xref: /netbsd-src/sys/kern/kern_time.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: kern_time.c,v 1.182 2015/10/06 15:03:34 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000, 2004, 2005, 2007, 2008, 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christopher G. Demetriou, and by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1982, 1986, 1989, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)kern_time.c	8.4 (Berkeley) 5/26/95
61  */
62 
63 #include <sys/cdefs.h>
64 __KERNEL_RCSID(0, "$NetBSD: kern_time.c,v 1.182 2015/10/06 15:03:34 christos Exp $");
65 
66 #include <sys/param.h>
67 #include <sys/resourcevar.h>
68 #include <sys/kernel.h>
69 #include <sys/systm.h>
70 #include <sys/proc.h>
71 #include <sys/vnode.h>
72 #include <sys/signalvar.h>
73 #include <sys/syslog.h>
74 #include <sys/timetc.h>
75 #include <sys/timex.h>
76 #include <sys/kauth.h>
77 #include <sys/mount.h>
78 #include <sys/syscallargs.h>
79 #include <sys/cpu.h>
80 
81 static void	timer_intr(void *);
82 static void	itimerfire(struct ptimer *);
83 static void	itimerfree(struct ptimers *, int);
84 
85 kmutex_t	timer_lock;
86 
87 static void	*timer_sih;
88 static TAILQ_HEAD(, ptimer) timer_queue;
89 
90 struct pool ptimer_pool, ptimers_pool;
91 
92 #define	CLOCK_VIRTUAL_P(clockid)	\
93 	((clockid) == CLOCK_VIRTUAL || (clockid) == CLOCK_PROF)
94 
95 CTASSERT(ITIMER_REAL == CLOCK_REALTIME);
96 CTASSERT(ITIMER_VIRTUAL == CLOCK_VIRTUAL);
97 CTASSERT(ITIMER_PROF == CLOCK_PROF);
98 CTASSERT(ITIMER_MONOTONIC == CLOCK_MONOTONIC);
99 
100 /*
101  * Initialize timekeeping.
102  */
103 void
104 time_init(void)
105 {
106 
107 	pool_init(&ptimer_pool, sizeof(struct ptimer), 0, 0, 0, "ptimerpl",
108 	    &pool_allocator_nointr, IPL_NONE);
109 	pool_init(&ptimers_pool, sizeof(struct ptimers), 0, 0, 0, "ptimerspl",
110 	    &pool_allocator_nointr, IPL_NONE);
111 }
112 
113 void
114 time_init2(void)
115 {
116 
117 	TAILQ_INIT(&timer_queue);
118 	mutex_init(&timer_lock, MUTEX_DEFAULT, IPL_SCHED);
119 	timer_sih = softint_establish(SOFTINT_CLOCK | SOFTINT_MPSAFE,
120 	    timer_intr, NULL);
121 }
122 
123 /* Time of day and interval timer support.
124  *
125  * These routines provide the kernel entry points to get and set
126  * the time-of-day and per-process interval timers.  Subroutines
127  * here provide support for adding and subtracting timeval structures
128  * and decrementing interval timers, optionally reloading the interval
129  * timers when they expire.
130  */
131 
132 /* This function is used by clock_settime and settimeofday */
133 static int
134 settime1(struct proc *p, const struct timespec *ts, bool check_kauth)
135 {
136 	struct timespec delta, now;
137 	int s;
138 
139 	/* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
140 	s = splclock();
141 	nanotime(&now);
142 	timespecsub(ts, &now, &delta);
143 
144 	if (check_kauth && kauth_authorize_system(kauth_cred_get(),
145 	    KAUTH_SYSTEM_TIME, KAUTH_REQ_SYSTEM_TIME_SYSTEM, __UNCONST(ts),
146 	    &delta, KAUTH_ARG(check_kauth ? false : true)) != 0) {
147 		splx(s);
148 		return (EPERM);
149 	}
150 
151 #ifdef notyet
152 	if ((delta.tv_sec < 86400) && securelevel > 0) { /* XXX elad - notyet */
153 		splx(s);
154 		return (EPERM);
155 	}
156 #endif
157 
158 	tc_setclock(ts);
159 
160 	timespecadd(&boottime, &delta, &boottime);
161 
162 	resettodr();
163 	splx(s);
164 
165 	return (0);
166 }
167 
168 int
169 settime(struct proc *p, struct timespec *ts)
170 {
171 	return (settime1(p, ts, true));
172 }
173 
174 /* ARGSUSED */
175 int
176 sys___clock_gettime50(struct lwp *l,
177     const struct sys___clock_gettime50_args *uap, register_t *retval)
178 {
179 	/* {
180 		syscallarg(clockid_t) clock_id;
181 		syscallarg(struct timespec *) tp;
182 	} */
183 	int error;
184 	struct timespec ats;
185 
186 	error = clock_gettime1(SCARG(uap, clock_id), &ats);
187 	if (error != 0)
188 		return error;
189 
190 	return copyout(&ats, SCARG(uap, tp), sizeof(ats));
191 }
192 
193 /* ARGSUSED */
194 int
195 sys___clock_settime50(struct lwp *l,
196     const struct sys___clock_settime50_args *uap, register_t *retval)
197 {
198 	/* {
199 		syscallarg(clockid_t) clock_id;
200 		syscallarg(const struct timespec *) tp;
201 	} */
202 	int error;
203 	struct timespec ats;
204 
205 	if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
206 		return error;
207 
208 	return clock_settime1(l->l_proc, SCARG(uap, clock_id), &ats, true);
209 }
210 
211 
212 int
213 clock_settime1(struct proc *p, clockid_t clock_id, const struct timespec *tp,
214     bool check_kauth)
215 {
216 	int error;
217 
218 	switch (clock_id) {
219 	case CLOCK_REALTIME:
220 		if ((error = settime1(p, tp, check_kauth)) != 0)
221 			return (error);
222 		break;
223 	case CLOCK_MONOTONIC:
224 		return (EINVAL);	/* read-only clock */
225 	default:
226 		return (EINVAL);
227 	}
228 
229 	return 0;
230 }
231 
232 int
233 sys___clock_getres50(struct lwp *l, const struct sys___clock_getres50_args *uap,
234     register_t *retval)
235 {
236 	/* {
237 		syscallarg(clockid_t) clock_id;
