freebsd-dev/sys/kern/kern_time.c
Konstantin Belousov 5c7bebf961 The process spin lock currently has the following distinct uses:
- Threads lifetime cycle, in particular, counting of the threads in
  the process, and interlocking with process mutex and thread lock.
  The main reason of this is that turnstile locks are after thread
  locks, so you e.g. cannot unlock blockable mutex (think process
  mutex) while owning thread lock.

- Virtual and profiling itimers, since the timers activation is done
  from the clock interrupt context.  Replace the p_slock by p_itimmtx
  and PROC_ITIMLOCK().

- Profiling code (profil(2)), for similar reason.  Replace the p_slock
  by p_profmtx and PROC_PROFLOCK().

- Resource usage accounting.  Need for the spinlock there is subtle,
  my understanding is that spinlock blocks context switching for the
  current thread, which prevents td_runtime and similar fields from
  changing (updates are done at the mi_switch()).  Replace the p_slock
  by p_statmtx and PROC_STATLOCK().

The split is done mostly for code clarity, and should not affect
scalability.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-26 14:10:00 +00:00

1664 lines
39 KiB
C

/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_time.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/limits.h>
#include <sys/clock.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysproto.h>
#include <sys/eventhandler.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/kernel.h>
#include <sys/sleepqueue.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/posix4.h>
#include <sys/time.h>
#include <sys/timers.h>
#include <sys/timetc.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#define MAX_CLOCKS (CLOCK_MONOTONIC+1)
#define CPUCLOCK_BIT 0x80000000
#define CPUCLOCK_PROCESS_BIT 0x40000000
#define CPUCLOCK_ID_MASK (~(CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT))
#define MAKE_THREAD_CPUCLOCK(tid) (CPUCLOCK_BIT|(tid))
#define MAKE_PROCESS_CPUCLOCK(pid) \
(CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT|(pid))
static struct kclock posix_clocks[MAX_CLOCKS];
static uma_zone_t itimer_zone = NULL;
/*
* Time of day and interval timer support.
*
* These routines provide the kernel entry points to get and set
* the time-of-day and per-process interval timers. Subroutines
* here provide support for adding and subtracting timeval structures
* and decrementing interval timers, optionally reloading the interval
* timers when they expire.
*/
static int settime(struct thread *, struct timeval *);
static void timevalfix(struct timeval *);
static void itimer_start(void);
static int itimer_init(void *, int, int);
static void itimer_fini(void *, int);
static void itimer_enter(struct itimer *);
static void itimer_leave(struct itimer *);
static struct itimer *itimer_find(struct proc *, int);
static void itimers_alloc(struct proc *);
static void itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp);
static void itimers_event_hook_exit(void *arg, struct proc *p);
static int realtimer_create(struct itimer *);
static int realtimer_gettime(struct itimer *, struct itimerspec *);
static int realtimer_settime(struct itimer *, int,
struct itimerspec *, struct itimerspec *);
static int realtimer_delete(struct itimer *);
static void realtimer_clocktime(clockid_t, struct timespec *);
static void realtimer_expire(void *);
int register_posix_clock(int, struct kclock *);
void itimer_fire(struct itimer *it);
int itimespecfix(struct timespec *ts);
#define CLOCK_CALL(clock, call, arglist) \
((*posix_clocks[clock].call) arglist)
SYSINIT(posix_timer, SI_SUB_P1003_1B, SI_ORDER_FIRST+4, itimer_start, NULL);
static int
settime(struct thread *td, struct timeval *tv)
{
struct timeval delta, tv1, tv2;
static struct timeval maxtime, laststep;
struct timespec ts;
int s;
s = splclock();
microtime(&tv1);
delta = *tv;
timevalsub(&delta, &tv1);
/*
* If the system is secure, we do not allow the time to be
* set to a value earlier than 1 second less than the highest
* time we have yet seen. The worst a miscreant can do in
* this circumstance is "freeze" time. He couldn't go
* back to the past.
*
* We similarly do not allow the clock to be stepped more
* than one second, nor more than once per second. This allows
* a miscreant to make the clock march double-time, but no worse.
*/
if (securelevel_gt(td->td_ucred, 1) != 0) {
if (delta.tv_sec < 0 || delta.tv_usec < 0) {
/*
* Update maxtime to latest time we've seen.
