Introduce static @hide PowerManager.isRebootingUserspaceSupportedImpl()

This method consolidates logic of testing whenever rebooting userspace
is supported in a place that can be used both from
PowerMager.isRebootingUserspaceSupported() API and from
PowerManagerService.reboot() implementation.

Consequently, this makes `adb shell svc power reboot userspace` also
benefit from that check, and fail userspace reboot on devices that don't
support it.

Also tweaked logic of ignoring RemoteException to take into account
userspace reboot.

Test: adb root
Test: adb shell setprop init.userspace_reboot.is_supported 0
Test: adb shell svc power reboot userspace & verified error message
Test: adb shell setprop init.userspace_reboot.is_supported 1
Test: adb shell svc power reboot userspace & verified no error message
Test: atest PowerManagerTest
Test: atest CtsUserspaceRebootHostSideTestCases
Bug: 152803929
Change-Id: I2d3a8e0ae1320c408a838c5c5fdf4cd977b167b3
Merged-In: I2d3a8e0ae1320c408a838c5c5fdf4cd977b167b3
(cherry picked from commit 57300d9057)

cmds/svc/src/com/android/commands/svc/PowerCommand.java

@@ -24,6 +24,7 @@ import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.SystemClock;
 import android.os.SystemProperties;
+import android.sysprop.InitProperties;
 
 public class PowerCommand extends Svc.Command {
     private static final int FORCE_SUSPEND_DELAY_DEFAULT_MILLIS = 0;
@@ -103,6 +104,8 @@ public class PowerCommand extends Svc.Command {
                         pm.reboot(false, mode, true);
                     } catch (RemoteException e) {
                         maybeLogRemoteException("Failed to reboot.");
+                    } catch (Exception e) {
+                        System.err.println("Failed to reboot: " + e.getMessage());
                     }
                     return;
                 } else if ("shutdown".equals(args[1])) {
@@ -138,7 +141,9 @@ public class PowerCommand extends Svc.Command {
     // if it is already in shutdown flow.
     private void maybeLogRemoteException(String msg) {
         String powerProp = SystemProperties.get("sys.powerctl");
-        if (powerProp.isEmpty()) {
+        // Also check if userspace reboot is ongoing, since in case of userspace reboot value of the
+        // sys.powerctl property will be reset.
+        if (powerProp.isEmpty() && !InitProperties.userspace_reboot_in_progress().orElse(false)) {
             System.err.println(msg);
         }
     }

core/java/android/os/PowerManager.java

@@ -1332,12 +1332,25 @@ public final class PowerManager {
         }
     }
 
+
+    /**
+     * Returns {@code true} if this device supports rebooting userspace.
+     *
+     * <p>This method exists solely for the sake of re-using same logic between {@code PowerManager}
+     * and {@code PowerManagerService}.
+     *
+     * @hide
+     */
+    public static boolean isRebootingUserspaceSupportedImpl() {
+        return InitProperties.is_userspace_reboot_supported().orElse(false);
+    }
+
     /**
      * Returns {@code true} if this device supports rebooting userspace.
      */
     // TODO(b/138605180): add link to documentation once it's ready.
     public boolean isRebootingUserspaceSupported() {
-        return InitProperties.is_userspace_reboot_supported().orElse(false);
+        return isRebootingUserspaceSupportedImpl();
     }
 
     /**

services/core/java/com/android/server/power/PowerManagerService.java

@@ -2838,6 +2838,10 @@ public final class PowerManagerService extends SystemService
     private void shutdownOrRebootInternal(final @HaltMode int haltMode, final boolean confirm,
             @Nullable final String reason, boolean wait) {
         if (PowerManager.REBOOT_USERSPACE.equals(reason)) {
+            if (!PowerManager.isRebootingUserspaceSupportedImpl()) {
+                throw new UnsupportedOperationException(
+                        "Attempted userspace reboot on a device that doesn't support it");
+            }
             UserspaceRebootLogger.noteUserspaceRebootWasRequested();
         }
         if (mHandler == null || !mSystemReady) {