1 /* $OpenBSD: kern_time.c,v 1.167 2023/10/17 00:04:02 cheloha Exp $ */
2 /* $NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $ */
3
4 /*
5 * Copyright (c) 1982, 1986, 1989, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95
33 */
34
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/systm.h>
38 #include <sys/clockintr.h>
39 #include <sys/mutex.h>
40 #include <sys/rwlock.h>
41 #include <sys/proc.h>
42 #include <sys/ktrace.h>
43 #include <sys/signalvar.h>
44 #include <sys/stdint.h>
45 #include <sys/pledge.h>
46 #include <sys/task.h>
47 #include <sys/time.h>
48 #include <sys/timeout.h>
49 #include <sys/timetc.h>
50
51 #include <sys/mount.h>
52 #include <sys/syscallargs.h>
53
54 #include <dev/clock_subr.h>
55
56 int itimerfix(struct itimerval *);
57 void process_reset_itimer_flag(struct process *);
58
59 /*
60 * Time of day and interval timer support.
61 *
62 * These routines provide the kernel entry points to get and set
63 * the time-of-day and per-process interval timers. Subroutines
64 * here provide support for adding and subtracting timeval structures
65 * and decrementing interval timers, optionally reloading the interval
66 * timers when they expire.
67 */
68
69 /* This function is used by clock_settime and settimeofday */
70 int
settime(const struct timespec * ts)71 settime(const struct timespec *ts)
72 {
73 struct timespec now;
74
75 /*
76 * Don't allow the time to be set forward so far it will wrap
77 * and become negative, thus allowing an attacker to bypass
78 * the next check below. The cutoff is 1 year before rollover
79 * occurs, so even if the attacker uses adjtime(2) to move
80 * the time past the cutoff, it will take a very long time
81 * to get to the wrap point.
82 *
83 * XXX: we check against UINT_MAX until we can figure out
84 * how to deal with the hardware RTCs.
85 */
86 if (ts->tv_sec > UINT_MAX - 365*24*60*60) {
87 printf("denied attempt to set clock forward to %lld\n",
88 (long long)ts->tv_sec);
89 return (EPERM);
90 }
91 /*
92 * If the system is secure, we do not allow the time to be
93 * set to an earlier value (it may be slowed using adjtime,
94 * but not set back). This feature prevent interlopers from
95 * setting arbitrary time stamps on files.
96 */
97 nanotime(&now);
98 if (securelevel > 1 && timespeccmp(ts, &now, <=)) {
99 printf("denied attempt to set clock back %lld seconds\n",
100 (long long)now.tv_sec - ts->tv_sec);
101 return (EPERM);
102 }
103
104 tc_setrealtimeclock(ts);
105 KERNEL_LOCK();
106 resettodr();
107 KERNEL_UNLOCK();
108
109 return (0);
110 }
111
112 int
clock_gettime(struct proc * p,clockid_t clock_id,struct timespec * tp)113 clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp)
114 {
115 struct proc *q;
116 int error = 0;
117
118 switch (clock_id) {
119 case CLOCK_REALTIME:
120 nanotime(tp);
121 break;
122 case CLOCK_UPTIME:
123 nanoruntime(tp);
124 break;
125 case CLOCK_MONOTONIC:
126 case CLOCK_BOOTTIME:
127 nanouptime(tp);
128 break;
129 case CLOCK_PROCESS_CPUTIME_ID:
130 nanouptime(tp);
131 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
132 timespecadd(tp, &p->p_p->ps_tu.tu_runtime, tp);
133 break;
134 case CLOCK_THREAD_CPUTIME_ID:
135 nanouptime(tp);
136 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
137 timespecadd(tp, &p->p_tu.tu_runtime, tp);
138 break;
139 default:
140 /* check for clock from pthread_getcpuclockid() */
141 if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
142 KERNEL_LOCK();
