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  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1989, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)kern_time.c 8.1 (Berkeley) 6/10/93
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: releng/12.0/sys/kern/kern_time.c 336914 2018-07-30 15:46:40Z asomers $");
   36 
   37 #include "opt_ktrace.h"
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/limits.h>
   42 #include <sys/clock.h>
   43 #include <sys/lock.h>
   44 #include <sys/mutex.h>
   45 #include <sys/sysproto.h>
   46 #include <sys/eventhandler.h>
   47 #include <sys/resourcevar.h>
   48 #include <sys/signalvar.h>
   49 #include <sys/kernel.h>
   50 #include <sys/sleepqueue.h>
   51 #include <sys/syscallsubr.h>
   52 #include <sys/sysctl.h>
   53 #include <sys/sysent.h>
   54 #include <sys/priv.h>
   55 #include <sys/proc.h>
   56 #include <sys/posix4.h>
   57 #include <sys/time.h>
   58 #include <sys/timers.h>
   59 #include <sys/timetc.h>
   60 #include <sys/vnode.h>
   61 #ifdef KTRACE
   62 #include <sys/ktrace.h>
   63 #endif
   64 
   65 #include <vm/vm.h>
   66 #include <vm/vm_extern.h>
   67 
   68 #define MAX_CLOCKS      (CLOCK_MONOTONIC+1)
   69 #define CPUCLOCK_BIT            0x80000000
   70 #define CPUCLOCK_PROCESS_BIT    0x40000000
   71 #define CPUCLOCK_ID_MASK        (~(CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT))
   72 #define MAKE_THREAD_CPUCLOCK(tid)       (CPUCLOCK_BIT|(tid))
   73 #define MAKE_PROCESS_CPUCLOCK(pid)      \
   74         (CPUCLOCK_BIT|CPUCLOCK_PROCESS_BIT|(pid))
   75 
   76 static struct kclock    posix_clocks[MAX_CLOCKS];
   77 static uma_zone_t       itimer_zone = NULL;
   78 
   79 /*
   80  * Time of day and interval timer support.
   81  *
   82  * These routines provide the kernel entry points to get and set
   83  * the time-of-day and per-process interval timers.  Subroutines
   84  * here provide support for adding and subtracting timeval structures
   85  * and decrementing interval timers, optionally reloading the interval
   86  * timers when they expire.
   87  */
   88 
   89 static int      settime(struct thread *, struct timeval *);
   90 static void     timevalfix(struct timeval *);
   91 static int      user_clock_nanosleep(struct thread *td, clockid_t clock_id,
   92                     int flags, const struct timespec *ua_rqtp,
   93                     struct timespec *ua_rmtp);
   94 
   95 static void     itimer_start(void);
   96 static int      itimer_init(void *, int, int);
   97 static void     itimer_fini(void *, int);
   98 static void     itimer_enter(struct itimer *);
   99 static void     itimer_leave(struct itimer *);
  100 static struct itimer *itimer_find(struct proc *, int);
  101 static void     itimers_alloc(struct proc *);
  102 static void     itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp);
  103 static void     itimers_event_hook_exit(void *arg, struct proc *p);
  104 static int      realtimer_create(struct itimer *);
  105 static int      realtimer_gettime(struct itimer *, struct itimerspec *);
  106 static int      realtimer_settime(struct itimer *, int,
  107                         struct itimerspec *, struct itimerspec *);
  108 static int      realtimer_delete(struct itimer *);
  109 static void     realtimer_clocktime(clockid_t, struct timespec *);
  110 static void     realtimer_expire(void *);
  111 
  112 int             register_posix_clock(int, struct kclock *);
  113 void            itimer_fire(struct itimer *it);
  114 int             itimespecfix(struct timespec *ts);
  115 
  116 #define CLOCK_CALL(clock, call, arglist)                \
  117         ((*posix_clocks[clock].call) arglist)
  118 
  119 SYSINIT(posix_timer, SI_SUB_P1003_1B, SI_ORDER_FIRST+4, itimer_start, NULL);
  120 
  121 
  122 static int
  123 settime(struct thread *td, struct timeval *tv)
  124 {
  125         struct timeval delta, tv1, tv2;
  126         static struct timeval maxtime, laststep;
  127         struct timespec ts;
  128 
  129         microtime(&tv1);
  130         delta = *tv;
  131         timevalsub(&delta, &tv1);
  132 
  133         /*
  134          * If the system is secure, we do not allow the time to be 
  135          * set to a value earlier than 1 second less than the highest
  136          * time we have yet seen. The worst a miscreant can do in
  137          * this circumstance is "freeze" time. He couldn't go
  138          * back to the past.
  139          *
  140          * We similarly do not allow the clock to be stepped more
  141          * than one second, nor more than once per second. This allows
  142          * a miscreant to make the clock march double-time, but no worse.
  143          */
  144         if (securelevel_gt(td->td_ucred, 1) != 0) {
  145                 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
  146                         /*
  147                          * Update maxtime to latest time we've seen.
  148                          */
  149                         if (tv1.tv_sec > maxtime.tv_sec)
  150                                 maxtime = tv1;
  151                         tv2 = *tv;
  152                         timevalsub(&tv2, &maxtime);
  153                         if (tv2.tv_sec < -1) {
  154                                 tv->tv_sec = maxtime.tv_sec - 1;
  155                                 printf("Time adjustment clamped to -1 second\n");
  156                         }
  157                 } else {
  158                         if (tv1.tv_sec == laststep.tv_sec)
  159                                 return (EPERM);
  160                         if (delta.tv_sec > 1) {
  161                                 tv->tv_sec = tv1.tv_sec + 1;
  162                                 printf("Time adjustment clamped to +1 second\n");
  163                         }
  164                         laststep = *tv;
  165                 }
  166         }
  167 
  168         ts.tv_sec = tv->tv_sec;
  169         ts.tv_nsec = tv->tv_usec * 1000;
  170         tc_setclock(&ts);
  171         resettodr();
  172         return (0);
  173 }
  174 
  175 #ifndef _SYS_SYSPROTO_H_
  176 struct clock_getcpuclockid2_args {
  177         id_t id;
  178         int which,
  179         clockid_t *clock_id;
  180 };
  181 #endif
  182 /* ARGSUSED */
  183 int
  184 sys_clock_getcpuclockid2(struct thread *td, struct clock_getcpuclockid2_args *uap)
  185 {
  186         clockid_t clk_id;
  187         int error;
  188 
  189         error = kern_clock_getcpuclockid2(td, uap->id, uap->which, &clk_id);
  190         if (error == 0)
  191                 error = copyout(&clk_id, uap->clock_id, sizeof(clockid_t));
  192         return (error);
  193 }
  194 
  195 int
  196 kern_clock_getcpuclockid2(struct thread *td, id_t id, int which,
  197     clockid_t *clk_id)
  198 {
  199         struct proc *p;
  200         pid_t pid;
  201         lwpid_t tid;
  202         int error;
  203 
  204         switch (which) {
  205         case CPUCLOCK_WHICH_PID:
  206                 if (id != 0) {
  207                         error = pget(id, PGET_CANSEE | PGET_NOTID, &p);
  208                         if (error != 0)
  209                                 return (error);
  210                         PROC_UNLOCK(p);
  211                         pid = id;
  212                 } else {
  213                         pid = td->td_proc->p_pid;
  214                 }
  215                 *clk_id = MAKE_PROCESS_CPUCLOCK(pid);
  216                 return (0);
  217         case CPUCLOCK_WHICH_TID:
  218                 tid = id == 0 ? td->td_tid : id;
  219                 *clk_id = MAKE_THREAD_CPUCLOCK(tid);
  220                 return (0);
  221         default:
  222                 return (EINVAL);
  223         }
  224 }
  225 
  226 #ifndef _SYS_SYSPROTO_H_
  227 struct clock_gettime_args {
  228         clockid_t clock_id;
  229         struct  timespec *tp;
  230 };
  231 #endif
  232 /* ARGSUSED */
  233 int
  234 sys_clock_gettime(struct thread *td, struct clock_gettime_args *uap)
  235 {
