xref: /freebsd/sys/kern/kern_resource.c (revision e14ddd1f16e7e5788392c50de21ea7c927e0690c)
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 /*
84  * Resource controls and accounting.
85  */
86 #ifndef _SYS_SYSPROTO_H_
87 struct getpriority_args {
88 	int	which;
89 	int	who;
90 };
91 #endif
92 int
93 sys_getpriority(td, uap)
94 	struct thread *td;
95 	register struct getpriority_args *uap;
96 {
97 	struct proc *p;
98 	struct pgrp *pg;
99 	int error, low;
100 
101 	error = 0;
102 	low = PRIO_MAX + 1;
103 	switch (uap->which) {
104 
105 	case PRIO_PROCESS:
106 		if (uap->who == 0)
107 			low = td->td_proc->p_nice;
108 		else {
109 			p = pfind(uap->who);
110 			if (p == NULL)
111 				break;
112 			if (p_cansee(td, p) == 0)
113 				low = p->p_nice;
114 			PROC_UNLOCK(p);
115 		}
116 		break;
117 
118 	case PRIO_PGRP:
119 		sx_slock(&proctree_lock);
120 		if (uap->who == 0) {
121 			pg = td->td_proc->p_pgrp;
122 			PGRP_LOCK(pg);
123 		} else {
124 			pg = pgfind(uap->who);
125 			if (pg == NULL) {
126 				sx_sunlock(&proctree_lock);
127 				break;
128 			}
129 		}
130 		sx_sunlock(&proctree_lock);
131 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
132 			PROC_LOCK(p);
133 			if (p->p_state == PRS_NORMAL &&
134 			    p_cansee(td, p) == 0) {
135 				if (p->p_nice < low)
136 					low = p->p_nice;
137 			}
138 			PROC_UNLOCK(p);
139 		}
140 		PGRP_UNLOCK(pg);
141 		break;
142 
143 	case PRIO_USER:
144 		if (uap->who == 0)
145 			uap->who = td->td_ucred->cr_uid;
146 		sx_slock(&allproc_lock);
147 		FOREACH_PROC_IN_SYSTEM(p) {
148 			PROC_LOCK(p);
149 			if (p->p_state == PRS_NORMAL &&
150 			    p_cansee(td, p) == 0 &&
151 			    p->p_ucred->cr_uid == uap->who) {
152 				if (p->p_nice < low)
153 					low = p->p_nice;
154 			}
155 			PROC_UNLOCK(p);
156 		}
157 		sx_sunlock(&allproc_lock);
158 		break;
159 
160 	default:
161 		error = EINVAL;
162 		break;
163 	}
164 	if (low == PRIO_MAX + 1 && error == 0)
165 		error = ESRCH;
166 	td->td_retval[0] = low;
167 	return (error);
168 }
169 
170 #ifndef _SYS_SYSPROTO_H_
171 struct setpriority_args {
172 	int	which;
173 	int	who;
174 	int	prio;
175 };
176 #endif
177 int
178 sys_setpriority(td, uap)
179 	struct thread *td;
180 	struct setpriority_args *uap;
181 {
182 	struct proc *curp, *p;
183 	struct pgrp *pg;
184 	int found = 0, error = 0;
185 
186 	curp = td->td_proc;
187 	switch (uap->which) {
188 	case PRIO_PROCESS:
189 		if (uap->who == 0) {
190 			PROC_LOCK(curp);
191 			error = donice(td, curp, uap->prio);
192 			PROC_UNLOCK(curp);
193 		} else {
194 			p = pfind(uap->who);
195 			if (p == NULL)
196 				break;
197 			error = p_cansee(td, p);
198 			if (error == 0)
199 				error = donice(td, p, uap->prio);
200 			PROC_UNLOCK(p);
201 		}
202 		found++;
203 		break;
204 
205 	case PRIO_PGRP:
206 		sx_slock(&proctree_lock);
207 		if (uap->who == 0) {
208 			pg = curp->p_pgrp;
209 			PGRP_LOCK(pg);
210 		} else {
211 			pg = pgfind(uap->who);
212 			if (pg == NULL) {
213 				sx_sunlock(&proctree_lock);
214 				break;
215 			}
216 		}
217 		sx_sunlock(&proctree_lock);
218 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
219 			PROC_LOCK(p);
220 			if (p->p_state == PRS_NORMAL &&
221 			    p_cansee(td, p) == 0) {
222 				error = donice(td, p, uap->prio);
223 				found++;
224 			}
225 			PROC_UNLOCK(p);
226 		}
227 		PGRP_UNLOCK(pg);
228 		break;
229 
230 	case PRIO_USER:
231 		if (uap->who == 0)
232 			uap->who = td->td_ucred->cr_uid;
233 		sx_slock(&allproc_lock);
234 		FOREACH_PROC_IN_SYSTEM(p) {
235 			PROC_LOCK(p);
236 			if (p->p_state == PRS_NORMAL &&
237 			    p->p_ucred->cr_uid == uap->who &&
238 			    p_cansee(td, p) == 0) {
239 				error = donice(td, p, uap->prio);
240 				found++;
241 			}
242 			PROC_UNLOCK(p);
243 		}
244 		sx_sunlock(&allproc_lock);
245 		break;
246 
247 	default:
248 		error = EINVAL;
249 		break;
250 	}
251 	if (found == 0 && error == 0)
252 		error = ESRCH;
253 	return (error);
254 }
255 
256 /*
257  * Set "nice" for a (whole) process.
