xref: /freebsd/sys/kern/kern_resource.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)kern_resource.c	8.5 (Berkeley) 1/21/94
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_compat.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/sysproto.h>
45 #include <sys/file.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mutex.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/refcount.h>
53 #include <sys/racct.h>
54 #include <sys/resourcevar.h>
55 #include <sys/rwlock.h>
56 #include <sys/sched.h>
57 #include <sys/sx.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/sysctl.h>
60 #include <sys/sysent.h>
61 #include <sys/time.h>
62 #include <sys/umtx.h>
63 
64 #include <vm/vm.h>
65 #include <vm/vm_param.h>
66 #include <vm/pmap.h>
67 #include <vm/vm_map.h>
68 
69 
70 static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
71 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
72 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
73 static struct rwlock uihashtbl_lock;
74 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
75 static u_long uihash;		/* size of hash table - 1 */
76 
77 static void	calcru1(struct proc *p, struct rusage_ext *ruxp,
78 		    struct timeval *up, struct timeval *sp);
79 static int	donice(struct thread *td, struct proc *chgp, int n);
80 static struct uidinfo *uilookup(uid_t uid);
81 static void	ruxagg_locked(struct rusage_ext *rux, struct thread *td);
82 
83 static __inline int	lim_shared(struct plimit *limp);
84 
85 /*
86  * Resource controls and accounting.
87  */
88 #ifndef _SYS_SYSPROTO_H_
89 struct getpriority_args {
90 	int	which;
91 	int	who;
92 };
93 #endif
94 int
95 sys_getpriority(td, uap)
96 	struct thread *td;
97 	register struct getpriority_args *uap;
98 {
99 	struct proc *p;
100 	struct pgrp *pg;
101 	int error, low;
102 
103 	error = 0;
104 	low = PRIO_MAX + 1;
105 	switch (uap->which) {
106 
107 	case PRIO_PROCESS:
108 		if (uap->who == 0)
109 			low = td->td_proc->p_nice;
110 		else {
111 			p = pfind(uap->who);
112 			if (p == NULL)
113 				break;
114 			if (p_cansee(td, p) == 0)
115 				low = p->p_nice;
116 			PROC_UNLOCK(p);
117 		}
118 		break;
119 
120 	case PRIO_PGRP:
121 		sx_slock(&proctree_lock);
122 		if (uap->who == 0) {
123 			pg = td->td_proc->p_pgrp;
124 			PGRP_LOCK(pg);
125 		} else {
126 			pg = pgfind(uap->who);
127 			if (pg == NULL) {
128 				sx_sunlock(&proctree_lock);
129 				break;
130 			}
131 		}
132 		sx_sunlock(&proctree_lock);
133 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
134 			PROC_LOCK(p);
135 			if (p->p_state == PRS_NORMAL &&
136 			    p_cansee(td, p) == 0) {
137 				if (p->p_nice < low)
138 					low = p->p_nice;
139 			}
140 			PROC_UNLOCK(p);
141 		}
142 		PGRP_UNLOCK(pg);
143 		break;
144 
145 	case PRIO_USER:
146 		if (uap->who == 0)
147 			uap->who = td->td_ucred->cr_uid;
148 		sx_slock(&allproc_lock);
149 		FOREACH_PROC_IN_SYSTEM(p) {
150 			PROC_LOCK(p);
151 			if (p->p_state == PRS_NORMAL &&
152 			    p_cansee(td, p) == 0 &&
153 			    p->p_ucred->cr_uid == uap->who) {
154 				if (p->p_nice < low)
155 					low = p->p_nice;
156 			}
157 			PROC_UNLOCK(p);
158 		}
159 		sx_sunlock(&allproc_lock);
160 		break;
161 
162 	default:
163 		error = EINVAL;
164 		break;
165 	}
166 	if (low == PRIO_MAX + 1 && error == 0)
167 		error = ESRCH;
168 	td->td_retval[0] = low;
169 	return (error);
170 }
171 
172 #ifndef _SYS_SYSPROTO_H_
173 struct setpriority_args {
174 	int	which;
175 	int	who;
176 	int	prio;
177 };
178 #endif
179 int
180 sys_setpriority(td, uap)
181 	struct thread *td;
182 	struct setpriority_args *uap;
183 {
184 	struct proc *curp, *p;
185 	struct pgrp *pg;
186 	int found = 0, error = 0;
187 
188 	curp = td->td_proc;
189 	switch (uap->which) {
190 	case PRIO_PROCESS:
191 		if (uap->who == 0) {
192 			PROC_LOCK(curp);
193 			error = donice(td, curp, uap->prio);
194 			PROC_UNLOCK(curp);
195 		} else {
196 			p = pfind(uap->who);
197 			if (p == NULL)
198 				break;
199 			error = p_cansee(td, p);
200 			if (error == 0)
201 				error = donice(td, p, uap->prio);
202 			PROC_UNLOCK(p);
203 		}
204 		found++;
205 		break;
206 
207 	case PRIO_PGRP:
208 		sx_slock(&proctree_lock);
209 		if (uap->who == 0) {
210 			pg = curp->p_pgrp;
211 			PGRP_LOCK(pg);
212 		} else {
213 			pg = pgfind(uap->who);
214 			if (pg == NULL) {
215 				sx_sunlock(&proctree_lock);
216 				break;
217 			}
218 		}
219 		sx_sunlock(&proctree_lock);
220 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
221 			PROC_LOCK(p);
222 			if (p->p_state == PRS_NORMAL &&
223 			    p_cansee(td, p) == 0) {
224 				error = donice(td, p, uap->prio);
225 				found++;
226 			}
227 			PROC_UNLOCK(p);
228 		}
229 		PGRP_UNLOCK(pg);
230 		break;
231 
232 	case PRIO_USER:
233 		if (uap->who == 0)
234 			uap->who = td->td_ucred->cr_uid;
235 		sx_slock(&allproc_lock);
236 		FOREACH_PROC_IN_SYSTEM(p) {
237 			PROC_LOCK(p);
238 			if (p->p_state == PRS_NORMAL &&
239 			    p->p_ucred->cr_uid == uap->who &&
240 			    p_cansee(td, p) == 0) {
241 				error = donice(td, p, uap->prio);
242 				found++;
243 			}
244 			PROC_UNLOCK(p);
245 		}
246 		sx_sunlock(&allproc_lock);
247 		break;
248 
249 	default:
250 		error = EINVAL;
251 		break;
252 	}
253 	if (found == 0 && error == 0)
254 		error = ESRCH;
255 	return (error);
256 }
257 
258 /*
259  * Set "nice" for a (whole) process.
