sysv_sem.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*      $NetBSD: sysv_sem.c,v 1.98 2019/08/07 00:38:02 pgoyette Exp $   */
    2 
    3 /*-
    4  * Copyright (c) 1999, 2007 The NetBSD Foundation, Inc.
    5  * All rights reserved.
    6  *
    7  * This code is derived from software contributed to The NetBSD Foundation
    8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
    9  * NASA Ames Research Center, and by Andrew Doran.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   30  * POSSIBILITY OF SUCH DAMAGE.
   31  */
   32 
   33 /*
   34  * Implementation of SVID semaphores
   35  *
   36  * Author: Daniel Boulet
   37  *
   38  * This software is provided ``AS IS'' without any warranties of any kind.
   39  */
   40 
   41 #include <sys/cdefs.h>
   42 __KERNEL_RCSID(0, "$NetBSD: sysv_sem.c,v 1.98 2019/08/07 00:38:02 pgoyette Exp $");
   43 
   44 #ifdef _KERNEL_OPT
   45 #include "opt_sysv.h"
   46 #endif
   47 
   48 #include <sys/param.h>
   49 #include <sys/kernel.h>
   50 #include <sys/sem.h>
   51 #include <sys/sysctl.h>
   52 #include <sys/kmem.h>
   53 #include <sys/mount.h>          /* XXX for <sys/syscallargs.h> */
   54 #include <sys/syscallargs.h>
   55 #include <sys/kauth.h>
   56 #include <sys/once.h>
   57 
   58 /* 
   59  * Memory areas:
   60  *  1st: Pool of semaphore identifiers
   61  *  2nd: Semaphores
   62  *  3rd: Conditional variables
   63  *  4th: Undo structures
   64  */
   65 struct semid_ds *       sema                    __read_mostly;
   66 static struct __sem *   sem                     __read_mostly;
   67 static kcondvar_t *     semcv                   __read_mostly;
   68 static int *            semu                    __read_mostly;
   69 
   70 static kmutex_t         semlock                 __cacheline_aligned;
   71 static bool             sem_realloc_state       __read_mostly;
   72 static kcondvar_t       sem_realloc_cv;
   73 
   74 /*
   75  * List of active undo structures, total number of semaphores,
   76  * and total number of semop waiters.
   77  */
   78 static struct sem_undo *semu_list               __read_mostly;
   79 static u_int            semtot                  __cacheline_aligned;
   80 static u_int            sem_waiters             __cacheline_aligned;
   81 
   82 /* Macro to find a particular sem_undo vector */
   83 #define SEMU(s, ix)     ((struct sem_undo *)(((long)s) + ix * seminfo.semusz))
   84 
   85 #ifdef SEM_DEBUG
   86 #define SEM_PRINTF(a) printf a
   87 #else
   88 #define SEM_PRINTF(a)
   89 #endif
   90 
   91 void *hook;     /* cookie from exithook_establish() */
   92 
   93 extern int kern_has_sysvsem;
   94 
   95 SYSCTL_SETUP_PROTO(sysctl_ipc_sem_setup);
   96 
   97 struct sem_undo *semu_alloc(struct proc *);
   98 int semundo_adjust(struct proc *, struct sem_undo **, int, int, int);
   99 void semundo_clear(int, int);
  100 
  101 static ONCE_DECL(exithook_control);
  102 static int seminit_exithook(void);
  103 
  104 int
  105 seminit(void)
  106 {
  107         int i, sz;
  108         vaddr_t v;
  109 
  110         mutex_init(&semlock, MUTEX_DEFAULT, IPL_NONE);
  111         cv_init(&sem_realloc_cv, "semrealc");
  112         sem_realloc_state = false;
  113         semtot = 0;
  114         sem_waiters = 0;
  115 
  116         /* Allocate the wired memory for our structures */
  117         sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) +
  118             ALIGN(seminfo.semmns * sizeof(struct __sem)) +
  119             ALIGN(seminfo.semmni * sizeof(kcondvar_t)) +
  120             ALIGN(seminfo.semmnu * seminfo.semusz);
  121         sz = round_page(sz);
  122         v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO);
  123         if (v == 0) {
  124                 printf("sysv_sem: cannot allocate memory");
  125                 return ENOMEM;
  126         }
  127         sema = (void *)v;
  128         sem = (void *)((uintptr_t)sema +
  129             ALIGN(seminfo.semmni * sizeof(struct semid_ds)));
  130         semcv = (void *)((uintptr_t)sem +
  131             ALIGN(seminfo.semmns * sizeof(struct __sem)));
  132         semu = (void *)((uintptr_t)semcv +
  133             ALIGN(seminfo.semmni * sizeof(kcondvar_t)));
  134 
  135         for (i = 0; i < seminfo.semmni; i++) {
  136                 sema[i]._sem_base = 0;
  137                 sema[i].sem_perm.mode = 0;
  138                 cv_init(&semcv[i], "semwait");
  139         }
  140         for (i = 0; i < seminfo.semmnu; i++) {
  141                 struct sem_undo *suptr = SEMU(semu, i);
  142                 suptr->un_proc = NULL;
  143         }
  144         semu_list = NULL;
  145 
  146         kern_has_sysvsem = 1;
  147 
  148         return 0;
  149 }
  150 
  151 static int
  152 seminit_exithook(void)
  153 {
  154 
  155         hook = exithook_establish(semexit, NULL);
  156         return 0;
  157 }
  158 
  159 int
  160 semfini(void)
  161 {
  162         int i, sz;
  163         vaddr_t v = (vaddr_t)sema;
  164 
  165         /* Don't allow module unload if we're busy */
  166         mutex_enter(&semlock);
  167         if (semtot) {
  168                 mutex_exit(&semlock);
  169                 return 1;
  170         }
  171 
  172         /* Remove the exit hook */
  173         if (hook)
  174                 exithook_disestablish(hook);
  175 
  176         /* Destroy all our condvars */
  177         for (i = 0; i < seminfo.semmni; i++) {
  178                 cv_destroy(&semcv[i]);
  179         }
  180 
  181         /* Free the wired memory that we allocated */
  182         sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) +
  183             ALIGN(seminfo.semmns * sizeof(struct __sem)) +
  184             ALIGN(seminfo.semmni * sizeof(kcondvar_t)) +
  185             ALIGN(seminfo.semmnu * seminfo.semusz);
  186         sz = round_page(sz);
  187         uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED);
  188 
  189         /* Destroy the last cv and mutex */
  190         cv_destroy(&sem_realloc_cv);
