diff --git a/init/Android.bp b/init/Android.bp
index 8292aa0..69ee34f 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -61,6 +61,7 @@
     static_libs: [
         "libseccomp_policy",
         "libavb",
+        "libcgrouprc_format",
         "libprotobuf-cpp-lite",
         "libpropertyinfoserializer",
         "libpropertyinfoparser",
@@ -82,6 +83,7 @@
         "liblogwrap",
         "liblp",
         "libprocessgroup",
+        "libprocessgroup_setup",
         "libselinux",
         "libutils",
     ],
diff --git a/init/init.cpp b/init/init.cpp
index cdec41c..0f44efd 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -45,6 +45,7 @@
 #include <libavb/libavb.h>
 #include <libgsi/libgsi.h>
 #include <processgroup/processgroup.h>
+#include <processgroup/setup.h>
 #include <selinux/android.h>
 
 #ifndef RECOVERY
@@ -358,7 +359,7 @@
     // 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 (!CgroupSetupCgroups()) {
+    if (!CgroupSetup()) {
         return ErrnoError() << "Failed to setup cgroups";
     }
 
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index a27ecef..619bc56 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -235,6 +235,7 @@
     "libbase",
     "libjsoncpp",
     "libprocessgroup",
+    "libcgrouprc",
 ]
 
 cc_test {
@@ -249,7 +250,10 @@
     name: "libcutils_test_static",
     test_suites: ["device-tests"],
     defaults: ["libcutils_test_default"],
-    static_libs: ["libc"] + test_libraries,
+    static_libs: [
+        "libc",
+        "libcgrouprc_format",
+    ] + test_libraries,
     stl: "libc++_static",
 
     target: {
diff --git a/libprocessgroup/Android.bp b/libprocessgroup/Android.bp
index 07cbce9..78a02e5 100644
--- a/libprocessgroup/Android.bp
+++ b/libprocessgroup/Android.bp
@@ -31,6 +31,7 @@
     },
     shared_libs: [
         "libbase",
+        "libcgrouprc",
         "libjsoncpp",
     ],
     // for cutils/android_filesystem_config.h
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index 1e66fa4..6cd6b6e 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -44,244 +44,42 @@
 using android::base::StringPrintf;
 using android::base::unique_fd;
 
-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* CGROUP_PROCS_FILE = "/cgroup.procs";
 static constexpr const char* CGROUP_TASKS_FILE = "/tasks";
 static constexpr const char* CGROUP_TASKS_FILE_V2 = "/cgroup.tasks";
 
-static bool Mkdir(const std::string& path, mode_t mode, const std::string& uid,
-                  const std::string& gid) {
-    if (mode == 0) {
-        mode = 0755;
-    }
-
-    if (mkdir(path.c_str(), mode) != 0) {
-        /* chmod in case the directory already exists */
-        if (errno == EEXIST) {
-            if (fchmodat(AT_FDCWD, path.c_str(), mode, AT_SYMLINK_NOFOLLOW) != 0) {
-                // /acct is a special case when the directory already exists
-                // TODO: check if file mode is already what we want instead of using EROFS
-                if (errno != EROFS) {
-                    PLOG(ERROR) << "fchmodat() failed for " << path;
-                    return false;
-                }
-            }
-        } else {
-            PLOG(ERROR) << "mkdir() failed for " << path;
-            return false;
-        }
-    }
-
-    if (uid.empty()) {
-        return true;
-    }
-
-    passwd* uid_pwd = getpwnam(uid.c_str());
-    if (!uid_pwd) {
-        PLOG(ERROR) << "Unable to decode UID for '" << uid << "'";
-        return false;
-    }
-
-    uid_t pw_uid = uid_pwd->pw_uid;
-    gid_t gr_gid = -1;
-    if (!gid.empty()) {
-        group* gid_pwd = getgrnam(gid.c_str());
-        if (!gid_pwd) {
-            PLOG(ERROR) << "Unable to decode GID for '" << gid << "'";
-            return false;
-        }
-        gr_gid = gid_pwd->gr_gid;
-    }
-
-    if (lchown(path.c_str(), pw_uid, gr_gid) < 0) {
-        PLOG(ERROR) << "lchown() failed for " << path;
-        return false;
-    }
-
-    /* chown may have cleared S_ISUID and S_ISGID, chmod again */
-    if (mode & (S_ISUID | S_ISGID)) {
-        if (fchmodat(AT_FDCWD, path.c_str(), mode, AT_SYMLINK_NOFOLLOW) != 0) {
-            PLOG(ERROR) << "fchmodat() failed for " << path;
-            return false;
-        }
-    }
-
-    return true;
+uint32_t CgroupController::version() const {
+    CHECK(HasValue());
+    return ACgroupController_getVersion(controller_);
 }
 
-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::Reader reader;
-    Json::Value root;
-    if (!reader.parse(json_doc, root)) {
-        LOG(ERROR) << "Failed to parse cgroups description: " << reader.getFormattedErrorMessages();
-        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();
-            auto iter = descriptors->find(name);
-            if (iter == descriptors->end()) {
-                descriptors->emplace(name, CgroupDescriptor(1, name, cgroups[i]["Path"].asString(),
-                                     std::strtoul(cgroups[i]["Mode"].asString().c_str(), 0, 8),
-                                     cgroups[i]["UID"].asString(), cgroups[i]["GID"].asString()));
-            } else {
-                iter->second = CgroupDescriptor(1, name, cgroups[i]["Path"].asString(),
-                                     std::strtoul(cgroups[i]["Mode"].asString().c_str(), 0, 8),
-                                     cgroups[i]["UID"].asString(), cgroups[i]["GID"].asString());
-            }
-        }
-    }
-
-    if (root.isMember("Cgroups2")) {
-        const Json::Value& cgroups2 = root["Cgroups2"];
-        auto iter = descriptors->find(CGROUPV2_CONTROLLER_NAME);
-        if (iter == descriptors->end()) {
-            descriptors->emplace(CGROUPV2_CONTROLLER_NAME, CgroupDescriptor(2, CGROUPV2_CONTROLLER_NAME, cgroups2["Path"].asString(),
-                                 std::strtoul(cgroups2["Mode"].asString().c_str(), 0, 8),
-                                 cgroups2["UID"].asString(), cgroups2["GID"].asString()));
-        } else {
-            iter->second = CgroupDescriptor(2, CGROUPV2_CONTROLLER_NAME, cgroups2["Path"].asString(),
-                                 std::strtoul(cgroups2["Mode"].asString().c_str(), 0, 8),
-                                 cgroups2["UID"].asString(), cgroups2["GID"].asString());
-        }
-    }
-
-    return true;
+const char* CgroupController::name() const {
+    CHECK(HasValue());
+    return ACgroupController_getName(controller_);
 }
 