143 q = tfind_user(__CLOCK_PTID(clock_id), p->p_p);
144 if (q == NULL)
145 error = ESRCH;
146 else
147 *tp = q->p_tu.tu_runtime;
148 KERNEL_UNLOCK();
149 } else
150 error = EINVAL;
151 break;
152 }
153 return (error);
154 }
155
156 int
sys_clock_gettime(struct proc * p,void * v,register_t * retval)157 sys_clock_gettime(struct proc *p, void *v, register_t *retval)
158 {
159 struct sys_clock_gettime_args /* {
160 syscallarg(clockid_t) clock_id;
161 syscallarg(struct timespec *) tp;
162 } */ *uap = v;
163 struct timespec ats;
164 int error;
165
166 memset(&ats, 0, sizeof(ats));
167 if ((error = clock_gettime(p, SCARG(uap, clock_id), &ats)) != 0)
168 return (error);
169
170 error = copyout(&ats, SCARG(uap, tp), sizeof(ats));
171 #ifdef KTRACE
172 if (error == 0 && KTRPOINT(p, KTR_STRUCT))
173 ktrabstimespec(p, &ats);
174 #endif
175 return (error);
176 }
177
178 int
sys_clock_settime(struct proc * p,void * v,register_t * retval)179 sys_clock_settime(struct proc *p, void *v, register_t *retval)
180 {
181 struct sys_clock_settime_args /* {
182 syscallarg(clockid_t) clock_id;
183 syscallarg(const struct timespec *) tp;
184 } */ *uap = v;
185 struct timespec ats;
186 clockid_t clock_id;
187 int error;
188
189 if ((error = suser(p)) != 0)
190 return (error);
191
192 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
193 return (error);
194
195 clock_id = SCARG(uap, clock_id);
196 switch (clock_id) {
197 case CLOCK_REALTIME:
198 if (!timespecisvalid(&ats))
199 return (EINVAL);
200 if ((error = settime(&ats)) != 0)
201 return (error);
202 break;
203 default: /* Other clocks are read-only */
204 return (EINVAL);
205 }
206
207 return (0);
208 }
209
210 int
sys_clock_getres(struct proc * p,void * v,register_t * retval)211 sys_clock_getres(struct proc *p, void *v, register_t *retval)
212 {
213 struct sys_clock_getres_args /* {
214 syscallarg(clockid_t) clock_id;
215 syscallarg(struct timespec *) tp;
216 } */ *uap = v;
217 clockid_t clock_id;
218 struct bintime bt;
219 struct timespec ts;
220 struct proc *q;
221 u_int64_t scale;
222 int error = 0;
223
224 memset(&ts, 0, sizeof(ts));
225 clock_id = SCARG(uap, clock_id);
226
227 switch (clock_id) {
228 case CLOCK_REALTIME:
229 case CLOCK_MONOTONIC:
230 case CLOCK_BOOTTIME:
231 case CLOCK_UPTIME:
232 memset(&bt, 0, sizeof(bt));
233 rw_enter_read(&tc_lock);
234 scale = ((1ULL << 63) / tc_getfrequency()) * 2;
235 bt.frac = tc_getprecision() * scale;
236 rw_exit_read(&tc_lock);
237 BINTIME_TO_TIMESPEC(&bt, &ts);
238 break;
239 case CLOCK_PROCESS_CPUTIME_ID:
240 case CLOCK_THREAD_CPUTIME_ID:
241 ts.tv_nsec = 1000000000 / stathz;
242 break;
243 default:
244 /* check for clock from pthread_getcpuclockid() */
245 if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
246 KERNEL_LOCK();
247 q = tfind_user(__CLOCK_PTID(clock_id), p->p_p);
248 if (q == NULL)
249 error = ESRCH;
250 else
251 ts.tv_nsec = 1000000000 / stathz;
252 KERNEL_UNLOCK();
253 } else
254 error = EINVAL;
255 break;
256 }
257
258 if (error == 0 && SCARG(uap, tp)) {
259 ts.tv_nsec = MAX(ts.tv_nsec, 1);
260 error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
261 #ifdef KTRACE
262 if (error == 0 && KTRPOINT(p, KTR_STRUCT))
263 ktrreltimespec(p, &ts);
264 #endif
265 }
266
267 return error;
268 }
269
270 int
sys_nanosleep(struct proc * p,void * v,register_t * retval)271 sys_nanosleep(struct proc *p, void *v, register_t *retval)
272 {
273 struct sys_nanosleep_args/* {
274 syscallarg(const struct timespec *) rqtp;
