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kern_resource.c revision 1.88
      1 /*	$NetBSD: kern_resource.c,v 1.88 2005/03/20 19:15:48 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 1.88 2005/03/20 19:15:48 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 struct simplelock uihashtbl_slock = SIMPLELOCK_INITIALIZER;
     68 
     69 
     70 /*
     71  * Resource controls and accounting.
     72  */
     73 
     74 int
     75 sys_getpriority(l, v, retval)
     76 	struct lwp *l;
     77 	void *v;
     78 	register_t *retval;
     79 {
     80 	struct sys_getpriority_args /* {
     81 		syscallarg(int) which;
     82 		syscallarg(id_t) who;
     83 	} */ *uap = v;
     84 	struct proc *curp = l->l_proc, *p;
     85 	int low = NZERO + PRIO_MAX + 1;
     86 
     87 	switch (SCARG(uap, which)) {
     88 
     89 	case PRIO_PROCESS:
     90 		if (SCARG(uap, who) == 0)
     91 			p = curp;
     92 		else
     93 			p = pfind(SCARG(uap, who));
     94 		if (p == 0)
     95 			break;
     96 		low = p->p_nice;
     97 		break;
     98 
     99 	case PRIO_PGRP: {
    100 		struct pgrp *pg;
    101 
    102 		if (SCARG(uap, who) == 0)
    103 			pg = curp->p_pgrp;
    104 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
    105 			break;
    106 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
    107 			if (p->p_nice < low)
    108 				low = p->p_nice;
    109 		}
    110 		break;
    111 	}
    112 
    113 	case PRIO_USER:
    114 		if (SCARG(uap, who) == 0)
    115 			SCARG(uap, who) = curp->p_ucred->cr_uid;
    116 		proclist_lock_read();
    117 		PROCLIST_FOREACH(p, &allproc) {
    118 			if (p->p_ucred->cr_uid == (uid_t) SCARG(uap, who) &&
    119 			    p->p_nice < low)
    120 				low = p->p_nice;
    121 		}
    122 		proclist_unlock_read();
    123 		break;
    124 
    125 	default:
    126 		return (EINVAL);
    127 	}
    128 	if (low == NZERO + PRIO_MAX + 1)
    129 		return (ESRCH);
    130 	*retval = low - NZERO;
    131 	return (0);
    132 }
    133 
    134 /* ARGSUSED */
    135 int
    136 sys_setpriority(l, v, retval)
    137 	struct lwp *l;
    138 	void *v;
    139 	register_t *retval;
    140 {
    141 	struct sys_setpriority_args /* {
    142 		syscallarg(int) which;
    143 		syscallarg(id_t) who;
    144 		syscallarg(int) prio;
    145 	} */ *uap = v;
    146 	struct proc *curp = l->l_proc, *p;
    147 	int found = 0, error = 0;
    148 
    149 	switch (SCARG(uap, which)) {
    150 
    151 	case PRIO_PROCESS:
    152 		if (SCARG(uap, who) == 0)
    153 			p = curp;
    154 		else
    155 			p = pfind(SCARG(uap, who));
    156 		if (p == 0)
    157 			break;
    158 		error = donice(curp, p, SCARG(uap, prio));
    159 		found++;
    160 		break;
    161 
    162 	case PRIO_PGRP: {
    163 		struct pgrp *pg;
    164 
    165 		if (SCARG(uap, who) == 0)
    166 			pg = curp->p_pgrp;
    167 		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
    168 			break;
    169 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
    170 			error = donice(curp, p, SCARG(uap, prio));
    171 			found++;
    172 		}
    173 		break;
    174 	}
    175 
    176 	case PRIO_USER:
    177 		if (SCARG(uap, who) == 0)
    178 			SCARG(uap, who) = curp->p_ucred->cr_uid;
    179 		proclist_lock_read();
    180 		PROCLIST_FOREACH(p, &allproc) {
    181 			if (p->p_ucred->cr_uid == (uid_t) SCARG(uap, who)) {
    182 				error = donice(curp, p, SCARG(uap, prio));
    183 				found++;
    184 			}
    185 		}
    186 		proclist_unlock_read();