*/
if (tv1.tv_sec > maxtime.tv_sec)
maxtime = tv1;
tv2 = *tv;
timevalsub(&tv2, &maxtime);
if (tv2.tv_sec < -1) {
tv->tv_sec = maxtime.tv_sec - 1;
printf("Time adjustment clamped to -1 second\n");
}
} else {
if (tv1.tv_sec == laststep.tv_sec) {
splx(s);
return (EPERM);
}
if (delta.tv_sec > 1) {
tv->tv_sec = tv1.tv_sec + 1;
printf("Time adjustment clamped to +1 second\n");
}
laststep = *tv;
}
}
ts.tv_sec = tv->tv_sec;
ts.tv_nsec = tv->tv_usec * 1000;
mtx_lock(&Giant);
tc_setclock(&ts);
resettodr();
mtx_unlock(&Giant);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct clock_getcpuclockid2_args {
id_t id;
int which,
clockid_t *clock_id;
};
#endif
/* ARGSUSED */
int
sys_clock_getcpuclockid2(struct thread *td, struct clock_getcpuclockid2_args *uap)
{
clockid_t clk_id;
int error;
error = kern_clock_getcpuclockid2(td, uap->id, uap->which, &clk_id);
if (error == 0)
error = copyout(&clk_id, uap->clock_id, sizeof(clockid_t));
return (error);
}
int
kern_clock_getcpuclockid2(struct thread *td, id_t id, int which,
clockid_t *clk_id)
{
struct proc *p;
pid_t pid;
lwpid_t tid;
int error;
switch (which) {
case CPUCLOCK_WHICH_PID:
if (id != 0) {
p = pfind(id);
if (p == NULL)
return (ESRCH);
error = p_cansee(td, p);
PROC_UNLOCK(p);
if (error != 0)
return (error);
pid = id;
} else {
pid = td->td_proc->p_pid;
}
*clk_id = MAKE_PROCESS_CPUCLOCK(pid);
return (0);
case CPUCLOCK_WHICH_TID:
tid = id == 0 ? td->td_tid : id;
*clk_id = MAKE_THREAD_CPUCLOCK(tid);
return (0);
default:
return (EINVAL);
}
}
#ifndef _SYS_SYSPROTO_H_
struct clock_gettime_args {
clockid_t clock_id;
struct timespec *tp;
};
#endif
/* ARGSUSED */
int
sys_clock_gettime(struct thread *td, struct clock_gettime_args *uap)
{
struct timespec ats;
int error;
error = kern_clock_gettime(td, uap->clock_id, &ats);
if (error == 0)
error = copyout(&ats, uap->tp, sizeof(ats));
return (error);
}
static inline void
cputick2timespec(uint64_t runtime, struct timespec *ats)
{
runtime = cputick2usec(runtime);
ats->tv_sec = runtime / 1000000;
ats->tv_nsec = runtime % 1000000 * 1000;
}
static void
get_thread_cputime(struct thread *targettd, struct timespec *ats)
{
uint64_t runtime, curtime, switchtime;
if (targettd == NULL) { /* current thread */
critical_enter();
switchtime = PCPU_GET(switchtime);
curtime = cpu_ticks();
runtime = curthread->td_runtime;
critical_exit();
runtime += curtime - switchtime;
} else {
thread_lock(targettd);
runtime = targettd->td_runtime;
thread_unlock(targettd);
}
cputick2timespec(runtime, ats);
}
static void
get_process_cputime(struct proc *targetp, struct timespec *ats)
{
uint64_t runtime;
struct rusage ru;
PROC_STATLOCK(targetp);
rufetch(targetp, &ru);
runtime = targetp->p_rux.rux_runtime;
PROC_STATUNLOCK(targetp);
cputick2timespec(runtime, ats);
}
static int
get_cputime(struct thread *td, clockid_t clock_id, struct timespec *ats)
{
struct proc *p, *p2;
struct thread *td2;
lwpid_t tid;
pid_t pid;
int error;
p = td->td_proc;
if ((clock_id & CPUCLOCK_PROCESS_BIT) == 0) {
tid = clock_id & CPUCLOCK_ID_MASK;
td2 = tdfind(tid, p->p_pid);
if (td2 == NULL)
return (EINVAL);
get_thread_cputime(td2, ats);
PROC_UNLOCK(td2->td_proc);
} else {
pid = clock_id & CPUCLOCK_ID_MASK;
error = pget(pid, PGET_CANSEE, &p2);
if (error != 0)
return (EINVAL);
get_process_cputime(p2, ats);
PROC_UNLOCK(p2);
}
return (0);
}
int
kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
{
struct timeval sys, user;
struct proc *p;
p = td->td_proc;
switch (clock_id) {
case CLOCK_REALTIME: /* Default to precise. */
case CLOCK_REALTIME_PRECISE:
nanotime(ats);
break;
case CLOCK_REALTIME_FAST:
getnanotime(ats);
break;
case CLOCK_VIRTUAL:
PROC_LOCK(p);
PROC_STATLOCK(p);
calcru(p, &user, &sys);
PROC_STATUNLOCK(p);
PROC_UNLOCK(p);
TIMEVAL_TO_TIMESPEC(&user, ats);
break;
case CLOCK_PROF:
PROC_LOCK(p);
PROC_STATLOCK(p);
calcru(p, &user, &sys);
PROC_STATUNLOCK(p);
PROC_UNLOCK(p);
timevaladd(&user, &sys);
TIMEVAL_TO_TIMESPEC(&user, ats);
break;
case CLOCK_MONOTONIC: /* Default to precise. */
case CLOCK_MONOTONIC_PRECISE:
case CLOCK_UPTIME:
case CLOCK_UPTIME_PRECISE:
nanouptime(ats);
break;
case CLOCK_UPTIME_FAST:
case CLOCK_MONOTONIC_FAST:
getnanouptime(ats);
break;
case CLOCK_SECOND:
ats->tv_sec = time_second;
ats->tv_nsec = 0;
break;
case CLOCK_THREAD_CPUTIME_ID:
get_thread_cputime(NULL, ats);
break;
case CLOCK_PROCESS_CPUTIME_ID:
PROC_LOCK(p);
get_process_cputime(p, ats);
PROC_UNLOCK(p);
break;
default:
if ((int)clock_id >= 0)
return (EINVAL);
return (get_cputime(td, clock_id, ats));
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct clock_settime_args {
clockid_t clock_id;
const struct timespec *tp;
};
#endif
/* ARGSUSED */
int
sys_clock_settime(struct thread *td, struct clock_settime_args *uap)
{
struct timespec ats;
int error;
if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
return (error);
return (kern_clock_settime(td, uap->clock_id, &ats));
}
int
kern_clock_settime(struct thread *td, clockid_t clock_id, struct timespec *ats)
{
struct timeval atv;
int error;
if ((error = priv_check(td, PRIV_CLOCK_SETTIME)) != 0)
return (error);
if (clock_id != CLOCK_REALTIME)
return (EINVAL);
if (ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000)
return (EINVAL);
/* XXX Don't convert nsec->usec and back */
TIMESPEC_TO_TIMEVAL(&atv, ats);
error = settime(td, &atv);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct clock_getres_args {
clockid_t clock_id;
struct timespec *tp;
};
#endif
int
sys_clock_getres(struct thread *td, struct clock_getres_args *uap)
{
struct timespec ts;
int error;
if (uap->tp == NULL)
return (0);
error = kern_clock_getres(td, uap->clock_id, &ts);
if (error == 0)
error = copyout(&ts, uap->tp, sizeof(ts));
return (error);
}
int
kern_clock_getres(struct thread *td, clockid_t clock_id, struct timespec *ts)
{
ts->tv_sec = 0;
switch (clock_id) {
case CLOCK_REALTIME:
case CLOCK_REALTIME_FAST:
case CLOCK_REALTIME_PRECISE:
case CLOCK_MONOTONIC:
case CLOCK_MONOTONIC_FAST:
case CLOCK_MONOTONIC_PRECISE:
case CLOCK_UPTIME:
case CLOCK_UPTIME_FAST:
case CLOCK_UPTIME_PRECISE:
/*
* Round up the result of the division cheaply by adding 1.
