http://www.tjd.phlegethon.org/software/linux/kpoke.c
/*
* Hack to frob a value in kernel space, when you can't be
* bothered using sysctl.
*
* Copyright (c) 2002 Tim Deegan <[EMAIL PROTECTED]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: kpoke.c,v 1.2 2002/03/26 12:14:46 tjd21 Exp $
*/
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
int main (int argc, char **argv)
{
int fd;
uintptr_t addr, value;
char *ap, *vp;
errno = 0;
if (argc != 3) {
fprintf (stderr, "%s: sets a (%i-byte) word of kernel memory\n",
argv[0], sizeof (value));
fprintf (stderr, "usage: %s <address> <value>\n", argv[0]);
exit(-1);
}
addr = strtoul(argv[1], &ap, 0);
value = strtoul(argv[2], &vp, 0);
if (errno != 0 || ap == argv[1] || vp == argv[2]) {
fprintf (stderr, "usage: %s <address> <value>\n", argv[0]);
exit(-1);
}
fd = open("/dev/kmem", O_RDWR);
if (fd == -1) {
perror ("open() failed:");
exit (-1);
}
if (lseek (fd, addr, SEEK_SET) == -1) {
perror ("lseek() failed:");
exit (-1);
}
if (write (fd, &value, sizeof(value)) == -1) {
perror ("write() failed:");
exit (-1);
}
if (lseek (fd, addr, SEEK_SET) == -1) {
perror ("lseek() failed:");
exit (-1);
}
if (read (fd, &value, sizeof(value)) != sizeof (value)) {
perror ("read() failed:");
exit (-1);
}
printf ("%#x: %#x\n", addr, value);
exit(0);
}
/*
* EOF
*/
