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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)kern_time.c 8.1 (Berkeley) 6/10/93
30 * $FreeBSD: src/sys/kern/kern_time.c,v 1.68.2.1 2002/10/01 08:00:41 bde Exp $
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/buf.h>
36 #include <sys/sysmsg.h>
37 #include <sys/resourcevar.h>
38 #include <sys/signalvar.h>
39 #include <sys/kernel.h>
40 #include <sys/sysent.h>
41 #include <sys/proc.h>
42 #include <sys/caps.h>
43 #include <sys/time.h>
44 #include <sys/vnode.h>
45 #include <sys/sysctl.h>
46 #include <sys/kern_syscall.h>
47 #include <sys/upmap.h>
48 #include <vm/vm.h>
49 #include <vm/vm_extern.h>
50
51 #include <sys/msgport2.h>
52 #include <sys/spinlock2.h>
53 #include <sys/thread2.h>
54
55 extern struct spinlock ntp_spin;
56
57 #define CPUCLOCK_BIT 0x80000000
58 #define CPUCLOCK_ID_MASK ~CPUCLOCK_BIT
59 #define CPUCLOCK2LWPID(clock_id) (((clockid_t)(clock_id) >> 32) & CPUCLOCK_ID_MASK)
60 #define CPUCLOCK2PID(clock_id) ((clock_id) & CPUCLOCK_ID_MASK)
61 #define MAKE_CPUCLOCK(pid, lwp_id) ((clockid_t)(lwp_id) << 32 | (pid) | CPUCLOCK_BIT)
62
63 struct timezone tz;
64
65 /*
66 * Time of day and interval timer support.
67 *
68 * These routines provide the kernel entry points to get and set
69 * the time-of-day and per-process interval timers. Subroutines
70 * here provide support for adding and subtracting timeval structures
71 * and decrementing interval timers, optionally reloading the interval
72 * timers when they expire.
73 */
74
75 static int settime(struct timeval *);
76 static void timevalfix(struct timeval *);
77 static void realitexpire(void *arg);
78
79 static int sysctl_gettimeofday_quick(SYSCTL_HANDLER_ARGS);
80
81
82 /*
83 * Nanosleep tries very hard to sleep for a precisely requested time
84 * interval, down to 1uS. The administrator can impose a minimum delay
85 * and a delay below which we hard-loop instead of initiate a timer
86 * interrupt and sleep.
87 *
88 * For machines under high loads it might be beneficial to increase min_us
89 * to e.g. 1000uS (1ms) so spining processes sleep meaningfully.
90 */
91 static int nanosleep_min_us = 10;
92 static int nanosleep_hard_us = 100;
93 static int gettimeofday_quick = 0;
94 SYSCTL_INT(_kern, OID_AUTO, nanosleep_min_us, CTLFLAG_RW,
95 &nanosleep_min_us, 0, "");
96 SYSCTL_INT(_kern, OID_AUTO, nanosleep_hard_us, CTLFLAG_RW,
97 &nanosleep_hard_us, 0, "");
98 SYSCTL_PROC(_kern, OID_AUTO, gettimeofday_quick, CTLTYPE_INT | CTLFLAG_RW,
99 0, 0, sysctl_gettimeofday_quick, "I", "Quick mode gettimeofday");
100
101 static struct lock masterclock_lock = LOCK_INITIALIZER("mstrclk", 0, 0);
102
103 static int
settime(struct timeval * tv)104 settime(struct timeval *tv)
105 {
106 struct timeval delta, tv1, tv2;
107 static struct timeval maxtime, laststep;
108 struct timespec ts;
109 int origcpu;
110
111 if ((origcpu = mycpu->gd_cpuid) != 0)
112 lwkt_setcpu_self(globaldata_find(0));
113
114 crit_enter();
115 microtime(&tv1);
116 delta = *tv;
117 timevalsub(&delta, &tv1);
118
119 /*
120 * If the system is secure, we do not allow the time to be
121 * set to a value earlier than 1 second less than the highest
122 * time we have yet seen. The worst a miscreant can do in
123 * this circumstance is "freeze" time. He couldn't go
124 * back to the past.
125 *
126 * We similarly do not allow the clock to be stepped more
127 * than one second, nor more than once per second. This allows
128 * a miscreant to make the clock march double-time, but no worse.
129 */
130 if (securelevel > 1) {
131 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
132 /*
133 * Update maxtime to latest time we've seen.
