kern_time.c revision 1.28
1 /* $NetBSD: kern_time.c,v 1.28 1997/04/21 16:56:54 jtc 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 void 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 void 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 time = *tv; 82 (void) splsoftclock(); 83 timeradd(&boottime, &delta, &boottime); 84 timeradd(&runtime, &delta, &runtime); 85 # if defined(NFS) || defined(NFSSERVER) 86 nqnfs_lease_updatetime(delta.tv_sec); 87 # endif 88 splx(s); 89 resettodr(); 90 } 91 92 /* ARGSUSED */ 93 int 94 sys_clock_gettime(p, v, retval) 95 struct proc *p; 96 void *v; 97 register_t *retval; 98 { 99 register struct sys_clock_gettime_args /* { 100 syscallarg(clockid_t) clock_id; 101 syscallarg(struct timespec *) tp; 102 } */ *uap = v; 103 clockid_t clock_id; 104 struct timeval atv; 105 struct timespec ats; 106 107 clock_id = SCARG(uap, clock_id); 108 if (clock_id != CLOCK_REALTIME) 109 return (EINVAL); 110 111 microtime(&atv); 112 TIMEVAL_TO_TIMESPEC(&atv,&ats); 113 114 return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 115 } 116 117 /* ARGSUSED */ 118 int 119 sys_clock_settime(p, v, retval) 120 struct proc *p; 121 void *v; 122 register_t *retval; 123 { 124 register struct sys_clock_settime_args /* { 125 syscallarg(clockid_t) clock_id; 126 syscallarg(const struct timespec *) tp; 127 } */ *uap = v; 128 clockid_t clock_id; 129 struct timeval atv; 130 struct timespec ats; 131 int error; 132 133 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 134 return (error); 135 136 clock_id = SCARG(uap, clock_id); 137 if (clock_id != CLOCK_REALTIME) 138 return (EINVAL); 139 140 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 141 return (error); 142 143 TIMESPEC_TO_TIMEVAL(&atv,&ats); 144 settime(&atv); 145 146 return 0; 147 } 148 149 int 150 sys_clock_getres(p, v, retval) 151 struct proc *p; 152 void *v; 153 register_t *retval; 154 { 155 register struct sys_clock_getres_args /* { 156 syscallarg(clockid_t) clock_id; 157 syscallarg(struct timespec *) tp; 158 } */ *uap = v; 159 clockid_t clock_id; 160 struct timespec ts; 161 int error = 0; 162 163 clock_id = SCARG(uap, clock_id); 164 if (clock_id != CLOCK_REALTIME) 165 return (EINVAL); 166 167 if (SCARG(uap, tp)) { 168 ts.tv_sec = 0; 169 ts.tv_nsec = 1000000000 / hz; 170 171 error = copyout(&ts, SCARG(uap, tp), sizeof (ts)); 172 } 173 174 return error; 175 } 176 177 /* ARGSUSED */ 178 int 179 sys_nanosleep(p, v, retval) 180 struct proc *p; 181 void *v; 182 register_t *retval; 183 { 184 static int nanowait; 185 register struct sys_nanosleep_args/* { 186 syscallarg(struct timespec *) rqtp; 187 syscallarg(struct timespec *) rmtp; 188 } */ *uap = v; 189 struct timespec rqt; 190 struct timespec rmt; 191 struct timeval atv, utv; 192 int error, s, timo; 193 194 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 195 sizeof(struct timespec)); 196 if (error) 197 return (error); 198 199 TIMESPEC_TO_TIMEVAL(&atv,&rqt) 200 if (itimerfix(&atv)) 201 return (EINVAL); 202 203 s = splclock(); 204 timeradd(&atv,&time,&atv); 205 timo = hzto(&atv); 206 /* 207 * Avoid inadvertantly sleeping forever 208 */ 209 if (timo == 0) 210 timo = 1; 211 splx(s); 212 213 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 214 if (error == ERESTART) 215 error = EINTR; 216 if (error == EWOULDBLOCK) 217 error = 0; 218 219 if (SCARG(uap, rmtp)) { 220 int error; 221 222 s = splclock(); 223 utv = time; 224 splx(s); 225 226 timersub(&atv, &utv, &utv); 