1 //===-- DWARFCallFrameInfo.cpp ----------------------------------*- 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 #include "lldb/Symbol/DWARFCallFrameInfo.h" 11 #include "lldb/Core/Module.h" 12 #include "lldb/Core/Section.h" 13 #include "lldb/Core/dwarf.h" 14 #include "lldb/Host/Host.h" 15 #include "lldb/Symbol/ObjectFile.h" 16 #include "lldb/Symbol/UnwindPlan.h" 17 #include "lldb/Target/RegisterContext.h" 18 #include "lldb/Target/Thread.h" 19 #include "lldb/Utility/ArchSpec.h" 20 #include "lldb/Utility/Log.h" 21 #include "lldb/Utility/Timer.h" 22 #include <list> 23 24 using namespace lldb; 25 using namespace lldb_private; 26 27 //---------------------------------------------------------------------- 28 // GetDwarfEHPtr 29 // 30 // Used for calls when the value type is specified by a DWARF EH Frame pointer 31 // encoding. 32 //---------------------------------------------------------------------- 33 static uint64_t 34 GetGNUEHPointer(const DataExtractor &DE, offset_t *offset_ptr, 35 uint32_t eh_ptr_enc, addr_t pc_rel_addr, addr_t text_addr, 36 addr_t data_addr) //, BSDRelocs *data_relocs) const 37 { 38 if (eh_ptr_enc == DW_EH_PE_omit) 39 return ULLONG_MAX; // Value isn't in the buffer... 40 41 uint64_t baseAddress = 0; 42 uint64_t addressValue = 0; 43 const uint32_t addr_size = DE.GetAddressByteSize(); 44 #ifdef LLDB_CONFIGURATION_DEBUG 45 assert(addr_size == 4 || addr_size == 8); 46 #endif 47 48 bool signExtendValue = false; 49 // Decode the base part or adjust our offset 50 switch (eh_ptr_enc & 0x70) { 51 case DW_EH_PE_pcrel: 52 signExtendValue = true; 53 baseAddress = *offset_ptr; 54 if (pc_rel_addr != LLDB_INVALID_ADDRESS) 55 baseAddress += pc_rel_addr; 56 // else 57 // Log::GlobalWarning ("PC relative pointer encoding found with 58 // invalid pc relative address."); 59 break; 60 61 case DW_EH_PE_textrel: 62 signExtendValue = true; 63 if (text_addr != LLDB_INVALID_ADDRESS) 64 baseAddress = text_addr; 65 // else 66 // Log::GlobalWarning ("text relative pointer encoding being 67 // decoded with invalid text section address, setting base address 68 // to zero."); 69 break; 70 71 case DW_EH_PE_datarel: 72 signExtendValue = true; 73 if (data_addr != LLDB_INVALID_ADDRESS) 74 baseAddress = data_addr; 75 // else 76 // Log::GlobalWarning ("data relative pointer encoding being 77 // decoded with invalid data section address, setting base address 78 // to zero."); 79 break; 80 81 case DW_EH_PE_funcrel: 82 signExtendValue = true; 83 break; 84 85 case DW_EH_PE_aligned: { 86 // SetPointerSize should be called prior to extracting these so the pointer 87 // size is cached 88 assert(addr_size != 0); 89 if (addr_size) { 90 // Align to a address size boundary first 91 uint32_t alignOffset = *offset_ptr % addr_size; 92 if (alignOffset) 93 offset_ptr += addr_size - alignOffset; 94 } 95 } break; 96 97 default: 98 break; 99 } 100 101 // Decode the value part 102 switch (eh_ptr_enc & DW_EH_PE_MASK_ENCODING) { 103 case DW_EH_PE_absptr: { 104 addressValue = DE.GetAddress(offset_ptr); 105 // if (data_relocs) 106 // addressValue = data_relocs->Relocate(*offset_ptr - 107 // addr_size, *this, addressValue); 108 } break; 109 case DW_EH_PE_uleb128: 110 addressValue = DE.GetULEB128(offset_ptr); 111 break; 112 case DW_EH_PE_udata2: 113 addressValue = DE.GetU16(offset_ptr); 114 break; 115 case DW_EH_PE_udata4: 116 addressValue = DE.GetU32(offset_ptr); 117 break; 118 case DW_EH_PE_udata8: 119 addressValue = DE.GetU64(offset_ptr); 120 break; 121 case DW_EH_PE_sleb128: 122 addressValue = DE.GetSLEB128(offset_ptr); 123 break; 124 case DW_EH_PE_sdata2: 125 addressValue = (int16_t)DE.GetU16(offset_ptr); 126 break; 127 case DW_EH_PE_sdata4: 128 addressValue = (int32_t)DE.GetU32(offset_ptr); 129 break; 130 case DW_EH_PE_sdata8: 131 addressValue = (int64_t)DE.GetU64(offset_ptr); 132 break; 133 default: 134 // Unhandled encoding type 135 assert(eh_ptr_enc); 136 break; 137 } 138 139 // Since we promote everything to 64 bit, we may need to sign extend 140 if (signExtendValue && addr_size < sizeof(baseAddress)) { 141 uint64_t sign_bit = 1ull << ((addr_size * 8ull) - 1ull); 142 if (sign_bit & addressValue) { 143 uint64_t mask = ~sign_bit + 1; 144 addressValue |= mask; 145 } 146 } 147 return baseAddress + addressValue; 148 } 149 150 DWARFCallFrameInfo::DWARFCallFrameInfo(ObjectFile &objfile, 151 SectionSP §ion_sp, Type type) 152 : m_objfile(objfile), m_section_sp(section_sp), m_type(type) {} 153 154 bool DWARFCallFrameInfo::GetUnwindPlan(Address addr, UnwindPlan &unwind_plan) { 155 FDEEntryMap::Entry fde_entry; 156 157 // Make sure that the Address we're searching for is the same object file as 158 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 159 ModuleSP module_sp = addr.GetModule(); 160 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 161 module_sp->GetObjectFile() != &m_objfile) 