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1/*
2 * Implement CPU time clocks for the POSIX clock interface.
3 */
4
5#include <linux/sched.h>
6#include <linux/posix-timers.h>
7#include <linux/errno.h>
8#include <linux/math64.h>
9#include <asm/uaccess.h>
10#include <linux/kernel_stat.h>
11#include <trace/events/timer.h>
12#include <linux/random.h>
13#include <linux/tick.h>
14#include <linux/workqueue.h>
15
16/*
17 * Called after updating RLIMIT_CPU to run cpu timer and update
18 * tsk->signal->cputime_expires expiration cache if necessary. Needs
19 * siglock protection since other code may update expiration cache as
20 * well.
21 */
22void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
23{
24 cputime_t cputime = secs_to_cputime(rlim_new);
25
26 spin_lock_irq(&task->sighand->siglock);
27 set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
28 spin_unlock_irq(&task->sighand->siglock);
29}
30
31static int check_clock(const clockid_t which_clock)
32{
33 int error = 0;
34 struct task_struct *p;
35 const pid_t pid = CPUCLOCK_PID(which_clock);
36
37 if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
38 return -EINVAL;
39
40 if (pid == 0)
41 return 0;
42
43 rcu_read_lock();
44 p = find_task_by_vpid(pid);
45 if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
46 same_thread_group(p, current) : has_group_leader_pid(p))) {
47 error = -EINVAL;
48 }
49 rcu_read_unlock();
50
51 return error;
52}
53
54static inline unsigned long long
55timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
56{
57 unsigned long long ret;
58
59 ret = 0; /* high half always zero when .cpu used */
60 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
61 ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
62 } else {
63 ret = cputime_to_expires(timespec_to_cputime(tp));
64 }
65 return ret;
66}
67
68static void sample_to_timespec(const clockid_t which_clock,
69 unsigned long long expires,
70 struct timespec *tp)
71{
72 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
73 *tp = ns_to_timespec(expires);
74 else
75 cputime_to_timespec((__force cputime_t)expires, tp);
76}
77
78/*
79 * Update expiry time from increment, and increase overrun count,
80 * given the current clock sample.
81 */
82static void bump_cpu_timer(struct k_itimer *timer,
83 unsigned long long now)
84{
85 int i;
86 unsigned long long delta, incr;
87
88 if (timer->it.cpu.incr == 0)
89 return;
90
91 if (now < timer->it.cpu.expires)
92 return;
93
94 incr = timer->it.cpu.incr;
95 delta = now + incr - timer->it.cpu.expires;
96
97 /* Don't use (incr*2 < delta), incr*2 might overflow. */
98 for (i = 0; incr < delta - incr; i++)
99 incr = incr << 1;
100
101 for (; i >= 0; incr >>= 1, i--) {
102 if (delta < incr)
103 continue;
104
105 timer->it.cpu.expires += incr;
106 timer->it_overrun += 1 << i;
107 delta -= incr;
108 }
109}
110
111/**
112 * task_cputime_zero - Check a task_cputime struct for all zero fields.
113 *
114 * @cputime: The struct to compare.
115 *
116 * Checks @cputime to see if all fields are zero. Returns true if all fields
117 * are zero, false if any field is nonzero.
118 */
119static inline int task_cputime_zero(const struct task_cputime *cputime)
120{
121 if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
122 return 1;
123 return 0;
124}
125
126static inline unsigned long long prof_ticks(struct task_struct *p)
127{
128 cputime_t utime, stime;
129
130 task_cputime(p, &utime, &stime);
131
132 return cputime_to_expires(utime + stime);
133}
134static inline unsigned long long virt_ticks(struct task_struct *p)
135{
136 cputime_t utime;
137
138 task_cputime(p, &utime, NULL);
139
140 return cputime_to_expires(utime);
141}
142
143static int
144posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
145{
146 int error = check_clock(which_clock);
147 if (!error) {
148 tp->tv_sec = 0;
149 tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
150 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
151 /*
152 * If sched_clock is using a cycle counter, we
153 * don't have any idea of its true resolution
154 * exported, but it is much more than 1s/HZ.
155 */
156 tp->tv_nsec = 1;
157 }
158 }
159 return error;
160}
161
162static int
163posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
164{
165 /*
166 * You can never reset a CPU clock, but we check for other errors
167 * in the call before failing with EPERM.
168 */
169 int error = check_clock(which_clock);
170 if (error == 0) {
171 error = -EPERM;
172 }
173 return error;
174}
175
176
177/*
178 * Sample a per-thread clock for the given task.
179 */
180static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
181 unsigned long long *sample)
182{
183 switch (CPUCLOCK_WHICH(which_clock)) {
184 default:
185 return -EINVAL;
186 case CPUCLOCK_PROF:
187 *sample = prof_ticks(p);
188 break;
189 case CPUCLOCK_VIRT:
190 *sample = virt_ticks(p);
191 break;
192 case CPUCLOCK_SCHED:
193 *sample = task_sched_runtime(p);
194 break;
195 }
196 return 0;
197}
198
199/*
200 * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
201 * to avoid race conditions with concurrent updates to cputime.
