xref: /netbsd/sys/kern/kern_resource.c (revision 6550d01e)
1 /*	$NetBSD: kern_resource.c,v 1.157 2010/07/01 02:38:30 rmind Exp $	*/
2 
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  *	@(#)kern_resource.c	8.8 (Berkeley) 2/14/95
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: kern_resource.c,v 1.157 2010/07/01 02:38:30 rmind Exp $");
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/file.h>
46 #include <sys/resourcevar.h>
47 #include <sys/malloc.h>
48 #include <sys/kmem.h>
49 #include <sys/namei.h>
50 #include <sys/pool.h>
51 #include <sys/proc.h>
52 #include <sys/sysctl.h>
53 #include <sys/timevar.h>
54 #include <sys/kauth.h>
55 #include <sys/atomic.h>
56 #include <sys/mount.h>
57 #include <sys/syscallargs.h>
58 #include <sys/atomic.h>
59 
60 #include <uvm/uvm_extern.h>
61 
62 /*
63  * Maximum process data and stack limits.
64  * They are variables so they are patchable.
65  */
66 rlim_t maxdmap = MAXDSIZ;
67 rlim_t maxsmap = MAXSSIZ;
68 
69 static pool_cache_t	plimit_cache;
70 static pool_cache_t	pstats_cache;
71 
72 static kauth_listener_t	resource_listener;
73 
74 static void sysctl_proc_setup(void);
75 
76 static int
77 resource_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
78     void *arg0, void *arg1, void *arg2, void *arg3)
79 {
80 	struct proc *p;
81 	int result;
82 
83 	result = KAUTH_RESULT_DEFER;
84 	p = arg0;
85 
86 	switch (action) {
87 	case KAUTH_PROCESS_NICE:
88 		if (kauth_cred_geteuid(cred) != kauth_cred_geteuid(p->p_cred) &&
89                     kauth_cred_getuid(cred) != kauth_cred_geteuid(p->p_cred)) {
90                         break;
91                 }
92 
93                 if ((u_long)arg1 >= p->p_nice)
94                         result = KAUTH_RESULT_ALLOW;
95 
96 		break;
97 
98 	case KAUTH_PROCESS_RLIMIT: {
99 		enum kauth_process_req req;
100 
101 		req = (enum kauth_process_req)(unsigned long)arg1;
102 
103 		switch (req) {
104 		case KAUTH_REQ_PROCESS_RLIMIT_GET:
105 			result = KAUTH_RESULT_ALLOW;
106 			break;
107 
108 		case KAUTH_REQ_PROCESS_RLIMIT_SET: {
109 			struct rlimit *new_rlimit;
110 			u_long which;
111 
112 			if ((p != curlwp->l_proc) &&
113 			    (proc_uidmatch(cred, p->p_cred) != 0))
114 				break;
115 
116 			new_rlimit = arg2;
117 			which = (u_long)arg3;
118 
119 			if (new_rlimit->rlim_max <= p->p_rlimit[which].rlim_max)
120 				result = KAUTH_RESULT_ALLOW;
121 
122 			break;
123 			}
124 
125 		default:
126 			break;
127 		}
128 
129 		break;
130 	}
131 
132 	default:
133 		break;
134 	}
135 
136 	return result;
137 }
138 
139 void
140 resource_init(void)
141 {
142 
143 	plimit_cache = pool_cache_init(sizeof(struct plimit), 0, 0, 0,
144 	    "plimitpl", NULL, IPL_NONE, NULL, NULL, NULL);
145 	pstats_cache = pool_cache_init(sizeof(struct pstats), 0, 0, 0,
146 	    "pstatspl", NULL, IPL_NONE, NULL, NULL, NULL);
147 
148 	resource_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
149 	    resource_listener_cb, NULL);
150 
151 	sysctl_proc_setup();
152 }
153 
154 /*
155  * Resource controls and accounting.
