1 //===-- DWARFCallFrameInfo.cpp --------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "lldb/Symbol/DWARFCallFrameInfo.h" 10 #include "lldb/Core/Module.h" 11 #include "lldb/Core/Section.h" 12 #include "lldb/Core/dwarf.h" 13 #include "lldb/Host/Host.h" 14 #include "lldb/Symbol/ObjectFile.h" 15 #include "lldb/Symbol/UnwindPlan.h" 16 #include "lldb/Target/RegisterContext.h" 17 #include "lldb/Target/Thread.h" 18 #include "lldb/Utility/ArchSpec.h" 19 #include "lldb/Utility/Log.h" 20 #include "lldb/Utility/Timer.h" 21 #include <list> 22 #include <cstring> 23 24 using namespace lldb; 25 using namespace lldb_private; 26 27 // GetDwarfEHPtr 28 // 29 // Used for calls when the value type is specified by a DWARF EH Frame pointer 30 // encoding. 31 static uint64_t 32 GetGNUEHPointer(const DataExtractor &DE, offset_t *offset_ptr, 33 uint32_t eh_ptr_enc, addr_t pc_rel_addr, addr_t text_addr, 34 addr_t data_addr) //, BSDRelocs *data_relocs) const 35 { 36 if (eh_ptr_enc == DW_EH_PE_omit) 37 return ULLONG_MAX; // Value isn't in the buffer... 38 39 uint64_t baseAddress = 0; 40 uint64_t addressValue = 0; 41 const uint32_t addr_size = DE.GetAddressByteSize(); 42 assert(addr_size == 4 || addr_size == 8); 43 44 bool signExtendValue = false; 45 // Decode the base part or adjust our offset 46 switch (eh_ptr_enc & 0x70) { 47 case DW_EH_PE_pcrel: 48 signExtendValue = true; 49 baseAddress = *offset_ptr; 50 if (pc_rel_addr != LLDB_INVALID_ADDRESS) 51 baseAddress += pc_rel_addr; 52 // else 53 // Log::GlobalWarning ("PC relative pointer encoding found with 54 // invalid pc relative address."); 55 break; 56 57 case DW_EH_PE_textrel: 58 signExtendValue = true; 59 if (text_addr != LLDB_INVALID_ADDRESS) 60 baseAddress = text_addr; 61 // else 62 // Log::GlobalWarning ("text relative pointer encoding being 63 // decoded with invalid text section address, setting base address 64 // to zero."); 65 break; 66 67 case DW_EH_PE_datarel: 68 signExtendValue = true; 69 if (data_addr != LLDB_INVALID_ADDRESS) 70 baseAddress = data_addr; 71 // else 72 // Log::GlobalWarning ("data relative pointer encoding being 73 // decoded with invalid data section address, setting base address 74 // to zero."); 75 break; 76 77 case DW_EH_PE_funcrel: 78 signExtendValue = true; 79 break; 80 81 case DW_EH_PE_aligned: { 82 // SetPointerSize should be called prior to extracting these so the pointer 83 // size is cached 84 assert(addr_size != 0); 85 if (addr_size) { 86 // Align to a address size boundary first 87 uint32_t alignOffset = *offset_ptr % addr_size; 88 if (alignOffset) 89 offset_ptr += addr_size - alignOffset; 90 } 91 } break; 92 93 default: 94 break; 95 } 96 97 // Decode the value part 98 switch (eh_ptr_enc & DW_EH_PE_MASK_ENCODING) { 99 case DW_EH_PE_absptr: { 100 addressValue = DE.GetAddress(offset_ptr); 101 // if (data_relocs) 102 // addressValue = data_relocs->Relocate(*offset_ptr - 103 // addr_size, *this, addressValue); 104 } break; 105 case DW_EH_PE_uleb128: 106 addressValue = DE.GetULEB128(offset_ptr); 107 break; 108 case DW_EH_PE_udata2: 109 addressValue = DE.GetU16(offset_ptr); 110 break; 111 case DW_EH_PE_udata4: 112 addressValue = DE.GetU32(offset_ptr); 113 break; 114 case DW_EH_PE_udata8: 115 addressValue = DE.GetU64(offset_ptr); 116 break; 117 case DW_EH_PE_sleb128: 118 addressValue = DE.GetSLEB128(offset_ptr); 119 break; 120 case DW_EH_PE_sdata2: 121 addressValue = (int16_t)DE.GetU16(offset_ptr); 122 break; 123 case DW_EH_PE_sdata4: 124 addressValue = (int32_t)DE.GetU32(offset_ptr); 125 break; 126 case DW_EH_PE_sdata8: 127 addressValue = (int64_t)DE.GetU64(offset_ptr); 128 break; 129 default: 130 // Unhandled encoding type 131 assert(eh_ptr_enc); 132 break; 133 } 134 135 // Since we promote everything to 64 bit, we may need to sign extend 136 if (signExtendValue && addr_size < sizeof(baseAddress)) { 