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Reapply "libprocessgroup: Remove cgroup.rc file"

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This reverts commit 972a2d30f8.

Change-Id: Icdf2824675e515ea3656b1c58ac55160ecc337df
This commit is contained in:
T.J. Mercier 2024-10-08 23:41:27 +00:00
parent eb34156abe
commit a09ee8ece6
23 changed files with 365 additions and 389 deletions
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7
fs_mgr/libsnapshot/snapuserd/Android.bp
View file

@ -85,9 +85,9 @@ cc_library_static {
"libsnapshot_cow",
"liburing",
"libprocessgroup",
"libprocessgroup_util",
"libjsoncpp",
"libcgrouprc",
"libcgrouprc_format",
],
include_dirs: ["bionic/libc/kernel"],
export_include_dirs: ["include"],
@ -129,9 +129,9 @@ cc_defaults {
"libsnapshot_cow",
"libsnapuserd",
"libprocessgroup",
"libprocessgroup_util",
"libjsoncpp",
"libcgrouprc",
"libcgrouprc_format",
"libsnapuserd_client",
"libz",
"liblz4",
@ -221,9 +221,9 @@ cc_defaults {
"libsnapshot_cow",
"libsnapuserd",
"libprocessgroup",
"libprocessgroup_util",
"libjsoncpp",
"libcgrouprc",
"libcgrouprc_format",
"liburing",
"libz",
],
@ -319,7 +319,6 @@ cc_binary_host {
"libprocessgroup",
"libjsoncpp",
"libcgrouprc",
"libcgrouprc_format",
"liburing",
"libz",
],

1
init/Android.bp
View file

@ -163,7 +163,6 @@ libinit_cc_defaults {
"libavb",
"libavf_cc_flags",
"libbootloader_message",
"libcgrouprc_format",
"liblmkd_utils",
"liblz4",
"libzstd",

3
init/init.cpp
View file

@ -636,9 +636,6 @@ static Result<void> SetupCgroupsAction(const BuiltinArguments&) {
LOG(INFO) << "Cgroups support in kernel is not enabled";
return {};
}
// Have to create <CGROUPS_RC_DIR> using make_dir function
// for appropriate sepolicy to be set for it
make_dir(android::base::Dirname(CGROUPS_RC_PATH), 0711);
if (!CgroupSetup()) {
return ErrnoError() << "Failed to setup cgroups";
}

2
libcutils/Android.bp
View file

@ -301,7 +301,7 @@ cc_defaults {
android: {
static_executable: true,
static_libs: [
"libcgrouprc_format",
"libprocessgroup_util",
] + test_libraries + always_static_test_libraries,
},
not_windows: {

3
libprocessgroup/Android.bp
View file

@ -17,7 +17,7 @@ soong_config_module_type {
libprocessgroup_flag_aware_cc_defaults {
name: "libprocessgroup_build_flags_cc",
cpp_std: "gnu++20",
cpp_std: "gnu++23",
soong_config_variables: {
memcg_v2_force_enabled: {
cflags: [
@ -116,5 +116,6 @@ cc_test {
],
static_libs: [
"libgmock",
"libprocessgroup_util",
],
}

4
libprocessgroup/cgroup_map.cpp
View file

@ -151,7 +151,7 @@ bool CgroupMap::LoadRcFile() {
void CgroupMap::Print() const {
if (!loaded_) {
LOG(ERROR) << "CgroupMap::Print called for [" << getpid()
<< "] failed, RC file was not initialized properly";
<< "] failed, cgroups were not initialized properly";
return;
}
LOG(INFO) << "File version = " << ACgroupFile_getVersion();
@ -221,7 +221,7 @@ int CgroupMap::ActivateControllers(const std::string& path) const {
if (__builtin_available(android 36, *)) {
max_activation_depth = ACgroupController_getMaxActivationDepth(controller);
}
const int depth = util::GetCgroupDepth(ACgroupController_getPath(controller), path);
const int depth = GetCgroupDepth(ACgroupController_getPath(controller), path);
if (flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
std::string str("+");

3
libprocessgroup/cgrouprc/Android.bp
View file

@ -49,7 +49,8 @@ cc_library {
"libbase",
],
static_libs: [
"libcgrouprc_format",
"libjsoncpp",
"libprocessgroup_util",
],
stubs: {
symbol_file: "libcgrouprc.map.txt",

