The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: 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  * 3. All advertising materials mentioning features or use of this software
   19  *    must display the following acknowledgement:
   20  *      This product includes software developed by the University of
   21  *      California, Berkeley and its contributors.
   22  * 4. Neither the name of the University nor the names of its contributors
   23  *    may be used to endorse or promote products derived from this software
   24  *    without specific prior written permission.
   25  *
   26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   36  * SUCH DAMAGE.
   37  *
   38  *      @(#)kern_resource.c     8.5 (Berkeley) 1/21/94
   39  * $FreeBSD: releng/5.1/sys/kern/kern_resource.c 113921 2003-04-23 18:48:55Z jhb $
   40  */
   41 
   42 #include "opt_compat.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/sysproto.h>
   47 #include <sys/file.h>
   48 #include <sys/kernel.h>
   49 #include <sys/lock.h>
   50 #include <sys/malloc.h>
   51 #include <sys/mutex.h>
   52 #include <sys/proc.h>
   53 #include <sys/resourcevar.h>
   54 #include <sys/sched.h>
   55 #include <sys/sx.h>
   56 #include <sys/sysent.h>
   57 #include <sys/time.h>
   58 
   59 #include <vm/vm.h>
   60 #include <vm/vm_param.h>
   61 #include <vm/pmap.h>
   62 #include <vm/vm_map.h>
   63 
   64 static int donice(struct thread *td, struct proc *chgp, int n);
   65 
   66 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
   67 #define UIHASH(uid)     (&uihashtbl[(uid) & uihash])
   68 static struct mtx uihashtbl_mtx;
   69 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
   70 static u_long uihash;           /* size of hash table - 1 */
   71 
   72 static struct uidinfo   *uilookup(uid_t uid);
   73 
   74 /*
   75  * Resource controls and accounting.
   76  */
   77 
   78 #ifndef _SYS_SYSPROTO_H_
   79 struct getpriority_args {
   80         int     which;
   81         int     who;
   82 };
   83 #endif
   84 /*
   85  * MPSAFE
   86  */
   87 int
   88 getpriority(td, uap)
   89         struct thread *td;
   90         register struct getpriority_args *uap;
   91 {
   92         struct proc *p;
   93         int low = PRIO_MAX + 1;
   94         int error = 0;
   95         struct ksegrp *kg;
   96 
   97         switch (uap->which) {
   98         case PRIO_PROCESS:
   99                 if (uap->who == 0)
  100                         low = td->td_ksegrp->kg_nice;
  101                 else {
  102                         p = pfind(uap->who);
  103                         if (p == NULL)
  104                                 break;
  105                         if (p_cansee(td, p) == 0) {
  106                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  107                                         if (kg->kg_nice < low)
  108                                                 low = kg->kg_nice;
  109                                 }
  110                         }
  111                         PROC_UNLOCK(p);
  112                 }
  113                 break;
  114 
  115         case PRIO_PGRP: {
  116                 register struct pgrp *pg;
  117 
  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_cansee(td, p)) {
  133                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  134                                         if (kg->kg_nice < low)
  135                                                 low = kg->kg_nice;
  136                                 }
  137                         }
  138                         PROC_UNLOCK(p);
  139                 }
  140                 PGRP_UNLOCK(pg);
  141                 break;
  142         }
  143 
  144         case PRIO_USER:
  145                 if (uap->who == 0)
  146                         uap->who = td->td_ucred->cr_uid;
  147                 sx_slock(&allproc_lock);
  148                 LIST_FOREACH(p, &allproc, p_list) {
  149                         PROC_LOCK(p);
  150                         if (!p_cansee(td, p) &&
  151                             p->p_ucred->cr_uid == uap->who) {
  152                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  153                                         if (kg->kg_nice < low)
  154                                                 low = kg->kg_nice;
  155                                 }
  156                         }
  157                         PROC_UNLOCK(p);
  158                 }
