| //===-- DWARFCallFrameInfo.cpp ----------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "lldb/Symbol/DWARFCallFrameInfo.h" |
| #include "lldb/Core/Module.h" |
| #include "lldb/Core/Section.h" |
| #include "lldb/Core/dwarf.h" |
| #include "lldb/Host/Host.h" |
| #include "lldb/Symbol/ObjectFile.h" |
| #include "lldb/Symbol/UnwindPlan.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Thread.h" |
| #include "lldb/Utility/ArchSpec.h" |
| #include "lldb/Utility/Log.h" |
| #include "lldb/Utility/Timer.h" |
| #include <list> |
| |
| using namespace lldb; |
| using namespace lldb_private; |
| |
| //---------------------------------------------------------------------- |
| // GetDwarfEHPtr |
| // |
| // Used for calls when the value type is specified by a DWARF EH Frame pointer |
| // encoding. |
| //---------------------------------------------------------------------- |
| static uint64_t |
| GetGNUEHPointer(const DataExtractor &DE, offset_t *offset_ptr, |
| uint32_t eh_ptr_enc, addr_t pc_rel_addr, addr_t text_addr, |
| addr_t data_addr) //, BSDRelocs *data_relocs) const |
| { |
| if (eh_ptr_enc == DW_EH_PE_omit) |
| return ULLONG_MAX; // Value isn't in the buffer... |
| |
| uint64_t baseAddress = 0; |
| uint64_t addressValue = 0; |
| const uint32_t addr_size = DE.GetAddressByteSize(); |
| #ifdef LLDB_CONFIGURATION_DEBUG |
| assert(addr_size == 4 || addr_size == 8); |
| #endif |
| |
| bool signExtendValue = false; |
| // Decode the base part or adjust our offset |
| switch (eh_ptr_enc & 0x70) { |
| case DW_EH_PE_pcrel: |
| signExtendValue = true; |
| baseAddress = *offset_ptr; |
| if (pc_rel_addr != LLDB_INVALID_ADDRESS) |
| baseAddress += pc_rel_addr; |
| // else |
| // Log::GlobalWarning ("PC relative pointer encoding found with |
| // invalid pc relative address."); |
| break; |
| |
| case DW_EH_PE_textrel: |
| signExtendValue = true; |
| if (text_addr != LLDB_INVALID_ADDRESS) |
| baseAddress = text_addr; |
| // else |
| // Log::GlobalWarning ("text relative pointer encoding being |
| // decoded with invalid text section address, setting base address |
| // to zero."); |
| break; |
| |
| case DW_EH_PE_datarel: |
| signExtendValue = true; |
| if (data_addr != LLDB_INVALID_ADDRESS) |
| baseAddress = data_addr; |
| // else |
| // Log::GlobalWarning ("data relative pointer encoding being |
| // decoded with invalid data section address, setting base address |
| // to zero."); |
| break; |
| |
| case DW_EH_PE_funcrel: |
| signExtendValue = true; |
| break; |
| |
| case DW_EH_PE_aligned: { |
| // SetPointerSize should be called prior to extracting these so the pointer |
| // size is cached |
| assert(addr_size != 0); |
| if (addr_size) { |
| // Align to a address size boundary first |
| uint32_t alignOffset = *offset_ptr % addr_size; |
| if (alignOffset) |
| offset_ptr += addr_size - alignOffset; |
| } |
| } break; |
| |
| default: |
| break; |
| } |
| |
| // Decode the value part |
| switch (eh_ptr_enc & DW_EH_PE_MASK_ENCODING) { |
| case DW_EH_PE_absptr: { |
| addressValue = DE.GetAddress(offset_ptr); |
| // if (data_relocs) |
| // addressValue = data_relocs->Relocate(*offset_ptr - |
| // addr_size, *this, addressValue); |
| } break; |
| case DW_EH_PE_uleb128: |
| addressValue = DE.GetULEB128(offset_ptr); |
| break; |
| case DW_EH_PE_udata2: |
| addressValue = DE.GetU16(offset_ptr); |
| break; |
| case DW_EH_PE_udata4: |
| addressValue = DE.GetU32(offset_ptr); |
| break; |
| case DW_EH_PE_udata8: |
| addressValue = DE.GetU64(offset_ptr); |
| break; |
| case DW_EH_PE_sleb128: |
| addressValue = DE.GetSLEB128(offset_ptr); |
| break; |
| case DW_EH_PE_sdata2: |
| addressValue = (int16_t)DE.GetU16(offset_ptr); |
| break; |
| case DW_EH_PE_sdata4: |
| addressValue = (int32_t)DE.GetU32(offset_ptr); |
| break; |
| case DW_EH_PE_sdata8: |
| addressValue = (int64_t)DE.GetU64(offset_ptr); |
| break; |
| default: |
| // Unhandled encoding type |
| assert(eh_ptr_enc); |
| break; |
| } |
| |
| // Since we promote everything to 64 bit, we may need to sign extend |
| if (signExtendValue && addr_size < sizeof(baseAddress)) { |
| uint64_t sign_bit = 1ull << ((addr_size * 8ull) - 1ull); |
| if (sign_bit & addressValue) { |
| uint64_t mask = ~sign_bit + 1; |
| addressValue |= mask; |
| } |
| } |
| return baseAddress + addressValue; |
| } |
| |
| DWARFCallFrameInfo::DWARFCallFrameInfo(ObjectFile &objfile, |
| SectionSP §ion_sp, Type type) |
| : m_objfile(objfile), m_section_sp(section_sp), m_type(type) {} |
| |
| bool DWARFCallFrameInfo::GetUnwindPlan(Address addr, UnwindPlan &unwind_plan) { |
| FDEEntryMap::Entry fde_entry; |
| |
| // Make sure that the Address we're searching for is the same object file as |
| // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. |
| ModuleSP module_sp = addr.GetModule(); |
| if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || |
| module_sp->GetObjectFile() != &m_objfile) |
| return false; |
| |
| if (GetFDEEntryByFileAddress(addr.GetFileAddress(), fde_entry) == false) |
| return false; |
| return FDEToUnwindPlan(fde_entry.data, addr, unwind_plan); |
| } |
| |
| bool DWARFCallFrameInfo::GetAddressRange(Address addr, AddressRange &range) { |
| |
| // Make sure that the Address we're searching for is the same object file as |
| // this DWARFCallFrameInfo, we only store File offsets in m_fde_index. |
| ModuleSP module_sp = addr.GetModule(); |
| if (module_sp.get() == nullptr || module_sp->GetObjectFile() == nullptr || |
| module_sp->GetObjectFile() != &m_objfile) |
| return false; |
| |
| if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) |
| return false; |
| GetFDEIndex(); |
| FDEEntryMap::Entry *fde_entry = |
| m_fde_index.FindEntryThatContains(addr.GetFileAddress()); |
| if (!fde_entry) |
| return false; |
| |
| range = AddressRange(fde_entry->base, fde_entry->size, |
| m_objfile.GetSectionList()); |
| return true; |
| } |
| |
| bool DWARFCallFrameInfo::GetFDEEntryByFileAddress( |
| addr_t file_addr, FDEEntryMap::Entry &fde_entry) { |
| if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) |
| return false; |
| |
| GetFDEIndex(); |
| |
| if (m_fde_index.IsEmpty()) |
| return false; |
| |
| FDEEntryMap::Entry *fde = m_fde_index.FindEntryThatContains(file_addr); |
| |
| if (fde == nullptr) |
| return false; |
| |
| fde_entry = *fde; |
| return true; |
| } |
| |
| void DWARFCallFrameInfo::GetFunctionAddressAndSizeVector( |
| FunctionAddressAndSizeVector &function_info) { |
| GetFDEIndex(); |
| const size_t count = m_fde_index.GetSize(); |
| function_info.Clear(); |
| if (count > 0) |
| function_info.Reserve(count); |
| for (size_t i = 0; i < count; ++i) { |
| const FDEEntryMap::Entry *func_offset_data_entry = |
| m_fde_index.GetEntryAtIndex(i); |
| if (func_offset_data_entry) { |
| FunctionAddressAndSizeVector::Entry function_offset_entry( |
| func_offset_data_entry->base, func_offset_data_entry->size); |
| function_info.Append(function_offset_entry); |
| } |
| } |
| } |
| |
| const DWARFCallFrameInfo::CIE * |
| DWARFCallFrameInfo::GetCIE(dw_offset_t cie_offset) { |
| cie_map_t::iterator pos = m_cie_map.find(cie_offset); |
| |
| if (pos != m_cie_map.end()) { |
| // Parse and cache the CIE |
| if (pos->second.get() == nullptr) |
| pos->second = ParseCIE(cie_offset); |
| |
| return pos->second.get(); |
| } |
| return nullptr; |
| } |
| |
| DWARFCallFrameInfo::CIESP |
| DWARFCallFrameInfo::ParseCIE(const dw_offset_t cie_offset) { |
| CIESP cie_sp(new CIE(cie_offset)); |
| lldb::offset_t offset = cie_offset; |
| if (m_cfi_data_initialized == false) |
| GetCFIData(); |
| uint32_t length = m_cfi_data.GetU32(&offset); |
| dw_offset_t cie_id, end_offset; |
| bool is_64bit = (length == UINT32_MAX); |
| if (is_64bit) { |
| length = m_cfi_data.GetU64(&offset); |
| cie_id = m_cfi_data.GetU64(&offset); |
| end_offset = cie_offset + length + 12; |
| } else { |
| cie_id = m_cfi_data.GetU32(&offset); |
| end_offset = cie_offset + length + 4; |
| } |
| if (length > 0 && ((m_type == DWARF && cie_id == UINT32_MAX) || |
| (m_type == EH && cie_id == 0ul))) { |
| size_t i; |
| // cie.offset = cie_offset; |
| // cie.length = length; |
| // cie.cieID = cieID; |
| cie_sp->ptr_encoding = DW_EH_PE_absptr; // default |
| cie_sp->version = m_cfi_data.GetU8(&offset); |
| if (cie_sp->version > CFI_VERSION4) { |
| Host::SystemLog(Host::eSystemLogError, |
| "CIE parse error: CFI version %d is not supported\n", |
| cie_sp->version); |
| return nullptr; |
| } |
| |
| for (i = 0; i < CFI_AUG_MAX_SIZE; ++i) { |
| cie_sp->augmentation[i] = m_cfi_data.GetU8(&offset); |
| if (cie_sp->augmentation[i] == '\0') { |
| // Zero out remaining bytes in augmentation string |
| for (size_t j = i + 1; j < CFI_AUG_MAX_SIZE; ++j) |
| cie_sp->augmentation[j] = '\0'; |
| |
| break; |
| } |
| } |
| |
| if (i == CFI_AUG_MAX_SIZE && |
| cie_sp->augmentation[CFI_AUG_MAX_SIZE - 1] != '\0') { |
| Host::SystemLog(Host::eSystemLogError, |
| "CIE parse error: CIE augmentation string was too large " |
| "for the fixed sized buffer of %d bytes.\n", |
| CFI_AUG_MAX_SIZE); |
| return nullptr; |
| } |
| |
| // m_cfi_data uses address size from target architecture of the process may |
| // ignore these fields? |
| if (m_type == DWARF && cie_sp->version >= CFI_VERSION4) { |
| cie_sp->address_size = m_cfi_data.GetU8(&offset); |
| cie_sp->segment_size = m_cfi_data.GetU8(&offset); |
| } |
| |
