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Linux/kernel/time/posix-timers.c

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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  */
 50 static struct kmem_cache *posix_timers_cache;
 51 
 52 static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
 53 static DEFINE_SPINLOCK(hash_lock);
 54 
 55 static const struct k_clock * const posix_clocks[];
 56 static const struct k_clock *clockid_to_kclock(const clockid_t id);
 57 static 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  */
105 static 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 
113 static 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 
118 static 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                 if ((timer->it_signal == sig) && (timer->it_id == id))
126                         return timer;
127         }
128         return NULL;
129 }
130 
131 static struct k_itimer *posix_timer_by_id(timer_t id)
132 {
133         struct signal_struct *sig = current->signal;
134         struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)];
135 
136         return __posix_timers_find(head, sig, id);
137 }
138 
139 static int posix_timer_add(struct k_itimer *timer)
140 {
141         struct signal_struct *sig = current->signal;
142         int first_free_id = sig->posix_timer_id;
143         struct hlist_head *head;
144         int ret = -ENOENT;
145 
146         do {
147                 spin_lock(&hash_lock);
148                 head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)];
149                 if (!__posix_timers_find(head, sig, sig->posix_timer_id)) {
150                         hlist_add_head_rcu(&timer->t_hash, head);
151                         ret = sig->posix_timer_id;
152                 }
153                 if (++sig->posix_timer_id < 0)
154                         sig->posix_timer_id = 0;
155                 if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT))
156                         /* Loop over all possible ids completed */
157                         ret = -EAGAIN;
158                 spin_unlock(&hash_lock);
159         } while (ret == -ENOENT);
160         return ret;
161 }
162 
163 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
164 {
165         spin_unlock_irqrestore(&timr->it_lock, flags);
166 }
167 
168 /* Get clock_realtime */
169 static int posix_get_realtime_timespec(clockid_t which_clock, struct timespec64 *tp)
170 {
171         ktime_get_real_ts64(tp);
172         return 0;
173 }
174 
175 static ktime_t posix_get_realtime_ktime(clockid_t which_clock)
176 {
177         return ktime_get_real();
178 }
179 
180 /* Set clock_realtime */
181 static int posix_clock_realtime_set(const clockid_t which_clock,
182                                     const struct timespec64 *tp)
183 {
184         return do_sys_settimeofday64(tp, NULL);
185 }
186 
187 static int posix_clock_realtime_adj(const clockid_t which_clock,
188                                     struct __kernel_timex *t)
189 {
190         return do_adjtimex(t);
191 }
192 
193 /*
194  * Get monotonic time for posix timers
195  */
196 static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp)
197 {
198         ktime_get_ts64(tp);
199         timens_add_monotonic(tp);
200         return 0;
201 }
202 
203 static ktime_t posix_get_monotonic_ktime(clockid_t which_clock)
204 {
205         return ktime_get();
206 }
207 
208 /*
209  * Get monotonic-raw time for posix timers
210  */
211 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
212 {
213         ktime_get_raw_ts64(tp);
214         timens_add_monotonic(tp);
215         return 0;
216 }
217 
218 
219 static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp)
220 {
221         ktime_get_coarse_real_ts64(tp);
222         return 0;
223 }
224 
225 static int posix_get_monotonic_coarse(clockid_t which_clock,
226                                                 struct timespec64 *tp)
227 {
228         ktime_get_coarse_ts64(tp);
229         timens_add_monotonic(tp);
230         return 0;
231 }
232 
233 static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
234 {
235         *tp = ktime_to_timespec64(KTIME_LOW_RES);
236         return 0;
237 }
238 
239 static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
240 {
241         ktime_get_boottime_ts64(tp);
242         timens_add_boottime(tp);
243         return 0;
244 }
245 
246 static ktime_t posix_get_boottime_ktime(const clockid_t which_clock)
247 {
248         return ktime_get_boottime();
249 }
250 
251 static int posix_get_tai_timespec(clockid_t which_clock, struct timespec64 *tp)
252 {
253         ktime_get_clocktai_ts64(tp);
254         return 0;
255 }
256 
257 static ktime_t posix_get_tai_ktime(clockid_t which_clock)
258 {
259         return ktime_get_clocktai();
260 }
261 
262 static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
263 {
264         tp->tv_sec = 0;
265         tp->tv_nsec = hrtimer_resolution;
266         return 0;
267 }
268 
269 /*
270  * Initialize everything, well, just everything in Posix clocks/timers ;)
271  */
272 static __init int init_posix_timers(void)
273 {
274         posix_timers_cache = kmem_cache_create("posix_timers_cache",
275                                         sizeof (struct k_itimer), 0, SLAB_PANIC,
276                                         NULL);
277         return 0;
278 }
279 __initcall(init_posix_timers);
280 
281 /*
282  * The siginfo si_overrun field and the return value of timer_getoverrun(2)
283  * are of type int. Clamp the overrun value to INT_MAX
284  */
285 static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
286 {
287         s64 sum = timr->it_overrun_last + (s64)baseval;
288 
289         return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
290 }
291 
292 static void common_hrtimer_rearm(struct k_itimer *timr)
293 {
294         struct hrtimer *timer = &timr->it.real.timer;
295 
296         timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
297                                             timr->it_interval);
298         hrtimer_restart(timer);
299 }
300 
301 /*
302  * This function is exported for use by the signal deliver code.  It is
303  * called just prior to the info block being released and passes that
304  * block to us.  It's function is to update the overrun entry AND to
305  * restart the timer.  It should only be called if the timer is to be
306  * restarted (i.e. we have flagged this in the sys_private entry of the
307  * info block).
