xref: /netbsd-src/sys/kern/kern_time.c (revision eb7c1594f145c931049e1fd9eb056a5987e87e59)
1 /*	$NetBSD: kern_time.c,v 1.72 2003/08/07 16:31:51 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000 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.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1982, 1986, 1989, 1993
41  *	The Regents of the University of California.  All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)kern_time.c	8.4 (Berkeley) 5/26/95
68  */
69 
70 #include <sys/cdefs.h>
71 __KERNEL_RCSID(0, "$NetBSD: kern_time.c,v 1.72 2003/08/07 16:31:51 agc Exp $");
72 
73 #include "fs_nfs.h"
74 #include "opt_nfs.h"
75 #include "opt_nfsserver.h"
76 
77 #include <sys/param.h>
78 #include <sys/resourcevar.h>
79 #include <sys/kernel.h>
80 #include <sys/systm.h>
81 #include <sys/malloc.h>
82 #include <sys/proc.h>
83 #include <sys/sa.h>
84 #include <sys/savar.h>
85 #include <sys/vnode.h>
86 #include <sys/signalvar.h>
87 #include <sys/syslog.h>
88 
89 #include <sys/mount.h>
90 #include <sys/syscallargs.h>
91 
92 #include <uvm/uvm_extern.h>
93 
94 #if defined(NFS) || defined(NFSSERVER)
95 #include <nfs/rpcv2.h>
96 #include <nfs/nfsproto.h>
97 #include <nfs/nfs_var.h>
98 #endif
99 
100 #include <machine/cpu.h>
101 
102 static void timerupcall(struct lwp *, void *);
103 
104 
105 /* Time of day and interval timer support.
106  *
107  * These routines provide the kernel entry points to get and set
108  * the time-of-day and per-process interval timers.  Subroutines
109  * here provide support for adding and subtracting timeval structures
110  * and decrementing interval timers, optionally reloading the interval
111  * timers when they expire.
112  */
113 
114 /* This function is used by clock_settime and settimeofday */
115 int
116 settime(struct timeval *tv)
117 {
118 	struct timeval delta;
119 	struct cpu_info *ci;
120 	int s;
121 
122 	/* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
123 	s = splclock();
124 	timersub(tv, &time, &delta);
125 	if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) {
126 		splx(s);
127 		return (EPERM);
128 	}
129 #ifdef notyet
130 	if ((delta.tv_sec < 86400) && securelevel > 0) {
131 		splx(s);
132 		return (EPERM);
133 	}
134 #endif
135 	time = *tv;
136 	(void) spllowersoftclock();
137 	timeradd(&boottime, &delta, &boottime);
138 	/*
139 	 * XXXSMP
140 	 * This is wrong.  We should traverse a list of all
141 	 * CPUs and add the delta to the runtime of those
142 	 * CPUs which have a process on them.
143 	 */
144 	ci = curcpu();
145 	timeradd(&ci->ci_schedstate.spc_runtime, &delta,
146 	    &ci->ci_schedstate.spc_runtime);
147 #	if (defined(NFS) && !defined (NFS_V2_ONLY)) || defined(NFSSERVER)
148 		nqnfs_lease_updatetime(delta.tv_sec);
149 #	endif
150 	splx(s);
151 	resettodr();
152 	return (0);
153 }
154 
155 /* ARGSUSED */
156 int
157 sys_clock_gettime(struct lwp *l, void *v, register_t *retval)
158 {
159 	struct sys_clock_gettime_args /* {
160 		syscallarg(clockid_t) clock_id;
161 		syscallarg(struct timespec *) tp;
162 	} */ *uap = v;
163 	clockid_t clock_id;
164 	struct timeval atv;
165 	struct timespec ats;
166 	int s;
167 
168 	clock_id = SCARG(uap, clock_id);
169 	switch (clock_id) {
170 	case CLOCK_REALTIME:
171 		microtime(&atv);
172 		TIMEVAL_TO_TIMESPEC(&atv,&ats);
173 		break;
174 	case CLOCK_MONOTONIC:
175 		/* XXX "hz" granularity */
176 		s = splclock();
177 		atv = mono_time;
178 		splx(s);
179 		TIMEVAL_TO_TIMESPEC(&atv,&ats);
180 		break;
181 	default:
182 		return (EINVAL);
183 	}
184 
185 	return copyout(&ats, SCARG(uap, tp), sizeof(ats));
186 }
187 
188 /* ARGSUSED */
189 int
190 sys_clock_settime(l, v, retval)
191 	struct lwp *l;
192 	void *v;
193 	register_t *retval;
194 {
195 	struct sys_clock_settime_args /* {
196 		syscallarg(clockid_t) clock_id;
197 		syscallarg(const struct timespec *) tp;
198 	} */ *uap = v;
199 	struct proc *p = l->l_proc;
200 	int error;
201 
202 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
203 		return (error);
204 
205 	return (clock_settime1(SCARG(uap, clock_id), SCARG(uap, tp)));
206 }
207 
208 
209 int
210 clock_settime1(clock_id, tp)
211 	clockid_t clock_id;
212 	const struct timespec *tp;
213 {
214 	struct timespec ats;
215 	struct timeval atv;
216 	int error;
217 
218 	if ((error = copyin(tp, &ats, sizeof(ats))) != 0)
219 		return (error);
220 
221 	switch (clock_id) {
222 	case CLOCK_REALTIME:
223 		TIMESPEC_TO_TIMEVAL(&atv, &ats);
