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kern_time.c revision 1.129
      1 /*	$NetBSD: kern_time.c,v 1.129 2007/10/08 20:06:19 ad Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2000, 2004, 2005 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 1.129 2007/10/08 20:06:19 ad Exp $");
     72 
     73 #include <sys/param.h>
     74 #include <sys/resourcevar.h>
     75 #include <sys/kernel.h>
     76 #include <sys/systm.h>
     77 #include <sys/proc.h>
     78 #include <sys/vnode.h>
     79 #include <sys/signalvar.h>
     80 #include <sys/syslog.h>
     81 #include <sys/timetc.h>
     82 #ifndef __HAVE_TIMECOUNTER
     83 #include <sys/timevar.h>
     84 #endif /* !__HAVE_TIMECOUNTER */
     85 #include <sys/kauth.h>
     86 
     87 #include <sys/mount.h>
     88 #include <sys/syscallargs.h>
     89 
     90 #include <uvm/uvm_extern.h>
     91 
     92 #include <machine/cpu.h>
     93 
     94 POOL_INIT(ptimer_pool, sizeof(struct ptimer), 0, 0, 0, "ptimerpl",
     95     &pool_allocator_nointr, IPL_NONE);
     96 POOL_INIT(ptimers_pool, sizeof(struct ptimers), 0, 0, 0, "ptimerspl",
     97     &pool_allocator_nointr, IPL_NONE);
     98 
     99 /* Time of day and interval timer support.
    100  *
    101  * These routines provide the kernel entry points to get and set
    102  * the time-of-day and per-process interval timers.  Subroutines
    103  * here provide support for adding and subtracting timeval structures
    104  * and decrementing interval timers, optionally reloading the interval
    105  * timers when they expire.
    106  */
    107 
    108 /* This function is used by clock_settime and settimeofday */
    109 int
    110 settime(struct proc *p, struct timespec *ts)
    111 {
    112 	struct timeval delta, tv;
    113 #ifdef __HAVE_TIMECOUNTER
    114 	struct timeval now;
    115 	struct timespec ts1;
    116 #endif /* !__HAVE_TIMECOUNTER */
    117 	lwp_t *l;
    118 	int s;
    119 
    120 	/*
    121 	 * Don't allow the time to be set forward so far it will wrap
    122 	 * and become negative, thus allowing an attacker to bypass
    123 	 * the next check below.  The cutoff is 1 year before rollover
    124 	 * occurs, so even if the attacker uses adjtime(2) to move
    125 	 * the time past the cutoff, it will take a very long time
    126 	 * to get to the wrap point.
    127 	 *
    128 	 * XXX: we check against INT_MAX since on 64-bit
    129 	 *	platforms, sizeof(int) != sizeof(long) and
    130 	 *	time_t is 32 bits even when atv.tv_sec is 64 bits.
    131 	 */
    132 	if (ts->tv_sec > INT_MAX - 365*24*60*60) {
    133 		struct proc *pp;
    134 
    135 		mutex_enter(&proclist_lock);
    136 		pp = p->p_pptr;
    137 		mutex_enter(&pp->p_mutex);
    138 		log(LOG_WARNING, "pid %d (%s) "
    139 		    "invoked by uid %d ppid %d (%s) "
    140 		    "tried to set clock forward to %ld\n",
    141 		    p->p_pid, p->p_comm, kauth_cred_geteuid(pp->p_cred),
    142 		    pp->p_pid, pp->p_comm, (long)ts->tv_sec);
    143 		mutex_exit(&pp->p_mutex);
    144 		mutex_exit(&proclist_lock);
    145 		return (EPERM);
    146 	}
    147 	TIMESPEC_TO_TIMEVAL(&tv, ts);
    148 
    149 	/* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
    150 	s = splclock();
    151 #ifdef __HAVE_TIMECOUNTER
    152 	microtime(&now);
    153 	timersub(&tv, &now, &delta);
    154 #else /* !__HAVE_TIMECOUNTER */
    155 	timersub(&tv, &time, &delta);
    156 #endif /* !__HAVE_TIMECOUNTER */
    157 	if ((delta.tv_sec < 0 || delta.tv_usec < 0) &&
    158 	    kauth_authorize_system(p->p_cred, KAUTH_SYSTEM_TIME,
    159 	    KAUTH_REQ_SYSTEM_TIME_BACKWARDS, NULL, NULL, NULL)) {
    160 		splx(s);
    161 		return (EPERM);
    162 	}
    163 #ifdef notyet
    164 	if ((delta.tv_sec < 86400) && securelevel > 0) { /* XXX elad - notyet */
    165 		splx(s);
    166 		return (EPERM);
    167 	}
    168 #endif
    169 
    170 #ifdef __HAVE_TIMECOUNTER
    171 	TIMEVAL_TO_TIMESPEC(&tv, &ts1);
    172 	tc_setclock(&ts1);
    173 #else /* !__HAVE_TIMECOUNTER */
    174 	time = tv;
    175 #endif /* !__HAVE_TIMECOUNTER */
    176 
    177 	timeradd(&boottime, &delta, &boottime);
    178 
    179 	/*
    180 	 * XXXSMP: There is a short race between setting the time above
    181 	 * and adjusting LWP's run times.  Fixing this properly means
    182 	 * pausing all CPUs while we adjust the clock.
