bsd/kern/kern_time.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)kern_time.c 8.4 (Berkeley) 5/26/95
  56  */
  57
  58 #include <sys/param.h>
  59 #include <sys/resourcevar.h>
  60 #include <sys/kernel.h>
  61 #include <sys/systm.h>
  62 #include <sys/proc_internal.h>
  63 #include <sys/kauth.h>
  64 #include <sys/vnode.h>
  65
  66 #include <sys/mount_internal.h>
  67 #include <sys/sysproto.h>
  68 #include <sys/signalvar.h>
  69
  70 #include <kern/clock.h>
  71 #include <kern/thread_call.h>
  72
  73 #define HZ      100     /* XXX */
  74
  75 /* simple lock used to access timezone, tz structure */
  76 lck_spin_t * tz_slock;
  77 lck_grp_t * tz_slock_grp;
  78 lck_attr_t * tz_slock_attr;
  79 lck_grp_attr_t  *tz_slock_grp_attr;
  80
  81 static void             setthetime(
  82                                         struct timeval  *tv);
  83
  84 void time_zone_slock_init(void);
  85
  86 int gettimeofday(struct proc *p,
  87 #ifdef __ppc__
  88                          struct ppc_gettimeofday_args *uap,
  89 #else
  90                          struct gettimeofday_args *uap,
  91 #endif
  92                          register_t *retval);
  93
  94 /*
  95  * Time of day and interval timer support.
  96  *
  97  * These routines provide the kernel entry points to get and set
  98  * the time-of-day and per-process interval timers.  Subroutines
  99  * here provide support for adding and subtracting timeval structures
 100  * and decrementing interval timers, optionally reloading the interval
 101  * timers when they expire.
 102  *
 103  * XXX Y2038 bug because of clock_get_calendar_microtime() first argument
 104  */
 105 /* ARGSUSED */
 106 int
 107 gettimeofday(__unused struct proc *p,
 108 #ifdef __ppc__
 109                          register struct ppc_gettimeofday_args *uap,
 110 #else
 111                          register struct gettimeofday_args *uap,
 112 #endif
 113                          __unused register_t *retval)
 114 {
 115         struct timeval atv;
 116         int error = 0;
 117         struct timezone ltz; /* local copy */
 118
 119 /*  NOTE THIS implementation is for non ppc architectures only */
 120
 121         if (uap->tp) {
 122                 clock_get_calendar_microtime((uint32_t *)&atv.tv_sec, &atv.tv_usec);
 123                 if (IS_64BIT_PROCESS(p)) {
 124                         struct user_timeval user_atv;
 125                         user_atv.tv_sec = atv.tv_sec;
 126                         user_atv.tv_usec = atv.tv_usec;
 127                         /*
 128                          * This cast is not necessary for PPC, but is
 129                          * mostly harmless.
 130                          */
 131                         error = copyout(&user_atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct user_timeval));
 132                 } else {
 133                         error = copyout(&atv, CAST_USER_ADDR_T(uap->tp), sizeof(struct timeval));
 134                 }
 135                 if (error)
 136                         return(error);
 137         }
 138
 139         if (uap->tzp) {
 140                 lck_spin_lock(tz_slock);
 141                 ltz = tz;
 142                 lck_spin_unlock(tz_slock);
 143                 error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp),
 144                     sizeof (tz));
 145         }
 146
 147         return(error);
 148 }
 149
 150 /*
 151  * XXX Y2038 bug because of setthetime() argument
 152  */
 153 /* ARGSUSED */
 154 int
 155 settimeofday(struct proc *p, struct settimeofday_args  *uap, __unused register_t *retval)
 156 {
 157         struct timeval atv;
 158         struct timezone atz;
 159         int error;
 160
 161         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 162                 return (error);
 163         /* Verify all parameters before changing time */
 164         if (uap->tv) {
 165                 if (IS_64BIT_PROCESS(p)) {
 166                         struct user_timeval user_atv;
 167                         error = copyin(uap->tv, &user_atv, sizeof(struct user_timeval));
 168                         atv.tv_sec = user_atv.tv_sec;
 169                         atv.tv_usec = user_atv.tv_usec;
 170                 } else {
 171                         error = copyin(uap->tv, &atv, sizeof(struct timeval));
 172                 }
 173                 if (error)
 174                         return (error);
 175         }
 176         if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
 177                 return (error);
 178         if (uap->tv) {
 179                 timevalfix(&atv);
 180                 if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
 181                         return (EPERM);
 182                 setthetime(&atv);
 183         }
 184         if (uap->tzp) {
 185                 lck_spin_lock(tz_slock);
 186                 tz = atz;
 187                 lck_spin_unlock(tz_slock);
 188         }
 189         return (0);
 190 }
 191
 192 static void
 193 setthetime(
 194         struct timeval  *tv)
 195 {
 196         clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
 197 }
 198
 199 /*
 200  * XXX Y2038 bug because of clock_adjtime() first argument
 201  */
 202 /* ARGSUSED */
 203 int
 204 adjtime(struct proc *p, register struct adjtime_args *uap, __unused register_t *retval)
 205 {
 206         struct timeval atv;
 207         int error;
 208
 209         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 210                 return (error);
 211         if (IS_64BIT_PROCESS(p)) {
 212                 struct user_timeval user_atv;
 213                 error = copyin(uap->delta, &user_atv, sizeof(struct user_timeval));
 214                 atv.tv_sec = user_atv.tv_sec;
 215                 atv.tv_usec = user_atv.tv_usec;
 216         } else {
 217                 error = copyin(uap->delta, &atv, sizeof(struct timeval));
 218         }
 219         if (error)
 220                 return (error);
 221
 222         /*
 223          * Compute the total correction and the rate at which to apply it.
