kern_time.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 4. Neither the name of the University nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      @(#)kern_time.c 8.1 (Berkeley) 6/10/93
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/limits.h>
   38 #include <sys/clock.h>
   39 #include <sys/lock.h>
   40 #include <sys/mutex.h>
   41 #include <sys/sysproto.h>
   42 #include <sys/eventhandler.h>
   43 #include <sys/resourcevar.h>
   44 #include <sys/signalvar.h>
   45 #include <sys/kernel.h>
   46 #include <sys/syscallsubr.h>
   47 #include <sys/sysctl.h>
   48 #include <sys/sysent.h>
   49 #include <sys/priv.h>
   50 #include <sys/proc.h>
   51 #include <sys/posix4.h>
   52 #include <sys/time.h>
   53 #include <sys/timers.h>
   54 #include <sys/timetc.h>
   55 #include <sys/vnode.h>
   56 
   57 #include <vm/vm.h>
   58 #include <vm/vm_extern.h>
   59 
   60 #define MAX_CLOCKS      (CLOCK_MONOTONIC+1)
   61 
   62 static struct kclock    posix_clocks[MAX_CLOCKS];
   63 static uma_zone_t       itimer_zone = NULL;
   64 
   65 /*
   66  * Time of day and interval timer support.
   67  *
   68  * These routines provide the kernel entry points to get and set
   69  * the time-of-day and per-process interval timers.  Subroutines
   70  * here provide support for adding and subtracting timeval structures
   71  * and decrementing interval timers, optionally reloading the interval
   72  * timers when they expire.
   73  */
   74 
   75 static int      settime(struct thread *, struct timeval *);
   76 static void     timevalfix(struct timeval *);
   77 static void     no_lease_updatetime(int);
   78 
   79 static void     itimer_start(void);
   80 static int      itimer_init(void *, int, int);
   81 static void     itimer_fini(void *, int);
   82 static void     itimer_enter(struct itimer *);
   83 static void     itimer_leave(struct itimer *);
   84 static struct itimer *itimer_find(struct proc *, int);
   85 static void     itimers_alloc(struct proc *);
   86 static void     itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp);
   87 static void     itimers_event_hook_exit(void *arg, struct proc *p);
   88 static int      realtimer_create(struct itimer *);
   89 static int      realtimer_gettime(struct itimer *, struct itimerspec *);
   90 static int      realtimer_settime(struct itimer *, int,
   91                         struct itimerspec *, struct itimerspec *);
   92 static int      realtimer_delete(struct itimer *);
   93 static void     realtimer_clocktime(clockid_t, struct timespec *);
   94 static void     realtimer_expire(void *);
   95 static int      kern_timer_create(struct thread *, clockid_t,
   96                         struct sigevent *, int *, int);
   97 static int      kern_timer_delete(struct thread *, int);
   98 
   99 int             register_posix_clock(int, struct kclock *);
  100 void            itimer_fire(struct itimer *it);
  101 int             itimespecfix(struct timespec *ts);
  102 
  103 #define CLOCK_CALL(clock, call, arglist)                \
  104         ((*posix_clocks[clock].call) arglist)
  105 
  106 SYSINIT(posix_timer, SI_SUB_P1003_1B, SI_ORDER_FIRST+4, itimer_start, NULL);
  107 
  108 
  109 static void 
  110 no_lease_updatetime(deltat)
  111         int deltat;
  112 {
  113 }
  114 
  115 void (*lease_updatetime)(int)  = no_lease_updatetime;
  116 
  117 static int
  118 settime(struct thread *td, struct timeval *tv)
  119 {
  120         struct timeval delta, tv1, tv2;
  121         static struct timeval maxtime, laststep;
  122         struct timespec ts;
  123         int s;
  124 
  125         s = splclock();
  126         microtime(&tv1);
  127         delta = *tv;
  128         timevalsub(&delta, &tv1);
  129 
  130         /*
  131          * If the system is secure, we do not allow the time to be 
  132          * set to a value earlier than 1 second less than the highest
  133          * time we have yet seen. The worst a miscreant can do in
  134          * this circumstance is "freeze" time. He couldn't go
  135          * back to the past.
  136          *
  137          * We similarly do not allow the clock to be stepped more
  138          * than one second, nor more than once per second. This allows
  139          * a miscreant to make the clock march double-time, but no worse.
  140          */
  141         if (securelevel_gt(td->td_ucred, 1) != 0) {
  142                 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
  143                         /*
  144                          * Update maxtime to latest time we've seen.
  145                          */
  146                         if (tv1.tv_sec > maxtime.tv_sec)
  147                                 maxtime = tv1;
  148                         tv2 = *tv;
  149                         timevalsub(&tv2, &maxtime);
  150                         if (tv2.tv_sec < -1) {
  151                                 tv->tv_sec = maxtime.tv_sec - 1;
  152                                 printf("Time adjustment clamped to -1 second\n");
  153                         }
  154                 } else {
  155                         if (tv1.tv_sec == laststep.tv_sec) {
  156                                 splx(s);
  157                                 return (EPERM);
  158                         }
  159                         if (delta.tv_sec > 1) {
  160                                 tv->tv_sec = tv1.tv_sec + 1;
  161                                 printf("Time adjustment clamped to +1 second\n");
  162                         }
  163                         laststep = *tv;
  164                 }
  165         }
  166 
  167         ts.tv_sec = tv->tv_sec;
  168         ts.tv_nsec = tv->tv_usec * 1000;
  169         mtx_lock(&Giant);
  170         tc_setclock(&ts);
  171         (void) splsoftclock();
  172         lease_updatetime(delta.tv_sec);
  173         splx(s);
  174         resettodr();
  175         mtx_unlock(&Giant);
  176         return (0);
  177 }
  178 
  179 #ifndef _SYS_SYSPROTO_H_
  180 struct clock_gettime_args {
  181         clockid_t clock_id;
  182         struct  timespec *tp;
  183 };
  184 #endif
  185 /* ARGSUSED */
  186 int
  187 clock_gettime(struct thread *td, struct clock_gettime_args *uap)
  188 {
  189         struct timespec ats;
  190         int error;
  191 
