Merge "Add ReadMapFileAsyncSafe function." (fa696425) · Commits · e / os / android_system_core

libprocinfo/Android.bp

+2 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@ cc_library {
		host_supported: true,
		srcs: [
		"process.cpp",
		"process_map.cpp",
		],

		local_include_dirs: ["include"],
		@@ -58,6 +59,7 @@ cc_test {
		name: "libprocinfo_test",
		defaults: ["libprocinfo_defaults"],
		host_supported: true,
		isolated: true,
		srcs: [
		"process_test.cpp",
		"process_map_test.cpp",

libprocinfo/include/procinfo/process_map.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -176,5 +176,9 @@ inline bool ReadProcessMaps(pid_t pid, std::vector<MapInfo>* maps) {
		const char* name) { maps->emplace_back(start, end, flags, pgoff, inode, name); });
		}

		bool ReadMapFileAsyncSafe(const char* map_file, void* buffer, size_t buffer_size,
		const std::function<void(uint64_t, uint64_t, uint16_t, uint64_t, ino_t,
		const char*)>& callback);

		} /* namespace procinfo */
		} /* namespace android */

libprocinfo/process_map.cpp

0 → 100644

+97 −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.
		*/

		#include <procinfo/process_map.h>

		#include <fcntl.h>
		#include <string.h>
		#include <unistd.h>

		#include <procinfo/process.h>

		namespace android {
		namespace procinfo {

		bool ReadMapFileAsyncSafe(const char* map_file, void* buffer, size_t buffer_size,
		const std::function<void(uint64_t, uint64_t, uint16_t, uint64_t, ino_t,
		const char*)>& callback) {
		if (buffer == nullptr \|\| buffer_size == 0) {
		return false;
		}

		int fd = open(map_file, O_RDONLY \| O_CLOEXEC);
		if (fd == -1) {
		return false;
		}

		char* char_buffer = reinterpret_cast<char*>(buffer);
		size_t start = 0;
		size_t read_bytes = 0;
		char* line = nullptr;
		bool read_complete = false;
		while (true) {
		ssize_t bytes =
		TEMP_FAILURE_RETRY(read(fd, char_buffer + read_bytes, buffer_size - read_bytes - 1));
		if (bytes <= 0) {
		if (read_bytes == 0) {
		close(fd);
		return bytes == 0;
		}
		// Treat the last piece of data as the last line.
		char_buffer[start + read_bytes] = '\n';
		bytes = 1;
		read_complete = true;
		}
		read_bytes += bytes;

		while (read_bytes > 0) {
		char* newline = reinterpret_cast<char*>(memchr(&char_buffer[start], '\n', read_bytes));
		if (newline == nullptr) {
		break;
		}
		*newline = '\0';
		line = &char_buffer[start];
		start = newline - char_buffer + 1;
		read_bytes -= newline - line + 1;

		// Ignore the return code, errors are okay.
		ReadMapFileContent(line, callback);
		}

		if (read_complete) {
		close(fd);
		return true;
		}

		if (start == 0 && read_bytes == buffer_size - 1) {
		// The buffer provided is too small to contain this line, give up
		// and indicate failure.
		close(fd);
		return false;
		}

		// Copy any leftover data to the front of the buffer.
		if (start > 0) {
		if (read_bytes > 0) {
		memmove(char_buffer, &char_buffer[start], read_bytes);
		}
		start = 0;
		}
		}
		}

		} /* namespace procinfo */
		} /* namespace android */

libprocinfo/process_map_test.cpp

+217 −0

Original line number	Diff line number	Diff line
		@@ -16,9 +16,14 @@

		#include <procinfo/process_map.h>

		#include <inttypes.h>
		#include <sys/mman.h>

		#include <string>
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/stringprintf.h>