  236         struct timespec ats;
  237         int error;
  238 
  239         error = kern_clock_gettime(td, uap->clock_id, &ats);
  240         if (error == 0)
  241                 error = copyout(&ats, uap->tp, sizeof(ats));
  242 
  243         return (error);
  244 }
  245 
  246 static inline void 
  247 cputick2timespec(uint64_t runtime, struct timespec *ats)
  248 {
  249         runtime = cputick2usec(runtime);
  250         ats->tv_sec = runtime / 1000000;
  251         ats->tv_nsec = runtime % 1000000 * 1000;
  252 }
  253 
  254 static void
  255 get_thread_cputime(struct thread *targettd, struct timespec *ats)
  256 {
  257         uint64_t runtime, curtime, switchtime;
  258 
  259         if (targettd == NULL) { /* current thread */
  260                 critical_enter();
  261                 switchtime = PCPU_GET(switchtime);
  262                 curtime = cpu_ticks();
  263                 runtime = curthread->td_runtime;
  264                 critical_exit();
  265                 runtime += curtime - switchtime;
  266         } else {
  267                 thread_lock(targettd);
  268                 runtime = targettd->td_runtime;
  269                 thread_unlock(targettd);
  270         }
  271         cputick2timespec(runtime, ats);
  272 }
  273 
  274 static void
  275 get_process_cputime(struct proc *targetp, struct timespec *ats)
  276 {
  277         uint64_t runtime;
  278         struct rusage ru;
  279 
  280         PROC_STATLOCK(targetp);
  281         rufetch(targetp, &ru);
  282         runtime = targetp->p_rux.rux_runtime;
  283         if (curthread->td_proc == targetp)
  284                 runtime += cpu_ticks() - PCPU_GET(switchtime);
  285         PROC_STATUNLOCK(targetp);
  286         cputick2timespec(runtime, ats);
  287 }
  288 
  289 static int
  290 get_cputime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  291 {
  292         struct proc *p, *p2;
  293         struct thread *td2;
  294         lwpid_t tid;
  295         pid_t pid;
  296         int error;
  297 
  298         p = td->td_proc;
  299         if ((clock_id & CPUCLOCK_PROCESS_BIT) == 0) {
  300                 tid = clock_id & CPUCLOCK_ID_MASK;
  301                 td2 = tdfind(tid, p->p_pid);
  302                 if (td2 == NULL)
  303                         return (EINVAL);
  304                 get_thread_cputime(td2, ats);
  305                 PROC_UNLOCK(td2->td_proc);
  306         } else {
  307                 pid = clock_id & CPUCLOCK_ID_MASK;
  308                 error = pget(pid, PGET_CANSEE, &p2);
  309                 if (error != 0)
  310                         return (EINVAL);
  311                 get_process_cputime(p2, ats);
  312                 PROC_UNLOCK(p2);
  313         }
  314         return (0);
  315 }
  316 
  317 int
  318 kern_clock_gettime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  319 {
  320         struct timeval sys, user;
  321         struct proc *p;
  322 
  323         p = td->td_proc;
  324         switch (clock_id) {
  325         case CLOCK_REALTIME:            /* Default to precise. */
  326         case CLOCK_REALTIME_PRECISE:
  327                 nanotime(ats);
  328                 break;
  329         case CLOCK_REALTIME_FAST:
  330                 getnanotime(ats);
  331                 break;
  332         case CLOCK_VIRTUAL:
  333                 PROC_LOCK(p);
  334                 PROC_STATLOCK(p);
  335                 calcru(p, &user, &sys);
  336                 PROC_STATUNLOCK(p);
  337                 PROC_UNLOCK(p);
  338                 TIMEVAL_TO_TIMESPEC(&user, ats);
  339                 break;
  340         case CLOCK_PROF:
  341                 PROC_LOCK(p);
  342                 PROC_STATLOCK(p);
  343                 calcru(p, &user, &sys);
  344                 PROC_STATUNLOCK(p);
  345                 PROC_UNLOCK(p);
  346                 timevaladd(&user, &sys);
  347                 TIMEVAL_TO_TIMESPEC(&user, ats);
  348                 break;
  349         case CLOCK_MONOTONIC:           /* Default to precise. */
  350         case CLOCK_MONOTONIC_PRECISE:
  351         case CLOCK_UPTIME:
  352         case CLOCK_UPTIME_PRECISE:
  353                 nanouptime(ats);
  354                 break;
  355         case CLOCK_UPTIME_FAST:
  356         case CLOCK_MONOTONIC_FAST:
  357                 getnanouptime(ats);
  358                 break;
  359         case CLOCK_SECOND:
  360                 ats->tv_sec = time_second;
  361                 ats->tv_nsec = 0;
  362                 break;
  363         case CLOCK_THREAD_CPUTIME_ID:
  364                 get_thread_cputime(NULL, ats);
  365                 break;
  366         case CLOCK_PROCESS_CPUTIME_ID:
  367                 PROC_LOCK(p);
  368                 get_process_cputime(p, ats);
  369                 PROC_UNLOCK(p);
  370                 break;
  371         default:
  372                 if ((int)clock_id >= 0)
  373                         return (EINVAL);
  374                 return (get_cputime(td, clock_id, ats));
  375         }
  376         return (0);
  377 }
  378 
  379 #ifndef _SYS_SYSPROTO_H_
  380 struct clock_settime_args {
  381         clockid_t clock_id;
  382         const struct    timespec *tp;
  383 };
  384 #endif
  385 /* ARGSUSED */
  386 int
  387 sys_clock_settime(struct thread *td, struct clock_settime_args *uap)
  388 {
  389         struct timespec ats;
  390         int error;
  391 
  392         if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
  393                 return (error);
  394         return (kern_clock_settime(td, uap->clock_id, &ats));
  395 }
  396 
  397 static int allow_insane_settime = 0;
  398 SYSCTL_INT(_debug, OID_AUTO, allow_insane_settime, CTLFLAG_RWTUN,
  399     &allow_insane_settime, 0,
  400     "do not perform possibly restrictive checks on settime(2) args");
  401 
  402 int
  403 kern_clock_settime(struct thread *td, clockid_t clock_id, struct timespec *ats)
  404 {
  405         struct timeval atv;
  406         int error;
  407 
  408         if ((error = priv_check(td, PRIV_CLOCK_SETTIME)) != 0)
  409                 return (error);
  410         if (clock_id != CLOCK_REALTIME)
  411                 return (EINVAL);
  412         if (ats->tv_nsec < 0 || ats->tv_nsec >= 1000000000 ||
  413             ats->tv_sec < 0)
  414                 return (EINVAL);
  415         if (!allow_insane_settime && ats->tv_sec > 8000ULL * 365 * 24 * 60 * 60)
  416                 return (EINVAL);
  417         /* XXX Don't convert nsec->usec and back */
  418         TIMESPEC_TO_TIMEVAL(&atv, ats);
  419         error = settime(td, &atv);
  420         return (error);
  421 }
  422 
  423 #ifndef _SYS_SYSPROTO_H_
  424 struct clock_getres_args {
  425         clockid_t clock_id;
  426         struct  timespec *tp;
  427 };
  428 #endif
  429 int
  430 sys_clock_getres(struct thread *td, struct clock_getres_args *uap)
  431 {
  432         struct timespec ts;
  433         int error;
  434 
  435         if (uap->tp == NULL)
  436                 return (0);
  437 
  438         error = kern_clock_getres(td, uap->clock_id, &ts);
  439         if (error == 0)
  440                 error = copyout(&ts, uap->tp, sizeof(ts));
  441         return (error);
  442 }
  443 
  444 int
  445 kern_clock_getres(struct thread *td, clockid_t clock_id, struct timespec *ts)
  446 {
  447 
  448         ts->tv_sec = 0;
  449         switch (clock_id) {
  450         case CLOCK_REALTIME:
  451         case CLOCK_REALTIME_FAST:
  452         case CLOCK_REALTIME_PRECISE:
  453         case CLOCK_MONOTONIC:
  454         case CLOCK_MONOTONIC_FAST:
  455         case CLOCK_MONOTONIC_PRECISE:
  456         case CLOCK_UPTIME:
  457         case CLOCK_UPTIME_FAST:
  458         case CLOCK_UPTIME_PRECISE:
  459                 /*
  460                  * Round up the result of the division cheaply by adding 1.
  461                  * Rounding up is especially important if rounding down
  462                  * would give 0.  Perfect rounding is unimportant.
