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

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    1 /*-
    2  * Implementation of SVID semaphores
    3  *
    4  * Author:  Daniel Boulet
    5  *
    6  * This software is provided ``AS IS'' without any warranties of any kind.
    7  */
    8 /*-
    9  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   10  *
   11  * Copyright (c) 2003-2005 McAfee, Inc.
   12  * Copyright (c) 2016-2017 Robert N. M. Watson
   13  * All rights reserved.
   14  *
   15  * This software was developed for the FreeBSD Project in part by McAfee
   16  * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
   17  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
   18  * program.
   19  *
   20  * Portions of this software were developed by BAE Systems, the University of
   21  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
   22  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
   23  * Computing (TC) research program.
   24  *
   25  * Redistribution and use in source and binary forms, with or without
   26  * modification, are permitted provided that the following conditions
   27  * are met:
   28  * 1. Redistributions of source code must retain the above copyright
   29  *    notice, this list of conditions and the following disclaimer.
   30  * 2. Redistributions in binary form must reproduce the above copyright
   31  *    notice, this list of conditions and the following disclaimer in the
   32  *    documentation and/or other materials provided with the distribution.
   33  *
   34  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   35  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   36  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   37  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   38  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   39  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   40  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   41  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   42  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   43  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   44  * SUCH DAMAGE.
   45  */
   46 
   47 #include <sys/cdefs.h>
   48 __FBSDID("$FreeBSD$");
   49 
   50 #include "opt_sysvipc.h"
   51 
   52 #include <sys/param.h>
   53 #include <sys/systm.h>
   54 #include <sys/sysproto.h>
   55 #include <sys/abi_compat.h>
   56 #include <sys/eventhandler.h>
   57 #include <sys/kernel.h>
   58 #include <sys/proc.h>
   59 #include <sys/lock.h>
   60 #include <sys/module.h>
   61 #include <sys/mutex.h>
   62 #include <sys/racct.h>
   63 #include <sys/sem.h>
   64 #include <sys/sx.h>
   65 #include <sys/syscall.h>
   66 #include <sys/syscallsubr.h>
   67 #include <sys/sysent.h>
   68 #include <sys/sysctl.h>
   69 #include <sys/uio.h>
   70 #include <sys/malloc.h>
   71 #include <sys/jail.h>
   72 
   73 #include <security/audit/audit.h>
   74 #include <security/mac/mac_framework.h>
   75 
   76 FEATURE(sysv_sem, "System V semaphores support");
   77 
   78 static MALLOC_DEFINE(M_SEM, "sem", "SVID compatible semaphores");
   79 
   80 #ifdef SEM_DEBUG
   81 #define DPRINTF(a)      printf a
   82 #else
   83 #define DPRINTF(a)
   84 #endif
   85 
   86 static int seminit(void);
   87 static int sysvsem_modload(struct module *, int, void *);
   88 static int semunload(void);
   89 static void semexit_myhook(void *arg, struct proc *p);
   90 static int sysctl_sema(SYSCTL_HANDLER_ARGS);
   91 static int semvalid(int semid, struct prison *rpr,
   92     struct semid_kernel *semakptr);
   93 static void sem_remove(int semidx, struct ucred *cred);
   94 static struct prison *sem_find_prison(struct ucred *);
   95 static int sem_prison_cansee(struct prison *, struct semid_kernel *);
   96 static int sem_prison_check(void *, void *);
   97 static int sem_prison_set(void *, void *);
   98 static int sem_prison_get(void *, void *);
   99 static int sem_prison_remove(void *, void *);
  100 static void sem_prison_cleanup(struct prison *);
  101 
  102 #ifndef _SYS_SYSPROTO_H_
  103 struct __semctl_args;
  104 int __semctl(struct thread *td, struct __semctl_args *uap);
  105 struct semget_args;
  106 int semget(struct thread *td, struct semget_args *uap);
  107 struct semop_args;
  108 int semop(struct thread *td, struct semop_args *uap);
  109 #endif
  110 
  111 static struct sem_undo *semu_alloc(struct thread *td);
  112 static int semundo_adjust(struct thread *td, struct sem_undo **supptr,
  113     int semid, int semseq, int semnum, int adjval);
  114 static void semundo_clear(int semid, int semnum);
  115 
  116 static struct mtx       sem_mtx;        /* semaphore global lock */
  117 static struct mtx sem_undo_mtx;
  118 static int      semtot = 0;
  119 static struct semid_kernel *sema;       /* semaphore id pool */
  120 static struct mtx *sema_mtx;    /* semaphore id pool mutexes*/
  121 static struct sem *sem;         /* semaphore pool */
  122 LIST_HEAD(, sem_undo) semu_list;        /* list of active undo structures */
  123 LIST_HEAD(, sem_undo) semu_free_list;   /* list of free undo structures */
  124 static int      *semu;          /* undo structure pool */
  125 static eventhandler_tag semexit_tag;
  126 static unsigned sem_prison_slot;        /* prison OSD slot */
  127 
  128 #define SEMUNDO_MTX             sem_undo_mtx
  129 #define SEMUNDO_LOCK()          mtx_lock(&SEMUNDO_MTX);
  130 #define SEMUNDO_UNLOCK()        mtx_unlock(&SEMUNDO_MTX);
  131 #define SEMUNDO_LOCKASSERT(how) mtx_assert(&SEMUNDO_MTX, (how));
  132 
  133 struct sem {
  134         u_short semval;         /* semaphore value */
  135         pid_t   sempid;         /* pid of last operation */
  136         u_short semncnt;        /* # awaiting semval > cval */
  137         u_short semzcnt;        /* # awaiting semval = 0 */
  138 };
  139 
  140 /*
  141  * Undo structure (one per process)
  142  */
  143 struct sem_undo {
  144         LIST_ENTRY(sem_undo) un_next;   /* ptr to next active undo structure */
  145         struct  proc *un_proc;          /* owner of this structure */
  146         short   un_cnt;                 /* # of active entries */
  147         struct undo {
  148                 short   un_adjval;      /* adjust on exit values */
  149                 short   un_num;         /* semaphore # */
  150                 int     un_id;          /* semid */
  151                 unsigned short un_seq;
  152         } un_ent[1];                    /* undo entries */
  153 };
  154 
  155 /*
  156  * Configuration parameters
  157  */
  158 #ifndef SEMMNI
  159 #define SEMMNI  50              /* # of semaphore identifiers */
  160 #endif
  161 #ifndef SEMMNS
  162 #define SEMMNS  340             /* # of semaphores in system */
  163 #endif
  164 #ifndef SEMUME
  165 #define SEMUME  50              /* max # of undo entries per process */
  166 #endif
  167 #ifndef SEMMNU
  168 #define SEMMNU  150             /* # of undo structures in system */
  169 #endif
  170 
  171 /* shouldn't need tuning */
  172 #ifndef SEMMSL
  173 #define SEMMSL  SEMMNS          /* max # of semaphores per id */
  174 #endif
  175 #ifndef SEMOPM
  176 #define SEMOPM  100             /* max # of operations per semop call */
  177 #endif
  178 
  179 #define SEMVMX  32767           /* semaphore maximum value */
  180 #define SEMAEM  16384           /* adjust on exit max value */
  181 
  182 /*
  183  * Due to the way semaphore memory is allocated, we have to ensure that
  184  * SEMUSZ is properly aligned.
