Register keyword removal
[dragonfly.git] / sys / kern / kern_time.c
CommitLineData
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1/*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)kern_time.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/kern/kern_time.c,v 1.68.2.1 2002/10/01 08:00:41 bde Exp $
1fd87d54 35 * $DragonFly: src/sys/kern/kern_time.c,v 1.7 2003/07/26 19:42:11 rob Exp $
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36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/buf.h>
41#include <sys/sysproto.h>
42#include <sys/resourcevar.h>
43#include <sys/signalvar.h>
44#include <sys/kernel.h>
45#include <sys/systm.h>
46#include <sys/sysent.h>
47#include <sys/proc.h>
48#include <sys/time.h>
49#include <sys/vnode.h>
50#include <vm/vm.h>
51#include <vm/vm_extern.h>
52
53struct timezone tz;
54
55/*
56 * Time of day and interval timer support.
57 *
58 * These routines provide the kernel entry points to get and set
59 * the time-of-day and per-process interval timers. Subroutines
60 * here provide support for adding and subtracting timeval structures
61 * and decrementing interval timers, optionally reloading the interval
62 * timers when they expire.
63 */
64
41c20dac 65static int nanosleep1 __P((struct timespec *rqt,
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66 struct timespec *rmt));
67static int settime __P((struct timeval *));
68static void timevalfix __P((struct timeval *));
69static void no_lease_updatetime __P((int));
70
71static void
72no_lease_updatetime(deltat)
73 int deltat;
74{
75}
76
77void (*lease_updatetime) __P((int)) = no_lease_updatetime;
78
79static int
80settime(tv)
81 struct timeval *tv;
82{
83 struct timeval delta, tv1, tv2;
84 static struct timeval maxtime, laststep;
85 struct timespec ts;
86 int s;
87
88 s = splclock();
89 microtime(&tv1);
90 delta = *tv;
91 timevalsub(&delta, &tv1);
92
93 /*
94 * If the system is secure, we do not allow the time to be
95 * set to a value earlier than 1 second less than the highest
96 * time we have yet seen. The worst a miscreant can do in
97 * this circumstance is "freeze" time. He couldn't go
98 * back to the past.
99 *
100 * We similarly do not allow the clock to be stepped more
101 * than one second, nor more than once per second. This allows
102 * a miscreant to make the clock march double-time, but no worse.
103 */
104 if (securelevel > 1) {
105 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
106 /*
107 * Update maxtime to latest time we've seen.
108 */
109 if (tv1.tv_sec > maxtime.tv_sec)
110 maxtime = tv1;
111 tv2 = *tv;
112 timevalsub(&tv2, &maxtime);
113 if (tv2.tv_sec < -1) {
114 tv->tv_sec = maxtime.tv_sec - 1;
115 printf("Time adjustment clamped to -1 second\n");
116 }
117 } else {
118 if (tv1.tv_sec == laststep.tv_sec) {
119 splx(s);
120 return (EPERM);
121 }
122 if (delta.tv_sec > 1) {
123 tv->tv_sec = tv1.tv_sec + 1;
124 printf("Time adjustment clamped to +1 second\n");
125 }
126 laststep = *tv;
127 }
128 }
129
130 ts.tv_sec = tv->tv_sec;
131 ts.tv_nsec = tv->tv_usec * 1000;
132 set_timecounter(&ts);
133 (void) splsoftclock();
134 lease_updatetime(delta.tv_sec);
135 splx(s);
136 resettodr();
137 return (0);
138}
139
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140/* ARGSUSED */
141int
41c20dac 142clock_gettime(struct clock_gettime_args *uap)
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143{
144 struct timespec ats;
145
146 if (SCARG(uap, clock_id) != CLOCK_REALTIME)
147 return (EINVAL);
148 nanotime(&ats);
149 return (copyout(&ats, SCARG(uap, tp), sizeof(ats)));
150}
151
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152/* ARGSUSED */
153int
41c20dac 154clock_settime(struct clock_settime_args *uap)
984263bc 155{
dadab5e9 156 struct thread *td = curthread;
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157 struct timeval atv;
158 struct timespec ats;
159 int error;
160
dadab5e9 161 if ((error = suser(td)) != 0)
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162 return (error);
163 if (SCARG(uap, clock_id) != CLOCK_REALTIME)
164 return (EINVAL);
165 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
166 return (error);
167 if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000)
168 return (EINVAL);
169 /* XXX Don't convert nsec->usec and back */
170 TIMESPEC_TO_TIMEVAL(&atv, &ats);
171 if ((error = settime(&atv)))
172 return (error);
173 return (0);
174}
175
984263bc 176int
41c20dac 177clock_getres(struct clock_getres_args *uap)
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178{
179 struct timespec ts;
180 int error;
181
182 if (SCARG(uap, clock_id) != CLOCK_REALTIME)
183 return (EINVAL);
184 error = 0;
185 if (SCARG(uap, tp)) {
186 ts.tv_sec = 0;
187 /*
188 * Round up the result of the division cheaply by adding 1.