  192         error = kern_clock_gettime(td, uap->clock_id, &ats);
  193         if (error == 0)
  194                 error = copyout(&ats, uap->tp, sizeof(ats));
  195 
  196         return (error);
  197 }
  198 
  199 int
  200 kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  201 {
  202         struct timeval sys, user;
  203         struct proc *p;
  204 
  205         p = td->td_proc;
  206         switch (clock_id) {
  207         case CLOCK_REALTIME:            /* Default to precise. */
  208         case CLOCK_REALTIME_PRECISE:
  209                 nanotime(ats);
  210                 break;
  211         case CLOCK_REALTIME_FAST:
  212                 getnanotime(ats);
  213                 break;
  214         case CLOCK_VIRTUAL:
  215                 PROC_LOCK(p);
  216                 PROC_SLOCK(p);
  217                 calcru(p, &user, &sys);
  218                 PROC_SUNLOCK(p);
  219                 PROC_UNLOCK(p);
  220                 TIMEVAL_TO_TIMESPEC(&user, ats);
  221                 break;
  222         case CLOCK_PROF:
  223                 PROC_LOCK(p);
  224                 PROC_SLOCK(p);
  225                 calcru(p, &user, &sys);
  226                 PROC_SUNLOCK(p);
  227                 PROC_UNLOCK(p);
  228                 timevaladd(&user, &sys);
  229                 TIMEVAL_TO_TIMESPEC(&user, ats);
  230                 break;
  231         case CLOCK_MONOTONIC:           /* Default to precise. */
  232         case CLOCK_MONOTONIC_PRECISE:
  233         case CLOCK_UPTIME:
  234         case CLOCK_UPTIME_PRECISE:
  235                 nanouptime(ats);
  236                 break;
  237         case CLOCK_UPTIME_FAST:
  238         case CLOCK_MONOTONIC_FAST:
  239                 getnanouptime(ats);
  240                 break;
  241         case CLOCK_SECOND:
  242                 ats->tv_sec = time_second;
  243                 ats->tv_nsec = 0;
  244                 break;
  245         default:
  246                 return (EINVAL);
  247         }
  248         return (0);
  249 }
  250 
  251 #ifndef _SYS_SYSPROTO_H_
  252 struct clock_settime_args {
  253         clockid_t clock_id;
  254         const struct    timespec *tp;
  255 };
  256 #endif
  257 /* ARGSUSED */
  258 int
  259 clock_settime(struct thread *td, struct clock_settime_args *uap)
  260 {
  261         struct timespec ats;
  262         int error;
  263 
  264         if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
  265                 return (error);
  266         return (kern_clock_settime(td, uap->clock_id, &ats));
  267 }
  268 
  269 int
  270 kern_clock_settime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  271 {
  272         struct timeval atv;
  273         int error;
  274 
  275         if ((error = priv_check(td, PRIV_CLOCK_SETTIME)) != 0)
  276                 return (error);
  277         if (clock_id != CLOCK_REALTIME)
  278                 return (EINVAL);
  279         if (ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000)
  280                 return (EINVAL);
  281         /* XXX Don't convert nsec->usec and back */
  282         TIMESPEC_TO_TIMEVAL(&atv, ats);
  283         error = settime(td, &atv);
  284         return (error);
  285 }
  286 
  287 #ifndef _SYS_SYSPROTO_H_
  288 struct clock_getres_args {
  289         clockid_t clock_id;
  290         struct  timespec *tp;
  291 };
  292 #endif
  293 int
  294 clock_getres(struct thread *td, struct clock_getres_args *uap)
  295 {
  296         struct timespec ts;
  297         int error;
  298 
  299         if (uap->tp == NULL)
  300                 return (0);
  301 
  302         error = kern_clock_getres(td, uap->clock_id, &ts);
  303         if (error == 0)
  304                 error = copyout(&ts, uap->tp, sizeof(ts));
  305         return (error);
  306 }
  307 
  308 int
  309 kern_clock_getres(struct thread *td, clockid_t clock_id, struct timespec *ts)
  310 {
  311 
  312         ts->tv_sec = 0;
  313         switch (clock_id) {
  314         case CLOCK_REALTIME:
  315         case CLOCK_REALTIME_FAST:
  316         case CLOCK_REALTIME_PRECISE:
  317         case CLOCK_MONOTONIC:
  318         case CLOCK_MONOTONIC_FAST:
  319         case CLOCK_MONOTONIC_PRECISE:
  320         case CLOCK_UPTIME:
  321         case CLOCK_UPTIME_FAST:
  322         case CLOCK_UPTIME_PRECISE:
  323                 /*
  324                  * Round up the result of the division cheaply by adding 1.
  325                  * Rounding up is especially important if rounding down
  326                  * would give 0.  Perfect rounding is unimportant.
  327                  */
  328                 ts->tv_nsec = 1000000000 / tc_getfrequency() + 1;
  329                 break;
  330         case CLOCK_VIRTUAL:
  331         case CLOCK_PROF:
  332                 /* Accurately round up here because we can do so cheaply. */
  333                 ts->tv_nsec = (1000000000 + hz - 1) / hz;
  334                 break;
  335         case CLOCK_SECOND:
  336                 ts->tv_sec = 1;
  337                 ts->tv_nsec = 0;
  338                 break;
  339         default:
  340                 return (EINVAL);
  341         }
  342         return (0);
  343 }
  344 
  345 static int nanowait;
  346 
  347 int
  348 kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
  349 {
  350         struct timespec ts, ts2, ts3;
  351         struct timeval tv;
  352         int error;
  353 
  354         if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
  355                 return (EINVAL);
  356         if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
  357                 return (0);
  358         getnanouptime(&ts);
  359         timespecadd(&ts, rqt);
  360         TIMESPEC_TO_TIMEVAL(&tv, rqt);
  361         for (;;) {
  362                 error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp",
  363                     tvtohz(&tv));
  364                 getnanouptime(&ts2);
  365                 if (error != EWOULDBLOCK) {
  366                         if (error == ERESTART)
  367                                 error = EINTR;
  368                         if (rmt != NULL) {
  369                                 timespecsub(&ts, &ts2);
  370                                 if (ts.tv_sec < 0)
