.\" -*- 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.\" manual page may be incorrect or out-of-date.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 1996-10-22 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1997-05-31 by Andries Brouwer <aeb@cwi.nl>
.\" Modified 2003-08-24 by Andries Brouwer <aeb@cwi.nl>
.\" Modified 2004-08-16 by Andi Kleen <ak@muc.de>
.\"
.\" 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>
.\" Updated and revised Fri Oct 24 20:17:47 JST 2003
.\"         by Suzuki Takashi.
.\" Updated & Modified Tue Feb  8 07:01:04 JST 2005
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated & Modified Sat Oct 15 00:30:46 JST 2005 by Yuichi SATO
.\"
.\"WORD: bitwise-or             ӥåȤȤ
.\"WORD: protection             ݸ
.\"WORD: read-only              ɤ߼
.\"
.TH MPROTECT 2 2003-08-24 "Linux 2.4" "Linux Programmer's Manual"
.SH "̾"
mprotect \- ΰΥĤ椹
.SH ""
.nf
.B #include <sys/mman.h>
.sp
\fBint mprotect(const void *\fIaddr\fB, size_t \fIlen\fB, int \fIprot\fB);
.fi
.SH ""
.BR mprotect ()
϶ [\fIaddr\fP,\fIaddr\fP+\fIlen\fP-1] ΰޤϤ٤Ƥޤ
ڡν˾Υݸꤹ롣
ꤷݸǶػߤ줿Ԥʤȡ
ץ
.B SIGSEGV
롣
.PP
.I prot
ϰʲͤΥӥåȤȤ (bitwize-or) Ǥ:
.TP 1.1i
.B PROT_NONE
ΥˤǤʤ
.TP
.B PROT_READ
Υɤ߼뤳ȤǤ롣
.TP
.B PROT_WRITE
Υ˽񤭹ळȤǤ롣
.TP
.B PROT_EXEC
Υ˼¹ԥɤޤळȤǤ롣
.PP
ݸϤޤǤΥݸ֤롣
㤨Сޤ \fBPROT_READ\fR ꤵƤΰФơ
\fIprot\fR  \fBPROT_WRITE\fR Ȥ \fBmprotect\fR() ƤӽФȡ
ΰϤϤɤ߼ǽǤϤʤʤ롣
.SH "֤"
硢
.BR mprotect ()
 0 ֤顼ξ \-1 ֤ꡢ
.I errno
Ŭڤꤵ롣
.SH "顼"
.TP
.B EACCES
ꤵ줿ꤹ뤳ȤǤʤ
ϡ㤨
եɤ߼Ѥ
.BR mmap (2)
ƤꡢΰФ
.BR mprotect ()
ƤӽФ
.B PROT_WRITE
ꤷ褦Ȥȯ롣
.TP
.B EFAULT
꤬ǽǤʤ
.TP
.B EINVAL
\fIaddr\fR ͭʥݥ󥿤ǤʤPAGESIZE ܿǤʤ
.TP
.B ENOMEM
ͥι¤ΤƤ뤳ȤǤʤä
⤷ϡ
.RI [ addr ,
.IR addr + len ]
ȤϰϤΥɥ쥹ץΥɥ쥹֤ȤǤ뤫
ϰϤΥɥ쥹ޥåפƤʤ 1 İʾΥڡؤ
.SH ""
.nf
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/mman.h>

#include <limits.h>    /* PAGESIZE Ѥ뤿 */
#ifndef PAGESIZE
#define PAGESIZE 4096
#endif

int
main(void)
{
    char *p;
    char c;

    /* Хåեݤ롣ǥեȤΥݸ
       PROT_READ|PROT_WRITE ˤʤ롣*/
    p = malloc(1024+PAGESIZE-1);
    if (!p) {
        perror("Couldn't malloc(1024)");
        exit(errno);
    }

    /* PAGESIZE ܿ˥饤Ȥ򤽤롣
       PAGESIZE  2 ߾ǤȲꤹ롣*/
    p = (char *)(((int) p + PAGESIZE-1) & ~(PAGESIZE-1));

    c = p[666];         /* ɤ߼;  */
    p[666] = 42;        /* 񤭹;  */

    /* Хåեɤ߼Ѥꤹ롣*/
    if (mprotect(p, 1024, PROT_READ)) {
        perror("Couldn't mprotect");
        exit(errno);
    }

    c = p[666];         /* ɤ߼;  */
    p[666] = 42;        /* 񤭹; ץ SIGSEGV Ƕλ */

    exit(0);
}
.fi
.SH ""
SVr4, POSIX.1-2001.
.\" SVr4 Ǥ¾˥顼 EAGAIN Ƥ롣
.\" SVr4 Υ顼 Linux ΤΤˤбʤ
POSIX Ǥϡ
.BR mprotect ()

.BR mmap (2)
dzΰФƤΤ߻ѤǤȤƤ롣
.SH 
Linux Ǥϡ(ͥ vsyscall ΰʳ)
ǤդΥץɥ쥹֤ˤ
.BR mprotect ()
ƤӽФȤ˵Ƥ롣
ä˴¸Υɥޥåԥ󥰤񤭹߲ǽˤ뤿˻Ȥ롣

.B PROT_EXEC

.B PROT_READ
ȰۤʤƶĤݤϡƥȥͥΥС˰¸롣
.SH "Ϣ"
.BR mmap (2)