275 syscallarg(struct timespec *) rmtp;
276 } */ *uap = v;
277 struct timespec elapsed, remainder, request, start, stop;
278 uint64_t nsecs;
279 struct timespec *rmtp;
280 int copyout_error, error;
281
282 rmtp = SCARG(uap, rmtp);
283 error = copyin(SCARG(uap, rqtp), &request, sizeof(request));
284 if (error)
285 return (error);
286 #ifdef KTRACE
287 if (KTRPOINT(p, KTR_STRUCT))
288 ktrreltimespec(p, &request);
289 #endif
290
291 if (request.tv_sec < 0 || !timespecisvalid(&request))
292 return (EINVAL);
293
294 do {
295 getnanouptime(&start);
296 nsecs = MAX(1, MIN(TIMESPEC_TO_NSEC(&request), MAXTSLP));
297 error = tsleep_nsec(&nowake, PWAIT | PCATCH, "nanoslp", nsecs);
298 getnanouptime(&stop);
299 timespecsub(&stop, &start, &elapsed);
300 timespecsub(&request, &elapsed, &request);
301 if (request.tv_sec < 0)
302 timespecclear(&request);
303 if (error != EWOULDBLOCK)
304 break;
305 } while (timespecisset(&request));
306
307 if (error == ERESTART)
308 error = EINTR;
309 if (error == EWOULDBLOCK)
310 error = 0;
311
312 if (rmtp) {
313 memset(&remainder, 0, sizeof(remainder));
314 remainder = request;
315 copyout_error = copyout(&remainder, rmtp, sizeof(remainder));
316 if (copyout_error)
317 error = copyout_error;
318 #ifdef KTRACE
319 if (copyout_error == 0 && KTRPOINT(p, KTR_STRUCT))
320 ktrreltimespec(p, &remainder);
321 #endif
322 }
323
324 return error;
325 }
326
327 int
sys_gettimeofday(struct proc * p,void * v,register_t * retval)328 sys_gettimeofday(struct proc *p, void *v, register_t *retval)
329 {
330 struct sys_gettimeofday_args /* {
331 syscallarg(struct timeval *) tp;
332 syscallarg(struct timezone *) tzp;
333 } */ *uap = v;
334 struct timeval atv;
335 static const struct timezone zerotz = { 0, 0 };
336 struct timeval *tp;
337 struct timezone *tzp;
338 int error = 0;
339
340 tp = SCARG(uap, tp);
341 tzp = SCARG(uap, tzp);
342
343 if (tp) {
344 memset(&atv, 0, sizeof(atv));
345 microtime(&atv);
346 if ((error = copyout(&atv, tp, sizeof (atv))))
347 return (error);
348 #ifdef KTRACE
349 if (KTRPOINT(p, KTR_STRUCT))
350 ktrabstimeval(p, &atv);
351 #endif
352 }
353 if (tzp)
354 error = copyout(&zerotz, tzp, sizeof(zerotz));
355 return (error);
356 }
357
358 int
sys_settimeofday(struct proc * p,void * v,register_t * retval)359 sys_settimeofday(struct proc *p, void *v, register_t *retval)
360 {
361 struct sys_settimeofday_args /* {
362 syscallarg(const struct timeval *) tv;
363 syscallarg(const struct timezone *) tzp;
364 } */ *uap = v;
365 struct timezone atz;
366 struct timeval atv;
367 const struct timeval *tv;
368 const struct timezone *tzp;
369 int error;
370
371 tv = SCARG(uap, tv);
372 tzp = SCARG(uap, tzp);
373
374 if ((error = suser(p)))
375 return (error);
376 /* Verify all parameters before changing time. */
377 if (tv && (error = copyin(tv, &atv, sizeof(atv))))
378 return (error);
379 if (tzp && (error = copyin(tzp, &atz, sizeof(atz))))
380 return (error);
381 if (tv) {
382 struct timespec ts;
383
384 #ifdef KTRACE
385 if (KTRPOINT(p, KTR_STRUCT))
386 ktrabstimeval(p, &atv);
387 #endif
388 if (!timerisvalid(&atv))
389 return (EINVAL);
390 TIMEVAL_TO_TIMESPEC(&atv, &ts);
391 if ((error = settime(&ts)) != 0)
392 return (error);
393 }
394
395 return (0);
396 }
397
398 #define ADJFREQ_MAX (500000000LL << 32)
399 #define ADJFREQ_MIN (-ADJFREQ_MAX)
400
401 int
sys_adjfreq(struct proc * p,void * v,register_t * retval)402 sys_adjfreq(struct proc *p, void *v, register_t *retval)
403 {
