xref: /freebsd/sys/kern/kern_resource.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
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  * $FreeBSD$
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/sx.h>
55 #include <sys/time.h>
56 
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_map.h>
61 
62 static int donice(struct proc *curp, struct proc *chgp, int n);
63 
64 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
65 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
66 static struct mtx uihashtbl_mtx;
67 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
68 static u_long uihash;		/* size of hash table - 1 */
69 
70 static struct uidinfo	*uilookup(uid_t uid);
71 
72 /*
73  * Resource controls and accounting.
74  */
75 
76 #ifndef _SYS_SYSPROTO_H_
77 struct getpriority_args {
78 	int	which;
79 	int	who;
80 };
81 #endif
82 /*
83  * MPSAFE
84  */
85 int
86 getpriority(td, uap)
87 	struct thread *td;
88 	register struct getpriority_args *uap;
89 {
90 	struct proc *curp = td->td_proc;
91 	register struct proc *p;
92 	register int low = PRIO_MAX + 1;
93 	int error = 0;
94 
95 	mtx_lock(&Giant);
96 
97 	switch (uap->which) {
98 	case PRIO_PROCESS:
99 		if (uap->who == 0)
100 			low = td->td_ksegrp->kg_nice;
101 		else {
102 			p = pfind(uap->who);
103 			if (p == NULL)
104 				break;
105 			if (p_cansee(curp, p) == 0)
106 				low = p->p_ksegrp.kg_nice /* XXXKSE */ ;
107 			PROC_UNLOCK(p);
108 		}
109 		break;
110 
111 	case PRIO_PGRP: {
112 		register struct pgrp *pg;
113 
114 		PGRPSESS_SLOCK();
115 		if (uap->who == 0) {
116 			pg = curp->p_pgrp;
117 			PGRP_LOCK(pg);
118 		} else {
119 			pg = pgfind(uap->who);
120 			if (pg == NULL) {
121 				PGRPSESS_SUNLOCK();
122 				break;
123 			}
124 		}
125 		PGRPSESS_SUNLOCK();
126 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
127 			PROC_LOCK(p);
128 			if (!p_cansee(curp, p) && p->p_ksegrp.kg_nice /* XXXKSE */  < low)
129 				low = p->p_ksegrp.kg_nice /* XXXKSE */ ;
130 			PROC_UNLOCK(p);
131 		}
132 		PGRP_UNLOCK(pg);
133 		break;
134 	}
135 
136 	case PRIO_USER:
137 		if (uap->who == 0)
138 			uap->who = curp->p_ucred->cr_uid;
139 		sx_slock(&allproc_lock);
140 		LIST_FOREACH(p, &allproc, p_list)
141 			if (!p_cansee(curp, p) &&
142 			    p->p_ucred->cr_uid == uap->who &&
143 			    p->p_ksegrp.kg_nice /* XXXKSE */  < low)
144 				low = p->p_ksegrp.kg_nice /* XXXKSE */ ;
145 		sx_sunlock(&allproc_lock);
146 		break;
147 
148 	default:
149 		error = EINVAL;
150 		break;
151 	}
152 	if (low == PRIO_MAX + 1 && error == 0)
153 		error = ESRCH;
154 	td->td_retval[0] = low;
155 	mtx_unlock(&Giant);
156 	return (error);
157 }
158 
159 #ifndef _SYS_SYSPROTO_H_
160 struct setpriority_args {
161 	int	which;
162 	int	who;
163 	int	prio;
164 };
165 #endif
166 /*
167  * MPSAFE
168  */
169 /* ARGSUSED */
170 int
171 setpriority(td, uap)
172 	struct thread *td;
173 	register struct setpriority_args *uap;
174 {
175 	struct proc *curp = td->td_proc;
176 	register struct proc *p;
177 	int found = 0, error = 0;
178 
179 	mtx_lock(&Giant);
180 
181 	switch (uap->which) {
