bsd/kern/kern_time.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  24 /*
  25  * Copyright (c) 1982, 1986, 1989, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  *
  56  *      @(#)kern_time.c 8.4 (Berkeley) 5/26/95
  57  */
  58
  59 #include <sys/param.h>
  60 #include <sys/resourcevar.h>
  61 #include <sys/kernel.h>
  62 #include <sys/systm.h>
  63 #include <sys/proc_internal.h>
  64 #include <sys/kauth.h>
  65 #include <sys/vnode.h>
  66
  67 #include <sys/mount_internal.h>
  68 #include <sys/sysproto.h>
  69 #include <sys/signalvar.h>
  70
  71 #include <kern/clock.h>
  72 #include <kern/thread_call.h>
  73
  74 #define HZ      100     /* XXX */
  75
  76 /* simple lock used to access timezone, tz structure */
  77 lck_spin_t * tz_slock;
  78 lck_grp_t * tz_slock_grp;
  79 lck_attr_t * tz_slock_attr;
  80 lck_grp_attr_t  *tz_slock_grp_attr;
  81
  82 static void             setthetime(
  83                                         struct timeval  *tv);
  84
  85 void time_zone_slock_init(void);
  86
  87 int gettimeofday(struct proc *p,
  88 #ifdef __ppc__
  89                          struct ppc_gettimeofday_args *uap,
  90 #else
  91                          struct gettimeofday_args *uap,
  92 #endif
  93                          register_t *retval);
  94
  95 /*
  96  * Time of day and interval timer support.
  97  *
  98  * These routines provide the kernel entry points to get and set
  99  * the time-of-day and per-process interval timers.  Subroutines
 100  * here provide support for adding and subtracting timeval structures
 101  * and decrementing interval timers, optionally reloading the interval
 102  * timers when they expire.
 103  *
 104  * XXX Y2038 bug because of clock_get_calendar_microtime() first argument
 105  */
 106 /* ARGSUSED */
 107 int
 108 gettimeofday(__unused struct proc *p,
 109 #ifdef __ppc__
 110                          register struct ppc_gettimeofday_args *uap,
 111 #else
 112                          register struct gettimeofday_args *uap,
 113 #endif
 114                          __unused register_t *retval)
 115 {
 116         struct timeval atv;
 117         int error = 0;
 118         struct timezone ltz; /* local copy */
 119
 120 /*  NOTE THIS implementation is for non ppc architectures only */
 121
 122         if (uap->tp) {
 123                 clock_get_calendar_microtime((uint32_t *)&atv.tv_sec, &atv.tv_usec);
 124                 if (IS_64BIT_PROCESS(p)) {
 125                         struct user_timeval user_atv;
 126                         user_atv.tv_sec = atv.tv_sec;
 127                         user_atv.tv_usec = atv.tv_usec;
 128                         /*
 129                          * This cast is not necessary for PPC, but is
 130                          * mostly harmless.
 131                          */
 132                         error = copyout(&user_atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct user_timeval));
 133                 } else {
 134                         error = copyout(&atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct timeval));
 135                 }
 136                 if (error)
 137                         return(error);
 138         }
 139
 140         if (uap->tzp) {
 141                 lck_spin_lock(tz_slock);
 142                 ltz = tz;
 143                 lck_spin_unlock(tz_slock);
 144                 error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp),
 145                     sizeof (tz));
 146         }
 147
 148         return(error);
 149 }
 150
 151 /*
 152  * XXX Y2038 bug because of setthetime() argument
 153  */
 154 /* ARGSUSED */
 155 int
 156 settimeofday(struct proc *p, struct settimeofday_args  *uap, __unused register_t *retval)
 157 {
 158         struct timeval atv;
 159         struct timezone atz;
 160         int error;
 161
 162         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 163                 return (error);
 164         /* Verify all parameters before changing time */
 165         if (uap->tv) {
 166                 if (IS_64BIT_PROCESS(p)) {
 167                         struct user_timeval user_atv;
 168                         error = copyin(uap->tv, &user_atv, sizeof(struct user_timeval));
 169                         atv.tv_sec = user_atv.tv_sec;
 170                         atv.tv_usec = user_atv.tv_usec;
 171                 } else {
 172                         error = copyin(uap->tv, &atv, sizeof(struct timeval));
 173                 }
 174                 if (error)
 175                         return (error);
 176         }
 177         if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
 178                 return (error);
 179         if (uap->tv) {
 180                 timevalfix(&atv);
 181                 if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
 182                         return (EPERM);
 183                 setthetime(&atv);
 184         }
 185         if (uap->tzp) {
 186                 lck_spin_lock(tz_slock);
 187                 tz = atz;
 188                 lck_spin_unlock(tz_slock);
 189         }
 190         return (0);
 191 }
 192
 193 static void
 194 setthetime(
 195         struct timeval  *tv)
 196 {
 197         clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
 198 }
 199
 200 /*
 201  * XXX Y2038 bug because of clock_adjtime() first argument
 202  */
 203 /* ARGSUSED */
 204 int
 205 adjtime(struct proc *p, register struct adjtime_args *uap, __unused register_t *retval)
 206 {
 207         struct timeval atv;
 208         int error;
 209
 210         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 211                 return (error);
 212         if (IS_64BIT_PROCESS(p)) {
 213                 struct user_timeval user_atv;
 214                 error = copyin(uap->delta, &user_atv, sizeof(struct user_timeval));
 215                 atv.tv_sec = user_atv.tv_sec;
 216                 atv.tv_usec = user_atv.tv_usec;
 217         } else {
 218                 error = copyin(uap->delta, &atv, sizeof(struct timeval));
 219         }
 220         if (error)
 221                 return (error);
 222
 223         /*
 224          * Compute the total correction and the rate at which to apply it.
