1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * Copyright (c) 2005 Robert N. M. Watson 8 * All rights reserved. 9 * 10 * All or some portions of this file are derived from material licensed 11 * to the University of California by American Telephone and Telegraph 12 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 13 * the permission of UNIX System Laboratories, Inc. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * Copyright (c) 1994 Christopher G. Demetriou 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. All advertising materials mentioning features or use of this software 50 * must display the following acknowledgement: 51 * This product includes software developed by the University of 52 * California, Berkeley and its contributors. 53 * 4. Neither the name of the University nor the names of its contributors 54 * may be used to endorse or promote products derived from this software 55 * without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 60 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 67 * SUCH DAMAGE. 68 * 69 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 70 */ 71 72 #include <sys/cdefs.h> 73 __FBSDID("$FreeBSD$"); 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/malloc.h> 84 #include <sys/mount.h> 85 #include <sys/mutex.h> 86 #include <sys/namei.h> 87 #include <sys/priv.h> 88 #include <sys/proc.h> 89 #include <sys/resourcevar.h> 90 #include <sys/sched.h> 91 #include <sys/sx.h> 92 #include <sys/sysctl.h> 93 #include <sys/sysent.h> 94 #include <sys/syslog.h> 95 #include <sys/sysproto.h> 96 #include <sys/tty.h> 97 #include <sys/vnode.h> 98 99 #include <security/mac/mac_framework.h> 100 101 _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_trailer) == 102 sizeof(struct acctv2) - offsetof(struct acctv2, ac_trailer), "trailer"); 103 _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_len2) == 104 sizeof(struct acctv2) - offsetof(struct acctv2, ac_len2), "len2"); 105 106 /* 107 * The routines implemented in this file are described in: 108 * Leffler, et al.: The Design and Implementation of the 4.3BSD 109 * UNIX Operating System (Addison Welley, 1989) 110 * on pages 62-63. 111 * On May 2007 the historic 3 bits base 8 exponent, 13 bit fraction 112 * compt_t representation described in the above reference was replaced 113 * with that of IEEE-754 floats. 114 * 115 * Arguably, to simplify accounting operations, this mechanism should 116 * be replaced by one in which an accounting log file (similar to /dev/klog) 117 * is read by a user process, etc. However, that has its own problems. 118 */ 119 120 /* Floating point definitions from <float.h>. */ 121 #define FLT_MANT_DIG 24 /* p */ 122 #define FLT_MAX_EXP 128 /* emax */ 123 124 /* 125 * Internal accounting functions. 126 * The former's operation is described in Leffler, et al., and the latter 127 * was provided by UCB with the 4.4BSD-Lite release 128 */ 129 static uint32_t encode_timeval(struct timeval); 130 static uint32_t encode_long(long); 131 static void acctwatch(void); 132 static void acct_thread(void *); 133 static int acct_disable(struct thread *, int); 134 135 /* 136 * Accounting vnode pointer, saved vnode pointer, and flags for each. 137 * acct_sx protects against changes to the active vnode and credentials 138 * while accounting records are being committed to disk. 139 */ 140 static int acct_configured; 141 static int acct_suspended; 142 static struct vnode *acct_vp; 143 static struct ucred *acct_cred; 144 static int acct_flags; 145 static struct sx acct_sx; 146 147 SX_SYSINIT(acct, &acct_sx, "acct_sx"); 148 149 /* 150 * State of the accounting kthread. 