bsd/kern/kern_time.c

   1 /*
   2  * Copyright (c) 2000-2005 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 /*
  93  * Time of day and interval timer support.
  94  *
  95  * These routines provide the kernel entry points to get and set
  96  * the time-of-day and per-process interval timers.  Subroutines
  97  * here provide support for adding and subtracting timeval structures
  98  * and decrementing interval timers, optionally reloading the interval
  99  * timers when they expire.
 100  */
 101 /* ARGSUSED */
 102 int
 103 gettimeofday(
 104 __unused        struct proc     *p,
 105                         struct gettimeofday_args *uap,
 106                         register_t *retval)
 107 {
 108         int error = 0;
 109         struct timezone ltz; /* local copy */
 110
 111         if (uap->tp)
 112                 clock_gettimeofday(&retval[0], &retval[1]);
 113
 114         if (uap->tzp) {
 115                 lck_spin_lock(tz_slock);
 116                 ltz = tz;
 117                 lck_spin_unlock(tz_slock);
 118
 119                 error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp), sizeof (tz));
 120         }
 121
 122         return (error);
 123 }
 124
 125 /*
 126  * XXX Y2038 bug because of setthetime() argument
 127  */
 128 /* ARGSUSED */
 129 int
 130 settimeofday(struct proc *p, struct settimeofday_args  *uap, __unused register_t *retval)
 131 {
 132         struct timeval atv;
 133         struct timezone atz;
 134         int error;
 135
 136         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 137                 return (error);
 138         /* Verify all parameters before changing time */
 139         if (uap->tv) {
 140                 if (IS_64BIT_PROCESS(p)) {
 141                         struct user_timeval user_atv;
 142                         error = copyin(uap->tv, &user_atv, sizeof(struct user_timeval));
 143                         atv.tv_sec = user_atv.tv_sec;
 144                         atv.tv_usec = user_atv.tv_usec;
 145                 } else {
 146                         error = copyin(uap->tv, &atv, sizeof(struct timeval));
 147                 }
 148                 if (error)
 149                         return (error);
 150         }
 151         if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
 152                 return (error);
 153         if (uap->tv) {
 154                 timevalfix(&atv);
 155                 if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
 156                         return (EPERM);
 157                 setthetime(&atv);
 158         }
 159         if (uap->tzp) {
 160                 lck_spin_lock(tz_slock);
 161                 tz = atz;
 162                 lck_spin_unlock(tz_slock);
 163         }
 164         return (0);
 165 }
 166
 167 static void
 168 setthetime(
 169         struct timeval  *tv)
 170 {
 171         clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
 172 }
 173
 174 /*
 175  * XXX Y2038 bug because of clock_adjtime() first argument
 176  */
 177 /* ARGSUSED */
 178 int
 179 adjtime(struct proc *p, register struct adjtime_args *uap, __unused register_t *retval)
 180 {
 181         struct timeval atv;
 182         int error;
 183
 184         if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 185                 return (error);
 186         if (IS_64BIT_PROCESS(p)) {
 187                 struct user_timeval user_atv;
 188                 error = copyin(uap->delta, &user_atv, sizeof(struct user_timeval));
 189                 atv.tv_sec = user_atv.tv_sec;
 190                 atv.tv_usec = user_atv.tv_usec;
 191         } else {
 192                 error = copyin(uap->delta, &atv, sizeof(struct timeval));
 193         }
 194         if (error)
 195                 return (error);
 196
 197         /*
 198          * Compute the total correction and the rate at which to apply it.
 199          */
 200         clock_adjtime((int32_t *)&atv.tv_sec, &atv.tv_usec);
 201
 202         if (uap->olddelta) {
 203                 if (IS_64BIT_PROCESS(p)) {
 204                         struct user_timeval user_atv;
 205                         user_atv.tv_sec = atv.tv_sec;
 206                         user_atv.tv_usec = atv.tv_usec;
 207                         error = copyout(&user_atv, uap->olddelta, sizeof(struct user_timeval));
 208                 } else {
 209                         error = copyout(&atv, uap->olddelta, sizeof(struct timeval));
 210                 }
 211         }
 212
 213         return (0);
 214 }
 215
 216 /*
 217  *      Verify the calendar value.  If negative,
 218  *      reset to zero (the epoch).
