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kern_resource.c revision 1.84
      1 /*	$NetBSD: kern_resource.c,v 1.84 2004/05/13 17:43:11 christos 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 1.84 2004/05/13 17:43:11 christos 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/pool.h>
     49 #include <sys/proc.h>
     50 #include <sys/sysctl.h>
     51 
     52 #include <sys/mount.h>
     53 #include <sys/sa.h>
     54 #include <sys/syscallargs.h>
     55 
     56 #include <uvm/uvm_extern.h>
     57 
     58 /*
     59  * Maximum process data and stack limits.
     60  * They are variables so they are patchable.
     61  */
     62 rlim_t maxdmap = MAXDSIZ;
     63 rlim_t maxsmap = MAXSSIZ;
     64 
     65 struct uihashhead *uihashtbl;
     66 u_long uihash;		/* size of hash table - 1 */
     67 
     68 static struct uidinfo *getuidinfo(uid_t);
     69 static void freeuidinfo(struct uidinfo *);
     70 static struct uidinfo *allocuidinfo(uid_t);
     71 
     72 /*
     73  * Resource controls and accounting.
     74  */
     75 
     76 int
     77 sys_getpriority(l, v, retval)
     78 	struct lwp *l;
     79 	void *v;
     80 	register_t *retval;
     81 {
     82 	struct sys_getpriority_args /* {
     83 		syscallarg(int) which;
     84 		syscallarg(id_t) who;
     85 	} */ *uap = v;
     86 	struct proc *curp = l->l_proc, *p;
     87 	int low = NZERO + PRIO_MAX + 1;
     88 
     89 	switch (SCARG(uap, which)) {
     90 
     91 	case PRIO_PROCESS:
     92 		if (SCARG(uap, who) == 0)
     93 			p = curp;
     94 		else
     95 			p = pfind(SCARG(uap, who));
     96 		if (p == 0)
     97 			break;
     98 		low = p->p_nice;
     99 		break;
    100 
    101 	case PRIO_PGRP: {
    102 		struct pgrp *pg;
    103 
    104 		if (SCARG(uap, who) == 0)
    105 			pg = curp->p_pgrp;
    106 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
    107 			break;
    108 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
    109 			if (p->p_nice < low)
    110 				low = p->p_nice;
    111 		}
    112 		break;
    113 	}
    114 
    115 	case PRIO_USER:
    116 		if (SCARG(uap, who) == 0)
    117 			SCARG(uap, who) = curp->p_ucred->cr_uid;
    118 		proclist_lock_read();
    119 		LIST_FOREACH(p, &allproc, p_list) {
    120 			if (p->p_ucred->cr_uid == (uid_t) SCARG(uap, who) &&
    121 			    p->p_nice < low)
    122 				low = p->p_nice;
    123 		}
    124 		proclist_unlock_read();
    125 		break;
    126 
    127 	default:
    128 		return (EINVAL);
    129 	}
    130 	if (low == NZERO + PRIO_MAX + 1)
    131 		return (ESRCH);
    132 	*retval = low - NZERO;
    133 	return (0);
    134 }
    135 
    136 /* ARGSUSED */
    137 int
    138 sys_setpriority(l, v, retval)
    139 	struct lwp *l;
    140 	void *v;
    141 	register_t *retval;
    142 {
    143 	struct sys_setpriority_args /* {
    144 		syscallarg(int) which;
    145 		syscallarg(id_t) who;
    146 		syscallarg(int) prio;
    147 	} */ *uap = v;
    148 	struct proc *curp = l->l_proc, *p;
    149 	int found = 0, error = 0;
    150 
    151 	switch (SCARG(uap, which)) {
    152 
    153 	case PRIO_PROCESS:
    154 		if (SCARG(uap, who) == 0)
    155 			p = curp;
    156 		else
    157 			p = pfind(SCARG(uap, who));
    158 		if (p == 0)
    159 			break;
    160 		error = donice(curp, p, SCARG(uap, prio));
    161 		found++;
    162 		break;
    163 
    164 	case PRIO_PGRP: {
    165 		struct pgrp *pg;
    166 
    167 		if (SCARG(uap, who) == 0)
    168 			pg = curp->p_pgrp;
    169 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
    170 			break;
    171 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
    172 			error = donice(curp, p, SCARG(uap, prio));
    173 			found++;
    174 		}
    175 		break;
    176 	}
    177 
    178 	case PRIO_USER:
    179 		if (SCARG(uap, who) == 0)