227 if (utv.tv_sec < 0) 228 timerclear(&utv); 229 230 TIMEVAL_TO_TIMESPEC(&utv,&rmt); 231 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp), 232 sizeof(rmt)); 233 if (error) 234 return (error); 235 } 236 237 return error; 238 } 239 240 /* ARGSUSED */ 241 int 242 sys_gettimeofday(p, v, retval) 243 struct proc *p; 244 void *v; 245 register_t *retval; 246 { 247 register struct sys_gettimeofday_args /* { 248 syscallarg(struct timeval *) tp; 249 syscallarg(struct timezone *) tzp; 250 } */ *uap = v; 251 struct timeval atv; 252 int error = 0; 253 struct timezone tzfake; 254 255 if (SCARG(uap, tp)) { 256 microtime(&atv); 257 error = copyout(&atv, SCARG(uap, tp), sizeof (atv)); 258 if (error) 259 return (error); 260 } 261 if (SCARG(uap, tzp)) { 262 /* 263 * NetBSD has no kernel notion of timezone, so we just 264 * fake up a timezone struct and return it if demanded. 265 */ 266 tzfake.tz_minuteswest = 0; 267 tzfake.tz_dsttime = 0; 268 error = copyout(&tzfake, SCARG(uap, tzp), sizeof (tzfake)); 269 } 270 return (error); 271 } 272 273 /* ARGSUSED */ 274 int 275 sys_settimeofday(p, v, retval) 276 struct proc *p; 277 void *v; 278 register_t *retval; 279 { 280 struct sys_settimeofday_args /* { 281 syscallarg(const struct timeval *) tv; 282 syscallarg(const struct timezone *) tzp; 283 } */ *uap = v; 284 struct timeval atv; 285 struct timezone atz; 286 int error; 287 288 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 289 return (error); 290 /* Verify all parameters before changing time. */ 291 if (SCARG(uap, tv) && (error = copyin(SCARG(uap, tv), 292 &atv, sizeof(atv)))) 293 return (error); 294 /* XXX since we don't use tz, probably no point in doing copyin. */ 295 if (SCARG(uap, tzp) && (error = copyin(SCARG(uap, tzp), 296 &atz, sizeof(atz)))) 297 return (error); 298 if (SCARG(uap, tv)) 299 settime(&atv); 300 /* 301 * NetBSD has no kernel notion of timezone, and only an 302 * obsolete program would try to set it, so we log a warning. 303 */ 304 if (SCARG(uap, tzp)) 305 log(LOG_WARNING, "pid %d attempted to set the " 306 "(obsolete) kernel timezone.", p->p_pid); 307 return (0); 308 } 309 310 int tickdelta; /* current clock skew, us. per tick */ 311 long timedelta; /* unapplied time correction, us. */ 312 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 313 314 /* ARGSUSED */ 315 int 316 sys_adjtime(p, v, retval) 317 struct proc *p; 318 void *v; 319 register_t *retval; 320 { 321 register struct sys_adjtime_args /* { 322 syscallarg(const struct timeval *) delta; 323 syscallarg(struct timeval *) olddelta; 324 } */ *uap = v; 325 struct timeval atv; 326 register long ndelta, ntickdelta, odelta; 327 int s, error; 328 329 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 330 return (error); 331 332 error = copyin(SCARG(uap, delta), &atv, sizeof(struct timeval)); 333 if (error) 334 return (error); 335 336 /* 337 * Compute the total correction and the rate at which to apply it. 338 * Round the adjustment down to a whole multiple of the per-tick 339 * delta, so that after some number of incremental changes in 340 * hardclock(), tickdelta will become zero, lest the correction 341 * overshoot and start taking us away from the desired final time. 342 */ 343 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 344 if (ndelta > bigadj) 345 ntickdelta = 10 * tickadj; 346 else 347 ntickdelta = tickadj; 348 if (ndelta % ntickdelta) 349 ndelta = ndelta / ntickdelta * ntickdelta; 350 351 /* 352 * To make hardclock()'s job easier, make the per-tick delta negative 353 * if we want time to run slower; then hardclock can simply compute 354 * tick + tickdelta, and subtract tickdelta from timedelta. 