| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| // |
| // Parses DWARF CFIs (FDEs and CIEs). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef __DWARF_PARSER_HPP__ |
| #define __DWARF_PARSER_HPP__ |
| |
| #include <inttypes.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "libunwind.h" |
| #include "dwarf2.h" |
| #include "Registers.hpp" |
| |
| #include "config.h" |
| |
| namespace libunwind { |
| |
| /// CFI_Parser does basic parsing of a CFI (Call Frame Information) records. |
| /// See DWARF Spec for details: |
| /// http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html |
| /// |
| template <typename A> |
| class CFI_Parser { |
| public: |
| typedef typename A::pint_t pint_t; |
| |
| /// Information encoded in a CIE (Common Information Entry) |
| struct CIE_Info { |
| pint_t cieStart; |
| pint_t cieLength; |
| pint_t cieInstructions; |
| uint8_t pointerEncoding; |
| uint8_t lsdaEncoding; |
| uint8_t personalityEncoding; |
| uint8_t personalityOffsetInCIE; |
| pint_t personality; |
| uint32_t codeAlignFactor; |
| int dataAlignFactor; |
| bool isSignalFrame; |
| bool fdesHaveAugmentationData; |
| uint8_t returnAddressRegister; |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| bool addressesSignedWithBKey; |
| bool mteTaggedFrame; |
| #endif |
| }; |
| |
| /// Information about an FDE (Frame Description Entry) |
| struct FDE_Info { |
| pint_t fdeStart; |
| pint_t fdeLength; |
| pint_t fdeInstructions; |
| pint_t pcStart; |
| pint_t pcEnd; |
| pint_t lsda; |
| }; |
| |
| enum { |
| kMaxRegisterNumber = _LIBUNWIND_HIGHEST_DWARF_REGISTER |
| }; |
| enum RegisterSavedWhere { |
| kRegisterUnused, |
| kRegisterUndefined, |
| kRegisterInCFA, |
| kRegisterInCFADecrypt, // sparc64 specific |
| kRegisterOffsetFromCFA, |
| kRegisterInRegister, |
| kRegisterAtExpression, |
| kRegisterIsExpression |
| }; |
| struct RegisterLocation { |
| RegisterSavedWhere location; |
| bool initialStateSaved; |
| int64_t value; |
| }; |
| /// Information about a frame layout and registers saved determined |
| /// by "running" the DWARF FDE "instructions" |
| struct PrologInfo { |
| uint32_t cfaRegister; |
| int32_t cfaRegisterOffset; // CFA = (cfaRegister)+cfaRegisterOffset |
| int64_t cfaExpression; // CFA = expression |
| uint32_t spExtraArgSize; |
| RegisterLocation savedRegisters[kMaxRegisterNumber + 1]; |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| pint_t ptrAuthDiversifier; |
| #endif |
| enum class InitializeTime { kLazy, kNormal }; |
| |
| // When saving registers, this data structure is lazily initialized. |
| PrologInfo(InitializeTime IT = InitializeTime::kNormal) { |
| if (IT == InitializeTime::kNormal) |
| memset(this, 0, sizeof(*this)); |
| } |
| void checkSaveRegister(uint64_t reg, PrologInfo &initialState) { |
| if (!savedRegisters[reg].initialStateSaved) { |
| initialState.savedRegisters[reg] = savedRegisters[reg]; |
| savedRegisters[reg].initialStateSaved = true; |
| } |
| } |
| void setRegister(uint64_t reg, RegisterSavedWhere newLocation, |
| int64_t newValue, PrologInfo &initialState) { |
| checkSaveRegister(reg, initialState); |
| savedRegisters[reg].location = newLocation; |
| savedRegisters[reg].value = newValue; |
| } |
| void setRegisterLocation(uint64_t reg, RegisterSavedWhere newLocation, |
| PrologInfo &initialState) { |
| checkSaveRegister(reg, initialState); |
| savedRegisters[reg].location = newLocation; |
| } |
| void setRegisterValue(uint64_t reg, int64_t newValue, |
| PrologInfo &initialState) { |
| checkSaveRegister(reg, initialState); |