    180 			SCARG(uap, who) = curp->p_ucred->cr_uid;
    181 		proclist_lock_read();
    182 		LIST_FOREACH(p, &allproc, p_list) {
    183 			if (p->p_ucred->cr_uid == (uid_t) SCARG(uap, who)) {
    184 				error = donice(curp, p, SCARG(uap, prio));
    185 				found++;
    186 			}
    187 		}
    188 		proclist_unlock_read();
    189 		break;
    190 
    191 	default:
    192 		return (EINVAL);
    193 	}
    194 	if (found == 0)
    195 		return (ESRCH);
    196 	return (error);
    197 }
    198 
    199 int
    200 donice(curp, chgp, n)
    201 	struct proc *curp, *chgp;
    202 	int n;
    203 {
    204 	struct pcred *pcred = curp->p_cred;
    205 	int s;
    206 
    207 	if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
    208 	    pcred->pc_ucred->cr_uid != chgp->p_ucred->cr_uid &&
    209 	    pcred->p_ruid != chgp->p_ucred->cr_uid)
    210 		return (EPERM);
    211 	if (n > PRIO_MAX)
    212 		n = PRIO_MAX;
    213 	if (n < PRIO_MIN)
    214 		n = PRIO_MIN;
    215 	n += NZERO;
    216 	if (n < chgp->p_nice && suser(pcred->pc_ucred, &curp->p_acflag))
    217 		return (EACCES);
    218 	chgp->p_nice = n;
    219 	SCHED_LOCK(s);
    220 	(void)resetprocpriority(chgp);
    221 	SCHED_UNLOCK(s);
    222 	return (0);
    223 }
    224 
    225 /* ARGSUSED */
    226 int
    227 sys_setrlimit(l, v, retval)
    228 	struct lwp *l;
    229 	void *v;
    230 	register_t *retval;
    231 {
    232 	struct sys_setrlimit_args /* {
    233 		syscallarg(int) which;
    234 		syscallarg(const struct rlimit *) rlp;
    235 	} */ *uap = v;
    236 	struct proc *p = l->l_proc;
    237 	int which = SCARG(uap, which);
    238 	struct rlimit alim;
    239 	int error;
    240 
    241 	error = copyin(SCARG(uap, rlp), &alim, sizeof(struct rlimit));
    242 	if (error)
    243 		return (error);
    244 	return (dosetrlimit(p, p->p_cred, which, &alim));
    245 }
    246 
    247 int
    248 dosetrlimit(p, cred, which, limp)
    249 	struct proc *p;
    250 	struct  pcred *cred;
    251 	int which;
    252 	struct rlimit *limp;
    253 {
    254 	struct rlimit *alimp;
    255 	struct plimit *oldplim;
    256 	int error;
    257 
    258 	if ((u_int)which >= RLIM_NLIMITS)
    259 		return (EINVAL);
    260 
    261 	if (limp->rlim_cur < 0 || limp->rlim_max < 0)
    262 		return (EINVAL);
    263 
    264 	alimp = &p->p_rlimit[which];
    265 	/* if we don't change the value, no need to limcopy() */
    266 	if (limp->rlim_cur == alimp->rlim_cur &&
    267 	    limp->rlim_max == alimp->rlim_max)
    268 		return 0;
    269 
    270 	if (limp->rlim_cur > limp->rlim_max) {
    271 		/*
    272 		 * This is programming error. According to SUSv2, we should
    273 		 * return error in this case.
    274 		 */
    275 		return (EINVAL);
    276 	}
    277 	if (limp->rlim_max > alimp->rlim_max
    278 	    && (error = suser(cred->pc_ucred, &p->p_acflag)) != 0)
    279 			return (error);
    280 
    281 	if (p->p_limit->p_refcnt > 1 &&
    282 	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
    283 		p->p_limit = limcopy(oldplim = p->p_limit);
    284 		limfree(oldplim);
    285 		alimp = &p->p_rlimit[which];
    286 	}
    287 
    288 	switch (which) {
    289 
    290 	case RLIMIT_DATA:
    291 		if (limp->rlim_cur > maxdmap)
    292 			limp->rlim_cur = maxdmap;
    293 		if (limp->rlim_max > maxdmap)
    294 			limp->rlim_max = maxdmap;
    295 		break;
    296 
    297 	case RLIMIT_STACK:
    298 		if (limp->rlim_cur > maxsmap)
    299 			limp->rlim_cur = maxsmap;
    300 		if (limp->rlim_max > maxsmap)
    301 			limp->rlim_max = maxsmap;
    302 
    303 		/*
    304 		 * Return EINVAL if the new stack size limit is lower than
    305 		 * current usage. Otherwise, the process would get SIGSEGV the
    306 		 * moment it would try to access anything on it's current stack.
