| 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 | * $FreeBSD: src/sys/kern/kern_time.c,v 1.68.2.1 2002/10/01 08:00:41 bde Exp $ |
| 35 | * $DragonFly: src/sys/kern/kern_time.c,v 1.15 2004/04/10 20:55:23 dillon Exp $ |
| 36 | */ |
| 37 | |
| 38 | #include <sys/param.h> |
| 39 | #include <sys/systm.h> |
| 40 | #include <sys/buf.h> |
| 41 | #include <sys/sysproto.h> |
| 42 | #include <sys/resourcevar.h> |
| 43 | #include <sys/signalvar.h> |
| 44 | #include <sys/kernel.h> |
| 45 | #include <sys/systm.h> |
| 46 | #include <sys/sysent.h> |
| 47 | #include <sys/sysunion.h> |
| 48 | #include <sys/proc.h> |
| 49 | #include <sys/time.h> |
| 50 | #include <sys/vnode.h> |
| 51 | #include <sys/sysctl.h> |
| 52 | #include <vm/vm.h> |
| 53 | #include <vm/vm_extern.h> |
| 54 | #include <sys/msgport2.h> |
| 55 | #include <sys/thread2.h> |
| 56 | |
| 57 | struct timezone tz; |
| 58 | |
| 59 | /* |
| 60 | * Time of day and interval timer support. |
| 61 | * |
| 62 | * These routines provide the kernel entry points to get and set |
| 63 | * the time-of-day and per-process interval timers. Subroutines |
| 64 | * here provide support for adding and subtracting timeval structures |
| 65 | * and decrementing interval timers, optionally reloading the interval |
| 66 | * timers when they expire. |
| 67 | */ |
| 68 | |
| 69 | static int nanosleep1 (struct timespec *rqt, |
| 70 | struct timespec *rmt); |
| 71 | static int settime (struct timeval *); |
| 72 | static void timevalfix (struct timeval *); |
| 73 | static void no_lease_updatetime (int); |
| 74 | |
| 75 | static int sleep_hard_us = 100; |
| 76 | SYSCTL_INT(_kern, OID_AUTO, sleep_hard_us, CTLFLAG_RW, &sleep_hard_us, 0, "") |
| 77 | |
| 78 | static void |
| 79 | no_lease_updatetime(deltat) |
| 80 | int deltat; |
| 81 | { |
| 82 | } |
| 83 | |
| 84 | void (*lease_updatetime) (int) = no_lease_updatetime; |
| 85 | |
| 86 | static int |
| 87 | settime(tv) |
| 88 | struct timeval *tv; |
| 89 | { |
| 90 | struct timeval delta, tv1, tv2; |
| 91 | static struct timeval maxtime, laststep; |
| 92 | struct timespec ts; |
| 93 | |
| 94 | crit_enter(); |
| 95 | microtime(&tv1); |
| 96 | delta = *tv; |
| 97 | timevalsub(&delta, &tv1); |
| 98 | |
| 99 | /* |
| 100 | * If the system is secure, we do not allow the time to be |
| 101 | * set to a value earlier than 1 second less than the highest |
| 102 | * time we have yet seen. The worst a miscreant can do in |
| 103 | * this circumstance is "freeze" time. He couldn't go |
| 104 | * back to the past. |
| 105 | * |
| 106 | * We similarly do not allow the clock to be stepped more |
| 107 | * than one second, nor more than once per second. This allows |
| 108 | * a miscreant to make the clock march double-time, but no worse. |
| 109 | */ |
| 110 | if (securelevel > 1) { |
| 111 | if (delta.tv_sec < 0 || delta.tv_usec < 0) { |
| 112 | /* |
| 113 | * Update maxtime to latest time we've seen. |
| 114 | */ |
| 115 | if (tv1.tv_sec > maxtime.tv_sec) |
| 116 | maxtime = tv1; |
| 117 | tv2 = *tv; |
| 118 | timevalsub(&tv2, &maxtime); |
| 119 | if (tv2.tv_sec < -1) { |
| 120 | tv->tv_sec = maxtime.tv_sec - 1; |
| 121 | printf("Time adjustment clamped to -1 second\n"); |
| 122 | } |
| 123 | } else { |
| 124 | if (tv1.tv_sec == laststep.tv_sec) { |
