platform_system_core/libprocessgroup/task_profiles.cpp
Yifan Hong 53e0deb7b2 libprocessgroup: use libcgrouprc to read cgroup.rc
Use the LL-NDK library to read cgroup.rc.

As a side-effect, the CgroupController class is changed
to a wrapper of ACgroupController* from the library. The
class itself essentially becomes the pointer, and can be
trivially copied. Modify all client code for this change.

Test: builds and boots
Bug: 123664216

Change-Id: I635d9885db62e82f37421f6d20f59c84a6f4cbb2
Merged-In: I635d9885db62e82f37421f6d20f59c84a6f4cbb2
2019-04-02 22:31:57 -07:00

430 lines
14 KiB
C++

/*
* 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 LOG_NDEBUG 0
#define LOG_TAG "libprocessgroup"
#include <fcntl.h>
#include <task_profiles.h>
#include <string>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/threads.h>
#include <cutils/android_filesystem_config.h>
#include <json/reader.h>
#include <json/value.h>
// To avoid issues in sdk_mac build
#if defined(__ANDROID__)
#include <sys/prctl.h>
#endif
using android::base::GetThreadId;
using android::base::StringPrintf;
using android::base::unique_fd;
using android::base::WriteStringToFile;
#define TASK_PROFILE_DB_FILE "/etc/task_profiles.json"
#define TASK_PROFILE_DB_VENDOR_FILE "/vendor/etc/task_profiles.json"
bool ProfileAttribute::GetPathForTask(int tid, std::string* path) const {
std::string subgroup;
if (!controller()->GetTaskGroup(tid, &subgroup)) {
return false;
}
if (path == nullptr) {
return true;
}
if (subgroup.empty()) {
*path = StringPrintf("%s/%s", controller()->path(), file_name_.c_str());
} else {
*path = StringPrintf("%s/%s/%s", controller()->path(), subgroup.c_str(),
file_name_.c_str());
}
return true;
}
bool SetClampsAction::ExecuteForProcess(uid_t, pid_t) const {
// TODO: add support when kernel supports util_clamp
LOG(WARNING) << "SetClampsAction::ExecuteForProcess is not supported";
return false;
}
bool SetClampsAction::ExecuteForTask(int) const {
// TODO: add support when kernel supports util_clamp
LOG(WARNING) << "SetClampsAction::ExecuteForTask is not supported";
return false;
}
// To avoid issues in sdk_mac build
#if defined(__ANDROID__)
bool SetTimerSlackAction::IsTimerSlackSupported(int tid) {
auto file = StringPrintf("/proc/%d/timerslack_ns", tid);
return (access(file.c_str(), W_OK) == 0);
}
bool SetTimerSlackAction::ExecuteForTask(int tid) const {
static bool sys_supports_timerslack = IsTimerSlackSupported(tid);
// v4.6+ kernels support the /proc/<tid>/timerslack_ns interface.
// TODO: once we've backported this, log if the open(2) fails.
if (sys_supports_timerslack) {
auto file = StringPrintf("/proc/%d/timerslack_ns", tid);
if (!WriteStringToFile(std::to_string(slack_), file)) {
if (errno == ENOENT) {
// This happens when process is already dead
return true;
}
PLOG(ERROR) << "set_timerslack_ns write failed";
}
}
// TODO: Remove when /proc/<tid>/timerslack_ns interface is backported.
if (tid == 0 || tid == GetThreadId()) {
if (prctl(PR_SET_TIMERSLACK, slack_) == -1) {
PLOG(ERROR) << "set_timerslack_ns prctl failed";
}
}
return true;
}
#endif
bool SetAttributeAction::ExecuteForProcess(uid_t, pid_t pid) const {
return ExecuteForTask(pid);
}
bool SetAttributeAction::ExecuteForTask(int tid) const {
std::string path;
if (!attribute_->GetPathForTask(tid, &path)) {
LOG(ERROR) << "Failed to find cgroup for tid " << tid;
return false;
}
if (!WriteStringToFile(value_, path)) {
PLOG(ERROR) << "Failed to write '" << value_ << "' to " << path;
return false;
}
return true;
}
bool SetCgroupAction::IsAppDependentPath(const std::string& path) {
return path.find("<uid>", 0) != std::string::npos || path.find("<pid>", 0) != std::string::npos;
}
SetCgroupAction::SetCgroupAction(const CgroupController& c, const std::string& p)
: controller_(c), path_(p) {
#ifdef CACHE_FILE_DESCRIPTORS
// cache file descriptor only if path is app independent
if (IsAppDependentPath(path_)) {
