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: releng/9.2/sys/kern/kern_time.c 244373 2012-12-18 04:18:42Z kib $");
   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 
   78 static void     itimer_start(void);
   79 static int      itimer_init(void *, int, int);
   80 static void     itimer_fini(void *, int);
   81 static void     itimer_enter(struct itimer *);
   82 static void     itimer_leave(struct itimer *);
   83 static struct itimer *itimer_find(struct proc *, int);
   84 static void     itimers_alloc(struct proc *);
   85 static void     itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp);
   86 static void     itimers_event_hook_exit(void *arg, struct proc *p);
   87 static int      realtimer_create(struct itimer *);
   88 static int      realtimer_gettime(struct itimer *, struct itimerspec *);
   89 static int      realtimer_settime(struct itimer *, int,
   90                         struct itimerspec *, struct itimerspec *);
   91 static int      realtimer_delete(struct itimer *);
   92 static void     realtimer_clocktime(clockid_t, struct timespec *);
   93 static void     realtimer_expire(void *);
   94 static int      kern_timer_create(struct thread *, clockid_t,
   95                         struct sigevent *, int *, int);
   96 static int      kern_timer_delete(struct thread *, int);
   97 
   98 int             register_posix_clock(int, struct kclock *);
   99 void            itimer_fire(struct itimer *it);
  100 int             itimespecfix(struct timespec *ts);
  101 
  102 #define CLOCK_CALL(clock, call, arglist)                \
  103         ((*posix_clocks[clock].call) arglist)
  104 
  105 SYSINIT(posix_timer, SI_SUB_P1003_1B, SI_ORDER_FIRST+4, itimer_start, NULL);
  106 
  107 
  108 static int
  109 settime(struct thread *td, struct timeval *tv)
  110 {
  111         struct timeval delta, tv1, tv2;
  112         static struct timeval maxtime, laststep;
  113         struct timespec ts;
  114         int s;
  115 
  116         s = splclock();
  117         microtime(&tv1);
  118         delta = *tv;
  119         timevalsub(&delta, &tv1);
  120 
  121         /*
  122          * If the system is secure, we do not allow the time to be 
  123          * set to a value earlier than 1 second less than the highest
  124          * time we have yet seen. The worst a miscreant can do in
  125          * this circumstance is "freeze" time. He couldn't go
  126          * back to the past.
  127          *
  128          * We similarly do not allow the clock to be stepped more
  129          * than one second, nor more than once per second. This allows
  130          * a miscreant to make the clock march double-time, but no worse.
  131          */
  132         if (securelevel_gt(td->td_ucred, 1) != 0) {
  133                 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
  134                         /*
  135                          * Update maxtime to latest time we've seen.
  136                          */
  137                         if (tv1.tv_sec > maxtime.tv_sec)
  138                                 maxtime = tv1;
  139                         tv2 = *tv;
  140                         timevalsub(&tv2, &maxtime);
  141                         if (tv2.tv_sec < -1) {
  142                                 tv->tv_sec = maxtime.tv_sec - 1;
  143                                 printf("Time adjustment clamped to -1 second\n");
  144                         }
  145                 } else {
  146                         if (tv1.tv_sec == laststep.tv_sec) {
  147                                 splx(s);
  148                                 return (EPERM);
  149                         }
  150                         if (delta.tv_sec > 1) {
  151                                 tv->tv_sec = tv1.tv_sec + 1;
  152                                 printf("Time adjustment clamped to +1 second\n");
  153                         }
  154                         laststep = *tv;
  155                 }
  156         }
  157 
  158         ts.tv_sec = tv->tv_sec;
  159         ts.tv_nsec = tv->tv_usec * 1000;
  160         mtx_lock(&Giant);
  161         tc_setclock(&ts);
  162         resettodr();
  163         mtx_unlock(&Giant);
  164         return (0);
  165 }
  166 
  167 #ifndef _SYS_SYSPROTO_H_
  168 struct clock_gettime_args {
  169         clockid_t clock_id;
  170         struct  timespec *tp;
  171 };
  172 #endif
  173 /* ARGSUSED */
  174 int
  175 sys_clock_gettime(struct thread *td, struct clock_gettime_args *uap)
  176 {
  177         struct timespec ats;
  178         int error;
  179 
  180         error = kern_clock_gettime(td, uap->clock_id, &ats);
  181         if (error == 0)
  182                 error = copyout(&ats, uap->tp, sizeof(ats));
  183 
  184         return (error);
  185 }
  186 
  187 int
  188 kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  189 {
  190         struct timeval sys, user;
  191         struct proc *p;
  192         uint64_t runtime, curtime, switchtime;
  193 
  194         p = td->td_proc;
  195         switch (clock_id) {
  196         case CLOCK_REALTIME:            /* Default to precise. */
  197         case CLOCK_REALTIME_PRECISE:
  198                 nanotime(ats);
  199                 break;
  200         case CLOCK_REALTIME_FAST:
  201                 getnanotime(ats);
  202                 break;
  203         case CLOCK_VIRTUAL:
  204                 PROC_LOCK(p);
  205                 PROC_SLOCK(p);
  206                 calcru(p, &user, &sys);
  207                 PROC_SUNLOCK(p);
  208                 PROC_UNLOCK(p);
  209                 TIMEVAL_TO_TIMESPEC(&user, ats);
  210                 break;
  211         case CLOCK_PROF:
  212                 PROC_LOCK(p);
  213                 PROC_SLOCK(p);
  214                 calcru(p, &user, &sys);
  215                 PROC_SUNLOCK(p);
  216                 PROC_UNLOCK(p);
  217                 timevaladd(&user, &sys);
  218                 TIMEVAL_TO_TIMESPEC(&user, ats);
  219                 break;
  220         case CLOCK_MONOTONIC:           /* Default to precise. */
  221         case CLOCK_MONOTONIC_PRECISE:
  222         case CLOCK_UPTIME:
  223         case CLOCK_UPTIME_PRECISE:
  224                 nanouptime(ats);
  225                 break;
  226         case CLOCK_UPTIME_FAST:
  227         case CLOCK_MONOTONIC_FAST:
  228                 getnanouptime(ats);
  229                 break;
  230         case CLOCK_SECOND:
  231                 ats->tv_sec = time_second;
  232                 ats->tv_nsec = 0;
  233                 break;
  234         case CLOCK_THREAD_CPUTIME_ID:
  235                 critical_enter();
  236                 switchtime = PCPU_GET(switchtime);
  237                 curtime = cpu_ticks();
  238                 runtime = td->td_runtime;
  239                 critical_exit();
  240                 runtime = cputick2usec(runtime + curtime - switchtime);
  241                 ats->tv_sec = runtime / 1000000;
  242                 ats->tv_nsec = runtime % 1000000 * 1000;
  243                 break;
  244         default:
  245                 return (EINVAL);
  246         }
  247         return (0);
  248 }
  249 
  250 #ifndef _SYS_SYSPROTO_H_
