xref: /netbsd-src/sys/kern/kern_resource.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: kern_resource.c,v 1.151 2009/03/29 01:02:50 mrg 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 1.151 2009/03/29 01:02:50 mrg 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 void
73 resource_init(void)
74 {
75 
76 	plimit_cache = pool_cache_init(sizeof(struct plimit), 0, 0, 0,
77 	    "plimitpl", NULL, IPL_NONE, NULL, NULL, NULL);
78 	pstats_cache = pool_cache_init(sizeof(struct pstats), 0, 0, 0,
79 	    "pstatspl", NULL, IPL_NONE, NULL, NULL, NULL);
80 }
81 
82 /*
83  * Resource controls and accounting.
84  */
85 
86 int
87 sys_getpriority(struct lwp *l, const struct sys_getpriority_args *uap,
88     register_t *retval)
89 {
90 	/* {
91 		syscallarg(int) which;
92 		syscallarg(id_t) who;
93 	} */
94 	struct proc *curp = l->l_proc, *p;
95 	int low = NZERO + PRIO_MAX + 1;
96 	int who = SCARG(uap, who);
97 
98 	mutex_enter(proc_lock);
99 	switch (SCARG(uap, which)) {
100 	case PRIO_PROCESS:
101 		if (who == 0)
102 			p = curp;
103 		else
104 			p = p_find(who, PFIND_LOCKED);
105 		if (p != NULL)
106 			low = p->p_nice;
107 		break;
108 
109 	case PRIO_PGRP: {
110 		struct pgrp *pg;
111 
112 		if (who == 0)
113 			pg = curp->p_pgrp;
114 		else if ((pg = pg_find(who, PFIND_LOCKED)) == NULL)
115 			break;
116 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
117 			if (p->p_nice < low)
118 				low = p->p_nice;
119 		}
120 		break;
121 	}
122 
123 	case PRIO_USER:
124 		if (who == 0)
125 			who = (int)kauth_cred_geteuid(l->l_cred);
126 		PROCLIST_FOREACH(p, &allproc) {
127 			if ((p->p_flag & PK_MARKER) != 0)
128 				continue;
129 			mutex_enter(p->p_lock);
130 			if (kauth_cred_geteuid(p->p_cred) ==
131 			    (uid_t)who && p->p_nice < low)
132 				low = p->p_nice;
133 			mutex_exit(p->p_lock);
134 		}
135 		break;
136 
137 	default:
138 		mutex_exit(proc_lock);
139 		return (EINVAL);
140 	}
141 	mutex_exit(proc_lock);
142 
143 	if (low == NZERO + PRIO_MAX + 1)
144 		return (ESRCH);
145 	*retval = low - NZERO;
146 	return (0);
147 }
148 
149 /* ARGSUSED */
150 int
151 sys_setpriority(struct lwp *l, const struct sys_setpriority_args *uap,
152     register_t *retval)
153 {
154 	/* {
155 		syscallarg(int) which;
156 		syscallarg(id_t) who;
157 		syscallarg(int) prio;
158 	} */
159 	struct proc *curp = l->l_proc, *p;
160 	int found = 0, error = 0;
161 	int who = SCARG(uap, who);
162 
163 	mutex_enter(proc_lock);
164 	switch (SCARG(uap, which)) {
165 	case PRIO_PROCESS:
166 		if (who == 0)
167 			p = curp;
168 		else
169 			p = p_find(who, PFIND_LOCKED);
170 		if (p != 0) {
171 			mutex_enter(p->p_lock);
172 			error = donice(l, p, SCARG(uap, prio));
173 			mutex_exit(p->p_lock);
174 			found++;
175 		}
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 = pg_find(who, PFIND_LOCKED)) == NULL)
184 			break;
185 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
186 			mutex_enter(p->p_lock);
187 			error = donice(l, p, SCARG(uap, prio));
188 			mutex_exit(p->p_lock);
189 			found++;
190 		}
191 		break;
192 	}
193 
194 	case PRIO_USER:
195 		if (who == 0)
196 			who = (int)kauth_cred_geteuid(l->l_cred);
197 		PROCLIST_FOREACH(p, &allproc) {
198 			if ((p->p_flag & PK_MARKER) != 0)
199 				continue;
200 			mutex_enter(p->p_lock);
201 			if (kauth_cred_geteuid(p->p_cred) ==
202 			    (uid_t)SCARG(uap, who)) {
203 				error = donice(l, p, SCARG(uap, prio));
204 				found++;
205 			}
206 			mutex_exit(p->p_lock);
207 		}
208 		break;
209 
210 	default:
211 		mutex_exit(proc_lock);
212 		return EINVAL;
213 	}
214 	mutex_exit(proc_lock);
215 	if (found == 0)
216 		return (ESRCH);
217 	return (error);
218 }
219 
220 /*
221  * Renice a process.