 219  */
 220 void
 221 inittodr(
 222         __unused time_t base)
 223 {
 224         struct timeval  tv;
 225
 226         /*
 227          * Assertion:
 228          * The calendar has already been
 229          * set up from the platform clock.
 230          *
 231          * The value returned by microtime()
 232          * is gotten from the calendar.
 233          */
 234         microtime(&tv);
 235
 236         if (tv.tv_sec < 0 || tv.tv_usec < 0) {
 237                 printf ("WARNING: preposterous time in Real Time Clock");
 238                 tv.tv_sec = 0;          /* the UNIX epoch */
 239                 tv.tv_usec = 0;
 240                 setthetime(&tv);
 241                 printf(" -- CHECK AND RESET THE DATE!\n");
 242         }
 243 }
 244
 245 time_t
 246 boottime_sec(void)
 247 {
 248         uint32_t        sec, nanosec;
 249         clock_get_boottime_nanotime(&sec, &nanosec);
 250         return (sec);
 251 }
 252
 253 uint64_t tvtoabstime(struct timeval *tvp);
 254
 255 /*
 256  * Get value of an interval timer.  The process virtual and
 257  * profiling virtual time timers are kept internally in the
 258  * way they are specified externally: in time until they expire.
 259  *
 260  * The real time interval timer expiration time (p_rtime)
 261  * is kept as an absolute time rather than as a delta, so that
 262  * it is easy to keep periodic real-time signals from drifting.
 263  *
 264  * Virtual time timers are processed in the hardclock() routine of
 265  * kern_clock.c.  The real time timer is processed by a callout
 266  * routine.  Since a callout may be delayed in real time due to
 267  * other processing in the system, it is possible for the real
 268  * time callout routine (realitexpire, given below), to be delayed
 269  * in real time past when it is supposed to occur.  It does not
 270  * suffice, therefore, to reload the real time .it_value from the
 271  * real time .it_interval.  Rather, we compute the next time in
 272  * absolute time when the timer should go off.
 273  */
 274
 275 /* ARGSUSED */
 276 int
 277 getitimer(struct proc *p, register struct getitimer_args *uap, __unused register_t *retval)
 278 {
 279         struct itimerval aitv;
 280
 281         if (uap->which > ITIMER_PROF)
 282                 return(EINVAL);
 283         if (uap->which == ITIMER_REAL) {
 284                 /*
 285                  * If time for real time timer has passed return 0,
 286                  * else return difference between current time and
 287                  * time for the timer to go off.
 288                  */
 289                 aitv = p->p_realtimer;
 290                 if (timerisset(&p->p_rtime)) {
 291                         struct timeval          now;
 292
 293                         microuptime(&now);
 294                         if (timercmp(&p->p_rtime, &now, <))
 295                                 timerclear(&aitv.it_value);
 296                         else {
 297                                 aitv.it_value = p->p_rtime;
 298                                 timevalsub(&aitv.it_value, &now);
 299                         }
 300                 }
 301                 else
 302                         timerclear(&aitv.it_value);
 303         }
 304         else
 305                 aitv = p->p_stats->p_timer[uap->which];
 306
 307         if (IS_64BIT_PROCESS(p)) {
 308                 struct user_itimerval user_itv;
 309                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 310                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 311                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 312                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 313                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (struct user_itimerval)));
 314         } else {
 315                 return (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)));
 316         }
 317 }
 318
 319 /* ARGSUSED */
 320 int
 321 setitimer(p, uap, retval)
 322         struct proc *p;
 323         register struct setitimer_args *uap;
 324         register_t *retval;
 325 {
 326         struct itimerval aitv;
 327         user_addr_t itvp;
 328         int error;
 329
 330         if (uap->which > ITIMER_PROF)
 331                 return (EINVAL);
 332         if ((itvp = uap->itv)) {
 333                 if (IS_64BIT_PROCESS(p)) {
 334                         struct user_itimerval user_itv;
 335                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (struct user_itimerval))))
 336                                 return (error);