  371                                         timespecclear(&ts);
  372                                 *rmt = ts;
  373                         }
  374                         return (error);
  375                 }
  376                 if (timespeccmp(&ts2, &ts, >=))
  377                         return (0);
  378                 ts3 = ts;
  379                 timespecsub(&ts3, &ts2);
  380                 TIMESPEC_TO_TIMEVAL(&tv, &ts3);
  381         }
  382 }
  383 
  384 #ifndef _SYS_SYSPROTO_H_
  385 struct nanosleep_args {
  386         struct  timespec *rqtp;
  387         struct  timespec *rmtp;
  388 };
  389 #endif
  390 /* ARGSUSED */
  391 int
  392 nanosleep(struct thread *td, struct nanosleep_args *uap)
  393 {
  394         struct timespec rmt, rqt;
  395         int error;
  396 
  397         error = copyin(uap->rqtp, &rqt, sizeof(rqt));
  398         if (error)
  399                 return (error);
  400 
  401         if (uap->rmtp &&
  402             !useracc((caddr_t)uap->rmtp, sizeof(rmt), VM_PROT_WRITE))
  403                         return (EFAULT);
  404         error = kern_nanosleep(td, &rqt, &rmt);
  405         if (error && uap->rmtp) {
  406                 int error2;
  407 
  408                 error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
  409                 if (error2)
  410                         error = error2;
  411         }
  412         return (error);
  413 }
  414 
  415 #ifndef _SYS_SYSPROTO_H_
  416 struct gettimeofday_args {
  417         struct  timeval *tp;
  418         struct  timezone *tzp;
  419 };
  420 #endif
  421 /* ARGSUSED */
  422 int
  423 gettimeofday(struct thread *td, struct gettimeofday_args *uap)
  424 {
  425         struct timeval atv;
  426         struct timezone rtz;
  427         int error = 0;
  428 
  429         if (uap->tp) {
  430                 microtime(&atv);
  431                 error = copyout(&atv, uap->tp, sizeof (atv));
  432         }
  433         if (error == 0 && uap->tzp != NULL) {
  434                 rtz.tz_minuteswest = tz_minuteswest;
  435                 rtz.tz_dsttime = tz_dsttime;
  436                 error = copyout(&rtz, uap->tzp, sizeof (rtz));
  437         }
  438         return (error);
  439 }
  440 
  441 #ifndef _SYS_SYSPROTO_H_
  442 struct settimeofday_args {
  443         struct  timeval *tv;
  444         struct  timezone *tzp;
  445 };
  446 #endif
  447 /* ARGSUSED */
  448 int
  449 settimeofday(struct thread *td, struct settimeofday_args *uap)
  450 {
  451         struct timeval atv, *tvp;
  452         struct timezone atz, *tzp;
  453         int error;
  454 
  455         if (uap->tv) {
  456                 error = copyin(uap->tv, &atv, sizeof(atv));
  457                 if (error)
  458                         return (error);
  459                 tvp = &atv;
  460         } else
  461                 tvp = NULL;
  462         if (uap->tzp) {
  463                 error = copyin(uap->tzp, &atz, sizeof(atz));
  464                 if (error)
  465                         return (error);
  466                 tzp = &atz;
  467         } else
  468                 tzp = NULL;
  469         return (kern_settimeofday(td, tvp, tzp));
  470 }
  471 
  472 int
  473 kern_settimeofday(struct thread *td, struct timeval *tv, struct timezone *tzp)
  474 {
  475         int error;
  476 
  477         error = priv_check(td, PRIV_SETTIMEOFDAY);
  478         if (error)
  479                 return (error);
  480         /* Verify all parameters before changing time. */
  481         if (tv) {
  482                 if (tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  483                         return (EINVAL);
  484                 error = settime(td, tv);
  485         }
  486         if (tzp && error == 0) {
  487                 tz_minuteswest = tzp->tz_minuteswest;
  488                 tz_dsttime = tzp->tz_dsttime;
  489         }
  490         return (error);
  491 }
  492 
  493 /*
  494  * Get value of an interval timer.  The process virtual and profiling virtual
  495  * time timers are kept in the p_stats area, since they can be swapped out.
  496  * These are kept internally in the way they are specified externally: in
  497  * time until they expire.
  498  *
  499  * The real time interval timer is kept in the process table slot for the
  500  * process, and its value (it_value) is kept as an absolute time rather than
  501  * as a delta, so that it is easy to keep periodic real-time signals from
  502  * drifting.
  503  *
  504  * Virtual time timers are processed in the hardclock() routine of
  505  * kern_clock.c.  The real time timer is processed by a timeout routine,
  506  * called from the softclock() routine.  Since a callout may be delayed in
  507  * real time due to interrupt processing in the system, it is possible for
  508  * the real time timeout routine (realitexpire, given below), to be delayed
  509  * in real time past when it is supposed to occur.  It does not suffice,
  510  * therefore, to reload the real timer .it_value from the real time timers
  511  * .it_interval.  Rather, we compute the next time in absolute time the timer
  512  * should go off.
  513  */
  514 #ifndef _SYS_SYSPROTO_H_
  515 struct getitimer_args {
  516         u_int   which;
  517         struct  itimerval *itv;
  518 };
  519 #endif
  520 int
  521 getitimer(struct thread *td, struct getitimer_args *uap)
  522 {
  523         struct itimerval aitv;
  524         int error;
  525 
  526         error = kern_getitimer(td, uap->which, &aitv);
  527         if (error != 0)
  528                 return (error);
  529         return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
  530 }
  531 
  532 int
  533 kern_getitimer(struct thread *td, u_int which, struct itimerval *aitv)
  534 {
  535         struct proc *p = td->td_proc;
  536         struct timeval ctv;
  537 
  538         if (which > ITIMER_PROF)
  539                 return (EINVAL);
  540 
  541         if (which == ITIMER_REAL) {
  542                 /*
  543                  * Convert from absolute to relative time in .it_value
  544                  * part of real time timer.  If time for real time timer
  545                  * has passed return 0, else return difference between
  546                  * current time and time for the timer to go off.
