The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/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/11.0/sys/kern/kern_time.c 303092 2016-07-20 15:02:37Z kib $");
   34 
   35 #include "opt_ktrace.h"
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/limits.h>
   40 #include <sys/clock.h>
   41 #include <sys/lock.h>
   42 #include <sys/mutex.h>
   43 #include <sys/sysproto.h>
   44 #include <sys/eventhandler.h>
   45 #include <sys/resourcevar.h>
   46 #include <sys/signalvar.h>
   47 #include <sys/kernel.h>
   48 #include <sys/sleepqueue.h>
   49 #include <sys/syscallsubr.h>
   50 #include <sys/sysctl.h>
   51 #include <sys/sysent.h>
   52 #include <sys/priv.h>
   53 #include <sys/proc.h>
   54 #include <sys/posix4.h>
   55 #include <sys/time.h>
   56 #include <sys/timers.h>
   57 #include <sys/timetc.h>
   58 #include <sys/vnode.h>
   59 #ifdef KTRACE
   60 #include <sys/ktrace.h>
   61 #endif
   62 
   63 #include <vm/vm.h>
   64 #include <vm/vm_extern.h>
   65 
   66 #define MAX_CLOCKS      (CLOCK_MONOTONIC+1)
   67 #define CPUCLOCK_BIT            0x80000000
   68 #define CPUCLOCK_PROCESS_BIT    0x40000000
   69 #define CPUCLOCK_ID_MASK        (~(CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT))
   70 #define MAKE_THREAD_CPUCLOCK(tid)       (CPUCLOCK_BIT|(tid))
   71 #define MAKE_PROCESS_CPUCLOCK(pid)      \
   72         (CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT|(pid))
   73 
   74 static struct kclock    posix_clocks[MAX_CLOCKS];
   75 static uma_zone_t       itimer_zone = NULL;
   76 
   77 /*
   78  * Time of day and interval timer support.
   79  *
   80  * These routines provide the kernel entry points to get and set
   81  * the time-of-day and per-process interval timers.  Subroutines
   82  * here provide support for adding and subtracting timeval structures
   83  * and decrementing interval timers, optionally reloading the interval
   84  * timers when they expire.
   85  */
   86 
   87 static int      settime(struct thread *, struct timeval *);
   88 static void     timevalfix(struct timeval *);
   89 
   90 static void     itimer_start(void);
   91 static int      itimer_init(void *, int, int);
   92 static void     itimer_fini(void *, int);
   93 static void     itimer_enter(struct itimer *);
   94 static void     itimer_leave(struct itimer *);
   95 static struct itimer *itimer_find(struct proc *, int);
   96 static void     itimers_alloc(struct proc *);
   97 static void     itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp);
   98 static void     itimers_event_hook_exit(void *arg, struct proc *p);
   99 static int      realtimer_create(struct itimer *);
  100 static int      realtimer_gettime(struct itimer *, struct itimerspec *);
  101 static int      realtimer_settime(struct itimer *, int,
  102                         struct itimerspec *, struct itimerspec *);
  103 static int      realtimer_delete(struct itimer *);
  104 static void     realtimer_clocktime(clockid_t, struct timespec *);
  105 static void     realtimer_expire(void *);
  106 
  107 int             register_posix_clock(int, struct kclock *);
  108 void            itimer_fire(struct itimer *it);
  109 int             itimespecfix(struct timespec *ts);
  110 
  111 #define CLOCK_CALL(clock, call, arglist)                \
  112         ((*posix_clocks[clock].call) arglist)
  113 
  114 SYSINIT(posix_timer, SI_SUB_P1003_1B, SI_ORDER_FIRST+4, itimer_start, NULL);
  115 
  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         resettodr();
  172         mtx_unlock(&Giant);
  173         return (0);
  174 }
  175 
  176 #ifndef _SYS_SYSPROTO_H_
  177 struct clock_getcpuclockid2_args {
  178         id_t id;
  179         int which,
  180         clockid_t *clock_id;
  181 };
  182 #endif
  183 /* ARGSUSED */
  184 int
  185 sys_clock_getcpuclockid2(struct thread *td, struct clock_getcpuclockid2_args *uap)
  186 {
  187         clockid_t clk_id;
  188         int error;
  189 
  190         error = kern_clock_getcpuclockid2(td, uap->id, uap->which, &clk_id);
  191         if (error == 0)
  192                 error = copyout(&clk_id, uap->clock_id, sizeof(clockid_t));
  193         return (error);
  194 }
  195 
  196 int
  197 kern_clock_getcpuclockid2(struct thread *td, id_t id, int which,
  198     clockid_t *clk_id)
  199 {
  200         struct proc *p;
  201         pid_t pid;
  202         lwpid_t tid;
  203         int error;
  204 
  205         switch (which) {
  206         case CPUCLOCK_WHICH_PID:
  207                 if (id != 0) {
  208                         error = pget(id, PGET_CANSEE | PGET_NOTID, &p);
  209                         if (error != 0)
  210                                 return (error);
  211                         PROC_UNLOCK(p);
  212                         pid = id;
  213                 } else {
  214                         pid = td->td_proc->p_pid;
  215                 }
  216                 *clk_id = MAKE_PROCESS_CPUCLOCK(pid);
  217                 return (0);
  218         case CPUCLOCK_WHICH_TID:
  219                 tid = id == 0 ? td->td_tid : id;
  220                 *clk_id = MAKE_THREAD_CPUCLOCK(tid);
  221                 return (0);
  222         default:
  223                 return (EINVAL);
  224         }
  225 }
  226 
  227 #ifndef _SYS_SYSPROTO_H_
  228 struct clock_gettime_args {
  229         clockid_t clock_id;
  230         struct  timespec *tp;
  231 };
  232 #endif
  233 /* ARGSUSED */
  234 int
  235 sys_clock_gettime(struct thread *td, struct clock_gettime_args *uap)
  236 {
  237         struct timespec ats;
  238         int error;
  239 
  240         error = kern_clock_gettime(td, uap->clock_id, &ats);
  241         if (error == 0)
  242                 error = copyout(&ats, uap->tp, sizeof(ats));
  243 
  244         return (error);
  245 }
  246 
  247 static inline void 
  248 cputick2timespec(uint64_t runtime, struct timespec *ats)
  249 {
  250         runtime = cputick2usec(runtime);
  251         ats->tv_sec = runtime / 1000000;
  252         ats->tv_nsec = runtime % 1000000 * 1000;
  253 }
  254 
  255 static void
  256 get_thread_cputime(struct thread *targettd, struct timespec *ats)
  257 {
  258         uint64_t runtime, curtime, switchtime;
  259 
  260         if (targettd == NULL) { /* current thread */
  261                 critical_enter();
  262                 switchtime = PCPU_GET(switchtime);
  263                 curtime = cpu_ticks();
  264                 runtime = curthread->td_runtime;
  265                 critical_exit();
