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.\" -*- nroff -*-
.\"
.\" Copyright (C) 1995 Michael Shields <shields@tembel.org>.
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and author of this work.
.\"
.\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified Sat May 31 15:32:03 MET 1997 by Andries Brouwer <aeb@cwi.nl>
.\"
.\" Japanese Version Copyright (c) 1997 HANATAKA Shinya
.\" all rights reserved.
.\" Translated Sun Jun 1 22:41:15 JST 1997
.\" by HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\"
.\"WORD: memory
.\"WORD: access
.\"WORD: bitwise-or ӥå OR
.\"WORD: read-only ɤ߹
.\"
.TH MPROTECT 2 "1997-05-31" "Linux 2.0" "Linux Programmer's Manual"
.SH ̾
mprotect \- ǽʥ椹
.SH
.nf
.B #include <sys/mman.h>
.sp
\fBint mprotect(const void *\fIaddr\fB, size_t \fIlen\fB, int \fIprot\fB);
.fi
.SH
.B mprotect
ϥ褬ɤΤ褦˥Ǥ뤫椹롣ݸͿ
ƥǤʤ硢ץ
.BR SIGSEGV
Ȥ롣
.PP
.I prot
ϰʲͤΥӥå OR Ǥ:
.TP 1.1i
.B PROT_NONE
ΥƤΥǤʤ
.TP
.B PROT_READ
Υɤ뤳ȤǤ롣
.TP
.B PROT_WRITE
ΥϽळȤǤ롣
.TP
.B PROT_EXEC
Υϼ¹ԥɤޤळȤǤ롣
.PP
ݸϺޤǤݸ֤롣㤨С꤬ˤ
\fBPROT_READ\fR ȥޡƤơ\fBmprotect\fR
\fIprot\fR \fBPROT_WRITE\fR ǸƤӽФ줿ϡ⤦ɤ߹߲ǽ
ǤϤʤ
.SH ֤
ϡ
.B mprotect
ϥ֤顼ξ \-1 ֤졢
.I errno
Ŭڤꤵ롣
.SH 顼
.TP
.B EINVAL
\fIaddr\fR
ͭʥݥǤʤPAGESIZE ܿǤʤ
.TP
.B EFAULT
꤬ǽǤʤ
.TP
.B EACCES
ꤵ줿Ϳ뤳ȤǤʤϡ㤨
եɤ߹Ѥ
.BR mmap (2)
Ƥꡢ
.B mprotect
.BR PROT_WRITE
˥ޡ褦Ȥ˵롣
.TP
.B ENOMEM
ͥι¤ΤƤ뤳ȤǤʤä
.SH
.nf
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/mman.h>
#include <limits.h> /* for PAGESIZE */
#ifndef PAGESIZE
#define PAGESIZE 4096
#endif
int
main(void)
{
char *p;
char c;
/* Allocate a buffer; it will have the default
protection of PROT_READ|PROT_WRITE. */
p = malloc(1024+PAGESIZE-1);
if (!p) {
perror("Couldn't malloc(1024)");
exit(errno);
}
/* Align to a multiple of PAGESIZE, assumed to be a power of two */
p = (char *)(((int) p + PAGESIZE-1) & ~(PAGESIZE-1));
c = p[666]; /* Read; ok */
p[666] = 42; /* Write; ok */
/* Mark the buffer read-only. */
if (mprotect(p, 1024, PROT_READ)) {
perror("Couldn't mprotect");
exit(errno);
}
c = p[666]; /* Read; ok */
p[666] = 42; /* Write; program dies on SIGSEGV */
exit(0);
}
.fi
.SH
SVr4, POSIX.1b ( POSIX.4). SVr4 ¾ EAGAIN 顼Ƥ롣
SVr4 Υ顼֤ Linux ΤΤбʤ
POSIX.1b Ǥ
.B mprotect
.BR mmap (2)
ΰΤߤѤǤȤƤ롣
.SH Ϣ
.BR mmap (2)
|