    307 		 * This conforms to SUSv2.
    308 		 */
    309 		if (limp->rlim_cur < p->p_vmspace->vm_ssize * PAGE_SIZE
    310 		    || limp->rlim_max < p->p_vmspace->vm_ssize * PAGE_SIZE)
    311 			return (EINVAL);
    312 
    313 		/*
    314 		 * Stack is allocated to the max at exec time with
    315 		 * only "rlim_cur" bytes accessible (In other words,
    316 		 * allocates stack dividing two contiguous regions at
    317 		 * "rlim_cur" bytes boundary).
    318 		 *
    319 		 * Since allocation is done in terms of page, roundup
    320 		 * "rlim_cur" (otherwise, contiguous regions
    321 		 * overlap).  If stack limit is going up make more
    322 		 * accessible, if going down make inaccessible.
    323 		 */
    324 		limp->rlim_cur = round_page(limp->rlim_cur);
    325 		if (limp->rlim_cur != alimp->rlim_cur) {
    326 			vaddr_t addr;
    327 			vsize_t size;
    328 			vm_prot_t prot;
    329 
    330 			if (limp->rlim_cur > alimp->rlim_cur) {
    331 				prot = VM_PROT_READ | VM_PROT_WRITE;
    332 				size = limp->rlim_cur - alimp->rlim_cur;
    333 				addr = USRSTACK - limp->rlim_cur;
    334 			} else {
    335 				prot = VM_PROT_NONE;
    336 				size = alimp->rlim_cur - limp->rlim_cur;
    337 				addr = USRSTACK - alimp->rlim_cur;
    338 			}
    339 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
    340 					      addr, addr+size, prot, FALSE);
    341 		}
    342 		break;
    343 
    344 	case RLIMIT_NOFILE:
    345 		if (limp->rlim_cur > maxfiles)
    346 			limp->rlim_cur = maxfiles;
    347 		if (limp->rlim_max > maxfiles)
    348 			limp->rlim_max = maxfiles;
    349 		break;
    350 
    351 	case RLIMIT_NPROC:
    352 		if (limp->rlim_cur > maxproc)
    353 			limp->rlim_cur = maxproc;
    354 		if (limp->rlim_max > maxproc)
    355 			limp->rlim_max = maxproc;
    356 		break;
    357 	}
    358 	*alimp = *limp;
    359 	return (0);
    360 }
    361 
    362 /* ARGSUSED */
    363 int
    364 sys_getrlimit(l, v, retval)
    365 	struct lwp *l;
    366 	void *v;
    367 	register_t *retval;
    368 {
    369 	struct sys_getrlimit_args /* {
    370 		syscallarg(int) which;
    371 		syscallarg(struct rlimit *) rlp;
    372 	} */ *uap = v;
    373 	struct proc *p = l->l_proc;
    374 	int which = SCARG(uap, which);
    375 
    376 	if ((u_int)which >= RLIM_NLIMITS)
    377 		return (EINVAL);
    378 	return (copyout(&p->p_rlimit[which], SCARG(uap, rlp),
    379 	    sizeof(struct rlimit)));
    380 }
    381 
    382 /*
    383  * Transform the running time and tick information in proc p into user,
    384  * system, and interrupt time usage.