  266                 runtime += curtime - switchtime;
  267         } else {
  268                 thread_lock(targettd);
  269                 runtime = targettd->td_runtime;
  270                 thread_unlock(targettd);
  271         }
  272         cputick2timespec(runtime, ats);
  273 }
  274 
  275 static void
  276 get_process_cputime(struct proc *targetp, struct timespec *ats)
  277 {
  278         uint64_t runtime;
  279         struct rusage ru;
  280 
  281         PROC_STATLOCK(targetp);
  282         rufetch(targetp, &ru);
  283         runtime = targetp->p_rux.rux_runtime;
  284         PROC_STATUNLOCK(targetp);
  285         cputick2timespec(runtime, ats);
  286 }
  287 
  288 static int
  289 get_cputime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  290 {
  291         struct proc *p, *p2;
  292         struct thread *td2;
  293         lwpid_t tid;
  294         pid_t pid;
  295         int error;
  296 
  297         p = td->td_proc;
  298         if ((clock_id & CPUCLOCK_PROCESS_BIT) == 0) {
  299                 tid = clock_id & CPUCLOCK_ID_MASK;
  300                 td2 = tdfind(tid, p->p_pid);
  301                 if (td2 == NULL)
  302                         return (EINVAL);
  303                 get_thread_cputime(td2, ats);
  304                 PROC_UNLOCK(td2->td_proc);
  305         } else {
  306                 pid = clock_id & CPUCLOCK_ID_MASK;
  307                 error = pget(pid, PGET_CANSEE, &p2);
  308                 if (error != 0)
  309                         return (EINVAL);
  310                 get_process_cputime(p2, ats);
  311                 PROC_UNLOCK(p2);
  312         }
  313         return (0);
  314 }
  315 
  316 int
  317 kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  318 {
  319         struct timeval sys, user;
  320         struct proc *p;
  321 
  322         p = td->td_proc;
  323         switch (clock_id) {
  324         case CLOCK_REALTIME:            /* Default to precise. */
  325         case CLOCK_REALTIME_PRECISE:
  326                 nanotime(ats);
  327                 break;
  328         case CLOCK_REALTIME_FAST:
  329                 getnanotime(ats);
  330                 break;
  331         case CLOCK_VIRTUAL:
  332                 PROC_LOCK(p);
  333                 PROC_STATLOCK(p);
  334                 calcru(p, &user, &sys);
  335                 PROC_STATUNLOCK(p);
  336                 PROC_UNLOCK(p);
  337                 TIMEVAL_TO_TIMESPEC(&user, ats);
  338                 break;
  339         case CLOCK_PROF:
  340                 PROC_LOCK(p);
  341                 PROC_STATLOCK(p);
  342                 calcru(p, &user, &sys);
  343                 PROC_STATUNLOCK(p);
  344                 PROC_UNLOCK(p);
  345                 timevaladd(&user, &sys);
  346                 TIMEVAL_TO_TIMESPEC(&user, ats);
  347                 break;
  348         case CLOCK_MONOTONIC:           /* Default to precise. */
  349         case CLOCK_MONOTONIC_PRECISE:
  350         case CLOCK_UPTIME:
  351         case CLOCK_UPTIME_PRECISE:
  352                 nanouptime(ats);
  353                 break;
  354         case CLOCK_UPTIME_FAST:
  355         case CLOCK_MONOTONIC_FAST:
  356                 getnanouptime(ats);
  357                 break;
  358         case CLOCK_SECOND:
  359                 ats->tv_sec = time_second;
  360                 ats->tv_nsec = 0;
  361                 break;
  362         case CLOCK_THREAD_CPUTIME_ID:
  363                 get_thread_cputime(NULL, ats);
  364                 break;
  365         case CLOCK_PROCESS_CPUTIME_ID:
  366                 PROC_LOCK(p);
  367                 get_process_cputime(p, ats);
  368                 PROC_UNLOCK(p);
  369                 break;
  370         default:
  371                 if ((int)clock_id >= 0)
  372                         return (EINVAL);
  373                 return (get_cputime(td, clock_id, ats));
  374         }
  375         return (0);
  376 }
  377 
  378 #ifndef _SYS_SYSPROTO_H_
  379 struct clock_settime_args {
  380         clockid_t clock_id;
  381         const struct    timespec *tp;
  382 };
  383 #endif
  384 /* ARGSUSED */
  385 int
  386 sys_clock_settime(struct thread *td, struct clock_settime_args *uap)
  387 {
  388         struct timespec ats;
  389         int error;
  390 
  391         if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
  392                 return (error);
  393         return (kern_clock_settime(td, uap->clock_id, &ats));
  394 }
  395 
  396 int
  397 kern_clock_settime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  398 {
  399         struct timeval atv;
  400         int error;
  401 
  402         if ((error = priv_check(td, PRIV_CLOCK_SETTIME)) != 0)
  403                 return (error);
  404         if (clock_id != CLOCK_REALTIME)
  405                 return (EINVAL);
  406         if (ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000 ||
  407             ats->tv_sec < 0)
  408                 return (EINVAL);
  409         /* XXX Don't convert nsec->usec and back */
  410         TIMESPEC_TO_TIMEVAL(&atv, ats);
  411         error = settime(td, &atv);
  412         return (error);
  413 }
  414 
  415 #ifndef _SYS_SYSPROTO_H_
  416 struct clock_getres_args {
  417         clockid_t clock_id;
  418         struct  timespec *tp;
  419 };
  420 #endif
  421 int
  422 sys_clock_getres(struct thread *td, struct clock_getres_args *uap)
  423 {
  424         struct timespec ts;
  425         int error;
  426 
  427         if (uap->tp == NULL)
  428                 return (0);
  429 
  430         error = kern_clock_getres(td, uap->clock_id, &ts);
  431         if (error == 0)
  432                 error = copyout(&ts, uap->tp, sizeof(ts));
  433         return (error);
  434 }
  435 
  436 int
  437 kern_clock_getres(struct thread *td, clockid_t clock_id, struct timespec *ts)
  438 {
  439 
  440         ts->tv_sec = 0;
  441         switch (clock_id) {
  442         case CLOCK_REALTIME:
  443         case CLOCK_REALTIME_FAST:
  444         case CLOCK_REALTIME_PRECISE:
  445         case CLOCK_MONOTONIC:
  446         case CLOCK_MONOTONIC_FAST:
  447         case CLOCK_MONOTONIC_PRECISE:
  448         case CLOCK_UPTIME:
  449         case CLOCK_UPTIME_FAST:
  450         case CLOCK_UPTIME_PRECISE:
  451                 /*
  452                  * Round up the result of the division cheaply by adding 1.
  453                  * Rounding up is especially important if rounding down
  454                  * would give 0.  Perfect rounding is unimportant.
