1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/sysproto.h>
40#include <sys/file.h>
41#include <sys/kernel.h>
42#include <sys/lock.h>
43#include <sys/malloc.h>
44#include <sys/mutex.h>
45#include <sys/priv.h>
46#include <sys/proc.h>
47#include <sys/refcount.h>
48#include <sys/racct.h>
49#include <sys/resourcevar.h>
50#include <sys/rwlock.h>
51#include <sys/sched.h>
52#include <sys/sx.h>
53#include <sys/syscallsubr.h>
54#include <sys/sysctl.h>
55#include <sys/sysent.h>
56#include <sys/time.h>
57#include <sys/umtxvar.h>
58
59#include <vm/vm.h>
60#include <vm/vm_param.h>
61#include <vm/pmap.h>
62#include <vm/vm_map.h>
63
64static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
65static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
66#define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
67static struct rwlock uihashtbl_lock;
68static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
69static u_long uihash;		/* size of hash table - 1 */
70
71static void	calcru1(struct proc *p, struct rusage_ext *ruxp,
72		    struct timeval *up, struct timeval *sp);
73static int	donice(struct thread *td, struct proc *chgp, int n);
74static struct uidinfo *uilookup(uid_t uid);
75static void	ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td);
76
77/*
78 * Resource controls and accounting.
79 */
80#ifndef _SYS_SYSPROTO_H_
81struct getpriority_args {
82	int	which;
83	int	who;
84};
85#endif
86int
87sys_getpriority(struct thread *td, struct getpriority_args *uap)
88{
89
90	return (kern_getpriority(td, uap->which, uap->who));
91}
92
93int
94kern_getpriority(struct thread *td, int which, int who)
95{
96	struct proc *p;
97	struct pgrp *pg;
98	int error, low;
99
100	error = 0;
101	low = PRIO_MAX + 1;
102	switch (which) {
103	case PRIO_PROCESS:
104		if (who == 0)
105			low = td->td_proc->p_nice;
106		else {
107			p = pfind(who);
108			if (p == NULL)
109				break;
110			if (p_cansee(td, p) == 0)
111				low = p->p_nice;
112			PROC_UNLOCK(p);
113		}
114		break;
115
116	case PRIO_PGRP:
117		sx_slock(&proctree_lock);
118		if (who == 0) {
119			pg = td->td_proc->p_pgrp;
120			PGRP_LOCK(pg);
121		} else {
122			pg = pgfind(who);
123			if (pg == NULL) {
124				sx_sunlock(&proctree_lock);
125				break;
126			}
127		}
128		sx_sunlock(&proctree_lock);
129		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
130			PROC_LOCK(p);
131			if (p->p_state == PRS_NORMAL &&
132			    p_cansee(td, p) == 0) {
133				if (p->p_nice < low)
134					low = p->p_nice;
135			}
136			PROC_UNLOCK(p);
137		}
138		PGRP_UNLOCK(pg);
139		break;
140
141	case PRIO_USER:
142		if (who == 0)
143			who = td->td_ucred->cr_uid;
144		sx_slock(&allproc_lock);
145		FOREACH_PROC_IN_SYSTEM(p) {
146			PROC_LOCK(p);
147			if (p->p_state == PRS_NORMAL &&
148			    p_cansee(td, p) == 0 &&
149			    p->p_ucred->cr_uid == who) {
150				if (p->p_nice < low)
151					low = p->p_nice;
152			}
153			PROC_UNLOCK(p);
154		}
155		sx_sunlock(&allproc_lock);
156		break;
157
158	default:
159		error = EINVAL;
160		break;
161	}
162	if (low == PRIO_MAX + 1 && error == 0)
163		error = ESRCH;
164	td->td_retval[0] = low;
165	return (error);
166}
167
168#ifndef _SYS_SYSPROTO_H_
169struct setpriority_args {
170	int	which;
171	int	who;
172	int	prio;
173};
174#endif
175int
176sys_setpriority(struct thread *td, struct setpriority_args *uap)
177{
178
179	return (kern_setpriority(td, uap->which, uap->who, uap->prio));
180}
181
182int
183kern_setpriority(struct thread *td, int which, int who, int prio)
184{
185	struct proc *curp, *p;
186	struct pgrp *pg;
187	int found = 0, error = 0;
188
189	curp = td->td_proc;
190	switch (which) {
191	case PRIO_PROCESS:
192		if (who == 0) {
193			PROC_LOCK(curp);
194			error = donice(td, curp, prio);
195			PROC_UNLOCK(curp);
196		} else {
197			p = pfind(who);
198			if (p == NULL)
199				break;
200			error = p_cansee(td, p);
201			if (error == 0)
202				error = donice(td, p, prio);
203			PROC_UNLOCK(p);
204		}
205		found++;
206		break;
207
208	case PRIO_PGRP:
209		sx_slock(&proctree_lock);
210		if (who == 0) {
211			pg = curp->p_pgrp;
212			PGRP_LOCK(pg);
213		} else {
214			pg = pgfind(who);
215			if (pg == NULL) {
216				sx_sunlock(&proctree_lock);
217				break;
218			}
219		}
220		sx_sunlock(&proctree_lock);
221		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
222			PROC_LOCK(p);
223			if (p->p_state == PRS_NORMAL &&
224			    p_cansee(td, p) == 0) {
225				error = donice(td, p, prio);
226				found++;
227			}
228			PROC_UNLOCK(p);
229		}
230		PGRP_UNLOCK(pg);
231		break;
232
233	case PRIO_USER:
234		if (who == 0)
235			who = td->td_ucred->cr_uid;
236		sx_slock(&allproc_lock);
237		FOREACH_PROC_IN_SYSTEM(p) {
238			PROC_LOCK(p);
239			if (p->p_state == PRS_NORMAL &&
240			    p->p_ucred->cr_uid == who &&
241			    p_cansee(td, p) == 0) {
242				error = donice(td, p, prio);
243				found++;
244			}
245			PROC_UNLOCK(p);
246		}
247		sx_sunlock(&allproc_lock);
248		break;
249
250	default:
251		error = EINVAL;
252		break;
253	}
254	if (found == 0 && error == 0)
255		error = ESRCH;
256	return (error);
257}
258
259/*
260 * Set "nice" for a (whole) process.