| cie_sp->code_align = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| cie_sp->data_align = (int32_t)m_cfi_data.GetSLEB128(&offset); |
| |
| cie_sp->return_addr_reg_num = |
| m_type == DWARF && cie_sp->version >= CFI_VERSION3 |
| ? static_cast<uint32_t>(m_cfi_data.GetULEB128(&offset)) |
| : m_cfi_data.GetU8(&offset); |
| |
| if (cie_sp->augmentation[0]) { |
| // Get the length of the eh_frame augmentation data which starts with a |
| // ULEB128 length in bytes |
| const size_t aug_data_len = (size_t)m_cfi_data.GetULEB128(&offset); |
| const size_t aug_data_end = offset + aug_data_len; |
| const size_t aug_str_len = strlen(cie_sp->augmentation); |
| // A 'z' may be present as the first character of the string. |
| // If present, the Augmentation Data field shall be present. The contents |
| // of the Augmentation Data shall be interpreted according to other |
| // characters in the Augmentation String. |
| if (cie_sp->augmentation[0] == 'z') { |
| // Extract the Augmentation Data |
| size_t aug_str_idx = 0; |
| for (aug_str_idx = 1; aug_str_idx < aug_str_len; aug_str_idx++) { |
| char aug = cie_sp->augmentation[aug_str_idx]; |
| switch (aug) { |
| case 'L': |
| // Indicates the presence of one argument in the Augmentation Data |
| // of the CIE, and a corresponding argument in the Augmentation |
| // Data of the FDE. The argument in the Augmentation Data of the |
| // CIE is 1-byte and represents the pointer encoding used for the |
| // argument in the Augmentation Data of the FDE, which is the |
| // address of a language-specific data area (LSDA). The size of the |
| // LSDA pointer is specified by the pointer encoding used. |
| cie_sp->lsda_addr_encoding = m_cfi_data.GetU8(&offset); |
| break; |
| |
| case 'P': |
| // Indicates the presence of two arguments in the Augmentation Data |
| // of the CIE. The first argument is 1-byte and represents the |
| // pointer encoding used for the second argument, which is the |
| // address of a personality routine handler. The size of the |
| // personality routine pointer is specified by the pointer encoding |
| // used. |
| // |
| // The address of the personality function will be stored at this |
| // location. Pre-execution, it will be all zero's so don't read it |
| // until we're trying to do an unwind & the reloc has been |
| // resolved. |
| { |
| uint8_t arg_ptr_encoding = m_cfi_data.GetU8(&offset); |
| const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); |
| cie_sp->personality_loc = GetGNUEHPointer( |
| m_cfi_data, &offset, arg_ptr_encoding, pc_rel_addr, |
| LLDB_INVALID_ADDRESS, LLDB_INVALID_ADDRESS); |
| } |
| break; |
| |
| case 'R': |
| // A 'R' may be present at any position after the |
| // first character of the string. The Augmentation Data shall |
| // include a 1 byte argument that represents the pointer encoding |
| // for the address pointers used in the FDE. Example: 0x1B == |
| // DW_EH_PE_pcrel | DW_EH_PE_sdata4 |
| cie_sp->ptr_encoding = m_cfi_data.GetU8(&offset); |
| break; |
| } |
| } |
| } else if (strcmp(cie_sp->augmentation, "eh") == 0) { |
| // If the Augmentation string has the value "eh", then the EH Data |
| // field shall be present |
| } |
| |
| // Set the offset to be the end of the augmentation data just in case we |
| // didn't understand any of the data. |
| offset = (uint32_t)aug_data_end; |
| } |
| |
| if (end_offset > offset) { |
| cie_sp->inst_offset = offset; |
| cie_sp->inst_length = end_offset - offset; |
| } |
| while (offset < end_offset) { |
| uint8_t inst = m_cfi_data.GetU8(&offset); |
| uint8_t primary_opcode = inst & 0xC0; |
| uint8_t extended_opcode = inst & 0x3F; |
| |
| if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, |
| cie_sp->data_align, offset, |
| cie_sp->initial_row)) |
| break; // Stop if we hit an unrecognized opcode |
| } |
| } |
| |
| return cie_sp; |
| } |
| |
| void DWARFCallFrameInfo::GetCFIData() { |
| if (m_cfi_data_initialized == false) { |
| Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); |
| if (log) |
| m_objfile.GetModule()->LogMessage(log, "Reading EH frame info"); |
| m_objfile.ReadSectionData(m_section_sp.get(), m_cfi_data); |
| m_cfi_data_initialized = true; |
| } |
| } |
| // Scan through the eh_frame or debug_frame section looking for FDEs and noting |
| // the start/end addresses of the functions and a pointer back to the |
| // function's FDE for later expansion. Internalize CIEs as we come across them. |
| |
| void DWARFCallFrameInfo::GetFDEIndex() { |
| if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) |
| return; |
| |
| if (m_fde_index_initialized) |
| return; |
| |
| std::lock_guard<std::mutex> guard(m_fde_index_mutex); |
| |
| if (m_fde_index_initialized) // if two threads hit the locker |
| return; |
| |