258  */
259 static int
260 donice(struct thread *td, struct proc *p, int n)
261 {
262 	int error;
263 
264 	PROC_LOCK_ASSERT(p, MA_OWNED);
265 	if ((error = p_cansched(td, p)))
266 		return (error);
267 	if (n > PRIO_MAX)
268 		n = PRIO_MAX;
269 	if (n < PRIO_MIN)
270 		n = PRIO_MIN;
271 	if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
272 		return (EACCES);
273 	sched_nice(p, n);
274 	return (0);
275 }
276 
277 static int unprivileged_idprio;
278 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
279     &unprivileged_idprio, 0, "Allow non-root users to set an idle priority");
280 
281 /*
282  * Set realtime priority for LWP.
283  */
284 #ifndef _SYS_SYSPROTO_H_
285 struct rtprio_thread_args {
286 	int		function;
287 	lwpid_t		lwpid;
288 	struct rtprio	*rtp;
289 };
290 #endif
291 int
292 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
293 {
294 	struct proc *p;
295 	struct rtprio rtp;
296 	struct thread *td1;
297 	int cierror, error;
298 
299 	/* Perform copyin before acquiring locks if needed. */
300 	if (uap->function == RTP_SET)
301 		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
302 	else
303 		cierror = 0;
304 
305 	if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
306 		p = td->td_proc;
307 		td1 = td;
308 		PROC_LOCK(p);
309 	} else {
310 		/* Only look up thread in current process */
311 		td1 = tdfind(uap->lwpid, curproc->p_pid);
312 		if (td1 == NULL)
313 			return (ESRCH);
314 		p = td1->td_proc;
315 	}
316 
317 	switch (uap->function) {
318 	case RTP_LOOKUP:
319 		if ((error = p_cansee(td, p)))
320 			break;
321 		pri_to_rtp(td1, &rtp);
322 		PROC_UNLOCK(p);
323 		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
324 	case RTP_SET:
325 		if ((error = p_cansched(td, p)) || (error = cierror))
326 			break;
327 
328 		/* Disallow setting rtprio in most cases if not superuser. */
329 
330 		/*
331 		 * Realtime priority has to be restricted for reasons which
332 		 * should be obvious.  However, for idleprio processes, there is
333 		 * a potential for system deadlock if an idleprio process gains
334 		 * a lock on a resource that other processes need (and the
335 		 * idleprio process can't run due to a CPU-bound normal
336 		 * process).  Fix me!  XXX
337 		 *
338 		 * This problem is not only related to idleprio process.
339 		 * A user level program can obtain a file lock and hold it
340 		 * indefinitely.  Additionally, without idleprio processes it is
341 		 * still conceivable that a program with low priority will never
342 		 * get to run.  In short, allowing this feature might make it
343 		 * easier to lock a resource indefinitely, but it is not the
344 		 * only thing that makes it possible.
345 		 */
346 		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
347 		    (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
348 		    unprivileged_idprio == 0)) {
349 			error = priv_check(td, PRIV_SCHED_RTPRIO);
350 			if (error)
351 				break;
352 		}
353 		error = rtp_to_pri(&rtp, td1);
354 		break;
355 	default:
356 		error = EINVAL;
357 		break;
358 	}
359 	PROC_UNLOCK(p);
360 	return (error);
361 }
362 
363 /*
364  * Set realtime priority.
365  */
366 #ifndef _SYS_SYSPROTO_H_
367 struct rtprio_args {
368 	int		function;
369 	pid_t		pid;
370 	struct rtprio	*rtp;
371 };
372 #endif
373 int
374 sys_rtprio(td, uap)
375 	struct thread *td;		/* curthread */
376 	register struct rtprio_args *uap;
377 {
378 	struct proc *p;
379 	struct thread *tdp;
380 	struct rtprio rtp;
381 	int cierror, error;
382 
383 	/* Perform copyin before acquiring locks if needed. */
384 	if (uap->function == RTP_SET)
385 		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
386 	else
387 		cierror = 0;
388 
389 	if (uap->pid == 0) {
390 		p = td->td_proc;
391 		PROC_LOCK(p);
392 	} else {
393 		p = pfind(uap->pid);
394 		if (p == NULL)
395 			return (ESRCH);
396 	}
397 
398 	switch (uap->function) {
399 	case RTP_LOOKUP:
400 		if ((error = p_cansee(td, p)))
401 			break;
402 		/*
403 		 * Return OUR priority if no pid specified,
404 		 * or if one is, report the highest priority
405 		 * in the process.  There isn't much more you can do as
406 		 * there is only room to return a single priority.
407 		 * Note: specifying our own pid is not the same
408 		 * as leaving it zero.
409 		 */
410 		if (uap->pid == 0) {
411 			pri_to_rtp(td, &rtp);
412 		} else {
413 			struct rtprio rtp2;
414 
415 			rtp.type = RTP_PRIO_IDLE;
416 			rtp.prio = RTP_PRIO_MAX;
417 			FOREACH_THREAD_IN_PROC(p, tdp) {
418 				pri_to_rtp(tdp, &rtp2);
419 				if (rtp2.type <  rtp.type ||
420 				    (rtp2.type == rtp.type &&
421 				    rtp2.prio < rtp.prio)) {
422 					rtp.type = rtp2.type;
423 					rtp.prio = rtp2.prio;
424 				}
425 			}
426 		}
427 		PROC_UNLOCK(p);
428 		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
429 	case RTP_SET:
430 		if ((error = p_cansched(td, p)) || (error = cierror))
431 			break;
432 
433 		/*
434 		 * Disallow setting rtprio in most cases if not superuser.
435 		 * See the comment in sys_rtprio_thread about idprio
436 		 * threads holding a lock.
437 		 */
438 		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
439 		    (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
440 		    !unprivileged_idprio)) {
441 			error = priv_check(td, PRIV_SCHED_RTPRIO);
442 			if (error)
443 				break;
444 		}
445 
446 		/*
447 		 * If we are setting our own priority, set just our
448 		 * thread but if we are doing another process,
449 		 * do all the threads on that process. If we
450 		 * specify our own pid we do the latter.
