1//===-- DWARFCallFrameInfo.cpp --------------------------------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8 9#include "lldb/Symbol/DWARFCallFrameInfo.h" 10#include "lldb/Core/Debugger.h" 11#include "lldb/Core/Module.h" 12#include "lldb/Core/Section.h" 13#include "lldb/Core/dwarf.h" 14#include "lldb/Host/Host.h" 15#include "lldb/Symbol/ObjectFile.h" 16#include "lldb/Symbol/UnwindPlan.h" 17#include "lldb/Target/RegisterContext.h" 18#include "lldb/Target/Thread.h" 19#include "lldb/Utility/ArchSpec.h" 20#include "lldb/Utility/LLDBLog.h" 21#include "lldb/Utility/Log.h" 22#include "lldb/Utility/Timer.h" 23#include <cstring> 24#include <list> 25#include <optional> 26 27using namespace lldb; 28using namespace lldb_private; 29using namespace lldb_private::dwarf; 30 31// GetDwarfEHPtr 32// 33// Used for calls when the value type is specified by a DWARF EH Frame pointer 34// encoding. 35static uint64_t 36GetGNUEHPointer(const DataExtractor &DE, offset_t *offset_ptr, 37 uint32_t eh_ptr_enc, addr_t pc_rel_addr, addr_t text_addr, 38 addr_t data_addr) //, BSDRelocs *data_relocs) const 39{ 40 if (eh_ptr_enc == DW_EH_PE_omit) 41 return ULLONG_MAX; // Value isn't in the buffer... 42 43 uint64_t baseAddress = 0; 44 uint64_t addressValue = 0; 45 const uint32_t addr_size = DE.GetAddressByteSize(); 46 assert(addr_size == 4 || addr_size == 8); 47 48 bool signExtendValue = false; 49 // Decode the base part or adjust our offset 50 switch (eh_ptr_enc & 0x70) { 51 case DW_EH_PE_pcrel: 52 signExtendValue = true; 53 baseAddress = *offset_ptr; 54 if (pc_rel_addr != LLDB_INVALID_ADDRESS) 55 baseAddress += pc_rel_addr; 56 // else 57 // Log::GlobalWarning ("PC relative pointer encoding found with 58 // invalid pc relative address."); 59 break; 60 61 case DW_EH_PE_textrel: 62 signExtendValue = true; 63 if (text_addr != LLDB_INVALID_ADDRESS) 64 baseAddress = text_addr; 65 // else 66 // Log::GlobalWarning ("text relative pointer encoding being 67 // decoded with invalid text section address, setting base address 68 // to zero."); 69 break; 70 71 case DW_EH_PE_datarel: 72 signExtendValue = true; 73 if (data_addr != LLDB_INVALID_ADDRESS) 74 baseAddress = data_addr; 75 // else 76 // Log::GlobalWarning ("data relative pointer encoding being 77 // decoded with invalid data section address, setting base address 78 // to zero."); 79 break; 80 81 case DW_EH_PE_funcrel: 82 signExtendValue = true; 83 break; 84 85 case DW_EH_PE_aligned: { 86 // SetPointerSize should be called prior to extracting these so the pointer 87 // size is cached 88 assert(addr_size != 0); 89 if (addr_size) { 90 // Align to a address size boundary first 91 uint32_t alignOffset = *offset_ptr % addr_size; 92 if (alignOffset) 93 offset_ptr += addr_size - alignOffset; 94 } 95 } break; 96 97 default: 98 break; 99 } 100 101 // Decode the value part 102 switch (eh_ptr_enc & DW_EH_PE_MASK_ENCODING) { 103 case DW_EH_PE_absptr: { 104 addressValue = DE.GetAddress(offset_ptr); 105 // if (data_relocs) 106 // addressValue = data_relocs->Relocate(*offset_ptr - 107 // addr_size, *this, addressValue); 108 } break; 109 case DW_EH_PE_uleb128: 110 addressValue = DE.GetULEB128(offset_ptr); 111 break; 112 case DW_EH_PE_udata2: 113 addressValue = DE.GetU16(offset_ptr); 114 break; 115 case DW_EH_PE_udata4: 116 addressValue = DE.GetU32(offset_ptr); 117 break; 118 case DW_EH_PE_udata8: 119 addressValue = DE.GetU64(offset_ptr); 120 break; 121 case DW_EH_PE_sleb128: 122 addressValue = DE.GetSLEB128(offset_ptr); 123 break; 124 case DW_EH_PE_sdata2: 125 addressValue = (int16_t)DE.GetU16(offset_ptr); 126 break; 127 case DW_EH_PE_sdata4: 128 addressValue = (int32_t)DE.GetU32(offset_ptr); 129 break; 130 case DW_EH_PE_sdata8: 131 addressValue = (int64_t)DE.GetU64(offset_ptr); 132 break; 133 default: 134 // Unhandled encoding type 135 assert(eh_ptr_enc); 136 break; 137 } 138 139 // Since we promote everything to 64 bit, we may need to sign extend 140 if (signExtendValue && addr_size < sizeof(baseAddress)) { 141 uint64_t sign_bit = 1ull << ((addr_size * 8ull) - 1ull); 142 if (sign_bit & addressValue) { 143 uint64_t mask = ~sign_bit + 1; 144 addressValue |= mask; 145 } 146 } 147 return baseAddress + addressValue; 148} 149 150DWARFCallFrameInfo::DWARFCallFrameInfo(ObjectFile &objfile, 151 SectionSP §ion_sp, Type type) 152 : m_objfile(objfile), m_section_sp(section_sp), m_type(type) {} 153 154bool DWARFCallFrameInfo::GetUnwindPlan(const Address &addr, 155 UnwindPlan &unwind_plan) { 156 return GetUnwindPlan(AddressRange(addr, 1), unwind_plan); 157} 158 159bool DWARFCallFrameInfo::GetUnwindPlan(const AddressRange &range, 160 UnwindPlan &unwind_plan) { 161 