/* $OpenBSD: exec_elf.c,v 1.17 2019/06/28 13:32:47 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 <sys/types.h> #include <sys/exec.h> #include <elf.h> #include <err.h> #include <errno.h> #include <fcntl.h> #include <nlist.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include "ukc.h" #include "config.h" #include "exec.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 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 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); } void loadkernel(char *file) { int fd; if ((fd = open(file, O_RDONLY | O_EXLOCK, 0)) == -1) 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 savekernel(char *outfile) { int fd; if ((fd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0700)) == -1) 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); }