  455                  */
  456                 ts->tv_nsec = 1000000000 / tc_getfrequency() + 1;
  457                 break;
  458         case CLOCK_VIRTUAL:
  459         case CLOCK_PROF:
  460                 /* Accurately round up here because we can do so cheaply. */
  461                 ts->tv_nsec = howmany(1000000000, hz);
  462                 break;
  463         case CLOCK_SECOND:
  464                 ts->tv_sec = 1;
  465                 ts->tv_nsec = 0;
  466                 break;
  467         case CLOCK_THREAD_CPUTIME_ID:
  468         case CLOCK_PROCESS_CPUTIME_ID:
  469         cputime:
  470                 /* sync with cputick2usec */
  471                 ts->tv_nsec = 1000000 / cpu_tickrate();
  472                 if (ts->tv_nsec == 0)
  473                         ts->tv_nsec = 1000;
  474                 break;
  475         default:
  476                 if ((int)clock_id < 0)
  477                         goto cputime;
  478                 return (EINVAL);
  479         }
  480         return (0);
  481 }
  482 
  483 static uint8_t nanowait[MAXCPU];
  484 
  485 int
  486 kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
  487 {
  488         struct timespec ts;
  489         sbintime_t sbt, sbtt, prec, tmp;
  490         time_t over;
  491         int error;
  492 
  493         if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
  494                 return (EINVAL);
  495         if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
  496                 return (0);
  497         ts = *rqt;
  498         if (ts.tv_sec > INT32_MAX / 2) {
  499                 over = ts.tv_sec - INT32_MAX / 2;
  500                 ts.tv_sec -= over;
  501         } else
  502                 over = 0;
  503         tmp = tstosbt(ts);
  504         prec = tmp;
  505         prec >>= tc_precexp;
  506         if (TIMESEL(&sbt, tmp))
  507                 sbt += tc_tick_sbt;
  508         sbt += tmp;
  509         error = tsleep_sbt(&nanowait[curcpu], PWAIT | PCATCH, "nanslp",
  510             sbt, prec, C_ABSOLUTE);
  511         if (error != EWOULDBLOCK) {
  512                 if (error == ERESTART)
  513                         error = EINTR;
  514                 TIMESEL(&sbtt, tmp);
  515                 if (rmt != NULL) {
  516                         ts = sbttots(sbt - sbtt);
  517                         ts.tv_sec += over;
  518                         if (ts.tv_sec < 0)
  519                                 timespecclear(&ts);
  520                         *rmt = ts;
  521                 }
  522                 if (sbtt >= sbt)
  523                         return (0);
  524                 return (error);
  525         }
  526         return (0);
  527 }
  528 
  529 #ifndef _SYS_SYSPROTO_H_
  530 struct nanosleep_args {
  531         struct  timespec *rqtp;
  532         struct  timespec *rmtp;
  533 };
  534 #endif
  535 /* ARGSUSED */
  536 int
  537 sys_nanosleep(struct thread *td, struct nanosleep_args *uap)
  538 {
  539         struct timespec rmt, rqt;
  540         int error;
  541 
  542         error = copyin(uap->rqtp, &rqt, sizeof(rqt));
  543         if (error)
  544                 return (error);
  545 
  546         if (uap->rmtp &&
  547             !useracc((caddr_t)uap->rmtp, sizeof(rmt), VM_PROT_WRITE))
  548                         return (EFAULT);
  549         error = kern_nanosleep(td, &rqt, &rmt);
  550         if (error && uap->rmtp) {
  551                 int error2;
  552 
  553                 error2 = copyout(&rmt, uap->rmtp, sizeof(rmt));
  554                 if (error2)
  555                         error = error2;
  556         }
  557         return (error);
  558 }
  559 
  560 #ifndef _SYS_SYSPROTO_H_
  561 struct gettimeofday_args {
  562         struct  timeval *tp;
  563         struct  timezone *tzp;
  564 };
  565 #endif
  566 /* ARGSUSED */
  567 int
  568 sys_gettimeofday(struct thread *td, struct gettimeofday_args *uap)
  569 {
  570         struct timeval atv;
  571         struct timezone rtz;
  572         int error = 0;
  573 
  574         if (uap->tp) {
  575                 microtime(&atv);
  576                 error = copyout(&atv, uap->tp, sizeof (atv));
  577         }
  578         if (error == 0 && uap->tzp != NULL) {
  579                 rtz.tz_minuteswest = tz_minuteswest;
  580                 rtz.tz_dsttime = tz_dsttime;
  581                 error = copyout(&rtz, uap->tzp, sizeof (rtz));
  582         }
  583         return (error);
  584 }
  585 
  586 #ifndef _SYS_SYSPROTO_H_
  587 struct settimeofday_args {
  588         struct  timeval *tv;
  589         struct  timezone *tzp;
  590 };
  591 #endif
  592 /* ARGSUSED */
  593 int
  594 sys_settimeofday(struct thread *td, struct settimeofday_args *uap)
  595 {
  596         struct timeval atv, *tvp;
  597         struct timezone atz, *tzp;
  598         int error;
  599 
  600         if (uap->tv) {
  601                 error = copyin(uap->tv, &atv, sizeof(atv));
  602                 if (error)
  603                         return (error);
  604                 tvp = &atv;
  605         } else
  606                 tvp = NULL;
  607         if (uap->tzp) {
  608                 error = copyin(uap->tzp, &atz, sizeof(atz));
  609                 if (error)
  610                         return (error);
  611                 tzp = &atz;
  612         } else
  613                 tzp = NULL;
  614         return (kern_settimeofday(td, tvp, tzp));
  615 }
  616 
  617 int
  618 kern_settimeofday(struct thread *td, struct timeval *tv, struct timezone *tzp)
  619 {
  620         int error;
  621 
  622         error = priv_check(td, PRIV_SETTIMEOFDAY);
  623         if (error)
  624                 return (error);
  625         /* Verify all parameters before changing time. */
  626         if (tv) {
  627                 if (tv->tv_usec < 0 || tv->tv_usec >= 1000000 ||
  628                     tv->tv_sec < 0)
  629                         return (EINVAL);
  630                 error = settime(td, tv);
  631         }
  632         if (tzp && error == 0) {
  633                 tz_minuteswest = tzp->tz_minuteswest;
  634                 tz_dsttime = tzp->tz_dsttime;
  635         }
  636         return (error);
  637 }
  638 
  639 /*
  640  * Get value of an interval timer.  The process virtual and profiling virtual
  641  * time timers are kept in the p_stats area, since they can be swapped out.
  642  * These are kept internally in the way they are specified externally: in
  643  * time until they expire.
  644  *
  645  * The real time interval timer is kept in the process table slot for the
  646  * process, and its value (it_value) is kept as an absolute time rather than
  647  * as a delta, so that it is easy to keep periodic real-time signals from
  648  * drifting.
  649  *
  650  * Virtual time timers are processed in the hardclock() routine of
  651  * kern_clock.c.  The real time timer is processed by a timeout routine,
  652  * called from the softclock() routine.  Since a callout may be delayed in
  653  * real time due to interrupt processing in the system, it is possible for
  654  * the real time timeout routine (realitexpire, given below), to be delayed
  655  * in real time past when it is supposed to occur.  It does not suffice,
  656  * therefore, to reload the real timer .it_value from the real time timers
  657  * .it_interval.  Rather, we compute the next time in absolute time the timer
  658  * should go off.
  659  */
  660 #ifndef _SYS_SYSPROTO_H_
  661 struct getitimer_args {
  662         u_int   which;
  663         struct  itimerval *itv;
  664 };
  665 #endif
  666 int
  667 sys_getitimer(struct thread *td, struct getitimer_args *uap)
  668 {
  669         struct itimerval aitv;
  670         int error;
  671 
  672         error = kern_getitimer(td, uap->which, &aitv);
  673         if (error != 0)
  674                 return (error);
  675         return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
  676 }
  677 
  678 int
  679 kern_getitimer(struct thread *td, u_int which, struct itimerval *aitv)
  680 {
  681         struct proc *p = td->td_proc;
  682         struct timeval ctv;
  683 
  684         if (which > ITIMER_PROF)
  685                 return (EINVAL);
  686 
  687         if (which == ITIMER_REAL) {
  688                 /*
  689                  * Convert from absolute to relative time in .it_value
  690                  * part of real time timer.  If time for real time timer
  691                  * has passed return 0, else return difference between
  692                  * current time and time for the timer to go off.
