kern_resource.c revision 110190
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	@(#)kern_resource.c	8.5 (Berkeley) 1/21/94
39 * $FreeBSD: head/sys/kern/kern_resource.c 110190 2003-02-01 12:17:09Z julian $
40 */
41
42#include "opt_compat.h"
43
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/sysproto.h>
47#include <sys/file.h>
48#include <sys/kernel.h>
49#include <sys/lock.h>
50#include <sys/malloc.h>
51#include <sys/mutex.h>
52#include <sys/proc.h>
53#include <sys/resourcevar.h>
54#include <sys/sched.h>
55#include <sys/sx.h>
56#include <sys/sysent.h>
57#include <sys/time.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 int donice(struct thread *td, struct proc *chgp, int n);
65
66static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
67#define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
68static struct mtx uihashtbl_mtx;
69static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
70static u_long uihash;		/* size of hash table - 1 */
71
72static struct uidinfo	*uilookup(uid_t uid);
73
74/*
75 * Resource controls and accounting.
76 */
77
78#ifndef _SYS_SYSPROTO_H_
79struct getpriority_args {
80	int	which;
81	int	who;
82};
83#endif
84/*
85 * MPSAFE
86 */
87int
88getpriority(td, uap)
89	struct thread *td;
90	register struct getpriority_args *uap;
91{
92	struct proc *p;
93	int low = PRIO_MAX + 1;
94	int error = 0;
95	struct ksegrp *kg;
96
97	mtx_lock(&Giant);
98
99	switch (uap->which) {
100	case PRIO_PROCESS:
101		if (uap->who == 0)
102			low = td->td_ksegrp->kg_nice;
103		else {
104			p = pfind(uap->who);
105			if (p == NULL)
106				break;
107			if (p_cansee(td, p) == 0) {
108				FOREACH_KSEGRP_IN_PROC(p, kg) {
109					if (kg->kg_nice < low)
110						low = kg->kg_nice;
111				}
112			}
113			PROC_UNLOCK(p);
114		}
115		break;
116
117	case PRIO_PGRP: {
118		register struct pgrp *pg;
119
120		sx_slock(&proctree_lock);
121		if (uap->who == 0) {
122			pg = td->td_proc->p_pgrp;
123			PGRP_LOCK(pg);
124		} else {
125			pg = pgfind(uap->who);
126			if (pg == NULL) {
127				sx_sunlock(&proctree_lock);
128				break;
129			}
130		}
131		sx_sunlock(&proctree_lock);
132		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
133			PROC_LOCK(p);
134			if (!p_cansee(td, p)) {
135				FOREACH_KSEGRP_IN_PROC(p, kg) {
136					if (kg->kg_nice < low)
137						low = kg->kg_nice;
138				}
139			}
140			PROC_UNLOCK(p);
141		}
142		PGRP_UNLOCK(pg);
143		break;
144	}
145
146	case PRIO_USER:
147		if (uap->who == 0)
148			uap->who = td->td_ucred->cr_uid;
149		sx_slock(&allproc_lock);
150		LIST_FOREACH(p, &allproc, p_list) {
151			PROC_LOCK(p);
152			if (!p_cansee(td, p) &&
153			    p->p_ucred->cr_uid == uap->who) {
154				FOREACH_KSEGRP_IN_PROC(p, kg) {
155					if (kg->kg_nice < low)
156						low = kg->kg_nice;
157				}
158			}
159			PROC_UNLOCK(p);
160		}
