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 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 ArchSpec arch; 428 if (m_objfile.GetArchitecture(arch)) { 429 if (arch.GetTriple().getArch() == llvm::Triple::arm || 430 arch.GetTriple().getArch() == llvm::Triple::thumb) 431 clear_address_zeroth_bit = true; 432 } 433 434 lldb::offset_t offset = 0; 435 if (m_cfi_data_initialized == false) 436 GetCFIData(); 437 while (m_cfi_data.ValidOffsetForDataOfSize(offset, 8)) { 438 const dw_offset_t current_entry = offset; 439 dw_offset_t cie_id, next_entry, cie_offset; 440 uint32_t len = m_cfi_data.GetU32(&offset); 441 bool is_64bit = (len == UINT32_MAX); 442 if (is_64bit) { 443 len = m_cfi_data.GetU64(&offset); 444 cie_id = m_cfi_data.GetU64(&offset); 445 next_entry = current_entry + len + 12; 446 cie_offset = current_entry + 12 - cie_id; 447 } else { 448 cie_id = m_cfi_data.GetU32(&offset); 449 next_entry = current_entry + len + 4; 450 cie_offset = current_entry + 4 - cie_id; 451 } 452 453 if (next_entry > m_cfi_data.GetByteSize() + 1) { 454 Host::SystemLog(Host::eSystemLogError, "error: Invalid fde/cie next " 455 "entry offset of 0x%x found in " 456 "cie/fde at 0x%x\n", 457 next_entry, current_entry); 458 // Don't trust anything in this eh_frame section if we find blatantly 459 // invalid data. 460 m_fde_index.Clear(); 461 m_fde_index_initialized = true; 462 return; 463 } 464 if (cie_offset > m_cfi_data.GetByteSize()) { 465 Host::SystemLog( 466 Host::eSystemLogError, 467 "error: Invalid cie offset of 0x%x found in cie/fde at 0x%x\n", 468 cie_offset, current_entry); 469 // Don't trust anything in this eh_frame section if we find blatantly 470 // invalid data. 471 m_fde_index.Clear(); 472 m_fde_index_initialized = true; 473 return; 474 } 475 476 if (cie_id == 0 || cie_id == UINT32_MAX || len == 0) { 477 m_cie_map[current_entry] = ParseCIE(current_entry); 478 offset = next_entry; 479 continue; 480 } 481 482 const CIE *cie = GetCIE(cie_offset); 483 if (cie) { 484 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 485 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 486 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 487 488 lldb::addr_t addr = 489 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 490 text_addr, data_addr); 491 if (clear_address_zeroth_bit) 492 addr &= ~1ull; 493 494 lldb::addr_t length = GetGNUEHPointer( 495 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 496 pc_rel_addr, text_addr, data_addr); 497 FDEEntryMap::Entry fde(addr, length, current_entry); 498 m_fde_index.Append(fde); 499 } else { 500 Host::SystemLog(Host::eSystemLogError, "error: unable to find CIE at " 501 "0x%8.8x for cie_id = 0x%8.8x for " 502 "entry at 0x%8.8x.\n", 503 cie_offset, cie_id, current_entry); 504 } 505 offset = next_entry; 506 } 507 m_fde_index.Sort(); 508 m_fde_index_initialized = true; 509 } 510 511 bool DWARFCallFrameInfo::FDEToUnwindPlan(dw_offset_t dwarf_offset, 512 Address startaddr, 513 UnwindPlan &unwind_plan) { 514 Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND); 515 lldb::offset_t offset = dwarf_offset; 516 lldb::offset_t current_entry = offset; 517 518 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 519 return false; 520 521 if (m_cfi_data_initialized == false) 522 GetCFIData(); 523 524 uint32_t length = m_cfi_data.GetU32(&offset); 525 dw_offset_t cie_offset; 526 bool is_64bit = (length == UINT32_MAX); 527 if (is_64bit) { 528 length = m_cfi_data.GetU64(&offset); 529 cie_offset = m_cfi_data.GetU64(&offset); 530 } else { 531 cie_offset = m_cfi_data.GetU32(&offset); 532 } 533 534 assert(cie_offset != 0 && cie_offset != UINT32_MAX); 535 536 // Translate the CIE_id from the eh_frame format, which 537 // is relative to the FDE offset, into a __eh_frame section 538 // offset 539 if (m_is_eh_frame) { 540 unwind_plan.SetSourceName("eh_frame CFI"); 541 cie_offset = current_entry + (is_64bit ? 