  185  */
  186 
  187 #define SEM_ALIGN(bytes) roundup2(bytes, sizeof(long))
  188 
  189 /* actual size of an undo structure */
  190 #define SEMUSZ(x)       SEM_ALIGN(offsetof(struct sem_undo, un_ent[(x)]))
  191 
  192 /*
  193  * Macro to find a particular sem_undo vector
  194  */
  195 #define SEMU(ix) \
  196         ((struct sem_undo *)(((intptr_t)semu) + (ix) * seminfo.semusz))
  197 
  198 /*
  199  * semaphore info struct
  200  */
  201 struct seminfo seminfo = {
  202         .semmni =       SEMMNI, /* # of semaphore identifiers */
  203         .semmns =       SEMMNS, /* # of semaphores in system */
  204         .semmnu =       SEMMNU, /* # of undo structures in system */
  205         .semmsl =       SEMMSL, /* max # of semaphores per id */
  206         .semopm =       SEMOPM, /* max # of operations per semop call */
  207         .semume =       SEMUME, /* max # of undo entries per process */
  208         .semusz =       SEMUSZ(SEMUME), /* size in bytes of undo structure */
  209         .semvmx =       SEMVMX, /* semaphore maximum value */
  210         .semaem =       SEMAEM, /* adjust on exit max value */
  211 };
  212 
  213 SYSCTL_INT(_kern_ipc, OID_AUTO, semmni, CTLFLAG_RDTUN, &seminfo.semmni, 0,
  214     "Number of semaphore identifiers");
  215 SYSCTL_INT(_kern_ipc, OID_AUTO, semmns, CTLFLAG_RDTUN, &seminfo.semmns, 0,
  216     "Maximum number of semaphores in the system");
  217 SYSCTL_INT(_kern_ipc, OID_AUTO, semmnu, CTLFLAG_RDTUN, &seminfo.semmnu, 0,
  218     "Maximum number of undo structures in the system");
  219 SYSCTL_INT(_kern_ipc, OID_AUTO, semmsl, CTLFLAG_RWTUN, &seminfo.semmsl, 0,
  220     "Max semaphores per id");
  221 SYSCTL_INT(_kern_ipc, OID_AUTO, semopm, CTLFLAG_RDTUN, &seminfo.semopm, 0,
  222     "Max operations per semop call");
  223 SYSCTL_INT(_kern_ipc, OID_AUTO, semume, CTLFLAG_RDTUN, &seminfo.semume, 0,
  224     "Max undo entries per process");
  225 SYSCTL_INT(_kern_ipc, OID_AUTO, semusz, CTLFLAG_RD, &seminfo.semusz, 0,
  226     "Size in bytes of undo structure");
  227 SYSCTL_INT(_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RWTUN, &seminfo.semvmx, 0,
  228     "Semaphore maximum value");
  229 SYSCTL_INT(_kern_ipc, OID_AUTO, semaem, CTLFLAG_RWTUN, &seminfo.semaem, 0,
  230     "Adjust on exit max value");
  231 SYSCTL_PROC(_kern_ipc, OID_AUTO, sema,
  232     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
  233     NULL, 0, sysctl_sema, "",
  234     "Array of struct semid_kernel for each potential semaphore");
  235 
  236 static struct syscall_helper_data sem_syscalls[] = {
  237         SYSCALL_INIT_HELPER(__semctl),
  238         SYSCALL_INIT_HELPER(semget),
  239         SYSCALL_INIT_HELPER(semop),
  240 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
  241     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
  242         SYSCALL_INIT_HELPER(semsys),
  243         SYSCALL_INIT_HELPER_COMPAT(freebsd7___semctl),
  244 #endif
  245         SYSCALL_INIT_LAST
  246 };
  247 
  248 #ifdef COMPAT_FREEBSD32
  249 #include <compat/freebsd32/freebsd32.h>
  250 #include <compat/freebsd32/freebsd32_ipc.h>
  251 #include <compat/freebsd32/freebsd32_proto.h>
  252 #include <compat/freebsd32/freebsd32_signal.h>
  253 #include <compat/freebsd32/freebsd32_syscall.h>
  254 #include <compat/freebsd32/freebsd32_util.h>
  255 
  256 static struct syscall_helper_data sem32_syscalls[] = {
  257         SYSCALL32_INIT_HELPER(freebsd32_semctl),
  258         SYSCALL32_INIT_HELPER_COMPAT(semget),
  259         SYSCALL32_INIT_HELPER_COMPAT(semop),
  260         SYSCALL32_INIT_HELPER(freebsd32_semsys),
  261 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
  262     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
  263         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_semctl),
  264 #endif
  265         SYSCALL_INIT_LAST
  266 };
  267 #endif
  268 
  269 static int
  270 seminit(void)
  271 {
  272         struct prison *pr;
  273         void **rsv;
  274         int i, error;
  275         osd_method_t methods[PR_MAXMETHOD] = {
  276             [PR_METHOD_CHECK] =         sem_prison_check,
  277             [PR_METHOD_SET] =           sem_prison_set,
  278             [PR_METHOD_GET] =           sem_prison_get,
  279             [PR_METHOD_REMOVE] =        sem_prison_remove,
  280         };
  281 
  282         sem = malloc(sizeof(struct sem) * seminfo.semmns, M_SEM, M_WAITOK);
  283         sema = malloc(sizeof(struct semid_kernel) * seminfo.semmni, M_SEM,
  284             M_WAITOK | M_ZERO);
  285         sema_mtx = malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM,
  286             M_WAITOK | M_ZERO);
  287         seminfo.semusz = SEMUSZ(seminfo.semume);
  288         semu = malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK);
  289 
  290         for (i = 0; i < seminfo.semmni; i++) {
  291                 sema[i].u.__sem_base = 0;
  292                 sema[i].u.sem_perm.mode = 0;
  293                 sema[i].u.sem_perm.seq = 0;
  294 #ifdef MAC
  295                 mac_sysvsem_init(&sema[i]);
  296 #endif
  297         }
  298         for (i = 0; i < seminfo.semmni; i++)
  299                 mtx_init(&sema_mtx[i], "semid", NULL, MTX_DEF);
  300         LIST_INIT(&semu_free_list);
  301         for (i = 0; i < seminfo.semmnu; i++) {
  302                 struct sem_undo *suptr = SEMU(i);
  303                 suptr->un_proc = NULL;
  304                 LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
  305         }
  306         LIST_INIT(&semu_list);
  307         mtx_init(&sem_mtx, "sem", NULL, MTX_DEF);
  308         mtx_init(&sem_undo_mtx, "semu", NULL, MTX_DEF);
  309         semexit_tag = EVENTHANDLER_REGISTER(process_exit, semexit_myhook, NULL,
  310             EVENTHANDLER_PRI_ANY);
  311 
  312         /* Set current prisons according to their allow.sysvipc. */
  313         sem_prison_slot = osd_jail_register(NULL, methods);
  314         rsv = osd_reserve(sem_prison_slot);
  315         prison_lock(&prison0);
  316         (void)osd_jail_set_reserved(&prison0, sem_prison_slot, rsv, &prison0);
  317         prison_unlock(&prison0);
  318         rsv = NULL;
  319         sx_slock(&allprison_lock);
  320         TAILQ_FOREACH(pr, &allprison, pr_list) {
  321                 if (rsv == NULL)
  322                         rsv = osd_reserve(sem_prison_slot);
  323                 prison_lock(pr);
  324                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
  325                         (void)osd_jail_set_reserved(pr, sem_prison_slot, rsv,
  326                             &prison0);
  327                         rsv = NULL;
  328                 }
  329                 prison_unlock(pr);
  330         }
  331         if (rsv != NULL)
  332                 osd_free_reserved(rsv);
  333         sx_sunlock(&allprison_lock);
  334 
  335         error = syscall_helper_register(sem_syscalls, SY_THR_STATIC_KLD);
  336         if (error != 0)
  337                 return (error);
  338 #ifdef COMPAT_FREEBSD32
  339         error = syscall32_helper_register(sem32_syscalls, SY_THR_STATIC_KLD);
  340         if (error != 0)
  341                 return (error);
  342 #endif
  343         return (0);
  344 }
  345 
  346 static int
  347 semunload(void)
  348 {
  349         int i;
  350 
  351         /* XXXKIB */
  352         if (semtot != 0)
  353                 return (EBUSY);
  354 
  355 #ifdef COMPAT_FREEBSD32
  356         syscall32_helper_unregister(sem32_syscalls);
  357 #endif
  358         syscall_helper_unregister(sem_syscalls);
  359         EVENTHANDLER_DEREGISTER(process_exit, semexit_tag);
  360         if (sem_prison_slot != 0)
  361                 osd_jail_deregister(sem_prison_slot);
  362 #ifdef MAC
  363         for (i = 0; i < seminfo.semmni; i++)
  364                 mac_sysvsem_destroy(&sema[i]);
  365 #endif
  366         free(sem, M_SEM);
  367         free(sema, M_SEM);
  368         free(semu, M_SEM);
  369         for (i = 0; i < seminfo.semmni; i++)
  370                 mtx_destroy(&sema_mtx[i]);
  371         free(sema_mtx, M_SEM);
  372         mtx_destroy(&sem_mtx);
  373         mtx_destroy(&sem_undo_mtx);
  374         return (0);
  375 }
  376 
  377 static int
  378 sysvsem_modload(struct module *module, int cmd, void *arg)
  379 {
  380         int error = 0;
  381 
  382         switch (cmd) {
  383         case MOD_LOAD:
  384                 error = seminit();
  385                 break;
  386         case MOD_UNLOAD:
  387                 error = semunload();
  388                 break;
  389         case MOD_SHUTDOWN:
  390                 break;
  391         default:
  392                 error = EINVAL;
  393                 break;
  394         }
  395         return (error);
  396 }
  397 
  398 static moduledata_t sysvsem_mod = {
  399         "sysvsem",
  400         &sysvsem_modload,
  401         NULL
  402 };
  403 
  404 DECLARE_MODULE(sysvsem, sysvsem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST);
  405 MODULE_VERSION(sysvsem, 1);
  406 
  407 /*
  408  * Allocate a new sem_undo structure for a process
  409  * (returns ptr to structure or NULL if no more room)
  410  */
  411 
  412 static struct sem_undo *
  413 semu_alloc(struct thread *td)
  414 {
  415         struct sem_undo *suptr;
  416 
  417         SEMUNDO_LOCKASSERT(MA_OWNED);
  418         if ((suptr = LIST_FIRST(&semu_free_list)) == NULL)
  419                 return (NULL);
  420         LIST_REMOVE(suptr, un_next);
  421         LIST_INSERT_HEAD(&semu_list, suptr, un_next);
  422         suptr->un_cnt = 0;
  423         suptr->un_proc = td->td_proc;
  424         return (suptr);
  425 }
  426 
  427 static int
  428 semu_try_free(struct sem_undo *suptr)
  429 {
  430 
  431         SEMUNDO_LOCKASSERT(MA_OWNED);
  432 
  433         if (suptr->un_cnt != 0)
  434                 return (0);
  435         LIST_REMOVE(suptr, un_next);
  436         LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
  437         return (1);
  438 }
  439 
  440 /*
  441  * Adjust a particular entry for a particular proc
  442  */
  443 
  444 static int
  445 semundo_adjust(struct thread *td, struct sem_undo **supptr, int semid,
  446     int semseq, int semnum, int adjval)
  447 {
  448         struct proc *p = td->td_proc;
  449         struct sem_undo *suptr;
  450         struct undo *sunptr;
  451         int i;
  452 
  453         SEMUNDO_LOCKASSERT(MA_OWNED);
  454         /* Look for and remember the sem_undo if the caller doesn't provide
  455            it */
  456 
  457         suptr = *supptr;
  458         if (suptr == NULL) {
  459                 LIST_FOREACH(suptr, &semu_list, un_next) {
  460                         if (suptr->un_proc == p) {
  461                                 *supptr = suptr;
  462                                 break;
  463                         }
  464                 }
  465                 if (suptr == NULL) {
  466                         if (adjval == 0)
  467                                 return(0);
  468                         suptr = semu_alloc(td);
  469                         if (suptr == NULL)
  470                                 return (ENOSPC);
  471                         *supptr = suptr;
  472                 }
  473         }
  474 
  475         /*
  476          * Look for the requested entry and adjust it (delete if adjval becomes
  477          * 0).