161		sx_sunlock(&allproc_lock);
162		break;
163
164	default:
165		error = EINVAL;
166		break;
167	}
168	if (low == PRIO_MAX + 1 && error == 0)
169		error = ESRCH;
170	td->td_retval[0] = low;
171	mtx_unlock(&Giant);
172	return (error);
173}
174
175#ifndef _SYS_SYSPROTO_H_
176struct setpriority_args {
177	int	which;
178	int	who;
179	int	prio;
180};
181#endif
182/*
183 * MPSAFE
184 */
185/* ARGSUSED */
186int
187setpriority(td, uap)
188	struct thread *td;
189	register struct setpriority_args *uap;
190{
191	struct proc *curp = td->td_proc;
192	register struct proc *p;
193	int found = 0, error = 0;
194
195	mtx_lock(&Giant);
196
197	switch (uap->which) {
198	case PRIO_PROCESS:
199		if (uap->who == 0) {
200			PROC_LOCK(curp);
201			error = donice(td, curp, uap->prio);
202			PROC_UNLOCK(curp);
203		} else {
204			p = pfind(uap->who);
205			if (p == 0)
206				break;
207			if (p_cansee(td, p) == 0)
208				error = donice(td, p, uap->prio);
209			PROC_UNLOCK(p);
210		}
211		found++;
212		break;
213
214	case PRIO_PGRP: {
215		register struct pgrp *pg;
216
217		sx_slock(&proctree_lock);
218		if (uap->who == 0) {
219			pg = curp->p_pgrp;
220			PGRP_LOCK(pg);
221		} else {
222			pg = pgfind(uap->who);
223			if (pg == NULL) {
224				sx_sunlock(&proctree_lock);
225				break;
226			}
227		}
228		sx_sunlock(&proctree_lock);
229		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
230			PROC_LOCK(p);
231			if (!p_cansee(td, p)) {
232				error = donice(td, p, uap->prio);
233				found++;
234			}
235			PROC_UNLOCK(p);
236		}
237		PGRP_UNLOCK(pg);
238		break;
239	}
240
241	case PRIO_USER:
242		if (uap->who == 0)
243			uap->who = td->td_ucred->cr_uid;
244		sx_slock(&allproc_lock);
245		FOREACH_PROC_IN_SYSTEM(p) {
246			PROC_LOCK(p);
247			if (p->p_ucred->cr_uid == uap->who &&
248			    !p_cansee(td, p)) {
249				error = donice(td, p, uap->prio);
250				found++;
251			}
252			PROC_UNLOCK(p);
253		}
254		sx_sunlock(&allproc_lock);
255		break;
256
257	default:
258		error = EINVAL;
259		break;
260	}
261	if (found == 0 && error == 0)
262		error = ESRCH;
263	mtx_unlock(&Giant);
264	return (error);
265}
266
267/*
268 * Set "nice" for a process. Doesn't really understand threaded processes well
269 * but does try. Has the unfortunate side effect of making all the NICE
270 * values for a process's ksegrps the same.. This suggests that
271 * NICE valuse should be stored as a process nice and deltas for the ksegrps.
272 * (but not yet).
273 */
274static int
275donice(struct thread *td, struct proc *p, int n)
276{
277	int	error;
278	int low = PRIO_MAX + 1;
279	struct ksegrp *kg;
280
281	PROC_LOCK_ASSERT(p, MA_OWNED);
282	if ((error = p_cansched(td, p)))
283		return (error);
284	if (n > PRIO_MAX)
285		n = PRIO_MAX;
286	if (n < PRIO_MIN)
287		n = PRIO_MIN;
288	/*
289	 * Only allow nicing if to more than the lowest nice.