| 125 | crit_exit(); |
| 126 | return (EPERM); |
| 127 | } |
| 128 | if (delta.tv_sec > 1) { |
| 129 | tv->tv_sec = tv1.tv_sec + 1; |
| 130 | printf("Time adjustment clamped to +1 second\n"); |
| 131 | } |
| 132 | laststep = *tv; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | ts.tv_sec = tv->tv_sec; |
| 137 | ts.tv_nsec = tv->tv_usec * 1000; |
| 138 | set_timeofday(&ts); |
| 139 | lease_updatetime(delta.tv_sec); |
| 140 | crit_exit(); |
| 141 | resettodr(); |
| 142 | return (0); |
| 143 | } |
| 144 | |
| 145 | /* ARGSUSED */ |
| 146 | int |
| 147 | clock_gettime(struct clock_gettime_args *uap) |
| 148 | { |
| 149 | struct timespec ats; |
| 150 | |
| 151 | if (SCARG(uap, clock_id) != CLOCK_REALTIME) |
| 152 | return (EINVAL); |
| 153 | nanotime(&ats); |
| 154 | return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); |
| 155 | } |
| 156 | |
| 157 | /* ARGSUSED */ |
| 158 | int |
| 159 | clock_settime(struct clock_settime_args *uap) |
| 160 | { |
| 161 | struct thread *td = curthread; |
| 162 | struct timeval atv; |
| 163 | struct timespec ats; |
| 164 | int error; |
| 165 | |
| 166 | if ((error = suser(td)) != 0) |
| 167 | return (error); |
| 168 | if (SCARG(uap, clock_id) != CLOCK_REALTIME) |
| 169 | return (EINVAL); |
| 170 | if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) |
| 171 | return (error); |
| 172 | if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) |
| 173 | return (EINVAL); |
| 174 | /* XXX Don't convert nsec->usec and back */ |
| 175 | TIMESPEC_TO_TIMEVAL(&atv, &ats); |
| 176 | if ((error = settime(&atv))) |
| 177 | return (error); |
| 178 | return (0); |
| 179 | } |
| 180 | |
| 181 | int |
| 182 | clock_getres(struct clock_getres_args *uap) |
| 183 | { |
| 184 | struct timespec ts; |
| 185 | int error; |
| 186 | |
| 187 | if (SCARG(uap, clock_id) != CLOCK_REALTIME) |
| 188 | return (EINVAL); |
| 189 | error = 0; |
| 190 | if (SCARG(uap, tp)) { |
| 191 | ts.tv_sec = 0; |
| 192 | /* |
| 193 | * Round up the result of the division cheaply by adding 1. |
| 194 | * Rounding up is especially important if rounding down |
| 195 | * would give 0. Perfect rounding is unimportant. |
| 196 | */ |
| 197 | ts.tv_nsec = 1000000000 / cputimer_freq + 1; |
| 198 | error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); |
| 199 | } |
| 200 | return (error); |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * nanosleep1() |
| 205 | * |
| 206 | * This is a general helper function for nanosleep() (aka sleep() aka |
| 207 | * usleep()). |
| 208 | * |
| 209 | * If there is less then one tick's worth of time left and |
| 210 | * we haven't done a yield, or the remaining microseconds is |
| 211 | * ridiculously low, do a yield. This avoids having |
| 212 | * to deal with systimer overheads when the system is under |
| 213 | * heavy loads. If we have done a yield already then use |
| 214 | * a systimer and an uninterruptable thread wait. |
| 215 | * |
| 216 | * If there is more then a tick's worth of time left, |
| 217 | * calculate the baseline ticks and use an interruptable |
| 218 | * tsleep, then handle the fine-grained delay on the next |
| 219 | * loop. This usually results in two sleeps occuring, a long one |
| 220 | * and a short one. |
