commit 3729e9ce4e17f82ed86566af0e7010b03bab28b5
author Makoto Onuki <omakoto@google.com> Tue Aug 07 15:57:13 2018 -0700
committer Makoto Onuki <omakoto@google.com> Fri Aug 17 21:09:03 2018 +0000
tree cfda9958a4394c8c383418243ec78c905887bbcf
parent 283f55f7de5b9866bf73ded9a36047637f9251b0

Default to FULL synchronous mode for sqlite DBs in system server

Test: change pin and immediately crash the kernel with
adb shell 'su root sh -c "echo c >/proc/sysrq-trigger"' and boot
Bug: 112175067

Change-Id: Ia5f43f3118e2297fbea43c805ef2f4577bf8a9bf
(cherry picked from commit 50e00c8dc48849280410e38bb05a1f11ce24ef01)

core/java/android/database/sqlite/SQLiteGlobal.java

diff --git a/core/java/android/database/sqlite/SQLiteGlobal.java b/core/java/android/database/sqlite/SQLiteGlobal.java
index d6d9764..e6b6acf 100644
--- a/core/java/android/database/sqlite/SQLiteGlobal.java
+++ b/core/java/android/database/sqlite/SQLiteGlobal.java
@@ -39,11 +39,18 @@
 public final class SQLiteGlobal {
     private static final String TAG = "SQLiteGlobal";
 
+    /** @hide */
+    public static final String SYNC_MODE_FULL = "FULL";
+
     private static final Object sLock = new Object();
+
     private static int sDefaultPageSize;
 
     private static native int nativeReleaseMemory();
 
+    /** @hide */
+    public static volatile String sDefaultSyncMode;
+
     private SQLiteGlobal() {
     }
 
@@ -103,6 +110,11 @@
      * Gets the default database synchronization mode when WAL is not in use.
      */
     public static String getDefaultSyncMode() {
+        // Use the FULL synchronous mode for system processes by default.
+        String defaultMode = sDefaultSyncMode;
+        if (defaultMode != null) {
+            return defaultMode;
+        }
         return SystemProperties.get("debug.sqlite.syncmode",
                 Resources.getSystem().getString(
                 com.android.internal.R.string.db_default_sync_mode));
@@ -112,6 +124,11 @@
      * Gets the database synchronization mode when in WAL mode.
      */
     public static String getWALSyncMode() {
+        // Use the FULL synchronous mode for system processes by default.
+        String defaultMode = sDefaultSyncMode;
+        if (defaultMode != null) {
+            return defaultMode;
+        }
         return SystemProperties.get("debug.sqlite.wal.syncmode",
                 Resources.getSystem().getString(
                 com.android.internal.R.string.db_wal_sync_mode));

services/java/com/android/server/SystemServer.java

diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index 1880e9f..3c833d8 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -28,6 +28,7 @@
 import android.content.res.Configuration;
 import android.content.res.Resources.Theme;
 import android.database.sqlite.SQLiteCompatibilityWalFlags;
+import android.database.sqlite.SQLiteGlobal;
 import android.os.BaseBundle;
 import android.os.Binder;
 import android.os.Build;
@@ -346,6 +347,10 @@
             Binder.setWarnOnBlocking(true);
             // The system server should always load safe labels
             PackageItemInfo.setForceSafeLabels(true);
+
+            // Default to FULL within the system server.
+            SQLiteGlobal.sDefaultSyncMode = SQLiteGlobal.SYNC_MODE_FULL;
+
             // Deactivate SQLiteCompatibilityWalFlags until settings provider is initialized
             SQLiteCompatibilityWalFlags.init(null);