* Rounding up is especially important if rounding down
* would give 0. Perfect rounding is unimportant.
*/
ts->tv_nsec = 1000000000 / tc_getfrequency() + 1;
break;
case CLOCK_VIRTUAL:
case CLOCK_PROF:
/* Accurately round up here because we can do so cheaply. */
ts->tv_nsec = (1000000000 + hz - 1) / hz;
break;
case CLOCK_SECOND:
ts->tv_sec = 1;
ts->tv_nsec = 0;
break;
case CLOCK_THREAD_CPUTIME_ID:
case CLOCK_PROCESS_CPUTIME_ID:
cputime:
/* sync with cputick2usec */
ts->tv_nsec = 1000000 / cpu_tickrate();
if (ts->tv_nsec == 0)
ts->tv_nsec = 1000;
break;
default:
if ((int)clock_id < 0)
goto cputime;
return (EINVAL);
}
return (0);
}
static uint8_t nanowait[MAXCPU];
int
kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
{
struct timespec ts;
sbintime_t sbt, sbtt, prec, tmp;
time_t over;
int error;
if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
return (EINVAL);
if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
return (0);
ts = *rqt;
if (ts.tv_sec > INT32_MAX / 2) {
over = ts.tv_sec - INT32_MAX / 2;
ts.tv_sec -= over;
} else
over = 0;
tmp = tstosbt(ts);
prec = tmp;
prec >>= tc_precexp;
if (TIMESEL(&sbt, tmp))
sbt += tc_tick_sbt;
sbt += tmp;
error = tsleep_sbt(&nanowait[curcpu], PWAIT | PCATCH, "nanslp",
sbt, prec, C_ABSOLUTE);
if (error != EWOULDBLOCK) {
if (error == ERESTART)
error = EINTR;
TIMESEL(&sbtt, tmp);
if (rmt != NULL) {
ts = sbttots(sbt - sbtt);
ts.tv_sec += over;
if (ts.tv_sec < 0)
timespecclear(&ts);
*rmt = ts;
}
if (sbtt >= sbt)
return (0);
return (error);
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct nanosleep_args {
struct timespec *rqtp;
struct timespec *rmtp;
};
#endif
/* ARGSUSED */
int
sys_nanosleep(struct thread *td, struct nanosleep_args *uap)
{
struct timespec rmt, rqt;
int error;
error = copyin(uap->rqtp, &rqt, sizeof(rqt));
if (error)
return (error);
if (uap->rmtp &&
!useracc((caddr_t)uap->rmtp, sizeof(rmt), VM_PROT_WRITE))
return (EFAULT);
error = kern_nanosleep(td, &rqt, &rmt);
if (error && uap->rmtp) {
int error2;
error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
if (error2)
error = error2;
}
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct gettimeofday_args {
struct timeval *tp;
struct timezone *tzp;
};
#endif
/* ARGSUSED */
int
sys_gettimeofday(struct thread *td, struct gettimeofday_args *uap)
{
struct timeval atv;
struct timezone rtz;
int error = 0;
if (uap->tp) {
microtime(&atv);
error = copyout(&atv, uap->tp, sizeof (atv));
}
if (error == 0 && uap->tzp != NULL) {
rtz.tz_minuteswest = tz_minuteswest;
rtz.tz_dsttime = tz_dsttime;
error = copyout(&rtz, uap->tzp, sizeof (rtz));
}
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct settimeofday_args {
struct timeval *tv;
struct timezone *tzp;
};
#endif
/* ARGSUSED */
int
sys_settimeofday(struct thread *td, struct settimeofday_args *uap)
{
struct timeval atv, *tvp;
struct timezone atz, *tzp;
int error;
if (uap->tv) {
error = copyin(uap->tv, &atv, sizeof(atv));
if (error)
return (error);
tvp = &atv;
} else
tvp = NULL;
if (uap->tzp) {
error = copyin(uap->tzp, &atz, sizeof(atz));
if (error)
return (error);
tzp = &atz;
} else
tzp = NULL;
return (kern_settimeofday(td, tvp, tzp));
}
int
kern_settimeofday(struct thread *td, struct timeval *tv, struct timezone *tzp)
{
int error;
error = priv_check(td, PRIV_SETTIMEOFDAY);
if (error)
return (error);
/* Verify all parameters before changing time. */
if (tv) {
if (tv->tv_usec < 0 || tv->tv_usec >= 1000000)
return (EINVAL);
error = settime(td, tv);
}
if (tzp && error == 0) {
tz_minuteswest = tzp->tz_minuteswest;
tz_dsttime = tzp->tz_dsttime;
}
return (error);
}
/*
* Get value of an interval timer. The process virtual and profiling virtual
* time timers are kept in the p_stats area, since they can be swapped out.