-static bool ReadDescriptors(std::map<std::string, CgroupDescriptor>* descriptors) {
-    // load system cgroup descriptors
-    if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, 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;
+const char* CgroupController::path() const {
+    CHECK(HasValue());
+    return ACgroupController_getPath(controller_);
 }
 
-// To avoid issues in sdk_mac build
-#if defined(__ANDROID__)
-
-static bool SetupCgroup(const CgroupDescriptor& descriptor) {
-    const CgroupController* controller = descriptor.controller();
-
-    // mkdir <path> [mode] [owner] [group]
-    if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
-        LOG(ERROR) << "Failed to create directory for " << controller->name() << " cgroup";
-        return false;
-    }
-
-    int result;
-    if (controller->version() == 2) {
-        result = mount("none", controller->path(), "cgroup2", MS_NODEV | MS_NOEXEC | MS_NOSUID,
-                       nullptr);
-    } else {
-        // Unfortunately historically cpuset controller was mounted using a mount command
-        // different from all other controllers. This results in controller attributes not
-        // to be prepended with controller name. For example this way instead of
-        // /dev/cpuset/cpuset.cpus the attribute becomes /dev/cpuset/cpus which is what
-        // the system currently expects.
-        if (!strcmp(controller->name(), "cpuset")) {
-            // mount cpuset none /dev/cpuset nodev noexec nosuid
-            result = mount("none", controller->path(), controller->name(),
-                           MS_NODEV | MS_NOEXEC | MS_NOSUID, nullptr);
-        } else {
-            // mount cgroup none <path> nodev noexec nosuid <controller>
-            result = mount("none", controller->path(), "cgroup", MS_NODEV | MS_NOEXEC | MS_NOSUID,
-                           controller->name());
-        }
-    }
-
-    if (result < 0) {
-        PLOG(ERROR) << "Failed to mount " << controller->name() << " cgroup";
-        return false;
-    }
-
-    return true;
+bool CgroupController::HasValue() const {
+    return controller_ != nullptr;
 }
 
-#else
+std::string CgroupController::GetTasksFilePath(const std::string& rel_path) const {
+    std::string tasks_path = path();
 
-// Stubs for non-Android targets.
-static bool SetupCgroup(const CgroupDescriptor&) {
-    return false;
+    if (!rel_path.empty()) {
+        tasks_path += "/" + rel_path;
+    }
+    return (version() == 1) ? tasks_path + CGROUP_TASKS_FILE : tasks_path + CGROUP_TASKS_FILE_V2;
 }
 
-#endif
-
-// WARNING: This function should be called only from SetupCgroups and only once.
-// It intentionally leaks an FD, so additional invocation will result in additional leak.
-static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) {
-    // WARNING: We are intentionally leaking the FD to keep the file open forever.
-    // Let init keep the FD open to prevent file mappings from becoming invalid in
-    // case the file gets deleted somehow.
-    int 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;
-    }
-
-    CgroupFile fl;
-    fl.version_ = 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(CgroupController)));
-        if (ret < 0) {
-            PLOG(ERROR) << "write() failed for " << CGROUPS_RC_PATH;
-            return false;
-        }
-    }
-
-    return true;
-}
-
-CgroupController::CgroupController(uint32_t version, const std::string& name,
-                                   const std::string& path) {
-    version_ = version;
-    strncpy(name_, name.c_str(), sizeof(name_) - 1);
-    name_[sizeof(name_) - 1] = '\0';
-    strncpy(path_, path.c_str(), sizeof(path_) - 1);
-    path_[sizeof(path_) - 1] = '\0';
-}
-
-std::string CgroupController::GetTasksFilePath(const std::string& path) const {
-    std::string tasks_path = path_;
-
-    if (!path.empty()) {
-        tasks_path += "/" + path;
-    }
-    return (version_ == 1) ? tasks_path + CGROUP_TASKS_FILE : tasks_path + CGROUP_TASKS_FILE_V2;
-}
-
-std::string CgroupController::GetProcsFilePath(const std::string& path, uid_t uid,
+std::string CgroupController::GetProcsFilePath(const std::string& rel_path, uid_t uid,
                                                pid_t pid) const {
-    std::string proc_path(path_);
-    proc_path.append("/").append(path);
+    std::string proc_path(path());
+    proc_path.append("/").append(rel_path);
     proc_path = regex_replace(proc_path, std::regex("<uid>"), std::to_string(uid));
     proc_path = regex_replace(proc_path, std::regex("<pid>"), std::to_string(pid));
 
@@ -302,7 +100,7 @@
         return true;
     }
 
-    std::string cg_tag = StringPrintf(":%s:", name_);
+    std::string cg_tag = StringPrintf(":%s:", name());
     size_t start_pos = content.find(cg_tag);
     if (start_pos == std::string::npos) {
         return false;
@@ -319,25 +117,12 @@
     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)
-    : controller_(version, name, path), mode_(mode), uid_(uid), gid_(gid) {}
-
-CgroupMap::CgroupMap() : cg_file_data_(nullptr), cg_file_size_(0) {
+CgroupMap::CgroupMap() {
     if (!LoadRcFile()) {
         LOG(ERROR) << "CgroupMap::LoadRcFile called for [" << getpid() << "] failed";
     }
 }
 