162 return false; 163 164 if (!GetFDEEntryByFileAddress(addr.GetFileAddress(), fde_entry)) 165 return false; 166 return FDEToUnwindPlan(fde_entry.data, addr, unwind_plan); 167 } 168 169 bool DWARFCallFrameInfo::GetAddressRange(Address addr, AddressRange &range) { 170 171 // Make sure that the Address we're searching for is the same object file as 172 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 173 ModuleSP module_sp = addr.GetModule(); 174 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 175 module_sp->GetObjectFile() != &m_objfile) 176 return false; 177 178 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 179 return false; 180 GetFDEIndex(); 181 FDEEntryMap::Entry *fde_entry = 182 m_fde_index.FindEntryThatContains(addr.GetFileAddress()); 183 if (!fde_entry) 184 return false; 185 186 range = AddressRange(fde_entry->base, fde_entry->size, 187 m_objfile.GetSectionList()); 188 return true; 189 } 190 191 bool DWARFCallFrameInfo::GetFDEEntryByFileAddress( 192 addr_t file_addr, FDEEntryMap::Entry &fde_entry) { 193 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 194 return false; 195 196 GetFDEIndex(); 197 198 if (m_fde_index.IsEmpty()) 199 return false; 200 201 FDEEntryMap::Entry *fde = m_fde_index.FindEntryThatContains(file_addr); 202 203 if (fde == nullptr) 204 return false; 205 206 fde_entry = *fde; 207 return true; 208 } 209 210 void DWARFCallFrameInfo::GetFunctionAddressAndSizeVector( 211 FunctionAddressAndSizeVector &function_info) { 212 GetFDEIndex(); 213 const size_t count = m_fde_index.GetSize(); 214 function_info.Clear(); 215 if (count > 0) 216 function_info.Reserve(count); 217 for (size_t i = 0; i < count; ++i) { 218 const FDEEntryMap::Entry *func_offset_data_entry = 219 m_fde_index.GetEntryAtIndex(i); 220 if (func_offset_data_entry) { 221 FunctionAddressAndSizeVector::Entry function_offset_entry( 222 func_offset_data_entry->base, func_offset_data_entry->size); 223 function_info.Append(function_offset_entry); 224 } 225 } 226 } 227 228 const DWARFCallFrameInfo::CIE * 229 DWARFCallFrameInfo::GetCIE(dw_offset_t cie_offset) { 230 cie_map_t::iterator pos = m_cie_map.find(cie_offset); 231 232 if (pos != m_cie_map.end()) { 233 // Parse and cache the CIE 234 if (pos->second.get() == nullptr) 235 pos->second = ParseCIE(cie_offset); 236 237 return pos->second.get(); 238 } 239 return nullptr; 240 } 241 242 DWARFCallFrameInfo::CIESP 243 DWARFCallFrameInfo::ParseCIE(const dw_offset_t cie_offset) { 244 CIESP cie_sp(new CIE(cie_offset)); 245 lldb::offset_t offset = cie_offset; 246 if (!m_cfi_data_initialized) 247 GetCFIData(); 248 uint32_t length = m_cfi_data.GetU32(&offset); 249 dw_offset_t cie_id, end_offset; 250 bool is_64bit = (length == UINT32_MAX); 251 if (is_64bit) { 252 length = m_cfi_data.GetU64(&offset); 253 cie_id = m_cfi_data.GetU64(&offset); 254 end_offset = cie_offset + length + 12; 255 } else { 256 cie_id = m_cfi_data.GetU32(&offset); 257 end_offset = cie_offset + length + 4; 258 } 259 if (length > 0 && ((m_type == DWARF && cie_id == UINT32_MAX) || 260 (m_type == EH && cie_id == 0ul))) { 261 size_t i; 262 // cie.offset = cie_offset; 263 // cie.length = length; 264 // cie.cieID = cieID; 265 cie_sp->ptr_encoding = DW_EH_PE_absptr; // default 266 cie_sp->version = m_cfi_data.GetU8(&offset); 267 if (cie_sp->version > CFI_VERSION4) { 268 Host::SystemLog(Host::eSystemLogError, 269 "CIE parse error: CFI version %d is not supported\n", 270 cie_sp->version); 271 return nullptr; 272 } 273 274 for (i = 0; i < CFI_AUG_MAX_SIZE; ++i) { 275 cie_sp->augmentation[i] = m_cfi_data.GetU8(&offset); 276 if (cie_sp->augmentation[i] == '\0') { 277 // Zero out remaining bytes in augmentation string 278 for (size_t j = i + 1; j < CFI_AUG_MAX_SIZE; ++j) 279 cie_sp->augmentation[j] = '\0'; 280 281 break; 282 } 283 } 284 285 if (i == CFI_AUG_MAX_SIZE && 286 cie_sp->augmentation[CFI_AUG_MAX_SIZE - 1] != '\0') { 287 Host::SystemLog(Host::eSystemLogError, 288 "CIE parse error: CIE augmentation string was too large " 289 "for the fixed sized buffer of %d bytes.\n", 290 CFI_AUG_MAX_SIZE); 291 return nullptr; 292 } 293 294 // m_cfi_data uses address size from target architecture of the process may 295 // ignore these fields? 296 if (m_type == DWARF && cie_sp->version >= CFI_VERSION4) { 297 cie_sp->address_size = m_cfi_data.GetU8(&offset); 298 cie_sp->segment_size = m_cfi_data.GetU8(&offset); 299 } 300 301 cie_sp->code_align = (uint32_t)m_cfi_data.GetULEB128(&offset); 302 cie_sp->data_align = (int32_t)m_cfi_data.GetSLEB128(&offset); 303 304 cie_sp->return_addr_reg_num = 305 m_type == DWARF && cie_sp->version >= CFI_VERSION3 306 ? static_cast<uint32_t>(m_cfi_data.GetULEB128(&offset)) 307 : m_cfi_data.GetU8(&offset); 308 309 if (cie_sp->augmentation[0]) { 310 // Get the length of the eh_frame augmentation data which starts with a 311 // ULEB128 length in bytes 312 const size_t aug_data_len = (size_t)m_cfi_data.GetULEB128(&offset); 313 const size_t aug_data_end = offset + aug_data_len; 314 const size_t aug_str_len = strlen(cie_sp->augmentation); 315 // A 'z' may be present as the first character of the string. 