88
libprocessgroup/cgrouprc/a_cgroup_file.cpp
View file

@ -14,93 +14,51 @@
* limitations under the License.
*/
#include <sys/mman.h>
#include <sys/stat.h>
#include <memory>
#include <iterator>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <android/cgrouprc.h>
#include <processgroup/processgroup.h>
#include <processgroup/util.h>
#include "cgrouprc_internal.h"
using android::base::StringPrintf;
using android::base::unique_fd;
using android::cgrouprc::format::CgroupController;
using android::cgrouprc::format::CgroupFile;
static CgroupFile* LoadRcFile() {
struct stat sb;
unique_fd fd(TEMP_FAILURE_RETRY(open(CGROUPS_RC_PATH, O_RDONLY | O_CLOEXEC)));
if (fd < 0) {
PLOG(ERROR) << "open() failed for " << CGROUPS_RC_PATH;
static CgroupDescriptorMap* LoadDescriptors() {
CgroupDescriptorMap* descriptors = new CgroupDescriptorMap;
if (!ReadDescriptors(descriptors)) {
LOG(ERROR) << "Failed to load cgroup description file";
return nullptr;
}
if (fstat(fd, &sb) < 0) {
PLOG(ERROR) << "fstat() failed for " << CGROUPS_RC_PATH;
return nullptr;
}
size_t file_size = sb.st_size;
if (file_size < sizeof(CgroupFile)) {
LOG(ERROR) << "Invalid file format " << CGROUPS_RC_PATH;
return nullptr;
}
CgroupFile* file_data = (CgroupFile*)mmap(nullptr, file_size, PROT_READ, MAP_SHARED, fd, 0);
if (file_data == MAP_FAILED) {
PLOG(ERROR) << "Failed to mmap " << CGROUPS_RC_PATH;
return nullptr;
}
if (file_data->version_ != CgroupFile::FILE_CURR_VERSION) {
LOG(ERROR) << CGROUPS_RC_PATH << " file version mismatch";
munmap(file_data, file_size);
return nullptr;
}
auto expected = sizeof(CgroupFile) + file_data->controller_count_ * sizeof(CgroupController);
if (file_size != expected) {
LOG(ERROR) << CGROUPS_RC_PATH << " file has invalid size, expected " << expected
<< ", actual " << file_size;
munmap(file_data, file_size);
return nullptr;
}
return file_data;
return descriptors;
}
static CgroupFile* GetInstance() {
static const CgroupDescriptorMap* GetInstance() {
// Deliberately leak this object (not munmap) to avoid a race between destruction on
// process exit and concurrent access from another thread.
static auto* file = LoadRcFile();
return file;
static const CgroupDescriptorMap* descriptors = LoadDescriptors();
return descriptors;
}
uint32_t ACgroupFile_getVersion() {
auto file = GetInstance();
if (file == nullptr) return 0;
return file->version_;
static constexpr uint32_t FILE_VERSION_1 = 1;
auto descriptors = GetInstance();
if (descriptors == nullptr) return 0;
// There has only ever been one version, and there will be no more since cgroup.rc is no more
return FILE_VERSION_1;
}
uint32_t ACgroupFile_getControllerCount() {
auto file = GetInstance();
if (file == nullptr) return 0;
return file->controller_count_;
auto descriptors = GetInstance();
if (descriptors == nullptr) return 0;
return descriptors->size();
}
const ACgroupController* ACgroupFile_getController(uint32_t index) {
auto file = GetInstance();
if (file == nullptr) return nullptr;
CHECK(index < file->controller_count_);
auto descriptors = GetInstance();
if (descriptors == nullptr) return nullptr;
CHECK(index < descriptors->size());
// Although the object is not actually an ACgroupController object, all ACgroupController_*
// functions implicitly convert ACgroupController* back to CgroupController* before invoking
// member functions.
return static_cast<ACgroupController*>(&file->controllers_[index]);
const CgroupController* p = std::next(descriptors->begin(), index)->second.controller();
return static_cast<const ACgroupController*>(p);
}

7
libprocessgroup/cgrouprc/cgrouprc_internal.h
View file

@ -16,9 +16,6 @@
#pragma once
#include <android/cgrouprc.h>
#include <processgroup/cgroup_controller.h>
#include <processgroup/format/cgroup_controller.h>
#include <processgroup/format/cgroup_file.h>
struct ACgroupController : android::cgrouprc::format::CgroupController {};
struct ACgroupController : CgroupController {};

13
libprocessgroup/cgrouprc_format/Android.bp
View file

@ -23,17 +23,4 @@ cc_library_static {
vendor_ramdisk_available: true,
recovery_available: true,
native_bridge_supported: true,
srcs: [
"cgroup_controller.cpp",
],
cflags: [
"-Wall",
"-Werror",
],
export_include_dirs: [
"include",
],
shared_libs: [
"libbase",
],
}

2
libprocessgroup/include/processgroup/processgroup.h
View file

@ -57,7 +57,7 @@ __BEGIN_DECLS
bool SetProcessProfilesCached(uid_t uid, pid_t pid, const std::vector<std::string>& profiles);
static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
[[deprecated]] static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
bool UsePerAppMemcg();

23
libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h → libprocessgroup/internal.h
View file