 225          */
 226         clock_adjtime((int32_t *)&atv.tv_sec, &atv.tv_usec);
 227
 228         if (uap->olddelta) {
 229                 if (IS_64BIT_PROCESS(p)) {
 230                         struct user_timeval user_atv;
 231                         user_atv.tv_sec = atv.tv_sec;
 232                         user_atv.tv_usec = atv.tv_usec;
 233                         error = copyout(&user_atv, uap->olddelta, sizeof(struct user_timeval));
 234                 } else {
 235                         error = copyout(&atv, uap->olddelta, sizeof(struct timeval));
 236                 }
 237         }
 238
 239         return (0);
 240 }
 241
 242 /*
 243  *      Verify the calendar value.  If negative,
 244  *      reset to zero (the epoch).
 245  */
 246 void
 247 inittodr(
 248         __unused time_t base)
 249 {
 250         struct timeval  tv;
 251
 252         /*
 253          * Assertion:
 254          * The calendar has already been
 255          * set up from the platform clock.
 256          *
 257          * The value returned by microtime()
 258          * is gotten from the calendar.
 259          */
 260         microtime(&tv);
 261
 262         if (tv.tv_sec < 0 || tv.tv_usec < 0) {
 263                 printf ("WARNING: preposterous time in Real Time Clock");
 264                 tv.tv_sec = 0;          /* the UNIX epoch */
 265                 tv.tv_usec = 0;
 266                 setthetime(&tv);
 267                 printf(" -- CHECK AND RESET THE DATE!\n");
 268         }
 269 }
 270
 271 time_t
 272 boottime_sec(void)
 273 {
 274         uint32_t        sec, nanosec;
 275         clock_get_boottime_nanotime(&sec, &nanosec);
 276         return (sec);
 277 }
 278
 279 uint64_t tvtoabstime(struct timeval *tvp);
 280
 281 /*
 282  * Get value of an interval timer.  The process virtual and
 283  * profiling virtual time timers are kept internally in the
 284  * way they are specified externally: in time until they expire.
 285  *
 286  * The real time interval timer expiration time (p_rtime)
 287  * is kept as an absolute time rather than as a delta, so that
 288  * it is easy to keep periodic real-time signals from drifting.
 289  *
 290  * Virtual time timers are processed in the hardclock() routine of
 291  * kern_clock.c.  The real time timer is processed by a callout
 292  * routine.  Since a callout may be delayed in real time due to
 293  * other processing in the system, it is possible for the real
 294  * time callout routine (realitexpire, given below), to be delayed
 295  * in real time past when it is supposed to occur.  It does not
 296  * suffice, therefore, to reload the real time .it_value from the
 297  * real time .it_interval.  Rather, we compute the next time in
 298  * absolute time when the timer should go off.
 299  */
 300
 301 /* ARGSUSED */
 302 int
 303 getitimer(struct proc *p, register struct getitimer_args *uap, __unused register_t *retval)
 304 {
 305         struct itimerval aitv;
 306
 307         if (uap->which > ITIMER_PROF)
 308                 return(EINVAL);
 309         if (uap->which == ITIMER_REAL) {
 310                 /*
 311                  * If time for real time timer has passed return 0,
 312                  * else return difference between current time and
 313                  * time for the timer to go off.
