xref: /openbsd-src/sys/kern/kern_resource.c (revision c90a81c56dcebd6a1b73fe4aff9b03385b8e63b3) 
1 /*	$OpenBSD: kern_resource.c,v 1.59 2019/01/06 12:59:45 visa Exp $	*/
2 /*	$NetBSD: kern_resource.c,v 1.38 1996/10/23 07:19:38 matthias Exp $	*/
3 
4 /*-
5  * Copyright (c) 1982, 1986, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  * (c) UNIX System Laboratories, Inc.
8  * All or some portions of this file are derived from material licensed
9  * to the University of California by American Telephone and Telegraph
10  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11  * the permission of UNIX System Laboratories, Inc.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)kern_resource.c	8.5 (Berkeley) 1/21/94
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/file.h>
44 #include <sys/resourcevar.h>
45 #include <sys/pool.h>
46 #include <sys/proc.h>
47 #include <sys/ktrace.h>
48 #include <sys/sched.h>
49 #include <sys/signalvar.h>
50 
51 #include <sys/mount.h>
52 #include <sys/syscallargs.h>
53 
54 #include <uvm/uvm_extern.h>
55 
56 void	tuagg_sub(struct tusage *, struct proc *);
57 
58 /*
59  * Patchable maximum data and stack limits.
60  */
61 rlim_t maxdmap = MAXDSIZ;
62 rlim_t maxsmap = MAXSSIZ;
63 
64 /*
65  * Resource controls and accounting.
66  */
67 
68 int
69 sys_getpriority(struct proc *curp, void *v, register_t *retval)
70 {
71 	struct sys_getpriority_args /* {
72 		syscallarg(int) which;
73 		syscallarg(id_t) who;
74 	} */ *uap = v;
75 	struct process *pr;
76 	int low = NZERO + PRIO_MAX + 1;
77 
78 	switch (SCARG(uap, which)) {
79 
80 	case PRIO_PROCESS:
81 		if (SCARG(uap, who) == 0)
82 			pr = curp->p_p;
83 		else
84 			pr = prfind(SCARG(uap, who));
85 		if (pr == NULL)
86 			break;
87 		if (pr->ps_nice < low)
88 			low = pr->ps_nice;
89 		break;
90 
91 	case PRIO_PGRP: {
92 		struct pgrp *pg;
93 
94 		if (SCARG(uap, who) == 0)
95 			pg = curp->p_p->ps_pgrp;
96 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
97 			break;
98 		LIST_FOREACH(pr, &pg->pg_members, ps_pglist)
99 			if (pr->ps_nice < low)
100 				low = pr->ps_nice;
101 		break;
102 	}
103 
104 	case PRIO_USER:
105 		if (SCARG(uap, who) == 0)
106 			SCARG(uap, who) = curp->p_ucred->cr_uid;
107 		LIST_FOREACH(pr, &allprocess, ps_list)
108 			if (pr->ps_ucred->cr_uid == SCARG(uap, who) &&
109 			    pr->ps_nice < low)
110 				low = pr->ps_nice;
111 		break;
112 
113 	default:
114 		return (EINVAL);
115 	}
116 	if (low == NZERO + PRIO_MAX + 1)
117 		return (ESRCH);
118 	*retval = low - NZERO;
119 	return (0);
120 }
121 
122 int
123 sys_setpriority(struct proc *curp, void *v, register_t *retval)
124 {
125 	struct sys_setpriority_args /* {
126 		syscallarg(int) which;
127 		syscallarg(id_t) who;
128 		syscallarg(int) prio;
129 	} */ *uap = v;
130 	struct process *pr;
131 	int found = 0, error = 0;
132 
133 	switch (SCARG(uap, which)) {
134 
135 	case PRIO_PROCESS:
136 		if (SCARG(uap, who) == 0)
137 			pr = curp->p_p;
138 		else
139 			pr = prfind(SCARG(uap, who));
140 		if (pr == NULL)
141 			break;
142 		error = donice(curp, pr, SCARG(uap, prio));
143 		found++;
144 		break;
145 
146 	case PRIO_PGRP: {
147 		struct pgrp *pg;
148 
149 		if (SCARG(uap, who) == 0)
150 			pg = curp->p_p->ps_pgrp;
151 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
152 			break;
