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freebsd-dev/sys/kern/kern_time.c
David Xu d6b6592ec0 In realtimer_delete(), clear timer's value and interval to tell 
realtimer_expire() to not rearm the timer, otherwise there is a chance
that a callout will be left there and be tiggered in future unexpectly.

Bug reported by: tegge@
2008-10-20 02:37:53 +00:00

1516 lines
35 KiB
C
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/*-
* 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/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)
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 no_lease_updatetime(int);
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 *);
static int kern_timer_create(struct thread *, clockid_t,
struct sigevent *, int *, int);
static int kern_timer_delete(struct thread *, int);
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 void
no_lease_updatetime(deltat)
int deltat;
{
}
void (*lease_updatetime)(int) = no_lease_updatetime;
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);
(void) splsoftclock();
lease_updatetime(delta.tv_sec);
splx(s);
resettodr();
mtx_unlock(&Giant);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct clock_gettime_args {
clockid_t clock_id;
struct timespec *tp;
};
#endif
/* ARGSUSED */
int
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);
}
int
kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
{
struct timeval sys, user;
struct proc *p;
uint64_t runtime, curtime, switchtime;
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_SLOCK(p);
calcru(p, &user, &sys);
PROC_SUNLOCK(p);
PROC_UNLOCK(p);
TIMEVAL_TO_TIMESPEC(&user, ats);
break;
case CLOCK_PROF:
PROC_LOCK(p);
PROC_SLOCK(p);
calcru(p, &user, &sys);
PROC_SUNLOCK(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:
critical_enter();
switchtime = PCPU_GET(switchtime);
curtime = cpu_ticks();
runtime = td->td_runtime;
critical_exit();
runtime = cputick2usec(runtime + curtime - switchtime);
ats->tv_sec = runtime / 1000000;
ats->tv_nsec = runtime % 1000000 * 1000;
break;
default:
return (EINVAL);
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct clock_settime_args {
clockid_t clock_id;
const struct timespec *tp;
};
#endif
/* ARGSUSED */
int
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
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:
/* sync with cputick2usec */
ts->tv_nsec = 1000000 / cpu_tickrate();
if (ts->tv_nsec == 0)
ts->tv_nsec = 1000;
break;
default:
return (EINVAL);
}
return (0);
}
static int nanowait;
int
kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
{
struct timespec ts, ts2, ts3;
struct timeval tv;
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);
getnanouptime(&ts);
timespecadd(&ts, rqt);
TIMESPEC_TO_TIMEVAL(&tv, rqt);
for (;;) {
error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp",
tvtohz(&tv));
getnanouptime(&ts2);
if (error != EWOULDBLOCK) {
if (error == ERESTART)
error = EINTR;
if (rmt != NULL) {
timespecsub(&ts, &ts2);
if (ts.tv_sec < 0)
timespecclear(&ts);
*rmt = ts;
}
return (error);
}
if (timespeccmp(&ts2, &ts, >=))
return (0);
ts3 = ts;
timespecsub(&ts3, &ts2);
TIMESPEC_TO_TIMEVAL(&tv, &ts3);
}
}
#ifndef _SYS_SYSPROTO_H_
struct nanosleep_args {
struct timespec *rqtp;
struct timespec *rmtp;
};
#endif
/* ARGSUSED */
int
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
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
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
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)) {
getmicrouptime(&ctv);
if (timevalcmp(&aitv->it_value, &ctv, <))
timevalclear(&aitv->it_value);
else
timevalsub(&aitv->it_value, &ctv);
}
} else {
PROC_SLOCK(p);
*aitv = p->p_stats->p_timer[which];
PROC_SUNLOCK(p);
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct setitimer_args {
u_int which;
struct itimerval *itv, *oitv;
};
#endif
int
setitimer(struct thread *td, struct setitimer_args *uap)
{
struct itimerval aitv, oitv;
int error;
if (uap->itv == NULL) {
uap->itv = uap->oitv;
return (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;
if (aitv == NULL)
return (kern_getitimer(td, which, oitv));
if (which > ITIMER_PROF)
return (EINVAL);
if (itimerfix(&aitv->it_value))
return (EINVAL);