  547                  */
  548                 PROC_LOCK(p);
  549                 *aitv = p->p_realtimer;
  550                 PROC_UNLOCK(p);
  551                 if (timevalisset(&aitv->it_value)) {
  552                         getmicrouptime(&ctv);
  553                         if (timevalcmp(&aitv->it_value, &ctv, <))
  554                                 timevalclear(&aitv->it_value);
  555                         else
  556                                 timevalsub(&aitv->it_value, &ctv);
  557                 }
  558         } else {
  559                 PROC_SLOCK(p);
  560                 *aitv = p->p_stats->p_timer[which];
  561                 PROC_SUNLOCK(p);
  562         }
  563         return (0);
  564 }
  565 
  566 #ifndef _SYS_SYSPROTO_H_
  567 struct setitimer_args {
  568         u_int   which;
  569         struct  itimerval *itv, *oitv;
  570 };
  571 #endif
  572 int
  573 setitimer(struct thread *td, struct setitimer_args *uap)
  574 {
  575         struct itimerval aitv, oitv;
  576         int error;
  577 
  578         if (uap->itv == NULL) {
  579                 uap->itv = uap->oitv;
  580                 return (getitimer(td, (struct getitimer_args *)uap));
  581         }
  582 
  583         if ((error = copyin(uap->itv, &aitv, sizeof(struct itimerval))))
  584                 return (error);
  585         error = kern_setitimer(td, uap->which, &aitv, &oitv);
  586         if (error != 0 || uap->oitv == NULL)
  587                 return (error);
  588         return (copyout(&oitv, uap->oitv, sizeof(struct itimerval)));
  589 }
  590 
  591 int
  592 kern_setitimer(struct thread *td, u_int which, struct itimerval *aitv,
  593     struct itimerval *oitv)
  594 {
  595         struct proc *p = td->td_proc;
  596         struct timeval ctv;
  597 
  598         if (aitv == NULL)
  599                 return (kern_getitimer(td, which, oitv));
  600 
  601         if (which > ITIMER_PROF)
  602                 return (EINVAL);
  603         if (itimerfix(&aitv->it_value))
  604                 return (EINVAL);
  605         if (!timevalisset(&aitv->it_value))
  606                 timevalclear(&aitv->it_interval);
  607         else if (itimerfix(&aitv->it_interval))
  608                 return (EINVAL);
  609 
  610         if (which == ITIMER_REAL) {
  611                 PROC_LOCK(p);
  612                 if (timevalisset(&p->p_realtimer.it_value))
  613                         callout_stop(&p->p_itcallout);
  614                 getmicrouptime(&ctv);
  615                 if (timevalisset(&aitv->it_value)) {
  616                         callout_reset(&p->p_itcallout, tvtohz(&aitv->it_value),
  617                             realitexpire, p);
  618                         timevaladd(&aitv->it_value, &ctv);
  619                 }
  620                 *oitv = p->p_realtimer;
  621                 p->p_realtimer = *aitv;
  622                 PROC_UNLOCK(p);
  623                 if (timevalisset(&oitv->it_value)) {
  624                         if (timevalcmp(&oitv->it_value, &ctv, <))
  625                                 timevalclear(&oitv->it_value);
  626                         else
  627                                 timevalsub(&oitv->it_value, &ctv);
  628                 }
  629         } else {
  630                 PROC_SLOCK(p);
  631                 *oitv = p->p_stats->p_timer[which];
  632                 p->p_stats->p_timer[which] = *aitv;
  633                 PROC_SUNLOCK(p);
  634         }
  635         return (0);
  636 }
  637 
  638 /*
  639  * Real interval timer expired:
  640  * send process whose timer expired an alarm signal.
  641  * If time is not set up to reload, then just return.
  642  * Else compute next time timer should go off which is > current time.
  643  * This is where delay in processing this timeout causes multiple
  644  * SIGALRM calls to be compressed into one.
  645  * tvtohz() always adds 1 to allow for the time until the next clock
  646  * interrupt being strictly less than 1 clock tick, but we don't want
  647  * that here since we want to appear to be in sync with the clock
  648  * interrupt even when we're delayed.
  649  */
  650 void
  651 realitexpire(void *arg)
  652 {
  653         struct proc *p;
  654         struct timeval ctv, ntv;
  655 
  656         p = (struct proc *)arg;
  657         PROC_LOCK(p);
  658         psignal(p, SIGALRM);
  659         if (!timevalisset(&p->p_realtimer.it_interval)) {
  660                 timevalclear(&p->p_realtimer.it_value);
  661                 if (p->p_flag & P_WEXIT)
  662                         wakeup(&p->p_itcallout);
  663                 PROC_UNLOCK(p);
  664                 return;
  665         }
  666         for (;;) {
  667                 timevaladd(&p->p_realtimer.it_value,
  668                     &p->p_realtimer.it_interval);
  669                 getmicrouptime(&ctv);
  670                 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
  671                         ntv = p->p_realtimer.it_value;
  672                         timevalsub(&ntv, &ctv);
  673                         callout_reset(&p->p_itcallout, tvtohz(&ntv) - 1,
  674                             realitexpire, p);
  675                         PROC_UNLOCK(p);
  676                         return;
  677                 }
  678         }
  679         /*NOTREACHED*/
  680 }
  681 
  682 /*
  683  * Check that a proposed value to load into the .it_value or
  684  * .it_interval part of an interval timer is acceptable, and
  685  * fix it to have at least minimal value (i.e. if it is less
  686  * than the resolution of the clock, round it up.)
  687  */
  688 int
  689 itimerfix(struct timeval *tv)
  690 {
  691 
  692         if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  693                 return (EINVAL);
  694         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
  695                 tv->tv_usec = tick;
  696         return (0);
  697 }
  698 
  699 /*
  700  * Decrement an interval timer by a specified number
  701  * of microseconds, which must be less than a second,
  702  * i.e. < 1000000.  If the timer expires, then reload
  703  * it.  In this case, carry over (usec - old value) to
  704  * reduce the value reloaded into the timer so that
  705  * the timer does not drift.  This routine assumes
  706  * that it is called in a context where the timers
  707  * on which it is operating cannot change in value.
  708  */
  709 int
  710 itimerdecr(struct itimerval *itp, int usec)
  711 {
  712 
  713         if (itp->it_value.tv_usec < usec) {
  714                 if (itp->it_value.tv_sec == 0) {
  715                         /* expired, and already in next interval */
  716                         usec -= itp->it_value.tv_usec;
  717                         goto expire;
  718                 }
  719                 itp->it_value.tv_usec += 1000000;
  720                 itp->it_value.tv_sec--;
  721         }
  722         itp->it_value.tv_usec -= usec;
  723         usec = 0;
  724         if (timevalisset(&itp->it_value))
  725                 return (1);
  726         /* expired, exactly at end of interval */
  727 expire:
  728         if (timevalisset(&itp->it_interval)) {
  729                 itp->it_value = itp->it_interval;
  730                 itp->it_value.tv_usec -= usec;
  731                 if (itp->it_value.tv_usec < 0) {
  732                         itp->it_value.tv_usec += 1000000;
  733                         itp->it_value.tv_sec--;
  734                 }
  735         } else
  736                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
  737         return (0);
  738 }
  739 
  740 /*
  741  * Add and subtract routines for timevals.
  742  * N.B.: subtract routine doesn't deal with
  743  * results which are before the beginning,
  744  * it just gets very confused in this case.
  745  * Caveat emptor.