| 221 | */ |
| 222 | static void |
| 223 | ns1_systimer(systimer_t info) |
| 224 | { |
| 225 | lwkt_schedule(info->data); |
| 226 | } |
| 227 | |
| 228 | static int |
| 229 | nanosleep1(struct timespec *rqt, struct timespec *rmt) |
| 230 | { |
| 231 | static int nanowait; |
| 232 | struct timespec ts, ts2, ts3; |
| 233 | struct timeval tv; |
| 234 | int error; |
| 235 | int tried_yield; |
| 236 | |
| 237 | if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) |
| 238 | return (EINVAL); |
| 239 | if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0)) |
| 240 | return (0); |
| 241 | nanouptime(&ts); |
| 242 | timespecadd(&ts, rqt); /* ts = target timestamp compare */ |
| 243 | TIMESPEC_TO_TIMEVAL(&tv, rqt); /* tv = sleep interval */ |
| 244 | tried_yield = 0; |
| 245 | |
| 246 | for (;;) { |
| 247 | int ticks; |
| 248 | struct systimer info; |
| 249 | |
| 250 | ticks = tv.tv_usec / tick; /* approximate */ |
| 251 | |
| 252 | if (tv.tv_sec == 0 && ticks == 0) { |
| 253 | thread_t td = curthread; |
| 254 | if (tried_yield || tv.tv_usec < sleep_hard_us) { |
| 255 | tried_yield = 0; |
| 256 | uio_yield(); |
| 257 | } else { |
| 258 | crit_enter_quick(td); |
| 259 | systimer_init_oneshot(&info, ns1_systimer, |
| 260 | td, tv.tv_usec); |
| 261 | lwkt_deschedule_self(td); |
| 262 | crit_exit_quick(td); |
| 263 | lwkt_switch(); |
| 264 | systimer_del(&info); /* make sure it's gone */ |
| 265 | } |
| 266 | error = iscaught(td->td_proc); |
| 267 | } else if (tv.tv_sec == 0) { |
| 268 | error = tsleep(&nanowait, PCATCH, "nanslp", ticks); |
| 269 | } else { |
| 270 | ticks = tvtohz_low(&tv); /* also handles overflow */ |
| 271 | error = tsleep(&nanowait, PCATCH, "nanslp", ticks); |
| 272 | } |
| 273 | nanouptime(&ts2); |
| 274 | if (error && error != EWOULDBLOCK) { |
| 275 | if (error == ERESTART) |
| 276 | error = EINTR; |
| 277 | if (rmt != NULL) { |
| 278 | timespecsub(&ts, &ts2); |
| 279 | if (ts.tv_sec < 0) |
| 280 | timespecclear(&ts); |
| 281 | *rmt = ts; |
| 282 | } |
| 283 | return (error); |
| 284 | } |
| 285 | if (timespeccmp(&ts2, &ts, >=)) |
| 286 | return (0); |
| 287 | ts3 = ts; |
| 288 | timespecsub(&ts3, &ts2); |
| 289 | TIMESPEC_TO_TIMEVAL(&tv, &ts3); |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | static void nanosleep_done(void *arg); |
| 294 | static void nanosleep_copyout(union sysunion *sysun); |
| 295 | |
| 296 | /* ARGSUSED */ |
| 297 | int |
| 298 | nanosleep(struct nanosleep_args *uap) |
| 299 | { |
| 300 | int error; |
| 301 | struct sysmsg_sleep *smsleep = &uap->sysmsg.sm.sleep; |
| 302 | |
| 303 | error = copyin(uap->rqtp, &smsleep->rqt, sizeof(smsleep->rqt)); |
| 304 | if (error) |
| 305 | return (error); |
| 306 | /* |
| 307 | * YYY clean this up to always use the callout, note that an abort |
| 308 | * implementation should record the residual in the async case. |
| 309 | */ |
| 310 | if (uap->sysmsg.lmsg.ms_flags & MSGF_ASYNC) { |
| 311 | quad_t ticks; |
| 312 | |
| 313 | ticks = (quad_t)smsleep->rqt.tv_nsec * hz / 1000000000LL; |
| 314 | if (smsleep->rqt.tv_sec) |
| 315 | ticks += (quad_t)smsleep->rqt.tv_sec * hz; |
| 316 | if (ticks <= 0) { |
| 317 | if (ticks == 0) |
| 318 | error = 0; |
| 319 | else |
| 320 | error = EINVAL; |
| 321 | } else { |