316 // If present, the Augmentation Data field shall be present. The contents 317 // of the Augmentation Data shall be interpreted according to other 318 // characters in the Augmentation String. 319 if (cie_sp->augmentation[0] == 'z') { 320 // Extract the Augmentation Data 321 size_t aug_str_idx = 0; 322 for (aug_str_idx = 1; aug_str_idx < aug_str_len; aug_str_idx++) { 323 char aug = cie_sp->augmentation[aug_str_idx]; 324 switch (aug) { 325 case 'L': 326 // Indicates the presence of one argument in the Augmentation Data 327 // of the CIE, and a corresponding argument in the Augmentation 328 // Data of the FDE. The argument in the Augmentation Data of the 329 // CIE is 1-byte and represents the pointer encoding used for the 330 // argument in the Augmentation Data of the FDE, which is the 331 // address of a language-specific data area (LSDA). The size of the 332 // LSDA pointer is specified by the pointer encoding used. 333 cie_sp->lsda_addr_encoding = m_cfi_data.GetU8(&offset); 334 break; 335 336 case 'P': 337 // Indicates the presence of two arguments in the Augmentation Data 338 // of the CIE. The first argument is 1-byte and represents the 339 // pointer encoding used for the second argument, which is the 340 // address of a personality routine handler. The size of the 341 // personality routine pointer is specified by the pointer encoding 342 // used. 343 // 344 // The address of the personality function will be stored at this 345 // location. Pre-execution, it will be all zero's so don't read it 346 // until we're trying to do an unwind & the reloc has been 347 // resolved. 348 { 349 uint8_t arg_ptr_encoding = m_cfi_data.GetU8(&offset); 350 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 351 cie_sp->personality_loc = GetGNUEHPointer( 352 m_cfi_data, &offset, arg_ptr_encoding, pc_rel_addr, 353 LLDB_INVALID_ADDRESS, LLDB_INVALID_ADDRESS); 354 } 355 break; 356 357 case 'R': 358 // A 'R' may be present at any position after the 359 // first character of the string. The Augmentation Data shall 360 // include a 1 byte argument that represents the pointer encoding 361 // for the address pointers used in the FDE. Example: 0x1B == 362 // DW_EH_PE_pcrel | DW_EH_PE_sdata4 363 cie_sp->ptr_encoding = m_cfi_data.GetU8(&offset); 364 break; 365 } 366 } 367 } else if (strcmp(cie_sp->augmentation, "eh") == 0) { 368 // If the Augmentation string has the value "eh", then the EH Data 369 // field shall be present 370 } 371 372 // Set the offset to be the end of the augmentation data just in case we 373 // didn't understand any of the data. 374 offset = (uint32_t)aug_data_end; 375 } 376 377 if (end_offset > offset) { 378 cie_sp->inst_offset = offset; 379 cie_sp->inst_length = end_offset - offset; 380 } 381 while (offset < end_offset) { 382 uint8_t inst = m_cfi_data.GetU8(&offset); 383 uint8_t primary_opcode = inst & 0xC0; 384 uint8_t extended_opcode = inst & 0x3F; 385 386 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, 387 cie_sp->data_align, offset, 388 cie_sp->initial_row)) 389 break; // Stop if we hit an unrecognized opcode 390 } 391 } 392 393 return cie_sp; 394 } 395 396 void DWARFCallFrameInfo::GetCFIData() { 397 if (!m_cfi_data_initialized) { 398 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 399 if (log) 400 m_objfile.GetModule()->LogMessage(log, "Reading EH frame info"); 401 m_objfile.ReadSectionData(m_section_sp.get(), m_cfi_data); 402 m_cfi_data_initialized = true; 403 } 404 } 405 // Scan through the eh_frame or debug_frame section looking for FDEs and noting 406 // the start/end addresses of the functions and a pointer back to the 407 // function's FDE for later expansion. Internalize CIEs as we come across them. 408 409 void DWARFCallFrameInfo::GetFDEIndex() { 410 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 411 return; 412 413 if (m_fde_index_initialized) 414 return; 415 416 std::lock_guard<std::mutex> guard(m_fde_index_mutex); 417 418 if (m_fde_index_initialized) // if two threads hit the locker 419 return; 420 421 static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); 422 Timer scoped_timer(func_cat, "%s - %s", LLVM_PRETTY_FUNCTION, 423 m_objfile.GetFileSpec().GetFilename().AsCString("")); 424 425 bool clear_address_zeroth_bit = false; 426 ArchSpec arch; 427 if (m_objfile.GetArchitecture(arch)) { 428 if (arch.GetTriple().getArch() == llvm::Triple::arm || 429 arch.GetTriple().getArch() == llvm::Triple::thumb) 430 clear_address_zeroth_bit = true; 431 } 432 433 lldb::offset_t offset = 0; 434 if (!m_cfi_data_initialized) 435 GetCFIData(); 436 while (m_cfi_data.ValidOffsetForDataOfSize(offset, 