Merge "Add section parsing and function name handling." (ee5c756d) · Commits · e / os / android_system_core

libunwindstack/Elf.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -45,8 +45,8 @@ class Elf {
		return valid_ && interface_->GetSoname(name);
		}

		bool GetFunctionName(uint64_t, std::string, uint64_t) {
		return false;
		bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) {
		return valid_ && interface_->GetFunctionName(addr, name, func_offset);
		}

		bool Step(uint64_t rel_pc, Regs* regs, Memory* process_memory) {

libunwindstack/ElfInterface.cpp

+95 −13

Original line number	Diff line number	Diff line
		@@ -22,9 +22,18 @@

		#include "DwarfDebugFrame.h"
		#include "DwarfEhFrame.h"
		#include "DwarfSection.h"
		#include "ElfInterface.h"
		#include "Log.h"
		#include "Memory.h"
		#include "Regs.h"
		#include "Symbols.h"

		ElfInterface::~ElfInterface() {
		for (auto symbol : symbols_) {
		delete symbol;
		}
		}

		template <typename AddressType>
		void ElfInterface::InitHeadersWithTemplate() {
		@@ -57,7 +66,13 @@ bool ElfInterface::ReadAllHeaders() {
		if (!ReadProgramHeaders<EhdrType, PhdrType>(ehdr)) {
		return false;
		}
		return ReadSectionHeaders<EhdrType, ShdrType>(ehdr);

		// We could still potentially unwind without the section header
		// information, so ignore any errors.
		if (!ReadSectionHeaders<EhdrType, ShdrType>(ehdr)) {
		log(0, "Malformed section header found, ignoring...");
		}
		return true;
		}

		template <typename EhdrType, typename PhdrType>
		@@ -147,12 +162,39 @@ bool ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
		}

		// Skip the first header, it's always going to be NULL.
		offset += ehdr.e_shentsize;
		for (size_t i = 1; i < ehdr.e_shnum; i++, offset += ehdr.e_shentsize) {
		if (!memory_->ReadField(offset, &shdr, &shdr.sh_type, sizeof(shdr.sh_type))) {
		return false;
		}

		if (shdr.sh_type == SHT_PROGBITS) {
		if (shdr.sh_type == SHT_SYMTAB \|\| shdr.sh_type == SHT_DYNSYM) {
		if (!memory_->Read(offset, &shdr, sizeof(shdr))) {
		return false;
		}
		// Need to go get the information about the section that contains
		// the string terminated names.
		ShdrType str_shdr;
		if (shdr.sh_link >= ehdr.e_shnum) {
		return false;
		}
		uint64_t str_offset = ehdr.e_shoff + shdr.sh_link * ehdr.e_shentsize;
		if (!memory_->ReadField(str_offset, &str_shdr, &str_shdr.sh_type, sizeof(str_shdr.sh_type))) {
		return false;
		}
		if (str_shdr.sh_type != SHT_STRTAB) {
		return false;
		}
		if (!memory_->ReadField(str_offset, &str_shdr, &str_shdr.sh_offset,
		sizeof(str_shdr.sh_offset))) {
		return false;
		}
		if (!memory_->ReadField(str_offset, &str_shdr, &str_shdr.sh_size, sizeof(str_shdr.sh_size))) {
		return false;
		}
		symbols_.push_back(new Symbols(shdr.sh_offset, shdr.sh_size, shdr.sh_entsize,
		str_shdr.sh_offset, str_shdr.sh_size));
		} else if (shdr.sh_type == SHT_PROGBITS && sec_size != 0) {
		// Look for the .debug_frame and .gnu_debugdata.
		if (!memory_->ReadField(offset, &shdr, &shdr.sh_name, sizeof(shdr.sh_name))) {
		return false;
		@@ -160,18 +202,20 @@ bool ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
		if (shdr.sh_name < sec_size) {
		std::string name;
		if (memory_->ReadString(sec_offset + shdr.sh_name, &name)) {
		uint64_t* offset_ptr = nullptr;
		uint64_t* size_ptr = nullptr;
		if (name == ".debug_frame") {
		if (memory_->ReadField(offset, &shdr, &shdr.sh_offset, sizeof(shdr.sh_offset)) &&
		memory_->ReadField(offset, &shdr, &shdr.sh_size, sizeof(shdr.sh_size))) {
		debug_frame_offset_ = shdr.sh_offset;
		debug_frame_size_ = shdr.sh_size;
		}
		offset_ptr = &debug_frame_offset_;
		size_ptr = &debug_frame_size_;
		} else if (name == ".gnu_debugdata") {
		if (memory_->ReadField(offset, &shdr, &shdr.sh_offset, sizeof(shdr.sh_offset)) &&
		memory_->ReadField(offset, &shdr, &shdr.sh_size, sizeof(shdr.sh_size))) {
		gnu_debugdata_offset_ = shdr.sh_offset;
		gnu_debugdata_size_ = shdr.sh_size;
		offset_ptr = &gnu_debugdata_offset_;
		size_ptr = &gnu_debugdata_size_;
		}
		if (offset_ptr != nullptr &&
		memory_->ReadField(offset, &shdr, &shdr.sh_offset, sizeof(shdr.sh_offset)) &&
		memory_->ReadField(offset, &shdr, &shdr.sh_size, sizeof(shdr.sh_size))) {
		*offset_ptr = shdr.sh_offset;
		*size_ptr = shdr.sh_size;
		}
		}
		}
		@@ -228,7 +272,40 @@ bool ElfInterface::GetSonameWithTemplate(std::string* soname) {
		return true;
		}

