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