260  */
261 static int
262 donice(struct thread *td, struct proc *p, int n)
263 {
264 	int error;
265 
266 	PROC_LOCK_ASSERT(p, MA_OWNED);
267 	if ((error = p_cansched(td, p)))
268 		return (error);
269 	if (n > PRIO_MAX)
270 		n = PRIO_MAX;
271 	if (n < PRIO_MIN)
272 		n = PRIO_MIN;
273 	if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
274 		return (EACCES);
275 	sched_nice(p, n);
276 	return (0);
277 }
278 
279 static int unprivileged_idprio;
280 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
281     &unprivileged_idprio, 0, "Allow non-root users to set an idle priority");
282 
283 /*
284  * Set realtime priority for LWP.
285  */
286 #ifndef _SYS_SYSPROTO_H_
287 struct rtprio_thread_args {
288 	int		function;
289 	lwpid_t		lwpid;
290 	struct rtprio	*rtp;
291 };
292 #endif
293 int
294 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
295 {
296 	struct proc *p;
297 	struct rtprio rtp;
298 	struct thread *td1;
299 	int cierror, error;
300 
301 	/* Perform copyin before acquiring locks if needed. */
302 	if (uap->function == RTP_SET)
303 		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
304 	else
305 		cierror = 0;
306 
307 	if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
308 		p = td->td_proc;
309 		td1 = td;
310 		PROC_LOCK(p);
311 	} else {
312 		/* Only look up thread in current process */
313 		td1 = tdfind(uap->lwpid, curproc->p_pid);
314 		if (td1 == NULL)
315 			return (ESRCH);
316 		p = td1->td_proc;
317 	}
318 
319 	switch (uap->function) {
320 	case RTP_LOOKUP:
321 		if ((error = p_cansee(td, p)))
322 			break;
323 		pri_to_rtp(td1, &rtp);
324 		PROC_UNLOCK(p);
325 		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
326 	case RTP_SET:
327 		if ((error = p_cansched(td, p)) || (error = cierror))
328 			break;
329 
330 		/* Disallow setting rtprio in most cases if not superuser. */
331 
332 		/*
333 		 * Realtime priority has to be restricted for reasons which
334 		 * should be obvious.  However, for idleprio processes, there is
335 		 * a potential for system deadlock if an idleprio process gains
336 		 * a lock on a resource that other processes need (and the
337 		 * idleprio process can't run due to a CPU-bound normal
338 		 * process).  Fix me!  XXX
339 		 *
340 		 * This problem is not only related to idleprio process.
341 		 * A user level program can obtain a file lock and hold it
342 		 * indefinitely.  Additionally, without idleprio processes it is
343 		 * still conceivable that a program with low priority will never
344 		 * get to run.  In short, allowing this feature might make it
345 		 * easier to lock a resource indefinitely, but it is not the
346 		 * only thing that makes it possible.
347 		 */
348 		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
349 		    (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
350 		    unprivileged_idprio == 0)) {
351 			error = priv_check(td, PRIV_SCHED_RTPRIO);
352 			if (error)
353 				break;
354 		}
355 		error = rtp_to_pri(&rtp, td1);
356 		break;
357 	default:
358 		error = EINVAL;
359 		break;
360 	}
361 	PROC_UNLOCK(p);
362 	return (error);
363 }
364 
365 /*
366  * Set realtime priority.
367  */
368 #ifndef _SYS_SYSPROTO_H_
369 struct rtprio_args {
370 	int		function;
371 	pid_t		pid;
372 	struct rtprio	*rtp;
373 };
374 #endif
375 int
376 sys_rtprio(td, uap)
377 	struct thread *td;		/* curthread */
378 	register struct rtprio_args *uap;
379 {
380 	struct proc *p;
381 	struct thread *tdp;
382 	struct rtprio rtp;
383 	int cierror, error;
384 
385 	/* Perform copyin before acquiring locks if needed. */
386 	if (uap->function == RTP_SET)
387 		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
388 	else
389 		cierror = 0;
390 
391 	if (uap->pid == 0) {
392 		p = td->td_proc;
393 		PROC_LOCK(p);
394 	} else {
395 		p = pfind(uap->pid);
396 		if (p == NULL)
397 			return (ESRCH);
398 	}
399 
400 	switch (uap->function) {
401 	case RTP_LOOKUP:
402 		if ((error = p_cansee(td, p)))
403 			break;
404 		/*
405 		 * Return OUR priority if no pid specified,
406 		 * or if one is, report the highest priority
407 		 * in the process.  There isn't much more you can do as
408 		 * there is only room to return a single priority.
409 		 * Note: specifying our own pid is not the same
410 		 * as leaving it zero.
411 		 */
412 		if (uap->pid == 0) {
413 			pri_to_rtp(td, &rtp);
414 		} else {
415 			struct rtprio rtp2;
416 
417 			rtp.type = RTP_PRIO_IDLE;
418 			rtp.prio = RTP_PRIO_MAX;
419 			FOREACH_THREAD_IN_PROC(p, tdp) {
420 				pri_to_rtp(tdp, &rtp2);
421 				if (rtp2.type <  rtp.type ||
422 				    (rtp2.type == rtp.type &&
423 				    rtp2.prio < rtp.prio)) {
424 					rtp.type = rtp2.type;
425 					rtp.prio = rtp2.prio;
426 				}
427 			}
428 		}
429 		PROC_UNLOCK(p);
430 		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
431 	case RTP_SET:
432 		if ((error = p_cansched(td, p)) || (error = cierror))
433 			break;
434 
435 		/*
436 		 * Disallow setting rtprio in most cases if not superuser.
