xref: /netbsd-src/sys/kern/kern_resource.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: kern_resource.c,v 1.147 2008/10/11 13:40:57 pooka 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 1.147 2008/10/11 13:40:57 pooka 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 < 0 || limp->rlim_max < 0)
273 		return (EINVAL);
274 
275 	if (limp->rlim_cur > limp->rlim_max) {
276 		/*
277 		 * This is programming error. According to SUSv2, we should
278 		 * return error in this case.
279 		 */
280 		return (EINVAL);
281 	}
282 
283 	alimp = &p->p_rlimit[which];
284 	/* if we don't change the value, no need to limcopy() */
285 	if (limp->rlim_cur == alimp->rlim_cur &&
286 	    limp->rlim_max == alimp->rlim_max)
287 		return 0;
288 
289 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
290 	    p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_SET), limp, KAUTH_ARG(which));
291 	if (error)
292 		return (error);
293 
294 	lim_privatise(p, false);
295 	/* p->p_limit is now unchangeable */
296 	alimp = &p->p_rlimit[which];
297 
298 	switch (which) {
299 
300 	case RLIMIT_DATA:
301 		if (limp->rlim_cur > maxdmap)
302 			limp->rlim_cur = maxdmap;
303 		if (limp->rlim_max > maxdmap)
304 			limp->rlim_max = maxdmap;
305 		break;
306 
307 	case RLIMIT_STACK:
308 		if (limp->rlim_cur > maxsmap)
309 			limp->rlim_cur = maxsmap;
310 		if (limp->rlim_max > maxsmap)
311 			limp->rlim_max = maxsmap;
312 
313 		/*
314 		 * Return EINVAL if the new stack size limit is lower than
315 		 * current usage. Otherwise, the process would get SIGSEGV the
316 		 * moment it would try to access anything on it's current stack.
317 		 * This conforms to SUSv2.
318 		 */
319 		if (limp->rlim_cur < p->p_vmspace->vm_ssize * PAGE_SIZE
320 		    || limp->rlim_max < p->p_vmspace->vm_ssize * PAGE_SIZE) {
321 			return (EINVAL);
322 		}
323 
324 		/*
325 		 * Stack is allocated to the max at exec time with
326 		 * only "rlim_cur" bytes accessible (In other words,
327 		 * allocates stack dividing two contiguous regions at
328 		 * "rlim_cur" bytes boundary).
329 		 *
330 		 * Since allocation is done in terms of page, roundup
331 		 * "rlim_cur" (otherwise, contiguous regions
332 		 * overlap).  If stack limit is going up make more
333 		 * accessible, if going down make inaccessible.
334 		 */
335 		limp->rlim_cur = round_page(limp->rlim_cur);
336 		if (limp->rlim_cur != alimp->rlim_cur) {
337 			vaddr_t addr;
338 			vsize_t size;
339 			vm_prot_t prot;
340 
341 			if (limp->rlim_cur > alimp->rlim_cur) {
342 				prot = VM_PROT_READ | VM_PROT_WRITE;
343 				size = limp->rlim_cur - alimp->rlim_cur;
344 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
345 				    limp->rlim_cur;
346 			} else {
347 				prot = VM_PROT_NONE;
348 				size = alimp->rlim_cur - limp->rlim_cur;
349 				addr = (vaddr_t)p->p_vmspace->vm_minsaddr -
350 				     alimp->rlim_cur;
351 			}
352 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
353 			    addr, addr+size, prot, false);
354 		}
355 		break;
356 
357 	case RLIMIT_NOFILE:
358 		if (limp->rlim_cur > maxfiles)
359 			limp->rlim_cur = maxfiles;
360 		if (limp->rlim_max > maxfiles)
361 			limp->rlim_max = maxfiles;
362 		break;
363 
364 	case RLIMIT_NPROC:
365 		if (limp->rlim_cur > maxproc)
366 			limp->rlim_cur = maxproc;
367 		if (limp->rlim_max > maxproc)
368 			limp->rlim_max = maxproc;
369 		break;
370 	}
371 
372 	mutex_enter(&p->p_limit->pl_lock);
373 	*alimp = *limp;
374 	mutex_exit(&p->p_limit->pl_lock);
375 	return (0);
376 }
377 
378 /* ARGSUSED */
379 int
380 sys_getrlimit(struct lwp *l, const struct sys_getrlimit_args *uap,
381     register_t *retval)
382 {
383 	/* {
384 		syscallarg(int) which;
385 		syscallarg(struct rlimit *) rlp;
386 	} */
387 	struct proc *p = l->l_proc;
388 	int which = SCARG(uap, which);
389 	struct rlimit rl;
390 
391 	if ((u_int)which >= RLIM_NLIMITS)
392 		return (EINVAL);
393 
394 	mutex_enter(p->p_lock);
395 	memcpy(&rl, &p->p_rlimit[which], sizeof(rl));
396 	mutex_exit(p->p_lock);
397 
398 	return copyout(&rl, SCARG(uap, rlp), sizeof(rl));
399 }
400 
401 /*
402  * Transform the running time and tick information in proc p into user,
403  * system, and interrupt time usage.