202 */
203static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime)
204{
205 u64 curr_cputime;
206retry:
207 curr_cputime = atomic64_read(cputime);
208 if (sum_cputime > curr_cputime) {
209 if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime)
210 goto retry;
211 }
212}
213
214static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
215{
216 __update_gt_cputime(&cputime_atomic->utime, sum->utime);
217 __update_gt_cputime(&cputime_atomic->stime, sum->stime);
218 __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
219}
220
221/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
222static inline void sample_cputime_atomic(struct task_cputime *times,
223 struct task_cputime_atomic *atomic_times)
224{
225 times->utime = atomic64_read(&atomic_times->utime);
226 times->stime = atomic64_read(&atomic_times->stime);
227 times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
228}
229
230void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
231{
232 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
233 struct task_cputime sum;
234
235 /* Check if cputimer isn't running. This is accessed without locking. */
236 if (!READ_ONCE(cputimer->running)) {
237 /*
238 * The POSIX timer interface allows for absolute time expiry
239 * values through the TIMER_ABSTIME flag, therefore we have
240 * to synchronize the timer to the clock every time we start it.
241 */
242 thread_group_cputime(tsk, &sum);
243 update_gt_cputime(&cputimer->cputime_atomic, &sum);
244
245 /*
246 * We're setting cputimer->running without a lock. Ensure
247 * this only gets written to in one operation. We set
248 * running after update_gt_cputime() as a small optimization,
249 * but barriers are not required because update_gt_cputime()
250 * can handle concurrent updates.
251 */
252 WRITE_ONCE(cputimer->running, true);
253 }
254 sample_cputime_atomic(times, &cputimer->cputime_atomic);
255}
256
257/*
258 * Sample a process (thread group) clock for the given group_leader task.
259 * Must be called with task sighand lock held for safe while_each_thread()
260 * traversal.
261 */
262static int cpu_clock_sample_group(const clockid_t which_clock,
263 struct task_struct *p,
264 unsigned long long *sample)
265{
266 struct task_cputime cputime;
267
268 switch (CPUCLOCK_WHICH(which_clock)) {
269 default:
270 return -EINVAL;
271 case CPUCLOCK_PROF:
272 thread_group_cputime(p, &cputime);
273 *sample = cputime_to_expires(cputime.utime + cputime.stime);
274 break;
275 case CPUCLOCK_VIRT:
276 thread_group_cputime(p, &cputime);
277 *sample = cputime_to_expires(cputime.utime);
278 break;
279 case CPUCLOCK_SCHED:
280 thread_group_cputime(p, &cputime);
281 *sample = cputime.sum_exec_runtime;
282 break;
283 }
284 return 0;
285}
286
287static int posix_cpu_clock_get_task(struct task_struct *tsk,
288 const clockid_t which_clock,
289 struct timespec *tp)
290{
291 int err = -EINVAL;
292 unsigned long long rtn;
293
294 if (CPUCLOCK_PERTHREAD(which_clock)) {
295 if (same_thread_group(tsk, current))
296 err = cpu_clock_sample(which_clock, tsk, &rtn);
297 } else {
298 if (tsk == current || thread_group_leader(tsk))
299 err = cpu_clock_sample_group(which_clock, tsk, &rtn);
300 }
301
302 if (!err)
303 sample_to_timespec(which_clock, rtn, tp);
304
305 return err;
306}
307
308
309static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
310{
311 const pid_t pid = CPUCLOCK_PID(which_clock);
312 int err = -EINVAL;
313
314 if (pid == 0) {
315 /*
316 * Special case constant value for our own clocks.
317 * We don't have to do any lookup to find ourselves.
318 */
319 err = posix_cpu_clock_get_task(current, which_clock, tp);
320 } else {
321 /*
322 * Find the given PID, and validate that the caller
323 * should be able to see it.
324 */
325 struct task_struct *p;
326 rcu_read_lock();
327 p = find_task_by_vpid(pid);
328 if (p)
329 err = posix_cpu_clock_get_task(p, which_clock, tp);
330 rcu_read_unlock();
331 }
332
333 return err;
334}
335
336/*
337 * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
338 * This is called from sys_timer_create() and do_cpu_nanosleep() with the
339 * new timer already all-zeros initialized.
340 */
341static int posix_cpu_timer_create(struct k_itimer *new_timer)
342{
343 int ret = 0;
344 const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
345 struct task_struct *p;
346
347 if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
348 return -EINVAL;
349
350 INIT_LIST_HEAD(&new_timer->it.cpu.entry);
351
352 rcu_read_lock();
353 if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
354 if (pid == 0) {
355 p = current;
356 } else {
357 p = find_task_by_vpid(pid);
358 if (p && !same_thread_group(p, current))
359 p = NULL;
360 }
361 } else {
362 if (pid == 0) {
363 p = current->group_leader;
364 } else {
365 p = find_task_by_vpid(pid);
366 if (p && !has_group_leader_pid(p))
367 p = NULL;
368 }
369 }
370 new_timer->it.cpu.task = p;
371 if (p) {
372 get_task_struct(p);
373 } else {
374 ret = -EINVAL;
375 }
376 rcu_read_unlock();
377
378 return ret;
379}
380
381/*
382 * Clean up a CPU-clock timer that is about to be destroyed.
383 * This is called from timer deletion with the timer already locked.
384 * If we return TIMER_RETRY, it's necessary to release the timer's lock
385 * and try again. (This happens when the timer is in the middle of firing.)
386 */
387static int posix_cpu_timer_del(struct k_itimer *timer)
388{
389 int ret = 0;
390 unsigned long flags;
391 struct sighand_struct *sighand;
392 struct task_struct *p = timer->it.cpu.task;
393
394 WARN_ON_ONCE(p == NULL);
395
396 /*
397 * Protect against sighand release/switch in exit/exec and process/
398 * thread timer list entry concurrent read/writes.
399 */
400 sighand = lock_task_sighand(p, &flags);
401 if (unlikely(sighand == NULL)) {
402 /*
403 * We raced with the reaping of the task.
404 * The deletion should have cleared us off the list.