8)) { 437 const dw_offset_t current_entry = offset; 438 dw_offset_t cie_id, next_entry, cie_offset; 439 uint32_t len = m_cfi_data.GetU32(&offset); 440 bool is_64bit = (len == UINT32_MAX); 441 if (is_64bit) { 442 len = m_cfi_data.GetU64(&offset); 443 cie_id = m_cfi_data.GetU64(&offset); 444 next_entry = current_entry + len + 12; 445 cie_offset = current_entry + 12 - cie_id; 446 } else { 447 cie_id = m_cfi_data.GetU32(&offset); 448 next_entry = current_entry + len + 4; 449 cie_offset = current_entry + 4 - cie_id; 450 } 451 452 if (next_entry > m_cfi_data.GetByteSize() + 1) { 453 Host::SystemLog(Host::eSystemLogError, "error: Invalid fde/cie next " 454 "entry offset of 0x%x found in " 455 "cie/fde at 0x%x\n", 456 next_entry, current_entry); 457 // Don't trust anything in this eh_frame section if we find blatantly 458 // invalid data. 459 m_fde_index.Clear(); 460 m_fde_index_initialized = true; 461 return; 462 } 463 464 // An FDE entry contains CIE_pointer in debug_frame in same place as cie_id 465 // in eh_frame. CIE_pointer is an offset into the .debug_frame section. So, 466 // variable cie_offset should be equal to cie_id for debug_frame. 467 // FDE entries with cie_id == 0 shouldn't be ignored for it. 468 if ((cie_id == 0 && m_type == EH) || cie_id == UINT32_MAX || len == 0) { 469 auto cie_sp = ParseCIE(current_entry); 470 if (!cie_sp) { 471 // Cannot parse, the reason is already logged 472 m_fde_index.Clear(); 473 m_fde_index_initialized = true; 474 return; 475 } 476 477 m_cie_map[current_entry] = std::move(cie_sp); 478 offset = next_entry; 479 continue; 480 } 481 482 if (m_type == DWARF) 483 cie_offset = cie_id; 484 485 if (cie_offset > m_cfi_data.GetByteSize()) { 486 Host::SystemLog(Host::eSystemLogError, 487 "error: Invalid cie offset of 0x%x " 488 "found in cie/fde at 0x%x\n", 489 cie_offset, current_entry); 490 // Don't trust anything in this eh_frame section if we find blatantly 491 // invalid data. 492 m_fde_index.Clear(); 493 m_fde_index_initialized = true; 494 return; 495 } 496 497 const CIE *cie = GetCIE(cie_offset); 498 if (cie) { 499 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 500 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 501 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 502 503 lldb::addr_t addr = 504 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 505 text_addr, data_addr); 506 if (clear_address_zeroth_bit) 507 addr &= ~1ull; 508 509 lldb::addr_t length = GetGNUEHPointer( 510 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 511 pc_rel_addr, text_addr, data_addr); 512 FDEEntryMap::Entry fde(addr, length, current_entry); 513 m_fde_index.Append(fde); 514 } else { 515 Host::SystemLog(Host::eSystemLogError, "error: unable to find CIE at " 516 "0x%8.8x for cie_id = 0x%8.8x for " 517 "entry at 0x%8.8x.\n", 518 cie_offset, cie_id, current_entry); 519 } 520 offset = next_entry; 521 } 522 m_fde_index.Sort(); 523 m_fde_index_initialized = true; 524 } 525 526 bool DWARFCallFrameInfo::FDEToUnwindPlan(dw_offset_t dwarf_offset, 527 Address startaddr, 528 UnwindPlan &unwind_plan) { 529 Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND); 530 lldb::offset_t offset = dwarf_offset; 531 lldb::offset_t current_entry = offset; 532 533 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 534 return false; 535 536 if (!m_cfi_data_initialized) 537 GetCFIData(); 538 539 uint32_t length = m_cfi_data.GetU32(&offset); 540 dw_offset_t cie_offset; 541 bool is_64bit = (length == UINT32_MAX); 542 if (is_64bit) { 543 length = m_cfi_data.GetU64(&offset); 544 cie_offset = m_cfi_data.GetU64(&offset); 545 } else { 546 cie_offset = m_cfi_data.GetU32(&offset); 547 } 548 549 // FDE entries with zeroth cie_offset may occur for debug_frame. 550 assert(!(m_type == EH && 0 == cie_offset) && cie_offset != UINT32_MAX); 551 552 // Translate the CIE_id from the eh_frame format, which is relative to the 553 // FDE offset, into a __eh_frame section offset 554 if (m_type == EH) { 555 unwind_plan.SetSourceName("eh_frame CFI"); 556 cie_offset = current_entry + (is_64bit ? 12 : 4) - cie_offset; 557 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 558 } else { 559 unwind_plan.SetSourceName("DWARF CFI"); 560 // In theory the debug_frame info should be valid at all call sites 561 // ("asynchronous unwind info" as it is sometimes called) but in practice 562 // gcc et al all emit call frame info for the prologue and call sites, but 563 // not for the epilogue or all the other locations during the function 564 // reliably. 565 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 566 } 567 unwind_plan.SetSourcedFromCompiler(eLazyBoolYes); 568 569 const CIE *cie = GetCIE(cie_offset); 570 assert(cie != nullptr); 571 572 const dw_offset_t end_offset = current_entry + length + (is_64bit ? 