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  */
   40 
   41 #include <sys/cdefs.h>
   42 __FBSDID("$FreeBSD: releng/5.2/sys/kern/kern_resource.c 121608 2003-10-27 07:15:47Z jeff $");
   43 
   44 #include "opt_compat.h"
   45 
   46 #include <sys/param.h>
   47 #include <sys/systm.h>
   48 #include <sys/sysproto.h>
   49 #include <sys/file.h>
   50 #include <sys/kernel.h>
   51 #include <sys/lock.h>
   52 #include <sys/malloc.h>
   53 #include <sys/mutex.h>
   54 #include <sys/proc.h>
   55 #include <sys/resourcevar.h>
   56 #include <sys/sched.h>
   57 #include <sys/sx.h>
   58 #include <sys/sysent.h>
   59 #include <sys/time.h>
   60 
   61 #include <vm/vm.h>
   62 #include <vm/vm_param.h>
   63 #include <vm/pmap.h>
   64 #include <vm/vm_map.h>
   65 
   66 static int donice(struct thread *td, struct proc *chgp, int n);
   67 
   68 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
   69 #define UIHASH(uid)     (&uihashtbl[(uid) & uihash])
   70 static struct mtx uihashtbl_mtx;
   71 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
   72 static u_long uihash;           /* size of hash table - 1 */
   73 
   74 static struct uidinfo   *uilookup(uid_t uid);
   75 
   76 /*
   77  * Resource controls and accounting.
   78  */
   79 
   80 #ifndef _SYS_SYSPROTO_H_
   81 struct getpriority_args {
   82         int     which;
   83         int     who;
   84 };
   85 #endif
   86 /*
   87  * MPSAFE
   88  */
   89 int
   90 getpriority(td, uap)
   91         struct thread *td;
   92         register struct getpriority_args *uap;
   93 {
   94         struct proc *p;
   95         int low = PRIO_MAX + 1;
   96         int error = 0;
   97         struct ksegrp *kg;
   98 
   99         switch (uap->which) {
  100         case PRIO_PROCESS:
  101                 if (uap->who == 0)
  102                         low = td->td_ksegrp->kg_nice;
  103                 else {
  104                         p = pfind(uap->who);
  105                         if (p == NULL)
  106                                 break;
  107                         if (p_cansee(td, p) == 0) {
  108                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  109                                         if (kg->kg_nice < low)
  110                                                 low = kg->kg_nice;
  111                                 }
  112                         }
  113                         PROC_UNLOCK(p);
  114                 }
  115                 break;
  116 
  117         case PRIO_PGRP: {
  118                 register struct pgrp *pg;
  119 
  120                 sx_slock(&proctree_lock);
  121                 if (uap->who == 0) {
  122                         pg = td->td_proc->p_pgrp;
  123                         PGRP_LOCK(pg);
  124                 } else {
  125                         pg = pgfind(uap->who);
  126                         if (pg == NULL) {
  127                                 sx_sunlock(&proctree_lock);
  128                                 break;
  129                         }
  130                 }
  131                 sx_sunlock(&proctree_lock);
  132                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  133                         PROC_LOCK(p);
  134                         if (!p_cansee(td, p)) {
  135                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  136                                         if (kg->kg_nice < low)
  137                                                 low = kg->kg_nice;
  138                                 }
  139                         }
  140                         PROC_UNLOCK(p);
  141                 }
  142                 PGRP_UNLOCK(pg);
  143                 break;
  144         }
  145 
  146         case PRIO_USER:
  147                 if (uap->who == 0)
  148                         uap->who = td->td_ucred->cr_uid;
  149                 sx_slock(&allproc_lock);
  150                 LIST_FOREACH(p, &allproc, p_list) {
  151                         PROC_LOCK(p);
  152                         if (!p_cansee(td, p) &&
  153                             p->p_ucred->cr_uid == uap->who) {
  154                                 FOREACH_KSEGRP_IN_PROC(p, kg) {
  155                                         if (kg->kg_nice < low)
  156                                                 low = kg->kg_nice;
  157                                 }
  158                         }
  159                         PROC_UNLOCK(p);
  160                 }