405 */
406 WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
407 } else {
408 if (timer->it.cpu.firing)
409 ret = TIMER_RETRY;
410 else
411 list_del(&timer->it.cpu.entry);
412
413 unlock_task_sighand(p, &flags);
414 }
415
416 if (!ret)
417 put_task_struct(p);
418
419 return ret;
420}
421
422static void cleanup_timers_list(struct list_head *head)
423{
424 struct cpu_timer_list *timer, *next;
425
426 list_for_each_entry_safe(timer, next, head, entry)
427 list_del_init(&timer->entry);
428}
429
430/*
431 * Clean out CPU timers still ticking when a thread exited. The task
432 * pointer is cleared, and the expiry time is replaced with the residual
433 * time for later timer_gettime calls to return.
434 * This must be called with the siglock held.
435 */
436static void cleanup_timers(struct list_head *head)
437{
438 cleanup_timers_list(head);
439 cleanup_timers_list(++head);
440 cleanup_timers_list(++head);
441}
442
443/*
444 * These are both called with the siglock held, when the current thread
445 * is being reaped. When the final (leader) thread in the group is reaped,
446 * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
447 */
448void posix_cpu_timers_exit(struct task_struct *tsk)
449{
450 add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
451 sizeof(unsigned long long));
452 cleanup_timers(tsk->cpu_timers);
453
454}
455void posix_cpu_timers_exit_group(struct task_struct *tsk)
456{
457 cleanup_timers(tsk->signal->cpu_timers);
458}
459
460static inline int expires_gt(cputime_t expires, cputime_t new_exp)
461{
462 return expires == 0 || expires > new_exp;
463}
464
465/*
466 * Insert the timer on the appropriate list before any timers that
467 * expire later. This must be called with the sighand lock held.
468 */
469static void arm_timer(struct k_itimer *timer)
470{
471 struct task_struct *p = timer->it.cpu.task;
472 struct list_head *head, *listpos;
473 struct task_cputime *cputime_expires;
474 struct cpu_timer_list *const nt = &timer->it.cpu;
475 struct cpu_timer_list *next;
476
477 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
478 head = p->cpu_timers;
479 cputime_expires = &p->cputime_expires;
480 } else {
481 head = p->signal->cpu_timers;
482 cputime_expires = &p->signal->cputime_expires;
483 }
484 head += CPUCLOCK_WHICH(timer->it_clock);
485
486 listpos = head;
487 list_for_each_entry(next, head, entry) {
488 if (nt->expires < next->expires)
489 break;
490 listpos = &next->entry;
491 }
492 list_add(&nt->entry, listpos);
493
494 if (listpos == head) {
495 unsigned long long exp = nt->expires;
496
497 /*
498 * We are the new earliest-expiring POSIX 1.b timer, hence
499 * need to update expiration cache. Take into account that
500 * for process timers we share expiration cache with itimers
501 * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
502 */
503
504 switch (CPUCLOCK_WHICH(timer->it_clock)) {
505 case CPUCLOCK_PROF:
506 if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp)))
507 cputime_expires->prof_exp = expires_to_cputime(exp);
508 break;
509 case CPUCLOCK_VIRT:
510 if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp)))
511 cputime_expires->virt_exp = expires_to_cputime(exp);
512 break;
513 case CPUCLOCK_SCHED:
514 if (cputime_expires->sched_exp == 0 ||
515 cputime_expires->sched_exp > exp)
516 cputime_expires->sched_exp = exp;
517 break;
518 }
519 if (CPUCLOCK_PERTHREAD(timer->it_clock))
520 tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
521 else
522 tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
523 }
524}
525
526/*
527 * The timer is locked, fire it and arrange for its reload.
528 */
529static void cpu_timer_fire(struct k_itimer *timer)
530{
531 if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
532 /*
533 * User don't want any signal.
534 */
535 timer->it.cpu.expires = 0;
536 } else if (unlikely(timer->sigq == NULL)) {
537 /*
538 * This a special case for clock_nanosleep,
539 * not a normal timer from sys_timer_create.
540 */
541 wake_up_process(timer->it_process);
542 timer->it.cpu.expires = 0;
543 } else if (timer->it.cpu.incr == 0) {
544 /*
545 * One-shot timer. Clear it as soon as it's fired.
546 */
547 posix_timer_event(timer, 0);
548 timer->it.cpu.expires = 0;
549 } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
550 /*
551 * The signal did not get queued because the signal
552 * was ignored, so we won't get any callback to
553 * reload the timer. But we need to keep it
554 * ticking in case the signal is deliverable next time.
555 */
556 posix_cpu_timer_schedule(timer);
557 }
558}
559
560/*
561 * Sample a process (thread group) timer for the given group_leader task.
562 * Must be called with task sighand lock held for safe while_each_thread()
563 * traversal.
564 */
565static int cpu_timer_sample_group(const clockid_t which_clock,
566 struct task_struct *p,
567 unsigned long long *sample)
568{
569 struct task_cputime cputime;
570
571 thread_group_cputimer(p, &cputime);
572 switch (CPUCLOCK_WHICH(which_clock)) {
573 default:
574 return -EINVAL;
575 case CPUCLOCK_PROF:
576 *sample = cputime_to_expires(cputime.utime + cputime.stime);
577 break;
578 case CPUCLOCK_VIRT:
579 *sample = cputime_to_expires(cputime.utime);
580 break;
581 case CPUCLOCK_SCHED:
582 *sample = cputime.sum_exec_runtime;
583 break;
584 }
585 return 0;
586}
587
588/*
589 * Guts of sys_timer_settime for CPU timers.
590 * This is called with the timer locked and interrupts disabled.
591 * If we return TIMER_RETRY, it's necessary to release the timer's lock
592 * and try again. (This happens when the timer is in the middle of firing.)