134 */
135 if (tv1.tv_sec > maxtime.tv_sec)
136 maxtime = tv1;
137 tv2 = *tv;
138 timevalsub(&tv2, &maxtime);
139 if (tv2.tv_sec < -1) {
140 tv->tv_sec = maxtime.tv_sec - 1;
141 kprintf("Time adjustment clamped to -1 second\n");
142 }
143 } else {
144 if (tv1.tv_sec == laststep.tv_sec) {
145 crit_exit();
146 return (EPERM);
147 }
148 if (delta.tv_sec > 1) {
149 tv->tv_sec = tv1.tv_sec + 1;
150 kprintf("Time adjustment clamped to +1 second\n");
151 }
152 laststep = *tv;
153 }
154 }
155
156 ts.tv_sec = tv->tv_sec;
157 ts.tv_nsec = tv->tv_usec * 1000;
158 set_timeofday(&ts);
159 crit_exit();
160
161 if (origcpu != 0)
162 lwkt_setcpu_self(globaldata_find(origcpu));
163
164 resettodr();
165 return (0);
166 }
167
168 static void
get_process_cputime(struct proc * p,struct timespec * ats)169 get_process_cputime(struct proc *p, struct timespec *ats)
170 {
171 struct rusage ru;
172
173 lwkt_gettoken(&p->p_token);
174 calcru_proc(p, &ru);
175 lwkt_reltoken(&p->p_token);
176 timevaladd(&ru.ru_utime, &ru.ru_stime);
177 TIMEVAL_TO_TIMESPEC(&ru.ru_utime, ats);
178 }
179
180 static void
get_process_usertime(struct proc * p,struct timespec * ats)181 get_process_usertime(struct proc *p, struct timespec *ats)
182 {
183 struct rusage ru;
184
185 lwkt_gettoken(&p->p_token);
186 calcru_proc(p, &ru);
187 lwkt_reltoken(&p->p_token);
188 TIMEVAL_TO_TIMESPEC(&ru.ru_utime, ats);
189 }
190
191 static void
get_thread_cputime(struct thread * td,struct timespec * ats)192 get_thread_cputime(struct thread *td, struct timespec *ats)
193 {
194 struct timeval sys, user;
195
196 calcru(td->td_lwp, &user, &sys);
197 timevaladd(&user, &sys);
198 TIMEVAL_TO_TIMESPEC(&user, ats);
199 }
200
201 /*
202 * MPSAFE
203 */
204 int
kern_clock_gettime(clockid_t clock_id,struct timespec * ats)205 kern_clock_gettime(clockid_t clock_id, struct timespec *ats)
206 {
207 struct proc *p;
208 struct lwp *lp;
209 lwpid_t lwp_id;
210
211 p = curproc;
212 switch(clock_id) {
213 case CLOCK_REALTIME:
214 case CLOCK_REALTIME_PRECISE:
215 nanotime(ats);
216 break;
217 case CLOCK_REALTIME_FAST:
218 getnanotime(ats);
219 break;
220 case CLOCK_MONOTONIC:
221 case CLOCK_MONOTONIC_PRECISE:
222 case CLOCK_UPTIME:
223 case CLOCK_UPTIME_PRECISE:
224 nanouptime(ats);
225 break;
226 case CLOCK_MONOTONIC_FAST:
227 case CLOCK_UPTIME_FAST:
228 getnanouptime(ats);
229 break;
230 case CLOCK_VIRTUAL:
231 get_process_usertime(p, ats);
232 break;
233 case CLOCK_PROF:
234 case CLOCK_PROCESS_CPUTIME_ID:
235 get_process_cputime(p, ats);
236 break;
237 case CLOCK_SECOND:
238 ats->tv_sec = time_second;
239 ats->tv_nsec = 0;
240 break;
241 case CLOCK_THREAD_CPUTIME_ID:
242 get_thread_cputime(curthread, ats);
243 break;
244 default:
245 if ((clock_id & CPUCLOCK_BIT) == 0)
246 return (EINVAL);
247 if ((p = pfind(CPUCLOCK2PID(clock_id))) == NULL)
248 return (EINVAL);
249 lwp_id = CPUCLOCK2LWPID(clock_id);
250 if (lwp_id == 0) {
251 get_process_cputime(p, ats);
252 } else {
253 lwkt_gettoken(&p->p_token);
254 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, lwp_id);
255 if (lp == NULL) {
256 lwkt_reltoken(&p->p_token);
257 PRELE(p);
258 return (EINVAL);
259 }
260 get_thread_cputime(lp->lwp_thread, ats);
261 lwkt_reltoken(&p->p_token);
262 }
263 PRELE(p);
264 }
265 return (0);
266 }
267
268 /*
269 * MPSAFE
270 */
271 int
sys_clock_gettime(struct sysmsg * sysmsg,const struct clock_gettime_args * uap)272 sys_clock_gettime(struct sysmsg *sysmsg, const struct clock_gettime_args *uap)
273 {
274 struct timespec ats;
275 int error;
276
277 error = kern_clock_gettime(uap->clock_id, &ats);
278 if (error == 0)
279 error = copyout(&ats, uap->tp, sizeof(ats));
280
281 return (error);
282 }
283
284 int
kern_clock_settime(clockid_t clock_id,struct timespec * ats)285 kern_clock_settime(clockid_t clock_id, struct timespec *ats)
286 {
287 struct timeval atv;
288 int error;
289
290 if ((error = caps_priv_check_self(SYSCAP_NOSETTIME)) != 0)
291 return (error);
292 if (clock_id != CLOCK_REALTIME)
293 return (EINVAL);
294 if (ats->tv_sec < 0 || ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000)
295 return (EINVAL);
296
297 lockmgr(&masterclock_lock, LK_EXCLUSIVE);
298 TIMESPEC_TO_TIMEVAL(&atv, ats);
299 error = settime(&atv);
300 lockmgr(&masterclock_lock, LK_RELEASE);
301
302 return (error);
303 }
304
305 /*
306 * MPALMOSTSAFE
307 */
308 int
sys_clock_settime(struct sysmsg * sysmsg,const struct clock_settime_args * uap)309 sys_clock_settime(struct sysmsg *sysmsg, const struct clock_settime_args *uap)
310 {
311 struct timespec ats;
312 int error;
313
314 if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
315 return (error);
316
317 error = kern_clock_settime(uap->clock_id, &ats);
318
319 return (error);
320 }
321
322 /*
323 * MPSAFE
324 */
325 int
kern_clock_getres(clockid_t clock_id,struct timespec * ts)326 kern_clock_getres(clockid_t clock_id, struct timespec *ts)
327 {
328 ts->tv_sec = 0;
329
330 switch (clock_id) {
331 case CLOCK_REALTIME:
332 case CLOCK_REALTIME_FAST:
333 case CLOCK_REALTIME_PRECISE:
334 case CLOCK_MONOTONIC:
335 case CLOCK_MONOTONIC_FAST:
336 case CLOCK_MONOTONIC_PRECISE:
337 case CLOCK_UPTIME:
338 case CLOCK_UPTIME_FAST:
339 case CLOCK_UPTIME_PRECISE:
340 /*
341 * Minimum reportable resolution is 1ns. Rounding is
342 * otherwise unimportant.
