Merge "Reland^2: "init: run property service in a thread""
diff --git a/init/Android.bp b/init/Android.bp
index 52cd1ca..9c4b5b9 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -129,6 +129,7 @@
         "persistent_properties.cpp",
         "persistent_properties.proto",
         "property_service.cpp",
+        "property_service.proto",
         "property_type.cpp",
         "reboot.cpp",
         "reboot_utils.cpp",
diff --git a/init/builtins.cpp b/init/builtins.cpp
index d2c73cb..21db8dc 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -80,6 +80,7 @@
 using namespace std::literals::string_literals;
 
 using android::base::Basename;
+using android::base::StartsWith;
 using android::base::StringPrintf;
 using android::base::unique_fd;
 using android::fs_mgr::Fstab;
@@ -701,6 +702,15 @@
 }
 
 static Result<void> do_setprop(const BuiltinArguments& args) {
+    if (StartsWith(args[1], "ctl.")) {
+        return Error()
+               << "Cannot set ctl. properties from init; call the Service functions directly";
+    }
+    if (args[1] == kRestoreconProperty) {
+        return Error() << "Cannot set '" << kRestoreconProperty
+                       << "' from init; use the restorecon builtin directly";
+    }
+
     property_set(args[1], args[2]);
     return {};
 }
@@ -1016,7 +1026,20 @@
 }
 
 static Result<void> do_load_persist_props(const BuiltinArguments& args) {
-    load_persist_props();
+    // Devices with FDE have load_persist_props called twice; the first time when the temporary
+    // /data partition is mounted and then again once /data is truly mounted.  We do not want to
+    // read persistent properties from the temporary /data partition or mark persistent properties
+    // as having been loaded during the first call, so we return in that case.
+    std::string crypto_state = android::base::GetProperty("ro.crypto.state", "");
+    std::string crypto_type = android::base::GetProperty("ro.crypto.type", "");
+    if (crypto_state == "encrypted" && crypto_type == "block") {
+        static size_t num_calls = 0;
+        if (++num_calls == 1) return {};
+    }
+
+    SendLoadPersistentPropertiesMessage();
+
+    start_waiting_for_property("ro.persistent_properties.ready", "true");
     return {};
 }
 
diff --git a/init/init.cpp b/init/init.cpp
index 1f74ab6..4e9a14f 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -28,6 +28,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
+#include <sys/_system_properties.h>
+
 #include <functional>
 #include <map>
 #include <memory>
@@ -60,6 +63,7 @@
 #include "mount_handler.h"
 #include "mount_namespace.h"
 #include "property_service.h"
+#include "proto_utils.h"
 #include "reboot.h"
 #include "reboot_utils.h"
 #include "security.h"
@@ -68,6 +72,7 @@
 #include "service.h"
 #include "service_parser.h"
 #include "sigchld_handler.h"
+#include "system/core/init/property_service.pb.h"
 #include "util.h"
 
 using namespace std::chrono_literals;
@@ -89,6 +94,7 @@
 static char qemu[32];
 
 static int signal_fd = -1;
+static int property_fd = -1;
 
 static std::unique_ptr<Timer> waiting_for_prop(nullptr);
 static std::string wait_prop_name;
@@ -614,6 +620,60 @@
                                 selinux_start_time_ns));
 }
 