189 * Rounding up is especially important if rounding down
190 * would give 0. Perfect rounding is unimportant.
191 */
192 ts.tv_nsec = 1000000000 / timecounter->tc_frequency + 1;
193 error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
194 }
195 return (error);
196}
197
198static int nanowait;
199
200static int
41c20dac 201nanosleep1(struct timespec *rqt, struct timespec *rmt)
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202{
203 struct timespec ts, ts2, ts3;
204 struct timeval tv;
205 int error;
206
207 if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
208 return (EINVAL);
209 if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
210 return (0);
211 getnanouptime(&ts);
212 timespecadd(&ts, rqt);
213 TIMESPEC_TO_TIMEVAL(&tv, rqt);
214 for (;;) {
377d4740 215 error = tsleep(&nanowait, PCATCH, "nanslp",
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216 tvtohz(&tv));
217 getnanouptime(&ts2);
218 if (error != EWOULDBLOCK) {
219 if (error == ERESTART)
220 error = EINTR;
221 if (rmt != NULL) {
222 timespecsub(&ts, &ts2);
223 if (ts.tv_sec < 0)
224 timespecclear(&ts);
225 *rmt = ts;
226 }
227 return (error);
228 }
229 if (timespeccmp(&ts2, &ts, >=))
230 return (0);
231 ts3 = ts;
232 timespecsub(&ts3, &ts2);
233 TIMESPEC_TO_TIMEVAL(&tv, &ts3);
234 }
235}
236
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237/* ARGSUSED */
238int
41c20dac 239nanosleep(struct nanosleep_args *uap)
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240{
241 struct timespec rmt, rqt;
242 int error, error2;
243
244 error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt));
245 if (error)
246 return (error);
247 if (SCARG(uap, rmtp))
248 if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt),
249 VM_PROT_WRITE))
250 return (EFAULT);
41c20dac 251 error = nanosleep1(&rqt, &rmt);
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252 if (error && SCARG(uap, rmtp)) {
253 error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt));
254 if (error2) /* XXX shouldn't happen, did useracc() above */
255 return (error2);
256 }
257 return (error);
258}
259
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260/* ARGSUSED */
261int
41c20dac 262gettimeofday(struct gettimeofday_args *uap)
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263{
264 struct timeval atv;
265 int error = 0;
266
267 if (uap->tp) {
268 microtime(&atv);
269 if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp,
270 sizeof (atv))))
271 return (error);
272 }
273 if (uap->tzp)
274 error = copyout((caddr_t)&tz, (caddr_t)uap->tzp,
275 sizeof (tz));
276 return (error);
277}
278
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279/* ARGSUSED */
280int
41c20dac 281settimeofday(struct settimeofday_args *uap)
984263bc 282{
dadab5e9 283 struct thread *td = curthread;
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284 struct timeval atv;
285 struct timezone atz;
286 int error;
287
dadab5e9 288 if ((error = suser(td)))
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289 return (error);
290 /* Verify all parameters before changing time. */
291 if (uap->tv) {
292 if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
293 sizeof(atv))))
294 return (error);
295 if (atv.tv_usec < 0 || atv.tv_usec >= 1000000)
296 return (EINVAL);
297 }
298 if (uap->tzp &&
299 (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz))))
300 return (error);
301 if (uap->tv && (error = settime(&atv)))
302 return (error);
303 if (uap->tzp)
304 tz = atz;
305 return (0);
306}
307
308int tickdelta; /* current clock skew, us. per tick */
309long timedelta; /* unapplied time correction, us. */
310static long bigadj = 1000000; /* use 10x skew above bigadj us. */
311
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312/* ARGSUSED */
313int
41c20dac 314adjtime(struct adjtime_args *uap)
984263bc 315{
dadab5e9 316 struct thread *td = curthread;
984263bc 317 struct timeval atv;
dadab5e9 318 long ndelta, ntickdelta, odelta;
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319 int s, error;
320
dadab5e9 321 if ((error = suser(td)))
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322 return (error);
323 if ((error =
324 copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval))))
325 return (error);
326
327 /*
328 * Compute the total correction and the rate at which to apply it.
329 * Round the adjustment down to a whole multiple of the per-tick
330 * delta, so that after some number of incremental changes in
331 * hardclock(), tickdelta will become zero, lest the correction
332 * overshoot and start taking us away from the desired final time.