if (!timevalisset(&aitv->it_value))
timevalclear(&aitv->it_interval);
else if (itimerfix(&aitv->it_interval))
return (EINVAL);
if (which == ITIMER_REAL) {
PROC_LOCK(p);
if (timevalisset(&p->p_realtimer.it_value))
callout_stop(&p->p_itcallout);
getmicrouptime(&ctv);
if (timevalisset(&aitv->it_value)) {
callout_reset(&p->p_itcallout, tvtohz(&aitv->it_value),
realitexpire, p);
timevaladd(&aitv->it_value, &ctv);
}
*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 {
PROC_SLOCK(p);
*oitv = p->p_stats->p_timer[which];
p->p_stats->p_timer[which] = *aitv;
PROC_SUNLOCK(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, ntv;
p = (struct proc *)arg;
PROC_LOCK(p);
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);
PROC_UNLOCK(p);
return;
}
for (;;) {
timevaladd(&p->p_realtimer.it_value,
&p->p_realtimer.it_interval);
getmicrouptime(&ctv);
if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
ntv = p->p_realtimer.it_value;
timevalsub(&ntv, &ctv);
callout_reset(&p->p_itcallout, tvtohz(&ntv) - 1,
realitexpire, p);
PROC_UNLOCK(p);
return;
}
}
/*NOTREACHED*/
}
/*
* 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 < tick)
tv->tv_usec = tick;
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
ktimer_create(struct thread *td, struct ktimer_create_args *uap)
{
struct sigevent *evp1, ev;
int id;
int error;
if (uap->evp != NULL) {
error = copyin(uap->evp, &ev, sizeof(ev));
if (error != 0)
return (error);
evp1 = &ev;
} else
evp1 = NULL;
error = kern_timer_create(td, uap->clock_id, evp1, &id, -1);
if (error == 0) {
error = copyout(&id, uap->timerid, sizeof(int));
if (error != 0)
kern_timer_delete(td, id);
}
return (error);
}
static int
kern_timer_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
ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
{
return (kern_timer_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 >= 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);
}
static int
kern_timer_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
ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
{
struct proc *p = td->td_proc;
struct itimer *it;
struct itimerspec val, oval, *ovalp;
int error;
error = copyin(uap->value, &val, sizeof(val));
if (error != 0)
return (error);
if (uap->ovalue != NULL)
ovalp = &oval;
else
ovalp = NULL;
PROC_LOCK(p);
if (uap->timerid < 3 ||
(it = itimer_find(p, uap->timerid)) == NULL) {
PROC_UNLOCK(p);
error = EINVAL;
} else {
PROC_UNLOCK(p);
itimer_enter(it);
error = CLOCK_CALL(it->it_clockid, timer_settime,
(it, uap->flags, &val, ovalp));
itimer_leave(it);
ITIMER_UNLOCK(it);
}
if (error == 0 && uap->ovalue != NULL)
error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ktimer_gettime_args {
int timerid;
struct itimerspec * value;
};
#endif
int
ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
{
struct proc *p = td->td_proc;
struct itimer *it;
struct itimerspec val;
int error;
PROC_LOCK(p);
if (uap->timerid < 3 ||
(it = itimer_find(p, uap->timerid)) == 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);
}
if (error == 0)
error = copyout(&val, uap->value, sizeof(val));
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct timer_getoverrun_args {
int timerid;
};
#endif
int
ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
{
struct proc *p = td->td_proc;
struct itimer *it;
int error ;
PROC_LOCK(p);
if (uap->timerid < 3 ||
(it = itimer_find(p, uap->timerid)) == 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;
struct proc *p;
it = (struct itimer *)arg;
p = it->it_proc;
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;
int ret;
if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
PROC_LOCK(p);
if (!KSI_ONQ(&it->it_ksi)) {
it->it_ksi.ksi_errno = 0;
ret = psignal_event(p, &it->it_sigev, &it->it_ksi);
if (__predict_false(ret != 0)) {
it->it_overrun++;
/*
* Broken userland code, thread went
* away, disarm the timer.
*/
if (ret == ESRCH) {
ITIMER_LOCK(it);
timespecclear(&it->it_time.it_value);
timespecclear(&it->it_time.it_interval);
callout_stop(&it->it_callout);
ITIMER_UNLOCK(it);
}
}
} 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_timer_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;
}
}
}
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