182 	case PRIO_PROCESS:
183 		if (uap->who == 0)
184 			error = donice(curp, curp, uap->prio);
185 		else {
186 			p = pfind(uap->who);
187 			if (p == 0)
188 				break;
189 			if (p_cansee(curp, p) == 0)
190 				error = donice(curp, p, uap->prio);
191 			PROC_UNLOCK(p);
192 		}
193 		found++;
194 		break;
195 
196 	case PRIO_PGRP: {
197 		register struct pgrp *pg;
198 
199 		PGRPSESS_SLOCK();
200 		if (uap->who == 0) {
201 			pg = curp->p_pgrp;
202 			PGRP_LOCK(pg);
203 		} else {
204 			pg = pgfind(uap->who);
205 			if (pg == NULL) {
206 				PGRPSESS_SUNLOCK();
207 				break;
208 			}
209 		}
210 		PGRPSESS_SUNLOCK();
211 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
212 			PROC_LOCK(p);
213 			if (!p_cansee(curp, p)) {
214 				error = donice(curp, p, uap->prio);
215 				found++;
216 			}
217 			PROC_UNLOCK(p);
218 		}
219 		PGRP_UNLOCK(pg);
220 		break;
221 	}
222 
223 	case PRIO_USER:
224 		if (uap->who == 0)
225 			uap->who = curp->p_ucred->cr_uid;
226 		sx_slock(&allproc_lock);
227 		FOREACH_PROC_IN_SYSTEM(p) {
228 			if (p->p_ucred->cr_uid == uap->who &&
229 			    !p_cansee(curp, p)) {
230 				error = donice(curp, p, uap->prio);
231 				found++;
232 			}
233 		}
234 		sx_sunlock(&allproc_lock);
235 		break;
236 
237 	default:
238 		error = EINVAL;
239 		break;
240 	}
241 	if (found == 0 && error == 0)
242 		error = ESRCH;
243 	mtx_unlock(&Giant);
244 	return (error);
245 }
246 
247 static int
248 donice(curp, chgp, n)
249 	register struct proc *curp, *chgp;
250 	register int n;
251 {
252 	int	error;
253 
254 	if ((error = p_cansched(curp, chgp)))
255 		return (error);
256 	if (n > PRIO_MAX)
257 		n = PRIO_MAX;
258 	if (n < PRIO_MIN)
259 		n = PRIO_MIN;
260 	if (n < chgp->p_ksegrp.kg_nice /* XXXKSE */  &&
261 	    suser_xxx(curp->p_ucred, NULL, 0))
262 		return (EACCES);
263 	chgp->p_ksegrp.kg_nice /* XXXKSE */  = n;
264 	(void)resetpriority(&chgp->p_ksegrp); /* XXXKSE */
265 	return (0);
266 }
267 
268 /* rtprio system call */
269 #ifndef _SYS_SYSPROTO_H_
270 struct rtprio_args {
271 	int		function;
272 	pid_t		pid;
273 	struct rtprio	*rtp;
274 };
275 #endif
276 
277 /*
278  * Set realtime priority
279  */
280 
281 /*
282  * MPSAFE
283  */
284 /* ARGSUSED */
285 int
286 rtprio(td, uap)
287 	struct thread *td;
288 	register struct rtprio_args *uap;
289 {
290 	struct proc *curp = td->td_proc;
291 	register struct proc *p;
292 	struct rtprio rtp;
293 	int error;
294 
295 	mtx_lock(&Giant);
296 
297 	if (uap->pid == 0) {
298 		p = curp;
299 		PROC_LOCK(p);
300 	} else {
301 		p = pfind(uap->pid);
302 	}
303 
304 	if (p == NULL) {
305 		error = ESRCH;
306 		goto done2;
307 	}
308 
309 	switch (uap->function) {
310 	case RTP_LOOKUP:
311 		if ((error = p_cansee(curp, p)))
312 			break;
313 		mtx_lock_spin(&sched_lock);
314 		pri_to_rtp(&p->p_ksegrp /* XXXKSE */ , &rtp);
315 		mtx_unlock_spin(&sched_lock);
316 		error = copyout(&rtp, uap->rtp, sizeof(struct rtprio));
317 		break;
318 	case RTP_SET:
319 		if ((error = p_cansched(curp, p)) ||
320 		    (error = copyin(uap->rtp, &rtp, sizeof(struct rtprio))))
321 			break;
