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 // C Includes 14 #include <stdint.h> 15 16 // C++ Includes 17 #include <functional> 18 #include <vector> 19 20 // Other libraries and framework includes 21 // Project includes 22 #include "lldb/lldb-private.h" 23 #include "lldb/Host/FileSpec.h" 24 #include "lldb/Symbol/ObjectFile.h" 25 #include "lldb/Core/UUID.h" 26 #include "lldb/Core/ArchSpec.h" 27 28 #include "ELFHeader.h" 29 30 struct ELFNote 31 { 32 elf::elf_word n_namesz; 33 elf::elf_word n_descsz; 34 elf::elf_word n_type; 35 36 std::string n_name; 37 38 ELFNote() : n_namesz(0), n_descsz(0), n_type(0) 39 { 40 } 41 42 /// Parse an ELFNote entry from the given DataExtractor starting at position 43 /// \p offset. 44 /// 45 /// @param[in] data 46 /// The DataExtractor to read from. 47 /// 48 /// @param[in,out] offset 49 /// Pointer to an offset in the data. On return the offset will be 50 /// advanced by the number of bytes read. 51 /// 52 /// @return 53 /// True if the ELFRel entry was successfully read and false otherwise. 54 bool 55 Parse(const lldb_private::DataExtractor &data, lldb::offset_t *offset); 56 57 size_t 58 GetByteSize() const 59 { 60 return 12 + llvm::alignTo (n_namesz, 4) + llvm::alignTo (n_descsz, 4); 61 } 62 }; 63 64 //------------------------------------------------------------------------------ 65 /// @class ObjectFileELF 66 /// @brief Generic ELF object file reader. 67 /// 68 /// This class provides a generic ELF (32/64 bit) reader plugin implementing the 69 /// ObjectFile protocol. 70 class ObjectFileELF : 71 public lldb_private::ObjectFile 72 { 73 public: 74 ~ObjectFileELF() override; 75 76 //------------------------------------------------------------------ 77 // Static Functions 78 //------------------------------------------------------------------ 79 static void 80 Initialize(); 81 82 static void 83 Terminate(); 84 85 static lldb_private::ConstString 86 GetPluginNameStatic(); 87 88 static const char * 89 GetPluginDescriptionStatic(); 90 91 static lldb_private::ObjectFile * 92 CreateInstance(const lldb::ModuleSP &module_sp, 93 lldb::DataBufferSP& data_sp, 94 lldb::offset_t data_offset, 95 const lldb_private::FileSpec* file, 96 lldb::offset_t file_offset, 97 lldb::offset_t length); 98 99 static lldb_private::ObjectFile * 100 CreateMemoryInstance (const lldb::ModuleSP &module_sp, 101 lldb::DataBufferSP& data_sp, 102 const lldb::ProcessSP &process_sp, 103 lldb::addr_t header_addr); 104 105 static size_t 106 GetModuleSpecifications (const lldb_private::FileSpec& file, 107 lldb::DataBufferSP& data_sp, 108 lldb::offset_t data_offset, 109 lldb::offset_t file_offset, 110 lldb::offset_t length, 111 lldb_private::ModuleSpecList &specs); 112 113 static bool 114 MagicBytesMatch (lldb::DataBufferSP& data_sp, 115 lldb::addr_t offset, 116 lldb::addr_t length); 117 118 //------------------------------------------------------------------ 119 // PluginInterface protocol 120 //------------------------------------------------------------------ 121 lldb_private::ConstString 122 GetPluginName() override; 123 124 uint32_t 125 GetPluginVersion() override; 126 127 //------------------------------------------------------------------ 128 // ObjectFile Protocol. 