    187 		break;
    188 
    189 	default:
    190 		return (EINVAL);
    191 	}
    192 	if (found == 0)
    193 		return (ESRCH);
    194 	return (error);
    195 }
    196 
    197 int
    198 donice(curp, chgp, n)
    199 	struct proc *curp, *chgp;
    200 	int n;
    201 {
    202 	struct pcred *pcred = curp->p_cred;
    203 	int s;
    204 
    205 	if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
    206 	    pcred->pc_ucred->cr_uid != chgp->p_ucred->cr_uid &&
    207 	    pcred->p_ruid != chgp->p_ucred->cr_uid)
    208 		return (EPERM);
    209 	if (n > PRIO_MAX)
    210 		n = PRIO_MAX;
    211 	if (n < PRIO_MIN)
    212 		n = PRIO_MIN;
    213 	n += NZERO;
    214 	if (n < chgp->p_nice && suser(pcred->pc_ucred, &curp->p_acflag))
    215 		return (EACCES);
    216 	chgp->p_nice = n;
    217 	SCHED_LOCK(s);
    218 	(void)resetprocpriority(chgp);
    219 	SCHED_UNLOCK(s);
    220 	return (0);
    221 }
    222 
    223 /* ARGSUSED */
    224 int
    225 sys_setrlimit(l, v, retval)
    226 	struct lwp *l;
    227 	void *v;
    228 	register_t *retval;
    229 {
    230 	struct sys_setrlimit_args /* {
    231 		syscallarg(int) which;
    232 		syscallarg(const struct rlimit *) rlp;
    233 	} */ *uap = v;
    234 	struct proc *p = l->l_proc;
    235 	int which = SCARG(uap, which);
    236 	struct rlimit alim;
    237 	int error;
    238 
    239 	error = copyin(SCARG(uap, rlp), &alim, sizeof(struct rlimit));
    240 	if (error)
    241 		return (error);
    242 	return (dosetrlimit(p, p->p_cred, which, &alim));
    243 }
    244 
    245 int
    246 dosetrlimit(p, cred, which, limp)
    247 	struct proc *p;
    248 	struct  pcred *cred;
    249 	int which;
    250 	struct rlimit *limp;
    251 {
    252 	struct rlimit *alimp;
    253 	struct plimit *oldplim;
    254 	int error;
    255 
    256 	if ((u_int)which >= RLIM_NLIMITS)
    257 		return (EINVAL);
    258 
    259 	if (limp->rlim_cur < 0 || limp->rlim_max < 0)
    260 		return (EINVAL);
    261 
    262 	alimp = &p->p_rlimit[which];
    263 	/* if we don't change the value, no need to limcopy() */
    264 	if (limp->rlim_cur == alimp->rlim_cur &&
    265 	    limp->rlim_max == alimp->rlim_max)
    266 		return 0;
    267 
    268 	if (limp->rlim_cur > limp->rlim_max) {
    269 		/*
    270 		 * This is programming error. According to SUSv2, we should
    271 		 * return error in this case.
    272 		 */
    273 		return (EINVAL);
    274 	}
    275 	if (limp->rlim_max > alimp->rlim_max
    276 	    && (error = suser(cred->pc_ucred, &p->p_acflag)) != 0)
    277 			return (error);
    278 
    279 	if (p->p_limit->p_refcnt > 1 &&
    280 	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
    281 		p->p_limit = limcopy(oldplim = p->p_limit);
    282 		limfree(oldplim);
    283 		alimp = &p->p_rlimit[which];
    284 	}
    285 
    286 	switch (which) {
    287 
    288 	case RLIMIT_DATA:
    289 		if (limp->rlim_cur > maxdmap)
    290 			limp->rlim_cur = maxdmap;
    291 		if (limp->rlim_max > maxdmap)
    292 			limp->rlim_max = maxdmap;
    293 		break;
    294 
    295 	case RLIMIT_STACK:
    296 		if (limp->rlim_cur > maxsmap)
    297 			limp->rlim_cur = maxsmap;
    298 		if (limp->rlim_max > maxsmap)
    299 			limp->rlim_max = maxsmap;
    300 
    301 		/*
    302 		 * Return EINVAL if the new stack size limit is lower than
    303 		 * current usage. Otherwise, the process would get SIGSEGV the
    304 		 * moment it would try to access anything on it's current stack.
