xref: /openbsd-src/sys/kern/kern_resource.c (revision 7824a83910e53cdd3a74d9833eb4c448966651e1) 
1 /*	$OpenBSD: kern_resource.c,v 1.35 2010/06/29 20:14:46 guenther 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/sched.h>
48 
49 #include <sys/mount.h>
50 #include <sys/syscallargs.h>
51 
52 #include <uvm/uvm_extern.h>
53 
54 /*
55  * Patchable maximum data and stack limits.
56  */
57 rlim_t maxdmap = MAXDSIZ;
58 rlim_t maxsmap = MAXSSIZ;
59 
60 /*
61  * Resource controls and accounting.
62  */
63 
64 int
65 sys_getpriority(struct proc *curp, void *v, register_t *retval)
66 {
67 	struct sys_getpriority_args /* {
68 		syscallarg(int) which;
69 		syscallarg(id_t) who;
70 	} */ *uap = v;
71 	struct proc *p;
72 	int low = NZERO + PRIO_MAX + 1;
73 
74 	switch (SCARG(uap, which)) {
75 
76 	case PRIO_PROCESS:
77 		if (SCARG(uap, who) == 0)
78 			p = curp;
79 		else
80 			p = pfind(SCARG(uap, who));
81 		if (p == 0)
82 			break;
83 		low = p->p_nice;
84 		break;
85 
86 	case PRIO_PGRP: {
87 		struct pgrp *pg;
88 
89 		if (SCARG(uap, who) == 0)
90 			pg = curp->p_pgrp;
91 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
92 			break;
93 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
94 			if (p->p_nice < low)
95 				low = p->p_nice;
96 		}
97 		break;
98 	}
99 
100 	case PRIO_USER:
101 		if (SCARG(uap, who) == 0)
102 			SCARG(uap, who) = curp->p_ucred->cr_uid;
103 		LIST_FOREACH(p, &allproc, p_list)
104 			if (p->p_ucred->cr_uid == SCARG(uap, who) &&
105 			    p->p_nice < low)
106 				low = p->p_nice;
107 		break;
108 
109 	default:
110 		return (EINVAL);
111 	}
112 	if (low == NZERO + PRIO_MAX + 1)
113 		return (ESRCH);
114 	*retval = low - NZERO;
115 	return (0);
116 }
117 
118 /* ARGSUSED */
119 int
120 sys_setpriority(struct proc *curp, void *v, register_t *retval)
121 {
122 	struct sys_setpriority_args /* {
123 		syscallarg(int) which;
124 		syscallarg(id_t) who;
125 		syscallarg(int) prio;
126 	} */ *uap = v;
127 	struct proc *p;
128 	int found = 0, error = 0;
129 
130 	switch (SCARG(uap, which)) {
131 
132 	case PRIO_PROCESS:
133 		if (SCARG(uap, who) == 0)
134 			p = curp;
135 		else
136 			p = pfind(SCARG(uap, who));
137 		if (p == 0)
138 			break;
139 		error = donice(curp, p, SCARG(uap, prio));
140 		found++;
141 		break;
142 
143 	case PRIO_PGRP: {
144 		struct pgrp *pg;
145 
146 		if (SCARG(uap, who) == 0)
147 			pg = curp->p_pgrp;
148 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
149 			break;
150 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
151 			error = donice(curp, p, SCARG(uap, prio));
152 			found++;
153 		}
154 		break;
155 	}
156 
157 	case PRIO_USER:
158 		if (SCARG(uap, who) == 0)
159 			SCARG(uap, who) = curp->p_ucred->cr_uid;
160 		LIST_FOREACH(p, &allproc, p_list)
161 			if (p->p_ucred->cr_uid == SCARG(uap, who)) {
162 				error = donice(curp, p, SCARG(uap, prio));
163 				found++;
164 			}
165 		break;
166 
167 	default:
168 		return (EINVAL);
169 	}
170 	if (found == 0)
171 		return (ESRCH);
172 	return (error);
173 }
174 
175 int
176 donice(struct proc *curp, struct proc *chgp, int n)
177 {
178 	struct pcred *pcred = curp->p_cred;
179 	int s;
180 
181 	if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
182 	    pcred->pc_ucred->cr_uid != chgp->p_ucred->cr_uid &&
183 	    pcred->p_ruid != chgp->p_ucred->cr_uid)
184 		return (EPERM);
185 	if (n > PRIO_MAX)
186 		n = PRIO_MAX;
187 	if (n < PRIO_MIN)
188 		n = PRIO_MIN;
189 	n += NZERO;
190 	if (n < chgp->p_nice && suser(curp, 0))
