kern_acct.c revision 181963
1/*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * Copyright (c) 2005 Robert N. M. Watson 6 * All rights reserved. 7 * 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * Copyright (c) 1994 Christopher G. Demetriou 38 * 39 * Redistribution and use in source and binary forms, with or without 40 * modification, are permitted provided that the following conditions 41 * are met: 42 * 1. Redistributions of source code must retain the above copyright 43 * notice, this list of conditions and the following disclaimer. 44 * 2. Redistributions in binary form must reproduce the above copyright 45 * notice, this list of conditions and the following disclaimer in the 46 * documentation and/or other materials provided with the distribution. 47 * 3. All advertising materials mentioning features or use of this software 48 * must display the following acknowledgement: 49 * This product includes software developed by the University of 50 * California, Berkeley and its contributors. 51 * 4. Neither the name of the University nor the names of its contributors 52 * may be used to endorse or promote products derived from this software 53 * without specific prior written permission. 54 * 55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 65 * SUCH DAMAGE. 66 * 67 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 68 */ 69 70#include <sys/cdefs.h> 71__FBSDID("$FreeBSD: head/sys/kern/kern_acct.c 181963 2008-08-21 15:02:17Z ed $"); 72 73#include "opt_mac.h" 74 75#include <sys/param.h> 76#include <sys/systm.h> 77#include <sys/acct.h> 78#include <sys/fcntl.h> 79#include <sys/kernel.h> 80#include <sys/kthread.h> 81#include <sys/limits.h> 82#include <sys/lock.h> 83#include <sys/mount.h> 84#include <sys/mutex.h> 85#include <sys/namei.h> 86#include <sys/priv.h> 87#include <sys/proc.h> 88#include <sys/resourcevar.h> 89#include <sys/sched.h> 90#include <sys/sx.h> 91#include <sys/sysctl.h> 92#include <sys/sysent.h> 93#include <sys/syslog.h> 94#include <sys/sysproto.h> 95#include <sys/tty.h> 96#include <sys/vnode.h> 97 98#include <security/mac/mac_framework.h> 99 100/* 101 * The routines implemented in this file are described in: 102 * Leffler, et al.: The Design and Implementation of the 4.3BSD 103 * UNIX Operating System (Addison Welley, 1989) 104 * on pages 62-63. 105 * On May 2007 the historic 3 bits base 8 exponent, 13 bit fraction 106 * compt_t representation described in the above reference was replaced 107 * with that of IEEE-754 floats. 108 * 109 * Arguably, to simplify accounting operations, this mechanism should 110 * be replaced by one in which an accounting log file (similar to /dev/klog) 111 * is read by a user process, etc. However, that has its own problems. 112 */ 113 114/* Floating point definitions from <float.h>. */ 115#define FLT_MANT_DIG 24 /* p */ 116#define FLT_MAX_EXP 128 /* emax */ 117 118/* 119 * Internal accounting functions. 120 * The former's operation is described in Leffler, et al., and the latter 121 * was provided by UCB with the 4.4BSD-Lite release 122 */ 123static uint32_t encode_timeval(struct timeval); 124static uint32_t encode_long(long); 125static void acctwatch(void); 126static void acct_thread(void *); 127static int acct_disable(struct thread *); 128 129/* 130 * Accounting vnode pointer, saved vnode pointer, and flags for each. 131 * acct_sx protects against changes to the active vnode and credentials 132 * while accounting records are being committed to disk. 133 */ 134static int acct_configured; 135static int acct_suspended; 136static struct vnode *acct_vp; 137static struct ucred *acct_cred; 138static int acct_flags; 139static struct sx acct_sx; 140 141SX_SYSINIT(acct, &acct_sx, "acct_sx"); 142 143/* 144 * State of the accounting kthread. 