Add support for optional cgroup attributes (59af6800) · Commits · e / os / android_system_core

libprocessgroup/Android.bp

+26 −0

Original line number	Diff line number	Diff line
		@@ -73,3 +73,29 @@ cc_library {
		],
		min_sdk_version: "29",
		}

		cc_test {
		name: "task_profiles_test",
		host_supported: true,
		cflags: [
		"-Wall",
		"-Werror",
		"-Wexit-time-destructors",
		"-Wno-unused-parameter",
		],
		srcs: [
		"task_profiles_test.cpp",
		],
		header_libs: [
		"libcutils_headers",
		"libprocessgroup_headers",
		],
		shared_libs: [
		"libbase",
		"libcgrouprc",
		"libprocessgroup",
		],
		static_libs: [
		"libgmock",
		],
		}

libprocessgroup/profiles/task_profiles.proto

+2 −1

Original line number	Diff line number	Diff line
		@@ -25,11 +25,12 @@ message TaskProfiles {
		repeated AggregateProfiles aggregateprofiles = 3 [json_name = "AggregateProfiles"];
		}

		// Next: 4
		// Next: 5
		message Attribute {
		string name = 1 [json_name = "Name"];
		string controller = 2 [json_name = "Controller"];
		string file = 3 [json_name = "File"];
		string optional = 4 [json_name = "Optional"];
		}

		// Next: 3

libprocessgroup/task_profiles.cpp

+11 −2

Original line number	Diff line number	Diff line
		@@ -206,6 +206,14 @@ bool SetAttributeAction::ExecuteForTask(int tid) const {
		}

		if (!WriteStringToFile(value_, path)) {
		if (errno == ENOENT) {
		if (optional_) {
		return true;
		} else {
		LOG(ERROR) << "No such cgroup attribute: " << path;
		return false;
		}
		}
		PLOG(ERROR) << "Failed to write '" << value_ << "' to " << path;
		return false;
		}
		@@ -675,11 +683,12 @@ bool TaskProfiles::Load(const CgroupMap& cg_map, const std::string& file_name) {
		} else if (action_name == "SetAttribute") {
		std::string attr_name = params_val["Name"].asString();
		std::string attr_value = params_val["Value"].asString();
		bool optional = strcmp(params_val["Optional"].asString().c_str(), "true") == 0;

		auto iter = attributes_.find(attr_name);
		if (iter != attributes_.end()) {
		profile->Add(
		std::make_unique<SetAttributeAction>(iter->second.get(), attr_value));
		profile->Add(std::make_unique<SetAttributeAction>(iter->second.get(),
		attr_value, optional));
		} else {
		LOG(WARNING) << "SetAttribute: unknown attribute: " << attr_name;
		}

libprocessgroup/task_profiles.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -102,8 +102,8 @@ class SetTimerSlackAction : public ProfileAction {
		// Set attribute profile element
		class SetAttributeAction : public ProfileAction {
		public:
		SetAttributeAction(const IProfileAttribute* attribute, const std::string& value)
		: attribute_(attribute), value_(value) {}
		SetAttributeAction(const IProfileAttribute* attribute, const std::string& value, bool optional)
		: attribute_(attribute), value_(value), optional_(optional) {}

		const char* Name() const override { return "SetAttribute"; }
		bool ExecuteForProcess(uid_t uid, pid_t pid) const override;
		@@ -112,6 +112,7 @@ class SetAttributeAction : public ProfileAction {
		private:
		const IProfileAttribute* attribute_;
		std::string value_;
		bool optional_;
		};

		// Set cgroup profile element

libprocessgroup/task_profiles_test.cpp

0 → 100644

+209 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2022 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 "task_profiles.h"
		#include <android-base/logging.h>
		#include <gtest/gtest.h>
		#include <mntent.h>
		#include <processgroup/processgroup.h>
		#include <stdio.h>
		#include <unistd.h>

		#include <fstream>

		using ::android::base::ERROR;
		using ::android::base::LogFunction;
		using ::android::base::LogId;
		using ::android::base::LogSeverity;
		using ::android::base::SetLogger;
		using ::android::base::VERBOSE;
		using ::testing::TestWithParam;
		using ::testing::Values;

		namespace {

		bool IsCgroupV2Mounted() {
		std::unique_ptr<FILE, int ()(FILE)> mnts(setmntent("/proc/mounts", "re"), endmntent);
		if (!mnts) {
		LOG(ERROR) << "Failed to open /proc/mounts";
		return false;
		}
		struct mntent* mnt;
		while ((mnt = getmntent(mnts.get()))) {
		if (strcmp(mnt->mnt_fsname, "cgroup2") == 0) {
		return true;
		}
		}
		return false;
		}

		class ScopedLogCapturer {
		public:
		struct log_args {
		LogId log_buffer_id;
		LogSeverity severity;
		std::string tag;
		std::string file;
		unsigned int line;
		std::string message;
		};

