Set system server's class loader for wrap.system_server

Root Cause: systemServer's class path is not set
  after set wrap.system_server property, and restart system_server,
  it shows a java.lang.RuntimeException:
    Missing class when invoking static main com.android.server.SystemServer

Solution: Correctly pass and parse a passed classpath.

Bug: 34692265
Test: adb root && adb shell stop && adb shell setprop wrap.system_server logwrapper && adb shell start
Change-Id: Ia6707dc05fa627af6cc28360d26b894487a6eff1

2 files changed, 24 insertions, 10 deletions

diff --git a/core/java/com/android/internal/os/WrapperInit.java b/core/java/com/android/internal/os/WrapperInit.java
index dbbebbe7f758..c329fd1b5e09 100644
--- a/core/java/com/android/internal/os/WrapperInit.java
+++ b/core/java/com/android/internal/os/WrapperInit.java
@@ -139,6 +139,21 @@ public class WrapperInit {
             Slog.d(RuntimeInit.TAG, "RuntimeInit: Starting application from wrapper");
         }
 
-        RuntimeInit.applicationInit(targetSdkVersion, argv, null);
+        // Check whether the first argument is a "-cp" in argv, and assume the next argument is the
+        // classpath. If found, create a PathClassLoader and use it for applicationInit.
+        ClassLoader classLoader = null;
+        if (argv != null && argv.length > 2 && argv[0].equals("-cp")) {
+            classLoader = ZygoteInit.createPathClassLoader(argv[1], targetSdkVersion);
+
+            // Install this classloader as the context classloader, too.
+            Thread.currentThread().setContextClassLoader(classLoader);
+
+            // Remove the classpath from the arguments.
+            String removedArgs[] = new String[argv.length - 2];
+            System.arraycopy(argv, 2, removedArgs, 0, argv.length - 2);
+            argv = removedArgs;
+        }
+
+        RuntimeInit.applicationInit(targetSdkVersion, argv, classLoader);
     }
 }
diff --git a/core/java/com/android/internal/os/ZygoteInit.java b/core/java/com/android/internal/os/ZygoteInit.java
index 1e0a9980a66f..e560c0c7811b 100644
--- a/core/java/com/android/internal/os/ZygoteInit.java
+++ b/core/java/com/android/internal/os/ZygoteInit.java
@@ -449,7 +449,8 @@ public class ZygoteInit {
                 String[] amendedArgs = new String[args.length + 2];
                 amendedArgs[0] = "-cp";
                 amendedArgs[1] = systemServerClasspath;
-                System.arraycopy(parsedArgs.remainingArgs, 0, amendedArgs, 2, parsedArgs.remainingArgs.length);
+                System.arraycopy(args, 0, amendedArgs, 2, args.length);
+                args = amendedArgs;
             }
 
             WrapperInit.execApplication(parsedArgs.invokeWith,
@@ -458,8 +459,7 @@ public class ZygoteInit {
         } else {
             ClassLoader cl = null;
             if (systemServerClasspath != null) {
-                cl = createSystemServerClassLoader(systemServerClasspath,
-                                                   parsedArgs.targetSdkVersion);
+                cl = createPathClassLoader(systemServerClasspath, parsedArgs.targetSdkVersion);
 
                 Thread.currentThread().setContextClassLoader(cl);
             }
@@ -474,15 +474,14 @@ public class ZygoteInit {
     }
 
     /**
-     * Creates a PathClassLoader for the system server. It also creates
-     * a shared namespace associated with the classloader to let it access
-     * platform-private native libraries.
+     * Creates a PathClassLoader for the given class path that is associated with a shared
+     * namespace, i.e., this classloader can access platform-private native libraries. The
+     * classloader will use java.library.path as the native library path.
      */
-    private static PathClassLoader createSystemServerClassLoader(String systemServerClasspath,
-                                                                 int targetSdkVersion) {
+    static PathClassLoader createPathClassLoader(String classPath, int targetSdkVersion) {
       String libraryPath = System.getProperty("java.library.path");
 
-      return PathClassLoaderFactory.createClassLoader(systemServerClasspath,
+      return PathClassLoaderFactory.createClassLoader(classPath,
                                                       libraryPath,
                                                       libraryPath,
                                                       ClassLoader.getSystemClassLoader(),