| savedRegisters[reg].value = newValue; |
| } |
| void restoreRegisterToInitialState(uint64_t reg, PrologInfo &initialState) { |
| if (savedRegisters[reg].initialStateSaved) |
| savedRegisters[reg] = initialState.savedRegisters[reg]; |
| // else the register still holds its initial state |
| } |
| }; |
| |
| struct PrologInfoStackEntry { |
| PrologInfoStackEntry(PrologInfoStackEntry *n, const PrologInfo &i) |
| : next(n), info(i) {} |
| PrologInfoStackEntry *next; |
| PrologInfo info; |
| }; |
| |
| struct RememberStack { |
| PrologInfoStackEntry *entry; |
| RememberStack() : entry(nullptr) {} |
| ~RememberStack() { |
| #if defined(_LIBUNWIND_REMEMBER_CLEANUP_NEEDED) |
| // Clean up rememberStack. Even in the case where every |
| // DW_CFA_remember_state is paired with a DW_CFA_restore_state, |
| // parseInstructions can skip restore opcodes if it reaches the target PC |
| // and stops interpreting, so we have to make sure we don't leak memory. |
| while (entry) { |
| PrologInfoStackEntry *next = entry->next; |
| _LIBUNWIND_REMEMBER_FREE(entry); |
| entry = next; |
| } |
| #endif |
| } |
| }; |
| |
| static bool findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart, |
| size_t sectionLength, pint_t fdeHint, FDE_Info *fdeInfo, |
| CIE_Info *cieInfo); |
| static const char *decodeFDE(A &addressSpace, pint_t fdeStart, |
| FDE_Info *fdeInfo, CIE_Info *cieInfo, |
| bool useCIEInfo = false); |
| static bool parseFDEInstructions(A &addressSpace, const FDE_Info &fdeInfo, |
| const CIE_Info &cieInfo, pint_t upToPC, |
| int arch, PrologInfo *results); |
| |
| static const char *parseCIE(A &addressSpace, pint_t cie, CIE_Info *cieInfo); |
| }; |
| |
| /// Parse a FDE into a CIE_Info and an FDE_Info. If useCIEInfo is |
| /// true, treat cieInfo as already-parsed CIE_Info (whose start offset |
| /// must match the one specified by the FDE) rather than parsing the |
| /// one indicated within the FDE. |
| template <typename A> |
| const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart, |
| FDE_Info *fdeInfo, CIE_Info *cieInfo, |
| bool useCIEInfo) { |
| pint_t p = fdeStart; |
| pint_t cfiLength = (pint_t)addressSpace.get32(p); |
| p += 4; |
| if (cfiLength == 0xffffffff) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = (pint_t)addressSpace.get64(p); |
| p += 8; |
| } |
| if (cfiLength == 0) |
| return "FDE has zero length"; // zero terminator |
| uint32_t ciePointer = addressSpace.get32(p); |
| if (ciePointer == 0) |
| return "FDE is really a CIE"; // this is a CIE not an FDE |
| pint_t nextCFI = p + cfiLength; |
| pint_t cieStart = p - ciePointer; |
| if (useCIEInfo) { |
| if (cieInfo->cieStart != cieStart) |
| return "CIE start does not match"; |
| } else { |
| const char *err = parseCIE(addressSpace, cieStart, cieInfo); |
| if (err != NULL) |
| return err; |
| } |
| p += 4; |
| // Parse pc begin and range. |
| pint_t pcStart = |
| addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| pint_t pcRange = |
| addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| // Parse rest of info. |
| fdeInfo->lsda = 0; |
| // Check for augmentation length. |
| if (cieInfo->fdesHaveAugmentationData) { |
| pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI); |
| pint_t endOfAug = p + augLen; |
| if (cieInfo->lsdaEncoding != DW_EH_PE_omit) { |
| // Peek at value (without indirection). Zero means no LSDA. |
| pint_t lsdaStart = p; |
| if (addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != |
| 0) { |
| // Reset pointer and re-parse LSDA address. |
| p = lsdaStart; |