224 		if ((error = settime(&atv)) != 0)
225 			return (error);
226 		break;
227 	case CLOCK_MONOTONIC:
228 		return (EINVAL);	/* read-only clock */
229 	default:
230 		return (EINVAL);
231 	}
232 
233 	return 0;
234 }
235 
236 int
237 sys_clock_getres(struct lwp *l, void *v, register_t *retval)
238 {
239 	struct sys_clock_getres_args /* {
240 		syscallarg(clockid_t) clock_id;
241 		syscallarg(struct timespec *) tp;
242 	} */ *uap = v;
243 	clockid_t clock_id;
244 	struct timespec ts;
245 	int error = 0;
246 
247 	clock_id = SCARG(uap, clock_id);
248 	switch (clock_id) {
249 	case CLOCK_REALTIME:
250 	case CLOCK_MONOTONIC:
251 		ts.tv_sec = 0;
252 		ts.tv_nsec = 1000000000 / hz;
253 		break;
254 	default:
255 		return (EINVAL);
256 	}
257 
258 	if (SCARG(uap, tp))
259 		error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
260 
261 	return error;
262 }
263 
264 /* ARGSUSED */
265 int
266 sys_nanosleep(struct lwp *l, void *v, register_t *retval)
267 {
268 	static int nanowait;
269 	struct sys_nanosleep_args/* {
270 		syscallarg(struct timespec *) rqtp;
271 		syscallarg(struct timespec *) rmtp;
272 	} */ *uap = v;
273 	struct timespec rqt;
274 	struct timespec rmt;
275 	struct timeval atv, utv;
276 	int error, s, timo;
277 
278 	error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt,
279 		       sizeof(struct timespec));
280 	if (error)
281 		return (error);
282 
283 	TIMESPEC_TO_TIMEVAL(&atv,&rqt)
284 	if (itimerfix(&atv) || atv.tv_sec > 1000000000)
285 		return (EINVAL);
286 
287 	s = splclock();
288 	timeradd(&atv,&time,&atv);
289 	timo = hzto(&atv);
290 	/*
291 	 * Avoid inadvertantly sleeping forever
292 	 */
293 	if (timo == 0)
294 		timo = 1;
295 	splx(s);
296 
297 	error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo);
298 	if (error == ERESTART)
299 		error = EINTR;
300 	if (error == EWOULDBLOCK)
301 		error = 0;
302 
303 	if (SCARG(uap, rmtp)) {
304 		int error;
305 
306 		s = splclock();
307 		utv = time;
308 		splx(s);
309 
310 		timersub(&atv, &utv, &utv);
311 		if (utv.tv_sec < 0)
312 			timerclear(&utv);
313 
314 		TIMEVAL_TO_TIMESPEC(&utv,&rmt);
315 		error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp),
316 			sizeof(rmt));
317 		if (error)
318 			return (error);
319 	}
320 
321 	return error;
322 }
323 
324 /* ARGSUSED */
325 int
326 sys_gettimeofday(struct lwp *l, void *v, register_t *retval)
327 {
328 	struct sys_gettimeofday_args /* {
329 		syscallarg(struct timeval *) tp;
330 		syscallarg(struct timezone *) tzp;
331 	} */ *uap = v;
332 	struct timeval atv;
333 	int error = 0;
334 	struct timezone tzfake;
335 
336 	if (SCARG(uap, tp)) {
337 		microtime(&atv);
338 		error = copyout(&atv, SCARG(uap, tp), sizeof(atv));
339 		if (error)
340 			return (error);
341 	}
342 	if (SCARG(uap, tzp)) {
343 		/*
344 		 * NetBSD has no kernel notion of time zone, so we just
345 		 * fake up a timezone struct and return it if demanded.
346 		 */
347 		tzfake.tz_minuteswest = 0;
348 		tzfake.tz_dsttime = 0;
349 		error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake));
350 	}
351 	return (error);
352 }
353 
354 /* ARGSUSED */
355 int
356 sys_settimeofday(struct lwp *l, void *v, register_t *retval)
357 {
358 	struct sys_settimeofday_args /* {
359 		syscallarg(const struct timeval *) tv;
360 		syscallarg(const struct timezone *) tzp;
361 	} */ *uap = v;
362 	struct proc *p = l->l_proc;
363 	int error;
364 
365 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
366 		return (error);
367 
368 	return settimeofday1(SCARG(uap, tv), SCARG(uap, tzp), p);
369 }
370 
371 int
372 settimeofday1(utv, utzp, p)
373 	const struct timeval *utv;
374 	const struct timezone *utzp;
375 	struct proc *p;
376 {
377 	struct timeval atv;
378 	struct timezone atz;
379 	struct timeval *tv = NULL;
380 	struct timezone *tzp = NULL;
381 	int error;
382 
383 	/* Verify all parameters before changing time. */
384 	if (utv) {
385 		if ((error = copyin(utv, &atv, sizeof(atv))) != 0)
386 			return (error);
387 		tv = &atv;
388 	}
389 	/* XXX since we don't use tz, probably no point in doing copyin. */
390 	if (utzp) {
391 		if ((error = copyin(utzp, &atz, sizeof(atz))) != 0)
392 			return (error);
393 		tzp = &atz;
394 	}
395 
396 	if (tv)
397 		if ((error = settime(tv)) != 0)
398 			return (error);
399 	/*
400 	 * NetBSD has no kernel notion of time zone, and only an
401 	 * obsolete program would try to set it, so we log a warning.