222  *
223  * Call with the target process' credentials locked.
224  */
225 int
226 donice(struct lwp *l, struct proc *chgp, int n)
227 {
228 	kauth_cred_t cred = l->l_cred;
229 
230 	KASSERT(mutex_owned(chgp->p_lock));
231 
232 	if (n > PRIO_MAX)
233 		n = PRIO_MAX;
234 	if (n < PRIO_MIN)
235 		n = PRIO_MIN;
236 	n += NZERO;
237 	if (kauth_authorize_process(cred, KAUTH_PROCESS_NICE, chgp,
238 	    KAUTH_ARG(n), NULL, NULL))
239 		return (EACCES);
240 	sched_nice(chgp, n);
241 	return (0);
242 }
243 
244 /* ARGSUSED */
245 int
246 sys_setrlimit(struct lwp *l, const struct sys_setrlimit_args *uap,
247     register_t *retval)
248 {
249 	/* {
250 		syscallarg(int) which;
251 		syscallarg(const struct rlimit *) rlp;
252 	} */
253 	int which = SCARG(uap, which);
254 	struct rlimit alim;
255 	int error;
256 
257 	error = copyin(SCARG(uap, rlp), &alim, sizeof(struct rlimit));
258 	if (error)
259 		return (error);
260 	return (dosetrlimit(l, l->l_proc, which, &alim));
261 }
262 
263 int
264 dosetrlimit(struct lwp *l, struct proc *p, int which, struct rlimit *limp)
265 {
266 	struct rlimit *alimp;
267 	int error;
268 
269 	if ((u_int)which >= RLIM_NLIMITS)
270 		return (EINVAL);
271 
272 	if (limp->rlim_cur > limp->rlim_max) {
273 		/*
274 		 * This is programming error. According to SUSv2, we should
275 		 * return error in this case.
276 		 */
277 		return (EINVAL);
278 	}
279 
280 	alimp = &p->p_rlimit[which];
281 	/* if we don't change the value, no need to limcopy() */
282 	if (limp->rlim_cur == alimp->rlim_cur &&
283 	    limp->rlim_max == alimp->rlim_max)
284 		return 0;
285 
286 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
287 	    p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_SET), limp, KAUTH_ARG(which));
288 	if (error)
289 		return (error);
290 
291 	lim_privatise(p, false);
292 	/* p->p_limit is now unchangeable */
293 	alimp = &p->p_rlimit[which];
294 
295 	switch (which) {
296 
297 	case RLIMIT_DATA:
298 		if (limp->rlim_cur > maxdmap)
299 			limp->rlim_cur = maxdmap;
300 		if (limp->rlim_max > maxdmap)
301 			limp->rlim_max = maxdmap;
302 		break;
303 
304 	case RLIMIT_STACK:
305 		if (limp->rlim_cur > maxsmap)
306 			limp->rlim_cur = maxsmap;
307 		if (limp->rlim_max > maxsmap)
308 			limp->rlim_max = maxsmap;
309 
310 		/*
311 		 * Return EINVAL if the new stack size limit is lower than
312 		 * current usage. Otherwise, the process would get SIGSEGV the
313 		 * moment it would try to access anything on it's current stack.
314 		 * This conforms to SUSv2.