  463                  */
  464                 ts->tv_nsec = 1000000000 / tc_getfrequency() + 1;
  465                 break;
  466         case CLOCK_VIRTUAL:
  467         case CLOCK_PROF:
  468                 /* Accurately round up here because we can do so cheaply. */
  469                 ts->tv_nsec = howmany(1000000000, hz);
  470                 break;
  471         case CLOCK_SECOND:
  472                 ts->tv_sec = 1;
  473                 ts->tv_nsec = 0;
  474                 break;
  475         case CLOCK_THREAD_CPUTIME_ID:
  476         case CLOCK_PROCESS_CPUTIME_ID:
  477         cputime:
  478                 /* sync with cputick2usec */
  479                 ts->tv_nsec = 1000000 / cpu_tickrate();
  480                 if (ts->tv_nsec == 0)
  481                         ts->tv_nsec = 1000;
  482                 break;
  483         default:
  484                 if ((int)clock_id < 0)
  485                         goto cputime;
  486                 return (EINVAL);
  487         }
  488         return (0);
  489 }
  490 
  491 int
  492 kern_nanosleep(struct thread *td, struct timespec *rqt, struct timespec *rmt)
  493 {
  494 
  495         return (kern_clock_nanosleep(td, CLOCK_REALTIME, TIMER_RELTIME, rqt,
  496             rmt));
  497 }
  498 
  499 static uint8_t nanowait[MAXCPU];
  500 
  501 int
  502 kern_clock_nanosleep(struct thread *td, clockid_t clock_id, int flags,
  503     const struct timespec *rqt, struct timespec *rmt)
  504 {
  505         struct timespec ts, now;
  506         sbintime_t sbt, sbtt, prec, tmp;
  507         time_t over;
  508         int error;
  509         bool is_abs_real;
  510 
  511         if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
  512                 return (EINVAL);
  513         if ((flags & ~TIMER_ABSTIME) != 0)
  514                 return (EINVAL);
  515         switch (clock_id) {
  516         case CLOCK_REALTIME:
  517         case CLOCK_REALTIME_PRECISE:
  518         case CLOCK_REALTIME_FAST:
  519         case CLOCK_SECOND:
  520                 is_abs_real = (flags & TIMER_ABSTIME) != 0;
  521                 break;
  522         case CLOCK_MONOTONIC:
  523         case CLOCK_MONOTONIC_PRECISE:
  524         case CLOCK_MONOTONIC_FAST:
  525         case CLOCK_UPTIME:
  526         case CLOCK_UPTIME_PRECISE:
  527         case CLOCK_UPTIME_FAST:
  528                 is_abs_real = false;
  529                 break;
  530         case CLOCK_VIRTUAL:
  531         case CLOCK_PROF:
  532         case CLOCK_PROCESS_CPUTIME_ID:
  533                 return (ENOTSUP);
  534         case CLOCK_THREAD_CPUTIME_ID:
  535         default:
  536                 return (EINVAL);
  537         }
  538         do {
  539                 ts = *rqt;
  540                 if ((flags & TIMER_ABSTIME) != 0) {
  541                         if (is_abs_real)
  542                                 td->td_rtcgen =
  543                                     atomic_load_acq_int(&rtc_generation);
  544                         error = kern_clock_gettime(td, clock_id, &now);
  545                         KASSERT(error == 0, ("kern_clock_gettime: %d", error));
  546                         timespecsub(&ts, &now, &ts);
  547                 }
  548                 if (ts.tv_sec < 0 || (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
  549                         error = EWOULDBLOCK;
  550                         break;
  551                 }
  552                 if (ts.tv_sec > INT32_MAX / 2) {
  553                         over = ts.tv_sec - INT32_MAX / 2;
  554                         ts.tv_sec -= over;
  555                 } else
  556                         over = 0;
  557                 tmp = tstosbt(ts);
  558                 prec = tmp;
  559                 prec >>= tc_precexp;
  560                 if (TIMESEL(&sbt, tmp))
  561                         sbt += tc_tick_sbt;
  562                 sbt += tmp;
  563                 error = tsleep_sbt(&nanowait[curcpu], PWAIT | PCATCH, "nanslp",
  564                     sbt, prec, C_ABSOLUTE);
  565         } while (error == 0 && is_abs_real && td->td_rtcgen == 0);
  566         td->td_rtcgen = 0;
  567         if (error != EWOULDBLOCK) {
  568                 if (TIMESEL(&sbtt, tmp))
  569                         sbtt += tc_tick_sbt;
  570                 if (sbtt >= sbt)
  571                         return (0);
  572                 if (error == ERESTART)
  573                         error = EINTR;
  574                 if ((flags & TIMER_ABSTIME) == 0 && rmt != NULL) {
  575                         ts = sbttots(sbt - sbtt);
  576                         ts.tv_sec += over;
  577                         if (ts.tv_sec < 0)
  578                                 timespecclear(&ts);
  579                         *rmt = ts;
  580                 }
  581                 return (error);
  582         }
  583         return (0);
  584 }
  585 
  586 #ifndef _SYS_SYSPROTO_H_
  587 struct nanosleep_args {
  588         struct  timespec *rqtp;
  589         struct  timespec *rmtp;
  590 };
  591 #endif
  592 /* ARGSUSED */
  593 int
  594 sys_nanosleep(struct thread *td, struct nanosleep_args *uap)
  595 {
  596 
  597         return (user_clock_nanosleep(td, CLOCK_REALTIME, TIMER_RELTIME,
  598             uap->rqtp, uap->rmtp));
  599 }
  600 
  601 #ifndef _SYS_SYSPROTO_H_
  602 struct clock_nanosleep_args {
  603         clockid_t clock_id;
  604         int       flags;
  605         struct  timespec *rqtp;
  606         struct  timespec *rmtp;
  607 };
  608 #endif
  609 /* ARGSUSED */
  610 int
  611 sys_clock_nanosleep(struct thread *td, struct clock_nanosleep_args *uap)
  612 {
  613         int error;
  614 
  615         error = user_clock_nanosleep(td, uap->clock_id, uap->flags, uap->rqtp,
  616             uap->rmtp);
  617         return (kern_posix_error(td, error));
  618 }
  619 
  620 static int
  621 user_clock_nanosleep(struct thread *td, clockid_t clock_id, int flags,
  622     const struct timespec *ua_rqtp, struct timespec *ua_rmtp)
  623 {
  624         struct timespec rmt, rqt;
  625         int error;
  626 
  627         error = copyin(ua_rqtp, &rqt, sizeof(rqt));
  628         if (error)
  629                 return (error);
  630         if (ua_rmtp != NULL && (flags & TIMER_ABSTIME) == 0 &&
  631             !useracc(ua_rmtp, sizeof(rmt), VM_PROT_WRITE))
  632                 return (EFAULT);
  633         error = kern_clock_nanosleep(td, clock_id, flags, &rqt, &rmt);
  634         if (error == EINTR && ua_rmtp != NULL && (flags & TIMER_ABSTIME) == 0) {
  635                 int error2;
  636 
  637                 error2 = copyout(&rmt, ua_rmtp, sizeof(rmt));
  638                 if (error2)
  639                         error = error2;
  640         }
  641         return (error);
  642 }
  643 
  644 #ifndef _SYS_SYSPROTO_H_
  645 struct gettimeofday_args {
  646         struct  timeval *tp;
  647         struct  timezone *tzp;
  648 };
  649 #endif
  650 /* ARGSUSED */
  651 int
  652 sys_gettimeofday(struct thread *td, struct gettimeofday_args *uap)
  653 {
  654         struct timeval atv;
  655         struct timezone rtz;
  656         int error = 0;
  657 
  658         if (uap->tp) {
  659                 microtime(&atv);
  660                 error = copyout(&atv, uap->tp, sizeof (atv));
  661         }
  662         if (error == 0 && uap->tzp != NULL) {
  663                 rtz.tz_minuteswest = tz_minuteswest;
  664                 rtz.tz_dsttime = tz_dsttime;
  665                 error = copyout(&rtz, uap->tzp, sizeof (rtz));
  666         }
  667         return (error);
  668 }
  669 
  670 #ifndef _SYS_SYSPROTO_H_
  671 struct settimeofday_args {
  672         struct  timeval *tv;
  673         struct  timezone *tzp;
  674 };
  675 #endif
  676 /* ARGSUSED */
  677 int
  678 sys_settimeofday(struct thread *td, struct settimeofday_args *uap)
  679 {
  680         struct timeval atv, *tvp;
  681         struct timezone atz, *tzp;
  682         int error;
  683 
  684         if (uap->tv) {
  685                 error = copyin(uap->tv, &atv, sizeof(atv));
  686                 if (error)
  687                         return (error);
  688                 tvp = &atv;
  689         } else
  690                 tvp = NULL;
  691         if (uap->tzp) {
  692                 error = copyin(uap->tzp, &atz, sizeof(atz));
  693                 if (error)
  694                         return (error);
  695                 tzp = &atz;
  696         } else
  697                 tzp = NULL;
  698         return (kern_settimeofday(td, tvp, tzp));
  699 }
  700 
  701 int
  702 kern_settimeofday(struct thread *td, struct timeval *tv, struct timezone *tzp)
  703 {
  704         int error;
  705 
  706         error = priv_check(td, PRIV_SETTIMEOFDAY);
  707         if (error)
  708                 return (error);
  709         /* Verify all parameters before changing time. */
  710         if (tv) {
  711                 if (tv->tv_usec < 0 || tv->tv_usec >= 1000000 ||
  712                     tv->tv_sec < 0)
  713                         return (EINVAL);
  714                 error = settime(td, tv);
  715         }
  716         if (tzp && error == 0) {
  717                 tz_minuteswest = tzp->tz_minuteswest;
  718                 tz_dsttime = tzp->tz_dsttime;
  719         }
  720         return (error);
  721 }
  722 
  723 /*
  724  * Get value of an interval timer.  The process virtual and profiling virtual
  725  * time timers are kept in the p_stats area, since they can be swapped out.