| fdeInfo->lsda = |
| addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| } |
| } |
| p = endOfAug; |
| } |
| fdeInfo->fdeStart = fdeStart; |
| fdeInfo->fdeLength = nextCFI - fdeStart; |
| fdeInfo->fdeInstructions = p; |
| fdeInfo->pcStart = pcStart; |
| fdeInfo->pcEnd = pcStart + pcRange; |
| return NULL; // success |
| } |
| |
| /// Scan an eh_frame section to find an FDE for a pc |
| template <typename A> |
| bool CFI_Parser<A>::findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart, |
| size_t sectionLength, pint_t fdeHint, |
| FDE_Info *fdeInfo, CIE_Info *cieInfo) { |
| //fprintf(stderr, "findFDE(0x%llX)\n", (long long)pc); |
| pint_t p = (fdeHint != 0) ? fdeHint : ehSectionStart; |
| const pint_t ehSectionEnd = (sectionLength == SIZE_MAX) |
| ? static_cast<pint_t>(-1) |
| : (ehSectionStart + sectionLength); |
| while (p < ehSectionEnd) { |
| pint_t currentCFI = p; |
| //fprintf(stderr, "findFDE() CFI at 0x%llX\n", (long long)p); |
| pint_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if (cfiLength == 0xffffffff) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = (pint_t)addressSpace.get64(p); |
| p += 8; |
| } |
| if (cfiLength == 0) |
| return false; // zero terminator |
| uint32_t id = addressSpace.get32(p); |
| if (id == 0) { |
| // Skip over CIEs. |
| p += cfiLength; |
| } else { |
| // Process FDE to see if it covers pc. |
| pint_t nextCFI = p + cfiLength; |
| uint32_t ciePointer = addressSpace.get32(p); |
| pint_t cieStart = p - ciePointer; |
| // Validate pointer to CIE is within section. |
| if ((ehSectionStart <= cieStart) && (cieStart < ehSectionEnd)) { |
| if (parseCIE(addressSpace, cieStart, cieInfo) == NULL) { |
| p += 4; |
| // Parse pc begin and range. |
| pint_t pcStart = |
| addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| pint_t pcRange = addressSpace.getEncodedP( |
| p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| // Test if pc is within the function this FDE covers. |
| if ((pcStart < pc) && (pc <= pcStart + pcRange)) { |
| // parse rest of info |
| fdeInfo->lsda = 0; |
| // check for augmentation length |
| if (cieInfo->fdesHaveAugmentationData) { |
| pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI); |
| pint_t endOfAug = p + augLen; |
| if (cieInfo->lsdaEncoding != DW_EH_PE_omit) { |
| // Peek at value (without indirection). Zero means no LSDA. |
| pint_t lsdaStart = p; |
| if (addressSpace.getEncodedP( |
| p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != 0) { |
| // Reset pointer and re-parse LSDA address. |
| p = lsdaStart; |
| fdeInfo->lsda = addressSpace |
| .getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| } |
| } |
| p = endOfAug; |
| } |
| fdeInfo->fdeStart = currentCFI; |
| fdeInfo->fdeLength = nextCFI - currentCFI; |
| fdeInfo->fdeInstructions = p; |
| fdeInfo->pcStart = pcStart; |
| fdeInfo->pcEnd = pcStart + pcRange; |
| return true; |
| } else { |
| // pc is not in begin/range, skip this FDE |
| } |
| } else { |
| // Malformed CIE, now augmentation describing pc range encoding. |
| } |
| } else { |
| // malformed FDE. CIE is bad |
| } |
| p = nextCFI; |
| } |
| } |
| return false; |
| } |
| |
| /// Extract info from a CIE |
| template <typename A> |
| const char *CFI_Parser<A>::parseCIE(A &addressSpace, pint_t cie, |
| CIE_Info *cieInfo) { |
| cieInfo->pointerEncoding = 0; |
| cieInfo->lsdaEncoding = DW_EH_PE_omit; |
| cieInfo->personalityEncoding = 0; |
| cieInfo->personalityOffsetInCIE = 0; |
| cieInfo->personality = 0; |
| cieInfo->codeAlignFactor = 0; |