238 		syscallarg(struct timespec *) tp;
239 	} */
240 	struct timespec ts;
241 	int error;
242 
243 	if ((error = clock_getres1(SCARG(uap, clock_id), &ts)) != 0)
244 		return error;
245 
246 	if (SCARG(uap, tp))
247 		error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
248 
249 	return error;
250 }
251 
252 int
253 clock_getres1(clockid_t clock_id, struct timespec *ts)
254 {
255 
256 	switch (clock_id) {
257 	case CLOCK_REALTIME:
258 	case CLOCK_MONOTONIC:
259 		ts->tv_sec = 0;
260 		if (tc_getfrequency() > 1000000000)
261 			ts->tv_nsec = 1;
262 		else
263 			ts->tv_nsec = 1000000000 / tc_getfrequency();
264 		break;
265 	default:
266 		return EINVAL;
267 	}
268 
269 	return 0;
270 }
271 
272 /* ARGSUSED */
273 int
274 sys___nanosleep50(struct lwp *l, const struct sys___nanosleep50_args *uap,
275     register_t *retval)
276 {
277 	/* {
278 		syscallarg(struct timespec *) rqtp;
279 		syscallarg(struct timespec *) rmtp;
280 	} */
281 	struct timespec rmt, rqt;
282 	int error, error1;
283 
284 	error = copyin(SCARG(uap, rqtp), &rqt, sizeof(struct timespec));
285 	if (error)
286 		return (error);
287 
288 	error = nanosleep1(l, CLOCK_MONOTONIC, 0, &rqt,
289 	    SCARG(uap, rmtp) ? &rmt : NULL);
290 	if (SCARG(uap, rmtp) == NULL || (error != 0 && error != EINTR))
291 		return error;
292 
293 	error1 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt));
294 	return error1 ? error1 : error;
295 }
296 
297 /* ARGSUSED */
298 int
299 sys_clock_nanosleep(struct lwp *l, const struct sys_clock_nanosleep_args *uap,
300     register_t *retval)
301 {
302 	/* {
303 		syscallarg(clockid_t) clock_id;
304 		syscallarg(int) flags;
305 		syscallarg(struct timespec *) rqtp;
306 		syscallarg(struct timespec *) rmtp;
307 	} */
308 	struct timespec rmt, rqt;
309 	int error, error1;
310 
311 	error = copyin(SCARG(uap, rqtp), &rqt, sizeof(struct timespec));
312 	if (error)
313 		goto out;
314 
315 	error = nanosleep1(l, SCARG(uap, clock_id), SCARG(uap, flags), &rqt,
316 	    SCARG(uap, rmtp) ? &rmt : NULL);
317 	if (SCARG(uap, rmtp) == NULL || (error != 0 && error != EINTR))
318 		goto out;
319 
320 	if ((error1 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt))) != 0)
321 		error = error1;
322 out:
323 	*retval = error;
324 	return 0;
325 }
326 
327 int
328 nanosleep1(struct lwp *l, clockid_t clock_id, int flags, struct timespec *rqt,
329     struct timespec *rmt)
330 {
331 	struct timespec rmtstart;
332 	int error, timo;
333 
334 	if ((error = ts2timo(clock_id, flags, rqt, &timo, &rmtstart)) != 0)
335 		return error == ETIMEDOUT ? 0 : error;
336 
337 	/*
338 	 * Avoid inadvertently sleeping forever
339 	 */
340 	if (timo == 0)
341 		timo = 1;
342 again:
343 	error = kpause("nanoslp", true, timo, NULL);
344 	if (rmt != NULL || error == 0) {
345 		struct timespec rmtend;
346 		struct timespec t0;
347 		struct timespec *t;
348 
349 		(void)clock_gettime1(clock_id, &rmtend);
350 		t = (rmt != NULL) ? rmt : &t0;
351 		if (flags & TIMER_ABSTIME) {
352 			timespecsub(rqt, &rmtend, t);
353 		} else {
354 			timespecsub(&rmtend, &rmtstart, t);
355 			timespecsub(rqt, t, t);
356 		}
357 		if (t->tv_sec < 0)
358 			timespecclear(t);
359 		if (error == 0) {
360 			timo = tstohz(t);
361 			if (timo > 0)
362 				goto again;
363 		}
364 	}
365 
366 	if (error == ERESTART)
367 		error = EINTR;
368 	if (error == EWOULDBLOCK)
369 		error = 0;
370 
371 	return error;
372 }
373 
374 /* ARGSUSED */
375 int
376 sys___gettimeofday50(struct lwp *l, const struct sys___gettimeofday50_args *uap,
377     register_t *retval)
378 {
379 	/* {
380 		syscallarg(struct timeval *) tp;
381 		syscallarg(void *) tzp;		really "struct timezone *";
382 	} */
383 	struct timeval atv;
384 	int error = 0;
385 	struct timezone tzfake;
386 
387 	if (SCARG(uap, tp)) {
388 		microtime(&atv);
389 		error = copyout(&atv, SCARG(uap, tp), sizeof(atv));
390 		if (error)
391 			return (error);
392 	}
393 	if (SCARG(uap, tzp)) {
394 		/*
395 		 * NetBSD has no kernel notion of time zone, so we just
396 		 * fake up a timezone struct and return it if demanded.
397 		 */
398 		tzfake.tz_minuteswest = 0;
399 		tzfake.tz_dsttime = 0;
400 		error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake));
401 	}
402 	return (error);
403 }
404 
405 /* ARGSUSED */
406 int
407 sys___settimeofday50(struct lwp *l, const struct sys___settimeofday50_args *uap,
408     register_t *retval)
409 {
410 	/* {
411 		syscallarg(const struct timeval *) tv;
412 		syscallarg(const void *) tzp; really "const struct timezone *";
413 	} */
414 
415 	return settimeofday1(SCARG(uap, tv), true, SCARG(uap, tzp), l, true);
416 }
417 
418 int
419 settimeofday1(const struct timeval *utv, bool userspace,
420     const void *utzp, struct lwp *l, bool check_kauth)
421 {
422 	struct timeval atv;
423 	struct timespec ts;
424 	int error;
425 
426 	/* Verify all parameters before changing time. */
427 
428 	/*
429 	 * NetBSD has no kernel notion of time zone, and only an
430 	 * obsolete program would try to set it, so we log a warning.