* These are kept internally in the way they are specified externally: in
* time until they expire.
*
* The real time interval timer is kept in the process table slot for the
* process, and its value (it_value) is kept as an absolute time rather than
* as a delta, so that it is easy to keep periodic real-time signals from
* drifting.
*
* Virtual time timers are processed in the hardclock() routine of
* kern_clock.c. The real time timer is processed by a timeout routine,
* called from the softclock() routine. Since a callout may be delayed in
* real time due to interrupt processing in the system, it is possible for
* the real time timeout routine (realitexpire, given below), to be delayed
* in real time past when it is supposed to occur. It does not suffice,
* therefore, to reload the real timer .it_value from the real time timers
* .it_interval. Rather, we compute the next time in absolute time the timer
* should go off.
*/
#ifndef _SYS_SYSPROTO_H_
struct getitimer_args {
u_int which;
struct itimerval *itv;
};
#endif
int
sys_getitimer(struct thread *td, struct getitimer_args *uap)
{
struct itimerval aitv;
int error;
error = kern_getitimer(td, uap->which, &aitv);
if (error != 0)
return (error);
return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
}
int
kern_getitimer(struct thread *td, u_int which, struct itimerval *aitv)
{
struct proc *p = td->td_proc;
struct timeval ctv;
if (which > ITIMER_PROF)
return (EINVAL);
if (which == ITIMER_REAL) {
/*
* Convert from absolute to relative time in .it_value
* part of real time timer. If time for real time timer
* has passed return 0, else return difference between
* current time and time for the timer to go off.
*/
PROC_LOCK(p);
*aitv = p->p_realtimer;
PROC_UNLOCK(p);
if (timevalisset(&aitv->it_value)) {
microuptime(&ctv);
if (timevalcmp(&aitv->it_value, &ctv, <))
timevalclear(&aitv->it_value);
else
timevalsub(&aitv->it_value, &ctv);
}
} else {
PROC_ITIMLOCK(p);
*aitv = p->p_stats->p_timer[which];
PROC_ITIMUNLOCK(p);
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct setitimer_args {
u_int which;
struct itimerval *itv, *oitv;
};
#endif
int
sys_setitimer(struct thread *td, struct setitimer_args *uap)
{
struct itimerval aitv, oitv;
int error;
if (uap->itv == NULL) {
uap->itv = uap->oitv;
return (sys_getitimer(td, (struct getitimer_args *)uap));
}
if ((error = copyin(uap->itv, &aitv, sizeof(struct itimerval))))
return (error);
error = kern_setitimer(td, uap->which, &aitv, &oitv);
if (error != 0 || uap->oitv == NULL)
return (error);
return (copyout(&oitv, uap->oitv, sizeof(struct itimerval)));
}
int
kern_setitimer(struct thread *td, u_int which, struct itimerval *aitv,
struct itimerval *oitv)
{
struct proc *p = td->td_proc;
struct timeval ctv;
sbintime_t sbt, pr;
if (aitv == NULL)
return (kern_getitimer(td, which, oitv));
if (which > ITIMER_PROF)
return (EINVAL);
if (itimerfix(&aitv->it_value) ||
aitv->it_value.tv_sec > INT32_MAX / 2)
return (EINVAL);
if (!timevalisset(&aitv->it_value))
timevalclear(&aitv->it_interval);
else if (itimerfix(&aitv->it_interval) ||
aitv->it_interval.tv_sec > INT32_MAX / 2)
return (EINVAL);
if (which == ITIMER_REAL) {
PROC_LOCK(p);
if (timevalisset(&p->p_realtimer.it_value))
callout_stop(&p->p_itcallout);
microuptime(&ctv);
if (timevalisset(&aitv->it_value)) {
pr = tvtosbt(aitv->it_value) >> tc_precexp;
timevaladd(&aitv->it_value, &ctv);
sbt = tvtosbt(aitv->it_value);
callout_reset_sbt(&p->p_itcallout, sbt, pr,
realitexpire, p, C_ABSOLUTE);
}
*oitv = p->p_realtimer;
p->p_realtimer = *aitv;
PROC_UNLOCK(p);
if (timevalisset(&oitv->it_value)) {
if (timevalcmp(&oitv->it_value, &ctv, <))
timevalclear(&oitv->it_value);
else
timevalsub(&oitv->it_value, &ctv);
}
} else {
if (aitv->it_interval.tv_sec == 0 &&
aitv->it_interval.tv_usec != 0 &&
aitv->it_interval.tv_usec < tick)
aitv->it_interval.tv_usec = tick;
if (aitv->it_value.tv_sec == 0 &&
aitv->it_value.tv_usec != 0 &&
aitv->it_value.tv_usec < tick)
aitv->it_value.tv_usec = tick;
PROC_ITIMLOCK(p);
*oitv = p->p_stats->p_timer[which];
p->p_stats->p_timer[which] = *aitv;
PROC_ITIMUNLOCK(p);
}
return (0);
}
/*
* Real interval timer expired:
* send process whose timer expired an alarm signal.
* If time is not set up to reload, then just return.
* Else compute next time timer should go off which is > current time.
* This is where delay in processing this timeout causes multiple
* SIGALRM calls to be compressed into one.
* tvtohz() always adds 1 to allow for the time until the next clock
* interrupt being strictly less than 1 clock tick, but we don't want
* that here since we want to appear to be in sync with the clock
* interrupt even when we're delayed.