| cieInfo->dataAlignFactor = 0; |
| cieInfo->isSignalFrame = false; |
| cieInfo->fdesHaveAugmentationData = false; |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| cieInfo->addressesSignedWithBKey = false; |
| cieInfo->mteTaggedFrame = false; |
| #endif |
| cieInfo->cieStart = cie; |
| pint_t p = cie; |
| pint_t cieLength = (pint_t)addressSpace.get32(p); |
| p += 4; |
| pint_t cieContentEnd = p + cieLength; |
| if (cieLength == 0xffffffff) { |
| // 0xffffffff means length is really next 8 bytes |
| cieLength = (pint_t)addressSpace.get64(p); |
| p += 8; |
| cieContentEnd = p + cieLength; |
| } |
| if (cieLength == 0) |
| return NULL; |
| // CIE ID is always 0 |
| if (addressSpace.get32(p) != 0) |
| return "CIE ID is not zero"; |
| p += 4; |
| // Version is always 1 or 3 |
| uint8_t version = addressSpace.get8(p); |
| if ((version != 1) && (version != 3)) |
| return "CIE version is not 1 or 3"; |
| ++p; |
| // save start of augmentation string and find end |
| pint_t strStart = p; |
| while (addressSpace.get8(p) != 0) |
| ++p; |
| ++p; |
| // parse code alignment factor |
| cieInfo->codeAlignFactor = (uint32_t)addressSpace.getULEB128(p, cieContentEnd); |
| // parse data alignment factor |
| cieInfo->dataAlignFactor = (int)addressSpace.getSLEB128(p, cieContentEnd); |
| // parse return address register |
| uint64_t raReg = (version == 1) ? addressSpace.get8(p++) |
| : addressSpace.getULEB128(p, cieContentEnd); |
| assert(raReg < 255 && "return address register too large"); |
| cieInfo->returnAddressRegister = (uint8_t)raReg; |
| // parse augmentation data based on augmentation string |
| const char *result = NULL; |
| if (addressSpace.get8(strStart) == 'z') { |
| // parse augmentation data length |
| addressSpace.getULEB128(p, cieContentEnd); |
| for (pint_t s = strStart; addressSpace.get8(s) != '\0'; ++s) { |
| switch (addressSpace.get8(s)) { |
| case 'z': |
| cieInfo->fdesHaveAugmentationData = true; |
| break; |
| case 'P': |
| cieInfo->personalityEncoding = addressSpace.get8(p); |
| ++p; |
| cieInfo->personalityOffsetInCIE = (uint8_t)(p - cie); |
| cieInfo->personality = addressSpace |
| .getEncodedP(p, cieContentEnd, cieInfo->personalityEncoding); |
| break; |
| case 'L': |
| cieInfo->lsdaEncoding = addressSpace.get8(p); |
| ++p; |
| break; |
| case 'R': |
| cieInfo->pointerEncoding = addressSpace.get8(p); |
| ++p; |
| break; |
| case 'S': |
| cieInfo->isSignalFrame = true; |
| break; |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| case 'B': |
| cieInfo->addressesSignedWithBKey = true; |
| break; |
| case 'G': |
| cieInfo->mteTaggedFrame = true; |
| break; |
| #endif |
| default: |
| // ignore unknown letters |
| break; |
| } |
| } |
| } |
| cieInfo->cieLength = cieContentEnd - cieInfo->cieStart; |
| cieInfo->cieInstructions = p; |
| return result; |
| } |
| |
| |
| /// "run" the DWARF instructions and create the abstract PrologInfo for an FDE |
| template <typename A> |
| bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace, |
| const FDE_Info &fdeInfo, |
| const CIE_Info &cieInfo, pint_t upToPC, |
| int arch, PrologInfo *results) { |
| // Alloca is used for the allocation of the rememberStack entries. It removes |
| // the dependency on new/malloc but the below for loop can not be refactored |
| // into functions. Entry could be saved during the processing of a CIE and |
| // restored by an FDE. |
| RememberStack rememberStack; |
| |
| struct ParseInfo { |
| pint_t instructions; |
| pint_t instructionsEnd; |
| pint_t pcoffset; |
| }; |
| |
| ParseInfo parseInfoArray[] = { |