156  */
157 
158 int
159 sys_getpriority(struct lwp *l, const struct sys_getpriority_args *uap,
160     register_t *retval)
161 {
162 	/* {
163 		syscallarg(int) which;
164 		syscallarg(id_t) who;
165 	} */
166 	struct proc *curp = l->l_proc, *p;
167 	int low = NZERO + PRIO_MAX + 1;
168 	int who = SCARG(uap, who);
169 
170 	mutex_enter(proc_lock);
171 	switch (SCARG(uap, which)) {
172 	case PRIO_PROCESS:
173 		p = who ? proc_find(who) : curp;;
174 		if (p != NULL)
175 			low = p->p_nice;
176 		break;
177 
178 	case PRIO_PGRP: {
179 		struct pgrp *pg;
180 
181 		if (who == 0)
182 			pg = curp->p_pgrp;
183 		else if ((pg = pgrp_find(who)) == NULL)
184 			break;
185 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
186 			if (p->p_nice < low)
187 				low = p->p_nice;
188 		}
189 		break;
190 	}
191 
192 	case PRIO_USER:
193 		if (who == 0)
194 			who = (int)kauth_cred_geteuid(l->l_cred);
195 		PROCLIST_FOREACH(p, &allproc) {
196 			mutex_enter(p->p_lock);
197 			if (kauth_cred_geteuid(p->p_cred) ==
198 			    (uid_t)who && p->p_nice < low)
199 				low = p->p_nice;
200 			mutex_exit(p->p_lock);
201 		}
202 		break;
203 
204 	default:
205 		mutex_exit(proc_lock);
206 		return (EINVAL);
207 	}
208 	mutex_exit(proc_lock);
209 
210 	if (low == NZERO + PRIO_MAX + 1)
211 		return (ESRCH);
212 	*retval = low - NZERO;
213 	return (0);
214 }
215 
216 /* ARGSUSED */
217 int
218 sys_setpriority(struct lwp *l, const struct sys_setpriority_args *uap,
219     register_t *retval)
220 {
221 	/* {
222 		syscallarg(int) which;
223 		syscallarg(id_t) who;
224 		syscallarg(int) prio;
225 	} */
226 	struct proc *curp = l->l_proc, *p;
227 	int found = 0, error = 0;
228 	int who = SCARG(uap, who);
229 
230 	mutex_enter(proc_lock);
231 	switch (SCARG(uap, which)) {
232 	case PRIO_PROCESS:
233 		p = who ? proc_find(who) : curp;
234 		if (p != NULL) {
235 			mutex_enter(p->p_lock);
236 			error = donice(l, p, SCARG(uap, prio));
237 			mutex_exit(p->p_lock);
238 			found++;
239 		}
240 		break;
241 
242 	case PRIO_PGRP: {
243 		struct pgrp *pg;
244 
245 		if (who == 0)
246 			pg = curp->p_pgrp;
247 		else if ((pg = pgrp_find(who)) == NULL)
248 			break;
249 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
250 			mutex_enter(p->p_lock);
251 			error = donice(l, p, SCARG(uap, prio));
252 			mutex_exit(p->p_lock);
253 			found++;
254 		}
255 		break;
256 	}
257 
258 	case PRIO_USER:
259 		if (who == 0)
260 			who = (int)kauth_cred_geteuid(l->l_cred);
261 		PROCLIST_FOREACH(p, &allproc) {
262 			mutex_enter(p->p_lock);
263 			if (kauth_cred_geteuid(p->p_cred) ==
264 			    (uid_t)SCARG(uap, who)) {
265 				error = donice(l, p, SCARG(uap, prio));
266 				found++;
267 			}
268 			mutex_exit(p->p_lock);
269 		}
270 		break;
271 
272 	default:
273 		mutex_exit(proc_lock);
274 		return EINVAL;
275 	}
276 	mutex_exit(proc_lock);
277 	if (found == 0)
278 		return (ESRCH);
279 	return (error);
280 }
281 
282 /*
283  * Renice a process.
284  *
285  * Call with the target process' credentials locked.
286  */
287 int
288 donice(struct lwp *l, struct proc *chgp, int n)
289 {
290 	kauth_cred_t cred = l->l_cred;
291 
292 	KASSERT(mutex_owned(chgp->p_lock));
293 
294 	if (kauth_cred_geteuid(cred) && kauth_cred_getuid(cred) &&
295 	    kauth_cred_geteuid(cred) != kauth_cred_geteuid(chgp->p_cred) &&
296 	    kauth_cred_getuid(cred) != kauth_cred_geteuid(chgp->p_cred))
297 		return (EPERM);
298 
299 	if (n > PRIO_MAX)
300 		n = PRIO_MAX;
301 	if (n < PRIO_MIN)
302 		n = PRIO_MIN;
303 	n += NZERO;
304 	if (kauth_authorize_process(cred, KAUTH_PROCESS_NICE, chgp,
305 	    KAUTH_ARG(n), NULL, NULL))
306 		return (EACCES);
307 	sched_nice(chgp, n);
308 	return (0);
309 }
310 
311 /* ARGSUSED */
312 int
313 sys_setrlimit(struct lwp *l, const struct sys_setrlimit_args *uap,
314     register_t *retval)
315 {
316 	/* {
317 		syscallarg(int) which;
318 		syscallarg(const struct rlimit *) rlp;
319 	} */
320 	int which = SCARG(uap, which);
321 	struct rlimit alim;
322 	int error;
323 
324 	error = copyin(SCARG(uap, rlp), &alim, sizeof(struct rlimit));
325 	if (error)
326 		return (error);
327 	return (dosetrlimit(l, l->l_proc, which, &alim));
328 }
329 
330 int
331 dosetrlimit(struct lwp *l, struct proc *p, int which, struct rlimit *limp)
332 {
333 	struct rlimit *alimp;
334 	int error;
335 
336 	if ((u_int)which >= RLIM_NLIMITS)
337 		return (EINVAL);
338 
339 	if (limp->rlim_cur > limp->rlim_max) {
340 		/*
341 		 * This is programming error. According to SUSv2, we should
342 		 * return error in this case.
