522 lines
14 KiB
C
522 lines
14 KiB
C
/* $NetBSD: sysv_shm.c,v 1.37 1996/03/16 23:17:13 christos 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 <sys/types.h>
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/shm.h>
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#include <sys/proc.h>
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#include <sys/uio.h>
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#include <sys/time.h>
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#include <sys/malloc.h>
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#include <sys/mman.h>
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#include <sys/systm.h>
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#include <sys/stat.h>
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#include <sys/mount.h>
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#include <sys/syscallargs.h>
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#include <vm/vm.h>
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#include <vm/vm_map.h>
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#include <vm/vm_map.h>
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#include <vm/vm_kern.h>
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struct shmid_ds *shm_find_segment_by_shmid __P((int));
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void shmexit __P((struct proc *));
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/*
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* Provides the following externally accessible functions:
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*
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* shminit(void); initialization
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* shmexit(struct proc *) cleanup
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* shmfork(struct proc *, struct proc *) fork handling
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* shmsys(arg1, arg2, arg3, arg4); shm{at,ctl,dt,get}(arg2, arg3, arg4)
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*
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* Structures:
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* shmsegs (an array of 'struct shmid_ds')
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* per proc array of 'struct shmmap_state'
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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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vm_map_t sysvshm_map;
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int shm_last_free, shm_nused, shm_committed;
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struct shm_handle {
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vm_offset_t kva;
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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 int shm_find_segment_by_key __P((key_t));
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static void shm_deallocate_segment __P((struct shmid_ds *));
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static int shm_delete_mapping __P((struct proc *, struct shmmap_state *));
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static int shmget_existing __P((struct proc *, struct sys_shmget_args *,
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int, int, register_t *));
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static int shmget_allocate_segment __P((struct proc *, struct sys_shmget_args *,
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int, register_t *));
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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 < shminfo.shmmni; 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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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 >= shminfo.shmmni)
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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 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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shm_handle = shmseg->shm_internal;
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size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
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vm_deallocate(sysvshm_map, shm_handle->kva, size);
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free((caddr_t)shm_handle, M_SHM);
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shmseg->shm_internal = NULL;
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shm_committed -= btoc(size);
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shmseg->shm_perm.mode = SHMSEG_FREE;
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shm_nused--;
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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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segnum = IPCID_TO_IX(shmmap_s->shmid);
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shmseg = &shmsegs[segnum];
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size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
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result = vm_deallocate(&p->p_vmspace->vm_map, 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.tv_sec;
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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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int
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sys_shmdt(p, v, retval)
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struct proc *p;
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void *v;
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register_t *retval;
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{
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struct sys_shmdt_args /* {
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syscallarg(void *) shmaddr;
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} */ *uap = v;
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struct shmmap_state *shmmap_s;
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int i;
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shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
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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)SCARG(uap, shmaddr))
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break;
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if (i == shminfo.shmseg)
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return EINVAL;
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return shm_delete_mapping(p, shmmap_s);
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}
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int
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sys_shmat(p, v, retval)
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struct proc *p;
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void *v;
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register_t *retval;
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{
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struct sys_shmat_args /* {
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syscallarg(int) shmid;
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syscallarg(void *) shmaddr;
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syscallarg(int) shmflg;
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} */ *uap = v;
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int error, i, flags;
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struct ucred *cred = p->p_ucred;
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struct shmid_ds *shmseg;
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struct shmmap_state *shmmap_s = NULL;
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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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shmmap_s = (struct shmmap_state *)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 = (caddr_t)shmmap_s;
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}
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shmseg = shm_find_segment_by_shmid(SCARG(uap, shmid));
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if (shmseg == NULL)
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return EINVAL;
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error = ipcperm(cred, &shmseg->shm_perm,
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(SCARG(uap, shmflg) & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
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if (error)
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return error;
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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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return EMFILE;
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size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
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prot = VM_PROT_READ;
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if ((SCARG(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 (SCARG(uap, shmaddr)) {
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flags |= MAP_FIXED;
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if (SCARG(uap, shmflg) & SHM_RND)
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attach_va =
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(vm_offset_t)SCARG(uap, shmaddr) & ~(SHMLBA-1);
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else if (((vm_offset_t)SCARG(uap, shmaddr) & (SHMLBA-1)) == 0)
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attach_va = (vm_offset_t)SCARG(uap, shmaddr);
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else
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return EINVAL;
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} else {
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/* This is just a hint to vm_mmap() about where to put it. */
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attach_va =
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round_page(p->p_vmspace->vm_taddr + MAXTSIZ + MAXDSIZ);
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}
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error = vm_mmap(&p->p_vmspace->vm_map, &attach_va, size, prot,
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VM_PROT_DEFAULT, flags, (caddr_t)(long)SCARG(uap, shmid), 0);
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if (error)
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return error;
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shmmap_s->va = attach_va;
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shmmap_s->shmid = SCARG(uap, shmid);
