1
2
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
13
14
15
16
17
18
19void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
20{
21 cputime_t cputime = secs_to_cputime(rlim_new);
22
23 spin_lock_irq(&task->sighand->siglock);
24 set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
25 spin_unlock_irq(&task->sighand->siglock);
26}
27
28static int check_clock(const clockid_t which_clock)
29{
30 int error = 0;
31 struct task_struct *p;
32 const pid_t pid = CPUCLOCK_PID(which_clock);
33
34 if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
35 return -EINVAL;
36
37 if (pid == 0)
38 return 0;
39
40 read_lock(&tasklist_lock);
41 p = find_task_by_vpid(pid);
42 if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
43 same_thread_group(p, current) : thread_group_leader(p))) {
44 error = -EINVAL;
45 }
46 read_unlock(&tasklist_lock);
47
48 return error;
49}
50
51static inline union cpu_time_count
52timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
53{
54 union cpu_time_count ret;
55 ret.sched = 0;
56 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
57 ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
58 } else {
59 ret.cpu = timespec_to_cputime(tp);
60 }
61 return ret;
62}
63
64static void sample_to_timespec(const clockid_t which_clock,
65 union cpu_time_count cpu,
66 struct timespec *tp)
67{
68 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
69 *tp = ns_to_timespec(cpu.sched);
70 else
71 cputime_to_timespec(cpu.cpu, tp);
72}
73
74static inline int cpu_time_before(const clockid_t which_clock,
75 union cpu_time_count now,
76 union cpu_time_count then)
77{
78 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
79 return now.sched < then.sched;
80 } else {
81 return cputime_lt(now.cpu, then.cpu);
82 }
83}
84static inline void cpu_time_add(const clockid_t which_clock,
85 union cpu_time_count *acc,
86 union cpu_time_count val)
87{
88 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
89 acc->sched += val.sched;
90 } else {
91 acc->cpu = cputime_add(acc->cpu, val.cpu);
92 }
93}
94static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
95 union cpu_time_count a,
96 union cpu_time_count b)
97{
98 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
99 a.sched -= b.sched;
100 } else {
101 a.cpu = cputime_sub(a.cpu, b.cpu);
102 }
103 return a;
104}
105
106
107
108
109
110
111
112static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
113{
114 cputime_t res = cputime_div(time, div);
115
116 return max_t(cputime_t, res, 1);
117}
118
119
120
121
122
123static void bump_cpu_timer(struct k_itimer *timer,
124 union cpu_time_count now)
125{
126 int i;
127
128 if (timer->it.cpu.incr.sched == 0)
129 return;
130
131 if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
132 unsigned long long delta, incr;
133
134 if (now.sched < timer->it.cpu.expires.sched)
135 return;
136 incr = timer->it.cpu.incr.sched;
137 delta = now.sched + incr - timer->it.cpu.expires.sched;
138
139 for (i = 0; incr < delta - incr; i++)
140 incr = incr << 1;
141 for (; i >= 0; incr >>= 1, i--) {
142 if (delta < incr)
143 continue;
144 timer->it.cpu.expires.sched += incr;
145 timer->it_overrun += 1 << i;
146 delta -= incr;
147 }
148 } else {
149 cputime_t delta, incr;
150
151 if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
152 return;
153 incr = timer->it.cpu.incr.cpu;
154 delta = cputime_sub(cputime_add(now.cpu, incr),
155 timer->it.cpu.expires.cpu);
156
157 for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
158 incr = cputime_add(incr, incr);
159 for (; i >= 0; incr = cputime_halve(incr), i--) {
160 if (cputime_lt(delta, incr))
161 continue;
162 timer->it.cpu.expires.cpu =
163 cputime_add(timer->it.cpu.expires.cpu, incr);
164 timer->it_overrun += 1 << i;
165 delta = cputime_sub(delta, incr);
166 }
167 }
168}
169
170static inline cputime_t prof_ticks(struct task_struct *p)
171{
172 return cputime_add(p->utime, p->stime);
173}
174static inline cputime_t virt_ticks(struct task_struct *p)
175{
176 return p->utime;
177}
178
179int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
180{
181 int error = check_clock(which_clock);
182 if (!error) {
183 tp->tv_sec = 0;
184 tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
185 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
186
187
188
189
190
191 tp->tv_nsec = 1;
192 }
193 }
194 return error;