404  *
405  * Should be called with p->p_lock held unless called from exit1().
406  */
407 void
408 calcru(struct proc *p, struct timeval *up, struct timeval *sp,
409     struct timeval *ip, struct timeval *rp)
410 {
411 	uint64_t u, st, ut, it, tot;
412 	struct lwp *l;
413 	struct bintime tm;
414 	struct timeval tv;
415 
416 	mutex_spin_enter(&p->p_stmutex);
417 	st = p->p_sticks;
418 	ut = p->p_uticks;
419 	it = p->p_iticks;
420 	mutex_spin_exit(&p->p_stmutex);
421 
422 	tm = p->p_rtime;
423 
424 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
425 		lwp_lock(l);
426 		bintime_add(&tm, &l->l_rtime);
427 		if ((l->l_pflag & LP_RUNNING) != 0) {
428 			struct bintime diff;
429 			/*
430 			 * Adjust for the current time slice.  This is
431 			 * actually fairly important since the error
432 			 * here is on the order of a time quantum,
433 			 * which is much greater than the sampling
434 			 * error.
435 			 */
436 			binuptime(&diff);
437 			bintime_sub(&diff, &l->l_stime);
438 			bintime_add(&tm, &diff);
439 		}
440 		lwp_unlock(l);
441 	}
442 
443 	tot = st + ut + it;
444 	bintime2timeval(&tm, &tv);
445 	u = (uint64_t)tv.tv_sec * 1000000ul + tv.tv_usec;
446 
447 	if (tot == 0) {
448 		/* No ticks, so can't use to share time out, split 50-50 */
449 		st = ut = u / 2;
450 	} else {
451 		st = (u * st) / tot;
452 		ut = (u * ut) / tot;
453 	}
454 	if (sp != NULL) {
455 		sp->tv_sec = st / 1000000;
456 		sp->tv_usec = st % 1000000;
457 	}
458 	if (up != NULL) {
459 		up->tv_sec = ut / 1000000;
460 		up->tv_usec = ut % 1000000;
461 	}
462 	if (ip != NULL) {
463 		if (it != 0)
464 			it = (u * it) / tot;
465 		ip->tv_sec = it / 1000000;
466 		ip->tv_usec = it % 1000000;
467 	}
468 	if (rp != NULL) {
469 		*rp = tv;
470 	}
471 }
472 
473 /* ARGSUSED */
474 int
475 sys_getrusage(struct lwp *l, const struct sys_getrusage_args *uap,
476     register_t *retval)
477 {
478 	/* {
479 		syscallarg(int) who;
480 		syscallarg(struct rusage *) rusage;
481 	} */
482 	struct rusage ru;
483 	struct proc *p = l->l_proc;
484 
485 	switch (SCARG(uap, who)) {
486 	case RUSAGE_SELF:
487 		mutex_enter(p->p_lock);
488 		memcpy(&ru, &p->p_stats->p_ru, sizeof(ru));
489 		calcru(p, &ru.ru_utime, &ru.ru_stime, NULL, NULL);
490 		rulwps(p, &ru);
491 		mutex_exit(p->p_lock);
492 		break;
493 
494 	case RUSAGE_CHILDREN:
495 		mutex_enter(p->p_lock);
496 		memcpy(&ru, &p->p_stats->p_cru, sizeof(ru));
497 		mutex_exit(p->p_lock);
498 		break;
499 
500 	default:
501 		return EINVAL;
502 	}
503 
504 	return copyout(&ru, SCARG(uap, rusage), sizeof(ru));
505 }
506 
507 void
508 ruadd(struct rusage *ru, struct rusage *ru2)
509 {
510 	long *ip, *ip2;
511 	int i;
512 
513 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
514 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
515 	if (ru->ru_maxrss < ru2->ru_maxrss)
516 		ru->ru_maxrss = ru2->ru_maxrss;
517 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
518 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
519 		*ip++ += *ip2++;
520 }
521 
522 void
523 rulwps(proc_t *p, struct rusage *ru)
524 {
525 	lwp_t *l;
526 
527 	KASSERT(mutex_owned(p->p_lock));
528 
529 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
530 		ruadd(ru, &l->l_ru);
531 		ru->ru_nvcsw += (l->l_ncsw - l->l_nivcsw);
532 		ru->ru_nivcsw += l->l_nivcsw;
533 	}
534 }
535 
536 /*
537  * Make a copy of the plimit structure.