12 : 4) - cie_offset; 542 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 543 } else { 544 unwind_plan.SetSourceName("DWARF CFI"); 545 // In theory the debug_frame info should be valid at all call sites 546 // ("asynchronous unwind info" as it is sometimes called) but in practice 547 // gcc et al all emit call frame info for the prologue and call sites, but 548 // not for the epilogue or all the other locations during the function 549 // reliably. 550 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 551 } 552 unwind_plan.SetSourcedFromCompiler(eLazyBoolYes); 553 554 const CIE *cie = GetCIE(cie_offset); 555 assert(cie != nullptr); 556 557 const dw_offset_t end_offset = current_entry + length + (is_64bit ? 12 : 4); 558 559 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 560 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 561 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 562 lldb::addr_t range_base = 563 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 564 text_addr, data_addr); 565 lldb::addr_t range_len = GetGNUEHPointer( 566 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 567 pc_rel_addr, text_addr, data_addr); 568 AddressRange range(range_base, m_objfile.GetAddressByteSize(), 569 m_objfile.GetSectionList()); 570 range.SetByteSize(range_len); 571 572 addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS; 573 574 if (cie->augmentation[0] == 'z') { 575 uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 576 if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) { 577 offset_t saved_offset = offset; 578 lsda_data_file_address = 579 GetGNUEHPointer(m_cfi_data, &offset, cie->lsda_addr_encoding, 580 pc_rel_addr, text_addr, data_addr); 581 if (offset - saved_offset != aug_data_len) { 582 // There is more in the augmentation region than we know how to process; 583 // don't read anything. 584 lsda_data_file_address = LLDB_INVALID_ADDRESS; 585 } 586 offset = saved_offset; 587 } 588 offset += aug_data_len; 589 } 590 Address lsda_data; 591 Address personality_function_ptr; 592 593 if (lsda_data_file_address != LLDB_INVALID_ADDRESS && 594 cie->personality_loc != LLDB_INVALID_ADDRESS) { 595 m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address, 596 lsda_data); 597 m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc, 598 personality_function_ptr); 599 } 600 601 if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { 602 unwind_plan.SetLSDAAddress(lsda_data); 603 unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr); 604 } 605 606 uint32_t code_align = cie->code_align; 607 int32_t data_align = cie->data_align; 608 609 unwind_plan.SetPlanValidAddressRange(range); 610 UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; 611 *cie_initial_row = cie->initial_row; 612 UnwindPlan::RowSP row(cie_initial_row); 613 614 unwind_plan.SetRegisterKind(m_reg_kind); 615 unwind_plan.SetReturnAddressRegister(cie->return_addr_reg_num); 616 617 std::vector<UnwindPlan::RowSP> stack; 618 619 UnwindPlan::Row::RegisterLocation reg_location; 620 while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { 621 uint8_t inst = m_cfi_data.GetU8(&offset); 622 uint8_t primary_opcode = inst & 0xC0; 623 uint8_t extended_opcode = inst & 0x3F; 624 625 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, 626 offset, *row)) { 627 if (primary_opcode) { 628 switch (primary_opcode) { 629 case DW_CFA_advance_loc: // (Row Creation Instruction) 630 { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta 631 // takes a single argument that represents a constant delta. The 632 // required action is to create a new table row with a location 633 // value that is computed by taking the current entry's location 634 // value and adding (delta * code_align). All other 635 // values in the new row are initially identical to the current row. 636 unwind_plan.AppendRow(row); 637 UnwindPlan::Row *newrow = new UnwindPlan::Row; 638 *newrow = *row.get(); 639 row.reset(newrow); 640 row->SlideOffset(extended_opcode * code_align); 641 break; 642 } 643 644 case DW_CFA_restore: { // 0xC0 - high 2 bits are 0x3, lower 6 bits are 645 // register 646 // takes a single argument that