195}
196
197int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
198{
199
200
201
202
203 int error = check_clock(which_clock);
204 if (error == 0) {
205 error = -EPERM;
206 }
207 return error;
208}
209
210
211
212
213
214static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
215 union cpu_time_count *cpu)
216{
217 switch (CPUCLOCK_WHICH(which_clock)) {
218 default:
219 return -EINVAL;
220 case CPUCLOCK_PROF:
221 cpu->cpu = prof_ticks(p);
222 break;
223 case CPUCLOCK_VIRT:
224 cpu->cpu = virt_ticks(p);
225 break;
226 case CPUCLOCK_SCHED:
227 cpu->sched = task_sched_runtime(p);
228 break;
229 }
230 return 0;
231}
232
233void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
234{
235 struct signal_struct *sig = tsk->signal;
236 struct task_struct *t;
237
238 times->utime = sig->utime;
239 times->stime = sig->stime;
240 times->sum_exec_runtime = sig->sum_sched_runtime;
241
242 rcu_read_lock();
243
244 if (!likely(pid_alive(tsk)))
245 goto out;
246
247 t = tsk;
248 do {
249 times->utime = cputime_add(times->utime, t->utime);
250 times->stime = cputime_add(times->stime, t->stime);
251 times->sum_exec_runtime += t->se.sum_exec_runtime;
252 } while_each_thread(tsk, t);
253out:
254 rcu_read_unlock();
255}
256
257static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
258{
259 if (cputime_gt(b->utime, a->utime))
260 a->utime = b->utime;
261
262 if (cputime_gt(b->stime, a->stime))
263 a->stime = b->stime;
264
265 if (b->sum_exec_runtime > a->sum_exec_runtime)
266 a->sum_exec_runtime = b->sum_exec_runtime;
267}
268
269void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
270{
271 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
272 struct task_cputime sum;
273 unsigned long flags;
274
275 spin_lock_irqsave(&cputimer->lock, flags);
276 if (!cputimer->running) {
277 cputimer->running = 1;
278
279
280
281
282
283
284 thread_group_cputime(tsk, &sum);
285 update_gt_cputime(&cputimer->cputime, &sum);
286 }
287 *times = cputimer->cputime;
288 spin_unlock_irqrestore(&cputimer->lock, flags);
289}
290
291
292
293
294
295static int cpu_clock_sample_group(const clockid_t which_clock,
296 struct task_struct *p,
297 union cpu_time_count *cpu)
298{
299 struct task_cputime cputime;
300
301 switch (CPUCLOCK_WHICH(which_clock)) {
302 default:
303 return -EINVAL;
304 case CPUCLOCK_PROF:
305 thread_group_cputime(p, &cputime);
306 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
307 break;
308 case CPUCLOCK_VIRT:
309 thread_group_cputime(p, &cputime);
310 cpu->cpu = cputime.utime;
311 break;
312 case CPUCLOCK_SCHED:
313 cpu->sched = thread_group_sched_runtime(p);
314 break;
315 }
316 return 0;
317}
318
319
320int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
321{
322 const pid_t pid = CPUCLOCK_PID(which_clock);
323 int error = -EINVAL;
324 union cpu_time_count rtn;
325
326 if (pid == 0) {
327
328
329
330
331 if (CPUCLOCK_PERTHREAD(which_clock)) {
332
333
334
335 error = cpu_clock_sample(which_clock,
336 current, &rtn);
337 } else {
338 read_lock(&tasklist_lock);
339 error = cpu_clock_sample_group(which_clock,
340 current, &rtn);
341 read_unlock(&tasklist_lock);
342 }
343 } else {
344
345
346
347
348 struct task_struct *p;
349 rcu_read_lock();
350 p = find_task_by_vpid(pid);
351 if (p) {
352 if (CPUCLOCK_PERTHREAD(which_clock)) {
353 if (same_thread_group(p, current)) {
354 error = cpu_clock_sample(which_clock,
355 p, &rtn);
356 }
357 } else {
358 read_lock(&tasklist_lock);
359 if (thread_group_leader(p) && p->sighand) {
360 error =
361 cpu_clock_sample_group(which_clock,
362 p, &rtn);
363 }
364 read_unlock(&tasklist_lock);
365 }
366 }
367 rcu_read_unlock();
368 }
369
370 if (error)
371 return error;
372 sample_to_timespec(which_clock, rtn, tp);
373 return 0;
374}
375
376
377
378
379
380
381
382int posix_cpu_timer_create(struct k_itimer *new_timer)
383{
384 int ret = 0;
385 const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
386 struct task_struct *p;
387
388 if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
389 return -EINVAL;
390
391 INIT_LIST_HEAD(&new_timer->it.cpu.entry);
392
393 read_lock(&tasklist_lock);
394 if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
395 if (pid == 0) {
396 p = current;
397 } else {
398 p = find_task_by_vpid(pid);
399 if (p && !same_thread_group(p, current))
400 p = NULL;
401 }
402 } else {
