kern_time.c revision 1.30
1 /* $NetBSD: kern_time.c,v 1.30 1997/10/15 17:04:08 mycroft 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 8.1 (Berkeley) 6/10/93 36 */ 37 38 #include <sys/param.h> 39 #include <sys/resourcevar.h> 40 #include <sys/kernel.h> 41 #include <sys/systm.h> 42 #include <sys/proc.h> 43 #include <sys/vnode.h> 44 #include <sys/signalvar.h> 45 #include <sys/syslog.h> 46 47 #include <sys/mount.h> 48 #include <sys/syscallargs.h> 49 50 #if defined(NFS) || defined(NFSSERVER) 51 #include <nfs/rpcv2.h> 52 #include <nfs/nfsproto.h> 53 #include <nfs/nfs_var.h> 54 #endif 55 56 #include <machine/cpu.h> 57 58 static int settime __P((struct timeval *)); 59 60 /* 61 * Time of day and interval timer support. 62 * 63 * These routines provide the kernel entry points to get and set 64 * the time-of-day and per-process interval timers. Subroutines 65 * here provide support for adding and subtracting timeval structures 66 * and decrementing interval timers, optionally reloading the interval 67 * timers when they expire. 68 */ 69 70 /* This function is used by clock_settime and settimeofday */ 71 static int 72 settime(tv) 73 struct timeval *tv; 74 { 75 struct timeval delta; 76 int s; 77 78 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ 79 s = splclock(); 80 timersub(tv, &time, &delta); 81 if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) 82 return (EPERM); 83 #ifdef notyet 84 if ((delta.tv_sec < 86400) && securelevel > 0) 85 return (EPERM); 86 #endif 87 time = *tv; 88 (void) splsoftclock(); 89 timeradd(&boottime, &delta, &boottime); 90 timeradd(&runtime, &delta, &runtime); 91 # if defined(NFS) || defined(NFSSERVER) 92 nqnfs_lease_updatetime(delta.tv_sec); 93 # endif 94 splx(s); 95 resettodr(); 96 return (0); 97 } 98 99 /* ARGSUSED */ 100 int 101 sys_clock_gettime(p, v, retval) 102 struct proc *p; 103 void *v; 104 register_t *retval; 105 { 106 register struct sys_clock_gettime_args /* { 107 syscallarg(clockid_t) clock_id; 108 syscallarg(struct timespec *) tp; 109 } */ *uap = v; 110 clockid_t clock_id; 111 struct timeval atv; 112 struct timespec ats; 113 114 clock_id = SCARG(uap, clock_id); 115 if (clock_id != CLOCK_REALTIME) 116 return (EINVAL); 117 118 microtime(&atv); 119 TIMEVAL_TO_TIMESPEC(&atv,&ats); 120 121 return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 122 } 123 124 /* ARGSUSED */ 125 int 126 sys_clock_settime(p, v, retval) 127 struct proc *p; 128 void *v; 129 register_t *retval; 130 { 131 register struct sys_clock_settime_args /* { 132 syscallarg(clockid_t) clock_id; 133 syscallarg(const struct timespec *) tp; 134 } */ *uap = v; 135 clockid_t clock_id; 136 struct timeval atv; 137 struct timespec ats; 138 int error; 139 140 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 141 return (error); 142 143 clock_id = SCARG(uap, clock_id); 144 if (clock_id != CLOCK_REALTIME) 145 return (EINVAL); 146 147 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 148 return (error); 149 150 TIMESPEC_TO_TIMEVAL(&atv,&ats); 151 if ((error = settime(&atv))) 152 return (error); 153 154 return 0; 155 } 156 157 int 158 sys_clock_getres(p, v, retval) 159 struct proc *p; 160 void *v; 161 register_t *retval; 162 { 163 register struct sys_clock_getres_args /* { 164 syscallarg(clockid_t) clock_id; 165 syscallarg(struct timespec *) tp; 166 } */ *uap = v; 167 clockid_t clock_id; 168 struct timespec ts; 169 int error = 0; 170 171 clock_id = SCARG(uap, clock_id); 172 if (clock_id != CLOCK_REALTIME) 173 return (EINVAL); 174 175 if (SCARG(uap, tp)) { 176 ts.tv_sec = 0; 177 ts.tv_nsec = 1000000000 / hz; 178 179 error = copyout(&ts, SCARG(uap, tp), sizeof (ts)); 180 } 181 182 return error; 183 } 184 185 /* ARGSUSED */ 186 int 187 sys_nanosleep(p, v, retval) 188 struct proc *p; 189 void *v; 190 register_t *retval; 191 { 192 static int nanowait; 193 register struct sys_nanosleep_args/* { 194 syscallarg(struct timespec *) rqtp; 195 syscallarg(struct timespec *) rmtp; 196 } */ *uap = v; 197 struct timespec rqt; 198 struct timespec rmt; 199 struct timeval atv, utv; 200 int error, s, timo; 201 202 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 203 sizeof(struct timespec)); 204 if (error) 205 return (error); 206 207 TIMESPEC_TO_TIMEVAL(&atv,&rqt) 208 if (itimerfix(&atv)) 209 return (EINVAL); 210 211 s = splclock(); 212 timeradd(&atv,&time,&atv); 213 timo = hzto(&atv); 214 /* 215 * Avoid inadvertantly sleeping forever 216 */ 217 if (timo == 0) 218 timo = 1; 219 splx(s); 220 221 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 222 if (error == ERESTART) 223 error = EINTR; 224 if (error == EWOULDBLOCK) 225 error = 0; 226 227 if (SCARG(uap, rmtp)) { 228 int error; 229 230 s = splclock(); 231 utv = time; 232 splx(s); 233 234 timersub(&atv, &utv, &utv); 235 if (utv.tv_sec < 0) 236 timerclear(&utv); 237 238 TIMEVAL_TO_TIMESPEC(&utv,&rmt); 239 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp), 240 sizeof(rmt)); 241 if (error) 242 return (error); 243 } 244 245 return error; 246 } 247 248 /* ARGSUSED */ 249 int 250 sys_gettimeofday(p, v, retval) 251 struct proc *p; 252 void *v; 253 register_t *retval; 254 { 255 register struct sys_gettimeofday_args /* { 256 syscallarg(struct timeval *) tp; 257 syscallarg(struct timezone *) tzp; 258 } */ *uap = v; 259 struct timeval atv; 260 int error = 0; 261 struct timezone tzfake; 262 263 if (SCARG(uap, tp)) { 264 microtime(&atv); 265 error = copyout(&atv, SCARG(uap, tp), sizeof (atv)); 266 if (error) 267 return (error); 268 } 269 if (SCARG(uap, tzp)) { 270 /* 271 * NetBSD has no kernel notion of timezone, so we just 272 * fake up a timezone struct and return it if demanded. 273 */ 274 tzfake.tz_minuteswest = 0; 275 tzfake.tz_dsttime = 0; 276 error = copyout(&tzfake, SCARG(uap, tzp), sizeof (tzfake)); 277 } 278 return (error); 279 } 280 281 /* ARGSUSED */ 282 int 283 sys_settimeofday(p, v, retval) 284 struct proc *p; 285 void *v; 286 register_t *retval; 287 { 288 struct sys_settimeofday_args /* { 289 syscallarg(const struct timeval *) tv; 290 syscallarg(const struct timezone *) tzp; 291 } */ *uap = v; 292 struct timeval atv; 293 struct timezone atz; 294 int error; 295 296 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 297 return (error); 298 /* Verify all parameters before changing time. */ 299 if (SCARG(uap, tv) && (error = copyin(SCARG(uap, tv), 300 &atv, sizeof(atv)))) 301 return (error); 302 /* XXX since we don't use tz, probably no point in doing copyin. */ 303 if (SCARG(uap, tzp) && (error = copyin(SCARG(uap, tzp), 304 &atz, sizeof(atz)))) 305 return (error); 306 if (SCARG(uap, tv)) 307 if ((error = settime(&atv))) 308 return (error); 309 /* 310 * NetBSD has no kernel notion of timezone, and only an 311 * obsolete program would try to set it, so we log a warning. 312 */ 313 if (SCARG(uap, tzp)) 314 log(LOG_WARNING, "pid %d attempted to set the " 315 "(obsolete) kernel timezone.", p->p_pid); 316 return (0); 317 } 318 319 int tickdelta; /* current clock skew, us. per tick */ 320 long timedelta; /* unapplied time correction, us. */ 321 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 322 323 /* ARGSUSED */ 324 int 325 sys_adjtime(p, v, retval) 326 struct proc *p; 327 void *v; 328 register_t *retval; 329 { 330 register struct sys_adjtime_args /* { 331 syscallarg(const struct timeval *) delta; 332 syscallarg(struct timeval *) olddelta; 333 } */ *uap = v; 334 struct timeval atv; 335 register long ndelta, ntickdelta, odelta; 336 int s, error; 337 338 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 339 return (error); 340 341 error = copyin(SCARG(uap, delta), &atv, sizeof(struct