linker.h revision 9ea64da6c511e8f9f4edae4c10c20879957631ab
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_PRELINKED 0x00000008 // This is a pre-linked lib 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 // buddy-allocator index, negative for prelinked libraries 99 int ba_index; 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 unsigned *preinit_array; 126 unsigned preinit_array_count; 127 128 unsigned *init_array; 129 unsigned init_array_count; 130 unsigned *fini_array; 131 unsigned fini_array_count; 132 133 void (*init_func)(void); 134 void (*fini_func)(void); 135 136#ifdef ANDROID_ARM_LINKER 137 /* ARM EABI section used for stack unwinding. */ 138 unsigned *ARM_exidx; 139 unsigned ARM_exidx_count; 140#endif 141 142 unsigned refcount; 143 struct link_map linkmap; 144}; 145 146 147extern soinfo libdl_info; 148 149/* these must all be powers of two */ 150#define LIBBASE 0x80000000 151#define LIBLAST 0x90000000 152#define LIBINC 0x00100000 153 154 155#ifdef ANDROID_ARM_LINKER 156 157#define R_ARM_COPY 20 158#define R_ARM_GLOB_DAT 21 159#define R_ARM_JUMP_SLOT 22 160#define R_ARM_RELATIVE 23 161 162#elif defined(ANDROID_X86_LINKER) 163 164#define R_386_32 1 165#define R_386_PC32 2 166#define R_386_GLOB_DAT 6 167#define R_386_JUMP_SLOT 7 168#define R_386_RELATIVE 8 169 170#endif /* ANDROID_*_LINKER */ 171 172 173#ifndef DT_INIT_ARRAY 174#define DT_INIT_ARRAY 25 175#endif 176 177#ifndef DT_FINI_ARRAY 178#define DT_FINI_ARRAY 26 179#endif 180 181#ifndef DT_INIT_ARRAYSZ 182#define DT_INIT_ARRAYSZ 27 183#endif 184 185#ifndef DT_FINI_ARRAYSZ 186#define DT_FINI_ARRAYSZ 28 187#endif 188 189#ifndef DT_PREINIT_ARRAY 190#define DT_PREINIT_ARRAY 32 191#endif 192 193#ifndef DT_PREINIT_ARRAYSZ 194#define DT_PREINIT_ARRAYSZ 33 195#endif 196 197/* in theory we only need the above relative relocations, 198 but in practice the following one turns up from time 199 to time. fushigi na. 200*/ 201#define R_ARM_ABS32 2 202 203soinfo *find_library(const char *name); 204unsigned unload_library(soinfo *si); 205Elf32_Sym *lookup_in_library(soinfo *si, const char *name); 206Elf32_Sym *lookup(const char *name, soinfo **found); 207const char *linker_get_error(void); 208 209#ifdef ANDROID_ARM_LINKER 210typedef long unsigned int *_Unwind_Ptr; 211_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount); 212#elif defined(ANDROID_X86_LINKER) 213int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *); 214#endif 215 216#endif 217