12 : 4); 573 574 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 575 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 576 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 577 lldb::addr_t range_base = 578 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 579 text_addr, data_addr); 580 lldb::addr_t range_len = GetGNUEHPointer( 581 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 582 pc_rel_addr, text_addr, data_addr); 583 AddressRange range(range_base, m_objfile.GetAddressByteSize(), 584 m_objfile.GetSectionList()); 585 range.SetByteSize(range_len); 586 587 addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS; 588 589 if (cie->augmentation[0] == 'z') { 590 uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 591 if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) { 592 offset_t saved_offset = offset; 593 lsda_data_file_address = 594 GetGNUEHPointer(m_cfi_data, &offset, cie->lsda_addr_encoding, 595 pc_rel_addr, text_addr, data_addr); 596 if (offset - saved_offset != aug_data_len) { 597 // There is more in the augmentation region than we know how to process; 598 // don't read anything. 599 lsda_data_file_address = LLDB_INVALID_ADDRESS; 600 } 601 offset = saved_offset; 602 } 603 offset += aug_data_len; 604 } 605 Address lsda_data; 606 Address personality_function_ptr; 607 608 if (lsda_data_file_address != LLDB_INVALID_ADDRESS && 609 cie->personality_loc != LLDB_INVALID_ADDRESS) { 610 m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address, 611 lsda_data); 612 m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc, 613 personality_function_ptr); 614 } 615 616 if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { 617 unwind_plan.SetLSDAAddress(lsda_data); 618 unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr); 619 } 620 621 uint32_t code_align = cie->code_align; 622 int32_t data_align = cie->data_align; 623 624 unwind_plan.SetPlanValidAddressRange(range); 625 UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; 626 *cie_initial_row = cie->initial_row; 627 UnwindPlan::RowSP row(cie_initial_row); 628 629 unwind_plan.SetRegisterKind(GetRegisterKind()); 630 unwind_plan.SetReturnAddressRegister(cie->return_addr_reg_num); 631 632 std::vector<UnwindPlan::RowSP> stack; 633 634 UnwindPlan::Row::RegisterLocation reg_location; 635 while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { 636 uint8_t inst = m_cfi_data.GetU8(&offset); 637 uint8_t primary_opcode = inst & 0xC0; 638 uint8_t extended_opcode = inst & 0x3F; 639 640 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, 641 offset, *row)) { 642 if (primary_opcode) { 643 switch (primary_opcode) { 644 case DW_CFA_advance_loc: // (Row Creation Instruction) 645 { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta 646 // takes a single argument that represents a constant delta. The 647 // required action is to create a new table row with a location value 648 // that is computed by taking the current entry's location value and 649 // adding (delta * code_align). All other values in the new row are 650 // initially identical to the current row. 651 unwind_plan.AppendRow(row); 652 UnwindPlan::Row *newrow = new UnwindPlan::Row; 653 *newrow = *row.get(); 654 row.reset(newrow); 655 row->SlideOffset(extended_opcode * code_align); 656 break; 657 } 658 659 case DW_CFA_restore: { // 0xC0 - high 2 bits are 0x3, lower 6 bits are 660 // register 661 // takes a single argument that represents a register number. The 662 // required action is to change the rule for the indicated register 663 // to the rule assigned it by the initial_instructions in the CIE. 664 uint32_t reg_num = extended_opcode; 665 // We only keep enough register locations around to unwind what is in 666 // our thread, and these are organized by the register index in that 667 // state, so we need to convert our eh_frame register number from the 668 // EH frame info, to a register index 669 670 if (unwind_plan.IsValidRowIndex(0) && 671 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 672 reg_location)) 673 row->SetRegisterInfo(reg_num, reg_location); 674 break; 675 } 676 } 677 } else { 678 switch (extended_opcode) { 679 case DW_CFA_set_loc: // 0x1 (Row Creation Instruction) 680 { 681 // DW_CFA_set_loc takes a single argument that represents an address. 682 // The required action is to create a new table row using the 683 // specified address as the location. All other values in the new row 684 // are initially identical to the current row. The new location value 685 // should always be greater than the current one. 686 unwind_plan.AppendRow(row); 687 UnwindPlan::Row *newrow = new UnwindPlan::Row; 688 *newrow = *row.get(); 689 row.reset(newrow); 690 row->SetOffset(m_cfi_data.GetPointer(&offset) - 691 startaddr.GetFileAddress()); 692 break; 693 } 694 695 case DW_CFA_advance_loc1: // 0x2 (Row Creation Instruction) 696 { 697 // takes a single uword argument that represents a constant delta. 