[LLDB] Add tests for handling invalid FDE entries and valid CIE markers

agontarek · agontarek · commit c2efe010994d · 2025-09-23T10:37:17.000-05:00
This commit introduces new unit tests to verify the handling of invalid Frame Description Entries (FDEs) with invalid CIE ID values for both DWARF32 and DWARF64 formats. Additionally, it includes tests for valid CIE markers in both eh_frame and debug_frame formats, ensuring that the unwind plans are correctly generated or returned as null when encountering invalid entries.
diff --git a/lldb/unittests/Symbol/TestDWARFCallFrameInfo.cpp b/lldb/unittests/Symbol/TestDWARFCallFrameInfo.cpp
@@ -380,3 +380,288 @@ void DWARFCallFrameInfoTest::TestValOffset(DWARFCallFrameInfo::Type type,
 TEST_F(DWARFCallFrameInfoTest, ValOffset_dwarf3) {
   TestValOffset(DWARFCallFrameInfo::DWARF, "debug_frame3");
 }
+
+// Test that we correctly handle invalid FDE entries that have CIE ID values
+TEST_F(DWARFCallFrameInfoTest, InvalidFDEWithCIEID_dwarf32) {
+  // Create an FDE with cie_offset of 0xFFFFFFFF (DW_CIE_ID) which is invalid
+  auto ExpectedFile = TestFile::fromYaml(R"(
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000000260
+    AddressAlign:    0x0000000000000010
+    Content:         554889E5897DFC8B45FC5DC3
+  - Name:            .debug_frame
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000008
+    # First, a valid CIE
+    # 00000000 0000000000000014 ffffffff CIE
+    #   Version:               3
+    #   Augmentation:          ""
+    #   Code alignment factor: 1
+    #   Data alignment factor: -8
+    #   Return address column: 16
+    Content:         14000000FFFFFFFF03000178100C0708900100000000000018000000FFFFFFFF60020000000000000C00000000000000
+    # Then an invalid FDE with CIE pointer = 0xFFFFFFFF (which would make it look like a CIE)
+    # 00000018 0000000000000018 ffffffff FDE cie=ffffffff pc=0000000000000260..000000000000026c
+    # The cie offset of 0xFFFFFFFF is invalid for an FDE in debug_frame
+Symbols:
+  - Name:            test_invalid
+    Type:            STT_FUNC
+    Section:         .text
+    Value:           0x0000000000000260
+    Size:            0x000000000000000C
+    Binding:         STB_GLOBAL
+...
+)");
+  ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
+
+  auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
+  SectionList *list = module_sp->GetSectionList();
+  ASSERT_NE(nullptr, list);
+
+  auto section_sp = list->FindSectionByType(eSectionTypeDWARFDebugFrame, false);
+  ASSERT_NE(nullptr, section_sp);
+
+  DWARFCallFrameInfo cfi(*module_sp->GetObjectFile(), section_sp,
+                         DWARFCallFrameInfo::DWARF);
+
+  // This should trigger our assertion or return nullptr because the FDE is
+  // invalid
+  const Symbol *sym = module_sp->FindFirstSymbolWithNameAndType(
+      ConstString("test_invalid"), eSymbolTypeAny);
+  ASSERT_NE(nullptr, sym);
+
+  std::unique_ptr<UnwindPlan> plan_up = cfi.GetUnwindPlan(sym->GetAddress());
+  // The plan should be null because we have an invalid FDE
+  EXPECT_EQ(nullptr, plan_up);
+}
+
+// Test that we correctly handle invalid FDE entries that have CIE ID values
+TEST_F(DWARFCallFrameInfoTest, InvalidFDEWithCIEID_dwarf64) {
+  // Create an FDE with cie_offset of 0xFFFFFFFFFFFFFFFF (DW64_CIE_ID) which is
+  // invalid
+  auto ExpectedFile = TestFile::fromYaml(R"(
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000000260
+    AddressAlign:    0x0000000000000010
+    Content:         554889E5897DFC8B45FC5DC3
+  - Name:            .debug_frame
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000008
+    # DWARF64 format CIE
+    # Initial length: 0xFFFFFFFF followed by 64-bit length
+    # 00000000 ffffffff 0000000000000014 ffffffffffffffff CIE
+    Content:         FFFFFFFF1400000000000000FFFFFFFFFFFFFFFF03000178100C0708900100000000FFFFFFFF1800000000000000FFFFFFFFFFFFFFFF60020000000000000C00000000000000
+    # DWARF64 FDE with invalid CIE pointer = 0xFFFFFFFFFFFFFFFF
+    # Initial length: 0xFFFFFFFF, followed by 64-bit length (0x18)
+    # Then 64-bit CIE pointer: 0xFFFFFFFFFFFFFFFF (which is DW64_CIE_ID, invalid for FDE)
+Symbols:
+  - Name:            test_invalid64
+    Type:            STT_FUNC
+    Section:         .text
+    Value:           0x0000000000000260
+    Size:            0x000000000000000C
+    Binding:         STB_GLOBAL
+...