403 if (pid == 0) {
404 p = current->group_leader;
405 } else {
406 p = find_task_by_vpid(pid);
407 if (p && !thread_group_leader(p))
408 p = NULL;
409 }
410 }
411 new_timer->it.cpu.task = p;
412 if (p) {
413 get_task_struct(p);
414 } else {
415 ret = -EINVAL;
416 }
417 read_unlock(&tasklist_lock);
418
419 return ret;
420}
421
422
423
424
425
426
427
428int posix_cpu_timer_del(struct k_itimer *timer)
429{
430 struct task_struct *p = timer->it.cpu.task;
431 int ret = 0;
432
433 if (likely(p != NULL)) {
434 read_lock(&tasklist_lock);
435 if (unlikely(p->sighand == NULL)) {
436
437
438
439
440 BUG_ON(!list_empty(&timer->it.cpu.entry));
441 } else {
442 spin_lock(&p->sighand->siglock);
443 if (timer->it.cpu.firing)
444 ret = TIMER_RETRY;
445 else
446 list_del(&timer->it.cpu.entry);
447 spin_unlock(&p->sighand->siglock);
448 }
449 read_unlock(&tasklist_lock);
450
451 if (!ret)
452 put_task_struct(p);
453 }
454
455 return ret;
456}
457
458
459
460
461
462
463
464static void cleanup_timers(struct list_head *head,
465 cputime_t utime, cputime_t stime,
466 unsigned long long sum_exec_runtime)
467{
468 struct cpu_timer_list *timer, *next;
469 cputime_t ptime = cputime_add(utime, stime);
470
471 list_for_each_entry_safe(timer, next, head, entry) {
472 list_del_init(&timer->entry);
473 if (cputime_lt(timer->expires.cpu, ptime)) {
474 timer->expires.cpu = cputime_zero;
475 } else {
476 timer->expires.cpu = cputime_sub(timer->expires.cpu,
477 ptime);
478 }
479 }
480
481 ++head;
482 list_for_each_entry_safe(timer, next, head, entry) {
483 list_del_init(&timer->entry);
484 if (cputime_lt(timer->expires.cpu, utime)) {
485 timer->expires.cpu = cputime_zero;
486 } else {
487 timer->expires.cpu = cputime_sub(timer->expires.cpu,
488 utime);
489 }
490 }
491
492 ++head;
493 list_for_each_entry_safe(timer, next, head, entry) {
494 list_del_init(&timer->entry);
495 if (timer->expires.sched < sum_exec_runtime) {
496 timer->expires.sched = 0;
497 } else {
498 timer->expires.sched -= sum_exec_runtime;
499 }
500 }
501}
502
503
504
505
506
507
508void posix_cpu_timers_exit(struct task_struct *tsk)
509{
510 cleanup_timers(tsk->cpu_timers,
511 tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
512
513}
514void posix_cpu_timers_exit_group(struct task_struct *tsk)
515{
516 struct signal_struct *const sig = tsk->signal;
517
518 cleanup_timers(tsk->signal->cpu_timers,
519 cputime_add(tsk->utime, sig->utime),
520 cputime_add(tsk->stime, sig->stime),
521 tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
522}
523
524static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
525{
526
527
528
529
530 put_task_struct(timer->it.cpu.task);
531 timer->it.cpu.task = NULL;
532 timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
533 timer->it.cpu.expires,
534 now);
535}
536
537static inline int expires_gt(cputime_t expires, cputime_t new_exp)
538{
539 return cputime_eq(expires, cputime_zero) ||
540 cputime_gt(expires, new_exp);
541}
542
543
544
545
546
547
548static void arm_timer(struct k_itimer *timer)
549{
550 struct task_struct *p = timer->it.cpu.task;
551 struct list_head *head, *listpos;
552 struct task_cputime *cputime_expires;
553 struct cpu_timer_list *const nt = &timer->it.cpu;
554 struct cpu_timer_list *next;
555
556 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
557 head = p->cpu_timers;
558 cputime_expires = &p->cputime_expires;
559 } else {
560 head = p->signal->cpu_timers;
561 cputime_expires = &p->signal->cputime_expires;
562 }
563 head += CPUCLOCK_WHICH(timer->it_clock);
564
565 listpos = head;
566 list_for_each_entry(next, head, entry) {
567 if (cpu_time_before(timer->it_clock, nt->expires, next->expires))
568 break;
569 listpos = &next->entry;
570 }
571 list_add(&nt->entry, listpos);
572
573 if (listpos == head) {
574 union cpu_time_count *exp = &nt->expires;
575
576
577
578
579
580
581
582
583 switch (CPUCLOCK_WHICH(timer->it_clock)) {
584 case CPUCLOCK_PROF:
585 if (expires_gt(cputime_expires->prof_exp, exp->cpu))
586 cputime_expires->prof_exp = exp->cpu;
587 break;
588 case CPUCLOCK_VIRT:
589 if (expires_gt(cputime_expires->virt_exp, exp->cpu))
590 cputime_expires->virt_exp = exp->cpu;
591 break;
592 case CPUCLOCK_SCHED:
593 if (cputime_expires->sched_exp == 0 ||
594 cputime_expires->sched_exp > exp->sched)
595 cputime_expires->sched_exp = exp->sched;