  191         mutex_exit(&semlock);
  192         mutex_destroy(&semlock);
  193 
  194         kern_has_sysvsem = 0;
  195 
  196         return 0;
  197 }
  198 
  199 static int
  200 semrealloc(int newsemmni, int newsemmns, int newsemmnu)
  201 {
  202         struct semid_ds *new_sema, *old_sema;
  203         struct __sem *new_sem;
  204         struct sem_undo *new_semu_list, *suptr, *nsuptr;
  205         int *new_semu;
  206         kcondvar_t *new_semcv;
  207         vaddr_t v;
  208         int i, j, lsemid, nmnus, sz;
  209 
  210         if (newsemmni < 1 || newsemmns < 1 || newsemmnu < 1)
  211                 return EINVAL;
  212 
  213         /* Allocate the wired memory for our structures */
  214         sz = ALIGN(newsemmni * sizeof(struct semid_ds)) +
  215             ALIGN(newsemmns * sizeof(struct __sem)) +
  216             ALIGN(newsemmni * sizeof(kcondvar_t)) +
  217             ALIGN(newsemmnu * seminfo.semusz);
  218         sz = round_page(sz);
  219         v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO);
  220         if (v == 0)
  221                 return ENOMEM;
  222 
  223         mutex_enter(&semlock);
  224         if (sem_realloc_state) {
  225                 mutex_exit(&semlock);
  226                 uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED);
  227                 return EBUSY;
  228         }
  229         sem_realloc_state = true;
  230         if (sem_waiters) {
  231                 /*
  232                  * Mark reallocation state, wake-up all waiters,
  233                  * and wait while they will all exit.
  234                  */
  235                 for (i = 0; i < seminfo.semmni; i++)
  236                         cv_broadcast(&semcv[i]);
  237                 while (sem_waiters)
  238                         cv_wait(&sem_realloc_cv, &semlock);
  239         }
  240         old_sema = sema;
  241 
  242         /* Get the number of last slot */
  243         lsemid = 0;
  244         for (i = 0; i < seminfo.semmni; i++)
  245                 if (sema[i].sem_perm.mode & SEM_ALLOC)
  246                         lsemid = i;
  247 
  248         /* Get the number of currently used undo structures */
  249         nmnus = 0;
  250         for (i = 0; i < seminfo.semmnu; i++) {
  251                 suptr = SEMU(semu, i);
  252                 if (suptr->un_proc == NULL)
  253                         continue;
  254                 nmnus++;
  255         }
  256 
  257         /* We cannot reallocate less memory than we use */
  258         if (lsemid >= newsemmni || semtot > newsemmns || nmnus > newsemmnu) {
  259                 mutex_exit(&semlock);
  260                 uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED);
  261                 return EBUSY;
  262         }
  263 
  264         new_sema = (void *)v;
  265         new_sem = (void *)((uintptr_t)new_sema +
  266             ALIGN(newsemmni * sizeof(struct semid_ds)));
  267         new_semcv = (void *)((uintptr_t)new_sem +
  268             ALIGN(newsemmns * sizeof(struct __sem)));
  269         new_semu = (void *)((uintptr_t)new_semcv +
  270             ALIGN(newsemmni * sizeof(kcondvar_t)));
  271 
  272         /* Initialize all semaphore identifiers and condvars */
  273         for (i = 0; i < newsemmni; i++) {
  274                 new_sema[i]._sem_base = 0;
  275                 new_sema[i].sem_perm.mode = 0;
  276                 cv_init(&new_semcv[i], "semwait");
  277         }
  278         for (i = 0; i < newsemmnu; i++) {
  279                 nsuptr = SEMU(new_semu, i);
  280                 nsuptr->un_proc = NULL;
  281         }
  282 
  283         /*
  284          * Copy all identifiers, semaphores and list of the
  285          * undo structures to the new memory allocation.
  286          */
  287         j = 0;
  288         for (i = 0; i <= lsemid; i++) {
  289                 if ((sema[i].sem_perm.mode & SEM_ALLOC) == 0)
  290                         continue;
  291                 memcpy(&new_sema[i], &sema[i], sizeof(struct semid_ds));
  292                 new_sema[i]._sem_base = &new_sem[j];
  293                 memcpy(new_sema[i]._sem_base, sema[i]._sem_base,
  294                     (sizeof(struct __sem) * sema[i].sem_nsems));
  295                 j += sema[i].sem_nsems;
  296         }
  297         KASSERT(j == semtot);
  298 
  299         j = 0;
  300         new_semu_list = NULL;
  301         for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next) {
  302                 KASSERT(j < newsemmnu);
  303                 nsuptr = SEMU(new_semu, j);
  304                 memcpy(nsuptr, suptr, SEMUSZ);
  305                 nsuptr->un_next = new_semu_list;
  306                 new_semu_list = nsuptr;
  307                 j++;
  308         }
  309 
  310         for (i = 0; i < seminfo.semmni; i++) {
  311                 KASSERT(cv_has_waiters(&semcv[i]) == false);
  312                 cv_destroy(&semcv[i]);
  313         }
  314 
  315         sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) +
  316             ALIGN(seminfo.semmns * sizeof(struct __sem)) +
  317             ALIGN(seminfo.semmni * sizeof(kcondvar_t)) +
  318             ALIGN(seminfo.semmnu * seminfo.semusz);
  319         sz = round_page(sz);
  320 
  321         /* Set the pointers and update the new values */
  322         sema = new_sema;
  323         sem = new_sem;
  324         semcv = new_semcv;
  325         semu = new_semu;
  326         semu_list = new_semu_list;
  327 
  328         seminfo.semmni = newsemmni;
  329         seminfo.semmns = newsemmns;
  330         seminfo.semmnu = newsemmnu;
  331 
  332         /* Reallocation completed - notify all waiters, if any */
  333         sem_realloc_state = false;
  334         cv_broadcast(&sem_realloc_cv);
  335         mutex_exit(&semlock);
  336 
  337         uvm_km_free(kernel_map, (vaddr_t)old_sema, sz, UVM_KMF_WIRED);
  338         return 0;
  339 }
  340 
  341 /*
  342  * Placebo.