| 322 | uap->sysmsg.copyout = nanosleep_copyout; |
| 323 | callout_init(&smsleep->timer); |
| 324 | callout_reset(&smsleep->timer, ticks, nanosleep_done, uap); |
| 325 | error = EASYNC; |
| 326 | } |
| 327 | } else { |
| 328 | /* |
| 329 | * Old synchronous sleep code, copyout the residual if |
| 330 | * nanosleep was interrupted. |
| 331 | */ |
| 332 | error = nanosleep1(&smsleep->rqt, &smsleep->rmt); |
| 333 | if (error && SCARG(uap, rmtp)) |
| 334 | error = copyout(&smsleep->rmt, SCARG(uap, rmtp), sizeof(smsleep->rmt)); |
| 335 | } |
| 336 | return (error); |
| 337 | } |
| 338 | |
| 339 | /* |
| 340 | * Asynch completion for the nanosleep() syscall. This function may be |
| 341 | * called from any context and cannot legally access the originating |
| 342 | * thread, proc, or its user space. |
| 343 | * |
| 344 | * YYY change the callout interface API so we can simply assign the replymsg |
| 345 | * function to it directly. |
| 346 | */ |
| 347 | static void |
| 348 | nanosleep_done(void *arg) |
| 349 | { |
| 350 | struct nanosleep_args *uap = arg; |
| 351 | |
| 352 | lwkt_replymsg(&uap->sysmsg.lmsg, 0); |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Asynch return for the nanosleep() syscall, called in the context of the |
| 357 | * originating thread when it pulls the message off the reply port. This |
| 358 | * function is responsible for any copyouts to userland. Kernel threads |
| 359 | * which do their own internal system calls will not usually call the return |
| 360 | * function. |
| 361 | */ |
| 362 | static void |
| 363 | nanosleep_copyout(union sysunion *sysun) |
| 364 | { |
| 365 | struct nanosleep_args *uap = &sysun->nanosleep; |
| 366 | struct sysmsg_sleep *smsleep = &uap->sysmsg.sm.sleep; |
| 367 | |
| 368 | if (sysun->lmsg.ms_error && uap->rmtp) { |
| 369 | sysun->lmsg.ms_error = |
| 370 | copyout(&smsleep->rmt, uap->rmtp, sizeof(smsleep->rmt)); |
| 371 | } |
| 372 | } |
| 373 | |
| 374 | /* ARGSUSED */ |
| 375 | int |
| 376 | gettimeofday(struct gettimeofday_args *uap) |
| 377 | { |
| 378 | struct timeval atv; |
| 379 | int error = 0; |
| 380 | |
| 381 | if (uap->tp) { |
| 382 | microtime(&atv); |
| 383 | if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp, |
| 384 | sizeof (atv)))) |
| 385 | return (error); |
| 386 | } |
| 387 | if (uap->tzp) |
| 388 | error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, |
| 389 | sizeof (tz)); |
| 390 | return (error); |
| 391 | } |
| 392 | |
| 393 | /* ARGSUSED */ |
| 394 | int |
| 395 | settimeofday(struct settimeofday_args *uap) |
| 396 | { |
| 397 | struct thread *td = curthread; |
| 398 | struct timeval atv; |
| 399 | struct timezone atz; |
| 400 | int error; |
| 401 | |
| 402 | if ((error = suser(td))) |
| 403 | return (error); |
| 404 | /* Verify all parameters before changing time. */ |
| 405 | if (uap->tv) { |
| 406 | if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv, |
| 407 | sizeof(atv)))) |
| 408 | return (error); |
| 409 | if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) |
| 410 | return (EINVAL); |
| 411 | } |
| 412 | if (uap->tzp && |
| 413 | (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) |
| 414 | return (error); |
| 415 | if (uap->tv && (error = settime(&atv))) |
| 416 | return (error); |
