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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1996 by Sun Microsystems, Inc.
*
* Map in a read-only page of zeroes at location zero, for stupid
* programs that think a null pointer is as good as a null string.
*
* Use:
* LD_PRELOAD=0@0.so.1 program args ...
*
*/
/* LINTLIBRARY */
#include <sys/types.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#pragma init(__zero_at_zero)
void
__zero_at_zero()
{
int fd;
if ((fd = open("/dev/zero", O_RDWR)) < 0)
return;
(void) mmap(0, 1, PROT_READ, MAP_PRIVATE|MAP_FIXED, fd, 0);
(void) close(fd);
}
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