343 		 */
344 		return (EINVAL);
345 	}
346 
347 	alimp = &p->p_rlimit[which];
348 	/* if we don't change the value, no need to limcopy() */
349 	if (limp->rlim_cur == alimp->rlim_cur &&
350 	    limp->rlim_max == alimp->rlim_max)
351 		return 0;
352 
353 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
354 	    p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_SET), limp, KAUTH_ARG(which));
355 	if (error)
356 		return (error);
357 
358 	lim_privatise(p, false);
359 	/* p->p_limit is now unchangeable */
360 	alimp = &p->p_rlimit[which];
361 
362 	switch (which) {
363 
364 	case RLIMIT_DATA:
365 		if (limp->rlim_cur > maxdmap)
366 			limp->rlim_cur = maxdmap;
367 		if (limp->rlim_max > maxdmap)
368 			limp->rlim_max = maxdmap;
369 		break;
370 
371 	case RLIMIT_STACK:
372 		if (limp->rlim_cur > maxsmap)
373 			limp->rlim_cur = maxsmap;
374 		if (limp->rlim_max > maxsmap)
375 			limp->rlim_max = maxsmap;
376 
377 		/*
378 		 * Return EINVAL if the new stack size limit is lower than
379 		 * current usage. Otherwise, the process would get SIGSEGV the
380 		 * moment it would try to access anything on it's current stack.
381 		 * This conforms to SUSv2.
382 		 */
383 		if (limp->rlim_cur < p->p_vmspace->vm_ssize * PAGE_SIZE
384 		    || limp->rlim_max < p->p_vmspace->vm_ssize * PAGE_SIZE) {
385 			return (EINVAL);
386 		}
387 
388 		/*
389 		 * Stack is allocated to the max at exec time with
390 		 * only "rlim_cur" bytes accessible (In other words,
391 		 * allocates stack dividing two contiguous regions at
392 		 * "rlim_cur" bytes boundary).
393 		 *
394 		 * Since allocation is done in terms of page, roundup
395 		 * "rlim_cur" (otherwise, contiguous regions
396 		 * overlap).  If stack limit is going up make more
397 		 * accessible, if going down make inaccessible.
398 		 */
399 		limp->rlim_cur = round_page(limp->rlim_cur);
400 		if (limp->rlim_cur != alimp->rlim_cur) {
401 			vaddr_t addr;
402 			vsize_t size;
403 			vm_prot_t prot;
404 
405 			if (limp->rlim_cur > alimp->rlim_cur) {
406 				prot = VM_PROT_READ | VM_PROT_WRITE;
407 				size = limp->rlim_cur - alimp->rlim_cur;
408 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
409 				    limp->rlim_cur;
410 			} else {
411 				prot = VM_PROT_NONE;
412 				size = alimp->rlim_cur - limp->rlim_cur;
413 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
414 				     alimp->rlim_cur;
415 			}
416 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
417 			    addr, addr+size, prot, false);
418 		}
419 		break;
420 
421 	case RLIMIT_NOFILE:
422 		if (limp->rlim_cur > maxfiles)
423 			limp->rlim_cur = maxfiles;
424 		if (limp->rlim_max > maxfiles)
425 			limp->rlim_max = maxfiles;
426 		break;
427 
428 	case RLIMIT_NPROC:
429 		if (limp->rlim_cur > maxproc)
430 			limp->rlim_cur = maxproc;
431 		if (limp->rlim_max > maxproc)
432 			limp->rlim_max = maxproc;
433 		break;
434 	}
435 
436 	mutex_enter(&p->p_limit->pl_lock);
437 	*alimp = *limp;
438 	mutex_exit(&p->p_limit->pl_lock);
439 	return (0);
440 }
441 
442 /* ARGSUSED */
443 int
444 sys_getrlimit(struct lwp *l, const struct sys_getrlimit_args *uap,
445     register_t *retval)
446 {
447 	/* {
448 		syscallarg(int) which;
449 		syscallarg(struct rlimit *) rlp;
450 	} */
451 	struct proc *p = l->l_proc;
452 	int which = SCARG(uap, which);
453 	struct rlimit rl;
454 
455 	if ((u_int)which >= RLIM_NLIMITS)
456 		return (EINVAL);
457 
458 	mutex_enter(p->p_lock);
459 	memcpy(&rl, &p->p_rlimit[which], sizeof(rl));
460 	mutex_exit(p->p_lock);
461 
462 	return copyout(&rl, SCARG(uap, rlp), sizeof(rl));
463 }
464 
465 /*
466  * Transform the running time and tick information in proc p into user,
467  * system, and interrupt time usage.