| {cieInfo.cieInstructions, cieInfo.cieStart + cieInfo.cieLength, |
| (pint_t)(-1)}, |
| {fdeInfo.fdeInstructions, fdeInfo.fdeStart + fdeInfo.fdeLength, |
| upToPC - fdeInfo.pcStart}}; |
| |
| for (const auto &info : parseInfoArray) { |
| pint_t p = info.instructions; |
| pint_t instructionsEnd = info.instructionsEnd; |
| pint_t pcoffset = info.pcoffset; |
| pint_t codeOffset = 0; |
| |
| // initialState initialized as registers in results are modified. Use |
| // PrologInfo accessor functions to avoid reading uninitialized data. |
| PrologInfo initialState(PrologInfo::InitializeTime::kLazy); |
| |
| _LIBUNWIND_TRACE_DWARF("parseFDEInstructions(instructions=0x%0" PRIx64 |
| ")\n", |
| static_cast<uint64_t>(instructionsEnd)); |
| |
| // see DWARF Spec, section 6.4.2 for details on unwind opcodes |
| while ((p < instructionsEnd) && (codeOffset < pcoffset)) { |
| uint64_t reg; |
| uint64_t reg2; |
| int64_t offset; |
| uint64_t length; |
| uint8_t opcode = addressSpace.get8(p); |
| uint8_t operand; |
| |
| ++p; |
| switch (opcode) { |
| case DW_CFA_nop: |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_nop\n"); |
| break; |
| case DW_CFA_set_loc: |
| codeOffset = addressSpace.getEncodedP(p, instructionsEnd, |
| cieInfo.pointerEncoding); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_set_loc\n"); |
| break; |
| case DW_CFA_advance_loc1: |
| codeOffset += (addressSpace.get8(p) * cieInfo.codeAlignFactor); |
| p += 1; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc1: new offset=%" PRIu64 "\n", |
| static_cast<uint64_t>(codeOffset)); |
| break; |
| case DW_CFA_advance_loc2: |
| codeOffset += (addressSpace.get16(p) * cieInfo.codeAlignFactor); |
| p += 2; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc2: new offset=%" PRIu64 "\n", |
| static_cast<uint64_t>(codeOffset)); |
| break; |
| case DW_CFA_advance_loc4: |
| codeOffset += (addressSpace.get32(p) * cieInfo.codeAlignFactor); |
| p += 4; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc4: new offset=%" PRIu64 "\n", |
| static_cast<uint64_t>(codeOffset)); |
| break; |
| case DW_CFA_offset_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_offset_extended DWARF unwind, reg too big"); |
| return false; |
| } |
| results->setRegister(reg, kRegisterInCFA, offset, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended(reg=%" PRIu64 ", " |
| "offset=%" PRId64 ")\n", |
| reg, offset); |
| break; |
| case DW_CFA_restore_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_restore_extended DWARF unwind, reg too big"); |
| return false; |
| } |
| results->restoreRegisterToInitialState(reg, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_restore_extended(reg=%" PRIu64 ")\n", |
| reg); |
| break; |
| case DW_CFA_undefined: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_undefined DWARF unwind, reg too big"); |
| return false; |
| } |
| results->setRegisterLocation(reg, kRegisterUndefined, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_undefined(reg=%" PRIu64 ")\n", reg); |
| break; |
| case DW_CFA_same_value: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_same_value DWARF unwind, reg too big"); |
| return false; |
| } |
| // <rdar://problem/8456377> DW_CFA_same_value unsupported |
| // "same value" means register was stored in frame, but its current |
| // value has not changed, so no need to restore from frame. |
| // We model this as if the register was never saved. |
| results->setRegisterLocation(reg, kRegisterUnused, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_same_value(reg=%" PRIu64 ")\n", reg); |
