linker.h revision e83c56dfbb6a9a61f0f18031620322af97e80162
1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#ifndef _LINKER_H_ 30#define _LINKER_H_ 31 32#include <unistd.h> 33#include <sys/types.h> 34#include <linux/elf.h> 35 36#undef PAGE_MASK 37#undef PAGE_SIZE 38#define PAGE_SIZE 4096 39#define PAGE_MASK 4095 40 41void debugger_init(); 42const char *addr_to_name(unsigned addr); 43 44/* magic shared structures that GDB knows about */ 45 46struct link_map 47{ 48 uintptr_t l_addr; 49 char * l_name; 50 uintptr_t l_ld; 51 struct link_map * l_next; 52 struct link_map * l_prev; 53}; 54 55/* needed for dl_iterate_phdr to be passed to the callbacks provided */ 56struct dl_phdr_info 57{ 58 Elf32_Addr dlpi_addr; 59 const char *dlpi_name; 60 const Elf32_Phdr *dlpi_phdr; 61 Elf32_Half dlpi_phnum; 62}; 63 64 65// Values for r_debug->state 66enum { 67 RT_CONSISTENT, 68 RT_ADD, 69 RT_DELETE 70}; 71 72struct r_debug 73{ 74 int32_t r_version; 75 struct link_map * r_map; 76 void (*r_brk)(void); 77 int32_t r_state; 78 uintptr_t r_ldbase; 79}; 80 81typedef struct soinfo soinfo; 82 83#define FLAG_LINKED 0x00000001 84#define FLAG_ERROR 0x00000002 85#define FLAG_EXE 0x00000004 // The main executable 86#define FLAG_LINKER 0x00000010 // The linker itself 87 88#define SOINFO_NAME_LEN 128 89 90struct soinfo 91{ 92 const char name[SOINFO_NAME_LEN]; 93 Elf32_Phdr *phdr; 94 int phnum; 95 unsigned entry; 96 unsigned base; 97 unsigned size; 98 99 int unused; // DO NOT USE, maintained for compatibility. 100 101 unsigned *dynamic; 102 103 unsigned wrprotect_start; 104 unsigned wrprotect_end; 105 106 soinfo *next; 107 unsigned flags; 108 109 const char *strtab; 110 Elf32_Sym *symtab; 111 112 unsigned nbucket; 113 unsigned nchain; 114 unsigned *bucket; 115 unsigned *chain; 116 117 unsigned *plt_got; 118 119 Elf32_Rel *plt_rel; 120 unsigned plt_rel_count; 121 122 Elf32_Rel *rel; 123 unsigned rel_count; 124 125#ifdef ANDROID_SH_LINKER 126 Elf32_Rela *plt_rela; 127 unsigned plt_rela_count; 128 129 Elf32_Rela *rela; 130 unsigned rela_count; 131#endif /* ANDROID_SH_LINKER */ 132 133 unsigned *preinit_array; 134 unsigned preinit_array_count; 135 136 unsigned *init_array; 137 unsigned init_array_count; 138 unsigned *fini_array; 139 unsigned fini_array_count; 140 141 void (*init_func)(void); 142 void (*fini_func)(void); 143 144#ifdef ANDROID_ARM_LINKER 145 /* ARM EABI section used for stack unwinding. */ 146 unsigned *ARM_exidx; 147 unsigned ARM_exidx_count; 148#endif 149 150 unsigned refcount; 151 struct link_map linkmap; 152 153 int constructors_called; 154}; 155 156 157extern soinfo libdl_info; 158 159#ifdef ANDROID_ARM_LINKER 160 161#define R_ARM_COPY 20 162#define R_ARM_GLOB_DAT 21 163#define R_ARM_JUMP_SLOT 22 164#define R_ARM_RELATIVE 23 165 166/* According to the AAPCS specification, we only 167 * need the above relocations. However, in practice, 168 * the following ones turn up from time to time. 169 */ 170#define R_ARM_ABS32 2 171#define R_ARM_REL32 3 172 173#elif defined(ANDROID_X86_LINKER) 174 175#define R_386_32 1 176#define R_386_PC32 2 177#define R_386_GLOB_DAT 6 178#define R_386_JUMP_SLOT 7 179#define R_386_RELATIVE 8 180 181#elif defined(ANDROID_SH_LINKER) 182 183#define R_SH_DIR32 1 184#define R_SH_GLOB_DAT 163 185#define R_SH_JUMP_SLOT 164 186#define R_SH_RELATIVE 165 187 188#endif /* ANDROID_*_LINKER */ 189 190 191#ifndef DT_INIT_ARRAY 192#define DT_INIT_ARRAY 25 193#endif 194 195#ifndef DT_FINI_ARRAY 196#define DT_FINI_ARRAY 26 197#endif 198 199#ifndef DT_INIT_ARRAYSZ 200#define DT_INIT_ARRAYSZ 27 201#endif 202 203#ifndef DT_FINI_ARRAYSZ 204#define DT_FINI_ARRAYSZ 28 205#endif 206 207#ifndef DT_PREINIT_ARRAY 208#define DT_PREINIT_ARRAY 32 209#endif 210 211#ifndef DT_PREINIT_ARRAYSZ 212#define DT_PREINIT_ARRAYSZ 33 213#endif 214 215soinfo *find_library(const char *name); 216unsigned unload_library(soinfo *si); 217Elf32_Sym *lookup_in_library(soinfo *si, const char *name); 218Elf32_Sym *lookup(const char *name, soinfo **found, soinfo *start); 219soinfo *find_containing_library(const void *addr); 220Elf32_Sym *find_containing_symbol(const void *addr, soinfo *si); 221const char *linker_get_error(void); 222void call_constructors_recursive(soinfo *si); 223 224#ifdef ANDROID_ARM_LINKER 225typedef long unsigned int *_Unwind_Ptr; 226_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount); 227#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_SH_LINKER) 228int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *); 229#endif 230 231#endif 232