| static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); |
| Timer scoped_timer(func_cat, "%s - %s", LLVM_PRETTY_FUNCTION, |
| m_objfile.GetFileSpec().GetFilename().AsCString("")); |
| |
| bool clear_address_zeroth_bit = false; |
| ArchSpec arch; |
| if (m_objfile.GetArchitecture(arch)) { |
| if (arch.GetTriple().getArch() == llvm::Triple::arm || |
| arch.GetTriple().getArch() == llvm::Triple::thumb) |
| clear_address_zeroth_bit = true; |
| } |
| |
| lldb::offset_t offset = 0; |
| if (m_cfi_data_initialized == false) |
| GetCFIData(); |
| while (m_cfi_data.ValidOffsetForDataOfSize(offset, 8)) { |
| const dw_offset_t current_entry = offset; |
| dw_offset_t cie_id, next_entry, cie_offset; |
| uint32_t len = m_cfi_data.GetU32(&offset); |
| bool is_64bit = (len == UINT32_MAX); |
| if (is_64bit) { |
| len = m_cfi_data.GetU64(&offset); |
| cie_id = m_cfi_data.GetU64(&offset); |
| next_entry = current_entry + len + 12; |
| cie_offset = current_entry + 12 - cie_id; |
| } else { |
| cie_id = m_cfi_data.GetU32(&offset); |
| next_entry = current_entry + len + 4; |
| cie_offset = current_entry + 4 - cie_id; |
| } |
| |
| if (next_entry > m_cfi_data.GetByteSize() + 1) { |
| Host::SystemLog(Host::eSystemLogError, "error: Invalid fde/cie next " |
| "entry offset of 0x%x found in " |
| "cie/fde at 0x%x\n", |
| next_entry, current_entry); |
| // Don't trust anything in this eh_frame section if we find blatantly |
| // invalid data. |
| m_fde_index.Clear(); |
| m_fde_index_initialized = true; |
| return; |
| } |
| |
| // An FDE entry contains CIE_pointer in debug_frame in same place as cie_id |
| // in eh_frame. CIE_pointer is an offset into the .debug_frame section. So, |
| // variable cie_offset should be equal to cie_id for debug_frame. |
| // FDE entries with cie_id == 0 shouldn't be ignored for it. |
| if ((cie_id == 0 && m_type == EH) || cie_id == UINT32_MAX || len == 0) { |
| auto cie_sp = ParseCIE(current_entry); |
| if (!cie_sp) { |
| // Cannot parse, the reason is already logged |
| m_fde_index.Clear(); |
| m_fde_index_initialized = true; |
| return; |
| } |
| |
| m_cie_map[current_entry] = std::move(cie_sp); |
| offset = next_entry; |
| continue; |
| } |
| |
| if (m_type == DWARF) |
| cie_offset = cie_id; |
| |
| if (cie_offset > m_cfi_data.GetByteSize()) { |
| Host::SystemLog(Host::eSystemLogError, |
| "error: Invalid cie offset of 0x%x " |
| "found in cie/fde at 0x%x\n", |
| cie_offset, current_entry); |
| // Don't trust anything in this eh_frame section if we find blatantly |
| // invalid data. |
| m_fde_index.Clear(); |
| m_fde_index_initialized = true; |
| return; |
| } |
| |
| const CIE *cie = GetCIE(cie_offset); |
| if (cie) { |
| const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); |
| const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; |
| const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; |
| |
| lldb::addr_t addr = |
| GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, |
| text_addr, data_addr); |
| if (clear_address_zeroth_bit) |
| addr &= ~1ull; |
| |
| lldb::addr_t length = GetGNUEHPointer( |
| m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, |
| pc_rel_addr, text_addr, data_addr); |
| FDEEntryMap::Entry fde(addr, length, current_entry); |
| m_fde_index.Append(fde); |
| } else { |
| Host::SystemLog(Host::eSystemLogError, "error: unable to find CIE at " |
| "0x%8.8x for cie_id = 0x%8.8x for " |
| "entry at 0x%8.8x.\n", |
| cie_offset, cie_id, current_entry); |
| } |
| offset = next_entry; |
| } |
| m_fde_index.Sort(); |
| m_fde_index_initialized = true; |
| } |
| |
| bool DWARFCallFrameInfo::FDEToUnwindPlan(dw_offset_t dwarf_offset, |
| Address startaddr, |
| UnwindPlan &unwind_plan) { |
| Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND); |
| lldb::offset_t offset = dwarf_offset; |
| lldb::offset_t current_entry = offset; |
| |
| if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) |
| return false; |
| |
| if (m_cfi_data_initialized == false) |
| GetCFIData(); |
| |
| uint32_t length = m_cfi_data.GetU32(&offset); |
| dw_offset_t cie_offset; |
| bool is_64bit = (length == UINT32_MAX); |
| if (is_64bit) { |
| length = m_cfi_data.GetU64(&offset); |
| cie_offset = m_cfi_data.GetU64(&offset); |
| } else { |
| cie_offset = m_cfi_data.GetU32(&offset); |
| } |
| |
| // FDE entries with zeroth cie_offset may occur for debug_frame. |
| assert(!(m_type == EH && 0 == cie_offset) && cie_offset != UINT32_MAX); |
| |
| // Translate the CIE_id from the eh_frame format, which is relative to the |
| // FDE offset, into a __eh_frame section offset |
| if (m_type == EH) { |
| unwind_plan.SetSourceName("eh_frame CFI"); |
| cie_offset = current_entry + (is_64bit ? 12 : 4) - cie_offset; |
| unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); |
| } else { |
| unwind_plan.SetSourceName("DWARF CFI"); |
| // In theory the debug_frame info should be valid at all call sites |
| // ("asynchronous unwind info" as it is sometimes called) but in practice |
| // gcc et al all emit call frame info for the prologue and call sites, but |
| // not for the epilogue or all the other locations during the function |
| // reliably. |
| unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo); |
| } |
| unwind_plan.SetSourcedFromCompiler(eLazyBoolYes); |
| |
| const CIE *cie = GetCIE(cie_offset); |
| assert(cie != nullptr); |
| |
| const dw_offset_t end_offset = current_entry + length + (is_64bit ? 12 : 4); |
| |
| const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); |
| const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; |
| const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; |
| lldb::addr_t range_base = |
| GetGNUEHPointer(m_cfi_data, &offset, cie->ptr_encoding, pc_rel_addr, |
| text_addr, data_addr); |
| lldb::addr_t range_len = GetGNUEHPointer( |
| m_cfi_data, &offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, |
| pc_rel_addr, text_addr, data_addr); |
| AddressRange range(range_base, m_objfile.GetAddressByteSize(), |
| m_objfile.GetSectionList()); |
| range.SetByteSize(range_len); |
| |
| addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS; |
| |
| if (cie->augmentation[0] == 'z') { |
| uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) { |
| offset_t saved_offset = offset; |
| lsda_data_file_address = |
| GetGNUEHPointer(m_cfi_data, &offset, cie->lsda_addr_encoding, |
| pc_rel_addr, text_addr, data_addr); |
| if (offset - saved_offset != aug_data_len) { |
| // There is more in the augmentation region than we know how to process; |
| // don't read anything. |
| lsda_data_file_address = LLDB_INVALID_ADDRESS; |
| } |
| offset = saved_offset; |
| } |
| offset += aug_data_len; |
| } |
| Address lsda_data; |
| Address personality_function_ptr; |
| |
| if (lsda_data_file_address != LLDB_INVALID_ADDRESS && |
| cie->personality_loc != LLDB_INVALID_ADDRESS) { |
| m_objfile.GetModule()->ResolveFileAddress(lsda_data_file_address, |
| lsda_data); |
| m_objfile.GetModule()->ResolveFileAddress(cie->personality_loc, |
| personality_function_ptr); |
| } |
| |
| if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { |
| unwind_plan.SetLSDAAddress(lsda_data); |
| unwind_plan.SetPersonalityFunctionPtr(personality_function_ptr); |
| } |
| |
| uint32_t code_align = cie->code_align; |
| int32_t data_align = cie->data_align; |
| |
| unwind_plan.SetPlanValidAddressRange(range); |
| UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; |
| *cie_initial_row = cie->initial_row; |
| UnwindPlan::RowSP row(cie_initial_row); |
| |
| unwind_plan.SetRegisterKind(GetRegisterKind()); |
| unwind_plan.SetReturnAddressRegister(cie->return_addr_reg_num); |
| |
| std::vector<UnwindPlan::RowSP> stack; |
| |
| UnwindPlan::Row::RegisterLocation reg_location; |
| while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { |
| uint8_t inst = m_cfi_data.GetU8(&offset); |
| uint8_t primary_opcode = inst & 0xC0; |
| uint8_t extended_opcode = inst & 0x3F; |
| |
| if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, |
| offset, *row)) { |
| if (primary_opcode) { |
| switch (primary_opcode) { |
| case DW_CFA_advance_loc: // (Row Creation Instruction) |
| { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta |
| // takes a single argument that represents a constant delta. The |
| // required action is to create a new table row with a location value |
| // that is computed by taking the current entry's location value and |
| // adding (delta * code_align). All other values in the new row are |
| // initially identical to the current row. |
| unwind_plan.AppendRow(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| row->SlideOffset(extended_opcode * code_align); |
| break; |
| } |
| |
| case DW_CFA_restore: { // 0xC0 - high 2 bits are 0x3, lower 6 bits are |
| // register |
| // takes a single argument that represents a register number. The |
| // required action is to change the rule for the indicated register |
| // to the rule assigned it by the initial_instructions in the CIE. |
| uint32_t reg_num = extended_opcode; |
| // We only keep enough register locations around to unwind what is in |
| // our thread, and these are organized by the register index in that |
| // state, so we need to convert our eh_frame register number from the |
| // EH frame info, to a register index |
| |
| if (unwind_plan.IsValidRowIndex(0) && |
| unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, |