  693                  */
  694                 PROC_LOCK(p);
  695                 *aitv = p->p_realtimer;
  696                 PROC_UNLOCK(p);
  697                 if (timevalisset(&aitv->it_value)) {
  698                         microuptime(&ctv);
  699                         if (timevalcmp(&aitv->it_value, &ctv, <))
  700                                 timevalclear(&aitv->it_value);
  701                         else
  702                                 timevalsub(&aitv->it_value, &ctv);
  703                 }
  704         } else {
  705                 PROC_ITIMLOCK(p);
  706                 *aitv = p->p_stats->p_timer[which];
  707                 PROC_ITIMUNLOCK(p);
  708         }
  709 #ifdef KTRACE
  710         if (KTRPOINT(td, KTR_STRUCT))
  711                 ktritimerval(aitv);
  712 #endif
  713         return (0);
  714 }
  715 
  716 #ifndef _SYS_SYSPROTO_H_
  717 struct setitimer_args {
  718         u_int   which;
  719         struct  itimerval *itv, *oitv;
  720 };
  721 #endif
  722 int
  723 sys_setitimer(struct thread *td, struct setitimer_args *uap)
  724 {
  725         struct itimerval aitv, oitv;
  726         int error;
  727 
  728         if (uap->itv == NULL) {
  729                 uap->itv = uap->oitv;
  730                 return (sys_getitimer(td, (struct getitimer_args *)uap));
  731         }
  732 
  733         if ((error = copyin(uap->itv, &aitv, sizeof(struct itimerval))))
  734                 return (error);
  735         error = kern_setitimer(td, uap->which, &aitv, &oitv);
  736         if (error != 0 || uap->oitv == NULL)
  737                 return (error);
  738         return (copyout(&oitv, uap->oitv, sizeof(struct itimerval)));
  739 }
  740 
  741 int
  742 kern_setitimer(struct thread *td, u_int which, struct itimerval *aitv,
  743     struct itimerval *oitv)
  744 {
  745         struct proc *p = td->td_proc;
  746         struct timeval ctv;
  747         sbintime_t sbt, pr;
  748 
  749         if (aitv == NULL)
  750                 return (kern_getitimer(td, which, oitv));
  751 
  752         if (which > ITIMER_PROF)
  753                 return (EINVAL);
  754 #ifdef KTRACE
  755         if (KTRPOINT(td, KTR_STRUCT))
  756                 ktritimerval(aitv);
  757 #endif
  758         if (itimerfix(&aitv->it_value) ||
  759             aitv->it_value.tv_sec > INT32_MAX / 2)
  760                 return (EINVAL);
  761         if (!timevalisset(&aitv->it_value))
  762                 timevalclear(&aitv->it_interval);
  763         else if (itimerfix(&aitv->it_interval) ||
  764             aitv->it_interval.tv_sec > INT32_MAX / 2)
  765                 return (EINVAL);
  766 
  767         if (which == ITIMER_REAL) {
  768                 PROC_LOCK(p);
  769                 if (timevalisset(&p->p_realtimer.it_value))
  770                         callout_stop(&p->p_itcallout);
  771                 microuptime(&ctv);
  772                 if (timevalisset(&aitv->it_value)) {
  773                         pr = tvtosbt(aitv->it_value) >> tc_precexp;
  774                         timevaladd(&aitv->it_value, &ctv);
  775                         sbt = tvtosbt(aitv->it_value);
  776                         callout_reset_sbt(&p->p_itcallout, sbt, pr,
  777                             realitexpire, p, C_ABSOLUTE);
  778                 }
  779                 *oitv = p->p_realtimer;
  780                 p->p_realtimer = *aitv;
  781                 PROC_UNLOCK(p);
  782                 if (timevalisset(&oitv->it_value)) {
  783                         if (timevalcmp(&oitv->it_value, &ctv, <))
  784                                 timevalclear(&oitv->it_value);
  785                         else
  786                                 timevalsub(&oitv->it_value, &ctv);
  787                 }
  788         } else {
  789                 if (aitv->it_interval.tv_sec == 0 &&
  790                     aitv->it_interval.tv_usec != 0 &&
  791                     aitv->it_interval.tv_usec < tick)
  792                         aitv->it_interval.tv_usec = tick;
  793                 if (aitv->it_value.tv_sec == 0 &&
  794                     aitv->it_value.tv_usec != 0 &&
  795                     aitv->it_value.tv_usec < tick)
  796                         aitv->it_value.tv_usec = tick;
  797                 PROC_ITIMLOCK(p);
  798                 *oitv = p->p_stats->p_timer[which];
  799                 p->p_stats->p_timer[which] = *aitv;
  800                 PROC_ITIMUNLOCK(p);
  801         }
  802 #ifdef KTRACE
  803         if (KTRPOINT(td, KTR_STRUCT))
  804                 ktritimerval(oitv);
  805 #endif
  806         return (0);
  807 }
  808 
  809 /*
  810  * Real interval timer expired:
  811  * send process whose timer expired an alarm signal.
  812  * If time is not set up to reload, then just return.
  813  * Else compute next time timer should go off which is > current time.
  814  * This is where delay in processing this timeout causes multiple
  815  * SIGALRM calls to be compressed into one.
  816  * tvtohz() always adds 1 to allow for the time until the next clock
  817  * interrupt being strictly less than 1 clock tick, but we don't want
  818  * that here since we want to appear to be in sync with the clock
  819  * interrupt even when we're delayed.
  820  */
  821 void
  822 realitexpire(void *arg)
  823 {
  824         struct proc *p;
  825         struct timeval ctv;
  826         sbintime_t isbt;
  827 
  828         p = (struct proc *)arg;
  829         kern_psignal(p, SIGALRM);
  830         if (!timevalisset(&p->p_realtimer.it_interval)) {
  831                 timevalclear(&p->p_realtimer.it_value);
  832                 if (p->p_flag & P_WEXIT)
  833                         wakeup(&p->p_itcallout);
  834                 return;
  835         }
  836         isbt = tvtosbt(p->p_realtimer.it_interval);
  837         if (isbt >= sbt_timethreshold)
  838                 getmicrouptime(&ctv);
  839         else
  840                 microuptime(&ctv);
  841         do {
  842                 timevaladd(&p->p_realtimer.it_value,
  843                     &p->p_realtimer.it_interval);
  844         } while (timevalcmp(&p->p_realtimer.it_value, &ctv, <=));
  845         callout_reset_sbt(&p->p_itcallout, tvtosbt(p->p_realtimer.it_value),
  846             isbt >> tc_precexp, realitexpire, p, C_ABSOLUTE);
  847 }
  848 
  849 /*
  850  * Check that a proposed value to load into the .it_value or
  851  * .it_interval part of an interval timer is acceptable, and
  852  * fix it to have at least minimal value (i.e. if it is less
  853  * than the resolution of the clock, round it up.)
  854  */
  855 int
  856 itimerfix(struct timeval *tv)
  857 {
  858 
  859         if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  860                 return (EINVAL);
  861         if (tv->tv_sec == 0 && tv->tv_usec != 0 &&
  862             tv->tv_usec < (u_int)tick / 16)
  863                 tv->tv_usec = (u_int)tick / 16;
  864         return (0);
  865 }
  866 
  867 /*
  868  * Decrement an interval timer by a specified number
  869  * of microseconds, which must be less than a second,
  870  * i.e. < 1000000.  If the timer expires, then reload
  871  * it.  In this case, carry over (usec - old value) to
  872  * reduce the value reloaded into the timer so that
  873  * the timer does not drift.  This routine assumes
  874  * that it is called in a context where the timers
  875  * on which it is operating cannot change in value.