468  *
469  * Should be called with p->p_lock held unless called from exit1().
470  */
471 void
472 calcru(struct proc *p, struct timeval *up, struct timeval *sp,
473     struct timeval *ip, struct timeval *rp)
474 {
475 	uint64_t u, st, ut, it, tot;
476 	struct lwp *l;
477 	struct bintime tm;
478 	struct timeval tv;
479 
480 	mutex_spin_enter(&p->p_stmutex);
481 	st = p->p_sticks;
482 	ut = p->p_uticks;
483 	it = p->p_iticks;
484 	mutex_spin_exit(&p->p_stmutex);
485 
486 	tm = p->p_rtime;
487 
488 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
489 		lwp_lock(l);
490 		bintime_add(&tm, &l->l_rtime);
491 		if ((l->l_pflag & LP_RUNNING) != 0) {
492 			struct bintime diff;
493 			/*
494 			 * Adjust for the current time slice.  This is
495 			 * actually fairly important since the error
496 			 * here is on the order of a time quantum,
497 			 * which is much greater than the sampling
498 			 * error.
499 			 */
500 			binuptime(&diff);
501 			bintime_sub(&diff, &l->l_stime);
502 			bintime_add(&tm, &diff);
503 		}
504 		lwp_unlock(l);
505 	}
506 
507 	tot = st + ut + it;
508 	bintime2timeval(&tm, &tv);
509 	u = (uint64_t)tv.tv_sec * 1000000ul + tv.tv_usec;
510 
511 	if (tot == 0) {
512 		/* No ticks, so can't use to share time out, split 50-50 */
513 		st = ut = u / 2;
514 	} else {
515 		st = (u * st) / tot;
516 		ut = (u * ut) / tot;
517 	}
518 	if (sp != NULL) {
519 		sp->tv_sec = st / 1000000;
520 		sp->tv_usec = st % 1000000;
521 	}
522 	if (up != NULL) {
523 		up->tv_sec = ut / 1000000;
524 		up->tv_usec = ut % 1000000;
525 	}
526 	if (ip != NULL) {
527 		if (it != 0)
528 			it = (u * it) / tot;
529 		ip->tv_sec = it / 1000000;
530 		ip->tv_usec = it % 1000000;
531 	}
532 	if (rp != NULL) {
533 		*rp = tv;
534 	}
535 }
536 
537 /* ARGSUSED */
538 int
539 sys___getrusage50(struct lwp *l, const struct sys___getrusage50_args *uap,
540     register_t *retval)
541 {
542 	/* {
543 		syscallarg(int) who;
544 		syscallarg(struct rusage *) rusage;
545 	} */
546 	struct rusage ru;
547 	struct proc *p = l->l_proc;
548 
549 	switch (SCARG(uap, who)) {
550 	case RUSAGE_SELF:
551 		mutex_enter(p->p_lock);
552 		memcpy(&ru, &p->p_stats->p_ru, sizeof(ru));
553 		calcru(p, &ru.ru_utime, &ru.ru_stime, NULL, NULL);
554 		rulwps(p, &ru);
555 		mutex_exit(p->p_lock);
556 		break;
557 
558 	case RUSAGE_CHILDREN:
559 		mutex_enter(p->p_lock);
560 		memcpy(&ru, &p->p_stats->p_cru, sizeof(ru));
561 		mutex_exit(p->p_lock);
562 		break;
563 
564 	default:
565 		return EINVAL;
566 	}
567 
568 	return copyout(&ru, SCARG(uap, rusage), sizeof(ru));
569 }
570 
571 void
572 ruadd(struct rusage *ru, struct rusage *ru2)
573 {
574 	long *ip, *ip2;
575 	int i;
576 
577 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
578 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
579 	if (ru->ru_maxrss < ru2->ru_maxrss)
580 		ru->ru_maxrss = ru2->ru_maxrss;
581 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
582 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
583 		*ip++ += *ip2++;
584 }
585 
586 void
587 rulwps(proc_t *p, struct rusage *ru)
588 {
589 	lwp_t *l;
590 
591 	KASSERT(mutex_owned(p->p_lock));
592 
593 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
594 		ruadd(ru, &l->l_ru);
595 		ru->ru_nvcsw += (l->l_ncsw - l->l_nivcsw);
596 		ru->ru_nivcsw += l->l_nivcsw;
597 	}
598 }
599 
600 /*
601  * Make a copy of the plimit structure.