 224          */
 225         clock_adjtime((int32_t *)&atv.tv_sec, &atv.tv_usec);
 226
 227         if (uap->olddelta) {
 228                 if (IS_64BIT_PROCESS(p)) {
 229                         struct user_timeval user_atv;
 230                         user_atv.tv_sec = atv.tv_sec;
 231                         user_atv.tv_usec = atv.tv_usec;
 232                         error = copyout(&user_atv, uap->olddelta, sizeof(struct user_timeval));
 233                 } else {
 234                         error = copyout(&atv, uap->olddelta, sizeof(struct timeval));
 235                 }
 236         }
 237
 238         return (0);
 239 }
 240
 241 /*
 242  *      Verify the calendar value.  If negative,
 243  *      reset to zero (the epoch).
 244  */
 245 void
 246 inittodr(
 247         __unused time_t base)
 248 {
 249         struct timeval  tv;
 250
 251         /*
 252          * Assertion:
 253          * The calendar has already been
 254          * set up from the platform clock.
 255          *
 256          * The value returned by microtime()
 257          * is gotten from the calendar.
 258          */
 259         microtime(&tv);
 260
 261         if (tv.tv_sec < 0 || tv.tv_usec < 0) {
 262                 printf ("WARNING: preposterous time in Real Time Clock");
 263                 tv.tv_sec = 0;          /* the UNIX epoch */
 264                 tv.tv_usec = 0;
 265                 setthetime(&tv);
 266                 printf(" -- CHECK AND RESET THE DATE!\n");
 267         }
 268 }
 269
 270 time_t
 271 boottime_sec(void)
 272 {
 273         uint32_t        sec, nanosec;
 274         clock_get_boottime_nanotime(&sec, &nanosec);
 275         return (sec);
 276 }
 277
 278 uint64_t tvtoabstime(struct timeval *tvp);
 279
 280 /*
 281  * Get value of an interval timer.  The process virtual and
 282  * profiling virtual time timers are kept internally in the
 283  * way they are specified externally: in time until they expire.
 284  *
 285  * The real time interval timer expiration time (p_rtime)
 286  * is kept as an absolute time rather than as a delta, so that
 287  * it is easy to keep periodic real-time signals from drifting.
 288  *
 289  * Virtual time timers are processed in the hardclock() routine of
 290  * kern_clock.c.  The real time timer is processed by a callout
 291  * routine.  Since a callout may be delayed in real time due to
 292  * other processing in the system, it is possible for the real
 293  * time callout routine (realitexpire, given below), to be delayed
 294  * in real time past when it is supposed to occur.  It does not
 295  * suffice, therefore, to reload the real time .it_value from the
 296  * real time .it_interval.  Rather, we compute the next time in
 297  * absolute time when the timer should go off.
 298  */
 299
 300 /* ARGSUSED */
 301 int
 302 getitimer(struct proc *p, register struct getitimer_args *uap, __unused register_t *retval)
 303 {
 304         struct itimerval aitv;
 305
 306         if (uap->which > ITIMER_PROF)
 307                 return(EINVAL);
 308         if (uap->which == ITIMER_REAL) {
 309                 /*
 310                  * If time for real time timer has passed return 0,
 311                  * else return difference between current time and
 312                  * time for the timer to go off.
