FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_time.c
1 /* $OpenBSD: kern_time.c,v 1.161 2023/01/02 23:09:48 guenther 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/mutex.h>
39 #include <sys/rwlock.h>
40 #include <sys/proc.h>
41 #include <sys/ktrace.h>
42 #include <sys/signalvar.h>
43 #include <sys/stdint.h>
44 #include <sys/pledge.h>
45 #include <sys/task.h>
46 #include <sys/timeout.h>
47 #include <sys/timetc.h>
48
49 #include <sys/mount.h>
50 #include <sys/syscallargs.h>
51
52 #include <dev/clock_subr.h>
53
54 int itimerfix(struct itimerval *);
55
56 /*
57 * Time of day and interval timer support.
58 *
59 * These routines provide the kernel entry points to get and set
60 * the time-of-day and per-process interval timers. Subroutines
61 * here provide support for adding and subtracting timeval structures
62 * and decrementing interval timers, optionally reloading the interval
63 * timers when they expire.
64 */
65
66 /* This function is used by clock_settime and settimeofday */
67 int
68 settime(const struct timespec *ts)
69 {
70 struct timespec now;
71
72 /*
73 * Don't allow the time to be set forward so far it will wrap
74 * and become negative, thus allowing an attacker to bypass
75 * the next check below. The cutoff is 1 year before rollover
76 * occurs, so even if the attacker uses adjtime(2) to move
77 * the time past the cutoff, it will take a very long time
78 * to get to the wrap point.
79 *
80 * XXX: we check against UINT_MAX until we can figure out
81 * how to deal with the hardware RTCs.
82 */
83 if (ts->tv_sec > UINT_MAX - 365*24*60*60) {
84 printf("denied attempt to set clock forward to %lld\n",
85 (long long)ts->tv_sec);
86 return (EPERM);
87 }
88 /*
89 * If the system is secure, we do not allow the time to be
90 * set to an earlier value (it may be slowed using adjtime,
91 * but not set back). This feature prevent interlopers from
92 * setting arbitrary time stamps on files.
93 */
94 nanotime(&now);
95 if (securelevel > 1 && timespeccmp(ts, &now, <=)) {
96 printf("denied attempt to set clock back %lld seconds\n",
97 (long long)now.tv_sec - ts->tv_sec);
98 return (EPERM);
99 }
100
101 tc_setrealtimeclock(ts);
102 KERNEL_LOCK();
103 resettodr();
104 KERNEL_UNLOCK();
105
106 return (0);
107 }
108
109 int
110 clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp)
111 {
112 struct proc *q;
113 int error = 0;
114
115 switch (clock_id) {
116 case CLOCK_REALTIME:
117 nanotime(tp);
118 break;
119 case CLOCK_UPTIME:
120 nanoruntime(tp);
121 break;
122 case CLOCK_MONOTONIC:
123 case CLOCK_BOOTTIME:
124 nanouptime(tp);
125 break;
126 case CLOCK_PROCESS_CPUTIME_ID:
127 nanouptime(tp);
128 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
129 timespecadd(tp, &p->p_p->ps_tu.tu_runtime, tp);
130 timespecadd(tp, &p->p_rtime, tp);
131 break;
132 case CLOCK_THREAD_CPUTIME_ID:
133 nanouptime(tp);
134 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
135 timespecadd(tp, &p->p_tu.tu_runtime, tp);
136 timespecadd(tp, &p->p_rtime, tp);
137 break;
138 default:
139 /* check for clock from pthread_getcpuclockid() */
140 if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
141 KERNEL_LOCK();
142 q = tfind_user(__CLOCK_PTID(clock_id), p->p_p);
143 if (q == NULL)
144 error = ESRCH;
145 else
146 *tp = q->p_tu.tu_runtime;
147 KERNEL_UNLOCK();
148 } else
149 error = EINVAL;
150 break;
151 }
152 return (error);
153 }
154
155 int