451 		 */
452 		if (uap->pid == 0) {
453 			error = rtp_to_pri(&rtp, td);
454 		} else {
455 			FOREACH_THREAD_IN_PROC(p, td) {
456 				if ((error = rtp_to_pri(&rtp, td)) != 0)
457 					break;
458 			}
459 		}
460 		break;
461 	default:
462 		error = EINVAL;
463 		break;
464 	}
465 	PROC_UNLOCK(p);
466 	return (error);
467 }
468 
469 int
470 rtp_to_pri(struct rtprio *rtp, struct thread *td)
471 {
472 	u_char  newpri, oldclass, oldpri;
473 
474 	switch (RTP_PRIO_BASE(rtp->type)) {
475 	case RTP_PRIO_REALTIME:
476 		if (rtp->prio > RTP_PRIO_MAX)
477 			return (EINVAL);
478 		newpri = PRI_MIN_REALTIME + rtp->prio;
479 		break;
480 	case RTP_PRIO_NORMAL:
481 		if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
482 			return (EINVAL);
483 		newpri = PRI_MIN_TIMESHARE + rtp->prio;
484 		break;
485 	case RTP_PRIO_IDLE:
486 		if (rtp->prio > RTP_PRIO_MAX)
487 			return (EINVAL);
488 		newpri = PRI_MIN_IDLE + rtp->prio;
489 		break;
490 	default:
491 		return (EINVAL);
492 	}
493 
494 	thread_lock(td);
495 	oldclass = td->td_pri_class;
496 	sched_class(td, rtp->type);	/* XXX fix */
497 	oldpri = td->td_user_pri;
498 	sched_user_prio(td, newpri);
499 	if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
500 	    td->td_pri_class != RTP_PRIO_NORMAL))
501 		sched_prio(td, td->td_user_pri);
502 	if (TD_ON_UPILOCK(td) && oldpri != newpri) {
503 		critical_enter();
504 		thread_unlock(td);
505 		umtx_pi_adjust(td, oldpri);
506 		critical_exit();
507 	} else
508 		thread_unlock(td);
509 	return (0);
510 }
511 
512 void
513 pri_to_rtp(struct thread *td, struct rtprio *rtp)
514 {
515 
516 	thread_lock(td);
517 	switch (PRI_BASE(td->td_pri_class)) {
518 	case PRI_REALTIME:
519 		rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
520 		break;
521 	case PRI_TIMESHARE:
522 		rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
523 		break;
524 	case PRI_IDLE:
525 		rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
526 		break;
527 	default:
528 		break;
529 	}
530 	rtp->type = td->td_pri_class;
531 	thread_unlock(td);
532 }
533 
534 #if defined(COMPAT_43)
535 #ifndef _SYS_SYSPROTO_H_
536 struct osetrlimit_args {
537 	u_int	which;
538 	struct	orlimit *rlp;
539 };
540 #endif
541 int
542 osetrlimit(td, uap)
543 	struct thread *td;
544 	register struct osetrlimit_args *uap;
545 {
546 	struct orlimit olim;
547 	struct rlimit lim;
548 	int error;
549 
550 	if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
551 		return (error);
552 	lim.rlim_cur = olim.rlim_cur;
553 	lim.rlim_max = olim.rlim_max;
554 	error = kern_setrlimit(td, uap->which, &lim);
555 	return (error);
556 }
557 
558 #ifndef _SYS_SYSPROTO_H_
559 struct ogetrlimit_args {
560 	u_int	which;
561 	struct	orlimit *rlp;
562 };
563 #endif
564 int
565 ogetrlimit(td, uap)
566 	struct thread *td;
567 	register struct ogetrlimit_args *uap;
568 {
569 	struct orlimit olim;
570 	struct rlimit rl;
571 	struct proc *p;
572 	int error;
573 
574 	if (uap->which >= RLIM_NLIMITS)
575 		return (EINVAL);
576 	p = td->td_proc;
577 	PROC_LOCK(p);
578 	lim_rlimit(p, uap->which, &rl);
579 	PROC_UNLOCK(p);
580 
581 	/*
582 	 * XXX would be more correct to convert only RLIM_INFINITY to the
583 	 * old RLIM_INFINITY and fail with EOVERFLOW for other larger
584 	 * values.  Most 64->32 and 32->16 conversions, including not
585 	 * unimportant ones of uids are even more broken than what we
586 	 * do here (they blindly truncate).  We don't do this correctly
587 	 * here since we have little experience with EOVERFLOW yet.
588 	 * Elsewhere, getuid() can't fail...
589 	 */
590 	olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
591 	olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
592 	error = copyout(&olim, uap->rlp, sizeof(olim));
593 	return (error);
594 }
595 #endif /* COMPAT_43 */
596 
597 #ifndef _SYS_SYSPROTO_H_
598 struct __setrlimit_args {
599 	u_int	which;
600 	struct	rlimit *rlp;
601 };
602 #endif
603 int
604 sys_setrlimit(td, uap)
605 	struct thread *td;
606 	register struct __setrlimit_args *uap;
607 {
608 	struct rlimit alim;
609 	int error;
610 
611 	if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
612 		return (error);
613 	error = kern_setrlimit(td, uap->which, &alim);
614 	return (error);
615 }
616 
617 static void
618 lim_cb(void *arg)
619 {
620 	struct rlimit rlim;
621 	struct thread *td;
622 	struct proc *p;
623 
624 	p = arg;
625 	PROC_LOCK_ASSERT(p, MA_OWNED);
626 	/*
627 	 * Check if the process exceeds its cpu resource allocation.  If
628 	 * it reaches the max, arrange to kill the process in ast().
