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/* $OpenBSD: exec_elf.c,v 1.12 2009/10/27 23:59:51 deraadt Exp $ */
/*
* Copyright (c) 1999 Mats O Jansson. All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <nlist.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/exec.h>
#include <sys/exec_elf.h>
#include <sys/types.h>
#include "ukc.h"
#include "config.h"
caddr_t ptr, rest, pre;
Elf_Ehdr elf_ex;
Elf_Phdr *elf_phdr;
Elf_Shdr *elf_shdr;
char *elf_total;
char *elf_shstrtab;
off_t elf_size;
caddr_t elf_adjust(caddr_t);
caddr_t elf_readjust(caddr_t);
int elf_check(char *);
void elf_loadkernel(char *);
void elf_savekernel(char *);
caddr_t
elf_adjust(caddr_t x)
{
int i;
Elf_Shdr *s;
unsigned long y = 0;
s = elf_shdr;
for (i = 0; i < elf_ex.e_shnum; i++) {
if (s[i].sh_addr == 0)
continue;
if (((unsigned long)x >= s[i].sh_addr) &&
((unsigned long)x < (s[i].sh_addr+s[i].sh_size))) {
y = (unsigned long)&elf_total[(unsigned long)x -
s[i].sh_addr + s[i].sh_offset];
break;
}
}
return((caddr_t)y);
}
caddr_t
elf_readjust(caddr_t x)
{
int i;
Elf_Shdr *s;
unsigned long y = 0;
s = elf_shdr;
for (i = 0; i < elf_ex.e_shnum; i++) {
if (s[i].sh_addr == 0)
continue;
if (((x - elf_total) >= s[i].sh_offset) &&
((x - elf_total) <= (s[i].sh_offset + s[i].sh_size)))
y = (unsigned long)x - (unsigned long)elf_total +
(unsigned long)s[i].sh_addr - s[i].sh_offset;
}
return((caddr_t)y);
}
int
elf_check(char *file)
{
int fd, ret = 1;
if ((fd = open(file, O_RDONLY | O_EXLOCK, 0)) < 0)
return (0);
if (read(fd, (char *)&elf_ex, sizeof(elf_ex)) != sizeof(elf_ex))
ret = 0;
if (ret) {
if (!IS_ELF(elf_ex))
ret = 0;
}
close(fd);
return (ret);
}
void
elf_loadkernel(char *file)
{
int fd;
if ((fd = open(file, O_RDONLY | O_EXLOCK, 0)) < 0)
err(1, "%s", file);
if (read(fd, (char *)&elf_ex, sizeof(elf_ex)) != sizeof(elf_ex))
errx(1, "can't read elf header");
if (!IS_ELF(elf_ex))
errx(1, "bad elf magic");
elf_size = lseek(fd, (off_t)0, SEEK_END);
(void)lseek(fd, (off_t)0, SEEK_SET);
elf_total = emalloc((size_t)elf_size);
if (read(fd, elf_total, (size_t)elf_size) != elf_size)
errx(1, "can't read elf kernel");
if (elf_ex.e_phoff > (size_t)elf_size)
errx(1, "incorrect ELF header or truncated file");
if (elf_ex.e_shoff > (size_t)elf_size)
errx(1, "incorrect ELF header or truncated file");
elf_phdr = (Elf_Phdr *)&elf_total[elf_ex.e_phoff];
elf_shdr = (Elf_Shdr *)&elf_total[elf_ex.e_shoff];
if ((char *)&elf_shdr[elf_ex.e_shstrndx] +
sizeof(elf_shdr[elf_ex.e_shstrndx]) >= elf_total + (size_t)elf_size)
errx(1, "incorrect ELF header or truncated file");
if ((char *)&elf_shdr[elf_ex.e_shstrndx].sh_offset +
sizeof(elf_shdr[elf_ex.e_shstrndx].sh_offset) >=
elf_total + (size_t)elf_size)
errx(1, "incorrect ELF header or truncated file");
elf_shstrtab = &elf_total[elf_shdr[elf_ex.e_shstrndx].sh_offset];
close(fd);
}
void
elf_savekernel(char *outfile)
{
int fd;
if ((fd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0755)) < 0)
err(1, "%s", outfile);
if (write(fd, elf_total, (size_t)elf_size) != elf_size)
errx(1, "can't write file %s", outfile);
close(fd);
}
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