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|
/* $OpenBSD: kern_time.c,v 1.103 2018/05/28 18:05:42 guenther Exp $ */
/* $NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $ */
/*
* 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.
* 3. 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 8.4 (Berkeley) 5/26/95
*/
#include <sys/param.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/ktrace.h>
#include <sys/vnode.h>
#include <sys/signalvar.h>
#include <sys/pledge.h>
#include <sys/task.h>
#include <sys/timeout.h>
#include <sys/timetc.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
int64_t adjtimedelta; /* unapplied time correction (microseconds) */
/*
* 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.
*/
/* This function is used by clock_settime and settimeofday */
int
settime(const struct timespec *ts)
{
struct timespec now;
/*
* Adjtime in progress is meaningless or harmful after
* setting the clock. Cancel adjtime and then set new time.
*/
adjtimedelta = 0;
/*
* Don't allow the time to be set forward so far it will wrap
* and become negative, thus allowing an attacker to bypass
* the next check below. The cutoff is 1 year before rollover
* occurs, so even if the attacker uses adjtime(2) to move
* the time past the cutoff, it will take a very long time
* to get to the wrap point.
*
* XXX: we check against UINT_MAX until we can figure out
* how to deal with the hardware RTCs.
*/
if (ts->tv_sec > UINT_MAX - 365*24*60*60) {
printf("denied attempt to set clock forward to %lld\n",
(long long)ts->tv_sec);
return (EPERM);
}
/*
* If the system is secure, we do not allow the time to be
* set to an earlier value (it may be slowed using adjtime,
* but not set back). This feature prevent interlopers from
* setting arbitrary time stamps on files.
*/
nanotime(&now);
if (securelevel > 1 && timespeccmp(ts, &now, <)) {
printf("denied attempt to set clock back %lld seconds\n",
(long long)now.tv_sec - ts->tv_sec);
return (EPERM);
}
tc_setrealtimeclock(ts);
resettodr();
return (0);
}
int
clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp)
{
struct bintime bt;
struct proc *q;
switch (clock_id) {
case CLOCK_REALTIME:
nanotime(tp);
break;
case CLOCK_UPTIME:
binuptime(&bt);
bintime_sub(&bt, &naptime);
bintime2timespec(&bt, tp);
break;
case CLOCK_MONOTONIC:
case CLOCK_BOOTTIME:
nanouptime(tp);
break;
case CLOCK_PROCESS_CPUTIME_ID:
nanouptime(tp);
timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
timespecadd(tp, &p->p_p->ps_tu.tu_runtime, tp);
timespecadd(tp, &p->p_rtime, tp);
break;
case CLOCK_THREAD_CPUTIME_ID:
nanouptime(tp);
timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp);
timespecadd(tp, &p->p_tu.tu_runtime, tp);
timespecadd(tp, &p->p_rtime, tp);
break;
default:
/* check for clock from pthread_getcpuclockid() */
if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
q = tfind(__CLOCK_PTID(clock_id) - THREAD_PID_OFFSET);
if (q == NULL || q->p_p != p->p_p)
return (ESRCH);
*tp = q->p_tu.tu_runtime;
} else
return (EINVAL);
}
return (0);
}
int
sys_clock_gettime(struct proc *p, void *v, register_t *retval)
{
struct sys_clock_gettime_args /* {
syscallarg(clockid_t) clock_id;
syscallarg(struct timespec *) tp;
} */ *uap = v;
struct timespec ats;
int error;
memset(&ats, 0, sizeof(ats));
if ((error = clock_gettime(p, SCARG(uap, clock_id), &ats)) != 0)
return (error);
error = copyout(&ats, SCARG(uap, tp), sizeof(ats));
#ifdef KTRACE
if (error == 0 && KTRPOINT(p, KTR_STRUCT)) {
KERNEL_LOCK();
ktrabstimespec(p, &ats);
KERNEL_UNLOCK();
}
#endif
return (error);
}
int
sys_clock_settime(struct proc *p, void *v, register_t *retval)
{
struct sys_clock_settime_args /* {
syscallarg(clockid_t) clock_id;
syscallarg(const struct timespec *) tp;
} */ *uap = v;
struct timespec ats;
clockid_t clock_id;
int error;
if ((error = suser(p)) != 0)
return (error);
if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
return (error);
clock_id = SCARG(uap, clock_id);