404 struct sys_adjfreq_args /* {
405 syscallarg(const int64_t *) freq;
406 syscallarg(int64_t *) oldfreq;
407 } */ *uap = v;
408 int error = 0;
409 int64_t f, oldf;
410 const int64_t *freq = SCARG(uap, freq);
411 int64_t *oldfreq = SCARG(uap, oldfreq);
412
413 if (freq) {
414 if ((error = suser(p)))
415 return (error);
416 if ((error = copyin(freq, &f, sizeof(f))))
417 return (error);
418 if (f < ADJFREQ_MIN || f > ADJFREQ_MAX)
419 return (EINVAL);
420 }
421
422 rw_enter(&tc_lock, (freq == NULL) ? RW_READ : RW_WRITE);
423 if (oldfreq) {
424 tc_adjfreq(&oldf, NULL);
425 if ((error = copyout(&oldf, oldfreq, sizeof(oldf))))
426 goto out;
427 }
428 if (freq)
429 tc_adjfreq(NULL, &f);
430 out:
431 rw_exit(&tc_lock);
432 return (error);
433 }
434
435 int
sys_adjtime(struct proc * p,void * v,register_t * retval)436 sys_adjtime(struct proc *p, void *v, register_t *retval)
437 {
438 struct sys_adjtime_args /* {
439 syscallarg(const struct timeval *) delta;
440 syscallarg(struct timeval *) olddelta;
441 } */ *uap = v;
442 struct timeval atv;
443 const struct timeval *delta = SCARG(uap, delta);
444 struct timeval *olddelta = SCARG(uap, olddelta);
445 int64_t adjustment, remaining;
446 int error;
447
448 error = pledge_adjtime(p, delta);
449 if (error)
450 return error;
451
452 if (delta) {
453 if ((error = suser(p)))
454 return (error);
455 if ((error = copyin(delta, &atv, sizeof(struct timeval))))
456 return (error);
457 #ifdef KTRACE
458 if (KTRPOINT(p, KTR_STRUCT))
459 ktrreltimeval(p, &atv);
460 #endif
461 if (!timerisvalid(&atv))
462 return (EINVAL);
463
464 if (atv.tv_sec > INT64_MAX / 1000000)
465 return EINVAL;
466 if (atv.tv_sec < INT64_MIN / 1000000)
467 return EINVAL;
468 adjustment = atv.tv_sec * 1000000;
469 if (adjustment > INT64_MAX - atv.tv_usec)
470 return EINVAL;
471 adjustment += atv.tv_usec;
472
473 rw_enter_write(&tc_lock);
474 }
475
476 if (olddelta) {
477 tc_adjtime(&remaining, NULL);
478 memset(&atv, 0, sizeof(atv));
479 atv.tv_sec = remaining / 1000000;
480 atv.tv_usec = remaining % 1000000;
481 if (atv.tv_usec < 0) {
482 atv.tv_usec += 1000000;
483 atv.tv_sec--;
484 }
485
486 if ((error = copyout(&atv, olddelta, sizeof(struct timeval))))
487 goto out;
488 }
489
490 if (delta)
491 tc_adjtime(NULL, &adjustment);
492 out:
493 if (delta)
494 rw_exit_write(&tc_lock);
495 return (error);
496 }
497
498
499 struct mutex itimer_mtx = MUTEX_INITIALIZER(IPL_CLOCK);
500
501 /*
502 * Get or set value of an interval timer. The process virtual and
503 * profiling virtual time timers are kept internally in the
504 * way they are specified externally: in time until they expire.
505 *
506 * The real time interval timer's it_value, in contrast, is kept as an
507 * absolute time rather than as a delta, so that it is easy to keep
508 * periodic real-time signals from drifting.
509 *
510 * Virtual time timers are processed in the hardclock() routine of
511 * kern_clock.c. The real time timer is processed by a timeout
512 * routine, called from the softclock() routine. Since a callout
513 * may be delayed in real time due to interrupt processing in the system,
514 * it is possible for the real time timeout routine (realitexpire, given below),
515 * to be delayed in real time past when it is supposed to occur. It
516 * does not suffice, therefore, to reload the real timer .it_value from the
517 * real time timers .it_interval. Rather, we compute the next time in
518 * absolute time the timer should go off.