  159                 sx_sunlock(&allproc_lock);
  160                 break;
  161 
  162         default:
  163                 error = EINVAL;
  164                 break;
  165         }
  166         if (low == PRIO_MAX + 1 && error == 0)
  167                 error = ESRCH;
  168         td->td_retval[0] = low;
  169         return (error);
  170 }
  171 
  172 #ifndef _SYS_SYSPROTO_H_
  173 struct setpriority_args {
  174         int     which;
  175         int     who;
  176         int     prio;
  177 };
  178 #endif
  179 /*
  180  * MPSAFE
  181  */
  182 /* ARGSUSED */
  183 int
  184 setpriority(td, uap)
  185         struct thread *td;
  186         register struct setpriority_args *uap;
  187 {
  188         struct proc *curp = td->td_proc;
  189         register struct proc *p;
  190         int found = 0, error = 0;
  191 
  192         switch (uap->which) {
  193         case PRIO_PROCESS:
  194                 if (uap->who == 0) {
  195                         PROC_LOCK(curp);
  196                         error = donice(td, curp, uap->prio);
  197                         PROC_UNLOCK(curp);
  198                 } else {
  199                         p = pfind(uap->who);
  200                         if (p == 0)
  201                                 break;
  202                         if (p_cansee(td, p) == 0)
  203                                 error = donice(td, p, uap->prio);
  204                         PROC_UNLOCK(p);
  205                 }
  206                 found++;
  207                 break;
  208 
  209         case PRIO_PGRP: {
  210                 register struct pgrp *pg;
  211 
  212                 sx_slock(&proctree_lock);
  213                 if (uap->who == 0) {
  214                         pg = curp->p_pgrp;
  215                         PGRP_LOCK(pg);
  216                 } else {
  217                         pg = pgfind(uap->who);
  218                         if (pg == NULL) {
  219                                 sx_sunlock(&proctree_lock);
  220                                 break;
  221                         }
  222                 }
  223                 sx_sunlock(&proctree_lock);
  224                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  225                         PROC_LOCK(p);
  226                         if (!p_cansee(td, p)) {
  227                                 error = donice(td, p, uap->prio);
  228                                 found++;
  229                         }
  230                         PROC_UNLOCK(p);
  231                 }
  232                 PGRP_UNLOCK(pg);
  233                 break;
  234         }
  235 
  236         case PRIO_USER:
  237                 if (uap->who == 0)
  238                         uap->who = td->td_ucred->cr_uid;
  239                 sx_slock(&allproc_lock);
  240                 FOREACH_PROC_IN_SYSTEM(p) {
  241                         PROC_LOCK(p);
  242                         if (p->p_ucred->cr_uid == uap->who &&
  243                             !p_cansee(td, p)) {
  244                                 error = donice(td, p, uap->prio);
  245                                 found++;
  246                         }
  247                         PROC_UNLOCK(p);
  248                 }
  249                 sx_sunlock(&allproc_lock);
  250                 break;
  251 
  252         default:
  253                 error = EINVAL;
  254                 break;
  255         }
  256         if (found == 0 && error == 0)
  257                 error = ESRCH;
  258         return (error);
  259 }
  260 
  261 /* 
  262  * Set "nice" for a process. Doesn't really understand threaded processes well
  263  * but does try. Has the unfortunate side effect of making all the NICE
  264  * values for a process's ksegrps the same.. This suggests that
  265  * NICE valuse should be stored as a process nice and deltas for the ksegrps.
  266  * (but not yet).
  267  */
  268 static int
  269 donice(struct thread *td, struct proc *p, int n)
  270 {
  271         int     error;
  272         int low = PRIO_MAX + 1;
  273         struct ksegrp *kg;
  274 
  275         PROC_LOCK_ASSERT(p, MA_OWNED);
  276         if ((error = p_cansched(td, p)))
  277                 return (error);
  278         if (n > PRIO_MAX)
  279                 n = PRIO_MAX;
  280         if (n < PRIO_MIN)
  281                 n = PRIO_MIN;
  282         /* 
  283          * Only allow nicing if to more than the lowest nice.
