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 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/acct.h>
76 #include <sys/fcntl.h>
77 #include <sys/kernel.h>
78 #include <sys/kthread.h>
79 #include <sys/limits.h>
80 #include <sys/lock.h>
81 #include <sys/malloc.h>
82 #include <sys/mount.h>
83 #include <sys/mutex.h>
84 #include <sys/namei.h>
85 #include <sys/priv.h>
86 #include <sys/proc.h>
87 #include <sys/resourcevar.h>
88 #include <sys/sched.h>
89 #include <sys/sx.h>
90 #include <sys/sysctl.h>
91 #include <sys/syslog.h>
92 #include <sys/sysproto.h>
93 #include <sys/tty.h>
94 #include <sys/vnode.h>
95
96 #include <security/mac/mac_framework.h>
97
98 _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_trailer) ==
99 sizeof(struct acctv2) - offsetof(struct acctv2, ac_trailer), "trailer");
100 _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_len2) ==
101 sizeof(struct acctv2) - offsetof(struct acctv2, ac_len2), "len2");
102
103 /*
104 * The routines implemented in this file are described in:
105 * Leffler, et al.: The Design and Implementation of the 4.3BSD
106 * UNIX Operating System (Addison Welley, 1989)
107 * on pages 62-63.
108 * On May 2007 the historic 3 bits base 8 exponent, 13 bit fraction
109 * compt_t representation described in the above reference was replaced
110 * with that of IEEE-754 floats.
111 *
112 * Arguably, to simplify accounting operations, this mechanism should
113 * be replaced by one in which an accounting log file (similar to /dev/klog)
114 * is read by a user process, etc. However, that has its own problems.
115 */
116
117 /* Floating point definitions from <float.h>. */
118 #define FLT_MANT_DIG 24 /* p */
119 #define FLT_MAX_EXP 128 /* emax */
120
121 /*
122 * Internal accounting functions.
123 * The former's operation is described in Leffler, et al., and the latter
124 * was provided by UCB with the 4.4BSD-Lite release
125 */
126 static uint32_t encode_timeval(struct timeval);
127 static uint32_t encode_long(long);
128 static void acctwatch(void);
129 static void acct_thread(void *);
130 static int acct_disable(struct thread *, int);
131
132 /*
133 * Accounting vnode pointer, saved vnode pointer, and flags for each.
134 * acct_sx protects against changes to the active vnode and credentials
135 * while accounting records are being committed to disk.
136 */
137 static int acct_configured;
138 static int acct_suspended;
139 static struct vnode *acct_vp;
140 static struct ucred *acct_cred;
141 static int acct_flags;
142 static struct sx acct_sx;
143
144 SX_SYSINIT(acct, &acct_sx, "acct_sx");
145
146 /*
147 * State of the accounting kthread.
148 */
149 static int acct_state;
150
151 #define ACCT_RUNNING 1 /* Accounting kthread is running. */
152 #define ACCT_EXITREQ 2 /* Accounting kthread should exit. */
153
154 /*
155 * Values associated with enabling and disabling accounting
156 */
157 static int acctsuspend = 2; /* stop accounting when < 2% free space left */
158 SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW,
159 &acctsuspend, 0, "percentage of free disk space below which accounting stops");
160
161 static int acctresume = 4; /* resume when free space risen to > 4% */
162 SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW,
163 &acctresume, 0, "percentage of free disk space above which accounting resumes");
164
165 static int acctchkfreq = 15; /* frequency (in seconds) to check space */
166
167 static int
sysctl_acct_chkfreq(SYSCTL_HANDLER_ARGS)168 sysctl_acct_chkfreq(SYSCTL_HANDLER_ARGS)
169 {
170 int error, value;
171
172 /* Write out the old value. */
173 error = SYSCTL_OUT(req, &acctchkfreq, sizeof(int));
174 if (error || req->newptr == NULL)
175 return (error);
176
177 /* Read in and verify the new value. */
178 error = SYSCTL_IN(req, &value, sizeof(int));
179 if (error)
180 return (error);
181 if (value <= 0)
182 return (EINVAL);
183 acctchkfreq = value;
184 return (0);
185 }
186 SYSCTL_PROC(_kern, OID_AUTO, acct_chkfreq,
187 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &acctchkfreq, 0,
188 sysctl_acct_chkfreq, "I",
189 "frequency for checking the free space");
190
191 SYSCTL_INT(_kern, OID_AUTO, acct_configured, CTLFLAG_RD, &acct_configured, 0,
192 "Accounting configured or not");
193
194 SYSCTL_INT(_kern, OID_AUTO, acct_suspended, CTLFLAG_RD, &acct_suspended, 0,
195 "Accounting suspended or not");
196
197 /*
198 * Accounting system call. Written based on the specification and previous
199 * implementation done by Mark Tinguely.