 314                  */
 315                 aitv = p->p_realtimer;
 316                 if (timerisset(&p->p_rtime)) {
 317                         struct timeval          now;
 318
 319                         microuptime(&now);
 320                         if (timercmp(&p->p_rtime, &now, <))
 321                                 timerclear(&aitv.it_value);
 322                         else {
 323                                 aitv.it_value = p->p_rtime;
 324                                 timevalsub(&aitv.it_value, &now);
 325                         }
 326                 }
 327                 else
 328                         timerclear(&aitv.it_value);
 329         }
 330         else
 331                 aitv = p->p_stats->p_timer[uap->which];
 332
 333         if (IS_64BIT_PROCESS(p)) {
 334                 struct user_itimerval user_itv;
 335                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 336                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 337                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 338                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 339                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (struct user_itimerval)));
 340         } else {
 341                 return (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)));
 342         }
 343 }
 344
 345 /* ARGSUSED */
 346 int
 347 setitimer(p, uap, retval)
 348         struct proc *p;
 349         register struct setitimer_args *uap;
 350         register_t *retval;
 351 {
 352         struct itimerval aitv;
 353         user_addr_t itvp;
 354         int error;
 355
 356         if (uap->which > ITIMER_PROF)
 357                 return (EINVAL);
 358         if ((itvp = uap->itv)) {
 359                 if (IS_64BIT_PROCESS(p)) {
 360                         struct user_itimerval user_itv;
 361                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (struct user_itimerval))))
 362                                 return (error);
 363                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 364                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 365                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 366                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 367                 } else {
 368                         if ((error = copyin(itvp, (caddr_t)&aitv, sizeof (struct itimerval))))
 369                                 return (error);
 370                 }
 371         }
 372         if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
 373                 return (error);
 374         if (itvp == 0)
 375                 return (0);
 376         if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
 377                 return (EINVAL);
 378         if (uap->which == ITIMER_REAL) {
 379                 thread_call_func_cancel((thread_call_func_t)realitexpire, (void *)p->p_pid, FALSE);
 380                 if (timerisset(&aitv.it_value)) {
 381                         microuptime(&p->p_rtime);
 382                         timevaladd(&p->p_rtime, &aitv.it_value);
 383                         thread_call_func_delayed(
 384                                                                 (thread_call_func_t)realitexpire, (void *)p->p_pid,
 385                                                                                 tvtoabstime(&p->p_rtime));
 386                 }
 387                 else
 388                         timerclear(&p->p_rtime);
 389
 390                 p->p_realtimer = aitv;
 391         }
 392         else
 393                 p->p_stats->p_timer[uap->which] = aitv;
 394
 395         return (0);
 396 }
 397
 398 /*
 399  * Real interval timer expired:
 400  * send process whose timer expired an alarm signal.
 401  * If time is not set up to reload, then just return.
 402  * Else compute next time timer should go off which is > current time.
 403  * This is where delay in processing this timeout causes multiple
 404  * SIGALRM calls to be compressed into one.
 405  */
 406 void
 407 realitexpire(
 408         void            *pid)
 409 {
 410         register struct proc *p;
 411         struct timeval  now;
 412         boolean_t               funnel_state;
 413
 414         funnel_state = thread_funnel_set(kernel_flock, TRUE);
 415         p = pfind((pid_t)pid);
 416         if (p == NULL) {
 417                 (void) thread_funnel_set(kernel_flock, FALSE);
 418                 return;
 419         }
 420
 421         if (!timerisset(&p->p_realtimer.it_interval)) {
 422                 timerclear(&p->p_rtime);
 423                 psignal(p, SIGALRM);
 424
 425                 (void) thread_funnel_set(kernel_flock, FALSE);
 426                 return;
 427         }
 428
 429         microuptime(&now);
 430         timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 431         if (timercmp(&p->p_rtime, &now, <=)) {
 432                 if ((p->p_rtime.tv_sec + 2) >= now.tv_sec) {
 433                         for (;;) {
 434                                 timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 435                                 if (timercmp(&p->p_rtime, &now, >))
 436                                         break;
 437                         }
 438                 }
 439                 else {
 440                         p->p_rtime = p->p_realtimer.it_interval;
 441                         timevaladd(&p->p_rtime, &now);
 442                 }
 443         }
 444
 445         psignal(p, SIGALRM);
 446
 447         thread_call_func_delayed((thread_call_func_t)realitexpire, pid, tvtoabstime(&p->p_rtime));
 448
 449         (void) thread_funnel_set(kernel_flock, FALSE);
 450 }
 451
 452 /*
 453  * Check that a proposed value to load into the .it_value or
 454  * .it_interval part of an interval timer is acceptable, and
 455  * fix it to have at least minimal value (i.e. if it is less
 456  * than the resolution of the clock, round it up.)
