The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_resource.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: stable/9/sys/kern/kern_resource.c 230754 2012-01-29 21:08:24Z trociny $");
   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/sysctl.h>
   60 #include <sys/sysent.h>
   61 #include <sys/time.h>
   62 #include <sys/umtx.h>
   63 
   64 #include <vm/vm.h>
   65 #include <vm/vm_param.h>
   66 #include <vm/pmap.h>
   67 #include <vm/vm_map.h>
   68 
   69 
   70 static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
   71 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
   72 #define UIHASH(uid)     (&uihashtbl[(uid) & uihash])
   73 static struct rwlock uihashtbl_lock;
   74 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
   75 static u_long uihash;           /* size of hash table - 1 */
   76 
   77 static void     calcru1(struct proc *p, struct rusage_ext *ruxp,
   78                     struct timeval *up, struct timeval *sp);
   79 static int      donice(struct thread *td, struct proc *chgp, int n);
   80 static struct uidinfo *uilookup(uid_t uid);
   81 static void     ruxagg_locked(struct rusage_ext *rux, struct thread *td);
   82 
   83 /*
   84  * Resource controls and accounting.
   85  */
   86 #ifndef _SYS_SYSPROTO_H_
   87 struct getpriority_args {
   88         int     which;
   89         int     who;
   90 };
   91 #endif
   92 int
   93 sys_getpriority(td, uap)
   94         struct thread *td;
   95         register struct getpriority_args *uap;
   96 {
   97         struct proc *p;
   98         struct pgrp *pg;
   99         int error, low;
  100 
  101         error = 0;
  102         low = PRIO_MAX + 1;
  103         switch (uap->which) {
  104 
  105         case PRIO_PROCESS:
  106                 if (uap->who == 0)
  107                         low = td->td_proc->p_nice;
  108                 else {
  109                         p = pfind(uap->who);
  110                         if (p == NULL)
  111                                 break;
  112                         if (p_cansee(td, p) == 0)
  113                                 low = p->p_nice;
  114                         PROC_UNLOCK(p);
  115                 }
  116                 break;
  117 
  118         case PRIO_PGRP:
  119                 sx_slock(&proctree_lock);
  120                 if (uap->who == 0) {
  121                         pg = td->td_proc->p_pgrp;
  122                         PGRP_LOCK(pg);
  123                 } else {
  124                         pg = pgfind(uap->who);
  125                         if (pg == NULL) {
  126                                 sx_sunlock(&proctree_lock);
  127                                 break;
  128                         }
  129                 }
  130                 sx_sunlock(&proctree_lock);
  131                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  132                         PROC_LOCK(p);
  133                         if (p->p_state == PRS_NORMAL &&
  134                             p_cansee(td, p) == 0) {
  135                                 if (p->p_nice < low)
  136                                         low = p->p_nice;
  137                         }
  138                         PROC_UNLOCK(p);
  139                 }
  140                 PGRP_UNLOCK(pg);
  141                 break;
  142 
  143         case PRIO_USER:
  144                 if (uap->who == 0)
  145                         uap->who = td->td_ucred->cr_uid;
  146                 sx_slock(&allproc_lock);
  147                 FOREACH_PROC_IN_SYSTEM(p) {
  148                         PROC_LOCK(p);
  149                         if (p->p_state == PRS_NORMAL &&
  150                             p_cansee(td, p) == 0 &&
  151                             p->p_ucred->cr_uid == uap->who) {
  152                                 if (p->p_nice < low)
  153                                         low = p->p_nice;
  154                         }
  155                         PROC_UNLOCK(p);
  156                 }
  157                 sx_sunlock(&allproc_lock);
  158                 break;
  159 
  160         default:
  161                 error = EINVAL;
  162                 break;
  163         }
  164         if (low == PRIO_MAX + 1 && error == 0)
  165                 error = ESRCH;
  166         td->td_retval[0] = low;
  167         return (error);
  168 }
  169 
  170 #ifndef _SYS_SYSPROTO_H_
  171 struct setpriority_args {
  172         int     which;
  173         int     who;
  174         int     prio;
  175 };
  176 #endif
  177 int
  178 sys_setpriority(td, uap)
  179         struct thread *td;
  180         struct setpriority_args *uap;
  181 {
  182         struct proc *curp, *p;
  183         struct pgrp *pg;
  184         int found = 0, error = 0;
  185 
  186         curp = td->td_proc;
  187         switch (uap->which) {
  188         case PRIO_PROCESS:
  189                 if (uap->who == 0) {
  190                         PROC_LOCK(curp);
  191                         error = donice(td, curp, uap->prio);
  192                         PROC_UNLOCK(curp);
  193                 } else {
  194                         p = pfind(uap->who);
  195                         if (p == NULL)
  196                                 break;
  197                         error = p_cansee(td, p);
  198                         if (error == 0)
  199                                 error = donice(td, p, uap->prio);
  200                         PROC_UNLOCK(p);
  201                 }
  202                 found++;
  203                 break;
  204 
  205         case PRIO_PGRP:
  206                 sx_slock(&proctree_lock);
  207                 if (uap->who == 0) {
  208                         pg = curp->p_pgrp;
  209                         PGRP_LOCK(pg);
  210                 } else {
  211                         pg = pgfind(uap->who);
  212                         if (pg == NULL) {
  213                                 sx_sunlock(&proctree_lock);
  214                                 break;
  215                         }
  216                 }
  217                 sx_sunlock(&proctree_lock);
  218                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  219                         PROC_LOCK(p);
  220                         if (p->p_state == PRS_NORMAL &&
  221                             p_cansee(td, p) == 0) {
  222                                 error = donice(td, p, uap->prio);
  223                                 found++;
  224                         }
  225                         PROC_UNLOCK(p);
  226                 }
  227                 PGRP_UNLOCK(pg);
  228                 break;
  229 
  230         case PRIO_USER:
  231                 if (uap->who == 0)
  232                         uap->who = td->td_ucred->cr_uid;
  233                 sx_slock(&allproc_lock);
  234                 FOREACH_PROC_IN_SYSTEM(p) {
  235                         PROC_LOCK(p);
  236                         if (p->p_state == PRS_NORMAL &&
  237                             p->p_ucred->cr_uid == uap->who &&
  238                             p_cansee(td, p) == 0) {
  239                                 error = donice(td, p, uap->prio);
  240                                 found++;
  241                         }
  242                         PROC_UNLOCK(p);
  243                 }
  244                 sx_sunlock(&allproc_lock);
  245                 break;
  246 
  247         default:
  248                 error = EINVAL;
  249                 break;
  250         }
  251         if (found == 0 && error == 0)
  252                 error = ESRCH;
  253         return (error);
  254 }
  255 
  256 /*
  257  * Set "nice" for a (whole) process.