333 */
334 ndelta = atv.tv_sec * 1000000 + atv.tv_usec;
335 if (ndelta > bigadj || ndelta < -bigadj)
336 ntickdelta = 10 * tickadj;
337 else
338 ntickdelta = tickadj;
339 if (ndelta % ntickdelta)
340 ndelta = ndelta / ntickdelta * ntickdelta;
341
342 /*
343 * To make hardclock()'s job easier, make the per-tick delta negative
344 * if we want time to run slower; then hardclock can simply compute
345 * tick + tickdelta, and subtract tickdelta from timedelta.
346 */
347 if (ndelta < 0)
348 ntickdelta = -ntickdelta;
349 s = splclock();
350 odelta = timedelta;
351 timedelta = ndelta;
352 tickdelta = ntickdelta;
353 splx(s);
354
355 if (uap->olddelta) {
356 atv.tv_sec = odelta / 1000000;
357 atv.tv_usec = odelta % 1000000;
358 (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta,
359 sizeof(struct timeval));
360 }
361 return (0);
362}
363
364/*
365 * Get value of an interval timer. The process virtual and
366 * profiling virtual time timers are kept in the p_stats area, since
367 * they can be swapped out. These are kept internally in the
368 * way they are specified externally: in time until they expire.
369 *
370 * The real time interval timer is kept in the process table slot
371 * for the process, and its value (it_value) is kept as an
372 * absolute time rather than as a delta, so that it is easy to keep
373 * periodic real-time signals from drifting.
374 *
375 * Virtual time timers are processed in the hardclock() routine of
376 * kern_clock.c. The real time timer is processed by a timeout
377 * routine, called from the softclock() routine. Since a callout
378 * may be delayed in real time due to interrupt processing in the system,
379 * it is possible for the real time timeout routine (realitexpire, given below),
380 * to be delayed in real time past when it is supposed to occur. It
381 * does not suffice, therefore, to reload the real timer .it_value from the
382 * real time timers .it_interval. Rather, we compute the next time in
383 * absolute time the timer should go off.
384 */
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385/* ARGSUSED */
386int
41c20dac 387getitimer(struct getitimer_args *uap)
984263bc 388{
41c20dac 389 struct proc *p = curproc;
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390 struct timeval ctv;
391 struct itimerval aitv;
392 int s;
393
394 if (uap->which > ITIMER_PROF)
395 return (EINVAL);
396 s = splclock(); /* XXX still needed ? */
397 if (uap->which == ITIMER_REAL) {
398 /*
399 * Convert from absolute to relative time in .it_value
400 * part of real time timer. If time for real time timer
401 * has passed return 0, else return difference between
402 * current time and time for the timer to go off.
403 */
404 aitv = p->p_realtimer;
405 if (timevalisset(&aitv.it_value)) {
406 getmicrouptime(&ctv);
407 if (timevalcmp(&aitv.it_value, &ctv, <))
408 timevalclear(&aitv.it_value);
409 else
410 timevalsub(&aitv.it_value, &ctv);
411 }
412 } else
413 aitv = p->p_stats->p_timer[uap->which];
414 splx(s);
415 return (copyout((caddr_t)&aitv, (caddr_t)uap->itv,
416 sizeof (struct itimerval)));
417}
418
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419/* ARGSUSED */
420int
41c20dac 421setitimer(struct setitimer_args *uap)
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422{
423 struct itimerval aitv;
424 struct timeval ctv;
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425 struct itimerval *itvp;
426 struct proc *p = curproc;
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427 int s, error;
428
429 if (uap->which > ITIMER_PROF)
430 return (EINVAL);
431 itvp = uap->itv;
432 if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv,
433 sizeof(struct itimerval))))
434 return (error);
435 if ((uap->itv = uap->oitv) &&
41c20dac 436 (error = getitimer((struct getitimer_args *)uap)))
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437 return (error);
438 if (itvp == 0)
439 return (0);
440 if (itimerfix(&aitv.it_value))
441 return (EINVAL);
442 if (!timevalisset(&aitv.it_value))
443 timevalclear(&aitv.it_interval);
444 else if (itimerfix(&aitv.it_interval))
445 return (EINVAL);
446 s = splclock(); /* XXX: still needed ? */
447 if (uap->which == ITIMER_REAL) {
448 if (timevalisset(&p->p_realtimer.it_value))
449 untimeout(realitexpire, (caddr_t)p, p->p_ithandle);
450 if (timevalisset(&aitv.it_value))
451 p->p_ithandle = timeout(realitexpire, (caddr_t)p,
452 tvtohz(&aitv.it_value));
453 getmicrouptime(&ctv);
454 timevaladd(&aitv.it_value, &ctv);
455 p->p_realtimer = aitv;
456 } else
457 p->p_stats->p_timer[uap->which] = aitv;
458 splx(s);
459 return (0);
460}
461
462/*
463 * Real interval timer expired:
464 * send process whose timer expired an alarm signal.
