da17295d91
p->p_vmspace->vm_shm would be NULL. Protected the rest of the cases where that might happen too. This was the reason why sunxdoom would panic the system in SVR4 emulation.
532 lines
14 KiB
C
532 lines
14 KiB
C
/* $NetBSD: sysv_shm.c,v 1.38 1996/09/01 22:53:06 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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if (shmmap_s == NULL)
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return EINVAL;
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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;
|
|
register_t *retval;
|
|
{
|
|
struct sys_shmget_args /* {
|
|
syscallarg(key_t) key;
|
|
syscallarg(int) size;
|
|
syscallarg(int) shmflg;
|
|
} */ *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;
|
|
|
|
if (p1->p_vmspace->vm_shm == NULL) {
|
|
p2->p_vmspace->vm_shm = NULL;
|
|
return;
|
|
}
|
|
|
|
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;
|
|
if (shmmap_s == NULL)
|
|
return;
|
|
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;
|
|
}
|