  726  * These are kept internally in the way they are specified externally: in
  727  * time until they expire.
  728  *
  729  * The real time interval timer is kept in the process table slot for the
  730  * process, and its value (it_value) is kept as an absolute time rather than
  731  * as a delta, so that it is easy to keep periodic real-time signals from
  732  * drifting.
  733  *
  734  * Virtual time timers are processed in the hardclock() routine of
  735  * kern_clock.c.  The real time timer is processed by a timeout routine,
  736  * called from the softclock() routine.  Since a callout may be delayed in
  737  * real time due to interrupt processing in the system, it is possible for
  738  * the real time timeout routine (realitexpire, given below), to be delayed
  739  * in real time past when it is supposed to occur.  It does not suffice,
  740  * therefore, to reload the real timer .it_value from the real time timers
  741  * .it_interval.  Rather, we compute the next time in absolute time the timer
  742  * should go off.
  743  */
  744 #ifndef _SYS_SYSPROTO_H_
  745 struct getitimer_args {
  746         u_int   which;
  747         struct  itimerval *itv;
  748 };
  749 #endif
  750 int
  751 sys_getitimer(struct thread *td, struct getitimer_args *uap)
  752 {
  753         struct itimerval aitv;
  754         int error;
  755 
  756         error = kern_getitimer(td, uap->which, &aitv);
  757         if (error != 0)
  758                 return (error);
  759         return (copyout(&aitv, uap->itv, sizeof (struct itimerval)));
  760 }
  761 
  762 int
  763 kern_getitimer(struct thread *td, u_int which, struct itimerval *aitv)
  764 {
  765         struct proc *p = td->td_proc;
  766         struct timeval ctv;
  767 
  768         if (which > ITIMER_PROF)
  769                 return (EINVAL);
  770 
  771         if (which == ITIMER_REAL) {
  772                 /*
  773                  * Convert from absolute to relative time in .it_value
  774                  * part of real time timer.  If time for real time timer
  775                  * has passed return 0, else return difference between
  776                  * current time and time for the timer to go off.
  777                  */
  778                 PROC_LOCK(p);
  779                 *aitv = p->p_realtimer;
  780                 PROC_UNLOCK(p);
  781                 if (timevalisset(&aitv->it_value)) {
  782                         microuptime(&ctv);
  783                         if (timevalcmp(&aitv->it_value, &ctv, <))
  784                                 timevalclear(&aitv->it_value);
  785                         else
  786                                 timevalsub(&aitv->it_value, &ctv);
  787                 }
  788         } else {
  789                 PROC_ITIMLOCK(p);
  790                 *aitv = p->p_stats->p_timer[which];
  791                 PROC_ITIMUNLOCK(p);
  792         }
  793 #ifdef KTRACE
  794         if (KTRPOINT(td, KTR_STRUCT))
  795                 ktritimerval(aitv);
  796 #endif
  797         return (0);
  798 }
  799 
  800 #ifndef _SYS_SYSPROTO_H_
  801 struct setitimer_args {
  802         u_int   which;
  803         struct  itimerval *itv, *oitv;
  804 };
  805 #endif
  806 int
  807 sys_setitimer(struct thread *td, struct setitimer_args *uap)
  808 {
  809         struct itimerval aitv, oitv;
  810         int error;
  811 
  812         if (uap->itv == NULL) {
  813                 uap->itv = uap->oitv;
  814                 return (sys_getitimer(td, (struct getitimer_args *)uap));
  815         }
  816 
  817         if ((error = copyin(uap->itv, &aitv, sizeof(struct itimerval))))
  818                 return (error);
  819         error = kern_setitimer(td, uap->which, &aitv, &oitv);
  820         if (error != 0 || uap->oitv == NULL)
  821                 return (error);
  822         return (copyout(&oitv, uap->oitv, sizeof(struct itimerval)));
  823 }
  824 
  825 int
  826 kern_setitimer(struct thread *td, u_int which, struct itimerval *aitv,
  827     struct itimerval *oitv)
  828 {
  829         struct proc *p = td->td_proc;
  830         struct timeval ctv;
  831         sbintime_t sbt, pr;
  832 
  833         if (aitv == NULL)
  834                 return (kern_getitimer(td, which, oitv));
  835 
  836         if (which > ITIMER_PROF)
  837                 return (EINVAL);
  838 #ifdef KTRACE
  839         if (KTRPOINT(td, KTR_STRUCT))
  840                 ktritimerval(aitv);
  841 #endif
  842         if (itimerfix(&aitv->it_value) ||
  843             aitv->it_value.tv_sec > INT32_MAX / 2)
  844                 return (EINVAL);
  845         if (!timevalisset(&aitv->it_value))
  846                 timevalclear(&aitv->it_interval);
  847         else if (itimerfix(&aitv->it_interval) ||
  848             aitv->it_interval.tv_sec > INT32_MAX / 2)
  849                 return (EINVAL);
  850 
  851         if (which == ITIMER_REAL) {
  852                 PROC_LOCK(p);
  853                 if (timevalisset(&p->p_realtimer.it_value))
  854                         callout_stop(&p->p_itcallout);
  855                 microuptime(&ctv);
  856                 if (timevalisset(&aitv->it_value)) {
  857                         pr = tvtosbt(aitv->it_value) >> tc_precexp;
  858                         timevaladd(&aitv->it_value, &ctv);
  859                         sbt = tvtosbt(aitv->it_value);
  860                         callout_reset_sbt(&p->p_itcallout, sbt, pr,
  861                             realitexpire, p, C_ABSOLUTE);
  862                 }
  863                 *oitv = p->p_realtimer;
  864                 p->p_realtimer = *aitv;
  865                 PROC_UNLOCK(p);
  866                 if (timevalisset(&oitv->it_value)) {
  867                         if (timevalcmp(&oitv->it_value, &ctv, <))
  868                                 timevalclear(&oitv->it_value);
  869                         else
  870                                 timevalsub(&oitv->it_value, &ctv);
  871                 }
  872         } else {
  873                 if (aitv->it_interval.tv_sec == 0 &&
  874                     aitv->it_interval.tv_usec != 0 &&
  875                     aitv->it_interval.tv_usec < tick)
  876                         aitv->it_interval.tv_usec = tick;
  877                 if (aitv->it_value.tv_sec == 0 &&
  878                     aitv->it_value.tv_usec != 0 &&
  879                     aitv->it_value.tv_usec < tick)
  880                         aitv->it_value.tv_usec = tick;
  881                 PROC_ITIMLOCK(p);
  882                 *oitv = p->p_stats->p_timer[which];
  883                 p->p_stats->p_timer[which] = *aitv;
  884                 PROC_ITIMUNLOCK(p);
  885         }
  886 #ifdef KTRACE
  887         if (KTRPOINT(td, KTR_STRUCT))
  888                 ktritimerval(oitv);
  889 #endif
  890         return (0);
  891 }
  892 
  893 /*
  894  * Real interval timer expired:
  895  * send process whose timer expired an alarm signal.
