diff --git a/adb/Android.bp b/adb/Android.bp
index f6aede8..6558b1b 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -436,7 +436,6 @@
             shared_libs: [
                 "libbootloader_message",
                 "libmdnssd",
-                "libext4_utils",
                 "libfec",
                 "libfs_mgr",
                 "libselinux",
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index a525bd5..ac15ce4 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -32,7 +32,6 @@
 #include <unistd.h>
 
 #include <algorithm>
-#include <map>
 #include <memory>
 #include <string>
 #include <vector>
@@ -518,10 +517,166 @@
     return ret;
 }
 
+bool fs_mgr_overlayfs_set_shared_mount(const std::string& mount_point, bool shared_flag) {
+    auto ret = mount(nullptr, mount_point.c_str(), nullptr, shared_flag ? MS_SHARED : MS_PRIVATE,
+                     nullptr);
+    if (ret) {
+        PERROR << "__mount(target=" << mount_point
+               << ",flag=" << (shared_flag ? "MS_SHARED" : "MS_PRIVATE") << ")=" << ret;
+        return false;
+    }
+    return true;
+}
+
+bool fs_mgr_overlayfs_move_mount(const std::string& source, const std::string& target) {
+    auto ret = mount(source.c_str(), target.c_str(), nullptr, MS_MOVE, nullptr);
+    if (ret) {
+        PERROR << "__mount(source=" << source << ",target=" << target << ",flag=MS_MOVE)=" << ret;
+        return false;
+    }
+    return true;
+}
+
+struct mount_info {
+    std::string mount_point;
+    bool shared_flag;
+};
+
+std::vector<mount_info> ReadMountinfoFromFile(const std::string& path) {
+    std::vector<mount_info> info;
+
+    auto file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path.c_str(), "re"), fclose};
+    if (!file) {
+        PERROR << __FUNCTION__ << "(): cannot open file: '" << path << "'";
+        return info;
+    }
+
+    ssize_t len;
+    size_t alloc_len = 0;
+    char* line = nullptr;
+    while ((len = getline(&line, &alloc_len, file.get())) != -1) {
+        /* if the last character is a newline, shorten the string by 1 byte */
+        if (line[len - 1] == '\n') {
+            line[len - 1] = '\0';
+        }
+
+        static constexpr char delim[] = " \t";
+        char* save_ptr;
+        if (!strtok_r(line, delim, &save_ptr)) {
+            LERROR << "Error parsing mount ID";
+            break;
+        }
+        if (!strtok_r(nullptr, delim, &save_ptr)) {
+            LERROR << "Error parsing parent ID";
+            break;
+        }
+        if (!strtok_r(nullptr, delim, &save_ptr)) {
+            LERROR << "Error parsing mount source";
+            break;
+        }
+        if (!strtok_r(nullptr, delim, &save_ptr)) {
+            LERROR << "Error parsing root";
+            break;
+        }
+
+        char* p;
+        if (!(p = strtok_r(nullptr, delim, &save_ptr))) {
+            LERROR << "Error parsing mount_point";
+            break;
+        }
+        mount_info entry = {p, false};
+
+        if (!strtok_r(nullptr, delim, &save_ptr)) {
+            LERROR << "Error parsing mount_flags";
+            break;
+        }
+
+        while ((p = strtok_r(nullptr, delim, &save_ptr))) {
+            if ((p[0] == '-') && (p[1] == '\0')) break;
+            if (android::base::StartsWith(p, "shared:")) entry.shared_flag = true;
+        }
+        if (!p) {
+            LERROR << "Error parsing fields";
+            break;
+        }
+        info.emplace_back(std::move(entry));
+    }
+
+    free(line);
+    if (info.empty()) {
+        LERROR << __FUNCTION__ << "(): failed to load mountinfo from : '" << path << "'";
+    }
+    return info;
+}
+
 bool fs_mgr_overlayfs_mount(const std::string& mount_point) {
     auto options = fs_mgr_get_overlayfs_options(mount_point);
     if (options.empty()) return false;
 