    305 		 * This conforms to SUSv2.
    306 		 */
    307 		if (limp->rlim_cur < p->p_vmspace->vm_ssize * PAGE_SIZE
    308 		    || limp->rlim_max < p->p_vmspace->vm_ssize * PAGE_SIZE)
    309 			return (EINVAL);
    310 
    311 		/*
    312 		 * Stack is allocated to the max at exec time with
    313 		 * only "rlim_cur" bytes accessible (In other words,
    314 		 * allocates stack dividing two contiguous regions at
    315 		 * "rlim_cur" bytes boundary).
    316 		 *
    317 		 * Since allocation is done in terms of page, roundup
    318 		 * "rlim_cur" (otherwise, contiguous regions
    319 		 * overlap).  If stack limit is going up make more
    320 		 * accessible, if going down make inaccessible.
    321 		 */
    322 		limp->rlim_cur = round_page(limp->rlim_cur);
    323 		if (limp->rlim_cur != alimp->rlim_cur) {
    324 			vaddr_t addr;
    325 			vsize_t size;
    326 			vm_prot_t prot;
    327 
    328 			if (limp->rlim_cur > alimp->rlim_cur) {
    329 				prot = VM_PROT_READ | VM_PROT_WRITE;
    330 				size = limp->rlim_cur - alimp->rlim_cur;
    331 				addr = USRSTACK - limp->rlim_cur;
    332 			} else {
    333 				prot = VM_PROT_NONE;
    334 				size = alimp->rlim_cur - limp->rlim_cur;
    335 				addr = USRSTACK - alimp->rlim_cur;
    336 			}
    337 			(void) uvm_map_protect(&p->p_vmspace->vm_map,
    338 					      addr, addr+size, prot, FALSE);
    339 		}
    340 		break;
    341 
    342 	case RLIMIT_NOFILE:
    343 		if (limp->rlim_cur > maxfiles)
    344 			limp->rlim_cur = maxfiles;
    345 		if (limp->rlim_max > maxfiles)
    346 			limp->rlim_max = maxfiles;
    347 		break;
    348 
    349 	case RLIMIT_NPROC:
    350 		if (limp->rlim_cur > maxproc)
    351 			limp->rlim_cur = maxproc;
    352 		if (limp->rlim_max > maxproc)
    353 			limp->rlim_max = maxproc;
    354 		break;
    355 	}
    356 	*alimp = *limp;
    357 	return (0);
    358 }
    359 
    360 /* ARGSUSED */
    361 int
    362 sys_getrlimit(l, v, retval)
    363 	struct lwp *l;
    364 	void *v;
    365 	register_t *retval;
    366 {
    367 	struct sys_getrlimit_args /* {
    368 		syscallarg(int) which;
    369 		syscallarg(struct rlimit *) rlp;
    370 	} */ *uap = v;
    371 	struct proc *p = l->l_proc;
    372 	int which = SCARG(uap, which);
    373 
    374 	if ((u_int)which >= RLIM_NLIMITS)
    375 		return (EINVAL);
    376 	return (copyout(&p->p_rlimit[which], SCARG(uap, rlp),
    377 	    sizeof(struct rlimit)));
    378 }
    379 
    380 /*
    381  * Transform the running time and tick information in proc p into user,
    382  * system, and interrupt time usage.