    183 	 */
    184 	mutex_enter(&proclist_lock);
    185 	LIST_FOREACH(l, &alllwp, l_list) {
    186 		lwp_lock(l);
    187 		timeradd(&l->l_stime, &delta, &l->l_stime);
    188 		lwp_unlock(l);
    189 	}
    190 	mutex_exit(&proclist_lock);
    191 	resettodr();
    192 	splx(s);
    193 
    194 	return (0);
    195 }
    196 
    197 /* ARGSUSED */
    198 int
    199 sys_clock_gettime(struct lwp *l, void *v, register_t *retval)
    200 {
    201 	struct sys_clock_gettime_args /* {
    202 		syscallarg(clockid_t) clock_id;
    203 		syscallarg(struct timespec *) tp;
    204 	} */ *uap = v;
    205 	clockid_t clock_id;
    206 	struct timespec ats;
    207 
    208 	clock_id = SCARG(uap, clock_id);
    209 	switch (clock_id) {
    210 	case CLOCK_REALTIME:
    211 		nanotime(&ats);
    212 		break;
    213 	case CLOCK_MONOTONIC:
    214 		nanouptime(&ats);
    215 		break;
    216 	default:
    217 		return (EINVAL);
    218 	}
    219 
    220 	return copyout(&ats, SCARG(uap, tp), sizeof(ats));
    221 }
    222 
    223 /* ARGSUSED */
    224 int
    225 sys_clock_settime(struct lwp *l, void *v, register_t *retval)
    226 {
    227 	struct sys_clock_settime_args /* {
    228 		syscallarg(clockid_t) clock_id;
    229 		syscallarg(const struct timespec *) tp;
    230 	} */ *uap = v;
    231 	int error;
    232 
    233 	if ((error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_TIME,
    234 	    KAUTH_REQ_SYSTEM_TIME_SYSTEM, NULL, NULL, NULL)) != 0)
    235 		return (error);
    236 
    237 	return clock_settime1(l->l_proc, SCARG(uap, clock_id), SCARG(uap, tp));
    238 }
    239 
    240 
    241 int
    242 clock_settime1(struct proc *p, clockid_t clock_id, const struct timespec *tp)
    243 {
    244 	struct timespec ats;
    245 	int error;
    246 
    247 	if ((error = copyin(tp, &ats, sizeof(ats))) != 0)
    248 		return (error);
    249 
    250 	switch (clock_id) {
    251 	case CLOCK_REALTIME:
    252 		if ((error = settime(p, &ats)) != 0)
    253 			return (error);
    254 		break;
    255 	case CLOCK_MONOTONIC:
    256 		return (EINVAL);	/* read-only clock */
    257 	default:
    258 		return (EINVAL);
    259 	}
    260 
    261 	return 0;
    262 }
    263 
    264 int
    265 sys_clock_getres(struct lwp *l, void *v, register_t *retval)
    266 {
    267 	struct sys_clock_getres_args /* {
    268 		syscallarg(clockid_t) clock_id;
    269 		syscallarg(struct timespec *) tp;
    270 	} */ *uap = v;
    271 	clockid_t clock_id;
    272 	struct timespec ts;
    273 	int error = 0;
    274 
    275 	clock_id = SCARG(uap, clock_id);
    276 	switch (clock_id) {
    277 	case CLOCK_REALTIME:
    278 	case CLOCK_MONOTONIC:
    279 		ts.tv_sec = 0;
    280 		if (tc_getfrequency() > 1000000000)
    281 			ts.tv_nsec = 1;
    282 		else
    283 			ts.tv_nsec = 1000000000 / tc_getfrequency();
    284 		break;
    285 	default:
    286 		return (EINVAL);
    287 	}
    288 
    289 	if (SCARG(uap, tp))
    290 		error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
    291 
    292 	return error;
    293 }
    294 
    295 /* ARGSUSED */
    296 int
    297 sys_nanosleep(struct lwp *l, void *v, register_t *retval)
    298 {
    299 	struct sys_nanosleep_args/* {
    300 		syscallarg(struct timespec *) rqtp;
    301 		syscallarg(struct timespec *) rmtp;
    302 	} */ *uap = v;
    303 	struct timespec rmt, rqt;
    304 	int error, error1;
    305 
    306 	error = copyin(SCARG(uap, rqtp), &rqt, sizeof(struct timespec));
    307 	if (error)
    308 		return (error);
    309 
    310 	error = nanosleep1(l, &rqt, SCARG(uap, rmtp) ? &rmt : NULL);
    311 	if (SCARG(uap, rmtp) == NULL || (error != 0 && error != EINTR))
    312 		return error;
    313 
    314 	error1 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt));
    315 	return error1 ? error1 : error;
    316 }
    317 
    318 int
    319 nanosleep1(struct lwp *l, struct timespec *rqt, struct timespec *rmt)
    320 {
    321 #ifdef __HAVE_TIMECOUNTER
    322 	int error, timo;
    323 
    324 	if (itimespecfix(rqt))
    325 		return (EINVAL);
    326 
    327 	timo = tstohz(rqt);
    328 	/*
    329 	 * Avoid inadvertantly sleeping forever
    330 	 */
    331 	if (timo == 0)
    332 		timo = 1;
    333 
    334 	if (rmt != NULL)
    335 		getnanouptime(rmt);
    336 
    337 	error = kpause("nanoslp", true, timo, NULL);
    338 	if (error == ERESTART)
    339 		error = EINTR;
    340 	if (error == EWOULDBLOCK)
    341 		error = 0;
    342 
    343 	if (rmt!= NULL) {
    344 		struct timespec rmtend;
    345 
    346 		getnanouptime(&rmtend);
    347 
    348 		timespecsub(&rmtend, rmt, rmt);
    349 		timespecsub(rqt, rmt, rmt);
    350 		if (rmt->tv_sec < 0)
    351 			timespecclear(rmt);
    352 	}
    353 
    354 	return error;
    355 #else /* !__HAVE_TIMECOUNTER */
    356 	struct timeval atv, utv;
    357 	int error, s, timo;
    358 
    359 	TIMESPEC_TO_TIMEVAL(&atv, rqt);
    360 	if (itimerfix(&atv))
    361 		return (EINVAL);
    362 
    363 	s = splclock();
    364 	timeradd(&atv,&time,&atv);
    365 	timo = hzto(&atv);
    366 	/*
    367 	 * Avoid inadvertantly sleeping forever
    368 	 */
    369 	if (timo == 0)
    370 		timo = 1;
    371 	splx(s);
    372 
    373 	error = kpause("nanoslp", true, timo, NULL);
    374 	if (error == ERESTART)
    375 		error = EINTR;
    376 	if (error == EWOULDBLOCK)
    377 		error = 0;
    378 
    379 	if (rmt != NULL) {
    380 		s = splclock();
    381 		utv = time;
    382 		splx(s);
    383 
    384 		timersub(&atv, &utv, &utv);
    385 		if (utv.tv_sec < 0)
    386 			timerclear(&utv);
    387 
    388 		TIMEVAL_TO_TIMESPEC(&utv, rmt);
    389 	}
    390 
    391 	return error;
    392 #endif /* !__HAVE_TIMECOUNTER */
    393 }
    394 
    395 /* ARGSUSED */
    396 int
    397 sys_gettimeofday(struct lwp *l, void *v, register_t *retval)
    398 {
    399 	struct sys_gettimeofday_args /* {
    400 		syscallarg(struct timeval *) tp;
    401 		syscallarg(void *) tzp;		really "struct timezone *"
    402 	} */ *uap = v;
    403 	struct timeval atv;
    404 	int error = 0;
    405 	struct timezone tzfake;
    406 
    407 	if (SCARG(uap, tp)) {
    408 		microtime(&atv);
    409 		error = copyout(&atv, SCARG(uap, tp), sizeof(atv));
    410 		if (error)
    411 			return (error);
    412 	}
    413 	if (SCARG(uap, tzp)) {
    414 		/*
    415 		 * NetBSD has no kernel notion of time zone, so we just
    416 		 * fake up a timezone struct and return it if demanded.
    417 		 */
    418 		tzfake.tz_minuteswest = 0;
    419 		tzfake.tz_dsttime = 0;
    420 		error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake));
    421 	}
    422 	return (error);
    423 }
    424 
    425 /* ARGSUSED */
    426 int
    427 sys_settimeofday(struct lwp *l, void *v, register_t *retval)
    428 {
    429 	struct sys_settimeofday_args /* {
    430 		syscallarg(const struct timeval *) tv;
    431 		syscallarg(const void *) tzp;	really "const struct timezone *"
    432 	} */ *uap = v;
    433 
    434 	return settimeofday1(SCARG(uap, tv), true, SCARG(uap, tzp), l, true);
    435 }
    436 
    437 int
    438 settimeofday1(const struct timeval *utv, bool userspace,
    439     const void *utzp, struct lwp *l, bool check_kauth)
    440 {
    441 	struct timeval atv;
    442 	struct timespec ts;
    443 	int error;
    444 
    445 	/* Verify all parameters before changing time. */
    446 
    447 	if (check_kauth) {
    448 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_TIME,
    449 		    KAUTH_REQ_SYSTEM_TIME_SYSTEM, NULL, NULL, NULL);
    450 		if (error != 0)
    451 			return (error);
    452 	}
    453 
    454 	/*
    455 	 * NetBSD has no kernel notion of time zone, and only an
    456 	 * obsolete program would try to set it, so we log a warning.
