1 //===-- ObjectFileELF.h --------------------------------------- -*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef liblldb_ObjectFileELF_h_ 11 #define liblldb_ObjectFileELF_h_ 12 13 #include <stdint.h> 14 #include <vector> 15 16 #include "lldb/lldb-private.h" 17 #include "lldb/Host/FileSpec.h" 18 #include "lldb/Symbol/ObjectFile.h" 19 #include "lldb/Core/UUID.h" 20 #include "lldb/Core/ArchSpec.h" 21 22 #include "ELFHeader.h" 23 24 struct ELFNote 25 { 26 elf::elf_word n_namesz; 27 elf::elf_word n_descsz; 28 elf::elf_word n_type; 29 30 std::string n_name; 31 32 ELFNote() : n_namesz(0), n_descsz(0), n_type(0) 33 { 34 } 35 36 /// Parse an ELFNote entry from the given DataExtractor starting at position 37 /// \p offset. 38 /// 39 /// @param[in] data 40 /// The DataExtractor to read from. 41 /// 42 /// @param[in,out] offset 43 /// Pointer to an offset in the data. On return the offset will be 44 /// advanced by the number of bytes read. 45 /// 46 /// @return 47 /// True if the ELFRel entry was successfully read and false otherwise. 48 bool 49 Parse(const lldb_private::DataExtractor &data, lldb::offset_t *offset); 50 }; 51 52 //------------------------------------------------------------------------------ 53 /// @class ObjectFileELF 54 /// @brief Generic ELF object file reader. 55 /// 56 /// This class provides a generic ELF (32/64 bit) reader plugin implementing the 57 /// ObjectFile protocol. 58 class ObjectFileELF : 59 public lldb_private::ObjectFile 60 { 61 public: 62 //------------------------------------------------------------------ 63 // Static Functions 64 //------------------------------------------------------------------ 65 static void 66 Initialize(); 67 68 static void 69 Terminate(); 70 71 static lldb_private::ConstString 72 GetPluginNameStatic(); 73 74 static const char * 75 GetPluginDescriptionStatic(); 76 77 static lldb_private::ObjectFile * 78 CreateInstance(const lldb::ModuleSP &module_sp, 79 lldb::DataBufferSP& data_sp, 80 lldb::offset_t data_offset, 81 const lldb_private::FileSpec* file, 82 lldb::offset_t file_offset, 83 lldb::offset_t length); 84 85 static lldb_private::ObjectFile * 86 CreateMemoryInstance (const lldb::ModuleSP &module_sp, 87 lldb::DataBufferSP& data_sp, 88 const lldb::ProcessSP &process_sp, 89 lldb::addr_t header_addr); 90 91 static size_t 92 GetModuleSpecifications (const lldb_private::FileSpec& file, 93 lldb::DataBufferSP& data_sp, 94 lldb::offset_t data_offset, 95 lldb::offset_t file_offset, 96 lldb::offset_t length, 97 lldb_private::ModuleSpecList &specs); 98 99 static bool 100 MagicBytesMatch (lldb::DataBufferSP& data_sp, 101 lldb::addr_t offset, 102 lldb::addr_t length); 103 104 //------------------------------------------------------------------ 105 // PluginInterface protocol 106 //------------------------------------------------------------------ 107 lldb_private::ConstString 108 GetPluginName() override; 109 110 uint32_t 111 GetPluginVersion() override; 112 113 //------------------------------------------------------------------ 114 // ObjectFile Protocol. 115 //------------------------------------------------------------------ 116 virtual 117 ~ObjectFileELF(); 118 119 bool 120 ParseHeader() override; 121 122 bool 123 SetLoadAddress (lldb_private::Target &target, 124 lldb::addr_t value, 125 bool value_is_offset) override; 126 127 lldb::ByteOrder 128 GetByteOrder() const override; 129 130 bool 131 IsExecutable () const override; 132 133 uint32_t 134 GetAddressByteSize() const override; 135 136 lldb::AddressClass 137 GetAddressClass (lldb::addr_t file_addr) override; 138 139 lldb_private::Symtab * 140 GetSymtab() override; 141 142 lldb_private::Symbol * 143 ResolveSymbolForAddress(const lldb_private::Address& so_addr, bool verify_unique) override; 144 145 bool 146 IsStripped () override; 147 148 void 149 CreateSections (lldb_private::SectionList &unified_section_list) override; 150 151 void 152 Dump(lldb_private::Stream *s) override; 153 154 bool 155 GetArchitecture (lldb_private::ArchSpec &arch) override; 156 157 bool 158 GetUUID(lldb_private::UUID* uuid) override; 159 160 lldb_private::FileSpecList 161 GetDebugSymbolFilePaths() override; 162 163 uint32_t 164 GetDependentModules(lldb_private::FileSpecList& files) override; 165 166 lldb_private::Address 167 GetImageInfoAddress(lldb_private::Target *target) override; 168 169 lldb_private::Address 170 GetEntryPointAddress () override; 171 172 ObjectFile::Type 173 CalculateType() override; 174 175 ObjectFile::Strata 176 CalculateStrata() override; 177 178 // Returns number of program headers found in the ELF file. 179 size_t 180 GetProgramHeaderCount(); 181 182 // Returns the program header with the given index. 