261 */
262static int
263donice(struct thread *td, struct proc *p, int n)
264{
265	int error;
266
267	PROC_LOCK_ASSERT(p, MA_OWNED);
268	if ((error = p_cansched(td, p)))
269		return (error);
270	if (n > PRIO_MAX)
271		n = PRIO_MAX;
272	if (n < PRIO_MIN)
273		n = PRIO_MIN;
274	if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
275		return (EACCES);
276	sched_nice(p, n);
277	return (0);
278}
279
280static int unprivileged_idprio;
281SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
282    &unprivileged_idprio, 0,
283    "Allow non-root users to set an idle priority (deprecated)");
284
285/*
286 * Set realtime priority for LWP.
287 */
288#ifndef _SYS_SYSPROTO_H_
289struct rtprio_thread_args {
290	int		function;
291	lwpid_t		lwpid;
292	struct rtprio	*rtp;
293};
294#endif
295int
296sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
297{
298	struct proc *p;
299	struct rtprio rtp;
300	struct thread *td1;
301	int cierror, error;
302
303	/* Perform copyin before acquiring locks if needed. */
304	if (uap->function == RTP_SET)
305		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
306	else
307		cierror = 0;
308
309	if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
310		p = td->td_proc;
311		td1 = td;
312		PROC_LOCK(p);
313	} else {
314		td1 = tdfind(uap->lwpid, -1);
315		if (td1 == NULL)
316			return (ESRCH);
317		p = td1->td_proc;
318	}
319
320	switch (uap->function) {
321	case RTP_LOOKUP:
322		if ((error = p_cansee(td, p)))
323			break;
324		pri_to_rtp(td1, &rtp);
325		PROC_UNLOCK(p);
326		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
327	case RTP_SET:
328		if ((error = p_cansched(td, p)) || (error = cierror))
329			break;
330
331		/* Disallow setting rtprio in most cases if not superuser. */
332
333		/*
334		 * Realtime priority has to be restricted for reasons which
335		 * should be obvious.  However, for idleprio processes, there is
336		 * a potential for system deadlock if an idleprio process gains
337		 * a lock on a resource that other processes need (and the
338		 * idleprio process can't run due to a CPU-bound normal
339		 * process).  Fix me!  XXX
340		 *
341		 * This problem is not only related to idleprio process.
342		 * A user level program can obtain a file lock and hold it
343		 * indefinitely.  Additionally, without idleprio processes it is
344		 * still conceivable that a program with low priority will never
345		 * get to run.  In short, allowing this feature might make it
346		 * easier to lock a resource indefinitely, but it is not the
347		 * only thing that makes it possible.
348		 */
349		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME &&
350		    (error = priv_check(td, PRIV_SCHED_RTPRIO)) != 0)
351			break;
352		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
353		    unprivileged_idprio == 0 &&
354		    (error = priv_check(td, PRIV_SCHED_IDPRIO)) != 0)
355			break;
356		error = rtp_to_pri(&rtp, td1);
357		break;
358	default:
359		error = EINVAL;
360		break;
361	}
362	PROC_UNLOCK(p);
363	return (error);
364}
365
366/*
367 * Set realtime priority.
368 */
369#ifndef _SYS_SYSPROTO_H_
370struct rtprio_args {
371	int		function;
372	pid_t		pid;
373	struct rtprio	*rtp;
374};
375#endif
376int
377sys_rtprio(struct thread *td, struct rtprio_args *uap)
378{
379	struct proc *p;
380	struct thread *tdp;
381	struct rtprio rtp;
382	int cierror, error;
383
384	/* Perform copyin before acquiring locks if needed. */
385	if (uap->function == RTP_SET)
386		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
387	else
388		cierror = 0;
389
390	if (uap->pid == 0) {
391		p = td->td_proc;
392		PROC_LOCK(p);
393	} else {
394		p = pfind(uap->pid);
395		if (p == NULL)
396			return (ESRCH);
397	}
398
399	switch (uap->function) {
400	case RTP_LOOKUP:
401		if ((error = p_cansee(td, p)))
402			break;
403		/*
404		 * Return OUR priority if no pid specified,
405		 * or if one is, report the highest priority
406		 * in the process.  There isn't much more you can do as
407		 * there is only room to return a single priority.
408		 * Note: specifying our own pid is not the same
409		 * as leaving it zero.
410		 */
411		if (uap->pid == 0) {
412			pri_to_rtp(td, &rtp);
413		} else {
414			struct rtprio rtp2;
415
416			rtp.type = RTP_PRIO_IDLE;
417			rtp.prio = RTP_PRIO_MAX;
418			FOREACH_THREAD_IN_PROC(p, tdp) {
419				pri_to_rtp(tdp, &rtp2);
420				if (rtp2.type <  rtp.type ||
421				    (rtp2.type == rtp.type &&
422				    rtp2.prio < rtp.prio)) {
423					rtp.type = rtp2.type;
424					rtp.prio = rtp2.prio;
425				}
426			}
427		}
428		PROC_UNLOCK(p);
429		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
430	case RTP_SET:
431		if ((error = p_cansched(td, p)) || (error = cierror))
432			break;
433
434		/*
435		 * Disallow setting rtprio in most cases if not superuser.
436		 * See the comment in sys_rtprio_thread about idprio
437		 * threads holding a lock.
438		 */
439		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME &&
440		    (error = priv_check(td, PRIV_SCHED_RTPRIO)) != 0)
441			break;
442		if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
443		    unprivileged_idprio == 0 &&
444		    (error = priv_check(td, PRIV_SCHED_IDPRIO)) != 0)
445			break;
446
447		/*
448		 * If we are setting our own priority, set just our
449		 * thread but if we are doing another process,
450		 * do all the threads on that process. If we
451		 * specify our own pid we do the latter.