538  * We share these structures copy-on-write after fork,
539  * and copy when a limit is changed.
540  *
541  * Unfortunately (due to PL_SHAREMOD) it is possibly for the structure
542  * we are copying to change beneath our feet!
543  */
544 struct plimit *
545 lim_copy(struct plimit *lim)
546 {
547 	struct plimit *newlim;
548 	char *corename;
549 	size_t alen, len;
550 
551 	newlim = pool_cache_get(plimit_cache, PR_WAITOK);
552 	mutex_init(&newlim->pl_lock, MUTEX_DEFAULT, IPL_NONE);
553 	newlim->pl_flags = 0;
554 	newlim->pl_refcnt = 1;
555 	newlim->pl_sv_limit = NULL;
556 
557 	mutex_enter(&lim->pl_lock);
558 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
559 	    sizeof(struct rlimit) * RLIM_NLIMITS);
560 
561 	alen = 0;
562 	corename = NULL;
563 	for (;;) {
564 		if (lim->pl_corename == defcorename) {
565 			newlim->pl_corename = defcorename;
566 			break;
567 		}
568 		len = strlen(lim->pl_corename) + 1;
569 		if (len <= alen) {
570 			newlim->pl_corename = corename;
571 			memcpy(corename, lim->pl_corename, len);
572 			corename = NULL;
573 			break;
574 		}
575 		mutex_exit(&lim->pl_lock);
576 		if (corename != NULL)
577 			free(corename, M_TEMP);
578 		alen = len;
579 		corename = malloc(alen, M_TEMP, M_WAITOK);
580 		mutex_enter(&lim->pl_lock);
581 	}
582 	mutex_exit(&lim->pl_lock);
583 	if (corename != NULL)
584 		free(corename, M_TEMP);
585 	return newlim;
586 }
587 
588 void
589 lim_addref(struct plimit *lim)
590 {
591 	atomic_inc_uint(&lim->pl_refcnt);
592 }
593 
594 /*
595  * Give a process it's own private plimit structure.
596  * This will only be shared (in fork) if modifications are to be shared.
597  */
598 void
599 lim_privatise(struct proc *p, bool set_shared)
600 {
601 	struct plimit *lim, *newlim;
602 
603 	lim = p->p_limit;
604 	if (lim->pl_flags & PL_WRITEABLE) {
605 		if (set_shared)
606 			lim->pl_flags |= PL_SHAREMOD;
607 		return;
608 	}
609 
610 	if (set_shared && lim->pl_flags & PL_SHAREMOD)
611 		return;
612 
613 	newlim = lim_copy(lim);
614 
615 	mutex_enter(p->p_lock);
616 	if (p->p_limit->pl_flags & PL_WRITEABLE) {
617 		/* Someone crept in while we were busy */
618 		mutex_exit(p->p_lock);
619 		limfree(newlim);
620 		if (set_shared)
621 			p->p_limit->pl_flags |= PL_SHAREMOD;
622 		return;
623 	}
624 
625 	/*
626 	 * Since most accesses to p->p_limit aren't locked, we must not
627 	 * delete the old limit structure yet.