322 		/* disallow setting rtprio in most cases if not superuser */
323 		if (suser_xxx(curp->p_ucred, NULL, 0) != 0) {
324 			/* can't set someone else's */
325 			if (uap->pid) {
326 				error = EPERM;
327 				break;
328 			}
329 			/* can't set realtime priority */
330 /*
331  * Realtime priority has to be restricted for reasons which should be
332  * obvious. However, for idle priority, there is a potential for
333  * system deadlock if an idleprio process gains a lock on a resource
334  * that other processes need (and the idleprio process can't run
335  * due to a CPU-bound normal process). Fix me! XXX
336  */
337 #if 0
338  			if (RTP_PRIO_IS_REALTIME(rtp.type))
339 #endif
340 			if (rtp.type != RTP_PRIO_NORMAL) {
341 				error = EPERM;
342 				break;
343 			}
344 		}
345 		mtx_lock_spin(&sched_lock);
346 		error = rtp_to_pri(&rtp, &p->p_ksegrp);
347 		mtx_unlock_spin(&sched_lock);
348 		break;
349 	default:
350 		error = EINVAL;
351 		break;
352 	}
353 	PROC_UNLOCK(p);
354 done2:
355 	mtx_unlock(&Giant);
356 	return (error);
357 }
358 
359 int
360 rtp_to_pri(struct rtprio *rtp, struct ksegrp *kg)
361 {
362 
363 	if (rtp->prio > RTP_PRIO_MAX)
364 		return (EINVAL);
365 	switch (RTP_PRIO_BASE(rtp->type)) {
366 	case RTP_PRIO_REALTIME:
367 		kg->kg_user_pri = PRI_MIN_REALTIME + rtp->prio;
368 		break;
369 	case RTP_PRIO_NORMAL:
370 		kg->kg_user_pri = PRI_MIN_TIMESHARE + rtp->prio;
371 		break;
372 	case RTP_PRIO_IDLE:
373 		kg->kg_user_pri = PRI_MIN_IDLE + rtp->prio;
374 		break;
375 	default:
376 		return (EINVAL);
377 	}
378 	kg->kg_pri_class = rtp->type;
379 	if (curthread->td_ksegrp == kg) {
380 		curthread->td_base_pri = kg->kg_user_pri;
381 		curthread->td_priority = kg->kg_user_pri; /* XXX dubious */
382 	}
383 	return (0);
384 }
385 
386 void
387 pri_to_rtp(struct ksegrp *kg, struct rtprio *rtp)
388 {
389 
390 	switch (PRI_BASE(kg->kg_pri_class)) {
391 	case PRI_REALTIME:
392 		rtp->prio = kg->kg_user_pri - PRI_MIN_REALTIME;
393 		break;
394 	case PRI_TIMESHARE:
395 		rtp->prio = kg->kg_user_pri - PRI_MIN_TIMESHARE;
396 		break;
397 	case PRI_IDLE:
398 		rtp->prio = kg->kg_user_pri - PRI_MIN_IDLE;
399 		break;
400 	default:
401 		break;
402 	}
403 	rtp->type = kg->kg_pri_class;
404 }
405 
406 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
407 #ifndef _SYS_SYSPROTO_H_
408 struct osetrlimit_args {
409 	u_int	which;
410 	struct	orlimit *rlp;
411 };
412 #endif
413 /*
414  * MPSAFE
415  */
416 /* ARGSUSED */
417 int
418 osetrlimit(td, uap)
419 	struct thread *td;
420 	register struct osetrlimit_args *uap;
421 {
422 	struct orlimit olim;
423 	struct rlimit lim;
424 	int error;
425 
426 	if ((error =
427 	    copyin((caddr_t)uap->rlp, (caddr_t)&olim, sizeof(struct orlimit))))
428 		return (error);
429 	lim.rlim_cur = olim.rlim_cur;
430 	lim.rlim_max = olim.rlim_max;
431 	mtx_lock(&Giant);
432 	error = dosetrlimit(td, uap->which, &lim);
433 	mtx_unlock(&Giant);
434 	return (error);
435 }
436 
437 #ifndef _SYS_SYSPROTO_H_
438 struct ogetrlimit_args {
439 	u_int	which;
440 	struct	orlimit *rlp;
441 };
442 #endif
443 /*
444  * MPSAFE
445  */