// file descriptor is not cached
fd_.reset(-2);
return;
}
std::string tasks_path = c.GetTasksFilePath(p);
if (access(tasks_path.c_str(), W_OK) != 0) {
// file is not accessible
fd_.reset(-1);
return;
}
unique_fd fd(TEMP_FAILURE_RETRY(open(tasks_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (fd < 0) {
PLOG(ERROR) << "Failed to cache fd '" << tasks_path << "'";
fd_.reset(-1);
return;
}
fd_ = std::move(fd);
#endif
}
bool SetCgroupAction::AddTidToCgroup(int tid, int fd) {
if (tid <= 0) {
return true;
}
std::string value = std::to_string(tid);
if (TEMP_FAILURE_RETRY(write(fd, value.c_str(), value.length())) < 0) {
// If the thread is in the process of exiting, don't flag an error
if (errno != ESRCH) {
PLOG(ERROR) << "AddTidToCgroup failed to write '" << value << "'; fd=" << fd;
return false;
}
}
return true;
}
bool SetCgroupAction::ExecuteForProcess(uid_t uid, pid_t pid) const {
#ifdef CACHE_FILE_DESCRIPTORS
if (fd_ >= 0) {
// fd is cached, reuse it
if (!AddTidToCgroup(pid, fd_)) {
LOG(ERROR) << "Failed to add task into cgroup";
return false;
}
return true;
}
if (fd_ == -1) {
// no permissions to access the file, ignore
return true;
}
// this is app-dependent path, file descriptor is not cached
std::string procs_path = controller()->GetProcsFilePath(path_, uid, pid);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(procs_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
PLOG(WARNING) << "Failed to open " << procs_path;
return false;
}
if (!AddTidToCgroup(pid, tmp_fd)) {
LOG(ERROR) << "Failed to add task into cgroup";
return false;
}
return true;
#else
std::string procs_path = controller()->GetProcsFilePath(path_, uid, pid);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(procs_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
// no permissions to access the file, ignore
return true;
}
if (!AddTidToCgroup(pid, tmp_fd)) {
LOG(ERROR) << "Failed to add task into cgroup";
return false;
}
return true;
#endif
}
bool SetCgroupAction::ExecuteForTask(int tid) const {
#ifdef CACHE_FILE_DESCRIPTORS
if (fd_ >= 0) {
// fd is cached, reuse it
if (!AddTidToCgroup(tid, fd_)) {
LOG(ERROR) << "Failed to add task into cgroup";
return false;
}
return true;
}
if (fd_ == -1) {
// no permissions to access the file, ignore
return true;
}
// application-dependent path can't be used with tid
LOG(ERROR) << "Application profile can't be applied to a thread";
return false;
#else
std::string tasks_path = controller()->GetTasksFilePath(path_);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(tasks_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
// no permissions to access the file, ignore
return true;
}
if (!AddTidToCgroup(tid, tmp_fd)) {
LOG(ERROR) << "Failed to add task into cgroup";
return false;
}
return true;
#endif
}
bool TaskProfile::ExecuteForProcess(uid_t uid, pid_t pid) const {
for (const auto& element : elements_) {
if (!element->ExecuteForProcess(uid, pid)) {
return false;
}
}
return true;
}
bool TaskProfile::ExecuteForTask(int tid) const {
if (tid == 0) {
tid = GetThreadId();
}
for (const auto& element : elements_) {
if (!element->ExecuteForTask(tid)) {
return false;
}
}
return true;
}
TaskProfiles& TaskProfiles::GetInstance() {
// Deliberately leak this object to avoid a race between destruction on
// process exit and concurrent access from another thread.
static auto* instance = new TaskProfiles;
return *instance;
}
TaskProfiles::TaskProfiles() {
// load system task profiles
if (!Load(CgroupMap::GetInstance(), TASK_PROFILE_DB_FILE)) {
LOG(ERROR) << "Loading " << TASK_PROFILE_DB_FILE << " for [" << getpid() << "] failed";
}
// load vendor task profiles if the file exists
if (!access(TASK_PROFILE_DB_VENDOR_FILE, F_OK) &&
!Load(CgroupMap::GetInstance(), TASK_PROFILE_DB_VENDOR_FILE)) {
LOG(ERROR) << "Loading " << TASK_PROFILE_DB_VENDOR_FILE << " for [" << getpid()
<< "] failed";
}
}