  258  */
  259 static int
  260 donice(struct thread *td, struct proc *p, int n)
  261 {
  262         int error;
  263 
  264         PROC_LOCK_ASSERT(p, MA_OWNED);
  265         if ((error = p_cansched(td, p)))
  266                 return (error);
  267         if (n > PRIO_MAX)
  268                 n = PRIO_MAX;
  269         if (n < PRIO_MIN)
  270                 n = PRIO_MIN;
  271         if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
  272                 return (EACCES);
  273         sched_nice(p, n);
  274         return (0);
  275 }
  276 
  277 static int unprivileged_idprio;
  278 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
  279     &unprivileged_idprio, 0, "Allow non-root users to set an idle priority");
  280 
  281 /*
  282  * Set realtime priority for LWP.
  283  */
  284 #ifndef _SYS_SYSPROTO_H_
  285 struct rtprio_thread_args {
  286         int             function;
  287         lwpid_t         lwpid;
  288         struct rtprio   *rtp;
  289 };
  290 #endif
  291 int
  292 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
  293 {
  294         struct proc *p;
  295         struct rtprio rtp;
  296         struct thread *td1;
  297         int cierror, error;
  298 
  299         /* Perform copyin before acquiring locks if needed. */
  300         if (uap->function == RTP_SET)
  301                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  302         else
  303                 cierror = 0;
  304 
  305         if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
  306                 p = td->td_proc;
  307                 td1 = td;
  308                 PROC_LOCK(p);
  309         } else {
  310                 /* Only look up thread in current process */
  311                 td1 = tdfind(uap->lwpid, curproc->p_pid);
  312                 if (td1 == NULL)
  313                         return (ESRCH);
  314                 p = td1->td_proc;
  315         }
  316 
  317         switch (uap->function) {
  318         case RTP_LOOKUP:
  319                 if ((error = p_cansee(td, p)))
  320                         break;
  321                 pri_to_rtp(td1, &rtp);
  322                 PROC_UNLOCK(p);
  323                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  324         case RTP_SET:
  325                 if ((error = p_cansched(td, p)) || (error = cierror))
  326                         break;
  327 
  328                 /* Disallow setting rtprio in most cases if not superuser. */
  329 
  330                 /*
  331                  * Realtime priority has to be restricted for reasons which
  332                  * should be obvious.  However, for idleprio processes, there is
  333                  * a potential for system deadlock if an idleprio process gains
  334                  * a lock on a resource that other processes need (and the
  335                  * idleprio process can't run due to a CPU-bound normal
  336                  * process).  Fix me!  XXX
  337                  *
  338                  * This problem is not only related to idleprio process.
  339                  * A user level program can obtain a file lock and hold it
  340                  * indefinitely.  Additionally, without idleprio processes it is
  341                  * still conceivable that a program with low priority will never
  342                  * get to run.  In short, allowing this feature might make it
  343                  * easier to lock a resource indefinitely, but it is not the
  344                  * only thing that makes it possible.
  345                  */
  346                 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
  347                     (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
  348                     unprivileged_idprio == 0)) {
  349                         error = priv_check(td, PRIV_SCHED_RTPRIO);
  350                         if (error)
  351                                 break;
  352                 }
  353                 error = rtp_to_pri(&rtp, td1);
  354                 break;
  355         default:
  356                 error = EINVAL;
  357                 break;
  358         }
  359         PROC_UNLOCK(p);
  360         return (error);
  361 }
  362 
  363 /*
  364  * Set realtime priority.
  365  */
  366 #ifndef _SYS_SYSPROTO_H_
  367 struct rtprio_args {
  368         int             function;
  369         pid_t           pid;
  370         struct rtprio   *rtp;
  371 };
  372 #endif
  373 int
  374 sys_rtprio(td, uap)
  375         struct thread *td;              /* curthread */
  376         register struct rtprio_args *uap;
  377 {
  378         struct proc *p;
  379         struct thread *tdp;
  380         struct rtprio rtp;
  381         int cierror, error;
  382 
  383         /* Perform copyin before acquiring locks if needed. */
  384         if (uap->function == RTP_SET)
  385                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  386         else
  387                 cierror = 0;
  388 
  389         if (uap->pid == 0) {
  390                 p = td->td_proc;
  391                 PROC_LOCK(p);
  392         } else {
  393                 p = pfind(uap->pid);
  394                 if (p == NULL)
  395                         return (ESRCH);
  396         }
  397 
  398         switch (uap->function) {
  399         case RTP_LOOKUP:
  400                 if ((error = p_cansee(td, p)))
  401                         break;
  402                 /*
  403                  * Return OUR priority if no pid specified,
  404                  * or if one is, report the highest priority
  405                  * in the process.  There isn't much more you can do as
  406                  * there is only room to return a single priority.
  407                  * Note: specifying our own pid is not the same
  408                  * as leaving it zero.
  409                  */
  410                 if (uap->pid == 0) {
  411                         pri_to_rtp(td, &rtp);
  412                 } else {
  413                         struct rtprio rtp2;
  414 
  415                         rtp.type = RTP_PRIO_IDLE;
  416                         rtp.prio = RTP_PRIO_MAX;
  417                         FOREACH_THREAD_IN_PROC(p, tdp) {
  418                                 pri_to_rtp(tdp, &rtp2);
  419                                 if (rtp2.type <  rtp.type ||
  420                                     (rtp2.type == rtp.type &&
  421                                     rtp2.prio < rtp.prio)) {
  422                                         rtp.type = rtp2.type;
  423                                         rtp.prio = rtp2.prio;
  424                                 }
  425                         }
  426                 }
  427                 PROC_UNLOCK(p);
  428                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  429         case RTP_SET:
  430                 if ((error = p_cansched(td, p)) || (error = cierror))
  431                         break;
  432 
  433                 /*
  434                  * Disallow setting rtprio in most cases if not superuser.
