//===--------------------------- DwarfParser.hpp --------------------------===//
//
// 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,
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,
uintptr_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);
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
template <typename A>
const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart,
FDE_Info *fdeInfo, CIE_Info *cieInfo) {
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;
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,
uintptr_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 == UINTPTR_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)
// 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_ARM64_RA_SIGN_STATE].value ^ 0x1;
results->setRegisterValue(UNW_ARM64_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
}
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__
