893 lines
21 KiB
C
893 lines
21 KiB
C
/* $FreeBSD$ */
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/* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */
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/*
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* Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Adam Glass and Charles
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* Hannum.
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* 4. The names of the authors may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "opt_compat.h"
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#include "opt_sysvipc.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/sysctl.h>
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#include <sys/shm.h>
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#include <sys/proc.h>
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#include <sys/malloc.h>
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#include <sys/mman.h>
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#include <sys/mutex.h>
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#include <sys/stat.h>
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#include <sys/syscall.h>
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#include <sys/sysent.h>
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#include <sys/sysproto.h>
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#include <sys/jail.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <vm/vm_object.h>
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#include <vm/vm_map.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pager.h>
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static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
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struct oshmctl_args;
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static int oshmctl(struct thread *td, struct oshmctl_args *uap);
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static int shmget_allocate_segment(struct thread *td,
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struct shmget_args *uap, int mode);
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static int shmget_existing(struct thread *td, struct shmget_args *uap,
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int mode, int segnum);
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/* XXX casting to (sy_call_t *) is bogus, as usual. */
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static sy_call_t *shmcalls[] = {
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(sy_call_t *)shmat, (sy_call_t *)oshmctl,
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(sy_call_t *)shmdt, (sy_call_t *)shmget,
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(sy_call_t *)shmctl
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};
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#define SHMSEG_FREE 0x0200
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#define SHMSEG_REMOVED 0x0400
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#define SHMSEG_ALLOCATED 0x0800
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#define SHMSEG_WANTED 0x1000
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static int shm_last_free, shm_nused, shm_committed, shmalloced;
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static struct shmid_ds *shmsegs;
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struct shm_handle {
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/* vm_offset_t kva; */
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vm_object_t shm_object;
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};
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struct shmmap_state {
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vm_offset_t va;
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int shmid;
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};
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static void shm_deallocate_segment(struct shmid_ds *);
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static int shm_find_segment_by_key(key_t);
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static struct shmid_ds *shm_find_segment_by_shmid(int);
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static struct shmid_ds *shm_find_segment_by_shmidx(int);
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static int shm_delete_mapping(struct proc *p, struct shmmap_state *);
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static void shmrealloc(void);
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static void shminit(void);
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static int sysvshm_modload(struct module *, int, void *);
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static int shmunload(void);
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static void shmexit_myhook(struct proc *p);
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static void shmfork_myhook(struct proc *p1, struct proc *p2);
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static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
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/*
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* Tuneable values.
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*/
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#ifndef SHMMAXPGS
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#define SHMMAXPGS 8192 /* Note: sysv shared memory is swap backed. */
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#endif
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#ifndef SHMMAX
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#define SHMMAX (SHMMAXPGS*PAGE_SIZE)
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#endif
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#ifndef SHMMIN
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#define SHMMIN 1
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#endif
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#ifndef SHMMNI
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#define SHMMNI 192
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#endif
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#ifndef SHMSEG
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#define SHMSEG 128
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#endif
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#ifndef SHMALL
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#define SHMALL (SHMMAXPGS)
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#endif
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struct shminfo shminfo = {
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SHMMAX,
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SHMMIN,
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SHMMNI,
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SHMSEG,
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SHMALL
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};
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static int shm_use_phys;
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SYSCTL_DECL(_kern_ipc);
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SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RD, &shminfo.shmseg, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW,
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&shm_use_phys, 0, "");
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SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLFLAG_RD,
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NULL, 0, sysctl_shmsegs, "", "");
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static int
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shm_find_segment_by_key(key)
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key_t key;
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{
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int i;
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for (i = 0; i < shmalloced; i++)
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if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
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shmsegs[i].shm_perm.key == key)
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return (i);
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return (-1);
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}
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static struct shmid_ds *
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shm_find_segment_by_shmid(shmid)
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int shmid;
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{
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int segnum;
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struct shmid_ds *shmseg;
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segnum = IPCID_TO_IX(shmid);
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if (segnum < 0 || segnum >= shmalloced)
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return (NULL);
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shmseg = &shmsegs[segnum];
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if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
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!= SHMSEG_ALLOCATED ||
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shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
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return (NULL);
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return (shmseg);
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}
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static struct shmid_ds *
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shm_find_segment_by_shmidx(int segnum)
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{
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struct shmid_ds *shmseg;
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if (segnum < 0 || segnum >= shmalloced)
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return (NULL);
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shmseg = &shmsegs[segnum];
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if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
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!= SHMSEG_ALLOCATED )
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return (NULL);
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return (shmseg);
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}
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static void
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shm_deallocate_segment(shmseg)
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struct shmid_ds *shmseg;
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{
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struct shm_handle *shm_handle;