308  *
309  * To protect against the timer going away while the interrupt is queued,
310  * we require that the it_requeue_pending flag be set.
311  */
312 void posixtimer_rearm(struct kernel_siginfo *info)
313 {
314         struct k_itimer *timr;
315         unsigned long flags;
316 
317         timr = lock_timer(info->si_tid, &flags);
318         if (!timr)
319                 return;
320 
321         if (timr->it_interval && timr->it_requeue_pending == info->si_sys_private) {
322                 timr->kclock->timer_rearm(timr);
323 
324                 timr->it_active = 1;
325                 timr->it_overrun_last = timr->it_overrun;
326                 timr->it_overrun = -1LL;
327                 ++timr->it_requeue_pending;
328 
329                 info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
330         }
331 
332         unlock_timer(timr, flags);
333 }
334 
335 int posix_timer_event(struct k_itimer *timr, int si_private)
336 {
337         enum pid_type type;
338         int ret = -1;
339         /*
340          * FIXME: if ->sigq is queued we can race with
341          * dequeue_signal()->posixtimer_rearm().
342          *
343          * If dequeue_signal() sees the "right" value of
344          * si_sys_private it calls posixtimer_rearm().
345          * We re-queue ->sigq and drop ->it_lock().
346          * posixtimer_rearm() locks the timer
347          * and re-schedules it while ->sigq is pending.
348          * Not really bad, but not that we want.
349          */
350         timr->sigq->info.si_sys_private = si_private;
351 
352         type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID;
353         ret = send_sigqueue(timr->sigq, timr->it_pid, type);
354         /* If we failed to send the signal the timer stops. */
355         return ret > 0;
356 }
357 
358 /*
359  * This function gets called when a POSIX.1b interval timer expires.  It
360  * is used as a callback from the kernel internal timer.  The
361  * run_timer_list code ALWAYS calls with interrupts on.
362 
363  * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
364  */
365 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
366 {
367         struct k_itimer *timr;
368         unsigned long flags;
369         int si_private = 0;
370         enum hrtimer_restart ret = HRTIMER_NORESTART;
371 
372         timr = container_of(timer, struct k_itimer, it.real.timer);
373         spin_lock_irqsave(&timr->it_lock, flags);
374 
375         timr->it_active = 0;
376         if (timr->it_interval != 0)
377                 si_private = ++timr->it_requeue_pending;
378 
379         if (posix_timer_event(timr, si_private)) {
380                 /*
381                  * signal was not sent because of sig_ignor
382                  * we will not get a call back to restart it AND
383                  * it should be restarted.
384                  */
385                 if (timr->it_interval != 0) {
386                         ktime_t now = hrtimer_cb_get_time(timer);
387 
388                         /*
389                          * FIXME: What we really want, is to stop this
390                          * timer completely and restart it in case the
391                          * SIG_IGN is removed. This is a non trivial
392                          * change which involves sighand locking
393                          * (sigh !), which we don't want to do late in
394                          * the release cycle.
395                          *
396                          * For now we just let timers with an interval
397                          * less than a jiffie expire every jiffie to
398                          * avoid softirq starvation in case of SIG_IGN
399                          * and a very small interval, which would put
400                          * the timer right back on the softirq pending
401                          * list. By moving now ahead of time we trick
402                          * hrtimer_forward() to expire the timer
403                          * later, while we still maintain the overrun
404                          * accuracy, but have some inconsistency in
405                          * the timer_gettime() case. This is at least
406                          * better than a starved softirq. A more
407                          * complex fix which solves also another related
408                          * inconsistency is already in the pipeline.
409                          */
410 #ifdef CONFIG_HIGH_RES_TIMERS
411                         {
412                                 ktime_t kj = NSEC_PER_SEC / HZ;
413 
414                                 if (timr->it_interval < kj)
415                                         now = ktime_add(now, kj);
416                         }
417 #endif
418                         timr->it_overrun += hrtimer_forward(timer, now,
419                                                             timr->it_interval);
420                         ret = HRTIMER_RESTART;
421                         ++timr->it_requeue_pending;
422                         timr->it_active = 1;
423                 }
424         }
425 
426         unlock_timer(timr, flags);
427         return ret;
428 }
429 
430 static struct pid *good_sigevent(sigevent_t * event)
431 {
432         struct pid *pid = task_tgid(current);
433         struct task_struct *rtn;
434 
435         switch (event->sigev_notify) {
436         case SIGEV_SIGNAL | SIGEV_THREAD_ID:
437                 pid = find_vpid(event->sigev_notify_thread_id);
438                 rtn = pid_task(pid, PIDTYPE_PID);
439                 if (!rtn || !same_thread_group(rtn, current))
440                         return NULL;
441                 /* FALLTHRU */
442         case SIGEV_SIGNAL:
443         case SIGEV_THREAD:
444                 if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
445                         return NULL;
446                 /* FALLTHRU */
447         case SIGEV_NONE:
448                 return pid;
449         default:
450                 return NULL;
451         }
452 }
453 
454 static struct k_itimer * alloc_posix_timer(void)
455 {
456         struct k_itimer *tmr;