represents a register number. The 647 // required action is to change the rule for the indicated register 648 // to the rule assigned it by the initial_instructions in the CIE. 649 uint32_t reg_num = extended_opcode; 650 // We only keep enough register locations around to 651 // unwind what is in our thread, and these are organized 652 // by the register index in that state, so we need to convert our 653 // eh_frame register number from the EH frame info, to a register 654 // index 655 656 if (unwind_plan.IsValidRowIndex(0) && 657 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 658 reg_location)) 659 row->SetRegisterInfo(reg_num, reg_location); 660 break; 661 } 662 } 663 } else { 664 switch (extended_opcode) { 665 case DW_CFA_set_loc: // 0x1 (Row Creation Instruction) 666 { 667 // DW_CFA_set_loc takes a single argument that represents an address. 668 // The required action is to create a new table row using the 669 // specified address as the location. All other values in the new row 670 // are initially identical to the current row. The new location value 671 // should always be greater than the current one. 672 unwind_plan.AppendRow(row); 673 UnwindPlan::Row *newrow = new UnwindPlan::Row; 674 *newrow = *row.get(); 675 row.reset(newrow); 676 row->SetOffset(m_cfi_data.GetPointer(&offset) - 677 startaddr.GetFileAddress()); 678 break; 679 } 680 681 case DW_CFA_advance_loc1: // 0x2 (Row Creation Instruction) 682 { 683 // takes a single uword argument that represents a constant delta. 684 // This instruction is identical to DW_CFA_advance_loc except for the 685 // encoding and size of the delta argument. 686 unwind_plan.AppendRow(row); 687 UnwindPlan::Row *newrow = new UnwindPlan::Row; 688 *newrow = *row.get(); 689 row.reset(newrow); 690 row->SlideOffset(m_cfi_data.GetU8(&offset) * code_align); 691 break; 692 } 693 694 case DW_CFA_advance_loc2: // 0x3 (Row Creation Instruction) 695 { 696 // takes a single uword argument that represents a constant delta. 697 // This instruction is identical to DW_CFA_advance_loc except for the 698 // encoding and size of the delta argument. 699 unwind_plan.AppendRow(row); 700 UnwindPlan::Row *newrow = new UnwindPlan::Row; 701 *newrow = *row.get(); 702 row.reset(newrow); 703 row->SlideOffset(m_cfi_data.GetU16(&offset) * code_align); 704 break; 705 } 706 707 case DW_CFA_advance_loc4: // 0x4 (Row Creation Instruction) 708 { 709 // takes a single uword argument that represents a constant delta. 710 // This instruction is identical to DW_CFA_advance_loc except for the 711 // encoding and size of the delta argument. 712 unwind_plan.AppendRow(row); 713 UnwindPlan::Row *newrow = new UnwindPlan::Row; 714 *newrow = *row.get(); 715 row.reset(newrow); 716 row->SlideOffset(m_cfi_data.GetU32(&offset) * code_align); 717 break; 718 } 719 720 case DW_CFA_restore_extended: // 0x6 721 { 722 // takes a single unsigned LEB128 argument that represents a register 723 // number. This instruction is identical to DW_CFA_restore except for 724 // the encoding and size of the register argument. 725 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 726 if (unwind_plan.IsValidRowIndex(0) && 727 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 728 reg_location)) 729 row->SetRegisterInfo(reg_num, reg_location); 730 break; 731 } 732 733 case DW_CFA_remember_state: // 0xA 734 { 735 // These instructions define a stack of information. Encountering the 736 // DW_CFA_remember_state instruction means to save the rules for every 737 // register on the current row on the stack. Encountering the 738 // DW_CFA_restore_state instruction means to pop the set of rules off 739 // the stack and place them in the current row. (This operation is 740 // useful for compilers that move epilogue code into the body of a 741 // function.) 