  896  * If time is not set up to reload, then just return.
  897  * Else compute next time timer should go off which is > current time.
  898  * This is where delay in processing this timeout causes multiple
  899  * SIGALRM calls to be compressed into one.
  900  * tvtohz() always adds 1 to allow for the time until the next clock
  901  * interrupt being strictly less than 1 clock tick, but we don't want
  902  * that here since we want to appear to be in sync with the clock
  903  * interrupt even when we're delayed.
  904  */
  905 void
  906 realitexpire(void *arg)
  907 {
  908         struct proc *p;
  909         struct timeval ctv;
  910         sbintime_t isbt;
  911 
  912         p = (struct proc *)arg;
  913         kern_psignal(p, SIGALRM);
  914         if (!timevalisset(&p->p_realtimer.it_interval)) {
  915                 timevalclear(&p->p_realtimer.it_value);
  916                 if (p->p_flag & P_WEXIT)
  917                         wakeup(&p->p_itcallout);
  918                 return;
  919         }
  920         isbt = tvtosbt(p->p_realtimer.it_interval);
  921         if (isbt >= sbt_timethreshold)
  922                 getmicrouptime(&ctv);
  923         else
  924                 microuptime(&ctv);
  925         do {
  926                 timevaladd(&p->p_realtimer.it_value,
  927                     &p->p_realtimer.it_interval);
  928         } while (timevalcmp(&p->p_realtimer.it_value, &ctv, <=));
  929         callout_reset_sbt(&p->p_itcallout, tvtosbt(p->p_realtimer.it_value),
  930             isbt >> tc_precexp, realitexpire, p, C_ABSOLUTE);
  931 }
  932 
  933 /*
  934  * Check that a proposed value to load into the .it_value or
  935  * .it_interval part of an interval timer is acceptable, and
  936  * fix it to have at least minimal value (i.e. if it is less
  937  * than the resolution of the clock, round it up.)
  938  */
  939 int
  940 itimerfix(struct timeval *tv)
  941 {
  942 
  943         if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000)
  944                 return (EINVAL);
  945         if (tv->tv_sec == 0 && tv->tv_usec != 0 &&
  946             tv->tv_usec < (u_int)tick / 16)
  947                 tv->tv_usec = (u_int)tick / 16;
  948         return (0);
  949 }
  950 
  951 /*
  952  * Decrement an interval timer by a specified number
  953  * of microseconds, which must be less than a second,
  954  * i.e. < 1000000.  If the timer expires, then reload
  955  * it.  In this case, carry over (usec - old value) to
  956  * reduce the value reloaded into the timer so that
  957  * the timer does not drift.  This routine assumes
  958  * that it is called in a context where the timers
  959  * on which it is operating cannot change in value.
  960  */
  961 int
  962 itimerdecr(struct itimerval *itp, int usec)
  963 {
  964 
  965         if (itp->it_value.tv_usec < usec) {
  966                 if (itp->it_value.tv_sec == 0) {
  967                         /* expired, and already in next interval */
  968                         usec -= itp->it_value.tv_usec;
  969                         goto expire;
  970                 }
  971                 itp->it_value.tv_usec += 1000000;
  972                 itp->it_value.tv_sec--;
  973         }
  974         itp->it_value.tv_usec -= usec;
  975         usec = 0;
  976         if (timevalisset(&itp->it_value))
  977                 return (1);
  978         /* expired, exactly at end of interval */
  979 expire:
  980         if (timevalisset(&itp->it_interval)) {
  981                 itp->it_value = itp->it_interval;
  982                 itp->it_value.tv_usec -= usec;
  983                 if (itp->it_value.tv_usec < 0) {
  984                         itp->it_value.tv_usec += 1000000;
  985                         itp->it_value.tv_sec--;
  986                 }
  987         } else
  988                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
  989         return (0);
  990 }
  991 
  992 /*
  993  * Add and subtract routines for timevals.
  994  * N.B.: subtract routine doesn't deal with
  995  * results which are before the beginning,
  996  * it just gets very confused in this case.
  997  * Caveat emptor.
  998  */
  999 void
 1000 timevaladd(struct timeval *t1, const struct timeval *t2)
 1001 {
 1002 
 1003         t1->tv_sec += t2->tv_sec;
 1004         t1->tv_usec += t2->tv_usec;
 1005         timevalfix(t1);
 1006 }
 1007 
 1008 void
 1009 timevalsub(struct timeval *t1, const struct timeval *t2)
 1010 {
 1011 
 1012         t1->tv_sec -= t2->tv_sec;
 1013         t1->tv_usec -= t2->tv_usec;
 1014         timevalfix(t1);
 1015 }
 1016 
 1017 static void
 1018 timevalfix(struct timeval *t1)
 1019 {
 1020 
 1021         if (t1->tv_usec < 0) {
 1022                 t1->tv_sec--;
 1023                 t1->tv_usec += 1000000;
 1024         }
 1025         if (t1->tv_usec >= 1000000) {
 1026                 t1->tv_sec++;
 1027                 t1->tv_usec -= 1000000;
 1028         }
 1029 }
 1030 
 1031 /*
 1032  * ratecheck(): simple time-based rate-limit checking.
 1033  */
 1034 int
 1035 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
 1036 {
 1037         struct timeval tv, delta;
 1038         int rv = 0;
 1039 
 1040         getmicrouptime(&tv);            /* NB: 10ms precision */
 1041         delta = tv;
 1042         timevalsub(&delta, lasttime);
 1043 
 1044         /*
 1045          * check for 0,0 is so that the message will be seen at least once,
 1046          * even if interval is huge.
 1047          */
 1048         if (timevalcmp(&delta, mininterval, >=) ||
 1049             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
 1050                 *lasttime = tv;
 1051                 rv = 1;
 1052         }
 1053 
 1054         return (rv);
 1055 }
 1056 
 1057 /*
 1058  * ppsratecheck(): packets (or events) per second limitation.
 1059  *
 1060  * Return 0 if the limit is to be enforced (e.g. the caller
 1061  * should drop a packet because of the rate limitation).
 1062  *
 1063  * maxpps of 0 always causes zero to be returned.  maxpps of -1
 1064  * always causes 1 to be returned; this effectively defeats rate
 1065  * limiting.
 1066  *
 1067  * Note that we maintain the struct timeval for compatibility
 1068  * with other bsd systems.  We reuse the storage and just monitor
 1069  * clock ticks for minimal overhead.  
 1070  */
 1071 int
 1072 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
 1073 {
 1074         int now;
 1075 
 1076         /*
 1077          * Reset the last time and counter if this is the first call
 1078          * or more than a second has passed since the last update of
 1079          * lasttime.