 313                  */
 314                 aitv = p->p_realtimer;
 315                 if (timerisset(&p->p_rtime)) {
 316                         struct timeval          now;
 317
 318                         microuptime(&now);
 319                         if (timercmp(&p->p_rtime, &now, <))
 320                                 timerclear(&aitv.it_value);
 321                         else {
 322                                 aitv.it_value = p->p_rtime;
 323                                 timevalsub(&aitv.it_value, &now);
 324                         }
 325                 }
 326                 else
 327                         timerclear(&aitv.it_value);
 328         }
 329         else
 330                 aitv = p->p_stats->p_timer[uap->which];
 331
 332         if (IS_64BIT_PROCESS(p)) {
 333                 struct user_itimerval user_itv;
 334                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 335                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 336                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 337                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 338                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (struct user_itimerval)));
 339         } else {
 340                 return (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)));
 341         }
 342 }
 343
 344 /* ARGSUSED */
 345 int
 346 setitimer(p, uap, retval)
 347         struct proc *p;
 348         register struct setitimer_args *uap;
 349         register_t *retval;
 350 {
 351         struct itimerval aitv;
 352         user_addr_t itvp;
 353         int error;
 354
 355         if (uap->which > ITIMER_PROF)
 356                 return (EINVAL);
 357         if ((itvp = uap->itv)) {
 358                 if (IS_64BIT_PROCESS(p)) {
 359                         struct user_itimerval user_itv;
 360                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (struct user_itimerval))))
 361                                 return (error);
 362                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 363                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 364                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 365                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 366                 } else {
 367                         if ((error = copyin(itvp, (caddr_t)&aitv, sizeof (struct itimerval))))
 368                                 return (error);
 369                 }
 370         }
 371         if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
 372                 return (error);
 373         if (itvp == 0)
 374                 return (0);
 375         if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
 376                 return (EINVAL);
 377         if (uap->which == ITIMER_REAL) {
 378                 thread_call_func_cancel((thread_call_func_t)realitexpire, (void *)p->p_pid, FALSE);
 379                 if (timerisset(&aitv.it_value)) {
 380                         microuptime(&p->p_rtime);
 381                         timevaladd(&p->p_rtime, &aitv.it_value);
 382                         thread_call_func_delayed(
 383                                                                 (thread_call_func_t)realitexpire, (void *)p->p_pid,
 384                                                                                 tvtoabstime(&p->p_rtime));
 385                 }
 386                 else
 387                         timerclear(&p->p_rtime);
 388
 389                 p->p_realtimer = aitv;
 390         }
 391         else
 392                 p->p_stats->p_timer[uap->which] = aitv;
 393
 394         return (0);
 395 }
 396
 397 /*
 398  * Real interval timer expired:
 399  * send process whose timer expired an alarm signal.
 400  * If time is not set up to reload, then just return.
 401  * Else compute next time timer should go off which is > current time.
 402  * This is where delay in processing this timeout causes multiple
 403  * SIGALRM calls to be compressed into one.
 404  */
 405 void
 406 realitexpire(
 407         void            *pid)
 408 {
 409         register struct proc *p;
 410         struct timeval  now;
 411         boolean_t               funnel_state;
 412
 413         funnel_state = thread_funnel_set(kernel_flock, TRUE);
 414         p = pfind((pid_t)pid);
 415         if (p == NULL) {
 416                 (void) thread_funnel_set(kernel_flock, FALSE);
 417                 return;
 418         }
 419
 420         if (!timerisset(&p->p_realtimer.it_interval)) {
 421                 timerclear(&p->p_rtime);
 422                 psignal(p, SIGALRM);
 423
 424                 (void) thread_funnel_set(kernel_flock, FALSE);
 425                 return;
 426         }
 427
 428         microuptime(&now);
 429         timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 430         if (timercmp(&p->p_rtime, &now, <=)) {
 431                 if ((p->p_rtime.tv_sec + 2) >= now.tv_sec) {
 432                         for (;;) {
 433                                 timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 434                                 if (timercmp(&p->p_rtime, &now, >))
 435                                         break;
 436                         }
 437                 }
 438                 else {
 439                         p->p_rtime = p->p_realtimer.it_interval;
 440                         timevaladd(&p->p_rtime, &now);
 441                 }
 442         }
 443
 444         psignal(p, SIGALRM);
 445
 446         thread_call_func_delayed((thread_call_func_t)realitexpire, pid, tvtoabstime(&p->p_rtime));
 447
 448         (void) thread_funnel_set(kernel_flock, FALSE);
 449 }
 450
 451 /*
 452  * Check that a proposed value to load into the .it_value or
 453  * .it_interval part of an interval timer is acceptable, and
 454  * fix it to have at least minimal value (i.e. if it is less
 455  * than the resolution of the clock, round it up.)
