bsd/kern/kern_time.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1982, 1986, 1989, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)kern_time.c 8.4 (Berkeley) 5/26/95
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/resourcevar.h>
  66 #include <sys/kernel.h>
  67 #include <sys/systm.h>
  68 #include <sys/proc_internal.h>
  69 #include <sys/kauth.h>
  70 #include <sys/vnode.h>
  71
  72 #include <sys/mount_internal.h>
  73 #include <sys/sysproto.h>
  74 #include <sys/signalvar.h>
  75
  76 #include <kern/clock.h>
  77 #include <kern/thread_call.h>
  78
  79 #define HZ      100     /* XXX */
  80
  81 /* simple lock used to access timezone, tz structure */
  82 lck_spin_t * tz_slock;
  83 lck_grp_t * tz_slock_grp;
  84 lck_attr_t * tz_slock_attr;
  85 lck_grp_attr_t  *tz_slock_grp_attr;
  86
  87 static void             setthetime(
  88                                         struct timeval  *tv);
  89
  90 void time_zone_slock_init(void);
  91
  92 int gettimeofday(struct proc *p,
  93 #ifdef __ppc__
  94                          struct ppc_gettimeofday_args *uap,
  95 #else
  96                          struct gettimeofday_args *uap,
  97 #endif
  98                          register_t *retval);
  99
 100 /*
 101  * Time of day and interval timer support.
 102  *
 103  * These routines provide the kernel entry points to get and set
 104  * the time-of-day and per-process interval timers.  Subroutines
 105  * here provide support for adding and subtracting timeval structures
 106  * and decrementing interval timers, optionally reloading the interval
 107  * timers when they expire.
 108  *
 109  * XXX Y2038 bug because of clock_get_calendar_microtime() first argument
 110  */
 111 /* ARGSUSED */
 112 int
 113 gettimeofday(__unused struct proc *p,
 114 #ifdef __ppc__
 115                          register struct ppc_gettimeofday_args *uap,
 116 #else
 117                          register struct gettimeofday_args *uap,
 118 #endif
 119                          __unused register_t *retval)
 120 {
 121         struct timeval atv;
 122         int error = 0;
 123         struct timezone ltz; /* local copy */
 124
 125 /*  NOTE THIS implementation is for non ppc architectures only */
 126
 127         if (uap->tp) {
 128                 clock_get_calendar_microtime((uint32_t *)&atv.tv_sec, &atv.tv_usec);
 129                 if (IS_64BIT_PROCESS(p)) {
 130                         struct user_timeval user_atv;
 131                         user_atv.tv_sec = atv.tv_sec;
 132                         user_atv.tv_usec = atv.tv_usec;
 133                         /*
 134                          * This cast is not necessary for PPC, but is
 135                          * mostly harmless.
 136                          */
 137                         error = copyout(&user_atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct user_timeval));
 138                 } else {
 139                         error = copyout(&atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct timeval));
 140                 }
 141                 if (error)
 142                         return(error);
 143         }
 144
 145         if (uap->tzp) {
 146                 lck_spin_lock(tz_slock);
 147                 ltz = tz;
 148                 lck_spin_unlock(tz_slock);
 149                 error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp),
 150                     sizeof (tz));
 151         }
 152
 153         return(error);
 154 }
 155
 156 /*
 157  * XXX Y2038 bug because of setthetime() argument
 158  */
 159 /* ARGSUSED */
 160 int
 161 settimeofday(struct proc *p, struct settimeofday_args  *uap, __unused register_t *retval)
 162 {
 163         struct timeval atv;
 164         struct timezone atz;
 165         int error;
 166
 167         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 168                 return (error);
 169         /* Verify all parameters before changing time */
 170         if (uap->tv) {
 171                 if (IS_64BIT_PROCESS(p)) {
 172                         struct user_timeval user_atv;
 173                         error = copyin(uap->tv, &user_atv, sizeof(struct user_timeval));
 174                         atv.tv_sec = user_atv.tv_sec;
 175                         atv.tv_usec = user_atv.tv_usec;
 176                 } else {
 177                         error = copyin(uap->tv, &atv, sizeof(struct timeval));
 178                 }
 179                 if (error)
 180                         return (error);
 181         }
 182         if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
 183                 return (error);
 184         if (uap->tv) {
 185                 timevalfix(&atv);
 186                 if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
 187                         return (EPERM);
 188                 setthetime(&atv);
 189         }
 190         if (uap->tzp) {
 191                 lck_spin_lock(tz_slock);
 192                 tz = atz;
 193                 lck_spin_unlock(tz_slock);
 194         }
 195         return (0);
 196 }
 197
 198 static void
 199 setthetime(
 200         struct timeval  *tv)
 201 {
 202         clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
 203 }
 204
 205 /*
 206  * XXX Y2038 bug because of clock_adjtime() first argument
 207  */
 208 /* ARGSUSED */
 209 int
 210 adjtime(struct proc *p, register struct adjtime_args *uap, __unused register_t *retval)
 211 {
 212         struct timeval atv;
 213         int error;
 214
 215         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 216                 return (error);
 217         if (IS_64BIT_PROCESS(p)) {
 218                 struct user_timeval user_atv;
 219                 error = copyin(uap->delta, &user_atv, sizeof(struct user_timeval));
 220                 atv.tv_sec = user_atv.tv_sec;
 221                 atv.tv_usec = user_atv.tv_usec;
 222         } else {
 223                 error = copyin(uap->delta, &atv, sizeof(struct timeval));
 224         }
 225         if (error)
 226                 return (error);
 227
 228         /*
 229          * Compute the total correction and the rate at which to apply it.