402 	 */
403 	if (tzp)
404 		log(LOG_WARNING, "pid %d attempted to set the "
405 		    "(obsolete) kernel time zone\n", p->p_pid);
406 	return (0);
407 }
408 
409 int	tickdelta;			/* current clock skew, us. per tick */
410 long	timedelta;			/* unapplied time correction, us. */
411 long	bigadj = 1000000;		/* use 10x skew above bigadj us. */
412 int	time_adjusted;			/* set if an adjustment is made */
413 
414 /* ARGSUSED */
415 int
416 sys_adjtime(struct lwp *l, void *v, register_t *retval)
417 {
418 	struct sys_adjtime_args /* {
419 		syscallarg(const struct timeval *) delta;
420 		syscallarg(struct timeval *) olddelta;
421 	} */ *uap = v;
422 	struct proc *p = l->l_proc;
423 	int error;
424 
425 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
426 		return (error);
427 
428 	return adjtime1(SCARG(uap, delta), SCARG(uap, olddelta), p);
429 }
430 
431 int
432 adjtime1(delta, olddelta, p)
433 	const struct timeval *delta;
434 	struct timeval *olddelta;
435 	struct proc *p;
436 {
437 	struct timeval atv;
438 	long ndelta, ntickdelta, odelta;
439 	int error;
440 	int s;
441 
442 	error = copyin(delta, &atv, sizeof(struct timeval));
443 	if (error)
444 		return (error);
445 
446 	if (olddelta != NULL) {
447 		if (uvm_useracc((caddr_t)olddelta,
448 		    sizeof(struct timeval), B_WRITE) == FALSE)
449 			return (EFAULT);
450 	}
451 
452 	/*
453 	 * Compute the total correction and the rate at which to apply it.
454 	 * Round the adjustment down to a whole multiple of the per-tick
455 	 * delta, so that after some number of incremental changes in
456 	 * hardclock(), tickdelta will become zero, lest the correction
457 	 * overshoot and start taking us away from the desired final time.
458 	 */
459 	ndelta = atv.tv_sec * 1000000 + atv.tv_usec;
460 	if (ndelta > bigadj || ndelta < -bigadj)
461 		ntickdelta = 10 * tickadj;
462 	else
463 		ntickdelta = tickadj;
464 	if (ndelta % ntickdelta)
465 		ndelta = ndelta / ntickdelta * ntickdelta;
466 
467 	/*
468 	 * To make hardclock()'s job easier, make the per-tick delta negative
469 	 * if we want time to run slower; then hardclock can simply compute
470 	 * tick + tickdelta, and subtract tickdelta from timedelta.
471 	 */
472 	if (ndelta < 0)
473 		ntickdelta = -ntickdelta;
474 	if (ndelta != 0)
475 		/* We need to save the system clock time during shutdown */
476 		time_adjusted |= 1;
477 	s = splclock();
478 	odelta = timedelta;
479 	timedelta = ndelta;
480 	tickdelta = ntickdelta;
481 	splx(s);
482 
483 	if (olddelta) {
484 		atv.tv_sec = odelta / 1000000;
485 		atv.tv_usec = odelta % 1000000;
486 		(void) copyout(&atv, olddelta, sizeof(struct timeval));
487 	}
488 	return (0);
489 }
490 
491 /*
492  * Interval timer support. Both the BSD getitimer() family and the POSIX
493  * timer_*() family of routines are supported.
494  *
495  * All timers are kept in an array pointed to by p_timers, which is
496  * allocated on demand - many processes don't use timers at all. The
497  * first three elements in this array are reserved for the BSD timers:
498  * element 0 is ITIMER_REAL, element 1 is ITIMER_VIRTUAL, and element
499  * 2 is ITIMER_PROF. The rest may be allocated by the timer_create()
500  * syscall.
501  *
502  * Realtime timers are kept in the ptimer structure as an absolute
503  * time; virtual time timers are kept as a linked list of deltas.
504  * Virtual time timers are processed in the hardclock() routine of
505  * kern_clock.c.  The real time timer is processed by a callout
506  * routine, called from the softclock() routine.  Since a callout may
507  * be delayed in real time due to interrupt processing in the system,
508  * it is possible for the real time timeout routine (realtimeexpire,
509  * given below), to be delayed in real time past when it is supposed
510  * to occur.  It does not suffice, therefore, to reload the real timer
511  * .it_value from the real time timers .it_interval.  Rather, we
512  * compute the next time in absolute time the timer should go off.  */
513 
514 /* Allocate a POSIX realtime timer. */
515 int
516 sys_timer_create(struct lwp *l, void *v, register_t *retval)
517 {
518 	struct sys_timer_create_args /* {
519 		syscallarg(clockid_t) clock_id;
520 		syscallarg(struct sigevent *) evp;
521 		syscallarg(timer_t *) timerid;
522 	} */ *uap = v;
523 	struct proc *p = l->l_proc;
524 	clockid_t id;
525 	struct sigevent *evp;
526 	struct ptimer *pt;
527 	timer_t timerid;
528 	int error;
529 
530 	id = SCARG(uap, clock_id);
531 	if (id < CLOCK_REALTIME ||
532 	    id > CLOCK_PROF)
533 		return (EINVAL);
534 
535 	if (p->p_timers == NULL)
536 		timers_alloc(p);
537 
538 	/* Find a free timer slot, skipping those reserved for setitimer(). */
539 	for (timerid = 3; timerid < TIMER_MAX; timerid++)
540 		if (p->p_timers->pts_timers[timerid] == NULL)