  343  */
  344 
  345 int
  346 sys_semconfig(struct lwp *l, const struct sys_semconfig_args *uap, register_t *retval)
  347 {
  348 
  349         RUN_ONCE(&exithook_control, seminit_exithook);
  350 
  351         *retval = 0;
  352         return 0;
  353 }
  354 
  355 /*
  356  * Allocate a new sem_undo structure for a process.
  357  * => Returns NULL on failure.
  358  */
  359 struct sem_undo *
  360 semu_alloc(struct proc *p)
  361 {
  362         struct sem_undo *suptr, **supptr;
  363         bool attempted = false;
  364         int i;
  365 
  366         KASSERT(mutex_owned(&semlock));
  367 again:
  368         /* Look for a free structure. */
  369         for (i = 0; i < seminfo.semmnu; i++) {
  370                 suptr = SEMU(semu, i);
  371                 if (suptr->un_proc == NULL) {
  372                         /* Found.  Fill it in and return. */
  373                         suptr->un_next = semu_list;
  374                         semu_list = suptr;
  375                         suptr->un_cnt = 0;
  376                         suptr->un_proc = p;
  377                         return suptr;
  378                 }
  379         }
  380 
  381         /* Not found.  Attempt to free some structures. */
  382         if (!attempted) {
  383                 bool freed = false;
  384 
  385                 attempted = true;
  386                 supptr = &semu_list;
  387                 while ((suptr = *supptr) != NULL) {
  388                         if (suptr->un_cnt == 0)  {
  389                                 suptr->un_proc = NULL;
  390                                 *supptr = suptr->un_next;
  391                                 freed = true;
  392                         } else {
  393                                 supptr = &suptr->un_next;
  394                         }
  395                 }
  396                 if (freed) {
  397                         goto again;
  398                 }
  399         }
  400         return NULL;
  401 }
  402 
  403 /*
  404  * Adjust a particular entry for a particular proc
  405  */
  406 
  407 int
  408 semundo_adjust(struct proc *p, struct sem_undo **supptr, int semid, int semnum,
  409     int adjval)
  410 {
  411         struct sem_undo *suptr;
  412         struct sem_undo_entry *sunptr;
  413         int i;
  414 
  415         KASSERT(mutex_owned(&semlock));
  416 
  417         /*
  418          * Look for and remember the sem_undo if the caller doesn't
  419          * provide it
  420          */
  421 
  422         suptr = *supptr;
  423         if (suptr == NULL) {
  424                 for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next)
  425                         if (suptr->un_proc == p)
  426                                 break;
  427 
  428                 if (suptr == NULL) {
  429                         suptr = semu_alloc(p);
  430                         if (suptr == NULL)
  431                                 return (ENOSPC);
  432                 }
  433                 *supptr = suptr;
  434         }
  435 
  436         /*
  437          * Look for the requested entry and adjust it (delete if
  438          * adjval becomes 0).
  439          */
  440         sunptr = &suptr->un_ent[0];
  441         for (i = 0; i < suptr->un_cnt; i++, sunptr++) {
  442                 if (sunptr->un_id != semid || sunptr->un_num != semnum)
  443                         continue;
  444                 sunptr->un_adjval += adjval;
  445                 if (sunptr->un_adjval == 0) {
  446                         suptr->un_cnt--;
  447                         if (i < suptr->un_cnt)
  448                                 suptr->un_ent[i] =
  449                                     suptr->un_ent[suptr->un_cnt];
  450                 }
  451                 return (0);
  452         }
  453 
  454         /* Didn't find the right entry - create it */
  455         if (suptr->un_cnt == SEMUME)
  456                 return (EINVAL);
  457 
  458         sunptr = &suptr->un_ent[suptr->un_cnt];
  459         suptr->un_cnt++;
  460         sunptr->un_adjval = adjval;
  461         sunptr->un_id = semid;
  462         sunptr->un_num = semnum;
  463         return (0);
  464 }
  465 
  466 void
  467 semundo_clear(int semid, int semnum)
  468 {
  469         struct sem_undo *suptr;
  470         struct sem_undo_entry *sunptr, *sunend;
  471 
  472         KASSERT(mutex_owned(&semlock));
  473 
  474         for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next)
  475                 for (sunptr = &suptr->un_ent[0],
  476                     sunend = sunptr + suptr->un_cnt; sunptr < sunend;) {
  477                         if (sunptr->un_id == semid) {
  478                                 if (semnum == -1 || sunptr->un_num == semnum) {
  479                                         suptr->un_cnt--;
  480                                         sunend--;
  481                                         if (sunptr != sunend)
  482                                                 *sunptr = *sunend;
  483                                         if (semnum != -1)
  484                                                 break;
  485                                         else
  486                                                 continue;
  487                                 }
  488                         }
  489                         sunptr++;
  490                 }
  491 }
  492 
  493 int
  494 sys_____semctl50(struct lwp *l, const struct sys_____semctl50_args *uap,
  495     register_t *retval)
  496 {
  497         /* {
  498                 syscallarg(int) semid;
  499                 syscallarg(int) semnum;
  500                 syscallarg(int) cmd;
  501                 syscallarg(union __semun *) arg;
  502         } */
  503         struct semid_ds sembuf;
  504         int cmd, error;
  505         void *pass_arg;
  506         union __semun karg;
  507 
  508         RUN_ONCE(&exithook_control, seminit_exithook);
  509 
  510         cmd = SCARG(uap, cmd);
  511 
  512         pass_arg = get_semctl_arg(cmd, &sembuf, &karg);
  513 
  514         if (pass_arg) {
  515                 error = copyin(SCARG(uap, arg), &karg, sizeof(karg));
  516                 if (error)
  517                         return error;
  518                 if (cmd == IPC_SET) {
  519                         error = copyin(karg.buf, &sembuf, sizeof(sembuf));