  161                 sx_sunlock(&allproc_lock);
  162                 break;
  163 
  164         default:
  165                 error = EINVAL;
  166                 break;
  167         }
  168         if (low == PRIO_MAX + 1 && error == 0)
  169                 error = ESRCH;
  170         td->td_retval[0] = low;
  171         return (error);
  172 }
  173 
  174 #ifndef _SYS_SYSPROTO_H_
  175 struct setpriority_args {
  176         int     which;
  177         int     who;
  178         int     prio;
  179 };
  180 #endif
  181 /*
  182  * MPSAFE
  183  */
  184 /* ARGSUSED */
  185 int
  186 setpriority(td, uap)
  187         struct thread *td;
  188         register struct setpriority_args *uap;
  189 {
  190         struct proc *curp = td->td_proc;
  191         register struct proc *p;
  192         int found = 0, error = 0;
  193 
  194         switch (uap->which) {
  195         case PRIO_PROCESS:
  196                 if (uap->who == 0) {
  197                         PROC_LOCK(curp);
  198                         error = donice(td, curp, uap->prio);
  199                         PROC_UNLOCK(curp);
  200                 } else {
  201                         p = pfind(uap->who);
  202                         if (p == 0)
  203                                 break;
  204                         if (p_cansee(td, p) == 0)
  205                                 error = donice(td, p, uap->prio);
  206                         PROC_UNLOCK(p);
  207                 }
  208                 found++;
  209                 break;
  210 
  211         case PRIO_PGRP: {
  212                 register struct pgrp *pg;
  213 
  214                 sx_slock(&proctree_lock);
  215                 if (uap->who == 0) {
  216                         pg = curp->p_pgrp;
  217                         PGRP_LOCK(pg);
  218                 } else {
  219                         pg = pgfind(uap->who);
  220                         if (pg == NULL) {
  221                                 sx_sunlock(&proctree_lock);
  222                                 break;
  223                         }
  224                 }
  225                 sx_sunlock(&proctree_lock);
  226                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
  227                         PROC_LOCK(p);
  228                         if (!p_cansee(td, p)) {
  229                                 error = donice(td, p, uap->prio);
  230                                 found++;
  231                         }
  232                         PROC_UNLOCK(p);
  233                 }
  234                 PGRP_UNLOCK(pg);
  235                 break;
  236         }
  237 
  238         case PRIO_USER:
  239                 if (uap->who == 0)
  240                         uap->who = td->td_ucred->cr_uid;
  241                 sx_slock(&allproc_lock);
  242                 FOREACH_PROC_IN_SYSTEM(p) {
  243                         PROC_LOCK(p);
  244                         if (p->p_ucred->cr_uid == uap->who &&
  245                             !p_cansee(td, p)) {
  246                                 error = donice(td, p, uap->prio);
  247                                 found++;
  248                         }
  249                         PROC_UNLOCK(p);
  250                 }
  251                 sx_sunlock(&allproc_lock);
  252                 break;
  253 
  254         default:
  255                 error = EINVAL;
  256                 break;
  257         }
  258         if (found == 0 && error == 0)
  259                 error = ESRCH;
  260         return (error);
  261 }
  262 
  263 /* 
  264  * Set "nice" for a process. Doesn't really understand threaded processes well
  265  * but does try. Has the unfortunate side effect of making all the NICE
  266  * values for a process's ksegrps the same.. This suggests that
  267  * NICE valuse should be stored as a process nice and deltas for the ksegrps.
  268  * (but not yet).
  269  */
  270 static int
  271 donice(struct thread *td, struct proc *p, int n)
  272 {
  273         int     error;
  274         int low = PRIO_MAX + 1;
  275         struct ksegrp *kg;
  276 
  277         PROC_LOCK_ASSERT(p, MA_OWNED);
  278         if ((error = p_cansched(td, p)))
  279                 return (error);
  280         if (n > PRIO_MAX)
  281                 n = PRIO_MAX;
  282         if (n < PRIO_MIN)
  283                 n = PRIO_MIN;
  284         /* 
  285          * Only allow nicing if to more than the lowest nice.