FDEEntryMap::Entry fde_entry; 162 Address addr = range.GetBaseAddress(); 163 164 // Make sure that the Address we're searching for is the same object file as 165 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 166 ModuleSP module_sp = addr.GetModule(); 167 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 168 module_sp->GetObjectFile() != &m_objfile) 169 return false; 170 171 if (std::optional<FDEEntryMap::Entry> entry = GetFirstFDEEntryInRange(range)) 172 return FDEToUnwindPlan(entry->data, addr, unwind_plan); 173 return false; 174} 175 176bool DWARFCallFrameInfo::GetAddressRange(Address addr, AddressRange &range) { 177 178 // Make sure that the Address we're searching for is the same object file as 179 // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. 180 ModuleSP module_sp = addr.GetModule(); 181 if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || 182 module_sp->GetObjectFile() != &m_objfile) 183 return false; 184 185 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 186 return false; 187 GetFDEIndex(); 188 FDEEntryMap::Entry *fde_entry = 189 m_fde_index.FindEntryThatContains(addr.GetFileAddress()); 190 if (!fde_entry) 191 return false; 192 193 range = AddressRange(fde_entry->base, fde_entry->size, 194 m_objfile.GetSectionList()); 195 return true; 196} 197 198std::optional<DWARFCallFrameInfo::FDEEntryMap::Entry> 199DWARFCallFrameInfo::GetFirstFDEEntryInRange(const AddressRange &range) { 200 if (!m_section_sp || m_section_sp->IsEncrypted()) 201 return std::nullopt; 202 203 GetFDEIndex(); 204 205 addr_t start_file_addr = range.GetBaseAddress().GetFileAddress(); 206 const FDEEntryMap::Entry *fde = 207 m_fde_index.FindEntryThatContainsOrFollows(start_file_addr); 208 if (fde && fde->DoesIntersect( 209 FDEEntryMap::Range(start_file_addr, range.GetByteSize()))) 210 return *fde; 211 212 return std::nullopt; 213} 214 215void DWARFCallFrameInfo::GetFunctionAddressAndSizeVector( 216 FunctionAddressAndSizeVector &function_info) { 217 GetFDEIndex(); 218 const size_t count = m_fde_index.GetSize(); 219 function_info.Clear(); 220 if (count > 0) 221 function_info.Reserve(count); 222 for (size_t i = 0; i < count; ++i) { 223 const FDEEntryMap::Entry *func_offset_data_entry = 224 m_fde_index.GetEntryAtIndex(i); 225 if (func_offset_data_entry) { 226 FunctionAddressAndSizeVector::Entry function_offset_entry( 227 func_offset_data_entry->base, func_offset_data_entry->size); 228 function_info.Append(function_offset_entry); 229 } 230 } 231} 232 233const DWARFCallFrameInfo::CIE * 234DWARFCallFrameInfo::GetCIE(dw_offset_t cie_offset) { 235 cie_map_t::iterator pos = m_cie_map.find(cie_offset); 236 237 if (pos != m_cie_map.end()) { 238 // Parse and cache the CIE 239 if (pos->second == nullptr) 240 pos->second = ParseCIE(cie_offset); 241 242 return pos->second.get(); 243 } 244 return nullptr; 245} 246 247DWARFCallFrameInfo::CIESP 248DWARFCallFrameInfo::ParseCIE(const dw_offset_t cie_offset) { 249 CIESP cie_sp(new CIE(cie_offset)); 250 lldb::offset_t offset = cie_offset; 251 if (!m_cfi_data_initialized) 252 GetCFIData(); 253 uint32_t length = m_cfi_data.GetU32(&offset); 254 dw_offset_t cie_id, end_offset; 255 bool is_64bit = (length == UINT32_MAX); 256 if (is_64bit) { 257 length = m_cfi_data.GetU64(&offset); 258 cie_id = m_cfi_data.GetU64(&offset); 259 end_offset = cie_offset + length + 12; 260 } else { 261 cie_id = m_cfi_data.GetU32(&offset); 262 end_offset = cie_offset + length + 4; 263 } 264 if (length > 0 && ((m_type == DWARF && cie_id == UINT32_MAX) || 265 (m_type == EH && cie_id == 0ul))) { 266 size_t i; 267 // cie.offset = cie_offset; 268 // cie.length = length; 269 // cie.cieID = cieID; 270 cie_sp->ptr_encoding = DW_EH_PE_absptr; // default 271 cie_sp->version = m_cfi_data.GetU8(&offset); 272 if (cie_sp->version > CFI_VERSION4) { 273 Debugger::ReportError( 274 llvm::formatv("CIE parse error: CFI version {0} is not supported", 275 cie_sp->version)); 276 return nullptr; 277 } 278 279 for (i = 0; i < CFI_AUG_MAX_SIZE; ++i) { 280 cie_sp->augmentation[i] = m_cfi_data.GetU8(&offset); 281 if (cie_sp->augmentation[i] == '\0') { 282 // Zero out remaining bytes in augmentation string 283 for (size_t j = i + 1; j < CFI_AUG_MAX_SIZE; ++j) 284 cie_sp->augmentation[j] = '\0'; 285 286 break; 287 } 288 } 289 290 if (i == CFI_AUG_MAX_SIZE && 291 cie_sp->augmentation[CFI_AUG_MAX_SIZE - 1] != '\0') { 292 Debugger::ReportError(llvm::formatv( 293 "CIE parse error: CIE augmentation string was too large " 294 "for the fixed sized buffer of {0} bytes.", 295 CFI_AUG_MAX_SIZE)); 296 return nullptr; 297 } 298 299 // m_cfi_data uses address size from target architecture of the process may 300 // ignore these fields? 