519 */
520 void
setitimer(int which,const struct itimerval * itv,struct itimerval * olditv)521 setitimer(int which, const struct itimerval *itv, struct itimerval *olditv)
522 {
523 struct itimerspec its, oldits;
524 struct timespec now;
525 struct itimerspec *itimer;
526 struct process *pr;
527
528 KASSERT(which >= ITIMER_REAL && which <= ITIMER_PROF);
529
530 pr = curproc->p_p;
531 itimer = &pr->ps_timer[which];
532
533 if (itv != NULL) {
534 TIMEVAL_TO_TIMESPEC(&itv->it_value, &its.it_value);
535 TIMEVAL_TO_TIMESPEC(&itv->it_interval, &its.it_interval);
536 }
537
538 if (which == ITIMER_REAL) {
539 mtx_enter(&pr->ps_mtx);
540 nanouptime(&now);
541 } else
542 mtx_enter(&itimer_mtx);
543
544 if (olditv != NULL)
545 oldits = *itimer;
546 if (itv != NULL) {
547 if (which == ITIMER_REAL) {
548 if (timespecisset(&its.it_value)) {
549 timespecadd(&its.it_value, &now, &its.it_value);
550 timeout_abs_ts(&pr->ps_realit_to,&its.it_value);
551 } else
552 timeout_del(&pr->ps_realit_to);
553 }
554 *itimer = its;
555 if (which == ITIMER_VIRTUAL || which == ITIMER_PROF) {
556 process_reset_itimer_flag(pr);
557 need_resched(curcpu());
558 }
559 }
560
561 if (which == ITIMER_REAL)
562 mtx_leave(&pr->ps_mtx);
563 else
564 mtx_leave(&itimer_mtx);
565
566 if (olditv != NULL) {
567 if (which == ITIMER_REAL && timespecisset(&oldits.it_value)) {
568 if (timespeccmp(&oldits.it_value, &now, <))
569 timespecclear(&oldits.it_value);
570 else {
571 timespecsub(&oldits.it_value, &now,
572 &oldits.it_value);
573 }
574 }
575 TIMESPEC_TO_TIMEVAL(&olditv->it_value, &oldits.it_value);
576 TIMESPEC_TO_TIMEVAL(&olditv->it_interval, &oldits.it_interval);
577 }
578 }
579
580 void
cancel_all_itimers(void)581 cancel_all_itimers(void)
582 {
583 struct itimerval itv;
584 int i;
585
586 timerclear(&itv.it_value);
587 timerclear(&itv.it_interval);
588
589 for (i = 0; i < nitems(curproc->p_p->ps_timer); i++)
590 setitimer(i, &itv, NULL);
591 }
592
593 int
sys_getitimer(struct proc * p,void * v,register_t * retval)594 sys_getitimer(struct proc *p, void *v, register_t *retval)
595 {
596 struct sys_getitimer_args /* {
597 syscallarg(int) which;
598 syscallarg(struct itimerval *) itv;
599 } */ *uap = v;
600 struct itimerval aitv;
601 int which;
602
603 which = SCARG(uap, which);
604 if (which < ITIMER_REAL || which > ITIMER_PROF)
605 return EINVAL;
606
607 memset(&aitv, 0, sizeof(aitv));
608
609 setitimer(which, NULL, &aitv);
610
611 return copyout(&aitv, SCARG(uap, itv), sizeof(aitv));
612 }
613
614 int
sys_setitimer(struct proc * p,void * v,register_t * retval)615 sys_setitimer(struct proc *p, void *v, register_t *retval)
616 {
617 struct sys_setitimer_args /* {
618 syscallarg(int) which;
619 syscallarg(const struct itimerval *) itv;
620 syscallarg(struct itimerval *) oitv;
621 } */ *uap = v;
622 struct itimerval aitv, olditv;
623 struct itimerval *newitvp, *olditvp;
624 int error, which;
625
626 which = SCARG(uap, which);
627 if (which < ITIMER_REAL || which > ITIMER_PROF)
628 return EINVAL;
629
630 newitvp = olditvp = NULL;
631 if (SCARG(uap, itv) != NULL) {
632 error = copyin(SCARG(uap, itv), &aitv, sizeof(aitv));
633 if (error)
634 return error;
635 error = itimerfix(&aitv);
636 if (error)
637 return error;
638 newitvp = &aitv;
639 }
640 if (SCARG(uap, oitv) != NULL) {
641 memset(&olditv, 0, sizeof(olditv));
642 olditvp = &olditv;
643 }
644 if (newitvp == NULL && olditvp == NULL)
645 return 0;
646
647 setitimer(which, newitvp, olditvp);
648
649 if (SCARG(uap, oitv) != NULL)
650 return copyout(&olditv, SCARG(uap, oitv), sizeof(olditv));
651
652 return 0;
653 }
654
655 /*
656 * Real interval timer expired:
657 * send process whose timer expired an alarm signal.