593 */
594static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
595 struct itimerspec *new, struct itimerspec *old)
596{
597 unsigned long flags;
598 struct sighand_struct *sighand;
599 struct task_struct *p = timer->it.cpu.task;
600 unsigned long long old_expires, new_expires, old_incr, val;
601 int ret;
602
603 WARN_ON_ONCE(p == NULL);
604
605 new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
606
607 /*
608 * Protect against sighand release/switch in exit/exec and p->cpu_timers
609 * and p->signal->cpu_timers read/write in arm_timer()
610 */
611 sighand = lock_task_sighand(p, &flags);
612 /*
613 * If p has just been reaped, we can no
614 * longer get any information about it at all.
615 */
616 if (unlikely(sighand == NULL)) {
617 return -ESRCH;
618 }
619
620 /*
621 * Disarm any old timer after extracting its expiry time.
622 */
623 WARN_ON_ONCE(!irqs_disabled());
624
625 ret = 0;
626 old_incr = timer->it.cpu.incr;
627 old_expires = timer->it.cpu.expires;
628 if (unlikely(timer->it.cpu.firing)) {
629 timer->it.cpu.firing = -1;
630 ret = TIMER_RETRY;
631 } else
632 list_del_init(&timer->it.cpu.entry);
633
634 /*
635 * We need to sample the current value to convert the new
636 * value from to relative and absolute, and to convert the
637 * old value from absolute to relative. To set a process
638 * timer, we need a sample to balance the thread expiry
639 * times (in arm_timer). With an absolute time, we must
640 * check if it's already passed. In short, we need a sample.
641 */
642 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
643 cpu_clock_sample(timer->it_clock, p, &val);
644 } else {
645 cpu_timer_sample_group(timer->it_clock, p, &val);
646 }
647
648 if (old) {
649 if (old_expires == 0) {
650 old->it_value.tv_sec = 0;
651 old->it_value.tv_nsec = 0;
652 } else {
653 /*
654 * Update the timer in case it has
655 * overrun already. If it has,
656 * we'll report it as having overrun
657 * and with the next reloaded timer
658 * already ticking, though we are
659 * swallowing that pending
660 * notification here to install the
661 * new setting.
662 */
663 bump_cpu_timer(timer, val);
664 if (val < timer->it.cpu.expires) {
665 old_expires = timer->it.cpu.expires - val;
666 sample_to_timespec(timer->it_clock,
667 old_expires,
668 &old->it_value);
669 } else {
670 old->it_value.tv_nsec = 1;
671 old->it_value.tv_sec = 0;
672 }
673 }
674 }
675
676 if (unlikely(ret)) {
677 /*
678 * We are colliding with the timer actually firing.
679 * Punt after filling in the timer's old value, and
680 * disable this firing since we are already reporting
681 * it as an overrun (thanks to bump_cpu_timer above).
682 */
683 unlock_task_sighand(p, &flags);
684 goto out;
685 }
686
687 if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
688 new_expires += val;
689 }
690
691 /*
692 * Install the new expiry time (or zero).
693 * For a timer with no notification action, we don't actually
694 * arm the timer (we'll just fake it for timer_gettime).
695 */
696 timer->it.cpu.expires = new_expires;
697 if (new_expires != 0 && val < new_expires) {
698 arm_timer(timer);
699 }
700
701 unlock_task_sighand(p, &flags);
702 /*
703 * Install the new reload setting, and
704 * set up the signal and overrun bookkeeping.
705 */
706 timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
707 &new->it_interval);
708
709 /*
710 * This acts as a modification timestamp for the timer,
711 * so any automatic reload attempt will punt on seeing
712 * that we have reset the timer manually.
713 */
714 timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
715 ~REQUEUE_PENDING;
716 timer->it_overrun_last = 0;
717 timer->it_overrun = -1;
718
719 if (new_expires != 0 && !(val < new_expires)) {
720 /*
721 * The designated time already passed, so we notify
722 * immediately, even if the thread never runs to
723 * accumulate more time on this clock.
724 */
725 cpu_timer_fire(timer);
726 }
727
728 ret = 0;
729 out:
730 if (old) {
731 sample_to_timespec(timer->it_clock,
732 old_incr, &old->it_interval);
733 }
734
735 return ret;
736}
737
738static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
739{
740 unsigned long long now;
741 struct task_struct *p = timer->it.cpu.task;
742
743 WARN_ON_ONCE(p == NULL);
744
745 /*
746 * Easy part: convert the reload time.
747 */
748 sample_to_timespec(timer->it_clock,
749 timer->it.cpu.incr, &itp->it_interval);
750
751 if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */
752 itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
753 return;
754 }
755
756 /*
757 * Sample the clock to take the difference with the expiry time.
758 */
759 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
760 cpu_clock_sample(timer->it_clock, p, &now);
761 } else {
762 struct sighand_struct *sighand;
763 unsigned long flags;
764
765 /*
766 * Protect against sighand release/switch in exit/exec and
767 * also make timer sampling safe if it ends up calling
768 * thread_group_cputime().
769 */
770 sighand = lock_task_sighand(p, &flags);
771 if (unlikely(sighand == NULL)) {
772 /*
773 * The process has been reaped.
774 * We can't even collect a sample any more.
775 * Call the timer disarmed, nothing else to do.
776 */
777 timer->it.cpu.expires = 0;
778 sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
779 &itp->it_value);
780 } else {
781 cpu_timer_sample_group(timer->it_clock, p, &now);
782 unlock_task_sighand(p, &flags);
783 }
784 }
785
786 if (now < timer->it.cpu.expires) {
787 sample_to_timespec(timer->it_clock,
788 timer->it.cpu.expires - now,
789 &itp->it_value);
790 } else {
791 /*
792 * The timer should have expired already, but the firing
793 * hasn't taken place yet. Say it's just about to expire.
