit or de_thread, only when nobody else can
1055 * modify the signal->posix_timers list. Yet we need sighand->siglock
1056 * to prevent the race with /proc/pid/timers.
1057 */
1058void exit_itimers(struct task_struct *tsk)
1059{
1060 struct list_head timers;
1061 struct k_itimer *tmr;
1062
1063 if (list_empty(&tsk->signal->posix_timers))
1064 return;
1065
1066 spin_lock_irq(&tsk->sighand->siglock);
1067 list_replace_init(&tsk->signal->posix_timers, &timers);
1068 spin_unlock_irq(&tsk->sighand->siglock);
1069
1070 while (!list_empty(&timers)) {
1071 tmr = list_first_entry(&timers, struct k_itimer, list);
1072 itimer_delete(tmr);
1073 }
1074}
1075
1076SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
1077 const struct __kernel_timespec __user *, tp)
1078{
1079 const struct k_clock *kc = clockid_to_kclock(which_clock);
1080 struct timespec64 new_tp;
1081
1082 if (!kc || !kc->clock_set)
1083 return -EINVAL;
1084
1085 if (get_timespec64(&new_tp, tp))
1086 return -EFAULT;
1087
1088 return kc->clock_set(which_clock, &new_tp);
1089}
1090
1091SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
1092 struct __kernel_timespec __user *, tp)
1093{
1094 const struct k_clock *kc = clockid_to_kclock(which_clock);
1095 struct timespec64 kernel_tp;
1096 int error;
1097
1098 if (!kc)
1099 return -EINVAL;
1100
1101 error = kc->clock_get_timespec(which_clock, &kernel_tp);
1102
1103 if (!error && put_timespec64(&kernel_tp, tp))
1104 error = -EFAULT;
1105
1106 return error;
1107}
1108
1109int do_clock_adjtime(const clockid_t which_clock, struct __kernel_timex * ktx)
1110{
1111 const struct k_clock *kc = clockid_to_kclock(which_clock);
1112
1113 if (!kc)
1114 return -EINVAL;
1115 if (!kc->clock_adj)
1116 return -EOPNOTSUPP;
1117
1118 return kc->clock_adj(which_clock, ktx);
1119}
1120
1121SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1122 struct __kernel_timex __user *, utx)
1123{
1124 struct __kernel_timex ktx;
1125 int err;
1126
1127 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1128 return -EFAULT;
1129
1130 err = do_clock_adjtime(which_clock, &ktx);
1131
1132 if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1133 return -EFAULT;
1134
1135 return err;
1136}
1137
1138SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1139 struct __kernel_timespec __user *, tp)
1140{
1141 const struct k_clock *kc = clockid_to_kclock(which_clock);
1142 struct timespec64 rtn_tp;
1143 int error;
1144
1145 if (!kc)
1146 return -EINVAL;
1147
1148 error = kc->clock_getres(which_clock, &rtn_tp);
1149
1150 if (!error && tp && put_timespec64(&rtn_tp, tp))
1151 error = -EFAULT;
1152
1153 return error;
1154}
1155
1156#ifdef CONFIG_COMPAT_32BIT_TIME
1157
1158SYSCALL_DEFINE2(clock_settime32, clockid_t, which_clock,
1159 struct old_timespec32 __user *, tp)
1160{
1161 const struct k_clock *kc = clockid_to_kclock(which_clock);
1162 struct timespec64 ts;
1163
1164 if (!kc || !kc->clock_set)
1165 return -EINVAL;
1166
1167 if (get_old_timespec32(&ts, tp))
1168 return -EFAULT;
1169
1170 return kc->clock_set(which_clock, &ts);
1171}
1172
1173SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock,
1174 struct old_timespec32 __user *, tp)
1175{
1176 const struct k_clock *kc = clockid_to_kclock(which_clock);
1177 struct timespec64 ts;
1178 int err;
1179
1180 if (!kc)
1181 return -EINVAL;
1182
1183 err = kc->clock_get_timespec(which_clock, &ts);
1184
1185 if (!err && put_old_timespec32(&ts, tp))
1186 err = -EFAULT;
1187
1188 return err;
1189}
1190
1191SYSCALL_DEFINE2(clock_adjtime32, clockid_t, which_clock,
1192 struct old_timex32 __user *, utp)
1193{
1194 struct __kernel_timex ktx;
1195 int err;
1196
1197 err = get_old_timex32(&ktx, utp);
1198 if (err)
1199 return err;
1200
1201 err = do_clock_adjtime(which_clock, &ktx);
1202
1203 if (err >= 0 && put_old_timex32(utp, &ktx))
1204 return -EFAULT;
1205
1206 return err;
1207}
1208
1209SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
1210 struct old_timespec32 __user *, tp)
1211{
1212 const struct k_clock *kc = clockid_to_kclock(which_clock);
1213 struct timespec64 ts;
1214 int err;
1215
1216 if (!kc)
1217 return -EINVAL;
1218
1219 err = kc->clock_getres(which_clock, &ts);
1220 if (!err && tp && put_old_timespec32(&ts, tp))
1221 return -EFAULT;
1222
1223 return err;
1224}
1225
1226#endif
1227
1228/*
1229 * nanosleep for monotonic and realtime clocks
1230 */
1231static int common_nsleep(const clockid_t which_clock, int flags,
1232 const struct timespec64 *rqtp)
1233{
1234 ktime_t texp = timespec64_to_ktime(*rqtp);
1235
1236 return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1237 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1238 which_clock);
1239}
1240
1241static int common_nsleep_timens(const clockid_t which_clock, int flags,
1242 const struct timespec64 *rqtp)
1243{
1244 ktime_t texp = timespec64_to_ktime(*rqtp);
1245
1246 if (flags & TIMER_ABSTIME)
1247 texp = timens_ktime_to_host(which_clock, texp);
1248
1249 return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1250 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1251 which_clock);
1252}
1253
1254SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1255 const struct __kernel_timespec __user *, rqtp,
1256 struct __kernel_timespec __user *, rmtp)
1257{
1258 const struct k_clock *kc = clockid_to_kclock(which_clock);
1259 struct timespec64 t;
1260
1261 if (!kc)
1262 return -EINVAL;
1263 if (!kc->nsleep)
1264 return -EOPNOTSUPP;
1265
1266 if (get_timespec64(&t, rqtp))
1267 return -EFAULT;
1268
1269 if (!timespec64_valid(&t))
1270 return -EINVAL;
1271 if (flags & TIMER_ABSTIME)
1272 rmtp = NULL;
1273 current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
1274 current->restart_block.nanosleep.rmtp = rmtp;
1275
1276 return kc->nsleep(which_clock, flags, &t);
1277}
1278
1279#ifdef CONFIG_COMPAT_32BIT_TIME
1280
1281SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
1282 struct old_timespec32 __user *, rqtp,
1283 struct old_timespec32 __user *, rmtp)
1284{
1285 const struct k_clock *kc = clockid_to_kclock(which_clock);
1286 struct timespec64 t;
1287
1288 if (!kc)
1289 return -EINVAL;
1290 if (!kc->nsleep)
1291 return -EOPNOTSUPP;
1292
1293 if (get_old_timespec32(&t, rqtp))
1294 return -EFAULT;
1295
1296 if (!timespec64_valid(&t))
1297 return -EINVAL;
1298 if (flags & TIMER_ABSTIME)
1299 rmtp = NULL;
1300 current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
1301 current->restart_block.nanosleep.compat_rmtp = rmtp;
1302
1303 return kc->nsleep(which_clock, flags, &t);
1304}
1305
1306#endif
1307
1308static const struct k_clock clock_realtime = {
1309 .clock_getres = posix_get_hrtimer_res,
1310 .clock_get_timespec = posix_get_realtime_timespec,
1311 .clock_get_ktime = posix_get_realtime_ktime,
1312 .clock_set = posix_clock_realtime_set,
1313 .clock_adj = posix_clock_realtime_adj,
1314 .nsleep = common_nsleep,
1315 .timer_create = common_timer_create,