628 	 */
629 	newlim->pl_sv_limit = p->p_limit;
630 	newlim->pl_flags |= PL_WRITEABLE;
631 	if (set_shared)
632 		newlim->pl_flags |= PL_SHAREMOD;
633 	p->p_limit = newlim;
634 	mutex_exit(p->p_lock);
635 }
636 
637 void
638 limfree(struct plimit *lim)
639 {
640 	struct plimit *sv_lim;
641 
642 	do {
643 		if (atomic_dec_uint_nv(&lim->pl_refcnt) > 0)
644 			return;
645 		if (lim->pl_corename != defcorename)
646 			free(lim->pl_corename, M_TEMP);
647 		sv_lim = lim->pl_sv_limit;
648 		mutex_destroy(&lim->pl_lock);
649 		pool_cache_put(plimit_cache, lim);
650 	} while ((lim = sv_lim) != NULL);
651 }
652 
653 struct pstats *
654 pstatscopy(struct pstats *ps)
655 {
656 
657 	struct pstats *newps;
658 
659 	newps = pool_cache_get(pstats_cache, PR_WAITOK);
660 
661 	memset(&newps->pstat_startzero, 0,
662 	(unsigned) ((char *)&newps->pstat_endzero -
663 		    (char *)&newps->pstat_startzero));
664 	memcpy(&newps->pstat_startcopy, &ps->pstat_startcopy,
665 	((char *)&newps->pstat_endcopy -
666 	 (char *)&newps->pstat_startcopy));
667 
668 	return (newps);
669 
670 }
671 
672 void
673 pstatsfree(struct pstats *ps)
674 {
675 
676 	pool_cache_put(pstats_cache, ps);
677 }
678 
679 /*
680  * sysctl interface in five parts
681  */
682 
683 /*
684  * a routine for sysctl proc subtree helpers that need to pick a valid
685  * process by pid.
686  */
687 static int
688 sysctl_proc_findproc(struct lwp *l, struct proc **p2, pid_t pid)
689 {
690 	struct proc *ptmp;
691 	int error = 0;
692 
693 	if (pid == PROC_CURPROC)
694 		ptmp = l->l_proc;
695 	else if ((ptmp = pfind(pid)) == NULL)
696 		error = ESRCH;
697 
698 	*p2 = ptmp;
699 	return (error);
700 }
701 
702 /*
703  * sysctl helper routine for setting a process's specific corefile
704  * name.  picks the process based on the given pid and checks the
705  * correctness of the new value.
706  */
707 static int
708 sysctl_proc_corename(SYSCTLFN_ARGS)
709 {
710 	struct proc *ptmp;
711 	struct plimit *lim;
712 	int error = 0, len;
713 	char *cname;
714 	char *ocore;
715 	char *tmp;
716 	struct sysctlnode node;
717 
718 	/*
719 	 * is this all correct?
720 	 */
721 	if (namelen != 0)
722 		return (EINVAL);
723 	if (name[-1] != PROC_PID_CORENAME)
724 		return (EINVAL);
725 
726 	/*
727 	 * whom are we tweaking?
728 	 */
729 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-2]);
730 	if (error)
731 		return (error);
732 
733 	/* XXX-elad */
734 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
735 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
736 	if (error)
737 		return (error);
738 
739 	if (newp == NULL) {
740 		error = kauth_authorize_process(l->l_cred,
741 		    KAUTH_PROCESS_CORENAME, ptmp,
742 		    KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_GET), NULL, NULL);
743 		if (error)
744 			return (error);
745 	}
746 
747 	/*
748 	 * let them modify a temporary copy of the core name
749 	 */
750 	cname = PNBUF_GET();
751 	lim = ptmp->p_limit;
752 	mutex_enter(&lim->pl_lock);
753 	strlcpy(cname, lim->pl_corename, MAXPATHLEN);
754 	mutex_exit(&lim->pl_lock);
755 
756 	node = *rnode;
757 	node.sysctl_data = cname;
758 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
759 
760 	/*
761 	 * if that failed, or they have nothing new to say, or we've
762 	 * heard it before...
763 	 */
764 	if (error || newp == NULL)
765 		goto done;
766 	lim = ptmp->p_limit;
767 	mutex_enter(&lim->pl_lock);
768 	error = strcmp(cname, lim->pl_corename);
769 	mutex_exit(&lim->pl_lock);
770 	if (error == 0)
771 		/* Unchanged */
772 		goto done;
773 
774 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CORENAME,
775 	    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_SET), cname, NULL);
776 	if (error)
777 		return (error);
778 
779 	/*
780 	 * no error yet and cname now has the new core name in it.
781 	 * let's see if it looks acceptable.  it must be either "core"
782 	 * or end in ".core" or "/core".
783 	 */
784 	len = strlen(cname);
785 	if (len < 4) {
786 		error = EINVAL;
787 	} else if (strcmp(cname + len - 4, "core") != 0) {
788 		error = EINVAL;
789 	} else if (len > 4 && cname[len - 5] != '/' && cname[len - 5] != '.') {
790 		error = EINVAL;
791 	}
792 	if (error != 0) {
793 		goto done;
794 	}
795 
796 	/*
797 	 * hmm...looks good.  now...where do we put it?