137 uint64_t sign_bit = 1ull << ((addr_size * 8ull) - 1ull); 138 if (sign_bit & addressValue) { 139 uint64_t mask = ~sign_bit + 1; 140 addressValue |= mask; 141 } 142 } 143 return baseAddress + addressValue; 144 } 145 146 DWARFCallFrameInfo::DWARFCallFrameInfo(ObjectFile &objfile, 147 SectionSP §ion_sp, Type type) 148 : m_objfile(objfile), m_section_sp(section_sp), m_type(type) {} 149 150 bool DWARFCallFrameInfo::GetUnwindPlan(const Address &addr, 151 UnwindPlan &unwind_plan) { 152 return GetUnwindPlan(AddressRange(addr, 1), unwind_plan); 153 } 154 155 bool DWARFCallFrameInfo::GetUnwindPlan(const AddressRange &range, 156 UnwindPlan &unwind_plan) { 157 FDEEntryMap::Entry fde_entry; 158 Address addr = range.GetBaseAddress(); 159 160 // Make sure that the Address we're searching for is the same object file as 161 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 162 ModuleSP module_sp = addr.GetModule(); 163 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 164 module_sp->GetObjectFile() != &m_objfile) 165 return false; 166 167 if (llvm::Optional<FDEEntryMap::Entry> entry = GetFirstFDEEntryInRange(range)) 168 return FDEToUnwindPlan(entry->data, addr, unwind_plan); 169 return false; 170 } 171 172 bool DWARFCallFrameInfo::GetAddressRange(Address addr, AddressRange &range) { 173 174 // Make sure that the Address we're searching for is the same object file as 175 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 176 ModuleSP module_sp = addr.GetModule(); 177 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 178 module_sp->GetObjectFile() != &m_objfile) 179 return false; 180 181 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 182 return false; 183 GetFDEIndex(); 184 FDEEntryMap::Entry *fde_entry = 185 m_fde_index.FindEntryThatContains(addr.GetFileAddress()); 186 if (!fde_entry) 187 return false; 188 189 range = AddressRange(fde_entry->base, fde_entry->size, 190 m_objfile.GetSectionList()); 191 return true; 192 } 193 194 llvm::Optional<DWARFCallFrameInfo::FDEEntryMap::Entry> 195 DWARFCallFrameInfo::GetFirstFDEEntryInRange(const AddressRange &range) { 196 if (!m_section_sp || m_section_sp->IsEncrypted()) 197 return llvm::None; 198 199 GetFDEIndex(); 200 201 addr_t start_file_addr = range.GetBaseAddress().GetFileAddress(); 202 const FDEEntryMap::Entry *fde = 203 m_fde_index.FindEntryThatContainsOrFollows(start_file_addr); 204 if (fde && fde->DoesIntersect( 205 FDEEntryMap::Range(start_file_addr, range.GetByteSize()))) 206 return *fde; 207 208 return llvm::None; 209 } 210 211 void DWARFCallFrameInfo::GetFunctionAddressAndSizeVector( 212 FunctionAddressAndSizeVector &function_info) { 213 GetFDEIndex(); 214 const size_t count = m_fde_index.GetSize(); 215 function_info.Clear(); 216 if (count > 0) 217 function_info.Reserve(count); 218 for (size_t i = 0; i < count; ++i) { 219 const FDEEntryMap::Entry *func_offset_data_entry = 220 m_fde_index.GetEntryAtIndex(i); 221 if (func_offset_data_entry) { 222 FunctionAddressAndSizeVector::Entry function_offset_entry( 223 func_offset_data_entry->base, func_offset_data_entry->size); 224 function_info.Append(function_offset_entry); 225 } 226 } 227 } 228 229 const DWARFCallFrameInfo::CIE * 230 DWARFCallFrameInfo::GetCIE(dw_offset_t cie_offset) { 231 cie_map_t::iterator pos = m_cie_map.find(cie_offset); 232 233 if (pos != m_cie_map.end()) { 234 // Parse and cache the CIE 235 if (pos->second == nullptr) 236 pos->second = ParseCIE(cie_offset); 237 238 return pos->second.get(); 239 } 240 return nullptr; 241 } 242 243 DWARFCallFrameInfo::CIESP 244 DWARFCallFrameInfo::ParseCIE(const dw_offset_t cie_offset) { 245 CIESP cie_sp(new CIE(cie_offset)); 246 lldb::offset_t offset = cie_offset; 247 if (!m_cfi_data_initialized) 248 GetCFIData(); 249 uint32_t length = m_cfi_data.GetU32(&offset); 250 dw_offset_t cie_id, end_offset; 251 bool