437 		 * See the comment in sys_rtprio_thread about idprio
438 		 * threads holding a lock.
439 		 */
440 		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
441 		    (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
442 		    !unprivileged_idprio)) {
443 			error = priv_check(td, PRIV_SCHED_RTPRIO);
444 			if (error)
445 				break;
446 		}
447 
448 		/*
449 		 * If we are setting our own priority, set just our
450 		 * thread but if we are doing another process,
451 		 * do all the threads on that process. If we
452 		 * specify our own pid we do the latter.
453 		 */
454 		if (uap->pid == 0) {
455 			error = rtp_to_pri(&rtp, td);
456 		} else {
457 			FOREACH_THREAD_IN_PROC(p, td) {
458 				if ((error = rtp_to_pri(&rtp, td)) != 0)
459 					break;
460 			}
461 		}
462 		break;
463 	default:
464 		error = EINVAL;
465 		break;
466 	}
467 	PROC_UNLOCK(p);
468 	return (error);
469 }
470 
471 int
472 rtp_to_pri(struct rtprio *rtp, struct thread *td)
473 {
474 	u_char  newpri, oldclass, oldpri;
475 
476 	switch (RTP_PRIO_BASE(rtp->type)) {
477 	case RTP_PRIO_REALTIME:
478 		if (rtp->prio > RTP_PRIO_MAX)
479 			return (EINVAL);
480 		newpri = PRI_MIN_REALTIME + rtp->prio;
481 		break;
482 	case RTP_PRIO_NORMAL:
483 		if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
484 			return (EINVAL);
485 		newpri = PRI_MIN_TIMESHARE + rtp->prio;
486 		break;
487 	case RTP_PRIO_IDLE:
488 		if (rtp->prio > RTP_PRIO_MAX)
489 			return (EINVAL);
490 		newpri = PRI_MIN_IDLE + rtp->prio;
491 		break;
492 	default:
493 		return (EINVAL);
494 	}
495 
496 	thread_lock(td);
497 	oldclass = td->td_pri_class;
498 	sched_class(td, rtp->type);	/* XXX fix */
499 	oldpri = td->td_user_pri;
500 	sched_user_prio(td, newpri);
501 	if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
502 	    td->td_pri_class != RTP_PRIO_NORMAL))
503 		sched_prio(td, td->td_user_pri);
504 	if (TD_ON_UPILOCK(td) && oldpri != newpri) {
505 		critical_enter();
506 		thread_unlock(td);
507 		umtx_pi_adjust(td, oldpri);
508 		critical_exit();
509 	} else
510 		thread_unlock(td);
511 	return (0);
512 }
513 
514 void
515 pri_to_rtp(struct thread *td, struct rtprio *rtp)
516 {
517 
518 	thread_lock(td);
519 	switch (PRI_BASE(td->td_pri_class)) {
520 	case PRI_REALTIME:
521 		rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
522 		break;
523 	case PRI_TIMESHARE:
524 		rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
525 		break;
526 	case PRI_IDLE:
527 		rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
528 		break;
529 	default:
530 		break;
531 	}
532 	rtp->type = td->td_pri_class;
533 	thread_unlock(td);
534 }
535 
536 #if defined(COMPAT_43)
537 #ifndef _SYS_SYSPROTO_H_
538 struct osetrlimit_args {
539 	u_int	which;
540 	struct	orlimit *rlp;
541 };
542 #endif
543 int
544 osetrlimit(td, uap)
545 	struct thread *td;
546 	register struct osetrlimit_args *uap;
547 {
548 	struct orlimit olim;
549 	struct rlimit lim;
550 	int error;
551 
552 	if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
553 		return (error);
554 	lim.rlim_cur = olim.rlim_cur;
555 	lim.rlim_max = olim.rlim_max;
556 	error = kern_setrlimit(td, uap->which, &lim);
557 	return (error);
558 }
559 
560 #ifndef _SYS_SYSPROTO_H_
561 struct ogetrlimit_args {
562 	u_int	which;
563 	struct	orlimit *rlp;
564 };
565 #endif
566 int
567 ogetrlimit(td, uap)
568 	struct thread *td;
569 	register struct ogetrlimit_args *uap;
570 {
571 	struct orlimit olim;
572 	struct rlimit rl;
573 	struct proc *p;
574 	int error;
575 
576 	if (uap->which >= RLIM_NLIMITS)
577 		return (EINVAL);
578 	p = td->td_proc;
579 	PROC_LOCK(p);
580 	lim_rlimit(p, uap->which, &rl);
581 	PROC_UNLOCK(p);
582 
583 	/*
584 	 * XXX would be more correct to convert only RLIM_INFINITY to the
585 	 * old RLIM_INFINITY and fail with EOVERFLOW for other larger
586 	 * values.  Most 64->32 and 32->16 conversions, including not
587 	 * unimportant ones of uids are even more broken than what we
588 	 * do here (they blindly truncate).  We don't do this correctly
589 	 * here since we have little experience with EOVERFLOW yet.
590 	 * Elsewhere, getuid() can't fail...
591 	 */
592 	olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
593 	olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
594 	error = copyout(&olim, uap->rlp, sizeof(olim));
595 	return (error);
596 }
597 #endif /* COMPAT_43 */
598 
599 #ifndef _SYS_SYSPROTO_H_
600 struct __setrlimit_args {
601 	u_int	which;
602 	struct	rlimit *rlp;
603 };
604 #endif
605 int
606 sys_setrlimit(td, uap)
607 	struct thread *td;
608 	register struct __setrlimit_args *uap;
609 {
610 	struct rlimit alim;
611 	int error;
612 
613 	if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
614 		return (error);
615 	error = kern_setrlimit(td, uap->which, &alim);
616 	return (error);
617 }
618 
619 static void
620 lim_cb(void *arg)
621 {
622 	struct rlimit rlim;
623 	struct thread *td;
624 	struct proc *p;
625 
626 	p = arg;
627 	PROC_LOCK_ASSERT(p, MA_OWNED);
628 	/*
629 	 * Check if the process exceeds its cpu resource allocation.  If
630 	 * it reaches the max, arrange to kill the process in ast().