151 */ 152 static int acct_state; 153 154 #define ACCT_RUNNING 1 /* Accounting kthread is running. */ 155 #define ACCT_EXITREQ 2 /* Accounting kthread should exit. */ 156 157 /* 158 * Values associated with enabling and disabling accounting 159 */ 160 static int acctsuspend = 2; /* stop accounting when < 2% free space left */ 161 SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW, 162 &acctsuspend, 0, "percentage of free disk space below which accounting stops"); 163 164 static int acctresume = 4; /* resume when free space risen to > 4% */ 165 SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW, 166 &acctresume, 0, "percentage of free disk space above which accounting resumes"); 167 168 static int acctchkfreq = 15; /* frequency (in seconds) to check space */ 169 170 static int 171 sysctl_acct_chkfreq(SYSCTL_HANDLER_ARGS) 172 { 173 int error, value; 174 175 /* Write out the old value. */ 176 error = SYSCTL_OUT(req, &acctchkfreq, sizeof(int)); 177 if (error || req->newptr == NULL) 178 return (error); 179 180 /* Read in and verify the new value. */ 181 error = SYSCTL_IN(req, &value, sizeof(int)); 182 if (error) 183 return (error); 184 if (value <= 0) 185 return (EINVAL); 186 acctchkfreq = value; 187 return (0); 188 } 189 SYSCTL_PROC(_kern, OID_AUTO, acct_chkfreq, 190 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &acctchkfreq, 0, 191 sysctl_acct_chkfreq, "I", 192 "frequency for checking the free space"); 193 194 SYSCTL_INT(_kern, OID_AUTO, acct_configured, CTLFLAG_RD, &acct_configured, 0, 195 "Accounting configured or not"); 196 197 SYSCTL_INT(_kern, OID_AUTO, acct_suspended, CTLFLAG_RD, &acct_suspended, 0, 198 "Accounting suspended or not"); 199 200 /* 201 * Accounting system call. Written based on the specification and previous 202 * implementation done by Mark Tinguely. 203 */ 204 int 205 sys_acct(struct thread *td, struct acct_args *uap) 206 { 207 struct nameidata nd; 208 int error, flags, replacing; 209 210 error = priv_check(td, PRIV_ACCT); 211 if (error) 212 return (error); 213 214 /* 215 * If accounting is to be started to a file, open that file for 216 * appending and make sure it's a 'normal'. 217 */ 218 if (uap->path != NULL) { 219 NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, 220 UIO_USERSPACE, uap->path, td); 221 flags = FWRITE | O_APPEND; 222 error = vn_open(&nd, &flags, 0, NULL); 223 if (error) 224 return (error); 225 NDFREE(&nd, NDF_ONLY_PNBUF); 226 #ifdef MAC 227 error = mac_system_check_acct(td->td_ucred, nd.ni_vp); 228 if (error) { 229 VOP_UNLOCK(nd.ni_vp); 230 vn_close(nd.ni_vp, flags, td->td_ucred, td); 231 return (error); 232 } 233 #endif 234 VOP_UNLOCK(nd.ni_vp); 235 if (nd.ni_vp->v_type != VREG) { 236 vn_close(nd.ni_vp, flags, td->td_ucred, td); 237 return (EACCES); 238 } 239 #ifdef MAC 240 } else { 241 error = mac_system_check_acct(td->td_ucred, NULL); 242 if (error) 243 return (error); 244 #endif 245 } 246 247 /* 248 * Disallow concurrent access to the accounting vnode while we swap 249 * it out, in order to prevent access after close. 250 */ 251 sx_xlock(&acct_sx); 252 253 /* 254 * Don't log spurious disable/enable messages if we are 255 * switching from one accounting file to another due to log 256 * rotation. 257 */ 258 replacing = (acct_vp != NULL && uap->path != NULL); 259 260 /* 261 * If accounting was previously enabled, kill the old space-watcher, 262 * close the file, and (if no new file was specified, leave). Reset 263 * the suspended state regardless of whether accounting remains 264 * enabled. 