602  * We share these structures copy-on-write after fork,
603  * and copy when a limit is changed.
604  *
605  * Unfortunately (due to PL_SHAREMOD) it is possibly for the structure
606  * we are copying to change beneath our feet!
607  */
608 struct plimit *
609 lim_copy(struct plimit *lim)
610 {
611 	struct plimit *newlim;
612 	char *corename;
613 	size_t alen, len;
614 
615 	newlim = pool_cache_get(plimit_cache, PR_WAITOK);
616 	mutex_init(&newlim->pl_lock, MUTEX_DEFAULT, IPL_NONE);
617 	newlim->pl_flags = 0;
618 	newlim->pl_refcnt = 1;
619 	newlim->pl_sv_limit = NULL;
620 
621 	mutex_enter(&lim->pl_lock);
622 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
623 	    sizeof(struct rlimit) * RLIM_NLIMITS);
624 
625 	alen = 0;
626 	corename = NULL;
627 	for (;;) {
628 		if (lim->pl_corename == defcorename) {
629 			newlim->pl_corename = defcorename;
630 			break;
631 		}
632 		len = strlen(lim->pl_corename) + 1;
633 		if (len <= alen) {
634 			newlim->pl_corename = corename;
635 			memcpy(corename, lim->pl_corename, len);
636 			corename = NULL;
637 			break;
638 		}
639 		mutex_exit(&lim->pl_lock);
640 		if (corename != NULL)
641 			free(corename, M_TEMP);
642 		alen = len;
643 		corename = malloc(alen, M_TEMP, M_WAITOK);
644 		mutex_enter(&lim->pl_lock);
645 	}
646 	mutex_exit(&lim->pl_lock);
647 	if (corename != NULL)
648 		free(corename, M_TEMP);
649 	return newlim;
650 }
651 
652 void
653 lim_addref(struct plimit *lim)
654 {
655 	atomic_inc_uint(&lim->pl_refcnt);
656 }
657 
658 /*
659  * Give a process it's own private plimit structure.
660  * This will only be shared (in fork) if modifications are to be shared.
661  */
662 void
663 lim_privatise(struct proc *p, bool set_shared)
664 {
665 	struct plimit *lim, *newlim;
666 
667 	lim = p->p_limit;
668 	if (lim->pl_flags & PL_WRITEABLE) {
669 		if (set_shared)
670 			lim->pl_flags |= PL_SHAREMOD;
671 		return;
672 	}
673 
674 	if (set_shared && lim->pl_flags & PL_SHAREMOD)
675 		return;
676 
677 	newlim = lim_copy(lim);
678 
679 	mutex_enter(p->p_lock);
680 	if (p->p_limit->pl_flags & PL_WRITEABLE) {
681 		/* Someone crept in while we were busy */
682 		mutex_exit(p->p_lock);
683 		limfree(newlim);
684 		if (set_shared)
685 			p->p_limit->pl_flags |= PL_SHAREMOD;
686 		return;
687 	}
688 
689 	/*
690 	 * Since most accesses to p->p_limit aren't locked, we must not
691 	 * delete the old limit structure yet.