798 	 */
799 	tmp = malloc(len + 1, M_TEMP, M_WAITOK|M_CANFAIL);
800 	if (tmp == NULL) {
801 		error = ENOMEM;
802 		goto done;
803 	}
804 	memcpy(tmp, cname, len + 1);
805 
806 	lim_privatise(ptmp, false);
807 	lim = ptmp->p_limit;
808 	mutex_enter(&lim->pl_lock);
809 	ocore = lim->pl_corename;
810 	lim->pl_corename = tmp;
811 	mutex_exit(&lim->pl_lock);
812 	if (ocore != defcorename)
813 		free(ocore, M_TEMP);
814 
815 done:
816 	PNBUF_PUT(cname);
817 	return error;
818 }
819 
820 /*
821  * sysctl helper routine for checking/setting a process's stop flags,
822  * one for fork and one for exec.
823  */
824 static int
825 sysctl_proc_stop(SYSCTLFN_ARGS)
826 {
827 	struct proc *ptmp;
828 	int i, f, error = 0;
829 	struct sysctlnode node;
830 
831 	if (namelen != 0)
832 		return (EINVAL);
833 
834 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-2]);
835 	if (error)
836 		return (error);
837 
838 	/* XXX-elad */
839 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
840 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
841 	if (error)
842 		return (error);
843 
844 	switch (rnode->sysctl_num) {
845 	case PROC_PID_STOPFORK:
846 		f = PS_STOPFORK;
847 		break;
848 	case PROC_PID_STOPEXEC:
849 		f = PS_STOPEXEC;
850 		break;
851 	case PROC_PID_STOPEXIT:
852 		f = PS_STOPEXIT;
853 		break;
854 	default:
855 		return (EINVAL);
856 	}
857 
858 	i = (ptmp->p_flag & f) ? 1 : 0;
859 	node = *rnode;
860 	node.sysctl_data = &i;
861 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
862 	if (error || newp == NULL)
863 		return (error);
864 
865 	mutex_enter(ptmp->p_lock);
866 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_STOPFLAG,
867 	    ptmp, KAUTH_ARG(f), NULL, NULL);
868 	if (!error) {
869 		if (i) {
870 			ptmp->p_sflag |= f;
871 		} else {
872 			ptmp->p_sflag &= ~f;
873 		}
874 	}
875 	mutex_exit(ptmp->p_lock);
876 
877 	return error;
878 }
879 
880 /*
881  * sysctl helper routine for a process's rlimits as exposed by sysctl.
882  */
883 static int
884 sysctl_proc_plimit(SYSCTLFN_ARGS)
885 {
886 	struct proc *ptmp;
887 	u_int limitno;
888 	int which, error = 0;
889         struct rlimit alim;
890 	struct sysctlnode node;
891 
892 	if (namelen != 0)
893 		return (EINVAL);
894 
895 	which = name[-1];
896 	if (which != PROC_PID_LIMIT_TYPE_SOFT &&
897 	    which != PROC_PID_LIMIT_TYPE_HARD)
898 		return (EINVAL);
899 
900 	limitno = name[-2] - 1;
901 	if (limitno >= RLIM_NLIMITS)
902 		return (EINVAL);
903 
904 	if (name[-3] != PROC_PID_LIMIT)
905 		return (EINVAL);
906 
907 	error = sysctl_proc_findproc(l, &ptmp, (pid_t)name[-4]);
908 	if (error)
909 		return (error);
910 
911 	/* XXX-elad */
912 	error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, ptmp,
913 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
914 	if (error)
915 		return (error);
916 
917 	/* Check if we can view limits. */
918 	if (newp == NULL) {
919 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
920 		    ptmp, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_GET), &alim,
921 		    KAUTH_ARG(which));
922 		if (error)
923 			return (error);
924 	}
925 
926 	node = *rnode;
927 	memcpy(&alim, &ptmp->p_rlimit[limitno], sizeof(alim));
928 	if (which == PROC_PID_LIMIT_TYPE_HARD)
929 		node.sysctl_data = &alim.rlim_max;
930 	else
931 		node.sysctl_data = &alim.rlim_cur;
932 
933 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
934 	if (error || newp == NULL)
935 		return (error);
936 
937 	return (dosetrlimit(l, ptmp, limitno, &alim));
938 }
939 
940 /*
941  * and finally, the actually glue that sticks it to the tree
942  */
943 SYSCTL_SETUP(sysctl_proc_setup, "sysctl proc subtree setup")
944 {
945 