1316 .timer_set = common_timer_set,
1317 .timer_get = common_timer_get,
1318 .timer_del = common_timer_del,
1319 .timer_rearm = common_hrtimer_rearm,
1320 .timer_forward = common_hrtimer_forward,
1321 .timer_remaining = common_hrtimer_remaining,
1322 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1323 .timer_wait_running = common_timer_wait_running,
1324 .timer_arm = common_hrtimer_arm,
1325};
1326
1327static const struct k_clock clock_monotonic = {
1328 .clock_getres = posix_get_hrtimer_res,
1329 .clock_get_timespec = posix_get_monotonic_timespec,
1330 .clock_get_ktime = posix_get_monotonic_ktime,
1331 .nsleep = common_nsleep_timens,
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_wait_running = common_timer_wait_running,
1341 .timer_arm = common_hrtimer_arm,
1342};
1343
1344static const struct k_clock clock_monotonic_raw = {
1345 .clock_getres = posix_get_hrtimer_res,
1346 .clock_get_timespec = posix_get_monotonic_raw,
1347};
1348
1349static const struct k_clock clock_realtime_coarse = {
1350 .clock_getres = posix_get_coarse_res,
1351 .clock_get_timespec = posix_get_realtime_coarse,
1352};
1353
1354static const struct k_clock clock_monotonic_coarse = {
1355 .clock_getres = posix_get_coarse_res,
1356 .clock_get_timespec = posix_get_monotonic_coarse,
1357};
1358
1359static const struct k_clock clock_tai = {
1360 .clock_getres = posix_get_hrtimer_res,
1361 .clock_get_ktime = posix_get_tai_ktime,
1362 .clock_get_timespec = posix_get_tai_timespec,
1363 .nsleep = common_nsleep,
1364 .timer_create = common_timer_create,
1365 .timer_set = common_timer_set,
1366 .timer_get = common_timer_get,
1367 .timer_del = common_timer_del,
1368 .timer_rearm = common_hrtimer_rearm,
1369 .timer_forward = common_hrtimer_forward,
1370 .timer_remaining = common_hrtimer_remaining,
1371 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1372 .timer_wait_running = common_timer_wait_running,
1373 .timer_arm = common_hrtimer_arm,
1374};
1375
1376static const struct k_clock clock_boottime = {
1377 .clock_getres = posix_get_hrtimer_res,
1378 .clock_get_ktime = posix_get_boottime_ktime,
1379 .clock_get_timespec = posix_get_boottime_timespec,
1380 .nsleep = common_nsleep_timens,
1381 .timer_create = common_timer_create,
1382 .timer_set = common_timer_set,
1383 .timer_get = common_timer_get,
1384 .timer_del = common_timer_del,
1385 .timer_rearm = common_hrtimer_rearm,
1386 .timer_forward = common_hrtimer_forward,
1387 .timer_remaining = common_hrtimer_remaining,
1388 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1389 .timer_wait_running = common_timer_wait_running,
1390 .timer_arm = common_hrtimer_arm,
1391};
1392
1393static const struct k_clock * const posix_clocks[] = {
1394 [CLOCK_REALTIME] = &clock_realtime,
1395 [CLOCK_MONOTONIC] = &clock_monotonic,
1396 [CLOCK_PROCESS_CPUTIME_ID] = &clock_process,
1397 [CLOCK_THREAD_CPUTIME_ID] = &clock_thread,
1398 [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw,
1399 [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse,
1400 [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse,
1401 [CLOCK_BOOTTIME] = &clock_boottime,
1402 [CLOCK_REALTIME_ALARM] = &alarm_clock,
1403 [CLOCK_BOOTTIME_ALARM] = &alarm_clock,
1404 [CLOCK_TAI] = &clock_tai,
1405};
1406
1407static const struct k_clock *clockid_to_kclock(const clockid_t id)
1408{
1409 clockid_t idx = id;
1410
1411 if (id < 0) {
1412 return (id & CLOCKFD_MASK) == CLOCKFD ?
1413 &clock_posix_dynamic : &clock_posix_cpu;
1414 }
1415
1416 if (id >= ARRAY_SIZE(posix_clocks))
1417 return NULL;
1418
1419 return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];
1420}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * 2002-10-15 Posix Clocks & timers
4 * by George Anzinger george@mvista.com
5 * Copyright (C) 2002 2003 by MontaVista Software.
6 *
7 * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
8 * Copyright (C) 2004 Boris Hu
9 *
10 * These are all the functions necessary to implement POSIX clocks & timers
11 */
12#include <linux/mm.h>
13#include <linux/interrupt.h>
14#include <linux/slab.h>
15#include <linux/time.h>
16#include <linux/mutex.h>
17#include <linux/sched/task.h>
18
19#include <linux/uaccess.h>
20#include <linux/list.h>
21#include <linux/init.h>
22#include <linux/compiler.h>
23#include <linux/hash.h>
24#include <linux/posix-clock.h>
25#include <linux/posix-timers.h>
26#include <linux/syscalls.h>
27#include <linux/wait.h>
28#include <linux/workqueue.h>
29#include <linux/export.h>
30#include <linux/hashtable.h>
31#include <linux/compat.h>
32#include <linux/nospec.h>
33#include <linux/time_namespace.h>
34
35#include "timekeeping.h"
36#include "posix-timers.h"
37
38static struct kmem_cache *posix_timers_cache;
39
40/*
41 * Timers are managed in a hash table for lockless lookup. The hash key is
42 * constructed from current::signal and the timer ID and the timer is
43 * matched against current::signal and the timer ID when walking the hash
44 * bucket list.
45 *
46 * This allows checkpoint/restore to reconstruct the exact timer IDs for
47 * a process.
48 */
49static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
50static DEFINE_SPINLOCK(hash_lock);
51
52static const struct k_clock * const posix_clocks[];
53static const struct k_clock *clockid_to_kclock(const clockid_t id);
54static const struct k_clock clock_realtime, clock_monotonic;
55
56/* SIGEV_THREAD_ID cannot share a bit with the other SIGEV values. */
57#if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
58 ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
59#error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
60#endif
61
62static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
63
64#define lock_timer(tid, flags) \
65({ struct k_itimer *__timr; \
66 __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \
67 __timr; \
68})
69
70static int hash(struct signal_struct *sig, unsigned int nr)
71{
72 return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable));
73}
74
75static struct k_itimer *__posix_timers_find(struct hlist_head *head,
76 struct signal_struct *sig,
77 timer_t id)
78{
79 struct k_itimer *timer;
80
81 hlist_for_each_entry_rcu(timer, head, t_hash, lockdep_is_held(&hash_lock)) {
82 /* timer->it_signal can be set concurrently */
83 if ((READ_ONCE(timer->it_signal) == sig) && (timer->it_id == id))
84 return timer;
85 }
86 return NULL;
87}
88
89static struct k_itimer *posix_timer_by_id(timer_t id)
90{
91 struct signal_struct *sig = current->signal;
92 struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)];
93
94 return __posix_timers_find(head, sig, id);
95}
96
97static int posix_timer_add(struct k_itimer *timer)
98{
99 struct signal_struct *sig = current->signal;
100 struct hlist_head *head;
101 unsigned int cnt, id;
102
103 /*
104 * FIXME: Replace this by a per signal struct xarray once there is
105 * a plan to handle the resulting CRIU regression gracefully.