145 */ 146static int acct_state; 147 148#define ACCT_RUNNING 1 /* Accounting kthread is running. */ 149#define ACCT_EXITREQ 2 /* Accounting kthread should exit. */ 150 151/* 152 * Values associated with enabling and disabling accounting 153 */ 154static int acctsuspend = 2; /* stop accounting when < 2% free space left */ 155SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW, 156 &acctsuspend, 0, "percentage of free disk space below which accounting stops"); 157 158static int acctresume = 4; /* resume when free space risen to > 4% */ 159SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW, 160 &acctresume, 0, "percentage of free disk space above which accounting resumes"); 161 162static int acctchkfreq = 15; /* frequency (in seconds) to check space */ 163 164static int 165sysctl_acct_chkfreq(SYSCTL_HANDLER_ARGS) 166{ 167 int error, value; 168 169 /* Write out the old value. */ 170 error = SYSCTL_OUT(req, &acctchkfreq, sizeof(int)); 171 if (error || req->newptr == NULL) 172 return (error); 173 174 /* Read in and verify the new value. */ 175 error = SYSCTL_IN(req, &value, sizeof(int)); 176 if (error) 177 return (error); 178 if (value <= 0) 179 return (EINVAL); 180 acctchkfreq = value; 181 return (0); 182} 183SYSCTL_PROC(_kern, OID_AUTO, acct_chkfreq, CTLTYPE_INT|CTLFLAG_RW, 184 &acctchkfreq, 0, sysctl_acct_chkfreq, "I", 185 "frequency for checking the free space"); 186 187SYSCTL_INT(_kern, OID_AUTO, acct_configured, CTLFLAG_RD, &acct_configured, 0, 188 "Accounting configured or not"); 189 190SYSCTL_INT(_kern, OID_AUTO, acct_suspended, CTLFLAG_RD, &acct_suspended, 0, 191 "Accounting suspended or not"); 192 193/* 194 * Accounting system call. Written based on the specification and previous 195 * implementation done by Mark Tinguely. 196 */ 197int 198acct(struct thread *td, struct acct_args *uap) 199{ 200 struct nameidata nd; 201 int error, flags, vfslocked; 202 203 error = priv_check(td, PRIV_ACCT); 204 if (error) 205 return (error); 206 207 /* 208 * If accounting is to be started to a file, open that file for 209 * appending and make sure it's a 'normal'. 210 */ 211 if (uap->path != NULL) { 212 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE | AUDITVNODE1, 213 UIO_USERSPACE, uap->path, td); 214 flags = FWRITE | O_APPEND; 215 error = vn_open(&nd, &flags, 0, NULL); 216 if (error) 217 return (error); 218 vfslocked = NDHASGIANT(&nd); 219 NDFREE(&nd, NDF_ONLY_PNBUF); 220#ifdef MAC 221 error = mac_system_check_acct(td->td_ucred, nd.ni_vp); 222 if (error) { 223 VOP_UNLOCK(nd.ni_vp, 0); 224 vn_close(nd.ni_vp, flags, td->td_ucred, td); 225 VFS_UNLOCK_GIANT(vfslocked); 226 return (error); 227 } 228#endif 229 VOP_UNLOCK(nd.ni_vp, 0); 230 if (nd.ni_vp->v_type != VREG) { 231 vn_close(nd.ni_vp, flags, td->td_ucred, td); 232 VFS_UNLOCK_GIANT(vfslocked); 233 return (EACCES); 234 } 235 VFS_UNLOCK_GIANT(vfslocked); 236#ifdef MAC 237 } else { 238 error = mac_system_check_acct(td->td_ucred, NULL); 239 if (error) 240 return (error); 241#endif 242 } 243 244 /* 245 * Disallow concurrent access to the accounting vnode while we swap 246 * it out, in order to prevent access after close. 247 */ 248 sx_xlock(&acct_sx); 249 250 /* 251 * If accounting was previously enabled, kill the old space-watcher, 252 * close the file, and (if no new file was specified, leave). Reset 253 * the suspended state regardless of whether accounting remains 254 * enabled. 