301 if (m_type == DWARF && cie_sp->version >= CFI_VERSION4) { 302 cie_sp->address_size = m_cfi_data.GetU8(&offset); 303 cie_sp->segment_size = m_cfi_data.GetU8(&offset); 304 } 305 306 cie_sp->code_align = (uint32_t)m_cfi_data.GetULEB128(&offset); 307 cie_sp->data_align = (int32_t)m_cfi_data.GetSLEB128(&offset); 308 309 cie_sp->return_addr_reg_num = 310 m_type == DWARF && cie_sp->version >= CFI_VERSION3 311 ? static_cast<uint32_t>(m_cfi_data.GetULEB128(&offset)) 312 : m_cfi_data.GetU8(&offset); 313 314 if (cie_sp->augmentation[0]) { 315 // Get the length of the eh_frame augmentation data which starts with a 316 // ULEB128 length in bytes 317 const size_t aug_data_len = (size_t)m_cfi_data.GetULEB128(&offset); 318 const size_t aug_data_end = offset + aug_data_len; 319 const size_t aug_str_len = strlen(cie_sp->augmentation); 320 // A 'z' may be present as the first character of the string. 321 // If present, the Augmentation Data field shall be present. The contents 322 // of the Augmentation Data shall be interpreted according to other 323 // characters in the Augmentation String. 324 if (cie_sp->augmentation[0] == 'z') { 325 // Extract the Augmentation Data 326 size_t aug_str_idx = 0; 327 for (aug_str_idx = 1; aug_str_idx < aug_str_len; aug_str_idx++) { 328 char aug = cie_sp->augmentation[aug_str_idx]; 329 switch (aug) { 330 case 'L': 331 // Indicates the presence of one argument in the Augmentation Data 332 // of the CIE, and a corresponding argument in the Augmentation 333 // Data of the FDE. The argument in the Augmentation Data of the 334 // CIE is 1-byte and represents the pointer encoding used for the 335 // argument in the Augmentation Data of the FDE, which is the 336 // address of a language-specific data area (LSDA). The size of the 337 // LSDA pointer is specified by the pointer encoding used. 338 cie_sp->lsda_addr_encoding = m_cfi_data.GetU8(&offset); 339 break; 340 341 case 'P': 342 // Indicates the presence of two arguments in the Augmentation Data 343 // of the CIE. The first argument is 1-byte and represents the 344 // pointer encoding used for the second argument, which is the 345 // address of a personality routine handler. The size of the 346 // personality routine pointer is specified by the pointer encoding 347 // used. 348 // 349 // The address of the personality function will be stored at this 350 // location. Pre-execution, it will be all zero's so don't read it 351 // until we're trying to do an unwind & the reloc has been 352 // resolved. 353 { 354 uint8_t arg_ptr_encoding = m_cfi_data.GetU8(&offset); 355 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 356 cie_sp->personality_loc = GetGNUEHPointer( 357 m_cfi_data, &offset, arg_ptr_encoding, pc_rel_addr, 358 LLDB_INVALID_ADDRESS, LLDB_INVALID_ADDRESS); 359 } 360 break; 361 362 case 'R': 363 // A 'R' may be present at any position after the 364 // first character of the string. The Augmentation Data shall 365 // include a 1 byte argument that represents the pointer encoding 366 // for the address pointers used in the FDE. Example: 0x1B == 367 // DW_EH_PE_pcrel | DW_EH_PE_sdata4 368 cie_sp->ptr_encoding = m_cfi_data.GetU8(&offset); 369 break; 370 } 371 } 372 } else if (strcmp(cie_sp->augmentation, "eh") == 0) { 373 // If the Augmentation string has the value "eh", then the EH Data 374 // field shall be present 375 } 376 377 // Set the offset to be the end of the augmentation data just in case we 378 // didn't understand any of the data. 379 offset = (uint32_t)aug_data_end; 380 } 381 382 if (end_offset > offset) { 383 cie_sp->inst_offset = offset; 384 cie_sp->inst_length = end_offset - offset; 385 } 386 while (offset < end_offset) { 387 uint8_t inst = m_cfi_data.GetU8(&offset); 388 uint8_t primary_opcode = inst & 0xC0; 389 uint8_t extended_opcode = inst & 0x3F; 390 391 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, 392 cie_sp->data_align, offset, 393 cie_sp->initial_row)) 394 break; // Stop if we hit an unrecognized opcode 395 } 396 } 397 398 return cie_sp; 399} 400 401void DWARFCallFrameInfo::GetCFIData() { 402 if (!m_cfi_data_initialized) { 403 Log *log = GetLog(LLDBLog::Unwind); 404 if (log) 405 m_objfile.GetModule()->LogMessage(log, "Reading EH frame info"); 406 m_objfile.ReadSectionData(m_section_sp.get(), m_cfi_data); 407 m_cfi_data_initialized = true; 408 } 409} 410// Scan through the eh_frame or debug_frame section looking for FDEs and noting 411// the start/end addresses of the functions and a pointer back to the 412// function's FDE for later expansion. Internalize CIEs as we come across them. 413 414void