742 stack.push_back(row); 743 UnwindPlan::Row *newrow = new UnwindPlan::Row; 744 *newrow = *row.get(); 745 row.reset(newrow); 746 break; 747 } 748 749 case DW_CFA_restore_state: // 0xB 750 { 751 // These instructions define a stack of information. Encountering the 752 // DW_CFA_remember_state instruction means to save the rules for every 753 // register on the current row on the stack. Encountering the 754 // DW_CFA_restore_state instruction means to pop the set of rules off 755 // the stack and place them in the current row. (This operation is 756 // useful for compilers that move epilogue code into the body of a 757 // function.) 758 if (stack.empty()) { 759 if (log) 760 log->Printf("DWARFCallFrameInfo::%s(dwarf_offset: %" PRIx32 761 ", startaddr: %" PRIx64 762 " encountered DW_CFA_restore_state but state stack " 763 "is empty. Corrupt unwind info?", 764 __FUNCTION__, dwarf_offset, 765 startaddr.GetFileAddress()); 766 break; 767 } 768 lldb::addr_t offset = row->GetOffset(); 769 row = stack.back(); 770 stack.pop_back(); 771 row->SetOffset(offset); 772 break; 773 } 774 775 case DW_CFA_GNU_args_size: // 0x2e 776 { 777 // The DW_CFA_GNU_args_size instruction takes an unsigned LEB128 778 // operand 779 // representing an argument size. This instruction specifies the total 780 // of 781 // the size of the arguments which have been pushed onto the stack. 782 783 // TODO: Figure out how we should handle this. 784 m_cfi_data.GetULEB128(&offset); 785 break; 786 } 787 788 case DW_CFA_val_offset: // 0x14 789 case DW_CFA_val_offset_sf: // 0x15 790 default: 791 break; 792 } 793 } 794 } 795 } 796 unwind_plan.AppendRow(row); 797 798 return true; 799 } 800 801 bool DWARFCallFrameInfo::HandleCommonDwarfOpcode(uint8_t primary_opcode, 802 uint8_t extended_opcode, 803 int32_t data_align, 804 lldb::offset_t &offset, 805 UnwindPlan::Row &row) { 806 UnwindPlan::Row::RegisterLocation reg_location; 807 808 if (primary_opcode) { 809 switch (primary_opcode) { 810 case DW_CFA_offset: { // 0x80 - high 2 bits are 0x2, lower 6 bits are 811 // register 812 // takes two arguments: an unsigned LEB128 constant representing a 813 // factored offset and a register number. The required action is to 814 // change the rule for the register indicated by the register number 815 // to be an offset(N) rule with a value of 816 // (N = factored offset * data_align). 817 uint8_t reg_num = extended_opcode; 818 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 819 reg_location.SetAtCFAPlusOffset(op_offset); 820 row.SetRegisterInfo(reg_num, reg_location); 821 return true; 822 } 823 } 824 } else { 825 switch (extended_opcode) { 826 case DW_CFA_nop: // 0x0 827 return true; 828 829 case DW_CFA_offset_extended: // 0x5 830 { 831 // takes two unsigned LEB128 arguments representing a register number 832 // and a factored offset. This instruction is identical to DW_CFA_offset 833 // except for the encoding and size of the register argument. 834 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 835 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 836 UnwindPlan::Row::RegisterLocation reg_location; 837 reg_location.SetAtCFAPlusOffset(op_offset); 838 row.SetRegisterInfo(reg_num, reg_location); 839 return true; 840 } 841 842 case DW_CFA_undefined: // 0x7 843 { 844 // takes a single unsigned LEB128 argument that represents a register 845 // number. The required action is to set the rule for the specified 846 // register to undefined. 847 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 848 UnwindPlan::Row::RegisterLocation reg_location; 849 reg_location.SetUndefined(); 850 row.SetRegisterInfo(reg_num, reg_location); 851 return true; 852 } 853 854 case DW_CFA_same_value: // 0x8 855 { 856 // takes a single unsigned LEB128 argument that represents a register 857 // number. The required action is to set the rule for the specified 858 // register to same value. 859 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 860 UnwindPlan::Row::RegisterLocation reg_location; 861 reg_location.SetSame(); 862 row.SetRegisterInfo(reg_num, reg_location); 863 return true; 864 } 865 866 case DW_CFA_register: // 0x9 867 { 868 // takes two unsigned LEB128 arguments representing register numbers. 