 1080          */
 1081         now = ticks;
 1082         if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
 1083                 lasttime->tv_sec = now;
 1084                 *curpps = 1;
 1085                 return (maxpps != 0);
 1086         } else {
 1087                 (*curpps)++;            /* NB: ignore potential overflow */
 1088                 return (maxpps < 0 || *curpps <= maxpps);
 1089         }
 1090 }
 1091 
 1092 static void
 1093 itimer_start(void)
 1094 {
 1095         struct kclock rt_clock = {
 1096                 .timer_create  = realtimer_create,
 1097                 .timer_delete  = realtimer_delete,
 1098                 .timer_settime = realtimer_settime,
 1099                 .timer_gettime = realtimer_gettime,
 1100                 .event_hook    = NULL
 1101         };
 1102 
 1103         itimer_zone = uma_zcreate("itimer", sizeof(struct itimer),
 1104                 NULL, NULL, itimer_init, itimer_fini, UMA_ALIGN_PTR, 0);
 1105         register_posix_clock(CLOCK_REALTIME,  &rt_clock);
 1106         register_posix_clock(CLOCK_MONOTONIC, &rt_clock);
 1107         p31b_setcfg(CTL_P1003_1B_TIMERS, 200112L);
 1108         p31b_setcfg(CTL_P1003_1B_DELAYTIMER_MAX, INT_MAX);
 1109         p31b_setcfg(CTL_P1003_1B_TIMER_MAX, TIMER_MAX);
 1110         EVENTHANDLER_REGISTER(process_exit, itimers_event_hook_exit,
 1111                 (void *)ITIMER_EV_EXIT, EVENTHANDLER_PRI_ANY);
 1112         EVENTHANDLER_REGISTER(process_exec, itimers_event_hook_exec,
 1113                 (void *)ITIMER_EV_EXEC, EVENTHANDLER_PRI_ANY);
 1114 }
 1115 
 1116 int
 1117 register_posix_clock(int clockid, struct kclock *clk)
 1118 {
 1119         if ((unsigned)clockid >= MAX_CLOCKS) {
 1120                 printf("%s: invalid clockid\n", __func__);
 1121                 return (0);
 1122         }
 1123         posix_clocks[clockid] = *clk;
 1124         return (1);
 1125 }
 1126 
 1127 static int
 1128 itimer_init(void *mem, int size, int flags)
 1129 {
 1130         struct itimer *it;
 1131 
 1132         it = (struct itimer *)mem;
 1133         mtx_init(&it->it_mtx, "itimer lock", NULL, MTX_DEF);
 1134         return (0);
 1135 }
 1136 
 1137 static void
 1138 itimer_fini(void *mem, int size)
 1139 {
 1140         struct itimer *it;
 1141 
 1142         it = (struct itimer *)mem;
 1143         mtx_destroy(&it->it_mtx);
 1144 }
 1145 
 1146 static void
 1147 itimer_enter(struct itimer *it)
 1148 {
 1149 
 1150         mtx_assert(&it->it_mtx, MA_OWNED);
 1151         it->it_usecount++;
 1152 }
 1153 
 1154 static void
 1155 itimer_leave(struct itimer *it)
 1156 {
 1157 
 1158         mtx_assert(&it->it_mtx, MA_OWNED);
 1159         KASSERT(it->it_usecount > 0, ("invalid it_usecount"));
 1160 
 1161         if (--it->it_usecount == 0 && (it->it_flags & ITF_WANTED) != 0)
 1162                 wakeup(it);
 1163 }
 1164 
 1165 #ifndef _SYS_SYSPROTO_H_
 1166 struct ktimer_create_args {
 1167         clockid_t clock_id;
 1168         struct sigevent * evp;
 1169         int * timerid;
 1170 };
 1171 #endif
 1172 int
 1173 sys_ktimer_create(struct thread *td, struct ktimer_create_args *uap)
 1174 {
 1175         struct sigevent *evp, ev;
 1176         int id;
 1177         int error;
 1178 
 1179         if (uap->evp == NULL) {
 1180                 evp = NULL;
 1181         } else {
 1182                 error = copyin(uap->evp, &ev, sizeof(ev));
 1183                 if (error != 0)
 1184                         return (error);
 1185                 evp = &ev;
 1186         }
 1187         error = kern_ktimer_create(td, uap->clock_id, evp, &id, -1);
 1188         if (error == 0) {
 1189                 error = copyout(&id, uap->timerid, sizeof(int));
 1190                 if (error != 0)
 1191                         kern_ktimer_delete(td, id);
 1192         }
 1193         return (error);
 1194 }
 1195 
 1196 int
 1197 kern_ktimer_create(struct thread *td, clockid_t clock_id, struct sigevent *evp,
 1198     int *timerid, int preset_id)
 1199 {
 1200         struct proc *p = td->td_proc;
 1201         struct itimer *it;
 1202         int id;
 1203         int error;
 1204 
 1205         if (clock_id < 0 || clock_id >= MAX_CLOCKS)
 1206                 return (EINVAL);
 1207 
 1208         if (posix_clocks[clock_id].timer_create == NULL)
 1209                 return (EINVAL);
 1210 
 1211         if (evp != NULL) {
 1212                 if (evp->sigev_notify != SIGEV_NONE &&
 1213                     evp->sigev_notify != SIGEV_SIGNAL &&
 1214                     evp->sigev_notify != SIGEV_THREAD_ID)
 1215                         return (EINVAL);
 1216                 if ((evp->sigev_notify == SIGEV_SIGNAL ||
 1217                      evp->sigev_notify == SIGEV_THREAD_ID) &&
 1218                         !_SIG_VALID(evp->sigev_signo))
 1219                         return (EINVAL);
 1220         }
 1221         
 1222         if (p->p_itimers == NULL)
 1223                 itimers_alloc(p);
 1224         
 1225         it = uma_zalloc(itimer_zone, M_WAITOK);
 1226         it->it_flags = 0;
 1227         it->it_usecount = 0;
 1228         it->it_active = 0;
 1229         timespecclear(&it->it_time.it_value);
 1230         timespecclear(&it->it_time.it_interval);
 1231         it->it_overrun = 0;
 1232         it->it_overrun_last = 0;
 1233         it->it_clockid = clock_id;
 1234         it->it_timerid = -1;
 1235         it->it_proc = p;
 1236         ksiginfo_init(&it->it_ksi);
 1237         it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
 1238         error = CLOCK_CALL(clock_id, timer_create, (it));
 1239         if (error != 0)
 1240                 goto out;
 1241 
 1242         PROC_LOCK(p);
 1243         if (preset_id != -1) {
 1244                 KASSERT(preset_id >= 0 && preset_id < 3, ("invalid preset_id"));
 1245                 id = preset_id;
 1246                 if (p->p_itimers->its_timers[id] != NULL) {
 1247                         PROC_UNLOCK(p);
 1248                         error = 0;
 1249                         goto out;
 1250                 }
 1251         } else {
 1252                 /*
 1253                  * Find a free timer slot, skipping those reserved
 1254                  * for setitimer().
 1255                  */
 1256                 for (id = 3; id < TIMER_MAX; id++)
 1257                         if (p->p_itimers->its_timers[id] == NULL)
 1258                                 break;
 1259                 if (id == TIMER_MAX) {
 1260                         PROC_UNLOCK(p);
 1261                         error = EAGAIN;
 1262                         goto out;
 1263                 }
 1264         }
 1265         it->it_timerid = id;
 1266         p->p_itimers->its_timers[id] = it;
 1267         if (evp != NULL)
 1268                 it->it_sigev = *evp;
 1269         else {
 1270                 it->it_sigev.sigev_notify = SIGEV_SIGNAL;
 1271                 switch (clock_id) {
 1272                 default:
 1273                 case CLOCK_REALTIME:
 1274                         it->it_sigev.sigev_signo = SIGALRM;
 1275                         break;
 1276                 case CLOCK_VIRTUAL:
 1277                         it->it_sigev.sigev_signo = SIGVTALRM;
 1278                         break;
 1279                 case CLOCK_PROF:
 1280                         it->it_sigev.sigev_signo = SIGPROF;
 1281                         break;
 1282                 }
 1283                 it->it_sigev.sigev_value.sival_int = id;
 1284         }
 1285 
 1286         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1287             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1288                 it->it_ksi.ksi_signo = it->it_sigev.sigev_signo;
 1289                 it->it_ksi.ksi_code = SI_TIMER;
 1290                 it->it_ksi.ksi_value = it->it_sigev.sigev_value;
 1291                 it->it_ksi.ksi_timerid = id;
 1292         }
 1293         PROC_UNLOCK(p);
 1294         *timerid = id;
 1295         return (0);
 1296 
 1297 out:
 1298         ITIMER_LOCK(it);
 1299         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1300         ITIMER_UNLOCK(it);
 1301         uma_zfree(itimer_zone, it);
 1302         return (error);
 1303 }
 1304 
 1305 #ifndef _SYS_SYSPROTO_H_
 1306 struct ktimer_delete_args {
 1307         int timerid;
 1308 };
 1309 #endif
 1310 int
 1311 sys_ktimer_delete(struct thread *td, struct ktimer_delete_args *uap)
 1312 {
 1313 
 1314         return (kern_ktimer_delete(td, uap->timerid));
 1315 }
 1316 