156 sys_clock_gettime(struct proc *p, void *v, register_t *retval)
157 {
158 struct sys_clock_gettime_args /* {
159 syscallarg(clockid_t) clock_id;
160 syscallarg(struct timespec *) tp;
161 } */ *uap = v;
162 struct timespec ats;
163 int error;
164
165 memset(&ats, 0, sizeof(ats));
166 if ((error = clock_gettime(p, SCARG(uap, clock_id), &ats)) != 0)
167 return (error);
168
169 error = copyout(&ats, SCARG(uap, tp), sizeof(ats));
170 #ifdef KTRACE
171 if (error == 0 && KTRPOINT(p, KTR_STRUCT))
172 ktrabstimespec(p, &ats);
173 #endif
174 return (error);
175 }
176
177 int
178 sys_clock_settime(struct proc *p, void *v, register_t *retval)
179 {
180 struct sys_clock_settime_args /* {
181 syscallarg(clockid_t) clock_id;
182 syscallarg(const struct timespec *) tp;
183 } */ *uap = v;
184 struct timespec ats;
185 clockid_t clock_id;
186 int error;
187
188 if ((error = suser(p)) != 0)
189 return (error);
190
191 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
192 return (error);
193
194 clock_id = SCARG(uap, clock_id);
195 switch (clock_id) {
196 case CLOCK_REALTIME:
197 if (!timespecisvalid(&ats))
198 return (EINVAL);
199 if ((error = settime(&ats)) != 0)
200 return (error);
201 break;
202 default: /* Other clocks are read-only */
203 return (EINVAL);
204 }
205
206 return (0);
207 }
208
209 int
210 sys_clock_getres(struct proc *p, void *v, register_t *retval)
211 {
212 struct sys_clock_getres_args /* {
213 syscallarg(clockid_t) clock_id;
214 syscallarg(struct timespec *) tp;
215 } */ *uap = v;
216 clockid_t clock_id;
217 struct bintime bt;
218 struct timespec ts;
219 struct proc *q;
220 u_int64_t scale;
221 int error = 0, realstathz;
222
223 memset(&ts, 0, sizeof(ts));
224 realstathz = (stathz == 0) ? hz : stathz;
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 / realstathz;
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 / realstathz;
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
271 sys_nanosleep(struct proc *p, void *v, register_t *retval)
272 {
273 static int chan;
274 struct sys_nanosleep_args/* {
275 syscallarg(const struct timespec *) rqtp;
276 syscallarg(struct timespec *) rmtp;
277 } */ *uap = v;
278 struct timespec elapsed, remainder, request, start, stop;
279 uint64_t nsecs;
280 struct timespec *rmtp;
281 int copyout_error, error;
282
283 rmtp = SCARG(uap, rmtp);
284 error = copyin(SCARG(uap, rqtp), &request, sizeof(request));
285 if (error)
286 return (error);
287 #ifdef KTRACE
288 if (KTRPOINT(p, KTR_STRUCT))
289 ktrreltimespec(p, &request);
290 #endif
291
292 if (request.tv_sec < 0 || !timespecisvalid(&request))
293 return (EINVAL);
294
295 do {
296 getnanouptime(&start);
297 nsecs = MAX(1, MIN(TIMESPEC_TO_NSEC(&request), MAXTSLP));
298 error = tsleep_nsec(&chan, PWAIT | PCATCH, "nanoslp", nsecs);
299 getnanouptime(&stop);
300 timespecsub(&stop, &start, &elapsed);
301 timespecsub(&request, &elapsed, &request);
302 if (request.tv_sec < 0)
303 timespecclear(&request);
304 if (error != EWOULDBLOCK)
305 break;
306 } while (timespecisset(&request));
307
308 if (error == ERESTART)
309 error = EINTR;
310 if (error == EWOULDBLOCK)
311 error = 0;
312
313 if (rmtp) {
314 memset(&remainder, 0, sizeof(remainder));
315 remainder = request;
316 copyout_error = copyout(&remainder, rmtp, sizeof(remainder));
317 if (copyout_error)
318 error = copyout_error;
319 #ifdef KTRACE
320 if (copyout_error == 0 && KTRPOINT(p, KTR_STRUCT))