+void SendLoadPersistentPropertiesMessage() {
+    auto init_message = InitMessage{};
+    init_message.set_load_persistent_properties(true);
+    if (auto result = SendMessage(property_fd, init_message); !result) {
+        LOG(ERROR) << "Failed to send load persistent properties message: " << result.error();
+    }
+}
+
+void SendStopSendingMessagesMessage() {
+    auto init_message = InitMessage{};
+    init_message.set_stop_sending_messages(true);
+    if (auto result = SendMessage(property_fd, init_message); !result) {
+        LOG(ERROR) << "Failed to send load persistent properties message: " << result.error();
+    }
+}
+
+static void HandlePropertyFd() {
+    auto message = ReadMessage(property_fd);
+    if (!message) {
+        LOG(ERROR) << "Could not read message from property service: " << message.error();
+        return;
+    }
+
+    auto property_message = PropertyMessage{};
+    if (!property_message.ParseFromString(*message)) {
+        LOG(ERROR) << "Could not parse message from property service";
+        return;
+    }
+
+    switch (property_message.msg_case()) {
+        case PropertyMessage::kControlMessage: {
+            auto& control_message = property_message.control_message();
+            bool success = HandleControlMessage(control_message.msg(), control_message.name(),
+                                                control_message.pid());
+
+            uint32_t response = success ? PROP_SUCCESS : PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+            if (control_message.has_fd()) {
+                int fd = control_message.fd();
+                TEMP_FAILURE_RETRY(send(fd, &response, sizeof(response), 0));
+                close(fd);
+            }
+            break;
+        }
+        case PropertyMessage::kChangedMessage: {
+            auto& changed_message = property_message.changed_message();
+            property_changed(changed_message.name(), changed_message.value());
+            break;
+        }
+        default:
+            LOG(ERROR) << "Unknown message type from property service: "
+                       << property_message.msg_case();
+    }
+}
+
 int SecondStageMain(int argc, char** argv) {
     if (REBOOT_BOOTLOADER_ON_PANIC) {
         InstallRebootSignalHandlers();
@@ -685,7 +745,12 @@
     UmountDebugRamdisk();
     fs_mgr_vendor_overlay_mount_all();
     export_oem_lock_status();
-    StartPropertyService(&epoll);
+
+    StartPropertyService(&property_fd);
+    if (auto result = epoll.RegisterHandler(property_fd, HandlePropertyFd); !result) {
+        LOG(FATAL) << "Could not register epoll handler for property fd: " << result.error();
+    }
+
     MountHandler mount_handler(&epoll);
     set_usb_controller();
 
diff --git a/init/init.h b/init/init.h
index cfc28f1..8ac52e2 100644
--- a/init/init.h
+++ b/init/init.h
@@ -31,16 +31,15 @@
 Parser CreateParser(ActionManager& action_manager, ServiceList& service_list);
 Parser CreateServiceOnlyParser(ServiceList& service_list);
 
-bool HandleControlMessage(const std::string& msg, const std::string& arg, pid_t pid);
-
-void property_changed(const std::string& name, const std::string& value);
-
 bool start_waiting_for_property(const char *name, const char *value);
 
 void DumpState();
 
 void ResetWaitForProp();
 
+void SendLoadPersistentPropertiesMessage();
+void SendStopSendingMessagesMessage();
+
 int SecondStageMain(int argc, char** argv);
 
 }  // namespace init
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 3408ff3..c18decc 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -42,6 +42,7 @@
 #include <map>
 #include <memory>
 #include <mutex>
+#include <optional>
 #include <queue>
 #include <thread>
 #include <vector>
@@ -63,8 +64,10 @@
 #include "init.h"
 #include "persistent_properties.h"
 #include "property_type.h"
+#include "proto_utils.h"
 #include "selinux.h"
 #include "subcontext.h"
+#include "system/core/init/property_service.pb.h"
 #include "util.h"
 
 using namespace std::literals;
@@ -76,6 +79,7 @@
 using android::base::StringPrintf;
 using android::base::Timer;
 using android::base::Trim;
+using android::base::unique_fd;
 using android::base::WriteStringToFile;
 using android::properties::BuildTrie;
 using android::properties::ParsePropertyInfoFile;
@@ -85,18 +89,13 @@
 namespace android {
 namespace init {
 
-static constexpr const char kRestoreconProperty[] = "selinux.restorecon_recursive";
-
 static bool persistent_properties_loaded = false;
 
 static int property_set_fd = -1;
+static int init_socket = -1;
 
 static PropertyInfoAreaFile property_info_area;
 