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size_t size;
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GIANT_REQUIRED;
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shm_handle = shmseg->shm_internal;
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vm_object_deallocate(shm_handle->shm_object);
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free(shm_handle, M_SHM);
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shmseg->shm_internal = NULL;
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size = round_page(shmseg->shm_segsz);
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shm_committed -= btoc(size);
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shm_nused--;
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shmseg->shm_perm.mode = SHMSEG_FREE;
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}
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static int
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shm_delete_mapping(p, shmmap_s)
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struct proc *p;
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struct shmmap_state *shmmap_s;
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{
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struct shmid_ds *shmseg;
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int segnum, result;
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size_t size;
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GIANT_REQUIRED;
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segnum = IPCID_TO_IX(shmmap_s->shmid);
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shmseg = &shmsegs[segnum];
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size = round_page(shmseg->shm_segsz);
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result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va,
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shmmap_s->va + size);
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if (result != KERN_SUCCESS)
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return (EINVAL);
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shmmap_s->shmid = -1;
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shmseg->shm_dtime = time_second;
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if ((--shmseg->shm_nattch <= 0) &&
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(shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
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shm_deallocate_segment(shmseg);
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shm_last_free = segnum;
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}
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return (0);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct shmdt_args {
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void *shmaddr;
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};
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#endif
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/*
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* MPSAFE
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*/
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int
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shmdt(td, uap)
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struct thread *td;
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struct shmdt_args *uap;
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{
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struct proc *p = td->td_proc;
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struct shmmap_state *shmmap_s;
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int i;
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int error = 0;
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if (!jail_sysvipc_allowed && jailed(td->td_ucred))
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return (ENOSYS);
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mtx_lock(&Giant);
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shmmap_s = p->p_vmspace->vm_shm;
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if (shmmap_s == NULL) {
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error = EINVAL;
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goto done2;
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}
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for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
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if (shmmap_s->shmid != -1 &&
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shmmap_s->va == (vm_offset_t)uap->shmaddr) {
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break;
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}
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}
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if (i == shminfo.shmseg) {
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error = EINVAL;
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goto done2;
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}
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error = shm_delete_mapping(p, shmmap_s);
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done2:
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mtx_unlock(&Giant);
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return (error);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct shmat_args {
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int shmid;
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void *shmaddr;
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int shmflg;
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};
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#endif
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/*
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* MPSAFE
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*/
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int
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shmat(td, uap)
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struct thread *td;
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struct shmat_args *uap;
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{
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struct proc *p = td->td_proc;
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int i, flags;
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struct shmid_ds *shmseg;
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struct shmmap_state *shmmap_s = NULL;
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struct shm_handle *shm_handle;
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vm_offset_t attach_va;
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vm_prot_t prot;
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vm_size_t size;
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int rv;
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int error = 0;
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if (!jail_sysvipc_allowed && jailed(td->td_ucred))
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return (ENOSYS);
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mtx_lock(&Giant);
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shmmap_s = p->p_vmspace->vm_shm;
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if (shmmap_s == NULL) {
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size = shminfo.shmseg * sizeof(struct shmmap_state);
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shmmap_s = malloc(size, M_SHM, M_WAITOK);
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for (i = 0; i < shminfo.shmseg; i++)
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shmmap_s[i].shmid = -1;
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p->p_vmspace->vm_shm = shmmap_s;
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}
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shmseg = shm_find_segment_by_shmid(uap->shmid);
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if (shmseg == NULL) {
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error = EINVAL;
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goto done2;
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}
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error = ipcperm(td, &shmseg->shm_perm,
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(uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
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if (error)
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goto done2;
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for (i = 0; i < shminfo.shmseg; i++) {
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if (shmmap_s->shmid == -1)
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break;
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shmmap_s++;
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}
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if (i >= shminfo.shmseg) {
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error = EMFILE;
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goto done2;
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}
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size = round_page(shmseg->shm_segsz);
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#ifdef VM_PROT_READ_IS_EXEC
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prot = VM_PROT_READ | VM_PROT_EXECUTE;
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#else
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prot = VM_PROT_READ;
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#endif
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if ((uap->shmflg & SHM_RDONLY) == 0)
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prot |= VM_PROT_WRITE;
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flags = MAP_ANON | MAP_SHARED;
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if (uap->shmaddr) {
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flags |= MAP_FIXED;
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if (uap->shmflg & SHM_RND) {
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attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1);
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} else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) {
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attach_va = (vm_offset_t)uap->shmaddr;
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} else {
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error = EINVAL;
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goto done2;
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}
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} else {
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/*
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* This is just a hint to vm_map_find() about where to
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* put it.