    383  */
    384 void
    385 calcru(p, up, sp, ip)
    386 	struct proc *p;
    387 	struct timeval *up;
    388 	struct timeval *sp;
    389 	struct timeval *ip;
    390 {
    391 	u_quad_t u, st, ut, it, tot;
    392 	unsigned long sec;
    393 	long usec;
    394 	int s;
    395 	struct timeval tv;
    396 	struct lwp *l;
    397 
    398 	s = splstatclock();
    399 	st = p->p_sticks;
    400 	ut = p->p_uticks;
    401 	it = p->p_iticks;
    402 	splx(s);
    403 
    404 	sec = p->p_rtime.tv_sec;
    405 	usec = p->p_rtime.tv_usec;
    406 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    407 		if (l->l_stat == LSONPROC) {
    408 			struct schedstate_percpu *spc;
    409 
    410 			KDASSERT(l->l_cpu != NULL);
    411 			spc = &l->l_cpu->ci_schedstate;
    412 
    413 			/*
    414 			 * Adjust for the current time slice.  This is
    415 			 * actually fairly important since the error
    416 			 * here is on the order of a time quantum,
    417 			 * which is much greater than the sampling
    418 			 * error.
    419 			 */
    420 			microtime(&tv);
    421 			sec += tv.tv_sec - spc->spc_runtime.tv_sec;
    422 			usec += tv.tv_usec - spc->spc_runtime.tv_usec;
    423 		}
    424 	}
    425 
    426 	tot = st + ut + it;
    427 	u = sec * 1000000ull + usec;
    428 
    429 	if (tot == 0) {
    430 		/* No ticks, so can't use to share time out, split 50-50 */
    431 		st = ut = u / 2;
    432 	} else {
    433 		st = (u * st) / tot;
    434 		ut = (u * ut) / tot;
    435 	}
    436 	sp->tv_sec = st / 1000000;
    437 	sp->tv_usec = st % 1000000;
    438 	up->tv_sec = ut / 1000000;
    439 	up->tv_usec = ut % 1000000;
    440 	if (ip != NULL) {
    441 		if (it != 0)
    442 			it = (u * it) / tot;
    443 		ip->tv_sec = it / 1000000;
    444 		ip->tv_usec = it % 1000000;
    445 	}
    446 }
    447 
    448 /* ARGSUSED */
    449 int
    450 sys_getrusage(l, v, retval)
    451 	struct lwp *l;
    452 	void *v;
    453 	register_t *retval;
    454 {
    455 	struct sys_getrusage_args /* {
    456 		syscallarg(int) who;
    457 		syscallarg(struct rusage *) rusage;
    458 	} */ *uap = v;
    459 	struct rusage *rup;
    460 	struct proc *p = l->l_proc;
    461 
    462 	switch (SCARG(uap, who)) {
    463 
    464 	case RUSAGE_SELF:
    465 		rup = &p->p_stats->p_ru;
    466 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
    467 		break;
    468 
    469 	case RUSAGE_CHILDREN:
    470 		rup = &p->p_stats->p_cru;
    471 		break;
    472 
    473 	default:
    474 		return (EINVAL);
    475 	}
    476 	return (copyout(rup, SCARG(uap, rusage), sizeof(struct rusage)));
    477 }
    478 
    479 void
    480 ruadd(ru, ru2)
    481 	struct rusage *ru, *ru2;
    482 {
    483 	long *ip, *ip2;
    484 	int i;
    485 
    486 	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
    487 	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
    488 	if (ru->ru_maxrss < ru2->ru_maxrss)
    489 		ru->ru_maxrss = ru2->ru_maxrss;
    490 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
    491 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
    492 		*ip++ += *ip2++;
    493 }
    494 
    495 /*
    496  * Make a copy of the plimit structure.
    497  * We share these structures copy-on-write after fork,
    498  * and copy when a limit is changed.