is_64bit = (length == UINT32_MAX); 252 if (is_64bit) { 253 length = m_cfi_data.GetU64(&offset); 254 cie_id = m_cfi_data.GetU64(&offset); 255 end_offset = cie_offset + length + 12; 256 } else { 257 cie_id = m_cfi_data.GetU32(&offset); 258 end_offset = cie_offset + length + 4; 259 } 260 if (length > 0 && ((m_type == DWARF && cie_id == UINT32_MAX) || 261 (m_type == EH && cie_id == 0ul))) { 262 size_t i; 263 // cie.offset = cie_offset; 264 // cie.length = length; 265 // cie.cieID = cieID; 266 cie_sp->ptr_encoding = DW_EH_PE_absptr; // default 267 cie_sp->version = m_cfi_data.GetU8(&offset); 268 if (cie_sp->version > CFI_VERSION4) { 269 Host::SystemLog(Host::eSystemLogError, 270 "CIE parse error: CFI version %d is not supported\n", 271 cie_sp->version); 272 return nullptr; 273 } 274 275 for (i = 0; i < CFI_AUG_MAX_SIZE; ++i) { 276 cie_sp->augmentation[i] = m_cfi_data.GetU8(&offset); 277 if (cie_sp->augmentation[i] == '\0') { 278 // Zero out remaining bytes in augmentation string 279 for (size_t j = i + 1; j < CFI_AUG_MAX_SIZE; ++j) 280 cie_sp->augmentation[j] = '\0'; 281 282 break; 283 } 284 } 285 286 if (i == CFI_AUG_MAX_SIZE && 287 cie_sp->augmentation[CFI_AUG_MAX_SIZE - 1] != '\0') { 288 Host::SystemLog(Host::eSystemLogError, 289 "CIE parse error: CIE augmentation string was too large " 290 "for the fixed sized buffer of %d bytes.\n", 291 CFI_AUG_MAX_SIZE); 292 return nullptr; 293 } 294 295 // m_cfi_data uses address size from target architecture of the process may 296 // ignore these fields? 297 if (m_type == DWARF && cie_sp->version >= CFI_VERSION4) { 298 cie_sp->address_size = m_cfi_data.GetU8(&offset); 299 cie_sp->segment_size = m_cfi_data.GetU8(&offset); 300 } 301 302 cie_sp->code_align = (uint32_t)m_cfi_data.GetULEB128(&offset); 303 cie_sp->data_align = (int32_t)m_cfi_data.GetSLEB128(&offset); 304 305 cie_sp->return_addr_reg_num = 306 m_type == DWARF && cie_sp->version >= CFI_VERSION3 307 ? static_cast<uint32_t>(m_cfi_data.GetULEB128(&offset)) 308 : m_cfi_data.GetU8(&offset); 309 310 if (cie_sp->augmentation[0]) { 311 // Get the length of the eh_frame augmentation data which starts with a 312 // ULEB128 length in bytes 313 const size_t aug_data_len = (size_t)m_cfi_data.GetULEB128(&offset); 314 const size_t aug_data_end = offset + aug_data_len; 315 const size_t aug_str_len = strlen(cie_sp->augmentation); 316 // A 'z' may be present as the first character of the string. 317 // If present, the Augmentation Data field shall be present. The contents 318 // of the Augmentation Data shall be interpreted according to other 319 // characters in the Augmentation String. 320 if (cie_sp->augmentation[0] == 'z') { 321 // Extract the Augmentation Data 322 size_t aug_str_idx = 0; 323 for (aug_str_idx = 1; aug_str_idx < aug_str_len; aug_str_idx++) { 324 char aug = cie_sp->augmentation[aug_str_idx]; 325 switch (aug) { 326 case 'L': 327 // Indicates the presence of one argument in the Augmentation Data 328 // of the CIE, and a corresponding argument in the Augmentation 329 // Data of the FDE. The argument in the Augmentation Data of the 330 // CIE is 1-byte and represents the pointer encoding used for the 331 // argument in the Augmentation Data of the FDE, which is the 332 // address of a language-specific data area (LSDA). The size of the 333 // LSDA pointer is specified by the pointer encoding used. 334 cie_sp->lsda_addr_encoding = m_cfi_data.GetU8(&offset); 335 break; 336 337 case 'P': 338 // Indicates the presence of two arguments in the Augmentation Data 339 // of the CIE. The first argument is 1-byte and represents the 340 // pointer encoding used for the second argument, which is the 341 // address of a personality routine handler. The size of the 342 // personality routine pointer is specified by the pointer encoding 343 // used. 344 // 345 // The address of the personality function will be stored at this 346 // location. Pre-execution, it will be all zero's so don't read it 347 // until we're trying to do an unwind & the reloc has been 348 // resolved. 