446 /* ARGSUSED */
447 int
448 ogetrlimit(td, uap)
449 	struct thread *td;
450 	register struct ogetrlimit_args *uap;
451 {
452 	struct proc *p = td->td_proc;
453 	struct orlimit olim;
454 	int error;
455 
456 	if (uap->which >= RLIM_NLIMITS)
457 		return (EINVAL);
458 	mtx_lock(&Giant);
459 	olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
460 	if (olim.rlim_cur == -1)
461 		olim.rlim_cur = 0x7fffffff;
462 	olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
463 	if (olim.rlim_max == -1)
464 		olim.rlim_max = 0x7fffffff;
465 	error = copyout((caddr_t)&olim, (caddr_t)uap->rlp, sizeof(olim));
466 	mtx_unlock(&Giant);
467 	return (error);
468 }
469 #endif /* COMPAT_43 || COMPAT_SUNOS */
470 
471 #ifndef _SYS_SYSPROTO_H_
472 struct __setrlimit_args {
473 	u_int	which;
474 	struct	rlimit *rlp;
475 };
476 #endif
477 /*
478  * MPSAFE
479  */
480 /* ARGSUSED */
481 int
482 setrlimit(td, uap)
483 	struct thread *td;
484 	register struct __setrlimit_args *uap;
485 {
486 	struct rlimit alim;
487 	int error;
488 
489 	if ((error =
490 	    copyin((caddr_t)uap->rlp, (caddr_t)&alim, sizeof (struct rlimit))))
491 		return (error);
492 	mtx_lock(&Giant);
493 	error = dosetrlimit(td, uap->which, &alim);
494 	mtx_unlock(&Giant);
495 	return (error);
496 }
497 
498 int
499 dosetrlimit(td, which, limp)
500 	struct thread *td;
501 	u_int which;
502 	struct rlimit *limp;
503 {
504 	struct proc *p = td->td_proc;
505 	register struct rlimit *alimp;
506 	int error;
507 
508 	GIANT_REQUIRED;
509 
510 	if (which >= RLIM_NLIMITS)
511 		return (EINVAL);
512 	alimp = &p->p_rlimit[which];
513 
514 	/*
515 	 * Preserve historical bugs by treating negative limits as unsigned.
516 	 */
517 	if (limp->rlim_cur < 0)
518 		limp->rlim_cur = RLIM_INFINITY;
519 	if (limp->rlim_max < 0)
520 		limp->rlim_max = RLIM_INFINITY;
521 
522 	if (limp->rlim_cur > alimp->rlim_max ||
523 	    limp->rlim_max > alimp->rlim_max)
524 		if ((error = suser_xxx(0, p, PRISON_ROOT)))
525 			return (error);
526 	if (limp->rlim_cur > limp->rlim_max)
527 		limp->rlim_cur = limp->rlim_max;
528 	if (p->p_limit->p_refcnt > 1 &&
529 	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
530 		p->p_limit->p_refcnt--;
531 		p->p_limit = limcopy(p->p_limit);
532 		alimp = &p->p_rlimit[which];
533 	}
534 
535 	switch (which) {
536 
537 	case RLIMIT_CPU:
538 		if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000)
539 			p->p_limit->p_cpulimit = RLIM_INFINITY;
540 		else
541 			p->p_limit->p_cpulimit =
542 			    (rlim_t)1000000 * limp->rlim_cur;
543 		break;
544 	case RLIMIT_DATA:
545 		if (limp->rlim_cur > maxdsiz)
546 			limp->rlim_cur = maxdsiz;
547 		if (limp->rlim_max > maxdsiz)
548 			limp->rlim_max = maxdsiz;
549 		break;
550 
551 	case RLIMIT_STACK:
552 		if (limp->rlim_cur > maxssiz)
553 			limp->rlim_cur = maxssiz;
554 		if (limp->rlim_max > maxssiz)
555 			limp->rlim_max = maxssiz;
556 		/*
557 		 * Stack is allocated to the max at exec time with only
558 		 * "rlim_cur" bytes accessible.  If stack limit is going
559 		 * up make more accessible, if going down make inaccessible.