431 	 */
432 	if (utzp)
433 		log(LOG_WARNING, "pid %d attempted to set the "
434 		    "(obsolete) kernel time zone\n", l->l_proc->p_pid);
435 
436 	if (utv == NULL)
437 		return 0;
438 
439 	if (userspace) {
440 		if ((error = copyin(utv, &atv, sizeof(atv))) != 0)
441 			return error;
442 		utv = &atv;
443 	}
444 
445 	TIMEVAL_TO_TIMESPEC(utv, &ts);
446 	return settime1(l->l_proc, &ts, check_kauth);
447 }
448 
449 int	time_adjusted;			/* set if an adjustment is made */
450 
451 /* ARGSUSED */
452 int
453 sys___adjtime50(struct lwp *l, const struct sys___adjtime50_args *uap,
454     register_t *retval)
455 {
456 	/* {
457 		syscallarg(const struct timeval *) delta;
458 		syscallarg(struct timeval *) olddelta;
459 	} */
460 	int error;
461 	struct timeval atv, oldatv;
462 
463 	if ((error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_TIME,
464 	    KAUTH_REQ_SYSTEM_TIME_ADJTIME, NULL, NULL, NULL)) != 0)
465 		return error;
466 
467 	if (SCARG(uap, delta)) {
468 		error = copyin(SCARG(uap, delta), &atv,
469 		    sizeof(*SCARG(uap, delta)));
470 		if (error)
471 			return (error);
472 	}
473 	adjtime1(SCARG(uap, delta) ? &atv : NULL,
474 	    SCARG(uap, olddelta) ? &oldatv : NULL, l->l_proc);
475 	if (SCARG(uap, olddelta))
476 		error = copyout(&oldatv, SCARG(uap, olddelta),
477 		    sizeof(*SCARG(uap, olddelta)));
478 	return error;
479 }
480 
481 void
482 adjtime1(const struct timeval *delta, struct timeval *olddelta, struct proc *p)
483 {
484 	extern int64_t time_adjtime;  /* in kern_ntptime.c */
485 
486 	if (olddelta) {
487 		mutex_spin_enter(&timecounter_lock);
488 		olddelta->tv_sec = time_adjtime / 1000000;
489 		olddelta->tv_usec = time_adjtime % 1000000;
490 		if (olddelta->tv_usec < 0) {
491 			olddelta->tv_usec += 1000000;
492 			olddelta->tv_sec--;
493 		}
494 		mutex_spin_exit(&timecounter_lock);
495 	}
496 
497 	if (delta) {
498 		mutex_spin_enter(&timecounter_lock);
499 		time_adjtime = delta->tv_sec * 1000000 + delta->tv_usec;
500 
501 		if (time_adjtime) {
502 			/* We need to save the system time during shutdown */
503 			time_adjusted |= 1;
504 		}
505 		mutex_spin_exit(&timecounter_lock);
506 	}
507 }
508 
509 /*
510  * Interval timer support. Both the BSD getitimer() family and the POSIX
511  * timer_*() family of routines are supported.
512  *
513  * All timers are kept in an array pointed to by p_timers, which is
514  * allocated on demand - many processes don't use timers at all. The
515  * first three elements in this array are reserved for the BSD timers:
516  * element 0 is ITIMER_REAL, element 1 is ITIMER_VIRTUAL, element
517  * 2 is ITIMER_PROF, and element 3 is ITIMER_MONOTONIC. The rest may be
518  * allocated by the timer_create() syscall.
519  *
520  * Realtime timers are kept in the ptimer structure as an absolute
521  * time; virtual time timers are kept as a linked list of deltas.
522  * Virtual time timers are processed in the hardclock() routine of
523  * kern_clock.c.  The real time timer is processed by a callout
524  * routine, called from the softclock() routine.  Since a callout may
525  * be delayed in real time due to interrupt processing in the system,
526  * it is possible for the real time timeout routine (realtimeexpire,
527  * given below), to be delayed in real time past when it is supposed
528  * to occur.  It does not suffice, therefore, to reload the real timer
529  * .it_value from the real time timers .it_interval.  Rather, we
530  * compute the next time in absolute time the timer should go off.  */
531 
532 /* Allocate a POSIX realtime timer. */
533 int
534 sys_timer_create(struct lwp *l, const struct sys_timer_create_args *uap,
535     register_t *retval)
536 {
537 	/* {
538 		syscallarg(clockid_t) clock_id;
539 		syscallarg(struct sigevent *) evp;
540 		syscallarg(timer_t *) timerid;
541 	} */
542 
543 	return timer_create1(SCARG(uap, timerid), SCARG(uap, clock_id),
544 	    SCARG(uap, evp), copyin, l);
545 }
546 
547 int
548 timer_create1(timer_t *tid, clockid_t id, struct sigevent *evp,
549     copyin_t fetch_event, struct lwp *l)
550 {
551 	int error;
552 	timer_t timerid;
553 	struct ptimers *pts;
554 	struct ptimer *pt;
555 	struct proc *p;
556 
557 	p = l->l_proc;
558 
559 	if ((u_int)id > CLOCK_MONOTONIC)
560 		return (EINVAL);
561 
562 	if ((pts = p->p_timers) == NULL)
563 		pts = timers_alloc(p);
564 
565 	pt = pool_get(&ptimer_pool, PR_WAITOK);
566 	if (evp != NULL) {
567 		if (((error =
568 		    (*fetch_event)(evp, &pt->pt_ev, sizeof(pt->pt_ev))) != 0) ||
569 		    ((pt->pt_ev.sigev_notify < SIGEV_NONE) ||
570 			(pt->pt_ev.sigev_notify > SIGEV_SA)) ||
571 			(pt->pt_ev.sigev_notify == SIGEV_SIGNAL &&
572 			 (pt->pt_ev.sigev_signo <= 0 ||
573 			  pt->pt_ev.sigev_signo >= NSIG))) {
574 			pool_put(&ptimer_pool, pt);
575 			return (error ? error : EINVAL);
576 		}
577 	}
578 
579 	/* Find a free timer slot, skipping those reserved for setitimer(). */
580 	mutex_spin_enter(&timer_lock);
