/* * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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 * $Id: kern_time.c,v 1.31 1997/08/13 17:55:11 ache Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct timezone tz; /* * 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 __P((struct timeval *)); static void timevalfix __P((struct timeval *)); static int nanosleep1 __P((struct proc *p, struct timespec *rqt, struct timespec *rmt)); static int settime(tv) struct timeval *tv; { struct timeval delta; struct proc *p; int s; /* * Must not set clock backwards in highly secure mode. */ s = splclock(); delta.tv_sec = tv->tv_sec - time.tv_sec; delta.tv_usec = tv->tv_usec - time.tv_usec; splx(s); timevalfix(&delta); if (delta.tv_sec < 0 && securelevel > 1) return (EPERM); s = splclock(); /* * Recalculate delta directly to minimize clock interrupt * latency. Fix it after the ipl has been lowered. */ delta.tv_sec = tv->tv_sec - time.tv_sec; delta.tv_usec = tv->tv_usec - time.tv_usec; time = *tv; /* * XXX should arrange for microtime() to agree with *tv if * it is called now. As it is, it may add up to about * `tick' unwanted usec. * Another problem is that clock interrupts may occur at * other than multiples of `tick'. It's not worth fixing * this here, since the problem is also caused by tick * adjustments. */ (void) splsoftclock(); timevalfix(&delta); timevaladd(&boottime, &delta); timevaladd(&runtime, &delta); for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { if (timerisset(&p->p_realtimer.it_value)) timevaladd(&p->p_realtimer.it_value, &delta); if (p->p_sleepend) timevaladd(p->p_sleepend, &delta); } #ifdef NFS lease_updatetime(delta.tv_sec); #endif splx(s); resettodr(); return (0); } #ifndef _SYS_SYSPROTO_H_ struct clock_gettime_args { clockid_t clock_id; struct timespec *tp; }; #endif /* ARGSUSED */ int clock_gettime(p, uap, retval) struct proc *p; struct clock_gettime_args *uap; register_t *retval; { struct timeval atv; struct timespec ats; if (SCARG(uap, clock_id) != CLOCK_REALTIME) return (EINVAL); microtime(&atv); TIMEVAL_TO_TIMESPEC(&atv, &ats); return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); } #ifndef _SYS_SYSPROTO_H_ struct clock_settime_args { clockid_t clock_id; const struct timespec *tp; }; #endif /* ARGSUSED */ int clock_settime(p, uap, retval) struct proc *p; struct clock_settime_args *uap; register_t *retval; { struct timeval atv; struct timespec ats; int error; if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) return (error); if (SCARG(uap, clock_id) != CLOCK_REALTIME) return (EINVAL); if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) return (error); if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) return (EINVAL); TIMESPEC_TO_TIMEVAL(&atv, &ats); if ((error = settime(&atv))) return (error); return (0); } #ifndef _SYS_SYSPROTO_H_ struct clock_getres_args { clockid_t clock_id; struct timespec *tp; }; #endif int clock_getres(p, uap, retval) struct proc *p; struct clock_getres_args *uap; register_t *retval; { struct timespec ts; int error; if (SCARG(uap, clock_id) != CLOCK_REALTIME) return (EINVAL); error = 0; if (SCARG(uap, tp)) { ts.tv_sec = 0; ts.tv_nsec = 1000000000 / hz; error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); } return (error); } static int nanowait; static int nanosleep1(p, rqt, rmt) struct proc *p; struct timespec *rqt, *rmt; { struct timeval atv, utv, rtv; int error, s, timo, i, n; if (rqt->tv_sec < 0 || rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) return (EINVAL); TIMESPEC_TO_TIMEVAL(&atv, rqt) if (itimerfix(&atv)) { n = atv.tv_sec / 100000000; rtv = atv; rtv.tv_sec %= 100000000; (void)itimerfix(&rtv); } else n = 0; for (i = 0, error = EWOULDBLOCK; i <= n && error == EWOULDBLOCK; i++) { if (n > 0) { if (i == n) atv = rtv; else { atv.tv_sec = 100000000; atv.tv_usec = 0; } } /* * XXX this is not as careful as settimeofday() about minimising * interrupt latency. The hzto() interface is inconvenient as usual. */ s = splclock(); timevaladd(&atv, &time); timo = hzto(&atv); splx(s); p->p_sleepend = &atv; error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp", timo); p->p_sleepend = NULL; if (error == ERESTART) error = EINTR; if (rmt != NULL && (i == n || error != EWOULDBLOCK)) { /*- * XXX this is unnecessary and