ACPR/android_system_core
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libprocessgroup: Remove dependency on libcgrouprc

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Read cgroup descriptors ourselves instead of going through the LLNDK
interface which performs the same thing.

Bug: 349105928
Change-Id: I94625ffd0d884d619eb3449e63a305ad5e1d77e3
This commit is contained in:
T.J. Mercier 2024-08-08 16:27:00 +00:00
parent ae4ce8ccc5
commit 9d84103bdd
3 changed files with 43 additions and 66 deletions
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1
libprocessgroup/Android.bp
View file

@ -75,7 +75,6 @@ cc_library {
double_loadable: true,
shared_libs: [
"libbase",
"libcgrouprc",
],
static_libs: [
"libjsoncpp",

95
libprocessgroup/cgroup_map.cpp
View file

@ -25,12 +25,10 @@
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <cgroup_map.h>
#include <processgroup/processgroup.h>
#include <processgroup/util.h>
using android::base::StartsWith;
using android::base::StringPrintf;
using android::base::WriteStringToFile;
@ -40,17 +38,17 @@ static constexpr const char* CGROUP_TASKS_FILE_V2 = "/cgroup.threads";
uint32_t CgroupControllerWrapper::version() const {
CHECK(HasValue());
return ACgroupController_getVersion(controller_);
return controller_->version();
}
const char* CgroupControllerWrapper::name() const {
CHECK(HasValue());
return ACgroupController_getName(controller_);
return controller_->name();
}
const char* CgroupControllerWrapper::path() const {
CHECK(HasValue());
return ACgroupController_getPath(controller_);
return controller_->path();
}
bool CgroupControllerWrapper::HasValue() const {
@ -62,7 +60,7 @@ bool CgroupControllerWrapper::IsUsable() {
if (state_ == UNKNOWN) {
if (__builtin_available(android 30, *)) {
uint32_t flags = ACgroupController_getFlags(controller_);
uint32_t flags = controller_->flags();
state_ = (flags & CGROUPRC_CONTROLLER_FLAG_MOUNTED) != 0 ? USABLE : MISSING;
} else {
state_ = access(GetProcsFilePath("", 0, 0).c_str(), F_OK) == 0 ? USABLE : MISSING;
@ -129,8 +127,8 @@ bool CgroupControllerWrapper::GetTaskGroup(pid_t tid, std::string* group) const
}
CgroupMap::CgroupMap() {
if (!LoadRcFile()) {
LOG(ERROR) << "CgroupMap::LoadRcFile called for [" << getpid() << "] failed";
if (!LoadDescriptors()) {
LOG(ERROR) << "CgroupMap::LoadDescriptors called for [" << getpid() << "] failed";
}
}
@ -141,9 +139,9 @@ CgroupMap& CgroupMap::GetInstance() {
return *instance;
}
bool CgroupMap::LoadRcFile() {
bool CgroupMap::LoadDescriptors() {
if (!loaded_) {
loaded_ = (ACgroupFile_getVersion() != 0);
loaded_ = ReadDescriptors(&descriptors_);
}
return loaded_;
}
@ -154,40 +152,27 @@ void CgroupMap::Print() const {
<< "] failed, cgroups were not initialized properly";
return;
}
LOG(INFO) << "File version = " << ACgroupFile_getVersion();
LOG(INFO) << "File controller count = " << ACgroupFile_getControllerCount();
LOG(INFO) << "Controller count = " << descriptors_.size();
LOG(INFO) << "Mounted cgroups:";
auto controller_count = ACgroupFile_getControllerCount();
for (uint32_t i = 0; i < controller_count; ++i) {
const ACgroupController* controller = ACgroupFile_getController(i);
if (__builtin_available(android 30, *)) {
LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
<< ACgroupController_getVersion(controller) << " path "
<< ACgroupController_getPath(controller) << " flags "
<< ACgroupController_getFlags(controller);
} else {
LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
<< ACgroupController_getVersion(controller) << " path "
<< ACgroupController_getPath(controller);
}
for (const auto& [name, descriptor] : descriptors_) {
LOG(INFO) << "\t" << descriptor.controller()->name() << " ver "
<< descriptor.controller()->version() << " path "
<< descriptor.controller()->path() << " flags "
<< descriptor.controller()->flags();
}
}
CgroupControllerWrapper CgroupMap::FindController(const std::string& name) const {
if (!loaded_) {
LOG(ERROR) << "CgroupMap::FindController called for [" << getpid()
<< "] failed, RC file was not initialized properly";
<< "] failed, cgroups were not initialized properly";
return CgroupControllerWrapper(nullptr);