541 			break;
542 
543 	if (timerid == TIMER_MAX)
544 		return EAGAIN;
545 
546 	pt = pool_get(&ptimer_pool, PR_WAITOK);
547 	evp = SCARG(uap, evp);
548 	if (evp) {
549 		if (((error =
550 		    copyin(evp, &pt->pt_ev, sizeof (pt->pt_ev))) != 0) ||
551 		    ((pt->pt_ev.sigev_notify < SIGEV_NONE) ||
552 			(pt->pt_ev.sigev_notify > SIGEV_SA))) {
553 			pool_put(&ptimer_pool, pt);
554 			return (error ? error : EINVAL);
555 		}
556 	} else {
557 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
558 		switch (id) {
559 		case CLOCK_REALTIME:
560 			pt->pt_ev.sigev_signo = SIGALRM;
561 			break;
562 		case CLOCK_VIRTUAL:
563 			pt->pt_ev.sigev_signo = SIGVTALRM;
564 			break;
565 		case CLOCK_PROF:
566 			pt->pt_ev.sigev_signo = SIGPROF;
567 			break;
568 		}
569 		pt->pt_ev.sigev_value.sival_int = timerid;
570 	}
571 	pt->pt_info.si_signo = pt->pt_ev.sigev_signo;
572 	pt->pt_info.si_errno = 0;
573 	pt->pt_info.si_code = 0;
574 	pt->pt_info.si_pid = p->p_pid;
575 	pt->pt_info.si_uid = p->p_cred->p_ruid;
576 	pt->pt_info.si_sigval = pt->pt_ev.sigev_value;
577 
578 	pt->pt_type = id;
579 	pt->pt_proc = p;
580 	pt->pt_overruns = 0;
581 	pt->pt_poverruns = 0;
582 	pt->pt_entry = timerid;
583 	timerclear(&pt->pt_time.it_value);
584 	if (id == CLOCK_REALTIME)
585 		callout_init(&pt->pt_ch);
586 	else
587 		pt->pt_active = 0;
588 
589 	p->p_timers->pts_timers[timerid] = pt;
590 
591 	return copyout(&timerid, SCARG(uap, timerid), sizeof(timerid));
592 }
593 
594 
595 /* Delete a POSIX realtime timer */
596 int
597 sys_timer_delete(struct lwp *l, void *v, register_t *retval)
598 {
599 	struct sys_timer_delete_args /*  {
600 		syscallarg(timer_t) timerid;
601 	} */ *uap = v;
602 	struct proc *p = l->l_proc;
603 	timer_t timerid;
604 	struct ptimer *pt, *ptn;
605 	int s;
606 
607 	timerid = SCARG(uap, timerid);
608 
609 	if ((p->p_timers == NULL) ||
610 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
611 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
612 		return (EINVAL);
613 
614 	if (pt->pt_type == CLOCK_REALTIME)
615 		callout_stop(&pt->pt_ch);
616 	else if (pt->pt_active) {
617 		s = splclock();
618 		ptn = LIST_NEXT(pt, pt_list);
619 		LIST_REMOVE(pt, pt_list);
620 		for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
621 			timeradd(&pt->pt_time.it_value, &ptn->pt_time.it_value,
622 			    &ptn->pt_time.it_value);
623 		splx(s);
624 	}
625 
626 	p->p_timers->pts_timers[timerid] = NULL;
627 	pool_put(&ptimer_pool, pt);
628 
629 	return (0);
630 }
631 
632 /*
633  * Set up the given timer. The value in pt->pt_time.it_value is taken
634  * to be an absolute time for CLOCK_REALTIME timers and a relative
635  * time for virtual timers.
636  * Must be called at splclock().
637  */
638 void
639 timer_settime(struct ptimer *pt)
640 {
641 	struct ptimer *ptn, *pptn;
642 	struct ptlist *ptl;
643 
644 	if (pt->pt_type == CLOCK_REALTIME) {
645 		callout_stop(&pt->pt_ch);
646 		if (timerisset(&pt->pt_time.it_value)) {
647 			/*
648 			 * Don't need to check hzto() return value, here.
649 			 * callout_reset() does it for us.
650 			 */
651 			callout_reset(&pt->pt_ch, hzto(&pt->pt_time.it_value),
652 			    realtimerexpire, pt);
653 		}
654 	} else {
655 		if (pt->pt_active) {
656 			ptn = LIST_NEXT(pt, pt_list);
657 			LIST_REMOVE(pt, pt_list);
658 			for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
659 				timeradd(&pt->pt_time.it_value,
660 				    &ptn->pt_time.it_value,
661 				    &ptn->pt_time.it_value);
662 		}
663 		if (timerisset(&pt->pt_time.it_value)) {
664 			if (pt->pt_type == CLOCK_VIRTUAL)
665 				ptl = &pt->pt_proc->p_timers->pts_virtual;
666 			else
667 				ptl = &pt->pt_proc->p_timers->pts_prof;
668 
669 			for (ptn = LIST_FIRST(ptl), pptn = NULL;
670 			     ptn && timercmp(&pt->pt_time.it_value,
671 				 &ptn->pt_time.it_value, >);
672 			     pptn = ptn, ptn = LIST_NEXT(ptn, pt_list))
673 				timersub(&pt->pt_time.it_value,
674 				    &ptn->pt_time.it_value,
675 				    &pt->pt_time.it_value);
676 
677 			if (pptn)
678 				LIST_INSERT_AFTER(pptn, pt, pt_list);
679 			else
680 				LIST_INSERT_HEAD(ptl, pt, pt_list);
681 
682 			for ( ; ptn ; ptn = LIST_NEXT(ptn, pt_list))
683 				timersub(&ptn->pt_time.it_value,
684 				    &pt->pt_time.it_value,
685 				    &ptn->pt_time.it_value);
686 
687 			pt->pt_active = 1;
688 		} else
689 			pt->pt_active = 0;
690 	}
691 }
692 
693 void
694 timer_gettime(struct ptimer *pt, struct itimerval *aitv)
695 {
696 	struct ptimer *ptn;
697 
698 	*aitv = pt->pt_time;
699 	if (pt->pt_type == CLOCK_REALTIME) {
700 		/*
701 		 * Convert from absolute to relative time in .it_value
702 		 * part of real time timer.  If time for real time
703 		 * timer has passed return 0, else return difference
704 		 * between current time and time for the timer to go
705 		 * off.
