1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)kern_time.c 8.1 (Berkeley) 6/10/93 34 * $Id: kern_time.c,v 1.64 1999/04/07 19:48:09 nsayer Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/buf.h> 39 #include <sys/sysproto.h> 40 #include <sys/resourcevar.h> 41 #include <sys/signalvar.h> 42 #include <sys/kernel.h> 43 #include <sys/systm.h> 44 #include <sys/sysent.h> 45 #include <sys/proc.h> 46 #include <sys/time.h> 47 #include <sys/vnode.h> 48 #include <vm/vm.h> 49 #include <vm/vm_extern.h> 50 51 struct timezone tz; 52 53 /* 54 * Time of day and interval timer support. 55 * 56 * These routines provide the kernel entry points to get and set 57 * the time-of-day and per-process interval timers. Subroutines 58 * here provide support for adding and subtracting timeval structures 59 * and decrementing interval timers, optionally reloading the interval 60 * timers when they expire. 61 */ 62 63 static int nanosleep1 __P((struct proc *p, struct timespec *rqt, 64 struct timespec *rmt)); 65 static int settime __P((struct timeval *)); 66 static void timevalfix __P((struct timeval *)); 67 static void no_lease_updatetime __P((int)); 68 69 static void 70 no_lease_updatetime(deltat) 71 int deltat; 72 { 73 } 74 75 void (*lease_updatetime) __P((int)) = no_lease_updatetime; 76 77 static int 78 settime(tv) 79 struct timeval *tv; 80 { 81 struct timeval delta, tv1, tv2; 82 static struct timeval maxtime, laststep; 83 struct timespec ts; 84 int s; 85 86 s = splclock(); 87 microtime(&tv1); 88 delta = *tv; 89 timevalsub(&delta, &tv1); 90 91 /* 92 * If the system is secure, we do not allow the time to be 93 * set to a value earlier than 1 second less than the highest 94 * time we have yet seen. The worst a miscreant can do in 95 * this circumstance is "freeze" time. He couldn't go 96 * back to the past. 97 * 98 * We similarly do not allow the clock to be stepped more 99 * than one second, nor more than once per second. This allows 100 * a miscreant to make the clock march double-time, but no worse. 101 */ 102 if (securelevel > 1) { 103 if (delta.tv_sec < 0 || delta.tv_usec < 0) { 104 /* 105 * Update maxtime to latest time we've seen. 106 */ 107 if (tv1.tv_sec > maxtime.tv_sec) 108 maxtime = tv1; 109 tv2 = *tv; 110 timevalsub(&tv2, &maxtime); 111 if (tv2.tv_sec < -1) { 112 tv->tv_sec = maxtime.tv_sec - 1; 113 printf("Time adjustment clamped to -1 second\n"); 114 } 115 } else { 116 if (tv1.tv_sec == laststep.tv_sec) { 117 splx(s); 118 return (EPERM); 119 } 120 if (delta.tv_sec > 1) { 121 tv->tv_sec = tv1.tv_sec + 1; 122 printf("Time adjustment clamped to +1 second\n"); 123 } 124 laststep = *tv; 125 } 126 } 127 128 ts.tv_sec = tv->tv_sec; 129 ts.tv_nsec = tv->tv_usec * 1000; 130 set_timecounter(&ts); 131 (void) splsoftclock(); 132 lease_updatetime(delta.tv_sec); 133 splx(s); 134 resettodr(); 135 return (0); 136 } 137 138 #ifndef _SYS_SYSPROTO_H_ 139 struct clock_gettime_args { 140 clockid_t clock_id; 141 struct timespec *tp; 142 }; 143 #endif 144 145 /* ARGSUSED */ 146 int 147 clock_gettime(p, uap) 148 struct proc *p; 149 struct clock_gettime_args *uap; 150 { 151 struct timespec ats; 152 153 if (SCARG(uap, clock_id) != CLOCK_REALTIME) 154 return (EINVAL); 155 nanotime(&ats); 156 return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); 157 } 158 159 #ifndef _SYS_SYSPROTO_H_ 160 struct clock_settime_args { 161 clockid_t clock_id; 162 const struct timespec *tp; 163 }; 164 #endif 165 166 /* ARGSUSED */ 167 