  520                         if (error)
  521                                 return (error);
  522                 }
  523         }
  524 
  525         error = semctl1(l, SCARG(uap, semid), SCARG(uap, semnum), cmd,
  526             pass_arg, retval);
  527 
  528         if (error == 0 && cmd == IPC_STAT)
  529                 error = copyout(&sembuf, karg.buf, sizeof(sembuf));
  530 
  531         return (error);
  532 }
  533 
  534 int
  535 semctl1(struct lwp *l, int semid, int semnum, int cmd, void *v,
  536     register_t *retval)
  537 {
  538         kauth_cred_t cred = l->l_cred;
  539         union __semun *arg = v;
  540         struct semid_ds *sembuf = v, *semaptr;
  541         int i, error, ix;
  542 
  543         SEM_PRINTF(("call to semctl(%d, %d, %d, %p)\n",
  544             semid, semnum, cmd, v));
  545 
  546         mutex_enter(&semlock);
  547 
  548         ix = IPCID_TO_IX(semid);
  549         if (ix < 0 || ix >= seminfo.semmni) {
  550                 mutex_exit(&semlock);
  551                 return (EINVAL);
  552         }
  553 
  554         semaptr = &sema[ix];
  555         if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 ||
  556             semaptr->sem_perm._seq != IPCID_TO_SEQ(semid)) {
  557                 mutex_exit(&semlock);
  558                 return (EINVAL);
  559         }
  560 
  561         switch (cmd) {
  562         case IPC_RMID:
  563                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M)) != 0)
  564                         break;
  565                 semaptr->sem_perm.cuid = kauth_cred_geteuid(cred);
  566                 semaptr->sem_perm.uid = kauth_cred_geteuid(cred);
  567                 semtot -= semaptr->sem_nsems;
  568                 for (i = semaptr->_sem_base - sem; i < semtot; i++)
  569                         sem[i] = sem[i + semaptr->sem_nsems];
  570                 for (i = 0; i < seminfo.semmni; i++) {
  571                         if ((sema[i].sem_perm.mode & SEM_ALLOC) &&
  572                             sema[i]._sem_base > semaptr->_sem_base)
  573                                 sema[i]._sem_base -= semaptr->sem_nsems;
  574                 }
  575                 semaptr->sem_perm.mode = 0;
  576                 semundo_clear(ix, -1);
  577                 cv_broadcast(&semcv[ix]);
  578                 break;
  579 
  580         case IPC_SET:
  581                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M)))
  582                         break;
  583                 KASSERT(sembuf != NULL);
  584                 semaptr->sem_perm.uid = sembuf->sem_perm.uid;
  585                 semaptr->sem_perm.gid = sembuf->sem_perm.gid;
  586                 semaptr->sem_perm.mode = (semaptr->sem_perm.mode & ~0777) |
  587                     (sembuf->sem_perm.mode & 0777);
  588                 semaptr->sem_ctime = time_second;
  589                 break;
  590 
  591         case IPC_STAT:
  592                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  593                         break;
  594                 KASSERT(sembuf != NULL);
  595                 memset(sembuf, 0, sizeof *sembuf);
  596                 sembuf->sem_perm = semaptr->sem_perm;
  597                 sembuf->sem_perm.mode &= 0777;
  598                 sembuf->sem_nsems = semaptr->sem_nsems;
  599                 sembuf->sem_otime = semaptr->sem_otime;
  600                 sembuf->sem_ctime = semaptr->sem_ctime;
  601                 break;
  602 
  603         case GETNCNT:
  604                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  605                         break;
  606                 if (semnum < 0 || semnum >= semaptr->sem_nsems) {
  607                         error = EINVAL;
  608                         break;
  609                 }
  610                 *retval = semaptr->_sem_base[semnum].semncnt;
  611                 break;
  612 
  613         case GETPID:
  614                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  615                         break;
  616                 if (semnum < 0 || semnum >= semaptr->sem_nsems) {
  617                         error = EINVAL;
  618                         break;
  619                 }
  620                 *retval = semaptr->_sem_base[semnum].sempid;
  621                 break;
  622 
  623         case GETVAL:
  624                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  625                         break;
  626                 if (semnum < 0 || semnum >= semaptr->sem_nsems) {
  627                         error = EINVAL;
  628                         break;
  629                 }
  630                 *retval = semaptr->_sem_base[semnum].semval;
  631                 break;
  632 
  633         case GETALL:
  634                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  635                         break;
  636                 KASSERT(arg != NULL);
  637                 for (i = 0; i < semaptr->sem_nsems; i++) {
  638                         error = copyout(&semaptr->_sem_base[i].semval,
  639                             &arg->array[i], sizeof(arg->array[i]));
  640                         if (error != 0)
  641                                 break;
  642                 }
  643                 break;
  644 
  645         case GETZCNT:
  646                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R)))
  647                         break;
  648                 if (semnum < 0 || semnum >= semaptr->sem_nsems) {
  649                         error = EINVAL;
  650                         break;
  651                 }
  652                 *retval = semaptr->_sem_base[semnum].semzcnt;
  653                 break;
  654 
  655         case SETVAL:
  656                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W)))
  657                         break;
  658                 if (semnum < 0 || semnum >= semaptr->sem_nsems) {
  659                         error = EINVAL;
  660                         break;
  661                 }
  662                 KASSERT(arg != NULL);
  663                 if ((unsigned int)arg->val > seminfo.semvmx) {
  664                         error = ERANGE;
  665                         break;
  666                 }
  667                 semaptr->_sem_base[semnum].semval = arg->val;
  668                 semundo_clear(ix, semnum);