452		 */
453		if (uap->pid == 0) {
454			error = rtp_to_pri(&rtp, td);
455		} else {
456			FOREACH_THREAD_IN_PROC(p, td) {
457				if ((error = rtp_to_pri(&rtp, td)) != 0)
458					break;
459			}
460		}
461		break;
462	default:
463		error = EINVAL;
464		break;
465	}
466	PROC_UNLOCK(p);
467	return (error);
468}
469
470int
471rtp_to_pri(struct rtprio *rtp, struct thread *td)
472{
473	u_char  newpri, oldclass, oldpri;
474
475	switch (RTP_PRIO_BASE(rtp->type)) {
476	case RTP_PRIO_REALTIME:
477		if (rtp->prio > RTP_PRIO_MAX)
478			return (EINVAL);
479		newpri = PRI_MIN_REALTIME + rtp->prio;
480		break;
481	case RTP_PRIO_NORMAL:
482		if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
483			return (EINVAL);
484		newpri = PRI_MIN_TIMESHARE + rtp->prio;
485		break;
486	case RTP_PRIO_IDLE:
487		if (rtp->prio > RTP_PRIO_MAX)
488			return (EINVAL);
489		newpri = PRI_MIN_IDLE + rtp->prio;
490		break;
491	default:
492		return (EINVAL);
493	}
494
495	thread_lock(td);
496	oldclass = td->td_pri_class;
497	sched_class(td, rtp->type);	/* XXX fix */
498	oldpri = td->td_user_pri;
499	sched_user_prio(td, newpri);
500	if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
501	    td->td_pri_class != RTP_PRIO_NORMAL))
502		sched_prio(td, td->td_user_pri);
503	if (TD_ON_UPILOCK(td) && oldpri != newpri) {
504		critical_enter();
505		thread_unlock(td);
506		umtx_pi_adjust(td, oldpri);
507		critical_exit();
508	} else
509		thread_unlock(td);
510	return (0);
511}
512
513void
514pri_to_rtp(struct thread *td, struct rtprio *rtp)
515{
516
517	thread_lock(td);
518	switch (PRI_BASE(td->td_pri_class)) {
519	case PRI_REALTIME:
520		rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
521		break;
522	case PRI_TIMESHARE:
523		rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
524		break;
525	case PRI_IDLE:
526		rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
527		break;
528	default:
529		break;
530	}
531	rtp->type = td->td_pri_class;
532	thread_unlock(td);
533}
534
535#if defined(COMPAT_43)
536#ifndef _SYS_SYSPROTO_H_
537struct osetrlimit_args {
538	u_int	which;
539	struct	orlimit *rlp;
540};
541#endif
542int
543osetrlimit(struct thread *td, struct osetrlimit_args *uap)
544{
545	struct orlimit olim;
546	struct rlimit lim;
547	int error;
548
549	if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
550		return (error);
551	lim.rlim_cur = olim.rlim_cur;
552	lim.rlim_max = olim.rlim_max;
553	error = kern_setrlimit(td, uap->which, &lim);
554	return (error);
555}
556
557#ifndef _SYS_SYSPROTO_H_
558struct ogetrlimit_args {
559	u_int	which;
560	struct	orlimit *rlp;
561};
562#endif
563int
564ogetrlimit(struct thread *td, struct ogetrlimit_args *uap)
565{
566	struct orlimit olim;
567	struct rlimit rl;
568	int error;
569
570	if (uap->which >= RLIM_NLIMITS)
571		return (EINVAL);
572	lim_rlimit(td, uap->which, &rl);
573
574	/*
575	 * XXX would be more correct to convert only RLIM_INFINITY to the
576	 * old RLIM_INFINITY and fail with EOVERFLOW for other larger
577	 * values.  Most 64->32 and 32->16 conversions, including not
578	 * unimportant ones of uids are even more broken than what we
579	 * do here (they blindly truncate).  We don't do this correctly
580	 * here since we have little experience with EOVERFLOW yet.
581	 * Elsewhere, getuid() can't fail...
582	 */
583	olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
584	olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
585	error = copyout(&olim, uap->rlp, sizeof(olim));
586	return (error);
587}
588#endif /* COMPAT_43 */
589
590#ifndef _SYS_SYSPROTO_H_
591struct setrlimit_args {
592	u_int	which;
593	struct	rlimit *rlp;
594};
595#endif
596int
597sys_setrlimit(struct thread *td, struct setrlimit_args *uap)
598{
599	struct rlimit alim;
600	int error;
601
602	if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
603		return (error);
604	error = kern_setrlimit(td, uap->which, &alim);
605	return (error);
606}
607
608static void
609lim_cb(void *arg)
610{
611	struct rlimit rlim;
612	struct thread *td;
613	struct proc *p;
614
615	p = arg;
616	PROC_LOCK_ASSERT(p, MA_OWNED);
617	/*
618	 * Check if the process exceeds its cpu resource allocation.  If
619	 * it reaches the max, arrange to kill the process in ast().
620	 */
621	if (p->p_cpulimit == RLIM_INFINITY)
622		return;
623	PROC_STATLOCK(p);
624	FOREACH_THREAD_IN_PROC(p, td) {
625		ruxagg(p, td);
626	}
627	PROC_STATUNLOCK(p);
628	if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
629		lim_rlimit_proc(p, RLIMIT_CPU, &rlim);
630		if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
631			killproc(p, "exceeded maximum CPU limit");
632		} else {
633			if (p->p_cpulimit < rlim.rlim_max)
634				p->p_cpulimit += 5;
635			kern_psignal(p, SIGXCPU);
636		}
637	}
638	if ((p->p_flag & P_WEXIT) == 0)
639		callout_reset_sbt(&p->p_limco, SBT_1S, 0,
640		    lim_cb, p, C_PREL(1));
641}
642
643int
644kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
645{
646
647	return (kern_proc_setrlimit(td, td->td_proc, which, limp));
648}
649
650int
651kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
652    struct rlimit *limp)
653{
654	struct plimit *newlim, *oldlim, *oldlim_td;
655	struct rlimit *alimp;
656	struct rlimit oldssiz;
657	int error;
658
659	if (which >= RLIM_NLIMITS)
660		return (EINVAL);
661
662	/*
663	 * Preserve historical bugs by treating negative limits as unsigned.