349 { 350 uint8_t arg_ptr_encoding = m_cfi_data.GetU8(&offset); 351 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 352 cie_sp->personality_loc = GetGNUEHPointer( 353 m_cfi_data, &offset, arg_ptr_encoding, pc_rel_addr, 354 LLDB_INVALID_ADDRESS, LLDB_INVALID_ADDRESS); 355 } 356 break; 357 358 case 'R': 359 // A 'R' may be present at any position after the 360 // first character of the string. The Augmentation Data shall 361 // include a 1 byte argument that represents the pointer encoding 362 // for the address pointers used in the FDE. Example: 0x1B == 363 // DW_EH_PE_pcrel | DW_EH_PE_sdata4 364 cie_sp->ptr_encoding = m_cfi_data.GetU8(&offset); 365 break; 366 } 367 } 368 } else if (strcmp(cie_sp->augmentation, "eh") == 0) { 369 // If the Augmentation string has the value "eh", then the EH Data 370 // field shall be present 371 } 372 373 // Set the offset to be the end of the augmentation data just in case we 374 // didn't understand any of the data. 375 offset = (uint32_t)aug_data_end; 376 } 377 378 if (end_offset > offset) { 379 cie_sp->inst_offset = offset; 380 cie_sp->inst_length = end_offset - offset; 381 } 382 while (offset < end_offset) { 383 uint8_t inst = m_cfi_data.GetU8(&offset); 384 uint8_t primary_opcode = inst & 0xC0; 385 uint8_t extended_opcode = inst & 0x3F; 386 387 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, 388 cie_sp->data_align, offset, 389 cie_sp->initial_row)) 390 break; // Stop if we hit an unrecognized opcode 391 } 392 } 393 394 return cie_sp; 395 } 396 397 void DWARFCallFrameInfo::GetCFIData() { 398 if (!m_cfi_data_initialized) { 399 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 400 if (log) 401 m_objfile.GetModule()->LogMessage(log, "Reading EH frame info"); 402 m_objfile.ReadSectionData(m_section_sp.get(), m_cfi_data); 403 m_cfi_data_initialized = true; 404 } 405 } 406 // Scan through the eh_frame or debug_frame section looking for FDEs and noting 407 // the start/end addresses of the functions and a pointer back to the 408 // function's FDE for later expansion. Internalize CIEs as we come across them. 409 410 void DWARFCallFrameInfo::GetFDEIndex() { 411 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 412 return; 413 414 if (m_fde_index_initialized) 415 return; 416 417 std::lock_guard<std::mutex> guard(m_fde_index_mutex); 418 419 if (m_fde_index_initialized) // if two threads hit the locker 420 return; 421 422 static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); 423 Timer scoped_timer(func_cat, "%s - %s", LLVM_PRETTY_FUNCTION, 424 m_objfile.GetFileSpec().GetFilename().AsCString("")); 425 426 bool clear_address_zeroth_bit = false; 427 if (ArchSpec arch = m_objfile.GetArchitecture()) { 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 unwind_plan.SetUnwindPlanForSignalTrap( 606 strchr(cie->augmentation, 'S') ? eLazyBoolYes : eLazyBoolNo); 607 608 Address lsda_data; 609 Address personality_function_ptr; 610 611 if (lsda_data_file_address != LLDB_INVALID_ADDRESS && 612 cie->personality_loc != LLDB_INVALID_ADDRESS) { 613 m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address, 614 lsda_data); 615 m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc, 616 personality_function_ptr); 617 } 618 619 if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { 620 unwind_plan.SetLSDAAddress(lsda_data); 621 unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr); 622 } 623 624 uint32_t code_align = cie->code_align; 625 int32_t data_align = cie->data_align; 626 627 unwind_plan.SetPlanValidAddressRange(range); 628 UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; 629 *cie_initial_row = cie->initial_row; 630 