  876  */
  877 int
  878 itimerdecr(struct itimerval *itp, int usec)
  879 {
  880 
  881         if (itp->it_value.tv_usec < usec) {
  882                 if (itp->it_value.tv_sec == 0) {
  883                         /* expired, and already in next interval */
  884                         usec -= itp->it_value.tv_usec;
  885                         goto expire;
  886                 }
  887                 itp->it_value.tv_usec += 1000000;
  888                 itp->it_value.tv_sec--;
  889         }
  890         itp->it_value.tv_usec -= usec;
  891         usec = 0;
  892         if (timevalisset(&itp->it_value))
  893                 return (1);
  894         /* expired, exactly at end of interval */
  895 expire:
  896         if (timevalisset(&itp->it_interval)) {
  897                 itp->it_value = itp->it_interval;
  898                 itp->it_value.tv_usec -= usec;
  899                 if (itp->it_value.tv_usec < 0) {
  900                         itp->it_value.tv_usec += 1000000;
  901                         itp->it_value.tv_sec--;
  902                 }
  903         } else
  904                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
  905         return (0);
  906 }
  907 
  908 /*
  909  * Add and subtract routines for timevals.
  910  * N.B.: subtract routine doesn't deal with
  911  * results which are before the beginning,
  912  * it just gets very confused in this case.
  913  * Caveat emptor.
  914  */
  915 void
  916 timevaladd(struct timeval *t1, const struct timeval *t2)
  917 {
  918 
  919         t1->tv_sec += t2->tv_sec;
  920         t1->tv_usec += t2->tv_usec;
  921         timevalfix(t1);
  922 }
  923 
  924 void
  925 timevalsub(struct timeval *t1, const struct timeval *t2)
  926 {
  927 
  928         t1->tv_sec -= t2->tv_sec;
  929         t1->tv_usec -= t2->tv_usec;
  930         timevalfix(t1);
  931 }
  932 
  933 static void
  934 timevalfix(struct timeval *t1)
  935 {
  936 
  937         if (t1->tv_usec < 0) {
  938                 t1->tv_sec--;
  939                 t1->tv_usec += 1000000;
  940         }
  941         if (t1->tv_usec >= 1000000) {
  942                 t1->tv_sec++;
  943                 t1->tv_usec -= 1000000;
  944         }
  945 }
  946 
  947 /*
  948  * ratecheck(): simple time-based rate-limit checking.
  949  */
  950 int
  951 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
  952 {
  953         struct timeval tv, delta;
  954         int rv = 0;
  955 
  956         getmicrouptime(&tv);            /* NB: 10ms precision */
  957         delta = tv;
  958         timevalsub(&delta, lasttime);
  959 
  960         /*
  961          * check for 0,0 is so that the message will be seen at least once,
  962          * even if interval is huge.
  963          */
  964         if (timevalcmp(&delta, mininterval, >=) ||
  965             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
  966                 *lasttime = tv;
  967                 rv = 1;
  968         }
  969 
  970         return (rv);
  971 }
  972 
  973 /*
  974  * ppsratecheck(): packets (or events) per second limitation.
  975  *
  976  * Return 0 if the limit is to be enforced (e.g. the caller
  977  * should drop a packet because of the rate limitation).
  978  *
  979  * maxpps of 0 always causes zero to be returned.  maxpps of -1
  980  * always causes 1 to be returned; this effectively defeats rate
  981  * limiting.
  982  *
  983  * Note that we maintain the struct timeval for compatibility
  984  * with other bsd systems.  We reuse the storage and just monitor
  985  * clock ticks for minimal overhead.  
  986  */
  987 int
  988 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
  989 {
  990         int now;
  991 
  992         /*
  993          * Reset the last time and counter if this is the first call
  994          * or more than a second has passed since the last update of
  995          * lasttime.
  996          */
  997         now = ticks;
  998         if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
  999                 lasttime->tv_sec = now;
 1000                 *curpps = 1;
 1001                 return (maxpps != 0);
 1002         } else {
 1003                 (*curpps)++;            /* NB: ignore potential overflow */
 1004                 return (maxpps < 0 || *curpps <= maxpps);
 1005         }
 1006 }
 1007 
 1008 static void
 1009 itimer_start(void)
 1010 {
 1011         struct kclock rt_clock = {
 1012                 .timer_create  = realtimer_create,
 1013                 .timer_delete  = realtimer_delete,
 1014                 .timer_settime = realtimer_settime,
 1015                 .timer_gettime = realtimer_gettime,
 1016                 .event_hook    = NULL
 1017         };
 1018 
 1019         itimer_zone = uma_zcreate("itimer", sizeof(struct itimer),
 1020                 NULL, NULL, itimer_init, itimer_fini, UMA_ALIGN_PTR, 0);
 1021         register_posix_clock(CLOCK_REALTIME,  &rt_clock);
 1022         register_posix_clock(CLOCK_MONOTONIC, &rt_clock);
 1023         p31b_setcfg(CTL_P1003_1B_TIMERS, 200112L);
 1024         p31b_setcfg(CTL_P1003_1B_DELAYTIMER_MAX, INT_MAX);
 1025         p31b_setcfg(CTL_P1003_1B_TIMER_MAX, TIMER_MAX);
 1026         EVENTHANDLER_REGISTER(process_exit, itimers_event_hook_exit,
 1027                 (void *)ITIMER_EV_EXIT, EVENTHANDLER_PRI_ANY);
 1028         EVENTHANDLER_REGISTER(process_exec, itimers_event_hook_exec,
 1029                 (void *)ITIMER_EV_EXEC, EVENTHANDLER_PRI_ANY);
 1030 }
 1031 
 1032 int
 1033 register_posix_clock(int clockid, struct kclock *clk)
 1034 {
 1035         if ((unsigned)clockid >= MAX_CLOCKS) {
 1036                 printf("%s: invalid clockid\n", __func__);
 1037                 return (0);
 1038         }
 1039         posix_clocks[clockid] = *clk;
 1040         return (1);
 1041 }
 1042 
 1043 static int
 1044 itimer_init(void *mem, int size, int flags)
 1045 {
 1046         struct itimer *it;
 1047 
 1048         it = (struct itimer *)mem;
 1049         mtx_init(&it->it_mtx, "itimer lock", NULL, MTX_DEF);
 1050         return (0);
 1051 }
 1052 
 1053 static void
 1054 itimer_fini(void *mem, int size)
 1055 {
 1056         struct itimer *it;
 1057 
 1058         it = (struct itimer *)mem;
 1059         mtx_destroy(&it->it_mtx);
 1060 }
 1061 
 1062 static void
 1063 itimer_enter(struct itimer *it)
 1064 {
 1065 
 1066         mtx_assert(&it->it_mtx, MA_OWNED);
 1067         it->it_usecount++;
 1068 }
 1069 
 1070 static void
 1071 itimer_leave(struct itimer *it)
 1072 {
 1073 
 1074         mtx_assert(&it->it_mtx, MA_OWNED);
 1075         KASSERT(it->it_usecount > 0, ("invalid it_usecount"));
 1076 
 1077         if (--it->it_usecount == 0 && (it->it_flags & ITF_WANTED) != 0)
 1078                 wakeup(it);
 1079 }
 1080 
 1081 #ifndef _SYS_SYSPROTO_H_
 1082 struct ktimer_create_args {
 1083         clockid_t clock_id;
 1084         struct sigevent * evp;