664	 */
665	if (limp->rlim_cur < 0)
666		limp->rlim_cur = RLIM_INFINITY;
667	if (limp->rlim_max < 0)
668		limp->rlim_max = RLIM_INFINITY;
669
670	oldssiz.rlim_cur = 0;
671	newlim = lim_alloc();
672	PROC_LOCK(p);
673	oldlim = p->p_limit;
674	alimp = &oldlim->pl_rlimit[which];
675	if (limp->rlim_cur > alimp->rlim_max ||
676	    limp->rlim_max > alimp->rlim_max)
677		if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
678			PROC_UNLOCK(p);
679			lim_free(newlim);
680			return (error);
681		}
682	if (limp->rlim_cur > limp->rlim_max)
683		limp->rlim_cur = limp->rlim_max;
684	lim_copy(newlim, oldlim);
685	alimp = &newlim->pl_rlimit[which];
686
687	switch (which) {
688	case RLIMIT_CPU:
689		if (limp->rlim_cur != RLIM_INFINITY &&
690		    p->p_cpulimit == RLIM_INFINITY)
691			callout_reset_sbt(&p->p_limco, SBT_1S, 0,
692			    lim_cb, p, C_PREL(1));
693		p->p_cpulimit = limp->rlim_cur;
694		break;
695	case RLIMIT_DATA:
696		if (limp->rlim_cur > maxdsiz)
697			limp->rlim_cur = maxdsiz;
698		if (limp->rlim_max > maxdsiz)
699			limp->rlim_max = maxdsiz;
700		break;
701
702	case RLIMIT_STACK:
703		if (limp->rlim_cur > maxssiz)
704			limp->rlim_cur = maxssiz;
705		if (limp->rlim_max > maxssiz)
706			limp->rlim_max = maxssiz;
707		oldssiz = *alimp;
708		if (p->p_sysent->sv_fixlimit != NULL)
709			p->p_sysent->sv_fixlimit(&oldssiz,
710			    RLIMIT_STACK);
711		break;
712
713	case RLIMIT_NOFILE:
714		if (limp->rlim_cur > maxfilesperproc)
715			limp->rlim_cur = maxfilesperproc;
716		if (limp->rlim_max > maxfilesperproc)
717			limp->rlim_max = maxfilesperproc;
718		break;
719
720	case RLIMIT_NPROC:
721		if (limp->rlim_cur > maxprocperuid)
722			limp->rlim_cur = maxprocperuid;
723		if (limp->rlim_max > maxprocperuid)
724			limp->rlim_max = maxprocperuid;
725		if (limp->rlim_cur < 1)
726			limp->rlim_cur = 1;
727		if (limp->rlim_max < 1)
728			limp->rlim_max = 1;
729		break;
730	}
731	if (p->p_sysent->sv_fixlimit != NULL)
732		p->p_sysent->sv_fixlimit(limp, which);
733	*alimp = *limp;
734	p->p_limit = newlim;
735	PROC_UPDATE_COW(p);
736	oldlim_td = NULL;
737	if (td == curthread && PROC_COW_CHANGECOUNT(td, p) == 1) {
738		oldlim_td = lim_cowsync();
739		thread_cow_synced(td);
740	}
741	PROC_UNLOCK(p);
742	if (oldlim_td != NULL) {
743		MPASS(oldlim_td == oldlim);
744		lim_freen(oldlim, 2);
745	} else {
746		lim_free(oldlim);
747	}
748
749	if (which == RLIMIT_STACK &&
750	    /*
751	     * Skip calls from exec_new_vmspace(), done when stack is
752	     * not mapped yet.
753	     */
754	    (td != curthread || (p->p_flag & P_INEXEC) == 0)) {
755		/*
756		 * Stack is allocated to the max at exec time with only
757		 * "rlim_cur" bytes accessible.  If stack limit is going
758		 * up make more accessible, if going down make inaccessible.
759		 */
760		if (limp->rlim_cur != oldssiz.rlim_cur) {
761			vm_offset_t addr;
762			vm_size_t size;
763			vm_prot_t prot;
764
765			if (limp->rlim_cur > oldssiz.rlim_cur) {
766				prot = p->p_sysent->sv_stackprot;
767				size = limp->rlim_cur - oldssiz.rlim_cur;
768				addr = round_page(p->p_vmspace->vm_stacktop) -
769				    limp->rlim_cur;
770			} else {
771				prot = VM_PROT_NONE;
772				size = oldssiz.rlim_cur - limp->rlim_cur;
773				addr = round_page(p->p_vmspace->vm_stacktop) -
774				    oldssiz.rlim_cur;
775			}
776			addr = trunc_page(addr);
777			size = round_page(size);
778			(void)vm_map_protect(&p->p_vmspace->vm_map,
779			    addr, addr + size, prot, 0,
780			    VM_MAP_PROTECT_SET_PROT);
781		}
782	}
783
784	return (0);
785}
786
787#ifndef _SYS_SYSPROTO_H_
788struct getrlimit_args {
789	u_int	which;
790	struct	rlimit *rlp;
791};
792#endif
793/* ARGSUSED */
794int
795sys_getrlimit(struct thread *td, struct getrlimit_args *uap)
796{
797	struct rlimit rlim;
798	int error;
799
800	if (uap->which >= RLIM_NLIMITS)
801		return (EINVAL);
802	lim_rlimit(td, uap->which, &rlim);
803	error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
804	return (error);
805}
806
807/*
808 * Transform the running time and tick information for children of proc p
809 * into user and system time usage.
810 */
811void
812calccru(struct proc *p, struct timeval *up, struct timeval *sp)
813{
814
815	PROC_LOCK_ASSERT(p, MA_OWNED);
816	calcru1(p, &p->p_crux, up, sp);
817}
818
819/*
820 * Transform the running time and tick information in proc p into user
821 * and system time usage.  If appropriate, include the current time slice
822 * on this CPU.
823 */
824void
825calcru(struct proc *p, struct timeval *up, struct timeval *sp)
826{
827	struct thread *td;
828	uint64_t runtime, u;
829
830	PROC_LOCK_ASSERT(p, MA_OWNED);
831	PROC_STATLOCK_ASSERT(p, MA_OWNED);
832	/*
833	 * If we are getting stats for the current process, then add in the
834	 * stats that this thread has accumulated in its current time slice.
835	 * We reset the thread and CPU state as if we had performed a context
836	 * switch right here.