 457  */
 458 int
 459 itimerfix(tv)
 460         struct timeval *tv;
 461 {
 462
 463         if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
 464             tv->tv_usec < 0 || tv->tv_usec >= 1000000)
 465                 return (EINVAL);
 466         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
 467                 tv->tv_usec = tick;
 468         return (0);
 469 }
 470
 471 /*
 472  * Decrement an interval timer by a specified number
 473  * of microseconds, which must be less than a second,
 474  * i.e. < 1000000.  If the timer expires, then reload
 475  * it.  In this case, carry over (usec - old value) to
 476  * reducint the value reloaded into the timer so that
 477  * the timer does not drift.  This routine assumes
 478  * that it is called in a context where the timers
 479  * on which it is operating cannot change in value.
 480  */
 481 int
 482 itimerdecr(itp, usec)
 483         register struct itimerval *itp;
 484         int usec;
 485 {
 486
 487         if (itp->it_value.tv_usec < usec) {
 488                 if (itp->it_value.tv_sec == 0) {
 489                         /* expired, and already in next interval */
 490                         usec -= itp->it_value.tv_usec;
 491                         goto expire;
 492                 }
 493                 itp->it_value.tv_usec += 1000000;
 494                 itp->it_value.tv_sec--;
 495         }
 496         itp->it_value.tv_usec -= usec;
 497         usec = 0;
 498         if (timerisset(&itp->it_value))
 499                 return (1);
 500         /* expired, exactly at end of interval */
 501 expire:
 502         if (timerisset(&itp->it_interval)) {
 503                 itp->it_value = itp->it_interval;
 504                 itp->it_value.tv_usec -= usec;
 505                 if (itp->it_value.tv_usec < 0) {
 506                         itp->it_value.tv_usec += 1000000;
 507                         itp->it_value.tv_sec--;
 508                 }
 509         } else
 510                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 511         return (0);
 512 }
 513
 514 /*
 515  * Add and subtract routines for timevals.
 516  * N.B.: subtract routine doesn't deal with
 517  * results which are before the beginning,
 518  * it just gets very confused in this case.
 519  * Caveat emptor.
 520  */
 521 void
 522 timevaladd(
 523         struct timeval *t1,
 524         struct timeval *t2)
 525 {
 526
 527         t1->tv_sec += t2->tv_sec;
 528         t1->tv_usec += t2->tv_usec;
 529         timevalfix(t1);
 530 }
 531 void
 532 timevalsub(
 533         struct timeval *t1,
 534         struct timeval *t2)
 535 {
 536
 537         t1->tv_sec -= t2->tv_sec;
 538         t1->tv_usec -= t2->tv_usec;
 539         timevalfix(t1);
 540 }
 541 void
 542 timevalfix(
 543         struct timeval *t1)
 544 {
 545
 546         if (t1->tv_usec < 0) {
 547                 t1->tv_sec--;
 548                 t1->tv_usec += 1000000;
 549         }
 550         if (t1->tv_usec >= 1000000) {
 551                 t1->tv_sec++;
 552                 t1->tv_usec -= 1000000;
 553         }
 554 }
 555
 556 /*
 557  * Return the best possible estimate of the time in the timeval
 558  * to which tvp points.
 559  */
 560 void
 561 microtime(
 562         struct timeval  *tvp)
 563 {
 564         clock_get_calendar_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 565 }
 566
 567 void
 568 microuptime(
 569         struct timeval  *tvp)
 570 {
 571         clock_get_system_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 572 }
 573
 574 /*
 575  * Ditto for timespec.
 576  */
 577 void
 578 nanotime(
 579         struct timespec *tsp)
 580 {
 581         clock_get_calendar_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 582 }
 583
 584 void
 585 nanouptime(
 586         struct timespec *tsp)
 587 {
 588         clock_get_system_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 589 }
 590
 591 uint64_t
 592 tvtoabstime(
 593         struct timeval  *tvp)
 594 {
 595         uint64_t        result, usresult;
 596
 597         clock_interval_to_absolutetime_interval(
 598                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 599         clock_interval_to_absolutetime_interval(
 600                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 601
 602         return (result + usresult);
 603 }
 604 void
 605 time_zone_slock_init(void)
 606 {
 607         /* allocate lock group attribute and group */
 608         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 609         lck_grp_attr_setstat(tz_slock_grp_attr);
 610
 611         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 612
 613         /* Allocate lock attribute */
 614         tz_slock_attr = lck_attr_alloc_init();
 615         //lck_attr_setdebug(tz_slock_attr);
 616
 617         /* Allocate the spin lock */
 618         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 619 }
 620