| break; |
| case DW_CFA_register: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| reg2 = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_register DWARF unwind, reg too big"); |
| return false; |
| } |
| if (reg2 > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_register DWARF unwind, reg2 too big"); |
| return false; |
| } |
| results->setRegister(reg, kRegisterInRegister, (int64_t)reg2, |
| initialState); |
| _LIBUNWIND_TRACE_DWARF( |
| "DW_CFA_register(reg=%" PRIu64 ", reg2=%" PRIu64 ")\n", reg, reg2); |
| break; |
| case DW_CFA_remember_state: { |
| // Avoid operator new because that would be an upward dependency. |
| // Avoid malloc because it needs heap allocation. |
| PrologInfoStackEntry *entry = |
| (PrologInfoStackEntry *)_LIBUNWIND_REMEMBER_ALLOC( |
| sizeof(PrologInfoStackEntry)); |
| if (entry != NULL) { |
| entry->next = rememberStack.entry; |
| entry->info = *results; |
| rememberStack.entry = entry; |
| } else { |
| return false; |
| } |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_remember_state\n"); |
| break; |
| } |
| case DW_CFA_restore_state: |
| if (rememberStack.entry != NULL) { |
| PrologInfoStackEntry *top = rememberStack.entry; |
| *results = top->info; |
| rememberStack.entry = top->next; |
| _LIBUNWIND_REMEMBER_FREE(top); |
| } else { |
| return false; |
| } |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_restore_state\n"); |
| break; |
| case DW_CFA_def_cfa: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0("malformed DW_CFA_def_cfa DWARF unwind, reg too big"); |
| return false; |
| } |
| results->cfaRegister = (uint32_t)reg; |
| results->cfaRegisterOffset = (int32_t)offset; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa(reg=%" PRIu64 ", offset=%" PRIu64 |
| ")\n", |
| reg, offset); |
| break; |
| case DW_CFA_def_cfa_register: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_def_cfa_register DWARF unwind, reg too big"); |
| return false; |
| } |
| results->cfaRegister = (uint32_t)reg; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_register(%" PRIu64 ")\n", reg); |
| break; |
| case DW_CFA_def_cfa_offset: |
| results->cfaRegisterOffset = |
| (int32_t)addressSpace.getULEB128(p, instructionsEnd); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_offset(%d)\n", |
| results->cfaRegisterOffset); |
| break; |
| case DW_CFA_def_cfa_expression: |
| results->cfaRegister = 0; |
| results->cfaExpression = (int64_t)p; |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| assert(length < static_cast<pint_t>(~0) && "pointer overflow"); |
| p += static_cast<pint_t>(length); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_expression(expression=0x%" PRIx64 |
| ", length=%" PRIu64 ")\n", |
| results->cfaExpression, length); |
| break; |
| case DW_CFA_expression: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_expression DWARF unwind, reg too big"); |
| return false; |
| } |
| results->setRegister(reg, kRegisterAtExpression, (int64_t)p, |
| initialState); |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| assert(length < static_cast<pint_t>(~0) && "pointer overflow"); |
| p += static_cast<pint_t>(length); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_expression(reg=%" PRIu64 ", " |
| "expression=0x%" PRIx64 ", " |
| "length=%" PRIu64 ")\n", |
| reg, results->savedRegisters[reg].value, length); |
| break; |
| case DW_CFA_offset_extended_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_offset_extended_sf DWARF unwind, reg too big"); |
| return false; |