*/
void
realitexpire(void *arg)
{
struct proc *p;
struct timeval ctv;
sbintime_t isbt;
p = (struct proc *)arg;
kern_psignal(p, SIGALRM);
if (!timevalisset(&p->p_realtimer.it_interval)) {
timevalclear(&p->p_realtimer.it_value);
if (p->p_flag & P_WEXIT)
wakeup(&p->p_itcallout);
return;
}
isbt = tvtosbt(p->p_realtimer.it_interval);
if (isbt >= sbt_timethreshold)
getmicrouptime(&ctv);
else
microuptime(&ctv);
do {
timevaladd(&p->p_realtimer.it_value,
&p->p_realtimer.it_interval);
} while (timevalcmp(&p->p_realtimer.it_value, &ctv, <=));
callout_reset_sbt(&p->p_itcallout, tvtosbt(p->p_realtimer.it_value),
isbt >> tc_precexp, realitexpire, p, C_ABSOLUTE);
}
/*
* Check that a proposed value to load into the .it_value or
* .it_interval part of an interval timer is acceptable, and
* fix it to have at least minimal value (i.e. if it is less
* than the resolution of the clock, round it up.)
*/
int
itimerfix(struct timeval *tv)
{
if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
return (EINVAL);
if (tv->tv_sec == 0 && tv->tv_usec != 0 &&
tv->tv_usec < (u_int)tick / 16)
tv->tv_usec = (u_int)tick / 16;
return (0);
}
/*
* Decrement an interval timer by a specified number
* of microseconds, which must be less than a second,
* i.e. < 1000000. If the timer expires, then reload
* it. In this case, carry over (usec - old value) to
* reduce the value reloaded into the timer so that
* the timer does not drift. This routine assumes
* that it is called in a context where the timers
* on which it is operating cannot change in value.
*/
int
itimerdecr(struct itimerval *itp, int usec)
{
if (itp->it_value.tv_usec < usec) {
if (itp->it_value.tv_sec == 0) {
/* expired, and already in next interval */
usec -= itp->it_value.tv_usec;
goto expire;
}
itp->it_value.tv_usec += 1000000;
itp->it_value.tv_sec--;
}
itp->it_value.tv_usec -= usec;
usec = 0;
if (timevalisset(&itp->it_value))
return (1);
/* expired, exactly at end of interval */
expire:
if (timevalisset(&itp->it_interval)) {
itp->it_value = itp->it_interval;
itp->it_value.tv_usec -= usec;
if (itp->it_value.tv_usec < 0) {
itp->it_value.tv_usec += 1000000;
itp->it_value.tv_sec--;
}
} else
itp->it_value.tv_usec = 0; /* sec is already 0 */
return (0);
}
/*
* Add and subtract routines for timevals.
* N.B.: subtract routine doesn't deal with
* results which are before the beginning,
* it just gets very confused in this case.
* Caveat emptor.
*/
void
timevaladd(struct timeval *t1, const struct timeval *t2)
{
t1->tv_sec += t2->tv_sec;
t1->tv_usec += t2->tv_usec;
timevalfix(t1);
}
void
timevalsub(struct timeval *t1, const struct timeval *t2)
{
t1->tv_sec -= t2->tv_sec;
t1->tv_usec -= t2->tv_usec;
timevalfix(t1);
}
static void
timevalfix(struct timeval *t1)
{
if (t1->tv_usec < 0) {
t1->tv_sec--;
t1->tv_usec += 1000000;
}
if (t1->tv_usec >= 1000000) {
t1->tv_sec++;
t1->tv_usec -= 1000000;
}
}
/*
* ratecheck(): simple time-based rate-limit checking.
*/
int
ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
{
struct timeval tv, delta;
int rv = 0;
getmicrouptime(&tv); /* NB: 10ms precision */
delta = tv;
timevalsub(&delta, lasttime);
/*
* check for 0,0 is so that the message will be seen at least once,
* even if interval is huge.
*/
if (timevalcmp(&delta, mininterval, >=) ||
(lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
*lasttime = tv;
rv = 1;
}
return (rv);
}
/*
* ppsratecheck(): packets (or events) per second limitation.
*
* Return 0 if the limit is to be enforced (e.g. the caller
* should drop a packet because of the rate limitation).
*
* maxpps of 0 always causes zero to be returned. maxpps of -1
* always causes 1 to be returned; this effectively defeats rate
* limiting.
*
* Note that we maintain the struct timeval for compatibility
* with other bsd systems. We reuse the storage and just monitor
* clock ticks for minimal overhead.
*/
int
ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
{
int now;
/*
* Reset the last time and counter if this is the first call
* or more than a second has passed since the last update of
* lasttime.