+    auto retval = true;
+    auto save_errno = errno;
+
+    struct move_entry {
+        std::string mount_point;
+        std::string dir;
+        bool shared_flag;
+    };
+    std::vector<move_entry> move;
+    auto parent_private = false;
+    auto parent_made_private = false;
+    auto dev_private = false;
+    auto dev_made_private = false;
+    for (auto& entry : ReadMountinfoFromFile("/proc/self/mountinfo")) {
+        if ((entry.mount_point == mount_point) && !entry.shared_flag) {
+            parent_private = true;
+        }
+        if ((entry.mount_point == "/dev") && !entry.shared_flag) {
+            dev_private = true;
+        }
+
+        if (!android::base::StartsWith(entry.mount_point, mount_point + "/")) {
+            continue;
+        }
+        if (std::find_if(move.begin(), move.end(), [&entry](const auto& it) {
+                return android::base::StartsWith(entry.mount_point, it.mount_point + "/");
+            }) != move.end()) {
+            continue;
+        }
+
+        // use as the bound directory in /dev.
+        auto new_context = fs_mgr_get_context(entry.mount_point);
+        if (!new_context.empty() && setfscreatecon(new_context.c_str())) {
+            PERROR << "setfscreatecon " << new_context;
+        }
+        move_entry new_entry = {std::move(entry.mount_point), "/dev/TemporaryDir-XXXXXX",
+                                entry.shared_flag};
+        const auto target = mkdtemp(new_entry.dir.data());
+        if (!target) {
+            retval = false;
+            save_errno = errno;
+            PERROR << "temporary directory for MS_BIND";
+            setfscreatecon(nullptr);
+            continue;
+        }
+        setfscreatecon(nullptr);
+
+        if (!parent_private && !parent_made_private) {
+            parent_made_private = fs_mgr_overlayfs_set_shared_mount(mount_point, false);
+        }
+        if (new_entry.shared_flag) {
+            new_entry.shared_flag = fs_mgr_overlayfs_set_shared_mount(new_entry.mount_point, false);
+        }
+        if (!fs_mgr_overlayfs_move_mount(new_entry.mount_point, new_entry.dir)) {
+            retval = false;
+            save_errno = errno;
+            if (new_entry.shared_flag) {
+                fs_mgr_overlayfs_set_shared_mount(new_entry.mount_point, true);
+            }
+            continue;
+        }
+        move.emplace_back(std::move(new_entry));
+    }
+
     // hijack __mount() report format to help triage
     auto report = "__mount(source=overlay,target="s + mount_point + ",type=overlay";
     const auto opt_list = android::base::Split(options, ",");
@@ -536,12 +691,38 @@
     auto ret = mount("overlay", mount_point.c_str(), "overlay", MS_RDONLY | MS_RELATIME,
                      options.c_str());
     if (ret) {
+        retval = false;
+        save_errno = errno;
         PERROR << report << ret;
-        return false;
     } else {
         LINFO << report << ret;
-        return true;
     }
+
+    // Move submounts back.
+    for (const auto& entry : move) {
+        if (!dev_private && !dev_made_private) {
+            dev_made_private = fs_mgr_overlayfs_set_shared_mount("/dev", false);
+        }
+
+        if (!fs_mgr_overlayfs_move_mount(entry.dir, entry.mount_point)) {
+            retval = false;
+            save_errno = errno;
+        } else if (entry.shared_flag &&
+                   !fs_mgr_overlayfs_set_shared_mount(entry.mount_point, true)) {
+            retval = false;
+            save_errno = errno;
+        }
+        rmdir(entry.dir.c_str());
+    }
+    if (dev_made_private) {
+        fs_mgr_overlayfs_set_shared_mount("/dev", true);
+    }
+    if (parent_made_private) {
+        fs_mgr_overlayfs_set_shared_mount(mount_point, true);
+    }
+
+    errno = save_errno;
+    return retval;
 }
 