153 		LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
154 			error = donice(curp, pr, SCARG(uap, prio));
155 			found++;
156 		}
157 		break;
158 	}
159 
160 	case PRIO_USER:
161 		if (SCARG(uap, who) == 0)
162 			SCARG(uap, who) = curp->p_ucred->cr_uid;
163 		LIST_FOREACH(pr, &allprocess, ps_list)
164 			if (pr->ps_ucred->cr_uid == SCARG(uap, who)) {
165 				error = donice(curp, pr, SCARG(uap, prio));
166 				found++;
167 			}
168 		break;
169 
170 	default:
171 		return (EINVAL);
172 	}
173 	if (found == 0)
174 		return (ESRCH);
175 	return (error);
176 }
177 
178 int
179 donice(struct proc *curp, struct process *chgpr, int n)
180 {
181 	struct ucred *ucred = curp->p_ucred;
182 	struct proc *p;
183 	int s;
184 
185 	if (ucred->cr_uid != 0 && ucred->cr_ruid != 0 &&
186 	    ucred->cr_uid != chgpr->ps_ucred->cr_uid &&
187 	    ucred->cr_ruid != chgpr->ps_ucred->cr_uid)
188 		return (EPERM);
189 	if (n > PRIO_MAX)
190 		n = PRIO_MAX;
191 	if (n < PRIO_MIN)
192 		n = PRIO_MIN;
193 	n += NZERO;
194 	if (n < chgpr->ps_nice && suser(curp))
195 		return (EACCES);
196 	chgpr->ps_nice = n;
197 	SCHED_LOCK(s);
198 	TAILQ_FOREACH(p, &chgpr->ps_threads, p_thr_link)
199 		(void)resetpriority(p);
200 	SCHED_UNLOCK(s);
201 	return (0);
202 }
203 
204 int
205 sys_setrlimit(struct proc *p, void *v, register_t *retval)
206 {
207 	struct sys_setrlimit_args /* {
208 		syscallarg(int) which;
209 		syscallarg(const struct rlimit *) rlp;
210 	} */ *uap = v;
211 	struct rlimit alim;
212 	int error;
213 
214 	error = copyin((caddr_t)SCARG(uap, rlp), (caddr_t)&alim,
215 		       sizeof (struct rlimit));
216 	if (error)
217 		return (error);
218 #ifdef KTRACE
219 	if (KTRPOINT(p, KTR_STRUCT))
220 		ktrrlimit(p, &alim);
221 #endif
222 	return (dosetrlimit(p, SCARG(uap, which), &alim));
223 }
224 
225 int
226 dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
227 {
228 	struct rlimit *alimp;
229 	rlim_t maxlim;
230 	int error;
231 
232 	if (which >= RLIM_NLIMITS || limp->rlim_cur > limp->rlim_max)
233 		return (EINVAL);
234 
235 	alimp = &p->p_rlimit[which];
236 	if (limp->rlim_max > alimp->rlim_max)
237 		if ((error = suser(p)) != 0)
238 			return (error);
239 	if (p->p_p->ps_limit->p_refcnt > 1) {
240 		struct plimit *l = p->p_p->ps_limit;
241 
242 		/* limcopy() can sleep, so copy before decrementing refcnt */
243 		p->p_p->ps_limit = limcopy(l);
244 		limfree(l);
245 		alimp = &p->p_rlimit[which];
246 	}
247 
248 	switch (which) {
249 	case RLIMIT_DATA:
250 		maxlim = maxdmap;
251 		break;
252 	case RLIMIT_STACK:
253 		maxlim = maxsmap;
254 		break;
255 	case RLIMIT_NOFILE:
256 		maxlim = maxfiles;
257 		break;
258 	case RLIMIT_NPROC:
259 		maxlim = maxprocess;
260 		break;
261 	default:
262 		maxlim = RLIM_INFINITY;
263 		break;
264 	}
265 
266 	if (limp->rlim_max > maxlim)
267 		limp->rlim_max = maxlim;
268 	if (limp->rlim_cur > limp->rlim_max)
269 		limp->rlim_cur = limp->rlim_max;
270 
271 	if (which == RLIMIT_CPU && limp->rlim_cur != RLIM_INFINITY &&
272 	    alimp->rlim_cur == RLIM_INFINITY)
273 		timeout_add_msec(&p->p_p->ps_rucheck_to, RUCHECK_INTERVAL);
274 
275 	if (which == RLIMIT_STACK) {
276 		/*
277 		 * Stack is allocated to the max at exec time with only
278 		 * "rlim_cur" bytes accessible.  If stack limit is going
279 		 * up make more accessible, if going down make inaccessible.
