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 <elf.h> 35 #include <sys/exec_elf.h> 36 37 #undef PAGE_MASK 38 #undef PAGE_SIZE 39 #define PAGE_SIZE 4096 40 #define PAGE_MASK 4095 41 42 void debugger_init(); 43 const char *addr_to_name(unsigned addr); 44 45 /* magic shared structures that GDB knows about */ 46 47 struct link_map 48 { 49 uintptr_t l_addr; 50 char * l_name; 51 uintptr_t l_ld; 52 struct link_map * l_next; 53 struct link_map * l_prev; 54 }; 55 56 /* needed for dl_iterate_phdr to be passed to the callbacks provided */ 57 struct dl_phdr_info 58 { 59 Elf32_Addr dlpi_addr; 60 const char *dlpi_name; 61 const Elf32_Phdr *dlpi_phdr; 62 Elf32_Half dlpi_phnum; 63 }; 64 65 66 // Values for r_debug->state 67 enum { 68 RT_CONSISTENT, 69 RT_ADD, 70 RT_DELETE 71 }; 72 73 struct r_debug 74 { 75 int32_t r_version; 76 struct link_map * r_map; 77 void (*r_brk)(void); 78 int32_t r_state; 79 uintptr_t r_ldbase; 80 }; 81 82 typedef struct soinfo soinfo; 83 84 #define FLAG_LINKED 0x00000001 85 #define FLAG_ERROR 0x00000002 86 #define FLAG_EXE 0x00000004 // The main executable 87 #define FLAG_LINKER 0x00000010 // The linker itself 88 89 #define SOINFO_NAME_LEN 128 90 91 struct soinfo 92 { 93 const char name[SOINFO_NAME_LEN]; 94 Elf32_Phdr *phdr; 95 int phnum; 96 unsigned entry; 97 unsigned base; 98 unsigned size; 99 100 int unused; // DO NOT USE, maintained for compatibility. 101 102 unsigned *dynamic; 103 104 unsigned wrprotect_start; 105 unsigned wrprotect_end; 106 107 soinfo *next; 108 unsigned flags; 109 110 const char *strtab; 111 Elf32_Sym *symtab; 112 113 unsigned nbucket; 114 unsigned nchain; 115 unsigned *bucket; 116 unsigned *chain; 117 118 unsigned *plt_got; 119 120 Elf32_Rel *plt_rel; 121 unsigned plt_rel_count; 122 123 Elf32_Rel *rel; 124 unsigned rel_count; 125 126 unsigned *preinit_array; 127 unsigned preinit_array_count; 128 129 unsigned *init_array; 130 unsigned init_array_count; 131 unsigned *fini_array; 132 unsigned fini_array_count; 133 134 void (*init_func)(void); 135 void (*fini_func)(void); 136 137 #ifdef ANDROID_ARM_LINKER 138 /* ARM EABI section used for stack unwinding. */ 139 unsigned *ARM_exidx; 140 unsigned ARM_exidx_count; 141 #endif 142 143 unsigned refcount; 144 struct link_map linkmap; 145 146 int constructors_called; 147 148 Elf32_Addr gnu_relro_start; 149 unsigned gnu_relro_len; 150 151 }; 152 153 154 extern soinfo libdl_info; 155 156 #ifdef ANDROID_ARM_LINKER 157 158 #define R_ARM_COPY 20 159 #define R_ARM_GLOB_DAT 21 160 #define R_ARM_JUMP_SLOT 22 161 #define R_ARM_RELATIVE 23 162 163 /* According to the AAPCS specification, we only 164 * need the above relocations. However, in practice, 165 * the following ones turn up from time to time. 166 */ 167 #define R_ARM_ABS32 2 168 #define R_ARM_REL32 3 169 170 #elif defined(ANDROID_X86_LINKER) 171 172 #define R_386_32 1 173 #define R_386_PC32 2 174 #define R_386_GLOB_DAT 6 175 #define R_386_JUMP_SLOT 7 176 #define R_386_RELATIVE 8 177 178 #endif 179 180 #ifndef DT_INIT_ARRAY 181 #define DT_INIT_ARRAY 25 182 #endif 183 184 #ifndef DT_FINI_ARRAY 185 #define DT_FINI_ARRAY 26 186 #endif 187 188 #ifndef DT_INIT_ARRAYSZ 189 #define DT_INIT_ARRAYSZ 27 190 #endif 191 192 #ifndef DT_FINI_ARRAYSZ 193 #define DT_FINI_ARRAYSZ 28 194 #endif 195 196 #ifndef DT_PREINIT_ARRAY 197 #define DT_PREINIT_ARRAY 32 198 #endif 199 200 #ifndef DT_PREINIT_ARRAYSZ 201 #define DT_PREINIT_ARRAYSZ 33 202 #endif 203 204 soinfo *find_library(const char *name); 205 unsigned unload_library(soinfo *si); 206 Elf32_Sym *lookup_in_library(soinfo *si, const char *name); 207 Elf32_Sym *lookup(const char *name, soinfo **found, soinfo *start); 208 soinfo *find_containing_library(const void *addr); 209 Elf32_Sym *find_containing_symbol(const void *addr, soinfo *si); 210 const char *linker_get_error(void); 211 void call_constructors_recursive(soinfo *si); 212 213 #ifdef ANDROID_ARM_LINKER 214 typedef long unsigned int *_Unwind_Ptr; 215 _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount); 216 #elif defined(ANDROID_X86_LINKER) 217 int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *); 218 #endif 219 220 #endif 221