457         tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
458         if (!tmr)
459                 return tmr;
460         if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
461                 kmem_cache_free(posix_timers_cache, tmr);
462                 return NULL;
463         }
464         clear_siginfo(&tmr->sigq->info);
465         return tmr;
466 }
467 
468 static void k_itimer_rcu_free(struct rcu_head *head)
469 {
470         struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
471 
472         kmem_cache_free(posix_timers_cache, tmr);
473 }
474 
475 #define IT_ID_SET       1
476 #define IT_ID_NOT_SET   0
477 static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
478 {
479         if (it_id_set) {
480                 unsigned long flags;
481                 spin_lock_irqsave(&hash_lock, flags);
482                 hlist_del_rcu(&tmr->t_hash);
483                 spin_unlock_irqrestore(&hash_lock, flags);
484         }
485         put_pid(tmr->it_pid);
486         sigqueue_free(tmr->sigq);
487         call_rcu(&tmr->rcu, k_itimer_rcu_free);
488 }
489 
490 static int common_timer_create(struct k_itimer *new_timer)
491 {
492         hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
493         return 0;
494 }
495 
496 /* Create a POSIX.1b interval timer. */
497 static int do_timer_create(clockid_t which_clock, struct sigevent *event,
498                            timer_t __user *created_timer_id)
499 {
500         const struct k_clock *kc = clockid_to_kclock(which_clock);
501         struct k_itimer *new_timer;
502         int error, new_timer_id;
503         int it_id_set = IT_ID_NOT_SET;
504 
505         if (!kc)
506                 return -EINVAL;
507         if (!kc->timer_create)
508                 return -EOPNOTSUPP;
509 
510         new_timer = alloc_posix_timer();
511         if (unlikely(!new_timer))
512                 return -EAGAIN;
513 
514         spin_lock_init(&new_timer->it_lock);
515         new_timer_id = posix_timer_add(new_timer);
516         if (new_timer_id < 0) {
517                 error = new_timer_id;
518                 goto out;
519         }
520 
521         it_id_set = IT_ID_SET;
522         new_timer->it_id = (timer_t) new_timer_id;
523         new_timer->it_clock = which_clock;
524         new_timer->kclock = kc;
525         new_timer->it_overrun = -1LL;
526 
527         if (event) {
528                 rcu_read_lock();
529                 new_timer->it_pid = get_pid(good_sigevent(event));
530                 rcu_read_unlock();
531                 if (!new_timer->it_pid) {
532                         error = -EINVAL;
533                         goto out;
534                 }
535                 new_timer->it_sigev_notify     = event->sigev_notify;
536                 new_timer->sigq->info.si_signo = event->sigev_signo;
537                 new_timer->sigq->info.si_value = event->sigev_value;
538         } else {
539                 new_timer->it_sigev_notify     = SIGEV_SIGNAL;
540                 new_timer->sigq->info.si_signo = SIGALRM;
541                 memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t));
542                 new_timer->sigq->info.si_value.sival_int = new_timer->it_id;
543                 new_timer->it_pid = get_pid(task_tgid(current));
544         }
545 
546         new_timer->sigq->info.si_tid   = new_timer->it_id;
547         new_timer->sigq->info.si_code  = SI_TIMER;
548 
549         if (copy_to_user(created_timer_id,
550                          &new_timer_id, sizeof (new_timer_id))) {
551                 error = -EFAULT;
552                 goto out;
553         }
554 
555         error = kc->timer_create(new_timer);
556         if (error)
557                 goto out;
558 
559         spin_lock_irq(&current->sighand->siglock);
560         new_timer->it_signal = current->signal;
561         list_add(&new_timer->list, &current->signal->posix_timers);
562         spin_unlock_irq(&current->sighand->siglock);
563 
564         return 0;
565         /*
566          * In the case of the timer belonging to another task, after
567          * the task is unlocked, the timer is owned by the other task
568          * and may cease to exist at any time.  Don't use or modify
569          * new_timer after the unlock call.
570          */
571 out:
572         release_posix_timer(new_timer, it_id_set);
573         return error;
574 }
575 
576 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
577                 struct sigevent __user *, timer_event_spec,
578                 timer_t __user *, created_timer_id)
579 {
580         if (timer_event_spec) {
581                 sigevent_t event;
582 
583                 if (copy_from_user(&event, timer_event_spec, sizeof (event)))
584                         return -EFAULT;
585                 return do_timer_create(which_clock, &event, created_timer_id);
586         }
587         return do_timer_create(which_clock, NULL, created_timer_id);
588 }
589 
590 #ifdef CONFIG_COMPAT
591 COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
592                        struct compat_sigevent __user *, timer_event_spec,
593                        timer_t __user *, created_timer_id)
594 {
595         if (timer_event_spec) {
596                 sigevent_t event;
597 
598                 if (get_compat_sigevent(&event, timer_event_spec))
599                         return -EFAULT;
600                 return do_timer_create(which_clock, &event, created_timer_id);
601         }
602         return do_timer_create(which_clock, NULL, created_timer_id);
603 }
604 #endif
605 
606 /*
607  * Locking issues: We need to protect the result of the id look up until
608  * we get the timer locked down so it is not deleted under us.  The
609  * removal is done under the idr spinlock so we use that here to bridge
610  * the find to the timer lock.  To avoid a dead lock, the timer id MUST
611  * be release with out holding the timer lock.
612  */
613 static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
614 {
615         struct k_itimer *timr;
616 
617         /*
618          * timer_t could be any type >= int and we want to make sure any
619          * @timer_id outside positive int range fails lookup.