290	 * e.g.  nices of 4,3,2  allow nice to 3 but not 1
291	 */
292	FOREACH_KSEGRP_IN_PROC(p, kg) {
293		if (kg->kg_nice < low)
294			low = kg->kg_nice;
295	}
296 	if (n < low && suser(td))
297		return (EACCES);
298	FOREACH_KSEGRP_IN_PROC(p, kg) {
299		sched_nice(kg, n);
300	}
301	return (0);
302}
303
304/* rtprio system call */
305#ifndef _SYS_SYSPROTO_H_
306struct rtprio_args {
307	int		function;
308	pid_t		pid;
309	struct rtprio	*rtp;
310};
311#endif
312
313/*
314 * Set realtime priority
315 */
316
317/*
318 * MPSAFE
319 */
320/* ARGSUSED */
321int
322rtprio(td, uap)
323	struct thread *td;
324	register struct rtprio_args *uap;
325{
326	struct proc *curp = td->td_proc;
327	register struct proc *p;
328	struct rtprio rtp;
329	int error, cierror = 0;
330
331	/* Perform copyin before acquiring locks if needed. */
332	if (uap->function == RTP_SET)
333		cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
334
335	if (uap->pid == 0) {
336		p = curp;
337		PROC_LOCK(p);
338	} else {
339		p = pfind(uap->pid);
340		if (p == NULL)
341			return (ESRCH);
342	}
343
344	switch (uap->function) {
345	case RTP_LOOKUP:
346		if ((error = p_cansee(td, p)))
347			break;
348		mtx_lock_spin(&sched_lock);
349		pri_to_rtp(FIRST_KSEGRP_IN_PROC(p), &rtp);
350		mtx_unlock_spin(&sched_lock);
351		PROC_UNLOCK(p);
352		return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
353	case RTP_SET:
354		if ((error = p_cansched(td, p)) || (error = cierror))
355			break;
356		/* disallow setting rtprio in most cases if not superuser */
357		if (suser(td) != 0) {
358			/* can't set someone else's */
359			if (uap->pid) {
360				error = EPERM;
361				break;
362			}
363			/* can't set realtime priority */
364/*
365 * Realtime priority has to be restricted for reasons which should be
366 * obvious. However, for idle priority, there is a potential for
367 * system deadlock if an idleprio process gains a lock on a resource
368 * that other processes need (and the idleprio process can't run
369 * due to a CPU-bound normal process). Fix me! XXX
370 */
371#if 0
372 			if (RTP_PRIO_IS_REALTIME(rtp.type))
373#endif
374			if (rtp.type != RTP_PRIO_NORMAL) {
375				error = EPERM;
376				break;
377			}
378		}
379		mtx_lock_spin(&sched_lock);
380		error = rtp_to_pri(&rtp, FIRST_KSEGRP_IN_PROC(p));
381		mtx_unlock_spin(&sched_lock);
382		break;
383	default:
384		error = EINVAL;
385		break;
386	}
387	PROC_UNLOCK(p);
388	return (error);
389}
390
391int
392rtp_to_pri(struct rtprio *rtp, struct ksegrp *kg)
393{
394
395	if (rtp->prio > RTP_PRIO_MAX)
396		return (EINVAL);
397	switch (RTP_PRIO_BASE(rtp->type)) {
398	case RTP_PRIO_REALTIME:
399		kg->kg_user_pri = PRI_MIN_REALTIME + rtp->prio;
400		break;
401	case RTP_PRIO_NORMAL:
402		kg->kg_user_pri = PRI_MIN_TIMESHARE + rtp->prio;
403		break;
404	case RTP_PRIO_IDLE:
405		kg->kg_user_pri = PRI_MIN_IDLE + rtp->prio;
406		break;
407	default:
408		return (EINVAL);
409	}
410	kg->kg_pri_class = rtp->type;
411	if (curthread->td_ksegrp == kg) {