  284          * e.g.  nices of 4,3,2  allow nice to 3 but not 1
  285          */
  286         FOREACH_KSEGRP_IN_PROC(p, kg) {
  287                 if (kg->kg_nice < low)
  288                         low = kg->kg_nice;
  289         }
  290         if (n < low && suser(td))
  291                 return (EACCES);
  292         mtx_lock_spin(&sched_lock);
  293         FOREACH_KSEGRP_IN_PROC(p, kg) {
  294                 sched_nice(kg, n);
  295         }
  296         mtx_unlock_spin(&sched_lock);
  297         return (0);
  298 }
  299 
  300 /* rtprio system call */
  301 #ifndef _SYS_SYSPROTO_H_
  302 struct rtprio_args {
  303         int             function;
  304         pid_t           pid;
  305         struct rtprio   *rtp;
  306 };
  307 #endif
  308 
  309 /*
  310  * Set realtime priority
  311  */
  312 
  313 /*
  314  * MPSAFE
  315  */
  316 /* ARGSUSED */
  317 int
  318 rtprio(td, uap)
  319         struct thread *td;
  320         register struct rtprio_args *uap;
  321 {
  322         struct proc *curp = td->td_proc;
  323         register struct proc *p;
  324         struct rtprio rtp;
  325         int error, cierror = 0;
  326 
  327         /* Perform copyin before acquiring locks if needed. */
  328         if (uap->function == RTP_SET)
  329                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  330 
  331         if (uap->pid == 0) {
  332                 p = curp;
  333                 PROC_LOCK(p);
  334         } else {
  335                 p = pfind(uap->pid);
  336                 if (p == NULL)
  337                         return (ESRCH);
  338         }
  339 
  340         switch (uap->function) {
  341         case RTP_LOOKUP:
  342                 if ((error = p_cansee(td, p)))
  343                         break;
  344                 mtx_lock_spin(&sched_lock);
  345                 pri_to_rtp(FIRST_KSEGRP_IN_PROC(p), &rtp);
  346                 mtx_unlock_spin(&sched_lock);
  347                 PROC_UNLOCK(p);
  348                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  349         case RTP_SET:
  350                 if ((error = p_cansched(td, p)) || (error = cierror))
  351                         break;
  352                 /* disallow setting rtprio in most cases if not superuser */
  353                 if (suser(td) != 0) {
  354                         /* can't set someone else's */
  355                         if (uap->pid) {
  356                                 error = EPERM;
  357                                 break;
  358                         }
  359                         /* can't set realtime priority */
  360 /*
  361  * Realtime priority has to be restricted for reasons which should be
  362  * obvious. However, for idle priority, there is a potential for
  363  * system deadlock if an idleprio process gains a lock on a resource
  364  * that other processes need (and the idleprio process can't run
  365  * due to a CPU-bound normal process). Fix me! XXX
  366  */
  367 #if 0
  368                         if (RTP_PRIO_IS_REALTIME(rtp.type))
  369 #endif
  370                         if (rtp.type != RTP_PRIO_NORMAL) {
  371                                 error = EPERM;
  372                                 break;
  373                         }
  374                 }
  375                 mtx_lock_spin(&sched_lock);
  376                 error = rtp_to_pri(&rtp, FIRST_KSEGRP_IN_PROC(p));
  377                 mtx_unlock_spin(&sched_lock);
  378                 break;
  379         default:
  380                 error = EINVAL;
  381                 break;
  382         }
  383         PROC_UNLOCK(p);
  384         return (error);
  385 }
  386 
  387 int
  388 rtp_to_pri(struct rtprio *rtp, struct ksegrp *kg)
  389 {
  390 
  391         mtx_assert(&sched_lock, MA_OWNED);
  392         if (rtp->prio > RTP_PRIO_MAX)
  393                 return (EINVAL);
  394         switch (RTP_PRIO_BASE(rtp->type)) {
  395         case RTP_PRIO_REALTIME:
  396                 kg->kg_user_pri = PRI_MIN_REALTIME + rtp->prio;
  397                 break;
  398         case RTP_PRIO_NORMAL:
  399                 kg->kg_user_pri = PRI_MIN_TIMESHARE + rtp->prio;
  400                 break;
  401         case RTP_PRIO_IDLE:
  402                 kg->kg_user_pri = PRI_MIN_IDLE + rtp->prio;
  403                 break;
  404         default:
  405                 return (EINVAL);
  406         }
  407         sched_class(kg, rtp->type);
  408         if (curthread->td_ksegrp == kg) {
  409                 curthread->td_base_pri = kg->kg_user_pri;
  410                 curthread->td_priority = kg->kg_user_pri; /* XXX dubious */
  411         }
  412         return (0);
  413 }
  414 
  415 void
  416 pri_to_rtp(struct ksegrp *kg, struct rtprio *rtp)
  417 {
  418 
  419         mtx_assert(&sched_lock, MA_OWNED);
  420         switch (PRI_BASE(kg->kg_pri_class)) {
  421         case PRI_REALTIME:
  422                 rtp->prio = kg->kg_user_pri - PRI_MIN_REALTIME;
  423                 break;
  424         case PRI_TIMESHARE:
  425                 rtp->prio = kg->kg_user_pri - PRI_MIN_TIMESHARE;
  426                 break;
  427         case PRI_IDLE:
  428                 rtp->prio = kg->kg_user_pri - PRI_MIN_IDLE;
  429                 break;
  430         default:
  431                 break;
  432         }
  433         rtp->type = kg->kg_pri_class;
  434 }
  435 
  436 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  437 #ifndef _SYS_SYSPROTO_H_
  438 struct osetrlimit_args {
  439         u_int   which;
  440         struct  orlimit *rlp;
  441 };
  442 #endif
  443 /*
  444  * MPSAFE
  445  */
  446 /* ARGSUSED */
  447 int
  448 osetrlimit(td, uap)
  449         struct thread *td;
  450         register struct osetrlimit_args *uap;
  451 {
  452         struct orlimit olim;
  453         struct rlimit lim;
  454         int error;
  455 
  456         if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
  457                 return (error);
  458         lim.rlim_cur = olim.rlim_cur;
  459         lim.rlim_max = olim.rlim_max;
  460         mtx_lock(&Giant);
  461         error = dosetrlimit(td, uap->which, &lim);
  462         mtx_unlock(&Giant);
  463         return (error);
  464 }
  465 
  466 #ifndef _SYS_SYSPROTO_H_
  467 struct ogetrlimit_args {
  468         u_int   which;
  469         struct  orlimit *rlp;
  470 };
  471 #endif
  472 /*
  473  * MPSAFE
  474  */
  475 /* ARGSUSED */
  476 int
  477 ogetrlimit(td, uap)
  478         struct thread *td;
  479         register struct ogetrlimit_args *uap;
  480 {
  481         struct proc *p = td->td_proc;
  482         struct orlimit olim;
  483         int error;
  484 
  485         if (uap->which >= RLIM_NLIMITS)
  486                 return (EINVAL);
  487         mtx_lock(&Giant);
  488         olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
  489         if (olim.rlim_cur == -1)
  490                 olim.rlim_cur = 0x7fffffff;
  491         olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
  492         if (olim.rlim_max == -1)
  493                 olim.rlim_max = 0x7fffffff;
  494         error = copyout(&olim, uap->rlp, sizeof(olim));
  495         mtx_unlock(&Giant);
  496         return (error);
  497 }
  498 #endif /* COMPAT_43 || COMPAT_SUNOS */
  499 
  500 #ifndef _SYS_SYSPROTO_H_
  501 struct __setrlimit_args {
  502         u_int   which;
  503         struct  rlimit *rlp;
  504 };
  505 #endif
  506 /*
  507  * MPSAFE
  508  */
  509 /* ARGSUSED */
  510 int
  511 setrlimit(td, uap)
  512         struct thread *td;
  513         register struct __setrlimit_args *uap;
  514 {
  515         struct rlimit alim;
  516         int error;
  517 
  518         if ((error = copyin(uap->rlp, &alim, sizeof (struct rlimit))))
  519                 return (error);
  520         mtx_lock(&Giant);
  521         error = dosetrlimit(td, uap->which, &alim);
  522         mtx_unlock(&Giant);
  523         return (error);
  524 }
  525 
  526 int
  527 dosetrlimit(td, which, limp)
  528         struct thread *td;
  529         u_int which;
  530         struct rlimit *limp;
  531 {
  532         struct proc *p = td->td_proc;
  533         register struct rlimit *alimp;
  534         int error;
  535 
  536         GIANT_REQUIRED;
  537 
  538         if (which >= RLIM_NLIMITS)
  539                 return (EINVAL);
  540         alimp = &p->p_rlimit[which];
  541 
  542         /*
  543          * Preserve historical bugs by treating negative limits as unsigned.