    385  */
    386 void
    387 calcru(p, up, sp, ip)
    388 	struct proc *p;
    389 	struct timeval *up;
    390 	struct timeval *sp;
    391 	struct timeval *ip;
    392 {
    393 	u_quad_t u, st, ut, it, tot;
    394 	unsigned long sec;
    395 	long usec;
    396 	int s;
    397 	struct timeval tv;
    398 	struct lwp *l;
    399 
    400 	s = splstatclock();
    401 	st = p->p_sticks;
    402 	ut = p->p_uticks;
    403 	it = p->p_iticks;
    404 	splx(s);
    405 
    406 	sec = p->p_rtime.tv_sec;
    407 	usec = p->p_rtime.tv_usec;
    408 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    409 		if (l->l_stat == LSONPROC) {
    410 			struct schedstate_percpu *spc;
    411 
    412 			KDASSERT(l->l_cpu != NULL);
    413 			spc = &l->l_cpu->ci_schedstate;
    414 
    415 			/*
    416 			 * Adjust for the current time slice.  This is
    417 			 * actually fairly important since the error
    418 			 * here is on the order of a time quantum,
    419 			 * which is much greater than the sampling
    420 			 * error.
    421 			 */
    422 			microtime(&tv);
    423 			sec += tv.tv_sec - spc->spc_runtime.tv_sec;
    424 			usec += tv.tv_usec - spc->spc_runtime.tv_usec;
    425 		}
    426 	}
    427 
    428 	tot = st + ut + it;
    429 	u = sec * 1000000ull + usec;
    430 
    431 	if (tot == 0) {
    432 		/* No ticks, so can't use to share time out, split 50-50 */
    433 		st = ut = u / 2;
    434 	} else {
    435 		st = (u * st) / tot;
    436 		ut = (u * ut) / tot;
    437 	}
    438 	sp->tv_sec = st / 1000000;
    439 	sp->tv_usec = st % 1000000;
    440 	up->tv_sec = ut / 1000000;
    441 	up->tv_usec = ut % 1000000;
    442 	if (ip != NULL) {
    443 		if (it != 0)
    444 			it = (u * it) / tot;
    445 		ip->tv_sec = it / 1000000;
    446 		ip->tv_usec = it % 1000000;
    447 	}
    448 }
    449 
    450 /* ARGSUSED */
    451 int
    452 sys_getrusage(l, v, retval)
    453 	struct lwp *l;
    454 	void *v;
    455 	register_t *retval;
    456 {
    457 	struct sys_getrusage_args /* {
    458 		syscallarg(int) who;
    459 		syscallarg(struct rusage *) rusage;
    460 	} */ *uap = v;
    461 	struct rusage *rup;
    462 	struct proc *p = l->l_proc;
    463 
    464 	switch (SCARG(uap, who)) {
    465 
    466 	case RUSAGE_SELF:
    467 		rup = &p->p_stats->p_ru;
    468 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
    469 		break;
    470 
    471 	case RUSAGE_CHILDREN:
    472 		rup = &p->p_stats->p_cru;
    473 		break;
    474 
    475 	default:
    476 		return (EINVAL);
    477 	}
    478 	return (copyout(rup, SCARG(uap, rusage), sizeof(struct rusage)));
    479 }
    480 
    481 void
    482 ruadd(ru, ru2)
    483 	struct rusage *ru, *ru2;
    484 {
    485 	long *ip, *ip2;
    486 	int i;
    487 
    488 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
    489 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
    490 	if (ru->ru_maxrss < ru2->ru_maxrss)
    491 		ru->ru_maxrss = ru2->ru_maxrss;
    492 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
    493 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
    494 		*ip++ += *ip2++;
    495 }
    496 
    497 /*
    498  * Make a copy of the plimit structure.
    499  * We share these structures copy-on-write after fork,
    500  * and copy when a limit is changed.