-uint32_t InitPropertySet(const std::string& name, const std::string& value);
-
-uint32_t (*property_set)(const std::string& name, const std::string& value) = InitPropertySet;
-
 void CreateSerializedPropertyInfo();
 
 struct PropertyAuditData {
@@ -164,6 +163,17 @@
     return has_access;
 }
 
+static void SendPropertyChanged(const std::string& name, const std::string& value) {
+    auto property_msg = PropertyMessage{};
+    auto* changed_message = property_msg.mutable_changed_message();
+    changed_message->set_name(name);
+    changed_message->set_value(value);
+
+    if (auto result = SendMessage(init_socket, property_msg); !result) {
+        LOG(ERROR) << "Failed to send property changed message: " << result.error();
+    }
+}
+
 static uint32_t PropertySet(const std::string& name, const std::string& value, std::string* error) {
     size_t valuelen = value.size();
 
@@ -199,7 +209,11 @@
     if (persistent_properties_loaded && StartsWith(name, "persist.")) {
         WritePersistentProperty(name, value);
     }
-    property_changed(name, value);
+    // If init hasn't started its main loop, then it won't be handling property changed messages
+    // anyway, so there's no need to try to send them.
+    if (init_socket != -1) {
+        SendPropertyChanged(name, value);
+    }
     return PROP_SUCCESS;
 }
 
@@ -239,35 +253,10 @@
     bool thread_started_ = false;
 };
 
-uint32_t InitPropertySet(const std::string& name, const std::string& value) {
-    if (StartsWith(name, "ctl.")) {
-        LOG(ERROR) << "InitPropertySet: Do not set ctl. properties from init; call the Service "
-                      "functions directly";
-        return PROP_ERROR_INVALID_NAME;
-    }
-    if (name == kRestoreconProperty) {
-        LOG(ERROR) << "InitPropertySet: Do not set '" << kRestoreconProperty
-                   << "' from init; use the restorecon builtin directly";
-        return PROP_ERROR_INVALID_NAME;
-    }
-
-    uint32_t result = 0;
-    ucred cr = {.pid = 1, .uid = 0, .gid = 0};
-    std::string error;
-    result = HandlePropertySet(name, value, kInitContext.c_str(), cr, &error);
-    if (result != PROP_SUCCESS) {
-        LOG(ERROR) << "Init cannot set '" << name << "' to '" << value << "': " << error;
-    }
-
-    return result;
-}
-
 class SocketConnection {
   public:
     SocketConnection(int socket, const ucred& cred) : socket_(socket), cred_(cred) {}
 
-    ~SocketConnection() { close(socket_); }
-
     bool RecvUint32(uint32_t* value, uint32_t* timeout_ms) {
         return RecvFully(value, sizeof(*value), timeout_ms);
     }
@@ -304,6 +293,9 @@
     }
 
     bool SendUint32(uint32_t value) {
+        if (!socket_.ok()) {
+            return true;
+        }
         int result = TEMP_FAILURE_RETRY(send(socket_, &value, sizeof(value), 0));
         return result == sizeof(value);
     }
@@ -318,7 +310,7 @@
         return true;
     }
 
-    int socket() { return socket_; }
+    [[nodiscard]] int Release() { return socket_.release(); }
 
     const ucred& cred() { return cred_; }
 
@@ -389,12 +381,46 @@
         return bytes_left == 0;
     }
 
-    int socket_;
+    unique_fd socket_;
     ucred cred_;
 
     DISALLOW_IMPLICIT_CONSTRUCTORS(SocketConnection);
 };
 