		bool ElfInterface::Step(uint64_t, Regs, Memory) {
		template <typename SymType>
		bool ElfInterface::GetFunctionNameWithTemplate(uint64_t addr, std::string* name,
		uint64_t* func_offset) {
		if (symbols_.empty()) {
		return false;
		}

		for (const auto symbol : symbols_) {
		if (symbol->GetName<SymType>(addr, load_bias_, memory_, name, func_offset)) {
		return true;
		}
		}
		return false;
		}

		bool ElfInterface::Step(uint64_t pc, Regs* regs, Memory* process_memory) {
		// Need to subtract off the load_bias to get the correct pc.
		if (pc < load_bias_) {
		return false;
		}
		pc -= load_bias_;

		// Try the eh_frame first.
		DwarfSection* eh_frame = eh_frame_.get();
		if (eh_frame != nullptr && eh_frame->Step(pc, regs, process_memory)) {
		return true;
		}

		// Try the debug_frame next.
		DwarfSection* debug_frame = debug_frame_.get();
		if (debug_frame != nullptr && debug_frame->Step(pc, regs, process_memory)) {
		return true;
		}

		return false;
		}

		@@ -247,3 +324,8 @@ template bool ElfInterface::ReadSectionHeaders<Elf64_Ehdr, Elf64_Shdr>(const Elf

		template bool ElfInterface::GetSonameWithTemplate<Elf32_Dyn>(std::string*);
		template bool ElfInterface::GetSonameWithTemplate<Elf64_Dyn>(std::string*);

		template bool ElfInterface::GetFunctionNameWithTemplate<Elf32_Sym>(uint64_t, std::string*,
		uint64_t*);
		template bool ElfInterface::GetFunctionNameWithTemplate<Elf64_Sym>(uint64_t, std::string*,
		uint64_t*);

libunwindstack/ElfInterface.h

+11 −5

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@
		// Forward declarations.
		class Memory;
		class Regs;
		class Symbols;

		struct LoadInfo {
		uint64_t offset;
		@@ -46,7 +47,7 @@ enum : uint8_t {
		class ElfInterface {
		public:
		ElfInterface(Memory* memory) : memory_(memory) {}
		virtual ~ElfInterface() = default;
		virtual ~ElfInterface();

		virtual bool Init() = 0;

		@@ -94,6 +95,9 @@ class ElfInterface {
		template <typename DynType>
		bool GetSonameWithTemplate(std::string* soname);

		template <typename SymType>
		bool GetFunctionNameWithTemplate(uint64_t addr, std::string* name, uint64_t* func_offset);

		virtual bool HandleType(uint64_t, uint32_t) { return false; }

		Memory* memory_;
		@@ -118,6 +122,8 @@ class ElfInterface {

		std::unique_ptr<DwarfSection> eh_frame_;
		std::unique_ptr<DwarfSection> debug_frame_;

		std::vector<Symbols*> symbols_;
		};

		class ElfInterface32 : public ElfInterface {
		@@ -135,8 +141,8 @@ class ElfInterface32 : public ElfInterface {
		return ElfInterface::GetSonameWithTemplate<Elf32_Dyn>(soname);
		}

		bool GetFunctionName(uint64_t, std::string, uint64_t) override {
		return false;
		bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) override {
		return ElfInterface::GetFunctionNameWithTemplate<Elf32_Sym>(addr, name, func_offset);
		}
		};