  286          * e.g.  nices of 4,3,2  allow nice to 3 but not 1
  287          */
  288         FOREACH_KSEGRP_IN_PROC(p, kg) {
  289                 if (kg->kg_nice < low)
  290                         low = kg->kg_nice;
  291         }
  292         if (n < low && suser(td))
  293                 return (EACCES);
  294         mtx_lock_spin(&sched_lock);
  295         FOREACH_KSEGRP_IN_PROC(p, kg) {
  296                 sched_nice(kg, n);
  297         }
  298         mtx_unlock_spin(&sched_lock);
  299         return (0);
  300 }
  301 
  302 /* rtprio system call */
  303 #ifndef _SYS_SYSPROTO_H_
  304 struct rtprio_args {
  305         int             function;
  306         pid_t           pid;
  307         struct rtprio   *rtp;
  308 };
  309 #endif
  310 
  311 /*
  312  * Set realtime priority
  313  */
  314 
  315 /*
  316  * MPSAFE
  317  */
  318 /* ARGSUSED */
  319 int
  320 rtprio(td, uap)
  321         struct thread *td;
  322         register struct rtprio_args *uap;
  323 {
  324         struct proc *curp = td->td_proc;
  325         register struct proc *p;
  326         struct rtprio rtp;
  327         int error, cierror = 0;
  328 
  329         /* Perform copyin before acquiring locks if needed. */
  330         if (uap->function == RTP_SET)
  331                 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
  332 
  333         if (uap->pid == 0) {
  334                 p = curp;
  335                 PROC_LOCK(p);
  336         } else {
  337                 p = pfind(uap->pid);
  338                 if (p == NULL)
  339                         return (ESRCH);
  340         }
  341 
  342         switch (uap->function) {
  343         case RTP_LOOKUP:
  344                 if ((error = p_cansee(td, p)))
  345                         break;
  346                 mtx_lock_spin(&sched_lock);
  347                 pri_to_rtp(FIRST_KSEGRP_IN_PROC(p), &rtp);
  348                 mtx_unlock_spin(&sched_lock);
  349                 PROC_UNLOCK(p);
  350                 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
  351         case RTP_SET:
  352                 if ((error = p_cansched(td, p)) || (error = cierror))
  353                         break;
  354                 /* disallow setting rtprio in most cases if not superuser */
  355                 if (suser(td) != 0) {
  356                         /* can't set someone else's */
  357                         if (uap->pid) {
  358                                 error = EPERM;
  359                                 break;
  360                         }
  361                         /* can't set realtime priority */
  362 /*
  363  * Realtime priority has to be restricted for reasons which should be
  364  * obvious. However, for idle priority, there is a potential for
  365  * system deadlock if an idleprio process gains a lock on a resource
  366  * that other processes need (and the idleprio process can't run
  367  * due to a CPU-bound normal process). Fix me! XXX
  368  */
  369 #if 0
  370                         if (RTP_PRIO_IS_REALTIME(rtp.type))
  371 #endif
  372                         if (rtp.type != RTP_PRIO_NORMAL) {
  373                                 error = EPERM;
  374                                 break;
  375                         }
  376                 }
  377                 mtx_lock_spin(&sched_lock);
  378                 error = rtp_to_pri(&rtp, FIRST_KSEGRP_IN_PROC(p));
  379                 mtx_unlock_spin(&sched_lock);
  380                 break;
  381         default:
  382                 error = EINVAL;
  383                 break;
  384         }
  385         PROC_UNLOCK(p);
  386         return (error);
  387 }
  388 
  389 int
  390 rtp_to_pri(struct rtprio *rtp, struct ksegrp *kg)
  391 {
  392 
  393         mtx_assert(&sched_lock, MA_OWNED);
  394         if (rtp->prio > RTP_PRIO_MAX)
  395                 return (EINVAL);
  396         switch (RTP_PRIO_BASE(rtp->type)) {
  397         case RTP_PRIO_REALTIME:
  398                 kg->kg_user_pri = PRI_MIN_REALTIME + rtp->prio;
  399                 break;
  400         case RTP_PRIO_NORMAL:
  401                 kg->kg_user_pri = PRI_MIN_TIMESHARE + rtp->prio;
  402                 break;
  403         case RTP_PRIO_IDLE:
  404                 kg->kg_user_pri = PRI_MIN_IDLE + rtp->prio;
  405                 break;
  406         default:
  407                 return (EINVAL);
  408         }
  409         sched_class(kg, rtp->type);
  410         if (curthread->td_ksegrp == kg) {
  411                 curthread->td_base_pri = kg->kg_user_pri;
  412                 sched_prio(curthread, kg->kg_user_pri); /* XXX dubious */
  413         }
  414         return (0);
  415 }
  416 
  417 void
  418 pri_to_rtp(struct ksegrp *kg, struct rtprio *rtp)
  419 {
  420 
  421         mtx_assert(&sched_lock, MA_OWNED);
  422         switch (PRI_BASE(kg->kg_pri_class)) {
  423         case PRI_REALTIME:
  424                 rtp->prio = kg->kg_user_pri - PRI_MIN_REALTIME;
  425                 break;
  426         case PRI_TIMESHARE:
  427                 rtp->prio = kg->kg_user_pri - PRI_MIN_TIMESHARE;
  428                 break;
  429         case PRI_IDLE:
  430                 rtp->prio = kg->kg_user_pri - PRI_MIN_IDLE;
  431                 break;
  432         default:
  433                 break;
  434         }
  435         rtp->type = kg->kg_pri_class;
  436 }
  437 
  438 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  439 #ifndef _SYS_SYSPROTO_H_
  440 struct osetrlimit_args {
  441         u_int   which;
  442         struct  orlimit *rlp;
  443 };
  444 #endif
  445 /*
  446  * MPSAFE
  447  */
  448 /* ARGSUSED */
  449 int
  450 osetrlimit(td, uap)
  451         struct thread *td;
  452         register struct osetrlimit_args *uap;
  453 {
  454         struct orlimit olim;
  455         struct rlimit lim;
  456         int error;
  457 
  458         if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
  459                 return (error);
  460         lim.rlim_cur = olim.rlim_cur;
  461         lim.rlim_max = olim.rlim_max;
  462         mtx_lock(&Giant);
  463         error = dosetrlimit(td, uap->which, &lim);
  464         mtx_unlock(&Giant);
  465         return (error);
  466 }
  467 
  468 #ifndef _SYS_SYSPROTO_H_
  469 struct ogetrlimit_args {
  470         u_int   which;
  471         struct  orlimit *rlp;
  472 };
  473 #endif
  474 /*
  475  * MPSAFE
  476  */
  477 /* ARGSUSED */
  478 int
  479 ogetrlimit(td, uap)
  480         struct thread *td;
  481         register struct ogetrlimit_args *uap;
  482 {
  483         struct proc *p = td->td_proc;
  484         struct orlimit olim;
  485         int error;
  486 
  487         if (uap->which >= RLIM_NLIMITS)
  488                 return (EINVAL);
  489         mtx_lock(&Giant);
  490         olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
  491         if (olim.rlim_cur == -1)
  492                 olim.rlim_cur = 0x7fffffff;
  493         olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
  494         if (olim.rlim_max == -1)
  495                 olim.rlim_max = 0x7fffffff;
  496         error = copyout(&olim, uap->rlp, sizeof(olim));
  497         mtx_unlock(&Giant);
  498         return (error);
  499 }
  500 #endif /* COMPAT_43 || COMPAT_SUNOS */
  501 
  502 #ifndef _SYS_SYSPROTO_H_
  503 struct __setrlimit_args {
  504         u_int   which;
  505         struct  rlimit *rlp;
  506 };
  507 #endif
  508 /*
  509  * MPSAFE
  510  */
  511 /* ARGSUSED */
  512 int
  513 setrlimit(td, uap)
  514         struct thread *td;
  515         register struct __setrlimit_args *uap;
  516 {
  517         struct rlimit alim;
  518         int error;
  519 
  520         if ((error = copyin(uap->rlp, &alim, sizeof (struct rlimit))))
  521                 return (error);
  522         mtx_lock(&Giant);
  523         error = dosetrlimit(td, uap->which, &alim);
  524         mtx_unlock(&Giant);
  525         return (error);
  526 }
  527 
  528 int
  529 dosetrlimit(td, which, limp)
  530         struct thread *td;
  531         u_int which;
  532         struct rlimit *limp;
  533 {
  534         struct proc *p = td->td_proc;
  535         register struct rlimit *alimp;
  536         int error;
  537 
  538         GIANT_REQUIRED;
  539 
  540         if (which >= RLIM_NLIMITS)
  541                 return (EINVAL);
  542         alimp = &p->p_rlimit[which];
  543 
  544         /*
  545          * Preserve historical bugs by treating negative limits as unsigned.