}
auto controller_count = ACgroupFile_getControllerCount();
for (uint32_t i = 0; i < controller_count; ++i) {
const ACgroupController* controller = ACgroupFile_getController(i);
if (name == ACgroupController_getName(controller)) {
return CgroupControllerWrapper(controller);
}
if (const auto it = descriptors_.find(name); it != descriptors_.end()) {
return CgroupControllerWrapper(it->second.controller());
}
return CgroupControllerWrapper(nullptr);
@ -196,15 +181,13 @@ CgroupControllerWrapper CgroupMap::FindController(const std::string& name) const
CgroupControllerWrapper CgroupMap::FindControllerByPath(const std::string& path) const {
if (!loaded_) {
LOG(ERROR) << "CgroupMap::FindControllerByPath called for [" << getpid()
<< "] failed, RC file was not initialized properly";
<< "] failed, cgroups were not initialized properly";
return CgroupControllerWrapper(nullptr);
}
auto controller_count = ACgroupFile_getControllerCount();
for (uint32_t i = 0; i < controller_count; ++i) {
const ACgroupController* controller = ACgroupFile_getController(i);
if (StartsWith(path, ACgroupController_getPath(controller))) {
return CgroupControllerWrapper(controller);
for (const auto& [name, descriptor] : descriptors_) {
if (path.starts_with(descriptor.controller()->path())) {
return CgroupControllerWrapper(descriptor.controller());
}
}
@ -212,31 +195,23 @@ CgroupControllerWrapper CgroupMap::FindControllerByPath(const std::string& path)
}
int CgroupMap::ActivateControllers(const std::string& path) const {
if (__builtin_available(android 30, *)) {
auto controller_count = ACgroupFile_getControllerCount();
for (uint32_t i = 0; i < controller_count; ++i) {
const ACgroupController* controller = ACgroupFile_getController(i);
const uint32_t flags = ACgroupController_getFlags(controller);
uint32_t max_activation_depth = UINT32_MAX;
if (__builtin_available(android 36, *)) {
max_activation_depth = ACgroupController_getMaxActivationDepth(controller);
}
const int depth = GetCgroupDepth(ACgroupController_getPath(controller), path);
for (const auto& [name, descriptor] : descriptors_) {
const uint32_t flags = descriptor.controller()->flags();
const uint32_t max_activation_depth = descriptor.controller()->max_activation_depth();
const int depth = GetCgroupDepth(descriptor.controller()->path(), path);
if (flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
std::string str("+");
str.append(ACgroupController_getName(controller));
if (!WriteStringToFile(str, path + "/cgroup.subtree_control")) {
if (flags & CGROUPRC_CONTROLLER_FLAG_OPTIONAL) {
PLOG(WARNING) << "Activation of cgroup controller " << str
<< " failed in path " << path;
} else {
return -errno;
}
if (flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
std::string str("+");
str.append(descriptor.controller()->name());
if (!WriteStringToFile(str, path + "/cgroup.subtree_control")) {
if (flags & CGROUPRC_CONTROLLER_FLAG_OPTIONAL) {
PLOG(WARNING) << "Activation of cgroup controller " << str
<< " failed in path " << path;
} else {
return -errno;
}
}
}
return 0;
}
return -ENOSYS;
return 0;
}

13
libprocessgroup/cgroup_map.h
View file

@ -18,15 +18,17 @@
#include <sys/types.h>
#include <cstdint>
#include <string>
#include <android/cgrouprc.h>
#include <processgroup/cgroup_controller.h>
#include <processgroup/util.h>
// Convenient wrapper of an ACgroupController pointer.
// Convenient wrapper of a CgroupController pointer.
class CgroupControllerWrapper {
public:
// Does not own controller
explicit CgroupControllerWrapper(const ACgroupController* controller)
explicit CgroupControllerWrapper(const CgroupController* controller)
: controller_(controller) {}
uint32_t version() const;
@ -47,7 +49,7 @@ class CgroupControllerWrapper {
MISSING = 2,
};
const ACgroupController* controller_ = nullptr;
const CgroupController* controller_ = nullptr; // CgroupMap owns the object behind this pointer
ControllerState state_ = ControllerState::UNKNOWN;
};
@ -60,7 +62,8 @@ class CgroupMap {
private:
bool loaded_ = false;
CgroupDescriptorMap descriptors_;
CgroupMap();
bool LoadRcFile();
bool LoadDescriptors();
void Print() const;
};