  251 struct clock_settime_args {
  252         clockid_t clock_id;
  253         const struct    timespec *tp;
  254 };
  255 #endif
  256 /* ARGSUSED */
  257 int
  258 sys_clock_settime(struct thread *td, struct clock_settime_args *uap)
  259 {
  260         struct timespec ats;
  261         int error;
  262 
  263         if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
  264                 return (error);
  265         return (kern_clock_settime(td, uap->clock_id, &ats));
  266 }
  267 
  268 int
  269 kern_clock_settime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  270 {
  271         struct timeval atv;
  272         int error;
  273 
  274         if ((error = priv_check(td, PRIV_CLOCK_SETTIME)) != 0)
  275                 return (error);
  276         if (clock_id != CLOCK_REALTIME)
  277                 return (EINVAL);
  278         if (ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000)
  279                 return (EINVAL);
  280         /* XXX Don't convert nsec->usec and back */
  281         TIMESPEC_TO_TIMEVAL(&atv, ats);
  282         error = settime(td, &atv);
  283         return (error);
  284 }
  285 
  286 #ifndef _SYS_SYSPROTO_H_
  287 struct clock_getres_args {
  288         clockid_t clock_id;
  289         struct  timespec *tp;
  290 };
  291 #endif
  292 int
  293 sys_clock_getres(struct thread *td, struct clock_getres_args *uap)
  294 {
  295         struct timespec ts;
  296         int error;
  297 
  298         if (uap->tp == NULL)
  299                 return (0);
  300 
  301         error = kern_clock_getres(td, uap->clock_id, &ts);
  302         if (error == 0)
  303                 error = copyout(&ts, uap->tp, sizeof(ts));
  304         return (error);
  305 }
  306 
  307 int
  308 kern_clock_getres(struct thread *td, clockid_t clock_id, struct timespec *ts)
  309 {
  310 
  311         ts->tv_sec = 0;
  312         switch (clock_id) {
  313         case CLOCK_REALTIME:
  314         case CLOCK_REALTIME_FAST:
  315         case CLOCK_REALTIME_PRECISE:
  316         case CLOCK_MONOTONIC:
  317         case CLOCK_MONOTONIC_FAST:
  318         case CLOCK_MONOTONIC_PRECISE:
  319         case CLOCK_UPTIME:
  320         case CLOCK_UPTIME_FAST:
  321         case CLOCK_UPTIME_PRECISE:
  322                 /*
  323                  * Round up the result of the division cheaply by adding 1.
  324                  * Rounding up is especially important if rounding down
  325                  * would give 0.  Perfect rounding is unimportant.
  326                  */
  327                 ts->tv_nsec = 1000000000 / tc_getfrequency() + 1;
  328                 break;
  329         case CLOCK_VIRTUAL:
  330         case CLOCK_PROF:
  331                 /* Accurately round up here because we can do so cheaply. */
  332                 ts->tv_nsec = (1000000000 + hz - 1) / hz;
  333                 break;
  334         case CLOCK_SECOND:
  335                 ts->tv_sec = 1;
  336                 ts->tv_nsec = 0;
  337                 break;
  338         case CLOCK_THREAD_CPUTIME_ID:
  339                 /* sync with cputick2usec */
  340                 ts->tv_nsec = 1000000 / cpu_tickrate();
  341                 if (ts->tv_nsec == 0)
  342                         ts->tv_nsec = 1000;
  343                 break;
  344         default:
  345                 return (EINVAL);
  346         }
  347         return (0);
  348 }
  349 
  350 static int nanowait;
  351 
  352 int
  353 kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
  354 {
  355         struct timespec ts, ts2, ts3;
  356         struct timeval tv;
  357         int error;
  358 
  359         if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
  360                 return (EINVAL);
  361         if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
  362                 return (0);
  363         getnanouptime(&ts);
  364         timespecadd(&ts, rqt);
  365         TIMESPEC_TO_TIMEVAL(&tv, rqt);
  366         for (;;) {
  367                 error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp",
  368                     tvtohz(&tv));
  369                 getnanouptime(&ts2);
  370                 if (error != EWOULDBLOCK) {
  371                         if (error == ERESTART)
  372                                 error = EINTR;
  373                         if (rmt != NULL) {
  374                                 timespecsub(&ts, &ts2);
  375                                 if (ts.tv_sec < 0)
  376                                         timespecclear(&ts);
  377                                 *rmt = ts;
  378                         }
  379                         return (error);
  380                 }
  381                 if (timespeccmp(&ts2, &ts, >=))
  382                         return (0);
  383                 ts3 = ts;
  384                 timespecsub(&ts3, &ts2);
  385                 TIMESPEC_TO_TIMEVAL(&tv, &ts3);
  386         }
  387 }
  388 
  389 #ifndef _SYS_SYSPROTO_H_
  390 struct nanosleep_args {
  391         struct  timespec *rqtp;
  392         struct  timespec *rmtp;
  393 };
  394 #endif
  395 /* ARGSUSED */
  396 int
  397 sys_nanosleep(struct thread *td, struct nanosleep_args *uap)
  398 {
  399         struct timespec rmt, rqt;
  400         int error;
  401 
  402         error = copyin(uap->rqtp, &rqt, sizeof(rqt));
  403         if (error)
  404                 return (error);
  405 
  406         if (uap->rmtp &&
  407             !useracc((caddr_t)uap->rmtp, sizeof(rmt), VM_PROT_WRITE))
  408                         return (EFAULT);
  409         error = kern_nanosleep(td, &rqt, &rmt);
  410         if (error && uap->rmtp) {
  411                 int error2;
  412 
  413                 error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
  414                 if (error2)
  415                         error = error2;
  416         }
  417         return (error);
  418 }
  419 
  420 #ifndef _SYS_SYSPROTO_H_
  421 struct gettimeofday_args {
  422         struct  timeval *tp;
  423         struct  timezone *tzp;
  424 };
  425 #endif
  426 /* ARGSUSED */
  427 int
  428 sys_gettimeofday(struct thread *td, struct gettimeofday_args *uap)
  429 {
  430         struct timeval atv;
  431         struct timezone rtz;
  432         int error = 0;
  433 
  434         if (uap->tp) {
  435                 microtime(&atv);
  436                 error = copyout(&atv, uap->tp, sizeof (atv));
  437         }
  438         if (error == 0 && uap->tzp != NULL) {
  439                 rtz.tz_minuteswest = tz_minuteswest;
  440                 rtz.tz_dsttime = tz_dsttime;
  441                 error = copyout(&rtz, uap->tzp, sizeof (rtz));
  442         }
  443         return (error);
  444 }
  445 
  446 #ifndef _SYS_SYSPROTO_H_
  447 struct settimeofday_args {
  448         struct  timeval *tv;
  449         struct  timezone *tzp;
  450 };
  451 #endif
  452 /* ARGSUSED */
  453 int
  454 sys_settimeofday(struct thread *td, struct settimeofday_args *uap)
  455 {
  456         struct timeval atv, *tvp;
  457         struct timezone atz, *tzp;
  458         int error;
  459 
  460         if (uap->tv) {
  461                 error = copyin(uap->tv, &atv, sizeof(atv));
  462                 if (error)