@ -1,5 +1,5 @@
/*
* Copyright (C) 2019 The Android Open Source Project
* Copyright (C) 2024 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.
@ -16,23 +16,6 @@
#pragma once
#include <cstdint>
#include <string>
#include <processgroup/format/cgroup_controller.h>
namespace android {
namespace cgrouprc {
namespace format {
struct CgroupFile {
uint32_t version_;
uint32_t controller_count_;
CgroupController controllers_[];
static constexpr uint32_t FILE_VERSION_1 = 1;
static constexpr uint32_t FILE_CURR_VERSION = FILE_VERSION_1;
};
} // namespace format
} // namespace cgrouprc
} // namespace android
static const std::string CGROUP_V2_ROOT_DEFAULT = "/sys/fs/cgroup";

1
libprocessgroup/setup/Android.bp
View file

@ -33,7 +33,6 @@ cc_library_shared {
"libjsoncpp",
],
static_libs: [
"libcgrouprc_format",
"libprocessgroup_util",
],
header_libs: [

12
libprocessgroup/setup/cgroup_descriptor.h
View file

@ -21,10 +21,7 @@
#include <sys/stat.h>
#include <processgroup/format/cgroup_controller.h>
namespace android {
namespace cgrouprc {
#include <processgroup/cgroup_controller.h>
// Complete controller description for mounting cgroups
class CgroupDescriptor {
@ -33,7 +30,7 @@ class CgroupDescriptor {
mode_t mode, const std::string& uid, const std::string& gid, uint32_t flags,
uint32_t max_activation_depth);
const format::CgroupController* controller() const { return &controller_; }
const CgroupController* controller() const { return &controller_; }
mode_t mode() const { return mode_; }
std::string uid() const { return uid_; }
std::string gid() const { return gid_; }
@ -41,11 +38,8 @@ class CgroupDescriptor {
void set_mounted(bool mounted);
private:
format::CgroupController controller_;
CgroupController controller_;
mode_t mode_ = 0;
std::string uid_;
std::string gid_;
};
} // namespace cgrouprc
} // namespace android