412		curthread->td_base_pri = kg->kg_user_pri;
413		curthread->td_priority = kg->kg_user_pri; /* XXX dubious */
414	}
415	return (0);
416}
417
418void
419pri_to_rtp(struct ksegrp *kg, struct rtprio *rtp)
420{
421
422	switch (PRI_BASE(kg->kg_pri_class)) {
423	case PRI_REALTIME:
424		rtp->prio = kg->kg_user_pri - PRI_MIN_REALTIME;
425		break;
426	case PRI_TIMESHARE:
427		rtp->prio = kg->kg_user_pri - PRI_MIN_TIMESHARE;
428		break;
429	case PRI_IDLE:
430		rtp->prio = kg->kg_user_pri - PRI_MIN_IDLE;
431		break;
432	default:
433		break;
434	}
435	rtp->type = kg->kg_pri_class;
436}
437
438#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
439#ifndef _SYS_SYSPROTO_H_
440struct osetrlimit_args {
441	u_int	which;
442	struct	orlimit *rlp;
443};
444#endif
445/*
446 * MPSAFE
447 */
448/* ARGSUSED */
449int
450osetrlimit(td, uap)
451	struct thread *td;
452	register struct osetrlimit_args *uap;
453{
454	struct orlimit olim;
455	struct rlimit lim;
456	int error;
457
458	if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
459		return (error);
460	lim.rlim_cur = olim.rlim_cur;
461	lim.rlim_max = olim.rlim_max;
462	mtx_lock(&Giant);
463	error = dosetrlimit(td, uap->which, &lim);
464	mtx_unlock(&Giant);
465	return (error);
466}
467
468#ifndef _SYS_SYSPROTO_H_
469struct ogetrlimit_args {
470	u_int	which;
471	struct	orlimit *rlp;
472};
473#endif
474/*
475 * MPSAFE
476 */
477/* ARGSUSED */
478int
479ogetrlimit(td, uap)
480	struct thread *td;
481	register struct ogetrlimit_args *uap;
482{
483	struct proc *p = td->td_proc;
484	struct orlimit olim;
485	int error;
486
487	if (uap->which >= RLIM_NLIMITS)
488		return (EINVAL);
489	mtx_lock(&Giant);
490	olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
491	if (olim.rlim_cur == -1)
492		olim.rlim_cur = 0x7fffffff;
493	olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
494	if (olim.rlim_max == -1)
495		olim.rlim_max = 0x7fffffff;
496	error = copyout(&olim, uap->rlp, sizeof(olim));
497	mtx_unlock(&Giant);
498	return (error);
499}
500#endif /* COMPAT_43 || COMPAT_SUNOS */
501
502#ifndef _SYS_SYSPROTO_H_
503struct __setrlimit_args {
504	u_int	which;
505	struct	rlimit *rlp;
506};
507#endif
508/*
509 * MPSAFE
510 */
511/* ARGSUSED */
512int
513setrlimit(td, uap)
514	struct thread *td;
515	register struct __setrlimit_args *uap;
516{
517	struct rlimit alim;
518	int error;
519
520	if ((error = copyin(uap->rlp, &alim, sizeof (struct rlimit))))
521		return (error);
522	mtx_lock(&Giant);
523	error = dosetrlimit(td, uap->which, &alim);
524	mtx_unlock(&Giant);
525	return (error);
526}
527
528int
529dosetrlimit(td, which, limp)
530	struct thread *td;
531	u_int which;
532	struct rlimit *limp;
533{
534	struct proc *p = td->td_proc;
535	register struct rlimit *alimp;
536	int error;
537
538	GIANT_REQUIRED;
539
540	if (which >= RLIM_NLIMITS)
541		return (EINVAL);
542	alimp = &p->p_rlimit[which];
543
544	/*
545	 * Preserve historical bugs by treating negative limits as unsigned.
