The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_resource.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1991, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)kern_resource.c     8.5 (Berkeley) 1/21/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/9.0/sys/kern/kern_resource.c 225617 2011-09-16 13:58:51Z kmacy $");
   39 
   40 #include "opt_compat.h"
   41 
   42 #include <sys/param.h>
   43 #include <sys/systm.h>
   44 #include <sys/sysproto.h>
   45 #include <sys/file.h>
   46 #include <sys/kernel.h>
   47 #include <sys/lock.h>
   48 #include <sys/malloc.h>
   49 #include <sys/mutex.h>
   50 #include <sys/priv.h>
   51 #include <sys/proc.h>
   52 #include <sys/refcount.h>
   53 #include <sys/racct.h>
   54 #include <sys/resourcevar.h>
   55 #include <sys/rwlock.h>
   56 #include <sys/sched.h>
   57 #include <sys/sx.h>
   58 #include <sys/syscallsubr.h>
   59 #include <sys/sysent.h>
   60 #include <sys/time.h>
   61 #include <sys/umtx.h>
   62 
   63 #include <vm/vm.h>
   64 #include <vm/vm_param.h>
   65 #include <vm/pmap.h>
   66 #include <vm/vm_map.h>
   67 
   68 
   69 static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
   70 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
   71 #define UIHASH(uid)     (&uihashtbl[(uid) & uihash])
   72 static struct rwlock uihashtbl_lock;
   73 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
   74 static u_long uihash;           /* size of hash table - 1 */
   75 
   76 static void     calcru1(struct proc *p, struct rusage_ext *ruxp,
   77                     struct timeval *up, struct timeval *sp);
   78 static int      donice(struct thread *td, struct proc *chgp, int n);
   79 static struct uidinfo *uilookup(uid_t uid);
   80 static void     ruxagg_locked(struct rusage_ext *rux, struct thread *td);
   81 
   82 /*
   83  * Resource controls and accounting.
   84  */
   85 #ifndef _SYS_SYSPROTO_H_
   86 struct getpriority_args {
   87         int     which;
   88         int     who;
   89 };
   90 #endif
   91 int
   92 sys_getpriority(td, uap)
   93         struct thread *td;
   94         register struct getpriority_args *uap;
   95 {
   96         struct proc *p;
   97         struct pgrp *pg;
   98         int error, low;
   99 
  100         error = 0;
  101         low = PRIO_MAX + 1;
  102         switch (uap->which) {
  103 
  104         case PRIO_PROCESS:
  105                 if (uap->who == 0)
  106                         low = td->td_proc->p_nice;
  107                 else {
  108                         p = pfind(uap->who);
  109                         if (p == NULL)
  110                                 break;
  111                         if (p_cansee(td, p) == 0)
  112                                 low = p->p_nice;
  113                         PROC_UNLOCK(p);
  114                 }
  115                 break;
  116 
  117         case PRIO_PGRP:
  118                 sx_slock(&proctree_lock);
  119                 if (uap->who == 0) {
  120                         pg = td->td_proc->p_pgrp;
  121                         PGRP_LOCK(pg);
  122                 } else {
  123                         pg = pgfind(uap->who);
  124                         if (pg == NULL) {
  125                                 sx_sunlock(&proctree_lock);
  126                                 break;
  127                         }
  128                 }
  129                 sx_sunlock(&proctree_lock);
  130                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  131                         PROC_LOCK(p);
  132                         if (p->p_state == PRS_NORMAL &&
  133                             p_cansee(td, p) == 0) {
  134                                 if (p->p_nice < low)
  135                                         low = p->p_nice;
  136                         }
  137                         PROC_UNLOCK(p);
  138                 }
  139                 PGRP_UNLOCK(pg);
  140                 break;
  141 
  142         case PRIO_USER:
  143                 if (uap->who == 0)
  144                         uap->who = td->td_ucred->cr_uid;
  145                 sx_slock(&allproc_lock);
  146                 FOREACH_PROC_IN_SYSTEM(p) {
  147                         PROC_LOCK(p);
  148                         if (p->p_state == PRS_NORMAL &&
  149                             p_cansee(td, p) == 0 &&
  150                             p->p_ucred->cr_uid == uap->who) {
  151                                 if (p->p_nice < low)
  152                                         low = p->p_nice;
  153                         }
  154                         PROC_UNLOCK(p);
  155                 }
  156                 sx_sunlock(&allproc_lock);
  157                 break;
  158 
  159         default:
  160                 error = EINVAL;
  161                 break;
  162         }
  163         if (low == PRIO_MAX + 1 && error == 0)
  164                 error = ESRCH;
  165         td->td_retval[0] = low;
  166         return (error);
  167 }
  168 
  169 #ifndef _SYS_SYSPROTO_H_
  170 struct setpriority_args {
  171         int     which;
  172         int     who;
  173         int     prio;
  174 };
  175 #endif
  176 int
  177 sys_setpriority(td, uap)
  178         struct thread *td;
  179         struct setpriority_args *uap;
  180 {
  181         struct proc *curp, *p;
  182         struct pgrp *pg;
  183         int found = 0, error = 0;
  184 
  185         curp = td->td_proc;
  186         switch (uap->which) {
  187         case PRIO_PROCESS:
  188                 if (uap->who == 0) {
  189                         PROC_LOCK(curp);
  190                         error = donice(td, curp, uap->prio);
  191                         PROC_UNLOCK(curp);
  192                 } else {
  193                         p = pfind(uap->who);
  194                         if (p == NULL)
  195                                 break;
  196                         error = p_cansee(td, p);
  197                         if (error == 0)
  198                                 error = donice(td, p, uap->prio);
  199                         PROC_UNLOCK(p);
  200                 }
  201                 found++;
  202                 break;
  203 
  204         case PRIO_PGRP:
  205                 sx_slock(&proctree_lock);
  206                 if (uap->who == 0) {
  207                         pg = curp->p_pgrp;
  208                         PGRP_LOCK(pg);
  209                 } else {
  210                         pg = pgfind(uap->who);
  211                         if (pg == NULL) {
  212                                 sx_sunlock(&proctree_lock);
  213                                 break;
  214                         }
  215                 }
  216                 sx_sunlock(&proctree_lock);
  217                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  218                         PROC_LOCK(p);
  219                         if (p->p_state == PRS_NORMAL &&
  220                             p_cansee(td, p) == 0) {
  221                                 error = donice(td, p, uap->prio);
  222                                 found++;
  223                         }
  224                         PROC_UNLOCK(p);
  225                 }
  226                 PGRP_UNLOCK(pg);
  227                 break;
  228 
  229         case PRIO_USER:
  230                 if (uap->who == 0)
  231                         uap->who = td->td_ucred->cr_uid;
  232                 sx_slock(&allproc_lock);
  233                 FOREACH_PROC_IN_SYSTEM(p) {
  234                         PROC_LOCK(p);
  235                         if (p->p_state == PRS_NORMAL &&
  236                             p->p_ucred->cr_uid == uap->who &&
  237                             p_cansee(td, p) == 0) {
  238                                 error = donice(td, p, uap->prio);
  239                                 found++;
  240                         }
  241                         PROC_UNLOCK(p);
  242                 }
  243                 sx_sunlock(&allproc_lock);
  244                 break;
  245 
  246         default:
  247                 error = EINVAL;
  248                 break;
  249         }
  250         if (found == 0 && error == 0)
  251                 error = ESRCH;
  252         return (error);
  253 }
  254 
  255 /*
  256  * Set "nice" for a (whole) process.
