Merge "Add function definitions for MapInfo." (4c1560ce) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+2 −0

Original line number	Diff line number	Diff line
		@@ -54,6 +54,7 @@ cc_defaults {
		"ElfInterfaceArm.cpp",
		"Log.cpp",
		"Regs.cpp",
		"MapInfo.cpp",
		"Maps.cpp",
		"Memory.cpp",
		"Symbols.cpp",
		@@ -98,6 +99,7 @@ cc_defaults {
		"tests/ElfInterfaceTest.cpp",
		"tests/ElfTest.cpp",
		"tests/LogFake.cpp",
		"tests/MapInfoTest.cpp",
		"tests/MapsTest.cpp",
		"tests/MemoryFake.cpp",
		"tests/MemoryFileTest.cpp",

libunwindstack/MapInfo.cpp

0 → 100644

+86 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2017 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.
		*/

		#include <sys/types.h>
		#include <unistd.h>

		#include <memory>
		#include <string>

		#include "Elf.h"
		#include "MapInfo.h"
		#include "Maps.h"
		#include "Memory.h"

		Memory* MapInfo::CreateMemory(pid_t pid) {
		if (end <= start) {
		return nullptr;
		}

		elf_offset = 0;

		// First try and use the file associated with the info.
		if (!name.empty()) {
		// Fail on device maps.
		if (flags & MAPS_FLAGS_DEVICE_MAP) {
		return nullptr;
		}

		std::unique_ptr<MemoryFileAtOffset> file_memory(new MemoryFileAtOffset);
		uint64_t map_size;
		if (offset != 0) {
		// Only map in a piece of the file.
		map_size = end - start;
		} else {
		map_size = UINT64_MAX;
		}
		if (file_memory->Init(name, offset, map_size)) {
		// It's possible that a non-zero offset might not be pointing to
		// valid elf data. Check if this is a valid elf, and if not assume
		// that this was meant to incorporate the entire file.
		if (offset != 0 && !Elf::IsValidElf(file_memory.get())) {
		// Don't bother checking the validity that will happen on the elf init.
		if (file_memory->Init(name, 0)) {
		elf_offset = offset;
		return file_memory.release();
		}
		// Fall through if the init fails.
		} else {
		return file_memory.release();
		}
		}
		}

		Memory* memory = nullptr;
		if (pid == getpid()) {
		memory = new MemoryLocal();
		} else {
		memory = new MemoryRemote(pid);
		}
		return new MemoryRange(memory, start, end);
		}

		Elf* MapInfo::GetElf(pid_t pid, bool) {
		if (elf) {
		return elf;
		}

		elf = new Elf(CreateMemory(pid));
		elf->Init();
		// If the init fails, keep the elf around as an invalid object so we
		// don't try to reinit the object.
		return elf;
		}

libunwindstack/MapInfo.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -39,6 +39,7 @@ struct MapInfo {
		uint64_t elf_offset;

		Memory* CreateMemory(pid_t pid);
		Elf* GetElf(pid_t pid, bool init_gnu_debugdata = false);
		};

		#endif // _LIBUNWINDSTACK_MAP_INFO_H

libunwindstack/tests/MapInfoTest.cpp

0 → 100644

+220 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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.
		*/

		#include <elf.h>
		#include <errno.h>
		#include <signal.h>
		#include <string.h>
		#include <sys/mman.h>
		#include <sys/ptrace.h>
		#include <sys/types.h>
		#include <unistd.h>

		#include <memory>
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/test_utils.h>
		#include <gtest/gtest.h>

		#include "Elf.h"
		#include "MapInfo.h"
		#include "Memory.h"

		class MapInfoTest : public ::testing::Test {
		protected:
		static void SetUpTestCase() {
		std::vector<uint8_t> buffer(1024);
		memcpy(buffer.data(), ELFMAG, SELFMAG);
		for (size_t i = SELFMAG; i < buffer.size(); i++) {
		buffer[i] = i / 256 + 1;
		}
		ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));

		for (size_t i = 0; i < 0x100; i++) {
		buffer[i] = i / 256 + 1;
		}
		memcpy(&buffer[0x100], ELFMAG, SELFMAG);
		for (size_t i = 0x100 + SELFMAG; i < buffer.size(); i++) {
		buffer[i] = i / 256 + 1;
		}
		ASSERT_TRUE(android::base::WriteFully(elf_at_100_.fd, buffer.data(), buffer.size()));
		}

		static TemporaryFile elf_;

		static TemporaryFile elf_at_100_;
		};
		TemporaryFile MapInfoTest::elf_;
		TemporaryFile MapInfoTest::elf_at_100_;

		TEST_F(MapInfoTest, end_le_start) {
		MapInfo info{.start = 0x100, .end = 0x100, .offset = 0, .name = elf_.path};

		std::unique_ptr<Memory> memory;
		memory.reset(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() == nullptr);

		info.end = 0xff;
		memory.reset(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() == nullptr);

		// Make sure this test is valid.
		info.end = 0x101;
		memory.reset(info.CreateMemory(getpid()));
		ASSERT_FALSE(info.CreateMemory(getpid()) == nullptr);
		}

		// Verify that if the offset is non-zero but there is no elf at the offset,
		// that the full file is used.
		TEST_F(MapInfoTest, create_memory_file_backed_non_zero_offset_full_file) {
		MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_.path};

		std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() != nullptr);
		ASSERT_EQ(0x100U, info.elf_offset);