837	 */
838	td = curthread;
839	if (td->td_proc == p) {
840		u = cpu_ticks();
841		runtime = u - PCPU_GET(switchtime);
842		td->td_runtime += runtime;
843		td->td_incruntime += runtime;
844		PCPU_SET(switchtime, u);
845	}
846	/* Make sure the per-thread stats are current. */
847	FOREACH_THREAD_IN_PROC(p, td) {
848		if (td->td_incruntime == 0)
849			continue;
850		ruxagg(p, td);
851	}
852	calcru1(p, &p->p_rux, up, sp);
853}
854
855/* Collect resource usage for a single thread. */
856void
857rufetchtd(struct thread *td, struct rusage *ru)
858{
859	struct proc *p;
860	uint64_t runtime, u;
861
862	p = td->td_proc;
863	PROC_STATLOCK_ASSERT(p, MA_OWNED);
864	THREAD_LOCK_ASSERT(td, MA_OWNED);
865	/*
866	 * If we are getting stats for the current thread, then add in the
867	 * stats that this thread has accumulated in its current time slice.
868	 * We reset the thread and CPU state as if we had performed a context
869	 * switch right here.
870	 */
871	if (td == curthread) {
872		u = cpu_ticks();
873		runtime = u - PCPU_GET(switchtime);
874		td->td_runtime += runtime;
875		td->td_incruntime += runtime;
876		PCPU_SET(switchtime, u);
877	}
878	ruxagg_locked(p, td);
879	*ru = td->td_ru;
880	calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
881}
882
883static uint64_t
884mul64_by_fraction(uint64_t a, uint64_t b, uint64_t c)
885{
886	uint64_t acc, bh, bl;
887	int i, s, sa, sb;
888
889	/*
890	 * Calculate (a * b) / c accurately enough without overflowing.  c
891	 * must be nonzero, and its top bit must be 0.  a or b must be
892	 * <= c, and the implementation is tuned for b <= c.
893	 *
894	 * The comments about times are for use in calcru1() with units of
895	 * microseconds for 'a' and stathz ticks at 128 Hz for b and c.
896	 *
897	 * Let n be the number of top zero bits in c.  Each iteration
898	 * either returns, or reduces b by right shifting it by at least n.
899	 * The number of iterations is at most 1 + 64 / n, and the error is
900	 * at most the number of iterations.
901	 *
902	 * It is very unusual to need even 2 iterations.  Previous
903	 * implementations overflowed essentially by returning early in the
904	 * first iteration, with n = 38 giving overflow at 105+ hours and
905	 * n = 32 giving overlow at at 388+ days despite a more careful
906	 * calculation.  388 days is a reasonable uptime, and the calculation
907	 * needs to work for the uptime times the number of CPUs since 'a'
908	 * is per-process.
909	 */
910	if (a >= (uint64_t)1 << 63)
911		return (0);		/* Unsupported arg -- can't happen. */
912	acc = 0;
913	for (i = 0; i < 128; i++) {
914		sa = flsll(a);
915		sb = flsll(b);
916		if (sa + sb <= 64)
917			/* Up to 105 hours on first iteration. */
918			return (acc + (a * b) / c);
919		if (a >= c) {
920			/*
921			 * This reduction is based on a = q * c + r, with the
922			 * remainder r < c.  'a' may be large to start, and
923			 * moving bits from b into 'a' at the end of the loop
924			 * sets the top bit of 'a', so the reduction makes
925			 * significant progress.
926			 */
927			acc += (a / c) * b;
928			a %= c;
929			sa = flsll(a);
930			if (sa + sb <= 64)
931				/* Up to 388 days on first iteration. */
932				return (acc + (a * b) / c);
933		}
934
935		/*
936		 * This step writes a * b as a * ((bh << s) + bl) =
937		 * a * (bh << s) + a * bl = (a << s) * bh + a * bl.  The 2
938		 * additive terms are handled separately.  Splitting in
939		 * this way is linear except for rounding errors.
940		 *
941		 * s = 64 - sa is the maximum such that a << s fits in 64
942		 * bits.  Since a < c and c has at least 1 zero top bit,
943		 * sa < 64 and s > 0.  Thus this step makes progress by
944		 * reducing b (it increases 'a', but taking remainders on
945		 * the next iteration completes the reduction).
946		 *
947		 * Finally, the choice for s is just what is needed to keep
948		 * a * bl from overflowing, so we don't need complications
949		 * like a recursive call mul64_by_fraction(a, bl, c) to
950		 * handle the second additive term.
951		 */
952		s = 64 - sa;
953		bh = b >> s;
954		bl = b - (bh << s);
955		acc += (a * bl) / c;
956		a <<= s;
957		b = bh;
958	}
959	return (0);		/* Algorithm failure -- can't happen. */
960}
961
962static void
963calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
964    struct timeval *sp)
965{
966	/* {user, system, interrupt, total} {ticks, usec}: */
967	uint64_t ut, uu, st, su, it, tt, tu;
968
969	ut = ruxp->rux_uticks;
970	st = ruxp->rux_sticks;
971	it = ruxp->rux_iticks;
972	tt = ut + st + it;
973	if (tt == 0) {
974		/* Avoid divide by zero */
975		st = 1;
976		tt = 1;
977	}
978	tu = cputick2usec(ruxp->rux_runtime);
979	if ((int64_t)tu < 0) {
980		/* XXX: this should be an assert /phk */
981		printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
982		    (intmax_t)tu, p->p_pid, p->p_comm);
983		tu = ruxp->rux_tu;
984	}
985
986	/* Subdivide tu.  Avoid overflow in the multiplications. */
987	if (__predict_true(tu <= ((uint64_t)1 << 38) && tt <= (1 << 26))) {
988		/* Up to 76 hours when stathz is 128. */
989		uu = (tu * ut) / tt;
990		su = (tu * st) / tt;
991	} else {
992		uu = mul64_by_fraction(tu, ut, tt);
993		su = mul64_by_fraction(tu, st, tt);
994	}
995
996	if (tu >= ruxp->rux_tu) {
997		/*
998		 * The normal case, time increased.
999		 * Enforce monotonicity of bucketed numbers.