596 break;
597 }
598 }
599}
600
601
602
603
604static void cpu_timer_fire(struct k_itimer *timer)
605{
606 if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
607
608
609
610 timer->it.cpu.expires.sched = 0;
611 } else if (unlikely(timer->sigq == NULL)) {
612
613
614
615
616 wake_up_process(timer->it_process);
617 timer->it.cpu.expires.sched = 0;
618 } else if (timer->it.cpu.incr.sched == 0) {
619
620
621
622 posix_timer_event(timer, 0);
623 timer->it.cpu.expires.sched = 0;
624 } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
625
626
627
628
629
630
631 posix_cpu_timer_schedule(timer);
632 }
633}
634
635
636
637
638
639static int cpu_timer_sample_group(const clockid_t which_clock,
640 struct task_struct *p,
641 union cpu_time_count *cpu)
642{
643 struct task_cputime cputime;
644
645 thread_group_cputimer(p, &cputime);
646 switch (CPUCLOCK_WHICH(which_clock)) {
647 default:
648 return -EINVAL;
649 case CPUCLOCK_PROF:
650 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
651 break;
652 case CPUCLOCK_VIRT:
653 cpu->cpu = cputime.utime;
654 break;
655 case CPUCLOCK_SCHED:
656 cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
657 break;
658 }
659 return 0;
660}
661
662
663
664
665
666
667
668int posix_cpu_timer_set(struct k_itimer *timer, int flags,
669 struct itimerspec *new, struct itimerspec *old)
670{
671 struct task_struct *p = timer->it.cpu.task;
672 union cpu_time_count old_expires, new_expires, old_incr, val;
673 int ret;
674
675 if (unlikely(p == NULL)) {
676
677
678
679 return -ESRCH;
680 }
681
682 new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
683
684 read_lock(&tasklist_lock);
685
686
687
688
689
690 if (unlikely(p->sighand == NULL)) {
691 read_unlock(&tasklist_lock);
692 put_task_struct(p);
693 timer->it.cpu.task = NULL;
694 return -ESRCH;
695 }
696
697
698
699
700 BUG_ON(!irqs_disabled());
701
702 ret = 0;
703 old_incr = timer->it.cpu.incr;
704 spin_lock(&p->sighand->siglock);
705 old_expires = timer->it.cpu.expires;
706 if (unlikely(timer->it.cpu.firing)) {
707 timer->it.cpu.firing = -1;
708 ret = TIMER_RETRY;
709 } else
710 list_del_init(&timer->it.cpu.entry);
711
712
713
714
715
716
717
718
719
720 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
721 cpu_clock_sample(timer->it_clock, p, &val);
722 } else {
723 cpu_timer_sample_group(timer->it_clock, p, &val);
724 }
725
726 if (old) {
727 if (old_expires.sched == 0) {
728 old->it_value.tv_sec = 0;
729 old->it_value.tv_nsec = 0;
730 } else {
731
732
733
734
735
736
737
738
739
740
741 bump_cpu_timer(timer, val);
742 if (cpu_time_before(timer->it_clock, val,
743 timer->it.cpu.expires)) {
744 old_expires = cpu_time_sub(
745 timer->it_clock,
746 timer->it.cpu.expires, val);
747 sample_to_timespec(timer->it_clock,
748 old_expires,
749 &old->it_value);
750 } else {
751 old->it_value.tv_nsec = 1;
752 old->it_value.tv_sec = 0;
753 }
754 }
755 }
756
757 if (unlikely(ret)) {
758
759
760
761
762
763
764 spin_unlock(&p->sighand->siglock);
765 read_unlock(&tasklist_lock);
766 goto out;
767 }
768
769 if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
770 cpu_time_add(timer->it_clock, &new_expires, val);
771 }
772
773
774
775
776
777
778 timer->it.cpu.expires = new_expires;
779 if (new_expires.sched != 0 &&
780 cpu_time_before(timer->it_clock, val, new_expires)) {
781 arm_timer(timer);
782 }
783
784 spin_unlock(&p->sighand->siglock);
785 read_unlock(&tasklist_lock);
786
787
788
789
790
791 timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
792 &new->it_interval);
793
794
795
796
797
798
799 timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
800 ~REQUEUE_PENDING;
801 timer->it_overrun_last = 0;
802 timer->it_overrun = -1;
803
804 if (new_expires.sched != 0 &&
805 !cpu_time_before(timer->it_clock, val, new_expires)) {
806
807
808
809
810
811 cpu_timer_fire(timer);
812 }
813
814 ret = 0;
815 out:
816 if (old) {
817 sample_to_timespec(timer->it_clock,
818 old_incr, &old->it_interval);
819 }
820 return ret;
821}
822
823void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
824{
825 union cpu_time_count now;
826 struct task_struct *p = timer->it.cpu.task;
827 int clear_dead;
828
829
830
831
832 sample_to_timespec(timer->it_clock,
833 timer->it.cpu.incr, &itp->it_interval);
834
835 if (timer->it.cpu.expires.sched == 0) {
836 itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