546	 */
547	if (limp->rlim_cur < 0)
548		limp->rlim_cur = RLIM_INFINITY;
549	if (limp->rlim_max < 0)
550		limp->rlim_max = RLIM_INFINITY;
551
552	if (limp->rlim_cur > alimp->rlim_max ||
553	    limp->rlim_max > alimp->rlim_max)
554		if ((error = suser_cred(td->td_ucred, PRISON_ROOT)))
555			return (error);
556	if (limp->rlim_cur > limp->rlim_max)
557		limp->rlim_cur = limp->rlim_max;
558	if (p->p_limit->p_refcnt > 1 &&
559	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
560		p->p_limit->p_refcnt--;
561		p->p_limit = limcopy(p->p_limit);
562		alimp = &p->p_rlimit[which];
563	}
564
565	switch (which) {
566
567	case RLIMIT_CPU:
568		mtx_lock_spin(&sched_lock);
569		p->p_cpulimit = limp->rlim_cur;
570		mtx_unlock_spin(&sched_lock);
571		break;
572	case RLIMIT_DATA:
573		if (limp->rlim_cur > maxdsiz)
574			limp->rlim_cur = maxdsiz;
575		if (limp->rlim_max > maxdsiz)
576			limp->rlim_max = maxdsiz;
577		break;
578
579	case RLIMIT_STACK:
580		if (limp->rlim_cur > maxssiz)
581			limp->rlim_cur = maxssiz;
582		if (limp->rlim_max > maxssiz)
583			limp->rlim_max = maxssiz;
584		/*
585		 * Stack is allocated to the max at exec time with only
586		 * "rlim_cur" bytes accessible.  If stack limit is going
587		 * up make more accessible, if going down make inaccessible.
588		 */
589		if (limp->rlim_cur != alimp->rlim_cur) {
590			vm_offset_t addr;
591			vm_size_t size;
592			vm_prot_t prot;
593
594			if (limp->rlim_cur > alimp->rlim_cur) {
595				prot = p->p_sysent->sv_stackprot;
596				size = limp->rlim_cur - alimp->rlim_cur;
597				addr = p->p_sysent->sv_usrstack -
598				    limp->rlim_cur;
599			} else {
600				prot = VM_PROT_NONE;
601				size = alimp->rlim_cur - limp->rlim_cur;
602				addr = p->p_sysent->sv_usrstack -
603				    alimp->rlim_cur;
604			}
605			addr = trunc_page(addr);
606			size = round_page(size);
607			(void) vm_map_protect(&p->p_vmspace->vm_map,
608					      addr, addr+size, prot, FALSE);
609		}
610		break;
611
612	case RLIMIT_NOFILE:
613		if (limp->rlim_cur > maxfilesperproc)
614			limp->rlim_cur = maxfilesperproc;
615		if (limp->rlim_max > maxfilesperproc)
616			limp->rlim_max = maxfilesperproc;
617		break;
618
619	case RLIMIT_NPROC:
620		if (limp->rlim_cur > maxprocperuid)
621			limp->rlim_cur = maxprocperuid;
622		if (limp->rlim_max > maxprocperuid)
623			limp->rlim_max = maxprocperuid;
624		if (limp->rlim_cur < 1)
625			limp->rlim_cur = 1;
626		if (limp->rlim_max < 1)
627			limp->rlim_max = 1;
628		break;
629	}
630	*alimp = *limp;
631	return (0);
632}
633
634#ifndef _SYS_SYSPROTO_H_
635struct __getrlimit_args {
636	u_int	which;
637	struct	rlimit *rlp;
638};
639#endif
640/*
641 * MPSAFE
642 */
643/* ARGSUSED */
644int
645getrlimit(td, uap)
646	struct thread *td;
647	register struct __getrlimit_args *uap;
648{
649	int error;
650	struct proc *p = td->td_proc;
651
652	if (uap->which >= RLIM_NLIMITS)
653		return (EINVAL);
654	mtx_lock(&Giant);
655	error = copyout(&p->p_rlimit[uap->which], uap->rlp,
656		    sizeof (struct rlimit));
657	mtx_unlock(&Giant);
658	return(error);
659}
660
661/*
662 * Transform the running time and tick information in proc p into user,
663 * system, and interrupt time usage.