  257  */
  258 static int
  259 donice(struct thread *td, struct proc *p, int n)
  260 {
  261         int error;
  262 
  263         PROC_LOCK_ASSERT(p, MA_OWNED);
  264         if ((error = p_cansched(td, p)))
  265                 return (error);
  266         if (n > PRIO_MAX)
  267                 n = PRIO_MAX;
  268         if (n < PRIO_MIN)
  269                 n = PRIO_MIN;
  270         if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
  271                 return (EACCES);
  272         sched_nice(p, n);
  273         return (0);
  274 }
  275 
  276 /*
  277  * Set realtime priority for LWP.
  278  */
  279 #ifndef _SYS_SYSPROTO_H_
  280 struct rtprio_thread_args {
  281         int             function;
  282         lwpid_t         lwpid;
  283         struct rtprio   *rtp;
  284 };
  285 #endif
  286 int
  287 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
  288 {
  289         struct proc *p;
  290         struct rtprio rtp;
  291         struct thread *td1;
  292         int cierror, error;
  293 
  294         /* Perform copyin before acquiring locks if needed. */
  295         if (uap->function == RTP_SET)
  296                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  297         else
  298                 cierror = 0;
  299 
  300         if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
  301                 p = td->td_proc;
  302                 td1 = td;
  303                 PROC_LOCK(p);
  304         } else {
  305                 /* Only look up thread in current process */
  306                 td1 = tdfind(uap->lwpid, curproc->p_pid);
  307                 if (td1 == NULL)
  308                         return (ESRCH);
  309                 p = td1->td_proc;
  310         }
  311 
  312         switch (uap->function) {
  313         case RTP_LOOKUP:
  314                 if ((error = p_cansee(td, p)))
  315                         break;
  316                 pri_to_rtp(td1, &rtp);
  317                 PROC_UNLOCK(p);
  318                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  319         case RTP_SET:
  320                 if ((error = p_cansched(td, p)) || (error = cierror))
  321                         break;
  322 
  323                 /* Disallow setting rtprio in most cases if not superuser. */
  324 /*
  325  * Realtime priority has to be restricted for reasons which should be
  326  * obvious.  However, for idle priority, there is a potential for
  327  * system deadlock if an idleprio process gains a lock on a resource
  328  * that other processes need (and the idleprio process can't run
  329  * due to a CPU-bound normal process).  Fix me!  XXX
  330  */
  331 #if 0
  332                 if (RTP_PRIO_IS_REALTIME(rtp.type)) {
  333 #else
  334                 if (rtp.type != RTP_PRIO_NORMAL) {
  335 #endif
  336                         error = priv_check(td, PRIV_SCHED_RTPRIO);
  337                         if (error)
  338                                 break;
  339                 }
  340                 error = rtp_to_pri(&rtp, td1);
  341                 break;
  342         default:
  343                 error = EINVAL;
  344                 break;
  345         }
  346         PROC_UNLOCK(p);
  347         return (error);
  348 }
  349 
  350 /*
  351  * Set realtime priority.
  352  */
  353 #ifndef _SYS_SYSPROTO_H_
  354 struct rtprio_args {
  355         int             function;
  356         pid_t           pid;
  357         struct rtprio   *rtp;
  358 };
  359 #endif
  360 int
  361 sys_rtprio(td, uap)
  362         struct thread *td;              /* curthread */
  363         register struct rtprio_args *uap;
  364 {
  365         struct proc *p;
  366         struct thread *tdp;
  367         struct rtprio rtp;
  368         int cierror, error;
  369 
  370         /* Perform copyin before acquiring locks if needed. */
  371         if (uap->function == RTP_SET)
  372                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  373         else
  374                 cierror = 0;
  375 
  376         if (uap->pid == 0) {
  377                 p = td->td_proc;
  378                 PROC_LOCK(p);
  379         } else {
  380                 p = pfind(uap->pid);
  381                 if (p == NULL)
  382                         return (ESRCH);
  383         }
  384 
  385         switch (uap->function) {
  386         case RTP_LOOKUP:
  387                 if ((error = p_cansee(td, p)))
  388                         break;
  389                 /*
  390                  * Return OUR priority if no pid specified,
  391                  * or if one is, report the highest priority
  392                  * in the process.  There isn't much more you can do as
  393                  * there is only room to return a single priority.
  394                  * Note: specifying our own pid is not the same
  395                  * as leaving it zero.