  544          */
  545         if (limp->rlim_cur < 0)
  546                 limp->rlim_cur = RLIM_INFINITY;
  547         if (limp->rlim_max < 0)
  548                 limp->rlim_max = RLIM_INFINITY;
  549 
  550         if (limp->rlim_cur > alimp->rlim_max ||
  551             limp->rlim_max > alimp->rlim_max)
  552                 if ((error = suser_cred(td->td_ucred, PRISON_ROOT)))
  553                         return (error);
  554         if (limp->rlim_cur > limp->rlim_max)
  555                 limp->rlim_cur = limp->rlim_max;
  556         if (p->p_limit->p_refcnt > 1) {
  557                 p->p_limit->p_refcnt--;
  558                 p->p_limit = limcopy(p->p_limit);
  559                 alimp = &p->p_rlimit[which];
  560         }
  561 
  562         switch (which) {
  563 
  564         case RLIMIT_CPU:
  565                 mtx_lock_spin(&sched_lock);
  566                 p->p_cpulimit = limp->rlim_cur;
  567                 mtx_unlock_spin(&sched_lock);
  568                 break;
  569         case RLIMIT_DATA:
  570                 if (limp->rlim_cur > maxdsiz)
  571                         limp->rlim_cur = maxdsiz;
  572                 if (limp->rlim_max > maxdsiz)
  573                         limp->rlim_max = maxdsiz;
  574                 break;
  575 
  576         case RLIMIT_STACK:
  577                 if (limp->rlim_cur > maxssiz)
  578                         limp->rlim_cur = maxssiz;
  579                 if (limp->rlim_max > maxssiz)
  580                         limp->rlim_max = maxssiz;
  581                 /*
  582                  * Stack is allocated to the max at exec time with only
  583                  * "rlim_cur" bytes accessible.  If stack limit is going
  584                  * up make more accessible, if going down make inaccessible.
  585                  */
  586                 if (limp->rlim_cur != alimp->rlim_cur) {
  587                         vm_offset_t addr;
  588                         vm_size_t size;
  589                         vm_prot_t prot;
  590 
  591                         if (limp->rlim_cur > alimp->rlim_cur) {
  592                                 prot = p->p_sysent->sv_stackprot;
  593                                 size = limp->rlim_cur - alimp->rlim_cur;
  594                                 addr = p->p_sysent->sv_usrstack -
  595                                     limp->rlim_cur;
  596                         } else {
  597                                 prot = VM_PROT_NONE;
  598                                 size = alimp->rlim_cur - limp->rlim_cur;
  599                                 addr = p->p_sysent->sv_usrstack -
  600                                     alimp->rlim_cur;
  601                         }
  602                         addr = trunc_page(addr);
  603                         size = round_page(size);
  604                         (void) vm_map_protect(&p->p_vmspace->vm_map,
  605                                               addr, addr+size, prot, FALSE);
  606                 }
  607                 break;
  608 
  609         case RLIMIT_NOFILE:
  610                 if (limp->rlim_cur > maxfilesperproc)
  611                         limp->rlim_cur = maxfilesperproc;
  612                 if (limp->rlim_max > maxfilesperproc)
  613                         limp->rlim_max = maxfilesperproc;
  614                 break;
  615 
  616         case RLIMIT_NPROC:
  617                 if (limp->rlim_cur > maxprocperuid)
  618                         limp->rlim_cur = maxprocperuid;
  619                 if (limp->rlim_max > maxprocperuid)
  620                         limp->rlim_max = maxprocperuid;
  621                 if (limp->rlim_cur < 1)
  622                         limp->rlim_cur = 1;
  623                 if (limp->rlim_max < 1)
  624                         limp->rlim_max = 1;
  625                 break;
  626         }
  627         *alimp = *limp;
  628         return (0);
  629 }
  630 
  631 #ifndef _SYS_SYSPROTO_H_
  632 struct __getrlimit_args {
  633         u_int   which;
  634         struct  rlimit *rlp;
  635 };
  636 #endif
  637 /*
  638  * MPSAFE
  639  */
  640 /* ARGSUSED */
  641 int
  642 getrlimit(td, uap)
  643         struct thread *td;
  644         register struct __getrlimit_args *uap;
  645 {
  646         int error;
  647         struct proc *p = td->td_proc;
  648 
  649         if (uap->which >= RLIM_NLIMITS)
  650                 return (EINVAL);
  651         mtx_lock(&Giant);
  652         error = copyout(&p->p_rlimit[uap->which], uap->rlp,
  653                     sizeof (struct rlimit));
  654         mtx_unlock(&Giant);
  655         return(error);
  656 }
  657 
  658 /*
  659  * Transform the running time and tick information in proc p into user,
  660  * system, and interrupt time usage.