355 */ 356 if (ndelta < 0) 357 ntickdelta = -ntickdelta; 358 s = splclock(); 359 odelta = timedelta; 360 timedelta = ndelta; 361 tickdelta = ntickdelta; 362 splx(s); 363 364 if (SCARG(uap, olddelta)) { 365 atv.tv_sec = odelta / 1000000; 366 atv.tv_usec = odelta % 1000000; 367 (void) copyout(&atv, SCARG(uap, olddelta), 368 sizeof(struct timeval)); 369 } 370 return (0); 371 } 372 373 /* 374 * Get value of an interval timer. The process virtual and 375 * profiling virtual time timers are kept in the p_stats area, since 376 * they can be swapped out. These are kept internally in the 377 * way they are specified externally: in time until they expire. 378 * 379 * The real time interval timer is kept in the process table slot 380 * for the process, and its value (it_value) is kept as an 381 * absolute time rather than as a delta, so that it is easy to keep 382 * periodic real-time signals from drifting. 383 * 384 * Virtual time timers are processed in the hardclock() routine of 385 * kern_clock.c. The real time timer is processed by a timeout 386 * routine, called from the softclock() routine. Since a callout 387 * may be delayed in real time due to interrupt processing in the system, 388 * it is possible for the real time timeout routine (realitexpire, given below), 389 * to be delayed in real time past when it is supposed to occur. It 390 * does not suffice, therefore, to reload the real timer .it_value from the 391 * real time timers .it_interval. Rather, we compute the next time in 392 * absolute time the timer should go off. 393 */ 394 /* ARGSUSED */ 395 int 396 sys_getitimer(p, v, retval) 397 struct proc *p; 398 void *v; 399 register_t *retval; 400 { 401 register struct sys_getitimer_args /* { 402 syscallarg(u_int) which; 403 syscallarg(struct itimerval *) itv; 404 } */ *uap = v; 405 struct itimerval aitv; 406 int s; 407 408 if (SCARG(uap, which) > ITIMER_PROF) 409 return (EINVAL); 410 s = splclock(); 411 if (SCARG(uap, which) == ITIMER_REAL) { 412 /* 413 * Convert from absolute to relative time in .it_value 414 * part of real time timer. If time for real time timer 415 * has passed return 0, else return difference between 416 * current time and time for the timer to go off. 417 */ 418 aitv = p->p_realtimer; 419 if (timerisset(&aitv.it_value)) 420 if (timercmp(&aitv.it_value, &time, <)) 421 timerclear(&aitv.it_value); 422 else 423 timersub(&aitv.it_value, &time, &aitv.it_value); 424 } else 425 aitv = p->p_stats->p_timer[SCARG(uap, which)]; 426 splx(s); 427 return (copyout(&aitv, SCARG(uap, itv), sizeof (struct itimerval))); 428 } 429 430 /* ARGSUSED */ 431 int 432 sys_setitimer(p, v, retval) 433 struct proc *p; 434 register void *v; 435 register_t *retval; 436 { 437 register struct sys_setitimer_args /* { 438 syscallarg(u_int) which; 439 syscallarg(const struct itimerval *) itv; 440 syscallarg(struct itimerval *) oitv; 441 } */ *uap = v; 442 struct sys_getitimer_args getargs; 443 struct itimerval aitv; 444 register const struct itimerval *itvp; 445 int s, error; 446 447 if (SCARG(uap, which) > ITIMER_PROF) 448 return (EINVAL); 449 itvp = SCARG(uap, itv); 450 if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 451 return (error); 452 if (SCARG(uap, oitv) != NULL) { 453 SCARG(&getargs, which) = SCARG(uap, which); 