  396                  */
  397                 if (uap->pid == 0) {
  398                         pri_to_rtp(td, &rtp);
  399                 } else {
  400                         struct rtprio rtp2;
  401 
  402                         rtp.type = RTP_PRIO_IDLE;
  403                         rtp.prio = RTP_PRIO_MAX;
  404                         FOREACH_THREAD_IN_PROC(p, tdp) {
  405                                 pri_to_rtp(tdp, &rtp2);
  406                                 if (rtp2.type <  rtp.type ||
  407                                     (rtp2.type == rtp.type &&
  408                                     rtp2.prio < rtp.prio)) {
  409                                         rtp.type = rtp2.type;
  410                                         rtp.prio = rtp2.prio;
  411                                 }
  412                         }
  413                 }
  414                 PROC_UNLOCK(p);
  415                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  416         case RTP_SET:
  417                 if ((error = p_cansched(td, p)) || (error = cierror))
  418                         break;
  419 
  420                 /* Disallow setting rtprio in most cases if not superuser. */
  421 /*
  422  * Realtime priority has to be restricted for reasons which should be
  423  * obvious.  However, for idle priority, there is a potential for
  424  * system deadlock if an idleprio process gains a lock on a resource
  425  * that other processes need (and the idleprio process can't run
  426  * due to a CPU-bound normal process).  Fix me!  XXX
  427  */
  428 #if 0
  429                 if (RTP_PRIO_IS_REALTIME(rtp.type)) {
  430 #else
  431                 if (rtp.type != RTP_PRIO_NORMAL) {
  432 #endif
  433                         error = priv_check(td, PRIV_SCHED_RTPRIO);
  434                         if (error)
  435                                 break;
  436                 }
  437 
  438                 /*
  439                  * If we are setting our own priority, set just our
  440                  * thread but if we are doing another process,
  441                  * do all the threads on that process. If we
  442                  * specify our own pid we do the latter.
  443                  */
  444                 if (uap->pid == 0) {
  445                         error = rtp_to_pri(&rtp, td);
  446                 } else {
  447                         FOREACH_THREAD_IN_PROC(p, td) {
  448                                 if ((error = rtp_to_pri(&rtp, td)) != 0)
  449                                         break;
  450                         }
  451                 }
  452                 break;
  453         default:
  454                 error = EINVAL;
  455                 break;
  456         }
  457         PROC_UNLOCK(p);
  458         return (error);
  459 }
  460 
  461 int
  462 rtp_to_pri(struct rtprio *rtp, struct thread *td)
  463 {
  464         u_char  newpri;
  465         u_char  oldpri;
  466 
  467         switch (RTP_PRIO_BASE(rtp->type)) {
  468         case RTP_PRIO_REALTIME:
  469                 if (rtp->prio > RTP_PRIO_MAX)
  470                         return (EINVAL);
  471                 newpri = PRI_MIN_REALTIME + rtp->prio;
  472                 break;
  473         case RTP_PRIO_NORMAL:
  474                 if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
  475                         return (EINVAL);
  476                 newpri = PRI_MIN_TIMESHARE + rtp->prio;
  477                 break;
  478         case RTP_PRIO_IDLE:
  479                 if (rtp->prio > RTP_PRIO_MAX)
  480                         return (EINVAL);
  481                 newpri = PRI_MIN_IDLE + rtp->prio;
  482                 break;
  483         default:
  484                 return (EINVAL);
  485         }
  486 
  487         thread_lock(td);
  488         sched_class(td, rtp->type);     /* XXX fix */
  489         oldpri = td->td_user_pri;
  490         sched_user_prio(td, newpri);
  491         if (curthread == td)
  492                 sched_prio(curthread, td->td_user_pri); /* XXX dubious */
  493         if (TD_ON_UPILOCK(td) && oldpri != newpri) {
  494                 critical_enter();
  495                 thread_unlock(td);
  496                 umtx_pi_adjust(td, oldpri);
  497                 critical_exit();
  498         } else
  499                 thread_unlock(td);
  500         return (0);
  501 }
  502 
  503 void
  504 pri_to_rtp(struct thread *td, struct rtprio *rtp)
  505 {
  506 
  507         thread_lock(td);
  508         switch (PRI_BASE(td->td_pri_class)) {
  509         case PRI_REALTIME:
  510                 rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
  511                 break;
  512         case PRI_TIMESHARE:
  513                 rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
  514                 break;
  515         case PRI_IDLE:
  516                 rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
  517                 break;
  518         default:
  519                 break;
  520         }
  521         rtp->type = td->td_pri_class;
  522         thread_unlock(td);
  523 }
  524 
  525 #if defined(COMPAT_43)
  526 #ifndef _SYS_SYSPROTO_H_
  527 struct osetrlimit_args {
  528         u_int   which;
  529         struct  orlimit *rlp;
  530 };
  531 #endif
  532 int
  533 osetrlimit(td, uap)
  534         struct thread *td;
  535         register struct osetrlimit_args *uap;
  536 {
  537         struct orlimit olim;
  538         struct rlimit lim;
  539         int error;
  540 
  541         if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
  542                 return (error);
  543         lim.rlim_cur = olim.rlim_cur;
  544         lim.rlim_max = olim.rlim_max;
  545         error = kern_setrlimit(td, uap->which, &lim);
  546         return (error);
  547 }
  548 
  549 #ifndef _SYS_SYSPROTO_H_
  550 struct ogetrlimit_args {
  551         u_int   which;
  552         struct  orlimit *rlp;
  553 };
  554 #endif
  555 int
  556 ogetrlimit(td, uap)
  557         struct thread *td;
  558         register struct ogetrlimit_args *uap;
  559 {
  560         struct orlimit olim;
  561         struct rlimit rl;
  562         struct proc *p;
  563         int error;
  564 
  565         if (uap->which >= RLIM_NLIMITS)
  566                 return (EINVAL);
  567         p = td->td_proc;
  568         PROC_LOCK(p);
  569         lim_rlimit(p, uap->which, &rl);
  570         PROC_UNLOCK(p);
  571 
  572         /*
  573          * XXX would be more correct to convert only RLIM_INFINITY to the
  574          * old RLIM_INFINITY and fail with EOVERFLOW for other larger
  575          * values.  Most 64->32 and 32->16 conversions, including not
  576          * unimportant ones of uids are even more broken than what we
  577          * do here (they blindly truncate).  We don't do this correctly
  578          * here since we have little experience with EOVERFLOW yet.