129 //------------------------------------------------------------------ 130 bool 131 ParseHeader() override; 132 133 bool 134 SetLoadAddress (lldb_private::Target &target, 135 lldb::addr_t value, 136 bool value_is_offset) override; 137 138 lldb::ByteOrder 139 GetByteOrder() const override; 140 141 bool 142 IsExecutable () const override; 143 144 uint32_t 145 GetAddressByteSize() const override; 146 147 lldb::AddressClass 148 GetAddressClass (lldb::addr_t file_addr) override; 149 150 lldb_private::Symtab * 151 GetSymtab() override; 152 153 bool 154 IsStripped () override; 155 156 void 157 CreateSections (lldb_private::SectionList &unified_section_list) override; 158 159 void 160 Dump(lldb_private::Stream *s) override; 161 162 bool 163 GetArchitecture (lldb_private::ArchSpec &arch) override; 164 165 bool 166 GetUUID(lldb_private::UUID* uuid) override; 167 168 lldb_private::FileSpecList 169 GetDebugSymbolFilePaths() override; 170 171 uint32_t 172 GetDependentModules(lldb_private::FileSpecList& files) override; 173 174 lldb_private::Address 175 GetImageInfoAddress(lldb_private::Target *target) override; 176 177 lldb_private::Address 178 GetEntryPointAddress () override; 179 180 ObjectFile::Type 181 CalculateType() override; 182 183 ObjectFile::Strata 184 CalculateStrata() override; 185 186 // Returns number of program headers found in the ELF file. 187 size_t 188 GetProgramHeaderCount(); 189 190 // Returns the program header with the given index. 191 const elf::ELFProgramHeader * 192 GetProgramHeaderByIndex(lldb::user_id_t id); 193 194 // Returns segment data for the given index. 195 lldb_private::DataExtractor 196 GetSegmentDataByIndex(lldb::user_id_t id); 197 198 std::string 199 StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const override; 200 201 private: 202 ObjectFileELF(const lldb::ModuleSP &module_sp, 203 lldb::DataBufferSP& data_sp, 204 lldb::offset_t data_offset, 205 const lldb_private::FileSpec* file, 206 lldb::offset_t offset, 207 lldb::offset_t length); 208 209 ObjectFileELF (const lldb::ModuleSP &module_sp, 210 lldb::DataBufferSP& header_data_sp, 211 const lldb::ProcessSP &process_sp, 212 lldb::addr_t header_addr); 213 214 typedef std::vector<elf::ELFProgramHeader> ProgramHeaderColl; 215 typedef ProgramHeaderColl::iterator ProgramHeaderCollIter; 216 typedef ProgramHeaderColl::const_iterator ProgramHeaderCollConstIter; 217 218 struct ELFSectionHeaderInfo : public elf::ELFSectionHeader 219 { 220 lldb_private::ConstString section_name; 221 }; 222 223 typedef std::vector<ELFSectionHeaderInfo> SectionHeaderColl; 224 typedef SectionHeaderColl::iterator SectionHeaderCollIter; 225 typedef SectionHeaderColl::const_iterator SectionHeaderCollConstIter; 226 227 typedef std::vector<elf::ELFDynamic> DynamicSymbolColl; 228 typedef DynamicSymbolColl::iterator DynamicSymbolCollIter; 229 typedef DynamicSymbolColl::const_iterator DynamicSymbolCollConstIter; 230 231 typedef std::map<lldb::addr_t, lldb::AddressClass> FileAddressToAddressClassMap; 232 typedef std::function<lldb::offset_t (lldb_private::DataExtractor &, lldb::offset_t, lldb::offset_t)> SetDataFunction; 233 234 /// Version of this reader common to all plugins based on this class. 235 static const uint32_t m_plugin_version = 1; 236 static const uint32_t g_core_uuid_magic; 237 238 /// ELF file header. 239 elf::ELFHeader m_header; 240 241 /// ELF build ID. 242 lldb_private::UUID m_uuid; 243 244 /// ELF .gnu_debuglink file and crc data if available. 245 std::string m_gnu_debuglink_file; 246 uint32_t m_gnu_debuglink_crc; 247 248 /// Collection of program headers. 249 ProgramHeaderColl m_program_headers; 250 251 /// Collection of section headers. 252 SectionHeaderColl m_section_headers; 253 254 /// Collection of symbols from the dynamic table. 