106 */
107 for (cnt = 0; cnt <= INT_MAX; cnt++) {
108 spin_lock(&hash_lock);
109 id = sig->next_posix_timer_id;
110
111 /* Write the next ID back. Clamp it to the positive space */
112 sig->next_posix_timer_id = (id + 1) & INT_MAX;
113
114 head = &posix_timers_hashtable[hash(sig, id)];
115 if (!__posix_timers_find(head, sig, id)) {
116 hlist_add_head_rcu(&timer->t_hash, head);
117 spin_unlock(&hash_lock);
118 return id;
119 }
120 spin_unlock(&hash_lock);
121 }
122 /* POSIX return code when no timer ID could be allocated */
123 return -EAGAIN;
124}
125
126static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
127{
128 spin_unlock_irqrestore(&timr->it_lock, flags);
129}
130
131static int posix_get_realtime_timespec(clockid_t which_clock, struct timespec64 *tp)
132{
133 ktime_get_real_ts64(tp);
134 return 0;
135}
136
137static ktime_t posix_get_realtime_ktime(clockid_t which_clock)
138{
139 return ktime_get_real();
140}
141
142static int posix_clock_realtime_set(const clockid_t which_clock,
143 const struct timespec64 *tp)
144{
145 return do_sys_settimeofday64(tp, NULL);
146}
147
148static int posix_clock_realtime_adj(const clockid_t which_clock,
149 struct __kernel_timex *t)
150{
151 return do_adjtimex(t);
152}
153
154static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp)
155{
156 ktime_get_ts64(tp);
157 timens_add_monotonic(tp);
158 return 0;
159}
160
161static ktime_t posix_get_monotonic_ktime(clockid_t which_clock)
162{
163 return ktime_get();
164}
165
166static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
167{
168 ktime_get_raw_ts64(tp);
169 timens_add_monotonic(tp);
170 return 0;
171}
172
173static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp)
174{
175 ktime_get_coarse_real_ts64(tp);
176 return 0;
177}
178
179static int posix_get_monotonic_coarse(clockid_t which_clock,
180 struct timespec64 *tp)
181{
182 ktime_get_coarse_ts64(tp);
183 timens_add_monotonic(tp);
184 return 0;
185}
186
187static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
188{
189 *tp = ktime_to_timespec64(KTIME_LOW_RES);
190 return 0;
191}
192
193static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
194{
195 ktime_get_boottime_ts64(tp);
196 timens_add_boottime(tp);
197 return 0;
198}
199
200static ktime_t posix_get_boottime_ktime(const clockid_t which_clock)
201{
202 return ktime_get_boottime();
203}
204
205static int posix_get_tai_timespec(clockid_t which_clock, struct timespec64 *tp)
206{
207 ktime_get_clocktai_ts64(tp);
208 return 0;
209}
210
211static ktime_t posix_get_tai_ktime(clockid_t which_clock)
212{
213 return ktime_get_clocktai();
214}
215
216static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
217{
218 tp->tv_sec = 0;
219 tp->tv_nsec = hrtimer_resolution;
220 return 0;
221}
222
223static __init int init_posix_timers(void)
224{
225 posix_timers_cache = kmem_cache_create("posix_timers_cache",
226 sizeof(struct k_itimer), 0,
227 SLAB_PANIC | SLAB_ACCOUNT, NULL);
228 return 0;
229}
230__initcall(init_posix_timers);
231
232/*
233 * The siginfo si_overrun field and the return value of timer_getoverrun(2)
234 * are of type int. Clamp the overrun value to INT_MAX
235 */
236static inline int timer_overrun_to_int(struct k_itimer *timr)
237{
238 if (timr->it_overrun_last > (s64)INT_MAX)
239 return INT_MAX;
240
241 return (int)timr->it_overrun_last;
242}
243
244static void common_hrtimer_rearm(struct k_itimer *timr)
245{
246 struct hrtimer *timer = &timr->it.real.timer;
247
248 timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
249 timr->it_interval);
250 hrtimer_restart(timer);
251}
252
253static bool __posixtimer_deliver_signal(struct kernel_siginfo *info, struct k_itimer *timr)
254{
255 guard(spinlock)(&timr->it_lock);
256
257 /*
258 * Check if the timer is still alive or whether it got modified
259 * since the signal was queued. In either case, don't rearm and
260 * drop the signal.
261 */
262 if (timr->it_signal_seq != timr->it_sigqueue_seq || WARN_ON_ONCE(!timr->it_signal))
263 return false;
264
265 if (!timr->it_interval || WARN_ON_ONCE(timr->it_status != POSIX_TIMER_REQUEUE_PENDING))
266 return true;
267
268 timr->kclock->timer_rearm(timr);
269 timr->it_status = POSIX_TIMER_ARMED;
270 timr->it_overrun_last = timr->it_overrun;
271 timr->it_overrun = -1LL;
272 ++timr->it_signal_seq;
273 info->si_overrun = timer_overrun_to_int(timr);
274 return true;
275}
276
277/*
278 * This function is called from the signal delivery code. It decides
279 * whether the signal should be dropped and rearms interval timers. The
280 * timer can be unconditionally accessed as there is a reference held on
281 * it.
282 */
283bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq)
284{
285 struct k_itimer *timr = container_of(timer_sigq, struct k_itimer, sigq);
286 bool ret;
287
288 /*
289 * Release siglock to ensure proper locking order versus
290 * timr::it_lock. Keep interrupts disabled.
291 */
292 spin_unlock(¤t->sighand->siglock);
293
294 ret = __posixtimer_deliver_signal(info, timr);
295
296 /* Drop the reference which was acquired when the signal was queued */
297 posixtimer_putref(timr);
298
299 spin_lock(¤t->sighand->siglock);
300 return ret;
301}
302
303void posix_timer_queue_signal(struct k_itimer *timr)
304{
305 lockdep_assert_held(&timr->it_lock);
306
307 timr->it_status = timr->it_interval ? POSIX_TIMER_REQUEUE_PENDING : POSIX_TIMER_DISARMED;
308 posixtimer_send_sigqueue(timr);
309}
310
311/*
312 * This function gets called when a POSIX.1b interval timer expires from
313 * the HRTIMER interrupt (soft interrupt on RT kernels).
314 *
315 * Handles CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME and CLOCK_TAI
316 * based timers.
317 */
318static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
319{
320 struct k_itimer *timr = container_of(timer, struct k_itimer, it.real.timer);
321
322 guard(spinlock_irqsave)(&timr->it_lock);
323 posix_timer_queue_signal(timr);
324 return HRTIMER_NORESTART;
325}
326
327static struct pid *good_sigevent(sigevent_t * event)
328{
329 struct pid *pid = task_tgid(current);
330 struct task_struct *rtn;
331
332 switch (event->sigev_notify) {
333 case SIGEV_SIGNAL | SIGEV_THREAD_ID:
334 pid = find_vpid(event->sigev_notify_thread_id);
335 rtn = pid_task(pid, PIDTYPE_PID);
336 if (!rtn || !same_thread_group(rtn, current))
337 return NULL;
338 fallthrough;
339 case SIGEV_SIGNAL:
340 case SIGEV_THREAD:
341 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
342 return NULL;
343 fallthrough;
344 case SIGEV_NONE:
345 return pid;
346 default:
347 return NULL;
348 }
349}
350
351static struct k_itimer *alloc_posix_timer(void)
352{
353 struct k_itimer *tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
354
355 if (!tmr)
356 return tmr;
357
358 if (unlikely(!posixtimer_init_sigqueue(&tmr->sigq))) {
359 kmem_cache_free(posix_timers_cache, tmr);
360 return NULL;
361 }
362 rcuref_init(&tmr->rcuref, 1);
363 return tmr;
364}
365
366void posixtimer_free_timer(struct k_itimer *tmr)
367{
368 put_pid(tmr->it_pid);
369 if (tmr->sigq.ucounts)
370 dec_rlimit_put_ucounts(tmr->sigq.ucounts, UCOUNT_RLIMIT_SIGPENDING);
371 kfree_rcu(tmr, rcu);
372}
373
374static void posix_timer_unhash_and_free(struct k_itimer *tmr)
375{
376 spin_lock(&hash_lock);
377 hlist_del_rcu(&tmr->t_hash);
378 spin_unlock(&hash_lock);
379 posixtimer_putref(tmr);
380}
381
382static int common_timer_create(struct k_itimer *new_timer)
383{
384 hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
385 return 0;
386}
387
388/* Create a POSIX.1b interval timer. */
389static int do_timer_create(clockid_t which_clock, struct sigevent *event,
390 timer_t __user *created_timer_id)
391{
392 const struct k_clock *kc = clockid_to_kclock(which_clock);
393 struct k_itimer *new_timer;
394 int error, new_timer_id;
395
396 if (!kc)
397 return -EINVAL;
398 if (!kc->timer_create)
399 return -EOPNOTSUPP;
400
401 new_timer = alloc_posix_timer();
402 if (unlikely(!new_timer))
403 return -EAGAIN;
404
405 spin_lock_init(&new_timer->it_lock);
406
407 /*
408 * Add the timer to the hash table. The timer is not yet valid
409 * because new_timer::it_signal is still NULL. The timer id is also
410 * not yet visible to user space.