 1085         int * timerid;
 1086 };
 1087 #endif
 1088 int
 1089 sys_ktimer_create(struct thread *td, struct ktimer_create_args *uap)
 1090 {
 1091         struct sigevent *evp, ev;
 1092         int id;
 1093         int error;
 1094 
 1095         if (uap->evp == NULL) {
 1096                 evp = NULL;
 1097         } else {
 1098                 error = copyin(uap->evp, &ev, sizeof(ev));
 1099                 if (error != 0)
 1100                         return (error);
 1101                 evp = &ev;
 1102         }
 1103         error = kern_ktimer_create(td, uap->clock_id, evp, &id, -1);
 1104         if (error == 0) {
 1105                 error = copyout(&id, uap->timerid, sizeof(int));
 1106                 if (error != 0)
 1107                         kern_ktimer_delete(td, id);
 1108         }
 1109         return (error);
 1110 }
 1111 
 1112 int
 1113 kern_ktimer_create(struct thread *td, clockid_t clock_id, struct sigevent *evp,
 1114     int *timerid, int preset_id)
 1115 {
 1116         struct proc *p = td->td_proc;
 1117         struct itimer *it;
 1118         int id;
 1119         int error;
 1120 
 1121         if (clock_id < 0 || clock_id >= MAX_CLOCKS)
 1122                 return (EINVAL);
 1123 
 1124         if (posix_clocks[clock_id].timer_create == NULL)
 1125                 return (EINVAL);
 1126 
 1127         if (evp != NULL) {
 1128                 if (evp->sigev_notify != SIGEV_NONE &&
 1129                     evp->sigev_notify != SIGEV_SIGNAL &&
 1130                     evp->sigev_notify != SIGEV_THREAD_ID)
 1131                         return (EINVAL);
 1132                 if ((evp->sigev_notify == SIGEV_SIGNAL ||
 1133                      evp->sigev_notify == SIGEV_THREAD_ID) &&
 1134                         !_SIG_VALID(evp->sigev_signo))
 1135                         return (EINVAL);
 1136         }
 1137         
 1138         if (p->p_itimers == NULL)
 1139                 itimers_alloc(p);
 1140         
 1141         it = uma_zalloc(itimer_zone, M_WAITOK);
 1142         it->it_flags = 0;
 1143         it->it_usecount = 0;
 1144         it->it_active = 0;
 1145         timespecclear(&it->it_time.it_value);
 1146         timespecclear(&it->it_time.it_interval);
 1147         it->it_overrun = 0;
 1148         it->it_overrun_last = 0;
 1149         it->it_clockid = clock_id;
 1150         it->it_timerid = -1;
 1151         it->it_proc = p;
 1152         ksiginfo_init(&it->it_ksi);
 1153         it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
 1154         error = CLOCK_CALL(clock_id, timer_create, (it));
 1155         if (error != 0)
 1156                 goto out;
 1157 
 1158         PROC_LOCK(p);
 1159         if (preset_id != -1) {
 1160                 KASSERT(preset_id >= 0 && preset_id < 3, ("invalid preset_id"));
 1161                 id = preset_id;
 1162                 if (p->p_itimers->its_timers[id] != NULL) {
 1163                         PROC_UNLOCK(p);
 1164                         error = 0;
 1165                         goto out;
 1166                 }
 1167         } else {
 1168                 /*
 1169                  * Find a free timer slot, skipping those reserved
 1170                  * for setitimer().
 1171                  */
 1172                 for (id = 3; id < TIMER_MAX; id++)
 1173                         if (p->p_itimers->its_timers[id] == NULL)
 1174                                 break;
 1175                 if (id == TIMER_MAX) {
 1176                         PROC_UNLOCK(p);
 1177                         error = EAGAIN;
 1178                         goto out;
 1179                 }
 1180         }
 1181         it->it_timerid = id;
 1182         p->p_itimers->its_timers[id] = it;
 1183         if (evp != NULL)
 1184                 it->it_sigev = *evp;
 1185         else {
 1186                 it->it_sigev.sigev_notify = SIGEV_SIGNAL;
 1187                 switch (clock_id) {
 1188                 default:
 1189                 case CLOCK_REALTIME:
 1190                         it->it_sigev.sigev_signo = SIGALRM;
 1191                         break;
 1192                 case CLOCK_VIRTUAL:
 1193                         it->it_sigev.sigev_signo = SIGVTALRM;
 1194                         break;
 1195                 case CLOCK_PROF:
 1196                         it->it_sigev.sigev_signo = SIGPROF;
 1197                         break;
 1198                 }
 1199                 it->it_sigev.sigev_value.sival_int = id;
 1200         }
 1201 
 1202         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1203             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1204                 it->it_ksi.ksi_signo = it->it_sigev.sigev_signo;
 1205                 it->it_ksi.ksi_code = SI_TIMER;
 1206                 it->it_ksi.ksi_value = it->it_sigev.sigev_value;
 1207                 it->it_ksi.ksi_timerid = id;
 1208         }
 1209         PROC_UNLOCK(p);
 1210         *timerid = id;
 1211         return (0);
 1212 
 1213 out:
 1214         ITIMER_LOCK(it);
 1215         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1216         ITIMER_UNLOCK(it);
 1217         uma_zfree(itimer_zone, it);
 1218         return (error);
 1219 }
 1220 
 1221 #ifndef _SYS_SYSPROTO_H_
 1222 struct ktimer_delete_args {
 1223         int timerid;
 1224 };
 1225 #endif
 1226 int
 1227 sys_ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
 1228 {
 1229 
 1230         return (kern_ktimer_delete(td, uap->timerid));
 1231 }
 1232 
 1233 static struct itimer *
 1234 itimer_find(struct proc *p, int timerid)
 1235 {
 1236         struct itimer *it;
 1237 
 1238         PROC_LOCK_ASSERT(p, MA_OWNED);
 1239         if ((p->p_itimers == NULL) ||
 1240             (timerid < 0) || (timerid >= TIMER_MAX) ||
 1241             (it = p->p_itimers->its_timers[timerid]) == NULL) {
 1242                 return (NULL);
 1243         }
 1244         ITIMER_LOCK(it);
 1245         if ((it->it_flags & ITF_DELETING) != 0) {
 1246                 ITIMER_UNLOCK(it);
 1247                 it = NULL;
 1248         }
 1249         return (it);
 1250 }
 1251 
 1252 int
 1253 kern_ktimer_delete(struct thread *td, int timerid)
 1254 {
 1255         struct proc *p = td->td_proc;
 1256         struct itimer *it;
 1257 
 1258         PROC_LOCK(p);
 1259         it = itimer_find(p, timerid);
 1260         if (it == NULL) {
 1261                 PROC_UNLOCK(p);
 1262                 return (EINVAL);
 1263         }
 1264         PROC_UNLOCK(p);
 1265 
 1266         it->it_flags |= ITF_DELETING;
 1267         while (it->it_usecount > 0) {
 1268                 it->it_flags |= ITF_WANTED;
 1269                 msleep(it, &it->it_mtx, PPAUSE, "itimer", 0);
 1270         }
 1271         it->it_flags &= ~ITF_WANTED;
 1272         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1273         ITIMER_UNLOCK(it);
 1274 
 1275         PROC_LOCK(p);
 1276         if (KSI_ONQ(&it->it_ksi))