 // Mount kScratchMountPoint
diff --git a/init/Android.bp b/init/Android.bp
index 6985677..ee339dd 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -242,11 +242,12 @@
     ],
     whole_static_libs: ["libcap"],
     shared_libs: [
-        "libprotobuf-cpp-lite",
-        "libhidl-gen-utils",
-        "libprocessgroup",
-        "liblog",
         "libcutils",
+        "libhidl-gen-utils",
+        "libjsoncpp",
+        "liblog",
+        "libprocessgroup",
+        "libprotobuf-cpp-lite",
     ],
     srcs: [
         "action.cpp",
diff --git a/init/action.cpp b/init/action.cpp
index a169591..8cf7645 100644
--- a/init/action.cpp
+++ b/init/action.cpp
@@ -95,7 +95,7 @@
 }
 
 void Action::AddCommand(BuiltinFunction f, std::vector<std::string>&& args, int line) {
-    commands_.emplace_back(f, false, std::move(args), line);
+    commands_.emplace_back(std::move(f), false, std::move(args), line);
 }
 
 std::size_t Action::NumCommands() const {
diff --git a/init/action_manager.cpp b/init/action_manager.cpp
index 985b8ad..541c8f2 100644
--- a/init/action_manager.cpp
+++ b/init/action_manager.cpp
@@ -47,7 +47,7 @@
 void ActionManager::QueueBuiltinAction(BuiltinFunction func, const std::string& name) {
     auto action = std::make_unique<Action>(true, nullptr, "<Builtin Action>", 0, name,
                                            std::map<std::string, std::string>{});
-    action->AddCommand(func, {name}, 0);
+    action->AddCommand(std::move(func), {name}, 0);
 
     event_queue_.emplace(action.get());
     actions_.emplace_back(std::move(action));
diff --git a/init/devices.h b/init/devices.h
index 9d39eaa..442c53f 100644
--- a/init/devices.h
+++ b/init/devices.h
@@ -84,9 +84,9 @@
     };
 
     Subsystem() {}
-    Subsystem(const std::string& name) : name_(name) {}
-    Subsystem(const std::string& name, DevnameSource source, const std::string& dir_name)
-        : name_(name), devname_source_(source), dir_name_(dir_name) {}
+    Subsystem(std::string name) : name_(std::move(name)) {}
+    Subsystem(std::string name, DevnameSource source, std::string dir_name)
+        : name_(std::move(name)), devname_source_(source), dir_name_(std::move(dir_name)) {}
 
     // Returns the full path for a uevent of a device that is a member of this subsystem,
     // according to the rules parsed from ueventd.rc
diff --git a/init/devices_test.cpp b/init/devices_test.cpp
index 3e7c1a8..c408bc1 100644
--- a/init/devices_test.cpp
+++ b/init/devices_test.cpp
@@ -30,7 +30,7 @@
 class DeviceHandlerTester {
   public:
     void TestGetSymlinks(const std::string& platform_device, const Uevent& uevent,
-                         const std::vector<std::string> expected_links) {
+                         const std::vector<std::string>& expected_links) {
         TemporaryDir fake_sys_root;
         device_handler_.sysfs_mount_point_ = fake_sys_root.path;
 
diff --git a/init/host_init_verifier.cpp b/init/host_init_verifier.cpp
index 8aa3509..92c2aa5 100644
--- a/init/host_init_verifier.cpp
+++ b/init/host_init_verifier.cpp
@@ -20,6 +20,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <fstream>
 #include <iostream>
 #include <iterator>
 #include <string>
@@ -29,6 +30,7 @@
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
+#include <json/json.h>
 
 #include "action.h"
 #include "action_manager.h"
@@ -129,21 +131,33 @@
     return nullptr;
 }
 
-static std::optional<std::set<std::string>> ReadKnownInterfaces(
-        const std::string& known_interfaces_file) {
-    if (known_interfaces_file.empty()) {
-        LOG(WARNING) << "Missing a known interfaces file.";
+static std::optional<android::init::InterfaceInheritanceHierarchyMap>
+ReadInterfaceInheritanceHierarchy(const std::string& interface_inheritance_hierarchy_file) {
+    if (interface_inheritance_hierarchy_file.empty()) {
+        LOG(WARNING) << "Missing an interface inheritance hierarchy file.";
         return {};
     }
 