  669                 cv_broadcast(&semcv[ix]);
  670                 break;
  671 
  672         case SETALL:
  673                 if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W)))
  674                         break;
  675                 KASSERT(arg != NULL);
  676                 for (i = 0; i < semaptr->sem_nsems; i++) {
  677                         unsigned short semval;
  678                         error = copyin(&arg->array[i], &semval,
  679                             sizeof(arg->array[i]));
  680                         if (error != 0)
  681                                 break;
  682                         if ((unsigned int)semval > seminfo.semvmx) {
  683                                 error = ERANGE;
  684                                 break;
  685                         }
  686                         semaptr->_sem_base[i].semval = semval;
  687                 }
  688                 semundo_clear(ix, -1);
  689                 cv_broadcast(&semcv[ix]);
  690                 break;
  691 
  692         default:
  693                 error = EINVAL;
  694                 break;
  695         }
  696 
  697         mutex_exit(&semlock);
  698         return (error);
  699 }
  700 
  701 int
  702 sys_semget(struct lwp *l, const struct sys_semget_args *uap, register_t *retval)
  703 {
  704         /* {
  705                 syscallarg(key_t) key;
  706                 syscallarg(int) nsems;
  707                 syscallarg(int) semflg;
  708         } */
  709         int semid, error = 0;
  710         int key = SCARG(uap, key);
  711         int nsems = SCARG(uap, nsems);
  712         int semflg = SCARG(uap, semflg);
  713         kauth_cred_t cred = l->l_cred;
  714 
  715         RUN_ONCE(&exithook_control, seminit_exithook);
  716 
  717         SEM_PRINTF(("semget(0x%x, %d, 0%o)\n", key, nsems, semflg));
  718 
  719         mutex_enter(&semlock);
  720 
  721         if (key != IPC_PRIVATE) {
  722                 for (semid = 0; semid < seminfo.semmni; semid++) {
  723                         if ((sema[semid].sem_perm.mode & SEM_ALLOC) &&
  724                             sema[semid].sem_perm._key == key)
  725                                 break;
  726                 }
  727                 if (semid < seminfo.semmni) {
  728                         SEM_PRINTF(("found public key\n"));
  729                         if ((error = ipcperm(cred, &sema[semid].sem_perm,
  730                             semflg & 0700)))
  731                                 goto out;
  732                         if (nsems > 0 && sema[semid].sem_nsems < nsems) {
  733                                 SEM_PRINTF(("too small\n"));
  734                                 error = EINVAL;
  735                                 goto out;
  736                         }
  737                         if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) {
  738                                 SEM_PRINTF(("not exclusive\n"));
  739                                 error = EEXIST;
  740                                 goto out;
  741                         }
  742                         goto found;
  743                 }
  744         }
  745 
  746         SEM_PRINTF(("need to allocate the semid_ds\n"));
  747         if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) {
  748                 if (nsems <= 0 || nsems > seminfo.semmsl) {
  749                         SEM_PRINTF(("nsems out of range (0<%d<=%d)\n", nsems,
  750                             seminfo.semmsl));
  751                         error = EINVAL;
  752                         goto out;
  753                 }
  754                 if (nsems > seminfo.semmns - semtot) {
  755                         SEM_PRINTF(("not enough semaphores left "
  756                             "(need %d, got %d)\n",
  757                             nsems, seminfo.semmns - semtot));
  758                         error = ENOSPC;
  759                         goto out;
  760                 }
  761                 for (semid = 0; semid < seminfo.semmni; semid++) {
  762                         if ((sema[semid].sem_perm.mode & SEM_ALLOC) == 0)
  763                                 break;
  764                 }
  765                 if (semid == seminfo.semmni) {
  766                         SEM_PRINTF(("no more semid_ds's available\n"));
  767                         error = ENOSPC;
  768                         goto out;
  769                 }
  770                 SEM_PRINTF(("semid %d is available\n", semid));
  771                 sema[semid].sem_perm._key = key;
  772                 sema[semid].sem_perm.cuid = kauth_cred_geteuid(cred);
  773                 sema[semid].sem_perm.uid = kauth_cred_geteuid(cred);
  774                 sema[semid].sem_perm.cgid = kauth_cred_getegid(cred);
  775                 sema[semid].sem_perm.gid = kauth_cred_getegid(cred);
  776                 sema[semid].sem_perm.mode = (semflg & 0777) | SEM_ALLOC;
  777                 sema[semid].sem_perm._seq =
  778                     (sema[semid].sem_perm._seq + 1) & 0x7fff;
  779                 sema[semid].sem_nsems = nsems;
  780                 sema[semid].sem_otime = 0;
  781                 sema[semid].sem_ctime = time_second;
  782                 sema[semid]._sem_base = &sem[semtot];
  783                 semtot += nsems;
  784                 memset(sema[semid]._sem_base, 0,
  785                     sizeof(sema[semid]._sem_base[0]) * nsems);
  786                 SEM_PRINTF(("sembase = %p, next = %p\n", sema[semid]._sem_base,
  787                     &sem[semtot]));
  788         } else {
  789                 SEM_PRINTF(("didn't find it and wasn't asked to create it\n"));
  790                 error = ENOENT;
  791                 goto out;
  792         }
  793 
  794  found:
  795         *retval = IXSEQ_TO_IPCID(semid, sema[semid].sem_perm);
  796  out:
  797         mutex_exit(&semlock);
  798         return (error);
  799 }
  800 
  801 #define SMALL_SOPS 8
  802 
  803 int
  804 sys_semop(struct lwp *l, const struct sys_semop_args *uap, register_t *retval)
  805 {
  806         /* {
  807                 syscallarg(int) semid;
  808                 syscallarg(struct sembuf *) sops;
  809                 syscallarg(size_t) nsops;
  810         } */
  811         struct proc *p = l->l_proc;
  812         int semid = SCARG(uap, semid), seq;
  813         size_t nsops = SCARG(uap, nsops);
