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Merge pull request #29 from ClickHouse/revert-27-cfa-loc-off-by-one
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Revert "Fix a suspected off-by-one error in parseFDEInstructions()"
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@antonio2368
antonio2368 authored Jul 22, 2024
2 parents 8f28e64 + d359824 commit fe85444
Showing 1 changed file with 27 additions and 29 deletions.
56 changes: 27 additions & 29 deletions src/DwarfParser.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -100,26 +100,26 @@ class CFI_Parser {
cfaRegister = (uint32_t)(-1);
}
}
void checkSaveRegister(uint64_t reg, PrologInfo &initialState, bool save) {
if (save && !savedRegisters[reg].initialStateSaved) {
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, bool save) {
checkSaveRegister(reg, initialState, save);
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, bool save) {
checkSaveRegister(reg, initialState, save);
PrologInfo &initialState) {
checkSaveRegister(reg, initialState);
savedRegisters[reg].location = newLocation;
}
void setRegisterValue(uint64_t reg, int64_t newValue,
PrologInfo &initialState, bool save) {
checkSaveRegister(reg, initialState, save);
PrologInfo &initialState) {
checkSaveRegister(reg, initialState);
savedRegisters[reg].value = newValue;
}
void restoreRegisterToInitialState(uint64_t reg, PrologInfo &initialState) {
Expand Down Expand Up @@ -430,20 +430,18 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
pint_t instructions;
pint_t instructionsEnd;
pint_t pcoffset;
bool save;
};

ParseInfo parseInfoArray[] = {
{cieInfo.cieInstructions, cieInfo.cieStart + cieInfo.cieLength,
(pint_t)(-1), false},
(pint_t)(-1)},
{fdeInfo.fdeInstructions, fdeInfo.fdeStart + fdeInfo.fdeLength,
upToPC - fdeInfo.pcStart, true}};
upToPC - fdeInfo.pcStart}};

for (const auto &info : parseInfoArray) {
pint_t p = info.instructions;
pint_t instructionsEnd = info.instructionsEnd;
pint_t pcoffset = info.pcoffset;
bool save = info.save;
pint_t codeOffset = 0;

// initialState initialized as registers in results are modified. Use
Expand All @@ -455,7 +453,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
static_cast<uint64_t>(instructionsEnd));

// see DWARF Spec, section 6.4.2 for details on unwind opcodes
while ((p < instructionsEnd) && (codeOffset <= pcoffset)) {
while ((p < instructionsEnd) && (codeOffset < pcoffset)) {
uint64_t reg;
uint64_t reg2;
int64_t offset;
Expand Down Expand Up @@ -500,7 +498,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
"malformed DW_CFA_offset_extended DWARF unwind, reg too big");
return false;
}
results->setRegister(reg, kRegisterInCFA, offset, initialState, save);
results->setRegister(reg, kRegisterInCFA, offset, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended(reg=%" PRIu64 ", "
"offset=%" PRId64 ")\n",
reg, offset);
Expand All @@ -523,7 +521,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
"malformed DW_CFA_undefined DWARF unwind, reg too big");
return false;
}
results->setRegisterLocation(reg, kRegisterUndefined, initialState, save);
results->setRegisterLocation(reg, kRegisterUndefined, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_undefined(reg=%" PRIu64 ")\n", reg);
break;
case DW_CFA_same_value:
Expand All @@ -537,7 +535,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
// "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, save);
results->setRegisterLocation(reg, kRegisterUnused, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_same_value(reg=%" PRIu64 ")\n", reg);
break;
case DW_CFA_register:
Expand All @@ -554,7 +552,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
return false;
}
results->setRegister(reg, kRegisterInRegister, (int64_t)reg2,
initialState, save);
initialState);
_LIBUNWIND_TRACE_DWARF(
"DW_CFA_register(reg=%" PRIu64 ", reg2=%" PRIu64 ")\n", reg, reg2);
break;
Expand Down Expand Up @@ -632,7 +630,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
return false;
}
results->setRegister(reg, kRegisterAtExpression, (int64_t)p,
initialState, save);
initialState);
length = addressSpace.getULEB128(p, instructionsEnd);
assert(length < static_cast<pint_t>(~0) && "pointer overflow");
p += static_cast<pint_t>(length);
Expand All @@ -650,7 +648,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
}
offset = addressSpace.getSLEB128(p, instructionsEnd) *
cieInfo.dataAlignFactor;
results->setRegister(reg, kRegisterInCFA, offset, initialState, save);
results->setRegister(reg, kRegisterInCFA, offset, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended_sf(reg=%" PRIu64 ", "
"offset=%" PRId64 ")\n",
reg, offset);
Expand Down Expand Up @@ -688,7 +686,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
}
offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
cieInfo.dataAlignFactor;
results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState, save);
results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset(reg=%" PRIu64 ", "
"offset=%" PRId64 "\n",
reg, offset);
Expand All @@ -702,7 +700,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
}
offset = addressSpace.getSLEB128(p, instructionsEnd) *
cieInfo.dataAlignFactor;
results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState, save);
results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset_sf(reg=%" PRIu64 ", "
"offset=%" PRId64 "\n",
reg, offset);
Expand All @@ -715,7 +713,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
return false;
}
results->setRegister(reg, kRegisterIsExpression, (int64_t)p,
initialState, save);
initialState);
length = addressSpace.getULEB128(p, instructionsEnd);
assert(length < static_cast<pint_t>(~0) && "pointer overflow");
p += static_cast<pint_t>(length);
Expand All @@ -738,7 +736,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
}
offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
cieInfo.dataAlignFactor;
results->setRegister(reg, kRegisterInCFA, -offset, initialState, save);
results->setRegister(reg, kRegisterInCFA, -offset, initialState);
_LIBUNWIND_TRACE_DWARF(
"DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", offset);
break;
Expand All @@ -756,7 +754,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
int64_t value =
results->savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value ^ 0x1;
results->setRegisterValue(UNW_AARCH64_RA_SIGN_STATE, value,
initialState, save);
initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_AARCH64_negate_ra_state\n");
} break;
#endif
Expand All @@ -768,13 +766,13 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
for (reg = UNW_SPARC_O0; reg <= UNW_SPARC_O7; reg++) {
results->setRegister(reg, kRegisterInRegister,
((int64_t)reg - UNW_SPARC_O0) + UNW_SPARC_I0,
initialState, save);
initialState);
}

for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) {
results->setRegister(reg, kRegisterInCFA,
((int64_t)reg - UNW_SPARC_L0) * 4,
initialState, save);
initialState);
}
break;
#endif
Expand All @@ -790,12 +788,12 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
results->setRegister(
reg, kRegisterInCFADecrypt,
static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
initialState, save);
initialState);
else
results->setRegister(
reg, kRegisterInCFA,
static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
initialState, save);
initialState);
}
_LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save\n");
break;
Expand All @@ -820,7 +818,7 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
}
offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
cieInfo.dataAlignFactor;
results->setRegister(reg, kRegisterInCFA, offset, initialState, save);
results->setRegister(reg, kRegisterInCFA, offset, initialState);
_LIBUNWIND_TRACE_DWARF("DW_CFA_offset(reg=%d, offset=%" PRId64 ")\n",
operand, offset);
break;
Expand Down

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