629 	 */
630 	if (p->p_cpulimit == RLIM_INFINITY)
631 		return;
632 	PROC_SLOCK(p);
633 	FOREACH_THREAD_IN_PROC(p, td) {
634 		ruxagg(p, td);
635 	}
636 	PROC_SUNLOCK(p);
637 	if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
638 		lim_rlimit(p, RLIMIT_CPU, &rlim);
639 		if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
640 			killproc(p, "exceeded maximum CPU limit");
641 		} else {
642 			if (p->p_cpulimit < rlim.rlim_max)
643 				p->p_cpulimit += 5;
644 			kern_psignal(p, SIGXCPU);
645 		}
646 	}
647 	if ((p->p_flag & P_WEXIT) == 0)
648 		callout_reset_sbt(&p->p_limco, SBT_1S, 0,
649 		    lim_cb, p, C_PREL(1));
650 }
651 
652 int
653 kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
654 {
655 
656 	return (kern_proc_setrlimit(td, td->td_proc, which, limp));
657 }
658 
659 int
660 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
661     struct rlimit *limp)
662 {
663 	struct plimit *newlim, *oldlim;
664 	register struct rlimit *alimp;
665 	struct rlimit oldssiz;
666 	int error;
667 
668 	if (which >= RLIM_NLIMITS)
669 		return (EINVAL);
670 
671 	/*
672 	 * Preserve historical bugs by treating negative limits as unsigned.
673 	 */
674 	if (limp->rlim_cur < 0)
675 		limp->rlim_cur = RLIM_INFINITY;
676 	if (limp->rlim_max < 0)
677 		limp->rlim_max = RLIM_INFINITY;
678 
679 	oldssiz.rlim_cur = 0;
680 	newlim = lim_alloc();
681 	PROC_LOCK(p);
682 	oldlim = p->p_limit;
683 	alimp = &oldlim->pl_rlimit[which];
684 	if (limp->rlim_cur > alimp->rlim_max ||
685 	    limp->rlim_max > alimp->rlim_max)
686 		if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
687 			PROC_UNLOCK(p);
688 			lim_free(newlim);
689 			return (error);
690 		}
691 	if (limp->rlim_cur > limp->rlim_max)
692 		limp->rlim_cur = limp->rlim_max;
693 	lim_copy(newlim, oldlim);
694 	alimp = &newlim->pl_rlimit[which];
695 
696 	switch (which) {
697 
698 	case RLIMIT_CPU:
699 		if (limp->rlim_cur != RLIM_INFINITY &&
700 		    p->p_cpulimit == RLIM_INFINITY)
701 			callout_reset_sbt(&p->p_limco, SBT_1S, 0,
702 			    lim_cb, p, C_PREL(1));
703 		p->p_cpulimit = limp->rlim_cur;
704 		break;
705 	case RLIMIT_DATA:
706 		if (limp->rlim_cur > maxdsiz)
707 			limp->rlim_cur = maxdsiz;
708 		if (limp->rlim_max > maxdsiz)
709 			limp->rlim_max = maxdsiz;
710 		break;
711 
712 	case RLIMIT_STACK:
713 		if (limp->rlim_cur > maxssiz)
714 			limp->rlim_cur = maxssiz;
715 		if (limp->rlim_max > maxssiz)
716 			limp->rlim_max = maxssiz;
717 		oldssiz = *alimp;
718 		if (p->p_sysent->sv_fixlimit != NULL)
719 			p->p_sysent->sv_fixlimit(&oldssiz,
720 			    RLIMIT_STACK);
721 		break;
722 
723 	case RLIMIT_NOFILE:
724 		if (limp->rlim_cur > maxfilesperproc)
725 			limp->rlim_cur = maxfilesperproc;
726 		if (limp->rlim_max > maxfilesperproc)
727 			limp->rlim_max = maxfilesperproc;
728 		break;
729 
730 	case RLIMIT_NPROC:
731 		if (limp->rlim_cur > maxprocperuid)
732 			limp->rlim_cur = maxprocperuid;
733 		if (limp->rlim_max > maxprocperuid)
734 			limp->rlim_max = maxprocperuid;
735 		if (limp->rlim_cur < 1)
736 			limp->rlim_cur = 1;
737 		if (limp->rlim_max < 1)
738 			limp->rlim_max = 1;
739 		break;
740 	}
741 	if (p->p_sysent->sv_fixlimit != NULL)
742 		p->p_sysent->sv_fixlimit(limp, which);
743 	*alimp = *limp;
744 	p->p_limit = newlim;
745 	PROC_UNLOCK(p);
746 	lim_free(oldlim);
747 
748 	if (which == RLIMIT_STACK) {
749 		/*
750 		 * Stack is allocated to the max at exec time with only
751 		 * "rlim_cur" bytes accessible.  If stack limit is going
752 		 * up make more accessible, if going down make inaccessible.