581 	for (timerid = 3; timerid < TIMER_MAX; timerid++)
582 		if (pts->pts_timers[timerid] == NULL)
583 			break;
584 	if (timerid == TIMER_MAX) {
585 		mutex_spin_exit(&timer_lock);
586 		pool_put(&ptimer_pool, pt);
587 		return EAGAIN;
588 	}
589 	if (evp == NULL) {
590 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
591 		switch (id) {
592 		case CLOCK_REALTIME:
593 		case CLOCK_MONOTONIC:
594 			pt->pt_ev.sigev_signo = SIGALRM;
595 			break;
596 		case CLOCK_VIRTUAL:
597 			pt->pt_ev.sigev_signo = SIGVTALRM;
598 			break;
599 		case CLOCK_PROF:
600 			pt->pt_ev.sigev_signo = SIGPROF;
601 			break;
602 		}
603 		pt->pt_ev.sigev_value.sival_int = timerid;
604 	}
605 	pt->pt_info.ksi_signo = pt->pt_ev.sigev_signo;
606 	pt->pt_info.ksi_errno = 0;
607 	pt->pt_info.ksi_code = 0;
608 	pt->pt_info.ksi_pid = p->p_pid;
609 	pt->pt_info.ksi_uid = kauth_cred_getuid(l->l_cred);
610 	pt->pt_info.ksi_value = pt->pt_ev.sigev_value;
611 	pt->pt_type = id;
612 	pt->pt_proc = p;
613 	pt->pt_overruns = 0;
614 	pt->pt_poverruns = 0;
615 	pt->pt_entry = timerid;
616 	pt->pt_queued = false;
617 	timespecclear(&pt->pt_time.it_value);
618 	if (!CLOCK_VIRTUAL_P(id))
619 		callout_init(&pt->pt_ch, CALLOUT_MPSAFE);
620 	else
621 		pt->pt_active = 0;
622 
623 	pts->pts_timers[timerid] = pt;
624 	mutex_spin_exit(&timer_lock);
625 
626 	return copyout(&timerid, tid, sizeof(timerid));
627 }
628 
629 /* Delete a POSIX realtime timer */
630 int
631 sys_timer_delete(struct lwp *l, const struct sys_timer_delete_args *uap,
632     register_t *retval)
633 {
634 	/* {
635 		syscallarg(timer_t) timerid;
636 	} */
637 	struct proc *p = l->l_proc;
638 	timer_t timerid;
639 	struct ptimers *pts;
640 	struct ptimer *pt, *ptn;
641 
642 	timerid = SCARG(uap, timerid);
643 	pts = p->p_timers;
644 
645 	if (pts == NULL || timerid < 2 || timerid >= TIMER_MAX)
646 		return (EINVAL);
647 
648 	mutex_spin_enter(&timer_lock);
649 	if ((pt = pts->pts_timers[timerid]) == NULL) {
650 		mutex_spin_exit(&timer_lock);
651 		return (EINVAL);
652 	}
653 	if (CLOCK_VIRTUAL_P(pt->pt_type)) {
654 		if (pt->pt_active) {
655 			ptn = LIST_NEXT(pt, pt_list);
656 			LIST_REMOVE(pt, pt_list);
657 			for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
658 				timespecadd(&pt->pt_time.it_value,
659 				    &ptn->pt_time.it_value,
660 				    &ptn->pt_time.it_value);
661 			pt->pt_active = 0;
662 		}
663 	}
664 	itimerfree(pts, timerid);
665 
666 	return (0);
667 }
668 
669 /*
670  * Set up the given timer. The value in pt->pt_time.it_value is taken
671  * to be an absolute time for CLOCK_REALTIME/CLOCK_MONOTONIC timers and
672  * a relative time for CLOCK_VIRTUAL/CLOCK_PROF timers.
673  */
674 void
675 timer_settime(struct ptimer *pt)
676 {
677 	struct ptimer *ptn, *pptn;
678 	struct ptlist *ptl;
679 
680 	KASSERT(mutex_owned(&timer_lock));
681 
682 	if (!CLOCK_VIRTUAL_P(pt->pt_type)) {
683 		callout_halt(&pt->pt_ch, &timer_lock);
684 		if (timespecisset(&pt->pt_time.it_value)) {
685 			/*
686 			 * Don't need to check tshzto() return value, here.
687 			 * callout_reset() does it for us.
688 			 */
689 			callout_reset(&pt->pt_ch,
690 			    pt->pt_type == CLOCK_MONOTONIC ?
691 			    tshztoup(&pt->pt_time.it_value) :
692 			    tshzto(&pt->pt_time.it_value),
693 			    realtimerexpire, pt);
694 		}
695 	} else {
696 		if (pt->pt_active) {
697 			ptn = LIST_NEXT(pt, pt_list);
698 			LIST_REMOVE(pt, pt_list);
699 			for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
700 				timespecadd(&pt->pt_time.it_value,
701 				    &ptn->pt_time.it_value,
702 				    &ptn->pt_time.it_value);
703 		}
704 		if (timespecisset(&pt->pt_time.it_value)) {
705 			if (pt->pt_type == CLOCK_VIRTUAL)
706 				ptl = &pt->pt_proc->p_timers->pts_virtual;
707 			else
708 				ptl = &pt->pt_proc->p_timers->pts_prof;
709 
710 			for (ptn = LIST_FIRST(ptl), pptn = NULL;
711 			     ptn && timespeccmp(&pt->pt_time.it_value,
712 				 &ptn->pt_time.it_value, >);
713 			     pptn = ptn, ptn = LIST_NEXT(ptn, pt_list))
714 				timespecsub(&pt->pt_time.it_value,
715 				    &ptn->pt_time.it_value,
716 				    &pt->pt_time.it_value);
717 
718 			if (pptn)
719 				LIST_INSERT_AFTER(pptn, pt, pt_list);
720 			else
721 				LIST_INSERT_HEAD(ptl, pt, pt_list);
722 
723 			for ( ; ptn ; ptn = LIST_NEXT(ptn, pt_list))
724 				timespecsub(&ptn->pt_time.it_value,
725 				    &pt->pt_time.it_value,
726 				    &ptn->pt_time.it_value);
727 
728 			pt->pt_active = 1;
729 		} else
730 			pt->pt_active = 0;
731 	}
732 }
733 
734 void
735 timer_gettime(struct ptimer *pt, struct itimerspec *aits)
736 {
737 	struct timespec now;
738 	struct ptimer *ptn;
739 
740 	KASSERT(mutex_owned(&timer_lock));
741 
742 	*aits = pt->pt_time;
743 	if (!CLOCK_VIRTUAL_P(pt->pt_type)) {
744 		/*
745 		 * Convert from absolute to relative time in .it_value
746 		 * part of real time timer.  If time for real time
747 		 * timer has passed return 0, else return difference
748 		 * between current time and time for the timer to go
749 		 * off.
