Merge "Add test of undefined return address." (0ac9b9a8) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -211,6 +211,7 @@ cc_test {
		"tests/UnwindOfflineTest.cpp",
		"tests/UnwindTest.cpp",
		"tests/UnwinderTest.cpp",
		"tests/VerifyBionicTerminationTest.cpp",
		],

		cflags: [

libunwindstack/Unwinder.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -309,7 +309,7 @@ void Unwinder::Unwind(const std::vector<std::string>* initial_map_names_to_skip,
		}
		}

		std::string Unwinder::FormatFrame(const FrameData& frame) {
		std::string Unwinder::FormatFrame(const FrameData& frame) const {
		std::string data;
		if (regs_->Is32Bit()) {
		data += android::base::StringPrintf(" #%02zu pc %08" PRIx64, frame.num, frame.rel_pc);
		@@ -355,7 +355,7 @@ std::string Unwinder::FormatFrame(const FrameData& frame) {
		return data;
		}

		std::string Unwinder::FormatFrame(size_t frame_num) {
		std::string Unwinder::FormatFrame(size_t frame_num) const {
		if (frame_num >= frames_.size()) {
		return "";
		}

libunwindstack/include/unwindstack/Unwinder.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -77,7 +77,7 @@ class Unwinder {
		void Unwind(const std::vector<std::string>* initial_map_names_to_skip = nullptr,
		const std::vector<std::string>* map_suffixes_to_ignore = nullptr);

		size_t NumFrames() { return frames_.size(); }
		size_t NumFrames() const { return frames_.size(); }

		const std::vector<FrameData>& frames() { return frames_; }

		@@ -87,8 +87,8 @@ class Unwinder {
		return frames;
		}

		std::string FormatFrame(size_t frame_num);
		std::string FormatFrame(const FrameData& frame);
		std::string FormatFrame(size_t frame_num) const;
		std::string FormatFrame(const FrameData& frame) const;

		void SetJitDebug(JitDebug* jit_debug, ArchEnum arch);

libunwindstack/tests/VerifyBionicTerminationTest.cpp

0 → 100644

+124 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2019 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#define _GNU_SOURCE 1
		#include <stdint.h>
		#include <string.h>

		#include <string>

		#if defined(__BIONIC__)

		#include <gtest/gtest.h>

		#include <unwindstack/DwarfSection.h>
		#include <unwindstack/Elf.h>
		#include <unwindstack/ElfInterface.h>
		#include <unwindstack/Regs.h>
		#include <unwindstack/RegsGetLocal.h>
		#include <unwindstack/Unwinder.h>

		// This test is specific to bionic to verify that __libc_init is
		// properly setting the return address to undefined so that the
		// unwind properly terminates.

		namespace unwindstack {

		static std::string DumpFrames(const UnwinderFromPid& unwinder) {
		std::string unwind;
		for (size_t i = 0; i < unwinder.NumFrames(); i++) {
		unwind += unwinder.FormatFrame(i) + '\n';
		}
		return unwind;
		}

		static DwarfLocationEnum GetReturnAddressLocation(uint64_t rel_pc, DwarfSection* section) {
		if (section == nullptr) {
		return DWARF_LOCATION_INVALID;
		}

		const DwarfFde* fde = section->GetFdeFromPc(rel_pc);
		if (fde == nullptr \|\| fde->cie == nullptr) {
		return DWARF_LOCATION_INVALID;
		}
		dwarf_loc_regs_t regs;
		if (!section->GetCfaLocationInfo(rel_pc, fde, &regs)) {
		return DWARF_LOCATION_INVALID;
		}

		auto reg_entry = regs.find(fde->cie->return_address_register);
		if (reg_entry == regs.end()) {
		return DWARF_LOCATION_INVALID;
		}
		return reg_entry->second.type;
		}

		static void VerifyReturnAddress(const FrameData& frame) {
		// Now go and find information about the register data and verify that the relative pc results in
		// an undefined register.
		Elf elf(Memory::CreateFileMemory(frame.map_name, 0).release());
		ASSERT_TRUE(elf.Init()) << "Failed to init elf object from " << frame.map_name;
		ASSERT_TRUE(elf.valid()) << "Elf " << frame.map_name << " is not valid.";
		ElfInterface* interface = elf.interface();

		// Only check the eh_frame and the debug_frame since the undefined register
		// is set using a cfi directive.
		// Check debug_frame first, then eh_frame since debug_frame always
		// contains the most specific data.
		DwarfLocationEnum location = GetReturnAddressLocation(frame.rel_pc, interface->debug_frame());
		if (location == DWARF_LOCATION_UNDEFINED) {
		return;
		}

		location = GetReturnAddressLocation(frame.rel_pc, interface->eh_frame());
		ASSERT_EQ(DWARF_LOCATION_UNDEFINED, location);
		}

		// This test assumes that it starts from the main thread, and that the
		// libc.so on device will include symbols so that function names can
		// be resolved.
		TEST(VerifyBionicTermination, local_terminate) {
		std::unique_ptr<Regs> regs(Regs::CreateFromLocal());

		UnwinderFromPid unwinder(512, getpid());
		ASSERT_TRUE(unwinder.Init(regs->Arch()));
		unwinder.SetRegs(regs.get());

		RegsGetLocal(regs.get());
		unwinder.Unwind();
		ASSERT_LT(0U, unwinder.NumFrames());

		SCOPED_TRACE(DumpFrames(unwinder));

		// Look for the frame that includes __libc_init, there should only
		// be one and it should be the last.
		bool found = false;
		const std::vector<FrameData>& frames = unwinder.frames();
		for (size_t i = 0; i < unwinder.NumFrames(); i++) {
		const FrameData& frame = frames[i];
		if (frame.function_name == "__libc_init" && !frame.map_name.empty() &&
		std::string("libc.so") == basename(frame.map_name.c_str())) {
		ASSERT_EQ(unwinder.NumFrames(), i + 1) << "__libc_init is not last frame.";
		ASSERT_NO_FATAL_FAILURE(VerifyReturnAddress(frame));
		found = true;
		}
		}
		ASSERT_TRUE(found) << "Unable to find libc.so:__libc_init frame\n";
		}

		} // namespace unwindstack

		#endif