753 		 */
754 		if (limp->rlim_cur != oldssiz.rlim_cur) {
755 			vm_offset_t addr;
756 			vm_size_t size;
757 			vm_prot_t prot;
758 
759 			if (limp->rlim_cur > oldssiz.rlim_cur) {
760 				prot = p->p_sysent->sv_stackprot;
761 				size = limp->rlim_cur - oldssiz.rlim_cur;
762 				addr = p->p_sysent->sv_usrstack -
763 				    limp->rlim_cur;
764 			} else {
765 				prot = VM_PROT_NONE;
766 				size = oldssiz.rlim_cur - limp->rlim_cur;
767 				addr = p->p_sysent->sv_usrstack -
768 				    oldssiz.rlim_cur;
769 			}
770 			addr = trunc_page(addr);
771 			size = round_page(size);
772 			(void)vm_map_protect(&p->p_vmspace->vm_map,
773 			    addr, addr + size, prot, FALSE);
774 		}
775 	}
776 
777 	return (0);
778 }
779 
780 #ifndef _SYS_SYSPROTO_H_
781 struct __getrlimit_args {
782 	u_int	which;
783 	struct	rlimit *rlp;
784 };
785 #endif
786 /* ARGSUSED */
787 int
788 sys_getrlimit(td, uap)
789 	struct thread *td;
790 	register struct __getrlimit_args *uap;
791 {
792 	struct rlimit rlim;
793 	struct proc *p;
794 	int error;
795 
796 	if (uap->which >= RLIM_NLIMITS)
797 		return (EINVAL);
798 	p = td->td_proc;
799 	PROC_LOCK(p);
800 	lim_rlimit(p, uap->which, &rlim);
801 	PROC_UNLOCK(p);
802 	error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
803 	return (error);
804 }
805 
806 /*
807  * Transform the running time and tick information for children of proc p
808  * into user and system time usage.
809  */
810 void
811 calccru(p, up, sp)
812 	struct proc *p;
813 	struct timeval *up;
814 	struct timeval *sp;
815 {
816 
817 	PROC_LOCK_ASSERT(p, MA_OWNED);
818 	calcru1(p, &p->p_crux, up, sp);
819 }
820 
821 /*
822  * Transform the running time and tick information in proc p into user
823  * and system time usage.  If appropriate, include the current time slice
824  * on this CPU.
825  */
826 void
827 calcru(struct proc *p, struct timeval *up, struct timeval *sp)
828 {
829 	struct thread *td;
830 	uint64_t runtime, u;
831 
832 	PROC_LOCK_ASSERT(p, MA_OWNED);
833 	PROC_SLOCK_ASSERT(p, MA_OWNED);
834 	/*
835 	 * If we are getting stats for the current process, then add in the
836 	 * stats that this thread has accumulated in its current time slice.
837 	 * We reset the thread and CPU state as if we had performed a context
838 	 * switch right here.
839 	 */
840 	td = curthread;
841 	if (td->td_proc == p) {
842 		u = cpu_ticks();
843 		runtime = u - PCPU_GET(switchtime);
844 		td->td_runtime += runtime;
845 		td->td_incruntime += runtime;
846 		PCPU_SET(switchtime, u);
847 	}
848 	/* Make sure the per-thread stats are current. */
849 	FOREACH_THREAD_IN_PROC(p, td) {
850 		if (td->td_incruntime == 0)
851 			continue;
852 		ruxagg(p, td);
853 	}
854 	calcru1(p, &p->p_rux, up, sp);
855 }
856 
857 /* Collect resource usage for a single thread. */
858 void
859 rufetchtd(struct thread *td, struct rusage *ru)
860 {
861 	struct proc *p;
862 	uint64_t runtime, u;
863 
864 	p = td->td_proc;
865 	PROC_SLOCK_ASSERT(p, MA_OWNED);
866 	THREAD_LOCK_ASSERT(td, MA_OWNED);
867 	/*
868 	 * If we are getting stats for the current thread, then add in the
869 	 * stats that this thread has accumulated in its current time slice.
870 	 * We reset the thread and CPU state as if we had performed a context
871 	 * switch right here.
872 	 */
873 	if (td == curthread) {
874 		u = cpu_ticks();
875 		runtime = u - PCPU_GET(switchtime);
876 		td->td_runtime += runtime;
877 		td->td_incruntime += runtime;
878 		PCPU_SET(switchtime, u);
879 	}
880 	ruxagg(p, td);
881 	*ru = td->td_ru;
882 	calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
883 }
884 
885 static void
886 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
887     struct timeval *sp)
888 {
889 	/* {user, system, interrupt, total} {ticks, usec}: */
890 	uint64_t ut, uu, st, su, it, tt, tu;
891 
892 	ut = ruxp->rux_uticks;
893 	st = ruxp->rux_sticks;
894 	it = ruxp->rux_iticks;
895 	tt = ut + st + it;
896 	if (tt == 0) {
897 		/* Avoid divide by zero */
898 		st = 1;
899 		tt = 1;
900 	}
901 	tu = cputick2usec(ruxp->rux_runtime);
902 	if ((int64_t)tu < 0) {
903 		/* XXX: this should be an assert /phk */
904 		printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
905 		    (intmax_t)tu, p->p_pid, p->p_comm);
906 		tu = ruxp->rux_tu;
907 	}
908 
909 	if (tu >= ruxp->rux_tu) {
910 		/*
911 		 * The normal case, time increased.
912 		 * Enforce monotonicity of bucketed numbers.
913 		 */
914 		uu = (tu * ut) / tt;
915 		if (uu < ruxp->rux_uu)
916 			uu = ruxp->rux_uu;
917 		su = (tu * st) / tt;
918 		if (su < ruxp->rux_su)
919 			su = ruxp->rux_su;
920 	} else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
921 		/*
922 		 * When we calibrate the cputicker, it is not uncommon to
923 		 * see the presumably fixed frequency increase slightly over
924 		 * time as a result of thermal stabilization and NTP
925 		 * discipline (of the reference clock).  We therefore ignore
926 		 * a bit of backwards slop because we  expect to catch up
927 		 * shortly.  We use a 3 microsecond limit to catch low
928 		 * counts and a 1% limit for high counts.
929 		 */
930 		uu = ruxp->rux_uu;
931 		su = ruxp->rux_su;
932 		tu = ruxp->rux_tu;
933 	} else { /* tu < ruxp->rux_tu */
934 		/*
935 		 * What happened here was likely that a laptop, which ran at
936 		 * a reduced clock frequency at boot, kicked into high gear.