315 		 */
316 		if (limp->rlim_cur < p->p_vmspace->vm_ssize * PAGE_SIZE
317 		    || limp->rlim_max < p->p_vmspace->vm_ssize * PAGE_SIZE) {
318 			return (EINVAL);
319 		}
320 
321 		/*
322 		 * Stack is allocated to the max at exec time with
323 		 * only "rlim_cur" bytes accessible (In other words,
324 		 * allocates stack dividing two contiguous regions at
325 		 * "rlim_cur" bytes boundary).
326 		 *
327 		 * Since allocation is done in terms of page, roundup
328 		 * "rlim_cur" (otherwise, contiguous regions
329 		 * overlap).  If stack limit is going up make more
330 		 * accessible, if going down make inaccessible.
331 		 */
332 		limp->rlim_cur = round_page(limp->rlim_cur);
333 		if (limp->rlim_cur != alimp->rlim_cur) {
334 			vaddr_t addr;
335 			vsize_t size;
336 			vm_prot_t prot;
337 
338 			if (limp->rlim_cur > alimp->rlim_cur) {
339 				prot = VM_PROT_READ | VM_PROT_WRITE;
340 				size = limp->rlim_cur - alimp->rlim_cur;
341 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
342 				    limp->rlim_cur;
343 			} else {
344 				prot = VM_PROT_NONE;
345 				size = alimp->rlim_cur - limp->rlim_cur;
346 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
347 				     alimp->rlim_cur;
348 			}
349 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
350 			    addr, addr+size, prot, false);
351 		}
352 		break;
353 
354 	case RLIMIT_NOFILE:
355 		if (limp->rlim_cur > maxfiles)
356 			limp->rlim_cur = maxfiles;
357 		if (limp->rlim_max > maxfiles)
358 			limp->rlim_max = maxfiles;
359 		break;
360 
361 	case RLIMIT_NPROC:
362 		if (limp->rlim_cur > maxproc)
363 			limp->rlim_cur = maxproc;
364 		if (limp->rlim_max > maxproc)
365 			limp->rlim_max = maxproc;
366 		break;
367 	}
368 
369 	mutex_enter(&p->p_limit->pl_lock);
370 	*alimp = *limp;
371 	mutex_exit(&p->p_limit->pl_lock);
372 	return (0);
373 }
374 
375 /* ARGSUSED */
376 int
377 sys_getrlimit(struct lwp *l, const struct sys_getrlimit_args *uap,
378     register_t *retval)
379 {
380 	/* {
381 		syscallarg(int) which;
382 		syscallarg(struct rlimit *) rlp;
383 	} */
384 	struct proc *p = l->l_proc;
385 	int which = SCARG(uap, which);
386 	struct rlimit rl;
387 
388 	if ((u_int)which >= RLIM_NLIMITS)
389 		return (EINVAL);
390 
391 	mutex_enter(p->p_lock);
392 	memcpy(&rl, &p->p_rlimit[which], sizeof(rl));
393 	mutex_exit(p->p_lock);
394 
395 	return copyout(&rl, SCARG(uap, rlp), sizeof(rl));
396 }
397 
398 /*
399  * Transform the running time and tick information in proc p into user,
400  * system, and interrupt time usage.
401  *
402  * Should be called with p->p_lock held unless called from exit1().
403  */
404 void
405 calcru(struct proc *p, struct timeval *up, struct timeval *sp,
406     struct timeval *ip, struct timeval *rp)
407 {
408 	uint64_t u, st, ut, it, tot;
409 	struct lwp *l;
410 	struct bintime tm;
411 	struct timeval tv;
412 
413 	mutex_spin_enter(&p->p_stmutex);
414 	st = p->p_sticks;
415 	ut = p->p_uticks;
416 	it = p->p_iticks;
417 	mutex_spin_exit(&p->p_stmutex);
418 
419 	tm = p->p_rtime;
420 
421 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
422 		lwp_lock(l);
423 		bintime_add(&tm, &l->l_rtime);
424 		if ((l->l_pflag & LP_RUNNING) != 0) {
425 			struct bintime diff;
426 			/*
427 			 * Adjust for the current time slice.  This is
428 			 * actually fairly important since the error
429 			 * here is on the order of a time quantum,
430 			 * which is much greater than the sampling
431 			 * error.