    457 	 */
    458 	if (utzp)
    459 		log(LOG_WARNING, "pid %d attempted to set the "
    460 		    "(obsolete) kernel time zone\n", l->l_proc->p_pid);
    461 
    462 	if (utv == NULL)
    463 		return 0;
    464 
    465 	if (userspace) {
    466 		if ((error = copyin(utv, &atv, sizeof(atv))) != 0)
    467 			return error;
    468 		utv = &atv;
    469 	}
    470 
    471 	TIMEVAL_TO_TIMESPEC(utv, &ts);
    472 	return settime(l->l_proc, &ts);
    473 }
    474 
    475 #ifndef __HAVE_TIMECOUNTER
    476 int	tickdelta;			/* current clock skew, us. per tick */
    477 long	timedelta;			/* unapplied time correction, us. */
    478 long	bigadj = 1000000;		/* use 10x skew above bigadj us. */
    479 #endif
    480 
    481 int	time_adjusted;			/* set if an adjustment is made */
    482 
    483 /* ARGSUSED */
    484 int
    485 sys_adjtime(struct lwp *l, void *v, register_t *retval)
    486 {
    487 	struct sys_adjtime_args /* {
    488 		syscallarg(const struct timeval *) delta;
    489 		syscallarg(struct timeval *) olddelta;
    490 	} */ *uap = v;
    491 	int error;
    492 
    493 	if ((error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_TIME,
    494 	    KAUTH_REQ_SYSTEM_TIME_ADJTIME, NULL, NULL, NULL)) != 0)
    495 		return (error);
    496 
    497 	return adjtime1(SCARG(uap, delta), SCARG(uap, olddelta), l->l_proc);
    498 }
    499 
    500 int
    501 adjtime1(const struct timeval *delta, struct timeval *olddelta, struct proc *p)
    502 {
    503 	struct timeval atv;
    504 	int error = 0;
    505 
    506 #ifdef __HAVE_TIMECOUNTER
    507 	extern int64_t time_adjtime;  /* in kern_ntptime.c */
    508 #else /* !__HAVE_TIMECOUNTER */
    509 	long ndelta, ntickdelta, odelta;
    510 	int s;
    511 #endif /* !__HAVE_TIMECOUNTER */
    512 
    513 #ifdef __HAVE_TIMECOUNTER
    514 	if (olddelta) {
    515 		atv.tv_sec = time_adjtime / 1000000;
    516 		atv.tv_usec = time_adjtime % 1000000;
    517 		if (atv.tv_usec < 0) {
    518 			atv.tv_usec += 1000000;
    519 			atv.tv_sec--;
    520 		}
    521 		error = copyout(&atv, olddelta, sizeof(struct timeval));
    522 		if (error)
    523 			return (error);
    524 	}
    525 
    526 	if (delta) {
    527 		error = copyin(delta, &atv, sizeof(struct timeval));
    528 		if (error)
    529 			return (error);
    530 
    531 		time_adjtime = (int64_t)atv.tv_sec * 1000000 +
    532 			atv.tv_usec;
    533 
    534 		if (time_adjtime)
    535 			/* We need to save the system time during shutdown */
    536 			time_adjusted |= 1;
    537 	}
    538 #else /* !__HAVE_TIMECOUNTER */
    539 	error = copyin(delta, &atv, sizeof(struct timeval));
    540 	if (error)
    541 		return (error);
    542 
    543 	/*
    544 	 * Compute the total correction and the rate at which to apply it.
    545 	 * Round the adjustment down to a whole multiple of the per-tick
    546 	 * delta, so that after some number of incremental changes in
    547 	 * hardclock(), tickdelta will become zero, lest the correction
    548 	 * overshoot and start taking us away from the desired final time.
    549 	 */
    550 	ndelta = atv.tv_sec * 1000000 + atv.tv_usec;
    551 	if (ndelta > bigadj || ndelta < -bigadj)
    552 		ntickdelta = 10 * tickadj;
    553 	else
    554 		ntickdelta = tickadj;
    555 	if (ndelta % ntickdelta)
    556 		ndelta = ndelta / ntickdelta * ntickdelta;
    557 
    558 	/*
    559 	 * To make hardclock()'s job easier, make the per-tick delta negative
    560 	 * if we want time to run slower; then hardclock can simply compute
    561 	 * tick + tickdelta, and subtract tickdelta from timedelta.
    562 	 */
    563 	if (ndelta < 0)
    564 		ntickdelta = -ntickdelta;
    565 	if (ndelta != 0)
    566 		/* We need to save the system clock time during shutdown */
    567 		time_adjusted |= 1;
    568 	s = splclock();
    569 	odelta = timedelta;
    570 	timedelta = ndelta;
    571 	tickdelta = ntickdelta;
    572 	splx(s);
    573 
    574 	if (olddelta) {
    575 		atv.tv_sec = odelta / 1000000;
    576 		atv.tv_usec = odelta % 1000000;
    577 		error = copyout(&atv, olddelta, sizeof(struct timeval));
    578 	}
    579 #endif /* __HAVE_TIMECOUNTER */
    580 
    581 	return error;
    582 }
    583 
    584 /*
    585  * Interval timer support. Both the BSD getitimer() family and the POSIX
    586  * timer_*() family of routines are supported.
    587  *
    588  * All timers are kept in an array pointed to by p_timers, which is
    589  * allocated on demand - many processes don't use timers at all. The
    590  * first three elements in this array are reserved for the BSD timers:
    591  * element 0 is ITIMER_REAL, element 1 is ITIMER_VIRTUAL, and element
    592  * 2 is ITIMER_PROF. The rest may be allocated by the timer_create()
    593  * syscall.
    594  *
    595  * Realtime timers are kept in the ptimer structure as an absolute
    596  * time; virtual time timers are kept as a linked list of deltas.