 230          */
 231         clock_adjtime((int32_t *)&atv.tv_sec, &atv.tv_usec);
 232
 233         if (uap->olddelta) {
 234                 if (IS_64BIT_PROCESS(p)) {
 235                         struct user_timeval user_atv;
 236                         user_atv.tv_sec = atv.tv_sec;
 237                         user_atv.tv_usec = atv.tv_usec;
 238                         error = copyout(&user_atv, uap->olddelta, sizeof(struct user_timeval));
 239                 } else {
 240                         error = copyout(&atv, uap->olddelta, sizeof(struct timeval));
 241                 }
 242         }
 243
 244         return (0);
 245 }
 246
 247 /*
 248  *      Verify the calendar value.  If negative,
 249  *      reset to zero (the epoch).
 250  */
 251 void
 252 inittodr(
 253         __unused time_t base)
 254 {
 255         struct timeval  tv;
 256
 257         /*
 258          * Assertion:
 259          * The calendar has already been
 260          * set up from the platform clock.
 261          *
 262          * The value returned by microtime()
 263          * is gotten from the calendar.
 264          */
 265         microtime(&tv);
 266
 267         if (tv.tv_sec < 0 || tv.tv_usec < 0) {
 268                 printf ("WARNING: preposterous time in Real Time Clock");
 269                 tv.tv_sec = 0;          /* the UNIX epoch */
 270                 tv.tv_usec = 0;
 271                 setthetime(&tv);
 272                 printf(" -- CHECK AND RESET THE DATE!\n");
 273         }
 274 }
 275
 276 time_t
 277 boottime_sec(void)
 278 {
 279         uint32_t        sec, nanosec;
 280         clock_get_boottime_nanotime(&sec, &nanosec);
 281         return (sec);
 282 }
 283
 284 uint64_t tvtoabstime(struct timeval *tvp);
 285
 286 /*
 287  * Get value of an interval timer.  The process virtual and
 288  * profiling virtual time timers are kept internally in the
 289  * way they are specified externally: in time until they expire.
 290  *
 291  * The real time interval timer expiration time (p_rtime)
 292  * is kept as an absolute time rather than as a delta, so that
 293  * it is easy to keep periodic real-time signals from drifting.
 294  *
 295  * Virtual time timers are processed in the hardclock() routine of
 296  * kern_clock.c.  The real time timer is processed by a callout
 297  * routine.  Since a callout may be delayed in real time due to
 298  * other processing in the system, it is possible for the real
 299  * time callout routine (realitexpire, given below), to be delayed
 300  * in real time past when it is supposed to occur.  It does not
 301  * suffice, therefore, to reload the real time .it_value from the
 302  * real time .it_interval.  Rather, we compute the next time in
 303  * absolute time when the timer should go off.
 304  */
 305
 306 /* ARGSUSED */
 307 int
 308 getitimer(struct proc *p, register struct getitimer_args *uap, __unused register_t *retval)
 309 {
 310         struct itimerval aitv;
 311
 312         if (uap->which > ITIMER_PROF)
 313                 return(EINVAL);
 314         if (uap->which == ITIMER_REAL) {
 315                 /*
 316                  * If time for real time timer has passed return 0,
 317                  * else return difference between current time and
 318                  * time for the timer to go off.