432 			 */
433 			binuptime(&diff);
434 			bintime_sub(&diff, &l->l_stime);
435 			bintime_add(&tm, &diff);
436 		}
437 		lwp_unlock(l);
438 	}
439 
440 	tot = st + ut + it;
441 	bintime2timeval(&tm, &tv);
442 	u = (uint64_t)tv.tv_sec * 1000000ul + tv.tv_usec;
443 
444 	if (tot == 0) {
445 		/* No ticks, so can't use to share time out, split 50-50 */
446 		st = ut = u / 2;
447 	} else {
448 		st = (u * st) / tot;
449 		ut = (u * ut) / tot;
450 	}
451 	if (sp != NULL) {
452 		sp->tv_sec = st / 1000000;
453 		sp->tv_usec = st % 1000000;
454 	}
455 	if (up != NULL) {
456 		up->tv_sec = ut / 1000000;
457 		up->tv_usec = ut % 1000000;
458 	}
459 	if (ip != NULL) {
460 		if (it != 0)
461 			it = (u * it) / tot;
462 		ip->tv_sec = it / 1000000;
463 		ip->tv_usec = it % 1000000;
464 	}
465 	if (rp != NULL) {
466 		*rp = tv;
467 	}
468 }
469 
470 /* ARGSUSED */
471 int
472 sys___getrusage50(struct lwp *l, const struct sys___getrusage50_args *uap,
473     register_t *retval)
474 {
475 	/* {
476 		syscallarg(int) who;
477 		syscallarg(struct rusage *) rusage;
478 	} */
479 	struct rusage ru;
480 	struct proc *p = l->l_proc;
481 
482 	switch (SCARG(uap, who)) {
483 	case RUSAGE_SELF:
484 		mutex_enter(p->p_lock);
485 		memcpy(&ru, &p->p_stats->p_ru, sizeof(ru));
486 		calcru(p, &ru.ru_utime, &ru.ru_stime, NULL, NULL);
487 		rulwps(p, &ru);
488 		mutex_exit(p->p_lock);
489 		break;
490 
491 	case RUSAGE_CHILDREN:
492 		mutex_enter(p->p_lock);
493 		memcpy(&ru, &p->p_stats->p_cru, sizeof(ru));
494 		mutex_exit(p->p_lock);
495 		break;
496 
497 	default:
498 		return EINVAL;
499 	}
500 
501 	return copyout(&ru, SCARG(uap, rusage), sizeof(ru));
502 }
503 
504 void
505 ruadd(struct rusage *ru, struct rusage *ru2)
506 {
507 	long *ip, *ip2;
508 	int i;
509 
510 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
511 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
512 	if (ru->ru_maxrss < ru2->ru_maxrss)
513 		ru->ru_maxrss = ru2->ru_maxrss;
514 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
515 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
516 		*ip++ += *ip2++;
517 }
518 
519 void
520 rulwps(proc_t *p, struct rusage *ru)
521 {
522 	lwp_t *l;
523 
524 	KASSERT(mutex_owned(p->p_lock));
525 
526 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
527 		ruadd(ru, &l->l_ru);
528 		ru->ru_nvcsw += (l->l_ncsw - l->l_nivcsw);
529 		ru->ru_nivcsw += l->l_nivcsw;
530 	}
531 }
532 
533 /*
534  * Make a copy of the plimit structure.
535  * We share these structures copy-on-write after fork,
536  * and copy when a limit is changed.
537  *
538  * Unfortunately (due to PL_SHAREMOD) it is possibly for the structure
539  * we are copying to change beneath our feet!