    597  * Virtual time timers are processed in the hardclock() routine of
    598  * kern_clock.c.  The real time timer is processed by a callout
    599  * routine, called from the softclock() routine.  Since a callout may
    600  * be delayed in real time due to interrupt processing in the system,
    601  * it is possible for the real time timeout routine (realtimeexpire,
    602  * given below), to be delayed in real time past when it is supposed
    603  * to occur.  It does not suffice, therefore, to reload the real timer
    604  * .it_value from the real time timers .it_interval.  Rather, we
    605  * compute the next time in absolute time the timer should go off.  */
    606 
    607 /* Allocate a POSIX realtime timer. */
    608 int
    609 sys_timer_create(struct lwp *l, void *v, register_t *retval)
    610 {
    611 	struct sys_timer_create_args /* {
    612 		syscallarg(clockid_t) clock_id;
    613 		syscallarg(struct sigevent *) evp;
    614 		syscallarg(timer_t *) timerid;
    615 	} */ *uap = v;
    616 
    617 	return timer_create1(SCARG(uap, timerid), SCARG(uap, clock_id),
    618 	    SCARG(uap, evp), copyin, l);
    619 }
    620 
    621 int
    622 timer_create1(timer_t *tid, clockid_t id, struct sigevent *evp,
    623     copyin_t fetch_event, struct lwp *l)
    624 {
    625 	int error;
    626 	timer_t timerid;
    627 	struct ptimer *pt;
    628 	struct proc *p;
    629 
    630 	p = l->l_proc;
    631 
    632 	if (id < CLOCK_REALTIME ||
    633 	    id > CLOCK_PROF)
    634 		return (EINVAL);
    635 
    636 	if (p->p_timers == NULL)
    637 		timers_alloc(p);
    638 
    639 	/* Find a free timer slot, skipping those reserved for setitimer(). */
    640 	for (timerid = 3; timerid < TIMER_MAX; timerid++)
    641 		if (p->p_timers->pts_timers[timerid] == NULL)
    642 			break;
    643 
    644 	if (timerid == TIMER_MAX)
    645 		return EAGAIN;
    646 
    647 	pt = pool_get(&ptimer_pool, PR_WAITOK);
    648 	if (evp) {
    649 		if (((error =
    650 		    (*fetch_event)(evp, &pt->pt_ev, sizeof(pt->pt_ev))) != 0) ||
    651 		    ((pt->pt_ev.sigev_notify < SIGEV_NONE) ||
    652 			(pt->pt_ev.sigev_notify > SIGEV_SA))) {
    653 			pool_put(&ptimer_pool, pt);
    654 			return (error ? error : EINVAL);
    655 		}
    656 	} else {
    657 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
    658 		switch (id) {
    659 		case CLOCK_REALTIME:
    660 			pt->pt_ev.sigev_signo = SIGALRM;
    661 			break;
    662 		case CLOCK_VIRTUAL:
    663 			pt->pt_ev.sigev_signo = SIGVTALRM;
    664 			break;
    665 		case CLOCK_PROF:
    666 			pt->pt_ev.sigev_signo = SIGPROF;
    667 			break;
    668 		}
    669 		pt->pt_ev.sigev_value.sival_int = timerid;
    670 	}
    671 	pt->pt_info.ksi_signo = pt->pt_ev.sigev_signo;
    672 	pt->pt_info.ksi_errno = 0;
    673 	pt->pt_info.ksi_code = 0;
    674 	pt->pt_info.ksi_pid = p->p_pid;
    675 	pt->pt_info.ksi_uid = kauth_cred_getuid(l->l_cred);
    676 	pt->pt_info.ksi_value = pt->pt_ev.sigev_value;
    677 
    678 	pt->pt_type = id;
    679 	pt->pt_proc = p;
    680 	pt->pt_overruns = 0;
    681 	pt->pt_poverruns = 0;
    682 	pt->pt_entry = timerid;
    683 	timerclear(&pt->pt_time.it_value);
    684 	if (id == CLOCK_REALTIME)
    685 		callout_init(&pt->pt_ch, 0);
    686 	else
    687 		pt->pt_active = 0;
    688 
    689 	p->p_timers->pts_timers[timerid] = pt;
    690 
    691 	return copyout(&timerid, tid, sizeof(timerid));
    692 }
    693 
    694 /* Delete a POSIX realtime timer */
    695 int
    696 sys_timer_delete(struct lwp *l, void *v, register_t *retval)
    697 {
    698 	struct sys_timer_delete_args /*  {
    699 		syscallarg(timer_t) timerid;
    700 	} */ *uap = v;
    701 	struct proc *p = l->l_proc;
    702 	timer_t timerid;
    703 	struct ptimer *pt, *ptn;
    704 	int s;
    705 
    706 	timerid = SCARG(uap, timerid);
    707 
    708 	if ((p->p_timers == NULL) ||
    709 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
    710 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
    711 		return (EINVAL);
    712 
    713 	if (pt->pt_type == CLOCK_REALTIME) {
    714 		callout_stop(&pt->pt_ch);
    715 		callout_destroy(&pt->pt_ch);
    716 	} else if (pt->pt_active) {
    717 		s = splclock();
    718 		ptn = LIST_NEXT(pt, pt_list);
    719 		LIST_REMOVE(pt, pt_list);
    720 		for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
    721 			timeradd(&pt->pt_time.it_value, &ptn->pt_time.it_value,
    722 			    &ptn->pt_time.it_value);
    723 		splx(s);
    724 	}
    725 
    726 	p->p_timers->pts_timers[timerid] = NULL;
    727 	pool_put(&ptimer_pool, pt);
    728 
    729 	return (0);
    730 }
    731 
    732 /*
    733  * Set up the given timer. The value in pt->pt_time.it_value is taken
    734  * to be an absolute time for CLOCK_REALTIME timers and a relative
    735  * time for virtual timers.
    736  * Must be called at splclock().
    737  */
    738 void
    739 timer_settime(struct ptimer *pt)
    740 {
    741 	struct ptimer *ptn, *pptn;
    742 	struct ptlist *ptl;
    743 
    744 	if (pt->pt_type == CLOCK_REALTIME) {
    745 		callout_stop(&pt->pt_ch);
    746 		if (timerisset(&pt->pt_time.it_value)) {
    747 			/*
    748 			 * Don't need to check hzto() return value, here.
    749 			 * callout_reset() does it for us.
    750 			 */
    751 			callout_reset(&pt->pt_ch, hzto(&pt->pt_time.it_value),
    752 			    realtimerexpire, pt);
    753 		}
    754 	} else {
    755 		if (pt->pt_active) {
    756 			ptn = LIST_NEXT(pt, pt_list);
    757 			LIST_REMOVE(pt, pt_list);
    758 			for ( ; ptn; ptn = LIST_NEXT(ptn, pt_list))
    759 				timeradd(&pt->pt_time.it_value,
    760 				    &ptn->pt_time.it_value,
    761 				    &ptn->pt_time.it_value);
    762 		}
    763 		if (timerisset(&pt->pt_time.it_value)) {
    764 			if (pt->pt_type == CLOCK_VIRTUAL)
    765 				ptl = &pt->pt_proc->p_timers->pts_virtual;
    766 			else
    767 				ptl = &pt->pt_proc->p_timers->pts_prof;
    768 
    769 			for (ptn = LIST_FIRST(ptl), pptn = NULL;
    770 			     ptn && timercmp(&pt->pt_time.it_value,
    771 				 &ptn->pt_time.it_value, >);
    772 			     pptn = ptn, ptn = LIST_NEXT(ptn, pt_list))
    773 				timersub(&pt->pt_time.it_value,
    774 				    &ptn->pt_time.it_value,
    775 				    &pt->pt_time.it_value);
    776 
    777 			if (pptn)
    778 				LIST_INSERT_AFTER(pptn, pt, pt_list);
    779 			else
    780 				LIST_INSERT_HEAD(ptl, pt, pt_list);
    781 
    782 			for ( ; ptn ; ptn = LIST_NEXT(ptn, pt_list))
    783 				timersub(&ptn->pt_time.it_value,
    784 				    &pt->pt_time.it_value,
    785 				    &ptn->pt_time.it_value);
    786 
    787 			pt->pt_active = 1;
    788 		} else
    789 			pt->pt_active = 0;
    790 	}
    791 }
    792 
    793 void
    794 timer_gettime(struct ptimer *pt, struct itimerval *aitv)
    795 {
    796 #ifdef __HAVE_TIMECOUNTER
    797 	struct timeval now;
    798 #endif
    799 	struct ptimer *ptn;
    800 
    801 	*aitv = pt->pt_time;
    802 	if (pt->pt_type == CLOCK_REALTIME) {
    803 		/*
    804 		 * Convert from absolute to relative time in .it_value
    805 		 * part of real time timer.  If time for real time
    806 		 * timer has passed return 0, else return difference
    807 		 * between current time and time for the timer to go
    808 		 * off.