 319                  */
 320                 aitv = p->p_realtimer;
 321                 if (timerisset(&p->p_rtime)) {
 322                         struct timeval          now;
 323
 324                         microuptime(&now);
 325                         if (timercmp(&p->p_rtime, &now, <))
 326                                 timerclear(&aitv.it_value);
 327                         else {
 328                                 aitv.it_value = p->p_rtime;
 329                                 timevalsub(&aitv.it_value, &now);
 330                         }
 331                 }
 332                 else
 333                         timerclear(&aitv.it_value);
 334         }
 335         else
 336                 aitv = p->p_stats->p_timer[uap->which];
 337
 338         if (IS_64BIT_PROCESS(p)) {
 339                 struct user_itimerval user_itv;
 340                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 341                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 342                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 343                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 344                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (struct user_itimerval)));
 345         } else {
 346                 return (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)));
 347         }
 348 }
 349
 350 /* ARGSUSED */
 351 int
 352 setitimer(p, uap, retval)
 353         struct proc *p;
 354         register struct setitimer_args *uap;
 355         register_t *retval;
 356 {
 357         struct itimerval aitv;
 358         user_addr_t itvp;
 359         int error;
 360
 361         if (uap->which > ITIMER_PROF)
 362                 return (EINVAL);
 363         if ((itvp = uap->itv)) {
 364                 if (IS_64BIT_PROCESS(p)) {
 365                         struct user_itimerval user_itv;
 366                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (struct user_itimerval))))
 367                                 return (error);
 368                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 369                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 370                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 371                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 372                 } else {
 373                         if ((error = copyin(itvp, (caddr_t)&aitv, sizeof (struct itimerval))))
 374                                 return (error);
 375                 }
 376         }
 377         if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
 378                 return (error);
 379         if (itvp == 0)
 380                 return (0);
 381         if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
 382                 return (EINVAL);
 383         if (uap->which == ITIMER_REAL) {
 384                 thread_call_func_cancel((thread_call_func_t)realitexpire, (void *)p->p_pid, FALSE);
 385                 if (timerisset(&aitv.it_value)) {
 386                         microuptime(&p->p_rtime);
 387                         timevaladd(&p->p_rtime, &aitv.it_value);
 388                         thread_call_func_delayed(
 389                                                                 (thread_call_func_t)realitexpire, (void *)p->p_pid,
 390                                                                                 tvtoabstime(&p->p_rtime));
 391                 }
 392                 else
 393                         timerclear(&p->p_rtime);
 394
 395                 p->p_realtimer = aitv;
 396         }
 397         else
 398                 p->p_stats->p_timer[uap->which] = aitv;
 399
 400         return (0);
 401 }
 402
 403 /*
 404  * Real interval timer expired:
 405  * send process whose timer expired an alarm signal.
 406  * If time is not set up to reload, then just return.
 407  * Else compute next time timer should go off which is > current time.
 408  * This is where delay in processing this timeout causes multiple
 409  * SIGALRM calls to be compressed into one.
 410  */
 411 void
 412 realitexpire(
 413         void            *pid)
 414 {
 415         register struct proc *p;
 416         struct timeval  now;
 417         boolean_t               funnel_state;
 418
 419         funnel_state = thread_funnel_set(kernel_flock, TRUE);
 420         p = pfind((pid_t)pid);
 421         if (p == NULL) {
 422                 (void) thread_funnel_set(kernel_flock, FALSE);
 423                 return;
 424         }
 425
 426         if (!timerisset(&p->p_realtimer.it_interval)) {
 427                 timerclear(&p->p_rtime);
 428                 psignal(p, SIGALRM);
 429
 430                 (void) thread_funnel_set(kernel_flock, FALSE);
 431                 return;
 432         }
 433
 434         microuptime(&now);
 435         timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 436         if (timercmp(&p->p_rtime, &now, <=)) {
 437                 if ((p->p_rtime.tv_sec + 2) >= now.tv_sec) {
 438                         for (;;) {
 439                                 timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 440                                 if (timercmp(&p->p_rtime, &now, >))
 441                                         break;
 442                         }
 443                 }
 444                 else {
 445                         p->p_rtime = p->p_realtimer.it_interval;
 446                         timevaladd(&p->p_rtime, &now);
 447                 }
 448         }
 449
 450         psignal(p, SIGALRM);
 451
 452         thread_call_func_delayed((thread_call_func_t)realitexpire, pid, tvtoabstime(&p->p_rtime));
 453
 454         (void) thread_funnel_set(kernel_flock, FALSE);
 455 }
 456
 457 /*
 458  * Check that a proposed value to load into the .it_value or
 459  * .it_interval part of an interval timer is acceptable, and
 460  * fix it to have at least minimal value (i.e. if it is less
 461  * than the resolution of the clock, round it up.)