265 */ 266 acct_suspended = 0; 267 if (acct_vp != NULL) 268 error = acct_disable(td, !replacing); 269 if (uap->path == NULL) { 270 if (acct_state & ACCT_RUNNING) { 271 acct_state |= ACCT_EXITREQ; 272 wakeup(&acct_state); 273 } 274 sx_xunlock(&acct_sx); 275 return (error); 276 } 277 278 /* 279 * Save the new accounting file vnode, and schedule the new 280 * free space watcher. 281 */ 282 acct_vp = nd.ni_vp; 283 acct_cred = crhold(td->td_ucred); 284 acct_flags = flags; 285 if (acct_state & ACCT_RUNNING) 286 acct_state &= ~ACCT_EXITREQ; 287 else { 288 /* 289 * Try to start up an accounting kthread. We may start more 290 * than one, but if so the extras will commit suicide as 291 * soon as they start up. 292 */ 293 error = kproc_create(acct_thread, NULL, NULL, 0, 0, 294 "accounting"); 295 if (error) { 296 (void) acct_disable(td, 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 if (!replacing) 305 log(LOG_NOTICE, "Accounting enabled\n"); 306 return (error); 307 } 308 309 /* 310 * Disable currently in-progress accounting by closing the vnode, dropping 311 * our reference to the credential, and clearing the vnode's flags. 312 */ 313 static int 314 acct_disable(struct thread *td, int logging) 315 { 316 int error; 317 318 sx_assert(&acct_sx, SX_XLOCKED); 319 error = vn_close(acct_vp, acct_flags, acct_cred, td); 320 crfree(acct_cred); 321 acct_configured = 0; 322 acct_vp = NULL; 323 acct_cred = NULL; 324 acct_flags = 0; 325 if (logging) 326 log(LOG_NOTICE, "Accounting disabled\n"); 327 return (error); 328 } 329 330 /* 331 * Write out process accounting information, on process exit. 332 * Data to be written out is specified in Leffler, et al. 333 * and are enumerated below. (They're also noted in the system 334 * "acct.h" header file.) 335 */ 336 int 337 acct_process(struct thread *td) 338 { 339 struct acctv3 acct; 340 struct timeval ut, st, tmp; 341 struct proc *p; 342 struct rusage ru; 343 int t, ret; 344 345 /* 346 * Lockless check of accounting condition before doing the hard 347 * work. 348 */ 349 if (acct_vp == NULL || acct_suspended) 350 return (0); 351 352 sx_slock(&acct_sx); 353 354 /* 355 * If accounting isn't enabled, don't bother. Have to check again 356 * once we own the lock in case we raced with disabling of accounting 357 * by another thread. 358 */ 359 if (acct_vp == NULL || acct_suspended) { 360 sx_sunlock(&acct_sx); 361 return (0); 362 } 363 364 p = td->td_proc; 365 td->td_pflags2 |= TDP2_ACCT; 366 367 /* 368 * Get process accounting information. 369 */ 370 371 sx_slock(&proctree_lock); 372 PROC_LOCK(p); 373 374 /* (1) The terminal from which the process was started */ 375 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 376 acct.ac_tty = tty_udev(p->p_pgrp->pg_session->s_ttyp); 377 else 378 acct.ac_tty = NODEV; 379 sx_sunlock(&proctree_lock); 380 381 /* (2) The name of the command that ran */ 382 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 383 384 /* (3) The amount of user and system time that was used */ 385 rufetchcalc(p, &ru, &ut, &st); 386 acct.ac_utime = encode_timeval(ut); 387 acct.ac_stime = encode_timeval(st); 388 389 /* (4) The elapsed time the command ran (and its starting time) */ 390 getboottime(&tmp); 391 timevaladd(&tmp, &p->p_stats->p_start); 392 acct.ac_btime = tmp.tv_sec; 393 microuptime(&tmp); 394 timevalsub(&tmp, &p->p_stats->p_start); 395 acct.ac_etime = encode_timeval(tmp); 396 397 /* (5) The average amount of memory used */ 398 tmp = ut; 399 timevaladd(&tmp, &st); 400 /* Convert tmp (i.e. u + s) into hz units to match ru_i*. */ 401 t = tmp.tv_sec * hz + tmp.tv_usec / tick; 402 if (t) 403 acct.ac_mem = encode_long((ru.ru_ixrss + ru.ru_idrss + 404 + ru.ru_isrss) / t); 405 else 406 acct.ac_mem = 0; 407 408 /* (6) The number of disk I/O operations done */ 409 acct.ac_io = encode_long(ru.ru_inblock + ru.ru_oublock); 410 411 /* (7) The UID and GID of the process */ 412 acct.ac_uid = p->p_ucred->cr_ruid; 413 acct.ac_gid = p->p_ucred->cr_rgid; 414 415 /* (8) The boolean flags that tell how the process terminated, etc. */ 416 acct.ac_flagx = p->p_acflag; 417 418 PROC_UNLOCK(p); 419 420 /* Setup ancillary structure fields. */ 421 acct.ac_flagx |= ANVER; 422 acct.ac_zero = 0; 423 acct.ac_version = 3; 424 acct.ac_len = acct.ac_len2 = sizeof(acct); 425 426 /* 427 * Write the accounting information to the file. 428 */ 429 ret = vn_rdwr(UIO_WRITE, acct_vp, (caddr_t)&acct, sizeof (acct), 430 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, acct_cred, NOCRED, 431 NULL, td); 432 sx_sunlock(&acct_sx); 433 td->td_pflags2 &= ~TDP2_ACCT; 434 return (ret); 435 } 436 437 /* FLOAT_CONVERSION_START (Regression testing; don't remove this line.) */ 438 439 /* Convert timevals and longs into IEEE-754 bit patterns. */ 440 441 /* Mantissa mask (MSB is implied, so subtract 1). */ 442 #define MANT_MASK ((1 << (FLT_MANT_DIG - 1)) - 1) 443 444 /* 445 * We calculate integer values to a precision of approximately 446 * 28 bits. 447 * This is high-enough precision to fill the 24 float bits 448 * and low-enough to avoid overflowing the 32 int bits. 449 */ 450 #define CALC_BITS 28 451 452 /* log_2(1000000). */ 453 #define LOG2_1M 20 454 455 /* 456 * Convert the elements of a timeval into a 32-bit word holding 457 * the bits of a IEEE-754 float. 458 * The float value represents the timeval's value in microsecond units. 459 */ 460 static uint32_t 461 encode_timeval(struct timeval tv) 462 { 463 int log2_s; 464 int val, exp; /* Unnormalized value and exponent */ 465 int norm_exp; /* Normalized exponent */ 466 int shift; 467 468 /* 469 * First calculate value and exponent to about CALC_BITS precision. 470 * Note that the following conditionals have been ordered so that 471 * the most common cases appear first. 472 */ 473 if (tv.tv_sec == 0) { 474 if (tv.tv_usec == 0) 475 return (0); 476 exp = 0; 477 val = tv.tv_usec; 478 } else { 479 /* 480 * Calculate the value to a precision of approximately 481 * CALC_BITS. 482 */ 483 log2_s = fls(tv.tv_sec) - 1; 484 if (log2_s + LOG2_1M < CALC_BITS) { 485 exp = 0; 486 val = 1000000 * tv.tv_sec + tv.tv_usec; 487 } else { 488 exp = log2_s + LOG2_1M - CALC_BITS; 489 val = (unsigned int)(((uint64_t)1000000 * tv.tv_sec + 490 tv.tv_usec) >> exp); 491 } 492 } 493 /* Now normalize and pack the value into an IEEE-754 float. */ 494 norm_exp = fls(val) - 1; 495 shift = FLT_MANT_DIG - norm_exp - 1; 496 #ifdef ACCT_DEBUG 497 printf("val=%d exp=%d shift=%d log2(val)=%d\n", 498 val, exp, shift, norm_exp); 499 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp, 500 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK)); 501 #endif 502 return (((FLT_MAX_EXP - 1 + exp + norm_exp) << (FLT_MANT_DIG - 1)) | 503 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK)); 504 } 505 506 /* 507 * Convert a non-negative long value into the bit pattern of 508 * an IEEE-754 float value. 