837 return;
838 }
839
840 if (unlikely(p == NULL)) {
841
842
843
844
845 dead:
846 sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
847 &itp->it_value);
848 return;
849 }
850
851
852
853
854 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
855 cpu_clock_sample(timer->it_clock, p, &now);
856 clear_dead = p->exit_state;
857 } else {
858 read_lock(&tasklist_lock);
859 if (unlikely(p->sighand == NULL)) {
860
861
862
863
864
865 put_task_struct(p);
866 timer->it.cpu.task = NULL;
867 timer->it.cpu.expires.sched = 0;
868 read_unlock(&tasklist_lock);
869 goto dead;
870 } else {
871 cpu_timer_sample_group(timer->it_clock, p, &now);
872 clear_dead = (unlikely(p->exit_state) &&
873 thread_group_empty(p));
874 }
875 read_unlock(&tasklist_lock);
876 }
877
878 if (unlikely(clear_dead)) {
879
880
881
882
883
884 clear_dead_task(timer, now);
885 goto dead;
886 }
887
888 if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
889 sample_to_timespec(timer->it_clock,
890 cpu_time_sub(timer->it_clock,
891 timer->it.cpu.expires, now),
892 &itp->it_value);
893 } else {
894
895
896
897
898 itp->it_value.tv_nsec = 1;
899 itp->it_value.tv_sec = 0;
900 }
901}
902
903
904
905
906
907
908static void check_thread_timers(struct task_struct *tsk,
909 struct list_head *firing)
910{
911 int maxfire;
912 struct list_head *timers = tsk->cpu_timers;
913 struct signal_struct *const sig = tsk->signal;
914 unsigned long soft;
915
916 maxfire = 20;
917 tsk->cputime_expires.prof_exp = cputime_zero;
918 while (!list_empty(timers)) {
919 struct cpu_timer_list *t = list_first_entry(timers,
920 struct cpu_timer_list,
921 entry);
922 if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
923 tsk->cputime_expires.prof_exp = t->expires.cpu;
924 break;
925 }
926 t->firing = 1;
927 list_move_tail(&t->entry, firing);
928 }
929
930 ++timers;
931 maxfire = 20;
932 tsk->cputime_expires.virt_exp = cputime_zero;
933 while (!list_empty(timers)) {
934 struct cpu_timer_list *t = list_first_entry(timers,
935 struct cpu_timer_list,
936 entry);
937 if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
938 tsk->cputime_expires.virt_exp = t->expires.cpu;
939 break;
940 }
941 t->firing = 1;
942 list_move_tail(&t->entry, firing);
943 }
944
945 ++timers;
946 maxfire = 20;
947 tsk->cputime_expires.sched_exp = 0;
948 while (!list_empty(timers)) {
949 struct cpu_timer_list *t = list_first_entry(timers,
950 struct cpu_timer_list,
951 entry);
952 if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
953 tsk->cputime_expires.sched_exp = t->expires.sched;
954 break;
955 }
956 t->firing = 1;
957 list_move_tail(&t->entry, firing);
958 }
959
960
961
962
963 soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
964 if (soft != RLIM_INFINITY) {
965 unsigned long hard =
966 ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
967
968 if (hard != RLIM_INFINITY &&
969 tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
970
971
972
973
974 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
975 return;
976 }
977 if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
978
979
980
981 if (soft < hard) {
982 soft += USEC_PER_SEC;
983 sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
984 }
985 printk(KERN_INFO
986 "RT Watchdog Timeout: %s[%d]\n",
987 tsk->comm, task_pid_nr(tsk));
988 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
989 }
990 }
991}
992
993static void stop_process_timers(struct signal_struct *sig)
994{
995 struct thread_group_cputimer *cputimer = &sig->cputimer;
996 unsigned long flags;
997
998 spin_lock_irqsave(&cputimer->lock, flags);
999 cputimer->running = 0;
1000 spin_unlock_irqrestore(&cputimer->lock, flags);
1001}
1002
1003static u32 onecputick;
1004
1005static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
1006 cputime_t *expires, cputime_t cur_time, int signo)
1007{
1008 if (cputime_eq(it->expires, cputime_zero))
1009 return;
1010
1011 if (cputime_ge(cur_time, it->expires)) {
1012 if (!cputime_eq(it->incr, cputime_zero)) {
1013 it->expires = cputime_add(it->expires, it->incr);
1014 it->error += it->incr_error;
1015 if (it->error >= onecputick) {
1016 it->expires = cputime_sub(it->expires,
1017 cputime_one_jiffy);
1018 it->error -= onecputick;
1019 }
1020 } else {
1021 it->expires = cputime_zero;
1022 }
1023
1024 trace_itimer_expire(signo == SIGPROF ?