-    std::string known_interfaces;
-    if (!ReadFileToString(known_interfaces_file, &known_interfaces)) {
-        LOG(ERROR) << "Failed to read known interfaces file '" << known_interfaces_file << "'";
+    Json::Value root;
+    Json::Reader reader;
+    std::ifstream stream(interface_inheritance_hierarchy_file);
+    if (!reader.parse(stream, root)) {
+        LOG(ERROR) << "Failed to read interface inheritance hierarchy file: "
+                   << interface_inheritance_hierarchy_file << "\n"
+                   << reader.getFormattedErrorMessages();
         return {};
     }
 
-    auto interfaces = Split(known_interfaces, " ");
-    return std::set<std::string>(interfaces.begin(), interfaces.end());
+    android::init::InterfaceInheritanceHierarchyMap result;
+    for (const Json::Value& entry : root) {
+        std::set<std::string> inherited_interfaces;
+        for (const Json::Value& intf : entry["inheritedInterfaces"]) {
+            inherited_interfaces.insert(intf.asString());
+        }
+        result[entry["interface"].asString()] = inherited_interfaces;
+    }
+
+    return result;
 }
 
 namespace android {
@@ -169,7 +183,7 @@
     android::base::InitLogging(argv, &android::base::StdioLogger);
     android::base::SetMinimumLogSeverity(android::base::ERROR);
 
-    std::string known_interfaces_file;
+    std::string interface_inheritance_hierarchy_file;
 
     while (true) {
         static const struct option long_options[] = {
@@ -177,7 +191,7 @@
                 {nullptr, 0, nullptr, 0},
         };
 
-        int arg = getopt_long(argc, argv, "p:k:", long_options, nullptr);
+        int arg = getopt_long(argc, argv, "p:i:", long_options, nullptr);
 
         if (arg == -1) {
             break;
@@ -190,8 +204,8 @@
             case 'p':
                 passwd_files.emplace_back(optarg);
                 break;
-            case 'k':
-                known_interfaces_file = optarg;
+            case 'i':
+                interface_inheritance_hierarchy_file = optarg;
                 break;
             default:
                 std::cerr << "getprop: getopt returned invalid result: " << arg << std::endl;
@@ -213,8 +227,10 @@
     ServiceList& sl = ServiceList::GetInstance();
     Parser parser;
     parser.AddSectionParser(
-            "service", std::make_unique<ServiceParser>(&sl, nullptr,
-                                                       ReadKnownInterfaces(known_interfaces_file)));
+            "service",
+            std::make_unique<ServiceParser>(
+                    &sl, nullptr,
+                    ReadInterfaceInheritanceHierarchy(interface_inheritance_hierarchy_file)));
     parser.AddSectionParser("on", std::make_unique<ActionParser>(&am, nullptr));
     parser.AddSectionParser("import", std::make_unique<HostImportParser>());
 
diff --git a/init/keychords.cpp b/init/keychords.cpp
index d0ca3e7..5f2682b 100644
--- a/init/keychords.cpp
+++ b/init/keychords.cpp
@@ -285,7 +285,7 @@
 
 void Keychords::Start(Epoll* epoll, std::function<void(const std::vector<int>&)> handler) {
     epoll_ = epoll;
-    handler_ = handler;
+    handler_ = std::move(handler);
     if (entries_.size()) GeteventOpenDevice();
 }
 
diff --git a/init/mount_handler.cpp b/init/mount_handler.cpp
index b0b63c5..791a019 100644
--- a/init/mount_handler.cpp
+++ b/init/mount_handler.cpp
@@ -140,11 +140,11 @@
         }
     }
     free(buf);
-    for (auto entry : untouched) {
+    for (auto& entry : untouched) {
         SetMountProperty(entry, false);
         mounts_.erase(entry);
     }
-    for (auto entry : touched) {
+    for (auto& entry : touched) {
         SetMountProperty(entry, true);
         mounts_.emplace(std::move(entry));
     }
diff --git a/init/parser.cpp b/init/parser.cpp
index bbfbdc6..6ab61cb 100644
--- a/init/parser.cpp
+++ b/init/parser.cpp
@@ -37,7 +37,7 @@
 }
 
 void Parser::AddSingleLineParser(const std::string& prefix, LineCallback callback) {
-    line_callbacks_.emplace_back(prefix, callback);
+    line_callbacks_.emplace_back(prefix, std::move(callback));
 }
 
 void Parser::ParseData(const std::string& filename, std::string* data) {
diff --git a/init/reboot.cpp b/init/reboot.cpp
index d9d885c..cb54d34 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -636,11 +636,9 @@
     bool run_fsck = false;
     bool command_invalid = false;
 