		// Read the entire file.
		std::vector<uint8_t> buffer(1024);
		ASSERT_TRUE(memory->Read(0, buffer.data(), 1024));
		ASSERT_TRUE(memcmp(buffer.data(), ELFMAG, SELFMAG) == 0);
		for (size_t i = SELFMAG; i < buffer.size(); i++) {
		ASSERT_EQ(i / 256 + 1, buffer[i]) << "Failed at byte " << i;
		}

		ASSERT_FALSE(memory->Read(1024, buffer.data(), 1));
		}

		// Verify that if the offset is non-zero and there is an elf at that
		// offset, that only part of the file is used.
		TEST_F(MapInfoTest, create_memory_file_backed_non_zero_offset_partial_file) {
		MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_at_100_.path};

		std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() != nullptr);
		ASSERT_EQ(0U, info.elf_offset);

		// Read the valid part of the file.
		std::vector<uint8_t> buffer(0x100);
		ASSERT_TRUE(memory->Read(0, buffer.data(), 0x100));
		ASSERT_TRUE(memcmp(buffer.data(), ELFMAG, SELFMAG) == 0);
		for (size_t i = SELFMAG; i < buffer.size(); i++) {
		ASSERT_EQ(2, buffer[i]) << "Failed at byte " << i;
		}

		ASSERT_FALSE(memory->Read(0x100, buffer.data(), 1));
		}

		// Verify that device file names will never result in Memory object creation.
		TEST_F(MapInfoTest, create_memory_check_device_maps) {
		// Set up some memory so that a valid local memory object would
		// be returned if the file mapping fails, but the device check is incorrect.
		std::vector<uint8_t> buffer(1024);
		MapInfo info;
		info.start = reinterpret_cast<uint64_t>(buffer.data());
		info.end = info.start + buffer.size();
		info.offset = 0;
		std::unique_ptr<Memory> memory;

		info.flags = 0x8000;
		info.name = "/dev/something";
		memory.reset(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() == nullptr);
		}

		TEST_F(MapInfoTest, create_memory_local_memory) {
		// Set up some memory for a valid local memory object.
		std::vector<uint8_t> buffer(1024);
		for (size_t i = 0; i < buffer.size(); i++) {
		buffer[i] = i % 256;
		}

		MapInfo info;
		info.start = reinterpret_cast<uint64_t>(buffer.data());
		info.end = info.start + buffer.size();
		info.offset = 0;

		std::unique_ptr<Memory> memory;
		memory.reset(info.CreateMemory(getpid()));
		ASSERT_TRUE(memory.get() != nullptr);

		std::vector<uint8_t> read_buffer(1024);
		ASSERT_TRUE(memory->Read(0, read_buffer.data(), read_buffer.size()));
		for (size_t i = 0; i < read_buffer.size(); i++) {
		ASSERT_EQ(i % 256, read_buffer[i]) << "Failed at byte " << i;
		}

		ASSERT_FALSE(memory->Read(read_buffer.size(), read_buffer.data(), 1));
		}

		TEST_F(MapInfoTest, create_memory_remote_memory) {
		std::vector<uint8_t> buffer(1024);
		memset(buffer.data(), 0xa, buffer.size());

		pid_t pid;
		if ((pid = fork()) == 0) {
		while (true)
		;
		exit(1);
		}
		ASSERT_LT(0, pid);

		ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) != -1);
		uint64_t iterations = 0;
		siginfo_t si;
		while (TEMP_FAILURE_RETRY(ptrace(PTRACE_GETSIGINFO, pid, 0, &si)) < 0 && errno == ESRCH) {
		usleep(30);
		iterations++;
		ASSERT_LT(iterations, 500000000ULL);
		}

		MapInfo info;
		info.start = reinterpret_cast<uint64_t>(buffer.data());
		info.end = info.start + buffer.size();
		info.offset = 0;

		std::unique_ptr<Memory> memory;
		memory.reset(info.CreateMemory(pid));
		ASSERT_TRUE(memory.get() != nullptr);
		// Set the local memory to a different value to guarantee we are reading
		// from the remote process.
		memset(buffer.data(), 0x1, buffer.size());
		std::vector<uint8_t> read_buffer(1024);
		ASSERT_TRUE(memory->Read(0, read_buffer.data(), read_buffer.size()));
		for (size_t i = 0; i < read_buffer.size(); i++) {
		ASSERT_EQ(0xaU, read_buffer[i]) << "Failed at byte " << i;
		}

		ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0);

		kill(pid, SIGKILL);
		}

		TEST_F(MapInfoTest, get_elf) {
		// Create a map to use as initialization data.
		void* map = mmap(nullptr, 1024, PROT_READ, MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
		ASSERT_NE(MAP_FAILED, map);

		uint64_t start = reinterpret_cast<uint64_t>(map);
		MapInfo info{.start = start, .end = start + 1024, .offset = 0, .name = ""};

		// The map contains garbage, but this should still produce an elf object.
		Elf* elf = info.GetElf(getpid(), false);
		ASSERT_TRUE(elf != nullptr);
		ASSERT_FALSE(elf->valid());

		ASSERT_EQ(0, munmap(map, 1024));
		}