343 */
344 ts->tv_nsec = 999999999 / sys_cputimer->freq + 1;
345 break;
346 case CLOCK_VIRTUAL:
347 case CLOCK_PROF:
348 /* Accurately round up here because we can do so cheaply. */
349 ts->tv_nsec = howmany(1000000000, hz);
350 break;
351 case CLOCK_SECOND:
352 ts->tv_sec = 1;
353 ts->tv_nsec = 0;
354 break;
355 case CLOCK_THREAD_CPUTIME_ID:
356 case CLOCK_PROCESS_CPUTIME_ID:
357 ts->tv_nsec = 1000;
358 break;
359 default:
360 if ((clock_id & CPUCLOCK_BIT) == CPUCLOCK_BIT) {
361 pid_t pid = CPUCLOCK2PID(clock_id);
362 if (pid < 2 || pid > PID_MAX)
363 return (EINVAL);
364 ts->tv_nsec = 1000;
365 } else {
366 return (EINVAL);
367 }
368 }
369
370 return (0);
371 }
372
373 /*
374 * MPSAFE
375 */
376 int
sys_clock_getres(struct sysmsg * sysmsg,const struct clock_getres_args * uap)377 sys_clock_getres(struct sysmsg *sysmsg, const struct clock_getres_args *uap)
378 {
379 int error;
380 struct timespec ts;
381
382 error = kern_clock_getres(uap->clock_id, &ts);
383 if (error == 0)
384 error = copyout(&ts, uap->tp, sizeof(ts));
385
386 return (error);
387 }
388
389 static int
kern_getcpuclockid(pid_t pid,lwpid_t lwp_id,clockid_t * clock_id)390 kern_getcpuclockid(pid_t pid, lwpid_t lwp_id, clockid_t *clock_id)
391 {
392 struct proc *p;
393 int error = 0;
394
395 if (pid == 0) {
396 p = curproc;
397 pid = p->p_pid;
398 PHOLD(p);
399 } else {
400 p = pfind(pid);
401 if (p == NULL)
402 return (ESRCH);
403 }
404 /* lwp_id can be 0 when called by clock_getcpuclockid() */
405 if (lwp_id < 0) {
406 error = EINVAL;
407 goto out;
408 }
409 lwkt_gettoken(&p->p_token);
410 if (lwp_id > 0 &&
411 lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, lwp_id) == NULL) {
412 lwkt_reltoken(&p->p_token);
413 error = ESRCH;
414 goto out;
415 }
416 *clock_id = MAKE_CPUCLOCK(pid, lwp_id);
417 lwkt_reltoken(&p->p_token);
418 out:
419 PRELE(p);
420 return (error);
421 }
422
423 int
sys_getcpuclockid(struct sysmsg * sysmsg,const struct getcpuclockid_args * uap)424 sys_getcpuclockid(struct sysmsg *sysmsg, const struct getcpuclockid_args *uap)
425 {
426 clockid_t clk_id;
427 int error;
428
429 error = kern_getcpuclockid(uap->pid, uap->lwp_id, &clk_id);
430 if (error == 0)
431 error = copyout(&clk_id, uap->clock_id, sizeof(clockid_t));
432
433 return (error);
434 }
435
436 /*
437 * clock_nanosleep1()
438 *
439 * This is a general helper function for clock_nanosleep() and
440 * nanosleep() (aka sleep(), aka usleep()).
441 *
442 * If there is less than one tick's worth of time left and
443 * we haven't done a yield, or the remaining microseconds is
444 * ridiculously low, do a yield. This avoids having
445 * to deal with systimer overheads when the system is under
446 * heavy loads. If we have done a yield already then use
447 * a systimer and an uninterruptable thread wait.
448 *
449 * If there is more than a tick's worth of time left,
450 * calculate the baseline ticks and use an interruptable
451 * tsleep, then handle the fine-grained delay on the next
452 * loop. This usually results in two sleeps occuring, a long one
453 * and a short one.