  478          */
  479         sunptr = &suptr->un_ent[0];
  480         for (i = 0; i < suptr->un_cnt; i++, sunptr++) {
  481                 if (sunptr->un_id != semid || sunptr->un_num != semnum)
  482                         continue;
  483                 if (adjval != 0) {
  484                         adjval += sunptr->un_adjval;
  485                         if (adjval > seminfo.semaem || adjval < -seminfo.semaem)
  486                                 return (ERANGE);
  487                 }
  488                 sunptr->un_adjval = adjval;
  489                 if (sunptr->un_adjval == 0) {
  490                         suptr->un_cnt--;
  491                         if (i < suptr->un_cnt)
  492                                 suptr->un_ent[i] =
  493                                     suptr->un_ent[suptr->un_cnt];
  494                         if (suptr->un_cnt == 0)
  495                                 semu_try_free(suptr);
  496                 }
  497                 return (0);
  498         }
  499 
  500         /* Didn't find the right entry - create it */
  501         if (adjval == 0)
  502                 return (0);
  503         if (adjval > seminfo.semaem || adjval < -seminfo.semaem)
  504                 return (ERANGE);
  505         if (suptr->un_cnt != seminfo.semume) {
  506                 sunptr = &suptr->un_ent[suptr->un_cnt];
  507                 suptr->un_cnt++;
  508                 sunptr->un_adjval = adjval;
  509                 sunptr->un_id = semid;
  510                 sunptr->un_num = semnum;
  511                 sunptr->un_seq = semseq;
  512         } else
  513                 return (EINVAL);
  514         return (0);
  515 }
  516 
  517 static void
  518 semundo_clear(int semid, int semnum)
  519 {
  520         struct sem_undo *suptr, *suptr1;
  521         struct undo *sunptr;
  522         int i;
  523 
  524         SEMUNDO_LOCKASSERT(MA_OWNED);
  525         LIST_FOREACH_SAFE(suptr, &semu_list, un_next, suptr1) {
  526                 sunptr = &suptr->un_ent[0];
  527                 for (i = 0; i < suptr->un_cnt; i++, sunptr++) {
  528                         if (sunptr->un_id != semid)
  529                                 continue;
  530                         if (semnum == -1 || sunptr->un_num == semnum) {
  531                                 suptr->un_cnt--;
  532                                 if (i < suptr->un_cnt) {
  533                                         suptr->un_ent[i] =
  534                                             suptr->un_ent[suptr->un_cnt];
  535                                         continue;
  536                                 }
  537                                 semu_try_free(suptr);
  538                         }
  539                         if (semnum != -1)
  540                                 break;
  541                 }
  542         }
  543 }
  544 
  545 static int
  546 semvalid(int semid, struct prison *rpr, struct semid_kernel *semakptr)
  547 {
  548 
  549         return ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
  550             semakptr->u.sem_perm.seq != IPCID_TO_SEQ(semid) ||
  551             sem_prison_cansee(rpr, semakptr) ? EINVAL : 0);
  552 }
  553 
  554 static void
  555 sem_remove(int semidx, struct ucred *cred)
  556 {
  557         struct semid_kernel *semakptr;
  558         int i;
  559 
  560         KASSERT(semidx >= 0 && semidx < seminfo.semmni,
  561             ("semidx out of bounds"));
  562         mtx_assert(&sem_mtx, MA_OWNED);
  563         semakptr = &sema[semidx];
  564         KASSERT(semakptr->u.__sem_base - sem + semakptr->u.sem_nsems <= semtot,
  565             ("sem_remove: sema %d corrupted sem pointer %p %p %d %d",
  566             semidx, semakptr->u.__sem_base, sem, semakptr->u.sem_nsems,
  567             semtot));
  568 
  569         semakptr->u.sem_perm.cuid = cred ? cred->cr_uid : 0;
  570         semakptr->u.sem_perm.uid = cred ? cred->cr_uid : 0;
  571         semakptr->u.sem_perm.mode = 0;
  572         racct_sub_cred(semakptr->cred, RACCT_NSEM, semakptr->u.sem_nsems);
  573         crfree(semakptr->cred);
  574         semakptr->cred = NULL;
  575         SEMUNDO_LOCK();
  576         semundo_clear(semidx, -1);
  577         SEMUNDO_UNLOCK();
  578 #ifdef MAC
  579         mac_sysvsem_cleanup(semakptr);
  580 #endif
  581         wakeup(semakptr);
  582         for (i = 0; i < seminfo.semmni; i++) {
  583                 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
  584                     sema[i].u.__sem_base > semakptr->u.__sem_base)
  585                         mtx_lock_flags(&sema_mtx[i], LOP_DUPOK);
  586         }
  587         for (i = semakptr->u.__sem_base - sem + semakptr->u.sem_nsems;
  588             i < semtot; i++)
  589                 sem[i - semakptr->u.sem_nsems] = sem[i];
  590         for (i = 0; i < seminfo.semmni; i++) {
  591                 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
  592                     sema[i].u.__sem_base > semakptr->u.__sem_base) {
  593                         sema[i].u.__sem_base -= semakptr->u.sem_nsems;
  594                         mtx_unlock(&sema_mtx[i]);
  595                 }
  596         }
  597         semtot -= semakptr->u.sem_nsems;
  598 }
  599 
  600 static struct prison *
  601 sem_find_prison(struct ucred *cred)
  602 {
  603         struct prison *pr, *rpr;
  604 
  605         pr = cred->cr_prison;
  606         prison_lock(pr);
  607         rpr = osd_jail_get(pr, sem_prison_slot);
  608         prison_unlock(pr);
  609         return rpr;
  610 }
  611 
  612 static int
  613 sem_prison_cansee(struct prison *rpr, struct semid_kernel *semakptr)
  614 {
  615 
  616         if (semakptr->cred == NULL ||
  617             !(rpr == semakptr->cred->cr_prison ||
  618               prison_ischild(rpr, semakptr->cred->cr_prison)))
  619                 return (EINVAL);
  620         return (0);
  621 }
  622 
  623 /*
  624  * Note that the user-mode half of this passes a union, not a pointer.
  625  */
  626 #ifndef _SYS_SYSPROTO_H_
  627 struct __semctl_args {
  628         int     semid;
  629         int     semnum;
  630         int     cmd;
  631         union   semun *arg;
  632 };
  633 #endif
  634 int
  635 sys___semctl(struct thread *td, struct __semctl_args *uap)
  636 {
  637         struct semid_ds dsbuf;
  638         union semun arg, semun;
  639         register_t rval;
  640         int error;
  641 
  642         switch (uap->cmd) {
  643         case SEM_STAT:
  644         case IPC_SET:
  645         case IPC_STAT:
  646         case GETALL:
  647         case SETVAL:
  648         case SETALL:
  649                 error = copyin(uap->arg, &arg, sizeof(arg));
  650                 if (error)
  651                         return (error);
  652                 break;
  653         }
  654 
  655         switch (uap->cmd) {
  656         case SEM_STAT:
  657         case IPC_STAT:
  658                 semun.buf = &dsbuf;
  659                 break;
  660         case IPC_SET:
  661                 error = copyin(arg.buf, &dsbuf, sizeof(dsbuf));
  662                 if (error)
  663                         return (error);
  664                 semun.buf = &dsbuf;
  665                 break;
  666         case GETALL:
  667         case SETALL:
  668                 semun.array = arg.array;
  669                 break;
  670         case SETVAL:
  671                 semun.val = arg.val;
  672                 break;          
  673         }
  674 
  675         error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
  676             &rval);
  677         if (error)
  678                 return (error);
  679 
  680         switch (uap->cmd) {
  681         case SEM_STAT:
  682         case IPC_STAT:
  683                 error = copyout(&dsbuf, arg.buf, sizeof(dsbuf));
  684                 break;
  685         }
  686 
  687         if (error == 0)
  688                 td->td_retval[0] = rval;
  689         return (error);
  690 }
  691 
  692 int
  693 kern_semctl(struct thread *td, int semid, int semnum, int cmd,
  694     union semun *arg, register_t *rval)
  695 {
  696         u_short *array;
  697         struct ucred *cred = td->td_ucred;
  698         int i, error;
  699         struct prison *rpr;
  700         struct semid_ds *sbuf;
  701         struct semid_kernel *semakptr;
  702         struct mtx *sema_mtxp;
  703         u_short usval, count;
  704         int semidx;
  705 
  706         DPRINTF(("call to semctl(%d, %d, %d, 0x%p)\n",
  707             semid, semnum, cmd, arg));
  708 
  709         AUDIT_ARG_SVIPC_CMD(cmd);
  710         AUDIT_ARG_SVIPC_ID(semid);
  711 
  712         rpr = sem_find_prison(td->td_ucred);
  713         if (sem == NULL)
  714                 return (ENOSYS);
  715 
  716         array = NULL;
  717 
  718         switch(cmd) {
  719         case SEM_STAT:
  720                 /*
  721                  * For this command we assume semid is an array index
  722                  * rather than an IPC id.