timeval)); 342 if (error) 343 return (error); 344 345 /* 346 * Compute the total correction and the rate at which to apply it. 347 * Round the adjustment down to a whole multiple of the per-tick 348 * delta, so that after some number of incremental changes in 349 * hardclock(), tickdelta will become zero, lest the correction 350 * overshoot and start taking us away from the desired final time. 351 */ 352 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 353 if (ndelta > bigadj) 354 ntickdelta = 10 * tickadj; 355 else 356 ntickdelta = tickadj; 357 if (ndelta % ntickdelta) 358 ndelta = ndelta / ntickdelta * ntickdelta; 359 360 /* 361 * To make hardclock()'s job easier, make the per-tick delta negative 362 * if we want time to run slower; then hardclock can simply compute 363 * tick + tickdelta, and subtract tickdelta from timedelta. 364 */ 365 if (ndelta < 0) 366 ntickdelta = -ntickdelta; 367 s = splclock(); 368 odelta = timedelta; 369 timedelta = ndelta; 370 tickdelta = ntickdelta; 371 splx(s); 372 373 if (SCARG(uap, olddelta)) { 374 atv.tv_sec = odelta / 1000000; 375 atv.tv_usec = odelta % 1000000; 376 (void) copyout(&atv, SCARG(uap, olddelta), 377 sizeof(struct timeval)); 378 } 379 return (0); 380 } 381 382 /* 383 * Get value of an interval timer. The process virtual and 384 * profiling virtual time timers are kept in the p_stats area, since 385 * they can be swapped out. These are kept internally in the 386 * way they are specified externally: in time until they expire. 387 * 388 * The real time interval timer is kept in the process table slot 389 * for the process, and its value (it_value) is kept as an 390 * absolute time rather than as a delta, so that it is easy to keep 391 * periodic real-time signals from drifting. 392 * 393 * Virtual time timers are processed in the hardclock() routine of 394 * kern_clock.c. The real time timer is processed by a timeout 395 * routine, called from the softclock() routine. Since a callout 396 * may be delayed in real time due to interrupt processing in the system, 397 * it is possible for the real time timeout routine (realitexpire, given below), 398 * to be delayed in real time past when it is supposed to occur. It 399 * does not suffice, therefore, to reload the real timer .it_value from the 400 * real time timers .it_interval. Rather, we compute the next time in 401 * absolute time the timer should go off. 402 */ 403 /* ARGSUSED */ 404 int 405 sys_getitimer(p, v, retval) 406 struct proc *p; 407 void *v; 408 register_t *retval; 409 { 410 register struct sys_getitimer_args /* { 411 syscallarg(int) which; 412 syscallarg(struct itimerval *) itv; 413 } */ *uap = v; 414 int which = SCARG(uap, which); 415 struct itimerval aitv; 416 int s; 417 418 if ((u_int)which > ITIMER_PROF) 419 return (EINVAL); 420 s = splclock(); 421 if (which == ITIMER_REAL) { 422 /* 423 * Convert from absolute to relative time in .it_value 424 * part of real time timer. If time for real time timer 425 * has passed return 0, else return difference between 426 * current time and time for the timer to go off. 427 */ 428 aitv = p->p_realtimer; 429 if (timerisset(&aitv.it_value)) 430 if (timercmp(&aitv.it_value, &time, <)) 431 timerclear(&aitv.it_value); 432 else 433 timersub(&aitv.it_value, &time, &aitv.it_value); 434 } else 435 aitv = p->p_stats->p_timer[which]; 436 splx(s); 437 return (copyout(&aitv, SCARG(uap, itv), sizeof (struct itimerval))); 438 } 439 440 /* ARGSUSED */ 441 int 442 sys_setitimer(p, v, retval) 443 struct proc *p; 444 register void *v; 445 register_t *retval; 446 { 447 register struct sys_setitimer_args /* { 448 syscallarg(int) which; 449 syscallarg(const struct itimerval *) itv; 450 syscallarg(struct itimerval *) oitv; 451 } */ *uap = v; 452 int which = SCARG(uap, which); 