| reg_location)) |
| row->SetRegisterInfo(reg_num, reg_location); |
| break; |
| } |
| } |
| } else { |
| switch (extended_opcode) { |
| case DW_CFA_set_loc: // 0x1 (Row Creation Instruction) |
| { |
| // DW_CFA_set_loc takes a single argument that represents an address. |
| // The required action is to create a new table row using the |
| // specified address as the location. All other values in the new row |
| // are initially identical to the current row. The new location value |
| // should always be greater than the current one. |
| unwind_plan.AppendRow(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| row->SetOffset(m_cfi_data.GetPointer(&offset) - |
| startaddr.GetFileAddress()); |
| break; |
| } |
| |
| case DW_CFA_advance_loc1: // 0x2 (Row Creation Instruction) |
| { |
| // takes a single uword argument that represents a constant delta. |
| // This instruction is identical to DW_CFA_advance_loc except for the |
| // encoding and size of the delta argument. |
| unwind_plan.AppendRow(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| row->SlideOffset(m_cfi_data.GetU8(&offset) * code_align); |
| break; |
| } |
| |
| case DW_CFA_advance_loc2: // 0x3 (Row Creation Instruction) |
| { |
| // takes a single uword argument that represents a constant delta. |
| // This instruction is identical to DW_CFA_advance_loc except for the |
| // encoding and size of the delta argument. |
| unwind_plan.AppendRow(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| row->SlideOffset(m_cfi_data.GetU16(&offset) * code_align); |
| break; |
| } |
| |
| case DW_CFA_advance_loc4: // 0x4 (Row Creation Instruction) |
| { |
| // takes a single uword argument that represents a constant delta. |
| // This instruction is identical to DW_CFA_advance_loc except for the |
| // encoding and size of the delta argument. |
| unwind_plan.AppendRow(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| row->SlideOffset(m_cfi_data.GetU32(&offset) * code_align); |
| break; |
| } |
| |
| case DW_CFA_restore_extended: // 0x6 |
| { |
| // takes a single unsigned LEB128 argument that represents a register |
| // number. This instruction is identical to DW_CFA_restore except for |
| // the encoding and size of the register argument. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| if (unwind_plan.IsValidRowIndex(0) && |
| unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, |
| reg_location)) |
| row->SetRegisterInfo(reg_num, reg_location); |
| break; |
| } |
| |
| case DW_CFA_remember_state: // 0xA |
| { |
| // These instructions define a stack of information. Encountering the |
| // DW_CFA_remember_state instruction means to save the rules for |
| // every register on the current row on the stack. Encountering the |
| // DW_CFA_restore_state instruction means to pop the set of rules off |
| // the stack and place them in the current row. (This operation is |
| // useful for compilers that move epilogue code into the body of a |
| // function.) |
| stack.push_back(row); |
| UnwindPlan::Row *newrow = new UnwindPlan::Row; |
| *newrow = *row.get(); |
| row.reset(newrow); |
| break; |
| } |
| |
| case DW_CFA_restore_state: // 0xB |
| { |
| // These instructions define a stack of information. Encountering the |
| // DW_CFA_remember_state instruction means to save the rules for |
| // every register on the current row on the stack. Encountering the |
| // DW_CFA_restore_state instruction means to pop the set of rules off |
| // the stack and place them in the current row. (This operation is |
| // useful for compilers that move epilogue code into the body of a |
| // function.) |
| if (stack.empty()) { |
| if (log) |
| log->Printf("DWARFCallFrameInfo::%s(dwarf_offset: %" PRIx32 |
| ", startaddr: %" PRIx64 |
| " encountered DW_CFA_restore_state but state stack " |
| "is empty. Corrupt unwind info?", |
| __FUNCTION__, dwarf_offset, |
| startaddr.GetFileAddress()); |
| break; |
| } |
| lldb::addr_t offset = row->GetOffset(); |
| row = stack.back(); |
| stack.pop_back(); |
| row->SetOffset(offset); |
| break; |
| } |
| |
| case DW_CFA_GNU_args_size: // 0x2e |
| { |
| // The DW_CFA_GNU_args_size instruction takes an unsigned LEB128 |
| // operand representing an argument size. This instruction specifies |
| // the total of the size of the arguments which have been pushed onto |
| // the stack. |
| |
| // TODO: Figure out how we should handle this. |
| m_cfi_data.GetULEB128(&offset); |
| break; |
| } |
| |
| case DW_CFA_val_offset: // 0x14 |
| case DW_CFA_val_offset_sf: // 0x15 |
| default: |
| break; |
| } |
| } |
| } |
| } |
| unwind_plan.AppendRow(row); |
| |
| return true; |
| } |
| |
| bool DWARFCallFrameInfo::HandleCommonDwarfOpcode(uint8_t primary_opcode, |