    809 		 */
    810 		if (timerisset(&aitv->it_value)) {
    811 #ifdef __HAVE_TIMECOUNTER
    812 			getmicrotime(&now);
    813 			if (timercmp(&aitv->it_value, &now, <))
    814 				timerclear(&aitv->it_value);
    815 			else
    816 				timersub(&aitv->it_value, &now,
    817 				    &aitv->it_value);
    818 #else /* !__HAVE_TIMECOUNTER */
    819 			if (timercmp(&aitv->it_value, &time, <))
    820 				timerclear(&aitv->it_value);
    821 			else
    822 				timersub(&aitv->it_value, &time,
    823 				    &aitv->it_value);
    824 #endif /* !__HAVE_TIMECOUNTER */
    825 		}
    826 	} else if (pt->pt_active) {
    827 		if (pt->pt_type == CLOCK_VIRTUAL)
    828 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_virtual);
    829 		else
    830 			ptn = LIST_FIRST(&pt->pt_proc->p_timers->pts_prof);
    831 		for ( ; ptn && ptn != pt; ptn = LIST_NEXT(ptn, pt_list))
    832 			timeradd(&aitv->it_value,
    833 			    &ptn->pt_time.it_value, &aitv->it_value);
    834 		KASSERT(ptn != NULL); /* pt should be findable on the list */
    835 	} else
    836 		timerclear(&aitv->it_value);
    837 }
    838 
    839 
    840 
    841 /* Set and arm a POSIX realtime timer */
    842 int
    843 sys_timer_settime(struct lwp *l, void *v, register_t *retval)
    844 {
    845 	struct sys_timer_settime_args /* {
    846 		syscallarg(timer_t) timerid;
    847 		syscallarg(int) flags;
    848 		syscallarg(const struct itimerspec *) value;
    849 		syscallarg(struct itimerspec *) ovalue;
    850 	} */ *uap = v;
    851 	int error;
    852 	struct itimerspec value, ovalue, *ovp = NULL;
    853 
    854 	if ((error = copyin(SCARG(uap, value), &value,
    855 	    sizeof(struct itimerspec))) != 0)
    856 		return (error);
    857 
    858 	if (SCARG(uap, ovalue))
    859 		ovp = &ovalue;
    860 
    861 	if ((error = dotimer_settime(SCARG(uap, timerid), &value, ovp,
    862 	    SCARG(uap, flags), l->l_proc)) != 0)
    863 		return error;
    864 
    865 	if (ovp)
    866 		return copyout(&ovalue, SCARG(uap, ovalue),
    867 		    sizeof(struct itimerspec));
    868 	return 0;
    869 }
    870 
    871 int
    872 dotimer_settime(int timerid, struct itimerspec *value,
    873     struct itimerspec *ovalue, int flags, struct proc *p)
    874 {
    875 #ifdef __HAVE_TIMECOUNTER
    876 	struct timeval now;
    877 #endif
    878 	struct itimerval val, oval;
    879 	struct ptimer *pt;
    880 	int s;
    881 
    882 	if ((p->p_timers == NULL) ||
    883 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
    884 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
    885 		return (EINVAL);
    886 
    887 	TIMESPEC_TO_TIMEVAL(&val.it_value, &value->it_value);
    888 	TIMESPEC_TO_TIMEVAL(&val.it_interval, &value->it_interval);
    889 	if (itimerfix(&val.it_value) || itimerfix(&val.it_interval))
    890 		return (EINVAL);
    891 
    892 	oval = pt->pt_time;
    893 	pt->pt_time = val;
    894 
    895 	s = splclock();
    896 	/*
    897 	 * If we've been passed a relative time for a realtime timer,
    898 	 * convert it to absolute; if an absolute time for a virtual
    899 	 * timer, convert it to relative and make sure we don't set it
    900 	 * to zero, which would cancel the timer, or let it go
    901 	 * negative, which would confuse the comparison tests.
    902 	 */
    903 	if (timerisset(&pt->pt_time.it_value)) {
    904 		if (pt->pt_type == CLOCK_REALTIME) {
    905 #ifdef __HAVE_TIMECOUNTER
    906 			if ((flags & TIMER_ABSTIME) == 0) {
    907 				getmicrotime(&now);
    908 				timeradd(&pt->pt_time.it_value, &now,
    909 				    &pt->pt_time.it_value);
    910 			}
    911 #else /* !__HAVE_TIMECOUNTER */
    912 			if ((flags & TIMER_ABSTIME) == 0)
    913 				timeradd(&pt->pt_time.it_value, &time,
    914 				    &pt->pt_time.it_value);
    915 #endif /* !__HAVE_TIMECOUNTER */
    916 		} else {
    917 			if ((flags & TIMER_ABSTIME) != 0) {
    918 #ifdef __HAVE_TIMECOUNTER
    919 				getmicrotime(&now);
    920 				timersub(&pt->pt_time.it_value, &now,
    921 				    &pt->pt_time.it_value);
    922 #else /* !__HAVE_TIMECOUNTER */
    923 				timersub(&pt->pt_time.it_value, &time,
    924 				    &pt->pt_time.it_value);
    925 #endif /* !__HAVE_TIMECOUNTER */
    926 				if (!timerisset(&pt->pt_time.it_value) ||
    927 				    pt->pt_time.it_value.tv_sec < 0) {
    928 					pt->pt_time.it_value.tv_sec = 0;
    929 					pt->pt_time.it_value.tv_usec = 1;
    930 				}
    931 			}
    932 		}
    933 	}
    934 
    935 	timer_settime(pt);
    936 	splx(s);
    937 
    938 	if (ovalue) {
    939 		TIMEVAL_TO_TIMESPEC(&oval.it_value, &ovalue->it_value);
    940 		TIMEVAL_TO_TIMESPEC(&oval.it_interval, &ovalue->it_interval);
    941 	}
    942 
    943 	return (0);
    944 }
    945 
    946 /* Return the time remaining until a POSIX timer fires. */
    947 int
    948 sys_timer_gettime(struct lwp *l, void *v, register_t *retval)
    949 {
    950 	struct sys_timer_gettime_args /* {
    951 		syscallarg(timer_t) timerid;
    952 		syscallarg(struct itimerspec *) value;
    953 	} */ *uap = v;
    954 	struct itimerspec its;
    955 	int error;
    956 
    957 	if ((error = dotimer_gettime(SCARG(uap, timerid), l->l_proc,
    958 	    &its)) != 0)
    959 		return error;
    960 
    961 	return copyout(&its, SCARG(uap, value), sizeof(its));
    962 }
    963 
    964 int
    965 dotimer_gettime(int timerid, struct proc *p, struct itimerspec *its)
    966 {
    967 	int s;
    968 	struct ptimer *pt;
    969 	struct itimerval aitv;
    970 
    971 	if ((p->p_timers == NULL) ||
    972 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
    973 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
    974 		return (EINVAL);
    975 
    976 	s = splclock();
    977 	timer_gettime(pt, &aitv);
    978 	splx(s);
    979 
    980 	TIMEVAL_TO_TIMESPEC(&aitv.it_interval, &its->it_interval);
    981 	TIMEVAL_TO_TIMESPEC(&aitv.it_value, &its->it_value);
    982 
    983 	return 0;
    984 }
    985 
    986 /*
    987  * Return the count of the number of times a periodic timer expired
    988  * while a notification was already pending. The counter is reset when
    989  * a timer expires and a notification can be posted.