  546          */
  547         if (limp->rlim_cur < 0)
  548                 limp->rlim_cur = RLIM_INFINITY;
  549         if (limp->rlim_max < 0)
  550                 limp->rlim_max = RLIM_INFINITY;
  551 
  552         if (limp->rlim_cur > alimp->rlim_max ||
  553             limp->rlim_max > alimp->rlim_max)
  554                 if ((error = suser_cred(td->td_ucred, PRISON_ROOT)))
  555                         return (error);
  556         if (limp->rlim_cur > limp->rlim_max)
  557                 limp->rlim_cur = limp->rlim_max;
  558         if (p->p_limit->p_refcnt > 1) {
  559                 p->p_limit->p_refcnt--;
  560                 p->p_limit = limcopy(p->p_limit);
  561                 alimp = &p->p_rlimit[which];
  562         }
  563 
  564         switch (which) {
  565 
  566         case RLIMIT_CPU:
  567                 mtx_lock_spin(&sched_lock);
  568                 p->p_cpulimit = limp->rlim_cur;
  569                 mtx_unlock_spin(&sched_lock);
  570                 break;
  571         case RLIMIT_DATA:
  572                 if (limp->rlim_cur > maxdsiz)
  573                         limp->rlim_cur = maxdsiz;
  574                 if (limp->rlim_max > maxdsiz)
  575                         limp->rlim_max = maxdsiz;
  576                 break;
  577 
  578         case RLIMIT_STACK:
  579                 if (limp->rlim_cur > maxssiz)
  580                         limp->rlim_cur = maxssiz;
  581                 if (limp->rlim_max > maxssiz)
  582                         limp->rlim_max = maxssiz;
  583                 /*
  584                  * Stack is allocated to the max at exec time with only
  585                  * "rlim_cur" bytes accessible.  If stack limit is going
  586                  * up make more accessible, if going down make inaccessible.
  587                  */
  588                 if (limp->rlim_cur != alimp->rlim_cur) {
  589                         vm_offset_t addr;
  590                         vm_size_t size;
  591                         vm_prot_t prot;
  592 
  593                         if (limp->rlim_cur > alimp->rlim_cur) {
  594                                 prot = p->p_sysent->sv_stackprot;
  595                                 size = limp->rlim_cur - alimp->rlim_cur;
  596                                 addr = p->p_sysent->sv_usrstack -
  597                                     limp->rlim_cur;
  598                         } else {
  599                                 prot = VM_PROT_NONE;
  600                                 size = alimp->rlim_cur - limp->rlim_cur;
  601                                 addr = p->p_sysent->sv_usrstack -
  602                                     alimp->rlim_cur;
  603                         }
  604                         addr = trunc_page(addr);
  605                         size = round_page(size);
  606                         (void) vm_map_protect(&p->p_vmspace->vm_map,
  607                                               addr, addr+size, prot, FALSE);
  608                 }
  609                 break;
  610 
  611         case RLIMIT_NOFILE:
  612                 if (limp->rlim_cur > maxfilesperproc)
  613                         limp->rlim_cur = maxfilesperproc;
  614                 if (limp->rlim_max > maxfilesperproc)
  615                         limp->rlim_max = maxfilesperproc;
  616                 break;
  617 
  618         case RLIMIT_NPROC:
  619                 if (limp->rlim_cur > maxprocperuid)
  620                         limp->rlim_cur = maxprocperuid;
  621                 if (limp->rlim_max > maxprocperuid)
  622                         limp->rlim_max = maxprocperuid;
  623                 if (limp->rlim_cur < 1)
  624                         limp->rlim_cur = 1;
  625                 if (limp->rlim_max < 1)
  626                         limp->rlim_max = 1;
  627                 break;
  628         }
  629         *alimp = *limp;
  630         return (0);
  631 }
  632 
  633 #ifndef _SYS_SYSPROTO_H_
  634 struct __getrlimit_args {
  635         u_int   which;
  636         struct  rlimit *rlp;
  637 };
  638 #endif
  639 /*
  640  * MPSAFE
  641  */
  642 /* ARGSUSED */
  643 int
  644 getrlimit(td, uap)
  645         struct thread *td;
  646         register struct __getrlimit_args *uap;
  647 {
  648         int error;
  649         struct proc *p = td->td_proc;
  650 
  651         if (uap->which >= RLIM_NLIMITS)
  652                 return (EINVAL);
  653         mtx_lock(&Giant);
  654         error = copyout(&p->p_rlimit[uap->which], uap->rlp,
  655                     sizeof (struct rlimit));
  656         mtx_unlock(&Giant);
  657         return(error);
  658 }
  659 
  660 /*
  661  * Transform the running time and tick information in proc p into user,
  662  * system, and interrupt time usage.