259
libprocessgroup/setup/cgroup_map_write.cpp
View file

@ -22,45 +22,28 @@
#include <fcntl.h>
#include <grp.h>
#include <pwd.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <optional>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <android/cgrouprc.h>
#include <json/reader.h>
#include <json/value.h>
#include <processgroup/format/cgroup_file.h>
#include <processgroup/cgroup_descriptor.h>
#include <processgroup/processgroup.h>
#include <processgroup/setup.h>
#include <processgroup/util.h>
#include "../build_flags.h"
#include "cgroup_descriptor.h"
using android::base::GetUintProperty;
using android::base::StringPrintf;
using android::base::unique_fd;
namespace android {
namespace cgrouprc {
#include "../internal.h"
static constexpr const char* CGROUPS_DESC_FILE = "/etc/cgroups.json";
static constexpr const char* CGROUPS_DESC_VENDOR_FILE = "/vendor/etc/cgroups.json";
static constexpr const char* TEMPLATE_CGROUPS_DESC_API_FILE = "/etc/task_profiles/cgroups_%u.json";
static const std::string CGROUP_V2_ROOT_DEFAULT = "/sys/fs/cgroup";
static bool ChangeDirModeAndOwner(const std::string& path, mode_t mode, const std::string& uid,
const std::string& gid, bool permissive_mode = false) {
uid_t pw_uid = -1;
@ -148,149 +131,15 @@ static bool Mkdir(const std::string& path, mode_t mode, const std::string& uid,
return true;
}
static void MergeCgroupToDescriptors(std::map<std::string, CgroupDescriptor>* descriptors,
const Json::Value& cgroup, const std::string& name,
const std::string& root_path, int cgroups_version) {
const std::string cgroup_path = cgroup["Path"].asString();
std::string path;
if (!root_path.empty()) {
path = root_path;
if (cgroup_path != ".") {
path += "/";
path += cgroup_path;
}
} else {
path = cgroup_path;
}
uint32_t controller_flags = 0;
if (cgroup["NeedsActivation"].isBool() && cgroup["NeedsActivation"].asBool()) {
controller_flags |= CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION;
}
if (cgroup["Optional"].isBool() && cgroup["Optional"].asBool()) {
controller_flags |= CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
}
uint32_t max_activation_depth = UINT32_MAX;
if (cgroup.isMember("MaxActivationDepth")) {
max_activation_depth = cgroup["MaxActivationDepth"].asUInt();
}
CgroupDescriptor descriptor(
cgroups_version, name, path, std::strtoul(cgroup["Mode"].asString().c_str(), 0, 8),
cgroup["UID"].asString(), cgroup["GID"].asString(), controller_flags,
max_activation_depth);
auto iter = descriptors->find(name);
if (iter == descriptors->end()) {
descriptors->emplace(name, descriptor);
} else {
iter->second = descriptor;
}
}
static const bool force_memcg_v2 = android::libprocessgroup_flags::force_memcg_v2();
static bool ReadDescriptorsFromFile(const std::string& file_name,
std::map<std::string, CgroupDescriptor>* descriptors) {
std::vector<CgroupDescriptor> result;
std::string json_doc;
if (!android::base::ReadFileToString(file_name, &json_doc)) {
PLOG(ERROR) << "Failed to read task profiles from " << file_name;
return false;
}
Json::CharReaderBuilder builder;
std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
Json::Value root;
std::string errorMessage;
if (!reader->parse(&*json_doc.begin(), &*json_doc.end(), &root, &errorMessage)) {
LOG(ERROR) << "Failed to parse cgroups description: " << errorMessage;
return false;
}
if (root.isMember("Cgroups")) {
const Json::Value& cgroups = root["Cgroups"];
for (Json::Value::ArrayIndex i = 0; i < cgroups.size(); ++i) {
std::string name = cgroups[i]["Controller"].asString();
if (force_memcg_v2 && name == "memory") continue;
MergeCgroupToDescriptors(descriptors, cgroups[i], name, "", 1);
}
}
bool memcgv2_present = false;
std::string root_path;
if (root.isMember("Cgroups2")) {
const Json::Value& cgroups2 = root["Cgroups2"];
root_path = cgroups2["Path"].asString();
MergeCgroupToDescriptors(descriptors, cgroups2, CGROUPV2_HIERARCHY_NAME, "", 2);
const Json::Value& childGroups = cgroups2["Controllers"];
for (Json::Value::ArrayIndex i = 0; i < childGroups.size(); ++i) {
std::string name = childGroups[i]["Controller"].asString();
if (force_memcg_v2 && name == "memory") memcgv2_present = true;
MergeCgroupToDescriptors(descriptors, childGroups[i], name, root_path, 2);
}
}
if (force_memcg_v2 && !memcgv2_present) {
LOG(INFO) << "Forcing memcg to v2 hierarchy";
Json::Value memcgv2;
memcgv2["Controller"] = "memory";
memcgv2["NeedsActivation"] = true;
memcgv2["Path"] = ".";
memcgv2["Optional"] = true; // In case of cgroup_disabled=memory, so we can still boot
MergeCgroupToDescriptors(descriptors, memcgv2, "memory",
root_path.empty() ? CGROUP_V2_ROOT_DEFAULT : root_path, 2);
}
return true;
}
static bool ReadDescriptors(std::map<std::string, CgroupDescriptor>* descriptors) {
// load system cgroup descriptors
if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, descriptors)) {
return false;
}
// load API-level specific system cgroups descriptors if available
unsigned int api_level = GetUintProperty<unsigned int>("ro.product.first_api_level", 0);
if (api_level > 0) {
std::string api_cgroups_path =
android::base::StringPrintf(TEMPLATE_CGROUPS_DESC_API_FILE, api_level);
if (!access(api_cgroups_path.c_str(), F_OK) || errno != ENOENT) {
if (!ReadDescriptorsFromFile(api_cgroups_path, descriptors)) {
return false;
}
}
}
// load vendor cgroup descriptors if the file exists
if (!access(CGROUPS_DESC_VENDOR_FILE, F_OK) &&
!ReadDescriptorsFromFile(CGROUPS_DESC_VENDOR_FILE, descriptors)) {
return false;
}
return true;
}
// To avoid issues in sdk_mac build
#if defined(__ANDROID__)
static bool IsOptionalController(const format::CgroupController* controller) {
static bool IsOptionalController(const CgroupController* controller) {
return controller->flags() & CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
}
static bool MountV2CgroupController(const CgroupDescriptor& descriptor) {
const format::CgroupController* controller = descriptor.controller();
const CgroupController* controller = descriptor.controller();
// /sys/fs/cgroup is created by cgroup2 with specific selinux permissions,
// try to create again in case the mount point is changed
@ -324,7 +173,7 @@ static bool MountV2CgroupController(const CgroupDescriptor& descriptor) {
}
static bool ActivateV2CgroupController(const CgroupDescriptor& descriptor) {
const format::CgroupController* controller = descriptor.controller();
const CgroupController* controller = descriptor.controller();
if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
LOG(ERROR) << "Failed to create directory for " << controller->name() << " cgroup";
@ -338,7 +187,7 @@ static bool ActivateV2CgroupController(const CgroupDescriptor& descriptor) {
std::string path = controller->path();