1000		 */
1001		if (uu < ruxp->rux_uu)
1002			uu = ruxp->rux_uu;
1003		if (su < ruxp->rux_su)
1004			su = ruxp->rux_su;
1005	} else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
1006		/*
1007		 * When we calibrate the cputicker, it is not uncommon to
1008		 * see the presumably fixed frequency increase slightly over
1009		 * time as a result of thermal stabilization and NTP
1010		 * discipline (of the reference clock).  We therefore ignore
1011		 * a bit of backwards slop because we  expect to catch up
1012		 * shortly.  We use a 3 microsecond limit to catch low
1013		 * counts and a 1% limit for high counts.
1014		 */
1015		uu = ruxp->rux_uu;
1016		su = ruxp->rux_su;
1017		tu = ruxp->rux_tu;
1018	} else if (vm_guest == VM_GUEST_NO) {  /* tu < ruxp->rux_tu */
1019		/*
1020		 * What happened here was likely that a laptop, which ran at
1021		 * a reduced clock frequency at boot, kicked into high gear.
1022		 * The wisdom of spamming this message in that case is
1023		 * dubious, but it might also be indicative of something
1024		 * serious, so lets keep it and hope laptops can be made
1025		 * more truthful about their CPU speed via ACPI.
1026		 */
1027		printf("calcru: runtime went backwards from %ju usec "
1028		    "to %ju usec for pid %d (%s)\n",
1029		    (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
1030		    p->p_pid, p->p_comm);
1031	}
1032
1033	ruxp->rux_uu = uu;
1034	ruxp->rux_su = su;
1035	ruxp->rux_tu = tu;
1036
1037	up->tv_sec = uu / 1000000;
1038	up->tv_usec = uu % 1000000;
1039	sp->tv_sec = su / 1000000;
1040	sp->tv_usec = su % 1000000;
1041}
1042
1043#ifndef _SYS_SYSPROTO_H_
1044struct getrusage_args {
1045	int	who;
1046	struct	rusage *rusage;
1047};
1048#endif
1049int
1050sys_getrusage(struct thread *td, struct getrusage_args *uap)
1051{
1052	struct rusage ru;
1053	int error;
1054
1055	error = kern_getrusage(td, uap->who, &ru);
1056	if (error == 0)
1057		error = copyout(&ru, uap->rusage, sizeof(struct rusage));
1058	return (error);
1059}
1060
1061int
1062kern_getrusage(struct thread *td, int who, struct rusage *rup)
1063{
1064	struct proc *p;
1065	int error;
1066
1067	error = 0;
1068	p = td->td_proc;
1069	PROC_LOCK(p);
1070	switch (who) {
1071	case RUSAGE_SELF:
1072		rufetchcalc(p, rup, &rup->ru_utime,
1073		    &rup->ru_stime);
1074		break;
1075
1076	case RUSAGE_CHILDREN:
1077		*rup = p->p_stats->p_cru;
1078		calccru(p, &rup->ru_utime, &rup->ru_stime);
1079		break;
1080
1081	case RUSAGE_THREAD:
1082		PROC_STATLOCK(p);
1083		thread_lock(td);
1084		rufetchtd(td, rup);
1085		thread_unlock(td);
1086		PROC_STATUNLOCK(p);
1087		break;
1088
1089	default:
1090		error = EINVAL;
1091	}
1092	PROC_UNLOCK(p);
1093	return (error);
1094}
1095
1096void
1097rucollect(struct rusage *ru, struct rusage *ru2)
1098{
1099	long *ip, *ip2;
1100	int i;
1101
1102	if (ru->ru_maxrss < ru2->ru_maxrss)
1103		ru->ru_maxrss = ru2->ru_maxrss;
1104	ip = &ru->ru_first;
1105	ip2 = &ru2->ru_first;
1106	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
1107		*ip++ += *ip2++;
1108}
1109
1110void
1111ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
1112    struct rusage_ext *rux2)
1113{
1114
1115	rux->rux_runtime += rux2->rux_runtime;
1116	rux->rux_uticks += rux2->rux_uticks;
1117	rux->rux_sticks += rux2->rux_sticks;
1118	rux->rux_iticks += rux2->rux_iticks;
1119	rux->rux_uu += rux2->rux_uu;
1120	rux->rux_su += rux2->rux_su;
1121	rux->rux_tu += rux2->rux_tu;
1122	rucollect(ru, ru2);
1123}
1124
1125/*
1126 * Aggregate tick counts into the proc's rusage_ext.
1127 */
1128static void
1129ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td)
1130{
1131
1132	rux->rux_runtime += td->td_incruntime;
1133	rux->rux_uticks += td->td_uticks;
1134	rux->rux_sticks += td->td_sticks;
1135	rux->rux_iticks += td->td_iticks;
1136}
1137
1138void
1139ruxagg_locked(struct proc *p, struct thread *td)
1140{
1141	THREAD_LOCK_ASSERT(td, MA_OWNED);
1142	PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED);
1143
1144	ruxagg_ext_locked(&p->p_rux, td);
1145	ruxagg_ext_locked(&td->td_rux, td);
1146	td->td_incruntime = 0;
1147	td->td_uticks = 0;
1148	td->td_iticks = 0;
1149	td->td_sticks = 0;
1150}
1151
1152void
1153ruxagg(struct proc *p, struct thread *td)
1154{
1155
1156	thread_lock(td);
1157	ruxagg_locked(p, td);
1158	thread_unlock(td);
1159}
1160
1161/*
1162 * Update the rusage_ext structure and fetch a valid aggregate rusage
1163 * for proc p if storage for one is supplied.
1164 */
1165void
1166rufetch(struct proc *p, struct rusage *ru)
1167{
1168	struct thread *td;
1169
1170	PROC_STATLOCK_ASSERT(p, MA_OWNED);
1171
1172	*ru = p->p_ru;
1173	if (p->p_numthreads > 0)  {
1174		FOREACH_THREAD_IN_PROC(p, td) {
1175			ruxagg(p, td);
1176			rucollect(ru, &td->td_ru);
1177		}
1178	}
1179}
1180
1181/*
1182 * Atomically perform a rufetch and a calcru together.
1183 * Consumers, can safely assume the calcru is executed only once
1184 * rufetch is completed.
