boot into recovery via the pre-recovery service

Change PowerManagerService to start the pre-recovery service rather
than rebooting directly, when requested to reboot into recovery.  Add
a new RECOVERY permission which a caller needs (in addition to REBOOT)
in order to go to recovery.

Bug: 12188746
Change-Id: I39121b701c4724558fe751adfbad79f8567faa43

1 files changed, 24 insertions, 5 deletions

diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index 7f03cc0..3692d76 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -1830,9 +1830,10 @@ public final class PowerManagerService extends com.android.server.SystemService
     }
 
     /**
-     * Low-level function to reboot the device. On success, this function
-     * doesn't return. If more than 5 seconds passes from the time,
-     * a reboot is requested, this method returns.
+     * Low-level function to reboot the device. On success, this
+     * function doesn't return. If more than 20 seconds passes from
+     * the time a reboot is requested (120 seconds for reboot to
+     * recovery), this method returns.
      *
      * @param reason code to pass to the kernel (e.g. "recovery"), or null.
      */
@@ -1840,9 +1841,24 @@ public final class PowerManagerService extends com.android.server.SystemService
         if (reason == null) {
             reason = "";
         }
-        SystemProperties.set("sys.powerctl", "reboot," + reason);
+        long duration;
+        if (reason.equals(PowerManager.REBOOT_RECOVERY)) {
+            // If we are rebooting to go into recovery, instead of
+            // setting sys.powerctl directly we'll start the
+            // pre-recovery service which will do some preparation for
+            // recovery and then reboot for us.
+            //
+            // This preparation can take more than 20 seconds if
+            // there's a very large update package, so lengthen the
+            // timeout.
+            SystemProperties.set("ctl.start", "pre-recovery");
+            duration = 120 * 1000L;
+        } else {
+            SystemProperties.set("sys.powerctl", "reboot," + reason);
+            duration = 20 * 1000L;
+        }
         try {
-            Thread.sleep(20000);
+            Thread.sleep(duration);
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
         }
@@ -2524,6 +2540,9 @@ public final class PowerManagerService extends com.android.server.SystemService
         @Override // Binder call
         public void reboot(boolean confirm, String reason, boolean wait) {
             mContext.enforceCallingOrSelfPermission(android.Manifest.permission.REBOOT, null);
+            if (PowerManager.REBOOT_RECOVERY.equals(reason)) {
+                mContext.enforceCallingOrSelfPermission(android.Manifest.permission.RECOVERY, null);
+            }
 
             final long ident = Binder.clearCallingIdentity();
             try {