750 		 */
751 		if (timespecisset(&aits->it_value)) {
752 			if (pt->pt_type == CLOCK_REALTIME) {
753 				getnanotime(&now);
754 			} else { /* CLOCK_MONOTONIC */
755 				getnanouptime(&now);
756 			}
757 			if (timespeccmp(&aits->it_value, &now, <))
758 				timespecclear(&aits->it_value);
759 			else
760 				timespecsub(&aits->it_value, &now,
761 				    &aits->it_value);
762 		}
763 	} else if (pt->pt_active) {
764 		if (pt->pt_type == CLOCK_VIRTUAL)
765 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_virtual);
766 		else
767 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_prof);
768 		for ( ; ptn && ptn != pt; ptn = LIST_NEXT(ptn, pt_list))
769 			timespecadd(&aits->it_value,
770 			    &ptn->pt_time.it_value, &aits->it_value);
771 		KASSERT(ptn != NULL); /* pt should be findable on the list */
772 	} else
773 		timespecclear(&aits->it_value);
774 }
775 
776 
777 
778 /* Set and arm a POSIX realtime timer */
779 int
780 sys___timer_settime50(struct lwp *l,
781     const struct sys___timer_settime50_args *uap,
782     register_t *retval)
783 {
784 	/* {
785 		syscallarg(timer_t) timerid;
786 		syscallarg(int) flags;
787 		syscallarg(const struct itimerspec *) value;
788 		syscallarg(struct itimerspec *) ovalue;
789 	} */
790 	int error;
791 	struct itimerspec value, ovalue, *ovp = NULL;
792 
793 	if ((error = copyin(SCARG(uap, value), &value,
794 	    sizeof(struct itimerspec))) != 0)
795 		return (error);
796 
797 	if (SCARG(uap, ovalue))
798 		ovp = &ovalue;
799 
800 	if ((error = dotimer_settime(SCARG(uap, timerid), &value, ovp,
801 	    SCARG(uap, flags), l->l_proc)) != 0)
802 		return error;
803 
804 	if (ovp)
805 		return copyout(&ovalue, SCARG(uap, ovalue),
806 		    sizeof(struct itimerspec));
807 	return 0;
808 }
809 
810 int
811 dotimer_settime(int timerid, struct itimerspec *value,
812     struct itimerspec *ovalue, int flags, struct proc *p)
813 {
814 	struct timespec now;
815 	struct itimerspec val, oval;
816 	struct ptimers *pts;
817 	struct ptimer *pt;
818 	int error;
819 
820 	pts = p->p_timers;
821 
822 	if (pts == NULL || timerid < 2 || timerid >= TIMER_MAX)
823 		return EINVAL;
824 	val = *value;
825 	if ((error = itimespecfix(&val.it_value)) != 0 ||
826 	    (error = itimespecfix(&val.it_interval)) != 0)
827 		return error;
828 
829 	mutex_spin_enter(&timer_lock);
830 	if ((pt = pts->pts_timers[timerid]) == NULL) {
831 		mutex_spin_exit(&timer_lock);
832 		return EINVAL;
833 	}
834 
835 	oval = pt->pt_time;
836 	pt->pt_time = val;
837 
838 	/*
839 	 * If we've been passed a relative time for a realtime timer,
840 	 * convert it to absolute; if an absolute time for a virtual
841 	 * timer, convert it to relative and make sure we don't set it
842 	 * to zero, which would cancel the timer, or let it go
843 	 * negative, which would confuse the comparison tests.
844 	 */
845 	if (timespecisset(&pt->pt_time.it_value)) {
846 		if (!CLOCK_VIRTUAL_P(pt->pt_type)) {
847 			if ((flags & TIMER_ABSTIME) == 0) {
848 				if (pt->pt_type == CLOCK_REALTIME) {
849 					getnanotime(&now);
850 				} else { /* CLOCK_MONOTONIC */
851 					getnanouptime(&now);
852 				}
853 				timespecadd(&pt->pt_time.it_value, &now,
854 				    &pt->pt_time.it_value);
855 			}
856 		} else {
857 			if ((flags & TIMER_ABSTIME) != 0) {
858 				getnanotime(&now);
859 				timespecsub(&pt->pt_time.it_value, &now,
860 				    &pt->pt_time.it_value);
861 				if (!timespecisset(&pt->pt_time.it_value) ||
862 				    pt->pt_time.it_value.tv_sec < 0) {
863 					pt->pt_time.it_value.tv_sec = 0;
864 					pt->pt_time.it_value.tv_nsec = 1;
865 				}
866 			}
867 		}
868 	}
869 
870 	timer_settime(pt);
871 	mutex_spin_exit(&timer_lock);
872 
873 	if (ovalue)
874 		*ovalue = oval;
875 
876 	return (0);
877 }
878 
879 /* Return the time remaining until a POSIX timer fires. */
880 int
881 sys___timer_gettime50(struct lwp *l,
882     const struct sys___timer_gettime50_args *uap, register_t *retval)
883 {
884 	/* {
885 		syscallarg(timer_t) timerid;
886 		syscallarg(struct itimerspec *) value;
887 	} */
888 	struct itimerspec its;
889 	int error;
890 
891 	if ((error = dotimer_gettime(SCARG(uap, timerid), l->l_proc,
892 	    &its)) != 0)
893 		return error;
894 
895 	return copyout(&its, SCARG(uap, value), sizeof(its));
896 }
897 
898 int
899 dotimer_gettime(int timerid, struct proc *p, struct itimerspec *its)
900 {
901 	struct ptimer *pt;
902 	struct ptimers *pts;
903 
904 	pts = p->p_timers;
905 	if (pts == NULL || timerid < 2 || timerid >= TIMER_MAX)
906 		return (EINVAL);
907 	mutex_spin_enter(&timer_lock);
908 	if ((pt = pts->pts_timers[timerid]) == NULL) {
909 		mutex_spin_exit(&timer_lock);
910 		return (EINVAL);
911 	}
912 	timer_gettime(pt, its);
913 	mutex_spin_exit(&timer_lock);
914 
915 	return 0;
916 }
917 
918 /*
919  * Return the count of the number of times a periodic timer expired
920  * while a notification was already pending. The counter is reset when
921  * a timer expires and a notification can be posted.
922  */
923 int
924 sys_timer_getoverrun(struct lwp *l, const struct sys_timer_getoverrun_args *uap,
925     register_t *retval)
926 {
927 	/* {
928 		syscallarg(timer_t) timerid;
929 	} */
930 	struct proc *p = l->l_proc;
931 	struct ptimers *pts;
932 	int timerid;
933 	struct ptimer *pt;
934 
935 	timerid = SCARG(uap, timerid);
936 
937 	pts = p->p_timers;
938 	if (pts == NULL || timerid < 2 || timerid >= TIMER_MAX)
939 		return (EINVAL);
940 	mutex_spin_enter(&timer_lock);
941 	if ((pt = pts->pts_timers[timerid]) == NULL) {
942 		mutex_spin_exit(&timer_lock);
943 		return (EINVAL);
944 	}
945 	*retval = pt->pt_poverruns;
946 	mutex_spin_exit(&timer_lock);
947 
948 	return (0);
949 }
950 
951 /*
952  * Real interval timer expired:
953  * send process whose timer expired an alarm signal.
954  * If time is not set up to reload, then just return.
955  * Else compute next time timer should go off which is > current time.
956  * This is where delay in processing this timeout causes multiple
957  * SIGALRM calls to be compressed into one.
