Merge "Add a skeleton of userspace reboot"

init/init.cpp

@@ -98,7 +98,6 @@ static int property_fd = -1;
 static std::unique_ptr<Timer> waiting_for_prop(nullptr);
 static std::string wait_prop_name;
 static std::string wait_prop_value;
-static bool shutting_down;
 static std::string shutdown_command;
 static bool do_shutdown = false;
 static bool load_debug_prop = false;
@@ -624,7 +623,15 @@ 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();
+        LOG(ERROR) << "Failed to send 'stop sending messages' message: " << result.error();
+    }
+}
+
+void SendStartSendingMessagesMessage() {
+    auto init_message = InitMessage{};
+    init_message.set_start_sending_messages(true);
+    if (auto result = SendMessage(property_fd, init_message); !result) {
+        LOG(ERROR) << "Failed to send 'start sending messages' message: " << result.error();
     }
 }
 
@@ -811,18 +818,16 @@ int SecondStageMain(int argc, char** argv) {
         // By default, sleep until something happens.
         auto epoll_timeout = std::optional<std::chrono::milliseconds>{};
 
-        if (do_shutdown && !shutting_down) {
+        if (do_shutdown && !IsShuttingDown()) {
             do_shutdown = false;
-            if (HandlePowerctlMessage(shutdown_command)) {
-                shutting_down = true;
-            }
+            HandlePowerctlMessage(shutdown_command);
         }
 
         if (!(waiting_for_prop || Service::is_exec_service_running())) {
             am.ExecuteOneCommand();
         }
         if (!(waiting_for_prop || Service::is_exec_service_running())) {
-            if (!shutting_down) {
+            if (!IsShuttingDown()) {
                 auto next_process_action_time = HandleProcessActions();
 
                 // If there's a process that needs restarting, wake up in time for that.

init/init.h

@@ -41,6 +41,7 @@ void ResetWaitForProp();
 
 void SendLoadPersistentPropertiesMessage();
 void SendStopSendingMessagesMessage();
+void SendStartSendingMessagesMessage();
 
 int SecondStageMain(int argc, char** argv);
 

init/property_service.cpp

@@ -93,6 +93,7 @@ static bool persistent_properties_loaded = false;
 
 static int property_set_fd = -1;
 static int init_socket = -1;
+static bool accept_messages = false;
 
 static PropertyInfoAreaFile property_info_area;
 
@@ -211,7 +212,7 @@ static uint32_t PropertySet(const std::string& name, const std::string& value, s
     }
     // 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) {
+    if (accept_messages) {
         SendPropertyChanged(name, value);
     }
     return PROP_SUCCESS;
@@ -389,7 +390,7 @@ class 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) {
+    if (!accept_messages) {
         *error = "Received control message after shutdown, ignoring";
         return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
     }
@@ -1035,7 +1036,11 @@ static void HandleInitSocket() {
             break;
         }
         case InitMessage::kStopSendingMessages: {
-            init_socket = -1;
+            accept_messages = false;
+            break;
+        }
+        case InitMessage::kStartSendingMessages: {
+            accept_messages = true;
             break;
         }
         default:
@@ -1078,6 +1083,7 @@ void StartPropertyService(int* epoll_socket) {
     }
     *epoll_socket = sockets[0];
     init_socket = sockets[1];
+    accept_messages = true;
 
     if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
                                    false, 0666, 0, 0, {})) {

init/property_service.proto

@@ -40,5 +40,6 @@ message InitMessage {
     oneof msg {
         bool load_persistent_properties = 1;
         bool stop_sending_messages = 2;
+        bool start_sending_messages = 3;
     };
 }

init/reboot.cpp

@@ -50,7 +50,9 @@
 #include <private/android_filesystem_config.h>
 #include <selinux/selinux.h>
 
+#include "action.h"
 #include "action_manager.h"
+#include "builtin_arguments.h"
 #include "init.h"
 #include "property_service.h"
 #include "reboot_utils.h"
@@ -71,6 +73,8 @@ using android::base::WriteStringToFile;
 namespace android {
 namespace init {
 
+static bool shutting_down = false;
+
 // represents umount status during reboot / shutdown.
 enum UmountStat {
     /* umount succeeded. */
@@ -655,12 +659,58 @@ static void DoReboot(unsigned int cmd, const std::string& reason, const std::str
     abort();
 }
 
