Merge "Do not remove speculative frames in all cases." (0d7c0f78) · Commits · e / os / android_system_core

libunwindstack/Unwinder.cpp

+8 −2

Original line number	Diff line number	Diff line
		@@ -239,8 +239,14 @@ void Unwinder::Unwind(const std::vector<std::string>* initial_map_names_to_skip,

		if (!stepped) {
		if (return_address_attempt) {
		// Only remove the speculative frame if there are more than two frames
		// or the pc in the first frame is in a valid map.
		// This allows for a case where the code jumps into the middle of
		// nowhere, but there is no other unwind information after that.
		if (frames_.size() != 2 \|\| maps_->Find(frames_[0].pc) != nullptr) {
		// Remove the speculative frame.
		frames_.pop_back();
		}
		break;
		} else if (in_device_map) {
		// Do not attempt any other unwinding, pc or sp is in a device

libunwindstack/tests/UnwinderTest.cpp

+63 −1

Original line number	Diff line number	Diff line
		@@ -659,6 +659,54 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
		ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
		ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));

		// Fake as if code called a nullptr function.
		regs_.set_pc(0x20000);
		regs_.set_sp(0x10000);
		ElfInterfaceFake::FakePushStepData(StepData(0, 0x10010, false));
		regs_.FakeSetReturnAddress(0x12);
		regs_.FakeSetReturnAddressValid(true);

		Unwinder unwinder(64, &maps_, &regs_, process_memory_);
		unwinder.Unwind();
		EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());

		ASSERT_EQ(2U, unwinder.NumFrames());

		auto* frame = &unwinder.frames()[0];
		EXPECT_EQ(0U, frame->num);
		EXPECT_EQ(0U, frame->rel_pc);
		EXPECT_EQ(0x20000U, frame->pc);
		EXPECT_EQ(0x10000U, frame->sp);
		EXPECT_EQ("Frame0", frame->function_name);
		EXPECT_EQ(0U, frame->function_offset);
		EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
		EXPECT_EQ(0U, frame->map_offset);
		EXPECT_EQ(0x20000U, frame->map_start);
		EXPECT_EQ(0x22000U, frame->map_end);
		EXPECT_EQ(0U, frame->map_load_bias);
		EXPECT_EQ(PROT_READ \| PROT_WRITE, frame->map_flags);

		frame = &unwinder.frames()[1];
		EXPECT_EQ(1U, frame->num);
		EXPECT_EQ(0U, frame->rel_pc);
		EXPECT_EQ(0U, frame->pc);
		EXPECT_EQ(0x10010U, frame->sp);
		EXPECT_EQ("", frame->function_name);
		EXPECT_EQ(0U, frame->function_offset);
		EXPECT_EQ("", frame->map_name);
		EXPECT_EQ(0U, frame->map_offset);
		EXPECT_EQ(0U, frame->map_start);
		EXPECT_EQ(0U, frame->map_end);
		EXPECT_EQ(0U, frame->map_load_bias);
		EXPECT_EQ(0, frame->map_flags);
		}

		// Verify that a speculative frame is added and left if there are only
		// two frames and the pc is in the middle nowhere.
		TEST_F(UnwinderTest, speculative_frame_not_removed_pc_bad) {
		ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
		ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));

		// Fake as if code called a nullptr function.
		regs_.set_pc(0);
		regs_.set_sp(0x10000);
		@@ -669,7 +717,7 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
		unwinder.Unwind();
		EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());

		ASSERT_EQ(1U, unwinder.NumFrames());
		ASSERT_EQ(2U, unwinder.NumFrames());

		auto* frame = &unwinder.frames()[0];
		EXPECT_EQ(0U, frame->num);
		@@ -684,6 +732,20 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
		EXPECT_EQ(0U, frame->map_end);
		EXPECT_EQ(0U, frame->map_load_bias);
		EXPECT_EQ(0, frame->map_flags);

		frame = &unwinder.frames()[1];
		EXPECT_EQ(1U, frame->num);
		EXPECT_EQ(0x200U, frame->rel_pc);
		EXPECT_EQ(0x1200U, frame->pc);
		EXPECT_EQ(0x10000U, frame->sp);
		EXPECT_EQ("Frame0", frame->function_name);
		EXPECT_EQ(0U, frame->function_offset);
		EXPECT_EQ("/system/fake/libc.so", frame->map_name);
		EXPECT_EQ(0U, frame->map_offset);
		EXPECT_EQ(0x1000U, frame->map_start);
		EXPECT_EQ(0x8000U, frame->map_end);
		EXPECT_EQ(0U, frame->map_load_bias);
		EXPECT_EQ(PROT_READ \| PROT_WRITE, frame->map_flags);
		}

		// Verify that an unwind stops when a frame is in given suffix.