  579          * Elsewhere, getuid() can't fail...
  580          */
  581         olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
  582         olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
  583         error = copyout(&olim, uap->rlp, sizeof(olim));
  584         return (error);
  585 }
  586 #endif /* COMPAT_43 */
  587 
  588 #ifndef _SYS_SYSPROTO_H_
  589 struct __setrlimit_args {
  590         u_int   which;
  591         struct  rlimit *rlp;
  592 };
  593 #endif
  594 int
  595 sys_setrlimit(td, uap)
  596         struct thread *td;
  597         register struct __setrlimit_args *uap;
  598 {
  599         struct rlimit alim;
  600         int error;
  601 
  602         if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
  603                 return (error);
  604         error = kern_setrlimit(td, uap->which, &alim);
  605         return (error);
  606 }
  607 
  608 static void
  609 lim_cb(void *arg)
  610 {
  611         struct rlimit rlim;
  612         struct thread *td;
  613         struct proc *p;
  614 
  615         p = arg;
  616         PROC_LOCK_ASSERT(p, MA_OWNED);
  617         /*
  618          * Check if the process exceeds its cpu resource allocation.  If
  619          * it reaches the max, arrange to kill the process in ast().
  620          */
  621         if (p->p_cpulimit == RLIM_INFINITY)
  622                 return;
  623         PROC_SLOCK(p);
  624         FOREACH_THREAD_IN_PROC(p, td) {
  625                 ruxagg(p, td);
  626         }
  627         PROC_SUNLOCK(p);
  628         if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
  629                 lim_rlimit(p, RLIMIT_CPU, &rlim);
  630                 if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
  631                         killproc(p, "exceeded maximum CPU limit");
  632                 } else {
  633                         if (p->p_cpulimit < rlim.rlim_max)
  634                                 p->p_cpulimit += 5;
  635                         kern_psignal(p, SIGXCPU);
  636                 }
  637         }
  638         if ((p->p_flag & P_WEXIT) == 0)
  639                 callout_reset(&p->p_limco, hz, lim_cb, p);
  640 }
  641 
  642 int
  643 kern_setrlimit(td, which, limp)
  644         struct thread *td;
  645         u_int which;
  646         struct rlimit *limp;
  647 {
  648         struct plimit *newlim, *oldlim;
  649         struct proc *p;
  650         register struct rlimit *alimp;
  651         struct rlimit oldssiz;
  652         int error;
  653 
  654         if (which >= RLIM_NLIMITS)
  655                 return (EINVAL);
  656 
  657         /*
  658          * Preserve historical bugs by treating negative limits as unsigned.
  659          */
  660         if (limp->rlim_cur < 0)
  661                 limp->rlim_cur = RLIM_INFINITY;
  662         if (limp->rlim_max < 0)
  663                 limp->rlim_max = RLIM_INFINITY;
  664 
  665         oldssiz.rlim_cur = 0;
  666         p = td->td_proc;
  667         newlim = lim_alloc();
  668         PROC_LOCK(p);
  669         oldlim = p->p_limit;
  670         alimp = &oldlim->pl_rlimit[which];
  671         if (limp->rlim_cur > alimp->rlim_max ||
  672             limp->rlim_max > alimp->rlim_max)
  673                 if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
  674                         PROC_UNLOCK(p);
  675                         lim_free(newlim);
  676                         return (error);
  677                 }
  678         if (limp->rlim_cur > limp->rlim_max)
  679                 limp->rlim_cur = limp->rlim_max;
  680         lim_copy(newlim, oldlim);
  681         alimp = &newlim->pl_rlimit[which];
  682 
  683         switch (which) {
  684 
  685         case RLIMIT_CPU:
  686                 if (limp->rlim_cur != RLIM_INFINITY &&
  687                     p->p_cpulimit == RLIM_INFINITY)
  688                         callout_reset(&p->p_limco, hz, lim_cb, p);
  689                 p->p_cpulimit = limp->rlim_cur;
  690                 break;
  691         case RLIMIT_DATA:
  692                 if (limp->rlim_cur > maxdsiz)
  693                         limp->rlim_cur = maxdsiz;
  694                 if (limp->rlim_max > maxdsiz)
  695                         limp->rlim_max = maxdsiz;
  696                 break;
  697 
  698         case RLIMIT_STACK:
  699                 if (limp->rlim_cur > maxssiz)
  700                         limp->rlim_cur = maxssiz;
  701                 if (limp->rlim_max > maxssiz)
  702                         limp->rlim_max = maxssiz;
  703                 oldssiz = *alimp;
  704                 if (p->p_sysent->sv_fixlimit != NULL)
  705                         p->p_sysent->sv_fixlimit(&oldssiz,
  706                             RLIMIT_STACK);
  707                 break;
  708 
  709         case RLIMIT_NOFILE:
  710                 if (limp->rlim_cur > maxfilesperproc)
  711                         limp->rlim_cur = maxfilesperproc;
  712                 if (limp->rlim_max > maxfilesperproc)
  713                         limp->rlim_max = maxfilesperproc;
  714                 break;
  715 
  716         case RLIMIT_NPROC:
  717                 if (limp->rlim_cur > maxprocperuid)
  718                         limp->rlim_cur = maxprocperuid;
  719                 if (limp->rlim_max > maxprocperuid)
  720                         limp->rlim_max = maxprocperuid;
  721                 if (limp->rlim_cur < 1)
  722                         limp->rlim_cur = 1;
  723                 if (limp->rlim_max < 1)
  724                         limp->rlim_max = 1;
  725                 break;
  726         }
  727         if (p->p_sysent->sv_fixlimit != NULL)
  728                 p->p_sysent->sv_fixlimit(limp, which);
  729         *alimp = *limp;
  730         p->p_limit = newlim;
  731         PROC_UNLOCK(p);
  732         lim_free(oldlim);
  733 
  734         if (which == RLIMIT_STACK) {
  735                 /*
  736                  * Stack is allocated to the max at exec time with only
  737                  * "rlim_cur" bytes accessible.  If stack limit is going
  738                  * up make more accessible, if going down make inaccessible.