  435                  * See the comment in sys_rtprio_thread about idprio
  436                  * threads holding a lock.
  437                  */
  438                 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
  439                     (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
  440                     !unprivileged_idprio)) {
  441                         error = priv_check(td, PRIV_SCHED_RTPRIO);
  442                         if (error)
  443                                 break;
  444                 }
  445 
  446                 /*
  447                  * If we are setting our own priority, set just our
  448                  * thread but if we are doing another process,
  449                  * do all the threads on that process. If we
  450                  * specify our own pid we do the latter.
  451                  */
  452                 if (uap->pid == 0) {
  453                         error = rtp_to_pri(&rtp, td);
  454                 } else {
  455                         FOREACH_THREAD_IN_PROC(p, td) {
  456                                 if ((error = rtp_to_pri(&rtp, td)) != 0)
  457                                         break;
  458                         }
  459                 }
  460                 break;
  461         default:
  462                 error = EINVAL;
  463                 break;
  464         }
  465         PROC_UNLOCK(p);
  466         return (error);
  467 }
  468 
  469 int
  470 rtp_to_pri(struct rtprio *rtp, struct thread *td)
  471 {
  472         u_char  newpri;
  473         u_char  oldpri;
  474 
  475         switch (RTP_PRIO_BASE(rtp->type)) {
  476         case RTP_PRIO_REALTIME:
  477                 if (rtp->prio > RTP_PRIO_MAX)
  478                         return (EINVAL);
  479                 newpri = PRI_MIN_REALTIME + rtp->prio;
  480                 break;
  481         case RTP_PRIO_NORMAL:
  482                 if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
  483                         return (EINVAL);
  484                 newpri = PRI_MIN_TIMESHARE + rtp->prio;
  485                 break;
  486         case RTP_PRIO_IDLE:
  487                 if (rtp->prio > RTP_PRIO_MAX)
  488                         return (EINVAL);
  489                 newpri = PRI_MIN_IDLE + rtp->prio;
  490                 break;
  491         default:
  492                 return (EINVAL);
  493         }
  494 
  495         thread_lock(td);
  496         sched_class(td, rtp->type);     /* XXX fix */
  497         oldpri = td->td_user_pri;
  498         sched_user_prio(td, newpri);
  499         if (td->td_user_pri != oldpri && (td == curthread ||
  500             td->td_priority == oldpri || td->td_user_pri <= PRI_MAX_REALTIME))
  501                 sched_prio(td, td->td_user_pri);
  502         if (TD_ON_UPILOCK(td) && oldpri != newpri) {
  503                 critical_enter();
  504                 thread_unlock(td);
  505                 umtx_pi_adjust(td, oldpri);
  506                 critical_exit();
  507         } else
  508                 thread_unlock(td);
  509         return (0);
  510 }
  511 
  512 void
  513 pri_to_rtp(struct thread *td, struct rtprio *rtp)
  514 {
  515 
  516         thread_lock(td);
  517         switch (PRI_BASE(td->td_pri_class)) {
  518         case PRI_REALTIME:
  519                 rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
  520                 break;
  521         case PRI_TIMESHARE:
  522                 rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
  523                 break;
  524         case PRI_IDLE:
  525                 rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
  526                 break;
  527         default:
  528                 break;
  529         }
  530         rtp->type = td->td_pri_class;
  531         thread_unlock(td);
  532 }
  533 
  534 #if defined(COMPAT_43)
  535 #ifndef _SYS_SYSPROTO_H_
  536 struct osetrlimit_args {
  537         u_int   which;
  538         struct  orlimit *rlp;
  539 };
  540 #endif
  541 int
  542 osetrlimit(td, uap)
  543         struct thread *td;
  544         register struct osetrlimit_args *uap;
  545 {
  546         struct orlimit olim;
  547         struct rlimit lim;
  548         int error;
  549 
  550         if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
  551                 return (error);
  552         lim.rlim_cur = olim.rlim_cur;
  553         lim.rlim_max = olim.rlim_max;
  554         error = kern_setrlimit(td, uap->which, &lim);
  555         return (error);
  556 }
  557 
  558 #ifndef _SYS_SYSPROTO_H_
  559 struct ogetrlimit_args {
  560         u_int   which;
  561         struct  orlimit *rlp;
  562 };
  563 #endif
  564 int
  565 ogetrlimit(td, uap)
  566         struct thread *td;
  567         register struct ogetrlimit_args *uap;
  568 {
  569         struct orlimit olim;
  570         struct rlimit rl;
  571         struct proc *p;
  572         int error;
  573 
  574         if (uap->which >= RLIM_NLIMITS)
  575                 return (EINVAL);
  576         p = td->td_proc;
  577         PROC_LOCK(p);
  578         lim_rlimit(p, uap->which, &rl);
  579         PROC_UNLOCK(p);
  580 
  581         /*
  582          * XXX would be more correct to convert only RLIM_INFINITY to the
  583          * old RLIM_INFINITY and fail with EOVERFLOW for other larger
  584          * values.  Most 64->32 and 32->16 conversions, including not
  585          * unimportant ones of uids are even more broken than what we
  586          * do here (they blindly truncate).  We don't do this correctly
  587          * here since we have little experience with EOVERFLOW yet.
  588          * Elsewhere, getuid() can't fail...