321 ktrreltimespec(p, &remainder);
322 #endif
323 }
324
325 return error;
326 }
327
328 int
329 sys_gettimeofday(struct proc *p, void *v, register_t *retval)
330 {
331 struct sys_gettimeofday_args /* {
332 syscallarg(struct timeval *) tp;
333 syscallarg(struct timezone *) tzp;
334 } */ *uap = v;
335 struct timeval atv;
336 static const struct timezone zerotz = { 0, 0 };
337 struct timeval *tp;
338 struct timezone *tzp;
339 int error = 0;
340
341 tp = SCARG(uap, tp);
342 tzp = SCARG(uap, tzp);
343
344 if (tp) {
345 memset(&atv, 0, sizeof(atv));
346 microtime(&atv);
347 if ((error = copyout(&atv, tp, sizeof (atv))))
348 return (error);
349 #ifdef KTRACE
350 if (KTRPOINT(p, KTR_STRUCT))
351 ktrabstimeval(p, &atv);
352 #endif
353 }
354 if (tzp)
355 error = copyout(&zerotz, tzp, sizeof(zerotz));
356 return (error);
357 }
358
359 int
360 sys_settimeofday(struct proc *p, void *v, register_t *retval)
361 {
362 struct sys_settimeofday_args /* {
363 syscallarg(const struct timeval *) tv;
364 syscallarg(const struct timezone *) tzp;
365 } */ *uap = v;
366 struct timezone atz;
367 struct timeval atv;
368 const struct timeval *tv;
369 const struct timezone *tzp;
370 int error;
371
372 tv = SCARG(uap, tv);
373 tzp = SCARG(uap, tzp);
374
375 if ((error = suser(p)))
376 return (error);
377 /* Verify all parameters before changing time. */
378 if (tv && (error = copyin(tv, &atv, sizeof(atv))))
379 return (error);
380 if (tzp && (error = copyin(tzp, &atz, sizeof(atz))))
381 return (error);
382 if (tv) {
383 struct timespec ts;
384
385 #ifdef KTRACE
386 if (KTRPOINT(p, KTR_STRUCT))
387 ktrabstimeval(p, &atv);
388 #endif
389 if (!timerisvalid(&atv))
390 return (EINVAL);
391 TIMEVAL_TO_TIMESPEC(&atv, &ts);
392 if ((error = settime(&ts)) != 0)
393 return (error);
394 }
395
396 return (0);
397 }
398
399 #define ADJFREQ_MAX (500000000LL << 32)
400 #define ADJFREQ_MIN (-ADJFREQ_MAX)
401
402 int
403 sys_adjfreq(struct proc *p, void *v, register_t *retval)
404 {
405 struct sys_adjfreq_args /* {
406 syscallarg(const int64_t *) freq;
407 syscallarg(int64_t *) oldfreq;
408 } */ *uap = v;
409 int error = 0;
410 int64_t f, oldf;
411 const int64_t *freq = SCARG(uap, freq);
412 int64_t *oldfreq = SCARG(uap, oldfreq);
413
414 if (freq) {
415 if ((error = suser(p)))
416 return (error);
417 if ((error = copyin(freq, &f, sizeof(f))))
418 return (error);
419 if (f < ADJFREQ_MIN || f > ADJFREQ_MAX)
420 return (EINVAL);
421 }
422
423 rw_enter(&tc_lock, (freq == NULL) ? RW_READ : RW_WRITE);
424 if (oldfreq) {
425 tc_adjfreq(&oldf, NULL);
426 if ((error = copyout(&oldf, oldfreq, sizeof(oldf))))
427 goto out;
428 }
429 if (freq)
430 tc_adjfreq(NULL, &f);
431 out:
432 rw_exit(&tc_lock);
433 return (error);
434 }
435
436 int
437 sys_adjtime(struct proc *p, void *v, register_t *retval)
438 {
439 struct sys_adjtime_args /* {
440 syscallarg(const struct timeval *) delta;
441 syscallarg(struct timeval *) olddelta;
442 } */ *uap = v;
443 struct timeval atv;
444 const struct timeval *delta = SCARG(uap, delta);
445 struct timeval *olddelta = SCARG(uap, olddelta);
446 int64_t adjustment, remaining;
447 int error;
448
449 error = pledge_adjtime(p, delta);
450 if (error)
451 return error;
452
453 if (delta) {
454 if ((error = suser(p)))
455 return (error);
456 if ((error = copyin(delta, &atv, sizeof(struct timeval))))
457 return (error);
458 #ifdef KTRACE
459 if (KTRPOINT(p, KTR_STRUCT))