540  */
541 struct plimit *
542 lim_copy(struct plimit *lim)
543 {
544 	struct plimit *newlim;
545 	char *corename;
546 	size_t alen, len;
547 
548 	newlim = pool_cache_get(plimit_cache, PR_WAITOK);
549 	mutex_init(&newlim->pl_lock, MUTEX_DEFAULT, IPL_NONE);
550 	newlim->pl_flags = 0;
551 	newlim->pl_refcnt = 1;
552 	newlim->pl_sv_limit = NULL;
553 
554 	mutex_enter(&lim->pl_lock);
555 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
556 	    sizeof(struct rlimit) * RLIM_NLIMITS);
557 
558 	alen = 0;
559 	corename = NULL;
560 	for (;;) {
561 		if (lim->pl_corename == defcorename) {
562 			newlim->pl_corename = defcorename;
563 			break;
564 		}
565 		len = strlen(lim->pl_corename) + 1;
566 		if (len <= alen) {
567 			newlim->pl_corename = corename;
568 			memcpy(corename, lim->pl_corename, len);
569 			corename = NULL;
570 			break;
571 		}
572 		mutex_exit(&lim->pl_lock);
573 		if (corename != NULL)
574 			free(corename, M_TEMP);
575 		alen = len;
576 		corename = malloc(alen, M_TEMP, M_WAITOK);
577 		mutex_enter(&lim->pl_lock);
578 	}
579 	mutex_exit(&lim->pl_lock);
580 	if (corename != NULL)
581 		free(corename, M_TEMP);
582 	return newlim;
583 }
584 
585 void
586 lim_addref(struct plimit *lim)
587 {
588 	atomic_inc_uint(&lim->pl_refcnt);
589 }
590 
591 /*
592  * Give a process it's own private plimit structure.
593  * This will only be shared (in fork) if modifications are to be shared.
594  */
595 void
596 lim_privatise(struct proc *p, bool set_shared)
597 {
598 	struct plimit *lim, *newlim;
599 
600 	lim = p->p_limit;
601 	if (lim->pl_flags & PL_WRITEABLE) {
602 		if (set_shared)
603 			lim->pl_flags |= PL_SHAREMOD;
604 		return;
605 	}
606 
607 	if (set_shared && lim->pl_flags & PL_SHAREMOD)
608 		return;
609 
610 	newlim = lim_copy(lim);
611 
612 	mutex_enter(p->p_lock);
613 	if (p->p_limit->pl_flags & PL_WRITEABLE) {
614 		/* Someone crept in while we were busy */
615 		mutex_exit(p->p_lock);
616 		limfree(newlim);
617 		if (set_shared)
618 			p->p_limit->pl_flags |= PL_SHAREMOD;
619 		return;
620 	}
621 
622 	/*
623 	 * Since most accesses to p->p_limit aren't locked, we must not
624 	 * delete the old limit structure yet.
625 	 */
626 	newlim->pl_sv_limit = p->p_limit;
627 	newlim->pl_flags |= PL_WRITEABLE;
628 	if (set_shared)
629 		newlim->pl_flags |= PL_SHAREMOD;
630 	p->p_limit = newlim;
631 	mutex_exit(p->p_lock);
632 }
633 
634 void
635 limfree(struct plimit *lim)
636 {
637 	struct plimit *sv_lim;
638 
639 	do {
640 		if (atomic_dec_uint_nv(&lim->pl_refcnt) > 0)
641 			return;
642 		if (lim->pl_corename != defcorename)
643 			free(lim->pl_corename, M_TEMP);
644 		sv_lim = lim->pl_sv_limit;
645 		mutex_destroy(&lim->pl_lock);
646 		pool_cache_put(plimit_cache, lim);
647 	} while ((lim = sv_lim) != NULL);
648 }
649 
650 struct pstats *
651 pstatscopy(struct pstats *ps)
652 {
653 
654 	struct pstats *newps;
655 
656 	newps = pool_cache_get(pstats_cache, PR_WAITOK);
657 
658 	memset(&newps->pstat_startzero, 0,
659 	(unsigned) ((char *)&newps->pstat_endzero -
660 		    (char *)&newps->pstat_startzero));
661 	memcpy(&newps->pstat_startcopy, &ps->pstat_startcopy,
662 	((char *)&newps->pstat_endcopy -
663 	 (char *)&newps->pstat_startcopy));
664 
665 	return (newps);
666 
667 }
668 
669 void
670 pstatsfree(struct pstats *ps)
671 {
672 
673 	pool_cache_put(pstats_cache, ps);
674 }
675 
676 /*
677  * sysctl interface in five parts
678  */
679 
680 /*
681  * a routine for sysctl proc subtree helpers that need to pick a valid
682  * process by pid.