706 		 */
707 		if (timerisset(&aitv->it_value)) {
708 			if (timercmp(&aitv->it_value, &time, <))
709 				timerclear(&aitv->it_value);
710 			else
711 				timersub(&aitv->it_value, &time,
712 				    &aitv->it_value);
713 		}
714 	} else if (pt->pt_active) {
715 		if (pt->pt_type == CLOCK_VIRTUAL)
716 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_virtual);
717 		else
718 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_prof);
719 		for ( ; ptn && ptn != pt; ptn = LIST_NEXT(ptn, pt_list))
720 			timeradd(&aitv->it_value,
721 			    &ptn->pt_time.it_value, &aitv->it_value);
722 		KASSERT(ptn != NULL); /* pt should be findable on the list */
723 	} else
724 		timerclear(&aitv->it_value);
725 }
726 
727 
728 
729 /* Set and arm a POSIX realtime timer */
730 int
731 sys_timer_settime(struct lwp *l, void *v, register_t *retval)
732 {
733 	struct sys_timer_settime_args /* {
734 		syscallarg(timer_t) timerid;
735 		syscallarg(int) flags;
736 		syscallarg(const struct itimerspec *) value;
737 		syscallarg(struct itimerspec *) ovalue;
738 	} */ *uap = v;
739 	struct proc *p = l->l_proc;
740 	int error, s, timerid;
741 	struct itimerval val, oval;
742 	struct itimerspec value, ovalue;
743 	struct ptimer *pt;
744 
745 	timerid = SCARG(uap, timerid);
746 
747 	if ((p->p_timers == NULL) ||
748 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
749 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
750 		return (EINVAL);
751 
752 	if ((error = copyin(SCARG(uap, value), &value,
753 	    sizeof(struct itimerspec))) != 0)
754 		return (error);
755 
756 	TIMESPEC_TO_TIMEVAL(&val.it_value, &value.it_value);
757 	TIMESPEC_TO_TIMEVAL(&val.it_interval, &value.it_interval);
758 	if (itimerfix(&val.it_value) || itimerfix(&val.it_interval))
759 		return (EINVAL);
760 
761 	oval = pt->pt_time;
762 	pt->pt_time = val;
763 
764 	s = splclock();
765 	/*
766 	 * If we've been passed a relative time for a realtime timer,
767 	 * convert it to absolute; if an absolute time for a virtual
768 	 * timer, convert it to relative and make sure we don't set it
769 	 * to zero, which would cancel the timer, or let it go
770 	 * negative, which would confuse the comparison tests.
771 	 */
772 	if (timerisset(&pt->pt_time.it_value)) {
773 		if (pt->pt_type == CLOCK_REALTIME) {
774 			if ((SCARG(uap, flags) & TIMER_ABSTIME) == 0)
775 				timeradd(&pt->pt_time.it_value, &time,
776 				    &pt->pt_time.it_value);
777 		} else {
778 			if ((SCARG(uap, flags) & TIMER_ABSTIME) != 0) {
779 				timersub(&pt->pt_time.it_value, &time,
780 				    &pt->pt_time.it_value);
781 				if (!timerisset(&pt->pt_time.it_value) ||
782 				    pt->pt_time.it_value.tv_sec < 0) {
783 					pt->pt_time.it_value.tv_sec = 0;
784 					pt->pt_time.it_value.tv_usec = 1;
785 				}
786 			}
787 		}
788 	}
789 
790 	timer_settime(pt);
791 	splx(s);
792 
793 	if (SCARG(uap, ovalue)) {
794 		TIMEVAL_TO_TIMESPEC(&oval.it_value, &ovalue.it_value);
795 		TIMEVAL_TO_TIMESPEC(&oval.it_interval, &ovalue.it_interval);
796 		return copyout(&ovalue, SCARG(uap, ovalue),
797 		    sizeof(struct itimerspec));
798 	}
799 
800 	return (0);
801 }
802 
803 /* Return the time remaining until a POSIX timer fires. */
804 int
805 sys_timer_gettime(struct lwp *l, void *v, register_t *retval)
806 {
807 	struct sys_timer_gettime_args /* {
808 		syscallarg(timer_t) timerid;
809 		syscallarg(struct itimerspec *) value;
810 	} */ *uap = v;
811 	struct itimerval aitv;
812 	struct itimerspec its;
813 	struct proc *p = l->l_proc;
814 	int s, timerid;
815 	struct ptimer *pt;
816 
817 	timerid = SCARG(uap, timerid);
818 
819 	if ((p->p_timers == NULL) ||
820 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
821 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
822 		return (EINVAL);
823 
824 	s = splclock();
825 	timer_gettime(pt, &aitv);
826 	splx(s);
827 
828 	TIMEVAL_TO_TIMESPEC(&aitv.it_interval, &its.it_interval);
829 	TIMEVAL_TO_TIMESPEC(&aitv.it_value, &its.it_value);
830 
831 	return copyout(&its, SCARG(uap, value), sizeof(its));
832 }
833 
834 /*
835  * Return the count of the number of times a periodic timer expired
836  * while a notification was already pending. The counter is reset when
837  * a timer expires and a notification can be posted.
838  */
839 int
840 sys_timer_getoverrun(struct lwp *l, void *v, register_t *retval)
841 {
842 	struct sys_timer_getoverrun_args /* {
843 		syscallarg(timer_t) timerid;
844 	} */ *uap = v;
845 	struct proc *p = l->l_proc;
846 	int timerid;
847 	struct ptimer *pt;
848 
849 	timerid = SCARG(uap, timerid);
850 
851 	if ((p->p_timers == NULL) ||
852 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
853 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
854 		return (EINVAL);
855 
856 	*retval = pt->pt_poverruns;
857 
858 	return (0);
859 }
860 
861 /* Glue function that triggers an upcall; called from userret(). */
862 static void
863 timerupcall(struct lwp *l, void *arg)
864 {
865 	struct ptimers *pt = (struct ptimers *)arg;
866 	unsigned int i, fired, done;
867 	KERNEL_PROC_LOCK(l);
868 
869 	{
870 		struct proc	*p = l->l_proc;
871 		struct sadata *sa = p->p_sa;
872 
873 		/* Bail out if we do not own the virtual processor */
874 		if (sa->sa_vp != l) {
875 			KERNEL_PROC_UNLOCK(l);
876 			return ;
877 		}
878 	}
879 
880 	fired = pt->pts_fired;
881 	done = 0;
882 	while ((i = ffs(fired)) != 0) {
883 		i--;
884 		if (sa_upcall(l, SA_UPCALL_SIGEV | SA_UPCALL_DEFER, NULL, l,
885 		    sizeof(siginfo_t), &pt->pts_timers[i]->pt_info) == 0)
886 			done |= 1 << i;
887 		fired &= ~(1 << i);
888 	}
889 	pt->pts_fired &= ~done;
890 	if (pt->pts_fired == 0)
891 		l->l_proc->p_userret = NULL;
892 
893 	KERNEL_PROC_UNLOCK(l);
894 }
895 
896 
897 /*
898  * Real interval timer expired:
899  * send process whose timer expired an alarm signal.