 1317 static struct itimer *
 1318 itimer_find(struct proc *p, int timerid)
 1319 {
 1320         struct itimer *it;
 1321 
 1322         PROC_LOCK_ASSERT(p, MA_OWNED);
 1323         if ((p->p_itimers == NULL) ||
 1324             (timerid < 0) || (timerid >= TIMER_MAX) ||
 1325             (it = p->p_itimers->its_timers[timerid]) == NULL) {
 1326                 return (NULL);
 1327         }
 1328         ITIMER_LOCK(it);
 1329         if ((it->it_flags & ITF_DELETING) != 0) {
 1330                 ITIMER_UNLOCK(it);
 1331                 it = NULL;
 1332         }
 1333         return (it);
 1334 }
 1335 
 1336 int
 1337 kern_ktimer_delete(struct thread *td, int timerid)
 1338 {
 1339         struct proc *p = td->td_proc;
 1340         struct itimer *it;
 1341 
 1342         PROC_LOCK(p);
 1343         it = itimer_find(p, timerid);
 1344         if (it == NULL) {
 1345                 PROC_UNLOCK(p);
 1346                 return (EINVAL);
 1347         }
 1348         PROC_UNLOCK(p);
 1349 
 1350         it->it_flags |= ITF_DELETING;
 1351         while (it->it_usecount > 0) {
 1352                 it->it_flags |= ITF_WANTED;
 1353                 msleep(it, &it->it_mtx, PPAUSE, "itimer", 0);
 1354         }
 1355         it->it_flags &= ~ITF_WANTED;
 1356         CLOCK_CALL(it->it_clockid, timer_delete, (it));
 1357         ITIMER_UNLOCK(it);
 1358 
 1359         PROC_LOCK(p);
 1360         if (KSI_ONQ(&it->it_ksi))
 1361                 sigqueue_take(&it->it_ksi);
 1362         p->p_itimers->its_timers[timerid] = NULL;
 1363         PROC_UNLOCK(p);
 1364         uma_zfree(itimer_zone, it);
 1365         return (0);
 1366 }
 1367 
 1368 #ifndef _SYS_SYSPROTO_H_
 1369 struct ktimer_settime_args {
 1370         int timerid;
 1371         int flags;
 1372         const struct itimerspec * value;
 1373         struct itimerspec * ovalue;
 1374 };
 1375 #endif
 1376 int
 1377 sys_ktimer_settime(struct thread *td, struct ktimer_settime_args *uap)
 1378 {
 1379         struct itimerspec val, oval, *ovalp;
 1380         int error;
 1381 
 1382         error = copyin(uap->value, &val, sizeof(val));
 1383         if (error != 0)
 1384                 return (error);
 1385         ovalp = uap->ovalue != NULL ? &oval : NULL;
 1386         error = kern_ktimer_settime(td, uap->timerid, uap->flags, &val, ovalp);
 1387         if (error == 0 && uap->ovalue != NULL)
 1388                 error = copyout(ovalp, uap->ovalue, sizeof(*ovalp));
 1389         return (error);
 1390 }
 1391 
 1392 int
 1393 kern_ktimer_settime(struct thread *td, int timer_id, int flags,
 1394     struct itimerspec *val, struct itimerspec *oval)
 1395 {
 1396         struct proc *p;
 1397         struct itimer *it;
 1398         int error;
 1399 
 1400         p = td->td_proc;
 1401         PROC_LOCK(p);
 1402         if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
 1403                 PROC_UNLOCK(p);
 1404                 error = EINVAL;
 1405         } else {
 1406                 PROC_UNLOCK(p);
 1407                 itimer_enter(it);
 1408                 error = CLOCK_CALL(it->it_clockid, timer_settime, (it,
 1409                     flags, val, oval));
 1410                 itimer_leave(it);
 1411                 ITIMER_UNLOCK(it);
 1412         }
 1413         return (error);
 1414 }
 1415 
 1416 #ifndef _SYS_SYSPROTO_H_
 1417 struct ktimer_gettime_args {
 1418         int timerid;
 1419         struct itimerspec * value;
 1420 };
 1421 #endif
 1422 int
 1423 sys_ktimer_gettime(struct thread *td, struct ktimer_gettime_args *uap)
 1424 {
 1425         struct itimerspec val;
 1426         int error;
 1427 
 1428         error = kern_ktimer_gettime(td, uap->timerid, &val);
 1429         if (error == 0)
 1430                 error = copyout(&val, uap->value, sizeof(val));
 1431         return (error);
 1432 }
 1433 
 1434 int
 1435 kern_ktimer_gettime(struct thread *td, int timer_id, struct itimerspec *val)
 1436 {
 1437         struct proc *p;
 1438         struct itimer *it;
 1439         int error;
 1440 
 1441         p = td->td_proc;
 1442         PROC_LOCK(p);
 1443         if (timer_id < 3 || (it = itimer_find(p, timer_id)) == NULL) {
 1444                 PROC_UNLOCK(p);
 1445                 error = EINVAL;
 1446         } else {
 1447                 PROC_UNLOCK(p);
 1448                 itimer_enter(it);
 1449                 error = CLOCK_CALL(it->it_clockid, timer_gettime, (it, val));
 1450                 itimer_leave(it);
 1451                 ITIMER_UNLOCK(it);
 1452         }
 1453         return (error);
 1454 }
 1455 
 1456 #ifndef _SYS_SYSPROTO_H_
 1457 struct timer_getoverrun_args {
 1458         int timerid;
 1459 };
 1460 #endif
 1461 int
 1462 sys_ktimer_getoverrun(struct thread *td, struct ktimer_getoverrun_args *uap)
 1463 {
 1464 
 1465         return (kern_ktimer_getoverrun(td, uap->timerid));
 1466 }
 1467 
 1468 int
 1469 kern_ktimer_getoverrun(struct thread *td, int timer_id)
 1470 {
 1471         struct proc *p = td->td_proc;
 1472         struct itimer *it;
 1473         int error ;
 1474 
 1475         PROC_LOCK(p);
 1476         if (timer_id < 3 ||
 1477             (it = itimer_find(p, timer_id)) == NULL) {
 1478                 PROC_UNLOCK(p);
 1479                 error = EINVAL;
 1480         } else {
 1481                 td->td_retval[0] = it->it_overrun_last;
 1482                 ITIMER_UNLOCK(it);
 1483                 PROC_UNLOCK(p);
 1484                 error = 0;
 1485         }
 1486         return (error);
 1487 }
 1488 
 1489 static int
 1490 realtimer_create(struct itimer *it)
 1491 {
 1492         callout_init_mtx(&it->it_callout, &it->it_mtx, 0);
 1493         return (0);
 1494 }
 1495 
 1496 static int
 1497 realtimer_delete(struct itimer *it)
 1498 {
 1499         mtx_assert(&it->it_mtx, MA_OWNED);
 1500         
 1501         /*
 1502          * clear timer's value and interval to tell realtimer_expire
 1503          * to not rearm the timer.
 1504          */
 1505         timespecclear(&it->it_time.it_value);
 1506         timespecclear(&it->it_time.it_interval);
 1507         ITIMER_UNLOCK(it);
 1508         callout_drain(&it->it_callout);
 1509         ITIMER_LOCK(it);
 1510         return (0);
 1511 }
 1512 
 1513 static int
 1514 realtimer_gettime(struct itimer *it, struct itimerspec *ovalue)
 1515 {
 1516         struct timespec cts;
 1517 
 1518         mtx_assert(&it->it_mtx, MA_OWNED);
 1519 
 1520         realtimer_clocktime(it->it_clockid, &cts);
 1521         *ovalue = it->it_time;
 1522         if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_nsec != 0) {
 1523                 timespecsub(&ovalue->it_value, &cts, &ovalue->it_value);
 1524                 if (ovalue->it_value.tv_sec < 0 ||
 1525                     (ovalue->it_value.tv_sec == 0 &&
 1526                      ovalue->it_value.tv_nsec == 0)) {
 1527                         ovalue->it_value.tv_sec  = 0;
 1528                         ovalue->it_value.tv_nsec = 1;
 1529                 }
 1530         }
 1531         return (0);
 1532 }
 1533 
 1534 static int
 1535 realtimer_settime(struct itimer *it, int flags,
 1536         struct itimerspec *value, struct itimerspec *ovalue)
 1537 {
 1538         struct timespec cts, ts;
 1539         struct timeval tv;
 1540         struct itimerspec val;
 1541 
 1542         mtx_assert(&it->it_mtx, MA_OWNED);
 1543 
 1544         val = *value;
 1545         if (itimespecfix(&val.it_value))
 1546                 return (EINVAL);
 1547 
 1548         if (timespecisset(&val.it_value)) {
 1549                 if (itimespecfix(&val.it_interval))
 1550                         return (EINVAL);
 1551         } else {
 1552                 timespecclear(&val.it_interval);
 1553         }
 1554         
 1555         if (ovalue != NULL)
 1556                 realtimer_gettime(it, ovalue);
 1557 
 1558         it->it_time = val;
 1559         if (timespecisset(&val.it_value)) {
 1560                 realtimer_clocktime(it->it_clockid, &cts);
 1561                 ts = val.it_value;
 1562                 if ((flags & TIMER_ABSTIME) == 0) {
 1563                         /* Convert to absolute time. */
 1564                         timespecadd(&it->it_time.it_value, &cts,
 1565                                 &it->it_time.it_value);
 1566                 } else {
 1567                         timespecsub(&ts, &cts, &ts);
 1568                         /*
 1569                          * We don't care if ts is negative, tztohz will
 1570                          * fix it.