-bool HandlePowerctlMessage(const std::string& command) {
+static void EnterShutdown() {
+    shutting_down = true;
+    // Skip wait for prop if it is in progress
+    ResetWaitForProp();
+    // Clear EXEC flag if there is one pending
+    for (const auto& s : ServiceList::GetInstance()) {
+        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();
+}
+
+static void LeaveShutdown() {
+    shutting_down = false;
+    SendStartSendingMessagesMessage();
+}
+
+static void DoUserspaceReboot() {
+    // Triggering userspace-reboot-requested will result in a bunch of set_prop
+    // actions. We should make sure, that all of them are propagated before
+    // proceeding with userspace reboot.
+    // TODO(b/135984674): implement proper synchronization logic.
+    std::this_thread::sleep_for(500ms);
+    EnterShutdown();
+    // TODO(b/135984674): tear down post-data services
+    LeaveShutdown();
+    // TODO(b/135984674): remount userdata
+    ActionManager::GetInstance().QueueEventTrigger("userspace-reboot-resume");
+}
+
+static void HandleUserspaceReboot() {
+    LOG(INFO) << "Clearing queue and starting userspace-reboot-requested trigger";
+    auto& am = ActionManager::GetInstance();
+    am.ClearQueue();
+    am.QueueEventTrigger("userspace-reboot-requested");
+    auto handler = [](const BuiltinArguments&) {
+        DoUserspaceReboot();
+        return Result<void>{};
+    };
+    am.QueueBuiltinAction(handler, "userspace-reboot");
+}
+
+void HandlePowerctlMessage(const std::string& command) {
     unsigned int cmd = 0;
     std::vector<std::string> cmd_params = Split(command, ",");
     std::string reboot_target = "";
     bool run_fsck = false;
     bool command_invalid = false;
+    bool userspace_reboot = false;
 
     if (cmd_params[0] == "shutdown") {
         cmd = ANDROID_RB_POWEROFF;
@@ -680,6 +730,10 @@ bool HandlePowerctlMessage(const std::string& command) {
         cmd = ANDROID_RB_RESTART2;
         if (cmd_params.size() >= 2) {
             reboot_target = cmd_params[1];
+            if (reboot_target == "userspace") {
+                LOG(INFO) << "Userspace reboot requested";
+                userspace_reboot = true;
+            }
             // adb reboot fastboot should boot into bootloader for devices not
             // supporting logical partitions.
             if (reboot_target == "fastboot" &&
@@ -706,7 +760,7 @@ bool HandlePowerctlMessage(const std::string& command) {
                     strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
                     if (std::string err; !write_bootloader_message(boot, &err)) {
                         LOG(ERROR) << "Failed to set bootloader message: " << err;
-                        return false;
+                        return;
                     }
                 }
             } else if (reboot_target == "sideload" || reboot_target == "sideload-auto-reboot" ||
@@ -719,7 +773,7 @@ bool HandlePowerctlMessage(const std::string& command) {
                 std::string err;
                 if (!write_bootloader_message(options, &err)) {
                     LOG(ERROR) << "Failed to set bootloader message: " << err;
-                    return false;
+                    return;
                 }
                 reboot_target = "recovery";
             }
@@ -734,7 +788,12 @@ bool HandlePowerctlMessage(const std::string& command) {
     }
     if (command_invalid) {
         LOG(ERROR) << "powerctl: unrecognized command '" << command << "'";
-        return false;
+        return;
+    }
+
+    if (userspace_reboot) {
+        HandleUserspaceReboot();
+        return;
     }
 
     LOG(INFO) << "Clear action queue and start shutdown trigger";
@@ -748,21 +807,11 @@ bool HandlePowerctlMessage(const std::string& command) {
     };
     ActionManager::GetInstance().QueueBuiltinAction(shutdown_handler, "shutdown_done");
 
-    // Skip wait for prop if it is in progress
-    ResetWaitForProp();
+    EnterShutdown();
+}
 
-    // Clear EXEC flag if there is one pending
-    for (const auto& s : ServiceList::GetInstance()) {
-        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;
+bool IsShuttingDown() {
+    return shutting_down;
 }
 
 }  // namespace init

init/reboot.h

@@ -23,8 +23,9 @@ namespace android {
 namespace init {
 
 // Parses and handles a setprop sys.powerctl message.
-bool HandlePowerctlMessage(const std::string& command);
+void HandlePowerctlMessage(const std::string& command);
 
+bool IsShuttingDown();
 }  // namespace init
 }  // namespace android
 

rootdir/init.rc

@@ -917,3 +917,15 @@ on property:ro.debuggable=1
 
 on init && property:ro.debuggable=1
     start console
+
+on userspace-reboot:
+  # TODO(b/135984674): reset all necessary properties here.
+  setprop sys.init.userspace_reboot_in_progress 1
+
+on userspace-reboot-resume:
+  # TODO(b/135984674): remount userdata and reset checkpointing
+  trigger nonencrypted
+  trigger post-fs-data
+  trigger zygote-start
+  trigger early-boot
+  trigger boot