-    if (cmd_params.size() > 3) {
-        command_invalid = true;
-    } else if (cmd_params[0] == "shutdown") {
+    if (cmd_params[0] == "shutdown") {
         cmd = ANDROID_RB_POWEROFF;
-        if (cmd_params.size() == 2) {
+        if (cmd_params.size() >= 2) {
             if (cmd_params[1] == "userrequested") {
                 // The shutdown reason is PowerManager.SHUTDOWN_USER_REQUESTED.
                 // Run fsck once the file system is remounted in read-only mode.
@@ -671,6 +669,13 @@
                                   "bootloader_message: "
                                << err;
                 }
+            } else if (reboot_target == "recovery") {
+                const std::vector<std::string> options = {};
+                std::string err;
+                if (!write_bootloader_message(options, &err)) {
+                    LOG(ERROR) << "Failed to set bootloader message: " << err;
+                    return false;
+                }
             } else if (reboot_target == "sideload" || reboot_target == "sideload-auto-reboot" ||
                        reboot_target == "fastboot") {
                 std::string arg = reboot_target == "sideload-auto-reboot" ? "sideload_auto_reboot"
@@ -686,9 +691,9 @@
                 reboot_target = "recovery";
             }
 
-            // If there is an additional parameter, pass it along
-            if ((cmd_params.size() == 3) && cmd_params[2].size()) {
-                reboot_target += "," + cmd_params[2];
+            // If there are additional parameter, pass them along
+            for (size_t i = 2; (cmd_params.size() > i) && cmd_params[i].size(); ++i) {
+                reboot_target += "," + cmd_params[i];
             }
         }
     } else {
diff --git a/init/security.cpp b/init/security.cpp
index 5d87f3c..586d0c7 100644
--- a/init/security.cpp
+++ b/init/security.cpp
@@ -83,7 +83,7 @@
     return {};
 }
 
-static bool SetHighestAvailableOptionValue(std::string path, int min, int max) {
+static bool SetHighestAvailableOptionValue(const std::string& path, int min, int max) {
     std::ifstream inf(path, std::fstream::in);
     if (!inf) {
         LOG(ERROR) << "Cannot open for reading: " << path;
diff --git a/init/service_parser.cpp b/init/service_parser.cpp
index ba35104..88ce364 100644
--- a/init/service_parser.cpp
+++ b/init/service_parser.cpp
@@ -18,6 +18,9 @@
 
 #include <linux/input.h>
 
+#include <algorithm>
+#include <sstream>
+
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
@@ -152,12 +155,6 @@
         return Error() << "Interface name must not be a value name '" << interface_name << "'";
     }
 
-    if (known_interfaces_ && known_interfaces_->count(interface_name) == 0) {
-        return Error() << "Interface is not in the known set of hidl_interfaces: '"
-                       << interface_name << "'. Please ensure the interface is built "
-                       << "by a hidl_interface target.";
-    }
-
     const std::string fullname = interface_name + "/" + instance_name;
 
     for (const auto& svc : *service_list_) {
@@ -540,6 +537,37 @@
         return {};
     }
 