1025 ITIMER_PROF : ITIMER_VIRTUAL,
1026 tsk->signal->leader_pid, cur_time);
1027 __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
1028 }
1029
1030 if (!cputime_eq(it->expires, cputime_zero) &&
1031 (cputime_eq(*expires, cputime_zero) ||
1032 cputime_lt(it->expires, *expires))) {
1033 *expires = it->expires;
1034 }
1035}
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045static inline int task_cputime_zero(const struct task_cputime *cputime)
1046{
1047 if (cputime_eq(cputime->utime, cputime_zero) &&
1048 cputime_eq(cputime->stime, cputime_zero) &&
1049 cputime->sum_exec_runtime == 0)
1050 return 1;
1051 return 0;
1052}
1053
1054
1055
1056
1057
1058
1059static void check_process_timers(struct task_struct *tsk,
1060 struct list_head *firing)
1061{
1062 int maxfire;
1063 struct signal_struct *const sig = tsk->signal;
1064 cputime_t utime, ptime, virt_expires, prof_expires;
1065 unsigned long long sum_sched_runtime, sched_expires;
1066 struct list_head *timers = sig->cpu_timers;
1067 struct task_cputime cputime;
1068 unsigned long soft;
1069
1070
1071
1072
1073 thread_group_cputimer(tsk, &cputime);
1074 utime = cputime.utime;
1075 ptime = cputime_add(utime, cputime.stime);
1076 sum_sched_runtime = cputime.sum_exec_runtime;
1077 maxfire = 20;
1078 prof_expires = cputime_zero;
1079 while (!list_empty(timers)) {
1080 struct cpu_timer_list *tl = list_first_entry(timers,
1081 struct cpu_timer_list,
1082 entry);
1083 if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
1084 prof_expires = tl->expires.cpu;
1085 break;
1086 }
1087 tl->firing = 1;
1088 list_move_tail(&tl->entry, firing);
1089 }
1090
1091 ++timers;
1092 maxfire = 20;
1093 virt_expires = cputime_zero;
1094 while (!list_empty(timers)) {
1095 struct cpu_timer_list *tl = list_first_entry(timers,
1096 struct cpu_timer_list,
1097 entry);
1098 if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
1099 virt_expires = tl->expires.cpu;
1100 break;
1101 }
1102 tl->firing = 1;
1103 list_move_tail(&tl->entry, firing);
1104 }
1105
1106 ++timers;
1107 maxfire = 20;
1108 sched_expires = 0;
1109 while (!list_empty(timers)) {
1110 struct cpu_timer_list *tl = list_first_entry(timers,
1111 struct cpu_timer_list,
1112 entry);
1113 if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
1114 sched_expires = tl->expires.sched;
1115 break;
1116 }
1117 tl->firing = 1;
1118 list_move_tail(&tl->entry, firing);
1119 }
1120
1121
1122
1123
1124 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
1125 SIGPROF);
1126 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
1127 SIGVTALRM);
1128 soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
1129 if (soft != RLIM_INFINITY) {
1130 unsigned long psecs = cputime_to_secs(ptime);
1131 unsigned long hard =
1132 ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
1133 cputime_t x;
1134 if (psecs >= hard) {
1135
1136
1137
1138
1139 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
1140 return;
1141 }
1142 if (psecs >= soft) {
1143
1144
1145
1146 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
1147 if (soft < hard) {
1148 soft++;
1149 sig->rlim[RLIMIT_CPU].rlim_cur = soft;
1150 }
1151 }
1152 x = secs_to_cputime(soft);
1153 if (cputime_eq(prof_expires, cputime_zero) ||
1154 cputime_lt(x, prof_expires)) {
1155 prof_expires = x;
1156 }
1157 }
1158
1159 sig->cputime_expires.prof_exp = prof_expires;
1160 sig->cputime_expires.virt_exp = virt_expires;
1161 sig->cputime_expires.sched_exp = sched_expires;
1162 if (task_cputime_zero(&sig->cputime_expires))
1163 stop_process_timers(sig);
1164}
1165
1166
1167
1168
1169
1170void posix_cpu_timer_schedule(struct k_itimer *timer)
1171{
1172 struct task_struct *p = timer->it.cpu.task;
1173 union cpu_time_count now;
1174
1175 if (unlikely(p == NULL))
1176
1177
1178
1179 goto out;
1180
1181
1182
1183
1184 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
1185 cpu_clock_sample(timer->it_clock, p, &now);
1186 bump_cpu_timer(timer, now);
1187 if (unlikely(p->exit_state)) {
1188 clear_dead_task(timer, now);
1189 goto out;
1190 }
1191 read_lock(&tasklist_lock);
1192 spin_lock(&p->sighand->siglock);
1193 } else {
1194 read_lock(&tasklist_lock);
1195 if (unlikely(p->sighand == NULL)) {
1196
1197
1198
1199
1200 put_task_struct(p);
1201 timer->it.cpu.task = p = NULL;
1202 timer->it.cpu.expires.sched = 0;
1203 goto out_unlock;
1204 } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
1205
1206
1207
1208
1209
1210 clear_dead_task(timer, now);
1211 goto out_unlock;
1212 }
1213 spin_lock(&p->sighand->siglock);
1214 cpu_timer_sample_group(timer->it_clock, p, &now);
1215 bump_cpu_timer(timer, now);
1216
1217 }
1218
1219
1220
1221
1222 BUG_ON(!irqs_disabled());
1223 arm_timer(timer);
1224 spin_unlock(&p->sighand->siglock);
1225
1226out_unlock:
1227 read_unlock(&tasklist_lock);
1228
1229out:
1230 timer->it_overrun_last = timer->it_overrun;
1231 timer->it_overrun = -1;
1232 ++timer->it_requeue_pending;
1233}
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245static inline int task_cputime_expired(const struct task_cputime *sample,
1246 const struct task_cputime *expires)
1247{
1248 if (!cputime_eq(expires->utime, cputime_zero) &&
1249 cputime_ge(sample->utime, expires->utime))
1250 return 1;
1251 if (!cputime_eq(expires->stime, cputime_zero) &&
1252 cputime_ge(cputime_add(sample->utime, sample->stime),
1253 expires->stime))
1254 return 1;
1255 if (expires->sum_exec_runtime != 0 &&
1256 sample->sum_exec_runtime >= expires->sum_exec_runtime)
1257 return 1;
1258 return 0;
1259}
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271static inline int fastpath_timer_check(struct task_struct *tsk)
1272{
1273 struct signal_struct *sig;
1274
1275 if (!task_cputime_zero(&tsk->cputime_expires)) {
1276 struct task_cputime task_sample = {
1277 .utime = tsk->utime,
1278 .stime = tsk->stime,
1279 .sum_exec_runtime = tsk->se.sum_exec_runtime
1280 };
1281
1282 if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
1283 return 1;
1284 }
1285
1286 sig = tsk->signal;
1287 if (sig->cputimer.running) {
1288 struct task_cputime group_sample;
1289
1290 spin_lock(&sig->cputimer.lock);
1291 group_sample = sig->cputimer.cputime;
1292 spin_unlock(&sig->cputimer.lock);
1293
1294 if (task_cputime_expired(&group_sample, &sig->cputime_expires))
1295 return 1;
1296 }
1297
1298 return 0;
1299}
1300
1301
1302
1303
1304
1305
1306void run_posix_cpu_timers(struct task_struct *tsk)
1307{
1308 LIST_HEAD(firing);
1309 struct k_itimer *timer, *next;
1310 unsigned long flags;
1311
1312 BUG_ON(!irqs_disabled());
1313
1314
1315
1316
1317
1318 if (!fastpath_timer_check(tsk))
1319 return;
1320
1321 if (!lock_task_sighand(tsk, &flags))
1322 return;
1323
1324
1325
1326
1327
1328 check_thread_timers(tsk, &firing);
1329
1330
1331
1332
1333 if (tsk->signal->cputimer.running)
1334 check_process_timers(tsk, &firing);
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344 unlock_task_sighand(tsk, &flags);
1345
1346
1347
1348
1349
1350
1351
1352 list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
1353 int cpu_firing;
1354
1355 spin_lock(&timer->it_lock);
1356 list_del_init(&timer->it.cpu.entry);
1357 cpu_firing = timer->it.cpu.firing;
1358 timer->it.cpu.firing = 0;
1359
1360
1361
1362
1363
1364 if (likely(cpu_firing >= 0))
1365 cpu_timer_fire(timer);
1366 spin_unlock(&timer->it_lock);
1367 }
1368}
1369
1370
1371
1372
1373
1374void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
1375 cputime_t *newval, cputime_t *oldval)
1376{
1377 union cpu_time_count now;
1378
1379 BUG_ON(clock_idx == CPUCLOCK_SCHED);
1380 cpu_timer_sample_group(clock_idx, tsk, &now);
1381
1382 if (oldval) {
1383
1384
1385
1386
1387
1388 if (!cputime_eq(*oldval, cputime_zero)) {
1389 if (cputime_le(*oldval, now.cpu)) {
1390
1391 *oldval = cputime_one_jiffy;
1392 } else {
1393 *oldval = cputime_sub(*oldval, now.cpu);
1394 }
1395 }
1396
1397 if (cputime_eq(*newval, cputime_zero))
1398 return;
1399 *newval = cputime_add(*newval, now.cpu);
1400 }
1401
1402
1403
1404
1405
1406 switch (clock_idx) {
1407 case CPUCLOCK_PROF:
1408 if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
1409 tsk->signal->cputime_expires.prof_exp = *newval;
1410 break;
1411 case CPUCLOCK_VIRT:
1412 if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
1413 tsk->signal->cputime_expires.virt_exp = *newval;
1414 break;
1415 }
1416}
1417
1418static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
1419 struct timespec *rqtp, struct itimerspec *it)
1420{
1421 struct k_itimer timer;
1422 int error;
1423
1424
1425
1426
1427 memset(&timer, 0, sizeof timer);
1428 spin_lock_init(&timer.it_lock);
1429 timer.it_clock = which_clock;
1430 timer.it_overrun = -1;
1431 error = posix_cpu_timer_create(&timer);
1432 timer.it_process = current;
1433 if (!error) {
1434 static struct itimerspec zero_it;
1435
1436 memset(it, 0, sizeof *it);
1437 it->it_value = *rqtp;
1438
1439 spin_lock_irq(&timer.it_lock);
1440 error = posix_cpu_timer_set(&timer, flags, it, NULL);
1441 if (error) {
1442 spin_unlock_irq(&timer.it_lock);
1443 return error;
1444 }
1445
1446 while (!signal_pending(current)) {
1447 if (timer.it.cpu.expires.sched == 0) {
1448
1449
1450
1451 spin_unlock_irq(&timer.it_lock);
1452 return 0;
1453 }
1454
1455
1456
1457
1458 __set_current_state(TASK_INTERRUPTIBLE);
1459 spin_unlock_irq(&timer.it_lock);
1460 schedule();
1461 spin_lock_irq(&timer.it_lock);
1462 }
1463
1464
1465
1466
1467 sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
1468 posix_cpu_timer_set(&timer, 0, &zero_it, it);
1469 spin_unlock_irq(&timer.it_lock);