| 417 | if (uap->tzp) |
| 418 | tz = atz; |
| 419 | return (0); |
| 420 | } |
| 421 | |
| 422 | int tickdelta; /* current clock skew, us. per tick */ |
| 423 | long timedelta; /* unapplied time correction, us. */ |
| 424 | static long bigadj = 1000000; /* use 10x skew above bigadj us. */ |
| 425 | |
| 426 | /* ARGSUSED */ |
| 427 | int |
| 428 | adjtime(struct adjtime_args *uap) |
| 429 | { |
| 430 | struct thread *td = curthread; |
| 431 | struct timeval atv; |
| 432 | long ndelta, ntickdelta, odelta; |
| 433 | int error; |
| 434 | |
| 435 | if ((error = suser(td))) |
| 436 | return (error); |
| 437 | if ((error = |
| 438 | copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval)))) |
| 439 | return (error); |
| 440 | |
| 441 | /* |
| 442 | * Compute the total correction and the rate at which to apply it. |
| 443 | * Round the adjustment down to a whole multiple of the per-tick |
| 444 | * delta, so that after some number of incremental changes in |
| 445 | * hardclock(), tickdelta will become zero, lest the correction |
| 446 | * overshoot and start taking us away from the desired final time. |
| 447 | */ |
| 448 | ndelta = atv.tv_sec * 1000000 + atv.tv_usec; |
| 449 | if (ndelta > bigadj || ndelta < -bigadj) |
| 450 | ntickdelta = 10 * tickadj; |
| 451 | else |
| 452 | ntickdelta = tickadj; |
| 453 | if (ndelta % ntickdelta) |
| 454 | ndelta = ndelta / ntickdelta * ntickdelta; |
| 455 | |
| 456 | /* |
| 457 | * To make hardclock()'s job easier, make the per-tick delta negative |
| 458 | * if we want time to run slower; then hardclock can simply compute |
| 459 | * tick + tickdelta, and subtract tickdelta from timedelta. |
| 460 | */ |
| 461 | if (ndelta < 0) |
| 462 | ntickdelta = -ntickdelta; |
| 463 | /* |
| 464 | * XXX not MP safe , but will probably work anyway. |
| 465 | */ |
| 466 | crit_enter(); |
| 467 | odelta = timedelta; |
| 468 | timedelta = ndelta; |
| 469 | tickdelta = ntickdelta; |
| 470 | crit_exit(); |
| 471 | |
| 472 | if (uap->olddelta) { |
| 473 | atv.tv_sec = odelta / 1000000; |
| 474 | atv.tv_usec = odelta % 1000000; |
| 475 | (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta, |
| 476 | sizeof(struct timeval)); |
| 477 | } |
| 478 | return (0); |
| 479 | } |
| 480 | |
| 481 | /* |
| 482 | * Get value of an interval timer. The process virtual and |
| 483 | * profiling virtual time timers are kept in the p_stats area, since |
| 484 | * they can be swapped out. These are kept internally in the |
| 485 | * way they are specified externally: in time until they expire. |
| 486 | * |
| 487 | * The real time interval timer is kept in the process table slot |
| 488 | * for the process, and its value (it_value) is kept as an |
| 489 | * absolute time rather than as a delta, so that it is easy to keep |
| 490 | * periodic real-time signals from drifting. |
| 491 | * |
| 492 | * Virtual time timers are processed in the hardclock() routine of |
| 493 | * kern_clock.c. The real time timer is processed by a timeout |
| 494 | * routine, called from the softclock() routine. Since a callout |
| 495 | * may be delayed in real time due to interrupt processing in the system, |
| 496 | * it is possible for the real time timeout routine (realitexpire, given below), |