560 		 */
561 		if (limp->rlim_cur != alimp->rlim_cur) {
562 			vm_offset_t addr;
563 			vm_size_t size;
564 			vm_prot_t prot;
565 
566 			if (limp->rlim_cur > alimp->rlim_cur) {
567 				prot = VM_PROT_ALL;
568 				size = limp->rlim_cur - alimp->rlim_cur;
569 				addr = USRSTACK - limp->rlim_cur;
570 			} else {
571 				prot = VM_PROT_NONE;
572 				size = alimp->rlim_cur - limp->rlim_cur;
573 				addr = USRSTACK - alimp->rlim_cur;
574 			}
575 			addr = trunc_page(addr);
576 			size = round_page(size);
577 			(void) vm_map_protect(&p->p_vmspace->vm_map,
578 					      addr, addr+size, prot, FALSE);
579 		}
580 		break;
581 
582 	case RLIMIT_NOFILE:
583 		if (limp->rlim_cur > maxfilesperproc)
584 			limp->rlim_cur = maxfilesperproc;
585 		if (limp->rlim_max > maxfilesperproc)
586 			limp->rlim_max = maxfilesperproc;
587 		break;
588 
589 	case RLIMIT_NPROC:
590 		if (limp->rlim_cur > maxprocperuid)
591 			limp->rlim_cur = maxprocperuid;
592 		if (limp->rlim_max > maxprocperuid)
593 			limp->rlim_max = maxprocperuid;
594 		if (limp->rlim_cur < 1)
595 			limp->rlim_cur = 1;
596 		if (limp->rlim_max < 1)
597 			limp->rlim_max = 1;
598 		break;
599 	}
600 	*alimp = *limp;
601 	return (0);
602 }
603 
604 #ifndef _SYS_SYSPROTO_H_
605 struct __getrlimit_args {
606 	u_int	which;
607 	struct	rlimit *rlp;
608 };
609 #endif
610 /*
611  * MPSAFE
612  */
613 /* ARGSUSED */
614 int
615 getrlimit(td, uap)
616 	struct thread *td;
617 	register struct __getrlimit_args *uap;
618 {
619 	int error;
620 	struct proc *p = td->td_proc;
621 
622 	if (uap->which >= RLIM_NLIMITS)
623 		return (EINVAL);
624 	mtx_lock(&Giant);
625 	error = copyout((caddr_t)&p->p_rlimit[uap->which], (caddr_t)uap->rlp,
626 		    sizeof (struct rlimit));
627 	mtx_unlock(&Giant);
628 	return(error);
629 }
630 
631 /*
632  * Transform the running time and tick information in proc p into user,
633  * system, and interrupt time usage.
634  */
635 void
636 calcru(p, up, sp, ip)
637 	struct proc *p;
638 	struct timeval *up;
639 	struct timeval *sp;
640 	struct timeval *ip;
641 {
642 	/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
643 	u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
644 	u_int64_t uut = 0, sut = 0, iut = 0;
645 	int s;
646 	struct timeval tv;
647 	struct bintime bt;
648 	struct kse *ke;
649 	struct ksegrp *kg;
650 
651 	mtx_assert(&sched_lock, MA_OWNED);
652 	/* XXX: why spl-protect ?  worst case is an off-by-one report */
653 
654 	FOREACH_KSEGRP_IN_PROC(p, kg) {
655 		/* we could accumulate per ksegrp and per process here*/
656 		FOREACH_KSE_IN_GROUP(kg, ke) {
657 			s = splstatclock();
658 			ut = ke->ke_uticks;
659 			st = ke->ke_sticks;
660 			it = ke->ke_iticks;
661 			splx(s);
662 
663 			tt = ut + st + it;
664 			if (tt == 0) {
665 				st = 1;
666 				tt = 1;
667 			}
668 
669 			if (ke == curthread->td_kse) {
670 		/*
671 		 * Adjust for the current time slice.  This is actually fairly
672 		 * important since the error here is on the order of a time
673 		 * quantum, which is much greater than the sampling error.
