/* Test program for elf_update function. Copyright (C) 2000, 2002, 2005, 2016 Red Hat, Inc. This file is part of elfutils. Written by Ulrich Drepper <drepper@redhat.com>, 2000. This file 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 3 of the License, or (at your option) any later version. elfutils 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, see <http://www.gnu.org/licenses/>. */ #ifdef HAVE_CONFIG_H # include <config.h> #endif #include <errno.h> #include <fcntl.h> #include <libelf.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include ELFUTILS_HEADER(dwelf) int main (int argc, char *argv[] __attribute__ ((unused))) { const char *fname = "xxx_update3"; int fd; Elf *elf; Elf32_Ehdr *ehdr; Elf32_Phdr *phdr; Elf_Scn *scn; Elf32_Shdr *shdr; Elf_Data *data; Dwelf_Strtab *shst; Dwelf_Strent *shstrtabse; int i; fd = open (fname, O_RDWR | O_CREAT | O_TRUNC, 0666); if (fd == -1) { printf ("cannot open `%s': %s\n", fname, strerror (errno)); exit (1); } elf_version (EV_CURRENT); elf_fill (0x42); elf = elf_begin (fd, ELF_C_WRITE, NULL); if (elf == NULL) { printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1)); exit (1); } /* Create an ELF header. */ ehdr = elf32_newehdr (elf); if (ehdr == NULL) { printf ("cannot create ELF header: %s\n", elf_errmsg (-1)); exit (1); } /* Print the ELF header values. */ if (argc > 1) { for (i = 0; i < EI_NIDENT; ++i) printf (" %02x", ehdr->e_ident[i]); printf ("\ \ntype = %hu\nmachine = %hu\nversion = %u\nentry = %u\nphoff = %u\n" "shoff = %u\nflags = %u\nehsize = %hu\nphentsize = %hu\n" "phnum = %hu\nshentsize = %hu\nshnum = %hu\nshstrndx = %hu\n", ehdr->e_type, ehdr->e_machine, ehdr->e_version, ehdr->e_entry, ehdr->e_phoff, ehdr->e_shoff, ehdr->e_flags, ehdr->e_ehsize, ehdr->e_phentsize, ehdr->e_phnum, ehdr->e_shentsize, ehdr->e_shnum, ehdr->e_shstrndx); } ehdr->e_ident[0] = 42; ehdr->e_ident[4] = 1; ehdr->e_ident[5] = 1; ehdr->e_ident[6] = 2; ehdr->e_type = ET_EXEC; ehdr->e_version = 1; ehdr->e_ehsize = 1; elf_flagehdr (elf, ELF_C_SET, ELF_F_DIRTY); /* Create the program header. */ phdr = elf32_newphdr (elf, 1); if (phdr == NULL) { printf ("cannot create program header: %s\n", elf_errmsg (-1)); exit (1); } phdr[0].p_type = PT_PHDR; elf_flagphdr (elf, ELF_C_SET, ELF_F_DIRTY); shst = dwelf_strtab_init (true); scn = elf_newscn (elf); if (scn == NULL) { printf ("cannot create SHSTRTAB section: %s\n", elf_errmsg (-1)); exit (1); } shdr = elf32_getshdr (scn); if (shdr == NULL) { printf ("cannot get header for SHSTRTAB section: %s\n", elf_errmsg (-1)); exit (1); } shstrtabse = dwelf_strtab_add (shst, ".shstrtab"); shdr->sh_type = SHT_STRTAB; shdr->sh_flags = 0; shdr->sh_addr = 0; shdr->sh_link = SHN_UNDEF; shdr->sh_info = SHN_UNDEF; shdr->sh_addralign = 1; shdr->sh_entsize = 0; /* We have to store the section index in the ELF header. */ ehdr->e_shstrndx = elf_ndxscn (scn); data = elf_newdata (scn); if (data == NULL) { printf ("cannot create data SHSTRTAB section: %s\n", elf_errmsg (-1)); exit (1); } /* No more sections, finalize the section header string table. */ dwelf_strtab_finalize (shst, data); shdr->sh_name = dwelf_strent_off (shstrtabse); /* Let the library compute the internal structure information. */ if (elf_update (elf, ELF_C_NULL) < 0) { printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1)); exit (1); } ehdr = elf32_getehdr (elf); phdr[0].p_offset = ehdr->e_phoff; phdr[0].p_offset = ehdr->e_phoff; phdr[0].p_vaddr = ehdr->e_phoff; phdr[0].p_paddr = ehdr->e_phoff; phdr[0].p_flags = PF_R | PF_X; phdr[0].p_filesz = ehdr->e_phnum * elf32_fsize (ELF_T_PHDR, 1, EV_CURRENT); phdr[0].p_memsz = ehdr->e_phnum * elf32_fsize (ELF_T_PHDR, 1, EV_CURRENT); phdr[0].p_align = sizeof (Elf32_Word); /* Write out the file. */ if (elf_update (elf, ELF_C_WRITE) < 0) { printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1)); exit (1); } /* We don't need the string table anymore. */ dwelf_strtab_free (shst); /* And the data allocated in the .shstrtab section. */ free (data->d_buf); /* Print the ELF header values. */ if (argc > 1) { for (i = 0; i < EI_NIDENT; ++i) printf (" %02x", ehdr->e_ident[i]); printf ("\ \ntype = %hu\nmachine = %hu\nversion = %u\nentry = %u\nphoff = %u\n" "shoff = %u\nflags = %u\nehsize = %hu\nphentsize = %hu\n" "phnum = %hu\nshentsize = %hu\nshnum = %hu\nshstrndx = %hu\n", ehdr->e_type, ehdr->e_machine, ehdr->e_version, ehdr->e_entry, ehdr->e_phoff, ehdr->e_shoff, ehdr->e_flags, ehdr->e_ehsize, ehdr->e_phentsize, ehdr->e_phnum, ehdr->e_shentsize, ehdr->e_shnum, ehdr->e_shstrndx); } if (elf_end (elf) != 0) { printf ("failure in elf_end: %s\n", elf_errmsg (-1)); exit (1); } unlink (fname); return 0; }