  739                  */
  740                 if (limp->rlim_cur != oldssiz.rlim_cur) {
  741                         vm_offset_t addr;
  742                         vm_size_t size;
  743                         vm_prot_t prot;
  744 
  745                         if (limp->rlim_cur > oldssiz.rlim_cur) {
  746                                 prot = p->p_sysent->sv_stackprot;
  747                                 size = limp->rlim_cur - oldssiz.rlim_cur;
  748                                 addr = p->p_sysent->sv_usrstack -
  749                                     limp->rlim_cur;
  750                         } else {
  751                                 prot = VM_PROT_NONE;
  752                                 size = oldssiz.rlim_cur - limp->rlim_cur;
  753                                 addr = p->p_sysent->sv_usrstack -
  754                                     oldssiz.rlim_cur;
  755                         }
  756                         addr = trunc_page(addr);
  757                         size = round_page(size);
  758                         (void)vm_map_protect(&p->p_vmspace->vm_map,
  759                             addr, addr + size, prot, FALSE);
  760                 }
  761         }
  762 
  763         return (0);
  764 }
  765 
  766 #ifndef _SYS_SYSPROTO_H_
  767 struct __getrlimit_args {
  768         u_int   which;
  769         struct  rlimit *rlp;
  770 };
  771 #endif
  772 /* ARGSUSED */
  773 int
  774 sys_getrlimit(td, uap)
  775         struct thread *td;
  776         register struct __getrlimit_args *uap;
  777 {
  778         struct rlimit rlim;
  779         struct proc *p;
  780         int error;
  781 
  782         if (uap->which >= RLIM_NLIMITS)
  783                 return (EINVAL);
  784         p = td->td_proc;
  785         PROC_LOCK(p);
  786         lim_rlimit(p, uap->which, &rlim);
  787         PROC_UNLOCK(p);
  788         error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
  789         return (error);
  790 }
  791 
  792 /*
  793  * Transform the running time and tick information for children of proc p
  794  * into user and system time usage.
  795  */
  796 void
  797 calccru(p, up, sp)
  798         struct proc *p;
  799         struct timeval *up;
  800         struct timeval *sp;
  801 {
  802 
  803         PROC_LOCK_ASSERT(p, MA_OWNED);
  804         calcru1(p, &p->p_crux, up, sp);
  805 }
  806 
  807 /*
  808  * Transform the running time and tick information in proc p into user
  809  * and system time usage.  If appropriate, include the current time slice
  810  * on this CPU.
  811  */
  812 void
  813 calcru(struct proc *p, struct timeval *up, struct timeval *sp)
  814 {
  815         struct thread *td;
  816         uint64_t runtime, u;
  817 
  818         PROC_LOCK_ASSERT(p, MA_OWNED);
  819         PROC_SLOCK_ASSERT(p, MA_OWNED);
  820         /*
  821          * If we are getting stats for the current process, then add in the
  822          * stats that this thread has accumulated in its current time slice.
  823          * We reset the thread and CPU state as if we had performed a context
  824          * switch right here.
  825          */
  826         td = curthread;
  827         if (td->td_proc == p) {
  828                 u = cpu_ticks();
  829                 runtime = u - PCPU_GET(switchtime);
  830                 td->td_runtime += runtime;
  831                 td->td_incruntime += runtime;
  832                 PCPU_SET(switchtime, u);
  833         }
  834         /* Make sure the per-thread stats are current. */
  835         FOREACH_THREAD_IN_PROC(p, td) {
  836                 if (td->td_incruntime == 0)
  837                         continue;
  838                 ruxagg(p, td);
  839         }
  840         calcru1(p, &p->p_rux, up, sp);
  841 }
  842 
  843 /* Collect resource usage for a single thread. */
  844 void
  845 rufetchtd(struct thread *td, struct rusage *ru)
  846 {
  847         struct proc *p;
  848         uint64_t runtime, u;
  849 
  850         p = td->td_proc;
  851         PROC_SLOCK_ASSERT(p, MA_OWNED);
  852         THREAD_LOCK_ASSERT(td, MA_OWNED);
  853         /*
  854          * If we are getting stats for the current thread, then add in the
  855          * stats that this thread has accumulated in its current time slice.
  856          * We reset the thread and CPU state as if we had performed a context
  857          * switch right here.
  858          */
  859         if (td == curthread) {
  860                 u = cpu_ticks();
  861                 runtime = u - PCPU_GET(switchtime);
  862                 td->td_runtime += runtime;
  863                 td->td_incruntime += runtime;
  864                 PCPU_SET(switchtime, u);
  865         }
  866         ruxagg(p, td);
  867         *ru = td->td_ru;
  868         calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
  869 }
  870 
  871 static void
  872 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
  873     struct timeval *sp)
  874 {
  875         /* {user, system, interrupt, total} {ticks, usec}: */
  876         uint64_t ut, uu, st, su, it, tt, tu;
  877 
  878         ut = ruxp->rux_uticks;
  879         st = ruxp->rux_sticks;
  880         it = ruxp->rux_iticks;
  881         tt = ut + st + it;
  882         if (tt == 0) {
  883                 /* Avoid divide by zero */
  884                 st = 1;
  885                 tt = 1;
  886         }
  887         tu = cputick2usec(ruxp->rux_runtime);
  888         if ((int64_t)tu < 0) {
  889                 /* XXX: this should be an assert /phk */
  890                 printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
  891                     (intmax_t)tu, p->p_pid, p->p_comm);
  892                 tu = ruxp->rux_tu;
  893         }
  894 
  895         if (tu >= ruxp->rux_tu) {
  896                 /*
  897                  * The normal case, time increased.
  898                  * Enforce monotonicity of bucketed numbers.
  899                  */
  900                 uu = (tu * ut) / tt;
  901                 if (uu < ruxp->rux_uu)
  902                         uu = ruxp->rux_uu;
  903                 su = (tu * st) / tt;
  904                 if (su < ruxp->rux_su)
  905                         su = ruxp->rux_su;
  906         } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
  907                 /*
  908                  * When we calibrate the cputicker, it is not uncommon to
  909                  * see the presumably fixed frequency increase slightly over
  910                  * time as a result of thermal stabilization and NTP
  911                  * discipline (of the reference clock).  We therefore ignore
  912                  * a bit of backwards slop because we  expect to catch up
  913                  * shortly.  We use a 3 microsecond limit to catch low
  914                  * counts and a 1% limit for high counts.