900  * If time is not set up to reload, then just return.
901  * Else compute next time timer should go off which is > current time.
902  * This is where delay in processing this timeout causes multiple
903  * SIGALRM calls to be compressed into one.
904  */
905 void
906 realtimerexpire(void *arg)
907 {
908 	struct ptimer *pt;
909 	int s;
910 
911 	pt = (struct ptimer *)arg;
912 
913 	itimerfire(pt);
914 
915 	if (!timerisset(&pt->pt_time.it_interval)) {
916 		timerclear(&pt->pt_time.it_value);
917 		return;
918 	}
919 	for (;;) {
920 		s = splclock();
921 		timeradd(&pt->pt_time.it_value,
922 		    &pt->pt_time.it_interval, &pt->pt_time.it_value);
923 		if (timercmp(&pt->pt_time.it_value, &time, >)) {
924 			/*
925 			 * Don't need to check hzto() return value, here.
926 			 * callout_reset() does it for us.
927 			 */
928 			callout_reset(&pt->pt_ch, hzto(&pt->pt_time.it_value),
929 			    realtimerexpire, pt);
930 			splx(s);
931 			return;
932 		}
933 		splx(s);
934 		pt->pt_overruns++;
935 	}
936 }
937 
938 /* BSD routine to get the value of an interval timer. */
939 /* ARGSUSED */
940 int
941 sys_getitimer(struct lwp *l, void *v, register_t *retval)
942 {
943 	struct sys_getitimer_args /* {
944 		syscallarg(int) which;
945 		syscallarg(struct itimerval *) itv;
946 	} */ *uap = v;
947 	struct proc *p = l->l_proc;
948 	struct itimerval aitv;
949 	int s, which;
950 
951 	which = SCARG(uap, which);
952 
953 	if ((u_int)which > ITIMER_PROF)
954 		return (EINVAL);
955 
956 	if ((p->p_timers == NULL) || (p->p_timers->pts_timers[which] == NULL)){
957 		timerclear(&aitv.it_value);
958 		timerclear(&aitv.it_interval);
959 	} else {
960 		s = splclock();
961 		timer_gettime(p->p_timers->pts_timers[which], &aitv);
962 		splx(s);
963 	}
964 
965 	return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval)));
966 
967 }
968 
969 /* BSD routine to set/arm an interval timer. */
970 /* ARGSUSED */
971 int
972 sys_setitimer(struct lwp *l, void *v, register_t *retval)
973 {
974 	struct sys_setitimer_args /* {
975 		syscallarg(int) which;
976 		syscallarg(const struct itimerval *) itv;
977 		syscallarg(struct itimerval *) oitv;
978 	} */ *uap = v;
979 	struct proc *p = l->l_proc;
980 	int which = SCARG(uap, which);
981 	struct sys_getitimer_args getargs;
982 	struct itimerval aitv;
983 	const struct itimerval *itvp;
984 	struct ptimer *pt;
985 	int s, error;
986 
987 	if ((u_int)which > ITIMER_PROF)
988 		return (EINVAL);
989 	itvp = SCARG(uap, itv);
990 	if (itvp &&
991 	    (error = copyin(itvp, &aitv, sizeof(struct itimerval)) != 0))
992 		return (error);
993 	if (SCARG(uap, oitv) != NULL) {
994 		SCARG(&getargs, which) = which;
995 		SCARG(&getargs, itv) = SCARG(uap, oitv);
996 		if ((error = sys_getitimer(l, &getargs, retval)) != 0)
997 			return (error);
998 	}
999 	if (itvp == 0)
1000 		return (0);
1001 	if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
1002 		return (EINVAL);
1003 
1004 	/*
1005 	 * Don't bother allocating data structures if the process just
1006 	 * wants to clear the timer.