int 168 clock_settime(p, uap) 169 struct proc *p; 170 struct clock_settime_args *uap; 171 { 172 struct timeval atv; 173 struct timespec ats; 174 int error; 175 176 if ((error = suser(p)) != 0) 177 return (error); 178 if (SCARG(uap, clock_id) != CLOCK_REALTIME) 179 return (EINVAL); 180 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 181 return (error); 182 if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) 183 return (EINVAL); 184 /* XXX Don't convert nsec->usec and back */ 185 TIMESPEC_TO_TIMEVAL(&atv, &ats); 186 if ((error = settime(&atv))) 187 return (error); 188 return (0); 189 } 190 191 #ifndef _SYS_SYSPROTO_H_ 192 struct clock_getres_args { 193 clockid_t clock_id; 194 struct timespec *tp; 195 }; 196 #endif 197 198 int 199 clock_getres(p, uap) 200 struct proc *p; 201 struct clock_getres_args *uap; 202 { 203 struct timespec ts; 204 int error; 205 206 if (SCARG(uap, clock_id) != CLOCK_REALTIME) 207 return (EINVAL); 208 error = 0; 209 if (SCARG(uap, tp)) { 210 ts.tv_sec = 0; 211 ts.tv_nsec = 1000000000 / timecounter->tc_frequency; 212 error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 213 } 214 return (error); 215 } 216 217 static int nanowait; 218 219 static int 220 nanosleep1(p, rqt, rmt) 221 struct proc *p; 222 struct timespec *rqt, *rmt; 223 { 224 struct timespec ts, ts2, ts3; 225 struct timeval tv; 226 int error; 227 228 if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) 229 return (EINVAL); 230 if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0)) 231 return (0); 232 getnanouptime(&ts); 233 timespecadd(&ts, rqt); 234 TIMESPEC_TO_TIMEVAL(&tv, rqt); 235 for (;;) { 236 error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp", 237 tvtohz(&tv)); 238 getnanouptime(&ts2); 239 if (error != EWOULDBLOCK) { 240 if (error == ERESTART) 241 error = EINTR; 242 if (rmt != NULL) { 243 timespecsub(&ts, &ts2); 244 if (ts.tv_sec < 0) 245 timespecclear(&ts); 246 *rmt = ts; 247 } 248 return (error); 249 } 250 if (timespeccmp(&ts2, &ts, >=)) 251 return (0); 252 ts3 = ts; 253 timespecsub(&ts3, &ts2); 254 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 255 } 256 } 257 258 #ifndef _SYS_SYSPROTO_H_ 259 struct nanosleep_args { 260 struct timespec *rqtp; 261 struct timespec *rmtp; 262 }; 263 #endif 264 265 /* ARGSUSED */ 266 int 267 nanosleep(p, uap) 268 struct proc *p; 269 struct nanosleep_args *uap; 270 { 271 struct timespec rmt, rqt; 272 int error, error2; 273 274 error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); 275 if (error) 276 return (error); 277 if (SCARG(uap, rmtp)) 278 if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), B_WRITE)) 279 return (EFAULT); 280 error = nanosleep1(p, &rqt, &rmt); 281 if (error && SCARG(uap, rmtp)) { 282 error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); 283 if (error2) /* XXX shouldn't happen, did useracc() above */ 284 return (error2); 285 } 286 return (error); 287 } 288 289 #ifndef _SYS_SYSPROTO_H_ 290 struct gettimeofday_args { 291 struct timeval *tp; 292 struct timezone *tzp; 293 }; 294 #endif 295 /* ARGSUSED */ 296 int 297 gettimeofday(p, uap) 298 struct proc *p; 299 register struct gettimeofday_args *uap; 300 { 301 struct timeval atv; 302 int error = 0; 303 304 if (uap->tp) { 305 microtime(&atv); 306 if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp, 307 sizeof (atv)))) 308 return (error); 309 } 310 if (uap->tzp) 311 error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, 312 sizeof (tz)); 