UnwindPlan::RowSP row(cie_initial_row); 631 632 unwind_plan.SetRegisterKind(GetRegisterKind()); 633 unwind_plan.SetReturnAddressRegister(cie->return_addr_reg_num); 634 635 std::vector<UnwindPlan::RowSP> stack; 636 637 UnwindPlan::Row::RegisterLocation reg_location; 638 while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { 639 uint8_t inst = m_cfi_data.GetU8(&offset); 640 uint8_t primary_opcode = inst & 0xC0; 641 uint8_t extended_opcode = inst & 0x3F; 642 643 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, 644 offset, *row)) { 645 if (primary_opcode) { 646 switch (primary_opcode) { 647 case DW_CFA_advance_loc: // (Row Creation Instruction) 648 { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta 649 // takes a single argument that represents a constant delta. The 650 // required action is to create a new table row with a location value 651 // that is computed by taking the current entry's location value and 652 // adding (delta * code_align). All other values in the new row are 653 // initially identical to the current row. 654 unwind_plan.AppendRow(row); 655 UnwindPlan::Row *newrow = new UnwindPlan::Row; 656 *newrow = *row.get(); 657 row.reset(newrow); 658 row->SlideOffset(extended_opcode * code_align); 659 break; 660 } 661 662 case DW_CFA_restore: { // 0xC0 - high 2 bits are 0x3, lower 6 bits are 663 // register 664 // takes a single argument that represents a register number. The 665 // required action is to change the rule for the indicated register 666 // to the rule assigned it by the initial_instructions in the CIE. 667 uint32_t reg_num = extended_opcode; 668 // We only keep enough register locations around to unwind what is in 669 // our thread, and these are organized by the register index in that 670 // state, so we need to convert our eh_frame register number from the 671 // EH frame info, to a register index 672 673 if (unwind_plan.IsValidRowIndex(0) && 674 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 675 reg_location)) 676 row->SetRegisterInfo(reg_num, reg_location); 677 break; 678 } 679 } 680 } else { 681 switch (extended_opcode) { 682 case DW_CFA_set_loc: // 0x1 (Row Creation Instruction) 683 { 684 // DW_CFA_set_loc takes a single argument that represents an address. 685 // The required action is to create a new table row using the 686 // specified address as the location. All other values in the new row 687 // are initially identical to the current row. The new location value 688 // should always be greater than the current one. 689 unwind_plan.AppendRow(row); 690 UnwindPlan::Row *newrow = new UnwindPlan::Row; 691 *newrow = *row.get(); 692 row.reset(newrow); 693 row->SetOffset(m_cfi_data.GetAddress(&offset) - 694 startaddr.GetFileAddress()); 695 break; 696 } 697 698 case DW_CFA_advance_loc1: // 0x2 (Row Creation Instruction) 699 { 700 // takes a single uword argument that represents a constant delta. 701 // This instruction is identical to DW_CFA_advance_loc except for the 702 // encoding and size of the delta argument. 703 unwind_plan.AppendRow(row); 704 UnwindPlan::Row *newrow = new UnwindPlan::Row; 705 *newrow = *row.get(); 706 row.reset(newrow); 707 row->SlideOffset(m_cfi_data.GetU8(&offset) * code_align); 708 break; 709 } 710 711 case DW_CFA_advance_loc2: // 0x3 (Row Creation Instruction) 712 { 713 // takes a single uword argument that represents a constant delta. 714 // This instruction is identical to DW_CFA_advance_loc except for the 715 // encoding and size of the delta argument. 716 unwind_plan.AppendRow(row); 717 UnwindPlan::Row *newrow = new UnwindPlan::Row; 718 *newrow = *row.get(); 719 row.reset(newrow); 720 row->SlideOffset(m_cfi_data.GetU16(&offset) * code_align); 721 break; 722 } 723 724 case DW_CFA_advance_loc4: // 0x4 (Row Creation Instruction) 725 { 726 // takes a single uword argument that represents a constant delta. 