+)");
+  ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
+
+  auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
+  SectionList *list = module_sp->GetSectionList();
+  ASSERT_NE(nullptr, list);
+
+  auto section_sp = list->FindSectionByType(eSectionTypeDWARFDebugFrame, false);
+  ASSERT_NE(nullptr, section_sp);
+
+  DWARFCallFrameInfo cfi(*module_sp->GetObjectFile(), section_sp,
+                         DWARFCallFrameInfo::DWARF);
+
+  const Symbol *sym = module_sp->FindFirstSymbolWithNameAndType(
+      ConstString("test_invalid64"), eSymbolTypeAny);
+  ASSERT_NE(nullptr, sym);
+
+  std::unique_ptr<UnwindPlan> plan_up = cfi.GetUnwindPlan(sym->GetAddress());
+  // The plan should be null because we have an invalid FDE
+  EXPECT_EQ(nullptr, plan_up);
+}
+
+// Test valid CIE markers in eh_frame format
+TEST_F(DWARFCallFrameInfoTest, ValidCIEMarkers_eh_frame) {
+  auto ExpectedFile = TestFile::fromYaml(R"(
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_DYN
+  Machine:         EM_X86_64
+  Entry:           0x0000000000000260
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000000260
+    AddressAlign:    0x0000000000000010
+    Content:         554889E5897DFC8B45FC5DC3
+  - Name:            .eh_frame
+    Type:            SHT_X86_64_UNWIND
+    Flags:           [ SHF_ALLOC ]
+    Address:         0x0000000000000290
+    AddressAlign:    0x0000000000000008
+    # eh_frame content
+    # CIE + FDE that works with address 0x260
+    Content:         1400000000000000017A5200017810011B0C0708900100001C0000001C000000B0FFFFFF0C00000000410E108602430D0600000000000000
+Symbols:
+  - Name:            simple_function
+    Type:            STT_FUNC
+    Section:         .text
+    Value:           0x0000000000000260
+    Size:            0x000000000000000F
+    Binding:         STB_GLOBAL
+...
+)");
+  ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
+
+  auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
+  SectionList *list = module_sp->GetSectionList();
+  ASSERT_NE(nullptr, list);
+
+  auto section_sp = list->FindSectionByType(eSectionTypeEHFrame, false);
+  ASSERT_NE(nullptr, section_sp);
+
+  DWARFCallFrameInfo cfi(*module_sp->GetObjectFile(), section_sp,
+                         DWARFCallFrameInfo::EH);
+
+  const Symbol *sym = module_sp->FindFirstSymbolWithNameAndType(
+      ConstString("simple_function"), eSymbolTypeAny);
+  ASSERT_NE(nullptr, sym);
+
+  std::unique_ptr<UnwindPlan> plan_up = cfi.GetUnwindPlan(sym->GetAddress());
+  // Should succeed with valid CIE and FDE
+  ASSERT_NE(nullptr, plan_up);
+  EXPECT_GE(plan_up->GetRowCount(), 1);
+}
+
+// Test valid CIE markers in debug_frame DWARF32 format
+TEST_F(DWARFCallFrameInfoTest, ValidCIEMarkers_dwarf32) {
+  auto ExpectedFile = TestFile::fromYaml(R"(
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000001130
+    AddressAlign:    0x0000000000000010
+    Content:         554889E5897DFC8B45FC83C0015DC3
+  - Name:            .debug_frame
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000008
+    # debug_frame content in DWARF32 format
+    # CIE (length=0x14, CIE_id=0xFFFFFFFF, version=4)
+    # FDE (length=0x24, CIE_offset=0)
+    Content:         14000000FFFFFFFF040008000178100C0708900100000000240000000000000030110000000000000F00000000000000410E108602430D064A0C070800000000
+Symbols:
+  - Name:            simple_function
+    Type:            STT_FUNC
+    Section:         .text
+    Value:           0x0000000000001130
+    Size:            0x000000000000000F
+    Binding:         STB_GLOBAL
+...