958  */
959 void
960 realtimerexpire(void *arg)
961 {
962 	uint64_t last_val, next_val, interval, now_ns;
963 	struct timespec now, next;
964 	struct ptimer *pt;
965 	int backwards;
966 
967 	pt = arg;
968 
969 	mutex_spin_enter(&timer_lock);
970 	itimerfire(pt);
971 
972 	if (!timespecisset(&pt->pt_time.it_interval)) {
973 		timespecclear(&pt->pt_time.it_value);
974 		mutex_spin_exit(&timer_lock);
975 		return;
976 	}
977 
978 	if (pt->pt_type == CLOCK_MONOTONIC) {
979 		getnanouptime(&now);
980 	} else {
981 		getnanotime(&now);
982 	}
983 	backwards = (timespeccmp(&pt->pt_time.it_value, &now, >));
984 	timespecadd(&pt->pt_time.it_value, &pt->pt_time.it_interval, &next);
985 	/* Handle the easy case of non-overflown timers first. */
986 	if (!backwards && timespeccmp(&next, &now, >)) {
987 		pt->pt_time.it_value = next;
988 	} else {
989 		now_ns = timespec2ns(&now);
990 		last_val = timespec2ns(&pt->pt_time.it_value);
991 		interval = timespec2ns(&pt->pt_time.it_interval);
992 
993 		next_val = now_ns +
994 		    (now_ns - last_val + interval - 1) % interval;
995 
996 		if (backwards)
997 			next_val += interval;
998 		else
999 			pt->pt_overruns += (now_ns - last_val) / interval;
1000 
1001 		pt->pt_time.it_value.tv_sec = next_val / 1000000000;
1002 		pt->pt_time.it_value.tv_nsec = next_val % 1000000000;
1003 	}
1004 
1005 	/*
1006 	 * Don't need to check tshzto() return value, here.
1007 	 * callout_reset() does it for us.
1008 	 */
1009 	callout_reset(&pt->pt_ch, pt->pt_type == CLOCK_MONOTONIC ?
1010 	    tshztoup(&pt->pt_time.it_value) : tshzto(&pt->pt_time.it_value),
1011 	    realtimerexpire, pt);
1012 	mutex_spin_exit(&timer_lock);
1013 }
1014 
1015 /* BSD routine to get the value of an interval timer. */
1016 /* ARGSUSED */
1017 int
1018 sys___getitimer50(struct lwp *l, const struct sys___getitimer50_args *uap,
1019     register_t *retval)
1020 {
1021 	/* {
1022 		syscallarg(int) which;
1023 		syscallarg(struct itimerval *) itv;
1024 	} */
1025 	struct proc *p = l->l_proc;
1026 	struct itimerval aitv;
1027 	int error;
1028 
1029 	error = dogetitimer(p, SCARG(uap, which), &aitv);
1030 	if (error)
1031 		return error;
1032 	return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval)));
1033 }
1034 
1035 int
1036 dogetitimer(struct proc *p, int which, struct itimerval *itvp)
1037 {
1038 	struct ptimers *pts;
1039 	struct ptimer *pt;
1040 	struct itimerspec its;
1041 
1042 	if ((u_int)which > ITIMER_MONOTONIC)
1043 		return (EINVAL);
1044 
1045 	mutex_spin_enter(&timer_lock);
1046 	pts = p->p_timers;
1047 	if (pts == NULL || (pt = pts->pts_timers[which]) == NULL) {
1048 		timerclear(&itvp->it_value);
1049 		timerclear(&itvp->it_interval);
1050 	} else {
1051 		timer_gettime(pt, &its);
1052 		TIMESPEC_TO_TIMEVAL(&itvp->it_value, &its.it_value);
1053 		TIMESPEC_TO_TIMEVAL(&itvp->it_interval, &its.it_interval);
1054 	}
1055 	mutex_spin_exit(&timer_lock);
1056 
1057 	return 0;
1058 }
1059 
1060 /* BSD routine to set/arm an interval timer. */
1061 /* ARGSUSED */
1062 int
1063 sys___setitimer50(struct lwp *l, const struct sys___setitimer50_args *uap,
1064     register_t *retval)
1065 {
1066 	/* {
1067 		syscallarg(int) which;
1068 		syscallarg(const struct itimerval *) itv;
1069 		syscallarg(struct itimerval *) oitv;
1070 	} */
1071 	struct proc *p = l->l_proc;
1072 	int which = SCARG(uap, which);
1073 	struct sys___getitimer50_args getargs;
1074 	const struct itimerval *itvp;
1075 	struct itimerval aitv;
1076 	int error;
1077 
1078 	if ((u_int)which > ITIMER_MONOTONIC)
1079 		return (EINVAL);
1080 	itvp = SCARG(uap, itv);
1081 	if (itvp &&
1082 	    (error = copyin(itvp, &aitv, sizeof(struct itimerval))) != 0)
1083 		return (error);
1084 	if (SCARG(uap, oitv) != NULL) {
1085 		SCARG(&getargs, which) = which;
1086 		SCARG(&getargs, itv) = SCARG(uap, oitv);
1087 		if ((error = sys___getitimer50(l, &getargs, retval)) != 0)
1088 			return (error);
1089 	}
1090 	if (itvp == 0)
1091 		return (0);
1092 
1093 	return dosetitimer(p, which, &aitv);
1094 }
1095 
1096 int
1097 dosetitimer(struct proc *p, int which, struct itimerval *itvp)
1098 {
1099 	struct timespec now;
1100 	struct ptimers *pts;
1101 	struct ptimer *pt, *spare;
1102 
1103 	KASSERT((u_int)which <= CLOCK_MONOTONIC);
1104 	if (itimerfix(&itvp->it_value) || itimerfix(&itvp->it_interval))
1105 		return (EINVAL);
1106 
1107 	/*
1108 	 * Don't bother allocating data structures if the process just
1109 	 * wants to clear the timer.