727 // This instruction is identical to DW_CFA_advance_loc except for the 728 // encoding and size of the delta argument. 729 unwind_plan.AppendRow(row); 730 UnwindPlan::Row *newrow = new UnwindPlan::Row; 731 *newrow = *row.get(); 732 row.reset(newrow); 733 row->SlideOffset(m_cfi_data.GetU32(&offset) * code_align); 734 break; 735 } 736 737 case DW_CFA_restore_extended: // 0x6 738 { 739 // takes a single unsigned LEB128 argument that represents a register 740 // number. This instruction is identical to DW_CFA_restore except for 741 // the encoding and size of the register argument. 742 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 743 if (unwind_plan.IsValidRowIndex(0) && 744 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 745 reg_location)) 746 row->SetRegisterInfo(reg_num, reg_location); 747 break; 748 } 749 750 case DW_CFA_remember_state: // 0xA 751 { 752 // These instructions define a stack of information. Encountering the 753 // DW_CFA_remember_state instruction means to save the rules for 754 // every register on the current row on the stack. Encountering the 755 // DW_CFA_restore_state instruction means to pop the set of rules off 756 // the stack and place them in the current row. (This operation is 757 // useful for compilers that move epilogue code into the body of a 758 // function.) 759 stack.push_back(row); 760 UnwindPlan::Row *newrow = new UnwindPlan::Row; 761 *newrow = *row.get(); 762 row.reset(newrow); 763 break; 764 } 765 766 case DW_CFA_restore_state: // 0xB 767 { 768 // These instructions define a stack of information. Encountering the 769 // DW_CFA_remember_state instruction means to save the rules for 770 // every register on the current row on the stack. Encountering the 771 // DW_CFA_restore_state instruction means to pop the set of rules off 772 // the stack and place them in the current row. (This operation is 773 // useful for compilers that move epilogue code into the body of a 774 // function.) 775 if (stack.empty()) { 776 LLDB_LOGF(log, 777 "DWARFCallFrameInfo::%s(dwarf_offset: %" PRIx32 778 ", startaddr: %" PRIx64 779 " encountered DW_CFA_restore_state but state stack " 780 "is empty. Corrupt unwind info?", 781 __FUNCTION__, dwarf_offset, startaddr.GetFileAddress()); 782 break; 783 } 784 lldb::addr_t offset = row->GetOffset(); 785 row = stack.back(); 786 stack.pop_back(); 787 row->SetOffset(offset); 788 break; 789 } 790 791 case DW_CFA_GNU_args_size: // 0x2e 792 { 793 // The DW_CFA_GNU_args_size instruction takes an unsigned LEB128 794 // operand representing an argument size. This instruction specifies 795 // the total of the size of the arguments which have been pushed onto 796 // the stack. 797 798 // TODO: Figure out how we should handle this. 799 m_cfi_data.GetULEB128(&offset); 800 break; 801 } 802 803 case DW_CFA_val_offset: // 0x14 804 case DW_CFA_val_offset_sf: // 0x15 805 default: 806 break; 807 } 808 } 809 } 810 } 811 unwind_plan.AppendRow(row); 812 813 return true; 814 } 815 816 bool DWARFCallFrameInfo::HandleCommonDwarfOpcode(uint8_t primary_opcode, 817 uint8_t extended_opcode, 818 int32_t data_align, 819 lldb::offset_t &offset, 820 UnwindPlan::Row &row) { 821 UnwindPlan::Row::RegisterLocation reg_location; 822 823 if (primary_opcode) { 824 switch (primary_opcode) { 825 case DW_CFA_offset: { // 0x80 - high 2 bits are 0x2, lower 6 bits are 826 // register 827 // takes two arguments: an unsigned LEB128 constant representing a 828 // factored offset and a register number. The required action is to 829 // change the rule for the register indicated by the register number to 830 // be an offset(N) rule with a value of (N = factored offset * 831 // data_align). 