*/
now = ticks;
if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
lasttime->tv_sec = now;
*curpps = 1;
return (maxpps != 0);
} else {
(*curpps)++; /* NB: ignore potential overflow */
return (maxpps < 0 || *curpps < maxpps);
}
}
static void
itimer_start(void)
{
struct kclock rt_clock = {
.timer_create = realtimer_create,
.timer_delete = realtimer_delete,
.timer_settime = realtimer_settime,
.timer_gettime = realtimer_gettime,
.event_hook = NULL
};
itimer_zone = uma_zcreate("itimer", sizeof(struct itimer),
NULL, NULL, itimer_init, itimer_fini, UMA_ALIGN_PTR, 0);
register_posix_clock(CLOCK_REALTIME, &rt_clock);
register_posix_clock(CLOCK_MONOTONIC, &rt_clock);
p31b_setcfg(CTL_P1003_1B_TIMERS, 200112L);
p31b_setcfg(CTL_P1003_1B_DELAYTIMER_MAX, INT_MAX);
p31b_setcfg(CTL_P1003_1B_TIMER_MAX, TIMER_MAX);
EVENTHANDLER_REGISTER(process_exit, itimers_event_hook_exit,
(void *)ITIMER_EV_EXIT, EVENTHANDLER_PRI_ANY);
EVENTHANDLER_REGISTER(process_exec, itimers_event_hook_exec,
(void *)ITIMER_EV_EXEC, EVENTHANDLER_PRI_ANY);
}
int
register_posix_clock(int clockid, struct kclock *clk)
{
if ((unsigned)clockid >= MAX_CLOCKS) {
printf("%s: invalid clockid\n", __func__);
return (0);
}
posix_clocks[clockid] = *clk;
return (1);
}
static int
itimer_init(void *mem, int size, int flags)
{
struct itimer *it;
it = (struct itimer *)mem;
mtx_init(&it->it_mtx, "itimer lock", NULL, MTX_DEF);
return (0);
}
static void
itimer_fini(void *mem, int size)
{
struct itimer *it;
it = (struct itimer *)mem;
mtx_destroy(&it->it_mtx);
}
static void
itimer_enter(struct itimer *it)
{
mtx_assert(&it->it_mtx, MA_OWNED);
it->it_usecount++;
}
static void
itimer_leave(struct itimer *it)
{
mtx_assert(&it->it_mtx, MA_OWNED);
KASSERT(it->it_usecount > 0, ("invalid it_usecount"));
if (--it->it_usecount == 0 && (it->it_flags & ITF_WANTED) != 0)
wakeup(it);
}
#ifndef _SYS_SYSPROTO_H_
struct ktimer_create_args {
clockid_t clock_id;
struct sigevent * evp;
int * timerid;
};
#endif
int
sys_ktimer_create(struct thread *td, struct ktimer_create_args *uap)
{
struct sigevent *evp, ev;
int id;
int error;
if (uap->evp == NULL) {
evp = NULL;
} else {
error = copyin(uap->evp, &ev, sizeof(ev));
if (error != 0)
return (error);
evp = &ev;
}
error = kern_ktimer_create(td, uap->clock_id, evp, &id, -1);
if (error == 0) {
error = copyout(&id, uap->timerid, sizeof(int));
if (error != 0)
kern_ktimer_delete(td, id);
}
return (error);
}
int
kern_ktimer_create(struct thread *td, clockid_t clock_id, struct sigevent *evp,
int *timerid, int preset_id)
{
struct proc *p = td->td_proc;
struct itimer *it;
int id;
int error;
if (clock_id < 0 || clock_id >= MAX_CLOCKS)
return (EINVAL);
if (posix_clocks[clock_id].timer_create == NULL)
return (EINVAL);
if (evp != NULL) {
if (evp->sigev_notify != SIGEV_NONE &&
evp->sigev_notify != SIGEV_SIGNAL &&
evp->sigev_notify != SIGEV_THREAD_ID)
return (EINVAL);
if ((evp->sigev_notify == SIGEV_SIGNAL ||
evp->sigev_notify == SIGEV_THREAD_ID) &&
!_SIG_VALID(evp->sigev_signo))
return (EINVAL);
}
if (p->p_itimers == NULL)
itimers_alloc(p);
it = uma_zalloc(itimer_zone, M_WAITOK);
it->it_flags = 0;
it->it_usecount = 0;
it->it_active = 0;
timespecclear(&it->it_time.it_value);
timespecclear(&it->it_time.it_interval);
it->it_overrun = 0;
it->it_overrun_last = 0;
it->it_clockid = clock_id;
it->it_timerid = -1;
it->it_proc = p;
ksiginfo_init(&it->it_ksi);
it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
error = CLOCK_CALL(clock_id, timer_create, (it));
if (error != 0)
goto out;
PROC_LOCK(p);
if (preset_id != -1) {
KASSERT(preset_id >= 0 && preset_id < 3, ("invalid preset_id"));
id = preset_id;
if (p->p_itimers->its_timers[id] != NULL) {
PROC_UNLOCK(p);
error = 0;
goto out;
}
} else {
/*
* Find a free timer slot, skipping those reserved
* for setitimer().