  463                         return (error);
  464                 tvp = &atv;
  465         } else
  466                 tvp = NULL;
  467         if (uap->tzp) {
  468                 error = copyin(uap->tzp, &atz, sizeof(atz));
  469                 if (error)
  470                         return (error);
  471                 tzp = &atz;
  472         } else
  473                 tzp = NULL;
  474         return (kern_settimeofday(td, tvp, tzp));
  475 }
  476 
  477 int
  478 kern_settimeofday(struct thread *td, struct timeval *tv, struct timezone *tzp)
  479 {
  480         int error;
  481 
  482         error = priv_check(td, PRIV_SETTIMEOFDAY);
  483         if (error)
  484                 return (error);
  485         /* Verify all parameters before changing time. */
  486         if (tv) {
  487                 if (tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  488                         return (EINVAL);
  489                 error = settime(td, tv);
  490         }
  491         if (tzp && error == 0) {
  492                 tz_minuteswest = tzp->tz_minuteswest;
  493                 tz_dsttime = tzp->tz_dsttime;
  494         }
  495         return (error);
  496 }
  497 
  498 /*
  499  * Get value of an interval timer.  The process virtual and profiling virtual
  500  * time timers are kept in the p_stats area, since they can be swapped out.
  501  * These are kept internally in the way they are specified externally: in
  502  * time until they expire.
  503  *
  504  * The real time interval timer is kept in the process table slot for the
  505  * process, and its value (it_value) is kept as an absolute time rather than
  506  * as a delta, so that it is easy to keep periodic real-time signals from
  507  * drifting.
  508  *
  509  * Virtual time timers are processed in the hardclock() routine of
  510  * kern_clock.c.  The real time timer is processed by a timeout routine,
  511  * called from the softclock() routine.  Since a callout may be delayed in
  512  * real time due to interrupt processing in the system, it is possible for
  513  * the real time timeout routine (realitexpire, given below), to be delayed
  514  * in real time past when it is supposed to occur.  It does not suffice,
  515  * therefore, to reload the real timer .it_value from the real time timers
  516  * .it_interval.  Rather, we compute the next time in absolute time the timer
  517  * should go off.
  518  */
  519 #ifndef _SYS_SYSPROTO_H_
  520 struct getitimer_args {
  521         u_int   which;
  522         struct  itimerval *itv;
  523 };
  524 #endif
  525 int
  526 sys_getitimer(struct thread *td, struct getitimer_args *uap)
  527 {
  528         struct itimerval aitv;
  529         int error;
  530 
  531         error = kern_getitimer(td, uap->which, &aitv);
  532         if (error != 0)
  533                 return (error);
  534         return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
  535 }
  536 
  537 int
  538 kern_getitimer(struct thread *td, u_int which, struct itimerval *aitv)
  539 {
  540         struct proc *p = td->td_proc;
  541         struct timeval ctv;
  542 
  543         if (which > ITIMER_PROF)
  544                 return (EINVAL);
  545 
  546         if (which == ITIMER_REAL) {
  547                 /*
  548                  * Convert from absolute to relative time in .it_value
  549                  * part of real time timer.  If time for real time timer
  550                  * has passed return 0, else return difference between
  551                  * current time and time for the timer to go off.
  552                  */
  553                 PROC_LOCK(p);
  554                 *aitv = p->p_realtimer;
  555                 PROC_UNLOCK(p);
  556                 if (timevalisset(&aitv->it_value)) {
  557                         getmicrouptime(&ctv);
  558                         if (timevalcmp(&aitv->it_value, &ctv, <))
  559                                 timevalclear(&aitv->it_value);
  560                         else
  561                                 timevalsub(&aitv->it_value, &ctv);
  562                 }
  563         } else {
  564                 PROC_SLOCK(p);
  565                 *aitv = p->p_stats->p_timer[which];
  566                 PROC_SUNLOCK(p);
  567         }
  568         return (0);
  569 }
  570 
  571 #ifndef _SYS_SYSPROTO_H_
  572 struct setitimer_args {
  573         u_int   which;
  574         struct  itimerval *itv, *oitv;
  575 };
  576 #endif
  577 int
  578 sys_setitimer(struct thread *td, struct setitimer_args *uap)
  579 {
  580         struct itimerval aitv, oitv;
  581         int error;
  582 
  583         if (uap->itv == NULL) {
  584                 uap->itv = uap->oitv;
  585                 return (sys_getitimer(td, (struct getitimer_args *)uap));
  586         }
  587 
  588         if ((error = copyin(uap->itv, &aitv, sizeof(struct itimerval))))
  589                 return (error);
  590         error = kern_setitimer(td, uap->which, &aitv, &oitv);
  591         if (error != 0 || uap->oitv == NULL)
  592                 return (error);
  593         return (copyout(&oitv, uap->oitv, sizeof(struct itimerval)));
  594 }
  595 
  596 int
  597 kern_setitimer(struct thread *td, u_int which, struct itimerval *aitv,
  598     struct itimerval *oitv)
  599 {
  600         struct proc *p = td->td_proc;
  601         struct timeval ctv;
  602 
  603         if (aitv == NULL)
  604                 return (kern_getitimer(td, which, oitv));
  605 
  606         if (which > ITIMER_PROF)
  607                 return (EINVAL);
  608         if (itimerfix(&aitv->it_value))
  609                 return (EINVAL);
  610         if (!timevalisset(&aitv->it_value))
  611                 timevalclear(&aitv->it_interval);
  612         else if (itimerfix(&aitv->it_interval))
  613                 return (EINVAL);
  614 
  615         if (which == ITIMER_REAL) {
  616                 PROC_LOCK(p);
  617                 if (timevalisset(&p->p_realtimer.it_value))
  618                         callout_stop(&p->p_itcallout);
  619                 getmicrouptime(&ctv);
  620                 if (timevalisset(&aitv->it_value)) {
  621                         callout_reset(&p->p_itcallout, tvtohz(&aitv->it_value),
  622                             realitexpire, p);
  623                         timevaladd(&aitv->it_value, &ctv);
  624                 }
  625                 *oitv = p->p_realtimer;
  626                 p->p_realtimer = *aitv;
  627                 PROC_UNLOCK(p);
  628                 if (timevalisset(&oitv->it_value)) {
  629                         if (timevalcmp(&oitv->it_value, &ctv, <))
  630                                 timevalclear(&oitv->it_value);
  631                         else
  632                                 timevalsub(&oitv->it_value, &ctv);
  633                 }
  634         } else {
  635                 PROC_SLOCK(p);
  636                 *oitv = p->p_stats->p_timer[which];
  637                 p->p_stats->p_timer[which] = *aitv;
  638                 PROC_SUNLOCK(p);
  639         }
  640         return (0);
  641 }
  642 
  643 /*
  644  * Real interval timer expired:
  645  * send process whose timer expired an alarm signal.