183 const elf::ELFProgramHeader * 184 GetProgramHeaderByIndex(lldb::user_id_t id); 185 186 // Returns segment data for the given index. 187 lldb_private::DataExtractor 188 GetSegmentDataByIndex(lldb::user_id_t id); 189 190 std::string 191 StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const override; 192 193 private: 194 ObjectFileELF(const lldb::ModuleSP &module_sp, 195 lldb::DataBufferSP& data_sp, 196 lldb::offset_t data_offset, 197 const lldb_private::FileSpec* file, 198 lldb::offset_t offset, 199 lldb::offset_t length); 200 201 ObjectFileELF (const lldb::ModuleSP &module_sp, 202 lldb::DataBufferSP& data_sp, 203 const lldb::ProcessSP &process_sp, 204 lldb::addr_t header_addr); 205 206 typedef std::vector<elf::ELFProgramHeader> ProgramHeaderColl; 207 typedef ProgramHeaderColl::iterator ProgramHeaderCollIter; 208 typedef ProgramHeaderColl::const_iterator ProgramHeaderCollConstIter; 209 210 struct ELFSectionHeaderInfo : public elf::ELFSectionHeader 211 { 212 lldb_private::ConstString section_name; 213 }; 214 typedef std::vector<ELFSectionHeaderInfo> SectionHeaderColl; 215 typedef SectionHeaderColl::iterator SectionHeaderCollIter; 216 typedef SectionHeaderColl::const_iterator SectionHeaderCollConstIter; 217 218 typedef std::vector<elf::ELFDynamic> DynamicSymbolColl; 219 typedef DynamicSymbolColl::iterator DynamicSymbolCollIter; 220 typedef DynamicSymbolColl::const_iterator DynamicSymbolCollConstIter; 221 222 /// Version of this reader common to all plugins based on this class. 223 static const uint32_t m_plugin_version = 1; 224 static const uint32_t g_core_uuid_magic; 225 226 /// ELF file header. 227 elf::ELFHeader m_header; 228 229 /// ELF build ID. 230 lldb_private::UUID m_uuid; 231 232 /// ELF .gnu_debuglink file and crc data if available. 233 std::string m_gnu_debuglink_file; 234 uint32_t m_gnu_debuglink_crc; 235 236 /// Collection of program headers. 237 ProgramHeaderColl m_program_headers; 238 239 /// Collection of section headers. 240 SectionHeaderColl m_section_headers; 241 242 /// Collection of symbols from the dynamic table. 243 DynamicSymbolColl m_dynamic_symbols; 244 245 /// List of file specifications corresponding to the modules (shared 246 /// libraries) on which this object file depends. 247 mutable std::unique_ptr<lldb_private::FileSpecList> m_filespec_ap; 248 249 /// Cached value of the entry point for this module. 250 lldb_private::Address m_entry_point_address; 251 252 /// The architecture detected from parsing elf file contents. 253 lldb_private::ArchSpec m_arch_spec; 254 255 /// Returns a 1 based index of the given section header. 256 size_t 257 SectionIndex(const SectionHeaderCollIter &I); 258 259 /// Returns a 1 based index of the given section header. 260 size_t 261 SectionIndex(const SectionHeaderCollConstIter &I) const; 262 263 // Parses the ELF program headers. 264 static size_t 265 GetProgramHeaderInfo(ProgramHeaderColl &program_headers, 266 lldb_private::DataExtractor &data, 267 const elf::ELFHeader &header); 268 269 // Finds PT_NOTE segments and calculates their crc sum. 270 static uint32_t 271 CalculateELFNotesSegmentsCRC32(const ProgramHeaderColl& program_headers, 272 lldb_private::DataExtractor &data); 273 274 /// Parses all section headers present in this object file and populates 275 /// m_program_headers. This method will compute the header list only once. 276 /// Returns the number of headers parsed. 277 size_t 278 ParseProgramHeaders(); 279 280 /// Parses all section headers present in this object file and populates 281 /// m_section_headers. This method will compute the header list only once. 282 /// Returns the number of headers parsed. 283 size_t 284 ParseSectionHeaders(); 285 286 /// Parses the elf section headers and returns the uuid, debug link name, crc, archspec. 287 static size_t 288 GetSectionHeaderInfo(SectionHeaderColl §ion_headers, 289 lldb_private::DataExtractor &data, 290 const elf::ELFHeader &header, 291 lldb_private::UUID &uuid, 292 std::string &gnu_debuglink_file, 293 uint32_t &gnu_debuglink_crc, 294 lldb_private::ArchSpec &arch_spec); 295 296 /// Scans the dynamic section and locates all dependent modules (shared 297 /// libraries) populating m_filespec_ap. This method will compute the 298 /// dependent module list only once. Returns the number of dependent 299 /// modules parsed. 