    990  */
    991 int
    992 sys_timer_getoverrun(struct lwp *l, void *v, register_t *retval)
    993 {
    994 	struct sys_timer_getoverrun_args /* {
    995 		syscallarg(timer_t) timerid;
    996 	} */ *uap = v;
    997 	struct proc *p = l->l_proc;
    998 	int timerid;
    999 	struct ptimer *pt;
   1000 
   1001 	timerid = SCARG(uap, timerid);
   1002 
   1003 	if ((p->p_timers == NULL) ||
   1004 	    (timerid < 2) || (timerid >= TIMER_MAX) ||
   1005 	    ((pt = p->p_timers->pts_timers[timerid]) == NULL))
   1006 		return (EINVAL);
   1007 
   1008 	*retval = pt->pt_poverruns;
   1009 
   1010 	return (0);
   1011 }
   1012 
   1013 /*
   1014  * Real interval timer expired:
   1015  * send process whose timer expired an alarm signal.
   1016  * If time is not set up to reload, then just return.
   1017  * Else compute next time timer should go off which is > current time.
   1018  * This is where delay in processing this timeout causes multiple
   1019  * SIGALRM calls to be compressed into one.
   1020  */
   1021 void
   1022 realtimerexpire(void *arg)
   1023 {
   1024 #ifdef __HAVE_TIMECOUNTER
   1025 	struct timeval now;
   1026 #endif
   1027 	struct ptimer *pt;
   1028 	int s;
   1029 
   1030 	pt = (struct ptimer *)arg;
   1031 
   1032 	itimerfire(pt);
   1033 
   1034 	if (!timerisset(&pt->pt_time.it_interval)) {
   1035 		timerclear(&pt->pt_time.it_value);
   1036 		return;
   1037 	}
   1038 #ifdef __HAVE_TIMECOUNTER
   1039 	for (;;) {
   1040 		s = splclock();	/* XXX need spl now? */
   1041 		timeradd(&pt->pt_time.it_value,
   1042 		    &pt->pt_time.it_interval, &pt->pt_time.it_value);
   1043 		getmicrotime(&now);
   1044 		if (timercmp(&pt->pt_time.it_value, &now, >)) {
   1045 			/*
   1046 			 * Don't need to check hzto() return value, here.
   1047 			 * callout_reset() does it for us.
   1048 			 */
   1049 			callout_reset(&pt->pt_ch, hzto(&pt->pt_time.it_value),
   1050 			    realtimerexpire, pt);
   1051 			splx(s);
   1052 			return;
   1053 		}
   1054 		splx(s);
   1055 		pt->pt_overruns++;
   1056 	}
   1057 #else /* !__HAVE_TIMECOUNTER */
   1058 	for (;;) {
   1059 		s = splclock();
   1060 		timeradd(&pt->pt_time.it_value,
   1061 		    &pt->pt_time.it_interval, &pt->pt_time.it_value);
   1062 		if (timercmp(&pt->pt_time.it_value, &time, >)) {
   1063 			/*
   1064 			 * Don't need to check hzto() return value, here.
   1065 			 * callout_reset() does it for us.
   1066 			 */
   1067 			callout_reset(&pt->pt_ch, hzto(&pt->pt_time.it_value),
   1068 			    realtimerexpire, pt);
   1069 			splx(s);
   1070 			return;
   1071 		}
   1072 		splx(s);
   1073 		pt->pt_overruns++;
   1074 	}
   1075 #endif /* !__HAVE_TIMECOUNTER */
   1076 }
   1077 
   1078 /* BSD routine to get the value of an interval timer. */
   1079 /* ARGSUSED */
   1080 int
   1081 sys_getitimer(struct lwp *l, void *v, register_t *retval)
   1082 {
   1083 	struct sys_getitimer_args /* {
   1084 		syscallarg(int) which;
   1085 		syscallarg(struct itimerval *) itv;
   1086 	} */ *uap = v;
   1087 	struct proc *p = l->l_proc;
   1088 	struct itimerval aitv;
   1089 	int error;
   1090 
   1091 	error = dogetitimer(p, SCARG(uap, which), &aitv);
   1092 	if (error)
   1093 		return error;
   1094 	return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval)));
   1095 }
   1096 
   1097 int
   1098 dogetitimer(struct proc *p, int which, struct itimerval *itvp)
   1099 {
   1100 	int s;
   1101 
   1102 	if ((u_int)which > ITIMER_PROF)
   1103 		return (EINVAL);
   1104 
   1105 	if ((p->p_timers == NULL) || (p->p_timers->pts_timers[which] == NULL)){
   1106 		timerclear(&itvp->it_value);
   1107 		timerclear(&itvp->it_interval);
   1108 	} else {
   1109 		s = splclock();
   1110 		timer_gettime(p->p_timers->pts_timers[which], itvp);
   1111 		splx(s);
   1112 	}
   1113 
   1114 	return 0;
   1115 }
   1116 
   1117 /* BSD routine to set/arm an interval timer. */
   1118 /* ARGSUSED */
   1119 int
   1120 sys_setitimer(struct lwp *l, void *v, register_t *retval)
   1121 {
   1122 	struct sys_setitimer_args /* {
   1123 		syscallarg(int) which;
   1124 		syscallarg(const struct itimerval *) itv;
   1125 		syscallarg(struct itimerval *) oitv;
   1126 	} */ *uap = v;
   1127 	struct proc *p = l->l_proc;
   1128 	int which = SCARG(uap, which);
   1129 	struct sys_getitimer_args getargs;
   1130 	const struct itimerval *itvp;
   1131 	struct itimerval aitv;
   1132 	int error;
   1133 
   1134 	if ((u_int)which > ITIMER_PROF)
   1135 		return (EINVAL);
   1136 	itvp = SCARG(uap, itv);
   1137 	if (itvp &&
   1138 	    (error = copyin(itvp, &aitv, sizeof(struct itimerval)) != 0))
   1139 		return (error);
   1140 	if (SCARG(uap, oitv) != NULL) {
   1141 		SCARG(&getargs, which) = which;
   1142 		SCARG(&getargs, itv) = SCARG(uap, oitv);
   1143 		if ((error = sys_getitimer(l, &getargs, retval)) != 0)
   1144 			return (error);
   1145 	}
   1146 	if (itvp == 0)
   1147 		return (0);
   1148 
   1149 	return dosetitimer(p, which, &aitv);
   1150 }
   1151 
   1152 int
   1153 dosetitimer(struct proc *p, int which, struct itimerval *itvp)
   1154 {
   1155 #ifdef __HAVE_TIMECOUNTER
   1156 	struct timeval now;
   1157 #endif
   1158 	struct ptimer *pt;
   1159 	int s;
   1160 
   1161 	if (itimerfix(&itvp->it_value) || itimerfix(&itvp->it_interval))
   1162 		return (EINVAL);
   1163 
   1164 	/*
   1165 	 * Don't bother allocating data structures if the process just
   1166 	 * wants to clear the timer.