switch (clock_id) {
case CLOCK_REALTIME:
if ((error = settime(&ats)) != 0)
return (error);
break;
default: /* Other clocks are read-only */
return (EINVAL);
}
return (0);
}
int
sys_clock_getres(struct proc *p, void *v, register_t *retval)
{
struct sys_clock_getres_args /* {
syscallarg(clockid_t) clock_id;
syscallarg(struct timespec *) tp;
} */ *uap = v;
clockid_t clock_id;
struct timespec ts;
struct proc *q;
int error = 0;
memset(&ts, 0, sizeof(ts));
clock_id = SCARG(uap, clock_id);
switch (clock_id) {
case CLOCK_REALTIME:
case CLOCK_MONOTONIC:
case CLOCK_BOOTTIME:
case CLOCK_UPTIME:
case CLOCK_PROCESS_CPUTIME_ID:
case CLOCK_THREAD_CPUTIME_ID:
ts.tv_sec = 0;
ts.tv_nsec = 1000000000 / hz;
break;
default:
/* check for clock from pthread_getcpuclockid() */
if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
q = tfind(__CLOCK_PTID(clock_id) - THREAD_PID_OFFSET);
if (q == NULL || q->p_p != p->p_p)
return (ESRCH);
ts.tv_sec = 0;
ts.tv_nsec = 1000000000 / hz;
} else
return (EINVAL);
}
if (SCARG(uap, tp)) {
error = copyout(&ts, SCARG(uap, tp), sizeof (ts));
#ifdef KTRACE
if (error == 0 && KTRPOINT(p, KTR_STRUCT)) {
KERNEL_LOCK();
ktrreltimespec(p, &ts);
KERNEL_UNLOCK();
}
#endif
}
return error;
}
int
sys_nanosleep(struct proc *p, void *v, register_t *retval)
{
static int nanowait;
struct sys_nanosleep_args/* {
syscallarg(const struct timespec *) rqtp;
syscallarg(struct timespec *) rmtp;
} */ *uap = v;
struct timespec rqt, rmt;
struct timespec sts, ets;
struct timespec *rmtp;
int error, error1;
rmtp = SCARG(uap, rmtp);
error = copyin(SCARG(uap, rqtp), &rqt, sizeof(struct timespec));
if (error)
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT)) {
KERNEL_LOCK();
ktrreltimespec(p, &rqt);
KERNEL_UNLOCK();
}
#endif
if (rqt.tv_sec > 100000000 || timespecfix(&rqt))
return (EINVAL);
if (rmtp)
getnanouptime(&sts);
error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep",
MAX(1, tstohz(&rqt)));
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
if (rmtp) {
getnanouptime(&ets);
memset(&rmt, 0, sizeof(rmt));
timespecsub(&ets, &sts, &sts);
timespecsub(&rqt, &sts, &rmt);
if (rmt.tv_sec < 0)
timespecclear(&rmt);
error1 = copyout(&rmt, rmtp, sizeof(rmt));
if (error1 != 0)
error = error1;
#ifdef KTRACE
if (error1 == 0 && KTRPOINT(p, KTR_STRUCT)) {
KERNEL_LOCK();
ktrreltimespec(p, &rmt);
KERNEL_UNLOCK();
}
#endif
}
return error;
}
int
sys_gettimeofday(struct proc *p, void *v, register_t *retval)
{
struct sys_gettimeofday_args /* {
syscallarg(struct timeval *) tp;
syscallarg(struct timezone *) tzp;
} */ *uap = v;
struct timeval atv;
struct timeval *tp;
struct timezone *tzp;
int error = 0;
tp = SCARG(uap, tp);
tzp = SCARG(uap, tzp);
if (tp) {
memset(&atv, 0, sizeof(atv));
microtime(&atv);
if ((error = copyout(&atv, tp, sizeof (atv))))
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT)) {
KERNEL_LOCK();
ktrabstimeval(p, &atv);
KERNEL_UNLOCK();
}
#endif
}
if (tzp)
error = copyout(&tz, tzp, sizeof (tz));
return (error);
}
int
sys_settimeofday(struct proc *p, void *v, register_t *retval)
{
struct sys_settimeofday_args /* {
syscallarg(const struct timeval *) tv;
syscallarg(const struct timezone *) tzp;
} */ *uap = v;
struct timezone atz;
struct timeval atv;
const struct timeval *tv;
const struct timezone *tzp;
int error;
tv = SCARG(uap, tv);
tzp = SCARG(uap, tzp);
if ((error = suser(p)))
return (error);
/* Verify all parameters before changing time. */
if (tv && (error = copyin(tv, &atv, sizeof(atv))))
return (error);
if (tzp && (error = copyin(tzp, &atz, sizeof(atz))))
return (error);
if (tv) {
struct timespec ts;
TIMEVAL_TO_TIMESPEC(&atv, &ts);
if ((error = settime(&ts)) != 0)
return (error);
}
if (tzp)
tz = atz;
return (0);
}
int
sys_adjfreq(struct proc *p, void *v, register_t *retval)
{
struct sys_adjfreq_args /* {
syscallarg(const int64_t *) freq;
syscallarg(int64_t *) oldfreq;
} */ *uap = v;
int error;
int64_t f;
const int64_t *freq = SCARG(uap, freq);