-CgroupMap::~CgroupMap() {
-    if (cg_file_data_) {
-        munmap(cg_file_data_, cg_file_size_);
-        cg_file_data_ = nullptr;
-        cg_file_size_ = 0;
-    }
-}
-
 CgroupMap& CgroupMap::GetInstance() {
     // Deliberately leak this object to avoid a race between destruction on
     // process exit and concurrent access from another thread.
@@ -346,139 +131,46 @@
 }
 
 bool CgroupMap::LoadRcFile() {
-    struct stat sb;
-
-    if (cg_file_data_) {
-        // Data already initialized
-        return true;
+    if (!loaded_) {
+        loaded_ = (ACgroupFile_getVersion() != 0);
     }
-
-    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;
-        return false;
-    }
-
-    if (fstat(fd, &sb) < 0) {
-        PLOG(ERROR) << "fstat() failed for " << CGROUPS_RC_PATH;
-        return false;
-    }
-
-    size_t file_size = sb.st_size;
-    if (file_size < sizeof(CgroupFile)) {
-        LOG(ERROR) << "Invalid file format " << CGROUPS_RC_PATH;
-        return false;
-    }
-
-    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 false;
-    }
-
-    if (file_data->version_ != CgroupFile::FILE_CURR_VERSION) {
-        LOG(ERROR) << CGROUPS_RC_PATH << " file version mismatch";
-        munmap(file_data, file_size);
-        return false;
-    }
-
-    if (file_size != sizeof(CgroupFile) + file_data->controller_count_ * sizeof(CgroupController)) {
-        LOG(ERROR) << CGROUPS_RC_PATH << " file has invalid size";
-        munmap(file_data, file_size);
-        return false;
-    }
-
-    cg_file_data_ = file_data;
-    cg_file_size_ = file_size;
-
-    return true;
+    return loaded_;
 }
 
 void CgroupMap::Print() const {
-    if (!cg_file_data_) {
+    if (!loaded_) {
         LOG(ERROR) << "CgroupMap::Print called for [" << getpid()
                    << "] failed, RC file was not initialized properly";
         return;
     }
-    LOG(INFO) << "File version = " << cg_file_data_->version_;
-    LOG(INFO) << "File controller count = " << cg_file_data_->controller_count_;
+    LOG(INFO) << "File version = " << ACgroupFile_getVersion();
+    LOG(INFO) << "File controller count = " << ACgroupFile_getControllerCount();
 
     LOG(INFO) << "Mounted cgroups:";
-    CgroupController* controller = (CgroupController*)(cg_file_data_ + 1);
-    for (int i = 0; i < cg_file_data_->controller_count_; i++, controller++) {
-        LOG(INFO) << "\t" << controller->name() << " ver " << controller->version() << " path "
-                  << controller->path();
+
+    auto controller_count = ACgroupFile_getControllerCount();
+    for (uint32_t i = 0; i < controller_count; ++i) {
+        const ACgroupController* controller = ACgroupFile_getController(i);
+        LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
+                  << ACgroupController_getVersion(controller) << " path "
+                  << ACgroupController_getPath(controller);
     }
 }
 
-bool CgroupMap::SetupCgroups() {
-    std::map<std::string, CgroupDescriptor> 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 SetupCgroups more than once";
-        return true;
-    }
-
-    // load cgroups.json file
-    if (!ReadDescriptors(&descriptors)) {
-        LOG(ERROR) << "Failed to load cgroup description file";
-        return false;
-    }
-
-    // setup cgroups
-    for (const auto& [name, descriptor] : descriptors) {
-        if (!SetupCgroup(descriptor)) {
-            // issue a warning and proceed with the next cgroup
-            // TODO: mark the descriptor as invalid and skip it in WriteRcFile()
-            LOG(WARNING) << "Failed to setup " << name << " cgroup";
-        }
-    }
-
-    // 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;
-}
-
-const CgroupController* CgroupMap::FindController(const std::string& name) const {
-    if (!cg_file_data_) {
+CgroupController CgroupMap::FindController(const std::string& name) const {
+    if (!loaded_) {
         LOG(ERROR) << "CgroupMap::FindController called for [" << getpid()
                    << "] failed, RC file was not initialized properly";
-        return nullptr;
+        return CgroupController(nullptr);
     }
 
-    // skip the file header to get to the first controller
-    CgroupController* controller = (CgroupController*)(cg_file_data_ + 1);
-    for (int i = 0; i < cg_file_data_->controller_count_; i++, controller++) {
-        if (name == controller->name()) {
-            return controller;
+    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 CgroupController(controller);
         }
     }
 
-    return nullptr;
+    return CgroupController(nullptr);
 }
diff --git a/libprocessgroup/cgroup_map.h b/libprocessgroup/cgroup_map.h
index 304ae15..d765e60 100644
--- a/libprocessgroup/cgroup_map.h
+++ b/libprocessgroup/cgroup_map.h
@@ -20,57 +20,30 @@
 #include <sys/types.h>
 
 #include <map>
+#include <memory>
 #include <mutex>
 #include <string>
+#include <vector>
 
-// Minimal controller description to be mmapped into process address space
+#include <android/cgrouprc.h>
+
+// Convenient wrapper of an ACgroupController pointer.
 class CgroupController {
   public:
-    CgroupController() {}
-    CgroupController(uint32_t version, const std::string& name, const std::string& path);
+    // Does not own controller
+    explicit CgroupController(const ACgroupController* controller) : controller_(controller) {}
 
-    uint32_t version() const { return version_; }
-    const char* name() const { return name_; }
-    const char* path() const { return path_; }
+    uint32_t version() const;
+    const char* name() const;
+    const char* path() const;
+
+    bool HasValue() const;
 
     std::string GetTasksFilePath(const std::string& path) const;
     std::string GetProcsFilePath(const std::string& path, uid_t uid, pid_t pid) const;
     bool GetTaskGroup(int tid, std::string* group) const;
-
   private:
-    static constexpr size_t CGROUP_NAME_BUF_SZ = 16;
-    static constexpr size_t CGROUP_PATH_BUF_SZ = 32;
-
-    uint32_t version_;
-    char name_[CGROUP_NAME_BUF_SZ];
-    char path_[CGROUP_PATH_BUF_SZ];
-};
-
-// 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);
-
-    const CgroupController* controller() const { return &controller_; }
-    mode_t mode() const { return mode_; }
-    std::string uid() const { return uid_; }
-    std::string gid() const { return gid_; }
-
-  private:
-    CgroupController controller_;
-    mode_t mode_;
-    std::string uid_;
-    std::string gid_;
-};
-
-struct CgroupFile {
-    static constexpr uint32_t FILE_VERSION_1 = 1;
-    static constexpr uint32_t FILE_CURR_VERSION = FILE_VERSION_1;
-
-    uint32_t version_;
-    uint32_t controller_count_;
-    CgroupController controllers_[];
+    const ACgroupController* controller_ = nullptr;
 };
 