1470
1471 if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
1472
1473
1474
1475 return 0;
1476 }
1477
1478 error = -ERESTART_RESTARTBLOCK;
1479 }
1480
1481 return error;
1482}
1483
1484int posix_cpu_nsleep(const clockid_t which_clock, int flags,
1485 struct timespec *rqtp, struct timespec __user *rmtp)
1486{
1487 struct restart_block *restart_block =
1488 ¤t_thread_info()->restart_block;
1489 struct itimerspec it;
1490 int error;
1491
1492
1493
1494
1495 if (CPUCLOCK_PERTHREAD(which_clock) &&
1496 (CPUCLOCK_PID(which_clock) == 0 ||
1497 CPUCLOCK_PID(which_clock) == current->pid))
1498 return -EINVAL;
1499
1500 error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
1501
1502 if (error == -ERESTART_RESTARTBLOCK) {
1503
1504 if (flags & TIMER_ABSTIME)
1505 return -ERESTARTNOHAND;
1506
1507
1508
1509 if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1510 return -EFAULT;
1511
1512 restart_block->fn = posix_cpu_nsleep_restart;
1513 restart_block->arg0 = which_clock;
1514 restart_block->arg1 = (unsigned long) rmtp;
1515 restart_block->arg2 = rqtp->tv_sec;
1516 restart_block->arg3 = rqtp->tv_nsec;
1517 }
1518 return error;
1519}
1520
1521long posix_cpu_nsleep_restart(struct restart_block *restart_block)
1522{
1523 clockid_t which_clock = restart_block->arg0;
1524 struct timespec __user *rmtp;
1525 struct timespec t;
1526 struct itimerspec it;
1527 int error;
1528
1529 rmtp = (struct timespec __user *) restart_block->arg1;
1530 t.tv_sec = restart_block->arg2;
1531 t.tv_nsec = restart_block->arg3;
1532
1533 restart_block->fn = do_no_restart_syscall;
1534 error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
1535
1536 if (error == -ERESTART_RESTARTBLOCK) {
1537
1538
1539
1540 if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1541 return -EFAULT;
1542
1543 restart_block->fn = posix_cpu_nsleep_restart;
1544 restart_block->arg0 = which_clock;
1545 restart_block->arg1 = (unsigned long) rmtp;
1546 restart_block->arg2 = t.tv_sec;
1547 restart_block->arg3 = t.tv_nsec;
1548 }
1549 return error;
1550
1551}
1552
1553
1554#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
1555#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
1556
1557static int process_cpu_clock_getres(const clockid_t which_clock,
1558 struct timespec *tp)
1559{
1560 return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
1561}
1562static int process_cpu_clock_get(const clockid_t which_clock,
1563 struct timespec *tp)
1564{
1565 return posix_cpu_clock_get(PROCESS_CLOCK, tp);
1566}
1567static int process_cpu_timer_create(struct k_itimer *timer)
1568{
1569 timer->it_clock = PROCESS_CLOCK;
1570 return posix_cpu_timer_create(timer);
1571}
1572static int process_cpu_nsleep(const clockid_t which_clock, int flags,
1573 struct timespec *rqtp,
1574 struct timespec __user *rmtp)
1575{
1576 return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
1577}
1578static long process_cpu_nsleep_restart(struct restart_block *restart_block)
1579{
1580 return -EINVAL;
1581}
1582static int thread_cpu_clock_getres(const clockid_t which_clock,
1583 struct timespec *tp)
1584{
1585 return posix_cpu_clock_getres(THREAD_CLOCK, tp);
1586}
1587static int thread_cpu_clock_get(const clockid_t which_clock,
1588 struct timespec *tp)
1589{
1590 return posix_cpu_clock_get(THREAD_CLOCK, tp);
1591}
1592static int thread_cpu_timer_create(struct k_itimer *timer)
1593{
1594 timer->it_clock = THREAD_CLOCK;
1595 return posix_cpu_timer_create(timer);
1596}
1597static int thread_cpu_nsleep(const clockid_t which_clock, int flags,
1598 struct timespec *rqtp, struct timespec __user *rmtp)
1599{
1600 return -EINVAL;
1601}
1602static long thread_cpu_nsleep_restart(struct restart_block *restart_block)
1603{
1604 return -EINVAL;
1605}
1606
1607static __init int init_posix_cpu_timers(void)
1608{
1609 struct k_clock process = {
1610 .clock_getres = process_cpu_clock_getres,
1611 .clock_get = process_cpu_clock_get,
1612 .clock_set = do_posix_clock_nosettime,
1613 .timer_create = process_cpu_timer_create,
1614 .nsleep = process_cpu_nsleep,
1615 .nsleep_restart = process_cpu_nsleep_restart,
1616 };
1617 struct k_clock thread = {
1618 .clock_getres = thread_cpu_clock_getres,
1619 .clock_get = thread_cpu_clock_get,
1620 .clock_set = do_posix_clock_nosettime,
1621 .timer_create = thread_cpu_timer_create,
1622 .nsleep = thread_cpu_nsleep,
1623 .nsleep_restart = thread_cpu_nsleep_restart,
1624 };
1625 struct timespec ts;
1626
1627 register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
1628 register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
1629
1630 cputime_to_timespec(cputime_one_jiffy, &ts);
1631 onecputick = ts.tv_nsec;
1632 WARN_ON(ts.tv_sec != 0);
1633
1634 return 0;
1635}
1636__initcall(init_posix_cpu_timers);
1637