  723                  */
  724                 if (semid < 0 || semid >= seminfo.semmni)
  725                         return (EINVAL);
  726                 semakptr = &sema[semid];
  727                 sema_mtxp = &sema_mtx[semid];
  728                 mtx_lock(sema_mtxp);
  729                 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) {
  730                         error = EINVAL;
  731                         goto done2;
  732                 }
  733                 if ((error = sem_prison_cansee(rpr, semakptr)))
  734                         goto done2;
  735                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  736                         goto done2;
  737 #ifdef MAC
  738                 error = mac_sysvsem_check_semctl(cred, semakptr, cmd);
  739                 if (error != 0)
  740                         goto done2;
  741 #endif
  742                 bcopy(&semakptr->u, arg->buf, sizeof(struct semid_ds));
  743                 if (cred->cr_prison != semakptr->cred->cr_prison)
  744                         arg->buf->sem_perm.key = IPC_PRIVATE;
  745                 *rval = IXSEQ_TO_IPCID(semid, semakptr->u.sem_perm);
  746                 mtx_unlock(sema_mtxp);
  747                 return (0);
  748         }
  749 
  750         semidx = IPCID_TO_IX(semid);
  751         if (semidx < 0 || semidx >= seminfo.semmni)
  752                 return (EINVAL);
  753 
  754         semakptr = &sema[semidx];
  755         sema_mtxp = &sema_mtx[semidx];
  756         if (cmd == IPC_RMID)
  757                 mtx_lock(&sem_mtx);
  758         mtx_lock(sema_mtxp);
  759 
  760 #ifdef MAC
  761         error = mac_sysvsem_check_semctl(cred, semakptr, cmd);
  762         if (error != 0)
  763                 goto done2;
  764 #endif
  765 
  766         error = 0;
  767         *rval = 0;
  768 
  769         switch (cmd) {
  770         case IPC_RMID:
  771                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  772                         goto done2;
  773                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M)))
  774                         goto done2;
  775                 sem_remove(semidx, cred);
  776                 break;
  777 
  778         case IPC_SET:
  779                 AUDIT_ARG_SVIPC_PERM(&arg->buf->sem_perm);
  780                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  781                         goto done2;
  782                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M)))
  783                         goto done2;
  784                 sbuf = arg->buf;
  785                 semakptr->u.sem_perm.uid = sbuf->sem_perm.uid;
  786                 semakptr->u.sem_perm.gid = sbuf->sem_perm.gid;
  787                 semakptr->u.sem_perm.mode = (semakptr->u.sem_perm.mode &
  788                     ~0777) | (sbuf->sem_perm.mode & 0777);
  789                 semakptr->u.sem_ctime = time_second;
  790                 break;
  791 
  792         case IPC_STAT:
  793                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  794                         goto done2;
  795                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  796                         goto done2;
  797                 bcopy(&semakptr->u, arg->buf, sizeof(struct semid_ds));
  798                 if (cred->cr_prison != semakptr->cred->cr_prison)
  799                         arg->buf->sem_perm.key = IPC_PRIVATE;
  800 
  801                 /*
  802                  * Try to hide the fact that the structure layout is shared by
  803                  * both the kernel and userland.  This pointer is not useful to
  804                  * userspace.
  805                  */
  806                 arg->buf->__sem_base = NULL;
  807                 break;
  808 
  809         case GETNCNT:
  810                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  811                         goto done2;
  812                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  813                         goto done2;
  814                 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
  815                         error = EINVAL;
  816                         goto done2;
  817                 }
  818                 *rval = semakptr->u.__sem_base[semnum].semncnt;
  819                 break;
  820 
  821         case GETPID:
  822                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  823                         goto done2;
  824                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  825                         goto done2;
  826                 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
  827                         error = EINVAL;
  828                         goto done2;
  829                 }
  830                 *rval = semakptr->u.__sem_base[semnum].sempid;
  831                 break;
  832 
  833         case GETVAL:
  834                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  835                         goto done2;
  836                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  837                         goto done2;
  838                 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
  839                         error = EINVAL;
  840                         goto done2;
  841                 }
  842                 *rval = semakptr->u.__sem_base[semnum].semval;
  843                 break;
  844 
  845         case GETALL:
  846                 /*
  847                  * Unfortunately, callers of this function don't know
  848                  * in advance how many semaphores are in this set.
  849                  * While we could just allocate the maximum size array
  850                  * and pass the actual size back to the caller, that
  851                  * won't work for SETALL since we can't copyin() more
  852                  * data than the user specified as we may return a
  853                  * spurious EFAULT.
  854                  * 
  855                  * Note that the number of semaphores in a set is
  856                  * fixed for the life of that set.  The only way that
  857                  * the 'count' could change while are blocked in
  858                  * malloc() is if this semaphore set were destroyed
  859                  * and a new one created with the same index.
  860                  * However, semvalid() will catch that due to the
  861                  * sequence number unless exactly 0x8000 (or a
  862                  * multiple thereof) semaphore sets for the same index
  863                  * are created and destroyed while we are in malloc!
  864                  *
  865                  */
  866                 count = semakptr->u.sem_nsems;
  867                 mtx_unlock(sema_mtxp);              
  868                 array = malloc(sizeof(*array) * count, M_TEMP, M_WAITOK);
  869                 mtx_lock(sema_mtxp);
  870                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  871                         goto done2;
  872                 KASSERT(count == semakptr->u.sem_nsems, ("nsems changed"));
  873                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  874                         goto done2;
  875                 for (i = 0; i < semakptr->u.sem_nsems; i++)
  876                         array[i] = semakptr->u.__sem_base[i].semval;
  877                 mtx_unlock(sema_mtxp);
  878                 error = copyout(array, arg->array, count * sizeof(*array));
  879                 mtx_lock(sema_mtxp);
  880                 break;
  881 
  882         case GETZCNT:
  883                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  884                         goto done2;
  885                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
  886                         goto done2;
  887                 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
  888                         error = EINVAL;
  889                         goto done2;
  890                 }
  891                 *rval = semakptr->u.__sem_base[semnum].semzcnt;
  892                 break;
  893 
  894         case SETVAL:
  895                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  896                         goto done2;
  897                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W)))
  898                         goto done2;
  899                 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
  900                         error = EINVAL;
  901                         goto done2;
  902                 }
  903                 if (arg->val < 0 || arg->val > seminfo.semvmx) {
  904                         error = ERANGE;
  905                         goto done2;
  906                 }
  907                 semakptr->u.__sem_base[semnum].semval = arg->val;
  908                 SEMUNDO_LOCK();
  909                 semundo_clear(semidx, semnum);
  910                 SEMUNDO_UNLOCK();
  911                 wakeup(semakptr);
  912                 break;
  913 
  914         case SETALL:
  915                 /*
  916                  * See comment on GETALL for why 'count' shouldn't change
  917                  * and why we require a userland buffer.
  918                  */
  919                 count = semakptr->u.sem_nsems;
  920                 mtx_unlock(sema_mtxp);              
  921                 array = malloc(sizeof(*array) * count, M_TEMP, M_WAITOK);
  922                 error = copyin(arg->array, array, count * sizeof(*array));
  923                 mtx_lock(sema_mtxp);
  924                 if (error)
  925                         break;
  926                 if ((error = semvalid(semid, rpr, semakptr)) != 0)
  927                         goto done2;
  928                 KASSERT(count == semakptr->u.sem_nsems, ("nsems changed"));
  929                 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W)))
  930                         goto done2;
  931                 for (i = 0; i < semakptr->u.sem_nsems; i++) {
  932                         usval = array[i];
  933                         if (usval > seminfo.semvmx) {
  934                                 error = ERANGE;
  935                                 break;
  936                         }
  937                         semakptr->u.__sem_base[i].semval = usval;
  938                 }
  939                 SEMUNDO_LOCK();
  940                 semundo_clear(semidx, -1);
  941                 SEMUNDO_UNLOCK();
  942                 wakeup(semakptr);
  943                 break;
  944 
  945         default:
  946                 error = EINVAL;
  947                 break;
  948         }
  949 
  950 done2:
  951         mtx_unlock(sema_mtxp);
  952         if (cmd == IPC_RMID)
  953                 mtx_unlock(&sem_mtx);
  954         if (array != NULL)
  955                 free(array, M_TEMP);
  956         return(error);
  957 }
  958 
  959 #ifndef _SYS_SYSPROTO_H_
  960 struct semget_args {
  961         key_t   key;
  962         int     nsems;
  963         int     semflg;
  964 };
  965 #endif
  966 int
  967 sys_semget(struct thread *td, struct semget_args *uap)
  968 {
  969         int semid, error = 0;
  970         int key = uap->key;
  971         int nsems = uap->nsems;