 class CgroupMap {
@@ -79,16 +52,11 @@
     static bool SetupCgroups();
 
     static CgroupMap& GetInstance();
-
-    const CgroupController* FindController(const std::string& name) const;
+    CgroupController FindController(const std::string& name) const;
 
   private:
-    struct CgroupFile* cg_file_data_;
-    size_t cg_file_size_;
-
+    bool loaded_ = false;
     CgroupMap();
-    ~CgroupMap();
-
     bool LoadRcFile();
     void Print() const;
 };
diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
new file mode 100644
index 0000000..774738d
--- /dev/null
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -0,0 +1,57 @@
+// 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.
+
+cc_library {
+    name: "libcgrouprc",
+    host_supported: true,
+    recovery_available: true,
+    // Do not ever mark this as vendor_available; otherwise, vendor modules
+    // that links to the static library will behave unexpectedly. All on-device
+    // modules should use libprocessgroup which links to the LL-NDK library
+    // defined below. The static library is built for tests.
+    vendor_available: false,
+    srcs: [
+        "cgroup_controller.cpp",
+        "cgroup_file.cpp",
+    ],
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+    export_include_dirs: [
+        "include",
+    ],
+    header_libs: [
+        "libprocessgroup_headers",
+    ],
+    shared_libs: [
+        "libbase",
+    ],
+    static_libs: [
+        "libcgrouprc_format",
+    ],
+    stubs: {
+        symbol_file: "libcgrouprc.map.txt",
+        versions: ["29"],
+    },
+    version_script: "libcgrouprc.map.txt",
+}
+
+llndk_library {
+    name: "libcgrouprc",
+    symbol_file: "libcgrouprc.map.txt",
+    export_include_dirs: [
+        "include",
+    ],
+}
diff --git a/libprocessgroup/cgrouprc/cgroup_controller.cpp b/libprocessgroup/cgrouprc/cgroup_controller.cpp
new file mode 100644
index 0000000..d064d31
--- /dev/null
+++ b/libprocessgroup/cgrouprc/cgroup_controller.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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.
+ */
+
+#include <android-base/logging.h>
+#include <android/cgrouprc.h>
+
+#include "cgrouprc_internal.h"
+
+// All ACgroupController_* functions implicitly convert the pointer back
+// to the original CgroupController pointer before invoking the member functions.
+
+uint32_t ACgroupController_getVersion(const ACgroupController* controller) {
+    CHECK(controller != nullptr);
+    return controller->version();
+}
+
+const char* ACgroupController_getName(const ACgroupController* controller) {
+    CHECK(controller != nullptr);
+    return controller->name();
+}
+
+const char* ACgroupController_getPath(const ACgroupController* controller) {
+    CHECK(controller != nullptr);
+    return controller->path();
+}
diff --git a/libprocessgroup/cgrouprc/cgroup_file.cpp b/libprocessgroup/cgrouprc/cgroup_file.cpp
new file mode 100644
index 0000000..e26d841
--- /dev/null
+++ b/libprocessgroup/cgrouprc/cgroup_file.cpp
@@ -0,0 +1,106 @@
+/*
+ * 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.
+ */
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <memory>
+
+#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 "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;
+        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;
+}
+
+static CgroupFile* 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;
+}
+
+uint32_t ACgroupFile_getVersion() {
+    auto file = GetInstance();
+    if (file == nullptr) return 0;
+    return file->version_;
+}
+
+uint32_t ACgroupFile_getControllerCount() {
+    auto file = GetInstance();
+    if (file == nullptr) return 0;
+    return file->controller_count_;
+}
+
+const ACgroupController* ACgroupFile_getController(uint32_t index) {
+    auto file = GetInstance();
+    if (file == nullptr) return nullptr;
+    CHECK(index < file->controller_count_);
+    // 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]);
+}
diff --git a/libprocessgroup/cgrouprc/cgrouprc_internal.h b/libprocessgroup/cgrouprc/cgrouprc_internal.h
new file mode 100644
index 0000000..cd02f03
--- /dev/null
+++ b/libprocessgroup/cgrouprc/cgrouprc_internal.h
@@ -0,0 +1,24 @@
+/*
+ * 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 <android/cgrouprc.h>
+
+#include <processgroup/format/cgroup_controller.h>
+#include <processgroup/format/cgroup_file.h>
+
+struct ACgroupController : android::cgrouprc::format::CgroupController {};
diff --git a/libprocessgroup/cgrouprc/include/android/cgrouprc.h b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
new file mode 100644
index 0000000..4edd239
--- /dev/null
+++ b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
@@ -0,0 +1,84 @@
+/*
+ * 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 <stdint.h>
+
+__BEGIN_DECLS
+
+// For host builds, __INTRODUCED_IN is not defined.
+#ifndef __INTRODUCED_IN
+#define __INTRODUCED_IN(x)
+#endif
+
+struct ACgroupController;
+typedef struct ACgroupController ACgroupController;
+
+#if __ANDROID_API__ >= __ANDROID_API_Q__
+
+// ACgroupFile
+
+/**
+ * Returns file version. See android::cgrouprc::format::CgroupFile for a list of valid versions
+ * for the file.
+ * If ACgroupFile_init() isn't called, initialization will be done first.
+ * If initialization failed, return 0.
+ */
+__attribute__((warn_unused_result)) uint32_t ACgroupFile_getVersion() __INTRODUCED_IN(29);
+
+/**
+ * Returns the number of controllers.
+ * If ACgroupFile_init() isn't called, initialization will be done first.
+ * If initialization failed, return 0.
+ */
+__attribute__((warn_unused_result)) uint32_t ACgroupFile_getControllerCount() __INTRODUCED_IN(29);
+
+/**
+ * Returns the controller at the given index.
+ * Returnss nullptr if the given index exceeds getControllerCount().
+ * If ACgroupFile_init() isn't called, initialization will be done first.
+ * If initialization failed, return 0.
+ */
+__attribute__((warn_unused_result)) const ACgroupController* ACgroupFile_getController(
+        uint32_t index) __INTRODUCED_IN(29);
+
+// ACgroupController
+
+/**
+ * Returns the version of the given controller.
+ * If the given controller is null, return 0.
+ */
+__attribute__((warn_unused_result)) uint32_t ACgroupController_getVersion(const ACgroupController*)
+        __INTRODUCED_IN(29);
+
+/**
+ * Returns the name of the given controller.
+ * If the given controller is null, return nullptr.
+ */
+__attribute__((warn_unused_result)) const char* ACgroupController_getName(const ACgroupController*)
+        __INTRODUCED_IN(29);
+
+/**
+ * Returns the path of the given controller.
+ * If the given controller is null, return nullptr.
+ */
+__attribute__((warn_unused_result)) const char* ACgroupController_getPath(const ACgroupController*)
+        __INTRODUCED_IN(29);
+
+__END_DECLS
+
+#endif
diff --git a/libprocessgroup/cgrouprc/libcgrouprc.map.txt b/libprocessgroup/cgrouprc/libcgrouprc.map.txt
new file mode 100644
index 0000000..91df392
--- /dev/null
+++ b/libprocessgroup/cgrouprc/libcgrouprc.map.txt
@@ -0,0 +1,11 @@
+LIBCGROUPRC { # introduced=29
+  global:
+    ACgroupFile_getVersion;
+    ACgroupFile_getControllerCount;
+    ACgroupFile_getController;
+    ACgroupController_getVersion;
+    ACgroupController_getName;
+    ACgroupController_getPath;
+  local:
+    *;
+};
diff --git a/libprocessgroup/cgrouprc_format/Android.bp b/libprocessgroup/cgrouprc_format/Android.bp
new file mode 100644
index 0000000..dfbeed7
--- /dev/null
+++ b/libprocessgroup/cgrouprc_format/Android.bp
@@ -0,0 +1,32 @@
+// 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.
+
+cc_library_static {
+    name: "libcgrouprc_format",
+    host_supported: true,
+    recovery_available: true,
+    srcs: [
+        "cgroup_controller.cpp",
+    ],
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+    export_include_dirs: [
+        "include",
+    ],
+    shared_libs: [
+        "libbase",
+    ],
+}
diff --git a/libprocessgroup/cgrouprc_format/cgroup_controller.cpp b/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
new file mode 100644
index 0000000..877eed8
--- /dev/null
+++ b/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#include <processgroup/format/cgroup_controller.h>
+
+namespace android {
+namespace cgrouprc {
+namespace format {
+
+CgroupController::CgroupController(uint32_t version, const std::string& name,
+                                   const std::string& path) {
+    // strlcpy isn't available on host. Although there is an implementation
+    // in licutils, libcutils itself depends on libcgrouprc_format, causing
+    // a circular dependency.
+    version_ = version;
+    strncpy(name_, name.c_str(), sizeof(name_) - 1);
+    name_[sizeof(name_) - 1] = '\0';
+    strncpy(path_, path.c_str(), sizeof(path_) - 1);
+    path_[sizeof(path_) - 1] = '\0';
+}
+
+uint32_t CgroupController::version() const {
+    return version_;
+}
+
+const char* CgroupController::name() const {
+    return name_;
+}
+
+const char* CgroupController::path() const {
+    return path_;
+}
+
+}  // namespace format
+}  // namespace cgrouprc
+}  // namespace android
diff --git a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
new file mode 100644
index 0000000..64c7532
--- /dev/null
+++ b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
@@ -0,0 +1,47 @@
+/*
+ * 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 <stdint.h>
+#include <string>
+
+namespace android {
+namespace cgrouprc {
+namespace format {
+
+// Minimal controller description to be mmapped into process address space
+struct CgroupController {
+  public:
+    CgroupController() {}
+    CgroupController(uint32_t version, const std::string& name, const std::string& path);
+
+    uint32_t version() const;
+    const char* name() const;
+    const char* path() const;
+
+  private:
+    static constexpr size_t CGROUP_NAME_BUF_SZ = 16;
+    static constexpr size_t CGROUP_PATH_BUF_SZ = 32;
+
+    uint32_t version_;
+    char name_[CGROUP_NAME_BUF_SZ];
+    char path_[CGROUP_PATH_BUF_SZ];
+};
+
+}  // namespace format
+}  // namespace cgrouprc
+}  // namespace android
diff --git a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h
new file mode 100644
index 0000000..f1678a1
--- /dev/null
+++ b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h
@@ -0,0 +1,36 @@
+/*
+ * 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 <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
diff --git a/libprocessgroup/include/processgroup/processgroup.h b/libprocessgroup/include/processgroup/processgroup.h
index 46b8676..86e6035 100644
--- a/libprocessgroup/include/processgroup/processgroup.h
+++ b/libprocessgroup/include/processgroup/processgroup.h
@@ -26,7 +26,6 @@
 static constexpr const char* CGROUPV2_CONTROLLER_NAME = "cgroup2";
 static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
 
