Merge "Fix support finding global variables." (2da8e3c2) · Commits · e / os / android_system_core

libunwindstack/Elf.cpp

+16 −18

Original line number	Diff line number	Diff line
		@@ -112,37 +112,35 @@ bool Elf::GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offse
		gnu_debugdata_interface_->GetFunctionName(addr, name, func_offset)));
		}

		bool Elf::GetGlobalVariable(const std::string& name, uint64_t* memory_address) {
		bool Elf::GetGlobalVariableOffset(const std::string& name, uint64_t* memory_offset) {
		if (!valid_) {
		return false;
		}

		if (!interface_->GetGlobalVariable(name, memory_address) &&
		uint64_t vaddr;
		if (!interface_->GetGlobalVariable(name, &vaddr) &&
		(gnu_debugdata_interface_ == nullptr \|\|
		!gnu_debugdata_interface_->GetGlobalVariable(name, memory_address))) {
		!gnu_debugdata_interface_->GetGlobalVariable(name, &vaddr))) {
		return false;
		}

		// Adjust by the load bias.
		if (load_bias_ > 0 && *memory_address < static_cast<uint64_t>(load_bias_)) {
		return false;
		// Check the .data section.
		uint64_t vaddr_start = interface_->data_vaddr_start();
		if (vaddr >= vaddr_start && vaddr < interface_->data_vaddr_end()) {
		*memory_offset = vaddr - vaddr_start + interface_->data_offset();
		return true;
		}

		*memory_address -= load_bias_;

		// If this winds up in the dynamic section, then we might need to adjust
		// the address.
		uint64_t dynamic_end = interface_->dynamic_vaddr() + interface_->dynamic_size();
		if (memory_address >= interface_->dynamic_vaddr() && memory_address < dynamic_end) {
		if (interface_->dynamic_vaddr() > interface_->dynamic_offset()) {
		*memory_address -= interface_->dynamic_vaddr() - interface_->dynamic_offset();
		} else {
		*memory_address += interface_->dynamic_offset() - interface_->dynamic_vaddr();
		}
		}
		// Check the .dynamic section.
		vaddr_start = interface_->dynamic_vaddr_start();
		if (vaddr >= vaddr_start && vaddr < interface_->dynamic_vaddr_end()) {
		*memory_offset = vaddr - vaddr_start + interface_->dynamic_offset();
		return true;
		}

		return false;
		}

		std::string Elf::GetBuildID() {
		if (!valid_) {
		return "";

libunwindstack/ElfInterface.cpp

+15 −3

Original line number	Diff line number	Diff line
		@@ -236,8 +236,12 @@ void ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, int64_t* load_bias)

		case PT_DYNAMIC:
		dynamic_offset_ = phdr.p_offset;
		dynamic_vaddr_ = phdr.p_vaddr;
		dynamic_size_ = phdr.p_memsz;
		dynamic_vaddr_start_ = phdr.p_vaddr;
		if (__builtin_add_overflow(dynamic_vaddr_start_, phdr.p_memsz, &dynamic_vaddr_end_)) {
		dynamic_offset_ = 0;
		dynamic_vaddr_start_ = 0;
		dynamic_vaddr_end_ = 0;
		}
		break;

		default:
		@@ -360,6 +364,14 @@ void ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
		eh_frame_hdr_offset_ = shdr.sh_offset;
		eh_frame_hdr_section_bias_ = static_cast<uint64_t>(shdr.sh_addr) - shdr.sh_offset;
		eh_frame_hdr_size_ = shdr.sh_size;
		} else if (name == ".data") {
		data_offset_ = shdr.sh_offset;
		data_vaddr_start_ = shdr.sh_addr;
		if (__builtin_add_overflow(data_vaddr_start_, shdr.sh_size, &data_vaddr_end_)) {
		data_offset_ = 0;
		data_vaddr_start_ = 0;
		data_vaddr_end_ = 0;
		}
		}
		}
		}
		@@ -398,7 +410,7 @@ std::string ElfInterface::GetSonameWithTemplate() {
		// Find the soname location from the dynamic headers section.
		DynType dyn;
		uint64_t offset = dynamic_offset_;
		uint64_t max_offset = offset + dynamic_size_;
		uint64_t max_offset = offset + dynamic_vaddr_end_ - dynamic_vaddr_start_;
		for (uint64_t offset = dynamic_offset_; offset < max_offset; offset += sizeof(DynType)) {
		if (!memory_->ReadFully(offset, &dyn, sizeof(dyn))) {
		last_error_.code = ERROR_MEMORY_INVALID;

libunwindstack/Global.cpp

+28 −31

Original line number	Diff line number	Diff line
		@@ -39,28 +39,22 @@ void Global::SetArch(ArchEnum arch) {
		}
		}