 337                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 338                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 339                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 340                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 341                 } else {
 342                         if ((error = copyin(itvp, (caddr_t)&aitv, sizeof (struct itimerval))))
 343                                 return (error);
 344                 }
 345         }
 346         if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
 347                 return (error);
 348         if (itvp == 0)
 349                 return (0);
 350         if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
 351                 return (EINVAL);
 352         if (uap->which == ITIMER_REAL) {
 353                 thread_call_func_cancel((thread_call_func_t)realitexpire, (void *)p->p_pid, FALSE);
 354                 if (timerisset(&aitv.it_value)) {
 355                         microuptime(&p->p_rtime);
 356                         timevaladd(&p->p_rtime, &aitv.it_value);
 357                         thread_call_func_delayed(
 358                                                                 (thread_call_func_t)realitexpire, (void *)p->p_pid,
 359                                                                                 tvtoabstime(&p->p_rtime));
 360                 }
 361                 else
 362                         timerclear(&p->p_rtime);
 363
 364                 p->p_realtimer = aitv;
 365         }
 366         else
 367                 p->p_stats->p_timer[uap->which] = aitv;
 368
 369         return (0);
 370 }
 371
 372 /*
 373  * Real interval timer expired:
 374  * send process whose timer expired an alarm signal.
 375  * If time is not set up to reload, then just return.
 376  * Else compute next time timer should go off which is > current time.
 377  * This is where delay in processing this timeout causes multiple
 378  * SIGALRM calls to be compressed into one.
 379  */
 380 void
 381 realitexpire(
 382         void            *pid)
 383 {
 384         register struct proc *p;
 385         struct timeval  now;
 386         boolean_t               funnel_state;
 387
 388         funnel_state = thread_funnel_set(kernel_flock, TRUE);
 389         p = pfind((pid_t)pid);
 390         if (p == NULL) {
 391                 (void) thread_funnel_set(kernel_flock, FALSE);
 392                 return;
 393         }
 394
 395         if (!timerisset(&p->p_realtimer.it_interval)) {
 396                 timerclear(&p->p_rtime);
 397                 psignal(p, SIGALRM);
 398
 399                 (void) thread_funnel_set(kernel_flock, FALSE);
 400                 return;
 401         }
 402
 403         microuptime(&now);
 404         timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 405         if (timercmp(&p->p_rtime, &now, <=)) {
 406                 if ((p->p_rtime.tv_sec + 2) >= now.tv_sec) {
 407                         for (;;) {
 408                                 timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 409                                 if (timercmp(&p->p_rtime, &now, >))
 410                                         break;
 411                         }
 412                 }
 413                 else {
 414                         p->p_rtime = p->p_realtimer.it_interval;
 415                         timevaladd(&p->p_rtime, &now);
 416                 }
 417         }
 418
 419         psignal(p, SIGALRM);
 420
 421         thread_call_func_delayed((thread_call_func_t)realitexpire, pid, tvtoabstime(&p->p_rtime));
 422
 423         (void) thread_funnel_set(kernel_flock, FALSE);
 424 }
 425
 426 /*
 427  * Check that a proposed value to load into the .it_value or
 428  * .it_interval part of an interval timer is acceptable, and
 429  * fix it to have at least minimal value (i.e. if it is less
 430  * than the resolution of the clock, round it up.)
 431  */
 432 int
 433 itimerfix(tv)
 434         struct timeval *tv;
 435 {
 436
 437         if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
 438             tv->tv_usec < 0 || tv->tv_usec >= 1000000)
 439                 return (EINVAL);
 440         if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
 441                 tv->tv_usec = tick;
 442         return (0);
 443 }
 444
 445 /*
 446  * Decrement an interval timer by a specified number
 447  * of microseconds, which must be less than a second,
 448  * i.e. < 1000000.  If the timer expires, then reload
 449  * it.  In this case, carry over (usec - old value) to
 450  * reducint the value reloaded into the timer so that
 451  * the timer does not drift.  This routine assumes
 452  * that it is called in a context where the timers
 453  * on which it is operating cannot change in value.