411 */
412 new_timer_id = posix_timer_add(new_timer);
413 if (new_timer_id < 0) {
414 posixtimer_free_timer(new_timer);
415 return new_timer_id;
416 }
417
418 new_timer->it_id = (timer_t) new_timer_id;
419 new_timer->it_clock = which_clock;
420 new_timer->kclock = kc;
421 new_timer->it_overrun = -1LL;
422
423 if (event) {
424 rcu_read_lock();
425 new_timer->it_pid = get_pid(good_sigevent(event));
426 rcu_read_unlock();
427 if (!new_timer->it_pid) {
428 error = -EINVAL;
429 goto out;
430 }
431 new_timer->it_sigev_notify = event->sigev_notify;
432 new_timer->sigq.info.si_signo = event->sigev_signo;
433 new_timer->sigq.info.si_value = event->sigev_value;
434 } else {
435 new_timer->it_sigev_notify = SIGEV_SIGNAL;
436 new_timer->sigq.info.si_signo = SIGALRM;
437 memset(&new_timer->sigq.info.si_value, 0, sizeof(sigval_t));
438 new_timer->sigq.info.si_value.sival_int = new_timer->it_id;
439 new_timer->it_pid = get_pid(task_tgid(current));
440 }
441
442 if (new_timer->it_sigev_notify & SIGEV_THREAD_ID)
443 new_timer->it_pid_type = PIDTYPE_PID;
444 else
445 new_timer->it_pid_type = PIDTYPE_TGID;
446
447 new_timer->sigq.info.si_tid = new_timer->it_id;
448 new_timer->sigq.info.si_code = SI_TIMER;
449
450 if (copy_to_user(created_timer_id, &new_timer_id, sizeof (new_timer_id))) {
451 error = -EFAULT;
452 goto out;
453 }
454 /*
455 * After succesful copy out, the timer ID is visible to user space
456 * now but not yet valid because new_timer::signal is still NULL.
457 *
458 * Complete the initialization with the clock specific create
459 * callback.
460 */
461 error = kc->timer_create(new_timer);
462 if (error)
463 goto out;
464
465 spin_lock_irq(¤t->sighand->siglock);
466 /* This makes the timer valid in the hash table */
467 WRITE_ONCE(new_timer->it_signal, current->signal);
468 hlist_add_head(&new_timer->list, ¤t->signal->posix_timers);
469 spin_unlock_irq(¤t->sighand->siglock);
470 /*
471 * After unlocking sighand::siglock @new_timer is subject to
472 * concurrent removal and cannot be touched anymore
473 */
474 return 0;
475out:
476 posix_timer_unhash_and_free(new_timer);
477 return error;
478}
479
480SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
481 struct sigevent __user *, timer_event_spec,
482 timer_t __user *, created_timer_id)
483{
484 if (timer_event_spec) {
485 sigevent_t event;
486
487 if (copy_from_user(&event, timer_event_spec, sizeof (event)))
488 return -EFAULT;
489 return do_timer_create(which_clock, &event, created_timer_id);
490 }
491 return do_timer_create(which_clock, NULL, created_timer_id);
492}
493
494#ifdef CONFIG_COMPAT
495COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
496 struct compat_sigevent __user *, timer_event_spec,
497 timer_t __user *, created_timer_id)
498{
499 if (timer_event_spec) {
500 sigevent_t event;
501
502 if (get_compat_sigevent(&event, timer_event_spec))
503 return -EFAULT;
504 return do_timer_create(which_clock, &event, created_timer_id);
505 }
506 return do_timer_create(which_clock, NULL, created_timer_id);
507}
508#endif
509
510static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
511{
512 struct k_itimer *timr;
513
514 /*
515 * timer_t could be any type >= int and we want to make sure any
516 * @timer_id outside positive int range fails lookup.
517 */
518 if ((unsigned long long)timer_id > INT_MAX)
519 return NULL;
520
521 /*
522 * The hash lookup and the timers are RCU protected.
523 *
524 * Timers are added to the hash in invalid state where
525 * timr::it_signal == NULL. timer::it_signal is only set after the
526 * rest of the initialization succeeded.
527 *
528 * Timer destruction happens in steps:
529 * 1) Set timr::it_signal to NULL with timr::it_lock held
530 * 2) Release timr::it_lock
531 * 3) Remove from the hash under hash_lock
532 * 4) Put the reference count.
533 *
534 * The reference count might not drop to zero if timr::sigq is
535 * queued. In that case the signal delivery or flush will put the
536 * last reference count.
537 *
538 * When the reference count reaches zero, the timer is scheduled
539 * for RCU removal after the grace period.
540 *
541 * Holding rcu_read_lock() accross the lookup ensures that
542 * the timer cannot be freed.
543 *
544 * The lookup validates locklessly that timr::it_signal ==
545 * current::it_signal and timr::it_id == @timer_id. timr::it_id
546 * can't change, but timr::it_signal becomes NULL during
547 * destruction.
548 */
549 rcu_read_lock();
550 timr = posix_timer_by_id(timer_id);
551 if (timr) {
552 spin_lock_irqsave(&timr->it_lock, *flags);
553 /*
554 * Validate under timr::it_lock that timr::it_signal is
555 * still valid. Pairs with #1 above.
556 */
557 if (timr->it_signal == current->signal) {
558 rcu_read_unlock();
559 return timr;
560 }
561 spin_unlock_irqrestore(&timr->it_lock, *flags);
562 }
563 rcu_read_unlock();
564
565 return NULL;
566}
567
568static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
569{
570 struct hrtimer *timer = &timr->it.real.timer;
571
572 return __hrtimer_expires_remaining_adjusted(timer, now);
573}
574
575static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
576{
577 struct hrtimer *timer = &timr->it.real.timer;
578
579 return hrtimer_forward(timer, now, timr->it_interval);
580}
581
582/*
583 * Get the time remaining on a POSIX.1b interval timer.
584 *
585 * Two issues to handle here:
586 *
587 * 1) The timer has a requeue pending. The return value must appear as
588 * if the timer has been requeued right now.
589 *
590 * 2) The timer is a SIGEV_NONE timer. These timers are never enqueued
591 * into the hrtimer queue and therefore never expired. Emulate expiry
592 * here taking #1 into account.
593 */
594void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
595{
596 const struct k_clock *kc = timr->kclock;
597 ktime_t now, remaining, iv;
598 bool sig_none;
599
600 sig_none = timr->it_sigev_notify == SIGEV_NONE;
601 iv = timr->it_interval;
602
603 /* interval timer ? */
604 if (iv) {
605 cur_setting->it_interval = ktime_to_timespec64(iv);
606 } else if (timr->it_status == POSIX_TIMER_DISARMED) {
607 /*
608 * SIGEV_NONE oneshot timers are never queued and therefore
609 * timr->it_status is always DISARMED. The check below
610 * vs. remaining time will handle this case.
611 *
612 * For all other timers there is nothing to update here, so
613 * return.
614 */
615 if (!sig_none)
616 return;
617 }
618
619 now = kc->clock_get_ktime(timr->it_clock);
620
621 /*
622 * If this is an interval timer and either has requeue pending or
623 * is a SIGEV_NONE timer move the expiry time forward by intervals,
624 * so expiry is > now.