  915                  */
  916                 uu = ruxp->rux_uu;
  917                 su = ruxp->rux_su;
  918                 tu = ruxp->rux_tu;
  919         } else { /* tu < ruxp->rux_tu */
  920                 /*
  921                  * What happened here was likely that a laptop, which ran at
  922                  * a reduced clock frequency at boot, kicked into high gear.
  923                  * The wisdom of spamming this message in that case is
  924                  * dubious, but it might also be indicative of something
  925                  * serious, so lets keep it and hope laptops can be made
  926                  * more truthful about their CPU speed via ACPI.
  927                  */
  928                 printf("calcru: runtime went backwards from %ju usec "
  929                     "to %ju usec for pid %d (%s)\n",
  930                     (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
  931                     p->p_pid, p->p_comm);
  932                 uu = (tu * ut) / tt;
  933                 su = (tu * st) / tt;
  934         }
  935 
  936         ruxp->rux_uu = uu;
  937         ruxp->rux_su = su;
  938         ruxp->rux_tu = tu;
  939 
  940         up->tv_sec = uu / 1000000;
  941         up->tv_usec = uu % 1000000;
  942         sp->tv_sec = su / 1000000;
  943         sp->tv_usec = su % 1000000;
  944 }
  945 
  946 #ifndef _SYS_SYSPROTO_H_
  947 struct getrusage_args {
  948         int     who;
  949         struct  rusage *rusage;
  950 };
  951 #endif
  952 int
  953 sys_getrusage(td, uap)
  954         register struct thread *td;
  955         register struct getrusage_args *uap;
  956 {
  957         struct rusage ru;
  958         int error;
  959 
  960         error = kern_getrusage(td, uap->who, &ru);
  961         if (error == 0)
  962                 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
  963         return (error);
  964 }
  965 
  966 int
  967 kern_getrusage(struct thread *td, int who, struct rusage *rup)
  968 {
  969         struct proc *p;
  970         int error;
  971 
  972         error = 0;
  973         p = td->td_proc;
  974         PROC_LOCK(p);
  975         switch (who) {
  976         case RUSAGE_SELF:
  977                 rufetchcalc(p, rup, &rup->ru_utime,
  978                     &rup->ru_stime);
  979                 break;
  980 
  981         case RUSAGE_CHILDREN:
  982                 *rup = p->p_stats->p_cru;
  983                 calccru(p, &rup->ru_utime, &rup->ru_stime);
  984                 break;
  985 
  986         case RUSAGE_THREAD:
  987                 PROC_SLOCK(p);
  988                 thread_lock(td);
  989                 rufetchtd(td, rup);
  990                 thread_unlock(td);
  991                 PROC_SUNLOCK(p);
  992                 break;
  993 
  994         default:
  995                 error = EINVAL;
  996         }
  997         PROC_UNLOCK(p);
  998         return (error);
  999 }
 1000 
 1001 void
 1002 rucollect(struct rusage *ru, struct rusage *ru2)
 1003 {
 1004         long *ip, *ip2;
 1005         int i;
 1006 
 1007         if (ru->ru_maxrss < ru2->ru_maxrss)
 1008                 ru->ru_maxrss = ru2->ru_maxrss;
 1009         ip = &ru->ru_first;
 1010         ip2 = &ru2->ru_first;
 1011         for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
 1012                 *ip++ += *ip2++;
 1013 }
 1014 
 1015 void
 1016 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
 1017     struct rusage_ext *rux2)
 1018 {
 1019 
 1020         rux->rux_runtime += rux2->rux_runtime;
 1021         rux->rux_uticks += rux2->rux_uticks;
 1022         rux->rux_sticks += rux2->rux_sticks;
 1023         rux->rux_iticks += rux2->rux_iticks;
 1024         rux->rux_uu += rux2->rux_uu;
 1025         rux->rux_su += rux2->rux_su;
 1026         rux->rux_tu += rux2->rux_tu;
 1027         rucollect(ru, ru2);
 1028 }
 1029 
 1030 /*
 1031  * Aggregate tick counts into the proc's rusage_ext.
 1032  */
 1033 static void
 1034 ruxagg_locked(struct rusage_ext *rux, struct thread *td)
 1035 {
 1036 
 1037         THREAD_LOCK_ASSERT(td, MA_OWNED);
 1038         PROC_SLOCK_ASSERT(td->td_proc, MA_OWNED);
 1039         rux->rux_runtime += td->td_incruntime;
 1040         rux->rux_uticks += td->td_uticks;
 1041         rux->rux_sticks += td->td_sticks;
 1042         rux->rux_iticks += td->td_iticks;
 1043 }
 1044 
 1045 void
 1046 ruxagg(struct proc *p, struct thread *td)
 1047 {
 1048 
 1049         thread_lock(td);
 1050         ruxagg_locked(&p->p_rux, td);
 1051         ruxagg_locked(&td->td_rux, td);
 1052         td->td_incruntime = 0;
 1053         td->td_uticks = 0;
 1054         td->td_iticks = 0;
 1055         td->td_sticks = 0;
 1056         thread_unlock(td);
 1057 }
 1058 
 1059 /*
 1060  * Update the rusage_ext structure and fetch a valid aggregate rusage
 1061  * for proc p if storage for one is supplied.
 1062  */
 1063 void
 1064 rufetch(struct proc *p, struct rusage *ru)
 1065 {
 1066         struct thread *td;
 1067 
 1068         PROC_SLOCK_ASSERT(p, MA_OWNED);
 1069 
 1070         *ru = p->p_ru;
 1071         if (p->p_numthreads > 0)  {
 1072                 FOREACH_THREAD_IN_PROC(p, td) {
 1073                         ruxagg(p, td);
 1074                         rucollect(ru, &td->td_ru);
 1075                 }
 1076         }
 1077 }
 1078 
 1079 /*
 1080  * Atomically perform a rufetch and a calcru together.