674 		 * XXXKSE use a different test due to threads on other
675 		 * processors also being 'current'.
676 		 */
677 
678 				binuptime(&bt);
679 				bintime_sub(&bt, PCPU_PTR(switchtime));
680 				bintime_add(&bt, &p->p_runtime);
681 			} else {
682 				bt = p->p_runtime;
683 			}
684 			bintime2timeval(&bt, &tv);
685 			tu = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
686 			ptu = ke->ke_uu + ke->ke_su + ke->ke_iu;
687 			if (tu < ptu || (int64_t)tu < 0) {
688 				/* XXX no %qd in kernel.  Truncate. */
689 				printf("calcru: negative time of %ld usec for pid %d (%s)\n",
690 		       		(long)tu, p->p_pid, p->p_comm);
691 				tu = ptu;
692 			}
693 
694 			/* Subdivide tu. */
695 			uu = (tu * ut) / tt;
696 			su = (tu * st) / tt;
697 			iu = tu - uu - su;
698 
699 			/* Enforce monotonicity. */
700 			if (uu < ke->ke_uu || su < ke->ke_su || iu < ke->ke_iu) {
701 				if (uu < ke->ke_uu)
702 					uu = ke->ke_uu;
703 				else if (uu + ke->ke_su + ke->ke_iu > tu)
704 					uu = tu - ke->ke_su - ke->ke_iu;
705 				if (st == 0)
706 					su = ke->ke_su;
707 				else {
708 					su = ((tu - uu) * st) / (st + it);
709 					if (su < ke->ke_su)
710 						su = ke->ke_su;
711 					else if (uu + su + ke->ke_iu > tu)
712 						su = tu - uu - ke->ke_iu;
713 				}
714 				KASSERT(uu + su + ke->ke_iu <= tu,
715 		    		("calcru: monotonisation botch 1"));
716 				iu = tu - uu - su;
717 				KASSERT(iu >= ke->ke_iu,
718 		    		("calcru: monotonisation botch 2"));
719 			}
720 			ke->ke_uu = uu;
721 			ke->ke_su = su;
722 			ke->ke_iu = iu;
723 			uut += uu;
724 			sut += su;
725 			iut += iu;
726 
727 		} /* end kse loop */
728 	} /* end kseg loop */
729 	up->tv_sec = uut / 1000000;
730 	up->tv_usec = uut % 1000000;
731 	sp->tv_sec = sut / 1000000;
732 	sp->tv_usec = sut % 1000000;
733 	if (ip != NULL) {
734 		ip->tv_sec = iut / 1000000;
735 		ip->tv_usec = iut % 1000000;
736 	}
737 }
738 
739 #ifndef _SYS_SYSPROTO_H_
740 struct getrusage_args {
741 	int	who;
742 	struct	rusage *rusage;
743 };
744 #endif
745 /*
746  * MPSAFE
747  */
748 /* ARGSUSED */
749 int
750 getrusage(td, uap)
751 	register struct thread *td;
752 	register struct getrusage_args *uap;
753 {
754 	struct proc *p = td->td_proc;
755 	register struct rusage *rup;
756 	int error = 0;
757 
758 	mtx_lock(&Giant);
759 
760 	switch (uap->who) {
761 	case RUSAGE_SELF:
762 		rup = &p->p_stats->p_ru;
763 		mtx_lock_spin(&sched_lock);
764 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
765 		mtx_unlock_spin(&sched_lock);
766 		break;
767 
768 	case RUSAGE_CHILDREN:
769 		rup = &p->p_stats->p_cru;
770 		break;
771 
772 	default:
773 		rup = NULL;
774 		error = EINVAL;
775 		break;
776 	}
777 	mtx_unlock(&Giant);
778 	if (error == 0) {
779 		error = copyout((caddr_t)rup, (caddr_t)uap->rusage,
780 		    sizeof (struct rusage));
781 	}
782 	return(error);
783 }
784 
785 void
786 ruadd(ru, ru2)
787 	register struct rusage *ru, *ru2;
788 {
789 	register long *ip, *ip2;
790 	register int i;
791 
792 	timevaladd(&ru->ru_utime, &ru2->ru_utime);
793 	timevaladd(&ru->ru_stime, &ru2->ru_stime);
794 	if (ru->ru_maxrss < ru2->ru_maxrss)
795 		ru->ru_maxrss = ru2->ru_maxrss;
796 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
797 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
798 		*ip++ += *ip2++;
799 }
800 
801 /*
802  * Make a copy of the plimit structure.