    501  */
    502 struct plimit *
    503 limcopy(lim)
    504 	struct plimit *lim;
    505 {
    506 	struct plimit *newlim;
    507 	size_t l = 0;
    508 
    509 	simple_lock(&lim->p_slock);
    510 	if (lim->pl_corename != defcorename)
    511 		l = strlen(lim->pl_corename) + 1;
    512 	simple_unlock(&lim->p_slock);
    513 
    514 	newlim = pool_get(&plimit_pool, PR_WAITOK);
    515 	simple_lock_init(&newlim->p_slock);
    516 	newlim->p_lflags = 0;
    517 	newlim->p_refcnt = 1;
    518 	newlim->pl_corename = (l != 0)
    519 		? malloc(l, M_TEMP, M_WAITOK)
    520 		: defcorename;
    521 
    522 	simple_lock(&lim->p_slock);
    523 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
    524 	    sizeof(struct rlimit) * RLIM_NLIMITS);
    525 
    526 	if (l != 0)
    527 		strlcpy(newlim->pl_corename, lim->pl_corename, l);
    528 	simple_unlock(&lim->p_slock);
    529 
    530 	return (newlim);
    531 }
    532 
    533 void
    534 limfree(lim)
    535 	struct plimit *lim;
    536 {
    537 	int n;
    538 	simple_lock(&lim->p_slock);
    539 	n = --lim->p_refcnt;
    540 	simple_unlock(&lim->p_slock);
    541 	if (n > 0)
    542 		return;
    543 #ifdef DIAGNOSTIC
    544 	if (n < 0)
    545 		panic("limfree");
    546 #endif
    547 	if (lim->pl_corename != defcorename)
    548 		free(lim->pl_corename, M_TEMP);
    549 	pool_put(&plimit_pool, lim);
    550 }
    551 
    552 struct pstats *
    553 pstatscopy(ps)
    554 	struct pstats *ps;
    555 {
    556 
    557 	struct pstats *newps;
    558 
    559 	newps = pool_get(&pstats_pool, PR_WAITOK);
    560 
    561 	memset(&newps->pstat_startzero, 0,
    562 	(unsigned) ((caddr_t)&newps->pstat_endzero -
    563 		    (caddr_t)&newps->pstat_startzero));
    564 	memcpy(&newps->pstat_startcopy, &ps->pstat_startcopy,
    565 	((caddr_t)&newps->pstat_endcopy -
    566 	 (caddr_t)&newps->pstat_startcopy));
    567 
    568 	return (newps);
    569 
    570 }
    571 
    572 void
    573 pstatsfree(ps)
    574 	struct pstats *ps;
    575 {
    576 
    577 	pool_put(&pstats_pool, ps);
    578 }
    579 
    580 /*
    581  * sysctl interface in five parts
    582  */
    583 
    584 /*
    585  * a routine for sysctl proc subtree helpers that need to pick a valid
    586  * process by pid.
    587  */
    588 static int
    589 sysctl_proc_findproc(struct proc *p, struct proc **p2, pid_t pid)
    590 {
    591 	struct proc *ptmp;
    592 	int i, error = 0;
    593 
    594 	if (pid == PROC_CURPROC)
    595 		ptmp = p;
    596 	else if ((ptmp = pfind(pid)) == NULL)
    597 		error = ESRCH;
    598 	else {
    599 		/*
    600 		 * suid proc of ours or proc not ours
    601 		 */
    602 		if (p->p_cred->p_ruid != ptmp->p_cred->p_ruid ||
    603 		    p->p_cred->p_ruid != ptmp->p_cred->p_svuid)
    604 			error = suser(p->p_ucred, &p->p_acflag);
    605 
    606 		/*
    607 		 * sgid proc has sgid back to us temporarily
    608 		 */
    609 		else if (ptmp->p_cred->p_rgid != ptmp->p_cred->p_svgid)
    610 			error = suser(p->p_ucred, &p->p_acflag);
    611 
    612 		/*
    613 		 * our rgid must be in target's group list (ie,
    614 		 * sub-processes started by a sgid process)
    615 		 */
    616 		else {
    617 			for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
    618 				if (p->p_ucred->cr_groups[i] ==
    619 				    ptmp->p_cred->p_rgid)
    620 					break;
    621 			}
    622 			if (i == p->p_ucred->cr_ngroups)
    623 				error = suser(p->p_ucred, &p->p_acflag);
    624 		}
    625 	}
    626 
    627 	*p2 = ptmp;
    628 	return (error);
    629 }
    630 
    631 /*
    632  * sysctl helper routine for setting a process's specific corefile
    633  * name.  picks the process based on the given pid and checks the
    634  * correctness of the new value.
    635  */
    636 static int
    637 sysctl_proc_corename(SYSCTLFN_ARGS)
    638 {
    639 	struct proc *ptmp, *p;
    640 	struct plimit *lim;
    641 	int error = 0, len;
    642 	char cname[MAXPATHLEN], *tmp;
    643 	struct sysctlnode node;
    644 
    645 	/*
    646 	 * is this all correct?
    647 	 */
    648 	if (namelen != 0)
    649 		return (EINVAL);
    650 	if (name[-1] != PROC_PID_CORENAME)
    651 		return (EINVAL);
    652 
    653 	/*
    654 	 * whom are we tweaking?