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*/
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attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr
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+ maxtsiz + maxdsiz);
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}
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shm_handle = shmseg->shm_internal;
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vm_object_reference(shm_handle->shm_object);
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rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
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0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
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if (rv != KERN_SUCCESS) {
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error = ENOMEM;
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goto done2;
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}
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vm_map_inherit(&p->p_vmspace->vm_map,
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attach_va, attach_va + size, VM_INHERIT_SHARE);
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shmmap_s->va = attach_va;
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shmmap_s->shmid = uap->shmid;
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shmseg->shm_lpid = p->p_pid;
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shmseg->shm_atime = time_second;
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shmseg->shm_nattch++;
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td->td_retval[0] = attach_va;
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done2:
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mtx_unlock(&Giant);
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return (error);
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}
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struct oshmid_ds {
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struct ipc_perm shm_perm; /* operation perms */
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int shm_segsz; /* size of segment (bytes) */
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ushort shm_cpid; /* pid, creator */
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ushort shm_lpid; /* pid, last operation */
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short shm_nattch; /* no. of current attaches */
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time_t shm_atime; /* last attach time */
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time_t shm_dtime; /* last detach time */
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time_t shm_ctime; /* last change time */
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void *shm_handle; /* internal handle for shm segment */
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};
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struct oshmctl_args {
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int shmid;
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int cmd;
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struct oshmid_ds *ubuf;
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};
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/*
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* MPSAFE
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*/
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static int
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oshmctl(td, uap)
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struct thread *td;
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struct oshmctl_args *uap;
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{
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#ifdef COMPAT_43
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int error = 0;
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struct shmid_ds *shmseg;
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struct oshmid_ds outbuf;
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if (!jail_sysvipc_allowed && jailed(td->td_ucred))
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return (ENOSYS);
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mtx_lock(&Giant);
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shmseg = shm_find_segment_by_shmid(uap->shmid);
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if (shmseg == NULL) {
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error = EINVAL;
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goto done2;
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}
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switch (uap->cmd) {
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case IPC_STAT:
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error = ipcperm(td, &shmseg->shm_perm, IPC_R);
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if (error)
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goto done2;
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outbuf.shm_perm = shmseg->shm_perm;
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outbuf.shm_segsz = shmseg->shm_segsz;
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outbuf.shm_cpid = shmseg->shm_cpid;
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outbuf.shm_lpid = shmseg->shm_lpid;
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outbuf.shm_nattch = shmseg->shm_nattch;
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outbuf.shm_atime = shmseg->shm_atime;