683  */
684 static int
685 sysctl_proc_findproc(struct lwp *l, struct proc **p2, pid_t pid)
686 {
687 	struct proc *ptmp;
688 	int error = 0;
689 
690 	if (pid == PROC_CURPROC)
691 		ptmp = l->l_proc;
692 	else if ((ptmp = pfind(pid)) == NULL)
693 		error = ESRCH;
694 
695 	*p2 = ptmp;
696 	return (error);
697 }
698 
699 /*
700  * sysctl helper routine for setting a process's specific corefile
701  * name.  picks the process based on the given pid and checks the
702  * correctness of the new value.
703  */
704 static int
705 sysctl_proc_corename(SYSCTLFN_ARGS)
706 {
707 	struct proc *ptmp;
708 	struct plimit *lim;
709 	int error = 0, len;
710 	char *cname;
711 	char *ocore;
712 	char *tmp;
713 	struct sysctlnode node;
714 
715 	/*
716 	 * is this all correct?
717 	 */
718 	if (namelen != 0)
719 		return (EINVAL);
720 	if (name[-1] != PROC_PID_CORENAME)
721 		return (EINVAL);
722 
723 	/*
724 	 * whom are we tweaking?
725 	 */
726 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-2]);
727 	if (error)
728 		return (error);
729 
730 	/* XXX-elad */
731 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
732 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
733 	if (error)
734 		return (error);
735 
736 	if (newp == NULL) {
737 		error = kauth_authorize_process(l->l_cred,
738 		    KAUTH_PROCESS_CORENAME, ptmp,
739 		    KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_GET), NULL, NULL);
740 		if (error)
741 			return (error);
742 	}
743 
744 	/*
745 	 * let them modify a temporary copy of the core name
746 	 */
747 	cname = PNBUF_GET();
748 	lim = ptmp->p_limit;
749 	mutex_enter(&lim->pl_lock);
750 	strlcpy(cname, lim->pl_corename, MAXPATHLEN);
751 	mutex_exit(&lim->pl_lock);
752 
753 	node = *rnode;
754 	node.sysctl_data = cname;
755 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
756 
757 	/*
758 	 * if that failed, or they have nothing new to say, or we've
759 	 * heard it before...
760 	 */
761 	if (error || newp == NULL)
762 		goto done;
763 	lim = ptmp->p_limit;
764 	mutex_enter(&lim->pl_lock);
765 	error = strcmp(cname, lim->pl_corename);
766 	mutex_exit(&lim->pl_lock);
767 	if (error == 0)
768 		/* Unchanged */
769 		goto done;
770 
771 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CORENAME,
772 	    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_SET), cname, NULL);
773 	if (error)
774 		return (error);
775 
776 	/*
777 	 * no error yet and cname now has the new core name in it.
778 	 * let's see if it looks acceptable.  it must be either "core"
779 	 * or end in ".core" or "/core".
780 	 */
781 	len = strlen(cname);
782 	if (len < 4) {
783 		error = EINVAL;
784 	} else if (strcmp(cname + len - 4, "core") != 0) {
785 		error = EINVAL;
786 	} else if (len > 4 && cname[len - 5] != '/' && cname[len - 5] != '.') {
787 		error = EINVAL;
788 	}
789 	if (error != 0) {
790 		goto done;
791 	}
792 
793 	/*
794 	 * hmm...looks good.  now...where do we put it?
795 	 */
796 	tmp = malloc(len + 1, M_TEMP, M_WAITOK|M_CANFAIL);
797 	if (tmp == NULL) {
798 		error = ENOMEM;
799 		goto done;
800 	}
801 	memcpy(tmp, cname, len + 1);
802 
803 	lim_privatise(ptmp, false);
804 	lim = ptmp->p_limit;
805 	mutex_enter(&lim->pl_lock);
806 	ocore = lim->pl_corename;
807 	lim->pl_corename = tmp;
808 	mutex_exit(&lim->pl_lock);
809 	if (ocore != defcorename)
810 		free(ocore, M_TEMP);
811 
812 done:
813 	PNBUF_PUT(cname);
814 	return error;
815 }
816 
817 /*
818  * sysctl helper routine for checking/setting a process's stop flags,
819  * one for fork and one for exec.