631 	 */
632 	if (p->p_cpulimit == RLIM_INFINITY)
633 		return;
634 	PROC_SLOCK(p);
635 	FOREACH_THREAD_IN_PROC(p, td) {
636 		ruxagg(p, td);
637 	}
638 	PROC_SUNLOCK(p);
639 	if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
640 		lim_rlimit(p, RLIMIT_CPU, &rlim);
641 		if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
642 			killproc(p, "exceeded maximum CPU limit");
643 		} else {
644 			if (p->p_cpulimit < rlim.rlim_max)
645 				p->p_cpulimit += 5;
646 			kern_psignal(p, SIGXCPU);
647 		}
648 	}
649 	if ((p->p_flag & P_WEXIT) == 0)
650 		callout_reset_sbt(&p->p_limco, SBT_1S, 0,
651 		    lim_cb, p, C_PREL(1));
652 }
653 
654 int
655 kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
656 {
657 
658 	return (kern_proc_setrlimit(td, td->td_proc, which, limp));
659 }
660 
661 int
662 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
663     struct rlimit *limp)
664 {
665 	struct plimit *newlim, *oldlim;
666 	register struct rlimit *alimp;
667 	struct rlimit oldssiz;
668 	int error;
669 
670 	if (which >= RLIM_NLIMITS)
671 		return (EINVAL);
672 
673 	/*
674 	 * Preserve historical bugs by treating negative limits as unsigned.
675 	 */
676 	if (limp->rlim_cur < 0)
677 		limp->rlim_cur = RLIM_INFINITY;
678 	if (limp->rlim_max < 0)
679 		limp->rlim_max = RLIM_INFINITY;
680 
681 	oldssiz.rlim_cur = 0;
682 	newlim = NULL;
683 	PROC_LOCK(p);
684 	if (lim_shared(p->p_limit)) {
685 		PROC_UNLOCK(p);
686 		newlim = lim_alloc();
687 		PROC_LOCK(p);
688 	}
689 	oldlim = p->p_limit;
690 	alimp = &oldlim->pl_rlimit[which];
691 	if (limp->rlim_cur > alimp->rlim_max ||
692 	    limp->rlim_max > alimp->rlim_max)
693 		if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
694 			PROC_UNLOCK(p);
695 			if (newlim != NULL)
696 				lim_free(newlim);
697 			return (error);
698 		}
699 	if (limp->rlim_cur > limp->rlim_max)
700 		limp->rlim_cur = limp->rlim_max;
701 	if (newlim != NULL) {
702 		lim_copy(newlim, oldlim);
703 		alimp = &newlim->pl_rlimit[which];
704 	}
705 
706 	switch (which) {
707 
708 	case RLIMIT_CPU:
709 		if (limp->rlim_cur != RLIM_INFINITY &&
710 		    p->p_cpulimit == RLIM_INFINITY)
711 			callout_reset_sbt(&p->p_limco, SBT_1S, 0,
712 			    lim_cb, p, C_PREL(1));
713 		p->p_cpulimit = limp->rlim_cur;
714 		break;
715 	case RLIMIT_DATA:
716 		if (limp->rlim_cur > maxdsiz)
717 			limp->rlim_cur = maxdsiz;
718 		if (limp->rlim_max > maxdsiz)
719 			limp->rlim_max = maxdsiz;
720 		break;
721 
722 	case RLIMIT_STACK:
723 		if (limp->rlim_cur > maxssiz)
724 			limp->rlim_cur = maxssiz;
725 		if (limp->rlim_max > maxssiz)
726 			limp->rlim_max = maxssiz;
727 		oldssiz = *alimp;
728 		if (p->p_sysent->sv_fixlimit != NULL)
729 			p->p_sysent->sv_fixlimit(&oldssiz,
730 			    RLIMIT_STACK);
731 		break;
732 
733 	case RLIMIT_NOFILE:
734 		if (limp->rlim_cur > maxfilesperproc)
735 			limp->rlim_cur = maxfilesperproc;
736 		if (limp->rlim_max > maxfilesperproc)
737 			limp->rlim_max = maxfilesperproc;
738 		break;
739 
740 	case RLIMIT_NPROC:
741 		if (limp->rlim_cur > maxprocperuid)
742 			limp->rlim_cur = maxprocperuid;
743 		if (limp->rlim_max > maxprocperuid)
744 			limp->rlim_max = maxprocperuid;
745 		if (limp->rlim_cur < 1)
746 			limp->rlim_cur = 1;
747 		if (limp->rlim_max < 1)
748 			limp->rlim_max = 1;
749 		break;
750 	}
751 	if (p->p_sysent->sv_fixlimit != NULL)
752 		p->p_sysent->sv_fixlimit(limp, which);
753 	*alimp = *limp;
754 	if (newlim != NULL)
755 		p->p_limit = newlim;
756 	PROC_UNLOCK(p);
757 	if (newlim != NULL)
758 		lim_free(oldlim);
759 
760 	if (which == RLIMIT_STACK) {
761 		/*
762 		 * Stack is allocated to the max at exec time with only
763 		 * "rlim_cur" bytes accessible.  If stack limit is going
764 		 * up make more accessible, if going down make inaccessible.