803  * We share these structures copy-on-write after fork,
804  * and copy when a limit is changed.
805  */
806 struct plimit *
807 limcopy(lim)
808 	struct plimit *lim;
809 {
810 	register struct plimit *copy;
811 
812 	MALLOC(copy, struct plimit *, sizeof(struct plimit),
813 	    M_SUBPROC, M_WAITOK);
814 	bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
815 	copy->p_lflags = 0;
816 	copy->p_refcnt = 1;
817 	return (copy);
818 }
819 
820 /*
821  * Find the uidinfo structure for a uid.  This structure is used to
822  * track the total resource consumption (process count, socket buffer
823  * size, etc.) for the uid and impose limits.
824  */
825 void
826 uihashinit()
827 {
828 
829 	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
830 	mtx_init(&uihashtbl_mtx, "uidinfo hash", MTX_DEF);
831 }
832 
833 /*
834  * lookup a uidinfo struct for the parameter uid.
835  * uihashtbl_mtx must be locked.
836  */
837 static struct uidinfo *
838 uilookup(uid)
839 	uid_t uid;
840 {
841 	struct	uihashhead *uipp;
842 	struct	uidinfo *uip;
843 
844 	mtx_assert(&uihashtbl_mtx, MA_OWNED);
845 	uipp = UIHASH(uid);
846 	LIST_FOREACH(uip, uipp, ui_hash)
847 		if (uip->ui_uid == uid)
848 			break;
849 
850 	return (uip);
851 }
852 
853 /*
854  * Find or allocate a struct uidinfo for a particular uid.
855  * Increase refcount on uidinfo struct returned.
856  * uifree() should be called on a struct uidinfo when released.
857  */
858 struct uidinfo *
859 uifind(uid)
860 	uid_t uid;
861 {
862 	struct	uidinfo *uip;
863 
864 	mtx_lock(&uihashtbl_mtx);
865 	uip = uilookup(uid);
866 	if (uip == NULL) {
867 		struct  uidinfo *old_uip;
868 
869 		mtx_unlock(&uihashtbl_mtx);
870 		uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
871 		mtx_lock(&uihashtbl_mtx);
872 		/*
873 		 * There's a chance someone created our uidinfo while we
874 		 * were in malloc and not holding the lock, so we have to
875 		 * make sure we don't insert a duplicate uidinfo
876 		 */
877 		if ((old_uip = uilookup(uid)) != NULL) {
878 			/* someone else beat us to it */
879 			free(uip, M_UIDINFO);
880 			uip = old_uip;
881 		} else {
882 			uip->ui_mtxp = mtx_pool_alloc();
883 			uip->ui_uid = uid;
884 			LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
885 		}
886 	}
887 	uihold(uip);
888 	mtx_unlock(&uihashtbl_mtx);
889 	return (uip);
890 }
891 
892 /*
893  * Place another refcount on a uidinfo struct.