path += "/cgroup.subtree_control";
if (!base::WriteStringToFile(str, path)) {
if (!android::base::WriteStringToFile(str, path)) {
if (IsOptionalController(controller)) {
PLOG(INFO) << "Failed to activate optional controller " << controller->name()
<< " at " << path;
@ -353,7 +202,7 @@ static bool ActivateV2CgroupController(const CgroupDescriptor& descriptor) {
}
static bool MountV1CgroupController(const CgroupDescriptor& descriptor) {
const format::CgroupController* controller = descriptor.controller();
const CgroupController* controller = descriptor.controller();
// mkdir <path> [mode] [owner] [group]
if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
@ -388,7 +237,7 @@ static bool MountV1CgroupController(const CgroupDescriptor& descriptor) {
}
static bool SetupCgroup(const CgroupDescriptor& descriptor) {
const format::CgroupController* controller = descriptor.controller();
const CgroupController* controller = descriptor.controller();
if (controller->version() == 2) {
if (!strcmp(controller->name(), CGROUPV2_HIERARCHY_NAME)) {
@ -410,35 +259,6 @@ static bool SetupCgroup(const CgroupDescriptor&) {
#endif
static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) {
unique_fd fd(TEMP_FAILURE_RETRY(open(CGROUPS_RC_PATH, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC,
S_IRUSR | S_IRGRP | S_IROTH)));
if (fd < 0) {
PLOG(ERROR) << "open() failed for " << CGROUPS_RC_PATH;
return false;
}
format::CgroupFile fl;
fl.version_ = format::CgroupFile::FILE_CURR_VERSION;
fl.controller_count_ = descriptors.size();
int ret = TEMP_FAILURE_RETRY(write(fd, &fl, sizeof(fl)));
if (ret < 0) {
PLOG(ERROR) << "write() failed for " << CGROUPS_RC_PATH;
return false;
}
for (const auto& [name, descriptor] : descriptors) {
ret = TEMP_FAILURE_RETRY(
write(fd, descriptor.controller(), sizeof(format::CgroupController)));
if (ret < 0) {
PLOG(ERROR) << "write() failed for " << CGROUPS_RC_PATH;
return false;
}
}
return true;
}
CgroupDescriptor::CgroupDescriptor(uint32_t version, const std::string& name,
const std::string& path, mode_t mode, const std::string& uid,
const std::string& gid, uint32_t flags,
@ -458,9 +278,6 @@ void CgroupDescriptor::set_mounted(bool mounted) {
controller_.set_flags(flags);
}
} // namespace cgrouprc
} // namespace android
static std::optional<bool> MGLRUDisabled() {
const std::string file_name = "/sys/kernel/mm/lru_gen/enabled";
std::string content;
@ -472,9 +289,8 @@ static std::optional<bool> MGLRUDisabled() {
return content == "0x0000";
}
static std::optional<bool> MEMCGDisabled(
const std::map<std::string, android::cgrouprc::CgroupDescriptor>& descriptors) {
std::string cgroup_v2_root = android::cgrouprc::CGROUP_V2_ROOT_DEFAULT;
static std::optional<bool> MEMCGDisabled(const CgroupDescriptorMap& descriptors) {
std::string cgroup_v2_root = CGROUP_V2_ROOT_DEFAULT;
const auto it = descriptors.find(CGROUPV2_HIERARCHY_NAME);
if (it == descriptors.end()) {
LOG(WARNING) << "No Cgroups2 path found in cgroups.json. Vendor has modified Android, and "
@ -495,14 +311,10 @@ static std::optional<bool> MEMCGDisabled(
return content.find("memory") == std::string::npos;
}
static bool CreateV2SubHierarchy(
const std::string& path,
const std::map<std::string, android::cgrouprc::CgroupDescriptor>& descriptors) {
using namespace android::cgrouprc;
static bool CreateV2SubHierarchy(const std::string& path, const CgroupDescriptorMap& descriptors) {
const auto cgv2_iter = descriptors.find(CGROUPV2_HIERARCHY_NAME);
if (cgv2_iter == descriptors.end()) return false;
const android::cgrouprc::CgroupDescriptor cgv2_descriptor = cgv2_iter->second;
const CgroupDescriptor cgv2_descriptor = cgv2_iter->second;
if (!Mkdir(path, cgv2_descriptor.mode(), cgv2_descriptor.uid(), cgv2_descriptor.gid())) {
PLOG(ERROR) << "Failed to create directory for " << path;
@ -512,10 +324,10 @@ static bool CreateV2SubHierarchy(
// Activate all v2 controllers in path so they can be activated in
// children as they are created.
for (const auto& [name, descriptor] : descriptors) {
const format::CgroupController* controller = descriptor.controller();
const CgroupController* controller = descriptor.controller();
std::uint32_t flags = controller->flags();
std::uint32_t max_activation_depth = controller->max_activation_depth();
const int depth = util::GetCgroupDepth(controller->path(), path);
const int depth = GetCgroupDepth(controller->path(), path);
if (controller->version() == 2 && name != CGROUPV2_HIERARCHY_NAME &&
flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
@ -535,22 +347,13 @@ static bool CreateV2SubHierarchy(
}
bool CgroupSetup() {
using namespace android::cgrouprc;
std::map<std::string, CgroupDescriptor> descriptors;
CgroupDescriptorMap descriptors;
if (getpid() != 1) {
LOG(ERROR) << "Cgroup setup can be done only by init process";
return false;
}
// Make sure we do this only one time. No need for std::call_once because
// init is a single-threaded process
if (access(CGROUPS_RC_PATH, F_OK) == 0) {
LOG(WARNING) << "Attempt to call CgroupSetup() more than once";
return true;
}
// load cgroups.json file
if (!ReadDescriptors(&descriptors)) {
LOG(ERROR) << "Failed to load cgroup description file";
@ -559,15 +362,18 @@ bool CgroupSetup() {
// setup cgroups
for (auto& [name, descriptor] : descriptors) {
if (SetupCgroup(descriptor)) {
descriptor.set_mounted(true);
} else {
if (descriptor.controller()->flags() & CGROUPRC_CONTROLLER_FLAG_MOUNTED) {
LOG(WARNING) << "Attempt to call CgroupSetup() more than once";
return true;
}
if (!SetupCgroup(descriptor)) {
// issue a warning and proceed with the next cgroup
LOG(WARNING) << "Failed to setup " << name << " cgroup";
}
}
if (force_memcg_v2) {
if (android::libprocessgroup_flags::force_memcg_v2()) {
if (MGLRUDisabled().value_or(false)) {
LOG(WARNING) << "Memcg forced to v2 hierarchy with MGLRU disabled! "
<< "Global reclaim performance will suffer.";
@ -593,26 +399,5 @@ bool CgroupSetup() {
}
}
// mkdir <CGROUPS_RC_DIR> 0711 system system
if (!Mkdir(android::base::Dirname(CGROUPS_RC_PATH), 0711, "system", "system")) {
LOG(ERROR) << "Failed to create directory for " << CGROUPS_RC_PATH << " file";
return false;
}
// Generate <CGROUPS_RC_FILE> file which can be directly mmapped into
// process memory. This optimizes performance, memory usage
// and limits infrormation shared with unprivileged processes
// to the minimum subset of information from cgroups.json
if (!WriteRcFile(descriptors)) {
LOG(ERROR) << "Failed to write " << CGROUPS_RC_PATH << " file";
return false;
}
// chmod 0644 <CGROUPS_RC_PATH>
if (fchmodat(AT_FDCWD, CGROUPS_RC_PATH, 0644, AT_SYMLINK_NOFOLLOW) < 0) {
PLOG(ERROR) << "fchmodat() failed";
return false;
}
return true;
}