| } |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| results->setRegister(reg, kRegisterInCFA, offset, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended_sf(reg=%" PRIu64 ", " |
| "offset=%" PRId64 ")\n", |
| reg, offset); |
| break; |
| case DW_CFA_def_cfa_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_def_cfa_sf DWARF unwind, reg too big"); |
| return false; |
| } |
| results->cfaRegister = (uint32_t)reg; |
| results->cfaRegisterOffset = (int32_t)offset; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_sf(reg=%" PRIu64 ", " |
| "offset=%" PRId64 ")\n", |
| reg, offset); |
| break; |
| case DW_CFA_def_cfa_offset_sf: |
| results->cfaRegisterOffset = |
| (int32_t)(addressSpace.getSLEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_offset_sf(%d)\n", |
| results->cfaRegisterOffset); |
| break; |
| case DW_CFA_val_offset: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG( |
| "malformed DW_CFA_val_offset DWARF unwind, reg (%" PRIu64 |
| ") out of range\n", |
| reg); |
| return false; |
| } |
| offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset(reg=%" PRIu64 ", " |
| "offset=%" PRId64 "\n", |
| reg, offset); |
| break; |
| case DW_CFA_val_offset_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_val_offset_sf DWARF unwind, reg too big"); |
| return false; |
| } |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset_sf(reg=%" PRIu64 ", " |
| "offset=%" PRId64 "\n", |
| reg, offset); |
| break; |
| case DW_CFA_val_expression: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0( |
| "malformed DW_CFA_val_expression DWARF unwind, reg too big"); |
| return false; |
| } |
| results->setRegister(reg, kRegisterIsExpression, (int64_t)p, |
| initialState); |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| assert(length < static_cast<pint_t>(~0) && "pointer overflow"); |
| p += static_cast<pint_t>(length); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_val_expression(reg=%" PRIu64 ", " |
| "expression=0x%" PRIx64 ", length=%" PRIu64 |
| ")\n", |
| reg, results->savedRegisters[reg].value, length); |
| break; |
| case DW_CFA_GNU_args_size: |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| results->spExtraArgSize = (uint32_t)length; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_args_size(%" PRIu64 ")\n", length); |
| break; |
| case DW_CFA_GNU_negative_offset_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG0("malformed DW_CFA_GNU_negative_offset_extended DWARF " |
| "unwind, reg too big"); |
| return false; |
| } |
| offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| results->setRegister(reg, kRegisterInCFA, -offset, initialState); |
| _LIBUNWIND_TRACE_DWARF( |
| "DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", offset); |
| break; |
| |
| #if defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_SPARC) || \ |
| defined(_LIBUNWIND_TARGET_SPARC64) |
| // The same constant is used to represent different instructions on |
| // AArch64 (negate_ra_state) and SPARC (window_save). |
| static_assert(DW_CFA_AARCH64_negate_ra_state == DW_CFA_GNU_window_save, |
| "uses the same constant"); |
| case DW_CFA_AARCH64_negate_ra_state: |
| switch (arch) { |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| case REGISTERS_ARM64: { |
| int64_t value = |
| results->savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value ^ 0x1; |
| results->setRegisterValue(UNW_AARCH64_RA_SIGN_STATE, value, |
| initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_AARCH64_negate_ra_state\n"); |
| } break; |
| #endif |