509 */ 510 static uint32_t 511 encode_long(long val) 512 { 513 int norm_exp; /* Normalized exponent */ 514 int shift; 515 516 if (val == 0) 517 return (0); 518 if (val < 0) { 519 log(LOG_NOTICE, 520 "encode_long: negative value %ld in accounting record\n", 521 val); 522 val = LONG_MAX; 523 } 524 norm_exp = fls(val) - 1; 525 shift = FLT_MANT_DIG - norm_exp - 1; 526 #ifdef ACCT_DEBUG 527 printf("val=%d shift=%d log2(val)=%d\n", 528 val, shift, norm_exp); 529 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp, 530 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK)); 531 #endif 532 return (((FLT_MAX_EXP - 1 + norm_exp) << (FLT_MANT_DIG - 1)) | 533 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK)); 534 } 535 536 /* FLOAT_CONVERSION_END (Regression testing; don't remove this line.) */ 537 538 /* 539 * Periodically check the filesystem to see if accounting 540 * should be turned on or off. Beware the case where the vnode 541 * has been vgone()'d out from underneath us, e.g. when the file 542 * system containing the accounting file has been forcibly unmounted. 543 */ 544 /* ARGSUSED */ 545 static void 546 acctwatch(void) 547 { 548 struct statfs *sp; 549 550 sx_assert(&acct_sx, SX_XLOCKED); 551 552 /* 553 * If accounting was disabled before our kthread was scheduled, 554 * then acct_vp might be NULL. If so, just ask our kthread to 555 * exit and return. 556 */ 557 if (acct_vp == NULL) { 558 acct_state |= ACCT_EXITREQ; 559 return; 560 } 561 562 /* 563 * If our vnode is no longer valid, tear it down and signal the 564 * accounting thread to die. 565 */ 566 if (acct_vp->v_type == VBAD) { 567 (void) acct_disable(NULL, 1); 568 acct_state |= ACCT_EXITREQ; 569 return; 570 } 571 572 /* 573 * Stopping here is better than continuing, maybe it will be VBAD 574 * next time around. 575 */ 576 sp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK); 577 if (VFS_STATFS(acct_vp->v_mount, sp) < 0) { 578 free(sp, M_STATFS); 579 return; 580 } 581 if (acct_suspended) { 582 if (sp->f_bavail > (int64_t)(acctresume * sp->f_blocks / 583 100)) { 584 acct_suspended = 0; 585 log(LOG_NOTICE, "Accounting resumed\n"); 586 } 587 } else { 588 if (sp->f_bavail <= (int64_t)(acctsuspend * sp->f_blocks / 589 100)) { 590 acct_suspended = 1; 591 log(LOG_NOTICE, "Accounting suspended\n"); 592 } 593 } 594 free(sp, M_STATFS); 595 } 596 597 /* 598 * The main loop for the dedicated kernel thread that periodically calls 599 * acctwatch(). 600 */ 601 static void 602 acct_thread(void *dummy) 603 { 604 u_char pri; 605 606 /* This is a low-priority kernel thread. */ 607 pri = PRI_MAX_KERN; 608 thread_lock(curthread); 609 sched_prio(curthread, pri); 610 thread_unlock(curthread); 611 612 /* If another accounting kthread is already running, just die. */ 613 sx_xlock(&acct_sx); 614 if (acct_state & ACCT_RUNNING) { 615 sx_xunlock(&acct_sx); 616 kproc_exit(0); 617 } 618 acct_state |= ACCT_RUNNING; 619 620 /* Loop until we are asked to exit. */ 621 while (!(acct_state & ACCT_EXITREQ)) { 622 /* Perform our periodic checks. */ 623 acctwatch(); 624 625 /* 626 * We check this flag again before sleeping since the 627 * acctwatch() might have shut down accounting and asked us 628 * to exit. 629 */ 630 if (!(acct_state & ACCT_EXITREQ)) { 631 sx_sleep(&acct_state, &acct_sx, 0, "-", 632 acctchkfreq * hz); 633 } 634 } 635 636 /* 637 * Acknowledge the exit request and shutdown. We clear both the 638 * exit request and running flags. 639 */ 640 acct_state = 0; 641 sx_xunlock(&acct_sx); 642 kproc_exit(0); 643 } 644