 1277                 sigqueue_take(&it->it_ksi);
 1278         p->p_itimers->its_timers[timerid] = NULL;
 1279         PROC_UNLOCK(p);
 1280         uma_zfree(itimer_zone, it);
 1281         return (0);
 1282 }
 1283 
 1284 #ifndef _SYS_SYSPROTO_H_
 1285 struct ktimer_settime_args {
 1286         int timerid;
 1287         int flags;
 1288         const struct itimerspec * value;
 1289         struct itimerspec * ovalue;
 1290 };
 1291 #endif
 1292 int
 1293 sys_ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
 1294 {
 1295         struct itimerspec val, oval, *ovalp;
 1296         int error;
 1297 
 1298         error = copyin(uap->value, &val, sizeof(val));
 1299         if (error != 0)
 1300                 return (error);
 1301         ovalp = uap->ovalue != NULL ? &oval : NULL;
 1302         error = kern_ktimer_settime(td, uap->timerid, uap->flags, &val, ovalp);
 1303         if (error == 0 && uap->ovalue != NULL)
 1304                 error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
 1305         return (error);
 1306 }
 1307 
 1308 int
 1309 kern_ktimer_settime(struct thread *td, int timer_id, int flags,
 1310     struct itimerspec *val, struct itimerspec *oval)
 1311 {
 1312         struct proc *p;
 1313         struct itimer *it;
 1314         int error;
 1315 
 1316         p = td->td_proc;
 1317         PROC_LOCK(p);
 1318         if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
 1319                 PROC_UNLOCK(p);
 1320                 error = EINVAL;
 1321         } else {
 1322                 PROC_UNLOCK(p);
 1323                 itimer_enter(it);
 1324                 error = CLOCK_CALL(it->it_clockid, timer_settime, (it,
 1325                     flags, val, oval));
 1326                 itimer_leave(it);
 1327                 ITIMER_UNLOCK(it);
 1328         }
 1329         return (error);
 1330 }
 1331 
 1332 #ifndef _SYS_SYSPROTO_H_
 1333 struct ktimer_gettime_args {
 1334         int timerid;
 1335         struct itimerspec * value;
 1336 };
 1337 #endif
 1338 int
 1339 sys_ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
 1340 {
 1341         struct itimerspec val;
 1342         int error;
 1343 
 1344         error = kern_ktimer_gettime(td, uap->timerid, &val);
 1345         if (error == 0)
 1346                 error = copyout(&val, uap->value, sizeof(val));
 1347         return (error);
 1348 }
 1349 
 1350 int
 1351 kern_ktimer_gettime(struct thread *td, int timer_id, struct itimerspec *val)
 1352 {
 1353         struct proc *p;
 1354         struct itimer *it;
 1355         int error;
 1356 
 1357         p = td->td_proc;
 1358         PROC_LOCK(p);
 1359         if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
 1360                 PROC_UNLOCK(p);
 1361                 error = EINVAL;
 1362         } else {
 1363                 PROC_UNLOCK(p);
 1364                 itimer_enter(it);
 1365                 error = CLOCK_CALL(it->it_clockid, timer_gettime, (it, val));
 1366                 itimer_leave(it);
 1367                 ITIMER_UNLOCK(it);
 1368         }
 1369         return (error);
 1370 }
 1371 
 1372 #ifndef _SYS_SYSPROTO_H_
 1373 struct timer_getoverrun_args {
 1374         int timerid;
 1375 };
 1376 #endif
 1377 int
 1378 sys_ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
 1379 {
 1380 
 1381         return (kern_ktimer_getoverrun(td, uap->timerid));
 1382 }
 1383 
 1384 int
 1385 kern_ktimer_getoverrun(struct thread *td, int timer_id)
 1386 {
 1387         struct proc *p = td->td_proc;
 1388         struct itimer *it;
 1389         int error ;
 1390 
 1391         PROC_LOCK(p);
 1392         if (timer_id < 3 ||
 1393             (it = itimer_find(p, timer_id)) == NULL) {
 1394                 PROC_UNLOCK(p);
 1395                 error = EINVAL;
 1396         } else {
 1397                 td->td_retval[0] = it->it_overrun_last;
 1398                 ITIMER_UNLOCK(it);
 1399                 PROC_UNLOCK(p);
 1400                 error = 0;
 1401         }
 1402         return (error);
 1403 }
 1404 
 1405 static int
 1406 realtimer_create(struct itimer *it)
 1407 {
 1408         callout_init_mtx(&it->it_callout, &it->it_mtx, 0);
 1409         return (0);
 1410 }
 1411 
 1412 static int
 1413 realtimer_delete(struct itimer *it)
 1414 {
 1415         mtx_assert(&it->it_mtx, MA_OWNED);
 1416         
 1417         /*
 1418          * clear timer's value and interval to tell realtimer_expire
 1419          * to not rearm the timer.
 1420          */
 1421         timespecclear(&it->it_time.it_value);
 1422         timespecclear(&it->it_time.it_interval);
 1423         ITIMER_UNLOCK(it);
 1424         callout_drain(&it->it_callout);
 1425         ITIMER_LOCK(it);
 1426         return (0);
 1427 }
 1428 
 1429 static int
 1430 realtimer_gettime(struct itimer *it, struct itimerspec *ovalue)
 1431 {
 1432         struct timespec cts;
 1433 
 1434         mtx_assert(&it->it_mtx, MA_OWNED);
 1435 
 1436         realtimer_clocktime(it->it_clockid, &cts);
 1437         *ovalue = it->it_time;
 1438         if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_nsec != 0) {
 1439                 timespecsub(&ovalue->it_value, &cts);
 1440                 if (ovalue->it_value.tv_sec < 0 ||
 1441                     (ovalue->it_value.tv_sec == 0 &&
 1442                      ovalue->it_value.tv_nsec == 0)) {
 1443                         ovalue->it_value.tv_sec  = 0;
 1444                         ovalue->it_value.tv_nsec = 1;
 1445                 }
 1446         }
 1447         return (0);
 1448 }
 1449 
 1450 static int
 1451 realtimer_settime(struct itimer *it, int flags,
 1452         struct itimerspec *value, struct itimerspec *ovalue)
 1453 {
 1454         struct timespec cts, ts;
 1455         struct timeval tv;
 1456         struct itimerspec val;
 1457 
 1458         mtx_assert(&it->it_mtx, MA_OWNED);
 1459 
 1460         val = *value;
 1461         if (itimespecfix(&val.it_value))
 1462                 return (EINVAL);
 1463 
 1464         if (timespecisset(&val.it_value)) {
 1465                 if (itimespecfix(&val.it_interval))
 1466                         return (EINVAL);
 1467         } else {
 1468                 timespecclear(&val.it_interval);
 1469         }
 1470         
 1471         if (ovalue != NULL)
 1472                 realtimer_gettime(it, ovalue);
 1473 
 1474         it->it_time = val;
 1475         if (timespecisset(&val.it_value)) {
 1476                 realtimer_clocktime(it->it_clockid, &cts);
 1477                 ts = val.it_value;
 1478                 if ((flags & TIMER_ABSTIME) == 0) {
 1479                         /* Convert to absolute time. */
 1480                         timespecadd(&it->it_time.it_value, &cts);
 1481                 } else {
 1482                         timespecsub(&ts, &cts);
 1483                         /*
 1484                          * We don't care if ts is negative, tztohz will
 1485                          * fix it.