*/
for (id = 3; id < TIMER_MAX; id++)
if (p->p_itimers->its_timers[id] == NULL)
break;
if (id == TIMER_MAX) {
PROC_UNLOCK(p);
error = EAGAIN;
goto out;
}
}
it->it_timerid = id;
p->p_itimers->its_timers[id] = it;
if (evp != NULL)
it->it_sigev = *evp;
else {
it->it_sigev.sigev_notify = SIGEV_SIGNAL;
switch (clock_id) {
default:
case CLOCK_REALTIME:
it->it_sigev.sigev_signo = SIGALRM;
break;
case CLOCK_VIRTUAL:
it->it_sigev.sigev_signo = SIGVTALRM;
break;
case CLOCK_PROF:
it->it_sigev.sigev_signo = SIGPROF;
break;
}
it->it_sigev.sigev_value.sival_int = id;
}
if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
it->it_ksi.ksi_signo = it->it_sigev.sigev_signo;
it->it_ksi.ksi_code = SI_TIMER;
it->it_ksi.ksi_value = it->it_sigev.sigev_value;
it->it_ksi.ksi_timerid = id;
}
PROC_UNLOCK(p);
*timerid = id;
return (0);
out:
ITIMER_LOCK(it);
CLOCK_CALL(it->it_clockid, timer_delete, (it));
ITIMER_UNLOCK(it);
uma_zfree(itimer_zone, it);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ktimer_delete_args {
int timerid;
};
#endif
int
sys_ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
{
return (kern_ktimer_delete(td, uap->timerid));
}
static struct itimer *
itimer_find(struct proc *p, int timerid)
{
struct itimer *it;
PROC_LOCK_ASSERT(p, MA_OWNED);
if ((p->p_itimers == NULL) ||
(timerid < 0) || (timerid >= TIMER_MAX) ||
(it = p->p_itimers->its_timers[timerid]) == NULL) {
return (NULL);
}
ITIMER_LOCK(it);
if ((it->it_flags & ITF_DELETING) != 0) {
ITIMER_UNLOCK(it);
it = NULL;
}
return (it);
}
int
kern_ktimer_delete(struct thread *td, int timerid)
{
struct proc *p = td->td_proc;
struct itimer *it;
PROC_LOCK(p);
it = itimer_find(p, timerid);
if (it == NULL) {
PROC_UNLOCK(p);
return (EINVAL);
}
PROC_UNLOCK(p);
it->it_flags |= ITF_DELETING;
while (it->it_usecount > 0) {
it->it_flags |= ITF_WANTED;
msleep(it, &it->it_mtx, PPAUSE, "itimer", 0);
}
it->it_flags &= ~ITF_WANTED;
CLOCK_CALL(it->it_clockid, timer_delete, (it));
ITIMER_UNLOCK(it);
PROC_LOCK(p);
if (KSI_ONQ(&it->it_ksi))
sigqueue_take(&it->it_ksi);
p->p_itimers->its_timers[timerid] = NULL;
PROC_UNLOCK(p);
uma_zfree(itimer_zone, it);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct ktimer_settime_args {
int timerid;
int flags;
const struct itimerspec * value;
struct itimerspec * ovalue;
};
#endif
int
sys_ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
{
struct itimerspec val, oval, *ovalp;
int error;
error = copyin(uap->value, &val, sizeof(val));
if (error != 0)
return (error);
ovalp = uap->ovalue != NULL ? &oval : NULL;
error = kern_ktimer_settime(td, uap->timerid, uap->flags, &val, ovalp);
if (error == 0 && uap->ovalue != NULL)
error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
return (error);
}
int
kern_ktimer_settime(struct thread *td, int timer_id, int flags,
struct itimerspec *val, struct itimerspec *oval)
{
struct proc *p;
struct itimer *it;
int error;
p = td->td_proc;
PROC_LOCK(p);
if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
PROC_UNLOCK(p);
error = EINVAL;
} else {
PROC_UNLOCK(p);
itimer_enter(it);
error = CLOCK_CALL(it->it_clockid, timer_settime, (it,
flags, val, oval));
itimer_leave(it);
ITIMER_UNLOCK(it);
}
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ktimer_gettime_args {
int timerid;
struct itimerspec * value;
};
#endif
int
sys_ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
{
struct itimerspec val;
int error;
error = kern_ktimer_gettime(td, uap->timerid, &val);
if (error == 0)
error = copyout(&val, uap->value, sizeof(val));
return (error);
}
int
kern_ktimer_gettime(struct thread *td, int timer_id, struct itimerspec *val)
{
struct proc *p;
struct itimer *it;
int error;
p = td->td_proc;
PROC_LOCK(p);
if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
PROC_UNLOCK(p);
error = EINVAL;
} else {
PROC_UNLOCK(p);
itimer_enter(it);
error = CLOCK_CALL(it->it_clockid, timer_gettime, (it, val));
itimer_leave(it);
ITIMER_UNLOCK(it);
}
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct timer_getoverrun_args {
int timerid;
};
#endif
int
sys_ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
{
return (kern_ktimer_getoverrun(td, uap->timerid));
}
int
kern_ktimer_getoverrun(struct thread *td, int timer_id)
{
struct proc *p = td->td_proc;
struct itimer *it;
int error ;
PROC_LOCK(p);
if (timer_id < 3 ||
(it = itimer_find(p, timer_id)) == NULL) {
PROC_UNLOCK(p);
error = EINVAL;
} else {
td->td_retval[0] = it->it_overrun_last;
ITIMER_UNLOCK(it);
PROC_UNLOCK(p);
error = 0;
}
return (error);
}
static int
realtimer_create(struct itimer *it)
{
callout_init_mtx(&it->it_callout, &it->it_mtx, 0);
return (0);
}
static int
realtimer_delete(struct itimer *it)
{
mtx_assert(&it->it_mtx, MA_OWNED);
/*
* clear timer's value and interval to tell realtimer_expire
* to not rearm the timer.
*/
timespecclear(&it->it_time.it_value);
timespecclear(&it->it_time.it_interval);
ITIMER_UNLOCK(it);
callout_drain(&it->it_callout);
ITIMER_LOCK(it);
return (0);
}
static int
realtimer_gettime(struct itimer *it, struct itimerspec *ovalue)
{
struct timespec cts;
mtx_assert(&it->it_mtx, MA_OWNED);
realtimer_clocktime(it->it_clockid, &cts);
*ovalue = it->it_time;
if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_nsec != 0) {
timespecsub(&ovalue->it_value, &cts);
if (ovalue->it_value.tv_sec < 0 ||
(ovalue->it_value.tv_sec == 0 &&
ovalue->it_value.tv_nsec == 0)) {
ovalue->it_value.tv_sec = 0;
ovalue->it_value.tv_nsec = 1;
}
}
return (0);
}
static int
realtimer_settime(struct itimer *it, int flags,
struct itimerspec *value, struct itimerspec *ovalue)
{
struct timespec cts, ts;
struct timeval tv;
struct itimerspec val;
mtx_assert(&it->it_mtx, MA_OWNED);
val = *value;
if (itimespecfix(&val.it_value))
return (EINVAL);
if (timespecisset(&val.it_value)) {
if (itimespecfix(&val.it_interval))
return (EINVAL);
} else {
timespecclear(&val.it_interval);
}
if (ovalue != NULL)
realtimer_gettime(it, ovalue);
it->it_time = val;
if (timespecisset(&val.it_value)) {
realtimer_clocktime(it->it_clockid, &cts);
ts = val.it_value;
if ((flags & TIMER_ABSTIME) == 0) {
/* Convert to absolute time. */
timespecadd(&it->it_time.it_value, &cts);
} else {
timespecsub(&ts, &cts);
/*
* We don't care if ts is negative, tztohz will
* fix it.