832 uint8_t reg_num = extended_opcode; 833 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 834 reg_location.SetAtCFAPlusOffset(op_offset); 835 row.SetRegisterInfo(reg_num, reg_location); 836 return true; 837 } 838 } 839 } else { 840 switch (extended_opcode) { 841 case DW_CFA_nop: // 0x0 842 return true; 843 844 case DW_CFA_offset_extended: // 0x5 845 { 846 // takes two unsigned LEB128 arguments representing a register number and 847 // a factored offset. This instruction is identical to DW_CFA_offset 848 // except for the encoding and size of the register argument. 849 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 850 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 851 UnwindPlan::Row::RegisterLocation reg_location; 852 reg_location.SetAtCFAPlusOffset(op_offset); 853 row.SetRegisterInfo(reg_num, reg_location); 854 return true; 855 } 856 857 case DW_CFA_undefined: // 0x7 858 { 859 // takes a single unsigned LEB128 argument that represents a register 860 // number. The required action is to set the rule for the specified 861 // register to undefined. 862 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 863 UnwindPlan::Row::RegisterLocation reg_location; 864 reg_location.SetUndefined(); 865 row.SetRegisterInfo(reg_num, reg_location); 866 return true; 867 } 868 869 case DW_CFA_same_value: // 0x8 870 { 871 // takes a single unsigned LEB128 argument that represents a register 872 // number. The required action is to set the rule for the specified 873 // register to same value. 874 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 875 UnwindPlan::Row::RegisterLocation reg_location; 876 reg_location.SetSame(); 877 row.SetRegisterInfo(reg_num, reg_location); 878 return true; 879 } 880 881 case DW_CFA_register: // 0x9 882 { 883 // takes two unsigned LEB128 arguments representing register numbers. The 884 // required action is to set the rule for the first register to be the 885 // second register. 886 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 887 uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 888 UnwindPlan::Row::RegisterLocation reg_location; 889 reg_location.SetInRegister(other_reg_num); 890 row.SetRegisterInfo(reg_num, reg_location); 891 return true; 892 } 893 894 case DW_CFA_def_cfa: // 0xC (CFA Definition Instruction) 895 { 896 // Takes two unsigned LEB128 operands representing a register number and 897 // a (non-factored) offset. The required action is to define the current 898 // CFA rule to use the provided register and offset. 899 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 900 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 901 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 902 return true; 903 } 904 905 case DW_CFA_def_cfa_register: // 0xD (CFA Definition Instruction) 906 { 907 // takes a single unsigned LEB128 argument representing a register 908 // number. The required action is to define the current CFA rule to use 909 // the provided register (but to keep the old offset). 910 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 911 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, 912 row.GetCFAValue().GetOffset()); 913 return true; 914 } 915 916 case DW_CFA_def_cfa_offset: // 0xE (CFA Definition Instruction) 917 { 918 // Takes a single unsigned LEB128 operand representing a (non-factored) 919 // offset. The required action is to define the current CFA rule to use 920 // the provided offset (but to keep the old register). 