620          */
621         if ((unsigned long long)timer_id > INT_MAX)
622                 return NULL;
623 
624         rcu_read_lock();
625         timr = posix_timer_by_id(timer_id);
626         if (timr) {
627                 spin_lock_irqsave(&timr->it_lock, *flags);
628                 if (timr->it_signal == current->signal) {
629                         rcu_read_unlock();
630                         return timr;
631                 }
632                 spin_unlock_irqrestore(&timr->it_lock, *flags);
633         }
634         rcu_read_unlock();
635 
636         return NULL;
637 }
638 
639 static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
640 {
641         struct hrtimer *timer = &timr->it.real.timer;
642 
643         return __hrtimer_expires_remaining_adjusted(timer, now);
644 }
645 
646 static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
647 {
648         struct hrtimer *timer = &timr->it.real.timer;
649 
650         return hrtimer_forward(timer, now, timr->it_interval);
651 }
652 
653 /*
654  * Get the time remaining on a POSIX.1b interval timer.  This function
655  * is ALWAYS called with spin_lock_irq on the timer, thus it must not
656  * mess with irq.
657  *
658  * We have a couple of messes to clean up here.  First there is the case
659  * of a timer that has a requeue pending.  These timers should appear to
660  * be in the timer list with an expiry as if we were to requeue them
661  * now.
662  *
663  * The second issue is the SIGEV_NONE timer which may be active but is
664  * not really ever put in the timer list (to save system resources).
665  * This timer may be expired, and if so, we will do it here.  Otherwise
666  * it is the same as a requeue pending timer WRT to what we should
667  * report.
668  */
669 void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
670 {
671         const struct k_clock *kc = timr->kclock;
672         ktime_t now, remaining, iv;
673         bool sig_none;
674 
675         sig_none = timr->it_sigev_notify == SIGEV_NONE;
676         iv = timr->it_interval;
677 
678         /* interval timer ? */
679         if (iv) {
680                 cur_setting->it_interval = ktime_to_timespec64(iv);
681         } else if (!timr->it_active) {
682                 /*
683                  * SIGEV_NONE oneshot timers are never queued. Check them
684                  * below.
685                  */
686                 if (!sig_none)
687                         return;
688         }
689 
690         now = kc->clock_get_ktime(timr->it_clock);
691 
692         /*
693          * When a requeue is pending or this is a SIGEV_NONE timer move the
694          * expiry time forward by intervals, so expiry is > now.
695          */
696         if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
697                 timr->it_overrun += kc->timer_forward(timr, now);
698 
699         remaining = kc->timer_remaining(timr, now);
700         /* Return 0 only, when the timer is expired and not pending */
701         if (remaining <= 0) {
702                 /*
703                  * A single shot SIGEV_NONE timer must return 0, when
704                  * it is expired !
705                  */
706                 if (!sig_none)
707                         cur_setting->it_value.tv_nsec = 1;
708         } else {
709                 cur_setting->it_value = ktime_to_timespec64(remaining);
710         }
711 }
712 
713 /* Get the time remaining on a POSIX.1b interval timer. */
714 static int do_timer_gettime(timer_t timer_id,  struct itimerspec64 *setting)
715 {
716         struct k_itimer *timr;
717         const struct k_clock *kc;
718         unsigned long flags;
719         int ret = 0;
720 
721         timr = lock_timer(timer_id, &flags);
722         if (!timr)
723                 return -EINVAL;
724 
725         memset(setting, 0, sizeof(*setting));
726         kc = timr->kclock;
727         if (WARN_ON_ONCE(!kc || !kc->timer_get))
728                 ret = -EINVAL;
729         else
730                 kc->timer_get(timr, setting);
731 
732         unlock_timer(timr, flags);
733         return ret;
734 }
735 
736 /* Get the time remaining on a POSIX.1b interval timer. */
737 SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
738                 struct __kernel_itimerspec __user *, setting)
739 {
740         struct itimerspec64 cur_setting;
741 
742         int ret = do_timer_gettime(timer_id, &cur_setting);
743         if (!ret) {
744                 if (put_itimerspec64(&cur_setting, setting))
745                         ret = -EFAULT;
746         }
747         return ret;
748 }
749 
750 #ifdef CONFIG_COMPAT_32BIT_TIME
751 
752 SYSCALL_DEFINE2(timer_gettime32, timer_t, timer_id,
753                 struct old_itimerspec32 __user *, setting)
754 {
755         struct itimerspec64 cur_setting;
756 
757         int ret = do_timer_gettime(timer_id, &cur_setting);
758         if (!ret) {
759                 if (put_old_itimerspec32(&cur_setting, setting))
760                         ret = -EFAULT;
761         }
762         return ret;
763 }
764 
765 #endif
766 
767 /*
768  * Get the number of overruns of a POSIX.1b interval timer.  This is to
769  * be the overrun of the timer last delivered.  At the same time we are
770  * accumulating overruns on the next timer.  The overrun is frozen when
771  * the signal is delivered, either at the notify time (if the info block
772  * is not queued) or at the actual delivery time (as we are informed by
773  * the call back to posixtimer_rearm().  So all we need to do is
774  * to pick up the frozen overrun.
775  */
776 SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
777 {
778         struct k_itimer *timr;
779         int overrun;
780         unsigned long flags;
781 
782         timr = lock_timer(timer_id, &flags);
783         if (!timr)
784                 return -EINVAL;
785 
786         overrun = timer_overrun_to_int(timr, 0);
787         unlock_timer(timr, flags);
788 
789         return overrun;
790 }
791 
792 static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
793                                bool absolute, bool sigev_none)
794 {
795         struct hrtimer *timer = &timr->it.real.timer;
796         enum hrtimer_mode mode;
797 
798         mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
799         /*
800          * Posix magic: Relative CLOCK_REALTIME timers are not affected by
801          * clock modifications, so they become CLOCK_MONOTONIC based under the
802          * hood. See hrtimer_init(). Update timr->kclock, so the generic
803          * functions which use timr->kclock->clock_get_*() work.