 1081  * Consumers, can safely assume the calcru is executed only once
 1082  * rufetch is completed.
 1083  */
 1084 void
 1085 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
 1086     struct timeval *sp)
 1087 {
 1088 
 1089         PROC_SLOCK(p);
 1090         rufetch(p, ru);
 1091         calcru(p, up, sp);
 1092         PROC_SUNLOCK(p);
 1093 }
 1094 
 1095 /*
 1096  * Allocate a new resource limits structure and initialize its
 1097  * reference count and mutex pointer.
 1098  */
 1099 struct plimit *
 1100 lim_alloc()
 1101 {
 1102         struct plimit *limp;
 1103 
 1104         limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
 1105         refcount_init(&limp->pl_refcnt, 1);
 1106         return (limp);
 1107 }
 1108 
 1109 struct plimit *
 1110 lim_hold(limp)
 1111         struct plimit *limp;
 1112 {
 1113 
 1114         refcount_acquire(&limp->pl_refcnt);
 1115         return (limp);
 1116 }
 1117 
 1118 void
 1119 lim_fork(struct proc *p1, struct proc *p2)
 1120 {
 1121         p2->p_limit = lim_hold(p1->p_limit);
 1122         callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
 1123         if (p1->p_cpulimit != RLIM_INFINITY)
 1124                 callout_reset(&p2->p_limco, hz, lim_cb, p2);
 1125 }
 1126 
 1127 void
 1128 lim_free(limp)
 1129         struct plimit *limp;
 1130 {
 1131 
 1132         KASSERT(limp->pl_refcnt > 0, ("plimit refcnt underflow"));
 1133         if (refcount_release(&limp->pl_refcnt))
 1134                 free((void *)limp, M_PLIMIT);
 1135 }
 1136 
 1137 /*
 1138  * Make a copy of the plimit structure.
 1139  * We share these structures copy-on-write after fork.
 1140  */
 1141 void
 1142 lim_copy(dst, src)
 1143         struct plimit *dst, *src;
 1144 {
 1145 
 1146         KASSERT(dst->pl_refcnt == 1, ("lim_copy to shared limit"));
 1147         bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
 1148 }
 1149 
 1150 /*
 1151  * Return the hard limit for a particular system resource.  The
 1152  * which parameter specifies the index into the rlimit array.
 1153  */
 1154 rlim_t
 1155 lim_max(struct proc *p, int which)
 1156 {
 1157         struct rlimit rl;
 1158 
 1159         lim_rlimit(p, which, &rl);
 1160         return (rl.rlim_max);
 1161 }
 1162 
 1163 /*
 1164  * Return the current (soft) limit for a particular system resource.
 1165  * The which parameter which specifies the index into the rlimit array
 1166  */
 1167 rlim_t
 1168 lim_cur(struct proc *p, int which)
 1169 {
 1170         struct rlimit rl;
 1171 
 1172         lim_rlimit(p, which, &rl);
 1173         return (rl.rlim_cur);
 1174 }
 1175 
 1176 /*
 1177  * Return a copy of the entire rlimit structure for the system limit
 1178  * specified by 'which' in the rlimit structure pointed to by 'rlp'.
 1179  */
 1180 void
 1181 lim_rlimit(struct proc *p, int which, struct rlimit *rlp)
 1182 {
 1183 
 1184         PROC_LOCK_ASSERT(p, MA_OWNED);
 1185         KASSERT(which >= 0 && which < RLIM_NLIMITS,
 1186             ("request for invalid resource limit"));
 1187         *rlp = p->p_limit->pl_rlimit[which];
 1188         if (p->p_sysent->sv_fixlimit != NULL)
 1189                 p->p_sysent->sv_fixlimit(rlp, which);
 1190 }
 1191 
 1192 void
 1193 uihashinit()
 1194 {
 1195 
 1196         uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
 1197         rw_init(&uihashtbl_lock, "uidinfo hash");
 1198 }
 1199 
 1200 /*
 1201  * Look up a uidinfo struct for the parameter uid.
 1202  * uihashtbl_lock must be locked.
 1203  */
 1204 static struct uidinfo *
 1205 uilookup(uid)
 1206         uid_t uid;
 1207 {
 1208         struct uihashhead *uipp;
 1209         struct uidinfo *uip;
 1210 
 1211         rw_assert(&uihashtbl_lock, RA_LOCKED);
 1212         uipp = UIHASH(uid);
 1213         LIST_FOREACH(uip, uipp, ui_hash)
 1214                 if (uip->ui_uid == uid)
 1215                         break;
 1216 
 1217         return (uip);
 1218 }
 1219 
 1220 /*
 1221  * Find or allocate a struct uidinfo for a particular uid.
 1222  * Increase refcount on uidinfo struct returned.
 1223  * uifree() should be called on a struct uidinfo when released.
 1224  */
 1225 struct uidinfo *
 1226 uifind(uid)
 1227         uid_t uid;
 1228 {
 1229         struct uidinfo *old_uip, *uip;
 1230 
 1231         rw_rlock(&uihashtbl_lock);
 1232         uip = uilookup(uid);
 1233         if (uip == NULL) {
 1234                 rw_runlock(&uihashtbl_lock);
 1235                 uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
 1236                 racct_create(&uip->ui_racct);
 1237                 rw_wlock(&uihashtbl_lock);
 1238                 /*
 1239                  * There's a chance someone created our uidinfo while we
 1240                  * were in malloc and not holding the lock, so we have to
 1241                  * make sure we don't insert a duplicate uidinfo.
 1242                  */
 1243                 if ((old_uip = uilookup(uid)) != NULL) {
 1244                         /* Someone else beat us to it. */
 1245                         racct_destroy(&uip->ui_racct);
 1246                         free(uip, M_UIDINFO);
 1247                         uip = old_uip;
 1248                 } else {
 1249                         refcount_init(&uip->ui_ref, 0);
 1250                         uip->ui_uid = uid;
 1251                         mtx_init(&uip->ui_vmsize_mtx, "ui_vmsize", NULL,
 1252                             MTX_DEF);
 1253                         LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
 1254                 }
 1255         }
 1256         uihold(uip);
 1257         rw_unlock(&uihashtbl_lock);
 1258         return (uip);
 1259 }
 1260 
 1261 /*
 1262  * Place another refcount on a uidinfo struct.