465 * If time is not set up to reload, then just return.
466 * Else compute next time timer should go off which is > current time.
467 * This is where delay in processing this timeout causes multiple
468 * SIGALRM calls to be compressed into one.
469 * tvtohz() always adds 1 to allow for the time until the next clock
470 * interrupt being strictly less than 1 clock tick, but we don't want
471 * that here since we want to appear to be in sync with the clock
472 * interrupt even when we're delayed.
473 */
474void
475realitexpire(arg)
476 void *arg;
477{
1fd87d54 478 struct proc *p;
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479 struct timeval ctv, ntv;
480 int s;
481
482 p = (struct proc *)arg;
483 psignal(p, SIGALRM);
484 if (!timevalisset(&p->p_realtimer.it_interval)) {
485 timevalclear(&p->p_realtimer.it_value);
486 return;
487 }
488 for (;;) {
489 s = splclock(); /* XXX: still neeeded ? */
490 timevaladd(&p->p_realtimer.it_value,
491 &p->p_realtimer.it_interval);
492 getmicrouptime(&ctv);
493 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
494 ntv = p->p_realtimer.it_value;
495 timevalsub(&ntv, &ctv);
496 p->p_ithandle = timeout(realitexpire, (caddr_t)p,
497 tvtohz(&ntv) - 1);
498 splx(s);
499 return;
500 }
501 splx(s);
502 }
503}
504
505/*
506 * Check that a proposed value to load into the .it_value or
507 * .it_interval part of an interval timer is acceptable, and
508 * fix it to have at least minimal value (i.e. if it is less
509 * than the resolution of the clock, round it up.)
510 */
511int
512itimerfix(tv)
513 struct timeval *tv;
514{
515
516 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
517 tv->tv_usec < 0 || tv->tv_usec >= 1000000)
518 return (EINVAL);
519 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
520 tv->tv_usec = tick;
521 return (0);
522}
523
524/*
525 * Decrement an interval timer by a specified number
526 * of microseconds, which must be less than a second,
527 * i.e. < 1000000. If the timer expires, then reload
528 * it. In this case, carry over (usec - old value) to
529 * reduce the value reloaded into the timer so that
530 * the timer does not drift. This routine assumes
531 * that it is called in a context where the timers
532 * on which it is operating cannot change in value.
533 */
534int
535itimerdecr(itp, usec)
1fd87d54 536 struct itimerval *itp;
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537 int usec;
538{
539
540 if (itp->it_value.tv_usec < usec) {
541 if (itp->it_value.tv_sec == 0) {
542 /* expired, and already in next interval */
543 usec -= itp->it_value.tv_usec;
544 goto expire;
545 }
546 itp->it_value.tv_usec += 1000000;
547 itp->it_value.tv_sec--;
548 }
549 itp->it_value.tv_usec -= usec;
550 usec = 0;
551 if (timevalisset(&itp->it_value))
552 return (1);
553 /* expired, exactly at end of interval */
554expire:
555 if (timevalisset(&itp->it_interval)) {
556 itp->it_value = itp->it_interval;
557 itp->it_value.tv_usec -= usec;
558 if (itp->it_value.tv_usec < 0) {
559 itp->it_value.tv_usec += 1000000;
560 itp->it_value.tv_sec--;
561 }
562 } else
563 itp->it_value.tv_usec = 0; /* sec is already 0 */
564 return (0);
565}
566
567/*
568 * Add and subtract routines for timevals.
569 * N.B.: subtract routine doesn't deal with
570 * results which are before the beginning,
571 * it just gets very confused in this case.
572 * Caveat emptor.
573 */
574void
575timevaladd(t1, t2)
576 struct timeval *t1, *t2;
577{
578
579 t1->tv_sec += t2->tv_sec;
580 t1->tv_usec += t2->tv_usec;
581 timevalfix(t1);
582}
583
584void
585timevalsub(t1, t2)
586 struct timeval *t1, *t2;
587{
588
589 t1->tv_sec -= t2->tv_sec;
590 t1->tv_usec -= t2->tv_usec;
591 timevalfix(t1);
592}
593
594static void
595timevalfix(t1)
596 struct timeval *t1;
597{
598
599 if (t1->tv_usec < 0) {
600 t1->tv_sec--;
601 t1->tv_usec += 1000000;
602 }
603 if (t1->tv_usec >= 1000000) {
604 t1->tv_sec++;
605 t1->tv_usec -= 1000000;
606 }
607}