894  */
895 void
896 uihold(uip)
897 	struct uidinfo *uip;
898 {
899 
900 	UIDINFO_LOCK(uip);
901 	uip->ui_ref++;
902 	UIDINFO_UNLOCK(uip);
903 }
904 
905 /*-
906  * Since uidinfo structs have a long lifetime, we use an
907  * opportunistic refcounting scheme to avoid locking the lookup hash
908  * for each release.
909  *
910  * If the refcount hits 0, we need to free the structure,
911  * which means we need to lock the hash.
912  * Optimal case:
913  *   After locking the struct and lowering the refcount, if we find
914  *   that we don't need to free, simply unlock and return.
915  * Suboptimal case:
916  *   If refcount lowering results in need to free, bump the count
917  *   back up, loose the lock and aquire the locks in the proper
918  *   order to try again.
919  */
920 void
921 uifree(uip)
922 	struct uidinfo *uip;
923 {
924 
925 	/* Prepare for optimal case. */
926 	UIDINFO_LOCK(uip);
927 
928 	if (--uip->ui_ref != 0) {
929 		UIDINFO_UNLOCK(uip);
930 		return;
931 	}
932 
933 	/* Prepare for suboptimal case. */
934 	uip->ui_ref++;
935 	UIDINFO_UNLOCK(uip);
936 	mtx_lock(&uihashtbl_mtx);
937 	UIDINFO_LOCK(uip);
938 
939 	/*
940 	 * We must subtract one from the count again because we backed out
941 	 * our initial subtraction before dropping the lock.
942 	 * Since another thread may have added a reference after we dropped the
943 	 * initial lock we have to test for zero again.
944 	 */
945 	if (--uip->ui_ref == 0) {
946 		LIST_REMOVE(uip, ui_hash);
947 		mtx_unlock(&uihashtbl_mtx);
948 		if (uip->ui_sbsize != 0)
949 			/* XXX no %qd in kernel.  Truncate. */
950 			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
951 			    uip->ui_uid, (long)uip->ui_sbsize);
952 		if (uip->ui_proccnt != 0)
953 			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
954 			    uip->ui_uid, uip->ui_proccnt);
955 		UIDINFO_UNLOCK(uip);
956 		FREE(uip, M_UIDINFO);
957 		return;
958 	}
959 
960 	mtx_unlock(&uihashtbl_mtx);
961 	UIDINFO_UNLOCK(uip);
962 }
963 
964 /*
965  * Change the count associated with number of processes
966  * a given user is using.  When 'max' is 0, don't enforce a limit
967  */
968 int
969 chgproccnt(uip, diff, max)
970 	struct	uidinfo	*uip;
971 	int	diff;
972 	int	max;
973 {
974 
975 	UIDINFO_LOCK(uip);
976 	/* don't allow them to exceed max, but allow subtraction */
977 	if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
978 		UIDINFO_UNLOCK(uip);
979 		return (0);
980 	}
981 	uip->ui_proccnt += diff;
982 	if (uip->ui_proccnt < 0)
983 		printf("negative proccnt for uid = %d\n", uip->ui_uid);
984 	UIDINFO_UNLOCK(uip);
985 	return (1);
986 }
987 
988 /*
989  * Change the total socket buffer size a user has used.
990  */
991 int
992 chgsbsize(uip, hiwat, to, max)
993 	struct	uidinfo	*uip;
994 	u_long *hiwat;
995 	u_long	to;
996 	rlim_t	max;
997 {
998 	rlim_t new;
999 	int s;
1000 
1001 	s = splnet();
1002 	UIDINFO_LOCK(uip);
1003 	new = uip->ui_sbsize + to - *hiwat;
1004 	/* don't allow them to exceed max, but allow subtraction */
1005 	if (to > *hiwat && new > max) {
1006 		splx(s);
1007 		UIDINFO_UNLOCK(uip);
1008 		return (0);
1009 	}
1010 	uip->ui_sbsize = new;
1011 	*hiwat = to;
1012 	if (uip->ui_sbsize < 0)
1013 		printf("negative sbsize for uid = %d\n", uip->ui_uid);
1014 	splx(s);
1015 	UIDINFO_UNLOCK(uip);
1016 	return (1);
1017 }
1018