possibly wrong if the timeout * expired. Then the remaining time should be zero. If the * calculation gives a nonzero value, then we have a bug. * (1) if settimeofday() was called, then the calculation is * probably wrong, since `time' has probably become * inconsistent with the ending time `atv'. * XXX (1) should be fixed now with p->p_sleepend; * (2) otherwise, our calculation of `timo' was wrong, perhaps * due to `tick' being wrong when hzto() was called or * changing afterwards (it can be wrong or change due to * hzto() not knowing about adjtime(2) or tickadj(8)). * Then we should be sleeping again instead instead of * returning. Rounding up in hzto() probably fixes this * problem for small timeouts, but the absolute error may * be large for large timeouts. */ s = splclock(); utv = time; splx(s); timevalsub(&atv, &utv); if (atv.tv_sec < 0) timerclear(&atv); if (n > 0) atv.tv_sec += (n - i) * 100000000; TIMEVAL_TO_TIMESPEC(&atv, rmt); } } return (error == EWOULDBLOCK ? 0 : error); } #ifndef _SYS_SYSPROTO_H_ struct nanosleep_args { struct timespec *rqtp; struct timespec *rmtp; }; #endif /* ARGSUSED */ int nanosleep(p, uap, retval) struct proc *p; struct nanosleep_args *uap; register_t *retval; { struct timespec rmt, rqt; int error, error2; error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); if (error) return (error); if (SCARG(uap, rmtp)) if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), B_WRITE)) return (EFAULT); error = nanosleep1(p, &rqt, &rmt); if (SCARG(uap, rmtp)) { error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); if (error2) /* XXX shouldn't happen, did useracc() above */ return (error2); } return (error); } #ifndef _SYS_SYSPROTO_H_ struct signanosleep_args { struct timespec *rqtp; struct timespec *rmtp; sigset_t *mask; }; #endif /* ARGSUSED */ int signanosleep(p, uap, retval) struct proc *p; struct signanosleep_args *uap; register_t *retval; { struct timespec rmt, rqt; int error, error2; struct sigacts *ps = p->p_sigacts; sigset_t mask; error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); if (error) return (error); if (SCARG(uap, rmtp)) if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), B_WRITE)) return (EFAULT); error = copyin(SCARG(uap, mask), &mask, sizeof(mask)); if (error) return (error); /* See kern_sig.c:sigsuspend() for explanation */ ps->ps_oldmask = p->p_sigmask; ps->ps_flags |= SAS_OLDMASK; p->p_sigmask = mask &~ sigcantmask; error = nanosleep1(p, &rqt, &rmt); p->p_sigmask = ps->ps_oldmask; /* in case timeout rather than sig */ ps->ps_flags &= ~SAS_OLDMASK; if (SCARG(uap, rmtp)) { error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); if (error2) /* XXX shouldn't happen, did useracc() above */ return (error2); } return (error); } #ifndef _SYS_SYSPROTO_H_ struct gettimeofday_args { struct timeval *tp; struct timezone *tzp; }; #endif /* ARGSUSED */ int gettimeofday(p, uap, retval) struct proc *p; register struct gettimeofday_args *uap; int *retval; { struct timeval atv; int error = 0; if (uap->tp) { microtime(&atv); if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv)))) return (error); } if (uap->tzp) error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, sizeof (tz)); return (error); } #ifndef _SYS_SYSPROTO_H_ struct settimeofday_args { struct timeval *tv; struct timezone *tzp; }; #endif /* ARGSUSED */ int settimeofday(p, uap, retval) struct proc *p; struct settimeofday_args *uap; int *retval; { struct timeval atv; struct timezone atz; int error; if ((error = suser(p->p_ucred, &p->p_acflag))) return (error); /* Verify all parameters before changing time. */ if (uap->tv) { if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof(atv)))) return (error); if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) return (EINVAL); } if (uap->tzp && (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) return (error); if (uap->tv && (error = settime(&atv))) return (error); if (uap->tzp) tz = atz; return (0); } int tickdelta; /* current clock skew, us. per tick */ long timedelta; /* unapplied time correction, us. */ static long bigadj = 1000000; /* use 10x skew above bigadj us. */ #ifndef _SYS_SYSPROTO_H_ struct adjtime_args { struct timeval *delta; struct timeval *olddelta; }; #endif /* ARGSUSED */ int adjtime(p, uap, retval) struct proc *p; register struct adjtime_args *uap; int *retval; { struct timeval atv; register long ndelta, ntickdelta, odelta; int s, error; if ((error = suser(p->p_ucred, &p->p_acflag))) return (error); if ((error = copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval)))) return (error); /* * Compute the total correction and the rate at which to apply it. * Round the adjustment down to a whole multiple of the per-tick * delta, so that after some number of incremental changes in * hardclock(), tickdelta will become zero, lest the correction * overshoot and start taking us away from the desired final time. */ ndelta = atv.tv_sec * 1000000 + atv.tv_usec; if (ndelta > bigadj || ndelta < -bigadj) ntickdelta = 10 * tickadj; else ntickdelta = tickadj; if (ndelta % ntickdelta) ndelta = ndelta / ntickdelta * ntickdelta; /* * To make hardclock()'s job easier, make the per-tick delta negative * if we want time to run slower; then hardclock can simply compute * tick + tickdelta, and subtract tickdelta from timedelta. */ if (ndelta < 0) ntickdelta = -ntickdelta; s = splclock(); odelta = timedelta; timedelta = ndelta; tickdelta = ntickdelta; splx(s); if (uap->olddelta) { atv.tv_sec = odelta / 1000000; atv.tv_usec = odelta % 1000000; (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta, sizeof(struct timeval)); } return (0); } /* * 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 /* ARGSUSED */ int getitimer(p, uap, retval) struct proc *p; register struct getitimer_args *uap; int *retval; { struct itimerval aitv; int s; if (uap->which > ITIMER_PROF) return (EINVAL); s = splclock(); if (uap->which == ITIMER_REAL) { /* * Convert from absoulte 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. */ aitv = p->p_realtimer; if (timerisset(&aitv.it_value)) if (timercmp(&aitv.it_value, &time, <)) timerclear(&aitv.it_value); else timevalsub(&aitv.it_value, &time); } else aitv = p->p_stats->p_timer[uap->which]; splx(s); return (copyout((caddr_t)&aitv, (caddr_t)uap->itv, sizeof (struct itimerval))); } #ifndef _SYS_SYSPROTO_H_ struct setitimer_args { u_int which; struct itimerval *itv, *oitv; }; #endif /* ARGSUSED */ int setitimer(p, uap, retval) struct proc *p; register struct setitimer_args *uap; int *retval; { struct itimerval aitv; register struct itimerval *itvp; int s, error; if (uap->which > ITIMER_PROF) return (EINVAL); itvp = uap->itv; if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, sizeof(struct itimerval)))) return (error); if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval))) return (error); if (itvp == 0) return (0); if (itimerfix(&aitv.it_value)) return (EINVAL); if (!timerisset(&aitv.it_value)) timerclear(&aitv.it_interval); else if (itimerfix(&aitv.it_interval)) return (EINVAL); s = splclock(); if (uap->which == ITIMER_REAL) { untimeout(realitexpire, (caddr_t)p); if (timerisset(&aitv.it_value)) { timevaladd(&aitv.it_value, &time); timeout(realitexpire, (caddr_t)p, hzto(&aitv.it_value)); } p->p_realtimer = aitv; } else p->p_stats->p_timer[uap->which] = aitv; splx(s); 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. * hzto() 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(arg) void *arg; { register struct proc *p; int s; p = (struct proc *)arg; psignal(p, SIGALRM); if (!timerisset(&p->p_realtimer.it_interval)) { timerclear(&p->p_realtimer.it_value); return; } for (;;) { s = splclock(); timevaladd(&p->p_realtimer.it_value, &p->p_realtimer.it_interval); if (timercmp(&p->p_realtimer.it_value, &time, >)) { timeout(realitexpire, (caddr_t)p, hzto(&p->p_realtimer.it_value) - 1); splx(s); return; } splx(s); } } /* * 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(tv) 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); } /* * 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(itp, usec) register 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 (timerisset(&itp->it_value)) 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 */ 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(t1, t2) struct timeval *t1, *t2; { t1->tv_sec += t2->tv_sec; t1->tv_usec += t2->tv_usec; timevalfix(t1); } void timevalsub(t1, t2) struct timeval *t1, *t2; { t1->tv_sec -= t2->tv_sec; t1->tv_usec -= t2->tv_usec; timevalfix(t1); } static void timevalfix(t1) 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; } }