794 */
795 itp->it_value.tv_nsec = 1;
796 itp->it_value.tv_sec = 0;
797 }
798}
799
800static unsigned long long
801check_timers_list(struct list_head *timers,
802 struct list_head *firing,
803 unsigned long long curr)
804{
805 int maxfire = 20;
806
807 while (!list_empty(timers)) {
808 struct cpu_timer_list *t;
809
810 t = list_first_entry(timers, struct cpu_timer_list, entry);
811
812 if (!--maxfire || curr < t->expires)
813 return t->expires;
814
815 t->firing = 1;
816 list_move_tail(&t->entry, firing);
817 }
818
819 return 0;
820}
821
822/*
823 * Check for any per-thread CPU timers that have fired and move them off
824 * the tsk->cpu_timers[N] list onto the firing list. Here we update the
825 * tsk->it_*_expires values to reflect the remaining thread CPU timers.
826 */
827static void check_thread_timers(struct task_struct *tsk,
828 struct list_head *firing)
829{
830 struct list_head *timers = tsk->cpu_timers;
831 struct signal_struct *const sig = tsk->signal;
832 struct task_cputime *tsk_expires = &tsk->cputime_expires;
833 unsigned long long expires;
834 unsigned long soft;
835
836 /*
837 * If cputime_expires is zero, then there are no active
838 * per thread CPU timers.
839 */
840 if (task_cputime_zero(&tsk->cputime_expires))
841 return;
842
843 expires = check_timers_list(timers, firing, prof_ticks(tsk));
844 tsk_expires->prof_exp = expires_to_cputime(expires);
845
846 expires = check_timers_list(++timers, firing, virt_ticks(tsk));
847 tsk_expires->virt_exp = expires_to_cputime(expires);
848
849 tsk_expires->sched_exp = check_timers_list(++timers, firing,
850 tsk->se.sum_exec_runtime);
851
852 /*
853 * Check for the special case thread timers.
854 */
855 soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
856 if (soft != RLIM_INFINITY) {
857 unsigned long hard =
858 READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
859
860 if (hard != RLIM_INFINITY &&
861 tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
862 /*
863 * At the hard limit, we just die.
864 * No need to calculate anything else now.
865 */
866 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
867 return;
868 }
869 if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
870 /*
871 * At the soft limit, send a SIGXCPU every second.
872 */
873 if (soft < hard) {
874 soft += USEC_PER_SEC;
875 sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
876 }
877 printk(KERN_INFO
878 "RT Watchdog Timeout: %s[%d]\n",
879 tsk->comm, task_pid_nr(tsk));
880 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
881 }
882 }
883 if (task_cputime_zero(tsk_expires))
884 tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
885}
886
887static inline void stop_process_timers(struct signal_struct *sig)
888{
889 struct thread_group_cputimer *cputimer = &sig->cputimer;
890
891 /* Turn off cputimer->running. This is done without locking. */
892 WRITE_ONCE(cputimer->running, false);
893 tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
894}
895
896static u32 onecputick;
897
898static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
899 unsigned long long *expires,
900 unsigned long long cur_time, int signo)
901{
902 if (!it->expires)
903 return;
904
905 if (cur_time >= it->expires) {
906 if (it->incr) {
907 it->expires += it->incr;
908 it->error += it->incr_error;
909 if (it->error >= onecputick) {
910 it->expires -= cputime_one_jiffy;
911 it->error -= onecputick;
912 }
913 } else {
914 it->expires = 0;
915 }
916
917 trace_itimer_expire(signo == SIGPROF ?
918 ITIMER_PROF : ITIMER_VIRTUAL,
919 tsk->signal->leader_pid, cur_time);
920 __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
921 }
922
923 if (it->expires && (!*expires || it->expires < *expires)) {
924 *expires = it->expires;
925 }
926}
927
928/*
929 * Check for any per-thread CPU timers that have fired and move them
930 * off the tsk->*_timers list onto the firing list. Per-thread timers
931 * have already been taken off.
932 */
933static void check_process_timers(struct task_struct *tsk,
934 struct list_head *firing)
935{
936 struct signal_struct *const sig = tsk->signal;
937 unsigned long long utime, ptime, virt_expires, prof_expires;
938 unsigned long long sum_sched_runtime, sched_expires;
939 struct list_head *timers = sig->cpu_timers;
940 struct task_cputime cputime;
941 unsigned long soft;
942
943 /*
944 * If cputimer is not running, then there are no active
945 * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU).
946 */
947 if (!READ_ONCE(tsk->signal->cputimer.running))
948 return;
949
950 /*
951 * Signify that a thread is checking for process timers.
952 * Write access to this field is protected by the sighand lock.
953 */
954 sig->cputimer.checking_timer = true;
955
956 /*
957 * Collect the current process totals.
958 */
959 thread_group_cputimer(tsk, &cputime);
960 utime = cputime_to_expires(cputime.utime);
961 ptime = utime + cputime_to_expires(cputime.stime);
962 sum_sched_runtime = cputime.sum_exec_runtime;
963
964 prof_expires = check_timers_list(timers, firing, ptime);
965 virt_expires = check_timers_list(++timers, firing, utime);
966 sched_expires = check_timers_list(++timers, firing, sum_sched_runtime);
967
968 /*
969 * Check for the special case process timers.
970 */
971 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
972 SIGPROF);
973 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
974 SIGVTALRM);
975 soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
976 if (soft != RLIM_INFINITY) {
977 unsigned long psecs = cputime_to_secs(ptime);
978 unsigned long hard =
979 READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
980 cputime_t x;
981 if (psecs >= hard) {
982 /*
983 * At the hard limit, we just die.