765 		 */
766 		if (limp->rlim_cur != oldssiz.rlim_cur) {
767 			vm_offset_t addr;
768 			vm_size_t size;
769 			vm_prot_t prot;
770 
771 			if (limp->rlim_cur > oldssiz.rlim_cur) {
772 				prot = p->p_sysent->sv_stackprot;
773 				size = limp->rlim_cur - oldssiz.rlim_cur;
774 				addr = p->p_sysent->sv_usrstack -
775 				    limp->rlim_cur;
776 			} else {
777 				prot = VM_PROT_NONE;
778 				size = oldssiz.rlim_cur - limp->rlim_cur;
779 				addr = p->p_sysent->sv_usrstack -
780 				    oldssiz.rlim_cur;
781 			}
782 			addr = trunc_page(addr);
783 			size = round_page(size);
784 			(void)vm_map_protect(&p->p_vmspace->vm_map,
785 			    addr, addr + size, prot, FALSE);
786 		}
787 	}
788 
789 	return (0);
790 }
791 
792 #ifndef _SYS_SYSPROTO_H_
793 struct __getrlimit_args {
794 	u_int	which;
795 	struct	rlimit *rlp;
796 };
797 #endif
798 /* ARGSUSED */
799 int
800 sys_getrlimit(td, uap)
801 	struct thread *td;
802 	register struct __getrlimit_args *uap;
803 {
804 	struct rlimit rlim;
805 	struct proc *p;
806 	int error;
807 
808 	if (uap->which >= RLIM_NLIMITS)
809 		return (EINVAL);
810 	p = td->td_proc;
811 	PROC_LOCK(p);
812 	lim_rlimit(p, uap->which, &rlim);
813 	PROC_UNLOCK(p);
814 	error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
815 	return (error);
816 }
817 
818 /*
819  * Transform the running time and tick information for children of proc p
820  * into user and system time usage.
821  */
822 void
823 calccru(p, up, sp)
824 	struct proc *p;
825 	struct timeval *up;
826 	struct timeval *sp;
827 {
828 
829 	PROC_LOCK_ASSERT(p, MA_OWNED);
830 	calcru1(p, &p->p_crux, up, sp);
831 }
832 
833 /*
834  * Transform the running time and tick information in proc p into user
835  * and system time usage.  If appropriate, include the current time slice
836  * on this CPU.
837  */
838 void
839 calcru(struct proc *p, struct timeval *up, struct timeval *sp)
840 {
841 	struct thread *td;
842 	uint64_t runtime, u;
843 
844 	PROC_LOCK_ASSERT(p, MA_OWNED);
845 	PROC_SLOCK_ASSERT(p, MA_OWNED);
846 	/*
847 	 * If we are getting stats for the current process, then add in the
848 	 * stats that this thread has accumulated in its current time slice.
849 	 * We reset the thread and CPU state as if we had performed a context
850 	 * switch right here.
851 	 */
852 	td = curthread;
853 	if (td->td_proc == p) {
854 		u = cpu_ticks();
855 		runtime = u - PCPU_GET(switchtime);
856 		td->td_runtime += runtime;
857 		td->td_incruntime += runtime;
858 		PCPU_SET(switchtime, u);
859 	}
860 	/* Make sure the per-thread stats are current. */
861 	FOREACH_THREAD_IN_PROC(p, td) {
862 		if (td->td_incruntime == 0)
863 			continue;
864 		ruxagg(p, td);
865 	}
866 	calcru1(p, &p->p_rux, up, sp);
867 }
868 
869 /* Collect resource usage for a single thread. */
870 void
871 rufetchtd(struct thread *td, struct rusage *ru)
872 {
873 	struct proc *p;
874 	uint64_t runtime, u;
875 
876 	p = td->td_proc;
877 	PROC_SLOCK_ASSERT(p, MA_OWNED);
878 	THREAD_LOCK_ASSERT(td, MA_OWNED);
879 	/*
880 	 * If we are getting stats for the current thread, then add in the
881 	 * stats that this thread has accumulated in its current time slice.
882 	 * We reset the thread and CPU state as if we had performed a context
883 	 * switch right here.
884 	 */
885 	if (td == curthread) {
886 		u = cpu_ticks();
887 		runtime = u - PCPU_GET(switchtime);
888 		td->td_runtime += runtime;
889 		td->td_incruntime += runtime;
890 		PCPU_SET(switchtime, u);
891 	}
892 	ruxagg(p, td);
893 	*ru = td->td_ru;
894 	calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
895 }
896 
897 static void
898 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
899     struct timeval *sp)
900 {
901 	/* {user, system, interrupt, total} {ticks, usec}: */
902 	uint64_t ut, uu, st, su, it, tt, tu;
903 
904 	ut = ruxp->rux_uticks;
905 	st = ruxp->rux_sticks;
906 	it = ruxp->rux_iticks;
907 	tt = ut + st + it;
908 	if (tt == 0) {
909 		/* Avoid divide by zero */
910 		st = 1;
911 		tt = 1;
912 	}
913 	tu = cputick2usec(ruxp->rux_runtime);
914 	if ((int64_t)tu < 0) {
915 		/* XXX: this should be an assert /phk */
916 		printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
917 		    (intmax_t)tu, p->p_pid, p->p_comm);
918 		tu = ruxp->rux_tu;
919 	}
920 
921 	if (tu >= ruxp->rux_tu) {
922 		/*
923 		 * The normal case, time increased.
924 		 * Enforce monotonicity of bucketed numbers.
925 		 */
926 		uu = (tu * ut) / tt;
927 		if (uu < ruxp->rux_uu)
928 			uu = ruxp->rux_uu;
929 		su = (tu * st) / tt;
930 		if (su < ruxp->rux_su)
931 			su = ruxp->rux_su;
932 	} else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
933 		/*
934 		 * When we calibrate the cputicker, it is not uncommon to
935 		 * see the presumably fixed frequency increase slightly over
936 		 * time as a result of thermal stabilization and NTP
937 		 * discipline (of the reference clock).  We therefore ignore
938 		 * a bit of backwards slop because we  expect to catch up
939 		 * shortly.  We use a 3 microsecond limit to catch low
940 		 * counts and a 1% limit for high counts.
941 		 */
942 		uu = ruxp->rux_uu;
943 		su = ruxp->rux_su;
944 		tu = ruxp->rux_tu;
945 	} else { /* tu < ruxp->rux_tu */
946 		/*
947 		 * What happened here was likely that a laptop, which ran at
948 		 * a reduced clock frequency at boot, kicked into high gear.
949 		 * The wisdom of spamming this message in that case is
950 		 * dubious, but it might also be indicative of something
951 		 * serious, so lets keep it and hope laptops can be made
952 		 * more truthful about their CPU speed via ACPI.