  646  * If time is not set up to reload, then just return.
  647  * Else compute next time timer should go off which is > current time.
  648  * This is where delay in processing this timeout causes multiple
  649  * SIGALRM calls to be compressed into one.
  650  * tvtohz() always adds 1 to allow for the time until the next clock
  651  * interrupt being strictly less than 1 clock tick, but we don't want
  652  * that here since we want to appear to be in sync with the clock
  653  * interrupt even when we're delayed.
  654  */
  655 void
  656 realitexpire(void *arg)
  657 {
  658         struct proc *p;
  659         struct timeval ctv, ntv;
  660 
  661         p = (struct proc *)arg;
  662         kern_psignal(p, SIGALRM);
  663         if (!timevalisset(&p->p_realtimer.it_interval)) {
  664                 timevalclear(&p->p_realtimer.it_value);
  665                 if (p->p_flag & P_WEXIT)
  666                         wakeup(&p->p_itcallout);
  667                 return;
  668         }
  669         for (;;) {
  670                 timevaladd(&p->p_realtimer.it_value,
  671                     &p->p_realtimer.it_interval);
  672                 getmicrouptime(&ctv);
  673                 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
  674                         ntv = p->p_realtimer.it_value;
  675                         timevalsub(&ntv, &ctv);
  676                         callout_reset(&p->p_itcallout, tvtohz(&ntv) - 1,
  677                             realitexpire, p);
  678                         return;
  679                 }
  680         }
  681         /*NOTREACHED*/
  682 }
  683 
  684 /*
  685  * Check that a proposed value to load into the .it_value or
  686  * .it_interval part of an interval timer is acceptable, and
  687  * fix it to have at least minimal value (i.e. if it is less
  688  * than the resolution of the clock, round it up.)
  689  */
  690 int
  691 itimerfix(struct timeval *tv)
  692 {
  693 
  694         if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  695                 return (EINVAL);
  696         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
  697                 tv->tv_usec = tick;
  698         return (0);
  699 }
  700 
  701 /*
  702  * Decrement an interval timer by a specified number
  703  * of microseconds, which must be less than a second,
  704  * i.e. < 1000000.  If the timer expires, then reload
  705  * it.  In this case, carry over (usec - old value) to
  706  * reduce the value reloaded into the timer so that
  707  * the timer does not drift.  This routine assumes
  708  * that it is called in a context where the timers
  709  * on which it is operating cannot change in value.
  710  */
  711 int
  712 itimerdecr(struct itimerval *itp, int usec)
  713 {
  714 
  715         if (itp->it_value.tv_usec < usec) {
  716                 if (itp->it_value.tv_sec == 0) {
  717                         /* expired, and already in next interval */
  718                         usec -= itp->it_value.tv_usec;
  719                         goto expire;
  720                 }
  721                 itp->it_value.tv_usec += 1000000;
  722                 itp->it_value.tv_sec--;
  723         }
  724         itp->it_value.tv_usec -= usec;
  725         usec = 0;
  726         if (timevalisset(&itp->it_value))
  727                 return (1);
  728         /* expired, exactly at end of interval */
  729 expire:
  730         if (timevalisset(&itp->it_interval)) {
  731                 itp->it_value = itp->it_interval;
  732                 itp->it_value.tv_usec -= usec;
  733                 if (itp->it_value.tv_usec < 0) {
  734                         itp->it_value.tv_usec += 1000000;
  735                         itp->it_value.tv_sec--;
  736                 }
  737         } else
  738                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
  739         return (0);
  740 }
  741 
  742 /*
  743  * Add and subtract routines for timevals.
  744  * N.B.: subtract routine doesn't deal with
  745  * results which are before the beginning,
  746  * it just gets very confused in this case.
  747  * Caveat emptor.
  748  */
  749 void
  750 timevaladd(struct timeval *t1, const struct timeval *t2)
  751 {
  752 
  753         t1->tv_sec += t2->tv_sec;
  754         t1->tv_usec += t2->tv_usec;
  755         timevalfix(t1);
  756 }
  757 
  758 void
  759 timevalsub(struct timeval *t1, const struct timeval *t2)
  760 {
  761 
  762         t1->tv_sec -= t2->tv_sec;
  763         t1->tv_usec -= t2->tv_usec;
  764         timevalfix(t1);
  765 }
  766 
  767 static void
  768 timevalfix(struct timeval *t1)
  769 {
  770 
  771         if (t1->tv_usec < 0) {
  772                 t1->tv_sec--;
  773                 t1->tv_usec += 1000000;
  774         }
  775         if (t1->tv_usec >= 1000000) {
  776                 t1->tv_sec++;
  777                 t1->tv_usec -= 1000000;
  778         }
  779 }
  780 
  781 /*
  782  * ratecheck(): simple time-based rate-limit checking.