 454  */
 455 int
 456 itimerdecr(itp, usec)
 457         register struct itimerval *itp;
 458         int usec;
 459 {
 460
 461         if (itp->it_value.tv_usec < usec) {
 462                 if (itp->it_value.tv_sec == 0) {
 463                         /* expired, and already in next interval */
 464                         usec -= itp->it_value.tv_usec;
 465                         goto expire;
 466                 }
 467                 itp->it_value.tv_usec += 1000000;
 468                 itp->it_value.tv_sec--;
 469         }
 470         itp->it_value.tv_usec -= usec;
 471         usec = 0;
 472         if (timerisset(&itp->it_value))
 473                 return (1);
 474         /* expired, exactly at end of interval */
 475 expire:
 476         if (timerisset(&itp->it_interval)) {
 477                 itp->it_value = itp->it_interval;
 478                 itp->it_value.tv_usec -= usec;
 479                 if (itp->it_value.tv_usec < 0) {
 480                         itp->it_value.tv_usec += 1000000;
 481                         itp->it_value.tv_sec--;
 482                 }
 483         } else
 484                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 485         return (0);
 486 }
 487
 488 /*
 489  * Add and subtract routines for timevals.
 490  * N.B.: subtract routine doesn't deal with
 491  * results which are before the beginning,
 492  * it just gets very confused in this case.
 493  * Caveat emptor.
 494  */
 495 void
 496 timevaladd(
 497         struct timeval *t1,
 498         struct timeval *t2)
 499 {
 500
 501         t1->tv_sec += t2->tv_sec;
 502         t1->tv_usec += t2->tv_usec;
 503         timevalfix(t1);
 504 }
 505 void
 506 timevalsub(
 507         struct timeval *t1,
 508         struct timeval *t2)
 509 {
 510
 511         t1->tv_sec -= t2->tv_sec;
 512         t1->tv_usec -= t2->tv_usec;
 513         timevalfix(t1);
 514 }
 515 void
 516 timevalfix(
 517         struct timeval *t1)
 518 {
 519
 520         if (t1->tv_usec < 0) {
 521                 t1->tv_sec--;
 522                 t1->tv_usec += 1000000;
 523         }
 524         if (t1->tv_usec >= 1000000) {
 525                 t1->tv_sec++;
 526                 t1->tv_usec -= 1000000;
 527         }
 528 }
 529
 530 /*
 531  * Return the best possible estimate of the time in the timeval
 532  * to which tvp points.
 533  */
 534 void
 535 microtime(
 536         struct timeval  *tvp)
 537 {
 538         clock_get_calendar_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 539 }
 540
 541 void
 542 microuptime(
 543         struct timeval  *tvp)
 544 {
 545         clock_get_system_microtime((uint32_t *)&tvp->tv_sec, &tvp->tv_usec);
 546 }
 547
 548 /*
 549  * Ditto for timespec.
 550  */
 551 void
 552 nanotime(
 553         struct timespec *tsp)
 554 {
 555         clock_get_calendar_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 556 }
 557
 558 void
 559 nanouptime(
 560         struct timespec *tsp)
 561 {
 562         clock_get_system_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
 563 }
 564
 565 uint64_t
 566 tvtoabstime(
 567         struct timeval  *tvp)
 568 {
 569         uint64_t        result, usresult;
 570
 571         clock_interval_to_absolutetime_interval(
 572                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 573         clock_interval_to_absolutetime_interval(
 574                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 575
 576         return (result + usresult);
 577 }
 578 void
 579 time_zone_slock_init(void)
 580 {
 581         /* allocate lock group attribute and group */
 582         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 583
 584         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 585
 586         /* Allocate lock attribute */
 587         tz_slock_attr = lck_attr_alloc_init();
 588
 589         /* Allocate the spin lock */
 590         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 591 }
 592