  972         int semflg = uap->semflg;
  973         struct ucred *cred = td->td_ucred;
  974 
  975         DPRINTF(("semget(0x%x, %d, 0%o)\n", key, nsems, semflg));
  976 
  977         AUDIT_ARG_VALUE(semflg);
  978 
  979         if (sem_find_prison(cred) == NULL)
  980                 return (ENOSYS);
  981 
  982         mtx_lock(&sem_mtx);
  983         if (key != IPC_PRIVATE) {
  984                 for (semid = 0; semid < seminfo.semmni; semid++) {
  985                         if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) &&
  986                             sema[semid].cred != NULL &&
  987                             sema[semid].cred->cr_prison == cred->cr_prison &&
  988                             sema[semid].u.sem_perm.key == key)
  989                                 break;
  990                 }
  991                 if (semid < seminfo.semmni) {
  992                         AUDIT_ARG_SVIPC_ID(semid);
  993                         DPRINTF(("found public key\n"));
  994                         if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) {
  995                                 DPRINTF(("not exclusive\n"));
  996                                 error = EEXIST;
  997                                 goto done2;
  998                         }
  999                         if ((error = ipcperm(td, &sema[semid].u.sem_perm,
 1000                             semflg & 0700))) {
 1001                                 goto done2;
 1002                         }
 1003                         if (nsems > 0 && sema[semid].u.sem_nsems < nsems) {
 1004                                 DPRINTF(("too small\n"));
 1005                                 error = EINVAL;
 1006                                 goto done2;
 1007                         }
 1008 #ifdef MAC
 1009                         error = mac_sysvsem_check_semget(cred, &sema[semid]);
 1010                         if (error != 0)
 1011                                 goto done2;
 1012 #endif
 1013                         goto found;
 1014                 }
 1015         }
 1016 
 1017         DPRINTF(("need to allocate the semid_kernel\n"));
 1018         if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) {
 1019                 if (nsems <= 0 || nsems > seminfo.semmsl) {
 1020                         DPRINTF(("nsems out of range (0<%d<=%d)\n", nsems,
 1021                             seminfo.semmsl));
 1022                         error = EINVAL;
 1023                         goto done2;
 1024                 }
 1025                 if (nsems > seminfo.semmns - semtot) {
 1026                         DPRINTF((
 1027                             "not enough semaphores left (need %d, got %d)\n",
 1028                             nsems, seminfo.semmns - semtot));
 1029                         error = ENOSPC;
 1030                         goto done2;
 1031                 }
 1032                 for (semid = 0; semid < seminfo.semmni; semid++) {
 1033                         if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) == 0)
 1034                                 break;
 1035                 }
 1036                 if (semid == seminfo.semmni) {
 1037                         DPRINTF(("no more semid_kernel's available\n"));
 1038                         error = ENOSPC;
 1039                         goto done2;
 1040                 }
 1041 #ifdef RACCT
 1042                 if (racct_enable) {
 1043                         PROC_LOCK(td->td_proc);
 1044                         error = racct_add(td->td_proc, RACCT_NSEM, nsems);
 1045                         PROC_UNLOCK(td->td_proc);
 1046                         if (error != 0) {
 1047                                 error = ENOSPC;
 1048                                 goto done2;
 1049                         }
 1050                 }
 1051 #endif
 1052                 DPRINTF(("semid %d is available\n", semid));
 1053                 mtx_lock(&sema_mtx[semid]);
 1054                 KASSERT((sema[semid].u.sem_perm.mode & SEM_ALLOC) == 0,
 1055                     ("Lost semaphore %d", semid));
 1056                 sema[semid].u.sem_perm.key = key;
 1057                 sema[semid].u.sem_perm.cuid = cred->cr_uid;
 1058                 sema[semid].u.sem_perm.uid = cred->cr_uid;
 1059                 sema[semid].u.sem_perm.cgid = cred->cr_gid;
 1060                 sema[semid].u.sem_perm.gid = cred->cr_gid;
 1061                 sema[semid].u.sem_perm.mode = (semflg & 0777) | SEM_ALLOC;
 1062                 sema[semid].cred = crhold(cred);
 1063                 sema[semid].u.sem_perm.seq =
 1064                     (sema[semid].u.sem_perm.seq + 1) & 0x7fff;
 1065                 sema[semid].u.sem_nsems = nsems;
 1066                 sema[semid].u.sem_otime = 0;
 1067                 sema[semid].u.sem_ctime = time_second;
 1068                 sema[semid].u.__sem_base = &sem[semtot];
 1069                 semtot += nsems;
 1070                 bzero(sema[semid].u.__sem_base,
 1071                     sizeof(sema[semid].u.__sem_base[0])*nsems);
 1072 #ifdef MAC
 1073                 mac_sysvsem_create(cred, &sema[semid]);
 1074 #endif
 1075                 mtx_unlock(&sema_mtx[semid]);
 1076                 DPRINTF(("sembase = %p, next = %p\n",
 1077                     sema[semid].u.__sem_base, &sem[semtot]));
 1078         } else {
 1079                 DPRINTF(("didn't find it and wasn't asked to create it\n"));
 1080                 error = ENOENT;
 1081                 goto done2;
 1082         }
 1083 
 1084 found:
 1085         td->td_retval[0] = IXSEQ_TO_IPCID(semid, sema[semid].u.sem_perm);
 1086 done2:
 1087         mtx_unlock(&sem_mtx);
 1088         return (error);
 1089 }
 1090 
 1091 #ifndef _SYS_SYSPROTO_H_
 1092 struct semop_args {
 1093         int     semid;
 1094         struct  sembuf *sops;
 1095         size_t  nsops;
 1096 };
 1097 #endif
 1098 int
 1099 sys_semop(struct thread *td, struct semop_args *uap)
 1100 {
 1101 #define SMALL_SOPS      8
 1102         struct sembuf small_sops[SMALL_SOPS];
 1103         int semid = uap->semid;
 1104         size_t nsops = uap->nsops;
 1105         struct prison *rpr;
 1106         struct sembuf *sops;
 1107         struct semid_kernel *semakptr;
 1108         struct sembuf *sopptr = NULL;
 1109         struct sem *semptr = NULL;
 1110         struct sem_undo *suptr;
 1111         struct mtx *sema_mtxp;
 1112         size_t i, j, k;
 1113         int error;
 1114         int do_wakeup, do_undos;
 1115         unsigned short seq;
 1116 
 1117 #ifdef SEM_DEBUG
 1118         sops = NULL;
 1119 #endif
 1120         DPRINTF(("call to semop(%d, %p, %u)\n", semid, sops, nsops));
 1121 
 1122         AUDIT_ARG_SVIPC_ID(semid);
 1123 
 1124         rpr = sem_find_prison(td->td_ucred);
 1125         if (sem == NULL)
 1126                 return (ENOSYS);
 1127 
 1128         semid = IPCID_TO_IX(semid);     /* Convert back to zero origin */
 1129 
 1130         if (semid < 0 || semid >= seminfo.semmni)
 1131                 return (EINVAL);
 1132 
 1133         /* Allocate memory for sem_ops */
 1134         if (nsops <= SMALL_SOPS)
 1135                 sops = small_sops;
 1136         else if (nsops > seminfo.semopm) {
 1137                 DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm,
 1138                     nsops));
 1139                 return (E2BIG);
 1140         } else {
 1141 #ifdef RACCT
 1142                 if (racct_enable) {
 1143                         PROC_LOCK(td->td_proc);
 1144                         if (nsops >
 1145                             racct_get_available(td->td_proc, RACCT_NSEMOP)) {
 1146                                 PROC_UNLOCK(td->td_proc);
 1147                                 return (E2BIG);
 1148                         }
 1149                         PROC_UNLOCK(td->td_proc);
 1150                 }
 1151 #endif
 1152 
 1153                 sops = malloc(nsops * sizeof(*sops), M_TEMP, M_WAITOK);
 1154         }
 1155         if ((error = copyin(uap->sops, sops, nsops * sizeof(sops[0]))) != 0) {
 1156                 DPRINTF(("error = %d from copyin(%p, %p, %d)\n", error,
 1157                     uap->sops, sops, nsops * sizeof(sops[0])));
 1158                 if (sops != small_sops)
 1159                         free(sops, M_TEMP);
 1160                 return (error);
 1161         }
 1162 
 1163         semakptr = &sema[semid];
 1164         sema_mtxp = &sema_mtx[semid];
 1165         mtx_lock(sema_mtxp);
 1166         if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) {
 1167                 error = EINVAL;
 1168                 goto done2;
 1169         }
 1170         seq = semakptr->u.sem_perm.seq;
 1171         if (seq != IPCID_TO_SEQ(uap->semid)) {
 1172                 error = EINVAL;
 1173                 goto done2;
 1174         }
 1175         if ((error = sem_prison_cansee(rpr, semakptr)) != 0)
 1176                 goto done2;
 1177         /*
 1178          * Initial pass through sops to see what permissions are needed.
 1179          * Also perform any checks that don't need repeating on each
 1180          * attempt to satisfy the request vector.
 1181          */
 1182         j = 0;          /* permission needed */
 1183         do_undos = 0;
 1184         for (i = 0; i < nsops; i++) {
 1185                 sopptr = &sops[i];
 1186                 if (sopptr->sem_num >= semakptr->u.sem_nsems) {
 1187                         error = EFBIG;
 1188                         goto done2;
 1189                 }
 1190                 if (sopptr->sem_flg & SEM_UNDO && sopptr->sem_op != 0)
 1191                         do_undos = 1;
 1192                 j |= (sopptr->sem_op == 0) ? SEM_R : SEM_A;
 1193         }
 1194 
 1195         if ((error = ipcperm(td, &semakptr->u.sem_perm, j))) {
 1196                 DPRINTF(("error = %d from ipaccess\n", error));
 1197                 goto done2;
 1198         }
 1199 #ifdef MAC
 1200         error = mac_sysvsem_check_semop(td->td_ucred, semakptr, j);
 1201         if (error != 0)
 1202                 goto done2;
 1203 #endif
 1204 
 1205         /*
 1206          * Loop trying to satisfy the vector of requests.
 1207          * If we reach a point where we must wait, any requests already
 1208          * performed are rolled back and we go to sleep until some other
 1209          * process wakes us up.  At this point, we start all over again.
 1210          *
 1211          * This ensures that from the perspective of other tasks, a set
 1212          * of requests is atomic (never partially satisfied).
 1213          */
 1214         for (;;) {
 1215                 do_wakeup = 0;
 1216                 error = 0;      /* error return if necessary */
 1217 
 1218                 for (i = 0; i < nsops; i++) {
 1219                         sopptr = &sops[i];
 1220                         semptr = &semakptr->u.__sem_base[sopptr->sem_num];
 1221 
 1222                         DPRINTF((
 1223                             "semop:  semakptr=%p, __sem_base=%p, "
 1224                             "semptr=%p, sem[%d]=%d : op=%d, flag=%s\n",
 1225                             semakptr, semakptr->u.__sem_base, semptr,
 1226                             sopptr->sem_num, semptr->semval, sopptr->sem_op,
 1227                             (sopptr->sem_flg & IPC_NOWAIT) ?