255 */ 256 acct_suspended = 0; 257 if (acct_vp != NULL) { 258 vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount); 259 error = acct_disable(td); 260 VFS_UNLOCK_GIANT(vfslocked); 261 } 262 if (uap->path == NULL) { 263 if (acct_state & ACCT_RUNNING) { 264 acct_state |= ACCT_EXITREQ; 265 wakeup(&acct_state); 266 } 267 sx_xunlock(&acct_sx); 268 return (error); 269 } 270 271 /* 272 * Save the new accounting file vnode, and schedule the new 273 * free space watcher. 274 */ 275 acct_vp = nd.ni_vp; 276 acct_cred = crhold(td->td_ucred); 277 acct_flags = flags; 278 if (acct_state & ACCT_RUNNING) 279 acct_state &= ~ACCT_EXITREQ; 280 else { 281 /* 282 * Try to start up an accounting kthread. We may start more 283 * than one, but if so the extras will commit suicide as 284 * soon as they start up. 285 */ 286 error = kproc_create(acct_thread, NULL, NULL, 0, 0, 287 "accounting"); 288 if (error) { 289 vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount); 290 (void) vn_close(acct_vp, acct_flags, acct_cred, td); 291 VFS_UNLOCK_GIANT(vfslocked); 292 crfree(acct_cred); 293 acct_configured = 0; 294 acct_vp = NULL; 295 acct_cred = NULL; 296 acct_flags = 0; 297 sx_xunlock(&acct_sx); 298 log(LOG_NOTICE, "Unable to start accounting thread\n"); 299 return (error); 300 } 301 } 302 acct_configured = 1; 303 sx_xunlock(&acct_sx); 304 log(LOG_NOTICE, "Accounting enabled\n"); 305 return (error); 306} 307 308/* 309 * Disable currently in-progress accounting by closing the vnode, dropping 310 * our reference to the credential, and clearing the vnode's flags. 311 */ 312static int 313acct_disable(struct thread *td) 314{ 315 int error; 316 317 sx_assert(&acct_sx, SX_XLOCKED); 318 error = vn_close(acct_vp, acct_flags, acct_cred, td); 319 crfree(acct_cred); 320 acct_configured = 0; 321 acct_vp = NULL; 322 acct_cred = NULL; 323 acct_flags = 0; 324 log(LOG_NOTICE, "Accounting disabled\n"); 325 return (error); 326} 327 328/* 329 * Write out process accounting information, on process exit. 330 * Data to be written out is specified in Leffler, et al. 331 * and are enumerated below. (They're also noted in the system 332 * "acct.h" header file.) 333 */ 334int 335acct_process(struct thread *td) 336{ 337 struct acctv2 acct; 338 struct timeval ut, st, tmp; 339 struct plimit *newlim, *oldlim; 340 struct proc *p; 341 struct rusage ru; 342 int t, ret, vfslocked; 343 344 /* 345 * Lockless check of accounting condition before doing the hard 346 * work. 347 */ 348 if (acct_vp == NULL || acct_suspended) 349 return (0); 350 351 sx_slock(&acct_sx); 352 353 /* 354 * If accounting isn't enabled, don't bother. Have to check again 355 * once we own the lock in case we raced with disabling of accounting 356 * by another thread. 357 */ 358 if (acct_vp == NULL || acct_suspended) { 359 sx_sunlock(&acct_sx); 360 return (0); 361 } 362 363 p = td->td_proc; 364 365 /* 366 * Get process accounting information. 367 */ 368 369 sx_slock(&proctree_lock); 370 PROC_LOCK(p); 371 372 /* (1) The terminal from which the process was started */ 373 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 374 acct.ac_tty = tty_udev(p->p_pgrp->pg_session->s_ttyp); 375 else 376 acct.ac_tty = NODEV; 377 sx_sunlock(&proctree_lock); 378 379 /* (2) The name of the command that ran */ 380 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 381 382 /* (3) The amount of user and system time that was used */ 383 rufetchcalc(p, &ru, &ut, &st); 384 acct.ac_utime = encode_timeval(ut); 385 acct.ac_stime = encode_timeval(st); 386 387 /* (4) The elapsed time the command ran (and its starting time) */ 388 tmp = boottime; 389 timevaladd(&tmp, &p->p_stats->p_start); 390 acct.ac_btime = tmp.tv_sec; 391 microuptime(&tmp); 392 timevalsub(&tmp, &p->p_stats->p_start); 393 acct.ac_etime = encode_timeval(tmp); 394 395 /* (5) The average amount of memory used */ 396 tmp = ut; 397 