/build/unix/elfhack/inject.c

 1/* ***** BEGIN LICENSE BLOCK *****
 2 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 3 *
 4 * The contents of this file are subject to the Mozilla Public License Version
 5 * 1.1 (the "License"); you may not use this file except in compliance with
 6 * the License. You may obtain a copy of the License at
 7 * http://www.mozilla.org/MPL/
 8 *
 9 * Software distributed under the License is distributed on an "AS IS" basis,
10 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11 * for the specific language governing rights and limitations under the
12 * License.
13 *
14 * The Original Code is elfhack.
15 *
16 * The Initial Developer of the Original Code is
17 * Mozilla Foundation.
18 * Portions created by the Initial Developer are Copyright (C) 2010
19 * the Initial Developer. All Rights Reserved.
20 *
21 * Contributor(s):
22 *   Mike Hommey <mh@glandium.org>
23 *
24 * Alternatively, the contents of this file may be used under the terms of
25 * either the GNU General Public License Version 2 or later (the "GPL"), or
26 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 * in which case the provisions of the GPL or the LGPL are applicable instead
28 * of those above. If you wish to allow use of your version of this file only
29 * under the terms of either the GPL or the LGPL, and not to allow others to
30 * use your version of this file under the terms of the MPL, indicate your
31 * decision by deleting the provisions above and replace them with the notice
32 * and other provisions required by the GPL or the LGPL. If you do not delete
33 * the provisions above, a recipient may use your version of this file under
34 * the terms of any one of the MPL, the GPL or the LGPL.
35 *
36 * ***** END LICENSE BLOCK ***** */
37
38#include <stdint.h>
39#include <elf.h>
40
41/* The Android NDK headers define those */
42#undef Elf_Ehdr
43#undef Elf_Addr
44
45#if BITS == 32
46#define Elf_Ehdr Elf32_Ehdr
47#define Elf_Addr Elf32_Addr
48#else
49#define Elf_Ehdr Elf64_Ehdr
50#define Elf_Addr Elf64_Addr
51#endif
52
53extern __attribute__((visibility("hidden"))) void original_init(int argc, char **argv, char **env);
54
55extern __attribute__((visibility("hidden"))) Elf32_Rel relhack[];
56extern __attribute__((visibility("hidden"))) Elf_Ehdr elf_header;
57
58void init(int argc, char **argv, char **env)
59{
60    Elf32_Rel *rel;
61    Elf_Addr *ptr, *start;
62    for (rel = relhack; rel->r_offset; rel++) {
63        start = (Elf_Addr *)((intptr_t)&elf_header + rel->r_offset);
64        for (ptr = start; ptr < &start[rel->r_info]; ptr++)
65            *ptr += (intptr_t)&elf_header;
66    }
67
68#ifndef NOINIT
69    original_init(argc, argv, env);
70#endif
71}