804          *
805          * Note: it_clock stays unmodified, because the next timer_set() might
806          * use ABSTIME, so it needs to switch back.
807          */
808         if (timr->it_clock == CLOCK_REALTIME)
809                 timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
810 
811         hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
812         timr->it.real.timer.function = posix_timer_fn;
813 
814         if (!absolute)
815                 expires = ktime_add_safe(expires, timer->base->get_time());
816         hrtimer_set_expires(timer, expires);
817 
818         if (!sigev_none)
819                 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
820 }
821 
822 static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
823 {
824         return hrtimer_try_to_cancel(&timr->it.real.timer);
825 }
826 
827 static void common_timer_wait_running(struct k_itimer *timer)
828 {
829         hrtimer_cancel_wait_running(&timer->it.real.timer);
830 }
831 
832 /*
833  * On PREEMPT_RT this prevent priority inversion against softirq kthread in
834  * case it gets preempted while executing a timer callback. See comments in
835  * hrtimer_cancel_wait_running. For PREEMPT_RT=n this just results in a
836  * cpu_relax().
837  */
838 static struct k_itimer *timer_wait_running(struct k_itimer *timer,
839                                            unsigned long *flags)
840 {
841         const struct k_clock *kc = READ_ONCE(timer->kclock);
842         timer_t timer_id = READ_ONCE(timer->it_id);
843 
844         /* Prevent kfree(timer) after dropping the lock */
845         rcu_read_lock();
846         unlock_timer(timer, *flags);
847 
848         if (!WARN_ON_ONCE(!kc->timer_wait_running))
849                 kc->timer_wait_running(timer);
850 
851         rcu_read_unlock();
852         /* Relock the timer. It might be not longer hashed. */
853         return lock_timer(timer_id, flags);
854 }
855 
856 /* Set a POSIX.1b interval timer. */
857 int common_timer_set(struct k_itimer *timr, int flags,
858                      struct itimerspec64 *new_setting,
859                      struct itimerspec64 *old_setting)
860 {
861         const struct k_clock *kc = timr->kclock;
862         bool sigev_none;
863         ktime_t expires;
864 
865         if (old_setting)
866                 common_timer_get(timr, old_setting);
867 
868         /* Prevent rearming by clearing the interval */
869         timr->it_interval = 0;
870         /*
871          * Careful here. On SMP systems the timer expiry function could be
872          * active and spinning on timr->it_lock.
873          */
874         if (kc->timer_try_to_cancel(timr) < 0)
875                 return TIMER_RETRY;
876 
877         timr->it_active = 0;
878         timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
879                 ~REQUEUE_PENDING;
880         timr->it_overrun_last = 0;
881 
882         /* Switch off the timer when it_value is zero */
883         if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
884                 return 0;
885 
886         timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
887         expires = timespec64_to_ktime(new_setting->it_value);
888         if (flags & TIMER_ABSTIME)
889                 expires = timens_ktime_to_host(timr->it_clock, expires);
890         sigev_none = timr->it_sigev_notify == SIGEV_NONE;
891 
892         kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
893         timr->it_active = !sigev_none;
894         return 0;
895 }
896 
897 static int do_timer_settime(timer_t timer_id, int tmr_flags,
898                             struct itimerspec64 *new_spec64,
899                             struct itimerspec64 *old_spec64)
900 {
901         const struct k_clock *kc;
902         struct k_itimer *timr;
903         unsigned long flags;
904         int error = 0;
905 
906         if (!timespec64_valid(&new_spec64->it_interval) ||
907             !timespec64_valid(&new_spec64->it_value))
908                 return -EINVAL;
909 
910         if (old_spec64)
911                 memset(old_spec64, 0, sizeof(*old_spec64));
912 
913         timr = lock_timer(timer_id, &flags);
914 retry:
915         if (!timr)
916                 return -EINVAL;
917 
918         kc = timr->kclock;
919         if (WARN_ON_ONCE(!kc || !kc->timer_set))
920                 error = -EINVAL;
921         else
922                 error = kc->timer_set(timr, tmr_flags, new_spec64, old_spec64);
923 
924         if (error == TIMER_RETRY) {
925                 // We already got the old time...