937 		 * The wisdom of spamming this message in that case is
938 		 * dubious, but it might also be indicative of something
939 		 * serious, so lets keep it and hope laptops can be made
940 		 * more truthful about their CPU speed via ACPI.
941 		 */
942 		printf("calcru: runtime went backwards from %ju usec "
943 		    "to %ju usec for pid %d (%s)\n",
944 		    (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
945 		    p->p_pid, p->p_comm);
946 		uu = (tu * ut) / tt;
947 		su = (tu * st) / tt;
948 	}
949 
950 	ruxp->rux_uu = uu;
951 	ruxp->rux_su = su;
952 	ruxp->rux_tu = tu;
953 
954 	up->tv_sec = uu / 1000000;
955 	up->tv_usec = uu % 1000000;
956 	sp->tv_sec = su / 1000000;
957 	sp->tv_usec = su % 1000000;
958 }
959 
960 #ifndef _SYS_SYSPROTO_H_
961 struct getrusage_args {
962 	int	who;
963 	struct	rusage *rusage;
964 };
965 #endif
966 int
967 sys_getrusage(td, uap)
968 	register struct thread *td;
969 	register struct getrusage_args *uap;
970 {
971 	struct rusage ru;
972 	int error;
973 
974 	error = kern_getrusage(td, uap->who, &ru);
975 	if (error == 0)
976 		error = copyout(&ru, uap->rusage, sizeof(struct rusage));
977 	return (error);
978 }
979 
980 int
981 kern_getrusage(struct thread *td, int who, struct rusage *rup)
982 {
983 	struct proc *p;
984 	int error;
985 
986 	error = 0;
987 	p = td->td_proc;
988 	PROC_LOCK(p);
989 	switch (who) {
990 	case RUSAGE_SELF:
991 		rufetchcalc(p, rup, &rup->ru_utime,
992 		    &rup->ru_stime);
993 		break;
994 
995 	case RUSAGE_CHILDREN:
996 		*rup = p->p_stats->p_cru;
997 		calccru(p, &rup->ru_utime, &rup->ru_stime);
998 		break;
999 
1000 	case RUSAGE_THREAD:
1001 		PROC_SLOCK(p);
1002 		thread_lock(td);
1003 		rufetchtd(td, rup);
1004 		thread_unlock(td);
1005 		PROC_SUNLOCK(p);
1006 		break;
1007 
1008 	default:
1009 		error = EINVAL;
1010 	}
1011 	PROC_UNLOCK(p);
1012 	return (error);
1013 }
1014 
1015 void
1016 rucollect(struct rusage *ru, struct rusage *ru2)
1017 {
1018 	long *ip, *ip2;
1019 	int i;
1020 
1021 	if (ru->ru_maxrss < ru2->ru_maxrss)
1022 		ru->ru_maxrss = ru2->ru_maxrss;
1023 	ip = &ru->ru_first;
1024 	ip2 = &ru2->ru_first;
1025 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
1026 		*ip++ += *ip2++;
1027 }
1028 
1029 void
1030 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
1031     struct rusage_ext *rux2)
1032 {
1033 
1034 	rux->rux_runtime += rux2->rux_runtime;
1035 	rux->rux_uticks += rux2->rux_uticks;
1036 	rux->rux_sticks += rux2->rux_sticks;
1037 	rux->rux_iticks += rux2->rux_iticks;
1038 	rux->rux_uu += rux2->rux_uu;
1039 	rux->rux_su += rux2->rux_su;
1040 	rux->rux_tu += rux2->rux_tu;
1041 	rucollect(ru, ru2);
1042 }
1043 
1044 /*
1045  * Aggregate tick counts into the proc's rusage_ext.
1046  */
1047 static void
1048 ruxagg_locked(struct rusage_ext *rux, struct thread *td)
1049 {
1050 
1051 	THREAD_LOCK_ASSERT(td, MA_OWNED);
1052 	PROC_SLOCK_ASSERT(td->td_proc, MA_OWNED);
1053 	rux->rux_runtime += td->td_incruntime;
1054 	rux->rux_uticks += td->td_uticks;
1055 	rux->rux_sticks += td->td_sticks;
1056 	rux->rux_iticks += td->td_iticks;
1057 }
1058 
1059 void
1060 ruxagg(struct proc *p, struct thread *td)
1061 {
1062 
1063 	thread_lock(td);
1064 	ruxagg_locked(&p->p_rux, td);
1065 	ruxagg_locked(&td->td_rux, td);
1066 	td->td_incruntime = 0;
1067 	td->td_uticks = 0;
1068 	td->td_iticks = 0;
1069 	td->td_sticks = 0;
1070 	thread_unlock(td);
1071 }
1072 
1073 /*
1074  * Update the rusage_ext structure and fetch a valid aggregate rusage
1075  * for proc p if storage for one is supplied.
1076  */
1077 void
1078 rufetch(struct proc *p, struct rusage *ru)
1079 {
1080 	struct thread *td;
1081 
1082 	PROC_SLOCK_ASSERT(p, MA_OWNED);
1083 
1084 	*ru = p->p_ru;
1085 	if (p->p_numthreads > 0)  {
1086 		FOREACH_THREAD_IN_PROC(p, td) {
1087 			ruxagg(p, td);
1088 			rucollect(ru, &td->td_ru);
1089 		}
1090 	}
1091 }
1092 
1093 /*
1094  * Atomically perform a rufetch and a calcru together.
1095  * Consumers, can safely assume the calcru is executed only once
1096  * rufetch is completed.
1097  */
1098 void
1099 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
1100     struct timeval *sp)
1101 {
1102 
1103 	PROC_SLOCK(p);
1104 	rufetch(p, ru);
1105 	calcru(p, up, sp);
1106 	PROC_SUNLOCK(p);
1107 }
1108 
1109 /*
1110  * Allocate a new resource limits structure and initialize its
1111  * reference count and mutex pointer.