953 		 */
954 		printf("calcru: runtime went backwards from %ju usec "
955 		    "to %ju usec for pid %d (%s)\n",
956 		    (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
957 		    p->p_pid, p->p_comm);
958 		uu = (tu * ut) / tt;
959 		su = (tu * st) / tt;
960 	}
961 
962 	ruxp->rux_uu = uu;
963 	ruxp->rux_su = su;
964 	ruxp->rux_tu = tu;
965 
966 	up->tv_sec = uu / 1000000;
967 	up->tv_usec = uu % 1000000;
968 	sp->tv_sec = su / 1000000;
969 	sp->tv_usec = su % 1000000;
970 }
971 
972 #ifndef _SYS_SYSPROTO_H_
973 struct getrusage_args {
974 	int	who;
975 	struct	rusage *rusage;
976 };
977 #endif
978 int
979 sys_getrusage(td, uap)
980 	register struct thread *td;
981 	register struct getrusage_args *uap;
982 {
983 	struct rusage ru;
984 	int error;
985 
986 	error = kern_getrusage(td, uap->who, &ru);
987 	if (error == 0)
988 		error = copyout(&ru, uap->rusage, sizeof(struct rusage));
989 	return (error);
990 }
991 
992 int
993 kern_getrusage(struct thread *td, int who, struct rusage *rup)
994 {
995 	struct proc *p;
996 	int error;
997 
998 	error = 0;
999 	p = td->td_proc;
1000 	PROC_LOCK(p);
1001 	switch (who) {
1002 	case RUSAGE_SELF:
1003 		rufetchcalc(p, rup, &rup->ru_utime,
1004 		    &rup->ru_stime);
1005 		break;
1006 
1007 	case RUSAGE_CHILDREN:
1008 		*rup = p->p_stats->p_cru;
1009 		calccru(p, &rup->ru_utime, &rup->ru_stime);
1010 		break;
1011 
1012 	case RUSAGE_THREAD:
1013 		PROC_SLOCK(p);
1014 		thread_lock(td);
1015 		rufetchtd(td, rup);
1016 		thread_unlock(td);
1017 		PROC_SUNLOCK(p);
1018 		break;
1019 
1020 	default:
1021 		error = EINVAL;
1022 	}
1023 	PROC_UNLOCK(p);
1024 	return (error);
1025 }
1026 
1027 void
1028 rucollect(struct rusage *ru, struct rusage *ru2)
1029 {
1030 	long *ip, *ip2;
1031 	int i;
1032 
1033 	if (ru->ru_maxrss < ru2->ru_maxrss)
1034 		ru->ru_maxrss = ru2->ru_maxrss;
1035 	ip = &ru->ru_first;
1036 	ip2 = &ru2->ru_first;
1037 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
1038 		*ip++ += *ip2++;
1039 }
1040 
1041 void
1042 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
1043     struct rusage_ext *rux2)
1044 {
1045 
1046 	rux->rux_runtime += rux2->rux_runtime;
1047 	rux->rux_uticks += rux2->rux_uticks;
1048 	rux->rux_sticks += rux2->rux_sticks;
1049 	rux->rux_iticks += rux2->rux_iticks;
1050 	rux->rux_uu += rux2->rux_uu;
1051 	rux->rux_su += rux2->rux_su;
1052 	rux->rux_tu += rux2->rux_tu;
1053 	rucollect(ru, ru2);
1054 }
1055 
1056 /*
1057  * Aggregate tick counts into the proc's rusage_ext.
1058  */
1059 static void
1060 ruxagg_locked(struct rusage_ext *rux, struct thread *td)
1061 {
1062 
1063 	THREAD_LOCK_ASSERT(td, MA_OWNED);
1064 	PROC_SLOCK_ASSERT(td->td_proc, MA_OWNED);
1065 	rux->rux_runtime += td->td_incruntime;
1066 	rux->rux_uticks += td->td_uticks;
1067 	rux->rux_sticks += td->td_sticks;
1068 	rux->rux_iticks += td->td_iticks;
1069 }
1070 
1071 void
1072 ruxagg(struct proc *p, struct thread *td)
1073 {
1074 
1075 	thread_lock(td);
1076 	ruxagg_locked(&p->p_rux, td);
1077 	ruxagg_locked(&td->td_rux, td);
1078 	td->td_incruntime = 0;
1079 	td->td_uticks = 0;
1080 	td->td_iticks = 0;
1081 	td->td_sticks = 0;
1082 	thread_unlock(td);
1083 }
1084 
1085 /*
1086  * Update the rusage_ext structure and fetch a valid aggregate rusage
1087  * for proc p if storage for one is supplied.
1088  */
1089 void
1090 rufetch(struct proc *p, struct rusage *ru)
1091 {
1092 	struct thread *td;
1093 
1094 	PROC_SLOCK_ASSERT(p, MA_OWNED);
1095 
1096 	*ru = p->p_ru;
1097 	if (p->p_numthreads > 0)  {
1098 		FOREACH_THREAD_IN_PROC(p, td) {
1099 			ruxagg(p, td);
1100 			rucollect(ru, &td->td_ru);
1101 		}
1102 	}
1103 }
1104 
1105 /*
1106  * Atomically perform a rufetch and a calcru together.
1107  * Consumers, can safely assume the calcru is executed only once
1108  * rufetch is completed.
1109  */
1110 void
1111 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
1112     struct timeval *sp)
1113 {
1114 
1115 	PROC_SLOCK(p);
1116 	rufetch(p, ru);
1117 	calcru(p, up, sp);
1118 	PROC_SUNLOCK(p);
1119 }
1120 
1121 /*
1122  * Allocate a new resource limits structure and initialize its
1123  * reference count and mutex pointer.