926                 old_spec64 = NULL;
927                 /* Unlocks and relocks the timer if it still exists */
928                 timr = timer_wait_running(timr, &flags);
929                 goto retry;
930         }
931         unlock_timer(timr, flags);
932 
933         return error;
934 }
935 
936 /* Set a POSIX.1b interval timer */
937 SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
938                 const struct __kernel_itimerspec __user *, new_setting,
939                 struct __kernel_itimerspec __user *, old_setting)
940 {
941         struct itimerspec64 new_spec, old_spec;
942         struct itimerspec64 *rtn = old_setting ? &old_spec : NULL;
943         int error = 0;
944 
945         if (!new_setting)
946                 return -EINVAL;
947 
948         if (get_itimerspec64(&new_spec, new_setting))
949                 return -EFAULT;
950 
951         error = do_timer_settime(timer_id, flags, &new_spec, rtn);
952         if (!error && old_setting) {
953                 if (put_itimerspec64(&old_spec, old_setting))
954                         error = -EFAULT;
955         }
956         return error;
957 }
958 
959 #ifdef CONFIG_COMPAT_32BIT_TIME
960 SYSCALL_DEFINE4(timer_settime32, timer_t, timer_id, int, flags,
961                 struct old_itimerspec32 __user *, new,
962                 struct old_itimerspec32 __user *, old)
963 {
964         struct itimerspec64 new_spec, old_spec;
965         struct itimerspec64 *rtn = old ? &old_spec : NULL;
966         int error = 0;
967 
968         if (!new)
969                 return -EINVAL;
970         if (get_old_itimerspec32(&new_spec, new))
971                 return -EFAULT;
972 
973         error = do_timer_settime(timer_id, flags, &new_spec, rtn);
974         if (!error && old) {
975                 if (put_old_itimerspec32(&old_spec, old))
976                         error = -EFAULT;
977         }
978         return error;
979 }
980 #endif
981 
982 int common_timer_del(struct k_itimer *timer)
983 {
984         const struct k_clock *kc = timer->kclock;
985 
986         timer->it_interval = 0;
987         if (kc->timer_try_to_cancel(timer) < 0)
988                 return TIMER_RETRY;
989         timer->it_active = 0;
990         return 0;
991 }
992 
993 static inline int timer_delete_hook(struct k_itimer *timer)
994 {
995         const struct k_clock *kc = timer->kclock;
996 
997         if (WARN_ON_ONCE(!kc || !kc->timer_del))
998                 return -EINVAL;
999         return kc->timer_del(timer);
1000 }
1001 
1002 /* Delete a POSIX.1b interval timer. */
1003 SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
1004 {
1005         struct k_itimer *timer;
1006         unsigned long flags;
1007 
1008         timer = lock_timer(timer_id, &flags);
1009 
1010 retry_delete:
1011         if (!timer)
1012                 return -EINVAL;
1013 
1014         if (unlikely(timer_delete_hook(timer) == TIMER_RETRY)) {
1015                 /* Unlocks and relocks the timer if it still exists */
1016                 timer = timer_wait_running(timer, &flags);
1017                 goto retry_delete;
1018         }
1019 
1020         spin_lock(&current->sighand->siglock);
1021         list_del(&timer->list);
1022         spin_unlock(&current->sighand->siglock);
1023         /*
1024          * This keeps any tasks waiting on the spin lock from thinking
1025          * they got something (see the lock code above).
1026          */
1027         timer->it_signal = NULL;
1028 
1029         unlock_timer(timer, flags);
1030         release_posix_timer(timer, IT_ID_SET);
1031         return 0;
1032 }
1033 
1034 /*
1035  * return timer owned by the process, used by exit_itimers
1036  */
1037 static void itimer_delete(struct k_itimer *timer)
1038 {
1039 retry_delete:
1040         spin_lock_irq(&timer->it_lock);
1041 
1042         if (timer_delete_hook(timer) == TIMER_RETRY) {
1043                 spin_unlock_irq(&timer->it_lock);
1044                 goto retry_delete;
1045         }
1046         list_del(&timer->list);
1047 
1048         spin_unlock_irq(&timer->it_lock);
1049         release_posix_timer(timer, IT_ID_SET);
1050 }
1051 
1052 /*
1053  * This is called by do_exit or de_thread, only when there are no more
1054  * references to the shared signal_struct.
1055  */
1056 void exit_itimers(struct signal_struct *sig)
1057 {
1058         struct k_itimer *tmr;
1059 
1060         while (!list_empty(&sig->posix_timers)) {
1061                 tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
1062                 itimer_delete(tmr);
1063         }
1064 }
1065 
1066 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
1067                 const struct __kernel_timespec __user *, tp)
1068 {
1069         const struct k_clock *kc = clockid_to_kclock(which_clock);
1070         struct timespec64 new_tp;
1071 
1072         if (!kc || !kc->clock_set)
1073                 return -EINVAL;
1074 
1075         if (get_timespec64(&new_tp, tp))
1076                 return -EFAULT;
1077 
1078         return kc->clock_set(which_clock, &new_tp);
1079 }
1080 
1081 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
1082                 struct __kernel_timespec __user *, tp)
1083 {
1084         const struct k_clock *kc = clockid_to_kclock(which_clock);
1085         struct timespec64 kernel_tp;
1086         int error;
1087 
1088         if (!kc)
1089                 return -EINVAL;
1090 
1091         error = kc->clock_get_timespec(which_clock, &kernel_tp);
1092 
1093         if (!error && put_timespec64(&kernel_tp, tp))
1094                 error = -EFAULT;
1095 
1096         return error;
1097 }
1098 
1099 int do_clock_adjtime(const clockid_t which_clock, struct __kernel_timex * ktx)
1100 {
1101         const struct k_clock *kc = clockid_to_kclock(which_clock);
1102 
1103         if (!kc)
1104                 return -EINVAL;
1105         if (!kc->clock_adj)