658 * If time is not set up to reload, then just return.
659 * Else compute next time timer should go off which is > current time.
660 * This is where delay in processing this timeout causes multiple
661 * SIGALRM calls to be compressed into one.
662 */
663 void
realitexpire(void * arg)664 realitexpire(void *arg)
665 {
666 struct timespec cts;
667 struct process *pr = arg;
668 struct itimerspec *tp = &pr->ps_timer[ITIMER_REAL];
669 int need_signal = 0;
670
671 mtx_enter(&pr->ps_mtx);
672
673 /*
674 * Do nothing if the timer was cancelled or rescheduled while we
675 * were entering the mutex.
676 */
677 if (!timespecisset(&tp->it_value) || timeout_pending(&pr->ps_realit_to))
678 goto out;
679
680 /* The timer expired. We need to send the signal. */
681 need_signal = 1;
682
683 /* One-shot timers are not reloaded. */
684 if (!timespecisset(&tp->it_interval)) {
685 timespecclear(&tp->it_value);
686 goto out;
687 }
688
689 /*
690 * Find the nearest future expiration point and restart
691 * the timeout.
692 */
693 nanouptime(&cts);
694 while (timespeccmp(&tp->it_value, &cts, <=))
695 timespecadd(&tp->it_value, &tp->it_interval, &tp->it_value);
696 if ((pr->ps_flags & PS_EXITING) == 0)
697 timeout_abs_ts(&pr->ps_realit_to, &tp->it_value);
698
699 out:
700 mtx_leave(&pr->ps_mtx);
701
702 if (need_signal)
703 prsignal(pr, SIGALRM);
704 }
705
706 /*
707 * Check if the given setitimer(2) input is valid. Clear it_interval
708 * if it_value is unset. Round it_interval up to the minimum interval
709 * if necessary.
710 */
711 int
itimerfix(struct itimerval * itv)712 itimerfix(struct itimerval *itv)
713 {
714 static const struct timeval max = { .tv_sec = UINT_MAX, .tv_usec = 0 };
715 struct timeval min_interval = { .tv_sec = 0, .tv_usec = tick };
716
717 if (itv->it_value.tv_sec < 0 || !timerisvalid(&itv->it_value))
718 return EINVAL;
719 if (timercmp(&itv->it_value, &max, >))
720 return EINVAL;
721 if (itv->it_interval.tv_sec < 0 || !timerisvalid(&itv->it_interval))
722 return EINVAL;
723 if (timercmp(&itv->it_interval, &max, >))
724 return EINVAL;
725
726 if (!timerisset(&itv->it_value))
727 timerclear(&itv->it_interval);
728 if (timerisset(&itv->it_interval)) {
729 if (timercmp(&itv->it_interval, &min_interval, <))
730 itv->it_interval = min_interval;
731 }
732
733 return 0;
734 }
735
736 /*
737 * Decrement an interval timer by the given duration.
738 * If the timer expires and it is periodic then reload it. When reloading
739 * the timer we subtract any overrun from the next period so that the timer
740 * does not drift.