313 return (error); 314 } 315 316 #ifndef _SYS_SYSPROTO_H_ 317 struct settimeofday_args { 318 struct timeval *tv; 319 struct timezone *tzp; 320 }; 321 #endif 322 /* ARGSUSED */ 323 int 324 settimeofday(p, uap) 325 struct proc *p; 326 struct settimeofday_args *uap; 327 { 328 struct timeval atv; 329 struct timezone atz; 330 int error; 331 332 if ((error = suser(p))) 333 return (error); 334 /* Verify all parameters before changing time. */ 335 if (uap->tv) { 336 if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv, 337 sizeof(atv)))) 338 return (error); 339 if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) 340 return (EINVAL); 341 } 342 if (uap->tzp && 343 (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) 344 return (error); 345 if (uap->tv && (error = settime(&atv))) 346 return (error); 347 if (uap->tzp) 348 tz = atz; 349 return (0); 350 } 351 352 int tickdelta; /* current clock skew, us. per tick */ 353 long timedelta; /* unapplied time correction, us. */ 354 static long bigadj = 1000000; /* use 10x skew above bigadj us. */ 355 356 #ifndef _SYS_SYSPROTO_H_ 357 struct adjtime_args { 358 struct timeval *delta; 359 struct timeval *olddelta; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 adjtime(p, uap) 365 struct proc *p; 366 register struct adjtime_args *uap; 367 { 368 struct timeval atv; 369 register long ndelta, ntickdelta, odelta; 370 int s, error; 371 372 if ((error = suser(p))) 373 return (error); 374 if ((error = 375 copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval)))) 376 return (error); 377 378 /* 379 * Compute the total correction and the rate at which to apply it. 380 * Round the adjustment down to a whole multiple of the per-tick 381 * delta, so that after some number of incremental changes in 382 * hardclock(), tickdelta will become zero, lest the correction 383 * overshoot and start taking us away from the desired final time. 384 */ 385 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 386 if (ndelta > bigadj || ndelta < -bigadj) 387 ntickdelta = 10 * tickadj; 388 else 389 ntickdelta = tickadj; 390 if (ndelta % ntickdelta) 391 ndelta = ndelta / ntickdelta * ntickdelta; 392 393 /* 394 * To make hardclock()'s job easier, make the per-tick delta negative 395 * if we want time to run slower; then hardclock can simply compute 396 * tick + tickdelta, and subtract tickdelta from timedelta. 397 */ 398 if (ndelta < 0) 399 ntickdelta = -ntickdelta; 400 s = splclock(); 401 odelta = timedelta; 402 timedelta = ndelta; 403 tickdelta = ntickdelta; 404 splx(s); 405 406 if (uap->olddelta) { 407 atv.tv_sec = odelta / 1000000; 408 atv.tv_usec = odelta % 1000000; 409 (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta, 410 sizeof(struct timeval)); 411 } 412 return (0); 413 } 414 415 /* 416 * Get value of an interval timer. The process virtual and 417 * profiling virtual time timers are kept in the p_stats area, since 418 * they can be swapped out. These are kept internally in the 419 * way they are specified externally: in time until they expire. 420 * 421 * The real time interval timer is kept in the process table slot 422 * for the process, and its value (it_value) is kept as an 423 * absolute time rather than as a delta, so that it is easy to keep 424 * periodic real-time signals from drifting. 