664 */
665void
666calcru(p, up, sp, ip)
667	struct proc *p;
668	struct timeval *up;
669	struct timeval *sp;
670	struct timeval *ip;
671{
672	/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
673	u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
674	u_int64_t uut = 0, sut = 0, iut = 0;
675	int s;
676	struct timeval tv;
677	struct bintime bt;
678	struct kse *ke;
679	struct ksegrp *kg;
680
681	mtx_assert(&sched_lock, MA_OWNED);
682	/* XXX: why spl-protect ?  worst case is an off-by-one report */
683
684	FOREACH_KSEGRP_IN_PROC(p, kg) {
685		/* we could accumulate per ksegrp and per process here*/
686		FOREACH_KSE_IN_GROUP(kg, ke) {
687			s = splstatclock();
688			ut = ke->ke_uticks;
689			st = ke->ke_sticks;
690			it = ke->ke_iticks;
691			splx(s);
692
693			tt = ut + st + it;
694			if (tt == 0) {
695				st = 1;
696				tt = 1;
697			}
698
699			if (ke == curthread->td_kse) {
700		/*
701		 * Adjust for the current time slice.  This is actually fairly
702		 * important since the error here is on the order of a time
703		 * quantum, which is much greater than the sampling error.
704		 * XXXKSE use a different test due to threads on other
705		 * processors also being 'current'.
706		 */
707
708				binuptime(&bt);
709				bintime_sub(&bt, PCPU_PTR(switchtime));
710				bintime_add(&bt, &p->p_runtime);
711			} else {
712				bt = p->p_runtime;
713			}
714			bintime2timeval(&bt, &tv);
715			tu = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
716			ptu = ke->ke_uu + ke->ke_su + ke->ke_iu;
717			if (tu < ptu || (int64_t)tu < 0) {
718				/* XXX no %qd in kernel.  Truncate. */
719				printf("calcru: negative time of %ld usec for pid %d (%s)\n",
720		       		(long)tu, p->p_pid, p->p_comm);
721				tu = ptu;
722			}
723
724			/* Subdivide tu. */
725			uu = (tu * ut) / tt;
726			su = (tu * st) / tt;
727			iu = tu - uu - su;
728
729			/* Enforce monotonicity. */
730			if (uu < ke->ke_uu || su < ke->ke_su || iu < ke->ke_iu) {
731				if (uu < ke->ke_uu)
732					uu = ke->ke_uu;
733				else if (uu + ke->ke_su + ke->ke_iu > tu)
734					uu = tu - ke->ke_su - ke->ke_iu;
735				if (st == 0)
736					su = ke->ke_su;
737				else {
738					su = ((tu - uu) * st) / (st + it);
739					if (su < ke->ke_su)
740						su = ke->ke_su;
741					else if (uu + su + ke->ke_iu > tu)
742						su = tu - uu - ke->ke_iu;
743				}
744				KASSERT(uu + su + ke->ke_iu <= tu,
745		    		("calcru: monotonisation botch 1"));
746				iu = tu - uu - su;
747				KASSERT(iu >= ke->ke_iu,
748		    		("calcru: monotonisation botch 2"));
749			}
750			ke->ke_uu = uu;
751			ke->ke_su = su;
752			ke->ke_iu = iu;
753			uut += uu;
754			sut += su;
755			iut += iu;
756
757		} /* end kse loop */
758	} /* end kseg loop */
759	up->tv_sec = uut / 1000000;
760	up->tv_usec = uut % 1000000;
761	sp->tv_sec = sut / 1000000;
762	sp->tv_usec = sut % 1000000;
763	if (ip != NULL) {
764		ip->tv_sec = iut / 1000000;
765		ip->tv_usec = iut % 1000000;
766	}
767}
768
769#ifndef _SYS_SYSPROTO_H_
770struct getrusage_args {
771	int	who;
772	struct	rusage *rusage;
773};
774#endif
775/*
776 * MPSAFE
777 */
778/* ARGSUSED */
779int
780getrusage(td, uap)
781	register struct thread *td;
782	register struct getrusage_args *uap;
783{
784	struct proc *p = td->td_proc;
785	register struct rusage *rup;
786	int error = 0;
787
788	mtx_lock(&Giant);
789
790	switch (uap->who) {
791	case RUSAGE_SELF:
792		rup = &p->p_stats->p_ru;
793		mtx_lock_spin(&sched_lock);
794		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
795		mtx_unlock_spin(&sched_lock);
796		break;
797
798	case RUSAGE_CHILDREN:
799		rup = &p->p_stats->p_cru;
800		break;
801
802	default:
803		rup = NULL;
804		error = EINVAL;
805		break;
806	}
807	mtx_unlock(&Giant);
808	if (error == 0) {
809		error = copyout(rup, uap->rusage, sizeof (struct rusage));
810	}
811	return(error);
812}
813
814void
815ruadd(ru, ru2)
816	register struct rusage *ru, *ru2;
817{
818	register long *ip, *ip2;
819	register int i;
820
821	timevaladd(&ru->ru_utime, &ru2->ru_utime);
822	timevaladd(&ru->ru_stime, &ru2->ru_stime);
823	if (ru->ru_maxrss < ru2->ru_maxrss)
824		ru->ru_maxrss = ru2->ru_maxrss;
825	ip = &ru->ru_first; ip2 = &ru2->ru_first;
826	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
827		*ip++ += *ip2++;
828}
829
830/*
831 * Make a copy of the plimit structure.