741 */
742 int
itimerdecr(struct itimerspec * itp,const struct timespec * decrement)743 itimerdecr(struct itimerspec *itp, const struct timespec *decrement)
744 {
745 timespecsub(&itp->it_value, decrement, &itp->it_value);
746 if (itp->it_value.tv_sec >= 0 && timespecisset(&itp->it_value))
747 return (1);
748 if (!timespecisset(&itp->it_interval)) {
749 timespecclear(&itp->it_value);
750 return (0);
751 }
752 while (itp->it_value.tv_sec < 0 || !timespecisset(&itp->it_value))
753 timespecadd(&itp->it_value, &itp->it_interval, &itp->it_value);
754 return (0);
755 }
756
757 void
itimer_update(struct clockrequest * cr,void * cf,void * arg)758 itimer_update(struct clockrequest *cr, void *cf, void *arg)
759 {
760 struct timespec elapsed;
761 uint64_t nsecs;
762 struct clockframe *frame = cf;
763 struct proc *p = curproc;
764 struct process *pr;
765
766 if (p == NULL || ISSET(p->p_flag, P_SYSTEM | P_WEXIT))
767 return;
768
769 pr = p->p_p;
770 if (!ISSET(pr->ps_flags, PS_ITIMER))
771 return;
772
773 nsecs = clockrequest_advance(cr, hardclock_period) * hardclock_period;
774 NSEC_TO_TIMESPEC(nsecs, &elapsed);
775
776 mtx_enter(&itimer_mtx);
777 if (CLKF_USERMODE(frame) &&
778 timespecisset(&pr->ps_timer[ITIMER_VIRTUAL].it_value) &&
779 itimerdecr(&pr->ps_timer[ITIMER_VIRTUAL], &elapsed) == 0) {
780 process_reset_itimer_flag(pr);
781 atomic_setbits_int(&p->p_flag, P_ALRMPEND);
782 need_proftick(p);
783 }
784 if (timespecisset(&pr->ps_timer[ITIMER_PROF].it_value) &&
785 itimerdecr(&pr->ps_timer[ITIMER_PROF], &elapsed) == 0) {
786 process_reset_itimer_flag(pr);
787 atomic_setbits_int(&p->p_flag, P_PROFPEND);
788 need_proftick(p);
789 }
790 mtx_leave(&itimer_mtx);
791 }
792
793 void
process_reset_itimer_flag(struct process * ps)794 process_reset_itimer_flag(struct process *ps)
795 {
796 if (timespecisset(&ps->ps_timer[ITIMER_VIRTUAL].it_value) ||
797 timespecisset(&ps->ps_timer[ITIMER_PROF].it_value))
798 atomic_setbits_int(&ps->ps_flags, PS_ITIMER);
799 else
800 atomic_clearbits_int(&ps->ps_flags, PS_ITIMER);
801 }
802
803 struct mutex ratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH);
804
805 /*
806 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9)
807 * for usage and rationale.
808 */
809 int
ratecheck(struct timeval * lasttime,const struct timeval * mininterval)810 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
811 {
812 struct timeval tv, delta;
813 int rv = 0;
814
815 getmicrouptime(&tv);
816
817 mtx_enter(&ratecheck_mtx);
818 timersub(&tv, lasttime, &delta);
819
820 /*
821 * check for 0,0 is so that the message will be seen at least once,
822 * even if interval is huge.
823 */
824 if (timercmp(&delta, mininterval, >=) ||
825 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
826 *lasttime = tv;
827 rv = 1;
828 }
829 mtx_leave(&ratecheck_mtx);
830
831 return (rv);
832 }
833
834 struct mutex ppsratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH);
835
836 /*
837 * ppsratecheck(): packets (or events) per second limitation.
838 */
839 int
ppsratecheck(struct timeval * lasttime,int * curpps,int maxpps)840 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
841 {
842 struct timeval tv, delta;
843 int rv;
844
845 microuptime(&tv);
846
847 mtx_enter(&ppsratecheck_mtx);
848 timersub(&tv, lasttime, &delta);
849
850 /*
851 * check for 0,0 is so that the message will be seen at least once.
852 * if more than one second have passed since the last update of
853 * lasttime, reset the counter.
854 *
855 * we do increment *curpps even in *curpps < maxpps case, as some may
856 * try to use *curpps for stat purposes as well.
857 */
858 if (maxpps == 0)
859 rv = 0;
860 else if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
861 delta.tv_sec >= 1) {
862 *lasttime = tv;
863 *curpps = 0;
864 rv = 1;
865 } else if (maxpps < 0)
866 rv = 1;
867 else if (*curpps < maxpps)
868 rv = 1;
869 else
870 rv = 0;
871
872 /* be careful about wrap-around */
873 if (*curpps + 1 > *curpps)
874 *curpps = *curpps + 1;
875
876 mtx_leave(&ppsratecheck_mtx);
877
878 return (rv);
879 }
880
881 todr_chip_handle_t todr_handle;
882 int inittodr_done;
883
884 #define MINYEAR ((OpenBSD / 100) - 1) /* minimum plausible year */
885
886 /*
887 * inittodr:
888 *
889 * Initialize time from the time-of-day register.