   1167 	 */
   1168 	if (!timerisset(&itvp->it_value) &&
   1169 	    ((p->p_timers == NULL) ||(p->p_timers->pts_timers[which] == NULL)))
   1170 		return (0);
   1171 
   1172 	if (p->p_timers == NULL)
   1173 		timers_alloc(p);
   1174 	if (p->p_timers->pts_timers[which] == NULL) {
   1175 		pt = pool_get(&ptimer_pool, PR_WAITOK);
   1176 		pt->pt_ev.sigev_notify = SIGEV_SIGNAL;
   1177 		pt->pt_ev.sigev_value.sival_int = which;
   1178 		pt->pt_overruns = 0;
   1179 		pt->pt_proc = p;
   1180 		pt->pt_type = which;
   1181 		pt->pt_entry = which;
   1182 		switch (which) {
   1183 		case ITIMER_REAL:
   1184 			callout_init(&pt->pt_ch, 0);
   1185 			pt->pt_ev.sigev_signo = SIGALRM;
   1186 			break;
   1187 		case ITIMER_VIRTUAL:
   1188 			pt->pt_active = 0;
   1189 			pt->pt_ev.sigev_signo = SIGVTALRM;
   1190 			break;
   1191 		case ITIMER_PROF:
   1192 			pt->pt_active = 0;
   1193 			pt->pt_ev.sigev_signo = SIGPROF;
   1194 			break;
   1195 		}
   1196 	} else
   1197 		pt = p->p_timers->pts_timers[which];
   1198 
   1199 	pt->pt_time = *itvp;
   1200 	p->p_timers->pts_timers[which] = pt;
   1201 
   1202 	s = splclock();
   1203 	if ((which == ITIMER_REAL) && timerisset(&pt->pt_time.it_value)) {
   1204 		/* Convert to absolute time */
   1205 #ifdef __HAVE_TIMECOUNTER
   1206 		/* XXX need to wrap in splclock for timecounters case? */
   1207 		getmicrotime(&now);
   1208 		timeradd(&pt->pt_time.it_value, &now, &pt->pt_time.it_value);
   1209 #else /* !__HAVE_TIMECOUNTER */
   1210 		timeradd(&pt->pt_time.it_value, &time, &pt->pt_time.it_value);
   1211 #endif /* !__HAVE_TIMECOUNTER */
   1212 	}
   1213 	timer_settime(pt);
   1214 	splx(s);
   1215 
   1216 	return (0);
   1217 }
   1218 
   1219 /* Utility routines to manage the array of pointers to timers. */
   1220 void
   1221 timers_alloc(struct proc *p)
   1222 {
   1223 	int i;
   1224 	struct ptimers *pts;
   1225 
   1226 	pts = pool_get(&ptimers_pool, PR_WAITOK);
   1227 	LIST_INIT(&pts->pts_virtual);
   1228 	LIST_INIT(&pts->pts_prof);
   1229 	for (i = 0; i < TIMER_MAX; i++)
   1230 		pts->pts_timers[i] = NULL;
   1231 	pts->pts_fired = 0;
   1232 	p->p_timers = pts;
   1233 }
   1234 
   1235 /*
   1236  * Clean up the per-process timers. If "which" is set to TIMERS_ALL,
   1237  * then clean up all timers and free all the data structures. If
   1238  * "which" is set to TIMERS_POSIX, only clean up the timers allocated
   1239  * by timer_create(), not the BSD setitimer() timers, and only free the
   1240  * structure if none of those remain.
   1241  */
   1242 void
   1243 timers_free(struct proc *p, int which)
   1244 {
   1245 	int i, s;
   1246 	struct ptimers *pts;
   1247 	struct ptimer *pt, *ptn;
   1248 	struct timeval tv;
   1249 
   1250 	if (p->p_timers) {
   1251 		pts = p->p_timers;
   1252 		if (which == TIMERS_ALL)
   1253 			i = 0;
   1254 		else {
   1255 			s = splclock();
   1256 			timerclear(&tv);
   1257 			for (ptn = LIST_FIRST(&p->p_timers->pts_virtual);
   1258 			     ptn && ptn != pts->pts_timers[ITIMER_VIRTUAL];
   1259 			     ptn = LIST_NEXT(ptn, pt_list))
   1260 				timeradd(&tv, &ptn->pt_time.it_value, &tv);
   1261 			LIST_FIRST(&p->p_timers->pts_virtual) = NULL;
   1262 			if (ptn) {
   1263 				timeradd(&tv, &ptn->pt_time.it_value,
   1264 				    &ptn->pt_time.it_value);
   1265 				LIST_INSERT_HEAD(&p->p_timers->pts_virtual,
   1266 				    ptn, pt_list);
   1267 			}
   1268 
   1269 			timerclear(&tv);
   1270 			for (ptn = LIST_FIRST(&p->p_timers->pts_prof);
   1271 			     ptn && ptn != pts->pts_timers[ITIMER_PROF];
   1272 			     ptn = LIST_NEXT(ptn, pt_list))
   1273 				timeradd(&tv, &ptn->pt_time.it_value, &tv);
   1274 			LIST_FIRST(&p->p_timers->pts_prof) = NULL;
   1275 			if (ptn) {
   1276 				timeradd(&tv, &ptn->pt_time.it_value,
   1277 				    &ptn->pt_time.it_value);
   1278 				LIST_INSERT_HEAD(&p->p_timers->pts_prof, ptn,
   1279 				    pt_list);
   1280 			}
   1281 			splx(s);
   1282 			i = 3;
   1283 		}
   1284 		for ( ; i < TIMER_MAX; i++)
   1285 			if ((pt = pts->pts_timers[i]) != NULL) {
   1286 				if (pt->pt_type == CLOCK_REALTIME) {
   1287 					callout_stop(&pt->pt_ch);
   1288 					callout_destroy(&pt->pt_ch);
   1289 				}
   1290 				pts->pts_timers[i] = NULL;
   1291 				pool_put(&ptimer_pool, pt);
   1292 			}
   1293 		if ((pts->pts_timers[0] == NULL) &&
   1294 		    (pts->pts_timers[1] == NULL) &&
   1295 		    (pts->pts_timers[2] == NULL)) {
   1296 			p->p_timers = NULL;
   1297 			pool_put(&ptimers_pool, pts);
   1298 		}
   1299 	}
   1300 }
   1301 
   1302 /*
   1303  * Decrement an interval timer by a specified number
   1304  * of microseconds, which must be less than a second,
   1305  * i.e. < 1000000.  If the timer expires, then reload
   1306  * it.  In this case, carry over (usec - old value) to
   1307  * reduce the value reloaded into the timer so that
   1308  * the timer does not drift.  This routine assumes
   1309  * that it is called in a context where the timers
   1310  * on which it is operating cannot change in value.