  746  */
  747 void
  748 timevaladd(struct timeval *t1, const struct timeval *t2)
  749 {
  750 
  751         t1->tv_sec += t2->tv_sec;
  752         t1->tv_usec += t2->tv_usec;
  753         timevalfix(t1);
  754 }
  755 
  756 void
  757 timevalsub(struct timeval *t1, const struct timeval *t2)
  758 {
  759 
  760         t1->tv_sec -= t2->tv_sec;
  761         t1->tv_usec -= t2->tv_usec;
  762         timevalfix(t1);
  763 }
  764 
  765 static void
  766 timevalfix(struct timeval *t1)
  767 {
  768 
  769         if (t1->tv_usec < 0) {
  770                 t1->tv_sec--;
  771                 t1->tv_usec += 1000000;
  772         }
  773         if (t1->tv_usec >= 1000000) {
  774                 t1->tv_sec++;
  775                 t1->tv_usec -= 1000000;
  776         }
  777 }
  778 
  779 /*
  780  * ratecheck(): simple time-based rate-limit checking.
  781  */
  782 int
  783 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
  784 {
  785         struct timeval tv, delta;
  786         int rv = 0;
  787 
  788         getmicrouptime(&tv);            /* NB: 10ms precision */
  789         delta = tv;
  790         timevalsub(&delta, lasttime);
  791 
  792         /*
  793          * check for 0,0 is so that the message will be seen at least once,
  794          * even if interval is huge.
  795          */
  796         if (timevalcmp(&delta, mininterval, >=) ||
  797             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
  798                 *lasttime = tv;
  799                 rv = 1;
  800         }
  801 
  802         return (rv);
  803 }
  804 
  805 /*
  806  * ppsratecheck(): packets (or events) per second limitation.
  807  *
  808  * Return 0 if the limit is to be enforced (e.g. the caller
  809  * should drop a packet because of the rate limitation).
  810  *
  811  * maxpps of 0 always causes zero to be returned.  maxpps of -1
  812  * always causes 1 to be returned; this effectively defeats rate
  813  * limiting.
  814  *
  815  * Note that we maintain the struct timeval for compatibility
  816  * with other bsd systems.  We reuse the storage and just monitor
  817  * clock ticks for minimal overhead.  
  818  */
  819 int
  820 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
  821 {
  822         int now;
  823 
  824         /*
  825          * Reset the last time and counter if this is the first call
  826          * or more than a second has passed since the last update of
  827          * lasttime.
  828          */
  829         now = ticks;
  830         if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
  831                 lasttime->tv_sec = now;
  832                 *curpps = 1;
  833                 return (maxpps != 0);
  834         } else {
  835                 (*curpps)++;            /* NB: ignore potential overflow */
  836                 return (maxpps < 0 || *curpps < maxpps);
  837         }
  838 }
  839 
  840 static void
  841 itimer_start(void)
  842 {
  843         struct kclock rt_clock = {
  844                 .timer_create  = realtimer_create,
  845                 .timer_delete  = realtimer_delete,
  846                 .timer_settime = realtimer_settime,
  847                 .timer_gettime = realtimer_gettime,
  848                 .event_hook    = NULL
  849         };
  850 
  851         itimer_zone = uma_zcreate("itimer", sizeof(struct itimer),
  852                 NULL, NULL, itimer_init, itimer_fini, UMA_ALIGN_PTR, 0);
  853         register_posix_clock(CLOCK_REALTIME,  &rt_clock);
  854         register_posix_clock(CLOCK_MONOTONIC, &rt_clock);
  855         p31b_setcfg(CTL_P1003_1B_TIMERS, 200112L);
  856         p31b_setcfg(CTL_P1003_1B_DELAYTIMER_MAX, INT_MAX);
  857         p31b_setcfg(CTL_P1003_1B_TIMER_MAX, TIMER_MAX);
  858         EVENTHANDLER_REGISTER(process_exit, itimers_event_hook_exit,
  859                 (void *)ITIMER_EV_EXIT, EVENTHANDLER_PRI_ANY);
  860         EVENTHANDLER_REGISTER(process_exec, itimers_event_hook_exec,
  861                 (void *)ITIMER_EV_EXEC, EVENTHANDLER_PRI_ANY);
  862 }
  863 
  864 int
  865 register_posix_clock(int clockid, struct kclock *clk)
  866 {
  867         if ((unsigned)clockid >= MAX_CLOCKS) {
  868                 printf("%s: invalid clockid\n", __func__);
  869                 return (0);
  870         }
  871         posix_clocks[clockid] = *clk;
  872         return (1);
  873 }
  874 
  875 static int
  876 itimer_init(void *mem, int size, int flags)
  877 {
  878         struct itimer *it;
  879 
  880         it = (struct itimer *)mem;
  881         mtx_init(&it->it_mtx, "itimer lock", NULL, MTX_DEF);
  882         return (0);
  883 }
  884 
  885 static void
  886 itimer_fini(void *mem, int size)
  887 {
  888         struct itimer *it;
  889 
  890         it = (struct itimer *)mem;
  891         mtx_destroy(&it->it_mtx);
  892 }
  893 
  894 static void
  895 itimer_enter(struct itimer *it)
  896 {
  897 
  898         mtx_assert(&it->it_mtx, MA_OWNED);
  899         it->it_usecount++;
  900 }
  901 
  902 static void
  903 itimer_leave(struct itimer *it)
  904 {
  905 
  906         mtx_assert(&it->it_mtx, MA_OWNED);
  907         KASSERT(it->it_usecount > 0, ("invalid it_usecount"));
  908 
  909         if (--it->it_usecount == 0 && (it->it_flags & ITF_WANTED) != 0)
  910                 wakeup(it);
  911 }
  912 
  913 #ifndef _SYS_SYSPROTO_H_
  914 struct ktimer_create_args {
  915         clockid_t clock_id;
  916         struct sigevent * evp;
  917         int * timerid;
  918 };
  919 #endif
  920 int
  921 ktimer_create(struct thread *td, struct ktimer_create_args *uap)
  922 {
  923         struct sigevent *evp1, ev;
  924         int id;
  925         int error;
  926 
  927         if (uap->evp != NULL) {
  928                 error = copyin(uap->evp, &ev, sizeof(ev));
  929                 if (error != 0)
  930                         return (error);
  931                 evp1 = &ev;
  932         } else
  933                 evp1 = NULL;
  934 
  935         error = kern_timer_create(td, uap->clock_id, evp1, &id, -1);
  936 
  937         if (error == 0) {
  938                 error = copyout(&id, uap->timerid, sizeof(int));
