Prevent OnePlus Android P from bootloop

Bridge/src/main/java/com/elderdrivers/riru/xposed/Main.java

@@ -43,7 +43,6 @@ public class Main implements KeepAll {
     // entry points
     ///////////////////////////////////////////////////////////////////////////////////////////////
 
-    @Deprecated
     public static void forkAndSpecializePre(int uid, int gid, int[] gids, int debugFlags,
                                             int[][] rlimits, int mountExternal, String seInfo,
                                             String niceName, int[] fdsToClose, int[] fdsToIgnore,
@@ -74,6 +73,7 @@ public class Main implements KeepAll {
     public static void forkAndSpecializePost(int pid, String appDataDir) {
         if (pid == 0) {
             Utils.logD(sForkAndSpecializePramsStr + " = " + Process.myPid());
+            Router.onEnterChildProcess();
             DynamicBridge.onForkPost();
             // in app process
             if (!sIsGlobalMode) {
@@ -106,6 +106,7 @@ public class Main implements KeepAll {
         if (pid == 0) {
             Utils.logD(sForkSystemServerPramsStr + " = " + Process.myPid());
             // in system_server process
+            Router.onEnterChildProcess();
             Router.prepare(true);
             Router.onProcessForked(true);
             Router.loadModulesSafely();

Bridge/src/main/java/com/elderdrivers/riru/xposed/core/HookMain.java

@@ -1,5 +1,6 @@
 package com.elderdrivers.riru.xposed.core;
 
+import com.elderdrivers.riru.xposed.entry.hooker.OnePlusWorkAroundHooker;
 import com.elderdrivers.riru.xposed.util.Utils;
 
 import java.lang.reflect.Constructor;
@@ -7,12 +8,16 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.Set;
 
 import static com.elderdrivers.riru.xposed.Main.backupAndHookNative;
 import static com.elderdrivers.riru.xposed.Main.findMethodNative;
 
 public class HookMain {
 
+    private static Set<String> hookItemWhiteList = Collections.singleton(OnePlusWorkAroundHooker.class.getName());
+
     public static void doHookDefault(ClassLoader patchClassLoader, ClassLoader originClassLoader, String hookInfoClassName) {
         try {
             Class<?> hookInfoClass = Class.forName(hookInfoClassName, true, patchClassLoader);
@@ -64,7 +69,9 @@ public class HookMain {
             }
             findAndBackupAndHook(clazz, methodName, methodSig, hook, backup);
         } catch (Throwable e) {
-            Utils.logE("error when hooking " + hookItemName, e);
+            if (!hookItemWhiteList.contains(hookItemName)) {
+                Utils.logE("error when hooking " + hookItemName, e);
+            }
         }
     }
 

Bridge/src/main/java/com/elderdrivers/riru/xposed/entry/Router.java

@@ -71,4 +71,10 @@ public class Router {
                 SystemMainHooker.systemServerCL,
                 SysInnerHookInfo.class.getName());
     }
+
+    public volatile static boolean forkCompleted = false;
+
+    public static void onEnterChildProcess() {
+        forkCompleted = true;
+    }
 }

Bridge/src/main/java/com/elderdrivers/riru/xposed/entry/bootstrap/AppBootstrapHookInfo.java

@@ -3,10 +3,12 @@ package com.elderdrivers.riru.xposed.entry.bootstrap;
 import com.elderdrivers.riru.common.KeepMembers;
 import com.elderdrivers.riru.xposed.entry.hooker.HandleBindAppHooker;
 import com.elderdrivers.riru.xposed.entry.hooker.LoadedApkConstructorHooker;
+import com.elderdrivers.riru.xposed.entry.hooker.OnePlusWorkAroundHooker;
 
 public class AppBootstrapHookInfo implements KeepMembers {
     public static String[] hookItemNames = {
             HandleBindAppHooker.class.getName(),
-            LoadedApkConstructorHooker.class.getName()
+            LoadedApkConstructorHooker.class.getName(),
+            OnePlusWorkAroundHooker.class.getName()
     };
 }

Bridge/src/main/java/com/elderdrivers/riru/xposed/entry/bootstrap/SysBootstrapHookInfo.java

@@ -3,12 +3,14 @@ package com.elderdrivers.riru.xposed.entry.bootstrap;
 import com.elderdrivers.riru.common.KeepMembers;
 import com.elderdrivers.riru.xposed.entry.hooker.HandleBindAppHooker;
 import com.elderdrivers.riru.xposed.entry.hooker.LoadedApkConstructorHooker;
+import com.elderdrivers.riru.xposed.entry.hooker.OnePlusWorkAroundHooker;
 import com.elderdrivers.riru.xposed.entry.hooker.SystemMainHooker;
 
 public class SysBootstrapHookInfo implements KeepMembers {
     public static String[] hookItemNames = {
             HandleBindAppHooker.class.getName(),
             SystemMainHooker.class.getName(),
-            LoadedApkConstructorHooker.class.getName()
+            LoadedApkConstructorHooker.class.getName(),
+            OnePlusWorkAroundHooker.class.getName()
     };
 }

Bridge/src/main/java/com/elderdrivers/riru/xposed/entry/hooker/OnePlusWorkAroundHooker.java

@@ -0,0 +1,42 @@
+package com.elderdrivers.riru.xposed.entry.hooker;
+
+import com.elderdrivers.riru.common.KeepMembers;
+import com.elderdrivers.riru.xposed.entry.Router;
+
+import de.robv.android.xposed.XposedBridge;
+
+import static de.robv.android.xposed.XposedInit.logD;
+
+/**
+ * On OnePlus stock roms (Android Pie), {@link dalvik.system.BaseDexClassLoader#findClass(String)}
+ * will open /dev/binder to communicate with PackageManagerService to check whether
+ * current package name inCompatConfigList, which is an OnePlus OEM feature enabled only when
+ * system prop "persist.sys.oem.region" set to "CN".(detail of related source code:
+ * https://gist.github.com/solohsu/ecc07141759958fc096ba0781fac0a5f)
+ * If we invoke intZygoteCallbacks in
+ * {@link com.elderdrivers.riru.xposed.Main#forkAndSpecializePre}, where in zygote process,
+ * we would get a chance to invoke findclass, leaving fd of /dev/binder open in zygote process,
+ * which is not allowed because /dev/binder is not in predefined whitelist here:
+ * http://androidxref.com/9.0.0_r3/xref/frameworks/base/core/jni/fd_utils.cpp#35
+ * So we just hook BaseDexClassLoader#inCompatConfigList to return false to prevent
+ * open of /dev/binder and we haven't found side effects yet.
+ * Other roms might share the same problems but not reported too.
+ */
+public class OnePlusWorkAroundHooker implements KeepMembers {
+
+    public static String className = "dalvik.system.BaseDexClassLoader";
+    public static String methodName = "inCompatConfigList";
+    public static String methodSig = "(ILjava/lang/String;)Z";
+
+    public static boolean hook(int type, String packageName) {
+        if (XposedBridge.disableHooks || Router.forkCompleted) {
+            return backup(type, packageName);
+        }
+        logD("BaseDexClassLoader#inCompatConfigList() starts");
+        return false;
+    }
+
+    public static boolean backup(int type, String packageName) {
+        return false;
+    }
+}