 1228                             "nowait" : "wait"));
 1229 
 1230                         if (sopptr->sem_op < 0) {
 1231                                 if (semptr->semval + sopptr->sem_op < 0) {
 1232                                         DPRINTF(("semop:  can't do it now\n"));
 1233                                         break;
 1234                                 } else {
 1235                                         semptr->semval += sopptr->sem_op;
 1236                                         if (semptr->semval == 0 &&
 1237                                             semptr->semzcnt > 0)
 1238                                                 do_wakeup = 1;
 1239                                 }
 1240                         } else if (sopptr->sem_op == 0) {
 1241                                 if (semptr->semval != 0) {
 1242                                         DPRINTF(("semop:  not zero now\n"));
 1243                                         break;
 1244                                 }
 1245                         } else if (semptr->semval + sopptr->sem_op >
 1246                             seminfo.semvmx) {
 1247                                 error = ERANGE;
 1248                                 break;
 1249                         } else {
 1250                                 if (semptr->semncnt > 0)
 1251                                         do_wakeup = 1;
 1252                                 semptr->semval += sopptr->sem_op;
 1253                         }
 1254                 }
 1255 
 1256                 /*
 1257                  * Did we get through the entire vector?
 1258                  */
 1259                 if (i >= nsops)
 1260                         goto done;
 1261 
 1262                 /*
 1263                  * No ... rollback anything that we've already done
 1264                  */
 1265                 DPRINTF(("semop:  rollback 0 through %d\n", i-1));
 1266                 for (j = 0; j < i; j++)
 1267                         semakptr->u.__sem_base[sops[j].sem_num].semval -=
 1268                             sops[j].sem_op;
 1269 
 1270                 /* If we detected an error, return it */
 1271                 if (error != 0)
 1272                         goto done2;
 1273 
 1274                 /*
 1275                  * If the request that we couldn't satisfy has the
 1276                  * NOWAIT flag set then return with EAGAIN.
 1277                  */
 1278                 if (sopptr->sem_flg & IPC_NOWAIT) {
 1279                         error = EAGAIN;
 1280                         goto done2;
 1281                 }
 1282 
 1283                 if (sopptr->sem_op == 0)
 1284                         semptr->semzcnt++;
 1285                 else
 1286                         semptr->semncnt++;
 1287 
 1288                 DPRINTF(("semop:  good night!\n"));
 1289                 error = msleep(semakptr, sema_mtxp, (PZERO - 4) | PCATCH,
 1290                     "semwait", 0);
 1291                 DPRINTF(("semop:  good morning (error=%d)!\n", error));
 1292                 /* return code is checked below, after sem[nz]cnt-- */
 1293 
 1294                 /*
 1295                  * Make sure that the semaphore still exists
 1296                  */
 1297                 seq = semakptr->u.sem_perm.seq;
 1298                 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
 1299                     seq != IPCID_TO_SEQ(uap->semid)) {
 1300                         error = EIDRM;
 1301                         goto done2;
 1302                 }
 1303 
 1304                 /*
 1305                  * Renew the semaphore's pointer after wakeup since
 1306                  * during msleep __sem_base may have been modified and semptr
 1307                  * is not valid any more
 1308                  */
 1309                 semptr = &semakptr->u.__sem_base[sopptr->sem_num];
 1310 
 1311                 /*
 1312                  * The semaphore is still alive.  Readjust the count of
 1313                  * waiting processes.
 1314                  */
 1315                 if (sopptr->sem_op == 0)
 1316                         semptr->semzcnt--;
 1317                 else
 1318                         semptr->semncnt--;
 1319 
 1320                 /*
 1321                  * Is it really morning, or was our sleep interrupted?
 1322                  * (Delayed check of msleep() return code because we
 1323                  * need to decrement sem[nz]cnt either way.)
 1324                  */
 1325                 if (error != 0) {
 1326                         error = EINTR;
 1327                         goto done2;
 1328                 }
 1329                 DPRINTF(("semop:  good morning!\n"));
 1330         }
 1331 
 1332 done:
 1333         /*
 1334          * Process any SEM_UNDO requests.
 1335          */
 1336         if (do_undos) {
 1337                 SEMUNDO_LOCK();
 1338                 suptr = NULL;
 1339                 for (i = 0; i < nsops; i++) {
 1340                         /*
 1341                          * We only need to deal with SEM_UNDO's for non-zero
 1342                          * op's.
 1343                          */
 1344                         int adjval;
 1345 
 1346                         if ((sops[i].sem_flg & SEM_UNDO) == 0)
 1347                                 continue;
 1348                         adjval = sops[i].sem_op;
 1349                         if (adjval == 0)
 1350                                 continue;
 1351                         error = semundo_adjust(td, &suptr, semid, seq,
 1352                             sops[i].sem_num, -adjval);
 1353                         if (error == 0)
 1354                                 continue;
 1355 
 1356                         /*
 1357                          * Oh-Oh!  We ran out of either sem_undo's or undo's.
 1358                          * Rollback the adjustments to this point and then
 1359                          * rollback the semaphore ups and down so we can return
 1360                          * with an error with all structures restored.  We
 1361                          * rollback the undo's in the exact reverse order that
 1362                          * we applied them.  This guarantees that we won't run
 1363                          * out of space as we roll things back out.
 1364                          */
 1365                         for (j = 0; j < i; j++) {
 1366                                 k = i - j - 1;
 1367                                 if ((sops[k].sem_flg & SEM_UNDO) == 0)
 1368                                         continue;
 1369                                 adjval = sops[k].sem_op;
 1370                                 if (adjval == 0)
 1371                                         continue;
 1372                                 if (semundo_adjust(td, &suptr, semid, seq,
 1373                                     sops[k].sem_num, adjval) != 0)
 1374                                         panic("semop - can't undo undos");
 1375                         }
 1376 
 1377                         for (j = 0; j < nsops; j++)
 1378                                 semakptr->u.__sem_base[sops[j].sem_num].semval -=
 1379                                     sops[j].sem_op;
 1380 
 1381                         DPRINTF(("error = %d from semundo_adjust\n", error));
 1382                         SEMUNDO_UNLOCK();
 1383                         goto done2;
 1384                 } /* loop through the sops */
 1385                 SEMUNDO_UNLOCK();
 1386         } /* if (do_undos) */
 1387 
 1388         /* We're definitely done - set the sempid's and time */
 1389         for (i = 0; i < nsops; i++) {
 1390                 sopptr = &sops[i];
 1391                 semptr = &semakptr->u.__sem_base[sopptr->sem_num];
 1392                 semptr->sempid = td->td_proc->p_pid;
 1393         }
 1394         semakptr->u.sem_otime = time_second;
 1395 
 1396         /*
 1397          * Do a wakeup if any semaphore was up'd whilst something was
 1398          * sleeping on it.
 1399          */
 1400         if (do_wakeup) {
 1401                 DPRINTF(("semop:  doing wakeup\n"));
 1402                 wakeup(semakptr);
 1403                 DPRINTF(("semop:  back from wakeup\n"));
 1404         }
 1405         DPRINTF(("semop:  done\n"));
 1406         td->td_retval[0] = 0;
 1407 done2:
 1408         mtx_unlock(sema_mtxp);
 1409         if (sops != small_sops)
 1410                 free(sops, M_TEMP);
 1411         return (error);
 1412 }
 1413 
 1414 /*
 1415  * Go through the undo structures for this process and apply the adjustments to
 1416  * semaphores.
 1417  */
 1418 static void
 1419 semexit_myhook(void *arg, struct proc *p)
 1420 {
 1421         struct sem_undo *suptr;
 1422         struct semid_kernel *semakptr;
 1423         struct mtx *sema_mtxp;
 1424         int semid, semnum, adjval, ix;
 1425         unsigned short seq;
 1426 
 1427         /*
 1428          * Go through the chain of undo vectors looking for one
 1429          * associated with this process.
 1430          */
 1431         if (LIST_EMPTY(&semu_list))
 1432                 return;
 1433         SEMUNDO_LOCK();
 1434         LIST_FOREACH(suptr, &semu_list, un_next) {
 1435                 if (suptr->un_proc == p)
 1436                         break;
 1437         }
 1438         if (suptr == NULL) {
 1439                 SEMUNDO_UNLOCK();
 1440                 return;
 1441         }
 1442         LIST_REMOVE(suptr, un_next);
 1443 
 1444         DPRINTF(("proc @%p has undo structure with %d entries\n", p,
 1445             suptr->un_cnt));
 1446 
 1447         /*
 1448          * If there are any active undo elements then process them.
 1449          */
 1450         if (suptr->un_cnt > 0) {
 1451                 SEMUNDO_UNLOCK();
 1452                 for (ix = 0; ix < suptr->un_cnt; ix++) {
 1453                         semid = suptr->un_ent[ix].un_id;
 1454                         semnum = suptr->un_ent[ix].un_num;
 1455                         adjval = suptr->un_ent[ix].un_adjval;
 1456                         seq = suptr->un_ent[ix].un_seq;
 1457                         semakptr = &sema[semid];
 1458                         sema_mtxp = &sema_mtx[semid];
 1459 
 1460                         mtx_lock(sema_mtxp);
 1461                         if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
 1462                             (semakptr->u.sem_perm.seq != seq)) {
 1463                                 mtx_unlock(sema_mtxp);
 1464                                 continue;
 1465                         }
 1466                         if (semnum >= semakptr->u.sem_nsems)
 1467                                 panic("semexit - semnum out of range");
 1468 
 1469                         DPRINTF((
 1470                             "semexit:  %p id=%d num=%d(adj=%d) ; sem=%d\n",
 1471                             suptr->un_proc, suptr->un_ent[ix].un_id,
 1472                             suptr->un_ent[ix].un_num,
 1473                             suptr->un_ent[ix].un_adjval,
 1474                             semakptr->u.__sem_base[semnum].semval));
 1475 
 1476                         if (adjval < 0 && semakptr->u.__sem_base[semnum].semval <
 1477                             -adjval)
 1478                                 semakptr->u.__sem_base[semnum].semval = 0;
 1479                         else
 1480                                 semakptr->u.__sem_base[semnum].semval += adjval;
 1481 
 1482                         wakeup(semakptr);
 1483                         DPRINTF(("semexit:  back from wakeup\n"));
 1484                         mtx_unlock(sema_mtxp);
 1485                 }
 1486                 SEMUNDO_LOCK();
 1487         }
 1488 
 1489         /*
 1490          * Deallocate the undo vector.