921 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 922 row.GetCFAValue().SetIsRegisterPlusOffset( 923 row.GetCFAValue().GetRegisterNumber(), op_offset); 924 return true; 925 } 926 927 case DW_CFA_def_cfa_expression: // 0xF (CFA Definition Instruction) 928 { 929 size_t block_len = (size_t)m_cfi_data.GetULEB128(&offset); 930 const uint8_t *block_data = 931 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 932 row.GetCFAValue().SetIsDWARFExpression(block_data, block_len); 933 return true; 934 } 935 936 case DW_CFA_expression: // 0x10 937 { 938 // Takes two operands: an unsigned LEB128 value representing a register 939 // number, and a DW_FORM_block value representing a DWARF expression. The 940 // required action is to change the rule for the register indicated by 941 // the register number to be an expression(E) rule where E is the DWARF 942 // expression. That is, the DWARF expression computes the address. The 943 // value of the CFA is pushed on the DWARF evaluation stack prior to 944 // execution of the DWARF expression. 945 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 946 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 947 const uint8_t *block_data = 948 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 949 UnwindPlan::Row::RegisterLocation reg_location; 950 reg_location.SetAtDWARFExpression(block_data, block_len); 951 row.SetRegisterInfo(reg_num, reg_location); 952 return true; 953 } 954 955 case DW_CFA_offset_extended_sf: // 0x11 956 { 957 // takes two operands: an unsigned LEB128 value representing a register 958 // number and a signed LEB128 factored offset. This instruction is 959 // identical to DW_CFA_offset_extended except that the second operand is 960 // signed and factored. 961 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 962 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 963 UnwindPlan::Row::RegisterLocation reg_location; 964 reg_location.SetAtCFAPlusOffset(op_offset); 965 row.SetRegisterInfo(reg_num, reg_location); 966 return true; 967 } 968 969 case DW_CFA_def_cfa_sf: // 0x12 (CFA Definition Instruction) 970 { 971 // Takes two operands: an unsigned LEB128 value representing a register 972 // number and a signed LEB128 factored offset. This instruction is 973 // identical to DW_CFA_def_cfa except that the second operand is signed 974 // and factored. 975 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 976 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 977 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 978 return true; 979 } 980 981 case DW_CFA_def_cfa_offset_sf: // 0x13 (CFA Definition Instruction) 982 { 983 // takes a signed LEB128 operand representing a factored offset. This 984 // instruction is identical to DW_CFA_def_cfa_offset except that the 985 // operand is signed and factored. 986 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 987 uint32_t cfa_regnum = row.GetCFAValue().GetRegisterNumber(); 988 row.GetCFAValue().SetIsRegisterPlusOffset(cfa_regnum, op_offset); 989 return true; 990 } 991 992 case DW_CFA_val_expression: // 0x16 993 { 994 // takes two operands: an unsigned LEB128 value representing a register 995 // number, and a DW_FORM_block value representing a DWARF expression. The 996 // required action is to change the rule for the register indicated by 997 // the register number to be a val_expression(E) rule where E is the 998 // DWARF expression. That is, the DWARF expression computes the value of 999 // the given register. The value of the CFA is pushed on the DWARF 1000 // evaluation stack prior to execution of the DWARF expression. 1001 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 1002 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 1003 const uint8_t *block_data = 1004 (const uint8_t *)m_cfi_data.GetData(&offset, block_len); 1005 reg_location.SetIsDWARFExpression(block_data, block_len); 1006 row.SetRegisterInfo(reg_num, reg_location); 1007 return true; 1008 } 1009 } 1010 } 1011 return false; 1012 } 1013 1014 void DWARFCallFrameInfo::ForEachFDEEntries( 1015 const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback) { 1016 GetFDEIndex(); 1017 1018 for (size_t i = 0, c = m_fde_index.GetSize(); i < c; ++i) { 1019 const FDEEntryMap::Entry &entry = m_fde_index.GetEntryRef(i); 1020 if (!callback(entry.base, entry.size, entry.data)) 1021 break; 1022 } 1023 } 1024