  939                 if (error != 0)
  940                         kern_timer_delete(td, id);
  941         }
  942         return (error);
  943 }
  944 
  945 static int
  946 kern_timer_create(struct thread *td, clockid_t clock_id,
  947         struct sigevent *evp, int *timerid, int preset_id)
  948 {
  949         struct proc *p = td->td_proc;
  950         struct itimer *it;
  951         int id;
  952         int error;
  953 
  954         if (clock_id < 0 || clock_id >= MAX_CLOCKS)
  955                 return (EINVAL);
  956 
  957         if (posix_clocks[clock_id].timer_create == NULL)
  958                 return (EINVAL);
  959 
  960         if (evp != NULL) {
  961                 if (evp->sigev_notify != SIGEV_NONE &&
  962                     evp->sigev_notify != SIGEV_SIGNAL &&
  963                     evp->sigev_notify != SIGEV_THREAD_ID)
  964                         return (EINVAL);
  965                 if ((evp->sigev_notify == SIGEV_SIGNAL ||
  966                      evp->sigev_notify == SIGEV_THREAD_ID) &&
  967                         !_SIG_VALID(evp->sigev_signo))
  968                         return (EINVAL);
  969         }
  970         
  971         if (p->p_itimers == NULL)
  972                 itimers_alloc(p);
  973         
  974         it = uma_zalloc(itimer_zone, M_WAITOK);
  975         it->it_flags = 0;
  976         it->it_usecount = 0;
  977         it->it_active = 0;
  978         timespecclear(&it->it_time.it_value);
  979         timespecclear(&it->it_time.it_interval);
  980         it->it_overrun = 0;
  981         it->it_overrun_last = 0;
  982         it->it_clockid = clock_id;
  983         it->it_timerid = -1;
  984         it->it_proc = p;
  985         ksiginfo_init(&it->it_ksi);
  986         it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
  987         error = CLOCK_CALL(clock_id, timer_create, (it));
  988         if (error != 0)
  989                 goto out;
  990 
  991         PROC_LOCK(p);
  992         if (preset_id != -1) {
  993                 KASSERT(preset_id >= 0 && preset_id < 3, ("invalid preset_id"));
  994                 id = preset_id;
  995                 if (p->p_itimers->its_timers[id] != NULL) {
  996                         PROC_UNLOCK(p);
  997                         error = 0;
  998                         goto out;
  999                 }
 1000         } else {
 1001                 /*
 1002                  * Find a free timer slot, skipping those reserved
 1003                  * for setitimer().
 1004                  */
 1005                 for (id = 3; id < TIMER_MAX; id++)
 1006                         if (p->p_itimers->its_timers[id] == NULL)
 1007                                 break;
 1008                 if (id == TIMER_MAX) {
 1009                         PROC_UNLOCK(p);
 1010                         error = EAGAIN;
 1011                         goto out;
 1012                 }
 1013         }
 1014         it->it_timerid = id;
 1015         p->p_itimers->its_timers[id] = it;
 1016         if (evp != NULL)
 1017                 it->it_sigev = *evp;
 1018         else {
 1019                 it->it_sigev.sigev_notify = SIGEV_SIGNAL;
 1020                 switch (clock_id) {
 1021                 default:
 1022                 case CLOCK_REALTIME:
 1023                         it->it_sigev.sigev_signo = SIGALRM;
 1024                         break;
 1025                 case CLOCK_VIRTUAL:
 1026                         it->it_sigev.sigev_signo = SIGVTALRM;
 1027                         break;
 1028                 case CLOCK_PROF:
 1029                         it->it_sigev.sigev_signo = SIGPROF;
 1030                         break;
 1031                 }
 1032                 it->it_sigev.sigev_value.sival_int = id;
 1033         }
 1034 
 1035         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1036             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1037                 it->it_ksi.ksi_signo = it->it_sigev.sigev_signo;
 1038                 it->it_ksi.ksi_code = SI_TIMER;
 1039                 it->it_ksi.ksi_value = it->it_sigev.sigev_value;
 1040                 it->it_ksi.ksi_timerid = id;
 1041         }
 1042         PROC_UNLOCK(p);
 1043         *timerid = id;
 1044         return (0);
 1045 
 1046 out:
 1047         ITIMER_LOCK(it);
 1048         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1049         ITIMER_UNLOCK(it);
 1050         uma_zfree(itimer_zone, it);
 1051         return (error);
 1052 }
 1053 
 1054 #ifndef _SYS_SYSPROTO_H_
 1055 struct ktimer_delete_args {
 1056         int timerid;
 1057 };
 1058 #endif
 1059 int
 1060 ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
 1061 {
 1062         return (kern_timer_delete(td, uap->timerid));
 1063 }
 1064 
 1065 static struct itimer *
 1066 itimer_find(struct proc *p, int timerid)
 1067 {
 1068         struct itimer *it;
 1069 
 1070         PROC_LOCK_ASSERT(p, MA_OWNED);
 1071         if ((p->p_itimers == NULL) ||
 1072             (timerid < 0) || (timerid >= TIMER_MAX) ||
 1073             (it = p->p_itimers->its_timers[timerid]) == NULL) {
 1074                 return (NULL);
 1075         }
 1076         ITIMER_LOCK(it);
 1077         if ((it->it_flags & ITF_DELETING) != 0) {
 1078                 ITIMER_UNLOCK(it);
 1079                 it = NULL;
 1080         }
 1081         return (it);
 1082 }
 1083 
 1084 static int
 1085 kern_timer_delete(struct thread *td, int timerid)
 1086 {
 1087         struct proc *p = td->td_proc;
 1088         struct itimer *it;
 1089 
 1090         PROC_LOCK(p);
 1091         it = itimer_find(p, timerid);
 1092         if (it == NULL) {
 1093                 PROC_UNLOCK(p);
 1094                 return (EINVAL);
 1095         }
 1096         PROC_UNLOCK(p);
 1097 
 1098         it->it_flags |= ITF_DELETING;
 1099         while (it->it_usecount > 0) {
 1100                 it->it_flags |= ITF_WANTED;
 1101                 msleep(it, &it->it_mtx, PPAUSE, "itimer", 0);
 1102         }
 1103         it->it_flags &= ~ITF_WANTED;
 1104         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1105         ITIMER_UNLOCK(it);
 1106 
 1107         PROC_LOCK(p);