bool TaskProfiles::Load(const CgroupMap& cg_map, const std::string& file_name) {
std::string json_doc;
if (!android::base::ReadFileToString(file_name, &json_doc)) {
LOG(ERROR) << "Failed to read task profiles from " << file_name;
return false;
}
Json::Reader reader;
Json::Value root;
if (!reader.parse(json_doc, root)) {
LOG(ERROR) << "Failed to parse task profiles: " << reader.getFormattedErrorMessages();
return false;
}
const Json::Value& attr = root["Attributes"];
for (Json::Value::ArrayIndex i = 0; i < attr.size(); ++i) {
std::string name = attr[i]["Name"].asString();
std::string controller_name = attr[i]["Controller"].asString();
std::string file_attr = attr[i]["File"].asString();
if (attributes_.find(name) == attributes_.end()) {
auto controller = cg_map.FindController(controller_name);
if (controller.HasValue()) {
attributes_[name] = std::make_unique<ProfileAttribute>(controller, file_attr);
} else {
LOG(WARNING) << "Controller " << controller_name << " is not found";
}
} else {
LOG(WARNING) << "Attribute " << name << " is already defined";
}
}
std::map<std::string, std::string> params;
const Json::Value& profiles_val = root["Profiles"];
for (Json::Value::ArrayIndex i = 0; i < profiles_val.size(); ++i) {
const Json::Value& profile_val = profiles_val[i];
std::string profile_name = profile_val["Name"].asString();
const Json::Value& actions = profile_val["Actions"];
auto profile = std::make_unique<TaskProfile>();
for (Json::Value::ArrayIndex act_idx = 0; act_idx < actions.size(); ++act_idx) {
const Json::Value& action_val = actions[act_idx];
std::string action_name = action_val["Name"].asString();
const Json::Value& params_val = action_val["Params"];
if (action_name == "JoinCgroup") {
std::string controller_name = params_val["Controller"].asString();
std::string path = params_val["Path"].asString();
auto controller = cg_map.FindController(controller_name);
if (controller.HasValue()) {
profile->Add(std::make_unique<SetCgroupAction>(controller, path));
} else {
LOG(WARNING) << "JoinCgroup: controller " << controller_name << " is not found";
}
} else if (action_name == "SetTimerSlack") {
std::string slack_value = params_val["Slack"].asString();
char* end;
unsigned long slack;
slack = strtoul(slack_value.c_str(), &end, 10);
if (end > slack_value.c_str()) {
profile->Add(std::make_unique<SetTimerSlackAction>(slack));
} else {
LOG(WARNING) << "SetTimerSlack: invalid parameter: " << slack_value;
}
} else if (action_name == "SetAttribute") {
std::string attr_name = params_val["Name"].asString();
std::string attr_value = params_val["Value"].asString();
auto iter = attributes_.find(attr_name);
if (iter != attributes_.end()) {
profile->Add(
std::make_unique<SetAttributeAction>(iter->second.get(), attr_value));
} else {
LOG(WARNING) << "SetAttribute: unknown attribute: " << attr_name;
}
} else if (action_name == "SetClamps") {
std::string boost_value = params_val["Boost"].asString();
std::string clamp_value = params_val["Clamp"].asString();
char* end;
unsigned long boost;
boost = strtoul(boost_value.c_str(), &end, 10);
if (end > boost_value.c_str()) {
unsigned long clamp = strtoul(clamp_value.c_str(), &end, 10);
if (end > clamp_value.c_str()) {
profile->Add(std::make_unique<SetClampsAction>(boost, clamp));
} else {
LOG(WARNING) << "SetClamps: invalid parameter " << clamp_value;
}
} else {
LOG(WARNING) << "SetClamps: invalid parameter: " << boost_value;
}
} else {
LOG(WARNING) << "Unknown profile action: " << action_name;
}
}
profiles_[profile_name] = std::move(profile);
}
return true;
}
const TaskProfile* TaskProfiles::GetProfile(const std::string& name) const {
auto iter = profiles_.find(name);
if (iter != profiles_.end()) {
return iter->second.get();
}
return nullptr;
}
const ProfileAttribute* TaskProfiles::GetAttribute(const std::string& name) const {
auto iter = attributes_.find(name);
if (iter != attributes_.end()) {
return iter->second.get();
}
return nullptr;
}