692 	 */
693 	newlim->pl_sv_limit = p->p_limit;
694 	newlim->pl_flags |= PL_WRITEABLE;
695 	if (set_shared)
696 		newlim->pl_flags |= PL_SHAREMOD;
697 	p->p_limit = newlim;
698 	mutex_exit(p->p_lock);
699 }
700 
701 void
702 limfree(struct plimit *lim)
703 {
704 	struct plimit *sv_lim;
705 
706 	do {
707 		if (atomic_dec_uint_nv(&lim->pl_refcnt) > 0)
708 			return;
709 		if (lim->pl_corename != defcorename)
710 			free(lim->pl_corename, M_TEMP);
711 		sv_lim = lim->pl_sv_limit;
712 		mutex_destroy(&lim->pl_lock);
713 		pool_cache_put(plimit_cache, lim);
714 	} while ((lim = sv_lim) != NULL);
715 }
716 
717 struct pstats *
718 pstatscopy(struct pstats *ps)
719 {
720 
721 	struct pstats *newps;
722 
723 	newps = pool_cache_get(pstats_cache, PR_WAITOK);
724 
725 	memset(&newps->pstat_startzero, 0,
726 	(unsigned) ((char *)&newps->pstat_endzero -
727 		    (char *)&newps->pstat_startzero));
728 	memcpy(&newps->pstat_startcopy, &ps->pstat_startcopy,
729 	((char *)&newps->pstat_endcopy -
730 	 (char *)&newps->pstat_startcopy));
731 
732 	return (newps);
733 
734 }
735 
736 void
737 pstatsfree(struct pstats *ps)
738 {
739 
740 	pool_cache_put(pstats_cache, ps);
741 }
742 
743 /*
744  * sysctl interface in five parts
745  */
746 
747 /*
748  * sysctl_proc_findproc: a routine for sysctl proc subtree helpers that
749  * need to pick a valid process by PID.
750  *
751  * => Hold a reference on the process, on success.
752  */
753 static int
754 sysctl_proc_findproc(lwp_t *l, pid_t pid, proc_t **p2)
755 {
756 	proc_t *p;
757 	int error;
758 
759 	if (pid == PROC_CURPROC) {
760 		p = l->l_proc;
761 	} else {
762 		mutex_enter(proc_lock);
763 		p = proc_find(pid);
764 		if (p == NULL) {
765 			mutex_exit(proc_lock);
766 			return ESRCH;
767 		}
768 	}
769 	error = rw_tryenter(&p->p_reflock, RW_READER) ? 0 : EBUSY;
770 	if (pid != PROC_CURPROC) {
771 		mutex_exit(proc_lock);
772 	}
773 	*p2 = p;
774 	return error;
775 }
776 
777 /*
778  * sysctl helper routine for setting a process's specific corefile
779  * name.  picks the process based on the given pid and checks the
780  * correctness of the new value.
781  */
782 static int
783 sysctl_proc_corename(SYSCTLFN_ARGS)
784 {
785 	struct proc *ptmp;
786 	struct plimit *lim;
787 	char *cname, *ocore, *tmp;
788 	struct sysctlnode node;
789 	int error = 0, len;
790 
791 	/*
792 	 * is this all correct?
793 	 */
794 	if (namelen != 0)
795 		return (EINVAL);
796 	if (name[-1] != PROC_PID_CORENAME)
797 		return (EINVAL);
798 
799 	/* Find the process.  Hold a reference (p_reflock), if found. */
800 	error = sysctl_proc_findproc(l, (pid_t)name[-2], &ptmp);
801 	if (error)
802 		return error;
803 
804 	/* XXX-elad */
805 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
806 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
807 	if (error) {
808 		rw_exit(&ptmp->p_reflock);
809 		return error;
810 	}
811 
812 	if (newp == NULL) {
813 		error = kauth_authorize_process(l->l_cred,
814 		    KAUTH_PROCESS_CORENAME, ptmp,
815 		    KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_GET), NULL, NULL);
816 		if (error) {
817 			rw_exit(&ptmp->p_reflock);
818 			return error;
819 		}
820 	}
821 
822 	/*
823 	 * let them modify a temporary copy of the core name
824 	 */
825 	cname = PNBUF_GET();
826 	lim = ptmp->p_limit;
827 	mutex_enter(&lim->pl_lock);
828 	strlcpy(cname, lim->pl_corename, MAXPATHLEN);
829 	mutex_exit(&lim->pl_lock);
830 
831 	node = *rnode;
832 	node.sysctl_data = cname;
833 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
834 
835 	/*
836 	 * if that failed, or they have nothing new to say, or we've
837 	 * heard it before...
838 	 */
839 	if (error || newp == NULL)
840 		goto done;
841 	lim = ptmp->p_limit;
842 	mutex_enter(&lim->pl_lock);
843 	error = strcmp(cname, lim->pl_corename);
844 	mutex_exit(&lim->pl_lock);
845 	if (error == 0) {
846 		/* Unchanged */
847 		goto done;
848 	}
849 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CORENAME,
850 	    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_SET), cname, NULL);
851 	if (error)
852 		goto done;
853 
854 	/*
855 	 * no error yet and cname now has the new core name in it.
856 	 * let's see if it looks acceptable.  it must be either "core"
857 	 * or end in ".core" or "/core".