    655 	 */
    656 	p = l->l_proc;
    657 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-2]);
    658 	if (error)
    659 		return (error);
    660 
    661 	/*
    662 	 * let them modify a temporary copy of the core name
    663 	 */
    664 	node = *rnode;
    665 	strlcpy(cname, ptmp->p_limit->pl_corename, sizeof(cname));
    666 	node.sysctl_data = cname;
    667 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    668 
    669 	/*
    670 	 * if that failed, or they have nothing new to say, or we've
    671 	 * heard it before...
    672 	 */
    673 	if (error || newp == NULL ||
    674 	    strcmp(cname, ptmp->p_limit->pl_corename) == 0)
    675 		return (error);
    676 
    677 	/*
    678 	 * no error yet and cname now has the new core name in it.
    679 	 * let's see if it looks acceptable.  it must be either "core"
    680 	 * or end in ".core" or "/core".
    681 	 */
    682 	len = strlen(cname);
    683 	if (len < 4)
    684 		return (EINVAL);
    685 	if (strcmp(cname + len - 4, "core") != 0)
    686 		return (EINVAL);
    687 	if (len > 4 && cname[len - 5] != '/' && cname[len - 5] != '.')
    688 		return (EINVAL);
    689 
    690 	/*
    691 	 * hmm...looks good.  now...where do we put it?
    692 	 */
    693 	tmp = malloc(len + 1, M_TEMP, M_WAITOK|M_CANFAIL);
    694 	if (tmp == NULL)
    695 		return (ENOMEM);
    696 	strlcpy(tmp, cname, len + 1);
    697 
    698 	lim = ptmp->p_limit;
    699 	if (lim->p_refcnt > 1 && (lim->p_lflags & PL_SHAREMOD) == 0) {
    700 		ptmp->p_limit = limcopy(lim);
    701 		limfree(lim);
    702 		lim = ptmp->p_limit;
    703 	}
    704 	if (lim->pl_corename != defcorename)
    705 		free(lim->pl_corename, M_TEMP);
    706 	lim->pl_corename = tmp;
    707 
    708 	return (error);
    709 }
    710 
    711 /*
    712  * sysctl helper routine for checking/setting a process's stop flags,
    713  * one for fork and one for exec.
    714  */
    715 static int
    716 sysctl_proc_stop(SYSCTLFN_ARGS)
    717 {
    718 	struct proc *p, *ptmp;
    719 	int i, f, error = 0;
    720 	struct sysctlnode node;
    721 
    722 	if (namelen != 0)
    723 		return (EINVAL);
    724 
    725 	p = l->l_proc;
    726 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-2]);
    727 	if (error)
    728 		return (error);
    729 
    730 	switch (rnode->sysctl_num) {
    731 	case PROC_PID_STOPFORK:
    732 		f = P_STOPFORK;
    733 		break;
    734 	case PROC_PID_STOPEXEC:
    735 		f = P_STOPEXEC;
    736 		break;
    737 	case PROC_PID_STOPEXIT:
    738 		f = P_STOPEXIT;
    739 		break;
    740 	default:
    741 		return (EINVAL);
    742 	}
    743 
    744 	i = (ptmp->p_flag & f) ? 1 : 0;
    745 	node = *rnode;
    746 	node.sysctl_data = &i;
    747 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    748 	if (error || newp == NULL)
    749 		return (error);
    750 
    751 	if (i)
    752 		ptmp->p_flag |= f;
    753 	else
    754 		ptmp->p_flag &= ~f;
    755 
    756 	return (0);
    757 }
    758 
    759 /*
    760  * sysctl helper routine for a process's rlimits as exposed by sysctl.