832 * We share these structures copy-on-write after fork,
833 * and copy when a limit is changed.
834 */
835struct plimit *
836limcopy(lim)
837	struct plimit *lim;
838{
839	register struct plimit *copy;
840
841	MALLOC(copy, struct plimit *, sizeof(struct plimit),
842	    M_SUBPROC, 0);
843	bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
844	copy->p_lflags = 0;
845	copy->p_refcnt = 1;
846	return (copy);
847}
848
849/*
850 * Find the uidinfo structure for a uid.  This structure is used to
851 * track the total resource consumption (process count, socket buffer
852 * size, etc.) for the uid and impose limits.
853 */
854void
855uihashinit()
856{
857
858	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
859	mtx_init(&uihashtbl_mtx, "uidinfo hash", NULL, MTX_DEF);
860}
861
862/*
863 * lookup a uidinfo struct for the parameter uid.
864 * uihashtbl_mtx must be locked.
865 */
866static struct uidinfo *
867uilookup(uid)
868	uid_t uid;
869{
870	struct	uihashhead *uipp;
871	struct	uidinfo *uip;
872
873	mtx_assert(&uihashtbl_mtx, MA_OWNED);
874	uipp = UIHASH(uid);
875	LIST_FOREACH(uip, uipp, ui_hash)
876		if (uip->ui_uid == uid)
877			break;
878
879	return (uip);
880}
881
882/*
883 * Find or allocate a struct uidinfo for a particular uid.
884 * Increase refcount on uidinfo struct returned.
885 * uifree() should be called on a struct uidinfo when released.
886 */
887struct uidinfo *
888uifind(uid)
889	uid_t uid;
890{
891	struct	uidinfo *uip;
892
893	mtx_lock(&uihashtbl_mtx);
894	uip = uilookup(uid);
895	if (uip == NULL) {
896		struct  uidinfo *old_uip;
897
898		mtx_unlock(&uihashtbl_mtx);
899		uip = malloc(sizeof(*uip), M_UIDINFO, M_ZERO);
900		mtx_lock(&uihashtbl_mtx);
901		/*
902		 * There's a chance someone created our uidinfo while we
903		 * were in malloc and not holding the lock, so we have to
904		 * make sure we don't insert a duplicate uidinfo
905		 */
906		if ((old_uip = uilookup(uid)) != NULL) {
907			/* someone else beat us to it */
908			free(uip, M_UIDINFO);
909			uip = old_uip;
910		} else {
911			uip->ui_mtxp = mtx_pool_alloc();
912			uip->ui_uid = uid;
913			LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
914		}
915	}
916	uihold(uip);
917	mtx_unlock(&uihashtbl_mtx);
918	return (uip);
919}
920
921/*
922 * Place another refcount on a uidinfo struct.