DWARFCallFrameInfo::GetFDEIndex() { 415 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 416 return; 417 418 if (m_fde_index_initialized) 419 return; 420 421 std::lock_guard<std::mutex> guard(m_fde_index_mutex); 422 423 if (m_fde_index_initialized) // if two threads hit the locker 424 return; 425 426 LLDB_SCOPED_TIMERF("%s - %s", LLVM_PRETTY_FUNCTION, 427 m_objfile.GetFileSpec().GetFilename().AsCString("")); 428 429 bool clear_address_zeroth_bit = false; 430 if (ArchSpec arch = m_objfile.GetArchitecture()) { 431 if (arch.GetTriple().getArch() == llvm::Triple::arm || 432 arch.GetTriple().getArch() == llvm::Triple::thumb) 433 clear_address_zeroth_bit = true; 434 } 435 436 lldb::offset_t offset = 0; 437 if (!m_cfi_data_initialized) 438 GetCFIData(); 439 while (m_cfi_data.ValidOffsetForDataOfSize(offset, 8)) { 440 const dw_offset_t current_entry = offset; 441 dw_offset_t cie_id, next_entry, cie_offset; 442 uint32_t len = m_cfi_data.GetU32(&offset); 443 bool is_64bit = (len == UINT32_MAX); 444 if (is_64bit) { 445 len = m_cfi_data.GetU64(&offset); 446 cie_id = m_cfi_data.GetU64(&offset); 447 next_entry = current_entry + len + 12; 448 cie_offset = current_entry + 12 - cie_id; 449 } else { 450 cie_id = m_cfi_data.GetU32(&offset); 451 next_entry = current_entry + len + 4; 452 cie_offset = current_entry + 4 - cie_id; 453 } 454 455 if (next_entry > m_cfi_data.GetByteSize() + 1) { 456 Debugger::ReportError(llvm::formatv("Invalid fde/cie next entry offset " 457 "of {0:x} found in cie/fde at {1:x}", 458 next_entry, current_entry)); 459 // Don't trust anything in this eh_frame section if we find blatantly 460 // invalid data. 461 m_fde_index.Clear(); 462 m_fde_index_initialized = true; 463 return; 464 } 465 466 // An FDE entry contains CIE_pointer in debug_frame in same place as cie_id 467 // in eh_frame. CIE_pointer is an offset into the .debug_frame section. So, 468 // variable cie_offset should be equal to cie_id for debug_frame. 469 // FDE entries with cie_id == 0 shouldn't be ignored for it. 470 if ((cie_id == 0 && m_type == EH) || cie_id == UINT32_MAX || len == 0) { 471 auto cie_sp = ParseCIE(current_entry); 472 if (!cie_sp) { 473 // Cannot parse, the reason is already logged 474 m_fde_index.Clear(); 475 m_fde_index_initialized = true; 476 return; 477 } 478 479 m_cie_map[current_entry] = std::move(cie_sp); 480 offset = next_entry; 481 continue; 482 } 483 484 if (m_type == DWARF) 485 cie_offset = cie_id; 486 487 if (cie_offset > m_cfi_data.GetByteSize()) { 488 Debugger::ReportError(llvm::formatv("Invalid cie offset of {0:x} " 489 "found in cie/fde at {1:x}", 490 cie_offset, current_entry)); 491 // Don't trust anything in this eh_frame section if we find blatantly 492 // invalid data. 493 m_fde_index.Clear(); 494 m_fde_index_initialized = true; 495 return; 496 } 497 498 const CIE *cie = GetCIE(cie_offset); 499 if (cie) { 500 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 501 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 502 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 503 504 lldb::addr_t addr = 505 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 506 text_addr, data_addr); 507 if (clear_address_zeroth_bit) 508 addr &= ~1ull; 509 510 lldb::addr_t length = GetGNUEHPointer( 511 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 512 pc_rel_addr, text_addr, data_addr); 513 FDEEntryMap::Entry fde(addr, length, current_entry); 514 m_fde_index.Append(fde); 515 } else { 516 Debugger::ReportError(llvm::formatv( 517 "unable to find CIE at {0:x} for cie_id = {1:x} for entry at {2:x}.", 518 cie_offset, cie_id, current_entry)); 519 } 520 offset = next_entry; 521 } 522 m_fde_index.Sort(); 523 m_fde_index_initialized = true; 524} 525 526bool DWARFCallFrameInfo::FDEToUnwindPlan(dw_offset_t dwarf_offset, 527 Address startaddr, 528 UnwindPlan &unwind_plan) { 529 Log *log = GetLog(LLDBLog::Unwind); 530 lldb::offset_t offset = dwarf_offset; 531 lldb::offset_t current_entry = offset; 532 533 if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) 534 return false; 535 536 if (!m_cfi_data_initialized) 537 GetCFIData(); 538 539 uint32_t length = m_cfi_data.GetU32(&offset); 540 dw_offset_t cie_offset; 541 bool is_64bit = (length == UINT32_MAX); 542 if (is_64bit) { 543 length = m_cfi_data.GetU64(&offset); 544 cie_offset = m_cfi_data.GetU64(&offset); 545 } else { 546 cie_offset = m_cfi_data.GetU32(&offset); 547 } 548 549 // FDE entries with zeroth cie_offset may occur for debug_frame. 550 assert(!(m_type == EH && 0 == cie_offset) && cie_offset != UINT32_MAX); 551 552 // Translate the CIE_id from the eh_frame format, which is relative to the 553 // FDE offset, into a __eh_frame section offset 554 if (m_type == EH) { 555 unwind_plan.SetSourceName("eh_frame CFI"); 556 cie_offset = current_entry + (is_64bit ? 