454 *
455 * MPSAFE
456 */
457 static void
ns1_systimer(systimer_t info,int in_ipi __unused,struct intrframe * frame __unused)458 ns1_systimer(systimer_t info, int in_ipi __unused,
459 struct intrframe *frame __unused)
460 {
461 lwkt_schedule(info->data);
462 }
463
464 int
clock_nanosleep1(clockid_t clock_id,int flags,struct timespec * rqt,struct timespec * rmt)465 clock_nanosleep1(clockid_t clock_id, int flags,
466 struct timespec *rqt, struct timespec *rmt)
467 {
468 static int nanowait;
469 struct timespec ts_cur, ts_tgt, ts_int;
470 struct timeval tv;
471 bool is_abs;
472 int error, error2;
473
474 if ((flags & ~(TIMER_RELTIME | TIMER_ABSTIME)) != 0)
475 return (EINVAL);
476 if (rqt->tv_sec < 0 || rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
477 return (EINVAL);
478 if (rqt->tv_sec == 0 && rqt->tv_nsec == 0)
479 return (0);
480
481 switch (clock_id) {
482 case CLOCK_REALTIME:
483 case CLOCK_REALTIME_FAST:
484 case CLOCK_REALTIME_PRECISE:
485 case CLOCK_SECOND:
486 case CLOCK_MONOTONIC:
487 case CLOCK_MONOTONIC_FAST:
488 case CLOCK_MONOTONIC_PRECISE:
489 case CLOCK_UPTIME:
490 case CLOCK_UPTIME_FAST:
491 case CLOCK_UPTIME_PRECISE:
492 is_abs = (flags & TIMER_ABSTIME) != 0;
493 break;
494 case CLOCK_VIRTUAL:
495 case CLOCK_PROF:
496 case CLOCK_PROCESS_CPUTIME_ID:
497 return (ENOTSUP);
498 case CLOCK_THREAD_CPUTIME_ID:
499 default:
500 return (EINVAL);
501 }
502
503 error = kern_clock_gettime(clock_id, &ts_cur);
504 if (error)
505 return (error);
506
507 if (is_abs) {
508 if (timespeccmp(&ts_cur, rqt, >=))
509 return (0);
510
511 ts_tgt = *rqt; /* target timestamp */
512 timespecsub(&ts_tgt, &ts_cur, &ts_int); /* sleep interval */
513 } else {
514 ts_int = *rqt; /* sleep interval */
515 timespecadd(&ts_cur, &ts_int, &ts_tgt); /* target timestamp */
516 }
517
518 for (;;) {
519 int ticks;
520 struct systimer info;
521 thread_t td;
522
523 timespecsub(&ts_tgt, &ts_cur, &ts_int);
524 TIMESPEC_TO_TIMEVAL(&tv, &ts_int);
525 ticks = tv.tv_usec / ustick; /* approximate */
526
527 if (tv.tv_sec == 0 && ticks == 0) {
528 td = curthread;
529 if (tv.tv_usec > 0 && tv.tv_usec < nanosleep_min_us)
530 tv.tv_usec = nanosleep_min_us;
531 if (tv.tv_usec < nanosleep_hard_us) {
532 lwkt_user_yield();
533 cpu_pause();
534 } else {
535 crit_enter_quick(td);
536 systimer_init_oneshot(&info, ns1_systimer,
537 td, tv.tv_usec);
538 lwkt_deschedule_self(td);
539 crit_exit_quick(td);
540 lwkt_switch();
541 systimer_del(&info); /* make sure it's gone */
542 }
543 error = iscaught(td->td_lwp);
544 } else if (tv.tv_sec == 0) {
545 error = tsleep(&nanowait, PCATCH, "nanslp", ticks);
546 } else {
547 ticks = tvtohz_low(&tv); /* also handles overflow */
548 error = tsleep(&nanowait, PCATCH, "nanslp", ticks);
549 }
550
551 error2 = kern_clock_gettime(clock_id, &ts_cur);
552 if (error2)
553 return (error2);
554
555 if (error && error != EWOULDBLOCK) {
556 if (error == ERESTART)
557 error = EINTR;
558 if (rmt != NULL && !is_abs) {
559 timespecsub(&ts_tgt, &ts_cur, &ts_int);
560 if (ts_int.tv_sec < 0)
561 timespecclear(&ts_int);
562 *rmt = ts_int;
563 }
564 return (error);
565 }
566 if (timespeccmp(&ts_cur, &ts_tgt, >=))
567 return (0);
568 }
569 }
570
571 int
nanosleep1(struct timespec * rqt,struct timespec * rmt)572 nanosleep1(struct timespec *rqt, struct timespec *rmt)
573 {
574 return clock_nanosleep1(CLOCK_REALTIME, TIMER_RELTIME, rqt, rmt);
575 }
576
577 /*
578 * MPSAFE
579 */
580 int
sys_clock_nanosleep(struct sysmsg * sysmsg,const struct clock_nanosleep_args * uap)581 sys_clock_nanosleep(struct sysmsg *sysmsg,
582 const struct clock_nanosleep_args *uap)
583 {
584 int error;
585 bool is_abs;
586 struct timespec rqt;
587 struct timespec rmt;
588
589 is_abs = (uap->flags & TIMER_ABSTIME) != 0;
590
591 error = copyin(uap->rqtp, &rqt, sizeof(rqt));
592 if (error) {
593 sysmsg->sysmsg_result = error;
594 return (0);
595 }
596
597 bzero(&rmt, sizeof(rmt));
598 error = clock_nanosleep1(uap->clock_id, uap->flags, &rqt, &rmt);
599
600 /*
601 * copyout the residual if nanosleep was interrupted.
602 */
603 if (error == EINTR && uap->rmtp != NULL && !is_abs) {
604 int error2;
605
606 error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
607 if (error2)
608 error = error2;
609 }
610
611 sysmsg->sysmsg_result = error;
612 return (0);
613 }
614
615 /*
616 * MPSAFE
617 */
618 int
sys_nanosleep(struct sysmsg * sysmsg,const struct nanosleep_args * uap)619 sys_nanosleep(struct sysmsg *sysmsg, const struct nanosleep_args *uap)
620 {
621 int error;
622 struct timespec rqt;
623 struct timespec rmt;
624
625 error = copyin(uap->rqtp, &rqt, sizeof(rqt));
626 if (error)
627 return (error);
628
629 bzero(&rmt, sizeof(rmt));
630 error = nanosleep1(&rqt, &rmt);
631
632 /*
633 * copyout the residual if nanosleep was interrupted.