int64_t *oldfreq = SCARG(uap, oldfreq);
if (oldfreq) {
if ((error = tc_adjfreq(&f, NULL)))
return (error);
if ((error = copyout(&f, oldfreq, sizeof(f))))
return (error);
}
if (freq) {
if ((error = suser(p)))
return (error);
if ((error = copyin(freq, &f, sizeof(f))))
return (error);
if ((error = tc_adjfreq(NULL, &f)))
return (error);
}
return (0);
}
int
sys_adjtime(struct proc *p, void *v, register_t *retval)
{
struct sys_adjtime_args /* {
syscallarg(const struct timeval *) delta;
syscallarg(struct timeval *) olddelta;
} */ *uap = v;
const struct timeval *delta = SCARG(uap, delta);
struct timeval *olddelta = SCARG(uap, olddelta);
struct timeval atv;
int error;
error = pledge_adjtime(p, delta);
if (error)
return error;
if (olddelta) {
memset(&atv, 0, sizeof(atv));
atv.tv_sec = adjtimedelta / 1000000;
atv.tv_usec = adjtimedelta % 1000000;
if (atv.tv_usec < 0) {
atv.tv_usec += 1000000;
atv.tv_sec--;
}
if ((error = copyout(&atv, olddelta, sizeof(struct timeval))))
return (error);
}
if (delta) {
if ((error = suser(p)))
return (error);
if ((error = copyin(delta, &atv, sizeof(struct timeval))))
return (error);
/* XXX Check for overflow? */
adjtimedelta = (int64_t)atv.tv_sec * 1000000 + atv.tv_usec;
}
return (0);
}
struct mutex itimer_mtx = MUTEX_INITIALIZER(IPL_CLOCK);
/*
* Get value of an interval timer. The process virtual and
* profiling virtual time timers are kept internally in the
* way they are specified externally: in time until they expire.
*
* The real time interval timer's it_value, in contrast, 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.
*/
int
sys_getitimer(struct proc *p, void *v, register_t *retval)
{
struct sys_getitimer_args /* {
syscallarg(int) which;
syscallarg(struct itimerval *) itv;
} */ *uap = v;
struct itimerval aitv;
int which;
which = SCARG(uap, which);
if (which < ITIMER_REAL || which > ITIMER_PROF)
return (EINVAL);
memset(&aitv, 0, sizeof(aitv));
mtx_enter(&itimer_mtx);
aitv.it_interval.tv_sec = p->p_p->ps_timer[which].it_interval.tv_sec;
aitv.it_interval.tv_usec = p->p_p->ps_timer[which].it_interval.tv_usec;
aitv.it_value.tv_sec = p->p_p->ps_timer[which].it_value.tv_sec;
aitv.it_value.tv_usec = p->p_p->ps_timer[which].it_value.tv_usec;
mtx_leave(&itimer_mtx);
if (which == ITIMER_REAL) {
struct timeval now;
getmicrouptime(&now);
/*
* 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.
*/
if (timerisset(&aitv.it_value)) {
if (timercmp(&aitv.it_value, &now, <))
timerclear(&aitv.it_value);
else
timersub(&aitv.it_value, &now,
&aitv.it_value);
}
}
return (copyout(&aitv, SCARG(uap, itv), sizeof (struct itimerval)));
}
int
sys_setitimer(struct proc *p, void *v, register_t *retval)
{
struct sys_setitimer_args /* {
syscallarg(int) which;
syscallarg(const struct itimerval *) itv;
syscallarg(struct itimerval *) oitv;
} */ *uap = v;
struct sys_getitimer_args getargs;
struct itimerval aitv;
const struct itimerval *itvp;
struct itimerval *oitv;
struct process *pr = p->p_p;
int error;
int timo;
int which;
which = SCARG(uap, which);
oitv = SCARG(uap, oitv);
if (which < ITIMER_REAL || which > ITIMER_PROF)
return (EINVAL);
itvp = SCARG(uap, itv);
if (itvp && (error = copyin((void *)itvp, (void *)&aitv,
sizeof(struct itimerval))))
return (error);
if (oitv != NULL) {
SCARG(&getargs, which) = which;
SCARG(&getargs, itv) = oitv;
if ((error = sys_getitimer(p, &getargs, retval)))
return (error);
}
if (itvp == 0)
return (0);
if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
return (EINVAL);
if (which == ITIMER_REAL) {
struct timeval ctv;
timeout_del(&pr->ps_realit_to);
getmicrouptime(&ctv);
if (timerisset(&aitv.it_value)) {
timo = tvtohz(&aitv.it_value);
timeout_add(&pr->ps_realit_to, timo);
timeradd(&aitv.it_value, &ctv, &aitv.it_value);
}
pr->ps_timer[ITIMER_REAL] = aitv;
} else {
itimerround(&aitv.it_interval);
mtx_enter(&itimer_mtx);
pr->ps_timer[which] = aitv;
mtx_leave(&itimer_mtx);
}
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.