1124  */
1125 struct plimit *
1126 lim_alloc()
1127 {
1128 	struct plimit *limp;
1129 
1130 	limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
1131 	refcount_init(&limp->pl_refcnt, 1);
1132 	return (limp);
1133 }
1134 
1135 struct plimit *
1136 lim_hold(limp)
1137 	struct plimit *limp;
1138 {
1139 
1140 	refcount_acquire(&limp->pl_refcnt);
1141 	return (limp);
1142 }
1143 
1144 static __inline int
1145 lim_shared(limp)
1146 	struct plimit *limp;
1147 {
1148 
1149 	return (limp->pl_refcnt > 1);
1150 }
1151 
1152 void
1153 lim_fork(struct proc *p1, struct proc *p2)
1154 {
1155 
1156 	PROC_LOCK_ASSERT(p1, MA_OWNED);
1157 	PROC_LOCK_ASSERT(p2, MA_OWNED);
1158 
1159 	p2->p_limit = lim_hold(p1->p_limit);
1160 	callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
1161 	if (p1->p_cpulimit != RLIM_INFINITY)
1162 		callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
1163 		    lim_cb, p2, C_PREL(1));
1164 }
1165 
1166 void
1167 lim_free(limp)
1168 	struct plimit *limp;
1169 {
1170 
1171 	KASSERT(limp->pl_refcnt > 0, ("plimit refcnt underflow"));
1172 	if (refcount_release(&limp->pl_refcnt))
1173 		free((void *)limp, M_PLIMIT);
1174 }
1175 
1176 /*
1177  * Make a copy of the plimit structure.
1178  * We share these structures copy-on-write after fork.
1179  */
1180 void
1181 lim_copy(dst, src)
1182 	struct plimit *dst, *src;
1183 {
1184 
1185 	KASSERT(!lim_shared(dst), ("lim_copy to shared limit"));
1186 	bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
1187 }
1188 
1189 /*
1190  * Return the hard limit for a particular system resource.  The
1191  * which parameter specifies the index into the rlimit array.
1192  */
1193 rlim_t
1194 lim_max(struct proc *p, int which)
1195 {
1196 	struct rlimit rl;
1197 
1198 	lim_rlimit(p, which, &rl);
1199 	return (rl.rlim_max);
1200 }
1201 
1202 /*
1203  * Return the current (soft) limit for a particular system resource.
1204  * The which parameter which specifies the index into the rlimit array
1205  */
1206 rlim_t
1207 lim_cur(struct proc *p, int which)
1208 {
1209 	struct rlimit rl;
1210 
1211 	lim_rlimit(p, which, &rl);
1212 	return (rl.rlim_cur);
1213 }
1214 
1215 /*
1216  * Return a copy of the entire rlimit structure for the system limit
1217  * specified by 'which' in the rlimit structure pointed to by 'rlp'.
1218  */
1219 void
1220 lim_rlimit(struct proc *p, int which, struct rlimit *rlp)
1221 {
1222 
1223 	PROC_LOCK_ASSERT(p, MA_OWNED);
1224 	KASSERT(which >= 0 && which < RLIM_NLIMITS,
1225 	    ("request for invalid resource limit"));
1226 	*rlp = p->p_limit->pl_rlimit[which];
1227 	if (p->p_sysent->sv_fixlimit != NULL)
1228 		p->p_sysent->sv_fixlimit(rlp, which);
1229 }
1230 
1231 void
1232 uihashinit()
1233 {
1234 
1235 	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
1236 	rw_init(&uihashtbl_lock, "uidinfo hash");
1237 }
1238 
1239 /*
1240  * Look up a uidinfo struct for the parameter uid.
1241  * uihashtbl_lock must be locked.
1242  */
1243 static struct uidinfo *
1244 uilookup(uid)
1245 	uid_t uid;
1246 {
1247 	struct uihashhead *uipp;
1248 	struct uidinfo *uip;
1249 
1250 	rw_assert(&uihashtbl_lock, RA_LOCKED);
1251 	uipp = UIHASH(uid);
1252 	LIST_FOREACH(uip, uipp, ui_hash)
1253 		if (uip->ui_uid == uid)
1254 			break;
1255 
1256 	return (uip);
1257 }
1258 
1259 /*
1260  * Find or allocate a struct uidinfo for a particular uid.
1261  * Increase refcount on uidinfo struct returned.
1262  * uifree() should be called on a struct uidinfo when released.
1263  */
1264 struct uidinfo *
1265 uifind(uid)
1266 	uid_t uid;
1267 {
1268 	struct uidinfo *old_uip, *uip;
1269 
1270 	rw_rlock(&uihashtbl_lock);
1271 	uip = uilookup(uid);
1272 	if (uip == NULL) {
1273 		rw_runlock(&uihashtbl_lock);
1274 		uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
1275 		racct_create(&uip->ui_racct);
1276 		rw_wlock(&uihashtbl_lock);
1277 		/*
1278 		 * There's a chance someone created our uidinfo while we
1279 		 * were in malloc and not holding the lock, so we have to
1280 		 * make sure we don't insert a duplicate uidinfo.
1281 		 */
1282 		if ((old_uip = uilookup(uid)) != NULL) {
1283 			/* Someone else beat us to it. */
1284 			racct_destroy(&uip->ui_racct);
1285 			free(uip, M_UIDINFO);
1286 			uip = old_uip;
1287 		} else {
1288 			refcount_init(&uip->ui_ref, 0);
1289 			uip->ui_uid = uid;
1290 			mtx_init(&uip->ui_vmsize_mtx, "ui_vmsize", NULL,
1291 			    MTX_DEF);
1292 			LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
1293 		}
1294 	}
1295 	uihold(uip);
1296 	rw_unlock(&uihashtbl_lock);
1297 	return (uip);
1298 }
1299 
1300 /*
1301  * Place another refcount on a uidinfo struct.
1302  */
1303 void
1304 uihold(uip)
1305 	struct uidinfo *uip;
1306 {
1307 
1308 	refcount_acquire(&uip->ui_ref);
1309 }
1310 
1311 /*-
1312  * Since uidinfo structs have a long lifetime, we use an
1313  * opportunistic refcounting scheme to avoid locking the lookup hash
1314  * for each release.