+    if (interface_inheritance_hierarchy_) {
+        std::set<std::string> interface_names;
+        for (const std::string& intf : service_->interfaces()) {
+            interface_names.insert(Split(intf, "/")[0]);
+        }
+        std::ostringstream error_stream;
+        for (const std::string& intf : interface_names) {
+            if (interface_inheritance_hierarchy_->count(intf) == 0) {
+                error_stream << "\nInterface is not in the known set of hidl_interfaces: '" << intf
+                             << "'. Please ensure the interface is spelled correctly and built "
+                             << "by a hidl_interface target.";
+                continue;
+            }
+            const std::set<std::string>& required_interfaces =
+                    (*interface_inheritance_hierarchy_)[intf];
+            std::set<std::string> diff;
+            std::set_difference(required_interfaces.begin(), required_interfaces.end(),
+                                interface_names.begin(), interface_names.end(),
+                                std::inserter(diff, diff.begin()));
+            if (!diff.empty()) {
+                error_stream << "\nInterface '" << intf << "' requires its full inheritance "
+                             << "hierarchy to be listed in this init_rc file. Missing "
+                             << "interfaces: [" << base::Join(diff, " ") << "]";
+            }
+        }
+        const std::string& errors = error_stream.str();
+        if (!errors.empty()) {
+            return Error() << errors;
+        }
+    }
+
     Service* old_service = service_list_->FindService(service_->name());
     if (old_service) {
         if (!service_->is_override()) {
diff --git a/init/service_parser.h b/init/service_parser.h
index 5a16768..5ad26ef 100644
--- a/init/service_parser.h
+++ b/init/service_parser.h
@@ -26,13 +26,16 @@
 namespace android {
 namespace init {
 
+using InterfaceInheritanceHierarchyMap = std::map<std::string, std::set<std::string>>;
+
 class ServiceParser : public SectionParser {
   public:
-    ServiceParser(ServiceList* service_list, std::vector<Subcontext>* subcontexts,
-                  const std::optional<std::set<std::string>>& known_interfaces)
+    ServiceParser(
+            ServiceList* service_list, std::vector<Subcontext>* subcontexts,
+            const std::optional<InterfaceInheritanceHierarchyMap>& interface_inheritance_hierarchy)
         : service_list_(service_list),
           subcontexts_(subcontexts),
-          known_interfaces_(known_interfaces),
+          interface_inheritance_hierarchy_(interface_inheritance_hierarchy),
           service_(nullptr) {}
     Result<void> ParseSection(std::vector<std::string>&& args, const std::string& filename,
                               int line) override;
@@ -85,7 +88,7 @@
 
     ServiceList* service_list_;
     std::vector<Subcontext>* subcontexts_;
-    std::optional<std::set<std::string>> known_interfaces_;
+    std::optional<InterfaceInheritanceHierarchyMap> interface_inheritance_hierarchy_;
     std::unique_ptr<Service> service_;
     std::string filename_;
 };
diff --git a/init/test_function_map.h b/init/test_function_map.h
index 293f1f9..466836c 100644
--- a/init/test_function_map.h
+++ b/init/test_function_map.h
@@ -30,17 +30,17 @@
   public:
     // Helper for argument-less functions
     using BuiltinFunctionNoArgs = std::function<void(void)>;
-    void Add(const std::string& name, const BuiltinFunctionNoArgs function) {
-        Add(name, 0, 0, false, [function](const BuiltinArguments&) {
-            function();
+    void Add(const std::string& name, BuiltinFunctionNoArgs function) {
+        Add(name, 0, 0, false, [f = std::move(function)](const BuiltinArguments&) {
+            f();
             return Result<void>{};
         });
     }
 
     void Add(const std::string& name, std::size_t min_parameters, std::size_t max_parameters,
-             bool run_in_subcontext, const BuiltinFunction function) {
-        builtin_functions_[name] =
-            make_tuple(min_parameters, max_parameters, make_pair(run_in_subcontext, function));
+             bool run_in_subcontext, BuiltinFunction function) {
+        builtin_functions_[name] = make_tuple(min_parameters, max_parameters,
+                                              make_pair(run_in_subcontext, std::move(function)));
     }
 
   private:
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index 3b9de0f..8b2cf62 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -146,7 +146,7 @@
 
 void ColdBoot::RegenerateUevents() {
     uevent_listener_.RegenerateUevents([this](const Uevent& uevent) {
-        uevent_queue_.emplace_back(std::move(uevent));
+        uevent_queue_.emplace_back(uevent);
         return ListenerAction::kContinue;
     });
 }
diff --git a/libutils/include/utils/RefBase.h b/libutils/include/utils/RefBase.h
index a105474..3a02a8a 100644
--- a/libutils/include/utils/RefBase.h
+++ b/libutils/include/utils/RefBase.h
@@ -188,9 +188,6 @@
 // ---------------------------------------------------------------------------
 namespace android {
 