-bool CgroupSetupCgroups();
 bool CgroupGetControllerPath(const std::string& cgroup_name, std::string* path);
 bool CgroupGetAttributePath(const std::string& attr_name, std::string* path);
 bool CgroupGetAttributePathForTask(const std::string& attr_name, int tid, std::string* path);
diff --git a/libprocessgroup/processgroup.cpp b/libprocessgroup/processgroup.cpp
index 8884650..abe63dd 100644
--- a/libprocessgroup/processgroup.cpp
+++ b/libprocessgroup/processgroup.cpp
@@ -55,19 +55,15 @@
 
 #define PROCESSGROUP_CGROUP_PROCS_FILE "/cgroup.procs"
 
-bool CgroupSetupCgroups() {
-    return CgroupMap::SetupCgroups();
-}
-
 bool CgroupGetControllerPath(const std::string& cgroup_name, std::string* path) {
-    const CgroupController* controller = CgroupMap::GetInstance().FindController(cgroup_name);
+    auto controller = CgroupMap::GetInstance().FindController(cgroup_name);
 
-    if (controller == nullptr) {
+    if (!controller.HasValue()) {
         return false;
     }
 
     if (path) {
-        *path = controller->path();
+        *path = controller.path();
     }
 
     return true;
@@ -111,7 +107,7 @@
 
 static bool isMemoryCgroupSupported() {
     std::string cgroup_name;
-    static bool memcg_supported = (CgroupMap::GetInstance().FindController("memory") != nullptr);
+    static bool memcg_supported = CgroupMap::GetInstance().FindController("memory").HasValue();
 
     return memcg_supported;
 }
diff --git a/libprocessgroup/sched_policy.cpp b/libprocessgroup/sched_policy.cpp
index 1eefada..c7d0cca 100644
--- a/libprocessgroup/sched_policy.cpp
+++ b/libprocessgroup/sched_policy.cpp
@@ -152,21 +152,21 @@
 }
 
 bool cpusets_enabled() {
-    static bool enabled = (CgroupMap::GetInstance().FindController("cpuset") != nullptr);
+    static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").HasValue());
     return enabled;
 }
 
 bool schedboost_enabled() {
-    static bool enabled = (CgroupMap::GetInstance().FindController("schedtune") != nullptr);
+    static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").HasValue());
     return enabled;
 }
 
 static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
-    const CgroupController* controller = CgroupMap::GetInstance().FindController(subsys);
+    auto controller = CgroupMap::GetInstance().FindController(subsys);
 
-    if (!controller) return -1;
+    if (!controller.HasValue()) return -1;
 