984 * No need to calculate anything else now.
985 */
986 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
987 return;
988 }
989 if (psecs >= soft) {
990 /*
991 * At the soft limit, send a SIGXCPU every second.
992 */
993 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
994 if (soft < hard) {
995 soft++;
996 sig->rlim[RLIMIT_CPU].rlim_cur = soft;
997 }
998 }
999 x = secs_to_cputime(soft);
1000 if (!prof_expires || x < prof_expires) {
1001 prof_expires = x;
1002 }
1003 }
1004
1005 sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires);
1006 sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires);
1007 sig->cputime_expires.sched_exp = sched_expires;
1008 if (task_cputime_zero(&sig->cputime_expires))
1009 stop_process_timers(sig);
1010
1011 sig->cputimer.checking_timer = false;
1012}
1013
1014/*
1015 * This is called from the signal code (via do_schedule_next_timer)
1016 * when the last timer signal was delivered and we have to reload the timer.
1017 */
1018void posix_cpu_timer_schedule(struct k_itimer *timer)
1019{
1020 struct sighand_struct *sighand;
1021 unsigned long flags;
1022 struct task_struct *p = timer->it.cpu.task;
1023 unsigned long long now;
1024
1025 WARN_ON_ONCE(p == NULL);
1026
1027 /*
1028 * Fetch the current sample and update the timer's expiry time.
1029 */
1030 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
1031 cpu_clock_sample(timer->it_clock, p, &now);
1032 bump_cpu_timer(timer, now);
1033 if (unlikely(p->exit_state))
1034 goto out;
1035
1036 /* Protect timer list r/w in arm_timer() */
1037 sighand = lock_task_sighand(p, &flags);
1038 if (!sighand)
1039 goto out;
1040 } else {
1041 /*
1042 * Protect arm_timer() and timer sampling in case of call to
1043 * thread_group_cputime().
1044 */
1045 sighand = lock_task_sighand(p, &flags);
1046 if (unlikely(sighand == NULL)) {
1047 /*
1048 * The process has been reaped.
1049 * We can't even collect a sample any more.
1050 */
1051 timer->it.cpu.expires = 0;
1052 goto out;
1053 } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
1054 unlock_task_sighand(p, &flags);
1055 /* Optimizations: if the process is dying, no need to rearm */
1056 goto out;
1057 }
1058 cpu_timer_sample_group(timer->it_clock, p, &now);
1059 bump_cpu_timer(timer, now);
1060 /* Leave the sighand locked for the call below. */
1061 }
1062
1063 /*
1064 * Now re-arm for the new expiry time.
1065 */
1066 WARN_ON_ONCE(!irqs_disabled());
1067 arm_timer(timer);
1068 unlock_task_sighand(p, &flags);
1069
1070out:
1071 timer->it_overrun_last = timer->it_overrun;
1072 timer->it_overrun = -1;
1073 ++timer->it_requeue_pending;
1074}
1075
1076/**
1077 * task_cputime_expired - Compare two task_cputime entities.
1078 *
1079 * @sample: The task_cputime structure to be checked for expiration.
1080 * @expires: Expiration times, against which @sample will be checked.
1081 *
1082 * Checks @sample against @expires to see if any field of @sample has expired.
1083 * Returns true if any field of the former is greater than the corresponding
1084 * field of the latter if the latter field is set. Otherwise returns false.
1085 */
1086static inline int task_cputime_expired(const struct task_cputime *sample,
1087 const struct task_cputime *expires)
1088{
1089 if (expires->utime && sample->utime >= expires->utime)
1090 return 1;
1091 if (expires->stime && sample->utime + sample->stime >= expires->stime)
1092 return 1;
1093 if (expires->sum_exec_runtime != 0 &&
1094 sample->sum_exec_runtime >= expires->sum_exec_runtime)
1095 return 1;
1096 return 0;
1097}
1098
1099/**
1100 * fastpath_timer_check - POSIX CPU timers fast path.
1101 *
1102 * @tsk: The task (thread) being checked.
1103 *
1104 * Check the task and thread group timers. If both are zero (there are no
1105 * timers set) return false. Otherwise snapshot the task and thread group
1106 * timers and compare them with the corresponding expiration times. Return
1107 * true if a timer has expired, else return false.
1108 */
1109static inline int fastpath_timer_check(struct task_struct *tsk)
1110{
1111 struct signal_struct *sig;
1112
1113 if (!task_cputime_zero(&tsk->cputime_expires)) {
1114 struct task_cputime task_sample;
1115
1116 task_cputime(tsk, &task_sample.utime, &task_sample.stime);
1117 task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
1118 if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
1119 return 1;
1120 }
1121
1122 sig = tsk->signal;
1123 /*
1124 * Check if thread group timers expired when the cputimer is
1125 * running and no other thread in the group is already checking
1126 * for thread group cputimers. These fields are read without the
1127 * sighand lock. However, this is fine because this is meant to
1128 * be a fastpath heuristic to determine whether we should try to
1129 * acquire the sighand lock to check/handle timers.
1130 *
1131 * In the worst case scenario, if 'running' or 'checking_timer' gets
1132 * set but the current thread doesn't see the change yet, we'll wait
1133 * until the next thread in the group gets a scheduler interrupt to
1134 * handle the timer. This isn't an issue in practice because these
1135 * types of delays with signals actually getting sent are expected.