    499  */
    500 struct plimit *
    501 limcopy(lim)
    502 	struct plimit *lim;
    503 {
    504 	struct plimit *newlim;
    505 	size_t l = 0;
    506 
    507 	simple_lock(&lim->p_slock);
    508 	if (lim->pl_corename != defcorename)
    509 		l = strlen(lim->pl_corename) + 1;
    510 	simple_unlock(&lim->p_slock);
    511 
    512 	newlim = pool_get(&plimit_pool, PR_WAITOK);
    513 	simple_lock_init(&newlim->p_slock);
    514 	newlim->p_lflags = 0;
    515 	newlim->p_refcnt = 1;
    516 	newlim->pl_corename = (l != 0)
    517 		? malloc(l, M_TEMP, M_WAITOK)
    518 		: defcorename;
    519 
    520 	simple_lock(&lim->p_slock);
    521 	memcpy(newlim->pl_rlimit, lim->pl_rlimit,
    522 	    sizeof(struct rlimit) * RLIM_NLIMITS);
    523 
    524 	if (l != 0)
    525 		strlcpy(newlim->pl_corename, lim->pl_corename, l);
    526 	simple_unlock(&lim->p_slock);
    527 
    528 	return (newlim);
    529 }
    530 
    531 void
    532 limfree(lim)
    533 	struct plimit *lim;
    534 {
    535 	int n;
    536 
    537 	simple_lock(&lim->p_slock);
    538 	n = --lim->p_refcnt;
    539 	simple_unlock(&lim->p_slock);
    540 	if (n > 0)
    541 		return;
    542 #ifdef DIAGNOSTIC
    543 	if (n < 0)
    544 		panic("limfree");
    545 #endif
    546 	if (lim->pl_corename != defcorename)
    547 		free(lim->pl_corename, M_TEMP);
    548 	pool_put(&plimit_pool, lim);
    549 }
    550 
    551 struct pstats *
    552 pstatscopy(ps)
    553 	struct pstats *ps;
    554 {
    555 
    556 	struct pstats *newps;
    557 
    558 	newps = pool_get(&pstats_pool, PR_WAITOK);
    559 
    560 	memset(&newps->pstat_startzero, 0,
    561 	(unsigned) ((caddr_t)&newps->pstat_endzero -
    562 		    (caddr_t)&newps->pstat_startzero));
    563 	memcpy(&newps->pstat_startcopy, &ps->pstat_startcopy,
    564 	((caddr_t)&newps->pstat_endcopy -
    565 	 (caddr_t)&newps->pstat_startcopy));
    566 
    567 	return (newps);
    568 
    569 }
    570 
    571 void
    572 pstatsfree(ps)
    573 	struct pstats *ps;
    574 {
    575 
    576 	pool_put(&pstats_pool, ps);
    577 }
    578 
    579 /*
    580  * sysctl interface in five parts
    581  */
    582 
    583 /*
    584  * a routine for sysctl proc subtree helpers that need to pick a valid
    585  * process by pid.
    586  */
    587 static int
    588 sysctl_proc_findproc(struct proc *p, struct proc **p2, pid_t pid)
    589 {
    590 	struct proc *ptmp;
    591 	int i, error = 0;
    592 
    593 	if (pid == PROC_CURPROC)
    594 		ptmp = p;
    595 	else if ((ptmp = pfind(pid)) == NULL)
    596 		error = ESRCH;
    597 	else {
    598 		/*
    599 		 * suid proc of ours or proc not ours
    600 		 */
    601 		if (p->p_cred->p_ruid != ptmp->p_cred->p_ruid ||
    602 		    p->p_cred->p_ruid != ptmp->p_cred->p_svuid)
    603 			error = suser(p->p_ucred, &p->p_acflag);
    604 
    605 		/*
    606 		 * sgid proc has sgid back to us temporarily
    607 		 */
    608 		else if (ptmp->p_cred->p_rgid != ptmp->p_cred->p_svgid)
    609 			error = suser(p->p_ucred, &p->p_acflag);
    610 
    611 		/*
    612 		 * our rgid must be in target's group list (ie,
    613 		 * sub-processes started by a sgid process)
    614 		 */
    615 		else {
    616 			for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
    617 				if (p->p_ucred->cr_groups[i] ==
    618 				    ptmp->p_cred->p_rgid)
    619 					break;
    620 			}
    621 			if (i == p->p_ucred->cr_ngroups)
    622 				error = suser(p->p_ucred, &p->p_acflag);
    623 		}
    624 	}
    625 
    626 	*p2 = ptmp;
    627 	return (error);
    628 }
    629 
    630 /*
    631  * sysctl helper routine for setting a process's specific corefile
    632  * name.  picks the process based on the given pid and checks the
    633  * correctness of the new value.