 1486                          */
 1487                 }
 1488                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1489                 callout_reset(&it->it_callout, tvtohz(&tv),
 1490                         realtimer_expire, it);
 1491         } else {
 1492                 callout_stop(&it->it_callout);
 1493         }
 1494 
 1495         return (0);
 1496 }
 1497 
 1498 static void
 1499 realtimer_clocktime(clockid_t id, struct timespec *ts)
 1500 {
 1501         if (id == CLOCK_REALTIME)
 1502                 getnanotime(ts);
 1503         else    /* CLOCK_MONOTONIC */
 1504                 getnanouptime(ts);
 1505 }
 1506 
 1507 int
 1508 itimer_accept(struct proc *p, int timerid, ksiginfo_t *ksi)
 1509 {
 1510         struct itimer *it;
 1511 
 1512         PROC_LOCK_ASSERT(p, MA_OWNED);
 1513         it = itimer_find(p, timerid);
 1514         if (it != NULL) {
 1515                 ksi->ksi_overrun = it->it_overrun;
 1516                 it->it_overrun_last = it->it_overrun;
 1517                 it->it_overrun = 0;
 1518                 ITIMER_UNLOCK(it);
 1519                 return (0);
 1520         }
 1521         return (EINVAL);
 1522 }
 1523 
 1524 int
 1525 itimespecfix(struct timespec *ts)
 1526 {
 1527 
 1528         if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
 1529                 return (EINVAL);
 1530         if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000)
 1531                 ts->tv_nsec = tick * 1000;
 1532         return (0);
 1533 }
 1534 
 1535 /* Timeout callback for realtime timer */
 1536 static void
 1537 realtimer_expire(void *arg)
 1538 {
 1539         struct timespec cts, ts;
 1540         struct timeval tv;
 1541         struct itimer *it;
 1542 
 1543         it = (struct itimer *)arg;
 1544 
 1545         realtimer_clocktime(it->it_clockid, &cts);
 1546         /* Only fire if time is reached. */
 1547         if (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1548                 if (timespecisset(&it->it_time.it_interval)) {
 1549                         timespecadd(&it->it_time.it_value,
 1550                                     &it->it_time.it_interval);
 1551                         while (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1552                                 if (it->it_overrun < INT_MAX)
 1553                                         it->it_overrun++;
 1554                                 else
 1555                                         it->it_ksi.ksi_errno = ERANGE;
 1556                                 timespecadd(&it->it_time.it_value,
 1557                                             &it->it_time.it_interval);
 1558                         }
 1559                 } else {
 1560                         /* single shot timer ? */
 1561                         timespecclear(&it->it_time.it_value);
 1562                 }
 1563                 if (timespecisset(&it->it_time.it_value)) {
 1564                         ts = it->it_time.it_value;
 1565                         timespecsub(&ts, &cts);
 1566                         TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1567                         callout_reset(&it->it_callout, tvtohz(&tv),
 1568                                  realtimer_expire, it);
 1569                 }
 1570                 itimer_enter(it);
 1571                 ITIMER_UNLOCK(it);
 1572                 itimer_fire(it);
 1573                 ITIMER_LOCK(it);
 1574                 itimer_leave(it);
 1575         } else if (timespecisset(&it->it_time.it_value)) {
 1576                 ts = it->it_time.it_value;
 1577                 timespecsub(&ts, &cts);
 1578                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1579                 callout_reset(&it->it_callout, tvtohz(&tv), realtimer_expire,
 1580                         it);
 1581         }
 1582 }
 1583 
 1584 void
 1585 itimer_fire(struct itimer *it)
 1586 {
 1587         struct proc *p = it->it_proc;
 1588         struct thread *td;
 1589 
 1590         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1591             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1592                 if (sigev_findtd(p, &it->it_sigev, &td) != 0) {
 1593                         ITIMER_LOCK(it);
 1594                         timespecclear(&it->it_time.it_value);
 1595                         timespecclear(&it->it_time.it_interval);
 1596                         callout_stop(&it->it_callout);
 1597                         ITIMER_UNLOCK(it);
 1598                         return;
 1599                 }
 1600                 if (!KSI_ONQ(&it->it_ksi)) {
 1601                         it->it_ksi.ksi_errno = 0;
 1602                         ksiginfo_set_sigev(&it->it_ksi, &it->it_sigev);
 1603                         tdsendsignal(p, td, it->it_ksi.ksi_signo, &it->it_ksi);
 1604                 } else {
 1605                         if (it->it_overrun < INT_MAX)
 1606                                 it->it_overrun++;
 1607                         else
 1608                                 it->it_ksi.ksi_errno = ERANGE;
 1609                 }
 1610                 PROC_UNLOCK(p);
 1611         }
 1612 }
 1613 
 1614 static void
 1615 itimers_alloc(struct proc *p)
 1616 {
 1617         struct itimers *its;
 1618         int i;
 1619 
 1620         its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
 1621         LIST_INIT(&its->its_virtual);
 1622         LIST_INIT(&its->its_prof);
 1623         TAILQ_INIT(&its->its_worklist);
 1624         for (i = 0; i < TIMER_MAX; i++)
 1625                 its->its_timers[i] = NULL;
 1626         PROC_LOCK(p);
 1627         if (p->p_itimers == NULL) {
 1628                 p->p_itimers = its;
 1629                 PROC_UNLOCK(p);
 1630         }
 1631         else {
 1632                 PROC_UNLOCK(p);
 1633                 free(its, M_SUBPROC);
 1634         }
 1635 }
 1636 
 1637 static void
 1638 itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
 1639 {
 1640         itimers_event_hook_exit(arg, p);
 1641 }
 1642 
 1643 /* Clean up timers when some process events are being triggered. */
 1644 static void
 1645 itimers_event_hook_exit(void *arg, struct proc *p)
 1646 {
 1647         struct itimers *its;
 1648         struct itimer *it;
 1649         int event = (int)(intptr_t)arg;
 1650         int i;
 1651 
 1652         if (p->p_itimers != NULL) {
 1653                 its = p->p_itimers;
 1654                 for (i = 0; i < MAX_CLOCKS; ++i) {
 1655                         if (posix_clocks[i].event_hook != NULL)
 1656                                 CLOCK_CALL(i, event_hook, (p, i, event));
 1657                 }
 1658                 /*
 1659                  * According to susv3, XSI interval timers should be inherited
 1660                  * by new image.
 1661                  */
 1662                 if (event == ITIMER_EV_EXEC)
 1663                         i = 3;
 1664                 else if (event == ITIMER_EV_EXIT)
 1665                         i = 0;
 1666                 else
 1667                         panic("unhandled event");
 1668                 for (; i < TIMER_MAX; ++i) {
 1669                         if ((it = its->its_timers[i]) != NULL)
 1670                                 kern_ktimer_delete(curthread, i);
 1671                 }
 1672                 if (its->its_timers[0] == NULL &&
 1673                     its->its_timers[1] == NULL &&
 1674                     its->its_timers[2] == NULL) {
 1675                         free(its, M_SUBPROC);
 1676                         p->p_itimers = NULL;
 1677                 }
 1678         }
 1679 }

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