 462  */
 463 int
 464 itimerfix(tv)
 465         struct timeval *tv;
 466 {
 467
 468         if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
 469             tv->tv_usec < 0 || tv->tv_usec >= 1000000)
 470                 return (EINVAL);
 471         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
 472                 tv->tv_usec = tick;
 473         return (0);
 474 }
 475
 476 /*
 477  * Decrement an interval timer by a specified number
 478  * of microseconds, which must be less than a second,
 479  * i.e. < 1000000.  If the timer expires, then reload
 480  * it.  In this case, carry over (usec - old value) to
 481  * reducint the value reloaded into the timer so that
 482  * the timer does not drift.  This routine assumes
 483  * that it is called in a context where the timers
 484  * on which it is operating cannot change in value.
 485  */
 486 int
 487 itimerdecr(itp, usec)
 488         register struct itimerval *itp;
 489         int usec;
 490 {
 491
 492         if (itp->it_value.tv_usec < usec) {
 493                 if (itp->it_value.tv_sec == 0) {
 494                         /* expired, and already in next interval */
 495                         usec -= itp->it_value.tv_usec;
 496                         goto expire;
 497                 }
 498                 itp->it_value.tv_usec += 1000000;
 499                 itp->it_value.tv_sec--;
 500         }
 501         itp->it_value.tv_usec -= usec;
 502         usec = 0;
 503         if (timerisset(&itp->it_value))
 504                 return (1);
 505         /* expired, exactly at end of interval */
 506 expire:
 507         if (timerisset(&itp->it_interval)) {
 508                 itp->it_value = itp->it_interval;
 509                 itp->it_value.tv_usec -= usec;
 510                 if (itp->it_value.tv_usec < 0) {
 511                         itp->it_value.tv_usec += 1000000;
 512                         itp->it_value.tv_sec--;
 513                 }
 514         } else
 515                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 516         return (0);
 517 }
 518
 519 /*
 520  * Add and subtract routines for timevals.
 521  * N.B.: subtract routine doesn't deal with
 522  * results which are before the beginning,
 523  * it just gets very confused in this case.
 524  * Caveat emptor.
 525  */
 526 void
 527 timevaladd(
 528         struct timeval *t1,
 529         struct timeval *t2)
 530 {
 531
 532         t1->tv_sec += t2->tv_sec;
 533         t1->tv_usec += t2->tv_usec;
 534         timevalfix(t1);
 535 }
 536 void
 537 timevalsub(
 538         struct timeval *t1,
 539         struct timeval *t2)
 540 {
 541
 542         t1->tv_sec -= t2->tv_sec;
 543         t1->tv_usec -= t2->tv_usec;
 544         timevalfix(t1);
 545 }
 546 void
 547 timevalfix(
 548         struct timeval *t1)
 549 {
 550
 551         if (t1->tv_usec < 0) {
 552                 t1->tv_sec--;
 553                 t1->tv_usec += 1000000;
 554         }
 555         if (t1->tv_usec >= 1000000) {
 556                 t1->tv_sec++;
 557                 t1->tv_usec -= 1000000;
 558         }
 559 }
 560
 561 /*
 562  * Return the best possible estimate of the time in the timeval
 563  * to which tvp points.
 564  */
 565 void
 566 microtime(
 567         struct timeval  *tvp)
 568 {
 569         clock_get_calendar_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 570 }
 571
 572 void
 573 microuptime(
 574         struct timeval  *tvp)
 575 {
 576         clock_get_system_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 577 }
 578
 579 /*
 580  * Ditto for timespec.
 581  */
 582 void
 583 nanotime(
 584         struct timespec *tsp)
 585 {
 586         clock_get_calendar_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 587 }
 588
 589 void
 590 nanouptime(
 591         struct timespec *tsp)
 592 {
 593         clock_get_system_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 594 }
 595
 596 uint64_t
 597 tvtoabstime(
 598         struct timeval  *tvp)
 599 {
 600         uint64_t        result, usresult;
 601
 602         clock_interval_to_absolutetime_interval(
 603                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 604         clock_interval_to_absolutetime_interval(
 605                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 606
 607         return (result + usresult);
 608 }
 609 void
 610 time_zone_slock_init(void)
 611 {
 612         /* allocate lock group attribute and group */
 613         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 614         lck_grp_attr_setstat(tz_slock_grp_attr);
 615
 616         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 617
 618         /* Allocate lock attribute */
 619         tz_slock_attr = lck_attr_alloc_init();
 620         //lck_attr_setdebug(tz_slock_attr);
 621
 622         /* Allocate the spin lock */
 623         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 624 }
 625