1112  */
1113 struct plimit *
1114 lim_alloc()
1115 {
1116 	struct plimit *limp;
1117 
1118 	limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
1119 	refcount_init(&limp->pl_refcnt, 1);
1120 	return (limp);
1121 }
1122 
1123 struct plimit *
1124 lim_hold(limp)
1125 	struct plimit *limp;
1126 {
1127 
1128 	refcount_acquire(&limp->pl_refcnt);
1129 	return (limp);
1130 }
1131 
1132 void
1133 lim_fork(struct proc *p1, struct proc *p2)
1134 {
1135 
1136 	PROC_LOCK_ASSERT(p1, MA_OWNED);
1137 	PROC_LOCK_ASSERT(p2, MA_OWNED);
1138 
1139 	p2->p_limit = lim_hold(p1->p_limit);
1140 	callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
1141 	if (p1->p_cpulimit != RLIM_INFINITY)
1142 		callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
1143 		    lim_cb, p2, C_PREL(1));
1144 }
1145 
1146 void
1147 lim_free(limp)
1148 	struct plimit *limp;
1149 {
1150 
1151 	KASSERT(limp->pl_refcnt > 0, ("plimit refcnt underflow"));
1152 	if (refcount_release(&limp->pl_refcnt))
1153 		free((void *)limp, M_PLIMIT);
1154 }
1155 
1156 /*
1157  * Make a copy of the plimit structure.
1158  * We share these structures copy-on-write after fork.
1159  */
1160 void
1161 lim_copy(dst, src)
1162 	struct plimit *dst, *src;
1163 {
1164 
1165 	KASSERT(dst->pl_refcnt == 1, ("lim_copy to shared limit"));
1166 	bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
1167 }
1168 
1169 /*
1170  * Return the hard limit for a particular system resource.  The
1171  * which parameter specifies the index into the rlimit array.
1172  */
1173 rlim_t
1174 lim_max(struct proc *p, int which)
1175 {
1176 	struct rlimit rl;
1177 
1178 	lim_rlimit(p, which, &rl);
1179 	return (rl.rlim_max);
1180 }
1181 
1182 /*
1183  * Return the current (soft) limit for a particular system resource.
1184  * The which parameter which specifies the index into the rlimit array
1185  */
1186 rlim_t
1187 lim_cur(struct proc *p, int which)
1188 {
1189 	struct rlimit rl;
1190 
1191 	lim_rlimit(p, which, &rl);
1192 	return (rl.rlim_cur);
1193 }
1194 
1195 /*
1196  * Return a copy of the entire rlimit structure for the system limit
1197  * specified by 'which' in the rlimit structure pointed to by 'rlp'.
1198  */
1199 void
1200 lim_rlimit(struct proc *p, int which, struct rlimit *rlp)
1201 {
1202 
1203 	PROC_LOCK_ASSERT(p, MA_OWNED);
1204 	KASSERT(which >= 0 && which < RLIM_NLIMITS,
1205 	    ("request for invalid resource limit"));
1206 	*rlp = p->p_limit->pl_rlimit[which];
1207 	if (p->p_sysent->sv_fixlimit != NULL)
1208 		p->p_sysent->sv_fixlimit(rlp, which);
1209 }
1210 
1211 void
1212 uihashinit()
1213 {
1214 
1215 	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
1216 	rw_init(&uihashtbl_lock, "uidinfo hash");
1217 }
1218 
1219 /*
1220  * Look up a uidinfo struct for the parameter uid.
1221  * uihashtbl_lock must be locked.
1222  */
1223 static struct uidinfo *
1224 uilookup(uid)
1225 	uid_t uid;
1226 {
1227 	struct uihashhead *uipp;
1228 	struct uidinfo *uip;
1229 
1230 	rw_assert(&uihashtbl_lock, RA_LOCKED);
1231 	uipp = UIHASH(uid);
1232 	LIST_FOREACH(uip, uipp, ui_hash)
1233 		if (uip->ui_uid == uid)
1234 			break;
1235 
1236 	return (uip);
1237 }
1238 
1239 /*
1240  * Find or allocate a struct uidinfo for a particular uid.
1241  * Increase refcount on uidinfo struct returned.
1242  * uifree() should be called on a struct uidinfo when released.
1243  */
1244 struct uidinfo *
1245 uifind(uid)
1246 	uid_t uid;
1247 {
1248 	struct uidinfo *old_uip, *uip;
1249 
1250 	rw_rlock(&uihashtbl_lock);
1251 	uip = uilookup(uid);
1252 	if (uip == NULL) {
1253 		rw_runlock(&uihashtbl_lock);
1254 		uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
1255 		racct_create(&uip->ui_racct);
1256 		rw_wlock(&uihashtbl_lock);
1257 		/*
1258 		 * There's a chance someone created our uidinfo while we
1259 		 * were in malloc and not holding the lock, so we have to
1260 		 * make sure we don't insert a duplicate uidinfo.
1261 		 */
1262 		if ((old_uip = uilookup(uid)) != NULL) {
1263 			/* Someone else beat us to it. */
1264 			racct_destroy(&uip->ui_racct);
1265 			free(uip, M_UIDINFO);
1266 			uip = old_uip;
1267 		} else {
1268 			refcount_init(&uip->ui_ref, 0);
1269 			uip->ui_uid = uid;
1270 			mtx_init(&uip->ui_vmsize_mtx, "ui_vmsize", NULL,
1271 			    MTX_DEF);
1272 			LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
1273 		}
1274 	}
1275 	uihold(uip);
1276 	rw_unlock(&uihashtbl_lock);
1277 	return (uip);
1278 }
1279 
1280 /*
1281  * Place another refcount on a uidinfo struct.