1185 */
1186void
1187rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
1188    struct timeval *sp)
1189{
1190
1191	PROC_STATLOCK(p);
1192	rufetch(p, ru);
1193	calcru(p, up, sp);
1194	PROC_STATUNLOCK(p);
1195}
1196
1197/*
1198 * Allocate a new resource limits structure and initialize its
1199 * reference count and mutex pointer.
1200 */
1201struct plimit *
1202lim_alloc(void)
1203{
1204	struct plimit *limp;
1205
1206	limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
1207	refcount_init(&limp->pl_refcnt, 1);
1208	return (limp);
1209}
1210
1211struct plimit *
1212lim_hold(struct plimit *limp)
1213{
1214
1215	refcount_acquire(&limp->pl_refcnt);
1216	return (limp);
1217}
1218
1219struct plimit *
1220lim_cowsync(void)
1221{
1222	struct thread *td;
1223	struct proc *p;
1224	struct plimit *oldlimit;
1225
1226	td = curthread;
1227	p = td->td_proc;
1228	PROC_LOCK_ASSERT(p, MA_OWNED);
1229
1230	if (td->td_limit == p->p_limit)
1231		return (NULL);
1232
1233	oldlimit = td->td_limit;
1234	td->td_limit = lim_hold(p->p_limit);
1235
1236	return (oldlimit);
1237}
1238
1239void
1240lim_fork(struct proc *p1, struct proc *p2)
1241{
1242
1243	PROC_LOCK_ASSERT(p1, MA_OWNED);
1244	PROC_LOCK_ASSERT(p2, MA_OWNED);
1245
1246	p2->p_limit = lim_hold(p1->p_limit);
1247	callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
1248	if (p1->p_cpulimit != RLIM_INFINITY)
1249		callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
1250		    lim_cb, p2, C_PREL(1));
1251}
1252
1253void
1254lim_free(struct plimit *limp)
1255{
1256
1257	if (refcount_release(&limp->pl_refcnt))
1258		free((void *)limp, M_PLIMIT);
1259}
1260
1261void
1262lim_freen(struct plimit *limp, int n)
1263{
1264
1265	if (refcount_releasen(&limp->pl_refcnt, n))
1266		free((void *)limp, M_PLIMIT);
1267}
1268
1269void
1270limbatch_add(struct limbatch *lb, struct thread *td)
1271{
1272	struct plimit *limp;
1273
1274	MPASS(td->td_limit != NULL);
1275	limp = td->td_limit;
1276
1277	if (lb->limp != limp) {
1278		if (lb->count != 0) {
1279			lim_freen(lb->limp, lb->count);
1280			lb->count = 0;
1281		}
1282		lb->limp = limp;
1283	}
1284
1285	lb->count++;
1286}
1287
1288void
1289limbatch_final(struct limbatch *lb)
1290{
1291
1292	MPASS(lb->count != 0);
1293	lim_freen(lb->limp, lb->count);
1294}
1295
1296/*
1297 * Make a copy of the plimit structure.
1298 * We share these structures copy-on-write after fork.
1299 */
1300void
1301lim_copy(struct plimit *dst, struct plimit *src)
1302{
1303
1304	KASSERT(dst->pl_refcnt <= 1, ("lim_copy to shared limit"));
1305	bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
1306}
1307
1308/*
1309 * Return the hard limit for a particular system resource.  The
1310 * which parameter specifies the index into the rlimit array.
1311 */
1312rlim_t
1313lim_max(struct thread *td, int which)
1314{
1315	struct rlimit rl;
1316
1317	lim_rlimit(td, which, &rl);
1318	return (rl.rlim_max);
1319}
1320
1321rlim_t
1322lim_max_proc(struct proc *p, int which)
1323{
1324	struct rlimit rl;
1325
1326	lim_rlimit_proc(p, which, &rl);
1327	return (rl.rlim_max);
1328}
1329
1330/*
1331 * Return the current (soft) limit for a particular system resource.
1332 * The which parameter which specifies the index into the rlimit array
1333 */
1334rlim_t
1335(lim_cur)(struct thread *td, int which)
1336{
1337	struct rlimit rl;
1338
1339	lim_rlimit(td, which, &rl);
1340	return (rl.rlim_cur);
1341}
1342
1343rlim_t
1344lim_cur_proc(struct proc *p, int which)
1345{
1346	struct rlimit rl;
1347
1348	lim_rlimit_proc(p, which, &rl);
1349	return (rl.rlim_cur);
1350}
1351
1352/*
1353 * Return a copy of the entire rlimit structure for the system limit
1354 * specified by 'which' in the rlimit structure pointed to by 'rlp'.
1355 */
1356void
1357lim_rlimit(struct thread *td, int which, struct rlimit *rlp)
1358{
1359	struct proc *p = td->td_proc;
1360
1361	MPASS(td == curthread);
1362	KASSERT(which >= 0 && which < RLIM_NLIMITS,
1363	    ("request for invalid resource limit"));
1364	*rlp = td->td_limit->pl_rlimit[which];
1365	if (p->p_sysent->sv_fixlimit != NULL)
1366		p->p_sysent->sv_fixlimit(rlp, which);
1367}
1368
1369void
1370lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp)
1371{
1372
1373	PROC_LOCK_ASSERT(p, MA_OWNED);
1374	KASSERT(which >= 0 && which < RLIM_NLIMITS,
1375	    ("request for invalid resource limit"));
1376	*rlp = p->p_limit->pl_rlimit[which];
1377	if (p->p_sysent->sv_fixlimit != NULL)
1378		p->p_sysent->sv_fixlimit(rlp, which);
1379}
1380
1381void
1382uihashinit(void)
1383{
1384
1385	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
1386	rw_init(&uihashtbl_lock, "uidinfo hash");
1387}
1388
1389/*
1390 * Look up a uidinfo struct for the parameter uid.
1391 * uihashtbl_lock must be locked.
1392 * Increase refcount on uidinfo struct returned.
1393 */
1394static struct uidinfo *
1395uilookup(uid_t uid)
1396{
1397	struct uihashhead *uipp;
1398	struct uidinfo *uip;
1399
1400	rw_assert(&uihashtbl_lock, RA_LOCKED);
1401	uipp = UIHASH(uid);
1402	LIST_FOREACH(uip, uipp, ui_hash)
1403		if (uip->ui_uid == uid) {
1404			uihold(uip);
1405			break;
1406		}
1407
1408	return (uip);
1409}
1410
1411/*
1412 * Find or allocate a struct uidinfo for a particular uid.