  814         struct sembuf small_sops[SMALL_SOPS];
  815         struct sembuf *sops;
  816         struct semid_ds *semaptr;
  817         struct sembuf *sopptr = NULL;
  818         struct __sem *semptr = NULL;
  819         struct sem_undo *suptr = NULL;
  820         kauth_cred_t cred = l->l_cred;
  821         int i, error;
  822         int do_wakeup, do_undos;
  823 
  824         RUN_ONCE(&exithook_control, seminit_exithook);
  825 
  826         SEM_PRINTF(("call to semop(%d, %p, %zd)\n", semid, SCARG(uap,sops), nsops));
  827 
  828         if (__predict_false((p->p_flag & PK_SYSVSEM) == 0)) {
  829                 mutex_enter(p->p_lock);
  830                 p->p_flag |= PK_SYSVSEM;
  831                 mutex_exit(p->p_lock);
  832         }
  833 
  834 restart:
  835         if (nsops <= SMALL_SOPS) {
  836                 sops = small_sops;
  837         } else if (nsops <= seminfo.semopm) {
  838                 sops = kmem_alloc(nsops * sizeof(*sops), KM_SLEEP);
  839         } else {
  840                 SEM_PRINTF(("too many sops (max=%d, nsops=%zd)\n",
  841                     seminfo.semopm, nsops));
  842                 return (E2BIG);
  843         }
  844 
  845         error = copyin(SCARG(uap, sops), sops, nsops * sizeof(sops[0]));
  846         if (error) {
  847                 SEM_PRINTF(("error = %d from copyin(%p, %p, %zd)\n", error,
  848                     SCARG(uap, sops), &sops, nsops * sizeof(sops[0])));
  849                 if (sops != small_sops)
  850                         kmem_free(sops, nsops * sizeof(*sops));
  851                 return error;
  852         }
  853 
  854         mutex_enter(&semlock);
  855         /* In case of reallocation, we will wait for completion */
  856         while (__predict_false(sem_realloc_state))
  857                 cv_wait(&sem_realloc_cv, &semlock);
  858 
  859         semid = IPCID_TO_IX(semid);     /* Convert back to zero origin */
  860         if (semid < 0 || semid >= seminfo.semmni) {
  861                 error = EINVAL;
  862                 goto out;
  863         }
  864 
  865         semaptr = &sema[semid];
  866         seq = IPCID_TO_SEQ(SCARG(uap, semid));
  867         if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 ||
  868             semaptr->sem_perm._seq != seq) {
  869                 error = EINVAL;
  870                 goto out;
  871         }
  872 
  873         if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) {
  874                 SEM_PRINTF(("error = %d from ipaccess\n", error));
  875                 goto out;
  876         }
  877 
  878         for (i = 0; i < nsops; i++)
  879                 if (sops[i].sem_num >= semaptr->sem_nsems) {
  880                         error = EFBIG;
  881                         goto out;
  882                 }
  883 
  884         /*
  885          * Loop trying to satisfy the vector of requests.
  886          * If we reach a point where we must wait, any requests already
  887          * performed are rolled back and we go to sleep until some other
  888          * process wakes us up.  At this point, we start all over again.
  889          *
  890          * This ensures that from the perspective of other tasks, a set
  891          * of requests is atomic (never partially satisfied).
  892          */
  893         do_undos = 0;
  894 
  895         for (;;) {
  896                 do_wakeup = 0;
  897 
  898                 for (i = 0; i < nsops; i++) {
  899                         sopptr = &sops[i];
  900                         semptr = &semaptr->_sem_base[sopptr->sem_num];
  901 
  902                         SEM_PRINTF(("semop:  semaptr=%p, sem_base=%p, "
  903                             "semptr=%p, sem[%d]=%d : op=%d, flag=%s\n",
  904                             semaptr, semaptr->_sem_base, semptr,
  905                             sopptr->sem_num, semptr->semval, sopptr->sem_op,
  906                             (sopptr->sem_flg & IPC_NOWAIT) ?
  907                             "nowait" : "wait"));
  908 
  909                         if (sopptr->sem_op < 0) {
  910                                 if ((int)(semptr->semval +
  911                                     sopptr->sem_op) < 0) {
  912                                         SEM_PRINTF(("semop:  "
  913                                             "can't do it now\n"));
  914                                         break;
  915                                 } else {
  916                                         semptr->semval += sopptr->sem_op;
  917                                         if (semptr->semval == 0 &&
  918                                             semptr->semzcnt > 0)
  919                                                 do_wakeup = 1;
  920                                 }
  921                                 if (sopptr->sem_flg & SEM_UNDO)
  922                                         do_undos = 1;
  923                         } else if (sopptr->sem_op == 0) {
  924                                 if (semptr->semval > 0) {
  925                                         SEM_PRINTF(("semop:  not zero now\n"));
  926                                         break;
  927                                 }
  928                         } else {
  929                                 if (semptr->semncnt > 0)
  930                                         do_wakeup = 1;
  931                                 semptr->semval += sopptr->sem_op;
  932                                 if (sopptr->sem_flg & SEM_UNDO)
  933                                         do_undos = 1;
  934                         }
  935                 }
  936 
  937                 /*
  938                  * Did we get through the entire vector?
  939                  */
  940                 if (i >= nsops)
  941                         goto done;
  942 
  943                 /*
  944                  * No ... rollback anything that we've already done
  945                  */
  946                 SEM_PRINTF(("semop:  rollback 0 through %d\n", i - 1));
  947                 while (i-- > 0)
  948                         semaptr->_sem_base[sops[i].sem_num].semval -=
  949                             sops[i].sem_op;
  950 
  951                 /*
  952                  * If the request that we couldn't satisfy has the
  953                  * NOWAIT flag set then return with EAGAIN.