+)");
+  ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
+
+  auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
+  SectionList *list = module_sp->GetSectionList();
+  ASSERT_NE(nullptr, list);
+
+  auto section_sp = list->FindSectionByType(eSectionTypeDWARFDebugFrame, false);
+  ASSERT_NE(nullptr, section_sp);
+
+  DWARFCallFrameInfo cfi(*module_sp->GetObjectFile(), section_sp,
+                         DWARFCallFrameInfo::DWARF);
+
+  const Symbol *sym = module_sp->FindFirstSymbolWithNameAndType(
+      ConstString("simple_function"), eSymbolTypeAny);
+  ASSERT_NE(nullptr, sym);
+
+  std::unique_ptr<UnwindPlan> plan_up = cfi.GetUnwindPlan(sym->GetAddress());
+  // Should succeed with valid CIE and FDE
+  ASSERT_NE(nullptr, plan_up);
+  EXPECT_GE(plan_up->GetRowCount(), 1);
+}
+
+// Test valid CIE markers in debug_frame DWARF64 format
+TEST_F(DWARFCallFrameInfoTest, ValidCIEMarkers_dwarf64) {
+  auto ExpectedFile = TestFile::fromYaml(R"(
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x0000000000001130
+    AddressAlign:    0x0000000000000010
+    Content:         554889E5897DFC8B45FC83C0015DC3
+  - Name:            .debug_frame
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x0000000000000008
+    # debug_frame content in DWARF64 format
+    # CIE: length_marker=0xFFFFFFFF, length=0x14, CIE_id=0xFFFFFFFFFFFFFFFF, version=4
+    # FDE: length_marker=0xFFFFFFFF, length=0x24, CIE_offset=0x0 (points to CIE)
+    Content:         FFFFFFFF1400000000000000FFFFFFFFFFFFFFFF040008000178100C07089001FFFFFFFF2400000000000000000000000000000030110000000000000F00000000000000410E108602430D064A0C0708
+Symbols:
+  - Name:            simple_function
+    Type:            STT_FUNC
+    Section:         .text
+    Value:           0x0000000000001130
+    Size:            0x000000000000000F
+    Binding:         STB_GLOBAL
+...
+)");
+  ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
+
+  auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
+  SectionList *list = module_sp->GetSectionList();
+  ASSERT_NE(nullptr, list);
+
+  auto section_sp = list->FindSectionByType(eSectionTypeDWARFDebugFrame, false);
+  ASSERT_NE(nullptr, section_sp);
+
+  DWARFCallFrameInfo cfi(*module_sp->GetObjectFile(), section_sp,
+                         DWARFCallFrameInfo::DWARF);
+
+  const Symbol *sym = module_sp->FindFirstSymbolWithNameAndType(
+      ConstString("simple_function"), eSymbolTypeAny);
+  ASSERT_NE(nullptr, sym);
+
+  std::unique_ptr<UnwindPlan> plan_up = cfi.GetUnwindPlan(sym->GetAddress());
+  // Should succeed with valid CIE and FDE
+  ASSERT_NE(nullptr, plan_up);
+  EXPECT_GE(plan_up->GetRowCount(), 1);
+}