191 		return (EACCES);
192 	chgp->p_nice = n;
193 	SCHED_LOCK(s);
194 	(void)resetpriority(chgp);
195 	SCHED_UNLOCK(s);
196 	return (0);
197 }
198 
199 /* ARGSUSED */
200 int
201 sys_setrlimit(struct proc *p, void *v, register_t *retval)
202 {
203 	struct sys_setrlimit_args /* {
204 		syscallarg(int) which;
205 		syscallarg(const struct rlimit *) rlp;
206 	} */ *uap = v;
207 	struct rlimit alim;
208 	int error;
209 
210 	error = copyin((caddr_t)SCARG(uap, rlp), (caddr_t)&alim,
211 		       sizeof (struct rlimit));
212 	if (error)
213 		return (error);
214 	return (dosetrlimit(p, SCARG(uap, which), &alim));
215 }
216 
217 int
218 dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
219 {
220 	struct rlimit *alimp;
221 	rlim_t maxlim;
222 	int error;
223 
224 	if (which >= RLIM_NLIMITS)
225 		return (EINVAL);
226 
227 	alimp = &p->p_rlimit[which];
228 	if (limp->rlim_cur > alimp->rlim_max ||
229 	    limp->rlim_max > alimp->rlim_max)
230 		if ((error = suser(p, 0)) != 0)
231 			return (error);
232 	if (p->p_p->ps_limit->p_refcnt > 1) {
233 		struct plimit *l = p->p_p->ps_limit;
234 
235 		/* limcopy() can sleep, so copy before decrementing refcnt */
236 		p->p_p->ps_limit = limcopy(l);
237 		l->p_refcnt--;
238 		alimp = &p->p_rlimit[which];
239 	}
240 
241 	switch (which) {
242 	case RLIMIT_DATA:
243 		maxlim = maxdmap;
244 		break;
245 	case RLIMIT_STACK:
246 		maxlim = maxsmap;
247 		break;
248 	case RLIMIT_NOFILE:
249 		maxlim = maxfiles;
250 		break;
251 	case RLIMIT_NPROC:
252 		maxlim = maxproc;
253 		break;
254 	default:
255 		maxlim = RLIM_INFINITY;
256 		break;
257 	}
258 
259 	if (limp->rlim_max > maxlim)
260 		limp->rlim_max = maxlim;
261 	if (limp->rlim_cur > limp->rlim_max)
262 		limp->rlim_cur = limp->rlim_max;
263 
264 	if (which == RLIMIT_STACK) {
265 		/*
266 		 * Stack is allocated to the max at exec time with only
267 		 * "rlim_cur" bytes accessible.  If stack limit is going
268 		 * up make more accessible, if going down make inaccessible.
269 		 */
270 		if (limp->rlim_cur != alimp->rlim_cur) {
271 			vaddr_t addr;
272 			vsize_t size;
273 			vm_prot_t prot;
274 
275 			if (limp->rlim_cur > alimp->rlim_cur) {
276 				prot = VM_PROT_READ|VM_PROT_WRITE;
277 				size = limp->rlim_cur - alimp->rlim_cur;
278 #ifdef MACHINE_STACK_GROWS_UP
279 				addr = USRSTACK + alimp->rlim_cur;
280 #else
281 				addr = USRSTACK - limp->rlim_cur;
282 #endif
283 			} else {
284 				prot = VM_PROT_NONE;
285 				size = alimp->rlim_cur - limp->rlim_cur;
286 #ifdef MACHINE_STACK_GROWS_UP
287 				addr = USRSTACK + limp->rlim_cur;
288 #else
289 				addr = USRSTACK - alimp->rlim_cur;
290 #endif
291 			}
292 			addr = trunc_page(addr);
293 			size = round_page(size);
294 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
295 					      addr, addr+size, prot, FALSE);
296 		}
297 	}
298 
299 	*alimp = *limp;
300 	return (0);
301 }
302 
303 /* ARGSUSED */
304 int
305 sys_getrlimit(struct proc *p, void *v, register_t *retval)
306 {
307 	struct sys_getrlimit_args /* {
308 		syscallarg(int) which;
309 		syscallarg(struct rlimit *) rlp;
310 	} */ *uap = v;
311 
312 	if (SCARG(uap, which) < 0 || SCARG(uap, which) >= RLIM_NLIMITS)
313 		return (EINVAL);
314 	return (copyout((caddr_t)&p->p_rlimit[SCARG(uap, which)],
315 	    (caddr_t)SCARG(uap, rlp), sizeof (struct rlimit)));
316 }
317 
318 /*
319  * Transform the running time and tick information in proc p into user,
320  * system, and interrupt time usage.