		@@ -155,8 +161,8 @@ class ElfInterface64 : public ElfInterface {
		return ElfInterface::GetSonameWithTemplate<Elf64_Dyn>(soname);
		}

		bool GetFunctionName(uint64_t, std::string, uint64_t) override {
		return false;
		bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) override {
		return ElfInterface::GetFunctionNameWithTemplate<Elf64_Sym>(addr, name, func_offset);
		}
		};

libunwindstack/tests/ElfInterfaceTest.cpp

+203 −0

Original line number	Diff line number	Diff line
		@@ -79,9 +79,37 @@ class ElfInterfaceTest : public ::testing::Test {
		template <typename ElfType>
		void InitHeadersDebugFrameFail();

		template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
		void InitSectionHeadersMalformed();

		template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
		void InitSectionHeaders(uint64_t entry_size);

		template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
		void InitSectionHeadersOffsets();

		template <typename Sym>
		void InitSym(uint64_t offset, uint32_t value, uint32_t size, uint32_t name_offset,
		uint64_t sym_offset, const char* name);

		MemoryFake memory_;
		};

		template <typename Sym>
		void ElfInterfaceTest::InitSym(uint64_t offset, uint32_t value, uint32_t size, uint32_t name_offset,
		uint64_t sym_offset, const char* name) {
		Sym sym;
		memset(&sym, 0, sizeof(sym));
		sym.st_info = STT_FUNC;
		sym.st_value = value;
		sym.st_size = size;
		sym.st_name = name_offset;
		sym.st_shndx = SHN_COMMON;

		memory_.SetMemory(offset, &sym, sizeof(sym));
		memory_.SetMemory(sym_offset + name_offset, name, strlen(name) + 1);
		}

		template <typename Ehdr, typename Phdr, typename Dyn, typename ElfInterfaceType>
		void ElfInterfaceTest::SinglePtLoad() {
		std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
		@@ -718,3 +746,178 @@ TEST_F(ElfInterfaceTest, init_headers_debug_frame32_fail) {
		TEST_F(ElfInterfaceTest, init_headers_debug_frame64_fail) {
		InitHeadersDebugFrameFail<MockElfInterface64>();
		}

		template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
		void ElfInterfaceTest::InitSectionHeadersMalformed() {
		std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));

		Ehdr ehdr;
		memset(&ehdr, 0, sizeof(ehdr));
		ehdr.e_shoff = 0x1000;
		ehdr.e_shnum = 10;
		ehdr.e_shentsize = sizeof(Shdr);
		memory_.SetMemory(0, &ehdr, sizeof(ehdr));

		ASSERT_TRUE(elf->Init());
		}

		TEST_F(ElfInterfaceTest, init_section_headers_malformed32) {
		InitSectionHeadersMalformed<Elf32_Ehdr, Elf32_Shdr, ElfInterface32>();
		}

		TEST_F(ElfInterfaceTest, init_section_headers_malformed64) {
		InitSectionHeadersMalformed<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
		}

		template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
		void ElfInterfaceTest::InitSectionHeaders(uint64_t entry_size) {
		std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));

		uint64_t offset = 0x1000;

		Ehdr ehdr;
		memset(&ehdr, 0, sizeof(ehdr));
		ehdr.e_shoff = offset;
		ehdr.e_shnum = 10;
		ehdr.e_shentsize = entry_size;
		memory_.SetMemory(0, &ehdr, sizeof(ehdr));

		offset += ehdr.e_shentsize;

		Shdr shdr;
		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_SYMTAB;
		shdr.sh_link = 4;
		shdr.sh_addr = 0x5000;
		shdr.sh_offset = 0x5000;
		shdr.sh_entsize = sizeof(Sym);
		shdr.sh_size = shdr.sh_entsize * 10;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_DYNSYM;
		shdr.sh_link = 4;
		shdr.sh_addr = 0x6000;
		shdr.sh_offset = 0x6000;
		shdr.sh_entsize = sizeof(Sym);
		shdr.sh_size = shdr.sh_entsize * 10;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_PROGBITS;
		shdr.sh_name = 0xa000;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		// The string data for the entries.
		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_STRTAB;
		shdr.sh_name = 0x20000;
		shdr.sh_offset = 0xf000;
		shdr.sh_size = 0x1000;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		InitSym<Sym>(0x5000, 0x90000, 0x1000, 0x100, 0xf000, "function_one");
		InitSym<Sym>(0x6000, 0xd0000, 0x1000, 0x300, 0xf000, "function_two");