12 : 4) - cie_offset; 557 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 558 } else { 559 unwind_plan.SetSourceName("DWARF CFI"); 560 // In theory the debug_frame info should be valid at all call sites 561 // ("asynchronous unwind info" as it is sometimes called) but in practice 562 // gcc et al all emit call frame info for the prologue and call sites, but 563 // not for the epilogue or all the other locations during the function 564 // reliably. 565 unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); 566 } 567 unwind_plan.SetSourcedFromCompiler(eLazyBoolYes); 568 569 const CIE *cie = GetCIE(cie_offset); 570 assert(cie != nullptr); 571 572 const dw_offset_t end_offset = current_entry + length + (is_64bit ? 12 : 4); 573 574 const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); 575 const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; 576 const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; 577 lldb::addr_t range_base = 578 GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, 579 text_addr, data_addr); 580 lldb::addr_t range_len = GetGNUEHPointer( 581 m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, 582 pc_rel_addr, text_addr, data_addr); 583 AddressRange range(range_base, m_objfile.GetAddressByteSize(), 584 m_objfile.GetSectionList()); 585 range.SetByteSize(range_len); 586 587 addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS; 588 589 if (cie->augmentation[0] == 'z') { 590 uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 591 if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) { 592 offset_t saved_offset = offset; 593 lsda_data_file_address = 594 GetGNUEHPointer(m_cfi_data, &offset, cie->lsda_addr_encoding, 595 pc_rel_addr, text_addr, data_addr); 596 if (offset - saved_offset != aug_data_len) { 597 // There is more in the augmentation region than we know how to process; 598 // don't read anything. 599 lsda_data_file_address = LLDB_INVALID_ADDRESS; 600 } 601 offset = saved_offset; 602 } 603 offset += aug_data_len; 604 } 605 unwind_plan.SetUnwindPlanForSignalTrap( 606 strchr(cie->augmentation, 'S') ? eLazyBoolYes : eLazyBoolNo); 607 608 Address lsda_data; 609 Address personality_function_ptr; 610 611 if (lsda_data_file_address != LLDB_INVALID_ADDRESS && 612 cie->personality_loc != LLDB_INVALID_ADDRESS) { 613 m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address, 614 lsda_data); 615 m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc, 616 personality_function_ptr); 617 } 618 619 if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { 620 unwind_plan.SetLSDAAddress(lsda_data); 621 unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr); 622 } 623 624 uint32_t code_align = cie->code_align; 625 int32_t data_align = cie->data_align; 626 627 unwind_plan.SetPlanValidAddressRange(range); 628 UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; 629 *cie_initial_row = cie->initial_row; 630 UnwindPlan::RowSP row(cie_initial_row); 631 632 unwind_plan.SetRegisterKind(GetRegisterKind()); 633 unwind_plan.SetReturnAddressRegister(cie->return_addr_reg_num); 634 635 std::vector<UnwindPlan::RowSP> stack; 636 637 UnwindPlan::Row::RegisterLocation reg_location; 638 while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { 639 uint8_t inst = m_cfi_data.GetU8(&offset); 640 uint8_t primary_opcode = inst & 0xC0; 641 uint8_t extended_opcode = inst & 0x3F; 642 643 if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, 644 offset, *row)) { 645 if (primary_opcode) { 646 switch (primary_opcode) { 647 case DW_CFA_advance_loc: // (Row Creation Instruction) 648 { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta 649 // takes a single argument that represents a constant delta. The 650 // required action is to create a new table row with a location value 651 // that is computed by taking the current entry's location value and 652 // adding (delta * code_align). All other values in the new row are 653 // initially identical to the current row. 654 unwind_plan.AppendRow(row); 655 UnwindPlan::Row *newrow = new UnwindPlan::Row; 656 *newrow = *row.get(); 657 row.reset(newrow); 658 row->SlideOffset(extended_opcode * code_align); 659 break; 660 } 661 662 case DW_CFA_restore: { // 0xC0 - high 2 bits are 0x3, lower 6 bits are 663 // register 664 // takes a single argument that represents a register number. The 665 // required action is to change the rule for the indicated register 666 // to the rule assigned it by the initial_instructions in the CIE. 667 uint32_t reg_num = extended_opcode; 668 // We only keep enough register locations around to unwind what is in 669 // our thread, and these are organized by the register index in that 670 // state, so we need to convert our eh_frame register number from the 671 // EH frame info, to a register index 672 673 if (unwind_plan.IsValidRowIndex(0) && 674 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 675 reg_location)) 676 row->SetRegisterInfo(reg_num, reg_location); 677 else { 678 // If the register was not set in the first row, remove the 679 // register info to keep the unmodified value from the caller. 