Merge "Revert "base: add support for tagged fd closure to unique_fd."" (ea674a38) · Commits · e / os / android_system_core

base/Android.bp

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -135,7 +135,6 @@ cc_test {
	"strings_test.cpp",		"strings_test.cpp",
	"test_main.cpp",		"test_main.cpp",
	"test_utils_test.cpp",		"test_utils_test.cpp",
	"unique_fd_test.cpp",
	],		],
	target: {		target: {
	android: {		android: {

base/include/android-base/unique_fd.h

+14 −68

Original line number	Original line	Diff line number	Diff line
	@@ -42,29 +42,10 @@
	//		//
	// unique_fd is also known as ScopedFd/ScopedFD/scoped_fd; mentioned here to help		// unique_fd is also known as ScopedFd/ScopedFD/scoped_fd; mentioned here to help
	// you find this class if you're searching for one of those names.		// you find this class if you're searching for one of those names.

	#if defined(__BIONIC__)
	#include <android/fdsan.h>
	#endif

	namespace android {		namespace android {
	namespace base {		namespace base {

	struct DefaultCloser {		struct DefaultCloser {
	#if defined(__BIONIC__)
	static void Tag(int fd, void* old_addr, void* new_addr) {
	uint64_t old_tag = android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD,
	reinterpret_cast<uint64_t>(old_addr));
	uint64_t new_tag = android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD,
	reinterpret_cast<uint64_t>(new_addr));
	android_fdsan_exchange_owner_tag(fd, old_tag, new_tag);
	}
	static void Close(int fd, void* addr) {
	uint64_t tag = android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD,
	reinterpret_cast<uint64_t>(addr));
	android_fdsan_close_with_tag(fd, tag);
	}
	#else
	static void Close(int fd) {		static void Close(int fd) {
	// Even if close(2) fails with EINTR, the fd will have been closed.		// Even if close(2) fails with EINTR, the fd will have been closed.
	// Using TEMP_FAILURE_RETRY will either lead to EBADF or closing someone		// Using TEMP_FAILURE_RETRY will either lead to EBADF or closing someone
	@@ -72,75 +53,40 @@ struct DefaultCloser {
	// http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html		// http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html
	::close(fd);		::close(fd);
	}		}
	#endif
	};		};

	template <typename Closer>		template <typename Closer>
	class unique_fd_impl final {		class unique_fd_impl final {
	public:		public:
	unique_fd_impl() {}		unique_fd_impl() : value_(-1) {}

	explicit unique_fd_impl(int fd) { reset(fd); }		explicit unique_fd_impl(int value) : value_(value) {}
	~unique_fd_impl() { reset(); }		~unique_fd_impl() { reset(); }

	unique_fd_impl(unique_fd_impl&& other) { reset(other.release()); }		unique_fd_impl(unique_fd_impl&& other) : value_(other.release()) {}
	unique_fd_impl& operator=(unique_fd_impl&& s) {		unique_fd_impl& operator=(unique_fd_impl&& s) {
	int fd = s.fd_;		reset(s.release());
	s.fd_ = -1;
	reset(fd, &s);
	return *this;		return *this;
	}		}

	void reset(int new_value = -1) { reset(new_value, nullptr); }		void reset(int new_value = -1) {
			if (value_ != -1) {
			Closer::Close(value_);
			}
			value_ = new_value;
			}

	int get() const { return fd_; }		int get() const { return value_; }
	operator int() const { return get(); }		operator int() const { return get(); }

	int release() __attribute__((warn_unused_result)) {		int release() __attribute__((warn_unused_result)) {
	tag(fd_, this, nullptr);		int ret = value_;
	int ret = fd_;		value_ = -1;
	fd_ = -1;
	return ret;		return ret;
	}		}

	private:		private:
	void reset(int new_value, void* previous_tag) {		int value_;
	if (fd_ != -1) {
	close(fd_, this);
	}

	fd_ = new_value;
	if (new_value != -1) {
	tag(new_value, previous_tag, this);
	}
	}

	int fd_ = -1;

	// Template magic to use Closer::Tag if available, and do nothing if not.
	// If Closer::Tag exists, this implementation is preferred, because int is a better match.
	// If not, this implementation is SFINAEd away, and the no-op below is the only one that exists.
	template <typename T = Closer>
	static auto tag(int fd, void* old_tag, void* new_tag)
	-> decltype(T::Tag(fd, old_tag, new_tag), void()) {
	T::Tag(fd, old_tag, new_tag);
	}

	template <typename T = Closer>
	static void tag(long, void, void) {
	// No-op.
	}

	// Same as above, to select between Closer::Close(int) and Closer::Close(int, void*).
	template <typename T = Closer>
	static auto close(int fd, void* tag_value) -> decltype(T::Close(fd, tag_value), void()) {
	T::Close(fd, tag_value);
	}

	template <typename T = Closer>
	static auto close(int fd, void*) -> decltype(T::Close(fd), void()) {
	T::Close(fd);
	}

	unique_fd_impl(const unique_fd_impl&);		unique_fd_impl(const unique_fd_impl&);
	void operator=(const unique_fd_impl&);		void operator=(const unique_fd_impl&);

base/unique_fd_test.cpp

deleted100644 → 0

+0 −54

Original line number	Original line	Diff line number	Diff line
	/*
	* Copyright (C) 2018 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 "android-base/unique_fd.h"

	#include <gtest/gtest.h>

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

	using android::base::unique_fd;

	TEST(unique_fd, unowned_close) {
	#if defined(__BIONIC__)
	unique_fd fd(open("/dev/null", O_RDONLY));
	EXPECT_DEATH(close(fd.get()), "incorrect tag");
	#endif
	}

	TEST(unique_fd, untag_on_release) {
	unique_fd fd(open("/dev/null", O_RDONLY));
	close(fd.release());
	}

	TEST(unique_fd, move) {
	unique_fd fd(open("/dev/null", O_RDONLY));
	unique_fd fd_moved = std::move(fd);
	ASSERT_EQ(-1, fd.get());
	ASSERT_GT(fd_moved.get(), -1);
	}

	TEST(unique_fd, unowned_close_after_move) {
	#if defined(__BIONIC__)
	unique_fd fd(open("/dev/null", O_RDONLY));
	unique_fd fd_moved = std::move(fd);
	ASSERT_EQ(-1, fd.get());
	ASSERT_GT(fd_moved.get(), -1);
	EXPECT_DEATH(close(fd_moved.get()), "incorrect tag");
	#endif
	}