8
libprocessgroup/util/Android.bp
View file

@ -37,8 +37,16 @@ cc_library_static {
"include",
],
srcs: [
"cgroup_controller.cpp",
"cgroup_descriptor.cpp",
"util.cpp",
],
shared_libs: [
"libbase",
],
static_libs: [
"libjsoncpp",
],
defaults: ["libprocessgroup_build_flags_cc"],
}

12
libprocessgroup/cgrouprc_format/cgroup_controller.cpp → libprocessgroup/util/cgroup_controller.cpp
View file

@ -14,11 +14,9 @@
* limitations under the License.
*/
#include <processgroup/format/cgroup_controller.h>
#include <processgroup/cgroup_controller.h>
namespace android {
namespace cgrouprc {
namespace format {
#include <cstring>
CgroupController::CgroupController(uint32_t version, uint32_t flags, const std::string& name,
const std::string& path, uint32_t max_activation_depth)
@ -54,8 +52,4 @@ const char* CgroupController::path() const {
void CgroupController::set_flags(uint32_t flags) {
flags_ = flags;
}
} // namespace format
} // namespace cgrouprc
} // namespace android
}

38
libprocessgroup/util/cgroup_descriptor.cpp Normal file
View file

@ -0,0 +1,38 @@
/*
* Copyright (C) 2024 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 <processgroup/cgroup_descriptor.h>
#include <processgroup/util.h> // For flag values
CgroupDescriptor::CgroupDescriptor(uint32_t version, const std::string& name,
const std::string& path, mode_t mode, const std::string& uid,
const std::string& gid, uint32_t flags,
uint32_t max_activation_depth)
: controller_(version, flags, name, path, max_activation_depth),
mode_(mode),
uid_(uid),
gid_(gid) {}
void CgroupDescriptor::set_mounted(bool mounted) {
uint32_t flags = controller_.flags();
if (mounted) {
flags |= CGROUPRC_CONTROLLER_FLAG_MOUNTED;
} else {
flags &= ~CGROUPRC_CONTROLLER_FLAG_MOUNTED;
}
controller_.set_flags(flags);
}

12
libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h → libprocessgroup/util/include/processgroup/cgroup_controller.h
View file

@ -20,11 +20,7 @@
#include <cstdint>
#include <string>
namespace android {
namespace cgrouprc {
namespace format {
// Minimal controller description to be mmapped into process address space
// Minimal controller description
struct CgroupController {
public:
CgroupController() = default;
@ -48,8 +44,4 @@ struct CgroupController {
uint32_t max_activation_depth_ = UINT32_MAX;
char name_[CGROUP_NAME_BUF_SZ] = {};
char path_[CGROUP_PATH_BUF_SZ] = {};
};
} // namespace format
} // namespace cgrouprc
} // namespace android
};

