Support persist.sys.audit_safemode

Don't leave safe more if persist.sys.audit_safemode is set, unless the
current build date is newer than the specified value.

This allows us to keep the device in safe mode across reboots until an
OTA has been applied or user data is wiped.

Bug: 26902605
Change-Id: I781c3059ea8d4fb2f0c923e4488b1932d69678d3

2 files changed, 21 insertions, 2 deletions

diff --git a/services/core/java/com/android/server/power/ShutdownThread.java b/services/core/java/com/android/server/power/ShutdownThread.java
index ac6a28e91ca8..225f9a9b3979 100644
--- a/services/core/java/com/android/server/power/ShutdownThread.java
+++ b/services/core/java/com/android/server/power/ShutdownThread.java
@@ -96,6 +96,9 @@ public final class ShutdownThread extends Thread {
     // Indicates whether we are rebooting into safe mode
     public static final String REBOOT_SAFEMODE_PROPERTY = "persist.sys.safemode";
 
+    // Indicates whether we should stay in safe mode until ro.build.date.utc is newer than this
+    public static final String AUDIT_SAFEMODE_PROPERTY = "persist.sys.audit_safemode";
+
     // static instance of this thread
     private static final ShutdownThread sInstance = new ShutdownThread();
 
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index aa74b424b5a1..6d3d5d6daa60 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -305,6 +305,8 @@ public class WindowManagerService extends IWindowManager.Stub
 
     private static final String PROPERTY_EMULATOR_CIRCULAR = "ro.emulator.circular";
 
+    private static final String PROPERTY_BUILD_DATE_UTC = "ro.build.date.utc";
+
     final private KeyguardDisableHandler mKeyguardDisableHandler;
 
     final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@@ -7629,8 +7631,22 @@ public class WindowManagerService extends IWindowManager.Stub
                 || volumeDownState > 0;
         try {
             if (SystemProperties.getInt(ShutdownThread.REBOOT_SAFEMODE_PROPERTY, 0) != 0) {
-                mSafeMode = true;
-                SystemProperties.set(ShutdownThread.REBOOT_SAFEMODE_PROPERTY, "");
+                int auditSafeMode = SystemProperties.getInt(ShutdownThread.AUDIT_SAFEMODE_PROPERTY, 0);
+
+                if (auditSafeMode == 0) {
+                    mSafeMode = true;
+                    SystemProperties.set(ShutdownThread.REBOOT_SAFEMODE_PROPERTY, "");
+                } else {
+                    // stay in safe mode until we have updated to a newer build
+                    int buildDate = SystemProperties.getInt(PROPERTY_BUILD_DATE_UTC, 0);
+
+                    if (auditSafeMode >= buildDate) {
+                        mSafeMode = true;
+                    } else {
+                        SystemProperties.set(ShutdownThread.REBOOT_SAFEMODE_PROPERTY, "");
+                        SystemProperties.set(ShutdownThread.AUDIT_SAFEMODE_PROPERTY, "");
+                    }
+                }
             }
         } catch (IllegalArgumentException e) {
         }