1413 * Returns with uidinfo struct referenced.
1414 * uifree() should be called on a struct uidinfo when released.
1415 */
1416struct uidinfo *
1417uifind(uid_t uid)
1418{
1419	struct uidinfo *new_uip, *uip;
1420	struct ucred *cred;
1421
1422	cred = curthread->td_ucred;
1423	if (cred->cr_uidinfo->ui_uid == uid) {
1424		uip = cred->cr_uidinfo;
1425		uihold(uip);
1426		return (uip);
1427	} else if (cred->cr_ruidinfo->ui_uid == uid) {
1428		uip = cred->cr_ruidinfo;
1429		uihold(uip);
1430		return (uip);
1431	}
1432
1433	rw_rlock(&uihashtbl_lock);
1434	uip = uilookup(uid);
1435	rw_runlock(&uihashtbl_lock);
1436	if (uip != NULL)
1437		return (uip);
1438
1439	new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO);
1440	racct_create(&new_uip->ui_racct);
1441	refcount_init(&new_uip->ui_ref, 1);
1442	new_uip->ui_uid = uid;
1443
1444	rw_wlock(&uihashtbl_lock);
1445	/*
1446	 * There's a chance someone created our uidinfo while we
1447	 * were in malloc and not holding the lock, so we have to
1448	 * make sure we don't insert a duplicate uidinfo.
1449	 */
1450	if ((uip = uilookup(uid)) == NULL) {
1451		LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash);
1452		rw_wunlock(&uihashtbl_lock);
1453		uip = new_uip;
1454	} else {
1455		rw_wunlock(&uihashtbl_lock);
1456		racct_destroy(&new_uip->ui_racct);
1457		free(new_uip, M_UIDINFO);
1458	}
1459	return (uip);
1460}
1461
1462/*
1463 * Place another refcount on a uidinfo struct.
1464 */
1465void
1466uihold(struct uidinfo *uip)
1467{
1468
1469	refcount_acquire(&uip->ui_ref);
1470}
1471
1472/*-
1473 * Since uidinfo structs have a long lifetime, we use an
1474 * opportunistic refcounting scheme to avoid locking the lookup hash
1475 * for each release.
1476 *
1477 * If the refcount hits 0, we need to free the structure,
1478 * which means we need to lock the hash.
1479 * Optimal case:
1480 *   After locking the struct and lowering the refcount, if we find
1481 *   that we don't need to free, simply unlock and return.
1482 * Suboptimal case:
1483 *   If refcount lowering results in need to free, bump the count
1484 *   back up, lose the lock and acquire the locks in the proper
1485 *   order to try again.
1486 */
1487void
1488uifree(struct uidinfo *uip)
1489{
1490
1491	if (refcount_release_if_not_last(&uip->ui_ref))
1492		return;
1493
1494	rw_wlock(&uihashtbl_lock);
1495	if (refcount_release(&uip->ui_ref) == 0) {
1496		rw_wunlock(&uihashtbl_lock);
1497		return;
1498	}
1499
1500	racct_destroy(&uip->ui_racct);
1501	LIST_REMOVE(uip, ui_hash);
1502	rw_wunlock(&uihashtbl_lock);
1503
1504	if (uip->ui_sbsize != 0)
1505		printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
1506		    uip->ui_uid, uip->ui_sbsize);
1507	if (uip->ui_proccnt != 0)
1508		printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
1509		    uip->ui_uid, uip->ui_proccnt);
1510	if (uip->ui_vmsize != 0)
1511		printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
1512		    uip->ui_uid, (unsigned long long)uip->ui_vmsize);
1513	free(uip, M_UIDINFO);
1514}
1515
1516#ifdef RACCT
1517void
1518ui_racct_foreach(void (*callback)(struct racct *racct,
1519    void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
1520    void *arg2, void *arg3)
1521{
1522	struct uidinfo *uip;
1523	struct uihashhead *uih;
1524
1525	rw_rlock(&uihashtbl_lock);
1526	if (pre != NULL)
1527		(pre)();
1528	for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
1529		LIST_FOREACH(uip, uih, ui_hash) {
1530			(callback)(uip->ui_racct, arg2, arg3);
1531		}
1532	}
1533	if (post != NULL)
1534		(post)();
1535	rw_runlock(&uihashtbl_lock);
1536}
1537#endif
1538
1539static inline int
1540chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name)
1541{
1542	long new;
1543
1544	/* Don't allow them to exceed max, but allow subtraction. */
1545	new = atomic_fetchadd_long(limit, (long)diff) + diff;
1546	if (diff > 0 && max != 0) {
1547		if (new < 0 || new > max) {
1548			atomic_subtract_long(limit, (long)diff);
1549			return (0);
1550		}
1551	} else if (new < 0)
1552		printf("negative %s for uid = %d\n", name, uip->ui_uid);
1553	return (1);
1554}
1555
1556/*
1557 * Change the count associated with number of processes
1558 * a given user is using.  When 'max' is 0, don't enforce a limit
1559 */
1560int
1561chgproccnt(struct uidinfo *uip, int diff, rlim_t max)
1562{
1563
1564	return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt"));
1565}
1566
1567/*
1568 * Change the total socket buffer size a user has used.
1569 */
1570int
1571chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max)
1572{
1573	int diff, rv;
1574
1575	diff = to - *hiwat;
1576	if (diff > 0 && max == 0) {
1577		rv = 0;
1578	} else {
1579		rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize");
1580		if (rv != 0)
1581			*hiwat = to;
1582	}
1583	return (rv);
1584}
1585
1586/*
1587 * Change the count associated with number of pseudo-terminals
1588 * a given user is using.  When 'max' is 0, don't enforce a limit
1589 */
1590int
1591chgptscnt(struct uidinfo *uip, int diff, rlim_t max)
1592{
1593
1594	return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt"));
1595}
1596
1597int
1598chgkqcnt(struct uidinfo *uip, int diff, rlim_t max)
1599{
1600
1601	return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt"));
1602}
1603
1604int
1605chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max)
1606{
1607
1608	return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt"));
1609}
1610