45
libprocessgroup/util/include/processgroup/cgroup_descriptor.h Normal file
View file

@ -0,0 +1,45 @@
/*
* 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.
*/
#pragma once
#include <cstdint>
#include <string>
#include <sys/stat.h>
#include <processgroup/cgroup_controller.h>
// Complete controller description for mounting cgroups
class CgroupDescriptor {
public:
CgroupDescriptor(uint32_t version, const std::string& name, const std::string& path,
mode_t mode, const std::string& uid, const std::string& gid, uint32_t flags,
uint32_t max_activation_depth);
const CgroupController* controller() const { return &controller_; }
mode_t mode() const { return mode_; }
std::string uid() const { return uid_; }
std::string gid() const { return gid_; }
void set_mounted(bool mounted);
private:
CgroupController controller_;
mode_t mode_ = 0;
std::string uid_;
std::string gid_;
};

12
libprocessgroup/util/include/processgroup/util.h
View file

@ -16,10 +16,18 @@
#pragma once
#include <map>
#include <string>
namespace util {
#include "cgroup_descriptor.h"
// Duplicated from cgrouprc.h. Don't depend on libcgrouprc here.
#define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
#define CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION 0x2
#define CGROUPRC_CONTROLLER_FLAG_OPTIONAL 0x4
unsigned int GetCgroupDepth(const std::string& controller_root, const std::string& cgroup_path);
} // namespace util
using CgroupControllerName = std::string;
using CgroupDescriptorMap = std::map<CgroupControllerName, CgroupDescriptor>;
bool ReadDescriptors(CgroupDescriptorMap* descriptors);

2
libprocessgroup/util/tests/util.cpp
View file

@ -18,8 +18,6 @@
#include "gtest/gtest.h"
using util::GetCgroupDepth;
TEST(EmptyInputs, bothEmpty) {
EXPECT_EQ(GetCgroupDepth({}, {}), 0);
}