  663  */
  664 void
  665 calcru(p, up, sp, ip)
  666         struct proc *p;
  667         struct timeval *up;
  668         struct timeval *sp;
  669         struct timeval *ip;
  670 {
  671         /* {user, system, interrupt, total} {ticks, usec}; previous tu: */
  672         u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
  673         struct timeval tv;
  674         struct bintime bt;
  675 
  676         mtx_assert(&sched_lock, MA_OWNED);
  677         /* XXX: why spl-protect ?  worst case is an off-by-one report */
  678 
  679         ut = p->p_uticks;
  680         st = p->p_sticks;
  681         it = p->p_iticks;
  682 
  683         tt = ut + st + it;
  684         if (tt == 0) {
  685                 st = 1;
  686                 tt = 1;
  687         }
  688                 
  689         if (curthread->td_proc == p) {
  690                 /*
  691                  * Adjust for the current time slice.  This is actually fairly
  692                  * important since the error here is on the order of a time
  693                  * quantum, which is much greater than the sampling error.
  694                  * XXXKSE use a different test due to threads on other 
  695                  * processors also being 'current'.
  696                  */
  697                                 
  698                 binuptime(&bt);
  699                 bintime_sub(&bt, PCPU_PTR(switchtime));
  700                 bintime_add(&bt, &p->p_runtime);
  701         } else {
  702                 bt = p->p_runtime;
  703         }
  704         bintime2timeval(&bt, &tv);
  705         tu = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
  706         ptu = p->p_uu + p->p_su + p->p_iu;
  707         if (tu < ptu || (int64_t)tu < 0) {
  708                 /* XXX no %qd in kernel.  Truncate. */
  709                 printf("calcru: negative time of %ld usec for pid %d (%s)\n",
  710                        (long)tu, p->p_pid, p->p_comm);
  711                 tu = ptu;
  712         }
  713 
  714         /* Subdivide tu. */
  715         uu = (tu * ut) / tt;
  716         su = (tu * st) / tt;
  717         iu = tu - uu - su;
  718                 
  719         /* Enforce monotonicity. */
  720         if (uu < p->p_uu || su < p->p_su || iu < p->p_iu) {
  721                 if (uu < p->p_uu)
  722                         uu = p->p_uu;
  723                 else if (uu + p->p_su + p->p_iu > tu)
  724                         uu = tu - p->p_su - p->p_iu;
  725                 if (st == 0)
  726                         su = p->p_su;
  727                 else {
  728                         su = ((tu - uu) * st) / (st + it);
  729                         if (su < p->p_su)
  730                                 su = p->p_su;
  731                         else if (uu + su + p->p_iu > tu)
  732                                 su = tu - uu - p->p_iu;
  733                 }
  734                 KASSERT(uu + su + p->p_iu <= tu,
  735                         ("calcru: monotonisation botch 1"));
  736                 iu = tu - uu - su;
  737                 KASSERT(iu >= p->p_iu,
  738                         ("calcru: monotonisation botch 2"));
  739         }
  740         p->p_uu = uu;
  741         p->p_su = su;
  742         p->p_iu = iu;
  743 
  744         up->tv_sec = uu / 1000000;
  745         up->tv_usec = uu % 1000000;
  746         sp->tv_sec = su / 1000000;
  747         sp->tv_usec = su % 1000000;
  748         if (ip != NULL) {
  749                 ip->tv_sec = iu / 1000000;
  750                 ip->tv_usec = iu % 1000000;
  751         }
  752 }
  753 
  754 #ifndef _SYS_SYSPROTO_H_
  755 struct getrusage_args {
  756         int     who;
  757         struct  rusage *rusage;
  758 };
  759 #endif
  760 /*
  761  * MPSAFE
  762  */
  763 /* ARGSUSED */
  764 int
  765 getrusage(td, uap)
  766         register struct thread *td;
  767         register struct getrusage_args *uap;
  768 {
  769         struct proc *p = td->td_proc;
  770         register struct rusage *rup;
  771         int error = 0;
  772 
  773         mtx_lock(&Giant);
  774 
  775         switch (uap->who) {
  776         case RUSAGE_SELF:
  777                 rup = &p->p_stats->p_ru;
  778                 mtx_lock_spin(&sched_lock);
  779                 calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
  780                 mtx_unlock_spin(&sched_lock);
  781                 break;
  782 
  783         case RUSAGE_CHILDREN:
  784                 rup = &p->p_stats->p_cru;
  785                 break;
  786 
  787         default:
  788                 rup = NULL;
  789                 error = EINVAL;
  790                 break;
  791         }
  792         mtx_unlock(&Giant);
  793         if (error == 0) {
  794                 /* XXX Unlocked access to p_stats->p_ru or p_cru. */
  795                 error = copyout(rup, uap->rusage, sizeof (struct rusage));
  796         }
  797         return(error);
  798 }
  799 
  800 void
  801 ruadd(ru, ru2)
  802         register struct rusage *ru, *ru2;
  803 {
  804         register long *ip, *ip2;
  805         register int i;
  806 
  807         timevaladd(&ru->ru_utime, &ru2->ru_utime);
  808         timevaladd(&ru->ru_stime, &ru2->ru_stime);
  809         if (ru->ru_maxrss < ru2->ru_maxrss)
  810                 ru->ru_maxrss = ru2->ru_maxrss;
  811         ip = &ru->ru_first; ip2 = &ru2->ru_first;
  812         for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
  813                 *ip++ += *ip2++;
  814 }
  815 
  816 /*
  817  * Make a copy of the plimit structure.