698 // This instruction is identical to DW_CFA_advance_loc except for the 699 // encoding and size of the delta argument. 700 unwind_plan.AppendRow(row); 701 UnwindPlan::Row *newrow = new UnwindPlan::Row; 702 *newrow = *row.get(); 703 row.reset(newrow); 704 row->SlideOffset(m_cfi_data.GetU8(&offset) * code_align); 705 break; 706 } 707 708 case DW_CFA_advance_loc2: // 0x3 (Row Creation Instruction) 709 { 710 // takes a single uword argument that represents a constant delta. 711 // This instruction is identical to DW_CFA_advance_loc except for the 712 // encoding and size of the delta argument. 713 unwind_plan.AppendRow(row); 714 UnwindPlan::Row *newrow = new UnwindPlan::Row; 715 *newrow = *row.get(); 716 row.reset(newrow); 717 row->SlideOffset(m_cfi_data.GetU16(&offset) * code_align); 718 break; 719 } 720 721 case DW_CFA_advance_loc4: // 0x4 (Row Creation Instruction) 722 { 723 // takes a single uword argument that represents a constant delta. 724 // This instruction is identical to DW_CFA_advance_loc except for the 725 // encoding and size of the delta argument. 726 unwind_plan.AppendRow(row); 727 UnwindPlan::Row *newrow = new UnwindPlan::Row; 728 *newrow = *row.get(); 729 row.reset(newrow); 730 row->SlideOffset(m_cfi_data.GetU32(&offset) * code_align); 731 break; 732 } 733 734 case DW_CFA_restore_extended: // 0x6 735 { 736 // takes a single unsigned LEB128 argument that represents a register 737 // number. This instruction is identical to DW_CFA_restore except for 738 // the encoding and size of the register argument. 739 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 740 if (unwind_plan.IsValidRowIndex(0) && 741 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 742 reg_location)) 743 row->SetRegisterInfo(reg_num, reg_location); 744 break; 745 } 746 747 case DW_CFA_remember_state: // 0xA 748 { 749 // These instructions define a stack of information. Encountering the 750 // DW_CFA_remember_state instruction means to save the rules for 751 // every register on the current row on the stack. Encountering the 752 // DW_CFA_restore_state instruction means to pop the set of rules off 753 // the stack and place them in the current row. (This operation is 754 // useful for compilers that move epilogue code into the body of a 755 // function.) 756 stack.push_back(row); 757 UnwindPlan::Row *newrow = new UnwindPlan::Row; 758 *newrow = *row.get(); 759 row.reset(newrow); 760 break; 761 } 762 763 case DW_CFA_restore_state: // 0xB 764 { 765 // These instructions define a stack of information. Encountering the 766 // DW_CFA_remember_state instruction means to save the rules for 767 // every register on the current row on the stack. Encountering the 768 // DW_CFA_restore_state instruction means to pop the set of rules off 769 // the stack and place them in the current row. (This operation is 770 // useful for compilers that move epilogue code into the body of a 771 // function.) 772 if (stack.empty()) { 773 if (log) 774 log->Printf("DWARFCallFrameInfo::%s(dwarf_offset: %" PRIx32 775 ", startaddr: %" PRIx64 776 " encountered DW_CFA_restore_state but state stack " 777 "is empty. Corrupt unwind info?", 778 __FUNCTION__, dwarf_offset, 779 startaddr.GetFileAddress()); 780 break; 781 } 782 lldb::addr_t offset = row->GetOffset(); 783 row = stack.back(); 784 stack.pop_back(); 785 row->SetOffset(offset); 786 break; 787 } 788 789 case DW_CFA_GNU_args_size: // 0x2e 790 { 791 // The DW_CFA_GNU_args_size instruction takes an unsigned LEB128 792 // operand representing an argument size. This instruction specifies 793 // the total of the size of the arguments which have been pushed onto 794 // the stack. 795 796 // TODO: Figure out how we should handle this. 797 m_cfi_data.GetULEB128(&offset); 798 break; 799 } 800 801 case DW_CFA_val_offset: // 0x14 802 case DW_CFA_val_offset_sf: // 0x15 803 default: 804 break; 805 } 806 } 807 } 808 } 809 unwind_plan.AppendRow(row); 810 811 return true; 812 } 813 814 bool DWARFCallFrameInfo::HandleCommonDwarfOpcode(uint8_t primary_opcode, 815 uint8_t extended_opcode, 816 int32_t data_align, 817 lldb::offset_t &offset, 818 UnwindPlan::Row &row) { 819 UnwindPlan::Row::RegisterLocation reg_location; 820 821 if (primary_opcode) { 822 switch (primary_opcode) { 823 case DW_CFA_offset: { // 0x80 - high 2 bits are 0x2, lower 6 bits are 824 // register 825 // takes two arguments: an unsigned LEB128 constant representing a 826 // factored offset and a register number. The required action is to 827 // change the rule for the register indicated by the register number to 828 // be an offset(N) rule with a value of (N = factored offset * 829 // data_align). 