+static uint32_t SendControlMessage(const std::string& msg, const std::string& name, pid_t pid,
+                                   SocketConnection* socket, std::string* error) {
+    if (init_socket == -1) {
+        *error = "Received control message after shutdown, ignoring";
+        return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+    }
+
+    auto property_msg = PropertyMessage{};
+    auto* control_message = property_msg.mutable_control_message();
+    control_message->set_msg(msg);
+    control_message->set_name(name);
+    control_message->set_pid(pid);
+
+    // We must release the fd before sending it to init, otherwise there will be a race with init.
+    // If init calls close() before Release(), then fdsan will see the wrong tag and abort().
+    int fd = -1;
+    if (socket != nullptr) {
+        fd = socket->Release();
+        control_message->set_fd(fd);
+    }
+
+    if (auto result = SendMessage(init_socket, property_msg); !result) {
+        // We've already released the fd above, so if we fail to send the message to init, we need
+        // to manually free it here.
+        if (fd != -1) {
+            close(fd);
+        }
+        *error = "Failed to send control message: " + result.error().message();
+        return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+    }
+
+    return PROP_SUCCESS;
+}
+
 bool CheckControlPropertyPerms(const std::string& name, const std::string& value,
                                const std::string& source_context, const ucred& cr) {
     // We check the legacy method first but these properties are dontaudit, so we only log an audit
@@ -462,15 +488,14 @@
 
 // This returns one of the enum of PROP_SUCCESS or PROP_ERROR*.
 uint32_t HandlePropertySet(const std::string& name, const std::string& value,
-                           const std::string& source_context, const ucred& cr, std::string* error) {
+                           const std::string& source_context, const ucred& cr,
+                           SocketConnection* socket, std::string* error) {
     if (auto ret = CheckPermissions(name, value, source_context, cr, error); ret != PROP_SUCCESS) {
         return ret;
     }
 
     if (StartsWith(name, "ctl.")) {
-        return HandleControlMessage(name.c_str() + 4, value, cr.pid)
-                       ? PROP_SUCCESS
-                       : PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+        return SendControlMessage(name.c_str() + 4, value, cr.pid, socket, error);
     }
 
     // sys.powerctl is a special property that is used to make the device reboot.  We want to log
@@ -501,6 +526,20 @@
     return PropertySet(name, value, error);
 }
 
+uint32_t InitPropertySet(const std::string& name, const std::string& value) {
+    uint32_t result = 0;
+    ucred cr = {.pid = 1, .uid = 0, .gid = 0};
+    std::string error;
+    result = HandlePropertySet(name, value, kInitContext.c_str(), cr, nullptr, &error);
+    if (result != PROP_SUCCESS) {
+        LOG(ERROR) << "Init cannot set '" << name << "' to '" << value << "': " << error;
+    }
+
+    return result;
+}
+
+uint32_t (*property_set)(const std::string& name, const std::string& value) = InitPropertySet;
+
 static void handle_property_set_fd() {
     static constexpr uint32_t kDefaultSocketTimeout = 2000; /* ms */
 
@@ -549,7 +588,8 @@
 
         const auto& cr = socket.cred();
         std::string error;
-        uint32_t result = HandlePropertySet(prop_name, prop_value, source_context, cr, &error);
+        uint32_t result =
+                HandlePropertySet(prop_name, prop_value, source_context, cr, nullptr, &error);
         if (result != PROP_SUCCESS) {
             LOG(ERROR) << "Unable to set property '" << prop_name << "' from uid:" << cr.uid
                        << " gid:" << cr.gid << " pid:" << cr.pid << ": " << error;
@@ -577,7 +617,7 @@
 
         const auto& cr = socket.cred();
         std::string error;
-        uint32_t result = HandlePropertySet(name, value, source_context, cr, &error);
+        uint32_t result = HandlePropertySet(name, value, source_context, cr, &socket, &error);
         if (result != PROP_SUCCESS) {
             LOG(ERROR) << "Unable to set property '" << name << "' from uid:" << cr.uid
                        << " gid:" << cr.gid << " pid:" << cr.pid << ": " << error;
@@ -741,33 +781,6 @@
     }
 }
 