300 size_t 301 ParseDependentModules(); 302 303 /// Parses the dynamic symbol table and populates m_dynamic_symbols. The 304 /// vector retains the order as found in the object file. Returns the 305 /// number of dynamic symbols parsed. 306 size_t 307 ParseDynamicSymbols(); 308 309 /// Populates m_symtab_ap will all non-dynamic linker symbols. This method 310 /// will parse the symbols only once. Returns the number of symbols parsed. 311 unsigned 312 ParseSymbolTable(lldb_private::Symtab *symbol_table, 313 lldb::user_id_t start_id, 314 lldb_private::Section *symtab); 315 316 /// Helper routine for ParseSymbolTable(). 317 unsigned 318 ParseSymbols(lldb_private::Symtab *symbol_table, 319 lldb::user_id_t start_id, 320 lldb_private::SectionList *section_list, 321 const size_t num_symbols, 322 const lldb_private::DataExtractor &symtab_data, 323 const lldb_private::DataExtractor &strtab_data); 324 325 /// Scans the relocation entries and adds a set of artificial symbols to the 326 /// given symbol table for each PLT slot. Returns the number of symbols 327 /// added. 328 unsigned 329 ParseTrampolineSymbols(lldb_private::Symtab *symbol_table, 330 lldb::user_id_t start_id, 331 const ELFSectionHeaderInfo *rela_hdr, 332 lldb::user_id_t section_id); 333 334 /// Relocates debug sections 335 unsigned 336 RelocateDebugSections(const elf::ELFSectionHeader *rel_hdr, lldb::user_id_t rel_id); 337 338 unsigned 339 RelocateSection(lldb_private::Symtab* symtab, const elf::ELFHeader *hdr, const elf::ELFSectionHeader *rel_hdr, 340 const elf::ELFSectionHeader *symtab_hdr, const elf::ELFSectionHeader *debug_hdr, 341 lldb_private::DataExtractor &rel_data, lldb_private::DataExtractor &symtab_data, 342 lldb_private::DataExtractor &debug_data, lldb_private::Section* rel_section); 343 344 /// Loads the section name string table into m_shstr_data. Returns the 345 /// number of bytes constituting the table. 346 size_t 347 GetSectionHeaderStringTable(); 348 349 /// Utility method for looking up a section given its name. Returns the 350 /// index of the corresponding section or zero if no section with the given 351 /// name can be found (note that section indices are always 1 based, and so 352 /// section index 0 is never valid). 353 lldb::user_id_t 354 GetSectionIndexByName(const char *name); 355 356 // Returns the ID of the first section that has the given type. 357 lldb::user_id_t 358 GetSectionIndexByType(unsigned type); 359 360 /// Returns the section header with the given id or NULL. 361 const ELFSectionHeaderInfo * 362 GetSectionHeaderByIndex(lldb::user_id_t id); 363 364 /// @name ELF header dump routines 365 //@{ 366 static void 367 DumpELFHeader(lldb_private::Stream *s, const elf::ELFHeader& header); 368 369 static void 370 DumpELFHeader_e_ident_EI_DATA(lldb_private::Stream *s, 371 unsigned char ei_data); 372 373 static void 374 DumpELFHeader_e_type(lldb_private::Stream *s, elf::elf_half e_type); 375 //@} 376 377 /// @name ELF program header dump routines 378 //@{ 379 void 380 DumpELFProgramHeaders(lldb_private::Stream *s); 381 382 static void 383 DumpELFProgramHeader(lldb_private::Stream *s, 384 const elf::ELFProgramHeader &ph); 385 386 static void 387 DumpELFProgramHeader_p_type(lldb_private::Stream *s, elf::elf_word p_type); 388 389 static void 390 DumpELFProgramHeader_p_flags(lldb_private::Stream *s, 391 elf::elf_word p_flags); 392 //@} 393 394 /// @name ELF section header dump routines 395 //@{ 396 void 397 DumpELFSectionHeaders(lldb_private::Stream *s); 398 399 static void 400 DumpELFSectionHeader(lldb_private::Stream *s, 401 const ELFSectionHeaderInfo& sh); 402 403 static void 404 DumpELFSectionHeader_sh_type(lldb_private::Stream *s, 405 elf::elf_word sh_type); 406 407 static void 408 DumpELFSectionHeader_sh_flags(lldb_private::Stream *s, 409 elf::elf_xword sh_flags); 410 //@} 411 412 /// ELF dependent module dump routine. 413 void 414 DumpDependentModules(lldb_private::Stream *s); 415 416 const elf::ELFDynamic * 417 FindDynamicSymbol(unsigned tag); 418 419 unsigned 420 PLTRelocationType(); 421 422 static lldb_private::Error 423 RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, lldb_private::ArchSpec &arch_spec, lldb_private::UUID &uuid); 424 }; 425 426 #endif // #ifndef liblldb_ObjectFileELF_h_ 427