| uint8_t extended_opcode, |
| int32_t data_align, |
| lldb::offset_t &offset, |
| UnwindPlan::Row &row) { |
| UnwindPlan::Row::RegisterLocation reg_location; |
| |
| if (primary_opcode) { |
| switch (primary_opcode) { |
| case DW_CFA_offset: { // 0x80 - high 2 bits are 0x2, lower 6 bits are |
| // register |
| // takes two arguments: an unsigned LEB128 constant representing a |
| // factored offset and a register number. The required action is to |
| // change the rule for the register indicated by the register number to |
| // be an offset(N) rule with a value of (N = factored offset * |
| // data_align). |
| uint8_t reg_num = extended_opcode; |
| int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; |
| reg_location.SetAtCFAPlusOffset(op_offset); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| } |
| } else { |
| switch (extended_opcode) { |
| case DW_CFA_nop: // 0x0 |
| return true; |
| |
| case DW_CFA_offset_extended: // 0x5 |
| { |
| // takes two unsigned LEB128 arguments representing a register number and |
| // a factored offset. This instruction is identical to DW_CFA_offset |
| // except for the encoding and size of the register argument. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetAtCFAPlusOffset(op_offset); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_undefined: // 0x7 |
| { |
| // takes a single unsigned LEB128 argument that represents a register |
| // number. The required action is to set the rule for the specified |
| // register to undefined. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetUndefined(); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_same_value: // 0x8 |
| { |
| // takes a single unsigned LEB128 argument that represents a register |
| // number. The required action is to set the rule for the specified |
| // register to same value. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetSame(); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_register: // 0x9 |
| { |
| // takes two unsigned LEB128 arguments representing register numbers. The |
| // required action is to set the rule for the first register to be the |
| // second register. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetInRegister(other_reg_num); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa: // 0xC (CFA Definition Instruction) |
| { |
| // Takes two unsigned LEB128 operands representing a register number and |
| // a (non-factored) offset. The required action is to define the current |
| // CFA rule to use the provided register and offset. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); |
| row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa_register: // 0xD (CFA Definition Instruction) |
| { |
| // takes a single unsigned LEB128 argument representing a register |
| // number. The required action is to define the current CFA rule to use |
| // the provided register (but to keep the old offset). |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, |
| row.GetCFAValue().GetOffset()); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa_offset: // 0xE (CFA Definition Instruction) |
| { |
| // Takes a single unsigned LEB128 operand representing a (non-factored) |
| // offset. The required action is to define the current CFA rule to use |
| // the provided offset (but to keep the old register). |
| int32_t op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); |
| row.GetCFAValue().SetIsRegisterPlusOffset( |
| row.GetCFAValue().GetRegisterNumber(), op_offset); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa_expression: // 0xF (CFA Definition Instruction) |
| { |
| size_t block_len = (size_t)m_cfi_data.GetULEB128(&offset); |
| const uint8_t *block_data = |
| static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); |
| row.GetCFAValue().SetIsDWARFExpression(block_data, block_len); |
| return true; |
| } |
| |
| case DW_CFA_expression: // 0x10 |
| { |
| // Takes two operands: an unsigned LEB128 value representing a register |
| // number, and a DW_FORM_block value representing a DWARF expression. The |
| // required action is to change the rule for the register indicated by |
| // the register number to be an expression(E) rule where E is the DWARF |
| // expression. That is, the DWARF expression computes the address. The |
| // value of the CFA is pushed on the DWARF evaluation stack prior to |
| // execution of the DWARF expression. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| const uint8_t *block_data = |
| static_cast<const uint8_t *>(m_cfi_data.GetData(&offset, block_len)); |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetAtDWARFExpression(block_data, block_len); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_offset_extended_sf: // 0x11 |