| 497 | * to be delayed in real time past when it is supposed to occur. It |
| 498 | * does not suffice, therefore, to reload the real timer .it_value from the |
| 499 | * real time timers .it_interval. Rather, we compute the next time in |
| 500 | * absolute time the timer should go off. |
| 501 | */ |
| 502 | /* ARGSUSED */ |
| 503 | int |
| 504 | getitimer(struct getitimer_args *uap) |
| 505 | { |
| 506 | struct proc *p = curproc; |
| 507 | struct timeval ctv; |
| 508 | struct itimerval aitv; |
| 509 | |
| 510 | if (uap->which > ITIMER_PROF) |
| 511 | return (EINVAL); |
| 512 | crit_enter(); |
| 513 | if (uap->which == ITIMER_REAL) { |
| 514 | /* |
| 515 | * Convert from absolute to relative time in .it_value |
| 516 | * part of real time timer. If time for real time timer |
| 517 | * has passed return 0, else return difference between |
| 518 | * current time and time for the timer to go off. |
| 519 | */ |
| 520 | aitv = p->p_realtimer; |
| 521 | if (timevalisset(&aitv.it_value)) { |
| 522 | getmicrouptime(&ctv); |
| 523 | if (timevalcmp(&aitv.it_value, &ctv, <)) |
| 524 | timevalclear(&aitv.it_value); |
| 525 | else |
| 526 | timevalsub(&aitv.it_value, &ctv); |
| 527 | } |
| 528 | } else { |
| 529 | aitv = p->p_stats->p_timer[uap->which]; |
| 530 | } |
| 531 | crit_exit(); |
| 532 | return (copyout((caddr_t)&aitv, (caddr_t)uap->itv, |
| 533 | sizeof (struct itimerval))); |
| 534 | } |
| 535 | |
| 536 | /* ARGSUSED */ |
| 537 | int |
| 538 | setitimer(struct setitimer_args *uap) |
| 539 | { |
| 540 | struct itimerval aitv; |
| 541 | struct timeval ctv; |
| 542 | struct itimerval *itvp; |
| 543 | struct proc *p = curproc; |
| 544 | int error; |
| 545 | |
| 546 | if (uap->which > ITIMER_PROF) |
| 547 | return (EINVAL); |
| 548 | itvp = uap->itv; |
| 549 | if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, |
| 550 | sizeof(struct itimerval)))) |
| 551 | return (error); |
| 552 | if ((uap->itv = uap->oitv) && |
| 553 | (error = getitimer((struct getitimer_args *)uap))) |
| 554 | return (error); |
| 555 | if (itvp == 0) |
| 556 | return (0); |
| 557 | if (itimerfix(&aitv.it_value)) |
| 558 | return (EINVAL); |
| 559 | if (!timevalisset(&aitv.it_value)) |
| 560 | timevalclear(&aitv.it_interval); |
| 561 | else if (itimerfix(&aitv.it_interval)) |
| 562 | return (EINVAL); |
| 563 | crit_enter(); |
| 564 | if (uap->which == ITIMER_REAL) { |
| 565 | if (timevalisset(&p->p_realtimer.it_value)) |
| 566 | untimeout(realitexpire, (caddr_t)p, p->p_ithandle); |
| 567 | if (timevalisset(&aitv.it_value)) |
| 568 | p->p_ithandle = timeout(realitexpire, (caddr_t)p, |
| 569 | tvtohz_high(&aitv.it_value)); |
| 570 | getmicrouptime(&ctv); |
| 571 | timevaladd(&aitv.it_value, &ctv); |
| 572 | p->p_realtimer = aitv; |
| 573 | } else { |
| 574 | p->p_stats->p_timer[uap->which] = aitv; |
| 575 | } |
| 576 | crit_exit(); |
| 577 | return (0); |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * Real interval timer expired: |
| 582 | * send process whose timer expired an alarm signal. |
| 583 | * If time is not set up to reload, then just return. |
| 584 | * Else compute next time timer should go off which is > current time. |
| 585 | * This is where delay in processing this timeout causes multiple |