  661  */
  662 void
  663 calcru(p, up, sp, ip)
  664         struct proc *p;
  665         struct timeval *up;
  666         struct timeval *sp;
  667         struct timeval *ip;
  668 {
  669         /* {user, system, interrupt, total} {ticks, usec}; previous tu: */
  670         u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
  671         struct timeval tv;
  672         struct bintime bt;
  673 
  674         mtx_assert(&sched_lock, MA_OWNED);
  675         /* XXX: why spl-protect ?  worst case is an off-by-one report */
  676 
  677         ut = p->p_uticks;
  678         st = p->p_sticks;
  679         it = p->p_iticks;
  680 
  681         tt = ut + st + it;
  682         if (tt == 0) {
  683                 st = 1;
  684                 tt = 1;
  685         }
  686                 
  687         if (curthread->td_proc == p) {
  688                 /*
  689                  * Adjust for the current time slice.  This is actually fairly
  690                  * important since the error here is on the order of a time
  691                  * quantum, which is much greater than the sampling error.
  692                  * XXXKSE use a different test due to threads on other 
  693                  * processors also being 'current'.
  694                  */
  695                                 
  696                 binuptime(&bt);
  697                 bintime_sub(&bt, PCPU_PTR(switchtime));
  698                 bintime_add(&bt, &p->p_runtime);
  699         } else {
  700                 bt = p->p_runtime;
  701         }
  702         bintime2timeval(&bt, &tv);
  703         tu = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
  704         ptu = p->p_uu + p->p_su + p->p_iu;
  705         if (tu < ptu || (int64_t)tu < 0) {
  706                 /* XXX no %qd in kernel.  Truncate. */
  707                 printf("calcru: negative time of %ld usec for pid %d (%s)\n",
  708                        (long)tu, p->p_pid, p->p_comm);
  709                 tu = ptu;
  710         }
  711 
  712         /* Subdivide tu. */
  713         uu = (tu * ut) / tt;
  714         su = (tu * st) / tt;
  715         iu = tu - uu - su;
  716                 
  717         /* Enforce monotonicity. */
  718         if (uu < p->p_uu || su < p->p_su || iu < p->p_iu) {
  719                 if (uu < p->p_uu)
  720                         uu = p->p_uu;
  721                 else if (uu + p->p_su + p->p_iu > tu)
  722                         uu = tu - p->p_su - p->p_iu;
  723                 if (st == 0)
  724                         su = p->p_su;
  725                 else {
  726                         su = ((tu - uu) * st) / (st + it);
  727                         if (su < p->p_su)
  728                                 su = p->p_su;
  729                         else if (uu + su + p->p_iu > tu)
  730                                 su = tu - uu - p->p_iu;
  731                 }
  732                 KASSERT(uu + su + p->p_iu <= tu,
  733                         ("calcru: monotonisation botch 1"));
  734                 iu = tu - uu - su;
  735                 KASSERT(iu >= p->p_iu,
  736                         ("calcru: monotonisation botch 2"));
  737         }
  738         p->p_uu = uu;
  739         p->p_su = su;
  740         p->p_iu = iu;
  741 
  742         up->tv_sec = uu / 1000000;
  743         up->tv_usec = uu % 1000000;
  744         sp->tv_sec = su / 1000000;
  745         sp->tv_usec = su % 1000000;
  746         if (ip != NULL) {
  747                 ip->tv_sec = iu / 1000000;
  748                 ip->tv_usec = iu % 1000000;
  749         }
  750 }
  751 
  752 #ifndef _SYS_SYSPROTO_H_
  753 struct getrusage_args {
  754         int     who;
  755         struct  rusage *rusage;
  756 };
  757 #endif
  758 /*
  759  * MPSAFE
  760  */
  761 /* ARGSUSED */
  762 int
  763 getrusage(td, uap)
  764         register struct thread *td;
  765         register struct getrusage_args *uap;
  766 {
  767         struct proc *p = td->td_proc;
  768         register struct rusage *rup;
  769         int error = 0;
  770 
  771         mtx_lock(&Giant);
  772 
  773         switch (uap->who) {
  774         case RUSAGE_SELF:
  775                 rup = &p->p_stats->p_ru;
  776                 mtx_lock_spin(&sched_lock);
  777                 calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
  778                 mtx_unlock_spin(&sched_lock);
  779                 break;
  780 
  781         case RUSAGE_CHILDREN:
  782                 rup = &p->p_stats->p_cru;
  783                 break;
  784 
  785         default:
  786                 rup = NULL;
  787                 error = EINVAL;
  788                 break;
  789         }
  790         mtx_unlock(&Giant);
  791         if (error == 0) {
  792                 /* XXX Unlocked access to p_stats->p_ru or p_cru. */
  793                 error = copyout(rup, uap->rusage, sizeof (struct rusage));
  794         }
  795         return(error);
  796 }
  797 
  798 void
  799 ruadd(ru, ru2)
  800         register struct rusage *ru, *ru2;
  801 {
  802         register long *ip, *ip2;
  803         register int i;
  804 
  805         timevaladd(&ru->ru_utime, &ru2->ru_utime);
  806         timevaladd(&ru->ru_stime, &ru2->ru_stime);
  807         if (ru->ru_maxrss < ru2->ru_maxrss)
  808                 ru->ru_maxrss = ru2->ru_maxrss;
  809         ip = &ru->ru_first; ip2 = &ru2->ru_first;
  810         for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
  811                 *ip++ += *ip2++;
  812 }
  813 
  814 /*
  815  * Make a copy of the plimit structure.