255 DynamicSymbolColl m_dynamic_symbols; 256 257 /// List of file specifications corresponding to the modules (shared 258 /// libraries) on which this object file depends. 259 mutable std::unique_ptr<lldb_private::FileSpecList> m_filespec_ap; 260 261 /// Cached value of the entry point for this module. 262 lldb_private::Address m_entry_point_address; 263 264 /// The architecture detected from parsing elf file contents. 265 lldb_private::ArchSpec m_arch_spec; 266 267 /// The address class for each symbol in the elf file 268 FileAddressToAddressClassMap m_address_class_map; 269 270 /// Returns a 1 based index of the given section header. 271 size_t 272 SectionIndex(const SectionHeaderCollIter &I); 273 274 /// Returns a 1 based index of the given section header. 275 size_t 276 SectionIndex(const SectionHeaderCollConstIter &I) const; 277 278 // Parses the ELF program headers. 279 static size_t 280 GetProgramHeaderInfo(ProgramHeaderColl &program_headers, 281 const SetDataFunction &set_data, 282 const elf::ELFHeader &header); 283 284 // Finds PT_NOTE segments and calculates their crc sum. 285 static uint32_t 286 CalculateELFNotesSegmentsCRC32(const ProgramHeaderColl& program_headers, 287 lldb_private::DataExtractor &data); 288 289 /// Parses all section headers present in this object file and populates 290 /// m_program_headers. This method will compute the header list only once. 291 /// Returns the number of headers parsed. 292 size_t 293 ParseProgramHeaders(); 294 295 /// Parses all section headers present in this object file and populates 296 /// m_section_headers. This method will compute the header list only once. 297 /// Returns the number of headers parsed. 298 size_t 299 ParseSectionHeaders(); 300 301 /// Parses the elf section headers and returns the uuid, debug link name, crc, archspec. 302 static size_t 303 GetSectionHeaderInfo(SectionHeaderColl §ion_headers, 304 const SetDataFunction &set_data, 305 const elf::ELFHeader &header, 306 lldb_private::UUID &uuid, 307 std::string &gnu_debuglink_file, 308 uint32_t &gnu_debuglink_crc, 309 lldb_private::ArchSpec &arch_spec); 310 311 /// Scans the dynamic section and locates all dependent modules (shared 312 /// libraries) populating m_filespec_ap. This method will compute the 313 /// dependent module list only once. Returns the number of dependent 314 /// modules parsed. 315 size_t 316 ParseDependentModules(); 317 318 /// Parses the dynamic symbol table and populates m_dynamic_symbols. The 319 /// vector retains the order as found in the object file. Returns the 320 /// number of dynamic symbols parsed. 321 size_t 322 ParseDynamicSymbols(); 323 324 /// Populates m_symtab_ap will all non-dynamic linker symbols. This method 325 /// will parse the symbols only once. Returns the number of symbols parsed. 326 unsigned 327 ParseSymbolTable(lldb_private::Symtab *symbol_table, 328 lldb::user_id_t start_id, 329 lldb_private::Section *symtab); 330 331 /// Helper routine for ParseSymbolTable(). 332 unsigned 333 ParseSymbols(lldb_private::Symtab *symbol_table, 334 lldb::user_id_t start_id, 335 lldb_private::SectionList *section_list, 336 const size_t num_symbols, 337 const lldb_private::DataExtractor &symtab_data, 338 const lldb_private::DataExtractor &strtab_data); 339 340 /// Scans the relocation entries and adds a set of artificial symbols to the 341 /// given symbol table for each PLT slot. Returns the number of symbols 342 /// added. 