michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <stdint.h>
michael@0: #include <elf.h>
michael@0: 
michael@0: /* The Android NDK headers define those */
michael@0: #undef Elf_Ehdr
michael@0: #undef Elf_Addr
michael@0: 
michael@0: #if defined(__LP64__)
michael@0: #define Elf_Ehdr Elf64_Ehdr
michael@0: #define Elf_Addr Elf64_Addr
michael@0: #else
michael@0: #define Elf_Ehdr Elf32_Ehdr
michael@0: #define Elf_Addr Elf32_Addr
michael@0: #endif
michael@0: 
michael@0: extern __attribute__((visibility("hidden"))) void original_init(int argc, char **argv, char **env);
michael@0: 
michael@0: extern __attribute__((visibility("hidden"))) Elf32_Rel relhack[];
michael@0: extern __attribute__((visibility("hidden"))) Elf_Ehdr elf_header;
michael@0: 
michael@0: static inline __attribute__((always_inline))
michael@0: void do_relocations(void)
michael@0: {
michael@0:     Elf32_Rel *rel;
michael@0:     Elf_Addr *ptr, *start;
michael@0:     for (rel = relhack; rel->r_offset; rel++) {
michael@0:         start = (Elf_Addr *)((intptr_t)&elf_header + rel->r_offset);
michael@0:         for (ptr = start; ptr < &start[rel->r_info]; ptr++)
michael@0:             *ptr += (intptr_t)&elf_header;
michael@0:     }
michael@0: }
michael@0: 
michael@0: __attribute__((section(".text._init_noinit")))
michael@0: int init_noinit(int argc, char **argv, char **env)
michael@0: {
michael@0:     do_relocations();
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: __attribute__((section(".text._init")))
michael@0: int init(int argc, char **argv, char **env)
michael@0: {
michael@0:     do_relocations();
michael@0:     original_init(argc, argv, env);
michael@0:     // Ensure there is no tail-call optimization, avoiding the use of the
michael@0:     // B.W instruction in Thumb for the call above.
michael@0:     return 0;
michael@0: }