 1263  */
 1264 void
 1265 uihold(uip)
 1266         struct uidinfo *uip;
 1267 {
 1268 
 1269         refcount_acquire(&uip->ui_ref);
 1270 }
 1271 
 1272 /*-
 1273  * Since uidinfo structs have a long lifetime, we use an
 1274  * opportunistic refcounting scheme to avoid locking the lookup hash
 1275  * for each release.
 1276  *
 1277  * If the refcount hits 0, we need to free the structure,
 1278  * which means we need to lock the hash.
 1279  * Optimal case:
 1280  *   After locking the struct and lowering the refcount, if we find
 1281  *   that we don't need to free, simply unlock and return.
 1282  * Suboptimal case:
 1283  *   If refcount lowering results in need to free, bump the count
 1284  *   back up, lose the lock and acquire the locks in the proper
 1285  *   order to try again.
 1286  */
 1287 void
 1288 uifree(uip)
 1289         struct uidinfo *uip;
 1290 {
 1291         int old;
 1292 
 1293         /* Prepare for optimal case. */
 1294         old = uip->ui_ref;
 1295         if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1))
 1296                 return;
 1297 
 1298         /* Prepare for suboptimal case. */
 1299         rw_wlock(&uihashtbl_lock);
 1300         if (refcount_release(&uip->ui_ref)) {
 1301                 racct_destroy(&uip->ui_racct);
 1302                 LIST_REMOVE(uip, ui_hash);
 1303                 rw_wunlock(&uihashtbl_lock);
 1304                 if (uip->ui_sbsize != 0)
 1305                         printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
 1306                             uip->ui_uid, uip->ui_sbsize);
 1307                 if (uip->ui_proccnt != 0)
 1308                         printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
 1309                             uip->ui_uid, uip->ui_proccnt);
 1310                 if (uip->ui_vmsize != 0)
 1311                         printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
 1312                             uip->ui_uid, (unsigned long long)uip->ui_vmsize);
 1313                 mtx_destroy(&uip->ui_vmsize_mtx);
 1314                 free(uip, M_UIDINFO);
 1315                 return;
 1316         }
 1317         /*
 1318          * Someone added a reference between atomic_cmpset_int() and
 1319          * rw_wlock(&uihashtbl_lock).
 1320          */
 1321         rw_wunlock(&uihashtbl_lock);
 1322 }
 1323 
 1324 void
 1325 ui_racct_foreach(void (*callback)(struct racct *racct,
 1326     void *arg2, void *arg3), void *arg2, void *arg3)
 1327 {
 1328         struct uidinfo *uip;
 1329         struct uihashhead *uih;
 1330 
 1331         rw_rlock(&uihashtbl_lock);
 1332         for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
 1333                 LIST_FOREACH(uip, uih, ui_hash) {
 1334                         (callback)(uip->ui_racct, arg2, arg3);
 1335                 }
 1336         }
 1337         rw_runlock(&uihashtbl_lock);
 1338 }
 1339 
 1340 /*
 1341  * Change the count associated with number of processes
 1342  * a given user is using.  When 'max' is 0, don't enforce a limit
 1343  */
 1344 int
 1345 chgproccnt(uip, diff, max)
 1346         struct  uidinfo *uip;
 1347         int     diff;
 1348         rlim_t  max;
 1349 {
 1350 
 1351         /* Don't allow them to exceed max, but allow subtraction. */
 1352         if (diff > 0 && max != 0) {
 1353                 if (atomic_fetchadd_long(&uip->ui_proccnt, (long)diff) + diff > max) {
 1354                         atomic_subtract_long(&uip->ui_proccnt, (long)diff);
 1355                         return (0);
 1356                 }
 1357         } else {
 1358                 atomic_add_long(&uip->ui_proccnt, (long)diff);
 1359                 if (uip->ui_proccnt < 0)
 1360                         printf("negative proccnt for uid = %d\n", uip->ui_uid);
 1361         }
 1362         return (1);
 1363 }
 1364 
 1365 /*
 1366  * Change the total socket buffer size a user has used.
 1367  */
 1368 int
 1369 chgsbsize(uip, hiwat, to, max)
 1370         struct  uidinfo *uip;
 1371         u_int  *hiwat;
 1372         u_int   to;
 1373         rlim_t  max;
 1374 {
 1375         int diff;
 1376 
 1377         diff = to - *hiwat;
 1378         if (diff > 0) {
 1379                 if (atomic_fetchadd_long(&uip->ui_sbsize, (long)diff) + diff > max) {
 1380                         atomic_subtract_long(&uip->ui_sbsize, (long)diff);
 1381                         return (0);
 1382                 }
 1383         } else {
 1384                 atomic_add_long(&uip->ui_sbsize, (long)diff);
 1385                 if (uip->ui_sbsize < 0)
 1386                         printf("negative sbsize for uid = %d\n", uip->ui_uid);
 1387         }
 1388         *hiwat = to;
 1389         return (1);
 1390 }
 1391 
 1392 /*
 1393  * Change the count associated with number of pseudo-terminals
 1394  * a given user is using.  When 'max' is 0, don't enforce a limit
 1395  */
 1396 int
 1397 chgptscnt(uip, diff, max)
 1398         struct  uidinfo *uip;
 1399         int     diff;
 1400         rlim_t  max;
 1401 {
 1402 
 1403         /* Don't allow them to exceed max, but allow subtraction. */
 1404         if (diff > 0 && max != 0) {
 1405                 if (atomic_fetchadd_long(&uip->ui_ptscnt, (long)diff) + diff > max) {
 1406                         atomic_subtract_long(&uip->ui_ptscnt, (long)diff);
 1407                         return (0);
 1408                 }
 1409         } else {
 1410                 atomic_add_long(&uip->ui_ptscnt, (long)diff);
 1411                 if (uip->ui_ptscnt < 0)
 1412                         printf("negative ptscnt for uid = %d\n", uip->ui_uid);
 1413         }
 1414         return (1);
 1415 }

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