 1108         if (KSI_ONQ(&it->it_ksi))
 1109                 sigqueue_take(&it->it_ksi);
 1110         p->p_itimers->its_timers[timerid] = NULL;
 1111         PROC_UNLOCK(p);
 1112         uma_zfree(itimer_zone, it);
 1113         return (0);
 1114 }
 1115 
 1116 #ifndef _SYS_SYSPROTO_H_
 1117 struct ktimer_settime_args {
 1118         int timerid;
 1119         int flags;
 1120         const struct itimerspec * value;
 1121         struct itimerspec * ovalue;
 1122 };
 1123 #endif
 1124 int
 1125 ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
 1126 {
 1127         struct proc *p = td->td_proc;
 1128         struct itimer *it;
 1129         struct itimerspec val, oval, *ovalp;
 1130         int error;
 1131 
 1132         error = copyin(uap->value, &val, sizeof(val));
 1133         if (error != 0)
 1134                 return (error);
 1135         
 1136         if (uap->ovalue != NULL)
 1137                 ovalp = &oval;
 1138         else
 1139                 ovalp = NULL;
 1140 
 1141         PROC_LOCK(p);
 1142         if (uap->timerid < 3 ||
 1143             (it = itimer_find(p, uap->timerid)) == NULL) {
 1144                 PROC_UNLOCK(p);
 1145                 error = EINVAL;
 1146         } else {
 1147                 PROC_UNLOCK(p);
 1148                 itimer_enter(it);
 1149                 error = CLOCK_CALL(it->it_clockid, timer_settime,
 1150                                 (it, uap->flags, &val, ovalp));
 1151                 itimer_leave(it);
 1152                 ITIMER_UNLOCK(it);
 1153         }
 1154         if (error == 0 && uap->ovalue != NULL)
 1155                 error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
 1156         return (error);
 1157 }
 1158 
 1159 #ifndef _SYS_SYSPROTO_H_
 1160 struct ktimer_gettime_args {
 1161         int timerid;
 1162         struct itimerspec * value;
 1163 };
 1164 #endif
 1165 int
 1166 ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
 1167 {
 1168         struct proc *p = td->td_proc;
 1169         struct itimer *it;
 1170         struct itimerspec val;
 1171         int error;
 1172 
 1173         PROC_LOCK(p);
 1174         if (uap->timerid < 3 ||
 1175            (it = itimer_find(p, uap->timerid)) == NULL) {
 1176                 PROC_UNLOCK(p);
 1177                 error = EINVAL;
 1178         } else {
 1179                 PROC_UNLOCK(p);
 1180                 itimer_enter(it);
 1181                 error = CLOCK_CALL(it->it_clockid, timer_gettime,
 1182                                 (it, &val));
 1183                 itimer_leave(it);
 1184                 ITIMER_UNLOCK(it);
 1185         }
 1186         if (error == 0)
 1187                 error = copyout(&val, uap->value, sizeof(val));
 1188         return (error);
 1189 }
 1190 
 1191 #ifndef _SYS_SYSPROTO_H_
 1192 struct timer_getoverrun_args {
 1193         int timerid;
 1194 };
 1195 #endif
 1196 int
 1197 ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
 1198 {
 1199         struct proc *p = td->td_proc;
 1200         struct itimer *it;
 1201         int error ;
 1202 
 1203         PROC_LOCK(p);
 1204         if (uap->timerid < 3 ||
 1205             (it = itimer_find(p, uap->timerid)) == NULL) {
 1206                 PROC_UNLOCK(p);
 1207                 error = EINVAL;
 1208         } else {
 1209                 td->td_retval[0] = it->it_overrun_last;
 1210                 ITIMER_UNLOCK(it);
 1211                 PROC_UNLOCK(p);
 1212                 error = 0;
 1213         }
 1214         return (error);
 1215 }
 1216 
 1217 static int
 1218 realtimer_create(struct itimer *it)
 1219 {
 1220         callout_init_mtx(&it->it_callout, &it->it_mtx, 0);
 1221         return (0);
 1222 }
 1223 
 1224 static int
 1225 realtimer_delete(struct itimer *it)
 1226 {
 1227         mtx_assert(&it->it_mtx, MA_OWNED);
 1228         
 1229         ITIMER_UNLOCK(it);
 1230         callout_drain(&it->it_callout);
 1231         ITIMER_LOCK(it);
 1232         return (0);
 1233 }
 1234 
 1235 static int
 1236 realtimer_gettime(struct itimer *it, struct itimerspec *ovalue)
 1237 {
 1238         struct timespec cts;
 1239 
 1240         mtx_assert(&it->it_mtx, MA_OWNED);
 1241 
 1242         realtimer_clocktime(it->it_clockid, &cts);
 1243         *ovalue = it->it_time;
 1244         if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_nsec != 0) {
 1245                 timespecsub(&ovalue->it_value, &cts);
 1246                 if (ovalue->it_value.tv_sec < 0 ||
 1247                     (ovalue->it_value.tv_sec == 0 &&
 1248                      ovalue->it_value.tv_nsec == 0)) {
 1249                         ovalue->it_value.tv_sec  = 0;
 1250                         ovalue->it_value.tv_nsec = 1;
 1251                 }
 1252         }
 1253         return (0);
 1254 }
 1255 
 1256 static int
 1257 realtimer_settime(struct itimer *it, int flags,
 1258         struct itimerspec *value, struct itimerspec *ovalue)
 1259 {
 1260         struct timespec cts, ts;
 1261         struct timeval tv;
 1262         struct itimerspec val;
 1263 
 1264         mtx_assert(&it->it_mtx, MA_OWNED);
 1265 
 1266         val = *value;
 1267         if (itimespecfix(&val.it_value))
 1268                 return (EINVAL);
 1269 
 1270         if (timespecisset(&val.it_value)) {
 1271                 if (itimespecfix(&val.it_interval))
 1272                         return (EINVAL);
 1273         } else {
 1274                 timespecclear(&val.it_interval);
 1275         }
 1276         
 1277         if (ovalue != NULL)
 1278                 realtimer_gettime(it, ovalue);
 1279 
 1280         it->it_time = val;
 1281         if (timespecisset(&val.it_value)) {
 1282                 realtimer_clocktime(it->it_clockid, &cts);
 1283                 ts = val.it_value;
 1284                 if ((flags & TIMER_ABSTIME) == 0) {
 1285                         /* Convert to absolute time. */
 1286                         timespecadd(&it->it_time.it_value, &cts);
 1287                 } else {
 1288                         timespecsub(&ts, &cts);
 1289                         /*
 1290                          * We don't care if ts is negative, tztohz will
 1291                          * fix it.