460 ktrreltimeval(p, &atv);
461 #endif
462 if (!timerisvalid(&atv))
463 return (EINVAL);
464
465 if (atv.tv_sec > INT64_MAX / 1000000)
466 return EINVAL;
467 if (atv.tv_sec < INT64_MIN / 1000000)
468 return EINVAL;
469 adjustment = atv.tv_sec * 1000000;
470 if (adjustment > INT64_MAX - atv.tv_usec)
471 return EINVAL;
472 adjustment += atv.tv_usec;
473
474 rw_enter_write(&tc_lock);
475 }
476
477 if (olddelta) {
478 tc_adjtime(&remaining, NULL);
479 memset(&atv, 0, sizeof(atv));
480 atv.tv_sec = remaining / 1000000;
481 atv.tv_usec = remaining % 1000000;
482 if (atv.tv_usec < 0) {
483 atv.tv_usec += 1000000;
484 atv.tv_sec--;
485 }
486
487 if ((error = copyout(&atv, olddelta, sizeof(struct timeval))))
488 goto out;
489 }
490
491 if (delta)
492 tc_adjtime(NULL, &adjustment);
493 out:
494 if (delta)
495 rw_exit_write(&tc_lock);
496 return (error);
497 }
498
499
500 struct mutex itimer_mtx = MUTEX_INITIALIZER(IPL_CLOCK);
501
502 /*
503 * Get or set value of an interval timer. The process virtual and
504 * profiling virtual time timers are kept internally in the
505 * way they are specified externally: in time until they expire.
506 *
507 * The real time interval timer's it_value, in contrast, is kept as an
508 * absolute time rather than as a delta, so that it is easy to keep
509 * periodic real-time signals from drifting.
510 *
511 * Virtual time timers are processed in the hardclock() routine of
512 * kern_clock.c. The real time timer is processed by a timeout
513 * routine, called from the softclock() routine. Since a callout
514 * may be delayed in real time due to interrupt processing in the system,
515 * it is possible for the real time timeout routine (realitexpire, given below),
516 * to be delayed in real time past when it is supposed to occur. It
517 * does not suffice, therefore, to reload the real timer .it_value from the
518 * real time timers .it_interval. Rather, we compute the next time in
519 * absolute time the timer should go off.
520 */
521 void
522 setitimer(int which, const struct itimerval *itv, struct itimerval *olditv)
523 {
524 struct itimerspec its, oldits;
525 struct timespec now;
526 struct itimerspec *itimer;
527 struct process *pr;
528
529 KASSERT(which >= ITIMER_REAL && which <= ITIMER_PROF);
530
531 pr = curproc->p_p;
532 itimer = &pr->ps_timer[which];
533
534 if (itv != NULL) {
535 TIMEVAL_TO_TIMESPEC(&itv->it_value, &its.it_value);
536 TIMEVAL_TO_TIMESPEC(&itv->it_interval, &its.it_interval);
537 }
538
539 if (which == ITIMER_REAL) {
540 mtx_enter(&pr->ps_mtx);
541 nanouptime(&now);
542 } else
543 mtx_enter(&itimer_mtx);
544
545 if (olditv != NULL)
546 oldits = *itimer;
547 if (itv != NULL) {
548 if (which == ITIMER_REAL) {
549 if (timespecisset(&its.it_value)) {
550 timespecadd(&its.it_value, &now, &its.it_value);
551 timeout_abs_ts(&pr->ps_realit_to,&its.it_value);
552 } else
553 timeout_del(&pr->ps_realit_to);
554 }
555 *itimer = its;
556 }
557
558 if (which == ITIMER_REAL)
559 mtx_leave(&pr->ps_mtx);
560 else
561 mtx_leave(&itimer_mtx);
562
563 if (olditv != NULL) {
564 if (which == ITIMER_REAL && timespecisset(&oldits.it_value)) {
565 if (timespeccmp(&oldits.it_value, &now, <))
566 timespecclear(&oldits.it_value);
567 else {
568 timespecsub(&oldits.it_value, &now,
569 &oldits.it_value);
570 }
571 }
572 TIMESPEC_TO_TIMEVAL(&olditv->it_value, &oldits.it_value);
573 TIMESPEC_TO_TIMEVAL(&olditv->it_interval, &oldits.it_interval);