  589          */
  590         olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
  591         olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
  592         error = copyout(&olim, uap->rlp, sizeof(olim));
  593         return (error);
  594 }
  595 #endif /* COMPAT_43 */
  596 
  597 #ifndef _SYS_SYSPROTO_H_
  598 struct __setrlimit_args {
  599         u_int   which;
  600         struct  rlimit *rlp;
  601 };
  602 #endif
  603 int
  604 sys_setrlimit(td, uap)
  605         struct thread *td;
  606         register struct __setrlimit_args *uap;
  607 {
  608         struct rlimit alim;
  609         int error;
  610 
  611         if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
  612                 return (error);
  613         error = kern_setrlimit(td, uap->which, &alim);
  614         return (error);
  615 }
  616 
  617 static void
  618 lim_cb(void *arg)
  619 {
  620         struct rlimit rlim;
  621         struct thread *td;
  622         struct proc *p;
  623 
  624         p = arg;
  625         PROC_LOCK_ASSERT(p, MA_OWNED);
  626         /*
  627          * Check if the process exceeds its cpu resource allocation.  If
  628          * it reaches the max, arrange to kill the process in ast().
  629          */
  630         if (p->p_cpulimit == RLIM_INFINITY)
  631                 return;
  632         PROC_SLOCK(p);
  633         FOREACH_THREAD_IN_PROC(p, td) {
  634                 ruxagg(p, td);
  635         }
  636         PROC_SUNLOCK(p);
  637         if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
  638                 lim_rlimit(p, RLIMIT_CPU, &rlim);
  639                 if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
  640                         killproc(p, "exceeded maximum CPU limit");
  641                 } else {
  642                         if (p->p_cpulimit < rlim.rlim_max)
  643                                 p->p_cpulimit += 5;
  644                         kern_psignal(p, SIGXCPU);
  645                 }
  646         }
  647         if ((p->p_flag & P_WEXIT) == 0)
  648                 callout_reset(&p->p_limco, hz, lim_cb, p);
  649 }
  650 
  651 int
  652 kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
  653 {
  654 
  655         return (kern_proc_setrlimit(td, td->td_proc, which, limp));
  656 }
  657 
  658 int
  659 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
  660     struct rlimit *limp)
  661 {
  662         struct plimit *newlim, *oldlim;
  663         register struct rlimit *alimp;
  664         struct rlimit oldssiz;
  665         int error;
  666 
  667         if (which >= RLIM_NLIMITS)
  668                 return (EINVAL);
  669 
  670         /*
  671          * Preserve historical bugs by treating negative limits as unsigned.
  672          */
  673         if (limp->rlim_cur < 0)
  674                 limp->rlim_cur = RLIM_INFINITY;
  675         if (limp->rlim_max < 0)
  676                 limp->rlim_max = RLIM_INFINITY;
  677 
  678         oldssiz.rlim_cur = 0;
  679         newlim = lim_alloc();
  680         PROC_LOCK(p);
  681         oldlim = p->p_limit;
  682         alimp = &oldlim->pl_rlimit[which];
  683         if (limp->rlim_cur > alimp->rlim_max ||
  684             limp->rlim_max > alimp->rlim_max)
  685                 if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
  686                         PROC_UNLOCK(p);
  687                         lim_free(newlim);
  688                         return (error);
  689                 }
  690         if (limp->rlim_cur > limp->rlim_max)
  691                 limp->rlim_cur = limp->rlim_max;
  692         lim_copy(newlim, oldlim);
  693         alimp = &newlim->pl_rlimit[which];
  694 
  695         switch (which) {
  696 
  697         case RLIMIT_CPU:
  698                 if (limp->rlim_cur != RLIM_INFINITY &&
  699                     p->p_cpulimit == RLIM_INFINITY)
  700                         callout_reset(&p->p_limco, hz, lim_cb, p);
  701                 p->p_cpulimit = limp->rlim_cur;
  702                 break;
  703         case RLIMIT_DATA:
  704                 if (limp->rlim_cur > maxdsiz)
  705                         limp->rlim_cur = maxdsiz;
  706                 if (limp->rlim_max > maxdsiz)
  707                         limp->rlim_max = maxdsiz;
  708                 break;
  709 
  710         case RLIMIT_STACK:
  711                 if (limp->rlim_cur > maxssiz)
  712                         limp->rlim_cur = maxssiz;
  713                 if (limp->rlim_max > maxssiz)
  714                         limp->rlim_max = maxssiz;
  715                 oldssiz = *alimp;
  716                 if (p->p_sysent->sv_fixlimit != NULL)
  717                         p->p_sysent->sv_fixlimit(&oldssiz,
  718                             RLIMIT_STACK);
  719                 break;
  720 
  721         case RLIMIT_NOFILE:
  722                 if (limp->rlim_cur > maxfilesperproc)
  723                         limp->rlim_cur = maxfilesperproc;
  724                 if (limp->rlim_max > maxfilesperproc)
  725                         limp->rlim_max = maxfilesperproc;
  726                 break;
  727 
  728         case RLIMIT_NPROC:
  729                 if (limp->rlim_cur > maxprocperuid)
  730                         limp->rlim_cur = maxprocperuid;
  731                 if (limp->rlim_max > maxprocperuid)
  732                         limp->rlim_max = maxprocperuid;
  733                 if (limp->rlim_cur < 1)
  734                         limp->rlim_cur = 1;
  735                 if (limp->rlim_max < 1)
  736                         limp->rlim_max = 1;
  737                 break;
  738         }
  739         if (p->p_sysent->sv_fixlimit != NULL)
  740                 p->p_sysent->sv_fixlimit(limp, which);
  741         *alimp = *limp;
  742         p->p_limit = newlim;
  743         PROC_UNLOCK(p);
  744         lim_free(oldlim);
  745 
  746         if (which == RLIMIT_STACK) {
  747                 /*
  748                  * Stack is allocated to the max at exec time with only
  749                  * "rlim_cur" bytes accessible.  If stack limit is going
  750                  * up make more accessible, if going down make inaccessible.