1282  */
1283 void
1284 uihold(uip)
1285 	struct uidinfo *uip;
1286 {
1287 
1288 	refcount_acquire(&uip->ui_ref);
1289 }
1290 
1291 /*-
1292  * Since uidinfo structs have a long lifetime, we use an
1293  * opportunistic refcounting scheme to avoid locking the lookup hash
1294  * for each release.
1295  *
1296  * If the refcount hits 0, we need to free the structure,
1297  * which means we need to lock the hash.
1298  * Optimal case:
1299  *   After locking the struct and lowering the refcount, if we find
1300  *   that we don't need to free, simply unlock and return.
1301  * Suboptimal case:
1302  *   If refcount lowering results in need to free, bump the count
1303  *   back up, lose the lock and acquire the locks in the proper
1304  *   order to try again.
1305  */
1306 void
1307 uifree(uip)
1308 	struct uidinfo *uip;
1309 {
1310 	int old;
1311 
1312 	/* Prepare for optimal case. */
1313 	old = uip->ui_ref;
1314 	if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1))
1315 		return;
1316 
1317 	/* Prepare for suboptimal case. */
1318 	rw_wlock(&uihashtbl_lock);
1319 	if (refcount_release(&uip->ui_ref)) {
1320 		racct_destroy(&uip->ui_racct);
1321 		LIST_REMOVE(uip, ui_hash);
1322 		rw_wunlock(&uihashtbl_lock);
1323 		if (uip->ui_sbsize != 0)
1324 			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
1325 			    uip->ui_uid, uip->ui_sbsize);
1326 		if (uip->ui_proccnt != 0)
1327 			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
1328 			    uip->ui_uid, uip->ui_proccnt);
1329 		if (uip->ui_vmsize != 0)
1330 			printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
1331 			    uip->ui_uid, (unsigned long long)uip->ui_vmsize);
1332 		mtx_destroy(&uip->ui_vmsize_mtx);
1333 		free(uip, M_UIDINFO);
1334 		return;
1335 	}
1336 	/*
1337 	 * Someone added a reference between atomic_cmpset_int() and
1338 	 * rw_wlock(&uihashtbl_lock).
1339 	 */
1340 	rw_wunlock(&uihashtbl_lock);
1341 }
1342 
1343 void
1344 ui_racct_foreach(void (*callback)(struct racct *racct,
1345     void *arg2, void *arg3), void *arg2, void *arg3)
1346 {
1347 	struct uidinfo *uip;
1348 	struct uihashhead *uih;
1349 
1350 	rw_rlock(&uihashtbl_lock);
1351 	for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
1352 		LIST_FOREACH(uip, uih, ui_hash) {
1353 			(callback)(uip->ui_racct, arg2, arg3);
1354 		}
1355 	}
1356 	rw_runlock(&uihashtbl_lock);
1357 }
1358 
1359 /*
1360  * Change the count associated with number of processes
1361  * a given user is using.  When 'max' is 0, don't enforce a limit
1362  */
1363 int
1364 chgproccnt(uip, diff, max)
1365 	struct	uidinfo	*uip;
1366 	int	diff;
1367 	rlim_t	max;
1368 {
1369 
1370 	/* Don't allow them to exceed max, but allow subtraction. */
1371 	if (diff > 0 && max != 0) {
1372 		if (atomic_fetchadd_long(&uip->ui_proccnt, (long)diff) + diff > max) {
1373 			atomic_subtract_long(&uip->ui_proccnt, (long)diff);
1374 			return (0);
1375 		}
1376 	} else {
1377 		atomic_add_long(&uip->ui_proccnt, (long)diff);
1378 		if (uip->ui_proccnt < 0)
1379 			printf("negative proccnt for uid = %d\n", uip->ui_uid);
1380 	}
1381 	return (1);
1382 }
1383 
1384 /*
1385  * Change the total socket buffer size a user has used.
1386  */
1387 int
1388 chgsbsize(uip, hiwat, to, max)
1389 	struct	uidinfo	*uip;
1390 	u_int  *hiwat;
1391 	u_int	to;
1392 	rlim_t	max;
1393 {
1394 	int diff;
1395 
1396 	diff = to - *hiwat;
1397 	if (diff > 0) {
1398 		if (atomic_fetchadd_long(&uip->ui_sbsize, (long)diff) + diff > max) {
1399 			atomic_subtract_long(&uip->ui_sbsize, (long)diff);
1400 			return (0);
1401 		}
1402 	} else {
1403 		atomic_add_long(&uip->ui_sbsize, (long)diff);
1404 		if (uip->ui_sbsize < 0)
1405 			printf("negative sbsize for uid = %d\n", uip->ui_uid);
1406 	}
1407 	*hiwat = to;
1408 	return (1);
1409 }
1410 
1411 /*
1412  * Change the count associated with number of pseudo-terminals
1413  * a given user is using.  When 'max' is 0, don't enforce a limit
1414  */
1415 int
1416 chgptscnt(uip, diff, max)
1417 	struct	uidinfo	*uip;
1418 	int	diff;
1419 	rlim_t	max;
1420 {
1421 
1422 	/* Don't allow them to exceed max, but allow subtraction. */
1423 	if (diff > 0 && max != 0) {
1424 		if (atomic_fetchadd_long(&uip->ui_ptscnt, (long)diff) + diff > max) {
1425 			atomic_subtract_long(&uip->ui_ptscnt, (long)diff);
1426 			return (0);
1427 		}
1428 	} else {
1429 		atomic_add_long(&uip->ui_ptscnt, (long)diff);
1430 		if (uip->ui_ptscnt < 0)
1431 			printf("negative ptscnt for uid = %d\n", uip->ui_uid);
1432 	}
1433 	return (1);
1434 }
1435