680 row->RemoveRegisterInfo(reg_num); 681 } 682 break; 683 } 684 } 685 } else { 686 switch (extended_opcode) { 687 case DW_CFA_set_loc: // 0x1 (Row Creation Instruction) 688 { 689 // DW_CFA_set_loc takes a single argument that represents an address. 690 // The required action is to create a new table row using the 691 // specified address as the location. All other values in the new row 692 // are initially identical to the current row. The new location value 693 // should always be greater than the current one. 694 unwind_plan.AppendRow(row); 695 UnwindPlan::Row *newrow = new UnwindPlan::Row; 696 *newrow = *row.get(); 697 row.reset(newrow); 698 row->SetOffset(m_cfi_data.GetAddress(&offset) - 699 startaddr.GetFileAddress()); 700 break; 701 } 702 703 case DW_CFA_advance_loc1: // 0x2 (Row Creation Instruction) 704 { 705 // takes a single uword argument that represents a constant delta. 706 // This instruction is identical to DW_CFA_advance_loc except for the 707 // encoding and size of the delta argument. 708 unwind_plan.AppendRow(row); 709 UnwindPlan::Row *newrow = new UnwindPlan::Row; 710 *newrow = *row.get(); 711 row.reset(newrow); 712 row->SlideOffset(m_cfi_data.GetU8(&offset) * code_align); 713 break; 714 } 715 716 case DW_CFA_advance_loc2: // 0x3 (Row Creation Instruction) 717 { 718 // takes a single uword argument that represents a constant delta. 719 // This instruction is identical to DW_CFA_advance_loc except for the 720 // encoding and size of the delta argument. 721 unwind_plan.AppendRow(row); 722 UnwindPlan::Row *newrow = new UnwindPlan::Row; 723 *newrow = *row.get(); 724 row.reset(newrow); 725 row->SlideOffset(m_cfi_data.GetU16(&offset) * code_align); 726 break; 727 } 728 729 case DW_CFA_advance_loc4: // 0x4 (Row Creation Instruction) 730 { 731 // takes a single uword argument that represents a constant delta. 732 // This instruction is identical to DW_CFA_advance_loc except for the 733 // encoding and size of the delta argument. 734 unwind_plan.AppendRow(row); 735 UnwindPlan::Row *newrow = new UnwindPlan::Row; 736 *newrow = *row.get(); 737 row.reset(newrow); 738 row->SlideOffset(m_cfi_data.GetU32(&offset) * code_align); 739 break; 740 } 741 742 case DW_CFA_restore_extended: // 0x6 743 { 744 // takes a single unsigned LEB128 argument that represents a register 745 // number. This instruction is identical to DW_CFA_restore except for 746 // the encoding and size of the register argument. 747 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 748 if (unwind_plan.IsValidRowIndex(0) && 749 unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, 750 reg_location)) 751 row->SetRegisterInfo(reg_num, reg_location); 752 break; 753 } 754 755 case DW_CFA_remember_state: // 0xA 756 { 757 // These instructions define a stack of information. Encountering the 758 // DW_CFA_remember_state instruction means to save the rules for 759 // every register on the current row on the stack. Encountering the 760 // DW_CFA_restore_state instruction means to pop the set of rules off 761 // the stack and place them in the current row. (This operation is 762 // useful for compilers that move epilogue code into the body of a 763 // function.) 764 stack.push_back(row); 765 UnwindPlan::Row *newrow = new UnwindPlan::Row; 766 *newrow = *row.get(); 767 row.reset(newrow); 768 break; 769 } 770 771 case DW_CFA_restore_state: // 0xB 772 { 773 // These instructions define a stack of information. Encountering the 774 // DW_CFA_remember_state instruction means to save the rules for 775 // every register on the current row on the stack. Encountering the 776 // DW_CFA_restore_state instruction means to pop the set of rules off 777 // the stack and place them in the current row. (This operation is 778 // useful for compilers that move epilogue code into the body of a 779 // function.) 