-/* When booting an encrypted system, /data is not mounted when the
- * property service is started, so any properties stored there are
- * not loaded.  Vold triggers init to load these properties once it
- * has mounted /data.
- */
-void load_persist_props(void) {
-    // Devices with FDE have load_persist_props called twice; the first time when the temporary
-    // /data partition is mounted and then again once /data is truly mounted.  We do not want to
-    // read persistent properties from the temporary /data partition or mark persistent properties
-    // as having been loaded during the first call, so we return in that case.
-    std::string crypto_state = android::base::GetProperty("ro.crypto.state", "");
-    std::string crypto_type = android::base::GetProperty("ro.crypto.type", "");
-    if (crypto_state == "encrypted" && crypto_type == "block") {
-        static size_t num_calls = 0;
-        if (++num_calls == 1) return;
-    }
-
-    load_override_properties();
-    /* Read persistent properties after all default values have been loaded. */
-    auto persistent_properties = LoadPersistentProperties();
-    for (const auto& persistent_property_record : persistent_properties.properties()) {
-        property_set(persistent_property_record.name(), persistent_property_record.value());
-    }
-    persistent_properties_loaded = true;
-    property_set("ro.persistent_properties.ready", "true");
-}
-
 // If the ro.product.[brand|device|manufacturer|model|name] properties have not been explicitly
 // set, derive them from ro.product.${partition}.* properties
 static void property_initialize_ro_product_props() {
@@ -985,21 +998,92 @@
     selinux_android_restorecon(kPropertyInfosPath, 0);
 }
 
-void StartPropertyService(Epoll* epoll) {
+static void HandleInitSocket() {
+    auto message = ReadMessage(init_socket);
+    if (!message) {
+        LOG(ERROR) << "Could not read message from init_dedicated_recv_socket: " << message.error();
+        return;
+    }
+
+    auto init_message = InitMessage{};
+    if (!init_message.ParseFromString(*message)) {
+        LOG(ERROR) << "Could not parse message from init";
+        return;
+    }
+
+    switch (init_message.msg_case()) {
+        case InitMessage::kLoadPersistentProperties: {
+            load_override_properties();
+            // Read persistent properties after all default values have been loaded.
+            auto persistent_properties = LoadPersistentProperties();
+            for (const auto& persistent_property_record : persistent_properties.properties()) {
+                InitPropertySet(persistent_property_record.name(),
+                                persistent_property_record.value());
+            }
+            InitPropertySet("ro.persistent_properties.ready", "true");
+            persistent_properties_loaded = true;
+            break;
+        }
+        case InitMessage::kStopSendingMessages: {
+            init_socket = -1;
+            break;
+        }
+        default:
+            LOG(ERROR) << "Unknown message type from init: " << init_message.msg_case();
+    }
+}
+
+static void PropertyServiceThread() {
+    Epoll epoll;
+    if (auto result = epoll.Open(); !result) {
+        LOG(FATAL) << result.error();
+    }
+
+    if (auto result = epoll.RegisterHandler(property_set_fd, handle_property_set_fd); !result) {
+        LOG(FATAL) << result.error();
+    }
+
+    if (auto result = epoll.RegisterHandler(init_socket, HandleInitSocket); !result) {
+        LOG(FATAL) << result.error();
+    }
+
+    while (true) {
+        auto pending_functions = epoll.Wait(std::nullopt);
+        if (!pending_functions) {
+            LOG(ERROR) << pending_functions.error();
+        } else {
+            for (const auto& function : *pending_functions) {
+                (*function)();
+            }
+        }
+    }
+}
+
+void StartPropertyService(int* epoll_socket) {
     property_set("ro.property_service.version", "2");
 
+    int sockets[2];
+    if (socketpair(AF_UNIX, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != 0) {
+        PLOG(FATAL) << "Failed to socketpair() between property_service and init";
+    }
+    *epoll_socket = sockets[0];
+    init_socket = sockets[1];
+
     if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
                                    false, 0666, 0, 0, {})) {
         property_set_fd = *result;
     } else {
-        PLOG(FATAL) << "start_property_service socket creation failed: " << result.error();
+        LOG(FATAL) << "start_property_service socket creation failed: " << result.error();
     }
 
     listen(property_set_fd, 8);
 
