Merge "libunwindstack: Support signal frame CIEs." am: f30b12e6ad (27dcf970) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+2 −0

Original line number	Diff line number	Diff line
		@@ -296,6 +296,8 @@ cc_defaults {
		"tests/files/offline/shared_lib_in_apk_memory_only_arm64/*",
		"tests/files/offline/shared_lib_in_apk_single_map_arm64/*",
		"tests/files/offline/signal_load_bias_arm/*",
		"tests/files/offline/signal_fde_x86/*",
		"tests/files/offline/signal_fde_x86_64/*",
		"tests/files/offline/straddle_arm/*",
		"tests/files/offline/straddle_arm64/*",
		],

libunwindstack/DwarfSection.cpp

+11 −3

Original line number	Diff line number	Diff line
		@@ -37,7 +37,8 @@ namespace unwindstack {

		DwarfSection::DwarfSection(Memory* memory) : memory_(memory) {}

		bool DwarfSection::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {
		bool DwarfSection::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished,
		bool* is_signal_frame) {
		// Lookup the pc in the cache.
		auto it = loc_regs_.upper_bound(pc);
		if (it == loc_regs_.end() \|\| pc < it->second.pc_start) {
		@@ -59,6 +60,8 @@ bool DwarfSection::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* f
		it = loc_regs_.emplace(loc_regs.pc_end, std::move(loc_regs)).first;
		}

		*is_signal_frame = it->second.cie->is_signal_frame;

		// Now eval the actual registers.
		return Eval(it->second.cie, process_memory, it->second, regs, finished);
		}
		@@ -241,6 +244,9 @@ bool DwarfSectionImpl<AddressType>::FillInCie(DwarfCie* cie) {
		return false;
		}
		break;
		case 'S':
		cie->is_signal_frame = true;
		break;
		}
		}
		return true;
		@@ -558,8 +564,10 @@ bool DwarfSectionImpl<AddressType>::Eval(const DwarfCie* cie, Memory* regular_me
		cur_regs->set_pc((*cur_regs)[cie->return_address_register]);
		}

		// If the pc was set to zero, consider this the final frame.
		*finished = (cur_regs->pc() == 0) ? true : false;
		// If the pc was set to zero, consider this the final frame. Exception: if
		// this is the sigreturn frame, then we want to try to recover the real PC
		// using the return address (from LR or the stack), so keep going.
		*finished = (cur_regs->pc() == 0 && !cie->is_signal_frame) ? true : false;

		cur_regs->set_sp(eval_info.cfa);

libunwindstack/Elf.cpp

+3 −2

Original line number	Diff line number	Diff line
		@@ -188,14 +188,15 @@ bool Elf::StepIfSignalHandler(uint64_t rel_pc, Regs* regs, Memory* process_memor
		}

		// The relative pc is always relative to the start of the map from which it comes.
		bool Elf::Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished) {
		bool Elf::Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished,
		bool* is_signal_frame) {
		if (!valid_) {
		return false;
		}

		// Lock during the step which can update information in the object.
		std::lock_guard<std::mutex> guard(lock_);
		return interface_->Step(rel_pc, regs, process_memory, finished);
		return interface_->Step(rel_pc, regs, process_memory, finished, is_signal_frame);
		}

		bool Elf::IsValidElf(Memory* memory) {

libunwindstack/ElfInterface.cpp

+6 −4

Original line number	Diff line number	Diff line
		@@ -499,25 +499,27 @@ bool ElfInterface::GetGlobalVariableWithTemplate(const std::string& name, uint64
		return false;
		}

		bool ElfInterface::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {
		bool ElfInterface::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished,
		bool* is_signal_frame) {
		last_error_.code = ERROR_NONE;
		last_error_.address = 0;

		// Try the debug_frame first since it contains the most specific unwind
		// information.
		DwarfSection* debug_frame = debug_frame_.get();
		if (debug_frame != nullptr && debug_frame->Step(pc, regs, process_memory, finished)) {
		if (debug_frame != nullptr &&
		debug_frame->Step(pc, regs, process_memory, finished, is_signal_frame)) {
		return true;
		}

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

		if (gnu_debugdata_interface_ != nullptr &&
		gnu_debugdata_interface_->Step(pc, regs, process_memory, finished)) {
		gnu_debugdata_interface_->Step(pc, regs, process_memory, finished, is_signal_frame)) {
		return true;
		}

libunwindstack/ElfInterfaceArm.cpp

+3 −2

Original line number	Diff line number	Diff line
		@@ -100,12 +100,13 @@ void ElfInterfaceArm::HandleUnknownType(uint32_t type, uint64_t ph_offset, uint6
		total_entries_ = ph_filesz / 8;
		}

		bool ElfInterfaceArm::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {
		bool ElfInterfaceArm::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished,
		bool* is_signal_frame) {
		// Dwarf unwind information is precise about whether a pc is covered or not,
		// but arm unwind information only has ranges of pc. In order to avoid
		// incorrectly doing a bad unwind using arm unwind information for a
		// different function, always try and unwind with the dwarf information first.
		return ElfInterface32::Step(pc, regs, process_memory, finished) \|\|
		return ElfInterface32::Step(pc, regs, process_memory, finished, is_signal_frame) \|\|
		StepExidx(pc, regs, process_memory, finished);
		}