timevaladd(&tmp, &st); 398 /* Convert tmp (i.e. u + s) into hz units to match ru_i*. */ 399 t = tmp.tv_sec * hz + tmp.tv_usec / tick; 400 if (t) 401 acct.ac_mem = encode_long((ru.ru_ixrss + ru.ru_idrss + 402 + ru.ru_isrss) / t); 403 else 404 acct.ac_mem = 0; 405 406 /* (6) The number of disk I/O operations done */ 407 acct.ac_io = encode_long(ru.ru_inblock + ru.ru_oublock); 408 409 /* (7) The UID and GID of the process */ 410 acct.ac_uid = p->p_ucred->cr_ruid; 411 acct.ac_gid = p->p_ucred->cr_rgid; 412 413 /* (8) The boolean flags that tell how the process terminated, etc. */ 414 acct.ac_flagx = p->p_acflag; 415 PROC_UNLOCK(p); 416 417 /* Setup ancillary structure fields. */ 418 acct.ac_flagx |= ANVER; 419 acct.ac_zero = 0; 420 acct.ac_version = 2; 421 acct.ac_len = acct.ac_len2 = sizeof(acct); 422 423 /* 424 * Eliminate any file size rlimit. 425 */ 426 newlim = lim_alloc(); 427 PROC_LOCK(p); 428 oldlim = p->p_limit; 429 lim_copy(newlim, oldlim); 430 newlim->pl_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 431 p->p_limit = newlim; 432 PROC_UNLOCK(p); 433 lim_free(oldlim); 434 435 /* 436 * Write the accounting information to the file. 437 */ 438 vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount); 439 VOP_LEASE(acct_vp, td, acct_cred, LEASE_WRITE); 440 ret = vn_rdwr(UIO_WRITE, acct_vp, (caddr_t)&acct, sizeof (acct), 441 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, acct_cred, NOCRED, 442 (int *)0, td); 443 VFS_UNLOCK_GIANT(vfslocked); 444 sx_sunlock(&acct_sx); 445 return (ret); 446} 447 448/* FLOAT_CONVERSION_START (Regression testing; don't remove this line.) */ 449 450/* Convert timevals and longs into IEEE-754 bit patterns. */ 451 452/* Mantissa mask (MSB is implied, so subtract 1). */ 453#define MANT_MASK ((1 << (FLT_MANT_DIG - 1)) - 1) 454 455/* 456 * We calculate integer values to a precision of approximately 457 * 28 bits. 458 * This is high-enough precision to fill the 24 float bits 459 * and low-enough to avoid overflowing the 32 int bits. 460 */ 461#define CALC_BITS 28 462 463/* log_2(1000000). */ 464#define LOG2_1M 20 465 466/* 467 * Convert the elements of a timeval into a 32-bit word holding 468 * the bits of a IEEE-754 float. 469 * The float value represents the timeval's value in microsecond units. 470 */ 471static uint32_t 472encode_timeval(struct timeval tv) 473{ 474 int log2_s; 475 int val, exp; /* Unnormalized value and exponent */ 476 int norm_exp; /* Normalized exponent */ 477 int shift; 478 479 /* 480 * First calculate value and exponent to about CALC_BITS precision. 481 * Note that the following conditionals have been ordered so that 482 * the most common cases appear first. 483 */ 484 if (tv.tv_sec == 0) { 485 if (tv.tv_usec == 0) 486 return (0); 487 exp = 0; 488 val = tv.tv_usec; 489 } else { 490 /* 491 * Calculate the value to a precision of approximately 492 * CALC_BITS. 493 */ 494 log2_s = fls(tv.tv_sec) - 1; 495 if (log2_s + LOG2_1M < CALC_BITS) { 496 exp = 0; 497 val = 1000000 * tv.tv_sec + tv.tv_usec; 498 } else { 499 exp = log2_s + LOG2_1M - CALC_BITS; 500 val = (unsigned int)(((u_int64_t)1000000 * tv.tv_sec + 501 tv.tv_usec) >> exp); 502 } 503 } 504 /* Now normalize and pack the value into an IEEE-754 float. */ 505 norm_exp = fls(val) - 1; 506 shift = FLT_MANT_DIG - norm_exp - 1; 507#ifdef ACCT_DEBUG 508 printf("val=%d exp=%d shift=%d log2(val)=%d\n", 509 val, exp, shift, norm_exp); 510 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp, 511 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK)); 512#endif 513 return (((FLT_MAX_EXP - 1 + exp + norm_exp) << (FLT_MANT_DIG - 1)) | 514 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK)); 515} 516 517/* 518 * Convert a non-negative long value into the bit pattern of 519 * an IEEE-754 float value. 