    634  */
    635 static int
    636 sysctl_proc_corename(SYSCTLFN_ARGS)
    637 {
    638 	struct proc *ptmp, *p;
    639 	struct plimit *lim;
    640 	int error = 0, len;
    641 	char cname[MAXPATHLEN], *tmp;
    642 	struct sysctlnode node;
    643 
    644 	/*
    645 	 * is this all correct?
    646 	 */
    647 	if (namelen != 0)
    648 		return (EINVAL);
    649 	if (name[-1] != PROC_PID_CORENAME)
    650 		return (EINVAL);
    651 
    652 	/*
    653 	 * whom are we tweaking?
    654 	 */
    655 	p = l->l_proc;
    656 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-2]);
    657 	if (error)
    658 		return (error);
    659 
    660 	/*
    661 	 * let them modify a temporary copy of the core name
    662 	 */
    663 	node = *rnode;
    664 	strlcpy(cname, ptmp->p_limit->pl_corename, sizeof(cname));
    665 	node.sysctl_data = cname;
    666 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    667 
    668 	/*
    669 	 * if that failed, or they have nothing new to say, or we've
    670 	 * heard it before...
    671 	 */
    672 	if (error || newp == NULL ||
    673 	    strcmp(cname, ptmp->p_limit->pl_corename) == 0)
    674 		return (error);
    675 
    676 	/*
    677 	 * no error yet and cname now has the new core name in it.
    678 	 * let's see if it looks acceptable.  it must be either "core"
    679 	 * or end in ".core" or "/core".
    680 	 */
    681 	len = strlen(cname);
    682 	if (len < 4)
    683 		return (EINVAL);
    684 	if (strcmp(cname + len - 4, "core") != 0)
    685 		return (EINVAL);
    686 	if (len > 4 && cname[len - 5] != '/' && cname[len - 5] != '.')
    687 		return (EINVAL);
    688 
    689 	/*
    690 	 * hmm...looks good.  now...where do we put it?
    691 	 */
    692 	tmp = malloc(len + 1, M_TEMP, M_WAITOK|M_CANFAIL);
    693 	if (tmp == NULL)
    694 		return (ENOMEM);
    695 	strlcpy(tmp, cname, len + 1);
    696 
    697 	lim = ptmp->p_limit;
    698 	if (lim->p_refcnt > 1 && (lim->p_lflags & PL_SHAREMOD) == 0) {
    699 		ptmp->p_limit = limcopy(lim);
    700 		limfree(lim);
    701 		lim = ptmp->p_limit;
    702 	}
    703 	if (lim->pl_corename != defcorename)
    704 		free(lim->pl_corename, M_TEMP);
    705 	lim->pl_corename = tmp;
    706 
    707 	return (error);
    708 }
    709 
    710 /*
    711  * sysctl helper routine for checking/setting a process's stop flags,
    712  * one for fork and one for exec.
    713  */
    714 static int
    715 sysctl_proc_stop(SYSCTLFN_ARGS)
    716 {
    717 	struct proc *p, *ptmp;
    718 	int i, f, error = 0;
    719 	struct sysctlnode node;
    720 
    721 	if (namelen != 0)
    722 		return (EINVAL);
    723 
    724 	p = l->l_proc;
    725 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-2]);
    726 	if (error)
    727 		return (error);
    728 
    729 	switch (rnode->sysctl_num) {
    730 	case PROC_PID_STOPFORK:
    731 		f = P_STOPFORK;
    732 		break;
    733 	case PROC_PID_STOPEXEC:
    734 		f = P_STOPEXEC;
    735 		break;
    736 	case PROC_PID_STOPEXIT:
    737 		f = P_STOPEXIT;
    738 		break;
    739 	default:
    740 		return (EINVAL);
    741 	}
    742 
    743 	i = (ptmp->p_flag & f) ? 1 : 0;
    744 	node = *rnode;
    745 	node.sysctl_data = &i;
    746 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    747 	if (error || newp == NULL)
    748 		return (error);
    749 
    750 	if (i)
    751 		ptmp->p_flag |= f;
    752 	else
    753 		ptmp->p_flag &= ~f;
    754 
    755 	return (0);
    756 }
    757 
    758 /*
    759  * sysctl helper routine for a process's rlimits as exposed by sysctl.