830 uint8_t reg_num = extended_opcode; 831 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 832 reg_location.SetAtCFAPlusOffset(op_offset); 833 row.SetRegisterInfo(reg_num, reg_location); 834 return true; 835 } 836 } 837 } else { 838 switch (extended_opcode) { 839 case DW_CFA_nop: // 0x0 840 return true; 841 842 case DW_CFA_offset_extended: // 0x5 843 { 844 // takes two unsigned LEB128 arguments representing a register number and 845 // a factored offset. This instruction is identical to DW_CFA_offset 846 // except for the encoding and size of the register argument. 847 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 848 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 849 UnwindPlan::Row::RegisterLocation reg_location; 850 reg_location.SetAtCFAPlusOffset(op_offset); 851 row.SetRegisterInfo(reg_num, reg_location); 852 return true; 853 } 854 855 case DW_CFA_undefined: // 0x7 856 { 857 // takes a single unsigned LEB128 argument that represents a register 858 // number. The required action is to set the rule for the specified 859 // register to undefined. 860 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 861 UnwindPlan::Row::RegisterLocation reg_location; 862 reg_location.SetUndefined(); 863 row.SetRegisterInfo(reg_num, reg_location); 864 return true; 865 } 866 867 case DW_CFA_same_value: // 0x8 868 { 869 // takes a single unsigned LEB128 argument that represents a register 870 // number. The required action is to set the rule for the specified 871 // register to same value. 872 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 873 UnwindPlan::Row::RegisterLocation reg_location; 874 reg_location.SetSame(); 875 row.SetRegisterInfo(reg_num, reg_location); 876 return true; 877 } 878 879 case DW_CFA_register: // 0x9 880 { 881 // takes two unsigned LEB128 arguments representing register numbers. The 882 // required action is to set the rule for the first register to be the 883 // second register. 884 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 885 uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 886 UnwindPlan::Row::RegisterLocation reg_location; 887 reg_location.SetInRegister(other_reg_num); 888 row.SetRegisterInfo(reg_num, reg_location); 889 return true; 890 } 891 892 case DW_CFA_def_cfa: // 0xC (CFA Definition Instruction) 893 { 894 // Takes two unsigned LEB128 operands representing a register number and 895 // a (non-factored) offset. The required action is to define the current 896 // CFA rule to use the provided register and offset. 897 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 898 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 899 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 900 return true; 901 } 902 903 case DW_CFA_def_cfa_register: // 0xD (CFA Definition Instruction) 904 { 905 // takes a single unsigned LEB128 argument representing a register 906 // number. The required action is to define the current CFA rule to use 907 // the provided register (but to keep the old offset). 908 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 909 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, 910 row.GetCFAValue().GetOffset()); 911 return true; 912 } 913 914 case DW_CFA_def_cfa_offset: // 0xE (CFA Definition Instruction) 915 { 916 // Takes a single unsigned LEB128 operand representing a (non-factored) 917 // offset. The required action is to define the current CFA rule to use 918 // the provided offset (but to keep the old register). 919 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 920 row.GetCFAValue().SetIsRegisterPlusOffset( 921 row.GetCFAValue().GetRegisterNumber(), op_offset); 922 return true; 923 } 924 925 case DW_CFA_def_cfa_expression: // 0xF (CFA Definition Instruction) 926 { 927 size_t block_len = (size_t)m_cfi_data.GetULEB128(&offset); 928 const uint8_t *block_data = 929 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 930 row.GetCFAValue().SetIsDWARFExpression(block_data, block_len); 931 return true; 932 } 933 934 case DW_CFA_expression: // 0x10 935 { 936 // Takes two operands: an unsigned LEB128 value representing a register 937 // number, and a DW_FORM_block value representing a DWARF expression. The 938 // required action is to change the rule for the register indicated by 939 // the register number to be an expression(E) rule where E is the DWARF 940 // expression. That is, the DWARF expression computes the address. The 941 // value of the CFA is pushed on the DWARF evaluation stack prior to 942 // execution of the DWARF expression. 943 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 944 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 945 const uint8_t *block_data = 946 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 947 UnwindPlan::Row::RegisterLocation reg_location; 948 reg_location.SetAtDWARFExpression(block_data, block_len); 949 row.SetRegisterInfo(reg_num, reg_location); 950 return true; 951 } 952 953 case DW_CFA_offset_extended_sf: // 0x11 954 { 955 // takes two operands: an unsigned LEB128 value representing a register 956 // number and a signed LEB128 factored offset. This instruction is 957 // identical to DW_CFA_offset_extended except that the second operand is 958 // signed and factored. 