		ASSERT_TRUE(elf->Init());
		EXPECT_EQ(0U, elf->debug_frame_offset());
		EXPECT_EQ(0U, elf->debug_frame_size());
		EXPECT_EQ(0U, elf->gnu_debugdata_offset());
		EXPECT_EQ(0U, elf->gnu_debugdata_size());

		// Look in the first symbol table.
		std::string name;
		uint64_t name_offset;
		ASSERT_TRUE(elf->GetFunctionName(0x90010, &name, &name_offset));
		EXPECT_EQ("function_one", name);
		EXPECT_EQ(16U, name_offset);
		ASSERT_TRUE(elf->GetFunctionName(0xd0020, &name, &name_offset));
		EXPECT_EQ("function_two", name);
		EXPECT_EQ(32U, name_offset);
		}

		TEST_F(ElfInterfaceTest, init_section_headers32) {
		InitSectionHeaders<Elf32_Ehdr, Elf32_Shdr, Elf32_Sym, ElfInterface32>(sizeof(Elf32_Shdr));
		}

		TEST_F(ElfInterfaceTest, init_section_headers64) {
		InitSectionHeaders<Elf64_Ehdr, Elf64_Shdr, Elf64_Sym, ElfInterface64>(sizeof(Elf64_Shdr));
		}

		TEST_F(ElfInterfaceTest, init_section_headers_non_std_entry_size32) {
		InitSectionHeaders<Elf32_Ehdr, Elf32_Shdr, Elf32_Sym, ElfInterface32>(0x100);
		}

		TEST_F(ElfInterfaceTest, init_section_headers_non_std_entry_size64) {
		InitSectionHeaders<Elf64_Ehdr, Elf64_Shdr, Elf64_Sym, ElfInterface64>(0x100);
		}

		template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
		void ElfInterfaceTest::InitSectionHeadersOffsets() {
		std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));

		uint64_t offset = 0x2000;

		Ehdr ehdr;
		memset(&ehdr, 0, sizeof(ehdr));
		ehdr.e_shoff = offset;
		ehdr.e_shnum = 10;
		ehdr.e_shentsize = sizeof(Shdr);
		ehdr.e_shstrndx = 2;
		memory_.SetMemory(0, &ehdr, sizeof(ehdr));

		offset += ehdr.e_shentsize;

		Shdr shdr;
		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_PROGBITS;
		shdr.sh_link = 2;
		shdr.sh_name = 0x200;
		shdr.sh_addr = 0x5000;
		shdr.sh_offset = 0x5000;
		shdr.sh_entsize = 0x100;
		shdr.sh_size = 0x800;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		// The string data for section header names.
		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_STRTAB;
		shdr.sh_name = 0x20000;
		shdr.sh_offset = 0xf000;
		shdr.sh_size = 0x1000;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		memset(&shdr, 0, sizeof(shdr));
		shdr.sh_type = SHT_PROGBITS;
		shdr.sh_link = 2;
		shdr.sh_name = 0x100;
		shdr.sh_addr = 0x6000;
		shdr.sh_offset = 0x6000;
		shdr.sh_entsize = 0x100;
		shdr.sh_size = 0x500;
		memory_.SetMemory(offset, &shdr, sizeof(shdr));
		offset += ehdr.e_shentsize;

		memory_.SetMemory(0xf100, ".debug_frame", sizeof(".debug_frame"));
		memory_.SetMemory(0xf200, ".gnu_debugdata", sizeof(".gnu_debugdata"));

		ASSERT_TRUE(elf->Init());
		EXPECT_EQ(0x6000U, elf->debug_frame_offset());
		EXPECT_EQ(0x500U, elf->debug_frame_size());
		EXPECT_EQ(0x5000U, elf->gnu_debugdata_offset());
		EXPECT_EQ(0x800U, elf->gnu_debugdata_size());
		}

		TEST_F(ElfInterfaceTest, init_section_headers_offsets32) {
		InitSectionHeadersOffsets<Elf32_Ehdr, Elf32_Shdr, ElfInterface32>();
		}

		TEST_F(ElfInterfaceTest, init_section_headers_offsets64) {
		InitSectionHeadersOffsets<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
		}