    760  */
    761 static int
    762 sysctl_proc_plimit(SYSCTLFN_ARGS)
    763 {
    764 	struct proc *ptmp, *p;
    765 	u_int limitno;
    766 	int which, error = 0;
    767         struct rlimit alim;
    768 	struct sysctlnode node;
    769 
    770 	if (namelen != 0)
    771 		return (EINVAL);
    772 
    773 	which = name[-1];
    774 	if (which != PROC_PID_LIMIT_TYPE_SOFT &&
    775 	    which != PROC_PID_LIMIT_TYPE_HARD)
    776 		return (EINVAL);
    777 
    778 	limitno = name[-2] - 1;
    779 	if (limitno >= RLIM_NLIMITS)
    780 		return (EINVAL);
    781 
    782 	if (name[-3] != PROC_PID_LIMIT)
    783 		return (EINVAL);
    784 
    785 	p = l->l_proc;
    786 	error = sysctl_proc_findproc(p, &ptmp, (pid_t)name[-4]);
    787 	if (error)
    788 		return (error);
    789 
    790 	node = *rnode;
    791 	memcpy(&alim, &ptmp->p_rlimit[limitno], sizeof(alim));
    792 	if (which == PROC_PID_LIMIT_TYPE_HARD)
    793 		node.sysctl_data = &alim.rlim_max;
    794 	else
    795 		node.sysctl_data = &alim.rlim_cur;
    796 
    797 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    798 	if (error || newp == NULL)
    799 		return (error);
    800 
    801 	return (dosetrlimit(ptmp, p->p_cred, limitno, &alim));
    802 }
    803 
    804 /*
    805  * and finally, the actually glue that sticks it to the tree
    806  */
    807 SYSCTL_SETUP(sysctl_proc_setup, "sysctl proc subtree setup")
    808 {
    809 
    810 	sysctl_createv(clog, 0, NULL, NULL,
    811 		       CTLFLAG_PERMANENT,
    812 		       CTLTYPE_NODE, "proc", NULL,
    813 		       NULL, 0, NULL, 0,
    814 		       CTL_PROC, CTL_EOL);
    815 	sysctl_createv(clog, 0, NULL, NULL,
    816 		       CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
    817 		       CTLTYPE_NODE, "curproc",
    818 		       SYSCTL_DESCR("Per-process settings"),
    819 		       NULL, 0, NULL, 0,
    820 		       CTL_PROC, PROC_CURPROC, CTL_EOL);
    821 
    822 	sysctl_createv(clog, 0, NULL, NULL,
    823 		       CTLFLAG_PERMANENT|CTLFLAG_READONLY2|CTLFLAG_ANYWRITE,
    824 		       CTLTYPE_STRING, "corename",
    825 		       SYSCTL_DESCR("Core file name"),
    826 		       sysctl_proc_corename, 0, NULL, MAXPATHLEN,
    827 		       CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
    828 	sysctl_createv(clog, 0, NULL, NULL,
    829 		       CTLFLAG_PERMANENT,
    830 		       CTLTYPE_NODE, "rlimit",
    831 		       SYSCTL_DESCR("Process limits"),
    832 		       NULL, 0, NULL, 0,
    833 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);
    834 
    835 #define create_proc_plimit(s, n) do {					\
    836 	sysctl_createv(clog, 0, NULL, NULL,				\
    837 		       CTLFLAG_PERMANENT,				\
    838 		       CTLTYPE_NODE, s,					\
    839 		       SYSCTL_DESCR("Process " s " limits"),		\
    840 		       NULL, 0, NULL, 0,				\
    841 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    842 		       CTL_EOL);					\
    843 	sysctl_createv(clog, 0, NULL, NULL,				\
    844 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
    845 		       CTLTYPE_QUAD, "soft",				\
    846 		       SYSCTL_DESCR("Process soft " s " limit"),	\
    847 		       sysctl_proc_plimit, 0, NULL, 0,			\
    848 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    849 		       PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL);		\
    850 	sysctl_createv(clog, 0, NULL, NULL,				\
    851 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
    852 		       CTLTYPE_QUAD, "hard",				\