1007 	 */
1008 	if (!timerisset(&aitv.it_value) &&
1009 	    ((p->p_timers == NULL) ||(p->p_timers->pts_timers[which] == NULL)))
1010 		return (0);
1011 
1012 	if (p->p_timers == NULL)
1013 		timers_alloc(p);
1014 	if (p->p_timers->pts_timers[which] == NULL) {
1015 		pt = pool_get(&ptimer_pool, PR_WAITOK);
1016 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
1017 		pt->pt_overruns = 0;
1018 		pt->pt_proc = p;
1019 		pt->pt_type = which;
1020 		pt->pt_entry = which;
1021 		switch (which) {
1022 		case ITIMER_REAL:
1023 			callout_init(&pt->pt_ch);
1024 			pt->pt_ev.sigev_signo = SIGALRM;
1025 			break;
1026 		case ITIMER_VIRTUAL:
1027 			pt->pt_active = 0;
1028 			pt->pt_ev.sigev_signo = SIGVTALRM;
1029 			break;
1030 		case ITIMER_PROF:
1031 			pt->pt_active = 0;
1032 			pt->pt_ev.sigev_signo = SIGPROF;
1033 			break;
1034 		}
1035 	} else
1036 		pt = p->p_timers->pts_timers[which];
1037 
1038 	pt->pt_time = aitv;
1039 	p->p_timers->pts_timers[which] = pt;
1040 
1041 	s = splclock();
1042 	if ((which == ITIMER_REAL) && timerisset(&pt->pt_time.it_value)) {
1043 		/* Convert to absolute time */
1044 		timeradd(&pt->pt_time.it_value, &time, &pt->pt_time.it_value);
1045 	}
1046 	timer_settime(pt);
1047 	splx(s);
1048 
1049 	return (0);
1050 }
1051 
1052 /* Utility routines to manage the array of pointers to timers. */
1053 void
1054 timers_alloc(struct proc *p)
1055 {
1056 	int i;
1057 	struct ptimers *pts;
1058 
1059 	pts = malloc(sizeof (struct ptimers), M_SUBPROC, 0);
1060 	LIST_INIT(&pts->pts_virtual);
1061 	LIST_INIT(&pts->pts_prof);
1062 	for (i = 0; i < TIMER_MAX; i++)
1063 		pts->pts_timers[i] = NULL;
1064 	pts->pts_fired = 0;
1065 	p->p_timers = pts;
1066 }
1067 
1068 /*
1069  * Clean up the per-process timers. If "which" is set to TIMERS_ALL,
1070  * then clean up all timers and free all the data structures. If
1071  * "which" is set to TIMERS_POSIX, only clean up the timers allocated
1072  * by timer_create(), not the BSD setitimer() timers, and only free the
1073  * structure if none of those remain.
1074  */
1075 void
1076 timers_free(struct proc *p, int which)
1077 {
1078 	int i, s;
1079 	struct ptimers *pts;
1080 	struct ptimer *pt, *ptn;
1081 	struct timeval tv;
1082 
1083 	if (p->p_timers) {
1084 		pts = p->p_timers;
1085 		if (which == TIMERS_ALL)
1086 			i = 0;
1087 		else {
1088 			s = splclock();
1089 			timerclear(&tv);
1090 			for (ptn = LIST_FIRST(&p->p_timers->pts_virtual);
1091 			     ptn && ptn != pts->pts_timers[ITIMER_VIRTUAL];
1092 			     ptn = LIST_NEXT(ptn, pt_list))
1093 				timeradd(&tv, &ptn->pt_time.it_value, &tv);
1094 			LIST_FIRST(&p->p_timers->pts_virtual) = NULL;
1095 			if (ptn) {
1096 				timeradd(&tv, &ptn->pt_time.it_value,
1097 				    &ptn->pt_time.it_value);
1098 				LIST_INSERT_HEAD(&p->p_timers->pts_virtual,
1099 				    ptn, pt_list);
1100 			}
1101 
1102 			timerclear(&tv);
1103 			for (ptn = LIST_FIRST(&p->p_timers->pts_prof);
1104 			     ptn && ptn != pts->pts_timers[ITIMER_PROF];
1105 			     ptn = LIST_NEXT(ptn, pt_list))
1106 				timeradd(&tv, &ptn->pt_time.it_value, &tv);
1107 			LIST_FIRST(&p->p_timers->pts_prof) = NULL;
1108 			if (ptn) {
1109 				timeradd(&tv, &ptn->pt_time.it_value,
1110 				    &ptn->pt_time.it_value);
1111 				LIST_INSERT_HEAD(&p->p_timers->pts_prof, ptn,
1112 				    pt_list);
1113 			}
1114 			splx(s);
1115 			i = 3;
1116 		}
1117 		for ( ; i < TIMER_MAX; i++)
1118 			if ((pt = pts->pts_timers[i]) != NULL) {
1119 				if (pt->pt_type == CLOCK_REALTIME)
1120 					callout_stop(&pt->pt_ch);
1121 				pts->pts_timers[i] = NULL;
1122 				pool_put(&ptimer_pool, pt);
1123 			}
1124 		if ((pts->pts_timers[0] == NULL) &&
1125 		    (pts->pts_timers[1] == NULL) &&
1126 		    (pts->pts_timers[2] == NULL)) {
1127 			p->p_timers = NULL;
1128 			free(pts, M_SUBPROC);
1129 		}
1130 	}
1131 }
1132 
1133 /*
1134  * Check that a proposed value to load into the .it_value or
1135  * .it_interval part of an interval timer is acceptable, and
1136  * fix it to have at least minimal value (i.e. if it is less
1137  * than the resolution of the clock, round it up.)
1138  */
1139 int
1140 itimerfix(struct timeval *tv)
1141 {
1142 
1143 	if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
1144 		return (EINVAL);
1145 	if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
1146 		tv->tv_usec = tick;
1147 	return (0);
1148 }
1149 
1150 /*
1151  * Decrement an interval timer by a specified number
1152  * of microseconds, which must be less than a second,
1153  * i.e. < 1000000.  If the timer expires, then reload
1154  * it.  In this case, carry over (usec - old value) to
1155  * reduce the value reloaded into the timer so that
1156  * the timer does not drift.  This routine assumes
1157  * that it is called in a context where the timers
1158  * on which it is operating cannot change in value.