820  */
821 static int
822 sysctl_proc_stop(SYSCTLFN_ARGS)
823 {
824 	struct proc *ptmp;
825 	int i, f, error = 0;
826 	struct sysctlnode node;
827 
828 	if (namelen != 0)
829 		return (EINVAL);
830 
831 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-2]);
832 	if (error)
833 		return (error);
834 
835 	/* XXX-elad */
836 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
837 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
838 	if (error)
839 		return (error);
840 
841 	switch (rnode->sysctl_num) {
842 	case PROC_PID_STOPFORK:
843 		f = PS_STOPFORK;
844 		break;
845 	case PROC_PID_STOPEXEC:
846 		f = PS_STOPEXEC;
847 		break;
848 	case PROC_PID_STOPEXIT:
849 		f = PS_STOPEXIT;
850 		break;
851 	default:
852 		return (EINVAL);
853 	}
854 
855 	i = (ptmp->p_flag & f) ? 1 : 0;
856 	node = *rnode;
857 	node.sysctl_data = &i;
858 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
859 	if (error || newp == NULL)
860 		return (error);
861 
862 	mutex_enter(ptmp->p_lock);
863 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_STOPFLAG,
864 	    ptmp, KAUTH_ARG(f), NULL, NULL);
865 	if (!error) {
866 		if (i) {
867 			ptmp->p_sflag |= f;
868 		} else {
869 			ptmp->p_sflag &= ~f;
870 		}
871 	}
872 	mutex_exit(ptmp->p_lock);
873 
874 	return error;
875 }
876 
877 /*
878  * sysctl helper routine for a process's rlimits as exposed by sysctl.
879  */
880 static int
881 sysctl_proc_plimit(SYSCTLFN_ARGS)
882 {
883 	struct proc *ptmp;
884 	u_int limitno;
885 	int which, error = 0;
886         struct rlimit alim;
887 	struct sysctlnode node;
888 
889 	if (namelen != 0)
890 		return (EINVAL);
891 
892 	which = name[-1];
893 	if (which != PROC_PID_LIMIT_TYPE_SOFT &&
894 	    which != PROC_PID_LIMIT_TYPE_HARD)
895 		return (EINVAL);
896 
897 	limitno = name[-2] - 1;
898 	if (limitno >= RLIM_NLIMITS)
899 		return (EINVAL);
900 
901 	if (name[-3] != PROC_PID_LIMIT)
902 		return (EINVAL);
903 
904 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-4]);
905 	if (error)
906 		return (error);
907 
908 	/* XXX-elad */
909 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
910 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
911 	if (error)
912 		return (error);
913 
914 	/* Check if we can view limits. */
915 	if (newp == NULL) {
916 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
917 		    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_GET), &alim,
918 		    KAUTH_ARG(which));
919 		if (error)
920 			return (error);
921 	}
922 
923 	node = *rnode;
924 	memcpy(&alim, &ptmp->p_rlimit[limitno], sizeof(alim));
925 	if (which == PROC_PID_LIMIT_TYPE_HARD)
926 		node.sysctl_data = &alim.rlim_max;
927 	else
928 		node.sysctl_data = &alim.rlim_cur;
929 
930 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
931 	if (error || newp == NULL)
932 		return (error);
933 
934 	return (dosetrlimit(l, ptmp, limitno, &alim));
935 }
936 
937 /*
938  * and finally, the actually glue that sticks it to the tree
939  */
940 SYSCTL_SETUP(sysctl_proc_setup, "sysctl proc subtree setup")
941 {
942 
943 	sysctl_createv(clog, 0, NULL, NULL,
944 		       CTLFLAG_PERMANENT,
945 		       CTLTYPE_NODE, "proc", NULL,
946 		       NULL, 0, NULL, 0,
947 		       CTL_PROC, CTL_EOL);
948 	sysctl_createv(clog, 0, NULL, NULL,
949 		       CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
950 		       CTLTYPE_NODE, "curproc",
951 		       SYSCTL_DESCR("Per-process settings"),