425 * 426 * Virtual time timers are processed in the hardclock() routine of 427 * kern_clock.c. The real time timer is processed by a timeout 428 * routine, called from the softclock() routine. Since a callout 429 * may be delayed in real time due to interrupt processing in the system, 430 * it is possible for the real time timeout routine (realitexpire, given below), 431 * to be delayed in real time past when it is supposed to occur. It 432 * does not suffice, therefore, to reload the real timer .it_value from the 433 * real time timers .it_interval. Rather, we compute the next time in 434 * absolute time the timer should go off. 435 */ 436 #ifndef _SYS_SYSPROTO_H_ 437 struct getitimer_args { 438 u_int which; 439 struct itimerval *itv; 440 }; 441 #endif 442 /* ARGSUSED */ 443 int 444 getitimer(p, uap) 445 struct proc *p; 446 register struct getitimer_args *uap; 447 { 448 struct timeval ctv; 449 struct itimerval aitv; 450 int s; 451 452 if (uap->which > ITIMER_PROF) 453 return (EINVAL); 454 s = splclock(); /* XXX still needed ? */ 455 if (uap->which == ITIMER_REAL) { 456 /* 457 * Convert from absolute to relative time in .it_value 458 * part of real time timer. If time for real time timer 459 * has passed return 0, else return difference between 460 * current time and time for the timer to go off. 461 */ 462 aitv = p->p_realtimer; 463 if (timevalisset(&aitv.it_value)) { 464 getmicrouptime(&ctv); 465 if (timevalcmp(&aitv.it_value, &ctv, <)) 466 timevalclear(&aitv.it_value); 467 else 468 timevalsub(&aitv.it_value, &ctv); 469 } 470 } else 471 aitv = p->p_stats->p_timer[uap->which]; 472 splx(s); 473 return (copyout((caddr_t)&aitv, (caddr_t)uap->itv, 474 sizeof (struct itimerval))); 475 } 476 477 #ifndef _SYS_SYSPROTO_H_ 478 struct setitimer_args { 479 u_int which; 480 struct itimerval *itv, *oitv; 481 }; 482 #endif 483 /* ARGSUSED */ 484 int 485 setitimer(p, uap) 486 struct proc *p; 487 register struct setitimer_args *uap; 488 { 489 struct itimerval aitv; 490 struct timeval ctv; 491 register struct itimerval *itvp; 492 int s, error; 493 494 if (uap->which > ITIMER_PROF) 495 return (EINVAL); 496 itvp = uap->itv; 497 if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, 498 sizeof(struct itimerval)))) 499 return (error); 500 if ((uap->itv = uap->oitv) && 501 (error = getitimer(p, (struct getitimer_args *)uap))) 502 return (error); 503 if (itvp == 0) 504 return (0); 505 if (itimerfix(&aitv.it_value)) 506 return (EINVAL); 507 if (!timevalisset(&aitv.it_value)) 508 timevalclear(&aitv.it_interval); 509 else if (itimerfix(&aitv.it_interval)) 510 return (EINVAL); 511 s = splclock(); /* XXX: still needed ? */ 512 if (uap->which == ITIMER_REAL) { 513 if (timevalisset(&p->p_realtimer.it_value)) 514 untimeout(realitexpire, (caddr_t)p, p->p_ithandle); 515 if (timevalisset(&aitv.it_value)) 516 p->p_ithandle = timeout(realitexpire, (caddr_t)p, 517 tvtohz(&aitv.it_value)); 518 getmicrouptime(&ctv); 519 timevaladd(&aitv.it_value, &ctv); 520 p->p_realtimer = aitv; 521 } else 522 p->p_stats->p_timer[uap->which] = aitv; 523 splx(s); 524 return (0); 525 } 526 527 /* 528 * Real interval timer expired: 529 * send process whose timer expired an alarm signal. 530 * If time is not set up to reload, then just return. 531 * Else compute next time timer should go off which is > current time. 532 * This is where delay in processing this timeout causes multiple 533 * SIGALRM calls to be compressed into one. 534 * tvtohz() always adds 1 to allow for the time until the next clock 535 * interrupt being strictly less than 1 clock tick, but we don't want 536 * that here since we want to appear to be in sync with the clock 537 * interrupt even when we're delayed. 