  751                  */
  752                 if (limp->rlim_cur != oldssiz.rlim_cur) {
  753                         vm_offset_t addr;
  754                         vm_size_t size;
  755                         vm_prot_t prot;
  756 
  757                         if (limp->rlim_cur > oldssiz.rlim_cur) {
  758                                 prot = p->p_sysent->sv_stackprot;
  759                                 size = limp->rlim_cur - oldssiz.rlim_cur;
  760                                 addr = p->p_sysent->sv_usrstack -
  761                                     limp->rlim_cur;
  762                         } else {
  763                                 prot = VM_PROT_NONE;
  764                                 size = oldssiz.rlim_cur - limp->rlim_cur;
  765                                 addr = p->p_sysent->sv_usrstack -
  766                                     oldssiz.rlim_cur;
  767                         }
  768                         addr = trunc_page(addr);
  769                         size = round_page(size);
  770                         (void)vm_map_protect(&p->p_vmspace->vm_map,
  771                             addr, addr + size, prot, FALSE);
  772                 }
  773         }
  774 
  775         return (0);
  776 }
  777 
  778 #ifndef _SYS_SYSPROTO_H_
  779 struct __getrlimit_args {
  780         u_int   which;
  781         struct  rlimit *rlp;
  782 };
  783 #endif
  784 /* ARGSUSED */
  785 int
  786 sys_getrlimit(td, uap)
  787         struct thread *td;
  788         register struct __getrlimit_args *uap;
  789 {
  790         struct rlimit rlim;
  791         struct proc *p;
  792         int error;
  793 
  794         if (uap->which >= RLIM_NLIMITS)
  795                 return (EINVAL);
  796         p = td->td_proc;
  797         PROC_LOCK(p);
  798         lim_rlimit(p, uap->which, &rlim);
  799         PROC_UNLOCK(p);
  800         error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
  801         return (error);
  802 }
  803 
  804 /*
  805  * Transform the running time and tick information for children of proc p
  806  * into user and system time usage.
  807  */
  808 void
  809 calccru(p, up, sp)
  810         struct proc *p;
  811         struct timeval *up;
  812         struct timeval *sp;
  813 {
  814 
  815         PROC_LOCK_ASSERT(p, MA_OWNED);
  816         calcru1(p, &p->p_crux, up, sp);
  817 }
  818 
  819 /*
  820  * Transform the running time and tick information in proc p into user
  821  * and system time usage.  If appropriate, include the current time slice
  822  * on this CPU.
  823  */
  824 void
  825 calcru(struct proc *p, struct timeval *up, struct timeval *sp)
  826 {
  827         struct thread *td;
  828         uint64_t runtime, u;
  829 
  830         PROC_LOCK_ASSERT(p, MA_OWNED);
  831         PROC_SLOCK_ASSERT(p, MA_OWNED);
  832         /*
  833          * If we are getting stats for the current process, then add in the
  834          * stats that this thread has accumulated in its current time slice.
  835          * We reset the thread and CPU state as if we had performed a context
  836          * switch right here.
  837          */
  838         td = curthread;
  839         if (td->td_proc == p) {
  840                 u = cpu_ticks();
  841                 runtime = u - PCPU_GET(switchtime);
  842                 td->td_runtime += runtime;
  843                 td->td_incruntime += runtime;
  844                 PCPU_SET(switchtime, u);
  845         }
  846         /* Make sure the per-thread stats are current. */
  847         FOREACH_THREAD_IN_PROC(p, td) {
  848                 if (td->td_incruntime == 0)
  849                         continue;
  850                 ruxagg(p, td);
  851         }
  852         calcru1(p, &p->p_rux, up, sp);
  853 }
  854 
  855 /* Collect resource usage for a single thread. */
  856 void
  857 rufetchtd(struct thread *td, struct rusage *ru)
  858 {
  859         struct proc *p;
  860         uint64_t runtime, u;
  861 
  862         p = td->td_proc;
  863         PROC_SLOCK_ASSERT(p, MA_OWNED);
  864         THREAD_LOCK_ASSERT(td, MA_OWNED);
  865         /*
  866          * If we are getting stats for the current thread, then add in the
  867          * stats that this thread has accumulated in its current time slice.
  868          * We reset the thread and CPU state as if we had performed a context
  869          * switch right here.
  870          */
  871         if (td == curthread) {
  872                 u = cpu_ticks();
  873                 runtime = u - PCPU_GET(switchtime);
  874                 td->td_runtime += runtime;
  875                 td->td_incruntime += runtime;
  876                 PCPU_SET(switchtime, u);
  877         }
  878         ruxagg(p, td);
  879         *ru = td->td_ru;
  880         calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
  881 }
  882 
  883 static void
  884 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
  885     struct timeval *sp)
  886 {
  887         /* {user, system, interrupt, total} {ticks, usec}: */
  888         uint64_t ut, uu, st, su, it, tt, tu;
  889 
  890         ut = ruxp->rux_uticks;
  891         st = ruxp->rux_sticks;
  892         it = ruxp->rux_iticks;
  893         tt = ut + st + it;
  894         if (tt == 0) {
  895                 /* Avoid divide by zero */
  896                 st = 1;
  897                 tt = 1;
  898         }
  899         tu = cputick2usec(ruxp->rux_runtime);
  900         if ((int64_t)tu < 0) {
  901                 /* XXX: this should be an assert /phk */
  902                 printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
  903                     (intmax_t)tu, p->p_pid, p->p_comm);
  904                 tu = ruxp->rux_tu;
  905         }
  906 
  907         if (tu >= ruxp->rux_tu) {
  908                 /*
  909                  * The normal case, time increased.
  910                  * Enforce monotonicity of bucketed numbers.
  911                  */
  912                 uu = (tu * ut) / tt;
  913                 if (uu < ruxp->rux_uu)
  914                         uu = ruxp->rux_uu;
  915                 su = (tu * st) / tt;
  916                 if (su < ruxp->rux_su)
  917                         su = ruxp->rux_su;
  918         } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
  919                 /*
  920                  * When we calibrate the cputicker, it is not uncommon to
  921                  * see the presumably fixed frequency increase slightly over
  922                  * time as a result of thermal stabilization and NTP
  923                  * discipline (of the reference clock).  We therefore ignore
  924                  * a bit of backwards slop because we  expect to catch up
  925                  * shortly.  We use a 3 microsecond limit to catch low
  926                  * counts and a 1% limit for high counts.