625 */
626 if (iv && timr->it_status != POSIX_TIMER_ARMED)
627 timr->it_overrun += kc->timer_forward(timr, now);
628
629 remaining = kc->timer_remaining(timr, now);
630 /*
631 * As @now is retrieved before a possible timer_forward() and
632 * cannot be reevaluated by the compiler @remaining is based on the
633 * same @now value. Therefore @remaining is consistent vs. @now.
634 *
635 * Consequently all interval timers, i.e. @iv > 0, cannot have a
636 * remaining time <= 0 because timer_forward() guarantees to move
637 * them forward so that the next timer expiry is > @now.
638 */
639 if (remaining <= 0) {
640 /*
641 * A single shot SIGEV_NONE timer must return 0, when it is
642 * expired! Timers which have a real signal delivery mode
643 * must return a remaining time greater than 0 because the
644 * signal has not yet been delivered.
645 */
646 if (!sig_none)
647 cur_setting->it_value.tv_nsec = 1;
648 } else {
649 cur_setting->it_value = ktime_to_timespec64(remaining);
650 }
651}
652
653static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting)
654{
655 const struct k_clock *kc;
656 struct k_itimer *timr;
657 unsigned long flags;
658 int ret = 0;
659
660 timr = lock_timer(timer_id, &flags);
661 if (!timr)
662 return -EINVAL;
663
664 memset(setting, 0, sizeof(*setting));
665 kc = timr->kclock;
666 if (WARN_ON_ONCE(!kc || !kc->timer_get))
667 ret = -EINVAL;
668 else
669 kc->timer_get(timr, setting);
670
671 unlock_timer(timr, flags);
672 return ret;
673}
674
675/* Get the time remaining on a POSIX.1b interval timer. */
676SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
677 struct __kernel_itimerspec __user *, setting)
678{
679 struct itimerspec64 cur_setting;
680
681 int ret = do_timer_gettime(timer_id, &cur_setting);
682 if (!ret) {
683 if (put_itimerspec64(&cur_setting, setting))
684 ret = -EFAULT;
685 }
686 return ret;
687}
688
689#ifdef CONFIG_COMPAT_32BIT_TIME
690
691SYSCALL_DEFINE2(timer_gettime32, timer_t, timer_id,
692 struct old_itimerspec32 __user *, setting)
693{
694 struct itimerspec64 cur_setting;
695
696 int ret = do_timer_gettime(timer_id, &cur_setting);
697 if (!ret) {
698 if (put_old_itimerspec32(&cur_setting, setting))
699 ret = -EFAULT;
700 }
701 return ret;
702}
703
704#endif
705
706/**
707 * sys_timer_getoverrun - Get the number of overruns of a POSIX.1b interval timer
708 * @timer_id: The timer ID which identifies the timer
709 *
710 * The "overrun count" of a timer is one plus the number of expiration
711 * intervals which have elapsed between the first expiry, which queues the
712 * signal and the actual signal delivery. On signal delivery the "overrun
713 * count" is calculated and cached, so it can be returned directly here.
714 *
715 * As this is relative to the last queued signal the returned overrun count
716 * is meaningless outside of the signal delivery path and even there it
717 * does not accurately reflect the current state when user space evaluates
718 * it.
719 *
720 * Returns:
721 * -EINVAL @timer_id is invalid
722 * 1..INT_MAX The number of overruns related to the last delivered signal
723 */
724SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
725{
726 struct k_itimer *timr;
727 unsigned long flags;
728 int overrun;
729
730 timr = lock_timer(timer_id, &flags);
731 if (!timr)
732 return -EINVAL;
733
734 overrun = timer_overrun_to_int(timr);
735 unlock_timer(timr, flags);
736
737 return overrun;
738}
739
740static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
741 bool absolute, bool sigev_none)
742{
743 struct hrtimer *timer = &timr->it.real.timer;
744 enum hrtimer_mode mode;
745
746 mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
747 /*
748 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
749 * clock modifications, so they become CLOCK_MONOTONIC based under the
750 * hood. See hrtimer_init(). Update timr->kclock, so the generic
751 * functions which use timr->kclock->clock_get_*() work.
752 *
753 * Note: it_clock stays unmodified, because the next timer_set() might
754 * use ABSTIME, so it needs to switch back.
755 */
756 if (timr->it_clock == CLOCK_REALTIME)
757 timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
758
759 hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
760 timr->it.real.timer.function = posix_timer_fn;
761
762 if (!absolute)
763 expires = ktime_add_safe(expires, timer->base->get_time());
764 hrtimer_set_expires(timer, expires);
765
766 if (!sigev_none)
767 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
768}
769
770static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
771{
772 return hrtimer_try_to_cancel(&timr->it.real.timer);
773}
774
775static void common_timer_wait_running(struct k_itimer *timer)
776{
777 hrtimer_cancel_wait_running(&timer->it.real.timer);
778}
779
780/*
781 * On PREEMPT_RT this prevents priority inversion and a potential livelock
782 * against the ksoftirqd thread in case that ksoftirqd gets preempted while
783 * executing a hrtimer callback.
784 *
785 * See the comments in hrtimer_cancel_wait_running(). For PREEMPT_RT=n this
786 * just results in a cpu_relax().
787 *
788 * For POSIX CPU timers with CONFIG_POSIX_CPU_TIMERS_TASK_WORK=n this is
789 * just a cpu_relax(). With CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y this
790 * prevents spinning on an eventually scheduled out task and a livelock
791 * when the task which tries to delete or disarm the timer has preempted
792 * the task which runs the expiry in task work context.
793 */
794static struct k_itimer *timer_wait_running(struct k_itimer *timer,
795 unsigned long *flags)
796{
797 const struct k_clock *kc = READ_ONCE(timer->kclock);
798 timer_t timer_id = READ_ONCE(timer->it_id);
799
800 /* Prevent kfree(timer) after dropping the lock */
801 rcu_read_lock();
802 unlock_timer(timer, *flags);
803
804 /*
805 * kc->timer_wait_running() might drop RCU lock. So @timer
806 * cannot be touched anymore after the function returns!
807 */
808 if (!WARN_ON_ONCE(!kc->timer_wait_running))
809 kc->timer_wait_running(timer);
810
811 rcu_read_unlock();
812 /* Relock the timer. It might be not longer hashed. */
813 return lock_timer(timer_id, flags);
814}
815
816/*
817 * Set up the new interval and reset the signal delivery data
818 */
819void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_setting)
820{
821 if (new_setting->it_value.tv_sec || new_setting->it_value.tv_nsec)
822 timer->it_interval = timespec64_to_ktime(new_setting->it_interval);
823 else
824 timer->it_interval = 0;
825
826 /* Reset overrun accounting */
827 timer->it_overrun_last = 0;
828 timer->it_overrun = -1LL;
829}
830
831/* Set a POSIX.1b interval timer. */
832int common_timer_set(struct k_itimer *timr, int flags,
833 struct itimerspec64 *new_setting,
834 struct itimerspec64 *old_setting)
835{
836 const struct k_clock *kc = timr->kclock;
837 bool sigev_none;
838 ktime_t expires;
839
840 if (old_setting)
841 common_timer_get(timr, old_setting);
842
843 /*
844 * Careful here. On SMP systems the timer expiry function could be
845 * active and spinning on timr->it_lock.