321  */
322 void
323 calcru(struct proc *p, struct timeval *up, struct timeval *sp,
324     struct timeval *ip)
325 {
326 	u_quad_t st, ut, it;
327 	int freq;
328 	int s;
329 
330 	s = splstatclock();
331 	st = p->p_sticks;
332 	ut = p->p_uticks;
333 	it = p->p_iticks;
334 	splx(s);
335 
336 	if (st + ut + it == 0) {
337 		timerclear(up);
338 		timerclear(sp);
339 		if (ip != NULL)
340 			timerclear(ip);
341 		return;
342 	}
343 
344 	freq = stathz ? stathz : hz;
345 
346 	st = st * 1000000 / freq;
347 	sp->tv_sec = st / 1000000;
348 	sp->tv_usec = st % 1000000;
349 	ut = ut * 1000000 / freq;
350 	up->tv_sec = ut / 1000000;
351 	up->tv_usec = ut % 1000000;
352 	if (ip != NULL) {
353 		it = it * 1000000 / freq;
354 		ip->tv_sec = it / 1000000;
355 		ip->tv_usec = it % 1000000;
356 	}
357 }
358 
359 /* ARGSUSED */
360 int
361 sys_getrusage(struct proc *p, void *v, register_t *retval)
362 {
363 	struct sys_getrusage_args /* {
364 		syscallarg(int) who;
365 		syscallarg(struct rusage *) rusage;
366 	} */ *uap = v;
367 	struct rusage *rup;
368 
369 	switch (SCARG(uap, who)) {
370 
371 	case RUSAGE_SELF:
372 		rup = &p->p_stats->p_ru;
373 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
374 		break;
375 
376 	case RUSAGE_CHILDREN:
377 		rup = &p->p_stats->p_cru;
378 		break;
379 
380 	default:
381 		return (EINVAL);
382 	}
383 	return (copyout((caddr_t)rup, (caddr_t)SCARG(uap, rusage),
384 	    sizeof (struct rusage)));
385 }
386 
387 void
388 ruadd(struct rusage *ru, struct rusage *ru2)
389 {
390 	long *ip, *ip2;
391 	int i;
392 
393 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
394 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
395 	if (ru->ru_maxrss < ru2->ru_maxrss)
396 		ru->ru_maxrss = ru2->ru_maxrss;
397 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
398 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
399 		*ip++ += *ip2++;
400 }
401 
402 struct pool plimit_pool;
403 
404 /*
405  * Make a copy of the plimit structure.
406  * We share these structures copy-on-write after fork,
407  * and copy when a limit is changed.
408  */
409 struct plimit *
410 limcopy(struct plimit *lim)
411 {
412 	struct plimit *newlim;
413 	static int initialized;
414 
415 	if (!initialized) {
416 		pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0,
417 		    "plimitpl", &pool_allocator_nointr);
418 		initialized = 1;
419 	}
420 
421 	newlim = pool_get(&plimit_pool, PR_WAITOK);
422 	bcopy(lim->pl_rlimit, newlim->pl_rlimit,
423 	    sizeof(struct rlimit) * RLIM_NLIMITS);
424 	newlim->p_refcnt = 1;
425 	return (newlim);
426 }
427 
428 void
429 limfree(struct plimit *lim)
430 {
431 	if (--lim->p_refcnt > 0)
432 		return;
433 	pool_put(&plimit_pool, lim);
434 }
435