  783  */
  784 int
  785 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
  786 {
  787         struct timeval tv, delta;
  788         int rv = 0;
  789 
  790         getmicrouptime(&tv);            /* NB: 10ms precision */
  791         delta = tv;
  792         timevalsub(&delta, lasttime);
  793 
  794         /*
  795          * check for 0,0 is so that the message will be seen at least once,
  796          * even if interval is huge.
  797          */
  798         if (timevalcmp(&delta, mininterval, >=) ||
  799             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
  800                 *lasttime = tv;
  801                 rv = 1;
  802         }
  803 
  804         return (rv);
  805 }
  806 
  807 /*
  808  * ppsratecheck(): packets (or events) per second limitation.
  809  *
  810  * Return 0 if the limit is to be enforced (e.g. the caller
  811  * should drop a packet because of the rate limitation).
  812  *
  813  * maxpps of 0 always causes zero to be returned.  maxpps of -1
  814  * always causes 1 to be returned; this effectively defeats rate
  815  * limiting.
  816  *
  817  * Note that we maintain the struct timeval for compatibility
  818  * with other bsd systems.  We reuse the storage and just monitor
  819  * clock ticks for minimal overhead.  
  820  */
  821 int
  822 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
  823 {
  824         int now;
  825 
  826         /*
  827          * Reset the last time and counter if this is the first call
  828          * or more than a second has passed since the last update of
  829          * lasttime.
  830          */
  831         now = ticks;
  832         if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
  833                 lasttime->tv_sec = now;
  834                 *curpps = 1;
  835                 return (maxpps != 0);
  836         } else {
  837                 (*curpps)++;            /* NB: ignore potential overflow */
  838                 return (maxpps < 0 || *curpps < maxpps);
  839         }
  840 }
  841 
  842 static void
  843 itimer_start(void)
  844 {
  845         struct kclock rt_clock = {
  846                 .timer_create  = realtimer_create,
  847                 .timer_delete  = realtimer_delete,
  848                 .timer_settime = realtimer_settime,
  849                 .timer_gettime = realtimer_gettime,
  850                 .event_hook    = NULL
  851         };
  852 
  853         itimer_zone = uma_zcreate("itimer", sizeof(struct itimer),
  854                 NULL, NULL, itimer_init, itimer_fini, UMA_ALIGN_PTR, 0);
  855         register_posix_clock(CLOCK_REALTIME,  &rt_clock);
  856         register_posix_clock(CLOCK_MONOTONIC, &rt_clock);
  857         p31b_setcfg(CTL_P1003_1B_TIMERS, 200112L);
  858         p31b_setcfg(CTL_P1003_1B_DELAYTIMER_MAX, INT_MAX);
  859         p31b_setcfg(CTL_P1003_1B_TIMER_MAX, TIMER_MAX);
  860         EVENTHANDLER_REGISTER(process_exit, itimers_event_hook_exit,
  861                 (void *)ITIMER_EV_EXIT, EVENTHANDLER_PRI_ANY);
  862         EVENTHANDLER_REGISTER(process_exec, itimers_event_hook_exec,
  863                 (void *)ITIMER_EV_EXEC, EVENTHANDLER_PRI_ANY);
  864 }
  865 
  866 int
  867 register_posix_clock(int clockid, struct kclock *clk)
  868 {
  869         if ((unsigned)clockid >= MAX_CLOCKS) {
  870                 printf("%s: invalid clockid\n", __func__);
  871                 return (0);
  872         }
  873         posix_clocks[clockid] = *clk;
  874         return (1);
  875 }
  876 
  877 static int
  878 itimer_init(void *mem, int size, int flags)
  879 {
  880         struct itimer *it;
  881 
  882         it = (struct itimer *)mem;
  883         mtx_init(&it->it_mtx, "itimer lock", NULL, MTX_DEF);
  884         return (0);
  885 }
  886 
  887 static void
  888 itimer_fini(void *mem, int size)
  889 {
  890         struct itimer *it;
  891 
  892         it = (struct itimer *)mem;
  893         mtx_destroy(&it->it_mtx);
  894 }
  895 
  896 static void
  897 itimer_enter(struct itimer *it)
  898 {
  899 
  900         mtx_assert(&it->it_mtx, MA_OWNED);
  901         it->it_usecount++;
  902 }
  903 
  904 static void
  905 itimer_leave(struct itimer *it)
  906 {
  907 
  908         mtx_assert(&it->it_mtx, MA_OWNED);
  909         KASSERT(it->it_usecount > 0, ("invalid it_usecount"));
  910 
  911         if (--it->it_usecount == 0 && (it->it_flags & ITF_WANTED) != 0)
  912                 wakeup(it);
  913 }
  914 
  915 #ifndef _SYS_SYSPROTO_H_
  916 struct ktimer_create_args {
  917         clockid_t clock_id;
  918         struct sigevent * evp;
  919         int * timerid;
  920 };
  921 #endif
  922 int
  923 sys_ktimer_create(struct thread *td, struct ktimer_create_args *uap)
  924 {
  925         struct sigevent *evp1, ev;
  926         int id;
  927         int error;
  928 
  929         if (uap->evp != NULL) {
  930                 error = copyin(uap->evp, &ev, sizeof(ev));
  931                 if (error != 0)
  932                         return (error);
  933                 evp1 = &ev;
  934         } else
  935                 evp1 = NULL;
  936 
  937         error = kern_timer_create(td, uap->clock_id, evp1, &id, -1);
  938 
  939         if (error == 0) {
  940                 error = copyout(&id, uap->timerid, sizeof(int));
  941                 if (error != 0)
  942                         kern_timer_delete(td, id);
  943         }
  944         return (error);
  945 }
  946 
  947 static int
  948 kern_timer_create(struct thread *td, clockid_t clock_id,
  949         struct sigevent *evp, int *timerid, int preset_id)
  950 {
  951         struct proc *p = td->td_proc;
  952         struct itimer *it;
  953         int id;
  954         int error;
  955 
  956         if (clock_id < 0 || clock_id >= MAX_CLOCKS)
  957                 return (EINVAL);
  958 
  959         if (posix_clocks[clock_id].timer_create == NULL)
  960                 return (EINVAL);
  961 
  962         if (evp != NULL) {
  963                 if (evp->sigev_notify != SIGEV_NONE &&
  964                     evp->sigev_notify != SIGEV_SIGNAL &&
  965                     evp->sigev_notify != SIGEV_THREAD_ID)
  966                         return (EINVAL);
  967                 if ((evp->sigev_notify == SIGEV_SIGNAL ||
  968                      evp->sigev_notify == SIGEV_THREAD_ID) &&
  969                         !_SIG_VALID(evp->sigev_signo))
  970                         return (EINVAL);
  971         }
  972         
  973         if (p->p_itimers == NULL)
  974                 itimers_alloc(p);
  975         
  976         it = uma_zalloc(itimer_zone, M_WAITOK);
  977         it->it_flags = 0;
  978         it->it_usecount = 0;
  979         it->it_active = 0;
  980         timespecclear(&it->it_time.it_value);
  981         timespecclear(&it->it_time.it_interval);
  982         it->it_overrun = 0;
  983         it->it_overrun_last = 0;
  984         it->it_clockid = clock_id;
  985         it->it_timerid = -1;
  986         it->it_proc = p;
  987         ksiginfo_init(&it->it_ksi);
  988         it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
  989         error = CLOCK_CALL(clock_id, timer_create, (it));
  990         if (error != 0)
  991                 goto out;
  992 
  993         PROC_LOCK(p);
  994         if (preset_id != -1) {
  995                 KASSERT(preset_id >= 0 && preset_id < 3, ("invalid preset_id"));
  996                 id = preset_id;
  997                 if (p->p_itimers->its_timers[id] != NULL) {
  998                         PROC_UNLOCK(p);
  999                         error = 0;
 1000                         goto out;
 1001                 }
 1002         } else {
 1003                 /*
 1004                  * Find a free timer slot, skipping those reserved
 1005                  * for setitimer().