280 		 */
281 		if (limp->rlim_cur != alimp->rlim_cur) {
282 			vaddr_t addr;
283 			vsize_t size;
284 			vm_prot_t prot;
285 			struct vmspace *vm = p->p_vmspace;
286 
287 			if (limp->rlim_cur > alimp->rlim_cur) {
288 				prot = PROT_READ | PROT_WRITE;
289 				size = limp->rlim_cur - alimp->rlim_cur;
290 #ifdef MACHINE_STACK_GROWS_UP
291 				addr = (vaddr_t)vm->vm_maxsaddr +
292 				    alimp->rlim_cur;
293 #else
294 				addr = (vaddr_t)vm->vm_minsaddr -
295 				    limp->rlim_cur;
296 #endif
297 			} else {
298 				prot = PROT_NONE;
299 				size = alimp->rlim_cur - limp->rlim_cur;
300 #ifdef MACHINE_STACK_GROWS_UP
301 				addr = (vaddr_t)vm->vm_maxsaddr +
302 				    limp->rlim_cur;
303 #else
304 				addr = (vaddr_t)vm->vm_minsaddr -
305 				    alimp->rlim_cur;
306 #endif
307 			}
308 			addr = trunc_page(addr);
309 			size = round_page(size);
310 			(void) uvm_map_protect(&vm->vm_map,
311 					      addr, addr+size, prot, FALSE);
312 		}
313 	}
314 
315 	*alimp = *limp;
316 	return (0);
317 }
318 
319 int
320 sys_getrlimit(struct proc *p, void *v, register_t *retval)
321 {
322 	struct sys_getrlimit_args /* {
323 		syscallarg(int) which;
324 		syscallarg(struct rlimit *) rlp;
325 	} */ *uap = v;
326 	struct rlimit *alimp;
327 	int error;
328 
329 	if (SCARG(uap, which) < 0 || SCARG(uap, which) >= RLIM_NLIMITS)
330 		return (EINVAL);
331 	alimp = &p->p_rlimit[SCARG(uap, which)];
332 	error = copyout(alimp, SCARG(uap, rlp), sizeof(struct rlimit));
333 #ifdef KTRACE
334 	if (error == 0 && KTRPOINT(p, KTR_STRUCT))
335 		ktrrlimit(p, alimp);
336 #endif
337 	return (error);
338 }
339 
340 void
341 tuagg_sub(struct tusage *tup, struct proc *p)
342 {
343 	timespecadd(&tup->tu_runtime, &p->p_rtime, &tup->tu_runtime);
344 	tup->tu_uticks += p->p_uticks;
345 	tup->tu_sticks += p->p_sticks;
346 	tup->tu_iticks += p->p_iticks;
347 }
348 
349 /*
350  * Aggregate a single thread's immediate time counts into the running
351  * totals for the thread and process
352  */
353 void
354 tuagg_unlocked(struct process *pr, struct proc *p)
355 {
356 	tuagg_sub(&pr->ps_tu, p);
357 	tuagg_sub(&p->p_tu, p);
358 	timespecclear(&p->p_rtime);
359 	p->p_uticks = 0;
360 	p->p_sticks = 0;
361 	p->p_iticks = 0;
362 }
363 
364 void
365 tuagg(struct process *pr, struct proc *p)
366 {
367 	int s;
368 
369 	SCHED_LOCK(s);
370 	tuagg_unlocked(pr, p);
371 	SCHED_UNLOCK(s);
372 }
373 
374 /*
375  * Transform the running time and tick information in a struct tusage
376  * into user, system, and interrupt time usage.
377  */
378 void
379 calctsru(struct tusage *tup, struct timespec *up, struct timespec *sp,
380     struct timespec *ip)
381 {
382 	u_quad_t st, ut, it;
383 	int freq;
384 
385 	st = tup->tu_sticks;
386 	ut = tup->tu_uticks;
387 	it = tup->tu_iticks;
388 
389 	if (st + ut + it == 0) {
390 		timespecclear(up);
391 		timespecclear(sp);
392 		if (ip != NULL)
393 			timespecclear(ip);
394 		return;
395 	}
396 
397 	freq = stathz ? stathz : hz;
398 
399 	st = st * 1000000000 / freq;
400 	sp->tv_sec = st / 1000000000;
401 	sp->tv_nsec = st % 1000000000;
402 	ut = ut * 1000000000 / freq;
403 	up->tv_sec = ut / 1000000000;
404 	up->tv_nsec = ut % 1000000000;
405 	if (ip != NULL) {
406 		it = it * 1000000000 / freq;
407 		ip->tv_sec = it / 1000000000;
408 		ip->tv_nsec = it % 1000000000;
409 	}
410 }
411 
412 void
413 calcru(struct tusage *tup, struct timeval *up, struct timeval *sp,
414     struct timeval *ip)
415 {
416 	struct timespec u, s, i;
417 
418 	calctsru(tup, &u, &s, ip != NULL ? &i : NULL);
419 	TIMESPEC_TO_TIMEVAL(up, &u);