		#include <gtest/gtest.h>

		@@ -63,3 +68,215 @@ TEST(process_map, ReadProcessMaps) {
		ASSERT_TRUE(android::procinfo::ReadProcessMaps(getpid(), &maps));
		ASSERT_GT(maps.size(), 0u);
		}

		extern "C" void malloc_disable();
		extern "C" void malloc_enable();

		struct TestMapInfo {
		TestMapInfo() = default;
		TestMapInfo(uint64_t start, uint64_t end, uint16_t flags, uint64_t pgoff, ino_t inode,
		const char* new_name)
		: start(start), end(end), flags(flags), pgoff(pgoff), inode(inode) {
		strcpy(name, new_name);
		}
		uint64_t start = 0;
		uint64_t end = 0;
		uint16_t flags = 0;
		uint64_t pgoff = 0;
		ino_t inode = 0;
		char name[100] = {};
		};

		void VerifyReadMapFileAsyncSafe(const char* maps_data,
		const std::vector<TestMapInfo>& expected_info) {
		TemporaryFile tf;
		ASSERT_TRUE(android::base::WriteStringToFd(maps_data, tf.fd));

		std::vector<TestMapInfo> saved_info(expected_info.size());
		size_t num_maps = 0;

		auto callback = [&](uint64_t start, uint64_t end, uint16_t flags, uint64_t pgoff, ino_t inode,
		const char* name) {
		if (num_maps != saved_info.size()) {
		TestMapInfo& saved = saved_info[num_maps];
		saved.start = start;
		saved.end = end;
		saved.flags = flags;
		saved.pgoff = pgoff;
		saved.inode = inode;
		strcpy(saved.name, name);
		}
		num_maps++;
		};

		std::vector<char> buffer(64 * 1024);

		#if defined(__BIONIC__)
		// Any allocations will block after this call.
		malloc_disable();
		#endif

		bool parsed =
		android::procinfo::ReadMapFileAsyncSafe(tf.path, buffer.data(), buffer.size(), callback);

		#if defined(__BIONIC__)
		malloc_enable();
		#endif

		ASSERT_TRUE(parsed) << "Parsing of data failed:\n" << maps_data;
		ASSERT_EQ(expected_info.size(), num_maps);
		for (size_t i = 0; i < expected_info.size(); i++) {
		const TestMapInfo& expected = expected_info[i];
		const TestMapInfo& saved = saved_info[i];
		EXPECT_EQ(expected.start, saved.start);
		EXPECT_EQ(expected.end, saved.end);
		EXPECT_EQ(expected.flags, saved.flags);
		EXPECT_EQ(expected.pgoff, saved.pgoff);
		EXPECT_EQ(expected.inode, saved.inode);
		EXPECT_STREQ(expected.name, saved.name);
		}
		}

		TEST(process_map, ReadMapFileAsyncSafe_invalid) {
		std::vector<TestMapInfo> expected_info;

		VerifyReadMapFileAsyncSafe("12c00000-2ac00000", expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_single) {
		std::vector<TestMapInfo> expected_info;
		expected_info.emplace_back(0x12c00000, 0x2ac00000, PROT_READ \| PROT_WRITE, 0x100, 10267643,
		"/lib/fake.so");

		VerifyReadMapFileAsyncSafe("12c00000-2ac00000 rw-p 00000100 00:05 10267643 /lib/fake.so",
		expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_single_with_newline) {
		std::vector<TestMapInfo> expected_info;
		expected_info.emplace_back(0x12c00000, 0x2ac00000, PROT_READ \| PROT_WRITE, 0x100, 10267643,
		"/lib/fake.so");

		VerifyReadMapFileAsyncSafe("12c00000-2ac00000 rw-p 00000100 00:05 10267643 /lib/fake.so\n",
		expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_single_no_library) {
		std::vector<TestMapInfo> expected_info;
		expected_info.emplace_back(0xa0000, 0xc0000, PROT_READ \| PROT_WRITE \| PROT_EXEC, 0xb00, 101, "");

		VerifyReadMapFileAsyncSafe("a0000-c0000 rwxp 00000b00 00:05 101", expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_multiple) {
		std::vector<TestMapInfo> expected_info;
		expected_info.emplace_back(0xa0000, 0xc0000, PROT_READ \| PROT_WRITE \| PROT_EXEC, 1, 100, "");
		expected_info.emplace_back(0xd0000, 0xe0000, PROT_READ, 2, 101, "/lib/libsomething1.so");
		expected_info.emplace_back(0xf0000, 0x100000, PROT_WRITE, 3, 102, "/lib/libsomething2.so");
		expected_info.emplace_back(0x110000, 0x120000, PROT_EXEC, 4, 103, "[anon:something or another]");

		std::string map_data =
		"0a0000-0c0000 rwxp 00000001 00:05 100\n"
		"0d0000-0e0000 r--p 00000002 00:05 101 /lib/libsomething1.so\n"
		"0f0000-100000 -w-p 00000003 00:05 102 /lib/libsomething2.so\n"
		"110000-120000 --xp 00000004 00:05 103 [anon:something or another]\n";