 1292                          */
 1293                 }
 1294                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1295                 callout_reset(&it->it_callout, tvtohz(&tv),
 1296                         realtimer_expire, it);
 1297         } else {
 1298                 callout_stop(&it->it_callout);
 1299         }
 1300 
 1301         return (0);
 1302 }
 1303 
 1304 static void
 1305 realtimer_clocktime(clockid_t id, struct timespec *ts)
 1306 {
 1307         if (id == CLOCK_REALTIME)
 1308                 getnanotime(ts);
 1309         else    /* CLOCK_MONOTONIC */
 1310                 getnanouptime(ts);
 1311 }
 1312 
 1313 int
 1314 itimer_accept(struct proc *p, int timerid, ksiginfo_t *ksi)
 1315 {
 1316         struct itimer *it;
 1317 
 1318         PROC_LOCK_ASSERT(p, MA_OWNED);
 1319         it = itimer_find(p, timerid);
 1320         if (it != NULL) {
 1321                 ksi->ksi_overrun = it->it_overrun;
 1322                 it->it_overrun_last = it->it_overrun;
 1323                 it->it_overrun = 0;
 1324                 ITIMER_UNLOCK(it);
 1325                 return (0);
 1326         }
 1327         return (EINVAL);
 1328 }
 1329 
 1330 int
 1331 itimespecfix(struct timespec *ts)
 1332 {
 1333 
 1334         if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
 1335                 return (EINVAL);
 1336         if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000)
 1337                 ts->tv_nsec = tick * 1000;
 1338         return (0);
 1339 }
 1340 
 1341 /* Timeout callback for realtime timer */
 1342 static void
 1343 realtimer_expire(void *arg)
 1344 {
 1345         struct timespec cts, ts;
 1346         struct timeval tv;
 1347         struct itimer *it;
 1348         struct proc *p;
 1349 
 1350         it = (struct itimer *)arg;
 1351         p = it->it_proc;
 1352 
 1353         realtimer_clocktime(it->it_clockid, &cts);
 1354         /* Only fire if time is reached. */
 1355         if (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1356                 if (timespecisset(&it->it_time.it_interval)) {
 1357                         timespecadd(&it->it_time.it_value,
 1358                                     &it->it_time.it_interval);
 1359                         while (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1360                                 if (it->it_overrun < INT_MAX)
 1361                                         it->it_overrun++;
 1362                                 else
 1363                                         it->it_ksi.ksi_errno = ERANGE;
 1364                                 timespecadd(&it->it_time.it_value,
 1365                                             &it->it_time.it_interval);
 1366                         }
 1367                 } else {
 1368                         /* single shot timer ? */
 1369                         timespecclear(&it->it_time.it_value);
 1370                 }
 1371                 if (timespecisset(&it->it_time.it_value)) {
 1372                         ts = it->it_time.it_value;
 1373                         timespecsub(&ts, &cts);
 1374                         TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1375                         callout_reset(&it->it_callout, tvtohz(&tv),
 1376                                  realtimer_expire, it);
 1377                 }
 1378                 ITIMER_UNLOCK(it);
 1379                 itimer_fire(it);
 1380                 ITIMER_LOCK(it);
 1381         } else if (timespecisset(&it->it_time.it_value)) {
 1382                 ts = it->it_time.it_value;
 1383                 timespecsub(&ts, &cts);
 1384                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1385                 callout_reset(&it->it_callout, tvtohz(&tv), realtimer_expire,
 1386                         it);
 1387         }
 1388 }
 1389 
 1390 void
 1391 itimer_fire(struct itimer *it)
 1392 {
 1393         struct proc *p = it->it_proc;
 1394         int ret;
 1395 
 1396         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1397             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1398                 PROC_LOCK(p);
 1399                 if (!KSI_ONQ(&it->it_ksi)) {
 1400                         it->it_ksi.ksi_errno = 0;
 1401                         ret = psignal_event(p, &it->it_sigev, &it->it_ksi);
 1402                         if (__predict_false(ret != 0)) {
 1403                                 it->it_overrun++;
 1404                                 /*
 1405                                  * Broken userland code, thread went
 1406                                  * away, disarm the timer.
 1407                                  */
 1408                                 if (ret == ESRCH) {
 1409                                         ITIMER_LOCK(it);
 1410                                         timespecclear(&it->it_time.it_value);
 1411                                         timespecclear(&it->it_time.it_interval);
 1412                                         callout_stop(&it->it_callout);
 1413                                         ITIMER_UNLOCK(it);
 1414                                 }
 1415                         }
 1416                 } else {
 1417                         if (it->it_overrun < INT_MAX)
 1418                                 it->it_overrun++;
 1419                         else
 1420                                 it->it_ksi.ksi_errno = ERANGE;
 1421                 }
 1422                 PROC_UNLOCK(p);
 1423         }
 1424 }
 1425 
 1426 static void
 1427 itimers_alloc(struct proc *p)
 1428 {
 1429         struct itimers *its;
 1430         int i;
 1431 
 1432         its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
 1433         LIST_INIT(&its->its_virtual);
 1434         LIST_INIT(&its->its_prof);
 1435         TAILQ_INIT(&its->its_worklist);
 1436         for (i = 0; i < TIMER_MAX; i++)
 1437                 its->its_timers[i] = NULL;
 1438         PROC_LOCK(p);
 1439         if (p->p_itimers == NULL) {
 1440                 p->p_itimers = its;
 1441                 PROC_UNLOCK(p);
 1442         }
 1443         else {
 1444                 PROC_UNLOCK(p);
 1445                 free(its, M_SUBPROC);
 1446         }
 1447 }
 1448 
 1449 static void
 1450 itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
 1451 {
 1452         itimers_event_hook_exit(arg, p);
 1453 }
 1454 
 1455 /* Clean up timers when some process events are being triggered. */
 1456 static void
 1457 itimers_event_hook_exit(void *arg, struct proc *p)
 1458 {
 1459         struct itimers *its;
 1460         struct itimer *it;
 1461         int event = (int)(intptr_t)arg;
 1462         int i;
 1463 
 1464         if (p->p_itimers != NULL) {
 1465                 its = p->p_itimers;
 1466                 for (i = 0; i < MAX_CLOCKS; ++i) {
 1467                         if (posix_clocks[i].event_hook != NULL)
 1468                                 CLOCK_CALL(i, event_hook, (p, i, event));
 1469                 }
 1470                 /*
 1471                  * According to susv3, XSI interval timers should be inherited
 1472                  * by new image.
 1473                  */
 1474                 if (event == ITIMER_EV_EXEC)
 1475                         i = 3;
 1476                 else if (event == ITIMER_EV_EXIT)
 1477                         i = 0;
 1478                 else
 1479                         panic("unhandled event");
 1480                 for (; i < TIMER_MAX; ++i) {
 1481                         if ((it = its->its_timers[i]) != NULL)
 1482                                 kern_timer_delete(curthread, i);
 1483                 }
 1484                 if (its->its_timers[0] == NULL &&
 1485                     its->its_timers[1] == NULL &&
 1486                     its->its_timers[2] == NULL) {
 1487                         free(its, M_SUBPROC);
 1488                         p->p_itimers = NULL;
 1489                 }
 1490         }
 1491 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/kern_time.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_time.c