1136 */
1137 if (READ_ONCE(sig->cputimer.running) &&
1138 !READ_ONCE(sig->cputimer.checking_timer)) {
1139 struct task_cputime group_sample;
1140
1141 sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
1142
1143 if (task_cputime_expired(&group_sample, &sig->cputime_expires))
1144 return 1;
1145 }
1146
1147 return 0;
1148}
1149
1150/*
1151 * This is called from the timer interrupt handler. The irq handler has
1152 * already updated our counts. We need to check if any timers fire now.
1153 * Interrupts are disabled.
1154 */
1155void run_posix_cpu_timers(struct task_struct *tsk)
1156{
1157 LIST_HEAD(firing);
1158 struct k_itimer *timer, *next;
1159 unsigned long flags;
1160
1161 WARN_ON_ONCE(!irqs_disabled());
1162
1163 /*
1164 * The fast path checks that there are no expired thread or thread
1165 * group timers. If that's so, just return.
1166 */
1167 if (!fastpath_timer_check(tsk))
1168 return;
1169
1170 if (!lock_task_sighand(tsk, &flags))
1171 return;
1172 /*
1173 * Here we take off tsk->signal->cpu_timers[N] and
1174 * tsk->cpu_timers[N] all the timers that are firing, and
1175 * put them on the firing list.
1176 */
1177 check_thread_timers(tsk, &firing);
1178
1179 check_process_timers(tsk, &firing);
1180
1181 /*
1182 * We must release these locks before taking any timer's lock.
1183 * There is a potential race with timer deletion here, as the
1184 * siglock now protects our private firing list. We have set
1185 * the firing flag in each timer, so that a deletion attempt
1186 * that gets the timer lock before we do will give it up and
1187 * spin until we've taken care of that timer below.
1188 */
1189 unlock_task_sighand(tsk, &flags);
1190
1191 /*
1192 * Now that all the timers on our list have the firing flag,
1193 * no one will touch their list entries but us. We'll take
1194 * each timer's lock before clearing its firing flag, so no
1195 * timer call will interfere.
1196 */
1197 list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
1198 int cpu_firing;
1199
1200 spin_lock(&timer->it_lock);
1201 list_del_init(&timer->it.cpu.entry);
1202 cpu_firing = timer->it.cpu.firing;
1203 timer->it.cpu.firing = 0;
1204 /*
1205 * The firing flag is -1 if we collided with a reset
1206 * of the timer, which already reported this
1207 * almost-firing as an overrun. So don't generate an event.
1208 */
1209 if (likely(cpu_firing >= 0))
1210 cpu_timer_fire(timer);
1211 spin_unlock(&timer->it_lock);
1212 }
1213}
1214
1215/*
1216 * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
1217 * The tsk->sighand->siglock must be held by the caller.
1218 */
1219void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
1220 cputime_t *newval, cputime_t *oldval)
1221{
1222 unsigned long long now;
1223
1224 WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
1225 cpu_timer_sample_group(clock_idx, tsk, &now);
1226
1227 if (oldval) {
1228 /*
1229 * We are setting itimer. The *oldval is absolute and we update
1230 * it to be relative, *newval argument is relative and we update
1231 * it to be absolute.
1232 */
1233 if (*oldval) {
1234 if (*oldval <= now) {
1235 /* Just about to fire. */
1236 *oldval = cputime_one_jiffy;
1237 } else {
1238 *oldval -= now;
1239 }
1240 }
1241
1242 if (!*newval)
1243 return;
1244 *newval += now;
1245 }
1246
1247 /*
1248 * Update expiration cache if we are the earliest timer, or eventually
1249 * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
1250 */
1251 switch (clock_idx) {
1252 case CPUCLOCK_PROF:
1253 if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
1254 tsk->signal->cputime_expires.prof_exp = *newval;
1255 break;
1256 case CPUCLOCK_VIRT:
1257 if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
1258 tsk->signal->cputime_expires.virt_exp = *newval;
1259 break;
1260 }
1261
1262 tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
1263}
1264
1265static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
1266 struct timespec *rqtp, struct itimerspec *it)
1267{
1268 struct k_itimer timer;
1269 int error;
1270
1271 /*
1272 * Set up a temporary timer and then wait for it to go off.
1273 */
1274 memset(&timer, 0, sizeof timer);
1275 spin_lock_init(&timer.it_lock);
1276 timer.it_clock = which_clock;
1277 timer.it_overrun = -1;
1278 error = posix_cpu_timer_create(&timer);
1279 timer.it_process = current;
1280 if (!error) {
1281 static struct itimerspec zero_it;
1282
1283 memset(it, 0, sizeof *it);
1284 it->it_value = *rqtp;
1285
1286 spin_lock_irq(&timer.it_lock);
1287 error = posix_cpu_timer_set(&timer, flags, it, NULL);
1288 if (error) {
1289 spin_unlock_irq(&timer.it_lock);
1290 return error;
1291 }
1292
1293 while (!signal_pending(current)) {
1294 if (timer.it.cpu.expires == 0) {
1295 /*
1296 * Our timer fired and was reset, below
1297 * deletion can not fail.
1298 */
1299 posix_cpu_timer_del(&timer);
1300 spin_unlock_irq(&timer.it_lock);
1301 return 0;
1302 }
1303
1304 /*
1305 * Block until cpu_timer_fire (or a signal) wakes us.
1306 */
1307 __set_current_state(TASK_INTERRUPTIBLE);
1308 spin_unlock_irq(&timer.it_lock);
1309 schedule();
1310 spin_lock_irq(&timer.it_lock);
1311 }
1312
1313 /*
1314 * We were interrupted by a signal.
1315 */
1316 sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
1317 error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
1318 if (!error) {
1319 /*
1320 * Timer is now unarmed, deletion can not fail.