343 unsigned 344 ParseTrampolineSymbols(lldb_private::Symtab *symbol_table, 345 lldb::user_id_t start_id, 346 const ELFSectionHeaderInfo *rela_hdr, 347 lldb::user_id_t section_id); 348 349 void 350 ParseUnwindSymbols(lldb_private::Symtab *symbol_table, 351 lldb_private::DWARFCallFrameInfo* eh_frame); 352 353 /// Relocates debug sections 354 unsigned 355 RelocateDebugSections(const elf::ELFSectionHeader *rel_hdr, lldb::user_id_t rel_id); 356 357 unsigned 358 RelocateSection(lldb_private::Symtab* symtab, const elf::ELFHeader *hdr, const elf::ELFSectionHeader *rel_hdr, 359 const elf::ELFSectionHeader *symtab_hdr, const elf::ELFSectionHeader *debug_hdr, 360 lldb_private::DataExtractor &rel_data, lldb_private::DataExtractor &symtab_data, 361 lldb_private::DataExtractor &debug_data, lldb_private::Section* rel_section); 362 363 /// Loads the section name string table into m_shstr_data. Returns the 364 /// number of bytes constituting the table. 365 size_t 366 GetSectionHeaderStringTable(); 367 368 /// Utility method for looking up a section given its name. Returns the 369 /// index of the corresponding section or zero if no section with the given 370 /// name can be found (note that section indices are always 1 based, and so 371 /// section index 0 is never valid). 372 lldb::user_id_t 373 GetSectionIndexByName(const char *name); 374 375 // Returns the ID of the first section that has the given type. 376 lldb::user_id_t 377 GetSectionIndexByType(unsigned type); 378 379 /// Returns the section header with the given id or NULL. 380 const ELFSectionHeaderInfo * 381 GetSectionHeaderByIndex(lldb::user_id_t id); 382 383 /// @name ELF header dump routines 384 //@{ 385 static void 386 DumpELFHeader(lldb_private::Stream *s, const elf::ELFHeader& header); 387 388 static void 389 DumpELFHeader_e_ident_EI_DATA(lldb_private::Stream *s, 390 unsigned char ei_data); 391 392 static void 393 DumpELFHeader_e_type(lldb_private::Stream *s, elf::elf_half e_type); 394 //@} 395 396 /// @name ELF program header dump routines 397 //@{ 398 void 399 DumpELFProgramHeaders(lldb_private::Stream *s); 400 401 static void 402 DumpELFProgramHeader(lldb_private::Stream *s, 403 const elf::ELFProgramHeader &ph); 404 405 static void 406 DumpELFProgramHeader_p_type(lldb_private::Stream *s, elf::elf_word p_type); 407 408 static void 409 DumpELFProgramHeader_p_flags(lldb_private::Stream *s, 410 elf::elf_word p_flags); 411 //@} 412 413 /// @name ELF section header dump routines 414 //@{ 415 void 416 DumpELFSectionHeaders(lldb_private::Stream *s); 417 418 static void 419 DumpELFSectionHeader(lldb_private::Stream *s, 420 const ELFSectionHeaderInfo& sh); 421 422 static void 423 DumpELFSectionHeader_sh_type(lldb_private::Stream *s, 424 elf::elf_word sh_type); 425 426 static void 427 DumpELFSectionHeader_sh_flags(lldb_private::Stream *s, 428 elf::elf_xword sh_flags); 429 //@} 430 431 /// ELF dependent module dump routine. 432 void 433 DumpDependentModules(lldb_private::Stream *s); 434 435 const elf::ELFDynamic * 436 FindDynamicSymbol(unsigned tag); 437 438 unsigned 439 PLTRelocationType(); 440 441 static lldb_private::Error 442 RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, lldb_private::ArchSpec &arch_spec, lldb_private::UUID &uuid); 443 444 445 static lldb::offset_t 446 SetData(const lldb_private::DataExtractor &src, lldb_private::DataExtractor &dst, lldb::offset_t offset, lldb::offset_t length); 447 448 lldb::offset_t 449 SetDataWithReadMemoryFallback(lldb_private::DataExtractor &dst, lldb::offset_t offset, lldb::offset_t length); 450 }; 451 452 #endif // liblldb_ObjectFileELF_h_ 453