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