780 if (stack.empty()) { 781 LLDB_LOG(log, 782 "DWARFCallFrameInfo::{0}(dwarf_offset: " 783 "{1:x16}, startaddr: [{2:x16}] encountered " 784 "DW_CFA_restore_state but state stack " 785 "is empty. Corrupt unwind info?", 786 __FUNCTION__, dwarf_offset, startaddr.GetFileAddress()); 787 break; 788 } 789 lldb::addr_t offset = row->GetOffset(); 790 row = stack.back(); 791 stack.pop_back(); 792 row->SetOffset(offset); 793 break; 794 } 795 796 case DW_CFA_GNU_args_size: // 0x2e 797 { 798 // The DW_CFA_GNU_args_size instruction takes an unsigned LEB128 799 // operand representing an argument size. This instruction specifies 800 // the total of the size of the arguments which have been pushed onto 801 // the stack. 802 803 // TODO: Figure out how we should handle this. 804 m_cfi_data.GetULEB128(&offset); 805 break; 806 } 807 808 case DW_CFA_val_offset: // 0x14 809 case DW_CFA_val_offset_sf: // 0x15 810 default: 811 break; 812 } 813 } 814 } 815 } 816 unwind_plan.AppendRow(row); 817 818 return true; 819} 820 821bool DWARFCallFrameInfo::HandleCommonDwarfOpcode(uint8_t primary_opcode, 822 uint8_t extended_opcode, 823 int32_t data_align, 824 lldb::offset_t &offset, 825 UnwindPlan::Row &row) { 826 UnwindPlan::Row::RegisterLocation reg_location; 827 828 if (primary_opcode) { 829 switch (primary_opcode) { 830 case DW_CFA_offset: { // 0x80 - high 2 bits are 0x2, lower 6 bits are 831 // register 832 // takes two arguments: an unsigned LEB128 constant representing a 833 // factored offset and a register number. The required action is to 834 // change the rule for the register indicated by the register number to 835 // be an offset(N) rule with a value of (N = factored offset * 836 // data_align). 837 uint8_t reg_num = extended_opcode; 838 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 839 reg_location.SetAtCFAPlusOffset(op_offset); 840 row.SetRegisterInfo(reg_num, reg_location); 841 return true; 842 } 843 } 844 } else { 845 switch (extended_opcode) { 846 case DW_CFA_nop: // 0x0 847 return true; 848 849 case DW_CFA_offset_extended: // 0x5 850 { 851 // takes two unsigned LEB128 arguments representing a register number and 852 // a factored offset. This instruction is identical to DW_CFA_offset 853 // except for the encoding and size of the register argument. 854 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 855 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; 856 UnwindPlan::Row::RegisterLocation reg_location; 857 reg_location.SetAtCFAPlusOffset(op_offset); 858 row.SetRegisterInfo(reg_num, reg_location); 859 return true; 860 } 861 862 case DW_CFA_undefined: // 0x7 863 { 864 // takes a single unsigned LEB128 argument that represents a register 865 // number. The required action is to set the rule for the specified 866 // register to undefined. 867 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 868 UnwindPlan::Row::RegisterLocation reg_location; 869 reg_location.SetUndefined(); 870 row.SetRegisterInfo(reg_num, reg_location); 871 return true; 872 } 873 874 case DW_CFA_same_value: // 0x8 875 { 876 // takes a single unsigned LEB128 argument that represents a register 877 // number. The required action is to set the rule for the specified 878 // register to same value. 879 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 880 UnwindPlan::Row::RegisterLocation reg_location; 881 reg_location.SetSame(); 882 row.SetRegisterInfo(reg_num, reg_location); 883 return true; 884 } 885 886 case DW_CFA_register: // 0x9 887 { 888 // takes two unsigned LEB128 arguments representing register numbers. The 889 // required action is to set the rule for the first register to be the 890 // second register. 891 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 892 uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 893 UnwindPlan::Row::RegisterLocation reg_location; 894 reg_location.SetInRegister(other_reg_num); 895 row.SetRegisterInfo(reg_num, reg_location); 896 return true; 897 } 898 899 case DW_CFA_def_cfa: // 0xC (CFA Definition Instruction) 900 { 901 // Takes two unsigned LEB128 operands representing a register number and 902 // a (non-factored) offset. The required action is to define the current 903 // CFA rule to use the provided register and offset. 904 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 905 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 906 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 907 return true; 908 } 909 910 case DW_CFA_def_cfa_register: // 0xD (CFA Definition Instruction) 911 { 912 // takes a single unsigned LEB128 argument representing a register 913 // number. The required action is to define the current CFA rule to use 914 // the provided register (but to keep the old offset). 