574 }
575 }
576
577 void
578 cancel_all_itimers(void)
579 {
580 struct itimerval itv;
581 int i;
582
583 timerclear(&itv.it_value);
584 timerclear(&itv.it_interval);
585
586 for (i = 0; i < nitems(curproc->p_p->ps_timer); i++)
587 setitimer(i, &itv, NULL);
588 }
589
590 int
591 sys_getitimer(struct proc *p, void *v, register_t *retval)
592 {
593 struct sys_getitimer_args /* {
594 syscallarg(int) which;
595 syscallarg(struct itimerval *) itv;
596 } */ *uap = v;
597 struct itimerval aitv;
598 int which;
599
600 which = SCARG(uap, which);
601 if (which < ITIMER_REAL || which > ITIMER_PROF)
602 return EINVAL;
603
604 memset(&aitv, 0, sizeof(aitv));
605
606 setitimer(which, NULL, &aitv);
607
608 return copyout(&aitv, SCARG(uap, itv), sizeof(aitv));
609 }
610
611 int
612 sys_setitimer(struct proc *p, void *v, register_t *retval)
613 {
614 struct sys_setitimer_args /* {
615 syscallarg(int) which;
616 syscallarg(const struct itimerval *) itv;
617 syscallarg(struct itimerval *) oitv;
618 } */ *uap = v;
619 struct itimerval aitv, olditv;
620 struct itimerval *newitvp, *olditvp;
621 int error, which;
622
623 which = SCARG(uap, which);
624 if (which < ITIMER_REAL || which > ITIMER_PROF)
625 return EINVAL;
626
627 newitvp = olditvp = NULL;
628 if (SCARG(uap, itv) != NULL) {
629 error = copyin(SCARG(uap, itv), &aitv, sizeof(aitv));
630 if (error)
631 return error;
632 error = itimerfix(&aitv);
633 if (error)
634 return error;
635 newitvp = &aitv;
636 }
637 if (SCARG(uap, oitv) != NULL) {
638 memset(&olditv, 0, sizeof(olditv));
639 olditvp = &olditv;
640 }
641 if (newitvp == NULL && olditvp == NULL)
642 return 0;
643
644 setitimer(which, newitvp, olditvp);
645
646 if (SCARG(uap, oitv) != NULL)
647 return copyout(&olditv, SCARG(uap, oitv), sizeof(olditv));
648
649 return 0;
650 }
651
652 /*
653 * Real interval timer expired:
654 * send process whose timer expired an alarm signal.
655 * If time is not set up to reload, then just return.
656 * Else compute next time timer should go off which is > current time.
657 * This is where delay in processing this timeout causes multiple
658 * SIGALRM calls to be compressed into one.
659 */
660 void
661 realitexpire(void *arg)
662 {
663 struct timespec cts;
664 struct process *pr = arg;
665 struct itimerspec *tp = &pr->ps_timer[ITIMER_REAL];
666 int need_signal = 0;
667
668 mtx_enter(&pr->ps_mtx);
669
670 /*
671 * Do nothing if the timer was cancelled or rescheduled while we
672 * were entering the mutex.
673 */
674 if (!timespecisset(&tp->it_value) || timeout_pending(&pr->ps_realit_to))
675 goto out;
676
677 /* The timer expired. We need to send the signal. */
678 need_signal = 1;
679
680 /* One-shot timers are not reloaded. */
681 if (!timespecisset(&tp->it_interval)) {
682 timespecclear(&tp->it_value);
683 goto out;
684 }
685
686 /*
687 * Find the nearest future expiration point and restart
688 * the timeout.
689 */
690 nanouptime(&cts);
691 while (timespeccmp(&tp->it_value, &cts, <=))
692 timespecadd(&tp->it_value, &tp->it_interval, &tp->it_value);
693 if ((pr->ps_flags & PS_EXITING) == 0)
694 timeout_abs_ts(&pr->ps_realit_to, &tp->it_value);
695
696 out:
697 mtx_leave(&pr->ps_mtx);
698
699 if (need_signal)
700 prsignal(pr, SIGALRM);
701 }
702
703 /*
704 * Check if the given setitimer(2) input is valid. Clear it_interval
705 * if it_value is unset. Round it_interval up to the minimum interval
706 * if necessary.