1106                 return -EOPNOTSUPP;
1107 
1108         return kc->clock_adj(which_clock, ktx);
1109 }
1110 
1111 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
1112                 struct __kernel_timex __user *, utx)
1113 {
1114         struct __kernel_timex ktx;
1115         int err;
1116 
1117         if (copy_from_user(&ktx, utx, sizeof(ktx)))
1118                 return -EFAULT;
1119 
1120         err = do_clock_adjtime(which_clock, &ktx);
1121 
1122         if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
1123                 return -EFAULT;
1124 
1125         return err;
1126 }
1127 
1128 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
1129                 struct __kernel_timespec __user *, tp)
1130 {
1131         const struct k_clock *kc = clockid_to_kclock(which_clock);
1132         struct timespec64 rtn_tp;
1133         int error;
1134 
1135         if (!kc)
1136                 return -EINVAL;
1137 
1138         error = kc->clock_getres(which_clock, &rtn_tp);
1139 
1140         if (!error && tp && put_timespec64(&rtn_tp, tp))
1141                 error = -EFAULT;
1142 
1143         return error;
1144 }
1145 
1146 #ifdef CONFIG_COMPAT_32BIT_TIME
1147 
1148 SYSCALL_DEFINE2(clock_settime32, clockid_t, which_clock,
1149                 struct old_timespec32 __user *, tp)
1150 {
1151         const struct k_clock *kc = clockid_to_kclock(which_clock);
1152         struct timespec64 ts;
1153 
1154         if (!kc || !kc->clock_set)
1155                 return -EINVAL;
1156 
1157         if (get_old_timespec32(&ts, tp))
1158                 return -EFAULT;
1159 
1160         return kc->clock_set(which_clock, &ts);
1161 }
1162 
1163 SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock,
1164                 struct old_timespec32 __user *, tp)
1165 {
1166         const struct k_clock *kc = clockid_to_kclock(which_clock);
1167         struct timespec64 ts;
1168         int err;
1169 
1170         if (!kc)
1171                 return -EINVAL;
1172 
1173         err = kc->clock_get_timespec(which_clock, &ts);
1174 
1175         if (!err && put_old_timespec32(&ts, tp))
1176                 err = -EFAULT;
1177 
1178         return err;
1179 }
1180 
1181 SYSCALL_DEFINE2(clock_adjtime32, clockid_t, which_clock,
1182                 struct old_timex32 __user *, utp)
1183 {
1184         struct __kernel_timex ktx;
1185         int err;
1186 
1187         err = get_old_timex32(&ktx, utp);
1188         if (err)
1189                 return err;
1190 
1191         err = do_clock_adjtime(which_clock, &ktx);
1192 
1193         if (err >= 0)
1194                 err = put_old_timex32(utp, &ktx);
1195 
1196         return err;
1197 }
1198 
1199 SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
1200                 struct old_timespec32 __user *, tp)
1201 {
1202         const struct k_clock *kc = clockid_to_kclock(which_clock);
1203         struct timespec64 ts;
1204         int err;
1205 
1206         if (!kc)
1207                 return -EINVAL;
1208 
1209         err = kc->clock_getres(which_clock, &ts);
1210         if (!err && tp && put_old_timespec32(&ts, tp))
1211                 return -EFAULT;
1212 
1213         return err;
1214 }
1215 
1216 #endif
1217 
1218 /*
1219  * nanosleep for monotonic and realtime clocks
1220  */
1221 static int common_nsleep(const clockid_t which_clock, int flags,
1222                          const struct timespec64 *rqtp)
1223 {
1224         ktime_t texp = timespec64_to_ktime(*rqtp);
1225 
1226         return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1227                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1228                                  which_clock);
1229 }
1230 
1231 static int common_nsleep_timens(const clockid_t which_clock, int flags,
1232                          const struct timespec64 *rqtp)
1233 {
1234         ktime_t texp = timespec64_to_ktime(*rqtp);
1235 
1236         if (flags & TIMER_ABSTIME)
1237                 texp = timens_ktime_to_host(which_clock, texp);
1238 
1239         return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
1240                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
1241                                  which_clock);
1242 }
1243 
1244 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
1245                 const struct __kernel_timespec __user *, rqtp,
1246                 struct __kernel_timespec __user *, rmtp)
1247 {
1248         const struct k_clock *kc = clockid_to_kclock(which_clock);
1249         struct timespec64 t;
1250 
1251         if (!kc)
1252                 return -EINVAL;
1253         if (!kc->nsleep)
1254                 return -EOPNOTSUPP;
1255 
1256         if (get_timespec64(&t, rqtp))
1257                 return -EFAULT;
1258 
1259         if (!timespec64_valid(&t))
1260                 return -EINVAL;
1261         if (flags & TIMER_ABSTIME)
1262                 rmtp = NULL;
1263         current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
1264         current->restart_block.nanosleep.rmtp = rmtp;
1265 
1266         return kc->nsleep(which_clock, flags, &t);
1267 }
1268 
1269 #ifdef CONFIG_COMPAT_32BIT_TIME
1270 
1271 SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
1272                 struct old_timespec32 __user *, rqtp,
1273                 struct old_timespec32 __user *, rmtp)
1274 {
1275         const struct k_clock *kc = clockid_to_kclock(which_clock);
1276         struct timespec64 t;
1277 
1278         if (!kc)
1279                 return -EINVAL;
1280         if (!kc->nsleep)
1281                 return -EOPNOTSUPP;
1282 
1283         if (get_old_timespec32(&t, rqtp))
1284                 return -EFAULT;
1285 
1286         if (!timespec64_valid(&t))
1287                 return -EINVAL;
1288         if (flags & TIMER_ABSTIME)
1289                 rmtp = NULL;
1290         current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