200 */
201 int
sys_acct(struct thread * td,struct acct_args * uap)202 sys_acct(struct thread *td, struct acct_args *uap)
203 {
204 struct nameidata nd;
205 int error, flags, replacing;
206
207 error = priv_check(td, PRIV_ACCT);
208 if (error)
209 return (error);
210
211 /*
212 * If accounting is to be started to a file, open that file for
213 * appending and make sure it's a 'normal'.
214 */
215 if (uap->path != NULL) {
216 NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, UIO_USERSPACE,
217 uap->path);
218 flags = FWRITE | O_APPEND;
219 error = vn_open(&nd, &flags, 0, NULL);
220 if (error)
221 return (error);
222 NDFREE_PNBUF(&nd);
223 #ifdef MAC
224 error = mac_system_check_acct(td->td_ucred, nd.ni_vp);
225 if (error) {
226 VOP_UNLOCK(nd.ni_vp);
227 vn_close(nd.ni_vp, flags, td->td_ucred, td);
228 return (error);
229 }
230 #endif
231 VOP_UNLOCK(nd.ni_vp);
232 if (nd.ni_vp->v_type != VREG) {
233 vn_close(nd.ni_vp, flags, td->td_ucred, td);
234 return (EACCES);
235 }
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 * Don't log spurious disable/enable messages if we are
252 * switching from one accounting file to another due to log
253 * rotation.
254 */
255 replacing = (acct_vp != NULL && uap->path != NULL);
256
257 /*
258 * If accounting was previously enabled, kill the old space-watcher,
259 * close the file, and (if no new file was specified, leave). Reset
260 * the suspended state regardless of whether accounting remains
261 * enabled.
262 */
263 acct_suspended = 0;
264 if (acct_vp != NULL)
265 error = acct_disable(td, !replacing);
266 if (uap->path == NULL) {
267 if (acct_state & ACCT_RUNNING) {
268 acct_state |= ACCT_EXITREQ;
269 wakeup(&acct_state);
270 }
271 sx_xunlock(&acct_sx);
272 return (error);
273 }
274
275 /*
276 * Save the new accounting file vnode, and schedule the new
277 * free space watcher.
278 */
279 acct_vp = nd.ni_vp;
280 acct_cred = crhold(td->td_ucred);
281 acct_flags = flags;
282 if (acct_state & ACCT_RUNNING)
283 acct_state &= ~ACCT_EXITREQ;
284 else {
285 /*
286 * Try to start up an accounting kthread. We may start more
287 * than one, but if so the extras will commit suicide as
288 * soon as they start up.
289 */
290 error = kproc_create(acct_thread, NULL, NULL, 0, 0,
291 "accounting");
292 if (error) {
293 (void) acct_disable(td, 0);
294 sx_xunlock(&acct_sx);
295 log(LOG_NOTICE, "Unable to start accounting thread\n");
296 return (error);
297 }
298 }
299 acct_configured = 1;
300 sx_xunlock(&acct_sx);
301 if (!replacing)
302 log(LOG_NOTICE, "Accounting enabled\n");
303 return (error);
304 }
305
306 /*
307 * Disable currently in-progress accounting by closing the vnode, dropping
308 * our reference to the credential, and clearing the vnode's flags.
309 */
310 static int
acct_disable(struct thread * td,int logging)311 acct_disable(struct thread *td, int logging)
312 {
313 int error;
314
315 sx_assert(&acct_sx, SX_XLOCKED);
316 error = vn_close(acct_vp, acct_flags, acct_cred, td);
317 crfree(acct_cred);
318 acct_configured = 0;
319 acct_vp = NULL;
320 acct_cred = NULL;
321 acct_flags = 0;
322 if (logging)
323 log(LOG_NOTICE, "Accounting disabled\n");
324 return (error);
325 }
326
327 /*
328 * Write out process accounting information, on process exit.
329 * Data to be written out is specified in Leffler, et al.
330 * and are enumerated below. (They're also noted in the system
331 * "acct.h" header file.)
332 */
333 int
acct_process(struct thread * td)334 acct_process(struct thread *td)
335 {
336 struct acctv3 acct;
337 struct timeval ut, st, tmp;
338 struct proc *p;
339 struct rusage ru;
340 int t, ret;
341
342 /*
343 * Lockless check of accounting condition before doing the hard
344 * work.
345 */
346 if (acct_vp == NULL || acct_suspended)
347 return (0);
348
349 memset(&acct, 0, sizeof(acct));
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 td->td_pflags2 |= TDP2_ACCT;
365
366 /*
367 * Get process accounting information.