| 586 | * SIGALRM calls to be compressed into one. |
| 587 | * tvtohz_high() always adds 1 to allow for the time until the next clock |
| 588 | * interrupt being strictly less than 1 clock tick, but we don't want |
| 589 | * that here since we want to appear to be in sync with the clock |
| 590 | * interrupt even when we're delayed. |
| 591 | */ |
| 592 | void |
| 593 | realitexpire(arg) |
| 594 | void *arg; |
| 595 | { |
| 596 | struct proc *p; |
| 597 | struct timeval ctv, ntv; |
| 598 | |
| 599 | p = (struct proc *)arg; |
| 600 | psignal(p, SIGALRM); |
| 601 | if (!timevalisset(&p->p_realtimer.it_interval)) { |
| 602 | timevalclear(&p->p_realtimer.it_value); |
| 603 | return; |
| 604 | } |
| 605 | for (;;) { |
| 606 | crit_enter(); |
| 607 | timevaladd(&p->p_realtimer.it_value, |
| 608 | &p->p_realtimer.it_interval); |
| 609 | getmicrouptime(&ctv); |
| 610 | if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) { |
| 611 | ntv = p->p_realtimer.it_value; |
| 612 | timevalsub(&ntv, &ctv); |
| 613 | p->p_ithandle = timeout(realitexpire, (caddr_t)p, |
| 614 | tvtohz_low(&ntv)); |
| 615 | crit_exit(); |
| 616 | return; |
| 617 | } |
| 618 | crit_exit(); |
| 619 | } |
| 620 | } |
| 621 | |
| 622 | /* |
| 623 | * Check that a proposed value to load into the .it_value or |
| 624 | * .it_interval part of an interval timer is acceptable, and |
| 625 | * fix it to have at least minimal value (i.e. if it is less |
| 626 | * than the resolution of the clock, round it up.) |
| 627 | */ |
| 628 | int |
| 629 | itimerfix(tv) |
| 630 | struct timeval *tv; |
| 631 | { |
| 632 | |
| 633 | if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || |
| 634 | tv->tv_usec < 0 || tv->tv_usec >= 1000000) |
| 635 | return (EINVAL); |
| 636 | if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) |
| 637 | tv->tv_usec = tick; |
| 638 | return (0); |
| 639 | } |
| 640 | |
| 641 | /* |
| 642 | * Decrement an interval timer by a specified number |
| 643 | * of microseconds, which must be less than a second, |
| 644 | * i.e. < 1000000. If the timer expires, then reload |
| 645 | * it. In this case, carry over (usec - old value) to |
| 646 | * reduce the value reloaded into the timer so that |
| 647 | * the timer does not drift. This routine assumes |
| 648 | * that it is called in a context where the timers |
| 649 | * on which it is operating cannot change in value. |
| 650 | */ |
| 651 | int |
| 652 | itimerdecr(itp, usec) |
| 653 | struct itimerval *itp; |
| 654 | int usec; |
| 655 | { |
| 656 | |
| 657 | if (itp->it_value.tv_usec < usec) { |
| 658 | if (itp->it_value.tv_sec == 0) { |
| 659 | /* expired, and already in next interval */ |
| 660 | usec -= itp->it_value.tv_usec; |
| 661 | goto expire; |
| 662 | } |
| 663 | itp->it_value.tv_usec += 1000000; |
| 664 | itp->it_value.tv_sec--; |
| 665 | } |
| 666 | itp->it_value.tv_usec -= usec; |
| 667 | usec = 0; |
| 668 | if (timevalisset(&itp->it_value)) |
| 669 | return (1); |
| 670 | /* expired, exactly at end of interval */ |
| 671 | expire: |
| 672 | if (timevalisset(&itp->it_interval)) { |
| 673 | itp->it_value = itp->it_interval; |
| 674 | itp->it_value.tv_usec -= usec; |
| 675 | if (itp->it_value.tv_usec < 0) { |
| 676 | itp->it_value.tv_usec += 1000000; |