846 */
847 if (kc->timer_try_to_cancel(timr) < 0)
848 return TIMER_RETRY;
849
850 timr->it_status = POSIX_TIMER_DISARMED;
851 posix_timer_set_common(timr, new_setting);
852
853 /* Keep timer disarmed when it_value is zero */
854 if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
855 return 0;
856
857 expires = timespec64_to_ktime(new_setting->it_value);
858 if (flags & TIMER_ABSTIME)
859 expires = timens_ktime_to_host(timr->it_clock, expires);
860 sigev_none = timr->it_sigev_notify == SIGEV_NONE;
861
862 kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
863 if (!sigev_none)
864 timr->it_status = POSIX_TIMER_ARMED;
865 return 0;
866}
867
868static int do_timer_settime(timer_t timer_id, int tmr_flags,
869 struct itimerspec64 *new_spec64,
870 struct itimerspec64 *old_spec64)
871{
872 const struct k_clock *kc;
873 struct k_itimer *timr;
874 unsigned long flags;
875 int error;
876
877 if (!timespec64_valid(&new_spec64->it_interval) ||
878 !timespec64_valid(&new_spec64->it_value))
879 return -EINVAL;
880
881 if (old_spec64)
882 memset(old_spec64, 0, sizeof(*old_spec64));
883
884 timr = lock_timer(timer_id, &flags);
885retry:
886 if (!timr)
887 return -EINVAL;
888
889 if (old_spec64)
890 old_spec64->it_interval = ktime_to_timespec64(timr->it_interval);
891
892 /* Prevent signal delivery and rearming. */
893 timr->it_signal_seq++;
894
895 kc = timr->kclock;
896 if (WARN_ON_ONCE(!kc || !kc->timer_set))
897 error = -EINVAL;
898 else
899 error = kc->timer_set(timr, tmr_flags, new_spec64, old_spec64);
900
901 if (error == TIMER_RETRY) {
902 // We already got the old time...
903 old_spec64 = NULL;
904 /* Unlocks and relocks the timer if it still exists */
905 timr = timer_wait_running(timr, &flags);
906 goto retry;
907 }
908 unlock_timer(timr, flags);
909
910 return error;
911}
912
913/* Set a POSIX.1b interval timer */
914SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
915 const struct __kernel_itimerspec __user *, new_setting,
916 struct __kernel_itimerspec __user *, old_setting)
917{
918 struct itimerspec64 new_spec, old_spec, *rtn;
919 int error = 0;
920
921 if (!new_setting)
922 return -EINVAL;
923
924 if (get_itimerspec64(&new_spec, new_setting))
925 return -EFAULT;
926
927 rtn = old_setting ? &old_spec : NULL;
928 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
929 if (!error && old_setting) {
930 if (put_itimerspec64(&old_spec, old_setting))
931 error = -EFAULT;
932 }
933 return error;
934}
935
936#ifdef CONFIG_COMPAT_32BIT_TIME
937SYSCALL_DEFINE4(timer_settime32, timer_t, timer_id, int, flags,
938 struct old_itimerspec32 __user *, new,
939 struct old_itimerspec32 __user *, old)
940{
941 struct itimerspec64 new_spec, old_spec;
942 struct itimerspec64 *rtn = old ? &old_spec : NULL;
943 int error = 0;
944
945 if (!new)
946 return -EINVAL;
947 if (get_old_itimerspec32(&new_spec, new))
948 return -EFAULT;
949
950 error = do_timer_settime(timer_id, flags, &new_spec, rtn);
951 if (!error && old) {
952 if (put_old_itimerspec32(&old_spec, old))
953 error = -EFAULT;
954 }
955 return error;
956}
957#endif
958
959int common_timer_del(struct k_itimer *timer)
960{
961 const struct k_clock *kc = timer->kclock;
962
963 if (kc->timer_try_to_cancel(timer) < 0)
964 return TIMER_RETRY;
965 timer->it_status = POSIX_TIMER_DISARMED;
966 return 0;
967}
968
969/*
970 * If the deleted timer is on the ignored list, remove it and
971 * drop the associated reference.
972 */
973static inline void posix_timer_cleanup_ignored(struct k_itimer *tmr)
974{
975 if (!hlist_unhashed(&tmr->ignored_list)) {
976 hlist_del_init(&tmr->ignored_list);
977 posixtimer_putref(tmr);
978 }
979}
980
981static inline int timer_delete_hook(struct k_itimer *timer)
982{
983 const struct k_clock *kc = timer->kclock;
984
985 /* Prevent signal delivery and rearming. */
986 timer->it_signal_seq++;
987
988 if (WARN_ON_ONCE(!kc || !kc->timer_del))
989 return -EINVAL;
990 return kc->timer_del(timer);
991}
992
993/* Delete a POSIX.1b interval timer. */
994SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
995{
996 struct k_itimer *timer;
997 unsigned long flags;
998
999 timer = lock_timer(timer_id, &flags);
1000
1001retry_delete:
1002 if (!timer)
1003 return -EINVAL;
1004
1005 if (unlikely(timer_delete_hook(timer) == TIMER_RETRY)) {
1006 /* Unlocks and relocks the timer if it still exists */
1007 timer = timer_wait_running(timer, &flags);
1008 goto retry_delete;
1009 }
1010
1011 spin_lock(¤t->sighand->siglock);
1012 hlist_del(&timer->list);
1013 posix_timer_cleanup_ignored(timer);
1014 /*
1015 * A concurrent lookup could check timer::it_signal lockless. It
1016 * will reevaluate with timer::it_lock held and observe the NULL.
1017 *
1018 * It must be written with siglock held so that the signal code
1019 * observes timer->it_signal == NULL in do_sigaction(SIG_IGN),
1020 * which prevents it from moving a pending signal of a deleted
1021 * timer to the ignore list.
1022 */
1023 WRITE_ONCE(timer->it_signal, NULL);
1024 spin_unlock(¤t->sighand->siglock);
1025
1026 unlock_timer(timer, flags);
1027 posix_timer_unhash_and_free(timer);
1028 return 0;
1029}
1030
1031/*
1032 * Delete a timer if it is armed, remove it from the hash and schedule it
1033 * for RCU freeing.
1034 */
1035static void itimer_delete(struct k_itimer *timer)
1036{
1037 unsigned long flags;
1038
1039 /*
1040 * irqsave is required to make timer_wait_running() work.
1041 */
1042 spin_lock_irqsave(&timer->it_lock, flags);
1043
1044retry_delete:
1045 /*
1046 * Even if the timer is not longer accessible from other tasks
1047 * it still might be armed and queued in the underlying timer
1048 * mechanism. Worse, that timer mechanism might run the expiry
1049 * function concurrently.
1050 */
1051 if (timer_delete_hook(timer) == TIMER_RETRY) {
1052 /*
1053 * Timer is expired concurrently, prevent livelocks
1054 * and pointless spinning on RT.
1055 *
1056 * timer_wait_running() drops timer::it_lock, which opens
1057 * the possibility for another task to delete the timer.
1058 *
1059 * That's not possible here because this is invoked from
1060 * do_exit() only for the last thread of the thread group.
1061 * So no other task can access and delete that timer.
1062 */
1063 if (WARN_ON_ONCE(timer_wait_running(timer, &flags) != timer))
1064 return;
1065
1066 goto retry_delete;
1067 }
1068 hlist_del(&timer->list);
1069
1070 posix_timer_cleanup_ignored(timer);
1071
1072 /*
1073 * Setting timer::it_signal to NULL is technically not required
1074 * here as nothing can access the timer anymore legitimately via
1075 * the hash table. Set it to NULL nevertheless so that all deletion
1076 * paths are consistent.
1077 */
1078 WRITE_ONCE(timer->it_signal, NULL);
1079
1080 spin_unlock_irqrestore(&timer->it_lock, flags);
1081 posix_timer_unhash_and_free(timer);
1082}
1083
1084/*
1085 * Invoked from do_exit() when the last thread of a thread group exits.
1086 * At that point no other task can access the timers of the dying
1087 * task anymore.
1088 */
1089void exit_itimers(struct task_struct *tsk)
1090{
1091 struct hlist_head timers;
1092
1093 if (hlist_empty(&tsk->signal->posix_timers))
1094 return;
1095
1096 /* Protect against concurrent read via /proc/$PID/timers */
1097 spin_lock_irq(&tsk->sighand->siglock);
1098 hlist_move_list(&tsk->signal->posix_timers, &timers);
1099 spin_unlock_irq(&tsk->sighand->siglock);
1100
1101 /* The timers are not longer accessible via tsk::signal */
1102 while (!hlist_empty(&timers))
1103 itimer_delete(hlist_entry(timers.first, struct k_itimer, list));
1104
1105 /*
1106 * There should be no timers on the ignored list. itimer_delete() has
1107 * mopped them up.
