xref: /openbsd-src/sys/kern/kern_resource.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2) 
1 /*	$OpenBSD: kern_resource.c,v 1.33 2008/05/22 17:04:59 thib 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 	    (p->p_p->ps_limit->p_lflags & PL_SHAREMOD) == 0) {
234 		p->p_p->ps_limit->p_refcnt--;
235 		p->p_p->ps_limit = limcopy(p->p_p->ps_limit);
236 		alimp = &p->p_rlimit[which];
237 	}
238 
239 	switch (which) {
240 	case RLIMIT_DATA:
241 		maxlim = maxdmap;
242 		break;
243 	case RLIMIT_STACK:
244 		maxlim = maxsmap;
245 		break;
246 	case RLIMIT_NOFILE:
247 		maxlim = maxfiles;
248 		break;
249 	case RLIMIT_NPROC:
250 		maxlim = maxproc;
251 		break;
252 	default:
253 		maxlim = RLIM_INFINITY;
254 		break;
255 	}
256 
257 	if (limp->rlim_max > maxlim)
258 		limp->rlim_max = maxlim;
259 	if (limp->rlim_cur > limp->rlim_max)
260 		limp->rlim_cur = limp->rlim_max;
261 
262 	if (which == RLIMIT_STACK) {
263 		/*
264 		 * Stack is allocated to the max at exec time with only
265 		 * "rlim_cur" bytes accessible.  If stack limit is going
266 		 * up make more accessible, if going down make inaccessible.
267 		 */
268 		if (limp->rlim_cur != alimp->rlim_cur) {
269 			vaddr_t addr;
270 			vsize_t size;
271 			vm_prot_t prot;
272 
273 			if (limp->rlim_cur > alimp->rlim_cur) {
274 				prot = VM_PROT_READ|VM_PROT_WRITE;
275 				size = limp->rlim_cur - alimp->rlim_cur;
276 #ifdef MACHINE_STACK_GROWS_UP
277 				addr = USRSTACK + alimp->rlim_cur;
278 #else
279 				addr = USRSTACK - limp->rlim_cur;
280 #endif
281 			} else {
282 				prot = VM_PROT_NONE;
283 				size = alimp->rlim_cur - limp->rlim_cur;
284 #ifdef MACHINE_STACK_GROWS_UP
285 				addr = USRSTACK + limp->rlim_cur;
286 #else
287 				addr = USRSTACK - alimp->rlim_cur;
288 #endif
289 			}
290 			addr = trunc_page(addr);
291 			size = round_page(size);
292 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
293 					      addr, addr+size, prot, FALSE);
294 		}
295 	}
296 
297 	*alimp = *limp;
298 	return (0);
299 }
300 
301 /* ARGSUSED */
302 int
303 sys_getrlimit(struct proc *p, void *v, register_t *retval)
304 {
305 	struct sys_getrlimit_args /* {
306 		syscallarg(int) which;
307 		syscallarg(struct rlimit *) rlp;
308 	} */ *uap = v;
309 
310 	if (SCARG(uap, which) < 0 || SCARG(uap, which) >= RLIM_NLIMITS)
311 		return (EINVAL);
312 	return (copyout((caddr_t)&p->p_rlimit[SCARG(uap, which)],
313 	    (caddr_t)SCARG(uap, rlp), sizeof (struct rlimit)));
314 }
315 
316 /*
317  * Transform the running time and tick information in proc p into user,
318  * system, and interrupt time usage.
319  */
320 void
321 calcru(struct proc *p, struct timeval *up, struct timeval *sp,
322     struct timeval *ip)
323 {
324 	u_quad_t st, ut, it;
325 	int freq;
326 	int s;
327 
328 	s = splstatclock();
329 	st = p->p_sticks;
330 	ut = p->p_uticks;
331 	it = p->p_iticks;
332 	splx(s);
333 
334 	if (st + ut + it == 0) {
335 		timerclear(up);
336 		timerclear(sp);
337 		if (ip != NULL)
338 			timerclear(ip);
339 		return;
340 	}
341 
342 	freq = stathz ? stathz : hz;
343 
344 	st = st * 1000000 / freq;
345 	sp->tv_sec = st / 1000000;
346 	sp->tv_usec = st % 1000000;
347 	ut = ut * 1000000 / freq;
348 	up->tv_sec = ut / 1000000;
349 	up->tv_usec = ut % 1000000;
350 	if (ip != NULL) {
351 		it = it * 1000000 / freq;
352 		ip->tv_sec = it / 1000000;
353 		ip->tv_usec = it % 1000000;
354 	}
355 }
356 
357 /* ARGSUSED */
358 int
359 sys_getrusage(struct proc *p, void *v, register_t *retval)
360 {
361 	struct sys_getrusage_args /* {
362 		syscallarg(int) who;
363 		syscallarg(struct rusage *) rusage;
364 	} */ *uap = v;
365 	struct rusage *rup;
366 
367 	switch (SCARG(uap, who)) {
368 
369 	case RUSAGE_SELF:
370 		rup = &p->p_stats->p_ru;
371 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
372 		break;
373 
374 	case RUSAGE_CHILDREN:
375 		rup = &p->p_stats->p_cru;
376 		break;
377 
378 	default:
379 		return (EINVAL);
380 	}
381 	return (copyout((caddr_t)rup, (caddr_t)SCARG(uap, rusage),
382 	    sizeof (struct rusage)));
383 }
384 
385 void
386 ruadd(struct rusage *ru, struct rusage *ru2)
387 {
388 	long *ip, *ip2;
389 	int i;
390 
391 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
392 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
393 	if (ru->ru_maxrss < ru2->ru_maxrss)
394 		ru->ru_maxrss = ru2->ru_maxrss;
395 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
396 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
397 		*ip++ += *ip2++;
398 }
399 
400 struct pool plimit_pool;
401 
402 /*
403  * Make a copy of the plimit structure.
404  * We share these structures copy-on-write after fork,
405  * and copy when a limit is changed.
406  */
407 struct plimit *
408 limcopy(struct plimit *lim)
409 {
410 	struct plimit *newlim;
411 	static int initialized;
412 
413 	if (!initialized) {
414 		pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0,
415 		    "plimitpl", &pool_allocator_nointr);
416 		initialized = 1;
417 	}
418 
419 	newlim = pool_get(&plimit_pool, PR_WAITOK);
420 	bcopy(lim->pl_rlimit, newlim->pl_rlimit,
421 	    sizeof(struct rlimit) * RLIM_NLIMITS);
422 	newlim->p_lflags = 0;
423 	newlim->p_refcnt = 1;
424 	return (newlim);
425 }
426 
427 void
428 limfree(struct plimit *lim)
429 {
430 	if (--lim->p_refcnt > 0)
431 		return;
432 	pool_put(&plimit_pool, lim);
433 }
434