    761  */
    762 static int
    763 sysctl_proc_plimit(SYSCTLFN_ARGS)
    764 {
    765 	struct proc *ptmp, *p;
    766 	u_int limitno;
    767 	int which, error = 0;
    768         struct rlimit alim;
    769 	struct sysctlnode node;
    770 
    771 	if (namelen != 0)
    772 		return (EINVAL);
    773 
    774 	which = name[-1];
    775 	if (which != PROC_PID_LIMIT_TYPE_SOFT &&
    776 	    which != PROC_PID_LIMIT_TYPE_HARD)
    777 		return (EINVAL);
    778 
    779 	limitno = name[-2] - 1;
    780 	if (limitno >= RLIM_NLIMITS)
    781 		return (EINVAL);
    782 
    783 	if (name[-3] != PROC_PID_LIMIT)
    784 		return (EINVAL);
    785 
    786 	p = l->l_proc;
    787 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-4]);
    788 	if (error)
    789 		return (error);
    790 
    791 	node = *rnode;
    792 	memcpy(&alim, &ptmp->p_rlimit[limitno], sizeof(alim));
    793 	if (which == PROC_PID_LIMIT_TYPE_HARD)
    794 		node.sysctl_data = &alim.rlim_max;
    795 	else
    796 		node.sysctl_data = &alim.rlim_cur;
    797 
    798 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    799 	if (error || newp == NULL)
    800 		return (error);
    801 
    802 	return (dosetrlimit(ptmp, p->p_cred, limitno, &alim));
    803 }
    804 
    805 /*
    806  * and finally, the actually glue that sticks it to the tree
    807  */
    808 SYSCTL_SETUP(sysctl_proc_setup, "sysctl proc subtree setup")
    809 {
    810 
    811 	sysctl_createv(clog, 0, NULL, NULL,
    812 		       CTLFLAG_PERMANENT,
    813 		       CTLTYPE_NODE, "proc", NULL,
    814 		       NULL, 0, NULL, 0,
    815 		       CTL_PROC, CTL_EOL);
    816 	sysctl_createv(clog, 0, NULL, NULL,
    817 		       CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
    818 		       CTLTYPE_NODE, "curproc",
    819 		       SYSCTL_DESCR("Per-process settings"),
    820 		       NULL, 0, NULL, 0,
    821 		       CTL_PROC, PROC_CURPROC, CTL_EOL);
    822 
    823 	sysctl_createv(clog, 0, NULL, NULL,
    824 		       CTLFLAG_PERMANENT|CTLFLAG_READONLY2|CTLFLAG_ANYWRITE,
    825 		       CTLTYPE_STRING, "corename",
    826 		       SYSCTL_DESCR("Core file name"),
    827 		       sysctl_proc_corename, 0, NULL, MAXPATHLEN,
    828 		       CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
    829 	sysctl_createv(clog, 0, NULL, NULL,
    830 		       CTLFLAG_PERMANENT,
    831 		       CTLTYPE_NODE, "rlimit",
    832 		       SYSCTL_DESCR("Process limits"),
    833 		       NULL, 0, NULL, 0,
    834 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);
    835 
    836 #define create_proc_plimit(s, n) do {					\
    837 	sysctl_createv(clog, 0, NULL, NULL,				\
    838 		       CTLFLAG_PERMANENT,				\
    839 		       CTLTYPE_NODE, s,					\
    840 		       SYSCTL_DESCR("Process " s " limits"),		\
    841 		       NULL, 0, NULL, 0,				\
    842 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    843 		       CTL_EOL);					\
    844 	sysctl_createv(clog, 0, NULL, NULL,				\
    845 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
    846 		       CTLTYPE_QUAD, "soft",				\
    847 		       SYSCTL_DESCR("Process soft " s " limit"),	\
    848 		       sysctl_proc_plimit, 0, NULL, 0,			\
    849 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    850 		       PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL);		\
    851 	sysctl_createv(clog, 0, NULL, NULL,				\
    852 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
    853 		       CTLTYPE_QUAD, "hard",				\
    854 		       SYSCTL_DESCR("Process hard " s " limit"),	\
    855 		       sysctl_proc_plimit, 0, NULL, 0,			\
    856 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    857 		       PROC_PID_LIMIT_TYPE_HARD, CTL_EOL);		\
    858 	} while (0/*CONSTCOND*/)
    859 
    860 	create_proc_plimit("cputime",		PROC_PID_LIMIT_CPU);
    861 	create_proc_plimit("filesize",		PROC_PID_LIMIT_FSIZE);