-    if (auto result = epoll->RegisterHandler(property_set_fd, handle_property_set_fd); !result) {
-        PLOG(FATAL) << result.error();
-    }
+    std::thread{PropertyServiceThread}.detach();
+
+    property_set = [](const std::string& key, const std::string& value) -> uint32_t {
+        android::base::SetProperty(key, value);
+        return 0;
+    };
 }
 
 }  // namespace init
diff --git a/init/property_service.h b/init/property_service.h
index 7f9f844..8f7d8d9 100644
--- a/init/property_service.h
+++ b/init/property_service.h
@@ -25,17 +25,15 @@
 namespace android {
 namespace init {
 
+static constexpr const char kRestoreconProperty[] = "selinux.restorecon_recursive";
+
 bool CanReadProperty(const std::string& source_context, const std::string& name);
 
 extern uint32_t (*property_set)(const std::string& name, const std::string& value);
 
-uint32_t HandlePropertySet(const std::string& name, const std::string& value,
-                           const std::string& source_context, const ucred& cr, std::string* error);
-
 void property_init();
 void property_load_boot_defaults(bool load_debug_prop);
-void load_persist_props();
-void StartPropertyService(Epoll* epoll);
+void StartPropertyService(int* epoll_socket);
 
 }  // namespace init
 }  // namespace android
diff --git a/init/property_service.proto b/init/property_service.proto
new file mode 100644
index 0000000..ea454d4
--- /dev/null
+++ b/init/property_service.proto
@@ -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.
+ */
+
+syntax = "proto2";
+option optimize_for = LITE_RUNTIME;
+
+message PropertyMessage {
+    message ControlMessage {
+        optional string msg = 1;
+        optional string name = 2;
+        optional int32 pid = 3;
+        optional int32 fd = 4;
+    }
+
+    message ChangedMessage {
+        optional string name = 1;
+        optional string value = 2;
+    }
+
+    oneof msg {
+        ControlMessage control_message = 1;
+        ChangedMessage changed_message = 2;
+    };
+}
+
+message InitMessage {
+    oneof msg {
+        bool load_persistent_properties = 1;
+        bool stop_sending_messages = 2;
+    };
+}
diff --git a/init/proto_utils.h b/init/proto_utils.h
new file mode 100644
index 0000000..93a7d57
--- /dev/null
+++ b/init/proto_utils.h
@@ -0,0 +1,62 @@
+/*
+ * 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 <sys/socket.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "result.h"
+
+namespace android {
+namespace init {
+
+constexpr size_t kBufferSize = 4096;
+
+inline Result<std::string> ReadMessage(int socket) {
+    char buffer[kBufferSize] = {};
+    auto result = TEMP_FAILURE_RETRY(recv(socket, buffer, sizeof(buffer), 0));
+    if (result == 0) {
+        return Error();
+    } else if (result < 0) {
+        return ErrnoError();
+    }
+    return std::string(buffer, result);
+}
+
+template <typename T>
+Result<void> SendMessage(int socket, const T& message) {
+    std::string message_string;
+    if (!message.SerializeToString(&message_string)) {
+        return Error() << "Unable to serialize message";
+    }
+
+    if (message_string.size() > kBufferSize) {
+        return Error() << "Serialized message too long to send";
+    }
+
+    if (auto result =
+                TEMP_FAILURE_RETRY(send(socket, message_string.c_str(), message_string.size(), 0));
+        result != static_cast<long>(message_string.size())) {
+        return ErrnoError() << "send() failed to send message contents";
+    }
+    return {};
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/reboot.cpp b/init/reboot.cpp
index b0b5b54..786a084 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -730,6 +730,12 @@
         s->UnSetExec();
     }
 
+    // We no longer process messages about properties changing coming from property service, so we
+    // need to tell property service to stop sending us these messages, otherwise it'll fill the
+    // buffers and block indefinitely, causing future property sets, including those that init makes
+    // during shutdown in Service::NotifyStateChange() to also block indefinitely.
+    SendStopSendingMessagesMessage();
+
     return true;
 }
 
