kern_time.c revision 1.40
1 /* $NetBSD: kern_time.c,v 1.40 1999/08/16 18:53:55 tron Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 36 */ 37 38 #include "fs_nfs.h" 39 #include "opt_nfsserver.h" 40 41 #include <sys/param.h> 42 #include <sys/resourcevar.h> 43 #include <sys/kernel.h> 44 #include <sys/systm.h> 45 #include <sys/proc.h> 46 #include <sys/vnode.h> 47 #include <sys/signalvar.h> 48 #include <sys/syslog.h> 49 50 #include <sys/mount.h> 51 #include <sys/syscallargs.h> 52 53 #include <vm/vm.h> 54 #include <uvm/uvm_extern.h> 55 56 #if defined(NFS) || defined(NFSSERVER) 57 #include <nfs/rpcv2.h> 58 #include <nfs/nfsproto.h> 59 #include <nfs/nfs_var.h> 60 #endif 61 62 #include <machine/cpu.h> 63 64 /* 65 * Time of day and interval timer support. 66 * 67 * These routines provide the kernel entry points to get and set 68 * the time-of-day and per-process interval timers. Subroutines 69 * here provide support for adding and subtracting timeval structures 70 * and decrementing interval timers, optionally reloading the interval 71 * timers when they expire. 72 */ 73 74 /* This function is used by clock_settime and settimeofday */ 75 int 76 settime(tv) 77 struct timeval *tv; 78 { 79 struct timeval delta; 80 int s; 81 82 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ 83 s = splclock(); 84 timersub(tv, &time, &delta); 85 if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) 86 return (EPERM); 87 #ifdef notyet 88 if ((delta.tv_sec < 86400) && securelevel > 0) 89 return (EPERM); 90 #endif 91 time = *tv; 92 (void) spllowersoftclock(); 93 timeradd(&boottime, &delta, &boottime); 94 timeradd(&runtime, &delta, &runtime); 95 # if defined(NFS) || defined(NFSSERVER) 96 nqnfs_lease_updatetime(delta.tv_sec); 97 # endif 98 splx(s); 99 resettodr(); 100 return (0); 101 } 102 103 /* ARGSUSED */ 104 int 105 sys_clock_gettime(p, v, retval) 106 struct proc *p; 107 void *v; 108 register_t *retval; 109 { 110 register struct sys_clock_gettime_args /* { 111 syscallarg(clockid_t) clock_id; 112 syscallarg(struct timespec *) tp; 113 } */ *uap = v; 114 clockid_t clock_id; 115 struct timeval atv; 116 struct timespec ats; 117 118 clock_id = SCARG(uap, clock_id); 119 if (clock_id != CLOCK_REALTIME) 120 return (EINVAL); 121 122 microtime(&atv); 123 TIMEVAL_TO_TIMESPEC(&atv,&ats); 124 125 return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 126 } 127 128 /* ARGSUSED */ 129 int 130 sys_clock_settime(p, v, retval) 131 struct proc *p; 132 void *v; 133 register_t *retval; 134 { 135 register struct sys_clock_settime_args /* { 136 syscallarg(clockid_t) clock_id; 137 syscallarg(const struct timespec *) tp; 138 } */ *uap = v; 139 clockid_t clock_id; 140 struct timeval atv; 141 struct timespec ats; 142 int error; 143 144 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 145 return (error); 146 147 clock_id = SCARG(uap, clock_id); 148 if (clock_id != CLOCK_REALTIME) 149 return (EINVAL); 150 151 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 152 return (error); 153 154 TIMESPEC_TO_TIMEVAL(&atv,&ats); 155 if ((error = settime(&atv))) 156 return (error); 157 158 return 0; 159 } 160 161 int 162 sys_clock_getres(p, v, retval) 163 struct proc *p; 164 void *v; 165 register_t *retval; 166 { 167 register struct sys_clock_getres_args /* { 168 syscallarg(clockid_t) clock_id; 169 syscallarg(struct timespec *) tp; 170 } */ *uap = v; 171 clockid_t clock_id; 172 struct timespec ts; 173 int error = 0; 174 175 clock_id = SCARG(uap, clock_id); 176 if (clock_id != CLOCK_REALTIME) 177 return (EINVAL); 178 179 if (SCARG(uap, tp)) { 180 ts.tv_sec = 0; 181 ts.tv_nsec = 1000000000 / hz; 182 183 error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 184 } 185 186 return error; 187 } 188 189 /* ARGSUSED */ 190 int 191 sys_nanosleep(p, v, retval) 192 struct proc *p; 193 void *v; 194 register_t *retval; 195 { 196 static int nanowait; 197 register struct sys_nanosleep_args/* { 198 syscallarg(struct timespec *) rqtp; 199 syscallarg(struct timespec *) rmtp; 200 } */ *uap = v; 201 struct timespec rqt; 202 struct timespec rmt; 203 struct timeval atv, utv; 204 int error, s, timo; 205 206 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 207 sizeof(struct timespec)); 208 if (error) 209 return (error); 210 211 TIMESPEC_TO_TIMEVAL(&atv,&rqt) 212 if (itimerfix(&atv)) 213 return (EINVAL); 214 215 s = splclock(); 216 timeradd(&atv,&time,&atv); 217 timo = hzto(&atv); 218 /* 219 * Avoid inadvertantly sleeping forever 220 */ 221 if (timo == 0) 222 timo = 1; 223 splx(s); 224 225 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 226 if (error == ERESTART) 227 error = EINTR; 228 if (error == EWOULDBLOCK) 229 error = 0; 230 231 if (SCARG(uap, rmtp)) { 232 int error; 233 234 s = splclock(); 235 utv = time; 236 splx(s); 237 238 timersub(&atv, &utv, &utv); 239 if (utv.tv_sec < 0) 240 timerclear(&utv); 241 242 TIMEVAL_TO_TIMESPEC(&utv,&rmt); 243 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp), 244 sizeof(rmt)); 245 if (error) 246 return (error); 247 } 248 249 return error; 250 } 251 252 /* ARGSUSED */ 253 int 254 sys_gettimeofday(p, v, retval) 255 struct proc *p; 256 void *v; 257 register_t *retval; 258 { 259 register struct sys_gettimeofday_args /* { 260 syscallarg(struct timeval *) tp; 261 syscallarg(struct timezone *) tzp; 262 } */ *uap = v; 263 struct timeval atv; 264 int error = 0; 265 struct timezone tzfake; 266 267 if (SCARG(uap, tp)) { 268 microtime(&atv); 269 error = copyout(&atv, SCARG(uap, tp), sizeof(atv)); 270 if (error) 271 return (error); 272 } 273 if (SCARG(uap, tzp)) { 274 /* 275 * NetBSD has no kernel notion of time zone, so we just 276 * fake up a timezone struct and return it if demanded. 277 */ 278 tzfake.tz_minuteswest = 0; 279 tzfake.tz_dsttime = 0; 280 error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake)); 281 } 282 return (error); 283 } 284 285 /* ARGSUSED */ 286 int 287 sys_settimeofday(p, v, retval) 288 struct proc *p; 289 void *v; 290 register_t *retval; 291 { 292 struct sys_settimeofday_args /* { 293 syscallarg(const struct timeval *) tv; 294 syscallarg(const struct timezone *) tzp; 295 } */ *uap = v; 296 struct timeval atv; 297 struct timezone atz; 298 int error; 299 300 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 301 return (error); 302 /* Verify all parameters before changing time. */ 303 if (SCARG(uap, tv) && (error = copyin(SCARG(uap, tv), 304 &atv, sizeof(atv)))) 305 return (error); 306 /* XXX since we don't use tz, probably no point in doing copyin. */ 307 if (SCARG(uap, tzp) && (error = copyin(SCARG(uap, tzp), 308 &atz, sizeof(atz)))) 309 return (error); 310 if (SCARG(uap, tv)) 311 if ((error = settime(&atv))) 312 return (error); 313 /* 314 * NetBSD has no kernel notion of time zone, and only an 315 * obsolete program would try to set it, so we log a warning. 316 */ 317 if (SCARG(uap, tzp)) 318 log(LOG_WARNING, "pid %d attempted to set the " 319 "(obsolete) kernel time zone\n", p->p_pid); 320 return (0); 321 } 322 323 int tickdelta; /* current clock skew, us. per tick */ 324 long timedelta; /* unapplied time correction, us. */ 325 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 326 327 /* ARGSUSED */ 328 int 329 sys_adjtime(p, v, retval) 330 struct proc *p; 331 void *v; 332 register_t *retval; 333 { 334 register struct sys_adjtime_args /* { 335 syscallarg(const struct timeval *) delta; 336 syscallarg(struct timeval *) olddelta; 337 } */ *uap = v; 338 struct timeval atv; 339 register long ndelta, ntickdelta, odelta; 340 int s, error; 341 342 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 343 return (error); 344 345 error = copyin(SCARG(uap, delta), &atv, sizeof(struct timeval)); 346 if (error) 347 return (error); 348 if (SCARG(uap, olddelta) != NULL && 349 uvm_useracc((caddr_t)SCARG(uap, olddelta), sizeof(struct timeval), 350 B_WRITE) == FALSE) 351 return (EFAULT); 352 353 /* 354 * Compute the total correction and the rate at which to apply it. 355 * Round the adjustment down to a whole multiple of the per-tick 356 * delta, so that after some number of incremental changes in 357 * hardclock(), tickdelta will become zero, lest the correction 358 * overshoot and start taking us away from the desired final time. 359 */ 360 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 361 if (ndelta > bigadj) 362 ntickdelta = 10 * tickadj; 363 else 364 ntickdelta = tickadj; 365 if (ndelta % ntickdelta) 366 ndelta = ndelta / ntickdelta * ntickdelta; 367 368 /* 369 * To make hardclock()'s job easier, make the per-tick delta negative 370 * if we want time to run slower; then hardclock can simply compute 371 * tick + tickdelta, and subtract tickdelta from timedelta. 372 */ 373 if (ndelta < 0) 374 ntickdelta = -ntickdelta; 375 s = splclock(); 376 odelta = timedelta; 377 timedelta = ndelta; 378 tickdelta = ntickdelta; 379 splx(s); 380 381 if (SCARG(uap, olddelta)) { 382 atv.tv_sec = odelta / 1000000; 383 atv.tv_usec = odelta % 1000000; 384 (void) copyout(&atv, SCARG(uap, olddelta), 385 sizeof(struct timeval)); 386 } 387 return (0); 388 } 389 390 /* 391 * Get value of an interval timer. The process virtual and 392 * profiling virtual time timers are kept in the p_stats area, since 393 * they can be swapped out. These are kept internally in the 394 * way they are specified externally: in time until they expire. 395 * 396 * The real time interval timer is kept in the process table slot 397 * for the process, and its value (it_value) is kept as an 398 * absolute time rather than as a delta, so that it is easy to keep 399 * periodic real-time signals from drifting. 400 * 401 * Virtual time timers are processed in the hardclock() routine of 402 * kern_clock.c. The real time timer is processed by a timeout 403 * routine, called from the softclock() routine. Since a callout 404 * may be delayed in real time due to interrupt processing in the system, 405 * it is possible for the real time timeout routine (realitexpire, given below), 406 * to be delayed in real time past when it is supposed to occur. It 407 * does not suffice, therefore, to reload the real timer .it_value from the 408 * real time timers .it_interval. Rather, we compute the next time in 409 * absolute time the timer should go off. 410 */ 411 /* ARGSUSED */ 412 int 413 sys_getitimer(p, v, retval) 414 struct proc *p; 415 void *v; 416 register_t *retval; 417 { 418 register struct sys_getitimer_args /* { 419 syscallarg(int) which; 420 syscallarg(struct itimerval *) itv; 421 } */ *uap = v; 422 int which = SCARG(uap, which); 423 struct itimerval aitv; 424 int s; 425 426 if ((u_int)which > ITIMER_PROF) 427 return (EINVAL); 428 s = splclock(); 429 if (which == ITIMER_REAL) { 430 /* 431 * Convert from absolute to relative time in .it_value 432 * part of real time timer. If time for real time timer 433 * has passed return 0, else return difference between 434 * current time and time for the timer to go off. 435 */ 436 aitv = p->p_realtimer; 437 if (timerisset(&aitv.it_value)) { 438 if (timercmp(&aitv.it_value, &time, <)) 439 timerclear(&aitv.it_value); 440 else 441 timersub(&aitv.it_value, &time, &aitv.it_value); 442 } 443 } else 444 aitv = p->p_stats->p_timer[which]; 445 splx(s); 446 return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval))); 447 } 448 449 /* ARGSUSED */ 450 int 451 sys_setitimer(p, v, retval) 452 struct proc *p; 453 register void *v; 454 register_t *retval; 455 { 456 register struct sys_setitimer_args /* { 457 syscallarg(int) which; 458 syscallarg(const struct itimerval *) itv; 459 syscallarg(struct itimerval *) oitv; 460 } */ *uap = v; 461 int which = SCARG(uap, which); 462 struct sys_getitimer_args getargs; 463 struct itimerval aitv; 464 register const struct itimerval *itvp; 465 int s, error; 466 467 if ((u_int)which > ITIMER_PROF) 468 return (EINVAL); 469 itvp = SCARG(uap, itv); 470 if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 471 return (error); 472 if (SCARG(uap, oitv) != NULL) { 473 SCARG(&getargs, which) = which; 474 SCARG(&getargs, itv) = SCARG(uap, oitv); 475 if ((error = sys_getitimer(p, &getargs, retval)) != 0) 476 return (error); 477 } 478 if (itvp == 0) 479 return (0); 480 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 481 return (EINVAL); 482 s = splclock(); 483 if (which == ITIMER_REAL) { 484 untimeout(realitexpire, p); 485 if (timerisset(&aitv.it_value)) { 486 timeradd(&aitv.it_value, &time, &aitv.it_value); 487 timeout(realitexpire, p, hzto(&aitv.it_value)); 488 } 489 p->p_realtimer = aitv; 490 } else 491 p->p_stats->p_timer[which] = aitv; 492 splx(s); 493 return (0); 494 } 495 496 /* 497 * Real interval timer expired: 498 * send process whose timer expired an alarm signal. 499 * If time is not set up to reload, then just return. 500 * Else compute next time timer should go off which is > current time. 501 * This is where delay in processing this timeout causes multiple 502 * SIGALRM calls to be compressed into one. 503 */ 504 void 505 realitexpire(arg) 506 void *arg; 507 { 508 register struct proc *p; 509 int s; 510 511 p = (struct proc *)arg; 512 psignal(p, SIGALRM); 513 if (!timerisset(&p->p_realtimer.it_interval)) { 514 timerclear(&p->p_realtimer.it_value); 515 return; 516 } 517 for (;;) { 518 s = splclock(); 519 timeradd(&p->p_realtimer.it_value, 520 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 521 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 522 timeout(realitexpire, p, 523 hzto(&p->p_realtimer.it_value)); 524 splx(s); 525 return; 526 } 527 splx(s); 528 } 529 } 530 531 /* 532 * Check that a proposed value to load into the .it_value or 533 * .it_interval part of an interval timer is acceptable, and 534 * fix it to have at least minimal value (i.e. if it is less 535 * than the resolution of the clock, round it up.) 536 */ 537 int 538 itimerfix(tv) 539 struct timeval *tv; 540 { 541 542 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 543 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 544 return (EINVAL); 545 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 546 tv->tv_usec = tick; 547 return (0); 548 } 549 550 /* 551 * Decrement an interval timer by a specified number 552 * of microseconds, which must be less than a second, 553 * i.e. < 1000000. If the timer expires, then reload 554 * it. In this case, carry over (usec - old value) to 555 * reduce the value reloaded into the timer so that 556 * the timer does not drift. This routine assumes 557 * that it is called in a context where the timers 558 * on which it is operating cannot change in value. 559 */ 560 int 561 itimerdecr(itp, usec) 562 register struct itimerval *itp; 563 int usec; 564 { 565 566 if (itp->it_value.tv_usec < usec) { 567 if (itp->it_value.tv_sec == 0) { 568 /* expired, and already in next interval */ 569 usec -= itp->it_value.tv_usec; 570 goto expire; 571 } 572 itp->it_value.tv_usec += 1000000; 573 itp->it_value.tv_sec--; 574 } 575 itp->it_value.tv_usec -= usec; 576 usec = 0; 577 if (timerisset(&itp->it_value)) 578 return (1); 579 /* expired, exactly at end of interval */ 580 expire: 581 if (timerisset(&itp->it_interval)) { 582 itp->it_value = itp->it_interval; 583 itp->it_value.tv_usec -= usec; 584 if (itp->it_value.tv_usec < 0) { 585 itp->it_value.tv_usec += 1000000; 586 itp->it_value.tv_sec--; 587 } 588 } else 589 itp->it_value.tv_usec = 0; /* sec is already 0 */ 590 return (0); 591 } 592
Indexes created Tue Sep 30 11:09:46 GMT 2025