 1006                  */
 1007                 for (id = 3; id < TIMER_MAX; id++)
 1008                         if (p->p_itimers->its_timers[id] == NULL)
 1009                                 break;
 1010                 if (id == TIMER_MAX) {
 1011                         PROC_UNLOCK(p);
 1012                         error = EAGAIN;
 1013                         goto out;
 1014                 }
 1015         }
 1016         it->it_timerid = id;
 1017         p->p_itimers->its_timers[id] = it;
 1018         if (evp != NULL)
 1019                 it->it_sigev = *evp;
 1020         else {
 1021                 it->it_sigev.sigev_notify = SIGEV_SIGNAL;
 1022                 switch (clock_id) {
 1023                 default:
 1024                 case CLOCK_REALTIME:
 1025                         it->it_sigev.sigev_signo = SIGALRM;
 1026                         break;
 1027                 case CLOCK_VIRTUAL:
 1028                         it->it_sigev.sigev_signo = SIGVTALRM;
 1029                         break;
 1030                 case CLOCK_PROF:
 1031                         it->it_sigev.sigev_signo = SIGPROF;
 1032                         break;
 1033                 }
 1034                 it->it_sigev.sigev_value.sival_int = id;
 1035         }
 1036 
 1037         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1038             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1039                 it->it_ksi.ksi_signo = it->it_sigev.sigev_signo;
 1040                 it->it_ksi.ksi_code = SI_TIMER;
 1041                 it->it_ksi.ksi_value = it->it_sigev.sigev_value;
 1042                 it->it_ksi.ksi_timerid = id;
 1043         }
 1044         PROC_UNLOCK(p);
 1045         *timerid = id;
 1046         return (0);
 1047 
 1048 out:
 1049         ITIMER_LOCK(it);
 1050         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1051         ITIMER_UNLOCK(it);
 1052         uma_zfree(itimer_zone, it);
 1053         return (error);
 1054 }
 1055 
 1056 #ifndef _SYS_SYSPROTO_H_
 1057 struct ktimer_delete_args {
 1058         int timerid;
 1059 };
 1060 #endif
 1061 int
 1062 sys_ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
 1063 {
 1064         return (kern_timer_delete(td, uap->timerid));
 1065 }
 1066 
 1067 static struct itimer *
 1068 itimer_find(struct proc *p, int timerid)
 1069 {
 1070         struct itimer *it;
 1071 
 1072         PROC_LOCK_ASSERT(p, MA_OWNED);
 1073         if ((p->p_itimers == NULL) ||
 1074             (timerid < 0) || (timerid >= TIMER_MAX) ||
 1075             (it = p->p_itimers->its_timers[timerid]) == NULL) {
 1076                 return (NULL);
 1077         }
 1078         ITIMER_LOCK(it);
 1079         if ((it->it_flags & ITF_DELETING) != 0) {
 1080                 ITIMER_UNLOCK(it);
 1081                 it = NULL;
 1082         }
 1083         return (it);
 1084 }
 1085 
 1086 static int
 1087 kern_timer_delete(struct thread *td, int timerid)
 1088 {
 1089         struct proc *p = td->td_proc;
 1090         struct itimer *it;
 1091 
 1092         PROC_LOCK(p);
 1093         it = itimer_find(p, timerid);
 1094         if (it == NULL) {
 1095                 PROC_UNLOCK(p);
 1096                 return (EINVAL);
 1097         }
 1098         PROC_UNLOCK(p);
 1099 
 1100         it->it_flags |= ITF_DELETING;
 1101         while (it->it_usecount > 0) {
 1102                 it->it_flags |= ITF_WANTED;
 1103                 msleep(it, &it->it_mtx, PPAUSE, "itimer", 0);
 1104         }
 1105         it->it_flags &= ~ITF_WANTED;
 1106         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1107         ITIMER_UNLOCK(it);
 1108 
 1109         PROC_LOCK(p);
 1110         if (KSI_ONQ(&it->it_ksi))
 1111                 sigqueue_take(&it->it_ksi);
 1112         p->p_itimers->its_timers[timerid] = NULL;
 1113         PROC_UNLOCK(p);
 1114         uma_zfree(itimer_zone, it);
 1115         return (0);
 1116 }
 1117 
 1118 #ifndef _SYS_SYSPROTO_H_
 1119 struct ktimer_settime_args {
 1120         int timerid;
 1121         int flags;
 1122         const struct itimerspec * value;
 1123         struct itimerspec * ovalue;
 1124 };
 1125 #endif
 1126 int
 1127 sys_ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
 1128 {
 1129         struct proc *p = td->td_proc;
 1130         struct itimer *it;
 1131         struct itimerspec val, oval, *ovalp;
 1132         int error;
 1133 
 1134         error = copyin(uap->value, &val, sizeof(val));
 1135         if (error != 0)
 1136                 return (error);
 1137         
 1138         if (uap->ovalue != NULL)
 1139                 ovalp = &oval;
 1140         else
 1141                 ovalp = NULL;
 1142 
 1143         PROC_LOCK(p);
 1144         if (uap->timerid < 3 ||
 1145             (it = itimer_find(p, uap->timerid)) == NULL) {
 1146                 PROC_UNLOCK(p);
 1147                 error = EINVAL;
 1148         } else {
 1149                 PROC_UNLOCK(p);
 1150                 itimer_enter(it);
 1151                 error = CLOCK_CALL(it->it_clockid, timer_settime,