		uint64_t Global::GetVariableOffset(MapInfo* info, const std::string& variable) {
		if (!search_libs_.empty()) {
		bool found = false;
		const char* lib = basename(info->name.c_str());
		for (const std::string& name : search_libs_) {
		if (name == lib) {
		found = true;
		break;
		}
		}
		if (!found) {
		return 0;
		bool Global::Searchable(const std::string& name) {
		if (search_libs_.empty()) {
		return true;
		}

		if (name.empty()) {
		return false;
		}

		Elf* elf = info->GetElf(memory_, arch());
		uint64_t ptr;
		// Find first non-empty list (libraries might be loaded multiple times).
		if (elf->GetGlobalVariable(variable, &ptr) && ptr != 0) {
		return ptr + info->start;
		const char* base_name = basename(name.c_str());
		for (const std::string& lib : search_libs_) {
		if (base_name == lib) {
		return true;
		}
		}
		return 0;
		return false;
		}

		void Global::FindAndReadVariable(Maps* maps, const char* var_str) {
		@@ -78,24 +72,27 @@ void Global::FindAndReadVariable(Maps* maps, const char* var_str) {
		// f2000-f3000 2000 rw- /system/lib/libc.so
		MapInfo* map_start = nullptr;
		for (const auto& info : *maps) {
		if (map_start != nullptr) {
		if (map_start->name == info->name) {
		if (map_start != nullptr && map_start->name == info->name) {
		if (info->offset != 0 &&
		(info->flags & (PROT_READ \| PROT_WRITE)) == (PROT_READ \| PROT_WRITE)) {
		uint64_t ptr = GetVariableOffset(map_start, variable);
		if (ptr != 0 && ReadVariableData(ptr)) {
		Elf* elf = map_start->GetElf(memory_, arch());
		uint64_t ptr;
		if (elf->GetGlobalVariableOffset(variable, &ptr) && ptr != 0) {
		uint64_t offset_end = info->offset + info->end - info->start;
		if (ptr >= info->offset && ptr < offset_end) {
		ptr = info->start + ptr - info->offset;
		if (ReadVariableData(ptr)) {
		break;
		} else {
		// Failed to find the global variable, do not bother trying again.
		map_start = nullptr;
		}
		}
		} else {
		}
		map_start = nullptr;
		}
		} else {
		map_start = nullptr;
		}
		if (map_start == nullptr && (info->flags & PROT_READ) && info->offset == 0 &&
		!info->name.empty()) {
		Searchable(info->name)) {
		map_start = info.get();
		}
		}

libunwindstack/include/unwindstack/Elf.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -63,7 +63,7 @@ class Elf {

		bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset);

		bool GetGlobalVariable(const std::string& name, uint64_t* memory_address);
		bool GetGlobalVariableOffset(const std::string& name, uint64_t* memory_offset);

		uint64_t GetRelPc(uint64_t pc, const MapInfo* map_info);

libunwindstack/include/unwindstack/ElfInterface.h

+11 −4

Original line number	Diff line number	Diff line
		@@ -77,8 +77,11 @@ class ElfInterface {
		void SetGnuDebugdataInterface(ElfInterface* interface) { gnu_debugdata_interface_ = interface; }

		uint64_t dynamic_offset() { return dynamic_offset_; }
		uint64_t dynamic_vaddr() { return dynamic_vaddr_; }
		uint64_t dynamic_size() { return dynamic_size_; }
		uint64_t dynamic_vaddr_start() { return dynamic_vaddr_start_; }
		uint64_t dynamic_vaddr_end() { return dynamic_vaddr_end_; }
		uint64_t data_offset() { return data_offset_; }
		uint64_t data_vaddr_start() { return data_vaddr_start_; }
		uint64_t data_vaddr_end() { return data_vaddr_end_; }
		uint64_t eh_frame_hdr_offset() { return eh_frame_hdr_offset_; }
		int64_t eh_frame_hdr_section_bias() { return eh_frame_hdr_section_bias_; }
		uint64_t eh_frame_hdr_size() { return eh_frame_hdr_size_; }
		@@ -141,8 +144,12 @@ class ElfInterface {

		// Stored elf data.
		uint64_t dynamic_offset_ = 0;
		uint64_t dynamic_vaddr_ = 0;
		uint64_t dynamic_size_ = 0;
		uint64_t dynamic_vaddr_start_ = 0;
		uint64_t dynamic_vaddr_end_ = 0;

		uint64_t data_offset_ = 0;
		uint64_t data_vaddr_start_ = 0;
		uint64_t data_vaddr_end_ = 0;

		uint64_t eh_frame_hdr_offset_ = 0;
		int64_t eh_frame_hdr_section_bias_ = 0;