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outbuf.shm_dtime = shmseg->shm_dtime;
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outbuf.shm_ctime = shmseg->shm_ctime;
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outbuf.shm_handle = shmseg->shm_internal;
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error = copyout(&outbuf, uap->ubuf, sizeof(outbuf));
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if (error)
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goto done2;
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break;
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default:
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/* XXX casting to (sy_call_t *) is bogus, as usual. */
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error = ((sy_call_t *)shmctl)(td, uap);
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break;
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}
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done2:
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mtx_unlock(&Giant);
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return (error);
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#else
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return (EINVAL);
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#endif
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}
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#ifndef _SYS_SYSPROTO_H_
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struct shmctl_args {
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int shmid;
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int cmd;
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struct shmid_ds *buf;
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};
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#endif
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/*
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* MPSAFE
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*/
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int
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shmctl(td, uap)
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struct thread *td;
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struct shmctl_args *uap;
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{
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int error = 0;
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struct shmid_ds inbuf;
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struct shmid_ds *shmseg;
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if (!jail_sysvipc_allowed && jailed(td->td_ucred))
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return (ENOSYS);
|
|
mtx_lock(&Giant);
|
|
switch (uap->cmd) {
|
|
case IPC_INFO:
|
|
error = copyout(&shminfo, uap->buf, sizeof(shminfo));
|
|
if (error)
|
|
goto done2;
|
|
td->td_retval[0] = shmalloced;
|
|
goto done2;
|
|
case SHM_INFO: {
|
|
struct shm_info shm_info;
|
|
shm_info.used_ids = shm_nused;
|
|
shm_info.shm_rss = 0; /*XXX where to get from ? */
|
|
shm_info.shm_tot = 0; /*XXX where to get from ? */
|
|
shm_info.shm_swp = 0; /*XXX where to get from ? */
|
|
shm_info.swap_attempts = 0; /*XXX where to get from ? */
|
|
shm_info.swap_successes = 0; /*XXX where to get from ? */
|
|
error = copyout(&shm_info, uap->buf, sizeof(shm_info));
|
|
if (error)
|
|
goto done2;
|
|
td->td_retval[0] = shmalloced;
|
|
goto done2;
|
|
}
|
|
}
|
|
if( (uap->cmd) == SHM_STAT )
|
|
shmseg = shm_find_segment_by_shmidx(uap->shmid);
|
|
else
|
|
shmseg = shm_find_segment_by_shmid(uap->shmid);
|
|
if (shmseg == NULL) {
|
|
error = EINVAL;
|
|
goto done2;
|
|
}
|
|
switch (uap->cmd) {
|
|
case SHM_STAT:
|
|
case IPC_STAT:
|
|
error = ipcperm(td, &shmseg->shm_perm, IPC_R);
|
|
if (error)
|
|
goto done2;
|
|
error = copyout(shmseg, uap->buf, sizeof(inbuf));
|
|
if (error)
|
|
goto done2;
|
|
else if( (uap->cmd) == SHM_STAT )
|
|
td->td_retval[0] = IXSEQ_TO_IPCID( uap->shmid, shmseg->shm_perm );
|
|
break;
|
|
case IPC_SET:
|
|
error = ipcperm(td, &shmseg->shm_perm, IPC_M);
|
|
if (error)
|
|
goto done2;
|
|
error = copyin(uap->buf, &inbuf, sizeof(inbuf));
|
|
if (error)
|
|
goto done2;
|
|
shmseg->shm_perm.uid = inbuf.shm_perm.uid;
|
|
shmseg->shm_perm.gid = inbuf.shm_perm.gid;
|
|
shmseg->shm_perm.mode =
|
|
(shmseg->shm_perm.mode & ~ACCESSPERMS) |
|
|
(inbuf.shm_perm.mode & ACCESSPERMS);
|
|
shmseg->shm_ctime = time_second;
|
|
break;
|
|
case IPC_RMID:
|
|
error = ipcperm(td, &shmseg->shm_perm, IPC_M);
|
|
if (error)
|
|
goto done2;
|
|
shmseg->shm_perm.key = IPC_PRIVATE;
|
|
shmseg->shm_perm.mode |= SHMSEG_REMOVED;
|
|
if (shmseg->shm_nattch <= 0) {
|
|
shm_deallocate_segment(shmseg);
|
|
shm_last_free = IPCID_TO_IX(uap->shmid);
|
|
}
|
|
break;
|
|
#if 0
|
|
case SHM_LOCK:
|
|
case SHM_UNLOCK:
|
|
#endif
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
done2:
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct shmget_args {
|
|
key_t key;
|
|
size_t size;
|
|
int shmflg;
|
|
};
|
|
#endif
|
|
|
|
static int
|
|
shmget_existing(td, uap, mode, segnum)
|
|
struct thread *td;
|
|
struct shmget_args *uap;
|
|
int mode;
|
|
int segnum;
|
|
{
|
|
struct shmid_ds *shmseg;
|
|
int error;
|
|
|
|
shmseg = &shmsegs[segnum];
|
|
if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
|
|
/*
|
|
* This segment is in the process of being allocated. Wait
|
|
* until it's done, and look the key up again (in case the
|
|
* allocation failed or it was freed).