 1152                                 (it, uap->flags, &val, ovalp));
 1153                 itimer_leave(it);
 1154                 ITIMER_UNLOCK(it);
 1155         }
 1156         if (error == 0 && uap->ovalue != NULL)
 1157                 error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
 1158         return (error);
 1159 }
 1160 
 1161 #ifndef _SYS_SYSPROTO_H_
 1162 struct ktimer_gettime_args {
 1163         int timerid;
 1164         struct itimerspec * value;
 1165 };
 1166 #endif
 1167 int
 1168 sys_ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
 1169 {
 1170         struct proc *p = td->td_proc;
 1171         struct itimer *it;
 1172         struct itimerspec val;
 1173         int error;
 1174 
 1175         PROC_LOCK(p);
 1176         if (uap->timerid < 3 ||
 1177            (it = itimer_find(p, uap->timerid)) == NULL) {
 1178                 PROC_UNLOCK(p);
 1179                 error = EINVAL;
 1180         } else {
 1181                 PROC_UNLOCK(p);
 1182                 itimer_enter(it);
 1183                 error = CLOCK_CALL(it->it_clockid, timer_gettime,
 1184                                 (it, &val));
 1185                 itimer_leave(it);
 1186                 ITIMER_UNLOCK(it);
 1187         }
 1188         if (error == 0)
 1189                 error = copyout(&val, uap->value, sizeof(val));
 1190         return (error);
 1191 }
 1192 
 1193 #ifndef _SYS_SYSPROTO_H_
 1194 struct timer_getoverrun_args {
 1195         int timerid;
 1196 };
 1197 #endif
 1198 int
 1199 sys_ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
 1200 {
 1201         struct proc *p = td->td_proc;
 1202         struct itimer *it;
 1203         int error ;
 1204 
 1205         PROC_LOCK(p);
 1206         if (uap->timerid < 3 ||
 1207             (it = itimer_find(p, uap->timerid)) == NULL) {
 1208                 PROC_UNLOCK(p);
 1209                 error = EINVAL;
 1210         } else {
 1211                 td->td_retval[0] = it->it_overrun_last;
 1212                 ITIMER_UNLOCK(it);
 1213                 PROC_UNLOCK(p);
 1214                 error = 0;
 1215         }
 1216         return (error);
 1217 }
 1218 
 1219 static int
 1220 realtimer_create(struct itimer *it)
 1221 {
 1222         callout_init_mtx(&it->it_callout, &it->it_mtx, 0);
 1223         return (0);
 1224 }
 1225 
 1226 static int
 1227 realtimer_delete(struct itimer *it)
 1228 {
 1229         mtx_assert(&it->it_mtx, MA_OWNED);
 1230         
 1231         /*
 1232          * clear timer's value and interval to tell realtimer_expire
 1233          * to not rearm the timer.
 1234          */
 1235         timespecclear(&it->it_time.it_value);
 1236         timespecclear(&it->it_time.it_interval);
 1237         ITIMER_UNLOCK(it);
 1238         callout_drain(&it->it_callout);
 1239         ITIMER_LOCK(it);
 1240         return (0);
 1241 }
 1242 
 1243 static int
 1244 realtimer_gettime(struct itimer *it, struct itimerspec *ovalue)
 1245 {
 1246         struct timespec cts;
 1247 
 1248         mtx_assert(&it->it_mtx, MA_OWNED);
 1249 
 1250         realtimer_clocktime(it->it_clockid, &cts);
 1251         *ovalue = it->it_time;
 1252         if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_nsec != 0) {
 1253                 timespecsub(&ovalue->it_value, &cts);
 1254                 if (ovalue->it_value.tv_sec < 0 ||
 1255                     (ovalue->it_value.tv_sec == 0 &&
 1256                      ovalue->it_value.tv_nsec == 0)) {
 1257                         ovalue->it_value.tv_sec  = 0;
 1258                         ovalue->it_value.tv_nsec = 1;
 1259                 }
 1260         }
 1261         return (0);
 1262 }
 1263 
 1264 static int
 1265 realtimer_settime(struct itimer *it, int flags,
 1266         struct itimerspec *value, struct itimerspec *ovalue)
 1267 {
 1268         struct timespec cts, ts;
 1269         struct timeval tv;
 1270         struct itimerspec val;
 1271 
 1272         mtx_assert(&it->it_mtx, MA_OWNED);
 1273 
 1274         val = *value;
 1275         if (itimespecfix(&val.it_value))
 1276                 return (EINVAL);
 1277 
 1278         if (timespecisset(&val.it_value)) {
 1279                 if (itimespecfix(&val.it_interval))
 1280                         return (EINVAL);
 1281         } else {
 1282                 timespecclear(&val.it_interval);
 1283         }
 1284         
 1285         if (ovalue != NULL)
 1286                 realtimer_gettime(it, ovalue);
 1287 
 1288         it->it_time = val;
 1289         if (timespecisset(&val.it_value)) {
 1290                 realtimer_clocktime(it->it_clockid, &cts);
 1291                 ts = val.it_value;
 1292                 if ((flags & TIMER_ABSTIME) == 0) {
 1293                         /* Convert to absolute time. */
 1294                         timespecadd(&it->it_time.it_value, &cts);
 1295                 } else {
 1296                         timespecsub(&ts, &cts);
 1297                         /*
 1298                          * We don't care if ts is negative, tztohz will
 1299                          * fix it.