-    if (!controller->GetTaskGroup(tid, &subgroup)) {
+    if (!controller.GetTaskGroup(tid, &subgroup)) {
         LOG(ERROR) << "Failed to find cgroup for tid " << tid;
         return -1;
     }
diff --git a/libprocessgroup/setup/Android.bp b/libprocessgroup/setup/Android.bp
new file mode 100644
index 0000000..f6fc066
--- /dev/null
+++ b/libprocessgroup/setup/Android.bp
@@ -0,0 +1,44 @@
+//
+// 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.
+//
+
+cc_library_shared {
+    name: "libprocessgroup_setup",
+    recovery_available: true,
+    srcs: [
+        "cgroup_map_write.cpp",
+    ],
+    export_include_dirs: [
+        "include",
+    ],
+    shared_libs: [
+        "libbase",
+        "libcgrouprc",
+        "libjsoncpp",
+    ],
+    static_libs: [
+        "libcgrouprc_format",
+    ],
+    header_libs: [
+        "libprocessgroup_headers",
+    ],
+    export_header_lib_headers: [
+        "libprocessgroup_headers",
+    ],
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+}
diff --git a/libprocessgroup/setup/cgroup_descriptor.h b/libprocessgroup/setup/cgroup_descriptor.h
new file mode 100644
index 0000000..597060e
--- /dev/null
+++ b/libprocessgroup/setup/cgroup_descriptor.h
@@ -0,0 +1,43 @@
+/*
+ * 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 <processgroup/format/cgroup_controller.h>
+
+namespace android {
+namespace cgrouprc {
+
+// 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);
+
+    const format::CgroupController* controller() const { return &controller_; }
+    mode_t mode() const { return mode_; }
+    std::string uid() const { return uid_; }
+    std::string gid() const { return gid_; }
+
+  private:
+    format::CgroupController controller_;
+    mode_t mode_ = 0;
+    std::string uid_;
+    std::string gid_;
+};
+
+}  // namespace cgrouprc
+}  // namespace android
diff --git a/libprocessgroup/setup/cgroup_map_write.cpp b/libprocessgroup/setup/cgroup_map_write.cpp
new file mode 100644
index 0000000..26703ee
--- /dev/null
+++ b/libprocessgroup/setup/cgroup_map_write.cpp
@@ -0,0 +1,334 @@
+/*
+ * 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 <errno.h>
+#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 <regex>
+
+#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 <json/reader.h>
+#include <json/value.h>
+#include <processgroup/format/cgroup_file.h>
+#include <processgroup/processgroup.h>
+#include <processgroup/setup.h>
+
+#include "cgroup_descriptor.h"
+
+using android::base::GetBoolProperty;
+using android::base::StringPrintf;
+using android::base::unique_fd;
+
+namespace android {
+namespace cgrouprc {
+
+static constexpr const char* CGROUPS_DESC_FILE = "/etc/cgroups.json";
+static constexpr const char* CGROUPS_DESC_VENDOR_FILE = "/vendor/etc/cgroups.json";
+
+static bool Mkdir(const std::string& path, mode_t mode, const std::string& uid,
+                  const std::string& gid) {
+    if (mode == 0) {
+        mode = 0755;
+    }
+
+    if (mkdir(path.c_str(), mode) != 0) {
+        /* chmod in case the directory already exists */
+        if (errno == EEXIST) {
+            if (fchmodat(AT_FDCWD, path.c_str(), mode, AT_SYMLINK_NOFOLLOW) != 0) {
+                // /acct is a special case when the directory already exists
+                // TODO: check if file mode is already what we want instead of using EROFS
+                if (errno != EROFS) {
+                    PLOG(ERROR) << "fchmodat() failed for " << path;
+                    return false;
+                }
+            }
+        } else {
+            PLOG(ERROR) << "mkdir() failed for " << path;
+            return false;
+        }
+    }
+
+    if (uid.empty()) {
+        return true;
+    }
+
+    passwd* uid_pwd = getpwnam(uid.c_str());
+    if (!uid_pwd) {
+        PLOG(ERROR) << "Unable to decode UID for '" << uid << "'";
+        return false;
+    }
+
+    uid_t pw_uid = uid_pwd->pw_uid;
+    gid_t gr_gid = -1;
+    if (!gid.empty()) {
+        group* gid_pwd = getgrnam(gid.c_str());
+        if (!gid_pwd) {
+            PLOG(ERROR) << "Unable to decode GID for '" << gid << "'";
+            return false;
+        }
+        gr_gid = gid_pwd->gr_gid;
+    }
+
+    if (lchown(path.c_str(), pw_uid, gr_gid) < 0) {
+        PLOG(ERROR) << "lchown() failed for " << path;
+        return false;
+    }
+
+    /* chown may have cleared S_ISUID and S_ISGID, chmod again */
+    if (mode & (S_ISUID | S_ISGID)) {
+        if (fchmodat(AT_FDCWD, path.c_str(), mode, AT_SYMLINK_NOFOLLOW) != 0) {
+            PLOG(ERROR) << "fchmodat() failed for " << path;
+            return false;
+        }
+    }
+
+    return true;
+}
+
+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::Reader reader;
+    Json::Value root;
+    if (!reader.parse(json_doc, root)) {
+        LOG(ERROR) << "Failed to parse cgroups description: " << reader.getFormattedErrorMessages();
+        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();
+            auto iter = descriptors->find(name);
+            if (iter == descriptors->end()) {
+                descriptors->emplace(
+                        name, CgroupDescriptor(
+                                      1, name, cgroups[i]["Path"].asString(),
+                                      std::strtoul(cgroups[i]["Mode"].asString().c_str(), 0, 8),
+                                      cgroups[i]["UID"].asString(), cgroups[i]["GID"].asString()));
+            } else {