1108 */
1109 if (!WARN_ON_ONCE(!hlist_empty(&tsk->signal->ignored_posix_timers)))
1110 return;
1111
1112 hlist_move_list(&tsk->signal->ignored_posix_timers, &timers);
1113 while (!hlist_empty(&timers)) {
1114 posix_timer_cleanup_ignored(hlist_entry(timers.first, struct k_itimer,
1115 ignored_list));
1116 }
1117}
1118
1119SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
1120 const struct __kernel_timespec __user *, tp)
1121{
1122 const struct k_clock *kc = clockid_to_kclock(which_clock);
1123 struct timespec64 new_tp;
1124
1125 if (!kc || !kc->clock_set)
1126 return -EINVAL;
1127
1128 if (get_timespec64(&new_tp, tp))
1129 return -EFAULT;
1130
1131 /*
1132 * Permission checks have to be done inside the clock specific
1133 * setter callback.
1134 */
1135 return kc->clock_set(which_clock, &new_tp);
1136}
1137
1138SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
1139 struct __kernel_timespec __user *, tp)
1140{
1141 const struct k_clock *kc = clockid_to_kclock(which_clock);
1142 struct timespec64 kernel_tp;
1143 int error;
1144
1145 if (!kc)
1146 return -EINVAL;
1147
1148 error = kc->clock_get_timespec(which_clock, &kernel_tp);
1149
1150 if (!error && put_timespec64(&kernel_tp, tp))
1151 error = -EFAULT;
1152
1153 return error;
1154}
1155
1156int do_clock_adjtime(const clockid_t which_clock, struct __kernel_timex * ktx)
1157{
1158 const struct k_clock *kc = clockid_to_kclock(which_clock);
1159
1160 if (!kc)
1161 return -EINVAL;
1162 if (!kc->clock_adj)
1163 return -EOPNOTSUPP;
1164
1165 return kc->clock_adj(which_clock, ktx);
1166}
1167
1168SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1169 struct __kernel_timex __user *, utx)
1170{
1171 struct __kernel_timex ktx;
1172 int err;
1173
1174 if (copy_from_user(&ktx, utx, sizeof(ktx)))
1175 return -EFAULT;
1176
1177 err = do_clock_adjtime(which_clock, &ktx);
1178
1179 if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1180 return -EFAULT;
1181
1182 return err;
1183}
1184
1185/**
1186 * sys_clock_getres - Get the resolution of a clock
1187 * @which_clock: The clock to get the resolution for
1188 * @tp: Pointer to a a user space timespec64 for storage
1189 *
1190 * POSIX defines:
1191 *
1192 * "The clock_getres() function shall return the resolution of any
1193 * clock. Clock resolutions are implementation-defined and cannot be set by
1194 * a process. If the argument res is not NULL, the resolution of the
1195 * specified clock shall be stored in the location pointed to by res. If
1196 * res is NULL, the clock resolution is not returned. If the time argument
1197 * of clock_settime() is not a multiple of res, then the value is truncated
1198 * to a multiple of res."
1199 *
1200 * Due to the various hardware constraints the real resolution can vary
1201 * wildly and even change during runtime when the underlying devices are
1202 * replaced. The kernel also can use hardware devices with different
1203 * resolutions for reading the time and for arming timers.
1204 *
1205 * The kernel therefore deviates from the POSIX spec in various aspects:
1206 *
1207 * 1) The resolution returned to user space
1208 *
1209 * For CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_TAI,
1210 * CLOCK_REALTIME_ALARM, CLOCK_BOOTTIME_ALAREM and CLOCK_MONOTONIC_RAW
1211 * the kernel differentiates only two cases:
1212 *
1213 * I) Low resolution mode:
1214 *
1215 * When high resolution timers are disabled at compile or runtime
1216 * the resolution returned is nanoseconds per tick, which represents
1217 * the precision at which timers expire.
1218 *
1219 * II) High resolution mode:
1220 *
1221 * When high resolution timers are enabled the resolution returned
1222 * is always one nanosecond independent of the actual resolution of
1223 * the underlying hardware devices.
1224 *
1225 * For CLOCK_*_ALARM the actual resolution depends on system
1226 * state. When system is running the resolution is the same as the
1227 * resolution of the other clocks. During suspend the actual
1228 * resolution is the resolution of the underlying RTC device which
1229 * might be way less precise than the clockevent device used during
1230 * running state.
1231 *
1232 * For CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE the resolution
1233 * returned is always nanoseconds per tick.
1234 *
1235 * For CLOCK_PROCESS_CPUTIME and CLOCK_THREAD_CPUTIME the resolution
1236 * returned is always one nanosecond under the assumption that the
1237 * underlying scheduler clock has a better resolution than nanoseconds
1238 * per tick.
1239 *
1240 * For dynamic POSIX clocks (PTP devices) the resolution returned is
1241 * always one nanosecond.
1242 *
1243 * 2) Affect on sys_clock_settime()
1244 *
1245 * The kernel does not truncate the time which is handed in to
1246 * sys_clock_settime(). The kernel internal timekeeping is always using
1247 * nanoseconds precision independent of the clocksource device which is
1248 * used to read the time from. The resolution of that device only
1249 * affects the presicion of the time returned by sys_clock_gettime().
1250 *
1251 * Returns:
1252 * 0 Success. @tp contains the resolution
1253 * -EINVAL @which_clock is not a valid clock ID
1254 * -EFAULT Copying the resolution to @tp faulted
1255 * -ENODEV Dynamic POSIX clock is not backed by a device
1256 * -EOPNOTSUPP Dynamic POSIX clock does not support getres()
1257 */
1258SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1259 struct __kernel_timespec __user *, tp)
1260{
1261 const struct k_clock *kc = clockid_to_kclock(which_clock);
1262 struct timespec64 rtn_tp;
1263 int error;
1264
1265 if (!kc)
1266 return -EINVAL;
1267
1268 error = kc->clock_getres(which_clock, &rtn_tp);
1269
1270 if (!error && tp && put_timespec64(&rtn_tp, tp))
1271 error = -EFAULT;
1272
1273 return error;
1274}
1275
1276#ifdef CONFIG_COMPAT_32BIT_TIME
1277
1278SYSCALL_DEFINE2(clock_settime32, clockid_t, which_clock,
1279 struct old_timespec32 __user *, tp)
1280{
1281 const struct k_clock *kc = clockid_to_kclock(which_clock);
1282 struct timespec64 ts;
1283
1284 if (!kc || !kc->clock_set)
1285 return -EINVAL;
1286
1287 if (get_old_timespec32(&ts, tp))
1288 return -EFAULT;
1289
1290 return kc->clock_set(which_clock, &ts);
1291}
1292
1293SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock,
1294 struct old_timespec32 __user *, tp)
1295{
1296 const struct k_clock *kc = clockid_to_kclock(which_clock);
1297 struct timespec64 ts;
1298 int err;
1299
1300 if (!kc)
1301 return -EINVAL;
1302
1303 err = kc->clock_get_timespec(which_clock, &ts);
1304
1305 if (!err && put_old_timespec32(&ts, tp))
1306 err = -EFAULT;
1307
1308 return err;
1309}
1310
1311SYSCALL_DEFINE2(clock_adjtime32, clockid_t, which_clock,
1312 struct old_timex32 __user *, utp)
1313{
1314 struct __kernel_timex ktx;
1315 int err;
1316
1317 err = get_old_timex32(&ktx, utp);
1318 if (err)
1319 return err;
1320
1321 err = do_clock_adjtime(which_clock, &ktx);
1322
1323 if (err >= 0 && put_old_timex32(utp, &ktx))
1324 return -EFAULT;
1325
1326 return err;
1327}
1328
1329SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
1330 struct old_timespec32 __user *, tp)
1331{
1332 const struct k_clock *kc = clockid_to_kclock(which_clock);
1333 struct timespec64 ts;
1334 int err;
1335
1336 if (!kc)
1337 return -EINVAL;
1338
1339 err = kc->clock_getres(which_clock, &ts);
1340 if (!err && tp && put_old_timespec32(&ts, tp))
1341 return -EFAULT;
1342
1343 return err;
1344}
1345
1346#endif
1347
1348/*
1349 * sys_clock_nanosleep() for CLOCK_REALTIME and CLOCK_TAI
1350 */
1351static int common_nsleep(const clockid_t which_clock, int flags,
1352 const struct timespec64 *rqtp)
1353{
1354 ktime_t texp = timespec64_to_ktime(*rqtp);
1355
1356 return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1357 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1358 which_clock);
1359}
1360
1361/*
1362 * sys_clock_nanosleep() for CLOCK_MONOTONIC and CLOCK_BOOTTIME
1363 *
1364 * Absolute nanosleeps for these clocks are time-namespace adjusted.