		// Constructor. Installs a new logger and saves the currently active logger.
		ScopedLogCapturer() {
		saved_severity_ = SetMinimumLogSeverity(android::base::VERBOSE);
		saved_logger_ = SetLogger([this](LogId log_buffer_id, LogSeverity severity, const char* tag,
		const char* file, unsigned int line, const char* message) {
		if (saved_logger_) {
		saved_logger_(log_buffer_id, severity, tag, file, line, message);
		}
		log_.emplace_back(log_args{.log_buffer_id = log_buffer_id,
		.severity = severity,
		.tag = tag,
		.file = file,
		.line = line,
		.message = message});
		});
		}
		// Destructor. Restores the original logger and log level.
		~ScopedLogCapturer() {
		SetLogger(std::move(saved_logger_));
		SetMinimumLogSeverity(saved_severity_);
		}
		ScopedLogCapturer(const ScopedLogCapturer&) = delete;
		ScopedLogCapturer& operator=(const ScopedLogCapturer&) = delete;
		// Returns the logged lines.
		const std::vector<log_args>& Log() const { return log_; }

		private:
		LogSeverity saved_severity_;
		LogFunction saved_logger_;
		std::vector<log_args> log_;
		};

		// cgroup attribute at the top level of the cgroup hierarchy.
		class ProfileAttributeMock : public IProfileAttribute {
		public:
		ProfileAttributeMock(const std::string& file_name) : file_name_(file_name) {}
		~ProfileAttributeMock() override = default;
		void Reset(const CgroupController& controller, const std::string& file_name) override {
		CHECK(false);
		}
		const CgroupController* controller() const override {
		CHECK(false);
		return {};
		}
		const std::string& file_name() const override { return file_name_; }
		bool GetPathForTask(int tid, std::string* path) const override {
		#ifdef __ANDROID__
		CHECK(CgroupGetControllerPath(CGROUPV2_CONTROLLER_NAME, path));
		CHECK_GT(path->length(), 0);
		if (path->rbegin()[0] != '/') {
		*path += "/";
		}
		#else
		// Not Android.
		*path = "/sys/fs/cgroup/";
		#endif
		*path += file_name_;
		return true;
		};

		private:
		const std::string file_name_;
		};

		struct TestParam {
		const char* attr_name;
		const char* attr_value;
		bool optional_attr;
		bool result;
		LogSeverity log_severity;
		const char* log_prefix;
		const char* log_suffix;
		};

		class SetAttributeFixture : public TestWithParam<TestParam> {
		public:
		~SetAttributeFixture() = default;
		};

		TEST_P(SetAttributeFixture, SetAttribute) {
		// Treehugger runs host tests inside a container without cgroupv2 support.
		if (!IsCgroupV2Mounted()) {
		GTEST_SKIP();
		return;
		}
		const TestParam params = GetParam();
		ScopedLogCapturer captured_log;
		ProfileAttributeMock pa(params.attr_name);
		SetAttributeAction a(&pa, params.attr_value, params.optional_attr);
		EXPECT_EQ(a.ExecuteForProcess(getuid(), getpid()), params.result);
		auto log = captured_log.Log();
		if (params.log_prefix \|\| params.log_suffix) {
		ASSERT_EQ(log.size(), 1);
		EXPECT_EQ(log[0].severity, params.log_severity);
		if (params.log_prefix) {
		EXPECT_EQ(log[0].message.find(params.log_prefix), 0);
		}
		if (params.log_suffix) {
		EXPECT_NE(log[0].message.find(params.log_suffix), std::string::npos);
		}
		} else {
		ASSERT_EQ(log.size(), 0);
		}
		}

		// Test the four combinations of optional_attr {false, true} and cgroup attribute { does not exist,
		// exists }.
		INSTANTIATE_TEST_SUITE_P(
		SetAttributeTestSuite, SetAttributeFixture,
		Values(
		// Test that attempting to write into a non-existing cgroup attribute fails and also
		// that an error message is logged.
		TestParam{.attr_name = "no-such-attribute",
		.attr_value = ".",
		.optional_attr = false,
		.result = false,
		.log_severity = ERROR,
		.log_prefix = "No such cgroup attribute"},
		// Test that attempting to write into an optional non-existing cgroup attribute
		// results in the return value 'true' and also that no messages are logged.
		TestParam{.attr_name = "no-such-attribute",
		.attr_value = ".",
		.optional_attr = true,
		.result = true},
		// Test that attempting to write an invalid value into an existing optional cgroup
		// attribute fails and also that it causes an error
		// message to be logged.
		TestParam{.attr_name = "cgroup.procs",
		.attr_value = "-1",
		.optional_attr = true,
		.result = false,
		.log_severity = ERROR,
		.log_prefix = "Failed to write",
		.log_suffix = geteuid() == 0 ? "Invalid argument" : "Permission denied"},
		// Test that attempting to write into an existing optional read-only cgroup
		// attribute fails and also that it causes an error message to be logged.
		TestParam{
		.attr_name = "cgroup.controllers",
		.attr_value = ".",
		.optional_attr = false,
		.result = false,
		.log_severity = ERROR,
		.log_prefix = "Failed to write",
		.log_suffix = geteuid() == 0 ? "Invalid argument" : "Permission denied"}));

		} // namespace