538 */ 539 void 540 realitexpire(arg) 541 void *arg; 542 { 543 register struct proc *p; 544 struct timeval ctv, ntv; 545 int s; 546 547 p = (struct proc *)arg; 548 psignal(p, SIGALRM); 549 if (!timevalisset(&p->p_realtimer.it_interval)) { 550 timevalclear(&p->p_realtimer.it_value); 551 return; 552 } 553 for (;;) { 554 s = splclock(); /* XXX: still neeeded ? */ 555 timevaladd(&p->p_realtimer.it_value, 556 &p->p_realtimer.it_interval); 557 getmicrouptime(&ctv); 558 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) { 559 ntv = p->p_realtimer.it_value; 560 timevalsub(&ntv, &ctv); 561 p->p_ithandle = timeout(realitexpire, (caddr_t)p, 562 tvtohz(&ntv) - 1); 563 splx(s); 564 return; 565 } 566 splx(s); 567 } 568 } 569 570 /* 571 * Check that a proposed value to load into the .it_value or 572 * .it_interval part of an interval timer is acceptable, and 573 * fix it to have at least minimal value (i.e. if it is less 574 * than the resolution of the clock, round it up.) 575 */ 576 int 577 itimerfix(tv) 578 struct timeval *tv; 579 { 580 581 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 582 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 583 return (EINVAL); 584 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 585 tv->tv_usec = tick; 586 return (0); 587 } 588 589 /* 590 * Decrement an interval timer by a specified number 591 * of microseconds, which must be less than a second, 592 * i.e. < 1000000. If the timer expires, then reload 593 * it. In this case, carry over (usec - old value) to 594 * reduce the value reloaded into the timer so that 595 * the timer does not drift. This routine assumes 596 * that it is called in a context where the timers 597 * on which it is operating cannot change in value. 598 */ 599 int 600 itimerdecr(itp, usec) 601 register struct itimerval *itp; 602 int usec; 603 { 604 605 if (itp->it_value.tv_usec < usec) { 606 if (itp->it_value.tv_sec == 0) { 607 /* expired, and already in next interval */ 608 usec -= itp->it_value.tv_usec; 609 goto expire; 610 } 611 itp->it_value.tv_usec += 1000000; 612 itp->it_value.tv_sec--; 613 } 614 itp->it_value.tv_usec -= usec; 615 usec = 0; 616 if (timevalisset(&itp->it_value)) 617 return (1); 618 /* expired, exactly at end of interval */ 619 expire: 620 if (timevalisset(&itp->it_interval)) { 621 itp->it_value = itp->it_interval; 622 itp->it_value.tv_usec -= usec; 623 if (itp->it_value.tv_usec < 0) { 624 itp->it_value.tv_usec += 1000000; 625 itp->it_value.tv_sec--; 626 } 627 } else 628 itp->it_value.tv_usec = 0; /* sec is already 0 */ 629 return (0); 630 } 631 632 /* 633 * Add and subtract routines for timevals. 634 * N.B.: subtract routine doesn't deal with 635 * results which are before the beginning, 636 * it just gets very confused in this case. 637 * Caveat emptor. 638 */ 639 void 640 timevaladd(t1, t2) 641 struct timeval *t1, *t2; 642 { 643 644 t1->tv_sec += t2->tv_sec; 645 t1->tv_usec += t2->tv_usec; 646 timevalfix(t1); 647 } 648 649 void 650 timevalsub(t1, t2) 651 struct timeval *t1, *t2; 652 { 653 654 t1->tv_sec -= t2->tv_sec; 655 t1->tv_usec -= t2->tv_usec; 656 timevalfix(t1); 657 } 658 659 static void 660 timevalfix(t1) 661 struct timeval *t1; 662 { 663 664 if (t1->tv_usec < 0) { 665 t1->tv_sec--; 666 t1->tv_usec += 1000000; 667 } 668 if (t1->tv_usec >= 1000000) { 669 t1->tv_sec++; 670 t1->tv_usec -= 1000000; 671 } 672 } 673