368 */
369
370 sx_slock(&proctree_lock);
371 PROC_LOCK(p);
372
373 /* (1) The terminal from which the process was started */
374 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
375 acct.ac_tty = tty_udev(p->p_pgrp->pg_session->s_ttyp);
376 else
377 acct.ac_tty = NODEV;
378 sx_sunlock(&proctree_lock);
379
380 /* (2) The name of the command that ran */
381 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);
382
383 /* (3) The amount of user and system time that was used */
384 rufetchcalc(p, &ru, &ut, &st);
385 acct.ac_utime = encode_timeval(ut);
386 acct.ac_stime = encode_timeval(st);
387
388 /* (4) The elapsed time the command ran (and its starting time) */
389 getboottime(&tmp);
390 timevaladd(&tmp, &p->p_stats->p_start);
391 acct.ac_btime = tmp.tv_sec;
392 microuptime(&tmp);
393 timevalsub(&tmp, &p->p_stats->p_start);
394 acct.ac_etime = encode_timeval(tmp);
395
396 /* (5) The average amount of memory used */
397 tmp = ut;
398 timevaladd(&tmp, &st);
399 /* Convert tmp (i.e. u + s) into hz units to match ru_i*. */
400 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
401 if (t)
402 acct.ac_mem = encode_long((ru.ru_ixrss + ru.ru_idrss +
403 + ru.ru_isrss) / t);
404 else
405 acct.ac_mem = 0;
406
407 /* (6) The number of disk I/O operations done */
408 acct.ac_io = encode_long(ru.ru_inblock + ru.ru_oublock);
409
410 /* (7) The UID and GID of the process */
411 acct.ac_uid = p->p_ucred->cr_ruid;
412 acct.ac_gid = p->p_ucred->cr_rgid;
413
414 /* (8) The boolean flags that tell how the process terminated, etc. */
415 acct.ac_flagx = p->p_acflag;
416
417 PROC_UNLOCK(p);
418
419 /* Setup ancillary structure fields. */
420 acct.ac_flagx |= ANVER;
421 acct.ac_zero = 0;
422 acct.ac_version = 3;
423 acct.ac_len = acct.ac_len2 = sizeof(acct);
424
425 /*
426 * Write the accounting information to the file.
427 */
428 ret = vn_rdwr(UIO_WRITE, acct_vp, (caddr_t)&acct, sizeof (acct),
429 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, acct_cred, NOCRED,
430 NULL, td);
431 sx_sunlock(&acct_sx);
432 td->td_pflags2 &= ~TDP2_ACCT;
433 return (ret);
434 }
435
436 /* FLOAT_CONVERSION_START (Regression testing; don't remove this line.) */
437
438 /* Convert timevals and longs into IEEE-754 bit patterns. */
439
440 /* Mantissa mask (MSB is implied, so subtract 1). */
441 #define MANT_MASK ((1 << (FLT_MANT_DIG - 1)) - 1)
442
443 /*
444 * We calculate integer values to a precision of approximately
445 * 28 bits.
446 * This is high-enough precision to fill the 24 float bits
447 * and low-enough to avoid overflowing the 32 int bits.
448 */
449 #define CALC_BITS 28
450
451 /* log_2(1000000). */
452 #define LOG2_1M 20
453
454 /*
455 * Convert the elements of a timeval into a 32-bit word holding
456 * the bits of a IEEE-754 float.
457 * The float value represents the timeval's value in microsecond units.
458 */
459 static uint32_t
encode_timeval(struct timeval tv)460 encode_timeval(struct timeval tv)
461 {
462 int log2_s;
463 int val, exp; /* Unnormalized value and exponent */
464 int norm_exp; /* Normalized exponent */
465 int shift;
466
467 /*
468 * First calculate value and exponent to about CALC_BITS precision.
469 * Note that the following conditionals have been ordered so that
470 * the most common cases appear first.
471 */
472 if (tv.tv_sec == 0) {
473 if (tv.tv_usec == 0)
474 return (0);
475 exp = 0;
476 val = tv.tv_usec;
477 } else {
478 /*
479 * Calculate the value to a precision of approximately
480 * CALC_BITS.
481 */
482 log2_s = fls(tv.tv_sec) - 1;
483 if (log2_s + LOG2_1M < CALC_BITS) {
484 exp = 0;
485 val = 1000000 * tv.tv_sec + tv.tv_usec;
486 } else {
487 exp = log2_s + LOG2_1M - CALC_BITS;
488 val = (unsigned int)(((uint64_t)1000000 * tv.tv_sec +
489 tv.tv_usec) >> exp);
490 }
491 }
492 /* Now normalize and pack the value into an IEEE-754 float. */
493 norm_exp = fls(val) - 1;
494 shift = FLT_MANT_DIG - norm_exp - 1;
495 #ifdef ACCT_DEBUG
496 printf("val=%d exp=%d shift=%d log2(val)=%d\n",
497 val, exp, shift, norm_exp);
498 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp,
499 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK));
500 #endif
501 return (((FLT_MAX_EXP - 1 + exp + norm_exp) << (FLT_MANT_DIG - 1)) |
502 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK));
503 }
504
505 /*
506 * Convert a non-negative long value into the bit pattern of
507 * an IEEE-754 float value.