952 		       NULL, 0, NULL, 0,
953 		       CTL_PROC, PROC_CURPROC, CTL_EOL);
954 
955 	sysctl_createv(clog, 0, NULL, NULL,
956 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
957 		       CTLTYPE_STRING, "corename",
958 		       SYSCTL_DESCR("Core file name"),
959 		       sysctl_proc_corename, 0, NULL, MAXPATHLEN,
960 		       CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
961 	sysctl_createv(clog, 0, NULL, NULL,
962 		       CTLFLAG_PERMANENT,
963 		       CTLTYPE_NODE, "rlimit",
964 		       SYSCTL_DESCR("Process limits"),
965 		       NULL, 0, NULL, 0,
966 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);
967 
968 #define create_proc_plimit(s, n) do {					\
969 	sysctl_createv(clog, 0, NULL, NULL,				\
970 		       CTLFLAG_PERMANENT,				\
971 		       CTLTYPE_NODE, s,					\
972 		       SYSCTL_DESCR("Process " s " limits"),		\
973 		       NULL, 0, NULL, 0,				\
974 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
975 		       CTL_EOL);					\
976 	sysctl_createv(clog, 0, NULL, NULL,				\
977 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
978 		       CTLTYPE_QUAD, "soft",				\
979 		       SYSCTL_DESCR("Process soft " s " limit"),	\
980 		       sysctl_proc_plimit, 0, NULL, 0,			\
981 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
982 		       PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL);		\
983 	sysctl_createv(clog, 0, NULL, NULL,				\
984 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
985 		       CTLTYPE_QUAD, "hard",				\
986 		       SYSCTL_DESCR("Process hard " s " limit"),	\
987 		       sysctl_proc_plimit, 0, NULL, 0,			\
988 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
989 		       PROC_PID_LIMIT_TYPE_HARD, CTL_EOL);		\
990 	} while (0/*CONSTCOND*/)
991 
992 	create_proc_plimit("cputime",		PROC_PID_LIMIT_CPU);
993 	create_proc_plimit("filesize",		PROC_PID_LIMIT_FSIZE);
994 	create_proc_plimit("datasize",		PROC_PID_LIMIT_DATA);
995 	create_proc_plimit("stacksize",		PROC_PID_LIMIT_STACK);
996 	create_proc_plimit("coredumpsize",	PROC_PID_LIMIT_CORE);
997 	create_proc_plimit("memoryuse",		PROC_PID_LIMIT_RSS);
998 	create_proc_plimit("memorylocked",	PROC_PID_LIMIT_MEMLOCK);
999 	create_proc_plimit("maxproc",		PROC_PID_LIMIT_NPROC);
1000 	create_proc_plimit("descriptors",	PROC_PID_LIMIT_NOFILE);
1001 	create_proc_plimit("sbsize",		PROC_PID_LIMIT_SBSIZE);
1002 	create_proc_plimit("vmemoryuse",	PROC_PID_LIMIT_AS);
1003 
1004 #undef create_proc_plimit
1005 
1006 	sysctl_createv(clog, 0, NULL, NULL,
1007 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1008 		       CTLTYPE_INT, "stopfork",
1009 		       SYSCTL_DESCR("Stop process at fork(2)"),
1010 		       sysctl_proc_stop, 0, NULL, 0,
1011 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
1012 	sysctl_createv(clog, 0, NULL, NULL,
1013 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1014 		       CTLTYPE_INT, "stopexec",
1015 		       SYSCTL_DESCR("Stop process at execve(2)"),
1016 		       sysctl_proc_stop, 0, NULL, 0,
1017 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
1018 	sysctl_createv(clog, 0, NULL, NULL,
1019 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1020 		       CTLTYPE_INT, "stopexit",
1021 		       SYSCTL_DESCR("Stop process before completing exit"),
1022 		       sysctl_proc_stop, 0, NULL, 0,
1023 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
1024 }
1025