869 // The required action is to set the rule for the first register to be 870 // the second register. 871 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 872 uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 873 UnwindPlan::Row::RegisterLocation reg_location; 874 reg_location.SetInRegister(other_reg_num); 875 row.SetRegisterInfo(reg_num, reg_location); 876 return true; 877 } 878 879 case DW_CFA_def_cfa: // 0xC (CFA Definition Instruction) 880 { 881 // Takes two unsigned LEB128 operands representing a register 882 // number and a (non-factored) offset. The required action 883 // is to define the current CFA rule to use the provided 884 // register and offset. 885 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 886 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 887 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 888 return true; 889 } 890 891 case DW_CFA_def_cfa_register: // 0xD (CFA Definition Instruction) 892 { 893 // takes a single unsigned LEB128 argument representing a register 894 // number. The required action is to define the current CFA rule to 895 // use the provided register (but to keep the old offset). 896 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 897 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, 898 row.GetCFAValue().GetOffset()); 899 return true; 900 } 901 902 case DW_CFA_def_cfa_offset: // 0xE (CFA Definition Instruction) 903 { 904 // Takes a single unsigned LEB128 operand representing a 905 // (non-factored) offset. The required action is to define 906 // the current CFA rule to use the provided offset (but 907 // to keep the old register). 908 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 909 row.GetCFAValue().SetIsRegisterPlusOffset( 910 row.GetCFAValue().GetRegisterNumber(), op_offset); 911 return true; 912 } 913 914 case DW_CFA_def_cfa_expression: // 0xF (CFA Definition Instruction) 915 { 916 size_t block_len = (size_t)m_cfi_data.GetULEB128(&offset); 917 const uint8_t *block_data = 918 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 919 row.GetCFAValue().SetIsDWARFExpression(block_data, block_len); 920 return true; 921 } 922 923 case DW_CFA_expression: // 0x10 924 { 925 // Takes two operands: an unsigned LEB128 value representing 926 // a register number, and a DW_FORM_block value representing a DWARF 927 // expression. The required action is to change the rule for the 928 // register indicated by the register number to be an expression(E) 929 // rule where E is the DWARF expression. That is, the DWARF 930 // expression computes the address. The value of the CFA is 931 // pushed on the DWARF evaluation stack prior to execution of 932 // the DWARF expression. 933 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 934 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 935 const uint8_t *block_data = 936 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 937 UnwindPlan::Row::RegisterLocation reg_location; 938 reg_location.SetAtDWARFExpression(block_data, block_len); 939 row.SetRegisterInfo(reg_num, reg_location); 940 return true; 941 } 942 943 case DW_CFA_offset_extended_sf: // 0x11 944 { 945 // takes two operands: an unsigned LEB128 value representing a 946 // register number and a signed LEB128 factored offset. This 947 // instruction is identical to DW_CFA_offset_extended except 948 // that the second operand is signed and factored. 949 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 950 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 951 UnwindPlan::Row::RegisterLocation reg_location; 952 reg_location.SetAtCFAPlusOffset(op_offset); 953 row.SetRegisterInfo(reg_num, reg_location); 954 return true; 955 } 956 957 case DW_CFA_def_cfa_sf: // 0x12 (CFA Definition Instruction) 958 { 959 // Takes two operands: an unsigned LEB128 value representing 960 // a register number and a signed LEB128 factored offset. 961 // This instruction is identical to DW_CFA_def_cfa except 962 // that the second operand is signed and factored. 