 456  */
 457 int
 458 itimerfix(tv)
 459         struct timeval *tv;
 460 {
 461
 462         if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
 463             tv->tv_usec < 0 || tv->tv_usec >= 1000000)
 464                 return (EINVAL);
 465         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
 466                 tv->tv_usec = tick;
 467         return (0);
 468 }
 469
 470 /*
 471  * Decrement an interval timer by a specified number
 472  * of microseconds, which must be less than a second,
 473  * i.e. < 1000000.  If the timer expires, then reload
 474  * it.  In this case, carry over (usec - old value) to
 475  * reducint the value reloaded into the timer so that
 476  * the timer does not drift.  This routine assumes
 477  * that it is called in a context where the timers
 478  * on which it is operating cannot change in value.
 479  */
 480 int
 481 itimerdecr(itp, usec)
 482         register struct itimerval *itp;
 483         int usec;
 484 {
 485
 486         if (itp->it_value.tv_usec < usec) {
 487                 if (itp->it_value.tv_sec == 0) {
 488                         /* expired, and already in next interval */
 489                         usec -= itp->it_value.tv_usec;
 490                         goto expire;
 491                 }
 492                 itp->it_value.tv_usec += 1000000;
 493                 itp->it_value.tv_sec--;
 494         }
 495         itp->it_value.tv_usec -= usec;
 496         usec = 0;
 497         if (timerisset(&itp->it_value))
 498                 return (1);
 499         /* expired, exactly at end of interval */
 500 expire:
 501         if (timerisset(&itp->it_interval)) {
 502                 itp->it_value = itp->it_interval;
 503                 itp->it_value.tv_usec -= usec;
 504                 if (itp->it_value.tv_usec < 0) {
 505                         itp->it_value.tv_usec += 1000000;
 506                         itp->it_value.tv_sec--;
 507                 }
 508         } else
 509                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 510         return (0);
 511 }
 512
 513 /*
 514  * Add and subtract routines for timevals.
 515  * N.B.: subtract routine doesn't deal with
 516  * results which are before the beginning,
 517  * it just gets very confused in this case.
 518  * Caveat emptor.
 519  */
 520 void
 521 timevaladd(
 522         struct timeval *t1,
 523         struct timeval *t2)
 524 {
 525
 526         t1->tv_sec += t2->tv_sec;
 527         t1->tv_usec += t2->tv_usec;
 528         timevalfix(t1);
 529 }
 530 void
 531 timevalsub(
 532         struct timeval *t1,
 533         struct timeval *t2)
 534 {
 535
 536         t1->tv_sec -= t2->tv_sec;
 537         t1->tv_usec -= t2->tv_usec;
 538         timevalfix(t1);
 539 }
 540 void
 541 timevalfix(
 542         struct timeval *t1)
 543 {
 544
 545         if (t1->tv_usec < 0) {
 546                 t1->tv_sec--;
 547                 t1->tv_usec += 1000000;
 548         }
 549         if (t1->tv_usec >= 1000000) {
 550                 t1->tv_sec++;
 551                 t1->tv_usec -= 1000000;
 552         }
 553 }
 554
 555 /*
 556  * Return the best possible estimate of the time in the timeval
 557  * to which tvp points.
 558  */
 559 void
 560 microtime(
 561         struct timeval  *tvp)
 562 {
 563         clock_get_calendar_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 564 }
 565
 566 void
 567 microuptime(
 568         struct timeval  *tvp)
 569 {
 570         clock_get_system_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 571 }
 572
 573 /*
 574  * Ditto for timespec.
 575  */
 576 void
 577 nanotime(
 578         struct timespec *tsp)
 579 {
 580         clock_get_calendar_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 581 }
 582
 583 void
 584 nanouptime(
 585         struct timespec *tsp)
 586 {
 587         clock_get_system_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 588 }
 589
 590 uint64_t
 591 tvtoabstime(
 592         struct timeval  *tvp)
 593 {
 594         uint64_t        result, usresult;
 595
 596         clock_interval_to_absolutetime_interval(
 597                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 598         clock_interval_to_absolutetime_interval(
 599                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 600
 601         return (result + usresult);
 602 }
 603 void
 604 time_zone_slock_init(void)
 605 {
 606         /* allocate lock group attribute and group */
 607         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 608         lck_grp_attr_setstat(tz_slock_grp_attr);
 609
 610         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 611
 612         /* Allocate lock attribute */
 613         tz_slock_attr = lck_attr_alloc_init();
 614         //lck_attr_setdebug(tz_slock_attr);
 615
 616         /* Allocate the spin lock */
 617         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 618 }
 619