    853 		       SYSCTL_DESCR("Process hard " s " limit"),	\
    854 		       sysctl_proc_plimit, 0, NULL, 0,			\
    855 		       CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n,	\
    856 		       PROC_PID_LIMIT_TYPE_HARD, CTL_EOL);		\
    857 	} while (0/*CONSTCOND*/)
    858 
    859 	create_proc_plimit("cputime",		PROC_PID_LIMIT_CPU);
    860 	create_proc_plimit("filesize",		PROC_PID_LIMIT_FSIZE);
    861 	create_proc_plimit("datasize",		PROC_PID_LIMIT_DATA);
    862 	create_proc_plimit("stacksize",		PROC_PID_LIMIT_STACK);
    863 	create_proc_plimit("coredumpsize",	PROC_PID_LIMIT_CORE);
    864 	create_proc_plimit("memoryuse",		PROC_PID_LIMIT_RSS);
    865 	create_proc_plimit("memorylocked",	PROC_PID_LIMIT_MEMLOCK);
    866 	create_proc_plimit("maxproc",		PROC_PID_LIMIT_NPROC);
    867 	create_proc_plimit("descriptors",	PROC_PID_LIMIT_NOFILE);
    868 	create_proc_plimit("sbsize",		PROC_PID_LIMIT_SBSIZE);
    869 
    870 #undef create_proc_plimit
    871 
    872 	sysctl_createv(clog, 0, NULL, NULL,
    873 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    874 		       CTLTYPE_INT, "stopfork",
    875 		       SYSCTL_DESCR("Stop process at fork(2)"),
    876 		       sysctl_proc_stop, 0, NULL, 0,
    877 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
    878 	sysctl_createv(clog, 0, NULL, NULL,
    879 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    880 		       CTLTYPE_INT, "stopexec",
    881 		       SYSCTL_DESCR("Stop process at execve(2)"),
    882 		       sysctl_proc_stop, 0, NULL, 0,
    883 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
    884 	sysctl_createv(clog, 0, NULL, NULL,
    885 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
    886 		       CTLTYPE_INT, "stopexit",
    887 		       SYSCTL_DESCR("Stop process before completing exit"),
    888 		       sysctl_proc_stop, 0, NULL, 0,
    889 		       CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
    890 }
    891 
    892 struct uidinfo *
    893 uid_find(uid_t uid)
    894 {
    895 	struct uidinfo *uip;
    896 	struct uihashhead *uipp;
    897 
    898 	simple_lock(&uihashtbl_slock);
    899 	uipp = UIHASH(uid);
    900 
    901 	LIST_FOREACH(uip, uipp, ui_hash)
    902 		if (uip->ui_uid == uid) {
    903 			simple_unlock(&uihashtbl_slock);
    904 			return uip;
    905 		}
    906 
    907 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK|M_ZERO);
    908 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
    909 	uip->ui_uid = uid;
    910 	simple_unlock(&uihashtbl_slock);
    911 	return uip;
    912 }
    913 
    914 /*
    915  * Change the count associated with number of processes
    916  * a given user is using.
    917  */
    918 int
    919 chgproccnt(uid_t uid, int diff)
    920 {
    921 	struct uidinfo *uip;
    922 
    923 	if (diff == 0)
    924 		return 0;
    925 
    926 	uip = uid_find(uid);
    927 	uip->ui_proccnt += diff;
    928 	KASSERT(uip->ui_proccnt >= 0);
    929 	return uip->ui_proccnt;
    930 }
    931 
    932 int
    933 chgsbsize(uid_t uid, u_long *hiwat, u_long to, rlim_t max)
    934 {
    935 	*hiwat = to;
    936 	return 1;
    937 	struct uidinfo *uip;
    938 	rlim_t nsb;
    939 
    940 	uip = uid_find(uid);
    941 	nsb = uip->ui_sbsize + to - *hiwat;
    942 	if (to > *hiwat && nsb > max)
    943 		return 0;
    944 	*hiwat = to;
    945 	uip->ui_sbsize = nsb;
    946 	KASSERT(uip->ui_sbsize >= 0);
    947 	return 1;
    948 }
    949