  816  * We share these structures copy-on-write after fork,
  817  * and copy when a limit is changed.
  818  */
  819 struct plimit *
  820 limcopy(lim)
  821         struct plimit *lim;
  822 {
  823         register struct plimit *copy;
  824 
  825         MALLOC(copy, struct plimit *, sizeof(struct plimit),
  826             M_SUBPROC, M_WAITOK);
  827         bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
  828         copy->p_refcnt = 1;
  829         return (copy);
  830 }
  831 
  832 /*
  833  * Find the uidinfo structure for a uid.  This structure is used to
  834  * track the total resource consumption (process count, socket buffer
  835  * size, etc.) for the uid and impose limits.
  836  */
  837 void
  838 uihashinit()
  839 {
  840 
  841         uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
  842         mtx_init(&uihashtbl_mtx, "uidinfo hash", NULL, MTX_DEF);
  843 }
  844 
  845 /*
  846  * lookup a uidinfo struct for the parameter uid.
  847  * uihashtbl_mtx must be locked.
  848  */
  849 static struct uidinfo *
  850 uilookup(uid)
  851         uid_t uid;
  852 {
  853         struct  uihashhead *uipp;
  854         struct  uidinfo *uip;
  855 
  856         mtx_assert(&uihashtbl_mtx, MA_OWNED);
  857         uipp = UIHASH(uid);
  858         LIST_FOREACH(uip, uipp, ui_hash)
  859                 if (uip->ui_uid == uid)
  860                         break;
  861 
  862         return (uip);
  863 }
  864 
  865 /*
  866  * Find or allocate a struct uidinfo for a particular uid.
  867  * Increase refcount on uidinfo struct returned.
  868  * uifree() should be called on a struct uidinfo when released.
  869  */
  870 struct uidinfo *
  871 uifind(uid)
  872         uid_t uid;
  873 {
  874         struct  uidinfo *uip;
  875 
  876         mtx_lock(&uihashtbl_mtx);
  877         uip = uilookup(uid);
  878         if (uip == NULL) {
  879                 struct  uidinfo *old_uip;
  880 
  881                 mtx_unlock(&uihashtbl_mtx);
  882                 uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
  883                 mtx_lock(&uihashtbl_mtx);
  884                 /*
  885                  * There's a chance someone created our uidinfo while we
  886                  * were in malloc and not holding the lock, so we have to
  887                  * make sure we don't insert a duplicate uidinfo
  888                  */
  889                 if ((old_uip = uilookup(uid)) != NULL) {
  890                         /* someone else beat us to it */
  891                         free(uip, M_UIDINFO);
  892                         uip = old_uip;
  893                 } else {
  894                         uip->ui_mtxp = mtx_pool_alloc();
  895                         uip->ui_uid = uid;
  896                         LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
  897                 }
  898         }
  899         uihold(uip);
  900         mtx_unlock(&uihashtbl_mtx);
  901         return (uip);
  902 }
  903 
  904 /*
  905  * Place another refcount on a uidinfo struct.