520 */ 521static uint32_t 522encode_long(long val) 523{ 524 int norm_exp; /* Normalized exponent */ 525 int shift; 526 527 if (val == 0) 528 return (0); 529 if (val < 0) { 530 log(LOG_NOTICE, 531 "encode_long: negative value %ld in accounting record\n", 532 val); 533 val = LONG_MAX; 534 } 535 norm_exp = fls(val) - 1; 536 shift = FLT_MANT_DIG - norm_exp - 1; 537#ifdef ACCT_DEBUG 538 printf("val=%d shift=%d log2(val)=%d\n", 539 val, shift, norm_exp); 540 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp, 541 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK)); 542#endif 543 return (((FLT_MAX_EXP - 1 + norm_exp) << (FLT_MANT_DIG - 1)) | 544 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK)); 545} 546 547/* FLOAT_CONVERSION_END (Regression testing; don't remove this line.) */ 548 549/* 550 * Periodically check the filesystem to see if accounting 551 * should be turned on or off. Beware the case where the vnode 552 * has been vgone()'d out from underneath us, e.g. when the file 553 * system containing the accounting file has been forcibly unmounted. 554 */ 555/* ARGSUSED */ 556static void 557acctwatch(void) 558{ 559 struct statfs sb; 560 int vfslocked; 561 562 sx_assert(&acct_sx, SX_XLOCKED); 563 564 /* 565 * If accounting was disabled before our kthread was scheduled, 566 * then acct_vp might be NULL. If so, just ask our kthread to 567 * exit and return. 568 */ 569 if (acct_vp == NULL) { 570 acct_state |= ACCT_EXITREQ; 571 return; 572 } 573 574 /* 575 * If our vnode is no longer valid, tear it down and signal the 576 * accounting thread to die. 577 */ 578 vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount); 579 if (acct_vp->v_type == VBAD) { 580 (void) acct_disable(NULL); 581 VFS_UNLOCK_GIANT(vfslocked); 582 acct_state |= ACCT_EXITREQ; 583 return; 584 } 585 586 /* 587 * Stopping here is better than continuing, maybe it will be VBAD 588 * next time around. 589 */ 590 if (VFS_STATFS(acct_vp->v_mount, &sb, curthread) < 0) { 591 VFS_UNLOCK_GIANT(vfslocked); 592 return; 593 } 594 VFS_UNLOCK_GIANT(vfslocked); 595 if (acct_suspended) { 596 if (sb.f_bavail > (int64_t)(acctresume * sb.f_blocks / 597 100)) { 598 acct_suspended = 0; 599 log(LOG_NOTICE, "Accounting resumed\n"); 600 } 601 } else { 602 if (sb.f_bavail <= (int64_t)(acctsuspend * sb.f_blocks / 603 100)) { 604 acct_suspended = 1; 605 log(LOG_NOTICE, "Accounting suspended\n"); 606 } 607 } 608} 609 610/* 611 * The main loop for the dedicated kernel thread that periodically calls 612 * acctwatch(). 613 */ 614static void 615acct_thread(void *dummy) 616{ 617 u_char pri; 618 619 /* This is a low-priority kernel thread. */ 620 pri = PRI_MAX_KERN; 621 thread_lock(curthread); 622 sched_prio(curthread, pri); 623 thread_unlock(curthread); 624 625 /* If another accounting kthread is already running, just die. */ 626 sx_xlock(&acct_sx); 627 if (acct_state & ACCT_RUNNING) { 628 sx_xunlock(&acct_sx); 629 kproc_exit(0); 630 } 631 acct_state |= ACCT_RUNNING; 632 633 /* Loop until we are asked to exit. */ 634 while (!(acct_state & ACCT_EXITREQ)) { 635 636 /* Perform our periodic checks. */ 637 acctwatch(); 638 639 /* 640 * We check this flag again before sleeping since the 641 * acctwatch() might have shut down accounting and asked us 642 * to exit. 643 */ 644 if (!(acct_state & ACCT_EXITREQ)) { 645 sx_sleep(&acct_state, &acct_sx, 0, "-", 646 acctchkfreq * hz); 647 } 648 } 649 650 /* 651 * Acknowledge the exit request and shutdown. We clear both the 652 * exit request and running flags. 653 */ 654 acct_state = 0; 655 sx_xunlock(&acct_sx); 656 kproc_exit(0); 657} 658