		VerifyReadMapFileAsyncSafe(map_data.c_str(), expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_multiple_reads) {
		std::vector<TestMapInfo> expected_info;
		std::string map_data;
		uint64_t start = 0xa0000;
		for (size_t i = 0; i < 10000; i++) {
		map_data += android::base::StringPrintf("%" PRIx64 "-%" PRIx64 " r--p %zx 01:20 %zu fake.so\n",
		start, start + 0x1000, i, 1000 + i);
		expected_info.emplace_back(start, start + 0x1000, PROT_READ, i, 1000 + i, "fake.so");
		}

		VerifyReadMapFileAsyncSafe(map_data.c_str(), expected_info);
		}

		TEST(process_map, ReadMapFileAsyncSafe_buffer_nullptr) {
		size_t num_calls = 0;
		auto callback = [&](uint64_t, uint64_t, uint16_t, uint64_t, ino_t, const char*) { num_calls++; };

		#if defined(__BIONIC__)
		// Any allocations will block after this call.
		malloc_disable();
		#endif

		bool parsed = android::procinfo::ReadMapFileAsyncSafe("/proc/self/maps", nullptr, 10, callback);

		#if defined(__BIONIC__)
		malloc_enable();
		#endif

		ASSERT_FALSE(parsed);
		EXPECT_EQ(0UL, num_calls);
		}

		TEST(process_map, ReadMapFileAsyncSafe_buffer_size_zero) {
		size_t num_calls = 0;
		auto callback = [&](uint64_t, uint64_t, uint16_t, uint64_t, ino_t, const char*) { num_calls++; };

		#if defined(__BIONIC__)
		// Any allocations will block after this call.
		malloc_disable();
		#endif

		char buffer[10];
		bool parsed = android::procinfo::ReadMapFileAsyncSafe("/proc/self/maps", buffer, 0, callback);

		#if defined(__BIONIC__)
		malloc_enable();
		#endif

		ASSERT_FALSE(parsed);
		EXPECT_EQ(0UL, num_calls);
		}

		TEST(process_map, ReadMapFileAsyncSafe_buffer_too_small_no_calls) {
		size_t num_calls = 0;
		auto callback = [&](uint64_t, uint64_t, uint16_t, uint64_t, ino_t, const char*) { num_calls++; };

		#if defined(__BIONIC__)
		// Any allocations will block after this call.
		malloc_disable();
		#endif

		char buffer[10];
		bool parsed =
		android::procinfo::ReadMapFileAsyncSafe("/proc/self/maps", buffer, sizeof(buffer), callback);

		#if defined(__BIONIC__)
		malloc_enable();
		#endif

		ASSERT_FALSE(parsed);
		EXPECT_EQ(0UL, num_calls);
		}

		TEST(process_map, ReadMapFileAsyncSafe_buffer_too_small_could_parse) {
		TemporaryFile tf;
		ASSERT_TRUE(android::base::WriteStringToFd(
		"0a0000-0c0000 rwxp 00000001 00:05 100 /fake/lib.so\n", tf.fd));

		size_t num_calls = 0;
		auto callback = [&](uint64_t, uint64_t, uint16_t, uint64_t, ino_t, const char*) { num_calls++; };

		#if defined(__BIONIC__)
		// Any allocations will block after this call.
		malloc_disable();
		#endif

		char buffer[39];
		bool parsed = android::procinfo::ReadMapFileAsyncSafe(tf.path, buffer, sizeof(buffer), callback);

		#if defined(__BIONIC__)
		malloc_enable();
		#endif

		ASSERT_FALSE(parsed);
		EXPECT_EQ(0UL, num_calls);
		}