1315  *
1316  * If the refcount hits 0, we need to free the structure,
1317  * which means we need to lock the hash.
1318  * Optimal case:
1319  *   After locking the struct and lowering the refcount, if we find
1320  *   that we don't need to free, simply unlock and return.
1321  * Suboptimal case:
1322  *   If refcount lowering results in need to free, bump the count
1323  *   back up, lose the lock and acquire the locks in the proper
1324  *   order to try again.
1325  */
1326 void
1327 uifree(uip)
1328 	struct uidinfo *uip;
1329 {
1330 	int old;
1331 
1332 	/* Prepare for optimal case. */
1333 	old = uip->ui_ref;
1334 	if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1))
1335 		return;
1336 
1337 	/* Prepare for suboptimal case. */
1338 	rw_wlock(&uihashtbl_lock);
1339 	if (refcount_release(&uip->ui_ref)) {
1340 		racct_destroy(&uip->ui_racct);
1341 		LIST_REMOVE(uip, ui_hash);
1342 		rw_wunlock(&uihashtbl_lock);
1343 		if (uip->ui_sbsize != 0)
1344 			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
1345 			    uip->ui_uid, uip->ui_sbsize);
1346 		if (uip->ui_proccnt != 0)
1347 			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
1348 			    uip->ui_uid, uip->ui_proccnt);
1349 		if (uip->ui_vmsize != 0)
1350 			printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
1351 			    uip->ui_uid, (unsigned long long)uip->ui_vmsize);
1352 		mtx_destroy(&uip->ui_vmsize_mtx);
1353 		free(uip, M_UIDINFO);
1354 		return;
1355 	}
1356 	/*
1357 	 * Someone added a reference between atomic_cmpset_int() and
1358 	 * rw_wlock(&uihashtbl_lock).
1359 	 */
1360 	rw_wunlock(&uihashtbl_lock);
1361 }
1362 
1363 void
1364 ui_racct_foreach(void (*callback)(struct racct *racct,
1365     void *arg2, void *arg3), void *arg2, void *arg3)
1366 {
1367 	struct uidinfo *uip;
1368 	struct uihashhead *uih;
1369 
1370 	rw_rlock(&uihashtbl_lock);
1371 	for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
1372 		LIST_FOREACH(uip, uih, ui_hash) {
1373 			(callback)(uip->ui_racct, arg2, arg3);
1374 		}
1375 	}
1376 	rw_runlock(&uihashtbl_lock);
1377 }
1378 
1379 /*
1380  * Change the count associated with number of processes
1381  * a given user is using.  When 'max' is 0, don't enforce a limit
1382  */
1383 int
1384 chgproccnt(uip, diff, max)
1385 	struct	uidinfo	*uip;
1386 	int	diff;
1387 	rlim_t	max;
1388 {
1389 
1390 	/* Don't allow them to exceed max, but allow subtraction. */
1391 	if (diff > 0 && max != 0) {
1392 		if (atomic_fetchadd_long(&uip->ui_proccnt, (long)diff) + diff > max) {
1393 			atomic_subtract_long(&uip->ui_proccnt, (long)diff);
1394 			return (0);
1395 		}
1396 	} else {
1397 		atomic_add_long(&uip->ui_proccnt, (long)diff);
1398 		if (uip->ui_proccnt < 0)
1399 			printf("negative proccnt for uid = %d\n", uip->ui_uid);
1400 	}
1401 	return (1);
1402 }
1403 
1404 /*
1405  * Change the total socket buffer size a user has used.
1406  */
1407 int
1408 chgsbsize(uip, hiwat, to, max)
1409 	struct	uidinfo	*uip;
1410 	u_int  *hiwat;
1411 	u_int	to;
1412 	rlim_t	max;
1413 {
1414 	int diff;
1415 
1416 	diff = to - *hiwat;
1417 	if (diff > 0) {
1418 		if (atomic_fetchadd_long(&uip->ui_sbsize, (long)diff) + diff > max) {
1419 			atomic_subtract_long(&uip->ui_sbsize, (long)diff);
1420 			return (0);
1421 		}
1422 	} else {
1423 		atomic_add_long(&uip->ui_sbsize, (long)diff);
1424 		if (uip->ui_sbsize < 0)
1425 			printf("negative sbsize for uid = %d\n", uip->ui_uid);
1426 	}
1427 	*hiwat = to;
1428 	return (1);
1429 }
1430 
1431 /*
1432  * Change the count associated with number of pseudo-terminals
1433  * a given user is using.  When 'max' is 0, don't enforce a limit
1434  */
1435 int
1436 chgptscnt(uip, diff, max)
1437 	struct	uidinfo	*uip;
1438 	int	diff;
1439 	rlim_t	max;
1440 {
1441 
1442 	/* Don't allow them to exceed max, but allow subtraction. */
1443 	if (diff > 0 && max != 0) {
1444 		if (atomic_fetchadd_long(&uip->ui_ptscnt, (long)diff) + diff > max) {
1445 			atomic_subtract_long(&uip->ui_ptscnt, (long)diff);
1446 			return (0);
1447 		}
1448 	} else {
1449 		atomic_add_long(&uip->ui_ptscnt, (long)diff);
1450 		if (uip->ui_ptscnt < 0)
1451 			printf("negative ptscnt for uid = %d\n", uip->ui_uid);
1452 	}
1453 	return (1);
1454 }
1455 
1456 int
1457 chgkqcnt(struct uidinfo *uip, int diff, rlim_t max)
1458 {
1459 
1460 	if (diff > 0 && max != 0) {
1461 		if (atomic_fetchadd_long(&uip->ui_kqcnt, (long)diff) +
1462 		    diff > max) {
1463 			atomic_subtract_long(&uip->ui_kqcnt, (long)diff);
1464 			return (0);
1465 		}
1466 	} else {
1467 		atomic_add_long(&uip->ui_kqcnt, (long)diff);
1468 		if (uip->ui_kqcnt < 0)
1469 			printf("negative kqcnt for uid = %d\n", uip->ui_uid);
1470 	}
1471 	return (1);
1472 }
1473