420 	TIMESPEC_TO_TIMEVAL(sp, &s);
421 	if (ip != NULL)
422 		TIMESPEC_TO_TIMEVAL(ip, &i);
423 }
424 
425 int
426 sys_getrusage(struct proc *p, void *v, register_t *retval)
427 {
428 	struct sys_getrusage_args /* {
429 		syscallarg(int) who;
430 		syscallarg(struct rusage *) rusage;
431 	} */ *uap = v;
432 	struct rusage ru;
433 	int error;
434 
435 	error = dogetrusage(p, SCARG(uap, who), &ru);
436 	if (error == 0) {
437 		error = copyout(&ru, SCARG(uap, rusage), sizeof(ru));
438 #ifdef KTRACE
439 		if (error == 0 && KTRPOINT(p, KTR_STRUCT))
440 			ktrrusage(p, &ru);
441 #endif
442 	}
443 	return (error);
444 }
445 
446 int
447 dogetrusage(struct proc *p, int who, struct rusage *rup)
448 {
449 	struct process *pr = p->p_p;
450 	struct proc *q;
451 
452 	switch (who) {
453 
454 	case RUSAGE_SELF:
455 		/* start with the sum of dead threads, if any */
456 		if (pr->ps_ru != NULL)
457 			*rup = *pr->ps_ru;
458 		else
459 			memset(rup, 0, sizeof(*rup));
460 
461 		/* add on all living threads */
462 		TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) {
463 			ruadd(rup, &q->p_ru);
464 			tuagg(pr, q);
465 		}
466 
467 		calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL);
468 		break;
469 
470 	case RUSAGE_THREAD:
471 		*rup = p->p_ru;
472 		calcru(&p->p_tu, &rup->ru_utime, &rup->ru_stime, NULL);
473 		break;
474 
475 	case RUSAGE_CHILDREN:
476 		*rup = pr->ps_cru;
477 		break;
478 
479 	default:
480 		return (EINVAL);
481 	}
482 	return (0);
483 }
484 
485 void
486 ruadd(struct rusage *ru, struct rusage *ru2)
487 {
488 	long *ip, *ip2;
489 	int i;
490 
491 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
492 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
493 	if (ru->ru_maxrss < ru2->ru_maxrss)
494 		ru->ru_maxrss = ru2->ru_maxrss;
495 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
496 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
497 		*ip++ += *ip2++;
498 }
499 
500 /*
501  * Check if the process exceeds its cpu resource allocation.
502  * If over max, kill it.
503  */
504 void
505 rucheck(void *arg)
506 {
507 	struct process *pr = arg;
508 	struct rlimit *rlim;
509 	rlim_t runtime;
510 	int s;
511 
512 	KERNEL_ASSERT_LOCKED();
513 
514 	SCHED_LOCK(s);
515 	runtime = pr->ps_tu.tu_runtime.tv_sec;
516 	SCHED_UNLOCK(s);
517 
518 	rlim = &pr->ps_limit->pl_rlimit[RLIMIT_CPU];
519 	if (runtime >= rlim->rlim_cur) {
520 		if (runtime >= rlim->rlim_max) {
521 			prsignal(pr, SIGKILL);
522 		} else {
523 			prsignal(pr, SIGXCPU);
524 			if (rlim->rlim_cur < rlim->rlim_max)
525 				rlim->rlim_cur = MIN(rlim->rlim_cur + 5,
526 				    rlim->rlim_max);
527 		}
528 	}
529 
530 	timeout_add_msec(&pr->ps_rucheck_to, RUCHECK_INTERVAL);
531 }
532 
533 struct pool plimit_pool;
534 
535 /*
536  * Make a copy of the plimit structure.
537  * We share these structures copy-on-write after fork,
538  * and copy when a limit is changed.
539  */
540 struct plimit *
541 limcopy(struct plimit *lim)
542 {
543 	struct plimit *newlim;
544 	static int initialized;
545 
546 	if (!initialized) {
547 		pool_init(&plimit_pool, sizeof(struct plimit), 0, IPL_NONE,
548 		    PR_WAITOK, "plimitpl", NULL);
549 		initialized = 1;
550 	}
551 
552 	newlim = pool_get(&plimit_pool, PR_WAITOK);
553 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
554 	    sizeof(struct rlimit) * RLIM_NLIMITS);
555 	newlim->p_refcnt = 1;
556 	return (newlim);
557 }
558 
559 void
560 limfree(struct plimit *lim)
561 {
562 	if (--lim->p_refcnt > 0)
563 		return;
564 	pool_put(&plimit_pool, lim);
565 }
566