+                iter->second = CgroupDescriptor(
+                        1, name, cgroups[i]["Path"].asString(),
+                        std::strtoul(cgroups[i]["Mode"].asString().c_str(), 0, 8),
+                        cgroups[i]["UID"].asString(), cgroups[i]["GID"].asString());
+            }
+        }
+    }
+
+    if (root.isMember("Cgroups2")) {
+        const Json::Value& cgroups2 = root["Cgroups2"];
+        auto iter = descriptors->find(CGROUPV2_CONTROLLER_NAME);
+        if (iter == descriptors->end()) {
+            descriptors->emplace(
+                    CGROUPV2_CONTROLLER_NAME,
+                    CgroupDescriptor(2, CGROUPV2_CONTROLLER_NAME, cgroups2["Path"].asString(),
+                                     std::strtoul(cgroups2["Mode"].asString().c_str(), 0, 8),
+                                     cgroups2["UID"].asString(), cgroups2["GID"].asString()));
+        } else {
+            iter->second =
+                    CgroupDescriptor(2, CGROUPV2_CONTROLLER_NAME, cgroups2["Path"].asString(),
+                                     std::strtoul(cgroups2["Mode"].asString().c_str(), 0, 8),
+                                     cgroups2["UID"].asString(), cgroups2["GID"].asString());
+        }
+    }
+
+    return true;
+}
+
+static bool ReadDescriptors(std::map<std::string, CgroupDescriptor>* descriptors) {
+    // load system cgroup descriptors
+    if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, 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 SetupCgroup(const CgroupDescriptor& descriptor) {
+    const format::CgroupController* controller = descriptor.controller();
+
+    // mkdir <path> [mode] [owner] [group]
+    if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
+        LOG(ERROR) << "Failed to create directory for " << controller->name() << " cgroup";
+        return false;
+    }
+
+    int result;
+    if (controller->version() == 2) {
+        result = mount("none", controller->path(), "cgroup2", MS_NODEV | MS_NOEXEC | MS_NOSUID,
+                       nullptr);
+    } else {
+        // Unfortunately historically cpuset controller was mounted using a mount command
+        // different from all other controllers. This results in controller attributes not
+        // to be prepended with controller name. For example this way instead of
+        // /dev/cpuset/cpuset.cpus the attribute becomes /dev/cpuset/cpus which is what
+        // the system currently expects.
+        if (!strcmp(controller->name(), "cpuset")) {
+            // mount cpuset none /dev/cpuset nodev noexec nosuid
+            result = mount("none", controller->path(), controller->name(),
+                           MS_NODEV | MS_NOEXEC | MS_NOSUID, nullptr);
+        } else {
+            // mount cgroup none <path> nodev noexec nosuid <controller>
+            result = mount("none", controller->path(), "cgroup", MS_NODEV | MS_NOEXEC | MS_NOSUID,
+                           controller->name());
+        }
+    }
+
+    if (result < 0) {
+        PLOG(ERROR) << "Failed to mount " << controller->name() << " cgroup";
+        return false;
+    }
+
+    return true;
+}
+
+#else
+
+// Stubs for non-Android targets.
+static bool SetupCgroup(const CgroupDescriptor&) {
+    return false;
+}
+
+#endif
+
+// WARNING: This function should be called only from SetupCgroups and only once.
+// It intentionally leaks an FD, so additional invocation will result in additional leak.
+static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) {
+    // WARNING: We are intentionally leaking the FD to keep the file open forever.
+    // Let init keep the FD open to prevent file mappings from becoming invalid in
+    // case the file gets deleted somehow.
+    int 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)
+    : controller_(version, name, path), mode_(mode), uid_(uid), gid_(gid) {}
+
+}  // namespace cgrouprc
+}  // namespace android
+
+bool CgroupSetup() {
+    using namespace android::cgrouprc;
+
+    std::map<std::string, CgroupDescriptor> 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 SetupCgroups more than once";
+        return true;
+    }
+
+    // load cgroups.json file
+    if (!ReadDescriptors(&descriptors)) {
+        LOG(ERROR) << "Failed to load cgroup description file";
+        return false;
+    }
+
+    // setup cgroups
+    for (const auto& [name, descriptor] : descriptors) {
+        if (!SetupCgroup(descriptor)) {
+            // issue a warning and proceed with the next cgroup
+            // TODO: mark the descriptor as invalid and skip it in WriteRcFile()
+            LOG(WARNING) << "Failed to setup " << name << " cgroup";
+        }
+    }
+
+    // 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;
+}
diff --git a/libprocessgroup/setup/include/processgroup/setup.h b/libprocessgroup/setup/include/processgroup/setup.h
new file mode 100644
index 0000000..6ea1979
--- /dev/null
+++ b/libprocessgroup/setup/include/processgroup/setup.h
@@ -0,0 +1,19 @@
+/*
+ * 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
+
+bool CgroupSetup();
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index 9362c03..4b45c87 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -46,7 +46,7 @@
 
 bool ProfileAttribute::GetPathForTask(int tid, std::string* path) const {
     std::string subgroup;
-    if (!controller_->GetTaskGroup(tid, &subgroup)) {
+    if (!controller()->GetTaskGroup(tid, &subgroup)) {
         return false;
     }
 