  906  */
  907 void
  908 uihold(uip)
  909         struct uidinfo *uip;
  910 {
  911 
  912         UIDINFO_LOCK(uip);
  913         uip->ui_ref++;
  914         UIDINFO_UNLOCK(uip);
  915 }
  916 
  917 /*-
  918  * Since uidinfo structs have a long lifetime, we use an
  919  * opportunistic refcounting scheme to avoid locking the lookup hash
  920  * for each release.
  921  *
  922  * If the refcount hits 0, we need to free the structure,
  923  * which means we need to lock the hash.
  924  * Optimal case:
  925  *   After locking the struct and lowering the refcount, if we find
  926  *   that we don't need to free, simply unlock and return.
  927  * Suboptimal case:
  928  *   If refcount lowering results in need to free, bump the count
  929  *   back up, loose the lock and aquire the locks in the proper
  930  *   order to try again.
  931  */
  932 void
  933 uifree(uip)
  934         struct uidinfo *uip;
  935 {
  936 
  937         /* Prepare for optimal case. */
  938         UIDINFO_LOCK(uip);
  939 
  940         if (--uip->ui_ref != 0) {
  941                 UIDINFO_UNLOCK(uip);
  942                 return;
  943         }
  944 
  945         /* Prepare for suboptimal case. */
  946         uip->ui_ref++;
  947         UIDINFO_UNLOCK(uip);
  948         mtx_lock(&uihashtbl_mtx);
  949         UIDINFO_LOCK(uip);
  950 
  951         /*
  952          * We must subtract one from the count again because we backed out
  953          * our initial subtraction before dropping the lock.
  954          * Since another thread may have added a reference after we dropped the
  955          * initial lock we have to test for zero again.
  956          */
  957         if (--uip->ui_ref == 0) {
  958                 LIST_REMOVE(uip, ui_hash);
  959                 mtx_unlock(&uihashtbl_mtx);
  960                 if (uip->ui_sbsize != 0)
  961                         /* XXX no %qd in kernel.  Truncate. */
  962                         printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
  963                             uip->ui_uid, (long)uip->ui_sbsize);
  964                 if (uip->ui_proccnt != 0)
  965                         printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
  966                             uip->ui_uid, uip->ui_proccnt);
  967                 UIDINFO_UNLOCK(uip);
  968                 FREE(uip, M_UIDINFO);
  969                 return;
  970         }
  971 
  972         mtx_unlock(&uihashtbl_mtx);
  973         UIDINFO_UNLOCK(uip);
  974 }
  975 
  976 /*
  977  * Change the count associated with number of processes
  978  * a given user is using.  When 'max' is 0, don't enforce a limit
  979  */
  980 int
  981 chgproccnt(uip, diff, max)
  982         struct  uidinfo *uip;
  983         int     diff;
  984         int     max;
  985 {
  986 
  987         UIDINFO_LOCK(uip);
  988         /* don't allow them to exceed max, but allow subtraction */
  989         if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
  990                 UIDINFO_UNLOCK(uip);
  991                 return (0);
  992         }
  993         uip->ui_proccnt += diff;
  994         if (uip->ui_proccnt < 0)
  995                 printf("negative proccnt for uid = %d\n", uip->ui_uid);
  996         UIDINFO_UNLOCK(uip);
  997         return (1);
  998 }
  999 
 1000 /*
 1001  * Change the total socket buffer size a user has used.
 1002  */
 1003 int
 1004 chgsbsize(uip, hiwat, to, max)
 1005         struct  uidinfo *uip;
 1006         u_int  *hiwat;
 1007         u_int   to;
 1008         rlim_t  max;
 1009 {
 1010         rlim_t new;
 1011         int s;
 1012 
 1013         s = splnet();
 1014         UIDINFO_LOCK(uip);
 1015         new = uip->ui_sbsize + to - *hiwat;
 1016         /* don't allow them to exceed max, but allow subtraction */
 1017         if (to > *hiwat && new > max) {
 1018                 splx(s);
 1019                 UIDINFO_UNLOCK(uip);
 1020                 return (0);
 1021         }
 1022         uip->ui_sbsize = new;
 1023         *hiwat = to;
 1024         if (uip->ui_sbsize < 0)
 1025                 printf("negative sbsize for uid = %d\n", uip->ui_uid);
 1026         splx(s);
 1027         UIDINFO_UNLOCK(uip);
 1028         return (1);
 1029 }

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