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shmseg->shm_lpid = p->p_pid;
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shmseg->shm_atime = time.tv_sec;
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shmseg->shm_nattch++;
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*retval = attach_va;
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return 0;
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}
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int
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sys_shmctl(p, v, retval)
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struct proc *p;
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void *v;
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register_t *retval;
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{
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struct sys_shmctl_args /* {
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syscallarg(int) shmid;
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syscallarg(int) cmd;
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syscallarg(struct shmid_ds *) buf;
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} */ *uap = v;
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int error;
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struct ucred *cred = p->p_ucred;
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struct shmid_ds inbuf;
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struct shmid_ds *shmseg;
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shmseg = shm_find_segment_by_shmid(SCARG(uap, shmid));
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if (shmseg == NULL)
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return EINVAL;
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switch (SCARG(uap, cmd)) {
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case IPC_STAT:
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if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_R)) != 0)
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return error;
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error = copyout((caddr_t)shmseg, SCARG(uap, buf),
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sizeof(inbuf));
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if (error)
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return error;
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break;
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case IPC_SET:
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if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0)
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return error;
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error = copyin(SCARG(uap, buf), (caddr_t)&inbuf,
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sizeof(inbuf));
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if (error)
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return error;
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shmseg->shm_perm.uid = inbuf.shm_perm.uid;
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shmseg->shm_perm.gid = inbuf.shm_perm.gid;
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shmseg->shm_perm.mode =
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(shmseg->shm_perm.mode & ~ACCESSPERMS) |
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(inbuf.shm_perm.mode & ACCESSPERMS);
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shmseg->shm_ctime = time.tv_sec;
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break;
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case IPC_RMID:
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if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0)
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return error;
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shmseg->shm_perm.key = IPC_PRIVATE;
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shmseg->shm_perm.mode |= SHMSEG_REMOVED;
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if (shmseg->shm_nattch <= 0) {
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shm_deallocate_segment(shmseg);
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shm_last_free = IPCID_TO_IX(SCARG(uap, shmid));
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}
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break;
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case SHM_LOCK:
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case SHM_UNLOCK:
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default:
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return EINVAL;
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}
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return 0;
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}
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static int
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shmget_existing(p, uap, mode, segnum, retval)
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struct proc *p;
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struct sys_shmget_args /* {
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syscallarg(key_t) key;
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syscallarg(int) size;
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syscallarg(int) shmflg;
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} */ *uap;
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int mode;
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int segnum;
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register_t *retval;
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{
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struct shmid_ds *shmseg;
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struct ucred *cred = p->p_ucred;
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int error;
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shmseg = &shmsegs[segnum];
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if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
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/*
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* This segment is in the process of being allocated. Wait
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* until it's done, and look the key up again (in case the
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* allocation failed or it was freed).
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*/
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shmseg->shm_perm.mode |= SHMSEG_WANTED;
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error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0);
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if (error)
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return error;
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return EAGAIN;
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}
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if ((error = ipcperm(cred, &shmseg->shm_perm, mode)) != 0)
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return error;
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if (SCARG(uap, size) && SCARG(uap, size) > shmseg->shm_segsz)
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return EINVAL;
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if ((SCARG(uap, shmflg) & (IPC_CREAT | IPC_EXCL)) ==
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(IPC_CREAT | IPC_EXCL))
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return EEXIST;
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*retval = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
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return 0;
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}
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static int
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shmget_allocate_segment(p, uap, mode, retval)
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struct proc *p;
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struct sys_shmget_args /* {
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syscallarg(key_t) key;
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syscallarg(int) size;
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syscallarg(int) shmflg;
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} */ *uap;
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int mode;
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register_t *retval;
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{
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int i, segnum, result, shmid, size;
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struct ucred *cred = p->p_ucred;
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struct shmid_ds *shmseg;
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struct shm_handle *shm_handle;
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if (SCARG(uap, size) < shminfo.shmmin ||
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SCARG(uap, size) > shminfo.shmmax)
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return EINVAL;
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if (shm_nused >= shminfo.shmmni) /* any shmids left? */
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return ENOSPC;
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size = (SCARG(uap, size) + CLOFSET) & ~CLOFSET;
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if (shm_committed + btoc(size) > shminfo.shmall)
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return ENOMEM;
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if (shm_last_free < 0) {
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for (i = 0; i < shminfo.shmmni; i++)
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if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
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break;
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if (i == shminfo.shmmni)
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panic("shmseg free count inconsistent");
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segnum = i;
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} else {
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segnum = shm_last_free;
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shm_last_free = -1;
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}
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shmseg = &shmsegs[segnum];
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/*
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* In case we sleep in malloc(), mark the segment present but deleted
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* so that noone else tries to create the same key.