453 struct sys_getitimer_args getargs; 454 struct itimerval aitv; 455 register const struct itimerval *itvp; 456 int s, error; 457 458 if ((u_int)which > ITIMER_PROF) 459 return (EINVAL); 460 itvp = SCARG(uap, itv); 461 if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 462 return (error); 463 if (SCARG(uap, oitv) != NULL) { 464 SCARG(&getargs, which) = which; 465 SCARG(&getargs, itv) = SCARG(uap, oitv); 466 if ((error = sys_getitimer(p, &getargs, retval)) != 0) 467 return (error); 468 } 469 if (itvp == 0) 470 return (0); 471 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 472 return (EINVAL); 473 s = splclock(); 474 if (which == ITIMER_REAL) { 475 untimeout(realitexpire, p); 476 if (timerisset(&aitv.it_value)) { 477 timeradd(&aitv.it_value, &time, &aitv.it_value); 478 timeout(realitexpire, p, hzto(&aitv.it_value)); 479 } 480 p->p_realtimer = aitv; 481 } else 482 p->p_stats->p_timer[which] = aitv; 483 splx(s); 484 return (0); 485 } 486 487 /* 488 * Real interval timer expired: 489 * send process whose timer expired an alarm signal. 490 * If time is not set up to reload, then just return. 491 * Else compute next time timer should go off which is > current time. 492 * This is where delay in processing this timeout causes multiple 493 * SIGALRM calls to be compressed into one. 494 */ 495 void 496 realitexpire(arg) 497 void *arg; 498 { 499 register struct proc *p; 500 int s; 501 502 p = (struct proc *)arg; 503 psignal(p, SIGALRM); 504 if (!timerisset(&p->p_realtimer.it_interval)) { 505 timerclear(&p->p_realtimer.it_value); 506 return; 507 } 508 for (;;) { 509 s = splclock(); 510 timeradd(&p->p_realtimer.it_value, 511 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 512 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 513 timeout(realitexpire, p, 514 hzto(&p->p_realtimer.it_value)); 515 splx(s); 516 return; 517 } 518 splx(s); 519 } 520 } 521 522 /* 523 * Check that a proposed value to load into the .it_value or 524 * .it_interval part of an interval timer is acceptable, and 525 * fix it to have at least minimal value (i.e. if it is less 526 * than the resolution of the clock, round it up.) 527 */ 528 int 529 itimerfix(tv) 530 struct timeval *tv; 531 { 532 533 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 534 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 535 return (EINVAL); 536 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 537 tv->tv_usec = tick; 538 return (0); 539 } 540 541 /* 542 * Decrement an interval timer by a specified number 543 * of microseconds, which must be less than a second, 544 * i.e. < 1000000. If the timer expires, then reload 545 * it. In this case, carry over (usec - old value) to 546 * reduce the value reloaded into the timer so that 547 * the timer does not drift. This routine assumes 548 * that it is called in a context where the timers 549 * on which it is operating cannot change in value. 550 */ 551 int 552 itimerdecr(itp, usec) 553 register struct itimerval *itp; 554 int usec; 555 { 556 557 if (itp->it_value.tv_usec < usec) { 558 if (itp->it_value.tv_sec == 0) { 559 /* expired, and already in next interval */ 560 usec -= itp->it_value.tv_usec; 561 goto expire; 562 } 563 itp->it_value.tv_usec += 1000000; 564 itp->it_value.tv_sec--; 565 } 566 itp->it_value.tv_usec -= usec; 567 usec = 0; 568 if (timerisset(&itp->it_value)) 569 return (1); 570 /* expired, exactly at end of interval */ 571 expire: 572 if (timerisset(&itp->it_interval)) { 573 itp->it_value = itp->it_interval; 574 itp->it_value.tv_usec -= usec; 575 if (itp->it_value.tv_usec < 0) { 576 itp->it_value.tv_usec += 1000000; 577 itp->it_value.tv_sec--; 578 } 579 } else 580 itp->it_value.tv_usec = 0; /* sec is already 0 */ 581 return (0); 582 } 583
Indexes created Thu Sep 25 16:09:42 GMT 2025