454 SCARG(&getargs, itv) = SCARG(uap, oitv); 455 if ((error = sys_getitimer(p, &getargs, retval)) != 0) 456 return (error); 457 } 458 if (itvp == 0) 459 return (0); 460 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 461 return (EINVAL); 462 s = splclock(); 463 if (SCARG(uap, which) == ITIMER_REAL) { 464 untimeout(realitexpire, p); 465 if (timerisset(&aitv.it_value)) { 466 timeradd(&aitv.it_value, &time, &aitv.it_value); 467 timeout(realitexpire, p, hzto(&aitv.it_value)); 468 } 469 p->p_realtimer = aitv; 470 } else 471 p->p_stats->p_timer[SCARG(uap, which)] = aitv; 472 splx(s); 473 return (0); 474 } 475 476 /* 477 * Real interval timer expired: 478 * send process whose timer expired an alarm signal. 479 * If time is not set up to reload, then just return. 480 * Else compute next time timer should go off which is > current time. 481 * This is where delay in processing this timeout causes multiple 482 * SIGALRM calls to be compressed into one. 483 */ 484 void 485 realitexpire(arg) 486 void *arg; 487 { 488 register struct proc *p; 489 int s; 490 491 p = (struct proc *)arg; 492 psignal(p, SIGALRM); 493 if (!timerisset(&p->p_realtimer.it_interval)) { 494 timerclear(&p->p_realtimer.it_value); 495 return; 496 } 497 for (;;) { 498 s = splclock(); 499 timeradd(&p->p_realtimer.it_value, 500 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 501 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 502 timeout(realitexpire, p, 503 hzto(&p->p_realtimer.it_value)); 504 splx(s); 505 return; 506 } 507 splx(s); 508 } 509 } 510 511 /* 512 * Check that a proposed value to load into the .it_value or 513 * .it_interval part of an interval timer is acceptable, and 514 * fix it to have at least minimal value (i.e. if it is less 515 * than the resolution of the clock, round it up.) 516 */ 517 int 518 itimerfix(tv) 519 struct timeval *tv; 520 { 521 522 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 523 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 524 return (EINVAL); 525 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 526 tv->tv_usec = tick; 527 return (0); 528 } 529 530 /* 531 * Decrement an interval timer by a specified number 532 * of microseconds, which must be less than a second, 533 * i.e. < 1000000. If the timer expires, then reload 534 * it. In this case, carry over (usec - old value) to 535 * reduce the value reloaded into the timer so that 536 * the timer does not drift. This routine assumes 537 * that it is called in a context where the timers 538 * on which it is operating cannot change in value. 539 */ 540 int 541 itimerdecr(itp, usec) 542 register struct itimerval *itp; 543 int usec; 544 { 545 546 if (itp->it_value.tv_usec < usec) { 547 if (itp->it_value.tv_sec == 0) { 548 /* expired, and already in next interval */ 549 usec -= itp->it_value.tv_usec; 550 goto expire; 551 } 552 itp->it_value.tv_usec += 1000000; 553 itp->it_value.tv_sec--; 554 } 555 itp->it_value.tv_usec -= usec; 556 usec = 0; 557 if (timerisset(&itp->it_value)) 558 return (1); 559 /* expired, exactly at end of interval */ 560 expire: 561 if (timerisset(&itp->it_interval)) { 562 itp->it_value = itp->it_interval; 563 itp->it_value.tv_usec -= usec; 564 if (itp->it_value.tv_usec < 0) { 565 itp->it_value.tv_usec += 1000000; 566 itp->it_value.tv_sec--; 567 } 568 } else 569 itp->it_value.tv_usec = 0; /* sec is already 0 */ 570 return (0); 571 } 572
Indexes created Wed Sep 24 05:09:52 GMT 2025