858 	 */
859 	len = strlen(cname);
860 	if (len < 4) {
861 		error = EINVAL;
862 	} else if (strcmp(cname + len - 4, "core") != 0) {
863 		error = EINVAL;
864 	} else if (len > 4 && cname[len - 5] != '/' && cname[len - 5] != '.') {
865 		error = EINVAL;
866 	}
867 	if (error != 0) {
868 		goto done;
869 	}
870 
871 	/*
872 	 * hmm...looks good.  now...where do we put it?
873 	 */
874 	tmp = malloc(len + 1, M_TEMP, M_WAITOK|M_CANFAIL);
875 	if (tmp == NULL) {
876 		error = ENOMEM;
877 		goto done;
878 	}
879 	memcpy(tmp, cname, len + 1);
880 
881 	lim_privatise(ptmp, false);
882 	lim = ptmp->p_limit;
883 	mutex_enter(&lim->pl_lock);
884 	ocore = lim->pl_corename;
885 	lim->pl_corename = tmp;
886 	mutex_exit(&lim->pl_lock);
887 	if (ocore != defcorename)
888 		free(ocore, M_TEMP);
889 
890 done:
891 	rw_exit(&ptmp->p_reflock);
892 	PNBUF_PUT(cname);
893 	return error;
894 }
895 
896 /*
897  * sysctl helper routine for checking/setting a process's stop flags,
898  * one for fork and one for exec.
899  */
900 static int
901 sysctl_proc_stop(SYSCTLFN_ARGS)
902 {
903 	struct proc *ptmp;
904 	int i, f, error = 0;
905 	struct sysctlnode node;
906 
907 	if (namelen != 0)
908 		return (EINVAL);
909 
910 	/* Find the process.  Hold a reference (p_reflock), if found. */
911 	error = sysctl_proc_findproc(l, (pid_t)name[-2], &ptmp);
912 	if (error)
913 		return error;
914 
915 	/* XXX-elad */
916 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
917 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
918 	if (error)
919 		goto out;
920 
921 	switch (rnode->sysctl_num) {
922 	case PROC_PID_STOPFORK:
923 		f = PS_STOPFORK;
924 		break;
925 	case PROC_PID_STOPEXEC:
926 		f = PS_STOPEXEC;
927 		break;
928 	case PROC_PID_STOPEXIT:
929 		f = PS_STOPEXIT;
930 		break;
931 	default:
932 		error = EINVAL;
933 		goto out;
934 	}
935 
936 	i = (ptmp->p_flag & f) ? 1 : 0;
937 	node = *rnode;
938 	node.sysctl_data = &i;
939 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
940 	if (error || newp == NULL)
941 		goto out;
942 
943 	mutex_enter(ptmp->p_lock);
944 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_STOPFLAG,
945 	    ptmp, KAUTH_ARG(f), NULL, NULL);
946 	if (!error) {
947 		if (i) {
948 			ptmp->p_sflag |= f;
949 		} else {
950 			ptmp->p_sflag &= ~f;
951 		}
952 	}
953 	mutex_exit(ptmp->p_lock);
954 out:
955 	rw_exit(&ptmp->p_reflock);
956 	return error;
957 }
958 
959 /*
960  * sysctl helper routine for a process's rlimits as exposed by sysctl.
961  */
962 static int
963 sysctl_proc_plimit(SYSCTLFN_ARGS)
964 {
965 	struct proc *ptmp;
966 	u_int limitno;
967 	int which, error = 0;
968         struct rlimit alim;
969 	struct sysctlnode node;
970 
971 	if (namelen != 0)
972 		return (EINVAL);
973 
974 	which = name[-1];
975 	if (which != PROC_PID_LIMIT_TYPE_SOFT &&
976 	    which != PROC_PID_LIMIT_TYPE_HARD)
977 		return (EINVAL);
978 
979 	limitno = name[-2] - 1;
980 	if (limitno >= RLIM_NLIMITS)
981 		return (EINVAL);
982 
983 	if (name[-3] != PROC_PID_LIMIT)
984 		return (EINVAL);
985 
986 	/* Find the process.  Hold a reference (p_reflock), if found. */
987 	error = sysctl_proc_findproc(l, (pid_t)name[-4], &ptmp);
988 	if (error)
989 		return error;
990 
991 	/* XXX-elad */
992 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
993 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
994 	if (error)
995 		goto out;
996 
997 	/* Check if we can view limits. */
998 	if (newp == NULL) {
999 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
1000 		    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_GET), &alim,
1001 		    KAUTH_ARG(which));
1002 		if (error)
1003 			goto out;
1004 	}
1005 
1006 	node = *rnode;
1007 	memcpy(&alim, &ptmp->p_rlimit[limitno], sizeof(alim));
1008 	if (which == PROC_PID_LIMIT_TYPE_HARD)
1009 		node.sysctl_data = &alim.rlim_max;
1010 	else
1011 		node.sysctl_data = &alim.rlim_cur;
1012 
1013 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1014 	if (error || newp == NULL) {
1015 		goto out;
1016 	}
1017 	error = dosetrlimit(l, ptmp, limitno, &alim);
1018 out:
1019 	rw_exit(&ptmp->p_reflock);
1020 	return error;
1021 }
1022 