*/
}
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&it->it_callout, tvtohz(&tv),
realtimer_expire, it);
} else {
callout_stop(&it->it_callout);
}
return (0);
}
static void
realtimer_clocktime(clockid_t id, struct timespec *ts)
{
if (id == CLOCK_REALTIME)
getnanotime(ts);
else /* CLOCK_MONOTONIC */
getnanouptime(ts);
}
int
itimer_accept(struct proc *p, int timerid, ksiginfo_t *ksi)
{
struct itimer *it;
PROC_LOCK_ASSERT(p, MA_OWNED);
it = itimer_find(p, timerid);
if (it != NULL) {
ksi->ksi_overrun = it->it_overrun;
it->it_overrun_last = it->it_overrun;
it->it_overrun = 0;
ITIMER_UNLOCK(it);
return (0);
}
return (EINVAL);
}
int
itimespecfix(struct timespec *ts)
{
if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
return (EINVAL);
if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000)
ts->tv_nsec = tick * 1000;
return (0);
}
/* Timeout callback for realtime timer */
static void
realtimer_expire(void *arg)
{
struct timespec cts, ts;
struct timeval tv;
struct itimer *it;
it = (struct itimer *)arg;
realtimer_clocktime(it->it_clockid, &cts);
/* Only fire if time is reached. */
if (timespeccmp(&cts, &it->it_time.it_value, >=)) {
if (timespecisset(&it->it_time.it_interval)) {
timespecadd(&it->it_time.it_value,
&it->it_time.it_interval);
while (timespeccmp(&cts, &it->it_time.it_value, >=)) {
if (it->it_overrun < INT_MAX)
it->it_overrun++;
else
it->it_ksi.ksi_errno = ERANGE;
timespecadd(&it->it_time.it_value,
&it->it_time.it_interval);
}
} else {
/* single shot timer ? */
timespecclear(&it->it_time.it_value);
}
if (timespecisset(&it->it_time.it_value)) {
ts = it->it_time.it_value;
timespecsub(&ts, &cts);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&it->it_callout, tvtohz(&tv),
realtimer_expire, it);
}
itimer_enter(it);
ITIMER_UNLOCK(it);
itimer_fire(it);
ITIMER_LOCK(it);
itimer_leave(it);
} else if (timespecisset(&it->it_time.it_value)) {
ts = it->it_time.it_value;
timespecsub(&ts, &cts);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
callout_reset(&it->it_callout, tvtohz(&tv), realtimer_expire,
it);
}
}
void
itimer_fire(struct itimer *it)
{
struct proc *p = it->it_proc;
struct thread *td;
if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
if (sigev_findtd(p, &it->it_sigev, &td) != 0) {
ITIMER_LOCK(it);
timespecclear(&it->it_time.it_value);
timespecclear(&it->it_time.it_interval);
callout_stop(&it->it_callout);
ITIMER_UNLOCK(it);
return;
}
if (!KSI_ONQ(&it->it_ksi)) {
it->it_ksi.ksi_errno = 0;
ksiginfo_set_sigev(&it->it_ksi, &it->it_sigev);
tdsendsignal(p, td, it->it_ksi.ksi_signo, &it->it_ksi);
} else {
if (it->it_overrun < INT_MAX)
it->it_overrun++;
else
it->it_ksi.ksi_errno = ERANGE;
}
PROC_UNLOCK(p);
}
}
static void
itimers_alloc(struct proc *p)
{
struct itimers *its;
int i;
its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
LIST_INIT(&its->its_virtual);
LIST_INIT(&its->its_prof);
TAILQ_INIT(&its->its_worklist);
for (i = 0; i < TIMER_MAX; i++)
its->its_timers[i] = NULL;
PROC_LOCK(p);
if (p->p_itimers == NULL) {
p->p_itimers = its;
PROC_UNLOCK(p);
}
else {
PROC_UNLOCK(p);
free(its, M_SUBPROC);
}
}
static void
itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
{
itimers_event_hook_exit(arg, p);
}
/* Clean up timers when some process events are being triggered. */
static void
itimers_event_hook_exit(void *arg, struct proc *p)
{
struct itimers *its;
struct itimer *it;
int event = (int)(intptr_t)arg;
int i;
if (p->p_itimers != NULL) {
its = p->p_itimers;
for (i = 0; i < MAX_CLOCKS; ++i) {
if (posix_clocks[i].event_hook != NULL)
CLOCK_CALL(i, event_hook, (p, i, event));
}
/*
* According to susv3, XSI interval timers should be inherited
* by new image.
*/
if (event == ITIMER_EV_EXEC)
i = 3;
else if (event == ITIMER_EV_EXIT)
i = 0;
else
panic("unhandled event");
for (; i < TIMER_MAX; ++i) {
if ((it = its->its_timers[i]) != NULL)
kern_ktimer_delete(curthread, i);
}
if (its->its_timers[0] == NULL &&
its->its_timers[1] == NULL &&
its->its_timers[2] == NULL) {
free(its, M_SUBPROC);
p->p_itimers = NULL;
}
}
}