 1491          */
 1492         DPRINTF(("removing vector\n"));
 1493         suptr->un_proc = NULL;
 1494         suptr->un_cnt = 0;
 1495         LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
 1496         SEMUNDO_UNLOCK();
 1497 }
 1498 
 1499 static int
 1500 sysctl_sema(SYSCTL_HANDLER_ARGS)
 1501 {
 1502         struct prison *pr, *rpr;
 1503         struct semid_kernel tsemak;
 1504 #ifdef COMPAT_FREEBSD32
 1505         struct semid_kernel32 tsemak32;
 1506 #endif
 1507         void *outaddr;
 1508         size_t outsize;
 1509         int error, i;
 1510 
 1511         pr = req->td->td_ucred->cr_prison;
 1512         rpr = sem_find_prison(req->td->td_ucred);
 1513         error = 0;
 1514         for (i = 0; i < seminfo.semmni; i++) {
 1515                 mtx_lock(&sema_mtx[i]);
 1516                 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) == 0 ||
 1517                     rpr == NULL || sem_prison_cansee(rpr, &sema[i]) != 0)
 1518                         bzero(&tsemak, sizeof(tsemak));
 1519                 else {
 1520                         tsemak = sema[i];
 1521                         if (tsemak.cred->cr_prison != pr)
 1522                                 tsemak.u.sem_perm.key = IPC_PRIVATE;
 1523                 }
 1524                 mtx_unlock(&sema_mtx[i]);
 1525 #ifdef COMPAT_FREEBSD32
 1526                 if (SV_CURPROC_FLAG(SV_ILP32)) {
 1527                         bzero(&tsemak32, sizeof(tsemak32));
 1528                         freebsd32_ipcperm_out(&tsemak.u.sem_perm,
 1529                             &tsemak32.u.sem_perm);
 1530                         /* Don't copy u.__sem_base */
 1531                         CP(tsemak, tsemak32, u.sem_nsems);
 1532                         CP(tsemak, tsemak32, u.sem_otime);
 1533                         CP(tsemak, tsemak32, u.sem_ctime);
 1534                         /* Don't copy label or cred */
 1535                         outaddr = &tsemak32;
 1536                         outsize = sizeof(tsemak32);
 1537                 } else
 1538 #endif
 1539                 {
 1540                         tsemak.u.__sem_base = NULL;
 1541                         tsemak.label = NULL;
 1542                         tsemak.cred = NULL;
 1543                         outaddr = &tsemak;
 1544                         outsize = sizeof(tsemak);
 1545                 }
 1546                 error = SYSCTL_OUT(req, outaddr, outsize);
 1547                 if (error != 0)
 1548                         break;
 1549         }
 1550         return (error);
 1551 }
 1552 
 1553 static int
 1554 sem_prison_check(void *obj, void *data)
 1555 {
 1556         struct prison *pr = obj;
 1557         struct prison *prpr;
 1558         struct vfsoptlist *opts = data;
 1559         int error, jsys;
 1560 
 1561         /*
 1562          * sysvsem is a jailsys integer.
 1563          * It must be "disable" if the parent jail is disabled.
 1564          */
 1565         error = vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys));
 1566         if (error != ENOENT) {
 1567                 if (error != 0)
 1568                         return (error);
 1569                 switch (jsys) {
 1570                 case JAIL_SYS_DISABLE:
 1571                         break;
 1572                 case JAIL_SYS_NEW:
 1573                 case JAIL_SYS_INHERIT:
 1574                         prison_lock(pr->pr_parent);
 1575                         prpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
 1576                         prison_unlock(pr->pr_parent);
 1577                         if (prpr == NULL)
 1578                                 return (EPERM);
 1579                         break;
 1580                 default:
 1581                         return (EINVAL);
 1582                 }
 1583         }
 1584 
 1585         return (0);
 1586 }
 1587 
 1588 static int
 1589 sem_prison_set(void *obj, void *data)
 1590 {
 1591         struct prison *pr = obj;
 1592         struct prison *tpr, *orpr, *nrpr, *trpr;
 1593         struct vfsoptlist *opts = data;
 1594         void *rsv;
 1595         int jsys, descend;
 1596 
 1597         /*
 1598          * sysvsem controls which jail is the root of the associated sems (this
 1599          * jail or same as the parent), or if the feature is available at all.
 1600          */
 1601         if (vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys)) == ENOENT)
 1602                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
 1603                     ? JAIL_SYS_INHERIT
 1604                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
 1605                     ? JAIL_SYS_DISABLE
 1606                     : -1;
 1607         if (jsys == JAIL_SYS_DISABLE) {
 1608                 prison_lock(pr);
 1609                 orpr = osd_jail_get(pr, sem_prison_slot);
 1610                 if (orpr != NULL)
 1611                         osd_jail_del(pr, sem_prison_slot);
 1612                 prison_unlock(pr);
 1613                 if (orpr != NULL) {
 1614                         if (orpr == pr)
 1615                                 sem_prison_cleanup(pr);
 1616                         /* Disable all child jails as well. */
 1617                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
 1618                                 prison_lock(tpr);
 1619                                 trpr = osd_jail_get(tpr, sem_prison_slot);
 1620                                 if (trpr != NULL) {
 1621                                         osd_jail_del(tpr, sem_prison_slot);
 1622                                         prison_unlock(tpr);
 1623                                         if (trpr == tpr)
 1624                                                 sem_prison_cleanup(tpr);
 1625                                 } else {
 1626                                         prison_unlock(tpr);
 1627                                         descend = 0;
 1628                                 }
 1629                         }
 1630                 }
 1631         } else if (jsys != -1) {
 1632                 if (jsys == JAIL_SYS_NEW)
 1633                         nrpr = pr;
 1634                 else {
 1635                         prison_lock(pr->pr_parent);
 1636                         nrpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
 1637                         prison_unlock(pr->pr_parent);
 1638                 }
 1639                 rsv = osd_reserve(sem_prison_slot);
 1640                 prison_lock(pr);
 1641                 orpr = osd_jail_get(pr, sem_prison_slot);
 1642                 if (orpr != nrpr)
 1643                         (void)osd_jail_set_reserved(pr, sem_prison_slot, rsv,
 1644                             nrpr);
 1645                 else
 1646                         osd_free_reserved(rsv);
 1647                 prison_unlock(pr);
 1648                 if (orpr != nrpr) {
 1649                         if (orpr == pr)
 1650                                 sem_prison_cleanup(pr);
 1651                         if (orpr != NULL) {
 1652                                 /* Change child jails matching the old root, */
 1653                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
 1654                                         prison_lock(tpr);
 1655                                         trpr = osd_jail_get(tpr,
 1656                                             sem_prison_slot);
 1657                                         if (trpr == orpr) {
 1658                                                 (void)osd_jail_set(tpr,
 1659                                                     sem_prison_slot, nrpr);
 1660                                                 prison_unlock(tpr);
 1661                                                 if (trpr == tpr)
 1662                                                         sem_prison_cleanup(tpr);
 1663                                         } else {
 1664                                                 prison_unlock(tpr);
 1665                                                 descend = 0;
 1666                                         }
 1667                                 }
 1668                         }
 1669                 }
 1670         }
 1671 
 1672         return (0);
 1673 }
 1674 
 1675 static int
 1676 sem_prison_get(void *obj, void *data)
 1677 {
 1678         struct prison *pr = obj;
 1679         struct prison *rpr;
 1680         struct vfsoptlist *opts = data;
 1681         int error, jsys;
 1682 
 1683         /* Set sysvsem based on the jail's root prison. */
 1684         prison_lock(pr);
 1685         rpr = osd_jail_get(pr, sem_prison_slot);
 1686         prison_unlock(pr);
 1687         jsys = rpr == NULL ? JAIL_SYS_DISABLE
 1688             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
 1689         error = vfs_setopt(opts, "sysvsem", &jsys, sizeof(jsys));
 1690         if (error == ENOENT)
 1691                 error = 0;
 1692         return (error);
 1693 }
 1694 
 1695 static int
 1696 sem_prison_remove(void *obj, void *data __unused)
 1697 {
 1698         struct prison *pr = obj;
 1699         struct prison *rpr;
 1700 
 1701         prison_lock(pr);
 1702         rpr = osd_jail_get(pr, sem_prison_slot);
 1703         prison_unlock(pr);
 1704         if (rpr == pr)
 1705                 sem_prison_cleanup(pr);
 1706         return (0);
 1707 }
 1708 
 1709 static void
 1710 sem_prison_cleanup(struct prison *pr)
 1711 {
 1712         int i;
 1713 
 1714         /* Remove any sems that belong to this jail. */
 1715         mtx_lock(&sem_mtx);
 1716         for (i = 0; i < seminfo.semmni; i++) {
 1717                 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
 1718                     sema[i].cred != NULL && sema[i].cred->cr_prison == pr) {
 1719                         mtx_lock(&sema_mtx[i]);
 1720                         sem_remove(i, NULL);
 1721                         mtx_unlock(&sema_mtx[i]);
 1722                 }
 1723         }
 1724         mtx_unlock(&sem_mtx);
 1725 }
 1726 
 1727 SYSCTL_JAIL_PARAM_SYS_NODE(sysvsem, CTLFLAG_RW, "SYSV semaphores");
 1728 
 1729 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 1730     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 1731 
 1732 /* XXX casting to (sy_call_t *) is bogus, as usual. */
 1733 static sy_call_t *semcalls[] = {
 1734         (sy_call_t *)freebsd7___semctl, (sy_call_t *)sys_semget,
 1735         (sy_call_t *)sys_semop
 1736 };
 1737 
 1738 /*
 1739  * Entry point for all SEM calls.