959 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 960 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 961 UnwindPlan::Row::RegisterLocation reg_location; 962 reg_location.SetAtCFAPlusOffset(op_offset); 963 row.SetRegisterInfo(reg_num, reg_location); 964 return true; 965 } 966 967 case DW_CFA_def_cfa_sf: // 0x12 (CFA Definition Instruction) 968 { 969 // Takes two operands: an unsigned LEB128 value representing a register 970 // number and a signed LEB128 factored offset. This instruction is 971 // identical to DW_CFA_def_cfa except that the second operand is signed 972 // and factored. 973 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 974 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 975 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 976 return true; 977 } 978 979 case DW_CFA_def_cfa_offset_sf: // 0x13 (CFA Definition Instruction) 980 { 981 // takes a signed LEB128 operand representing a factored offset. This 982 // instruction is identical to DW_CFA_def_cfa_offset except that the 983 // operand is signed and factored. 984 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 985 uint32_t cfa_regnum = row.GetCFAValue().GetRegisterNumber(); 986 row.GetCFAValue().SetIsRegisterPlusOffset(cfa_regnum, op_offset); 987 return true; 988 } 989 990 case DW_CFA_val_expression: // 0x16 991 { 992 // takes two operands: an unsigned LEB128 value representing a register 993 // number, and a DW_FORM_block value representing a DWARF expression. The 994 // required action is to change the rule for the register indicated by 995 // the register number to be a val_expression(E) rule where E is the 996 // DWARF expression. That is, the DWARF expression computes the value of 997 // the given register. The value of the CFA is pushed on the DWARF 998 // evaluation stack prior to execution of the DWARF expression. 999 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 1000 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 1001 const uint8_t *block_data = 1002 (const uint8_t *)m_cfi_data.GetData(&offset, block_len); 1003 //#if defined(__i386__) || defined(__x86_64__) 1004 // // The EH frame info for EIP and RIP contains code that 1005 // looks for traps to 1006 // // be a specific type and increments the PC. 1007 // // For i386: 1008 // // DW_CFA_val_expression where: 1009 // // eip = DW_OP_breg6(+28), DW_OP_deref, DW_OP_dup, 1010 // DW_OP_plus_uconst(0x34), 1011 // // DW_OP_deref, DW_OP_swap, DW_OP_plus_uconst(0), 1012 // DW_OP_deref, 1013 // // DW_OP_dup, DW_OP_lit3, DW_OP_ne, DW_OP_swap, 1014 // DW_OP_lit4, DW_OP_ne, 1015 // // DW_OP_and, DW_OP_plus 1016 // // This basically does a: 1017 // // eip = ucontenxt.mcontext32->gpr.eip; 1018 // // if (ucontenxt.mcontext32->exc.trapno != 3 && 1019 // ucontenxt.mcontext32->exc.trapno != 4) 1020 // // eip++; 1021 // // 1022 // // For x86_64: 1023 // // DW_CFA_val_expression where: 1024 // // rip = DW_OP_breg3(+48), DW_OP_deref, DW_OP_dup, 1025 // DW_OP_plus_uconst(0x90), DW_OP_deref, 1026 // // DW_OP_swap, DW_OP_plus_uconst(0), 1027 // DW_OP_deref_size(4), DW_OP_dup, DW_OP_lit3, 1028 // // DW_OP_ne, DW_OP_swap, DW_OP_lit4, DW_OP_ne, 1029 // DW_OP_and, DW_OP_plus 1030 // // This basically does a: 1031 // // rip = ucontenxt.mcontext64->gpr.rip; 1032 // // if (ucontenxt.mcontext64->exc.trapno != 3 && 1033 // ucontenxt.mcontext64->exc.trapno != 4) 1034 // // rip++; 1035 // // The trap comparisons and increments are not needed as 1036 // it hoses up the unwound PC which 1037 // // is expected to point at least past the instruction that 1038 // causes the fault/trap. So we 1039 // // take it out by trimming the expression right at the 1040 // first "DW_OP_swap" opcodes 1041 // if (block_data != NULL && thread->GetPCRegNum(Thread::GCC) 1042 // == reg_num) 1043 // { 1044 // if (thread->Is64Bit()) 1045 // { 1046 // if (block_len > 9 && block_data[8] == DW_OP_swap 1047 // && block_data[9] == DW_OP_plus_uconst) 1048 // block_len = 8; 1049 // } 1050 // else 1051 // { 1052 // if (block_len > 8 && block_data[7] == DW_OP_swap 1053 // && block_data[8] == DW_OP_plus_uconst) 1054 // block_len = 7; 1055 // } 1056 // } 1057 //#endif 1058 reg_location.SetIsDWARFExpression(block_data, block_len); 1059 row.SetRegisterInfo(reg_num, reg_location); 1060 return true; 1061 } 1062 } 1063 } 1064 return false; 1065 } 1066 1067 void DWARFCallFrameInfo::ForEachFDEEntries( 1068 const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback) { 1069 GetFDEIndex(); 1070 1071 for (size_t i = 0, c = m_fde_index.GetSize(); i < c; ++i) { 1072 const FDEEntryMap::Entry &entry = m_fde_index.GetEntryRef(i); 1073 if (!callback(entry.base, entry.size, entry.data)) 1074 break; 1075 } 1076 } 1077