1110 	 */
1111 	spare = NULL;
1112 	pts = p->p_timers;
1113  retry:
1114 	if (!timerisset(&itvp->it_value) && (pts == NULL ||
1115 	    pts->pts_timers[which] == NULL))
1116 		return (0);
1117 	if (pts == NULL)
1118 		pts = timers_alloc(p);
1119 	mutex_spin_enter(&timer_lock);
1120 	pt = pts->pts_timers[which];
1121 	if (pt == NULL) {
1122 		if (spare == NULL) {
1123 			mutex_spin_exit(&timer_lock);
1124 			spare = pool_get(&ptimer_pool, PR_WAITOK);
1125 			goto retry;
1126 		}
1127 		pt = spare;
1128 		spare = NULL;
1129 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
1130 		pt->pt_ev.sigev_value.sival_int = which;
1131 		pt->pt_overruns = 0;
1132 		pt->pt_proc = p;
1133 		pt->pt_type = which;
1134 		pt->pt_entry = which;
1135 		pt->pt_queued = false;
1136 		if (pt->pt_type == CLOCK_REALTIME)
1137 			callout_init(&pt->pt_ch, CALLOUT_MPSAFE);
1138 		else
1139 			pt->pt_active = 0;
1140 
1141 		switch (which) {
1142 		case ITIMER_REAL:
1143 		case ITIMER_MONOTONIC:
1144 			pt->pt_ev.sigev_signo = SIGALRM;
1145 			break;
1146 		case ITIMER_VIRTUAL:
1147 			pt->pt_ev.sigev_signo = SIGVTALRM;
1148 			break;
1149 		case ITIMER_PROF:
1150 			pt->pt_ev.sigev_signo = SIGPROF;
1151 			break;
1152 		}
1153 		pts->pts_timers[which] = pt;
1154 	}
1155 
1156 	TIMEVAL_TO_TIMESPEC(&itvp->it_value, &pt->pt_time.it_value);
1157 	TIMEVAL_TO_TIMESPEC(&itvp->it_interval, &pt->pt_time.it_interval);
1158 
1159 	if (timespecisset(&pt->pt_time.it_value)) {
1160 		/* Convert to absolute time */
1161 		/* XXX need to wrap in splclock for timecounters case? */
1162 		switch (which) {
1163 		case ITIMER_REAL:
1164 			getnanotime(&now);
1165 			timespecadd(&pt->pt_time.it_value, &now,
1166 			    &pt->pt_time.it_value);
1167 			break;
1168 		case ITIMER_MONOTONIC:
1169 			getnanouptime(&now);
1170 			timespecadd(&pt->pt_time.it_value, &now,
1171 			    &pt->pt_time.it_value);
1172 			break;
1173 		default:
1174 			break;
1175 		}
1176 	}
1177 	timer_settime(pt);
1178 	mutex_spin_exit(&timer_lock);
1179 	if (spare != NULL)
1180 		pool_put(&ptimer_pool, spare);
1181 
1182 	return (0);
1183 }
1184 
1185 /* Utility routines to manage the array of pointers to timers. */
1186 struct ptimers *
1187 timers_alloc(struct proc *p)
1188 {
1189 	struct ptimers *pts;
1190 	int i;
1191 
1192 	pts = pool_get(&ptimers_pool, PR_WAITOK);
1193 	LIST_INIT(&pts->pts_virtual);
1194 	LIST_INIT(&pts->pts_prof);
1195 	for (i = 0; i < TIMER_MAX; i++)
1196 		pts->pts_timers[i] = NULL;
1197 	pts->pts_fired = 0;
1198 	mutex_spin_enter(&timer_lock);
1199 	if (p->p_timers == NULL) {
1200 		p->p_timers = pts;
1201 		mutex_spin_exit(&timer_lock);
1202 		return pts;
1203 	}
1204 	mutex_spin_exit(&timer_lock);
1205 	pool_put(&ptimers_pool, pts);
1206 	return p->p_timers;
1207 }
1208 
1209 /*
1210  * Clean up the per-process timers. If "which" is set to TIMERS_ALL,
1211  * then clean up all timers and free all the data structures. If
1212  * "which" is set to TIMERS_POSIX, only clean up the timers allocated
1213  * by timer_create(), not the BSD setitimer() timers, and only free the
1214  * structure if none of those remain.
1215  */
1216 void
1217 timers_free(struct proc *p, int which)
1218 {
1219 	struct ptimers *pts;
1220 	struct ptimer *ptn;
1221 	struct timespec ts;
1222 	int i;
1223 
1224 	if (p->p_timers == NULL)
1225 		return;
1226 
1227 	pts = p->p_timers;
1228 	mutex_spin_enter(&timer_lock);
1229 	if (which == TIMERS_ALL) {
1230 		p->p_timers = NULL;
1231 		i = 0;
1232 	} else {
1233 		timespecclear(&ts);
1234 		for (ptn = LIST_FIRST(&pts->pts_virtual);
1235 		     ptn && ptn != pts->pts_timers[ITIMER_VIRTUAL];
1236 		     ptn = LIST_NEXT(ptn, pt_list)) {
1237 			KASSERT(ptn->pt_type == CLOCK_VIRTUAL);
1238 			timespecadd(&ts, &ptn->pt_time.it_value, &ts);
1239 		}
1240 		LIST_FIRST(&pts->pts_virtual) = NULL;
1241 		if (ptn) {
1242 			KASSERT(ptn->pt_type == CLOCK_VIRTUAL);
1243 			timespecadd(&ts, &ptn->pt_time.it_value,
1244 			    &ptn->pt_time.it_value);
1245 			LIST_INSERT_HEAD(&pts->pts_virtual, ptn, pt_list);
1246 		}
1247 		timespecclear(&ts);
1248 		for (ptn = LIST_FIRST(&pts->pts_prof);
1249 		     ptn && ptn != pts->pts_timers[ITIMER_PROF];
1250 		     ptn = LIST_NEXT(ptn, pt_list)) {
1251 			KASSERT(ptn->pt_type == CLOCK_PROF);
1252 			timespecadd(&ts, &ptn->pt_time.it_value, &ts);
1253 		}
1254 		LIST_FIRST(&pts->pts_prof) = NULL;
1255 		if (ptn) {
1256 			KASSERT(ptn->pt_type == CLOCK_PROF);
1257 			timespecadd(&ts, &ptn->pt_time.it_value,
1258 			    &ptn->pt_time.it_value);
1259 			LIST_INSERT_HEAD(&pts->pts_prof, ptn, pt_list);
1260 		}
1261 		i = 3;
1262 	}
1263 	for ( ; i < TIMER_MAX; i++) {
1264 		if (pts->pts_timers[i] != NULL) {
1265 			itimerfree(pts, i);
1266 			mutex_spin_enter(&timer_lock);
1267 		}
1268 	}
1269 	if (pts->pts_timers[0] == NULL && pts->pts_timers[1] == NULL &&
1270 	    pts->pts_timers[2] == NULL) {
1271 		p->p_timers = NULL;
1272 		mutex_spin_exit(&timer_lock);
1273 		pool_put(&ptimers_pool, pts);
1274 	} else
1275 		mutex_spin_exit(&timer_lock);
1276 }
1277 
1278 static void
1279 itimerfree(struct ptimers *pts, int index)
1280 {
1281 	struct ptimer *pt;
1282 
1283 	KASSERT(mutex_owned(&timer_lock));
1284 
1285 	pt = pts->pts_timers[index];
1286 	pts->pts_timers[index] = NULL;
1287 	if (!CLOCK_VIRTUAL_P(pt->pt_type))
1288 		callout_halt(&pt->pt_ch, &timer_lock);
1289 	if (pt->pt_queued)
1290 		TAILQ_REMOVE(&timer_queue, pt, pt_chain);
1291 	mutex_spin_exit(&timer_lock);
1292 	if (!CLOCK_VIRTUAL_P(pt->pt_type))
1293 		callout_destroy(&pt->pt_ch);
1294 	pool_put(&ptimer_pool, pt);
1295 }
1296 
1297 /*
1298  * Decrement an interval timer by a specified number
1299  * of nanoseconds, which must be less than a second,
1300  * i.e. < 1000000000.  If the timer expires, then reload
1301  * it.  In this case, carry over (nsec - old value) to
1302  * reduce the value reloaded into the timer so that
1303  * the timer does not drift.  This routine assumes
1304  * that it is called in a context where the timers
1305  * on which it is operating cannot change in value.