634 */
635 if (error == EINTR && uap->rmtp != NULL) {
636 int error2;
637
638 error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
639 if (error2)
640 error = error2;
641 }
642 return (error);
643 }
644
645 /*
646 * The gettimeofday() system call is supposed to return a fine-grained
647 * realtime stamp. However, acquiring a fine-grained stamp can create a
648 * bottleneck when multiple cpu cores are trying to accessing e.g. the
649 * HPET hardware timer all at the same time, so we have a sysctl that
650 * allows its behavior to be changed to a more coarse-grained timestamp
651 * which does not have to access a hardware timer.
652 */
653 int
sys_gettimeofday(struct sysmsg * sysmsg,const struct gettimeofday_args * uap)654 sys_gettimeofday(struct sysmsg *sysmsg, const struct gettimeofday_args *uap)
655 {
656 struct timeval atv;
657 int error = 0;
658
659 if (uap->tp) {
660 if (gettimeofday_quick)
661 getmicrotime(&atv);
662 else
663 microtime(&atv);
664 if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp,
665 sizeof (atv))))
666 return (error);
667 }
668 if (uap->tzp)
669 error = copyout((caddr_t)&tz, (caddr_t)uap->tzp,
670 sizeof (tz));
671 return (error);
672 }
673
674 /*
675 * MPALMOSTSAFE
676 */
677 int
sys_settimeofday(struct sysmsg * sysmsg,const struct settimeofday_args * uap)678 sys_settimeofday(struct sysmsg *sysmsg, const struct settimeofday_args *uap)
679 {
680 struct timeval atv;
681 struct timezone atz;
682 int error;
683
684 if ((error = caps_priv_check_self(SYSCAP_NOSETTIME)))
685 return (error);
686 /*
687 * Verify all parameters before changing time.
688 *
689 * XXX: We do not allow the time to be set to 0.0, which also by
690 * happy coincidence works around a pkgsrc bulk build bug.
691 */
692 if (uap->tv) {
693 if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
694 sizeof(atv))))
695 return (error);
696 if (atv.tv_usec < 0 || atv.tv_usec >= 1000000)
697 return (EINVAL);
698 if (atv.tv_sec == 0 && atv.tv_usec == 0)
699 return (EINVAL);
700 }
701 if (uap->tzp &&
702 (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz))))
703 return (error);
704
705 lockmgr(&masterclock_lock, LK_EXCLUSIVE);
706 if (uap->tv && (error = settime(&atv))) {
707 lockmgr(&masterclock_lock, LK_RELEASE);
708 return (error);
709 }
710 lockmgr(&masterclock_lock, LK_RELEASE);
711
712 if (uap->tzp)
713 tz = atz;
714 return (0);
715 }
716
717 /*
718 * WARNING! Run with ntp_spin held
719 */
720 static void
kern_adjtime_common(void)721 kern_adjtime_common(void)
722 {
723 if ((ntp_delta >= 0 && ntp_delta < ntp_default_tick_delta) ||
724 (ntp_delta < 0 && ntp_delta > -ntp_default_tick_delta))
725 ntp_tick_delta = ntp_delta;
726 else if (ntp_delta > ntp_big_delta)
727 ntp_tick_delta = 10 * ntp_default_tick_delta;
728 else if (ntp_delta < -ntp_big_delta)
729 ntp_tick_delta = -10 * ntp_default_tick_delta;
730 else if (ntp_delta > 0)
731 ntp_tick_delta = ntp_default_tick_delta;
732 else
733 ntp_tick_delta = -ntp_default_tick_delta;
734 }
735
736 void
kern_adjtime(int64_t delta,int64_t * odelta)737 kern_adjtime(int64_t delta, int64_t *odelta)
738 {
739 spin_lock(&ntp_spin);
740 *odelta = ntp_delta;
741 ntp_delta = delta;
742 kern_adjtime_common();
743 spin_unlock(&ntp_spin);
744 }
745
746 static void
kern_get_ntp_delta(int64_t * delta)747 kern_get_ntp_delta(int64_t *delta)
748 {
749 *delta = ntp_delta;
750 }
751
752 void
kern_reladjtime(int64_t delta)753 kern_reladjtime(int64_t delta)
754 {
755 spin_lock(&ntp_spin);
756 ntp_delta += delta;
757 kern_adjtime_common();
758 spin_unlock(&ntp_spin);
759 }
760
761 static void
kern_adjfreq(int64_t rate)762 kern_adjfreq(int64_t rate)
763 {
764 spin_lock(&ntp_spin);
765 ntp_tick_permanent = rate;
766 spin_unlock(&ntp_spin);
767 }
768
769 /*
770 * MPALMOSTSAFE
771 */
772 int
sys_adjtime(struct sysmsg * sysmsg,const struct adjtime_args * uap)773 sys_adjtime(struct sysmsg *sysmsg, const struct adjtime_args *uap)
774 {
775 struct timeval atv;
776 int64_t ndelta, odelta;
777 int error;
778
779 if ((error = caps_priv_check_self(SYSCAP_NOSETTIME)))
780 return (error);
781 error = copyin(uap->delta, &atv, sizeof(struct timeval));
782 if (error)
783 return (error);
784
785 /*
786 * Compute the total correction and the rate at which to apply it.
787 * Round the adjustment down to a whole multiple of the per-tick
788 * delta, so that after some number of incremental changes in
789 * hardclock(), tickdelta will become zero, lest the correction
790 * overshoot and start taking us away from the desired final time.
