freebsd-nq/sys/sys/ipc.h
Matthew Dillon 3db161e079 It is possible for an active aio to prevent shared memory from being
dereferenced when a process exits due to the vmspace ref-count being
bumped.  Change shmexit() and shmexit_myhook() to take a vmspace instead
of a process and call it in vmspace_dofree().  This way if it is missed
in exit1()'s early-resource-free it will still be caught when the zombie is
reaped.

Also fix a potential race in shmexit_myhook() by NULLing out
vmspace->vm_shm prior to calling shm_delete_mapping() and free().

MFC after:	7 days
2003-01-13 23:04:32 +00:00

133 lines
4.4 KiB
C

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ipc.h 8.4 (Berkeley) 2/19/95
* $FreeBSD$
*/
/*
* SVID compatible ipc.h file
*/
#ifndef _SYS_IPC_H_
#define _SYS_IPC_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
#ifndef _GID_T_DECLARED
typedef __gid_t gid_t;
#define _GID_T_DECLARED
#endif
#ifndef _KEY_T_DECLARED
typedef __key_t key_t;
#define _KEY_T_DECLARED
#endif
#ifndef _MODE_T_DECLARED
typedef __mode_t mode_t;
#define _MODE_T_DECLARED
#endif
#ifndef _UID_T_DECLARED
typedef __uid_t uid_t;
#define _UID_T_DECLARED
#endif
/*
* XXX almost all members have wrong types.
*/
struct ipc_perm {
unsigned short cuid; /* creator user id */
unsigned short cgid; /* creator group id */
unsigned short uid; /* user id */
unsigned short gid; /* group id */
unsigned short mode; /* r/w permission */
unsigned short seq; /* sequence # (to generate unique ipcid) */
key_t key; /* user specified msg/sem/shm key */
};
#if __BSD_VISIBLE
/* common mode bits */
#define IPC_R 000400 /* read permission */
#define IPC_W 000200 /* write/alter permission */
#define IPC_M 010000 /* permission to change control info */
#endif
/* SVID required constants (same values as system 5) */
#define IPC_CREAT 001000 /* create entry if key does not exist */
#define IPC_EXCL 002000 /* fail if key exists */
#define IPC_NOWAIT 004000 /* error if request must wait */
#define IPC_PRIVATE (key_t)0 /* private key */
#define IPC_RMID 0 /* remove identifier */
#define IPC_SET 1 /* set options */
#define IPC_STAT 2 /* get options */
#if __BSD_VISIBLE
#define IPC_INFO 3 /* get info */
#endif
#ifdef _KERNEL
/* Macros to convert between ipc ids and array indices or sequence ids */
#define IPCID_TO_IX(id) ((id) & 0xffff)
#define IPCID_TO_SEQ(id) (((id) >> 16) & 0xffff)
#define IXSEQ_TO_IPCID(ix,perm) (((perm.seq) << 16) | (ix & 0xffff))
struct thread;
struct proc;
struct vmspace;
int ipcperm(struct thread *, struct ipc_perm *, int);
extern void (*shmfork_hook)(struct proc *, struct proc *);
extern void (*shmexit_hook)(struct vmspace *);
#else /* ! _KERNEL */
__BEGIN_DECLS
key_t ftok(const char *, int);
__END_DECLS
#endif /* _KERNEL */
#endif /* !_SYS_IPC_H_ */