915 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 916 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, 917 row.GetCFAValue().GetOffset()); 918 return true; 919 } 920 921 case DW_CFA_def_cfa_offset: // 0xE (CFA Definition Instruction) 922 { 923 // Takes a single unsigned LEB128 operand representing a (non-factored) 924 // offset. The required action is to define the current CFA rule to use 925 // the provided offset (but to keep the old register). 926 int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); 927 row.GetCFAValue().SetIsRegisterPlusOffset( 928 row.GetCFAValue().GetRegisterNumber(), op_offset); 929 return true; 930 } 931 932 case DW_CFA_def_cfa_expression: // 0xF (CFA Definition Instruction) 933 { 934 size_t block_len = (size_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 row.GetCFAValue().SetIsDWARFExpression(block_data, block_len); 938 return true; 939 } 940 941 case DW_CFA_expression: // 0x10 942 { 943 // Takes two operands: an unsigned LEB128 value representing a register 944 // number, and a DW_FORM_block value representing a DWARF expression. The 945 // required action is to change the rule for the register indicated by 946 // the register number to be an expression(E) rule where E is the DWARF 947 // expression. That is, the DWARF expression computes the address. The 948 // value of the CFA is pushed on the DWARF evaluation stack prior to 949 // execution of the DWARF expression. 950 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 951 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 952 const uint8_t *block_data = 953 static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); 954 UnwindPlan::Row::RegisterLocation reg_location; 955 reg_location.SetAtDWARFExpression(block_data, block_len); 956 row.SetRegisterInfo(reg_num, reg_location); 957 return true; 958 } 959 960 case DW_CFA_offset_extended_sf: // 0x11 961 { 962 // takes two operands: an unsigned LEB128 value representing a register 963 // number and a signed LEB128 factored offset. This instruction is 964 // identical to DW_CFA_offset_extended except that the second operand is 965 // signed and factored. 966 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 967 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 968 UnwindPlan::Row::RegisterLocation reg_location; 969 reg_location.SetAtCFAPlusOffset(op_offset); 970 row.SetRegisterInfo(reg_num, reg_location); 971 return true; 972 } 973 974 case DW_CFA_def_cfa_sf: // 0x12 (CFA Definition Instruction) 975 { 976 // Takes two operands: an unsigned LEB128 value representing a register 977 // number and a signed LEB128 factored offset. This instruction is 978 // identical to DW_CFA_def_cfa except that the second operand is signed 979 // and factored. 980 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 981 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 982 row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); 983 return true; 984 } 985 986 case DW_CFA_def_cfa_offset_sf: // 0x13 (CFA Definition Instruction) 987 { 988 // takes a signed LEB128 operand representing a factored offset. This 989 // instruction is identical to DW_CFA_def_cfa_offset except that the 990 // operand is signed and factored. 991 int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; 992 uint32_t cfa_regnum = row.GetCFAValue().GetRegisterNumber(); 993 row.GetCFAValue().SetIsRegisterPlusOffset(cfa_regnum, op_offset); 994 return true; 995 } 996 997 case DW_CFA_val_expression: // 0x16 998 { 999 // takes two operands: an unsigned LEB128 value representing a register 1000 // number, and a DW_FORM_block value representing a DWARF expression. The 1001 // required action is to change the rule for the register indicated by 1002 // the register number to be a val_expression(E) rule where E is the 1003 // DWARF expression. That is, the DWARF expression computes the value of 1004 // the given register. The value of the CFA is pushed on the DWARF 1005 // evaluation stack prior to execution of the DWARF expression. 1006 uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); 1007 uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); 1008 const uint8_t *block_data = 1009 (const uint8_t *)m_cfi_data.GetData(&offset, block_len); 1010 reg_location.SetIsDWARFExpression(block_data, block_len); 1011 row.SetRegisterInfo(reg_num, reg_location); 1012 return true; 1013 } 1014 } 1015 } 1016 return false; 1017} 1018 1019void DWARFCallFrameInfo::ForEachFDEEntries( 1020 const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback) { 1021 GetFDEIndex(); 1022 1023 for (size_t i = 0, c = m_fde_index.GetSize(); i < c; ++i) { 1024 const FDEEntryMap::Entry &entry = m_fde_index.GetEntryRef(i); 1025 if (!callback(entry.base, entry.size, entry.data)) 1026 break; 1027 } 1028} 1029