946 	sysctl_createv(clog, 0, NULL, NULL,
947 		       CTLFLAG_PERMANENT,
948 		       CTLTYPE_NODE, "proc", NULL,
949 		       NULL, 0, NULL, 0,
950 		       CTL_PROC, CTL_EOL);
951 	sysctl_createv(clog, 0, NULL, NULL,
952 		       CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
953 		       CTLTYPE_NODE, "curproc",
954 		       SYSCTL_DESCR("Per-process settings"),
955 		       NULL, 0, NULL, 0,
956 		       CTL_PROC, PROC_CURPROC, CTL_EOL);
957 
958 	sysctl_createv(clog, 0, NULL, NULL,
959 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
960 		       CTLTYPE_STRING, "corename",
961 		       SYSCTL_DESCR("Core file name"),
962 		       sysctl_proc_corename, 0, NULL, MAXPATHLEN,
963 		       CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
964 	sysctl_createv(clog, 0, NULL, NULL,
965 		       CTLFLAG_PERMANENT,
966 		       CTLTYPE_NODE, "rlimit",
967 		       SYSCTL_DESCR("Process limits"),
968 		       NULL, 0, NULL, 0,
969 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);
970 
971 #define create_proc_plimit(s, n) do {					\
972 	sysctl_createv(clog, 0, NULL, NULL,				\
973 		       CTLFLAG_PERMANENT,				\
974 		       CTLTYPE_NODE, s,					\
975 		       SYSCTL_DESCR("Process " s " limits"),		\
976 		       NULL, 0, NULL, 0,				\
977 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
978 		       CTL_EOL);					\
979 	sysctl_createv(clog, 0, NULL, NULL,				\
980 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
981 		       CTLTYPE_QUAD, "soft",				\
982 		       SYSCTL_DESCR("Process soft " s " limit"),	\
983 		       sysctl_proc_plimit, 0, NULL, 0,			\
984 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
985 		       PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL);		\
986 	sysctl_createv(clog, 0, NULL, NULL,				\
987 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
988 		       CTLTYPE_QUAD, "hard",				\
989 		       SYSCTL_DESCR("Process hard " s " limit"),	\
990 		       sysctl_proc_plimit, 0, NULL, 0,			\
991 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
992 		       PROC_PID_LIMIT_TYPE_HARD, CTL_EOL);		\
993 	} while (0/*CONSTCOND*/)
994 
995 	create_proc_plimit("cputime",		PROC_PID_LIMIT_CPU);
996 	create_proc_plimit("filesize",		PROC_PID_LIMIT_FSIZE);
997 	create_proc_plimit("datasize",		PROC_PID_LIMIT_DATA);
998 	create_proc_plimit("stacksize",		PROC_PID_LIMIT_STACK);
999 	create_proc_plimit("coredumpsize",	PROC_PID_LIMIT_CORE);
1000 	create_proc_plimit("memoryuse",		PROC_PID_LIMIT_RSS);
1001 	create_proc_plimit("memorylocked",	PROC_PID_LIMIT_MEMLOCK);
1002 	create_proc_plimit("maxproc",		PROC_PID_LIMIT_NPROC);
1003 	create_proc_plimit("descriptors",	PROC_PID_LIMIT_NOFILE);
1004 	create_proc_plimit("sbsize",		PROC_PID_LIMIT_SBSIZE);
1005 
1006 #undef create_proc_plimit
1007 
1008 	sysctl_createv(clog, 0, NULL, NULL,
1009 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1010 		       CTLTYPE_INT, "stopfork",
1011 		       SYSCTL_DESCR("Stop process at fork(2)"),
1012 		       sysctl_proc_stop, 0, NULL, 0,
1013 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
1014 	sysctl_createv(clog, 0, NULL, NULL,
1015 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1016 		       CTLTYPE_INT, "stopexec",
1017 		       SYSCTL_DESCR("Stop process at execve(2)"),
1018 		       sysctl_proc_stop, 0, NULL, 0,
1019 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
1020 	sysctl_createv(clog, 0, NULL, NULL,
1021 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
1022 		       CTLTYPE_INT, "stopexit",
1023 		       SYSCTL_DESCR("Stop process before completing exit"),
1024 		       sysctl_proc_stop, 0, NULL, 0,
1025 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
1026 }
1027