707 */
708 int
709 itimerfix(struct itimerval *itv)
710 {
711 static const struct timeval max = { .tv_sec = UINT_MAX, .tv_usec = 0 };
712 struct timeval min_interval = { .tv_sec = 0, .tv_usec = tick };
713
714 if (itv->it_value.tv_sec < 0 || !timerisvalid(&itv->it_value))
715 return EINVAL;
716 if (timercmp(&itv->it_value, &max, >))
717 return EINVAL;
718 if (itv->it_interval.tv_sec < 0 || !timerisvalid(&itv->it_interval))
719 return EINVAL;
720 if (timercmp(&itv->it_interval, &max, >))
721 return EINVAL;
722
723 if (!timerisset(&itv->it_value))
724 timerclear(&itv->it_interval);
725 if (timerisset(&itv->it_interval)) {
726 if (timercmp(&itv->it_interval, &min_interval, <))
727 itv->it_interval = min_interval;
728 }
729
730 return 0;
731 }
732
733 /*
734 * Decrement an interval timer by the given number of nanoseconds.
735 * If the timer expires and it is periodic then reload it. When reloading
736 * the timer we subtract any overrun from the next period so that the timer
737 * does not drift.
738 */
739 int
740 itimerdecr(struct itimerspec *itp, long nsec)
741 {
742 struct timespec decrement;
743
744 NSEC_TO_TIMESPEC(nsec, &decrement);
745
746 mtx_enter(&itimer_mtx);
747
748 /*
749 * Double-check that the timer is enabled. A different thread
750 * in setitimer(2) may have disabled it while we were entering
751 * the mutex.
752 */
753 if (!timespecisset(&itp->it_value)) {
754 mtx_leave(&itimer_mtx);
755 return (1);
756 }
757
758 /*
759 * The timer is enabled. Update and reload it as needed.
760 */
761 timespecsub(&itp->it_value, &decrement, &itp->it_value);
762 if (itp->it_value.tv_sec >= 0 && timespecisset(&itp->it_value)) {
763 mtx_leave(&itimer_mtx);
764 return (1);
765 }
766 if (!timespecisset(&itp->it_interval)) {
767 timespecclear(&itp->it_value);
768 mtx_leave(&itimer_mtx);
769 return (0);
770 }
771 while (itp->it_value.tv_sec < 0 || !timespecisset(&itp->it_value))
772 timespecadd(&itp->it_value, &itp->it_interval, &itp->it_value);
773 mtx_leave(&itimer_mtx);
774 return (0);
775 }
776
777 struct mutex ratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH);
778
779 /*
780 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9)
781 * for usage and rationale.
782 */
783 int
784 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
785 {
786 struct timeval tv, delta;
787 int rv = 0;
788
789 getmicrouptime(&tv);
790
791 mtx_enter(&ratecheck_mtx);
792 timersub(&tv, lasttime, &delta);
793
794 /*
795 * check for 0,0 is so that the message will be seen at least once,
796 * even if interval is huge.
797 */
798 if (timercmp(&delta, mininterval, >=) ||
799 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
800 *lasttime = tv;
801 rv = 1;
802 }
803 mtx_leave(&ratecheck_mtx);
804
805 return (rv);
806 }
807
808 struct mutex ppsratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH);
809
810 /*
811 * ppsratecheck(): packets (or events) per second limitation.
812 */
813 int
814 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
815 {
816 struct timeval tv, delta;
817 int rv;
818
819 microuptime(&tv);
820
821 mtx_enter(&ppsratecheck_mtx);
822 timersub(&tv, lasttime, &delta);
823
824 /*
825 * check for 0,0 is so that the message will be seen at least once.
826 * if more than one second have passed since the last update of
827 * lasttime, reset the counter.
828 *
829 * we do increment *curpps even in *curpps < maxpps case, as some may
830 * try to use *curpps for stat purposes as well.
831 */
832 if (maxpps == 0)
833 rv = 0;
834 else if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
835 delta.tv_sec >= 1) {
836 *lasttime = tv;
837 *curpps = 0;
838 rv = 1;
839 } else if (maxpps < 0)
840 rv = 1;
841 else if (*curpps < maxpps)
842 rv = 1;
843 else
844 rv = 0;
845
846 /* be careful about wrap-around */
847 if (*curpps + 1 > *curpps)
848 *curpps = *curpps + 1;
849
850 mtx_leave(&ppsratecheck_mtx);
851
852 return (rv);
853 }
854
855 todr_chip_handle_t todr_handle;
856 int inittodr_done;
857
858 #define MINYEAR ((OpenBSD / 100) - 1) /* minimum plausible year */
859
860 /*
861 * inittodr:
862 *
863 * Initialize time from the time-of-day register.
