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