  818  * We share these structures copy-on-write after fork,
  819  * and copy when a limit is changed.
  820  */
  821 struct plimit *
  822 limcopy(lim)
  823         struct plimit *lim;
  824 {
  825         register struct plimit *copy;
  826 
  827         MALLOC(copy, struct plimit *, sizeof(struct plimit),
  828             M_SUBPROC, M_WAITOK);
  829         bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
  830         copy->p_refcnt = 1;
  831         return (copy);
  832 }
  833 
  834 /*
  835  * Find the uidinfo structure for a uid.  This structure is used to
  836  * track the total resource consumption (process count, socket buffer
  837  * size, etc.) for the uid and impose limits.
  838  */
  839 void
  840 uihashinit()
  841 {
  842 
  843         uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
  844         mtx_init(&uihashtbl_mtx, "uidinfo hash", NULL, MTX_DEF);
  845 }
  846 
  847 /*
  848  * lookup a uidinfo struct for the parameter uid.
  849  * uihashtbl_mtx must be locked.
  850  */
  851 static struct uidinfo *
  852 uilookup(uid)
  853         uid_t uid;
  854 {
  855         struct  uihashhead *uipp;
  856         struct  uidinfo *uip;
  857 
  858         mtx_assert(&uihashtbl_mtx, MA_OWNED);
  859         uipp = UIHASH(uid);
  860         LIST_FOREACH(uip, uipp, ui_hash)
  861                 if (uip->ui_uid == uid)
  862                         break;
  863 
  864         return (uip);
  865 }
  866 
  867 /*
  868  * Find or allocate a struct uidinfo for a particular uid.
  869  * Increase refcount on uidinfo struct returned.
  870  * uifree() should be called on a struct uidinfo when released.
  871  */
  872 struct uidinfo *
  873 uifind(uid)
  874         uid_t uid;
  875 {
  876         struct  uidinfo *uip;
  877 
  878         mtx_lock(&uihashtbl_mtx);
  879         uip = uilookup(uid);
  880         if (uip == NULL) {
  881                 struct  uidinfo *old_uip;
  882 
  883                 mtx_unlock(&uihashtbl_mtx);
  884                 uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
  885                 mtx_lock(&uihashtbl_mtx);
  886                 /*
  887                  * There's a chance someone created our uidinfo while we
  888                  * were in malloc and not holding the lock, so we have to
  889                  * make sure we don't insert a duplicate uidinfo
  890                  */
  891                 if ((old_uip = uilookup(uid)) != NULL) {
  892                         /* someone else beat us to it */
  893                         free(uip, M_UIDINFO);
  894                         uip = old_uip;
  895                 } else {
  896                         uip->ui_mtxp = mtx_pool_alloc(mtxpool_sleep);
  897                         uip->ui_uid = uid;
  898                         LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
  899                 }
  900         }
  901         uihold(uip);
  902         mtx_unlock(&uihashtbl_mtx);
  903         return (uip);
  904 }
  905 
  906 /*
  907  * Place another refcount on a uidinfo struct.
