other-licenses/android/linker.h

   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
  41 void debugger_init();
  42 const char *addr_to_name(unsigned addr);
  43
  44 /* magic shared structures that GDB knows about */
  45
  46 struct 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 */
  56 struct 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
  66 enum {
  67     RT_CONSISTENT,
  68     RT_ADD,
  69     RT_DELETE
  70 };
  71
  72 struct 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
  81 typedef 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
  90 struct 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 #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
 154
 155 extern soinfo libdl_info;
 156
 157 /* these must all be powers of two */
 158 #ifdef ARCH_SH
 159 #define LIBBASE 0x60000000
 160 #define LIBLAST 0x70000000
 161 #define LIBINC  0x00100000
 162 #else
 163 #define LIBBASE 0x70000000
 164 #define LIBLAST 0x80000000
 165 #define LIBINC  0x00100000
 166 #endif
 167
 168 #ifdef ANDROID_ARM_LINKER
 169
 170 #define R_ARM_COPY       20
 171 #define R_ARM_GLOB_DAT   21
 172 #define R_ARM_JUMP_SLOT  22
 173 #define R_ARM_RELATIVE   23
 174
 175 /* According to the AAPCS specification, we only
 176  * need the above relocations. However, in practice,
 177  * the following ones turn up from time to time.
 178  */
 179 #define R_ARM_ABS32      2
 180 #define R_ARM_REL32      3
 181
 182 #elif defined(ANDROID_X86_LINKER)
 183
 184 #define R_386_32         1
 185 #define R_386_PC32       2
 186 #define R_386_GLOB_DAT   6
 187 #define R_386_JUMP_SLOT  7
 188 #define R_386_RELATIVE   8
 189
 190 #elif defined(ANDROID_SH_LINKER)
 191
 192 #define R_SH_DIR32      1
 193 #define R_SH_GLOB_DAT   163
 194 #define R_SH_JUMP_SLOT  164
 195 #define R_SH_RELATIVE   165
 196
 197 #endif /* ANDROID_*_LINKER */
 198
 199
 200 #ifndef DT_INIT_ARRAY
 201 #define DT_INIT_ARRAY      25
 202 #endif
 203
 204 #ifndef DT_FINI_ARRAY
 205 #define DT_FINI_ARRAY      26
 206 #endif
 207
 208 #ifndef DT_INIT_ARRAYSZ
 209 #define DT_INIT_ARRAYSZ    27
 210 #endif
 211
 212 #ifndef DT_FINI_ARRAYSZ
 213 #define DT_FINI_ARRAYSZ    28
 214 #endif
 215
 216 #ifndef DT_PREINIT_ARRAY
 217 #define DT_PREINIT_ARRAY   32
 218 #endif
 219
 220 #ifndef DT_PREINIT_ARRAYSZ
 221 #define DT_PREINIT_ARRAYSZ 33
 222 #endif
 223
 224 soinfo *find_library(const char *name);
 225 soinfo *find_mapped_library(const char *name, int fd,
 226                             void *mem, size_t len, size_t offset);
 227 unsigned unload_library(soinfo *si);
 228 Elf32_Sym *lookup_in_library(soinfo *si, const char *name);
 229 Elf32_Sym *lookup(const char *name, soinfo **found, soinfo *start);
 230 soinfo *find_containing_library(void *addr);
 231 Elf32_Sym *find_containing_symbol(void *addr, soinfo *si);
 232 const char *linker_get_error(void);
 233 void simple_linker_init(void);
 234
 235 #ifdef ANDROID_ARM_LINKER
 236 typedef long unsigned int *_Unwind_Ptr;
 237 _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount);
 238 #elif defined(ANDROID_X86_LINKER) || defined(ANDROID_SH_LINKER)
 239 int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *);
 240 #endif
 241
 242 #endif