890 */
891 void
inittodr(time_t base)892 inittodr(time_t base)
893 {
894 time_t deltat;
895 struct timeval rtctime;
896 struct timespec ts;
897 int badbase;
898
899 inittodr_done = 1;
900
901 if (base < (MINYEAR - 1970) * SECYR) {
902 printf("WARNING: preposterous time in file system\n");
903 /* read the system clock anyway */
904 base = (MINYEAR - 1970) * SECYR;
905 badbase = 1;
906 } else
907 badbase = 0;
908
909 rtctime.tv_sec = base;
910 rtctime.tv_usec = 0;
911
912 if (todr_handle == NULL ||
913 todr_gettime(todr_handle, &rtctime) != 0 ||
914 rtctime.tv_sec < (MINYEAR - 1970) * SECYR) {
915 /*
916 * Believe the time in the file system for lack of
917 * anything better, resetting the TODR.
918 */
919 rtctime.tv_sec = base;
920 rtctime.tv_usec = 0;
921 if (todr_handle != NULL && !badbase)
922 printf("WARNING: bad clock chip time\n");
923 ts.tv_sec = rtctime.tv_sec;
924 ts.tv_nsec = rtctime.tv_usec * 1000;
925 tc_setclock(&ts);
926 goto bad;
927 } else {
928 ts.tv_sec = rtctime.tv_sec;
929 ts.tv_nsec = rtctime.tv_usec * 1000;
930 tc_setclock(&ts);
931 }
932
933 if (!badbase) {
934 /*
935 * See if we gained/lost two or more days; if
936 * so, assume something is amiss.
937 */
938 deltat = rtctime.tv_sec - base;
939 if (deltat < 0)
940 deltat = -deltat;
941 if (deltat < 2 * SECDAY)
942 return; /* all is well */
943 #ifndef SMALL_KERNEL
944 printf("WARNING: clock %s %lld days\n",
945 rtctime.tv_sec < base ? "lost" : "gained",
946 (long long)(deltat / SECDAY));
947 #endif
948 }
949 bad:
950 printf("WARNING: CHECK AND RESET THE DATE!\n");
951 }
952
953 /*
954 * resettodr:
955 *
956 * Reset the time-of-day register with the current time.
957 */
958 void
resettodr(void)959 resettodr(void)
960 {
961 struct timeval rtctime;
962
963 /*
964 * Skip writing the RTC if inittodr(9) never ran. We don't
965 * want to overwrite a reasonable value with a nonsense value.
966 */
967 if (!inittodr_done)
968 return;
969
970 microtime(&rtctime);
971
972 if (todr_handle != NULL &&
973 todr_settime(todr_handle, &rtctime) != 0)
974 printf("WARNING: can't update clock chip time\n");
975 }
976
977 void
todr_attach(struct todr_chip_handle * todr)978 todr_attach(struct todr_chip_handle *todr)
979 {
980 if (todr_handle == NULL ||
981 todr->todr_quality > todr_handle->todr_quality)
982 todr_handle = todr;
983 }
984
985 #define RESETTODR_PERIOD 1800
986
987 void periodic_resettodr(void *);
988 void perform_resettodr(void *);
989
990 struct timeout resettodr_to = TIMEOUT_INITIALIZER(periodic_resettodr, NULL);
991 struct task resettodr_task = TASK_INITIALIZER(perform_resettodr, NULL);
992
993 void
periodic_resettodr(void * arg __unused)994 periodic_resettodr(void *arg __unused)
995 {
996 task_add(systq, &resettodr_task);
997 }
998
999 void
perform_resettodr(void * arg __unused)1000 perform_resettodr(void *arg __unused)
1001 {
1002 resettodr();
1003 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
1004 }
1005
1006 void
start_periodic_resettodr(void)1007 start_periodic_resettodr(void)
1008 {
1009 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
1010 }
1011
1012 void
stop_periodic_resettodr(void)1013 stop_periodic_resettodr(void)
1014 {
1015 timeout_del(&resettodr_to);
1016 task_del(systq, &resettodr_task);
1017 }
1018