    862 	create_proc_plimit("datasize",		PROC_PID_LIMIT_DATA);
    863 	create_proc_plimit("stacksize",		PROC_PID_LIMIT_STACK);
    864 	create_proc_plimit("coredumpsize",	PROC_PID_LIMIT_CORE);
    865 	create_proc_plimit("memoryuse",		PROC_PID_LIMIT_RSS);
    866 	create_proc_plimit("memorylocked",	PROC_PID_LIMIT_MEMLOCK);
    867 	create_proc_plimit("maxproc",		PROC_PID_LIMIT_NPROC);
    868 	create_proc_plimit("descriptors",	PROC_PID_LIMIT_NOFILE);
    869 	create_proc_plimit("sbsize",		PROC_PID_LIMIT_SBSIZE);
    870 
    871 #undef create_proc_plimit
    872 
    873 	sysctl_createv(clog, 0, NULL, NULL,
    874 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    875 		       CTLTYPE_INT, "stopfork",
    876 		       SYSCTL_DESCR("Stop process at fork(2)"),
    877 		       sysctl_proc_stop, 0, NULL, 0,
    878 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
    879 	sysctl_createv(clog, 0, NULL, NULL,
    880 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    881 		       CTLTYPE_INT, "stopexec",
    882 		       SYSCTL_DESCR("Stop process at execve(2)"),
    883 		       sysctl_proc_stop, 0, NULL, 0,
    884 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
    885 	sysctl_createv(clog, 0, NULL, NULL,
    886 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    887 		       CTLTYPE_INT, "stopexit",
    888 		       SYSCTL_DESCR("Stop process before completing exit"),
    889 		       sysctl_proc_stop, 0, NULL, 0,
    890 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
    891 }
    892 
    893 static struct uidinfo *
    894 getuidinfo(uid_t uid)
    895 {
    896 	struct uidinfo *uip;
    897 	struct uihashhead *uipp;
    898 
    899 	uipp = UIHASH(uid);
    900 
    901 	LIST_FOREACH(uip, uipp, ui_hash)
    902 		if (uip->ui_uid == uid)
    903 			return uip;
    904 	return NULL;
    905 }
    906 
    907 static void
    908 freeuidinfo(struct uidinfo *uip)
    909 {
    910 	LIST_REMOVE(uip, ui_hash);
    911 	FREE(uip, M_PROC);
    912 }
    913 
    914 static struct uidinfo *
    915 allocuidinfo(uid_t uid)
    916 {
    917 	struct uidinfo *uip;
    918 	struct uihashhead *uipp;
    919 
    920 	uipp = UIHASH(uid);
    921 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
    922 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
    923 	uip->ui_uid = uid;
    924 	uip->ui_proccnt = 0;
    925 	uip->ui_sbsize = 0;
    926 	return uip;
    927 }
    928 
    929 /*
    930  * Change the count associated with number of processes
    931  * a given user is using.
    932  */
    933 int
    934 chgproccnt(uid_t uid, int diff)
    935 {
    936 	struct uidinfo *uip;
    937 
    938 	if (diff == 0)
    939 		return 0;
    940 
    941 	if ((uip = getuidinfo(uid)) != NULL) {
    942 		uip->ui_proccnt += diff;
    943 		KASSERT(uip->ui_proccnt >= 0);
    944 		if (uip->ui_proccnt > 0)
    945 			return uip->ui_proccnt;
    946 		else {
    947 			if (uip->ui_sbsize == 0)
    948 				freeuidinfo(uip);
    949 			return 0;
    950 		}
    951 	} else {
    952 		if (diff < 0)
    953 			panic("chgproccnt: lost user %lu", (unsigned long)uid);
    954 		uip = allocuidinfo(uid);
    955 		uip->ui_proccnt = diff;
    956 		return uip->ui_proccnt;
    957 	}
    958 }
    959 
    960 int
    961 chgsbsize(uid_t uid, u_long *hiwat, u_long to, rlim_t max)
    962 {
    963 	*hiwat = to;
    964 	return 1;
    965 #ifdef notyet
    966 	struct uidinfo *uip;
    967 	rlim_t nsb;
    968 	int rv = 0;
    969 
    970 	if ((uip = getuidinfo(uid)) == NULL)
    971 		uip = allocuidinfo(uid);
    972 	nsb = uip->ui_sbsize + to - *hiwat;
    973 	if (to > *hiwat && nsb > max)
    974 		goto done;
    975 	*hiwat = to;
    976 	uip->ui_sbsize = nsb;
    977 	rv = 1;
    978 	KASSERT(uip->ui_sbsize >= 0);
    979 done:
    980 	if (uip->ui_sbsize == 0 && uip->ui_proccnt == 0)
    981 		freeuidinfo(uip);
    982 	return rv;
    983 #endif
    984 }
    985