  954                  */
  955                 if (sopptr->sem_flg & IPC_NOWAIT) {
  956                         error = EAGAIN;
  957                         goto out;
  958                 }
  959 
  960                 if (sopptr->sem_op == 0)
  961                         semptr->semzcnt++;
  962                 else
  963                         semptr->semncnt++;
  964 
  965                 sem_waiters++;
  966                 SEM_PRINTF(("semop:  good night!\n"));
  967                 error = cv_wait_sig(&semcv[semid], &semlock);
  968                 SEM_PRINTF(("semop:  good morning (error=%d)!\n", error));
  969                 sem_waiters--;
  970 
  971                 /* Notify reallocator, if it is waiting */
  972                 cv_broadcast(&sem_realloc_cv);
  973 
  974                 /*
  975                  * Make sure that the semaphore still exists
  976                  */
  977                 if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 ||
  978                     semaptr->sem_perm._seq != seq) {
  979                         error = EIDRM;
  980                         goto out;
  981                 }
  982 
  983                 /*
  984                  * The semaphore is still alive.  Readjust the count of
  985                  * waiting processes.
  986                  */
  987                 semptr = &semaptr->_sem_base[sopptr->sem_num];
  988                 if (sopptr->sem_op == 0)
  989                         semptr->semzcnt--;
  990                 else
  991                         semptr->semncnt--;
  992 
  993                 /* In case of such state, restart the call */
  994                 if (sem_realloc_state) {
  995                         mutex_exit(&semlock);
  996                         goto restart;
  997                 }
  998 
  999                 /* Is it really morning, or was our sleep interrupted? */
 1000                 if (error != 0) {
 1001                         error = EINTR;
 1002                         goto out;
 1003                 }
 1004                 SEM_PRINTF(("semop:  good morning!\n"));
 1005         }
 1006 
 1007 done:
 1008         /*
 1009          * Process any SEM_UNDO requests.
 1010          */
 1011         if (do_undos) {
 1012                 for (i = 0; i < nsops; i++) {
 1013                         /*
 1014                          * We only need to deal with SEM_UNDO's for non-zero
 1015                          * op's.
 1016                          */
 1017                         int adjval;
 1018 
 1019                         if ((sops[i].sem_flg & SEM_UNDO) == 0)
 1020                                 continue;
 1021                         adjval = sops[i].sem_op;
 1022                         if (adjval == 0)
 1023                                 continue;
 1024                         error = semundo_adjust(p, &suptr, semid,
 1025                             sops[i].sem_num, -adjval);
 1026                         if (error == 0)
 1027                                 continue;
 1028 
 1029                         /*
 1030                          * Oh-Oh!  We ran out of either sem_undo's or undo's.
 1031                          * Rollback the adjustments to this point and then
 1032                          * rollback the semaphore ups and down so we can return
 1033                          * with an error with all structures restored.  We
 1034                          * rollback the undo's in the exact reverse order that
 1035                          * we applied them.  This guarantees that we won't run
 1036                          * out of space as we roll things back out.
 1037                          */
 1038                         while (i-- > 0) {
 1039                                 if ((sops[i].sem_flg & SEM_UNDO) == 0)
 1040                                         continue;
 1041                                 adjval = sops[i].sem_op;
 1042                                 if (adjval == 0)
 1043                                         continue;
 1044                                 if (semundo_adjust(p, &suptr, semid,
 1045                                     sops[i].sem_num, adjval) != 0)
 1046                                         panic("semop - can't undo undos");
 1047                         }
 1048 
 1049                         for (i = 0; i < nsops; i++)
 1050                                 semaptr->_sem_base[sops[i].sem_num].semval -=
 1051                                     sops[i].sem_op;
 1052 
 1053                         SEM_PRINTF(("error = %d from semundo_adjust\n", error));
 1054                         goto out;
 1055                 } /* loop through the sops */
 1056         } /* if (do_undos) */
 1057 
 1058         /* We're definitely done - set the sempid's */
 1059         for (i = 0; i < nsops; i++) {
 1060                 sopptr = &sops[i];
 1061                 semptr = &semaptr->_sem_base[sopptr->sem_num];
 1062                 semptr->sempid = p->p_pid;
 1063         }
 1064 
 1065         /* Update sem_otime */
 1066         semaptr->sem_otime = time_second;
 1067 
 1068         /* Do a wakeup if any semaphore was up'd. */
 1069         if (do_wakeup) {
 1070                 SEM_PRINTF(("semop:  doing wakeup\n"));
 1071                 cv_broadcast(&semcv[semid]);
 1072                 SEM_PRINTF(("semop:  back from wakeup\n"));
 1073         }
 1074         SEM_PRINTF(("semop:  done\n"));
 1075         *retval = 0;
 1076 
 1077  out:
 1078         mutex_exit(&semlock);
 1079         if (sops != small_sops)
 1080                 kmem_free(sops, nsops * sizeof(*sops));
 1081         return error;
 1082 }
 1083 
 1084 /*
 1085  * Go through the undo structures for this process and apply the
 1086  * adjustments to semaphores.
 1087  */
 1088 /*ARGSUSED*/
 1089 void
 1090 semexit(struct proc *p, void *v)
 1091 {
 1092         struct sem_undo *suptr;
 1093         struct sem_undo **supptr;
 1094 
 1095         if ((p->p_flag & PK_SYSVSEM) == 0)
 1096                 return;
 1097 
 1098         mutex_enter(&semlock);
 1099 
 1100         /*
 1101          * Go through the chain of undo vectors looking for one
 1102          * associated with this process.
 1103          */
 1104 
 1105         for (supptr = &semu_list; (suptr = *supptr) != NULL;
 1106             supptr = &suptr->un_next) {
 1107                 if (suptr->un_proc == p)
 1108                         break;
 1109         }
 1110 
 1111         /*
 1112          * If there is no undo vector, skip to the end.