@@ -55,9 +55,10 @@
     }
 
     if (subgroup.empty()) {
-        *path = StringPrintf("%s/%s", controller_->path(), file_name_.c_str());
+        *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());
+        *path = StringPrintf("%s/%s/%s", controller()->path(), subgroup.c_str(),
+                             file_name_.c_str());
     }
     return true;
 }
@@ -135,7 +136,7 @@
     return path.find("<uid>", 0) != std::string::npos || path.find("<pid>", 0) != std::string::npos;
 }
 
-SetCgroupAction::SetCgroupAction(const CgroupController* c, const std::string& p)
+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
@@ -145,7 +146,7 @@
         return;
     }
 
-    std::string tasks_path = c->GetTasksFilePath(p.c_str());
+    std::string tasks_path = c.GetTasksFilePath(p);
 
     if (access(tasks_path.c_str(), W_OK) != 0) {
         // file is not accessible
@@ -199,7 +200,7 @@
     }
 
     // this is app-dependent path, file descriptor is not cached
-    std::string procs_path = controller_->GetProcsFilePath(path_, uid, pid);
+    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;
@@ -212,7 +213,7 @@
 
     return true;
 #else
-    std::string procs_path = controller_->GetProcsFilePath(path_, uid, pid);
+    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
@@ -247,7 +248,7 @@
     LOG(ERROR) << "Application profile can't be applied to a thread";
     return false;
 #else
-    std::string tasks_path = controller_->GetTasksFilePath(path_);
+    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
@@ -326,8 +327,8 @@
         std::string file_attr = attr[i]["File"].asString();
 
         if (attributes_.find(name) == attributes_.end()) {
-            const CgroupController* controller = cg_map.FindController(controller_name);
-            if (controller) {
+            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";
@@ -355,8 +356,8 @@
                 std::string controller_name = params_val["Controller"].asString();
                 std::string path = params_val["Path"].asString();
 
-                const CgroupController* controller = cg_map.FindController(controller_name);
-                if (controller) {
+                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";
diff --git a/libprocessgroup/task_profiles.h b/libprocessgroup/task_profiles.h
index 9ee81c1..37cc305 100644
--- a/libprocessgroup/task_profiles.h
+++ b/libprocessgroup/task_profiles.h
@@ -27,16 +27,16 @@
 
 class ProfileAttribute {
   public:
-    ProfileAttribute(const CgroupController* controller, const std::string& file_name)
+    ProfileAttribute(const CgroupController& controller, const std::string& file_name)
         : controller_(controller), file_name_(file_name) {}
 
-    const CgroupController* controller() const { return controller_; }
+    const CgroupController* controller() const { return &controller_; }
     const std::string& file_name() const { return file_name_; }
 
     bool GetPathForTask(int tid, std::string* path) const;
 
   private:
-    const CgroupController* controller_;
+    CgroupController controller_;
     std::string file_name_;
 };
 
@@ -106,16 +106,16 @@
 // Set cgroup profile element
 class SetCgroupAction : public ProfileAction {
   public:
-    SetCgroupAction(const CgroupController* c, const std::string& p);
+    SetCgroupAction(const CgroupController& c, const std::string& p);
 
     virtual bool ExecuteForProcess(uid_t uid, pid_t pid) const;
     virtual bool ExecuteForTask(int tid) const;
 
-    const CgroupController* controller() const { return controller_; }
+    const CgroupController* controller() const { return &controller_; }
     std::string path() const { return path_; }
 
   private:
-    const CgroupController* controller_;
+    CgroupController controller_;
     std::string path_;
 #ifdef CACHE_FILE_DESCRIPTORS
     android::base::unique_fd fd_;
diff --git a/rootdir/etc/ld.config.legacy.txt b/rootdir/etc/ld.config.legacy.txt
index 0fccd31..7324ba9 100644
--- a/rootdir/etc/ld.config.legacy.txt
+++ b/rootdir/etc/ld.config.legacy.txt
@@ -100,6 +100,7 @@
 namespace.media.link.default.shared_libs  = libandroid.so
 namespace.media.link.default.shared_libs += libbinder_ndk.so
 namespace.media.link.default.shared_libs += libc.so
+namespace.media.link.default.shared_libs += libcgrouprc.so
 namespace.media.link.default.shared_libs += libdl.so
 namespace.media.link.default.shared_libs += liblog.so
 namespace.media.link.default.shared_libs += libmediametrics.so
@@ -143,6 +144,7 @@
 namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
 namespace.resolv.links = default
 namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libcgrouprc.so
 namespace.resolv.link.default.shared_libs += libm.so
 namespace.resolv.link.default.shared_libs += libdl.so
 namespace.resolv.link.default.shared_libs += libbinder_ndk.so
diff --git a/rootdir/etc/ld.config.txt b/rootdir/etc/ld.config.txt
index 84651fb..45e80e1 100644
--- a/rootdir/etc/ld.config.txt
+++ b/rootdir/etc/ld.config.txt
@@ -212,6 +212,7 @@
 namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
 namespace.resolv.links = default
 namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libcgrouprc.so
 namespace.resolv.link.default.shared_libs += libm.so
 namespace.resolv.link.default.shared_libs += libdl.so
 namespace.resolv.link.default.shared_libs += libbinder_ndk.so
diff --git a/rootdir/etc/ld.config.vndk_lite.txt b/rootdir/etc/ld.config.vndk_lite.txt
index 272485f..a762ba8 100644
--- a/rootdir/etc/ld.config.vndk_lite.txt
+++ b/rootdir/etc/ld.config.vndk_lite.txt
@@ -154,6 +154,7 @@
 namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
 namespace.resolv.links = default
 namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libcgrouprc.so
 namespace.resolv.link.default.shared_libs += libm.so
 namespace.resolv.link.default.shared_libs += libdl.so
 namespace.resolv.link.default.shared_libs += libbinder_ndk.so
@@ -476,6 +477,7 @@
 namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
 namespace.resolv.links = default
 namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libcgrouprc.so
 namespace.resolv.link.default.shared_libs += libm.so
 namespace.resolv.link.default.shared_libs += libdl.so
 namespace.resolv.link.default.shared_libs += libbinder_ndk.so