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[Cherry-pick into stable/20230725] [libDebugInfo] Prevent infinite recursion in DWARFDie::getTypeSize() (#74681) #7864

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Merged
merged 1 commit into from
Dec 11, 2023
Merged

[Cherry-pick into stable/20230725] [libDebugInfo] Prevent infinite recursion in DWARFDie::getTypeSize() (#74681) #7864

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34 changes: 23 additions & 11 deletions llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//

#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
Expand Down Expand Up @@ -487,18 +488,23 @@ void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
CallDiscriminator = toUnsigned(find(DW_AT_GNU_discriminator), 0);
}

std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
if (auto SizeAttr = find(DW_AT_byte_size))
static std::optional<uint64_t>
getTypeSizeImpl(DWARFDie Die, uint64_t PointerSize,
SmallPtrSetImpl<const DWARFDebugInfoEntry *> &Visited) {
// Cycle detected?
if (!Visited.insert(Die.getDebugInfoEntry()).second)
return {};
if (auto SizeAttr = Die.find(DW_AT_byte_size))
if (std::optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
return Size;

switch (getTag()) {
switch (Die.getTag()) {
case DW_TAG_pointer_type:
case DW_TAG_reference_type:
case DW_TAG_rvalue_reference_type:
return PointerSize;
case DW_TAG_ptr_to_member_type: {
if (DWARFDie BaseType = getAttributeValueAsReferencedDie(DW_AT_type))
if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
if (BaseType.getTag() == DW_TAG_subroutine_type)
return 2 * PointerSize;
return PointerSize;
Expand All @@ -508,19 +514,20 @@ std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
case DW_TAG_volatile_type:
case DW_TAG_restrict_type:
case DW_TAG_typedef: {
if (DWARFDie BaseType = getAttributeValueAsReferencedDie(DW_AT_type))
return BaseType.getTypeSize(PointerSize);
if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
return getTypeSizeImpl(BaseType, PointerSize, Visited);
break;
}
case DW_TAG_array_type: {
DWARFDie BaseType = getAttributeValueAsReferencedDie(DW_AT_type);
DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type);
if (!BaseType)
return std::nullopt;
std::optional<uint64_t> BaseSize = BaseType.getTypeSize(PointerSize);
std::optional<uint64_t> BaseSize =
getTypeSizeImpl(BaseType, PointerSize, Visited);
if (!BaseSize)
return std::nullopt;
uint64_t Size = *BaseSize;
for (DWARFDie Child : *this) {
for (DWARFDie Child : Die) {
if (Child.getTag() != DW_TAG_subrange_type)
continue;

Expand All @@ -540,13 +547,18 @@ std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
return Size;
}
default:
if (DWARFDie BaseType = getAttributeValueAsReferencedDie(DW_AT_type))
return BaseType.getTypeSize(PointerSize);
if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
return getTypeSizeImpl(BaseType, PointerSize, Visited);
break;
}
return std::nullopt;
}

std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
SmallPtrSet<const DWARFDebugInfoEntry *, 4> Visited;
return getTypeSizeImpl(*this, PointerSize, Visited);
}

/// Helper to dump a DIE with all of its parents, but no siblings.
static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
DIDumpOptions DumpOpts, unsigned Depth = 0) {
Expand Down
36 changes: 36 additions & 0 deletions llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1660,6 +1660,42 @@ TEST(DWARFDebugInfo, TestFindRecurse) {
EXPECT_EQ(AbsDieName, StringOpt.value_or(nullptr));
}

TEST(DWARFDebugInfo, TestSelfRecursiveType) {
typedef uint32_t AddrType;
Triple Triple = getDefaultTargetTripleForAddrSize(sizeof(AddrType));
if (!isConfigurationSupported(Triple))
GTEST_SKIP();

auto ExpectedDG = dwarfgen::Generator::create(Triple, 4);
ASSERT_THAT_EXPECTED(ExpectedDG, Succeeded());
dwarfgen::Generator *DG = ExpectedDG.get().get();
dwarfgen::CompileUnit &CU = DG->addCompileUnit();
dwarfgen::DIE CUDie = CU.getUnitDIE();

// Create an invalid self-recursive typedef.
dwarfgen::DIE TypedefDie = CUDie.addChild(DW_TAG_typedef);
TypedefDie.addAttribute(DW_AT_name, DW_FORM_strp, "illegal");
TypedefDie.addAttribute(DW_AT_type, DW_FORM_ref_addr, TypedefDie);

MemoryBufferRef FileBuffer(DG->generate(), "dwarf");
auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
EXPECT_TRUE((bool)Obj);
std::unique_ptr<DWARFContext> DwarfContext = DWARFContext::create(**Obj);

// Verify the number of compile units is correct.
uint32_t NumCUs = DwarfContext->getNumCompileUnits();
EXPECT_EQ(NumCUs, 1u);
DWARFCompileUnit *U = cast<DWARFCompileUnit>(DwarfContext->getUnitAtIndex(0));
{
DWARFDie CUDie = U->getUnitDIE(false);
EXPECT_TRUE(CUDie.isValid());
DWARFDie TypedefDie = CUDie.getFirstChild();

// Test that getTypeSize doesn't get into an infinite loop.
EXPECT_EQ(TypedefDie.getTypeSize(sizeof(AddrType)), std::nullopt);
}
}

TEST(DWARFDebugInfo, TestDwarfToFunctions) {
// Test all of the dwarf::toXXX functions that take a
// std::optional<DWARFFormValue> and extract the values from it.
Expand Down