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*/
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shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
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shmseg->shm_perm.key = SCARG(uap, key);
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shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
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shm_handle = (struct shm_handle *)
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malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
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shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
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result = vm_mmap(sysvshm_map, &shm_handle->kva, size, VM_PROT_ALL,
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VM_PROT_DEFAULT, MAP_ANON, (caddr_t)(long)shmid, 0);
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if (result != KERN_SUCCESS) {
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shmseg->shm_perm.mode = SHMSEG_FREE;
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shm_last_free = segnum;
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free((caddr_t)shm_handle, M_SHM);
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/* Just in case. */
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wakeup((caddr_t)shmseg);
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return ENOMEM;
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}
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shmseg->shm_internal = shm_handle;
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shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
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shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
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shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
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(mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
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shmseg->shm_segsz = SCARG(uap, size);
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shmseg->shm_cpid = p->p_pid;
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shmseg->shm_lpid = shmseg->shm_nattch = 0;
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shmseg->shm_atime = shmseg->shm_dtime = 0;
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shmseg->shm_ctime = time.tv_sec;
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shm_committed += btoc(size);
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shm_nused++;
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if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
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/*
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* Somebody else wanted this key while we were asleep. Wake
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* them up now.
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*/
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shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
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wakeup((caddr_t)shmseg);
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}
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*retval = shmid;
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return 0;
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}
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int
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sys_shmget(p, v, retval)
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struct proc *p;
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void *v;
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register_t *retval;
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{
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struct sys_shmget_args /* {
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syscallarg(key_t) key;
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syscallarg(int) size;
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syscallarg(int) shmflg;
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|
} */ *uap = v;
|
|
int segnum, mode, error;
|
|
|
|
mode = SCARG(uap, shmflg) & ACCESSPERMS;
|
|
if (SCARG(uap, key) != IPC_PRIVATE) {
|
|
again:
|
|
segnum = shm_find_segment_by_key(SCARG(uap, key));
|
|
if (segnum >= 0) {
|
|
error = shmget_existing(p, uap, mode, segnum, retval);
|
|
if (error == EAGAIN)
|
|
goto again;
|
|
return error;
|
|
}
|
|
if ((SCARG(uap, shmflg) & IPC_CREAT) == 0)
|
|
return ENOENT;
|
|
}
|
|
return shmget_allocate_segment(p, uap, mode, retval);
|
|
}
|
|
|
|
void
|
|
shmfork(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((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size);
|
|
p2->p_vmspace->vm_shm = (caddr_t)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++;
|
|
}
|
|
|
|
void
|
|
shmexit(p)
|
|
struct proc *p;
|
|
{
|
|
struct shmmap_state *shmmap_s;
|
|
int i;
|
|
|
|
shmmap_s = (struct shmmap_state *)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((caddr_t)p->p_vmspace->vm_shm, M_SHM);
|
|
p->p_vmspace->vm_shm = NULL;
|
|
}
|
|
|
|
void
|
|
shminit()
|
|
{
|
|
int i;
|
|
vm_offset_t garbage1, garbage2;
|
|
|
|
shminfo.shmmax *= NBPG;
|
|
|
|
/* actually this *should* be pageable. SHM_{LOCK,UNLOCK} */
|
|
sysvshm_map = kmem_suballoc(kernel_map, &garbage1, &garbage2,
|
|
shminfo.shmall * NBPG, TRUE);
|
|
for (i = 0; i < shminfo.shmmni; i++) {
|
|
shmsegs[i].shm_perm.mode = SHMSEG_FREE;
|
|
shmsegs[i].shm_perm.seq = 0;
|
|
}
|
|
shm_last_free = 0;
|
|
shm_nused = 0;
|
|
shm_committed = 0;
|
|
}
|