197
libprocessgroup/util/util.cpp
View file

@ -18,9 +18,33 @@
#include <algorithm>
#include <iterator>
#include <optional>
#include <string_view>
#include <mntent.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <json/reader.h>
#include <json/value.h>
#include "../build_flags.h"
#include "../internal.h"
using android::base::GetUintProperty;
namespace {
constexpr const char* CGROUPS_DESC_FILE = "/etc/cgroups.json";
constexpr const char* CGROUPS_DESC_VENDOR_FILE = "/vendor/etc/cgroups.json";
constexpr const char* TEMPLATE_CGROUPS_DESC_API_FILE = "/etc/task_profiles/cgroups_%u.json";
// This should match the publicly declared value in processgroup.h,
// but we don't want this library to depend on libprocessgroup.
constexpr std::string CGROUPV2_HIERARCHY_NAME_INTERNAL = "cgroup2";
const char SEP = '/';
std::string DeduplicateAndTrimSeparators(const std::string& path) {
@ -42,9 +66,135 @@ std::string DeduplicateAndTrimSeparators(const std::string& path) {
return ret;
}
void MergeCgroupToDescriptors(CgroupDescriptorMap* descriptors, const Json::Value& cgroup,
const std::string& name, const std::string& root_path,
int cgroups_version) {
const std::string cgroup_path = cgroup["Path"].asString();
std::string path;
if (!root_path.empty()) {
path = root_path;
if (cgroup_path != ".") {
path += "/";
path += cgroup_path;
}
} else {
path = cgroup_path;
}
uint32_t controller_flags = 0;
if (cgroup["NeedsActivation"].isBool() && cgroup["NeedsActivation"].asBool()) {
controller_flags |= CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION;
}
if (cgroup["Optional"].isBool() && cgroup["Optional"].asBool()) {
controller_flags |= CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
}
uint32_t max_activation_depth = UINT32_MAX;
if (cgroup.isMember("MaxActivationDepth")) {
max_activation_depth = cgroup["MaxActivationDepth"].asUInt();
}
CgroupDescriptor descriptor(
cgroups_version, name, path, std::strtoul(cgroup["Mode"].asString().c_str(), 0, 8),
cgroup["UID"].asString(), cgroup["GID"].asString(), controller_flags,
max_activation_depth);
auto iter = descriptors->find(name);
if (iter == descriptors->end()) {
descriptors->emplace(name, descriptor);
} else {
iter->second = descriptor;
}
}
bool ReadDescriptorsFromFile(const std::string& file_name, CgroupDescriptorMap* descriptors) {
static constexpr bool force_memcg_v2 = android::libprocessgroup_flags::force_memcg_v2();
std::vector<CgroupDescriptor> result;
std::string json_doc;
if (!android::base::ReadFileToString(file_name, &json_doc)) {
PLOG(ERROR) << "Failed to read task profiles from " << file_name;
return false;
}
Json::CharReaderBuilder builder;
std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
Json::Value root;
std::string errorMessage;
if (!reader->parse(&*json_doc.begin(), &*json_doc.end(), &root, &errorMessage)) {
LOG(ERROR) << "Failed to parse cgroups description: " << errorMessage;
return false;
}
if (root.isMember("Cgroups")) {
const Json::Value& cgroups = root["Cgroups"];
for (Json::Value::ArrayIndex i = 0; i < cgroups.size(); ++i) {
std::string name = cgroups[i]["Controller"].asString();
if (force_memcg_v2 && name == "memory") continue;
MergeCgroupToDescriptors(descriptors, cgroups[i], name, "", 1);
}
}
bool memcgv2_present = false;
std::string root_path;
if (root.isMember("Cgroups2")) {
const Json::Value& cgroups2 = root["Cgroups2"];
root_path = cgroups2["Path"].asString();
MergeCgroupToDescriptors(descriptors, cgroups2, CGROUPV2_HIERARCHY_NAME_INTERNAL, "", 2);
const Json::Value& childGroups = cgroups2["Controllers"];
for (Json::Value::ArrayIndex i = 0; i < childGroups.size(); ++i) {
std::string name = childGroups[i]["Controller"].asString();
if (force_memcg_v2 && name == "memory") memcgv2_present = true;
MergeCgroupToDescriptors(descriptors, childGroups[i], name, root_path, 2);
}
}
if (force_memcg_v2 && !memcgv2_present) {
LOG(INFO) << "Forcing memcg to v2 hierarchy";
Json::Value memcgv2;
memcgv2["Controller"] = "memory";
memcgv2["NeedsActivation"] = true;
memcgv2["Path"] = ".";
memcgv2["Optional"] = true; // In case of cgroup_disabled=memory, so we can still boot
MergeCgroupToDescriptors(descriptors, memcgv2, "memory",
root_path.empty() ? CGROUP_V2_ROOT_DEFAULT : root_path, 2);
}
return true;
}
using MountDir = std::string;
using MountOpts = std::string;
static std::optional<std::map<MountDir, MountOpts>> ReadCgroupV1Mounts() {
FILE* fp = setmntent("/proc/mounts", "r");
if (fp == nullptr) {
PLOG(ERROR) << "Failed to read mounts";
return std::nullopt;
}
std::map<MountDir, MountOpts> mounts;
const std::string_view CGROUP_V1_TYPE = "cgroup";
for (mntent* mentry = getmntent(fp); mentry != nullptr; mentry = getmntent(fp)) {
if (mentry->mnt_type && CGROUP_V1_TYPE == mentry->mnt_type &&
mentry->mnt_dir && mentry->mnt_opts) {
mounts[mentry->mnt_dir] = mentry->mnt_opts;
}
}
endmntent(fp);
return mounts;
}
} // anonymous namespace
namespace util {
unsigned int GetCgroupDepth(const std::string& controller_root, const std::string& cgroup_path) {
const std::string deduped_root = DeduplicateAndTrimSeparators(controller_root);
@ -56,4 +206,47 @@ unsigned int GetCgroupDepth(const std::string& controller_root, const std::strin
return std::count(deduped_path.begin() + deduped_root.size(), deduped_path.end(), SEP);
}
} // namespace util
bool ReadDescriptors(CgroupDescriptorMap* descriptors) {
// load system cgroup descriptors
if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, descriptors)) {
return false;
}
// load API-level specific system cgroups descriptors if available
unsigned int api_level = GetUintProperty<unsigned int>("ro.product.first_api_level", 0);
if (api_level > 0) {
std::string api_cgroups_path =
android::base::StringPrintf(TEMPLATE_CGROUPS_DESC_API_FILE, api_level);
if (!access(api_cgroups_path.c_str(), F_OK) || errno != ENOENT) {
if (!ReadDescriptorsFromFile(api_cgroups_path, descriptors)) {
return false;
}
}
}
// load vendor cgroup descriptors if the file exists
if (!access(CGROUPS_DESC_VENDOR_FILE, F_OK) &&
!ReadDescriptorsFromFile(CGROUPS_DESC_VENDOR_FILE, descriptors)) {
return false;
}
// check for v1 mount/usability status
std::optional<std::map<MountDir, MountOpts>> v1Mounts;
for (auto& [name, descriptor] : *descriptors) {
const CgroupController* const controller = descriptor.controller();
if (controller->version() != 1) continue;
// Read only once, and only if we have at least one v1 controller
if (!v1Mounts) {
v1Mounts = ReadCgroupV1Mounts();
if (!v1Mounts) return false;
}
if (const auto it = v1Mounts->find(controller->path()); it != v1Mounts->end()) {
if (it->second.contains(controller->name())) descriptor.set_mounted(true);
}
}
return true;
}