791 */
792 ndelta = (int64_t)atv.tv_sec * 1000000000 + atv.tv_usec * 1000;
793 kern_adjtime(ndelta, &odelta);
794
795 if (uap->olddelta) {
796 atv.tv_sec = odelta / 1000000000;
797 atv.tv_usec = odelta % 1000000000 / 1000;
798 copyout(&atv, uap->olddelta, sizeof(struct timeval));
799 }
800 return (0);
801 }
802
803 static int
sysctl_adjtime(SYSCTL_HANDLER_ARGS)804 sysctl_adjtime(SYSCTL_HANDLER_ARGS)
805 {
806 int64_t delta;
807 int error;
808
809 if (req->newptr != NULL) {
810 if (caps_priv_check_self(SYSCAP_RESTRICTEDROOT))
811 return (EPERM);
812 error = SYSCTL_IN(req, &delta, sizeof(delta));
813 if (error)
814 return (error);
815 kern_reladjtime(delta);
816 }
817
818 if (req->oldptr)
819 kern_get_ntp_delta(&delta);
820 error = SYSCTL_OUT(req, &delta, sizeof(delta));
821 return (error);
822 }
823
824 /*
825 * delta is in nanoseconds.
826 */
827 static int
sysctl_delta(SYSCTL_HANDLER_ARGS)828 sysctl_delta(SYSCTL_HANDLER_ARGS)
829 {
830 int64_t delta, old_delta;
831 int error;
832
833 if (req->newptr != NULL) {
834 if (caps_priv_check_self(SYSCAP_RESTRICTEDROOT))
835 return (EPERM);
836 error = SYSCTL_IN(req, &delta, sizeof(delta));
837 if (error)
838 return (error);
839 kern_adjtime(delta, &old_delta);
840 }
841
842 if (req->oldptr != NULL)
843 kern_get_ntp_delta(&old_delta);
844 error = SYSCTL_OUT(req, &old_delta, sizeof(old_delta));
845 return (error);
846 }
847
848 /*
849 * frequency is in nanoseconds per second shifted left 32.
850 * kern_adjfreq() needs it in nanoseconds per tick shifted left 32.
851 */
852 static int
sysctl_adjfreq(SYSCTL_HANDLER_ARGS)853 sysctl_adjfreq(SYSCTL_HANDLER_ARGS)
854 {
855 int64_t freqdelta;
856 int error;
857
858 if (req->newptr != NULL) {
859 if (caps_priv_check_self(SYSCAP_RESTRICTEDROOT))
860 return (EPERM);
861 error = SYSCTL_IN(req, &freqdelta, sizeof(freqdelta));
862 if (error)
863 return (error);
864
865 freqdelta /= hz;
866 kern_adjfreq(freqdelta);
867 }
868
869 if (req->oldptr != NULL)
870 freqdelta = ntp_tick_permanent * hz;
871 error = SYSCTL_OUT(req, &freqdelta, sizeof(freqdelta));
872 if (error)
873 return (error);
874
875 return (0);
876 }
877
878 SYSCTL_NODE(_kern, OID_AUTO, ntp, CTLFLAG_RW, 0, "NTP related controls");
879 SYSCTL_PROC(_kern_ntp, OID_AUTO, permanent,
880 CTLTYPE_QUAD|CTLFLAG_RW, 0, 0,
881 sysctl_adjfreq, "Q", "permanent correction per second");
882 SYSCTL_PROC(_kern_ntp, OID_AUTO, delta,
883 CTLTYPE_QUAD|CTLFLAG_RW, 0, 0,
884 sysctl_delta, "Q", "one-time delta");
885 SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, big_delta, CTLFLAG_RD,
886 &ntp_big_delta, sizeof(ntp_big_delta), "Q",
887 "threshold for fast adjustment");
888 SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, tick_delta, CTLFLAG_RD,
889 &ntp_tick_delta, sizeof(ntp_tick_delta), "LU",
890 "per-tick adjustment");
891 SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, default_tick_delta, CTLFLAG_RD,
892 &ntp_default_tick_delta, sizeof(ntp_default_tick_delta), "LU",
893 "default per-tick adjustment");
894 SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, next_leap_second, CTLFLAG_RW,
895 &ntp_leap_second, sizeof(ntp_leap_second), "LU",
896 "next leap second");
897 SYSCTL_INT(_kern_ntp, OID_AUTO, insert_leap_second, CTLFLAG_RW,
898 &ntp_leap_insert, 0, "insert or remove leap second");
899 SYSCTL_PROC(_kern_ntp, OID_AUTO, adjust,
900 CTLTYPE_QUAD|CTLFLAG_RW, 0, 0,
901 sysctl_adjtime, "Q", "relative adjust for delta");
902
903 /*
904 * Get value of an interval timer. The process virtual and
905 * profiling virtual time timers are kept in the p_stats area, since
906 * they can be swapped out. These are kept internally in the
907 * way they are specified externally: in time until they expire.
908 *
909 * The real time interval timer is kept in the process table slot
910 * for the process, and its value (it_value) is kept as an
911 * absolute time rather than as a delta, so that it is easy to keep
912 * periodic real-time signals from drifting.
913 *
914 * Virtual time timers are processed in the hardclock() routine of
915 * kern_clock.c. The real time timer is processed by a timeout
916 * routine, called from the softclock() routine. Since a callout
917 * may be delayed in real time due to interrupt processing in the system,
918 * it is possible for the real time timeout routine (realitexpire, given below),
919 * to be delayed in real time past when it is supposed to occur. It
920 * does not suffice, therefore, to reload the real timer .it_value from the
921 * real time timers .it_interval. Rather, we compute the next time in
922 * absolute time the timer should go off.