1321 */
1322 posix_cpu_timer_del(&timer);
1323 }
1324 spin_unlock_irq(&timer.it_lock);
1325
1326 while (error == TIMER_RETRY) {
1327 /*
1328 * We need to handle case when timer was or is in the
1329 * middle of firing. In other cases we already freed
1330 * resources.
1331 */
1332 spin_lock_irq(&timer.it_lock);
1333 error = posix_cpu_timer_del(&timer);
1334 spin_unlock_irq(&timer.it_lock);
1335 }
1336
1337 if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
1338 /*
1339 * It actually did fire already.
1340 */
1341 return 0;
1342 }
1343
1344 error = -ERESTART_RESTARTBLOCK;
1345 }
1346
1347 return error;
1348}
1349
1350static long posix_cpu_nsleep_restart(struct restart_block *restart_block);
1351
1352static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
1353 struct timespec *rqtp, struct timespec __user *rmtp)
1354{
1355 struct restart_block *restart_block = ¤t->restart_block;
1356 struct itimerspec it;
1357 int error;
1358
1359 /*
1360 * Diagnose required errors first.
1361 */
1362 if (CPUCLOCK_PERTHREAD(which_clock) &&
1363 (CPUCLOCK_PID(which_clock) == 0 ||
1364 CPUCLOCK_PID(which_clock) == current->pid))
1365 return -EINVAL;
1366
1367 error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
1368
1369 if (error == -ERESTART_RESTARTBLOCK) {
1370
1371 if (flags & TIMER_ABSTIME)
1372 return -ERESTARTNOHAND;
1373 /*
1374 * Report back to the user the time still remaining.
1375 */
1376 if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1377 return -EFAULT;
1378
1379 restart_block->fn = posix_cpu_nsleep_restart;
1380 restart_block->nanosleep.clockid = which_clock;
1381 restart_block->nanosleep.rmtp = rmtp;
1382 restart_block->nanosleep.expires = timespec_to_ns(rqtp);
1383 }
1384 return error;
1385}
1386
1387static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
1388{
1389 clockid_t which_clock = restart_block->nanosleep.clockid;
1390 struct timespec t;
1391 struct itimerspec it;
1392 int error;
1393
1394 t = ns_to_timespec(restart_block->nanosleep.expires);
1395
1396 error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
1397
1398 if (error == -ERESTART_RESTARTBLOCK) {
1399 struct timespec __user *rmtp = restart_block->nanosleep.rmtp;
1400 /*
1401 * Report back to the user the time still remaining.
1402 */
1403 if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1404 return -EFAULT;
1405
1406 restart_block->nanosleep.expires = timespec_to_ns(&t);
1407 }
1408 return error;
1409
1410}
1411
1412#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
1413#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
1414
1415static int process_cpu_clock_getres(const clockid_t which_clock,
1416 struct timespec *tp)
1417{
1418 return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
1419}
1420static int process_cpu_clock_get(const clockid_t which_clock,
1421 struct timespec *tp)
1422{
1423 return posix_cpu_clock_get(PROCESS_CLOCK, tp);
1424}
1425static int process_cpu_timer_create(struct k_itimer *timer)
1426{
1427 timer->it_clock = PROCESS_CLOCK;
1428 return posix_cpu_timer_create(timer);
1429}
1430static int process_cpu_nsleep(const clockid_t which_clock, int flags,
1431 struct timespec *rqtp,
1432 struct timespec __user *rmtp)
1433{
1434 return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
1435}
1436static long process_cpu_nsleep_restart(struct restart_block *restart_block)
1437{
1438 return -EINVAL;
1439}
1440static int thread_cpu_clock_getres(const clockid_t which_clock,
1441 struct timespec *tp)
1442{
1443 return posix_cpu_clock_getres(THREAD_CLOCK, tp);
1444}
1445static int thread_cpu_clock_get(const clockid_t which_clock,
1446 struct timespec *tp)
1447{
1448 return posix_cpu_clock_get(THREAD_CLOCK, tp);
1449}
1450static int thread_cpu_timer_create(struct k_itimer *timer)
1451{
1452 timer->it_clock = THREAD_CLOCK;
1453 return posix_cpu_timer_create(timer);
1454}
1455
1456struct k_clock clock_posix_cpu = {
1457 .clock_getres = posix_cpu_clock_getres,
1458 .clock_set = posix_cpu_clock_set,
1459 .clock_get = posix_cpu_clock_get,
1460 .timer_create = posix_cpu_timer_create,
1461 .nsleep = posix_cpu_nsleep,
1462 .nsleep_restart = posix_cpu_nsleep_restart,
1463 .timer_set = posix_cpu_timer_set,
1464 .timer_del = posix_cpu_timer_del,
1465 .timer_get = posix_cpu_timer_get,
1466};
1467
1468static __init int init_posix_cpu_timers(void)
1469{
1470 struct k_clock process = {
1471 .clock_getres = process_cpu_clock_getres,
1472 .clock_get = process_cpu_clock_get,
1473 .timer_create = process_cpu_timer_create,
1474 .nsleep = process_cpu_nsleep,
1475 .nsleep_restart = process_cpu_nsleep_restart,
1476 };
1477 struct k_clock thread = {
1478 .clock_getres = thread_cpu_clock_getres,
1479 .clock_get = thread_cpu_clock_get,
1480 .timer_create = thread_cpu_timer_create,
1481 };
1482 struct timespec ts;
1483
1484 posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
1485 posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
1486
1487 cputime_to_timespec(cputime_one_jiffy, &ts);
1488 onecputick = ts.tv_nsec;
1489 WARN_ON(ts.tv_sec != 0);
1490
1491 return 0;
1492}
1493__initcall(init_posix_cpu_timers);