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- //===----------------------------------------------------------------------===//
- //
- // 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;
- #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];
- 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;
- #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 aligment 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;
- #endif
- default:
- // ignore unknown letters
- break;
- }
- }
- }
- cieInfo->cieLength = cieContentEnd - cieInfo->cieStart;
- cieInfo->cieInstructions = p;
- return result;
- }
- /// "run" the DWARF instructions and create the abstact 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;
- #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__
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