  927                  */
  928                 uu = ruxp->rux_uu;
  929                 su = ruxp->rux_su;
  930                 tu = ruxp->rux_tu;
  931         } else { /* tu < ruxp->rux_tu */
  932                 /*
  933                  * What happened here was likely that a laptop, which ran at
  934                  * a reduced clock frequency at boot, kicked into high gear.
  935                  * The wisdom of spamming this message in that case is
  936                  * dubious, but it might also be indicative of something
  937                  * serious, so lets keep it and hope laptops can be made
  938                  * more truthful about their CPU speed via ACPI.
  939                  */
  940                 printf("calcru: runtime went backwards from %ju usec "
  941                     "to %ju usec for pid %d (%s)\n",
  942                     (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
  943                     p->p_pid, p->p_comm);
  944                 uu = (tu * ut) / tt;
  945                 su = (tu * st) / tt;
  946         }
  947 
  948         ruxp->rux_uu = uu;
  949         ruxp->rux_su = su;
  950         ruxp->rux_tu = tu;
  951 
  952         up->tv_sec = uu / 1000000;
  953         up->tv_usec = uu % 1000000;
  954         sp->tv_sec = su / 1000000;
  955         sp->tv_usec = su % 1000000;
  956 }
  957 
  958 #ifndef _SYS_SYSPROTO_H_
  959 struct getrusage_args {
  960         int     who;
  961         struct  rusage *rusage;
  962 };
  963 #endif
  964 int
  965 sys_getrusage(td, uap)
  966         register struct thread *td;
  967         register struct getrusage_args *uap;
  968 {
  969         struct rusage ru;
  970         int error;
  971 
  972         error = kern_getrusage(td, uap->who, &ru);
  973         if (error == 0)
  974                 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
  975         return (error);
  976 }
  977 
  978 int
  979 kern_getrusage(struct thread *td, int who, struct rusage *rup)
  980 {
  981         struct proc *p;
  982         int error;
  983 
  984         error = 0;
  985         p = td->td_proc;
  986         PROC_LOCK(p);
  987         switch (who) {
  988         case RUSAGE_SELF:
  989                 rufetchcalc(p, rup, &rup->ru_utime,
  990                     &rup->ru_stime);
  991                 break;
  992 
  993         case RUSAGE_CHILDREN:
  994                 *rup = p->p_stats->p_cru;
  995                 calccru(p, &rup->ru_utime, &rup->ru_stime);
  996                 break;
  997 
  998         case RUSAGE_THREAD:
  999                 PROC_SLOCK(p);
 1000                 thread_lock(td);
 1001                 rufetchtd(td, rup);
 1002                 thread_unlock(td);
 1003                 PROC_SUNLOCK(p);
 1004                 break;
 1005 
 1006         default:
 1007                 error = EINVAL;
 1008         }
 1009         PROC_UNLOCK(p);
 1010         return (error);
 1011 }
 1012 
 1013 void
 1014 rucollect(struct rusage *ru, struct rusage *ru2)
 1015 {
 1016         long *ip, *ip2;
 1017         int i;
 1018 
 1019         if (ru->ru_maxrss < ru2->ru_maxrss)
 1020                 ru->ru_maxrss = ru2->ru_maxrss;
 1021         ip = &ru->ru_first;
 1022         ip2 = &ru2->ru_first;
 1023         for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
 1024                 *ip++ += *ip2++;
 1025 }
 1026 
 1027 void
 1028 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
 1029     struct rusage_ext *rux2)
 1030 {
 1031 
 1032         rux->rux_runtime += rux2->rux_runtime;
 1033         rux->rux_uticks += rux2->rux_uticks;
 1034         rux->rux_sticks += rux2->rux_sticks;
 1035         rux->rux_iticks += rux2->rux_iticks;
 1036         rux->rux_uu += rux2->rux_uu;
 1037         rux->rux_su += rux2->rux_su;
 1038         rux->rux_tu += rux2->rux_tu;
 1039         rucollect(ru, ru2);
 1040 }
 1041 
 1042 /*
 1043  * Aggregate tick counts into the proc's rusage_ext.
 1044  */
 1045 static void
 1046 ruxagg_locked(struct rusage_ext *rux, struct thread *td)
 1047 {
 1048 
 1049         THREAD_LOCK_ASSERT(td, MA_OWNED);
 1050         PROC_SLOCK_ASSERT(td->td_proc, MA_OWNED);
 1051         rux->rux_runtime += td->td_incruntime;
 1052         rux->rux_uticks += td->td_uticks;
 1053         rux->rux_sticks += td->td_sticks;
 1054         rux->rux_iticks += td->td_iticks;
 1055 }
 1056 
 1057 void
 1058 ruxagg(struct proc *p, struct thread *td)
 1059 {
 1060 
 1061         thread_lock(td);
 1062         ruxagg_locked(&p->p_rux, td);
 1063         ruxagg_locked(&td->td_rux, td);
 1064         td->td_incruntime = 0;
 1065         td->td_uticks = 0;
 1066         td->td_iticks = 0;
 1067         td->td_sticks = 0;
 1068         thread_unlock(td);
 1069 }
 1070 
 1071 /*
 1072  * Update the rusage_ext structure and fetch a valid aggregate rusage
 1073  * for proc p if storage for one is supplied.
 1074  */
 1075 void
 1076 rufetch(struct proc *p, struct rusage *ru)
 1077 {
 1078         struct thread *td;
 1079 
 1080         PROC_SLOCK_ASSERT(p, MA_OWNED);
 1081 
 1082         *ru = p->p_ru;
 1083         if (p->p_numthreads > 0)  {
 1084                 FOREACH_THREAD_IN_PROC(p, td) {
 1085                         ruxagg(p, td);
 1086                         rucollect(ru, &td->td_ru);
 1087                 }
 1088         }
 1089 }
 1090 
 1091 /*
 1092  * Atomically perform a rufetch and a calcru together.
 1093  * Consumers, can safely assume the calcru is executed only once
 1094  * rufetch is completed.
