1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/build/unix/elfhack/inject.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,52 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include <stdint.h>
1.9 +#include <elf.h>
1.10 +
1.11 +/* The Android NDK headers define those */
1.12 +#undef Elf_Ehdr
1.13 +#undef Elf_Addr
1.14 +
1.15 +#if defined(__LP64__)
1.16 +#define Elf_Ehdr Elf64_Ehdr
1.17 +#define Elf_Addr Elf64_Addr
1.18 +#else
1.19 +#define Elf_Ehdr Elf32_Ehdr
1.20 +#define Elf_Addr Elf32_Addr
1.21 +#endif
1.22 +
1.23 +extern __attribute__((visibility("hidden"))) void original_init(int argc, char **argv, char **env);
1.24 +
1.25 +extern __attribute__((visibility("hidden"))) Elf32_Rel relhack[];
1.26 +extern __attribute__((visibility("hidden"))) Elf_Ehdr elf_header;
1.27 +
1.28 +static inline __attribute__((always_inline))
1.29 +void do_relocations(void)
1.30 +{
1.31 + Elf32_Rel *rel;
1.32 + Elf_Addr *ptr, *start;
1.33 + for (rel = relhack; rel->r_offset; rel++) {
1.34 + start = (Elf_Addr *)((intptr_t)&elf_header + rel->r_offset);
1.35 + for (ptr = start; ptr < &start[rel->r_info]; ptr++)
1.36 + *ptr += (intptr_t)&elf_header;
1.37 + }
1.38 +}
1.39 +
1.40 +__attribute__((section(".text._init_noinit")))
1.41 +int init_noinit(int argc, char **argv, char **env)
1.42 +{
1.43 + do_relocations();
1.44 + return 0;
1.45 +}
1.46 +
1.47 +__attribute__((section(".text._init")))
1.48 +int init(int argc, char **argv, char **env)
1.49 +{
1.50 + do_relocations();
1.51 + original_init(argc, argv, env);
1.52 + // Ensure there is no tail-call optimization, avoiding the use of the
1.53 + // B.W instruction in Thumb for the call above.
1.54 + return 0;
1.55 +}