 1740  */
 1741 int
 1742 sys_semsys(td, uap)
 1743         struct thread *td;
 1744         /* XXX actually varargs. */
 1745         struct semsys_args /* {
 1746                 int     which;
 1747                 int     a2;
 1748                 int     a3;
 1749                 int     a4;
 1750                 int     a5;
 1751         } */ *uap;
 1752 {
 1753         int error;
 1754 
 1755         AUDIT_ARG_SVIPC_WHICH(uap->which);
 1756         if (uap->which < 0 || uap->which >= nitems(semcalls))
 1757                 return (EINVAL);
 1758         error = (*semcalls[uap->which])(td, &uap->a2);
 1759         return (error);
 1760 }
 1761 
 1762 #ifndef _SYS_SYSPROTO_H_
 1763 struct freebsd7___semctl_args {
 1764         int     semid;
 1765         int     semnum;
 1766         int     cmd;
 1767         union   semun_old *arg;
 1768 };
 1769 #endif
 1770 int
 1771 freebsd7___semctl(struct thread *td, struct freebsd7___semctl_args *uap)
 1772 {
 1773         struct semid_ds_old dsold;
 1774         struct semid_ds dsbuf;
 1775         union semun_old arg;
 1776         union semun semun;
 1777         register_t rval;
 1778         int error;
 1779 
 1780         switch (uap->cmd) {
 1781         case SEM_STAT:
 1782         case IPC_SET:
 1783         case IPC_STAT:
 1784         case GETALL:
 1785         case SETVAL:
 1786         case SETALL:
 1787                 error = copyin(uap->arg, &arg, sizeof(arg));
 1788                 if (error)
 1789                         return (error);
 1790                 break;
 1791         }
 1792 
 1793         switch (uap->cmd) {
 1794         case SEM_STAT:
 1795         case IPC_STAT:
 1796                 semun.buf = &dsbuf;
 1797                 break;
 1798         case IPC_SET:
 1799                 error = copyin(arg.buf, &dsold, sizeof(dsold));
 1800                 if (error)
 1801                         return (error);
 1802                 ipcperm_old2new(&dsold.sem_perm, &dsbuf.sem_perm);
 1803                 CP(dsold, dsbuf, __sem_base);
 1804                 CP(dsold, dsbuf, sem_nsems);
 1805                 CP(dsold, dsbuf, sem_otime);
 1806                 CP(dsold, dsbuf, sem_ctime);
 1807                 semun.buf = &dsbuf;
 1808                 break;
 1809         case GETALL:
 1810         case SETALL:
 1811                 semun.array = arg.array;
 1812                 break;
 1813         case SETVAL:
 1814                 semun.val = arg.val;
 1815                 break;          
 1816         }
 1817 
 1818         error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
 1819             &rval);
 1820         if (error)
 1821                 return (error);
 1822 
 1823         switch (uap->cmd) {
 1824         case SEM_STAT:
 1825         case IPC_STAT:
 1826                 bzero(&dsold, sizeof(dsold));
 1827                 ipcperm_new2old(&dsbuf.sem_perm, &dsold.sem_perm);
 1828                 CP(dsbuf, dsold, __sem_base);
 1829                 CP(dsbuf, dsold, sem_nsems);
 1830                 CP(dsbuf, dsold, sem_otime);
 1831                 CP(dsbuf, dsold, sem_ctime);
 1832                 error = copyout(&dsold, arg.buf, sizeof(dsold));
 1833                 break;
 1834         }
 1835 
 1836         if (error == 0)
 1837                 td->td_retval[0] = rval;
 1838         return (error);
 1839 }
 1840 
 1841 #endif /* COMPAT_FREEBSD{4,5,6,7} */
 1842 
 1843 #ifdef COMPAT_FREEBSD32
 1844 
 1845 int
 1846 freebsd32_semsys(struct thread *td, struct freebsd32_semsys_args *uap)
 1847 {
 1848 
 1849 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 1850     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 1851         AUDIT_ARG_SVIPC_WHICH(uap->which);
 1852         switch (uap->which) {
 1853         case 0:
 1854                 return (freebsd7_freebsd32_semctl(td,
 1855                     (struct freebsd7_freebsd32_semctl_args *)&uap->a2));
 1856         default:
 1857                 return (sys_semsys(td, (struct semsys_args *)uap));
 1858         }
 1859 #else
 1860         return (nosys(td, NULL));
 1861 #endif
 1862 }
 1863 
 1864 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 1865     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 1866 int
 1867 freebsd7_freebsd32_semctl(struct thread *td,
 1868     struct freebsd7_freebsd32_semctl_args *uap)
 1869 {
 1870         struct semid_ds32_old dsbuf32;
 1871         struct semid_ds dsbuf;
 1872         union semun semun;
 1873         union semun32 arg;
 1874         register_t rval;
 1875         int error;
 1876 
 1877         switch (uap->cmd) {
 1878         case SEM_STAT:
 1879         case IPC_SET:
 1880         case IPC_STAT:
 1881         case GETALL:
 1882         case SETVAL:
 1883         case SETALL:
 1884                 error = copyin(uap->arg, &arg, sizeof(arg));
 1885                 if (error)
 1886                         return (error);         
 1887                 break;
 1888         }
 1889 
 1890         switch (uap->cmd) {
 1891         case SEM_STAT:
 1892         case IPC_STAT:
 1893                 semun.buf = &dsbuf;
 1894                 break;
 1895         case IPC_SET:
 1896                 error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
 1897                 if (error)
 1898                         return (error);
 1899                 freebsd32_ipcperm_old_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
 1900                 PTRIN_CP(dsbuf32, dsbuf, __sem_base);
 1901                 CP(dsbuf32, dsbuf, sem_nsems);
 1902                 CP(dsbuf32, dsbuf, sem_otime);
 1903                 CP(dsbuf32, dsbuf, sem_ctime);
 1904                 semun.buf = &dsbuf;
 1905                 break;
 1906         case GETALL:
 1907         case SETALL:
 1908                 semun.array = PTRIN(arg.array);
 1909                 break;
 1910         case SETVAL:
 1911                 semun.val = arg.val;
 1912                 break;
 1913         }
 1914 
 1915         error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
 1916             &rval);
 1917         if (error)
 1918                 return (error);
 1919 
 1920         switch (uap->cmd) {
 1921         case SEM_STAT:
 1922         case IPC_STAT:
 1923                 bzero(&dsbuf32, sizeof(dsbuf32));
 1924                 freebsd32_ipcperm_old_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
 1925                 PTROUT_CP(dsbuf, dsbuf32, __sem_base);
 1926                 CP(dsbuf, dsbuf32, sem_nsems);
 1927                 CP(dsbuf, dsbuf32, sem_otime);
 1928                 CP(dsbuf, dsbuf32, sem_ctime);
 1929                 error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
 1930                 break;
 1931         }
 1932 
 1933         if (error == 0)
 1934                 td->td_retval[0] = rval;
 1935         return (error);
 1936 }
 1937 #endif
 1938 
 1939 int
 1940 freebsd32_semctl(struct thread *td, struct freebsd32_semctl_args *uap)
 1941 {
 1942         struct semid_ds32 dsbuf32;
 1943         struct semid_ds dsbuf;
 1944         union semun semun;
 1945         union semun32 arg;
 1946         register_t rval;
 1947         int error;
 1948 
 1949         switch (uap->cmd) {
 1950         case SEM_STAT:
 1951         case IPC_SET:
 1952         case IPC_STAT:
 1953         case GETALL:
 1954         case SETVAL:
 1955         case SETALL:
 1956                 error = copyin(uap->arg, &arg, sizeof(arg));
 1957                 if (error)
 1958                         return (error);         
 1959                 break;
 1960         }
 1961 
 1962         switch (uap->cmd) {
 1963         case SEM_STAT:
 1964         case IPC_STAT:
 1965                 semun.buf = &dsbuf;
 1966                 break;
 1967         case IPC_SET:
 1968                 error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
 1969                 if (error)
 1970                         return (error);
 1971                 freebsd32_ipcperm_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
 1972                 PTRIN_CP(dsbuf32, dsbuf, __sem_base);
 1973                 CP(dsbuf32, dsbuf, sem_nsems);
 1974                 CP(dsbuf32, dsbuf, sem_otime);
 1975                 CP(dsbuf32, dsbuf, sem_ctime);
 1976                 semun.buf = &dsbuf;
 1977                 break;
 1978         case GETALL:
 1979         case SETALL:
 1980                 semun.array = PTRIN(arg.array);
 1981                 break;
 1982         case SETVAL:
 1983                 semun.val = arg.val;
 1984                 break;          
 1985         }
 1986 
 1987         error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
 1988             &rval);
 1989         if (error)
 1990                 return (error);
 1991 
 1992         switch (uap->cmd) {
 1993         case SEM_STAT:
 1994         case IPC_STAT:
 1995                 bzero(&dsbuf32, sizeof(dsbuf32));
 1996                 freebsd32_ipcperm_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
 1997                 PTROUT_CP(dsbuf, dsbuf32, __sem_base);
 1998                 CP(dsbuf, dsbuf32, sem_nsems);
 1999                 CP(dsbuf, dsbuf32, sem_otime);
 2000                 CP(dsbuf, dsbuf32, sem_ctime);
 2001                 error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
 2002                 break;
 2003         }
 2004 
 2005         if (error == 0)
 2006                 td->td_retval[0] = rval;
 2007         return (error);
 2008 }
 2009 
 2010 #endif /* COMPAT_FREEBSD32 */

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