508 */
509 static uint32_t
encode_long(long val)510 encode_long(long val)
511 {
512 int norm_exp; /* Normalized exponent */
513 int shift;
514
515 if (val == 0)
516 return (0);
517 if (val < 0) {
518 log(LOG_NOTICE,
519 "encode_long: negative value %ld in accounting record\n",
520 val);
521 val = LONG_MAX;
522 }
523 norm_exp = fls(val) - 1;
524 shift = FLT_MANT_DIG - norm_exp - 1;
525 #ifdef ACCT_DEBUG
526 printf("val=%d shift=%d log2(val)=%d\n",
527 val, shift, norm_exp);
528 printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp,
529 ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK));
530 #endif
531 return (((FLT_MAX_EXP - 1 + norm_exp) << (FLT_MANT_DIG - 1)) |
532 ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK));
533 }
534
535 /* FLOAT_CONVERSION_END (Regression testing; don't remove this line.) */
536
537 /*
538 * Periodically check the filesystem to see if accounting
539 * should be turned on or off. Beware the case where the vnode
540 * has been vgone()'d out from underneath us, e.g. when the file
541 * system containing the accounting file has been forcibly unmounted.
542 */
543 /* ARGSUSED */
544 static void
acctwatch(void)545 acctwatch(void)
546 {
547 struct statfs *sp;
548
549 sx_assert(&acct_sx, SX_XLOCKED);
550
551 /*
552 * If accounting was disabled before our kthread was scheduled,
553 * then acct_vp might be NULL. If so, just ask our kthread to
554 * exit and return.
555 */
556 if (acct_vp == NULL) {
557 acct_state |= ACCT_EXITREQ;
558 return;
559 }
560
561 /*
562 * If our vnode is no longer valid, tear it down and signal the
563 * accounting thread to die.
564 */
565 if (acct_vp->v_type == VBAD) {
566 (void) acct_disable(NULL, 1);
567 acct_state |= ACCT_EXITREQ;
568 return;
569 }
570
571 /*
572 * Stopping here is better than continuing, maybe it will be VBAD
573 * next time around.
574 */
575 sp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
576 if (VFS_STATFS(acct_vp->v_mount, sp) < 0) {
577 free(sp, M_STATFS);
578 return;
579 }
580 if (acct_suspended) {
581 if (sp->f_bavail > (int64_t)(acctresume * sp->f_blocks /
582 100)) {
583 acct_suspended = 0;
584 log(LOG_NOTICE, "Accounting resumed\n");
585 }
586 } else {
587 if (sp->f_bavail <= (int64_t)(acctsuspend * sp->f_blocks /
588 100)) {
589 acct_suspended = 1;
590 log(LOG_NOTICE, "Accounting suspended\n");
591 }
592 }
593 free(sp, M_STATFS);
594 }
595
596 /*
597 * The main loop for the dedicated kernel thread that periodically calls
598 * acctwatch().
599 */
600 static void
acct_thread(void * dummy)601 acct_thread(void *dummy)
602 {
603 u_char pri;
604
605 /* This is a low-priority kernel thread. */
606 pri = PRI_MAX_KERN;
607 thread_lock(curthread);
608 sched_prio(curthread, pri);
609 thread_unlock(curthread);
610
611 /* If another accounting kthread is already running, just die. */
612 sx_xlock(&acct_sx);
613 if (acct_state & ACCT_RUNNING) {
614 sx_xunlock(&acct_sx);
615 kproc_exit(0);
616 }
617 acct_state |= ACCT_RUNNING;
618
619 /* Loop until we are asked to exit. */
620 while (!(acct_state & ACCT_EXITREQ)) {
621 /* Perform our periodic checks. */
622 acctwatch();
623
624 /*
625 * We check this flag again before sleeping since the
626 * acctwatch() might have shut down accounting and asked us
627 * to exit.
628 */
629 if (!(acct_state & ACCT_EXITREQ)) {
630 sx_sleep(&acct_state, &acct_sx, 0, "-",
631 acctchkfreq * hz);
632 }
633 }
634
635 /*
636 * Acknowledge the exit request and shutdown. We clear both the
637 * exit request and running flags.
638 */
639 acct_state = 0;
640 sx_xunlock(&acct_sx);
641 kproc_exit(0);
642 }
643