1365 */
1366static int common_nsleep_timens(const clockid_t which_clock, int flags,
1367 const struct timespec64 *rqtp)
1368{
1369 ktime_t texp = timespec64_to_ktime(*rqtp);
1370
1371 if (flags & TIMER_ABSTIME)
1372 texp = timens_ktime_to_host(which_clock, texp);
1373
1374 return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1375 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1376 which_clock);
1377}
1378
1379SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1380 const struct __kernel_timespec __user *, rqtp,
1381 struct __kernel_timespec __user *, rmtp)
1382{
1383 const struct k_clock *kc = clockid_to_kclock(which_clock);
1384 struct timespec64 t;
1385
1386 if (!kc)
1387 return -EINVAL;
1388 if (!kc->nsleep)
1389 return -EOPNOTSUPP;
1390
1391 if (get_timespec64(&t, rqtp))
1392 return -EFAULT;
1393
1394 if (!timespec64_valid(&t))
1395 return -EINVAL;
1396 if (flags & TIMER_ABSTIME)
1397 rmtp = NULL;
1398 current->restart_block.fn = do_no_restart_syscall;
1399 current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
1400 current->restart_block.nanosleep.rmtp = rmtp;
1401
1402 return kc->nsleep(which_clock, flags, &t);
1403}
1404
1405#ifdef CONFIG_COMPAT_32BIT_TIME
1406
1407SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
1408 struct old_timespec32 __user *, rqtp,
1409 struct old_timespec32 __user *, rmtp)
1410{
1411 const struct k_clock *kc = clockid_to_kclock(which_clock);
1412 struct timespec64 t;
1413
1414 if (!kc)
1415 return -EINVAL;
1416 if (!kc->nsleep)
1417 return -EOPNOTSUPP;
1418
1419 if (get_old_timespec32(&t, rqtp))
1420 return -EFAULT;
1421
1422 if (!timespec64_valid(&t))
1423 return -EINVAL;
1424 if (flags & TIMER_ABSTIME)
1425 rmtp = NULL;
1426 current->restart_block.fn = do_no_restart_syscall;
1427 current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
1428 current->restart_block.nanosleep.compat_rmtp = rmtp;
1429
1430 return kc->nsleep(which_clock, flags, &t);
1431}
1432
1433#endif
1434
1435static const struct k_clock clock_realtime = {
1436 .clock_getres = posix_get_hrtimer_res,
1437 .clock_get_timespec = posix_get_realtime_timespec,
1438 .clock_get_ktime = posix_get_realtime_ktime,
1439 .clock_set = posix_clock_realtime_set,
1440 .clock_adj = posix_clock_realtime_adj,
1441 .nsleep = common_nsleep,
1442 .timer_create = common_timer_create,
1443 .timer_set = common_timer_set,
1444 .timer_get = common_timer_get,
1445 .timer_del = common_timer_del,
1446 .timer_rearm = common_hrtimer_rearm,
1447 .timer_forward = common_hrtimer_forward,
1448 .timer_remaining = common_hrtimer_remaining,
1449 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1450 .timer_wait_running = common_timer_wait_running,
1451 .timer_arm = common_hrtimer_arm,
1452};
1453
1454static const struct k_clock clock_monotonic = {
1455 .clock_getres = posix_get_hrtimer_res,
1456 .clock_get_timespec = posix_get_monotonic_timespec,
1457 .clock_get_ktime = posix_get_monotonic_ktime,
1458 .nsleep = common_nsleep_timens,
1459 .timer_create = common_timer_create,
1460 .timer_set = common_timer_set,
1461 .timer_get = common_timer_get,
1462 .timer_del = common_timer_del,
1463 .timer_rearm = common_hrtimer_rearm,
1464 .timer_forward = common_hrtimer_forward,
1465 .timer_remaining = common_hrtimer_remaining,
1466 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1467 .timer_wait_running = common_timer_wait_running,
1468 .timer_arm = common_hrtimer_arm,
1469};
1470
1471static const struct k_clock clock_monotonic_raw = {
1472 .clock_getres = posix_get_hrtimer_res,
1473 .clock_get_timespec = posix_get_monotonic_raw,
1474};
1475
1476static const struct k_clock clock_realtime_coarse = {
1477 .clock_getres = posix_get_coarse_res,
1478 .clock_get_timespec = posix_get_realtime_coarse,
1479};
1480
1481static const struct k_clock clock_monotonic_coarse = {
1482 .clock_getres = posix_get_coarse_res,
1483 .clock_get_timespec = posix_get_monotonic_coarse,
1484};
1485
1486static const struct k_clock clock_tai = {
1487 .clock_getres = posix_get_hrtimer_res,
1488 .clock_get_ktime = posix_get_tai_ktime,
1489 .clock_get_timespec = posix_get_tai_timespec,
1490 .nsleep = common_nsleep,
1491 .timer_create = common_timer_create,
1492 .timer_set = common_timer_set,
1493 .timer_get = common_timer_get,
1494 .timer_del = common_timer_del,
1495 .timer_rearm = common_hrtimer_rearm,
1496 .timer_forward = common_hrtimer_forward,
1497 .timer_remaining = common_hrtimer_remaining,
1498 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1499 .timer_wait_running = common_timer_wait_running,
1500 .timer_arm = common_hrtimer_arm,
1501};
1502
1503static const struct k_clock clock_boottime = {
1504 .clock_getres = posix_get_hrtimer_res,
1505 .clock_get_ktime = posix_get_boottime_ktime,
1506 .clock_get_timespec = posix_get_boottime_timespec,
1507 .nsleep = common_nsleep_timens,
1508 .timer_create = common_timer_create,
1509 .timer_set = common_timer_set,
1510 .timer_get = common_timer_get,
1511 .timer_del = common_timer_del,
1512 .timer_rearm = common_hrtimer_rearm,
1513 .timer_forward = common_hrtimer_forward,
1514 .timer_remaining = common_hrtimer_remaining,
1515 .timer_try_to_cancel = common_hrtimer_try_to_cancel,
1516 .timer_wait_running = common_timer_wait_running,
1517 .timer_arm = common_hrtimer_arm,
1518};
1519
1520static const struct k_clock * const posix_clocks[] = {
1521 [CLOCK_REALTIME] = &clock_realtime,
1522 [CLOCK_MONOTONIC] = &clock_monotonic,
1523 [CLOCK_PROCESS_CPUTIME_ID] = &clock_process,
1524 [CLOCK_THREAD_CPUTIME_ID] = &clock_thread,
1525 [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw,
1526 [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse,
1527 [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse,
1528 [CLOCK_BOOTTIME] = &clock_boottime,
1529 [CLOCK_REALTIME_ALARM] = &alarm_clock,
1530 [CLOCK_BOOTTIME_ALARM] = &alarm_clock,
1531 [CLOCK_TAI] = &clock_tai,
1532};
1533
1534static const struct k_clock *clockid_to_kclock(const clockid_t id)
1535{
1536 clockid_t idx = id;
1537
1538 if (id < 0) {
1539 return (id & CLOCKFD_MASK) == CLOCKFD ?
1540 &clock_posix_dynamic : &clock_posix_cpu;
1541 }
1542
1543 if (id >= ARRAY_SIZE(posix_clocks))
1544 return NULL;
1545
1546 return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];
1547}