923 *
924 * MPALMOSTSAFE
925 */
926 int
sys_getitimer(struct sysmsg * sysmsg,const struct getitimer_args * uap)927 sys_getitimer(struct sysmsg *sysmsg, const struct getitimer_args *uap)
928 {
929 struct proc *p = curproc;
930 struct timeval ctv;
931 struct itimerval aitv;
932
933 if (uap->which > ITIMER_PROF)
934 return (EINVAL);
935 lwkt_gettoken(&p->p_token);
936 if (uap->which == ITIMER_REAL) {
937 /*
938 * Convert from absolute to relative time in .it_value
939 * part of real time timer. If time for real time timer
940 * has passed return 0, else return difference between
941 * current time and time for the timer to go off.
942 */
943 aitv = p->p_realtimer;
944 if (timevalisset(&aitv.it_value)) {
945 getmicrouptime(&ctv);
946 if (timevalcmp(&aitv.it_value, &ctv, <))
947 timevalclear(&aitv.it_value);
948 else
949 timevalsub(&aitv.it_value, &ctv);
950 }
951 } else {
952 aitv = p->p_timer[uap->which];
953 }
954 lwkt_reltoken(&p->p_token);
955 return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
956 }
957
958 /*
959 * MPALMOSTSAFE
960 */
961 int
sys_setitimer(struct sysmsg * sysmsg,const struct setitimer_args * uap)962 sys_setitimer(struct sysmsg *sysmsg, const struct setitimer_args *uap)
963 {
964 struct itimerval aitv;
965 struct timeval ctv;
966 struct itimerval *itvp;
967 struct proc *p = curproc;
968 struct getitimer_args gitargs;
969 int error;
970
971 if (uap->which > ITIMER_PROF)
972 return (EINVAL);
973 itvp = uap->itv;
974 if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv,
975 sizeof(struct itimerval))))
976 return (error);
977
978 if (uap->oitv) {
979 gitargs.which = uap->which;
980 gitargs.itv = uap->oitv;
981 error = sys_getitimer(sysmsg, &gitargs);
982 if (error)
983 return error;
984 }
985 if (itvp == NULL)
986 return (0);
987 if (itimerfix(&aitv.it_value))
988 return (EINVAL);
989 if (!timevalisset(&aitv.it_value))
990 timevalclear(&aitv.it_interval);
991 else if (itimerfix(&aitv.it_interval))
992 return (EINVAL);
993 lwkt_gettoken(&p->p_token);
994 if (uap->which == ITIMER_REAL) {
995 if (timevalisset(&p->p_realtimer.it_value))
996 callout_cancel(&p->p_ithandle);
997 if (timevalisset(&aitv.it_value))
998 callout_reset(&p->p_ithandle,
999 tvtohz_high(&aitv.it_value), realitexpire, p);
1000 getmicrouptime(&ctv);
1001 timevaladd(&aitv.it_value, &ctv);
1002 p->p_realtimer = aitv;
1003 } else {
1004 p->p_timer[uap->which] = aitv;
1005 switch(uap->which) {
1006 case ITIMER_VIRTUAL:
1007 p->p_flags &= ~P_SIGVTALRM;
1008 break;
1009 case ITIMER_PROF:
1010 p->p_flags &= ~P_SIGPROF;
1011 break;
1012 }
1013 }
1014 lwkt_reltoken(&p->p_token);
1015 return (0);
1016 }
1017
1018 /*
1019 * Real interval timer expired:
1020 * send process whose timer expired an alarm signal.
1021 * If time is not set up to reload, then just return.
1022 * Else compute next time timer should go off which is > current time.
1023 * This is where delay in processing this timeout causes multiple
1024 * SIGALRM calls to be compressed into one.
1025 * tvtohz_high() always adds 1 to allow for the time until the next clock
1026 * interrupt being strictly less than 1 clock tick, but we don't want
1027 * that here since we want to appear to be in sync with the clock
1028 * interrupt even when we're delayed.
1029 */
1030 static
1031 void
realitexpire(void * arg)1032 realitexpire(void *arg)
1033 {
1034 struct proc *p;
1035 struct timeval ctv, ntv;
1036
1037 p = (struct proc *)arg;
1038 PHOLD(p);
1039 lwkt_gettoken(&p->p_token);
1040 ksignal(p, SIGALRM);
1041 if (!timevalisset(&p->p_realtimer.it_interval)) {
1042 timevalclear(&p->p_realtimer.it_value);
1043 goto done;
1044 }
1045 for (;;) {
1046 timevaladd(&p->p_realtimer.it_value,
1047 &p->p_realtimer.it_interval);
1048 getmicrouptime(&ctv);
1049 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
1050 ntv = p->p_realtimer.it_value;
1051 timevalsub(&ntv, &ctv);
1052 callout_reset(&p->p_ithandle, tvtohz_low(&ntv),
1053 realitexpire, p);
1054 goto done;
1055 }
1056 }
1057 done:
1058 lwkt_reltoken(&p->p_token);
1059 PRELE(p);
1060 }
1061
1062 /*
1063 * Used to validate itimer timeouts and utimes*() timespecs.
1064 */
1065 int
itimerfix(struct timeval * tv)1066 itimerfix(struct timeval *tv)
1067 {
1068 if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
1069 return (EINVAL);
1070 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < ustick)
1071 tv->tv_usec = ustick;
1072 return (0);
1073 }
1074
1075 /*
1076 * Used to validate timeouts and utimes*() timespecs.