 1571                          */
 1572                 }
 1573                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1574                 callout_reset(&it->it_callout, tvtohz(&tv),
 1575                         realtimer_expire, it);
 1576         } else {
 1577                 callout_stop(&it->it_callout);
 1578         }
 1579 
 1580         return (0);
 1581 }
 1582 
 1583 static void
 1584 realtimer_clocktime(clockid_t id, struct timespec *ts)
 1585 {
 1586         if (id == CLOCK_REALTIME)
 1587                 getnanotime(ts);
 1588         else    /* CLOCK_MONOTONIC */
 1589                 getnanouptime(ts);
 1590 }
 1591 
 1592 int
 1593 itimer_accept(struct proc *p, int timerid, ksiginfo_t *ksi)
 1594 {
 1595         struct itimer *it;
 1596 
 1597         PROC_LOCK_ASSERT(p, MA_OWNED);
 1598         it = itimer_find(p, timerid);
 1599         if (it != NULL) {
 1600                 ksi->ksi_overrun = it->it_overrun;
 1601                 it->it_overrun_last = it->it_overrun;
 1602                 it->it_overrun = 0;
 1603                 ITIMER_UNLOCK(it);
 1604                 return (0);
 1605         }
 1606         return (EINVAL);
 1607 }
 1608 
 1609 int
 1610 itimespecfix(struct timespec *ts)
 1611 {
 1612 
 1613         if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
 1614                 return (EINVAL);
 1615         if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000)
 1616                 ts->tv_nsec = tick * 1000;
 1617         return (0);
 1618 }
 1619 
 1620 /* Timeout callback for realtime timer */
 1621 static void
 1622 realtimer_expire(void *arg)
 1623 {
 1624         struct timespec cts, ts;
 1625         struct timeval tv;
 1626         struct itimer *it;
 1627 
 1628         it = (struct itimer *)arg;
 1629 
 1630         realtimer_clocktime(it->it_clockid, &cts);
 1631         /* Only fire if time is reached. */
 1632         if (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1633                 if (timespecisset(&it->it_time.it_interval)) {
 1634                         timespecadd(&it->it_time.it_value,
 1635                                     &it->it_time.it_interval,
 1636                                     &it->it_time.it_value);
 1637                         while (timespeccmp(&cts, &it->it_time.it_value, >=)) {
 1638                                 if (it->it_overrun < INT_MAX)
 1639                                         it->it_overrun++;
 1640                                 else
 1641                                         it->it_ksi.ksi_errno = ERANGE;
 1642                                 timespecadd(&it->it_time.it_value,
 1643                                             &it->it_time.it_interval,
 1644                                             &it->it_time.it_value);
 1645                         }
 1646                 } else {
 1647                         /* single shot timer ? */
 1648                         timespecclear(&it->it_time.it_value);
 1649                 }
 1650                 if (timespecisset(&it->it_time.it_value)) {
 1651                         timespecsub(&it->it_time.it_value, &cts, &ts);
 1652                         TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1653                         callout_reset(&it->it_callout, tvtohz(&tv),
 1654                                  realtimer_expire, it);
 1655                 }
 1656                 itimer_enter(it);
 1657                 ITIMER_UNLOCK(it);
 1658                 itimer_fire(it);
 1659                 ITIMER_LOCK(it);
 1660                 itimer_leave(it);
 1661         } else if (timespecisset(&it->it_time.it_value)) {
 1662                 ts = it->it_time.it_value;
 1663                 timespecsub(&ts, &cts, &ts);
 1664                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
 1665                 callout_reset(&it->it_callout, tvtohz(&tv), realtimer_expire,
 1666                         it);
 1667         }
 1668 }
 1669 
 1670 void
 1671 itimer_fire(struct itimer *it)
 1672 {
 1673         struct proc *p = it->it_proc;
 1674         struct thread *td;
 1675 
 1676         if (it->it_sigev.sigev_notify == SIGEV_SIGNAL ||
 1677             it->it_sigev.sigev_notify == SIGEV_THREAD_ID) {
 1678                 if (sigev_findtd(p, &it->it_sigev, &td) != 0) {
 1679                         ITIMER_LOCK(it);
 1680                         timespecclear(&it->it_time.it_value);
 1681                         timespecclear(&it->it_time.it_interval);
 1682                         callout_stop(&it->it_callout);
 1683                         ITIMER_UNLOCK(it);
 1684                         return;
 1685                 }
 1686                 if (!KSI_ONQ(&it->it_ksi)) {
 1687                         it->it_ksi.ksi_errno = 0;
 1688                         ksiginfo_set_sigev(&it->it_ksi, &it->it_sigev);
 1689                         tdsendsignal(p, td, it->it_ksi.ksi_signo, &it->it_ksi);
 1690                 } else {
 1691                         if (it->it_overrun < INT_MAX)
 1692                                 it->it_overrun++;
 1693                         else
 1694                                 it->it_ksi.ksi_errno = ERANGE;
 1695                 }
 1696                 PROC_UNLOCK(p);
 1697         }
 1698 }
 1699 
 1700 static void
 1701 itimers_alloc(struct proc *p)
 1702 {
 1703         struct itimers *its;
 1704         int i;
 1705 
 1706         its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
 1707         LIST_INIT(&its->its_virtual);
 1708         LIST_INIT(&its->its_prof);
 1709         TAILQ_INIT(&its->its_worklist);
 1710         for (i = 0; i < TIMER_MAX; i++)
 1711                 its->its_timers[i] = NULL;
 1712         PROC_LOCK(p);
 1713         if (p->p_itimers == NULL) {
 1714                 p->p_itimers = its;
 1715                 PROC_UNLOCK(p);
 1716         }
 1717         else {
 1718                 PROC_UNLOCK(p);
 1719                 free(its, M_SUBPROC);
 1720         }
 1721 }
 1722 
 1723 static void
 1724 itimers_event_hook_exec(void *arg, struct proc *p, struct image_params *imgp __unused)
 1725 {
 1726         itimers_event_hook_exit(arg, p);
 1727 }
 1728 
 1729 /* Clean up timers when some process events are being triggered. */
 1730 static void
 1731 itimers_event_hook_exit(void *arg, struct proc *p)
 1732 {
 1733         struct itimers *its;
 1734         struct itimer *it;
 1735         int event = (int)(intptr_t)arg;
 1736         int i;
 1737 
 1738         if (p->p_itimers != NULL) {
 1739                 its = p->p_itimers;
 1740                 for (i = 0; i < MAX_CLOCKS; ++i) {
 1741                         if (posix_clocks[i].event_hook != NULL)
 1742                                 CLOCK_CALL(i, event_hook, (p, i, event));
 1743                 }
 1744                 /*
 1745                  * According to susv3, XSI interval timers should be inherited
 1746                  * by new image.
 1747                  */
 1748                 if (event == ITIMER_EV_EXEC)
 1749                         i = 3;
 1750                 else if (event == ITIMER_EV_EXIT)
 1751                         i = 0;
 1752                 else
 1753                         panic("unhandled event");
 1754                 for (; i < TIMER_MAX; ++i) {
 1755                         if ((it = its->its_timers[i]) != NULL)
 1756                                 kern_ktimer_delete(curthread, i);
 1757                 }
 1758                 if (its->its_timers[0] == NULL &&
 1759                     its->its_timers[1] == NULL &&
 1760                     its->its_timers[2] == NULL) {
 1761                         free(its, M_SUBPROC);
 1762                         p->p_itimers = NULL;
 1763                 }
 1764         }
 1765 }

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