 1095  */
 1096 void
 1097 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
 1098     struct timeval *sp)
 1099 {
 1100 
 1101         PROC_SLOCK(p);
 1102         rufetch(p, ru);
 1103         calcru(p, up, sp);
 1104         PROC_SUNLOCK(p);
 1105 }
 1106 
 1107 /*
 1108  * Allocate a new resource limits structure and initialize its
 1109  * reference count and mutex pointer.
 1110  */
 1111 struct plimit *
 1112 lim_alloc()
 1113 {
 1114         struct plimit *limp;
 1115 
 1116         limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
 1117         refcount_init(&limp->pl_refcnt, 1);
 1118         return (limp);
 1119 }
 1120 
 1121 struct plimit *
 1122 lim_hold(limp)
 1123         struct plimit *limp;
 1124 {
 1125 
 1126         refcount_acquire(&limp->pl_refcnt);
 1127         return (limp);
 1128 }
 1129 
 1130 void
 1131 lim_fork(struct proc *p1, struct proc *p2)
 1132 {
 1133         p2->p_limit = lim_hold(p1->p_limit);
 1134         callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
 1135         if (p1->p_cpulimit != RLIM_INFINITY)
 1136                 callout_reset(&p2->p_limco, hz, lim_cb, p2);
 1137 }
 1138 
 1139 void
 1140 lim_free(limp)
 1141         struct plimit *limp;
 1142 {
 1143 
 1144         KASSERT(limp->pl_refcnt > 0, ("plimit refcnt underflow"));
 1145         if (refcount_release(&limp->pl_refcnt))
 1146                 free((void *)limp, M_PLIMIT);
 1147 }
 1148 
 1149 /*
 1150  * Make a copy of the plimit structure.
 1151  * We share these structures copy-on-write after fork.
 1152  */
 1153 void
 1154 lim_copy(dst, src)
 1155         struct plimit *dst, *src;
 1156 {
 1157 
 1158         KASSERT(dst->pl_refcnt == 1, ("lim_copy to shared limit"));
 1159         bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
 1160 }
 1161 
 1162 /*
 1163  * Return the hard limit for a particular system resource.  The
 1164  * which parameter specifies the index into the rlimit array.
 1165  */
 1166 rlim_t
 1167 lim_max(struct proc *p, int which)
 1168 {
 1169         struct rlimit rl;
 1170 
 1171         lim_rlimit(p, which, &rl);
 1172         return (rl.rlim_max);
 1173 }
 1174 
 1175 /*
 1176  * Return the current (soft) limit for a particular system resource.
 1177  * The which parameter which specifies the index into the rlimit array
 1178  */
 1179 rlim_t
 1180 lim_cur(struct proc *p, int which)
 1181 {
 1182         struct rlimit rl;
 1183 
 1184         lim_rlimit(p, which, &rl);
 1185         return (rl.rlim_cur);
 1186 }
 1187 
 1188 /*
 1189  * Return a copy of the entire rlimit structure for the system limit
 1190  * specified by 'which' in the rlimit structure pointed to by 'rlp'.
 1191  */
 1192 void
 1193 lim_rlimit(struct proc *p, int which, struct rlimit *rlp)
 1194 {
 1195 
 1196         PROC_LOCK_ASSERT(p, MA_OWNED);
 1197         KASSERT(which >= 0 && which < RLIM_NLIMITS,
 1198             ("request for invalid resource limit"));
 1199         *rlp = p->p_limit->pl_rlimit[which];
 1200         if (p->p_sysent->sv_fixlimit != NULL)
 1201                 p->p_sysent->sv_fixlimit(rlp, which);
 1202 }
 1203 
 1204 void
 1205 uihashinit()
 1206 {
 1207 
 1208         uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
 1209         rw_init(&uihashtbl_lock, "uidinfo hash");
 1210 }
 1211 
 1212 /*
 1213  * Look up a uidinfo struct for the parameter uid.
 1214  * uihashtbl_lock must be locked.
 1215  */
 1216 static struct uidinfo *
 1217 uilookup(uid)
 1218         uid_t uid;
 1219 {
 1220         struct uihashhead *uipp;
 1221         struct uidinfo *uip;
 1222 
 1223         rw_assert(&uihashtbl_lock, RA_LOCKED);
 1224         uipp = UIHASH(uid);
 1225         LIST_FOREACH(uip, uipp, ui_hash)
 1226                 if (uip->ui_uid == uid)
 1227                         break;
 1228 
 1229         return (uip);
 1230 }
 1231 
 1232 /*
 1233  * Find or allocate a struct uidinfo for a particular uid.
 1234  * Increase refcount on uidinfo struct returned.
 1235  * uifree() should be called on a struct uidinfo when released.
 1236  */
 1237 struct uidinfo *
 1238 uifind(uid)
 1239         uid_t uid;
 1240 {
 1241         struct uidinfo *old_uip, *uip;
 1242 
 1243         rw_rlock(&uihashtbl_lock);
 1244         uip = uilookup(uid);
 1245         if (uip == NULL) {
 1246                 rw_runlock(&uihashtbl_lock);
 1247                 uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
 1248                 racct_create(&uip->ui_racct);
 1249                 rw_wlock(&uihashtbl_lock);
 1250                 /*
 1251                  * There's a chance someone created our uidinfo while we
 1252                  * were in malloc and not holding the lock, so we have to
 1253                  * make sure we don't insert a duplicate uidinfo.
 1254                  */
 1255                 if ((old_uip = uilookup(uid)) != NULL) {
 1256                         /* Someone else beat us to it. */
 1257                         racct_destroy(&uip->ui_racct);
 1258                         free(uip, M_UIDINFO);
 1259                         uip = old_uip;
 1260                 } else {
 1261                         refcount_init(&uip->ui_ref, 0);
 1262                         uip->ui_uid = uid;
 1263                         mtx_init(&uip->ui_vmsize_mtx, "ui_vmsize", NULL,
 1264                             MTX_DEF);
 1265                         LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
 1266                 }
 1267         }
 1268         uihold(uip);
 1269         rw_unlock(&uihashtbl_lock);
 1270         return (uip);
 1271 }
 1272 
 1273 /*
 1274  * Place another refcount on a uidinfo struct.