1159  */
1160 int
1161 itimerdecr(struct ptimer *pt, int usec)
1162 {
1163 	struct itimerval *itp;
1164 
1165 	itp = &pt->pt_time;
1166 	if (itp->it_value.tv_usec < usec) {
1167 		if (itp->it_value.tv_sec == 0) {
1168 			/* expired, and already in next interval */
1169 			usec -= itp->it_value.tv_usec;
1170 			goto expire;
1171 		}
1172 		itp->it_value.tv_usec += 1000000;
1173 		itp->it_value.tv_sec--;
1174 	}
1175 	itp->it_value.tv_usec -= usec;
1176 	usec = 0;
1177 	if (timerisset(&itp->it_value))
1178 		return (1);
1179 	/* expired, exactly at end of interval */
1180 expire:
1181 	if (timerisset(&itp->it_interval)) {
1182 		itp->it_value = itp->it_interval;
1183 		itp->it_value.tv_usec -= usec;
1184 		if (itp->it_value.tv_usec < 0) {
1185 			itp->it_value.tv_usec += 1000000;
1186 			itp->it_value.tv_sec--;
1187 		}
1188 		timer_settime(pt);
1189 	} else
1190 		itp->it_value.tv_usec = 0;		/* sec is already 0 */
1191 	return (0);
1192 }
1193 
1194 void
1195 itimerfire(struct ptimer *pt)
1196 {
1197 	struct proc *p = pt->pt_proc;
1198 #if 0
1199 	int s;
1200 #endif
1201 	if (pt->pt_ev.sigev_notify == SIGEV_SIGNAL) {
1202 		/*
1203 		 * No RT signal infrastructure exists at this time;
1204 		 * just post the signal number and throw away the
1205 		 * value.
1206 		 */
1207 		if (sigismember(&p->p_sigctx.ps_siglist, pt->pt_ev.sigev_signo))
1208 			pt->pt_overruns++;
1209 		else {
1210 			pt->pt_poverruns = pt->pt_overruns;
1211 			pt->pt_overruns = 0;
1212 			psignal(p, pt->pt_ev.sigev_signo);
1213 		}
1214 	} else if (pt->pt_ev.sigev_notify == SIGEV_SA && (p->p_flag & P_SA)) {
1215 		/* Cause the process to generate an upcall when it returns. */
1216 		struct sadata *sa = p->p_sa;
1217 		unsigned int i;
1218 
1219 		if (p->p_userret == NULL) {
1220 			/*
1221 			 * XXX stop signals can be processed inside tsleep,
1222 			 * which can be inside sa_yield's inner loop, which
1223 			 * makes testing for sa_idle alone insuffucent to
1224 			 * determine if we really should call setrunnable.
1225 			 */
1226 #if 0
1227 
1228 		        if ((sa->sa_idle) && (p->p_stat != SSTOP)) {
1229 				SCHED_LOCK(s);
1230 				setrunnable(sa->sa_idle);
1231 				SCHED_UNLOCK(s);
1232 			}
1233 #endif
1234 			pt->pt_poverruns = pt->pt_overruns;
1235 			pt->pt_overruns = 0;
1236 			i = 1 << pt->pt_entry;
1237 			p->p_timers->pts_fired = i;
1238 			p->p_userret = timerupcall;
1239 			p->p_userret_arg = p->p_timers;
1240 
1241 			if (sa->sa_idle)
1242 				wakeup(sa->sa_idle);
1243 
1244 		} else if (p->p_userret == timerupcall) {
1245 			i = 1 << pt->pt_entry;
1246 			if ((p->p_timers->pts_fired & i) == 0) {
1247 				pt->pt_poverruns = pt->pt_overruns;
1248 				pt->pt_overruns = 0;
1249 				p->p_timers->pts_fired |= i;
1250 			} else
1251 				pt->pt_overruns++;
1252 		} else {
1253 			pt->pt_overruns++;
1254 			printf("itimerfire(%d): overrun %d on timer %x (userret is %p)\n",
1255 			    p->p_pid, pt->pt_overruns,
1256 			    pt->pt_ev.sigev_value.sival_int,
1257 			    p->p_userret);
1258 		}
1259 	}
1260 
1261 }
1262 
1263 /*
1264  * ratecheck(): simple time-based rate-limit checking.  see ratecheck(9)
1265  * for usage and rationale.
1266  */
1267 int
1268 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
1269 {
1270 	struct timeval tv, delta;
1271 	int s, rv = 0;
1272 
1273 	s = splclock();
1274 	tv = mono_time;
1275 	splx(s);
1276 
1277 	timersub(&tv, lasttime, &delta);
1278 
1279 	/*
1280 	 * check for 0,0 is so that the message will be seen at least once,
1281 	 * even if interval is huge.
1282 	 */
1283 	if (timercmp(&delta, mininterval, >=) ||
1284 	    (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
1285 		*lasttime = tv;
1286 		rv = 1;
1287 	}
1288 
1289 	return (rv);
1290 }
1291 
1292 /*
1293  * ppsratecheck(): packets (or events) per second limitation.
1294  */
1295 int
1296 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
1297 {
1298 	struct timeval tv, delta;
1299 	int s, rv;
1300 
1301 	s = splclock();
1302 	tv = mono_time;
1303 	splx(s);
1304 
1305 	timersub(&tv, lasttime, &delta);
1306 
1307 	/*
1308 	 * check for 0,0 is so that the message will be seen at least once.
1309 	 * if more than one second have passed since the last update of
1310 	 * lasttime, reset the counter.
1311 	 *
1312 	 * we do increment *curpps even in *curpps < maxpps case, as some may
1313 	 * try to use *curpps for stat purposes as well.
1314 	 */
1315 	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
1316 	    delta.tv_sec >= 1) {
1317 		*lasttime = tv;
1318 		*curpps = 0;
1319 	}
1320 	if (maxpps < 0)
1321 		rv = 1;
1322 	else if (*curpps < maxpps)
1323 		rv = 1;
1324 	else
1325 		rv = 0;
1326 
1327 #if 1 /*DIAGNOSTIC?*/
1328 	/* be careful about wrap-around */
1329 	if (*curpps + 1 > *curpps)
1330 		*curpps = *curpps + 1;
1331 #else
1332 	/*
1333 	 * assume that there's not too many calls to this function.
1334 	 * not sure if the assumption holds, as it depends on *caller's*
1335 	 * behavior, not the behavior of this function.
1336 	 * IMHO it is wrong to make assumption on the caller's behavior,
1337 	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
1338 	 */
1339 	*curpps = *curpps + 1;
1340 #endif
1341 
1342 	return (rv);
1343 }
1344