*/
void
realitexpire(void *arg)
{
struct process *pr = arg;
struct itimerval *tp = &pr->ps_timer[ITIMER_REAL];
prsignal(pr, SIGALRM);
if (!timerisset(&tp->it_interval)) {
timerclear(&tp->it_value);
return;
}
for (;;) {
struct timeval ctv, ntv;
int timo;
timeradd(&tp->it_value, &tp->it_interval, &tp->it_value);
getmicrouptime(&ctv);
if (timercmp(&tp->it_value, &ctv, >)) {
ntv = tp->it_value;
timersub(&ntv, &ctv, &ntv);
timo = tvtohz(&ntv) - 1;
if (timo <= 0)
timo = 1;
if ((pr->ps_flags & PS_EXITING) == 0)
timeout_add(&pr->ps_realit_to, timo);
return;
}
}
}
/*
* Check that a timespec value is legit
*/
int
timespecfix(struct timespec *ts)
{
if (ts->tv_sec < 0 ||
ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
return (EINVAL);
if (ts->tv_sec > 100000000)
ts->tv_sec = 100000000;
return (0);
}
/*
* Check that a proposed value to load into the .it_value or
* .it_interval part of an interval timer is acceptable.
*/
int
itimerfix(struct timeval *tv)
{
if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
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);
}
/*
* Nonzero timer interval smaller than the resolution of the
* system clock are rounded up.
*/
void
itimerround(struct timeval *tv)
{
if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
tv->tv_usec = tick;
}
/*
* 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)
{
mtx_enter(&itimer_mtx);
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 (timerisset(&itp->it_value)) {
mtx_leave(&itimer_mtx);
return (1);
}
/* expired, exactly at end of interval */
expire:
if (timerisset(&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 */
mtx_leave(&itimer_mtx);
return (0);
}
/*
* ratecheck(): simple time-based rate-limit checking. see ratecheck(9)
* for usage and rationale.
*/
int
ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
{
struct timeval tv, delta;
int rv = 0;
getmicrouptime(&tv);
timersub(&tv, lasttime, &delta);
/*
* check for 0,0 is so that the message will be seen at least once,
* even if interval is huge.
*/
if (timercmp(&delta, mininterval, >=) ||
(lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
*lasttime = tv;
rv = 1;
}
return (rv);
}
/*
* ppsratecheck(): packets (or events) per second limitation.
*/
int
ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
{
struct timeval tv, delta;
int rv;
microuptime(&tv);
timersub(&tv, lasttime, &delta);
/*
* check for 0,0 is so that the message will be seen at least once.
* if more than one second have passed since the last update of
* lasttime, reset the counter.
*
* we do increment *curpps even in *curpps < maxpps case, as some may
* try to use *curpps for stat purposes as well.
*/
if (maxpps == 0)
rv = 0;
else if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
delta.tv_sec >= 1) {
*lasttime = tv;
*curpps = 0;
rv = 1;
} else if (maxpps < 0)
rv = 1;
else if (*curpps < maxpps)
rv = 1;
else
rv = 0;
#if 1 /*DIAGNOSTIC?*/
/* be careful about wrap-around */
if (*curpps + 1 > *curpps)
*curpps = *curpps + 1;
#else
/*
* assume that there's not too many calls to this function.
* not sure if the assumption holds, as it depends on *caller's*
* behavior, not the behavior of this function.
* IMHO it is wrong to make assumption on the caller's behavior,
* so the above #if is #if 1, not #ifdef DIAGNOSTIC.
*/
*curpps = *curpps + 1;
#endif
return (rv);
}
#define RESETTODR_PERIOD 1800
void periodic_resettodr(void *);
void perform_resettodr(void *);
struct timeout resettodr_to = TIMEOUT_INITIALIZER(periodic_resettodr, NULL);
struct task resettodr_task = TASK_INITIALIZER(perform_resettodr, NULL);
void
periodic_resettodr(void *arg __unused)
{
task_add(systq, &resettodr_task);
}
void
perform_resettodr(void *arg __unused)
{
resettodr();
timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
}
void
start_periodic_resettodr(void)
{
timeout_add_sec(&resettodr_to, RESETTODR_PERIOD);
}
void
stop_periodic_resettodr(void)
{
timeout_del(&resettodr_to);
task_del(systq, &resettodr_task);
}
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