923 */
924void
925uihold(uip)
926	struct uidinfo *uip;
927{
928
929	UIDINFO_LOCK(uip);
930	uip->ui_ref++;
931	UIDINFO_UNLOCK(uip);
932}
933
934/*-
935 * Since uidinfo structs have a long lifetime, we use an
936 * opportunistic refcounting scheme to avoid locking the lookup hash
937 * for each release.
938 *
939 * If the refcount hits 0, we need to free the structure,
940 * which means we need to lock the hash.
941 * Optimal case:
942 *   After locking the struct and lowering the refcount, if we find
943 *   that we don't need to free, simply unlock and return.
944 * Suboptimal case:
945 *   If refcount lowering results in need to free, bump the count
946 *   back up, loose the lock and aquire the locks in the proper
947 *   order to try again.
948 */
949void
950uifree(uip)
951	struct uidinfo *uip;
952{
953
954	/* Prepare for optimal case. */
955	UIDINFO_LOCK(uip);
956
957	if (--uip->ui_ref != 0) {
958		UIDINFO_UNLOCK(uip);
959		return;
960	}
961
962	/* Prepare for suboptimal case. */
963	uip->ui_ref++;
964	UIDINFO_UNLOCK(uip);
965	mtx_lock(&uihashtbl_mtx);
966	UIDINFO_LOCK(uip);
967
968	/*
969	 * We must subtract one from the count again because we backed out
970	 * our initial subtraction before dropping the lock.
971	 * Since another thread may have added a reference after we dropped the
972	 * initial lock we have to test for zero again.
973	 */
974	if (--uip->ui_ref == 0) {
975		LIST_REMOVE(uip, ui_hash);
976		mtx_unlock(&uihashtbl_mtx);
977		if (uip->ui_sbsize != 0)
978			/* XXX no %qd in kernel.  Truncate. */
979			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
980			    uip->ui_uid, (long)uip->ui_sbsize);
981		if (uip->ui_proccnt != 0)
982			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
983			    uip->ui_uid, uip->ui_proccnt);
984		UIDINFO_UNLOCK(uip);
985		FREE(uip, M_UIDINFO);
986		return;
987	}
988
989	mtx_unlock(&uihashtbl_mtx);
990	UIDINFO_UNLOCK(uip);
991}
992
993/*
994 * Change the count associated with number of processes
995 * a given user is using.  When 'max' is 0, don't enforce a limit
996 */
997int
998chgproccnt(uip, diff, max)
999	struct	uidinfo	*uip;
1000	int	diff;
1001	int	max;
1002{
1003
1004	UIDINFO_LOCK(uip);
1005	/* don't allow them to exceed max, but allow subtraction */
1006	if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
1007		UIDINFO_UNLOCK(uip);
1008		return (0);
1009	}
1010	uip->ui_proccnt += diff;
1011	if (uip->ui_proccnt < 0)
1012		printf("negative proccnt for uid = %d\n", uip->ui_uid);
1013	UIDINFO_UNLOCK(uip);
1014	return (1);
1015}
1016
1017/*
1018 * Change the total socket buffer size a user has used.
1019 */
1020int
1021chgsbsize(uip, hiwat, to, max)
1022	struct	uidinfo	*uip;
1023	u_int  *hiwat;
1024	u_int	to;
1025	rlim_t	max;
1026{
1027	rlim_t new;
1028	int s;
1029
1030	s = splnet();
1031	UIDINFO_LOCK(uip);
1032	new = uip->ui_sbsize + to - *hiwat;
1033	/* don't allow them to exceed max, but allow subtraction */
1034	if (to > *hiwat && new > max) {
1035		splx(s);
1036		UIDINFO_UNLOCK(uip);
1037		return (0);
1038	}
1039	uip->ui_sbsize = new;
1040	*hiwat = to;
1041	if (uip->ui_sbsize < 0)
1042		printf("negative sbsize for uid = %d\n", uip->ui_uid);
1043	splx(s);
1044	UIDINFO_UNLOCK(uip);
1045	return (1);
1046}
1047