1291         current->restart_block.nanosleep.compat_rmtp = rmtp;
1292 
1293         return kc->nsleep(which_clock, flags, &t);
1294 }
1295 
1296 #endif
1297 
1298 static const struct k_clock clock_realtime = {
1299         .clock_getres           = posix_get_hrtimer_res,
1300         .clock_get_timespec     = posix_get_realtime_timespec,
1301         .clock_get_ktime        = posix_get_realtime_ktime,
1302         .clock_set              = posix_clock_realtime_set,
1303         .clock_adj              = posix_clock_realtime_adj,
1304         .nsleep                 = common_nsleep,
1305         .timer_create           = common_timer_create,
1306         .timer_set              = common_timer_set,
1307         .timer_get              = common_timer_get,
1308         .timer_del              = common_timer_del,
1309         .timer_rearm            = common_hrtimer_rearm,
1310         .timer_forward          = common_hrtimer_forward,
1311         .timer_remaining        = common_hrtimer_remaining,
1312         .timer_try_to_cancel    = common_hrtimer_try_to_cancel,
1313         .timer_wait_running     = common_timer_wait_running,
1314         .timer_arm              = common_hrtimer_arm,
1315 };
1316 
1317 static const struct k_clock clock_monotonic = {
1318         .clock_getres           = posix_get_hrtimer_res,
1319         .clock_get_timespec     = posix_get_monotonic_timespec,
1320         .clock_get_ktime        = posix_get_monotonic_ktime,
1321         .nsleep                 = common_nsleep_timens,
1322         .timer_create           = common_timer_create,
1323         .timer_set              = common_timer_set,
1324         .timer_get              = common_timer_get,
1325         .timer_del              = common_timer_del,
1326         .timer_rearm            = common_hrtimer_rearm,
1327         .timer_forward          = common_hrtimer_forward,
1328         .timer_remaining        = common_hrtimer_remaining,
1329         .timer_try_to_cancel    = common_hrtimer_try_to_cancel,
1330         .timer_wait_running     = common_timer_wait_running,
1331         .timer_arm              = common_hrtimer_arm,
1332 };
1333 
1334 static const struct k_clock clock_monotonic_raw = {
1335         .clock_getres           = posix_get_hrtimer_res,
1336         .clock_get_timespec     = posix_get_monotonic_raw,
1337 };
1338 
1339 static const struct k_clock clock_realtime_coarse = {
1340         .clock_getres           = posix_get_coarse_res,
1341         .clock_get_timespec     = posix_get_realtime_coarse,
1342 };
1343 
1344 static const struct k_clock clock_monotonic_coarse = {
1345         .clock_getres           = posix_get_coarse_res,
1346         .clock_get_timespec     = posix_get_monotonic_coarse,
1347 };
1348 
1349 static const struct k_clock clock_tai = {
1350         .clock_getres           = posix_get_hrtimer_res,
1351         .clock_get_ktime        = posix_get_tai_ktime,
1352         .clock_get_timespec     = posix_get_tai_timespec,
1353         .nsleep                 = common_nsleep,
1354         .timer_create           = common_timer_create,
1355         .timer_set              = common_timer_set,
1356         .timer_get              = common_timer_get,
1357         .timer_del              = common_timer_del,
1358         .timer_rearm            = common_hrtimer_rearm,
1359         .timer_forward          = common_hrtimer_forward,
1360         .timer_remaining        = common_hrtimer_remaining,
1361         .timer_try_to_cancel    = common_hrtimer_try_to_cancel,
1362         .timer_wait_running     = common_timer_wait_running,
1363         .timer_arm              = common_hrtimer_arm,
1364 };
1365 
1366 static const struct k_clock clock_boottime = {
1367         .clock_getres           = posix_get_hrtimer_res,
1368         .clock_get_ktime        = posix_get_boottime_ktime,
1369         .clock_get_timespec     = posix_get_boottime_timespec,
1370         .nsleep                 = common_nsleep_timens,
1371         .timer_create           = common_timer_create,
1372         .timer_set              = common_timer_set,
1373         .timer_get              = common_timer_get,
1374         .timer_del              = common_timer_del,
1375         .timer_rearm            = common_hrtimer_rearm,
1376         .timer_forward          = common_hrtimer_forward,
1377         .timer_remaining        = common_hrtimer_remaining,
1378         .timer_try_to_cancel    = common_hrtimer_try_to_cancel,
1379         .timer_wait_running     = common_timer_wait_running,
1380         .timer_arm              = common_hrtimer_arm,
1381 };
1382 
1383 static const struct k_clock * const posix_clocks[] = {
1384         [CLOCK_REALTIME]                = &clock_realtime,
1385         [CLOCK_MONOTONIC]               = &clock_monotonic,
1386         [CLOCK_PROCESS_CPUTIME_ID]      = &clock_process,
1387         [CLOCK_THREAD_CPUTIME_ID]       = &clock_thread,
1388         [CLOCK_MONOTONIC_RAW]           = &clock_monotonic_raw,
1389         [CLOCK_REALTIME_COARSE]         = &clock_realtime_coarse,
1390         [CLOCK_MONOTONIC_COARSE]        = &clock_monotonic_coarse,
1391         [CLOCK_BOOTTIME]                = &clock_boottime,
1392         [CLOCK_REALTIME_ALARM]          = &alarm_clock,
1393         [CLOCK_BOOTTIME_ALARM]          = &alarm_clock,
1394         [CLOCK_TAI]                     = &clock_tai,
1395 };
1396 
1397 static const struct k_clock *clockid_to_kclock(const clockid_t id)
1398 {
1399         clockid_t idx = id;
1400 
1401         if (id < 0) {
1402                 return (id & CLOCKFD_MASK) == CLOCKFD ?
1403                         &clock_posix_dynamic : &clock_posix_cpu;
1404         }
1405 
1406         if (id >= ARRAY_SIZE(posix_clocks))
1407                 return NULL;
1408 
1409         return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))];
1410 }
1411 

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