|
|
*/
|
|
shmseg->shm_perm.mode |= SHMSEG_WANTED;
|
|
error = tsleep(shmseg, PLOCK | PCATCH, "shmget", 0);
|
|
if (error)
|
|
return (error);
|
|
return (EAGAIN);
|
|
}
|
|
if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
|
|
return (EEXIST);
|
|
error = ipcperm(td, &shmseg->shm_perm, mode);
|
|
if (error)
|
|
return (error);
|
|
if (uap->size && uap->size > shmseg->shm_segsz)
|
|
return (EINVAL);
|
|
td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
shmget_allocate_segment(td, uap, mode)
|
|
struct thread *td;
|
|
struct shmget_args *uap;
|
|
int mode;
|
|
{
|
|
int i, segnum, shmid, size;
|
|
struct ucred *cred = td->td_ucred;
|
|
struct shmid_ds *shmseg;
|
|
struct shm_handle *shm_handle;
|
|
|
|
GIANT_REQUIRED;
|
|
|
|
if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
|
|
return (EINVAL);
|
|
if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
|
|
return (ENOSPC);
|
|
size = round_page(uap->size);
|
|
if (shm_committed + btoc(size) > shminfo.shmall)
|
|
return (ENOMEM);
|
|
if (shm_last_free < 0) {
|
|
shmrealloc(); /* Maybe expand the shmsegs[] array. */
|
|
for (i = 0; i < shmalloced; i++)
|
|
if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
|
|
break;
|
|
if (i == shmalloced)
|
|
return (ENOSPC);
|
|
segnum = i;
|
|
} else {
|
|
segnum = shm_last_free;
|
|
shm_last_free = -1;
|
|
}
|
|
shmseg = &shmsegs[segnum];
|
|
/*
|
|
* In case we sleep in malloc(), mark the segment present but deleted
|
|
* so that noone else tries to create the same key.
|
|
*/
|
|
shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
|
|
shmseg->shm_perm.key = uap->key;
|
|
shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
|
|
shm_handle = (struct shm_handle *)
|
|
malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
|
|
shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
|
|
|
|
/*
|
|
* We make sure that we have allocated a pager before we need
|
|
* to.
|
|
*/
|
|
if (shm_use_phys) {
|
|
shm_handle->shm_object =
|
|
vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0);
|
|
} else {
|
|
shm_handle->shm_object =
|
|
vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
|
|
}
|
|
vm_object_lock(shm_handle->shm_object);
|
|
vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
|
|
vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
|
|
vm_object_unlock(shm_handle->shm_object);
|
|
|
|
shmseg->shm_internal = shm_handle;
|
|
shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
|
|
shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
|
|
shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
|
|
(mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
|
|
shmseg->shm_segsz = uap->size;
|
|
shmseg->shm_cpid = td->td_proc->p_pid;
|
|
shmseg->shm_lpid = shmseg->shm_nattch = 0;
|
|
shmseg->shm_atime = shmseg->shm_dtime = 0;
|
|
shmseg->shm_ctime = time_second;
|
|
shm_committed += btoc(size);
|
|
shm_nused++;
|
|
if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
|
|
/*
|
|
* Somebody else wanted this key while we were asleep. Wake
|
|
* them up now.
|
|
*/
|
|
shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
|
|
wakeup(shmseg);
|
|
}
|
|
td->td_retval[0] = shmid;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
int
|
|
shmget(td, uap)
|
|
struct thread *td;
|
|
struct shmget_args *uap;
|
|
{
|
|
int segnum, mode;
|
|
int error;
|
|
|
|
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
|
|
return (ENOSYS);
|
|
mtx_lock(&Giant);
|
|
mode = uap->shmflg & ACCESSPERMS;
|
|
if (uap->key != IPC_PRIVATE) {
|
|
again:
|
|
segnum = shm_find_segment_by_key(uap->key);
|
|
if (segnum >= 0) {
|
|
error = shmget_existing(td, uap, mode, segnum);
|
|
if (error == EAGAIN)
|
|
goto again;
|
|
goto done2;
|
|
}
|
|
if ((uap->shmflg & IPC_CREAT) == 0) {
|
|
error = ENOENT;
|
|
goto done2;
|
|
}
|
|
}
|
|
error = shmget_allocate_segment(td, uap, mode);