1023 static struct sysctllog *proc_sysctllog;
1024 
1025 /*
1026  * and finally, the actually glue that sticks it to the tree
1027  */
1028 static void
1029 sysctl_proc_setup()
1030 {
1031 
1032 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1033 		       CTLFLAG_PERMANENT,
1034 		       CTLTYPE_NODE, "proc", NULL,
1035 		       NULL, 0, NULL, 0,
1036 		       CTL_PROC, CTL_EOL);
1037 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1038 		       CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
1039 		       CTLTYPE_NODE, "curproc",
1040 		       SYSCTL_DESCR("Per-process settings"),
1041 		       NULL, 0, NULL, 0,
1042 		       CTL_PROC, PROC_CURPROC, CTL_EOL);
1043 
1044 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1045 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1046 		       CTLTYPE_STRING, "corename",
1047 		       SYSCTL_DESCR("Core file name"),
1048 		       sysctl_proc_corename, 0, NULL, MAXPATHLEN,
1049 		       CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
1050 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1051 		       CTLFLAG_PERMANENT,
1052 		       CTLTYPE_NODE, "rlimit",
1053 		       SYSCTL_DESCR("Process limits"),
1054 		       NULL, 0, NULL, 0,
1055 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);
1056 
1057 #define create_proc_plimit(s, n) do {					\
1058 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,			\
1059 		       CTLFLAG_PERMANENT,				\
1060 		       CTLTYPE_NODE, s,					\
1061 		       SYSCTL_DESCR("Process " s " limits"),		\
1062 		       NULL, 0, NULL, 0,				\
1063 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
1064 		       CTL_EOL);					\
1065 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,			\
1066 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
1067 		       CTLTYPE_QUAD, "soft",				\
1068 		       SYSCTL_DESCR("Process soft " s " limit"),	\
1069 		       sysctl_proc_plimit, 0, NULL, 0,			\
1070 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
1071 		       PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL);		\
1072 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,			\
1073 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
1074 		       CTLTYPE_QUAD, "hard",				\
1075 		       SYSCTL_DESCR("Process hard " s " limit"),	\
1076 		       sysctl_proc_plimit, 0, NULL, 0,			\
1077 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
1078 		       PROC_PID_LIMIT_TYPE_HARD, CTL_EOL);		\
1079 	} while (0/*CONSTCOND*/)
1080 
1081 	create_proc_plimit("cputime",		PROC_PID_LIMIT_CPU);
1082 	create_proc_plimit("filesize",		PROC_PID_LIMIT_FSIZE);
1083 	create_proc_plimit("datasize",		PROC_PID_LIMIT_DATA);
1084 	create_proc_plimit("stacksize",		PROC_PID_LIMIT_STACK);
1085 	create_proc_plimit("coredumpsize",	PROC_PID_LIMIT_CORE);
1086 	create_proc_plimit("memoryuse",		PROC_PID_LIMIT_RSS);
1087 	create_proc_plimit("memorylocked",	PROC_PID_LIMIT_MEMLOCK);
1088 	create_proc_plimit("maxproc",		PROC_PID_LIMIT_NPROC);
1089 	create_proc_plimit("descriptors",	PROC_PID_LIMIT_NOFILE);
1090 	create_proc_plimit("sbsize",		PROC_PID_LIMIT_SBSIZE);
1091 	create_proc_plimit("vmemoryuse",	PROC_PID_LIMIT_AS);
1092 
1093 #undef create_proc_plimit
1094 
1095 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1096 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1097 		       CTLTYPE_INT, "stopfork",
1098 		       SYSCTL_DESCR("Stop process at fork(2)"),
1099 		       sysctl_proc_stop, 0, NULL, 0,
1100 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
1101 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1102 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1103 		       CTLTYPE_INT, "stopexec",
1104 		       SYSCTL_DESCR("Stop process at execve(2)"),
1105 		       sysctl_proc_stop, 0, NULL, 0,
1106 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
1107 	sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
1108 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1109 		       CTLTYPE_INT, "stopexit",
1110 		       SYSCTL_DESCR("Stop process before completing exit"),
1111 		       sysctl_proc_stop, 0, NULL, 0,
1112 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
1113 }
1114