1077 */
1078 int
itimespecfix(struct timespec * ts)1079 itimespecfix(struct timespec *ts)
1080 {
1081 if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000ULL)
1082 return (EINVAL);
1083 if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < nstick)
1084 ts->tv_nsec = nstick;
1085 return (0);
1086 }
1087
1088 /*
1089 * Decrement an interval timer by a specified number
1090 * of microseconds, which must be less than a second,
1091 * i.e. < 1000000. If the timer expires, then reload
1092 * it. In this case, carry over (usec - old value) to
1093 * reduce the value reloaded into the timer so that
1094 * the timer does not drift. This routine assumes
1095 * that it is called in a context where the timers
1096 * on which it is operating cannot change in value.
1097 */
1098 int
itimerdecr(struct itimerval * itp,int usec)1099 itimerdecr(struct itimerval *itp, int usec)
1100 {
1101
1102 if (itp->it_value.tv_usec < usec) {
1103 if (itp->it_value.tv_sec == 0) {
1104 /* expired, and already in next interval */
1105 usec -= itp->it_value.tv_usec;
1106 goto expire;
1107 }
1108 itp->it_value.tv_usec += 1000000;
1109 itp->it_value.tv_sec--;
1110 }
1111 itp->it_value.tv_usec -= usec;
1112 usec = 0;
1113 if (timevalisset(&itp->it_value))
1114 return (1);
1115 /* expired, exactly at end of interval */
1116 expire:
1117 if (timevalisset(&itp->it_interval)) {
1118 itp->it_value = itp->it_interval;
1119 itp->it_value.tv_usec -= usec;
1120 if (itp->it_value.tv_usec < 0) {
1121 itp->it_value.tv_usec += 1000000;
1122 itp->it_value.tv_sec--;
1123 }
1124 } else
1125 itp->it_value.tv_usec = 0; /* sec is already 0 */
1126 return (0);
1127 }
1128
1129 /*
1130 * Add and subtract routines for timevals.
1131 * N.B.: subtract routine doesn't deal with
1132 * results which are before the beginning,
1133 * it just gets very confused in this case.
1134 * Caveat emptor.
1135 */
1136 void
timevaladd(struct timeval * t1,const struct timeval * t2)1137 timevaladd(struct timeval *t1, const struct timeval *t2)
1138 {
1139
1140 t1->tv_sec += t2->tv_sec;
1141 t1->tv_usec += t2->tv_usec;
1142 timevalfix(t1);
1143 }
1144
1145 void
timevalsub(struct timeval * t1,const struct timeval * t2)1146 timevalsub(struct timeval *t1, const struct timeval *t2)
1147 {
1148
1149 t1->tv_sec -= t2->tv_sec;
1150 t1->tv_usec -= t2->tv_usec;
1151 timevalfix(t1);
1152 }
1153
1154 static void
timevalfix(struct timeval * t1)1155 timevalfix(struct timeval *t1)
1156 {
1157
1158 if (t1->tv_usec < 0) {
1159 t1->tv_sec--;
1160 t1->tv_usec += 1000000;
1161 }
1162 if (t1->tv_usec >= 1000000) {
1163 t1->tv_sec++;
1164 t1->tv_usec -= 1000000;
1165 }
1166 }
1167
1168 /*
1169 * ratecheck(): simple time-based rate-limit checking.
1170 */
1171 int
ratecheck(struct timeval * lasttime,const struct timeval * mininterval)1172 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
1173 {
1174 struct timeval tv, delta;
1175 int rv = 0;
1176
1177 getmicrouptime(&tv); /* NB: 10ms precision */
1178 delta = tv;
1179 timevalsub(&delta, lasttime);
1180
1181 /*
1182 * check for 0,0 is so that the message will be seen at least once,
1183 * even if interval is huge.
1184 */
1185 if (timevalcmp(&delta, mininterval, >=) ||
1186 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
1187 *lasttime = tv;
1188 rv = 1;
1189 }
1190
1191 return (rv);
1192 }
1193
1194 /*
1195 * ppsratecheck(): packets (or events) per second limitation.
1196 *
1197 * Return 0 if the limit is to be enforced (e.g. the caller
1198 * should drop a packet because of the rate limitation).
1199 *
1200 * maxpps of 0 always causes zero to be returned. maxpps of -1
1201 * always causes 1 to be returned; this effectively defeats rate
1202 * limiting.
1203 *
1204 * Note that we maintain the struct timeval for compatibility
1205 * with other bsd systems. We reuse the storage and just monitor
1206 * clock ticks for minimal overhead.
1207 */
1208 int
ppsratecheck(struct timeval * lasttime,int * curpps,int maxpps)1209 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
1210 {
1211 int now;
1212
1213 /*
1214 * Reset the last time and counter if this is the first call
1215 * or more than a second has passed since the last update of
1216 * lasttime.
1217 */
1218 now = ticks;
1219 if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
1220 lasttime->tv_sec = now;
1221 *curpps = 1;
1222 return (maxpps != 0);
1223 } else {
1224 (*curpps)++; /* NB: ignore potential overflow */
1225 return (maxpps < 0 || *curpps < maxpps);
1226 }
1227 }
1228
1229 static int
sysctl_gettimeofday_quick(SYSCTL_HANDLER_ARGS)1230 sysctl_gettimeofday_quick(SYSCTL_HANDLER_ARGS)
1231 {
1232 int error;
1233 int gtod;
1234
1235 gtod = gettimeofday_quick;
1236 error = sysctl_handle_int(oidp, >od, 0, req);
1237 if (error || req->newptr == NULL)
1238 return error;
1239 gettimeofday_quick = gtod;
1240 if (kpmap)
1241 kpmap->fast_gtod = gtod;
1242 return 0;
1243 }
1244