864 */
865 void
866 inittodr(time_t base)
867 {
868 time_t deltat;
869 struct timeval rtctime;
870 struct timespec ts;
871 int badbase;
872
873 inittodr_done = 1;
874
875 if (base < (MINYEAR - 1970) * SECYR) {
876 printf("WARNING: preposterous time in file system\n");
877 /* read the system clock anyway */
878 base = (MINYEAR - 1970) * SECYR;
879 badbase = 1;
880 } else
881 badbase = 0;
882
883 rtctime.tv_sec = base;
884 rtctime.tv_usec = 0;
885
886 if (todr_handle == NULL ||
887 todr_gettime(todr_handle, &rtctime) != 0 ||
888 rtctime.tv_sec < (MINYEAR - 1970) * SECYR) {
889 /*
890 * Believe the time in the file system for lack of
891 * anything better, resetting the TODR.
892 */
893 rtctime.tv_sec = base;
894 rtctime.tv_usec = 0;
895 if (todr_handle != NULL && !badbase)
896 printf("WARNING: bad clock chip time\n");
897 ts.tv_sec = rtctime.tv_sec;
898 ts.tv_nsec = rtctime.tv_usec * 1000;
899 tc_setclock(&ts);
900 goto bad;
901 } else {
902 ts.tv_sec = rtctime.tv_sec;
903 ts.tv_nsec = rtctime.tv_usec * 1000;
904 tc_setclock(&ts);
905 }
906
907 if (!badbase) {
908 /*
909 * See if we gained/lost two or more days; if
910 * so, assume something is amiss.
911 */
912 deltat = rtctime.tv_sec - base;
913 if (deltat < 0)
914 deltat = -deltat;
915 if (deltat < 2 * SECDAY)
916 return; /* all is well */
917 #ifndef SMALL_KERNEL
918 printf("WARNING: clock %s %lld days\n",
919 rtctime.tv_sec < base ? "lost" : "gained",
920 (long long)(deltat / SECDAY));
921 #endif
922 }
923 bad:
924 printf("WARNING: CHECK AND RESET THE DATE!\n");
925 }
926
927 /*
928 * resettodr:
929 *
930 * Reset the time-of-day register with the current time.
931 */
932 void
933 resettodr(void)
934 {
935 struct timeval rtctime;
936
937 /*
938 * Skip writing the RTC if inittodr(9) never ran. We don't
939 * want to overwrite a reasonable value with a nonsense value.
940 */
941 if (!inittodr_done)
942 return;
943
944 microtime(&rtctime);
945
946 if (todr_handle != NULL &&
947 todr_settime(todr_handle, &rtctime) != 0)
948 printf("WARNING: can't update clock chip time\n");
949 }
950
951 void
952 todr_attach(struct todr_chip_handle *todr)
953 {
954 if (todr_handle == NULL ||
955 todr->todr_quality > todr_handle->todr_quality)
956 todr_handle = todr;
957 }
958
959 #define RESETTODR_PERIOD 1800
960
961 void periodic_resettodr(void *);
962 void perform_resettodr(void *);
963
964 struct timeout resettodr_to = TIMEOUT_INITIALIZER(periodic_resettodr, NULL);
965 struct task resettodr_task = TASK_INITIALIZER(perform_resettodr, NULL);
966
967 void
968 periodic_resettodr(void *arg __unused)
969 {
970 task_add(systq, &resettodr_task);
971 }
972
973 void
974 perform_resettodr(void *arg __unused)
975 {
976 resettodr();
977 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
978 }
979
980 void
981 start_periodic_resettodr(void)
982 {
983 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
984 }
985
986 void
987 stop_periodic_resettodr(void)
988 {
989 timeout_del(&resettodr_to);
990 task_del(systq, &resettodr_task);
991 }
Cache object: 5aad8e65bfb5f894ca6c8752a726188a
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