| |
| #if defined(_LIBUNWIND_TARGET_SPARC) |
| // case DW_CFA_GNU_window_save: |
| case REGISTERS_SPARC: |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save()\n"); |
| for (reg = UNW_SPARC_O0; reg <= UNW_SPARC_O7; reg++) { |
| results->setRegister(reg, kRegisterInRegister, |
| ((int64_t)reg - UNW_SPARC_O0) + UNW_SPARC_I0, |
| initialState); |
| } |
| |
| for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) { |
| results->setRegister(reg, kRegisterInCFA, |
| ((int64_t)reg - UNW_SPARC_L0) * 4, |
| initialState); |
| } |
| break; |
| #endif |
| |
| #if defined(_LIBUNWIND_TARGET_SPARC64) |
| // case DW_CFA_GNU_window_save: |
| case REGISTERS_SPARC64: |
| // Don't save %o0-%o7 on sparc64. |
| // https://reviews.llvm.org/D32450#736405 |
| |
| for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) { |
| if (reg == UNW_SPARC_I7) |
| results->setRegister( |
| reg, kRegisterInCFADecrypt, |
| static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)), |
| initialState); |
| else |
| results->setRegister( |
| reg, kRegisterInCFA, |
| static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)), |
| initialState); |
| } |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save\n"); |
| break; |
| #endif |
| } |
| break; |
| |
| #if defined(_LIBUNWIND_TARGET_AARCH64) |
| case DW_CFA_AARCH64_negate_ra_state_with_pc: { |
| int64_t value = |
| results->savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value ^ 0x3; |
| results->setRegisterValue(UNW_AARCH64_RA_SIGN_STATE, value, |
| initialState); |
| // When calculating the value of the PC, it is assumed that the CFI |
| // instruction is placed before the signing instruction, however it is |
| // placed after. Because of this, we need to take into account the CFI |
| // instruction is one instruction call later than expected, and reduce |
| // the PC value by 4 bytes to compensate. |
| results->ptrAuthDiversifier = fdeInfo.pcStart + codeOffset - 0x4; |
| _LIBUNWIND_TRACE_DWARF( |
| "DW_CFA_AARCH64_negate_ra_state_with_pc(pc=0x%" PRIx64 ")\n", |
| static_cast<uint64_t>(results->ptrAuthDiversifier)); |
| } break; |
| #endif |
| |
| #else |
| (void)arch; |
| #endif |
| |
| default: |
| operand = opcode & 0x3F; |
| switch (opcode & 0xC0) { |
| case DW_CFA_offset: |
| reg = operand; |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG("malformed DW_CFA_offset DWARF unwind, reg (%" PRIu64 |
| ") out of range", |
| reg); |
| return false; |
| } |
| offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) * |
| cieInfo.dataAlignFactor; |
| results->setRegister(reg, kRegisterInCFA, offset, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_offset(reg=%d, offset=%" PRId64 ")\n", |
| operand, offset); |
| break; |
| case DW_CFA_advance_loc: |
| codeOffset += operand * cieInfo.codeAlignFactor; |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc: new offset=%" PRIu64 "\n", |
| static_cast<uint64_t>(codeOffset)); |
| break; |
| case DW_CFA_restore: |
| reg = operand; |
| if (reg > kMaxRegisterNumber) { |
| _LIBUNWIND_LOG( |
| "malformed DW_CFA_restore DWARF unwind, reg (%" PRIu64 |
| ") out of range", |
| reg); |
| return false; |
| } |
| results->restoreRegisterToInitialState(reg, initialState); |
| _LIBUNWIND_TRACE_DWARF("DW_CFA_restore(reg=%" PRIu64 ")\n", |
| static_cast<uint64_t>(operand)); |
| break; |
| default: |
| _LIBUNWIND_TRACE_DWARF("unknown CFA opcode 0x%02X\n", opcode); |
| return false; |
| } |
| } |
| } |
| } |
| return true; |
| } |
| |
| } // namespace libunwind |
| |
| #endif // __DWARF_PARSER_HPP__ |