963 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 964 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 965 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 966 return true; 967 } 968 969 case DW_CFA_def_cfa_offset_sf: // 0x13 (CFA Definition Instruction) 970 { 971 // takes a signed LEB128 operand representing a factored 972 // offset. This instruction is identical to DW_CFA_def_cfa_offset 973 // except that the operand is signed and factored. 974 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 975 uint32_t cfa_regnum = row.GetCFAValue().GetRegisterNumber(); 976 row.GetCFAValue().SetIsRegisterPlusOffset(cfa_regnum, op_offset); 977 return true; 978 } 979 980 case DW_CFA_val_expression: // 0x16 981 { 982 // takes two operands: an unsigned LEB128 value representing a register 983 // number, and a DW_FORM_block value representing a DWARF expression. 984 // The required action is to change the rule for the register indicated 985 // by the register number to be a val_expression(E) rule where E is the 986 // DWARF expression. That is, the DWARF expression computes the value of 987 // the given register. The value of the CFA is pushed on the DWARF 988 // evaluation stack prior to execution of the DWARF expression. 989 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 990 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 991 const uint8_t *block_data = 992 (const uint8_t *)m_cfi_data.GetData(&offset, block_len); 993 //#if defined(__i386__) || defined(__x86_64__) 994 // // The EH frame info for EIP and RIP contains code that 995 // looks for traps to 996 // // be a specific type and increments the PC. 997 // // For i386: 998 // // DW_CFA_val_expression where: 999 // // eip = DW_OP_breg6(+28), DW_OP_deref, DW_OP_dup, 1000 // DW_OP_plus_uconst(0x34), 1001 // // DW_OP_deref, DW_OP_swap, DW_OP_plus_uconst(0), 1002 // DW_OP_deref, 1003 // // DW_OP_dup, DW_OP_lit3, DW_OP_ne, DW_OP_swap, 1004 // DW_OP_lit4, DW_OP_ne, 1005 // // DW_OP_and, DW_OP_plus 1006 // // This basically does a: 1007 // // eip = ucontenxt.mcontext32->gpr.eip; 1008 // // if (ucontenxt.mcontext32->exc.trapno != 3 && 1009 // ucontenxt.mcontext32->exc.trapno != 4) 1010 // // eip++; 1011 // // 1012 // // For x86_64: 1013 // // DW_CFA_val_expression where: 1014 // // rip = DW_OP_breg3(+48), DW_OP_deref, DW_OP_dup, 1015 // DW_OP_plus_uconst(0x90), DW_OP_deref, 1016 // // DW_OP_swap, DW_OP_plus_uconst(0), 1017 // DW_OP_deref_size(4), DW_OP_dup, DW_OP_lit3, 1018 // // DW_OP_ne, DW_OP_swap, DW_OP_lit4, DW_OP_ne, 1019 // DW_OP_and, DW_OP_plus 1020 // // This basically does a: 1021 // // rip = ucontenxt.mcontext64->gpr.rip; 1022 // // if (ucontenxt.mcontext64->exc.trapno != 3 && 1023 // ucontenxt.mcontext64->exc.trapno != 4) 1024 // // rip++; 1025 // // The trap comparisons and increments are not needed as 1026 // it hoses up the unwound PC which 1027 // // is expected to point at least past the instruction that 1028 // causes the fault/trap. So we 1029 // // take it out by trimming the expression right at the 1030 // first "DW_OP_swap" opcodes 1031 // if (block_data != NULL && thread->GetPCRegNum(Thread::GCC) 1032 // == reg_num) 1033 // { 1034 // if (thread->Is64Bit()) 1035 // { 1036 // if (block_len > 9 && block_data[8] == DW_OP_swap 1037 // && block_data[9] == DW_OP_plus_uconst) 1038 // block_len = 8; 1039 // } 1040 // else 1041 // { 1042 // if (block_len > 8 && block_data[7] == DW_OP_swap 1043 // && block_data[8] == DW_OP_plus_uconst) 1044 // block_len = 7; 1045 // } 1046 // } 1047 //#endif 1048 reg_location.SetIsDWARFExpression(block_data, block_len); 1049 row.SetRegisterInfo(reg_num, reg_location); 1050 return true; 1051 } 1052 } 1053 } 1054 return false; 1055 } 1056 1057 void DWARFCallFrameInfo::ForEachFDEEntries( 1058 const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback) { 1059 GetFDEIndex(); 1060 1061 for (size_t i = 0, c = m_fde_index.GetSize(); i < c; ++i) { 1062 const FDEEntryMap::Entry &entry = m_fde_index.GetEntryRef(i); 1063 if (!callback(entry.base, entry.size, entry.data)) 1064 break; 1065 } 1066 } 1067