 1275  */
 1276 void
 1277 uihold(uip)
 1278         struct uidinfo *uip;
 1279 {
 1280 
 1281         refcount_acquire(&uip->ui_ref);
 1282 }
 1283 
 1284 /*-
 1285  * Since uidinfo structs have a long lifetime, we use an
 1286  * opportunistic refcounting scheme to avoid locking the lookup hash
 1287  * for each release.
 1288  *
 1289  * If the refcount hits 0, we need to free the structure,
 1290  * which means we need to lock the hash.
 1291  * Optimal case:
 1292  *   After locking the struct and lowering the refcount, if we find
 1293  *   that we don't need to free, simply unlock and return.
 1294  * Suboptimal case:
 1295  *   If refcount lowering results in need to free, bump the count
 1296  *   back up, lose the lock and acquire the locks in the proper
 1297  *   order to try again.
 1298  */
 1299 void
 1300 uifree(uip)
 1301         struct uidinfo *uip;
 1302 {
 1303         int old;
 1304 
 1305         /* Prepare for optimal case. */
 1306         old = uip->ui_ref;
 1307         if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1))
 1308                 return;
 1309 
 1310         /* Prepare for suboptimal case. */
 1311         rw_wlock(&uihashtbl_lock);
 1312         if (refcount_release(&uip->ui_ref)) {
 1313                 racct_destroy(&uip->ui_racct);
 1314                 LIST_REMOVE(uip, ui_hash);
 1315                 rw_wunlock(&uihashtbl_lock);
 1316                 if (uip->ui_sbsize != 0)
 1317                         printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
 1318                             uip->ui_uid, uip->ui_sbsize);
 1319                 if (uip->ui_proccnt != 0)
 1320                         printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
 1321                             uip->ui_uid, uip->ui_proccnt);
 1322                 if (uip->ui_vmsize != 0)
 1323                         printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
 1324                             uip->ui_uid, (unsigned long long)uip->ui_vmsize);
 1325                 mtx_destroy(&uip->ui_vmsize_mtx);
 1326                 free(uip, M_UIDINFO);
 1327                 return;
 1328         }
 1329         /*
 1330          * Someone added a reference between atomic_cmpset_int() and
 1331          * rw_wlock(&uihashtbl_lock).
 1332          */
 1333         rw_wunlock(&uihashtbl_lock);
 1334 }
 1335 
 1336 void
 1337 ui_racct_foreach(void (*callback)(struct racct *racct,
 1338     void *arg2, void *arg3), void *arg2, void *arg3)
 1339 {
 1340         struct uidinfo *uip;
 1341         struct uihashhead *uih;
 1342 
 1343         rw_rlock(&uihashtbl_lock);
 1344         for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
 1345                 LIST_FOREACH(uip, uih, ui_hash) {
 1346                         (callback)(uip->ui_racct, arg2, arg3);
 1347                 }
 1348         }
 1349         rw_runlock(&uihashtbl_lock);
 1350 }
 1351 
 1352 /*
 1353  * Change the count associated with number of processes
 1354  * a given user is using.  When 'max' is 0, don't enforce a limit
 1355  */
 1356 int
 1357 chgproccnt(uip, diff, max)
 1358         struct  uidinfo *uip;
 1359         int     diff;
 1360         rlim_t  max;
 1361 {
 1362 
 1363         /* Don't allow them to exceed max, but allow subtraction. */
 1364         if (diff > 0 && max != 0) {
 1365                 if (atomic_fetchadd_long(&uip->ui_proccnt, (long)diff) + diff > max) {
 1366                         atomic_subtract_long(&uip->ui_proccnt, (long)diff);
 1367                         return (0);
 1368                 }
 1369         } else {
 1370                 atomic_add_long(&uip->ui_proccnt, (long)diff);
 1371                 if (uip->ui_proccnt < 0)
 1372                         printf("negative proccnt for uid = %d\n", uip->ui_uid);
 1373         }
 1374         return (1);
 1375 }
 1376 
 1377 /*
 1378  * Change the total socket buffer size a user has used.
 1379  */
 1380 int
 1381 chgsbsize(uip, hiwat, to, max)
 1382         struct  uidinfo *uip;
 1383         u_int  *hiwat;
 1384         u_int   to;
 1385         rlim_t  max;
 1386 {
 1387         int diff;
 1388 
 1389         diff = to - *hiwat;
 1390         if (diff > 0) {
 1391                 if (atomic_fetchadd_long(&uip->ui_sbsize, (long)diff) + diff > max) {
 1392                         atomic_subtract_long(&uip->ui_sbsize, (long)diff);
 1393                         return (0);
 1394                 }
 1395         } else {
 1396                 atomic_add_long(&uip->ui_sbsize, (long)diff);
 1397                 if (uip->ui_sbsize < 0)
 1398                         printf("negative sbsize for uid = %d\n", uip->ui_uid);
 1399         }
 1400         *hiwat = to;
 1401         return (1);
 1402 }
 1403 
 1404 /*
 1405  * Change the count associated with number of pseudo-terminals
 1406  * a given user is using.  When 'max' is 0, don't enforce a limit
 1407  */
 1408 int
 1409 chgptscnt(uip, diff, max)
 1410         struct  uidinfo *uip;
 1411         int     diff;
 1412         rlim_t  max;
 1413 {
 1414 
 1415         /* Don't allow them to exceed max, but allow subtraction. */
 1416         if (diff > 0 && max != 0) {
 1417                 if (atomic_fetchadd_long(&uip->ui_ptscnt, (long)diff) + diff > max) {
 1418                         atomic_subtract_long(&uip->ui_ptscnt, (long)diff);
 1419                         return (0);
 1420                 }
 1421         } else {
 1422                 atomic_add_long(&uip->ui_ptscnt, (long)diff);
 1423                 if (uip->ui_ptscnt < 0)
 1424                         printf("negative ptscnt for uid = %d\n", uip->ui_uid);
 1425         }
 1426         return (1);
 1427 }

Cache object: 2de9d8a1539c36e61779f118acc1889f


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.