 1300                          */
 1301                 }
 1302                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1303                 callout_reset(&it->it_callout, tvtohz(&tv),
 1304                         realtimer_expire, it);
 1305         } else {
 1306                 callout_stop(&it->it_callout);
 1307         }
 1308 
 1309         return (0);
 1310 }
 1311 
 1312 static void
 1313 realtimer_clocktime(clockid_t id, struct timespec *ts)
 1314 {
 1315         if (id == CLOCK_REALTIME)
 1316                 getnanotime(ts);
 1317         else    /* CLOCK_MONOTONIC */
 1318                 getnanouptime(ts);
 1319 }
 1320 
 1321 int
 1322 itimer_accept(struct proc *p, int timerid, ksiginfo_t *ksi)
 1323 {
 1324         struct itimer *it;
 1325 
 1326         PROC_LOCK_ASSERT(p, MA_OWNED);
 1327         it = itimer_find(p, timerid);
 1328         if (it != NULL) {
 1329                 ksi->ksi_overrun = it->it_overrun;
 1330                 it->it_overrun_last = it->it_overrun;
 1331                 it->it_overrun = 0;
 1332                 ITIMER_UNLOCK(it);
 1333                 return (0);
 1334         }
 1335         return (EINVAL);
 1336 }
 1337 
 1338 int
 1339 itimespecfix(struct timespec *ts)
 1340 {
 1341 
 1342         if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
 1343                 return (EINVAL);
 1344         if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000)
 1345                 ts->tv_nsec = tick * 1000;
 1346         return (0);
 1347 }
 1348 
 1349 /* Timeout callback for realtime timer */
 1350 static void
 1351 realtimer_expire(void *arg)
 1352 {
 1353         struct timespec cts, ts;
 1354         struct timeval tv;
 1355         struct itimer *it;
 1356 
 1357         it = (struct itimer *)arg;
 1358 
 1359         realtimer_clocktime(it->it_clockid, &cts);
 1360         /* Only fire if time is reached. */
 1361         if (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1362                 if (timespecisset(&it->it_time.it_interval)) {
 1363                         timespecadd(&it->it_time.it_value,
 1364                                     &it->it_time.it_interval);
 1365                         while (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1366                                 if (it->it_overrun < INT_MAX)
 1367                                         it->it_overrun++;
 1368                                 else
 1369                                         it->it_ksi.ksi_errno = ERANGE;
 1370                                 timespecadd(&it->it_time.it_value,
 1371                                             &it->it_time.it_interval);
 1372                         }
 1373                 } else {
 1374                         /* single shot timer ? */
 1375                         timespecclear(&it->it_time.it_value);
 1376                 }
 1377                 if (timespecisset(&it->it_time.it_value)) {
 1378                         ts = it->it_time.it_value;
 1379                         timespecsub(&ts, &cts);
 1380                         TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1381                         callout_reset(&it->it_callout, tvtohz(&tv),
 1382                                  realtimer_expire, it);
 1383                 }
 1384                 itimer_enter(it);
 1385                 ITIMER_UNLOCK(it);
 1386                 itimer_fire(it);
 1387                 ITIMER_LOCK(it);
 1388                 itimer_leave(it);
 1389         } else if (timespecisset(&it->it_time.it_value)) {
 1390                 ts = it->it_time.it_value;
 1391                 timespecsub(&ts, &cts);
 1392                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1393                 callout_reset(&it->it_callout, tvtohz(&tv), realtimer_expire,
 1394                         it);
 1395         }
 1396 }
 1397 
 1398 void
 1399 itimer_fire(struct itimer *it)
 1400 {
 1401         struct proc *p = it->it_proc;
 1402         struct thread *td;
 1403 
 1404         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1405             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1406                 if (sigev_findtd(p, &it->it_sigev, &td) != 0) {
 1407                         ITIMER_LOCK(it);
 1408                         timespecclear(&it->it_time.it_value);
 1409                         timespecclear(&it->it_time.it_interval);
 1410                         callout_stop(&it->it_callout);
 1411                         ITIMER_UNLOCK(it);
 1412                         return;
 1413                 }
 1414                 if (!KSI_ONQ(&it->it_ksi)) {
 1415                         it->it_ksi.ksi_errno = 0;
 1416                         ksiginfo_set_sigev(&it->it_ksi, &it->it_sigev);
 1417                         tdsendsignal(p, td, it->it_ksi.ksi_signo, &it->it_ksi);
 1418                 } else {
 1419                         if (it->it_overrun < INT_MAX)
 1420                                 it->it_overrun++;
 1421                         else
 1422                                 it->it_ksi.ksi_errno = ERANGE;
 1423                 }
 1424                 PROC_UNLOCK(p);
 1425         }
 1426 }
 1427 
 1428 static void
 1429 itimers_alloc(struct proc *p)
 1430 {
 1431         struct itimers *its;
 1432         int i;
 1433 
 1434         its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
 1435         LIST_INIT(&its->its_virtual);
 1436         LIST_INIT(&its->its_prof);
 1437         TAILQ_INIT(&its->its_worklist);
 1438         for (i = 0; i < TIMER_MAX; i++)
 1439                 its->its_timers[i] = NULL;
 1440         PROC_LOCK(p);
 1441         if (p->p_itimers == NULL) {
 1442                 p->p_itimers = its;
 1443                 PROC_UNLOCK(p);
 1444         }
 1445         else {
 1446                 PROC_UNLOCK(p);
 1447                 free(its, M_SUBPROC);
 1448         }
 1449 }
 1450 
 1451 static void
 1452 itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
 1453 {
 1454         itimers_event_hook_exit(arg, p);
 1455 }
 1456 
 1457 /* Clean up timers when some process events are being triggered. */
 1458 static void
 1459 itimers_event_hook_exit(void *arg, struct proc *p)
 1460 {
 1461         struct itimers *its;
 1462         struct itimer *it;
 1463         int event = (int)(intptr_t)arg;
 1464         int i;
 1465 
 1466         if (p->p_itimers != NULL) {
 1467                 its = p->p_itimers;
 1468                 for (i = 0; i < MAX_CLOCKS; ++i) {
 1469                         if (posix_clocks[i].event_hook != NULL)
 1470                                 CLOCK_CALL(i, event_hook, (p, i, event));
 1471                 }
 1472                 /*
 1473                  * According to susv3, XSI interval timers should be inherited
 1474                  * by new image.
 1475                  */
 1476                 if (event == ITIMER_EV_EXEC)
 1477                         i = 3;
 1478                 else if (event == ITIMER_EV_EXIT)
 1479                         i = 0;
 1480                 else
 1481                         panic("unhandled event");
 1482                 for (; i < TIMER_MAX; ++i) {
 1483                         if ((it = its->its_timers[i]) != NULL)
 1484                                 kern_timer_delete(curthread, i);
 1485                 }
 1486                 if (its->its_timers[0] == NULL &&
 1487                     its->its_timers[1] == NULL &&
 1488                     its->its_timers[2] == NULL) {
 1489                         free(its, M_SUBPROC);
 1490                         p->p_itimers = NULL;
 1491                 }
 1492         }
 1493 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/kern_time.c

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