| { |
| // takes two operands: an unsigned LEB128 value representing a register |
| // number and a signed LEB128 factored offset. This instruction is |
| // identical to DW_CFA_offset_extended except that the second operand is |
| // signed and factored. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; |
| UnwindPlan::Row::RegisterLocation reg_location; |
| reg_location.SetAtCFAPlusOffset(op_offset); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa_sf: // 0x12 (CFA Definition Instruction) |
| { |
| // Takes two operands: an unsigned LEB128 value representing a register |
| // number and a signed LEB128 factored offset. This instruction is |
| // identical to DW_CFA_def_cfa except that the second operand is signed |
| // and factored. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; |
| row.GetCFAValue().SetIsRegisterPlusOffset(reg_num, op_offset); |
| return true; |
| } |
| |
| case DW_CFA_def_cfa_offset_sf: // 0x13 (CFA Definition Instruction) |
| { |
| // takes a signed LEB128 operand representing a factored offset. This |
| // instruction is identical to DW_CFA_def_cfa_offset except that the |
| // operand is signed and factored. |
| int32_t op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; |
| uint32_t cfa_regnum = row.GetCFAValue().GetRegisterNumber(); |
| row.GetCFAValue().SetIsRegisterPlusOffset(cfa_regnum, op_offset); |
| return true; |
| } |
| |
| case DW_CFA_val_expression: // 0x16 |
| { |
| // takes two operands: an unsigned LEB128 value representing a register |
| // number, and a DW_FORM_block value representing a DWARF expression. The |
| // required action is to change the rule for the register indicated by |
| // the register number to be a val_expression(E) rule where E is the |
| // DWARF expression. That is, the DWARF expression computes the value of |
| // the given register. The value of the CFA is pushed on the DWARF |
| // evaluation stack prior to execution of the DWARF expression. |
| uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); |
| const uint8_t *block_data = |
| (const uint8_t *)m_cfi_data.GetData(&offset, block_len); |
| //#if defined(__i386__) || defined(__x86_64__) |
| // // The EH frame info for EIP and RIP contains code that |
| // looks for traps to |
| // // be a specific type and increments the PC. |
| // // For i386: |
| // // DW_CFA_val_expression where: |
| // // eip = DW_OP_breg6(+28), DW_OP_deref, DW_OP_dup, |
| // DW_OP_plus_uconst(0x34), |
| // // DW_OP_deref, DW_OP_swap, DW_OP_plus_uconst(0), |
| // DW_OP_deref, |
| // // DW_OP_dup, DW_OP_lit3, DW_OP_ne, DW_OP_swap, |
| // DW_OP_lit4, DW_OP_ne, |
| // // DW_OP_and, DW_OP_plus |
| // // This basically does a: |
| // // eip = ucontenxt.mcontext32->gpr.eip; |
| // // if (ucontenxt.mcontext32->exc.trapno != 3 && |
| // ucontenxt.mcontext32->exc.trapno != 4) |
| // // eip++; |
| // // |
| // // For x86_64: |
| // // DW_CFA_val_expression where: |
| // // rip = DW_OP_breg3(+48), DW_OP_deref, DW_OP_dup, |
| // DW_OP_plus_uconst(0x90), DW_OP_deref, |
| // // DW_OP_swap, DW_OP_plus_uconst(0), |
| // DW_OP_deref_size(4), DW_OP_dup, DW_OP_lit3, |
| // // DW_OP_ne, DW_OP_swap, DW_OP_lit4, DW_OP_ne, |
| // DW_OP_and, DW_OP_plus |
| // // This basically does a: |
| // // rip = ucontenxt.mcontext64->gpr.rip; |
| // // if (ucontenxt.mcontext64->exc.trapno != 3 && |
| // ucontenxt.mcontext64->exc.trapno != 4) |
| // // rip++; |
| // // The trap comparisons and increments are not needed as |
| // it hoses up the unwound PC which |
| // // is expected to point at least past the instruction that |
| // causes the fault/trap. So we |
| // // take it out by trimming the expression right at the |
| // first "DW_OP_swap" opcodes |
| // if (block_data != NULL && thread->GetPCRegNum(Thread::GCC) |
| // == reg_num) |
| // { |
| // if (thread->Is64Bit()) |
| // { |
| // if (block_len > 9 && block_data[8] == DW_OP_swap |
| // && block_data[9] == DW_OP_plus_uconst) |
| // block_len = 8; |
| // } |
| // else |
| // { |
| // if (block_len > 8 && block_data[7] == DW_OP_swap |
| // && block_data[8] == DW_OP_plus_uconst) |
| // block_len = 7; |
| // } |
| // } |
| //#endif |
| reg_location.SetIsDWARFExpression(block_data, block_len); |
| row.SetRegisterInfo(reg_num, reg_location); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| void DWARFCallFrameInfo::ForEachFDEEntries( |
| const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback) { |
| GetFDEIndex(); |
| |
| for (size_t i = 0, c = m_fde_index.GetSize(); i < c; ++i) { |
| const FDEEntryMap::Entry &entry = m_fde_index.GetEntryRef(i); |
| if (!callback(entry.base, entry.size, entry.data)) |
| break; |
| } |
| } |