 1113          */
 1114 
 1115         if (suptr == NULL) {
 1116                 mutex_exit(&semlock);
 1117                 return;
 1118         }
 1119 
 1120         /*
 1121          * We now have an undo vector for this process.
 1122          */
 1123 
 1124         SEM_PRINTF(("proc @%p has undo structure with %d entries\n", p,
 1125             suptr->un_cnt));
 1126 
 1127         /*
 1128          * If there are any active undo elements then process them.
 1129          */
 1130         if (suptr->un_cnt > 0) {
 1131                 int ix;
 1132 
 1133                 for (ix = 0; ix < suptr->un_cnt; ix++) {
 1134                         int semid = suptr->un_ent[ix].un_id;
 1135                         int semnum = suptr->un_ent[ix].un_num;
 1136                         int adjval = suptr->un_ent[ix].un_adjval;
 1137                         struct semid_ds *semaptr;
 1138 
 1139                         semaptr = &sema[semid];
 1140                         if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0)
 1141                         if (semnum >= semaptr->sem_nsems)
 1142                                 panic("semexit - semnum out of range");
 1143 
 1144                         SEM_PRINTF(("semexit:  %p id=%d num=%d(adj=%d) ; "
 1145                             "sem=%d\n",
 1146                             suptr->un_proc, suptr->un_ent[ix].un_id,
 1147                             suptr->un_ent[ix].un_num,
 1148                             suptr->un_ent[ix].un_adjval,
 1149                             semaptr->_sem_base[semnum].semval));
 1150 
 1151                         if (adjval < 0 &&
 1152                             semaptr->_sem_base[semnum].semval < -adjval)
 1153                                 semaptr->_sem_base[semnum].semval = 0;
 1154                         else
 1155                                 semaptr->_sem_base[semnum].semval += adjval;
 1156 
 1157                         cv_broadcast(&semcv[semid]);
 1158                         SEM_PRINTF(("semexit:  back from wakeup\n"));
 1159                 }
 1160         }
 1161 
 1162         /*
 1163          * Deallocate the undo vector.
 1164          */
 1165         SEM_PRINTF(("removing vector\n"));
 1166         suptr->un_proc = NULL;
 1167         *supptr = suptr->un_next;
 1168         mutex_exit(&semlock);
 1169 }
 1170 
 1171 /*
 1172  * Sysctl initialization and nodes.
 1173  */
 1174 
 1175 static int
 1176 sysctl_ipc_semmni(SYSCTLFN_ARGS)
 1177 {
 1178         int newsize, error;
 1179         struct sysctlnode node;
 1180         node = *rnode;
 1181         node.sysctl_data = &newsize;
 1182 
 1183         newsize = seminfo.semmni;
 1184         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 1185         if (error || newp == NULL)
 1186                 return error;
 1187 
 1188         return semrealloc(newsize, seminfo.semmns, seminfo.semmnu);
 1189 }
 1190 
 1191 static int
 1192 sysctl_ipc_semmns(SYSCTLFN_ARGS)
 1193 {
 1194         int newsize, error;
 1195         struct sysctlnode node;
 1196         node = *rnode;
 1197         node.sysctl_data = &newsize;
 1198 
 1199         newsize = seminfo.semmns;
 1200         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 1201         if (error || newp == NULL)
 1202                 return error;
 1203 
 1204         return semrealloc(seminfo.semmni, newsize, seminfo.semmnu);
 1205 }
 1206 
 1207 static int
 1208 sysctl_ipc_semmnu(SYSCTLFN_ARGS)
 1209 {
 1210         int newsize, error;
 1211         struct sysctlnode node;
 1212         node = *rnode;
 1213         node.sysctl_data = &newsize;
 1214 
 1215         newsize = seminfo.semmnu;
 1216         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 1217         if (error || newp == NULL)
 1218                 return error;
 1219 
 1220         return semrealloc(seminfo.semmni, seminfo.semmns, newsize);
 1221 }
 1222 
 1223 SYSCTL_SETUP(sysctl_ipc_sem_setup, "sysctl kern.ipc subtree setup")
 1224 {
 1225         const struct sysctlnode *node = NULL;
 1226 
 1227         sysctl_createv(clog, 0, NULL, &node,
 1228                 CTLFLAG_PERMANENT,
 1229                 CTLTYPE_NODE, "ipc",
 1230                 SYSCTL_DESCR("SysV IPC options"),
 1231                 NULL, 0, NULL, 0,
 1232                 CTL_KERN, KERN_SYSVIPC, CTL_EOL);
 1233 
 1234         if (node == NULL)
 1235                 return;
 1236 
 1237         sysctl_createv(clog, 0, &node, NULL,
 1238                 CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
 1239                 CTLTYPE_INT, "semmni",
 1240                 SYSCTL_DESCR("Max number of number of semaphore identifiers"),
 1241                 sysctl_ipc_semmni, 0, &seminfo.semmni, 0,
 1242                 CTL_CREATE, CTL_EOL);
 1243         sysctl_createv(clog, 0, &node, NULL,
 1244                 CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
 1245                 CTLTYPE_INT, "semmns",
 1246                 SYSCTL_DESCR("Max number of number of semaphores in system"),
 1247                 sysctl_ipc_semmns, 0, &seminfo.semmns, 0,
 1248                 CTL_CREATE, CTL_EOL);
 1249         sysctl_createv(clog, 0, &node, NULL,
 1250                 CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
 1251                 CTLTYPE_INT, "semmnu",
 1252                 SYSCTL_DESCR("Max number of undo structures in system"),
 1253                 sysctl_ipc_semmnu, 0, &seminfo.semmnu, 0,
 1254                 CTL_CREATE, CTL_EOL);
 1255 }
Cache object: 129d4396f5ea0242ea535fc559eb81cd
[ 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.
FreeBSD/Linux Kernel Cross Reference sys/kern/sysv_sem.c

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