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index 00f91d8..ec93b58 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -18,16 +18,17 @@
 
 #include <fcntl.h>
 #include <poll.h>
-#include <sys/socket.h>
 #include <unistd.h>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android-base/strings.h>
 #include <selinux/android.h>
 
 #include "action.h"
 #include "builtins.h"
+#include "proto_utils.h"
 #include "util.h"
 
 #if defined(__ANDROID__)
@@ -59,45 +60,6 @@
 
 namespace {
 
-constexpr size_t kBufferSize = 4096;
-
-Result<std::string> ReadMessage(int socket) {
-    char buffer[kBufferSize] = {};
-    auto result = TEMP_FAILURE_RETRY(recv(socket, buffer, sizeof(buffer), 0));
-    if (result == 0) {
-        return Error();
-    } else if (result < 0) {
-        return ErrnoError();
-    }
-    return std::string(buffer, result);
-}
-
-template <typename T>
-Result<void> SendMessage(int socket, const T& message) {
-    std::string message_string;
-    if (!message.SerializeToString(&message_string)) {
-        return Error() << "Unable to serialize message";
-    }
-
-    if (message_string.size() > kBufferSize) {
-        return Error() << "Serialized message too long to send";
-    }
-
-    if (auto result =
-            TEMP_FAILURE_RETRY(send(socket, message_string.c_str(), message_string.size(), 0));
-        result != static_cast<long>(message_string.size())) {
-        return ErrnoError() << "send() failed to send message contents";
-    }
-    return {};
-}
-
-std::vector<std::pair<std::string, std::string>> properties_to_set;
-
-uint32_t SubcontextPropertySet(const std::string& name, const std::string& value) {
-    properties_to_set.emplace_back(name, value);
-    return 0;
-}
-
 class SubcontextProcess {
   public:
     SubcontextProcess(const BuiltinFunctionMap* function_map, std::string context, int init_fd)
@@ -131,14 +93,6 @@
         result = RunBuiltinFunction(map_result->function, args, context_);
     }
 
-    for (const auto& [name, value] : properties_to_set) {
-        auto property = reply->add_properties_to_set();
-        property->set_name(name);
-        property->set_value(value);
-    }
-
-    properties_to_set.clear();
-
     if (result) {
         reply->set_success(true);
     } else {
@@ -224,7 +178,10 @@
 
     SelabelInitialize();
 
-    property_set = SubcontextPropertySet;
+    property_set = [](const std::string& key, const std::string& value) -> uint32_t {
+        android::base::SetProperty(key, value);
+        return 0;
+    };
 
     auto subcontext_process = SubcontextProcess(function_map, context, init_fd);
     subcontext_process.MainLoop();
@@ -311,15 +268,6 @@
         return subcontext_reply.error();
     }
 
-    for (const auto& property : subcontext_reply->properties_to_set()) {
-        ucred cr = {.pid = pid_, .uid = 0, .gid = 0};
-        std::string error;
-        if (HandlePropertySet(property.name(), property.value(), context_, cr, &error) != 0) {
-            LOG(ERROR) << "Subcontext init could not set '" << property.name() << "' to '"
-                       << property.value() << "': " << error;
-        }
-    }
-
     if (subcontext_reply->reply_case() == SubcontextReply::kFailure) {
         auto& failure = subcontext_reply->failure();
         return ResultError(failure.error_string(), failure.error_errno());
diff --git a/init/subcontext.proto b/init/subcontext.proto
index c31f4fb..e68115e 100644
--- a/init/subcontext.proto
+++ b/init/subcontext.proto
@@ -38,10 +38,4 @@
         Failure failure = 2;
         ExpandArgsReply expand_args_reply = 3;
     }
-
-    message PropertyToSet {
-        optional string name = 1;
-        optional string value = 2;
-    }
-    repeated PropertyToSet properties_to_set = 4;
 }
\ No newline at end of file