  908  */
  909 void
  910 uihold(uip)
  911         struct uidinfo *uip;
  912 {
  913 
  914         UIDINFO_LOCK(uip);
  915         uip->ui_ref++;
  916         UIDINFO_UNLOCK(uip);
  917 }
  918 
  919 /*-
  920  * Since uidinfo structs have a long lifetime, we use an
  921  * opportunistic refcounting scheme to avoid locking the lookup hash
  922  * for each release.
  923  *
  924  * If the refcount hits 0, we need to free the structure,
  925  * which means we need to lock the hash.
  926  * Optimal case:
  927  *   After locking the struct and lowering the refcount, if we find
  928  *   that we don't need to free, simply unlock and return.
  929  * Suboptimal case:
  930  *   If refcount lowering results in need to free, bump the count
  931  *   back up, loose the lock and aquire the locks in the proper
  932  *   order to try again.
  933  */
  934 void
  935 uifree(uip)
  936         struct uidinfo *uip;
  937 {
  938 
  939         /* Prepare for optimal case. */
  940         UIDINFO_LOCK(uip);
  941 
  942         if (--uip->ui_ref != 0) {
  943                 UIDINFO_UNLOCK(uip);
  944                 return;
  945         }
  946 
  947         /* Prepare for suboptimal case. */
  948         uip->ui_ref++;
  949         UIDINFO_UNLOCK(uip);
  950         mtx_lock(&uihashtbl_mtx);
  951         UIDINFO_LOCK(uip);
  952 
  953         /*
  954          * We must subtract one from the count again because we backed out
  955          * our initial subtraction before dropping the lock.
  956          * Since another thread may have added a reference after we dropped the
  957          * initial lock we have to test for zero again.
  958          */
  959         if (--uip->ui_ref == 0) {
  960                 LIST_REMOVE(uip, ui_hash);
  961                 mtx_unlock(&uihashtbl_mtx);
  962                 if (uip->ui_sbsize != 0)
  963                         /* XXX no %qd in kernel.  Truncate. */
  964                         printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
  965                             uip->ui_uid, (long)uip->ui_sbsize);
  966                 if (uip->ui_proccnt != 0)
  967                         printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
  968                             uip->ui_uid, uip->ui_proccnt);
  969                 UIDINFO_UNLOCK(uip);
  970                 FREE(uip, M_UIDINFO);
  971                 return;
  972         }
  973 
  974         mtx_unlock(&uihashtbl_mtx);
  975         UIDINFO_UNLOCK(uip);
  976 }
  977 
  978 /*
  979  * Change the count associated with number of processes
  980  * a given user is using.  When 'max' is 0, don't enforce a limit
  981  */
  982 int
  983 chgproccnt(uip, diff, max)
  984         struct  uidinfo *uip;
  985         int     diff;
  986         int     max;
  987 {
  988 
  989         UIDINFO_LOCK(uip);
  990         /* don't allow them to exceed max, but allow subtraction */
  991         if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
  992                 UIDINFO_UNLOCK(uip);
  993                 return (0);
  994         }
  995         uip->ui_proccnt += diff;
  996         if (uip->ui_proccnt < 0)
  997                 printf("negative proccnt for uid = %d\n", uip->ui_uid);
  998         UIDINFO_UNLOCK(uip);
  999         return (1);
 1000 }
 1001 
 1002 /*
 1003  * Change the total socket buffer size a user has used.
 1004  */
 1005 int
 1006 chgsbsize(uip, hiwat, to, max)
 1007         struct  uidinfo *uip;
 1008         u_int  *hiwat;
 1009         u_int   to;
 1010         rlim_t  max;
 1011 {
 1012         rlim_t new;
 1013         int s;
 1014 
 1015         s = splnet();
 1016         UIDINFO_LOCK(uip);
 1017         new = uip->ui_sbsize + to - *hiwat;
 1018         /* don't allow them to exceed max, but allow subtraction */
 1019         if (to > *hiwat && new > max) {
 1020                 splx(s);
 1021                 UIDINFO_UNLOCK(uip);
 1022                 return (0);
 1023         }
 1024         uip->ui_sbsize = new;
 1025         *hiwat = to;
 1026         if (uip->ui_sbsize < 0)
 1027                 printf("negative sbsize for uid = %d\n", uip->ui_uid);
 1028         splx(s);
 1029         UIDINFO_UNLOCK(uip);
 1030         return (1);
 1031 }

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