   1311  */
   1312 int
   1313 itimerdecr(struct ptimer *pt, int usec)
   1314 {
   1315 	struct itimerval *itp;
   1316 
   1317 	itp = &pt->pt_time;
   1318 	if (itp->it_value.tv_usec < usec) {
   1319 		if (itp->it_value.tv_sec == 0) {
   1320 			/* expired, and already in next interval */
   1321 			usec -= itp->it_value.tv_usec;
   1322 			goto expire;
   1323 		}
   1324 		itp->it_value.tv_usec += 1000000;
   1325 		itp->it_value.tv_sec--;
   1326 	}
   1327 	itp->it_value.tv_usec -= usec;
   1328 	usec = 0;
   1329 	if (timerisset(&itp->it_value))
   1330 		return (1);
   1331 	/* expired, exactly at end of interval */
   1332 expire:
   1333 	if (timerisset(&itp->it_interval)) {
   1334 		itp->it_value = itp->it_interval;
   1335 		itp->it_value.tv_usec -= usec;
   1336 		if (itp->it_value.tv_usec < 0) {
   1337 			itp->it_value.tv_usec += 1000000;
   1338 			itp->it_value.tv_sec--;
   1339 		}
   1340 		timer_settime(pt);
   1341 	} else
   1342 		itp->it_value.tv_usec = 0;		/* sec is already 0 */
   1343 	return (0);
   1344 }
   1345 
   1346 void
   1347 itimerfire(struct ptimer *pt)
   1348 {
   1349 	struct proc *p = pt->pt_proc;
   1350 
   1351 	if (pt->pt_ev.sigev_notify == SIGEV_SIGNAL) {
   1352 		/*
   1353 		 * No RT signal infrastructure exists at this time;
   1354 		 * just post the signal number and throw away the
   1355 		 * value.
   1356 		 */
   1357 		if (sigismember(&p->p_sigpend.sp_set, pt->pt_ev.sigev_signo))
   1358 			pt->pt_overruns++;
   1359 		else {
   1360 			ksiginfo_t ksi;
   1361 			KSI_INIT(&ksi);
   1362 			ksi.ksi_signo = pt->pt_ev.sigev_signo;
   1363 			ksi.ksi_code = SI_TIMER;
   1364 			ksi.ksi_value = pt->pt_ev.sigev_value;
   1365 			pt->pt_poverruns = pt->pt_overruns;
   1366 			pt->pt_overruns = 0;
   1367 			mutex_enter(&proclist_mutex);
   1368 			kpsignal(p, &ksi, NULL);
   1369 			mutex_exit(&proclist_mutex);
   1370 		}
   1371 	}
   1372 }
   1373 
   1374 /*
   1375  * ratecheck(): simple time-based rate-limit checking.  see ratecheck(9)
   1376  * for usage and rationale.
   1377  */
   1378 int
   1379 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
   1380 {
   1381 	struct timeval tv, delta;
   1382 	int rv = 0;
   1383 #ifndef __HAVE_TIMECOUNTER
   1384 	int s;
   1385 #endif
   1386 
   1387 #ifdef __HAVE_TIMECOUNTER
   1388 	getmicrouptime(&tv);
   1389 #else /* !__HAVE_TIMECOUNTER */
   1390 	s = splclock();
   1391 	tv = mono_time;
   1392 	splx(s);
   1393 #endif /* !__HAVE_TIMECOUNTER */
   1394 	timersub(&tv, lasttime, &delta);
   1395 
   1396 	/*
   1397 	 * check for 0,0 is so that the message will be seen at least once,
   1398 	 * even if interval is huge.
   1399 	 */
   1400 	if (timercmp(&delta, mininterval, >=) ||
   1401 	    (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
   1402 		*lasttime = tv;
   1403 		rv = 1;
   1404 	}
   1405 
   1406 	return (rv);
   1407 }
   1408 
   1409 /*
   1410  * ppsratecheck(): packets (or events) per second limitation.
   1411  */
   1412 int
   1413 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
   1414 {
   1415 	struct timeval tv, delta;
   1416 	int rv;
   1417 #ifndef __HAVE_TIMECOUNTER
   1418 	int s;
   1419 #endif
   1420 
   1421 #ifdef __HAVE_TIMECOUNTER
   1422 	getmicrouptime(&tv);
   1423 #else /* !__HAVE_TIMECOUNTER */
   1424 	s = splclock();
   1425 	tv = mono_time;
   1426 	splx(s);
   1427 #endif /* !__HAVE_TIMECOUNTER */
   1428 	timersub(&tv, lasttime, &delta);
   1429 
   1430 	/*
   1431 	 * check for 0,0 is so that the message will be seen at least once.
   1432 	 * if more than one second have passed since the last update of
   1433 	 * lasttime, reset the counter.
   1434 	 *
   1435 	 * we do increment *curpps even in *curpps < maxpps case, as some may
   1436 	 * try to use *curpps for stat purposes as well.
   1437 	 */
   1438 	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
   1439 	    delta.tv_sec >= 1) {
   1440 		*lasttime = tv;
   1441 		*curpps = 0;
   1442 	}
   1443 	if (maxpps < 0)
   1444 		rv = 1;
   1445 	else if (*curpps < maxpps)
   1446 		rv = 1;
   1447 	else
   1448 		rv = 0;
   1449 
   1450 #if 1 /*DIAGNOSTIC?*/
   1451 	/* be careful about wrap-around */
   1452 	if (*curpps + 1 > *curpps)
   1453 		*curpps = *curpps + 1;
   1454 #else
   1455 	/*
   1456 	 * assume that there's not too many calls to this function.
   1457 	 * not sure if the assumption holds, as it depends on *caller's*
   1458 	 * behavior, not the behavior of this function.
   1459 	 * IMHO it is wrong to make assumption on the caller's behavior,
   1460 	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
   1461 	 */
   1462 	*curpps = *curpps + 1;
   1463 #endif
   1464 
   1465 	return (rv);
   1466 }
   1467