1306  */
1307 static int
1308 itimerdecr(struct ptimer *pt, int nsec)
1309 {
1310 	struct itimerspec *itp;
1311 
1312 	KASSERT(mutex_owned(&timer_lock));
1313 	KASSERT(CLOCK_VIRTUAL_P(pt->pt_type));
1314 
1315 	itp = &pt->pt_time;
1316 	if (itp->it_value.tv_nsec < nsec) {
1317 		if (itp->it_value.tv_sec == 0) {
1318 			/* expired, and already in next interval */
1319 			nsec -= itp->it_value.tv_nsec;
1320 			goto expire;
1321 		}
1322 		itp->it_value.tv_nsec += 1000000000;
1323 		itp->it_value.tv_sec--;
1324 	}
1325 	itp->it_value.tv_nsec -= nsec;
1326 	nsec = 0;
1327 	if (timespecisset(&itp->it_value))
1328 		return (1);
1329 	/* expired, exactly at end of interval */
1330 expire:
1331 	if (timespecisset(&itp->it_interval)) {
1332 		itp->it_value = itp->it_interval;
1333 		itp->it_value.tv_nsec -= nsec;
1334 		if (itp->it_value.tv_nsec < 0) {
1335 			itp->it_value.tv_nsec += 1000000000;
1336 			itp->it_value.tv_sec--;
1337 		}
1338 		timer_settime(pt);
1339 	} else
1340 		itp->it_value.tv_nsec = 0;		/* sec is already 0 */
1341 	return (0);
1342 }
1343 
1344 static void
1345 itimerfire(struct ptimer *pt)
1346 {
1347 
1348 	KASSERT(mutex_owned(&timer_lock));
1349 
1350 	/*
1351 	 * XXX Can overrun, but we don't do signal queueing yet, anyway.
1352 	 * XXX Relying on the clock interrupt is stupid.
1353 	 */
1354 	if (pt->pt_ev.sigev_notify != SIGEV_SIGNAL || pt->pt_queued) {
1355 		return;
1356 	}
1357 	TAILQ_INSERT_TAIL(&timer_queue, pt, pt_chain);
1358 	pt->pt_queued = true;
1359 	softint_schedule(timer_sih);
1360 }
1361 
1362 void
1363 timer_tick(lwp_t *l, bool user)
1364 {
1365 	struct ptimers *pts;
1366 	struct ptimer *pt;
1367 	proc_t *p;
1368 
1369 	p = l->l_proc;
1370 	if (p->p_timers == NULL)
1371 		return;
1372 
1373 	mutex_spin_enter(&timer_lock);
1374 	if ((pts = l->l_proc->p_timers) != NULL) {
1375 		/*
1376 		 * Run current process's virtual and profile time, as needed.
1377 		 */
1378 		if (user && (pt = LIST_FIRST(&pts->pts_virtual)) != NULL)
1379 			if (itimerdecr(pt, tick * 1000) == 0)
1380 				itimerfire(pt);
1381 		if ((pt = LIST_FIRST(&pts->pts_prof)) != NULL)
1382 			if (itimerdecr(pt, tick * 1000) == 0)
1383 				itimerfire(pt);
1384 	}
1385 	mutex_spin_exit(&timer_lock);
1386 }
1387 
1388 static void
1389 timer_intr(void *cookie)
1390 {
1391 	ksiginfo_t ksi;
1392 	struct ptimer *pt;
1393 	proc_t *p;
1394 
1395 	mutex_enter(proc_lock);
1396 	mutex_spin_enter(&timer_lock);
1397 	while ((pt = TAILQ_FIRST(&timer_queue)) != NULL) {
1398 		TAILQ_REMOVE(&timer_queue, pt, pt_chain);
1399 		KASSERT(pt->pt_queued);
1400 		pt->pt_queued = false;
1401 
1402 		if (pt->pt_proc->p_timers == NULL) {
1403 			/* Process is dying. */
1404 			continue;
1405 		}
1406 		p = pt->pt_proc;
1407 		if (pt->pt_ev.sigev_notify != SIGEV_SIGNAL) {
1408 			continue;
1409 		}
1410 		if (sigismember(&p->p_sigpend.sp_set, pt->pt_ev.sigev_signo)) {
1411 			pt->pt_overruns++;
1412 			continue;
1413 		}
1414 
1415 		KSI_INIT(&ksi);
1416 		ksi.ksi_signo = pt->pt_ev.sigev_signo;
1417 		ksi.ksi_code = SI_TIMER;
1418 		ksi.ksi_value = pt->pt_ev.sigev_value;
1419 		pt->pt_poverruns = pt->pt_overruns;
1420 		pt->pt_overruns = 0;
1421 		mutex_spin_exit(&timer_lock);
1422 		kpsignal(p, &ksi, NULL);
1423 		mutex_spin_enter(&timer_lock);
1424 	}
1425 	mutex_spin_exit(&timer_lock);
1426 	mutex_exit(proc_lock);
1427 }
1428 
1429 /*
1430  * Check if the time will wrap if set to ts.
1431  *
1432  * ts - timespec describing the new time
1433  * delta - the delta between the current time and ts
1434  */
1435 bool
1436 time_wraps(struct timespec *ts, struct timespec *delta)
1437 {
1438 
1439 	/*
1440 	 * Don't allow the time to be set forward so far it
1441 	 * will wrap and become negative, thus allowing an
1442 	 * attacker to bypass the next check below.  The
1443 	 * cutoff is 1 year before rollover occurs, so even
1444 	 * if the attacker uses adjtime(2) to move the time
1445 	 * past the cutoff, it will take a very long time
1446 	 * to get to the wrap point.
1447 	 */
1448 	if ((ts->tv_sec > LLONG_MAX - 365*24*60*60) ||
1449 	    (delta->tv_sec < 0 || delta->tv_nsec < 0))
1450 		return true;
1451 
1452 	return false;
1453 }
1454