-class TextOutput;
-TextOutput& printWeakPointer(TextOutput& to, const void* val);
-
 // ---------------------------------------------------------------------------
 
 #define COMPARE_WEAK(_op_)                                      \
@@ -459,9 +456,6 @@
     weakref_type*   m_refs;
 };
 
-template <typename T>
-TextOutput& operator<<(TextOutput& to, const wp<T>& val);
-
 #undef COMPARE_WEAK
 
 // ---------------------------------------------------------------------------
@@ -635,12 +629,6 @@
     }
 }
 
-template <typename T>
-inline TextOutput& operator<<(TextOutput& to, const wp<T>& val)
-{
-    return printWeakPointer(to, val.unsafe_get());
-}
-
 // ---------------------------------------------------------------------------
 
 // this class just serves as a namespace so TYPE::moveReferences can stay
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 48140b8..42af751 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -79,6 +79,7 @@
 #define MEMCG_MEMORYSW_USAGE "/dev/memcg/memory.memsw.usage_in_bytes"
 #define ZONEINFO_PATH "/proc/zoneinfo"
 #define MEMINFO_PATH "/proc/meminfo"
+#define PROC_STATUS_TGID_FIELD "Tgid:"
 #define LINE_MAX 128
 
 /* Android Logger event logtags (see event.logtags) */
@@ -551,6 +552,49 @@
            (to->tv_nsec - from->tv_nsec) / (long)NS_PER_MS;
 }
 
+static int proc_get_tgid(int pid) {
+    char path[PATH_MAX];
+    char buf[PAGE_SIZE];
+    int fd;
+    ssize_t size;
+    char *pos;
+    int64_t tgid = -1;
+
+    snprintf(path, PATH_MAX, "/proc/%d/status", pid);
+    fd = open(path, O_RDONLY | O_CLOEXEC);
+    if (fd < 0) {
+        return -1;
+    }
+
+    size = read_all(fd, buf, sizeof(buf) - 1);
+    if (size < 0) {
+        goto out;
+    }
+    buf[size] = 0;
+
+    pos = buf;
+    while (true) {
+        pos = strstr(pos, PROC_STATUS_TGID_FIELD);
+        /* Stop if TGID tag not found or found at the line beginning */
+        if (pos == NULL || pos == buf || pos[-1] == '\n') {
+            break;
+        }
+        pos++;
+    }
+
+    if (pos == NULL) {
+        goto out;
+    }
+
+    pos += strlen(PROC_STATUS_TGID_FIELD);
+    while (*pos == ' ') pos++;
+    parse_int64(pos, &tgid);
+
+out:
+    close(fd);
+    return (int)tgid;
+}
+
 static void cmd_procprio(LMKD_CTRL_PACKET packet) {
     struct proc *procp;
     char path[80];
@@ -559,6 +603,7 @@
     struct lmk_procprio params;
     bool is_system_server;
     struct passwd *pwdrec;
+    int tgid;
 
     lmkd_pack_get_procprio(packet, &params);
 
@@ -568,6 +613,14 @@
         return;
     }
 
+    /* Check if registered process is a thread group leader */
+    tgid = proc_get_tgid(params.pid);
+    if (tgid >= 0 && tgid != params.pid) {
+        ALOGE("Attempt to register a task that is not a thread group leader (tid %d, tgid %d)",
+            params.pid, tgid);
+        return;
+    }
+
     /* gid containing AID_READPROC required */
     /* CAP_SYS_RESOURCE required */
     /* CAP_DAC_OVERRIDE required */
@@ -1332,6 +1385,7 @@
 static int kill_one_process(struct proc* procp, int min_oom_score) {
     int pid = procp->pid;
     uid_t uid = procp->uid;
+    int tgid;
     char *taskname;
     int tasksize;
     int r;
@@ -1345,6 +1399,12 @@
     (void)(min_oom_score);
 #endif
 
+    tgid = proc_get_tgid(pid);
+    if (tgid >= 0 && tgid != pid) {
+        ALOGE("Possible pid reuse detected (pid %d, tgid %d)!", pid, tgid);
+        goto out;
+    }
+
     taskname = proc_get_name(pid);
     if (!taskname) {
         goto out;