|
|
done2:
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
int
|
|
shmsys(td, uap)
|
|
struct thread *td;
|
|
/* XXX actually varargs. */
|
|
struct shmsys_args /* {
|
|
u_int which;
|
|
int a2;
|
|
int a3;
|
|
int a4;
|
|
} */ *uap;
|
|
{
|
|
int error;
|
|
|
|
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
|
|
return (ENOSYS);
|
|
if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
|
|
return (EINVAL);
|
|
mtx_lock(&Giant);
|
|
error = (*shmcalls[uap->which])(td, &uap->a2);
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
static void
|
|
shmfork_myhook(p1, p2)
|
|
struct proc *p1, *p2;
|
|
{
|
|
struct shmmap_state *shmmap_s;
|
|
size_t size;
|
|
int i;
|
|
|
|
size = shminfo.shmseg * sizeof(struct shmmap_state);
|
|
shmmap_s = malloc(size, M_SHM, M_WAITOK);
|
|
bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
|
|
p2->p_vmspace->vm_shm = shmmap_s;
|
|
for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
|
|
if (shmmap_s->shmid != -1)
|
|
shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
|
|
}
|
|
|
|
static void
|
|
shmexit_myhook(p)
|
|
struct proc *p;
|
|
{
|
|
struct shmmap_state *shmmap_s;
|
|
int i;
|
|
|
|
GIANT_REQUIRED;
|
|
|
|
shmmap_s = p->p_vmspace->vm_shm;
|
|
for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
|
|
if (shmmap_s->shmid != -1)
|
|
shm_delete_mapping(p, shmmap_s);
|
|
free(p->p_vmspace->vm_shm, M_SHM);
|
|
p->p_vmspace->vm_shm = NULL;
|
|
}
|
|
|
|
static void
|
|
shmrealloc(void)
|
|
{
|
|
int i;
|
|
struct shmid_ds *newsegs;
|
|
|
|
if (shmalloced >= shminfo.shmmni)
|
|
return;
|
|
|
|
newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
|
|
if (newsegs == NULL)
|
|
return;
|
|
for (i = 0; i < shmalloced; i++)
|
|
bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
|
|
for (; i < shminfo.shmmni; i++) {
|
|
shmsegs[i].shm_perm.mode = SHMSEG_FREE;
|
|
shmsegs[i].shm_perm.seq = 0;
|
|
}
|
|
free(shmsegs, M_SHM);
|
|
shmsegs = newsegs;
|
|
shmalloced = shminfo.shmmni;
|
|
}
|
|
|
|
static void
|
|
shminit()
|
|
{
|
|
int i;
|
|
|
|
TUNABLE_INT_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall);
|
|
shminfo.shmmax = shminfo.shmall * PAGE_SIZE;
|
|
TUNABLE_INT_FETCH("kern.ipc.shmmin", &shminfo.shmmin);
|
|
TUNABLE_INT_FETCH("kern.ipc.shmmni", &shminfo.shmmni);
|
|
TUNABLE_INT_FETCH("kern.ipc.shmseg", &shminfo.shmseg);
|
|
TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys);
|
|
|
|
shmalloced = shminfo.shmmni;
|
|
shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
|
|
if (shmsegs == NULL)
|
|
panic("cannot allocate initial memory for sysvshm");
|
|
for (i = 0; i < shmalloced; i++) {
|
|
shmsegs[i].shm_perm.mode = SHMSEG_FREE;
|
|
shmsegs[i].shm_perm.seq = 0;
|
|
}
|
|
shm_last_free = 0;
|
|
shm_nused = 0;
|
|
shm_committed = 0;
|
|
shmexit_hook = &shmexit_myhook;
|
|
shmfork_hook = &shmfork_myhook;
|
|
}
|
|
|
|
static int
|
|
shmunload()
|
|
{
|
|
|
|
if (shm_nused > 0)
|
|
return (EBUSY);
|
|
|
|
free(shmsegs, M_SHM);
|
|
shmexit_hook = NULL;
|
|
shmfork_hook = NULL;
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
|
|
return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])));
|
|
}
|
|
|
|
static int
|
|
sysvshm_modload(struct module *module, int cmd, void *arg)
|
|
{
|
|
int error = 0;
|
|
|
|
switch (cmd) {
|
|
case MOD_LOAD:
|
|
shminit();
|
|
break;
|
|
case MOD_UNLOAD:
|
|
error = shmunload();
|
|
break;
|
|
case MOD_SHUTDOWN:
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
static moduledata_t sysvshm_mod = {
|
|
"sysvshm",
|
|
&sysvshm_modload,
|
|
NULL
|
|
};
|
|
|
|
SYSCALL_MODULE_HELPER(shmsys);
|
|
SYSCALL_MODULE_HELPER(shmat);
|
|
SYSCALL_MODULE_HELPER(shmctl);
|
|
SYSCALL_MODULE_HELPER(shmdt);
|
|
SYSCALL_MODULE_HELPER(shmget);
|
|
|
|
DECLARE_MODULE(sysvshm, sysvshm_mod,
|
|
SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
|
|
MODULE_VERSION(sysvshm, 1);
|