| 677 | itp->it_value.tv_sec--; |
| 678 | } |
| 679 | } else |
| 680 | itp->it_value.tv_usec = 0; /* sec is already 0 */ |
| 681 | return (0); |
| 682 | } |
| 683 | |
| 684 | /* |
| 685 | * Add and subtract routines for timevals. |
| 686 | * N.B.: subtract routine doesn't deal with |
| 687 | * results which are before the beginning, |
| 688 | * it just gets very confused in this case. |
| 689 | * Caveat emptor. |
| 690 | */ |
| 691 | void |
| 692 | timevaladd(t1, t2) |
| 693 | struct timeval *t1, *t2; |
| 694 | { |
| 695 | |
| 696 | t1->tv_sec += t2->tv_sec; |
| 697 | t1->tv_usec += t2->tv_usec; |
| 698 | timevalfix(t1); |
| 699 | } |
| 700 | |
| 701 | void |
| 702 | timevalsub(t1, t2) |
| 703 | struct timeval *t1, *t2; |
| 704 | { |
| 705 | |
| 706 | t1->tv_sec -= t2->tv_sec; |
| 707 | t1->tv_usec -= t2->tv_usec; |
| 708 | timevalfix(t1); |
| 709 | } |
| 710 | |
| 711 | static void |
| 712 | timevalfix(t1) |
| 713 | struct timeval *t1; |
| 714 | { |
| 715 | |
| 716 | if (t1->tv_usec < 0) { |
| 717 | t1->tv_sec--; |
| 718 | t1->tv_usec += 1000000; |
| 719 | } |
| 720 | if (t1->tv_usec >= 1000000) { |
| 721 | t1->tv_sec++; |
| 722 | t1->tv_usec -= 1000000; |
| 723 | } |
| 724 | } |
| 725 | |
| 726 | /* |
| 727 | * ratecheck(): simple time-based rate-limit checking. |
| 728 | */ |
| 729 | int |
| 730 | ratecheck(struct timeval *lasttime, const struct timeval *mininterval) |
| 731 | { |
| 732 | struct timeval tv, delta; |
| 733 | int rv = 0; |
| 734 | |
| 735 | getmicrouptime(&tv); /* NB: 10ms precision */ |
| 736 | delta = tv; |
| 737 | timevalsub(&delta, lasttime); |
| 738 | |
| 739 | /* |
| 740 | * check for 0,0 is so that the message will be seen at least once, |
| 741 | * even if interval is huge. |
| 742 | */ |
| 743 | if (timevalcmp(&delta, mininterval, >=) || |
| 744 | (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) { |
| 745 | *lasttime = tv; |
| 746 | rv = 1; |
| 747 | } |
| 748 | |
| 749 | return (rv); |
| 750 | } |
| 751 | |
| 752 | /* |
| 753 | * ppsratecheck(): packets (or events) per second limitation. |
| 754 | * |
| 755 | * Return 0 if the limit is to be enforced (e.g. the caller |
| 756 | * should drop a packet because of the rate limitation). |
| 757 | * |
| 758 | * maxpps of 0 always causes zero to be returned. maxpps of -1 |
| 759 | * always causes 1 to be returned; this effectively defeats rate |
| 760 | * limiting. |
| 761 | * |
| 762 | * Note that we maintain the struct timeval for compatibility |
| 763 | * with other bsd systems. We reuse the storage and just monitor |
| 764 | * clock ticks for minimal overhead. |
| 765 | */ |
| 766 | int |
| 767 | ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps) |
| 768 | { |
| 769 | int now; |
| 770 | |
| 771 | /* |
| 772 | * Reset the last time and counter if this is the first call |
| 773 | * or more than a second has passed since the last update of |
| 774 | * lasttime. |
| 775 | */ |
| 776 | now = ticks; |
| 777 | if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) { |
| 778 | lasttime->tv_sec = now; |
| 779 | *curpps = 1; |
| 780 | return (maxpps != 0); |
| 781 | } else { |
| 782 | (*curpps)++; /* NB: ignore potential overflow */ |
| 783 | return (maxpps < 0 || *curpps < maxpps); |
| 784 | } |
| 785 | } |
| 786 | |