6636650: (cl) Resurrected ClassLoaders can still have children

Prevent classloader from resurrection

Reviewed-by: hawtin

jdk/src/share/classes/java/lang/ClassLoader.java

@@ -186,11 +186,6 @@ public abstract class ClassLoader {
         parallelLoaders.add(ClassLoader.class);
     }
 
-    // If initialization succeed this is set to true and security checks will
-    // succeed.  Otherwise the object is not initialized and the object is
-    // useless.
-    private final boolean initialized;
-
     // The parent class loader for delegation
     // Note: VM hardcoded the offset of this field, thus all new fields
     // must be added *after* it.
@@ -232,6 +227,31 @@ public abstract class ClassLoader {
     private final HashMap<String, Package> packages =
         new HashMap<String, Package>();
 
+    private static Void checkCreateClassLoader() {
+        SecurityManager security = System.getSecurityManager();
+        if (security != null) {
+            security.checkCreateClassLoader();
+        }
+        return null;
+    }
+
+    private ClassLoader(Void unused, ClassLoader parent) {
+        this.parent = parent;
+        if (parallelLoaders.contains(this.getClass())) {
+            parallelLockMap = new ConcurrentHashMap<String, Object>();
+            package2certs = new ConcurrentHashMap<String, Certificate[]>();
+            domains =
+                Collections.synchronizedSet(new HashSet<ProtectionDomain>());
+            assertionLock = new Object();
+        } else {
+            // no finer-grained lock; lock on the classloader instance
+            parallelLockMap = null;
+            package2certs = new Hashtable<String, Certificate[]>();
+            domains = new HashSet<ProtectionDomain>();
+            assertionLock = this;
+        }
+    }
+
     /**
      * Creates a new class loader using the specified parent class loader for
      * delegation.
@@ -252,25 +272,7 @@ public abstract class ClassLoader {
      * @since  1.2
      */
     protected ClassLoader(ClassLoader parent) {
-        SecurityManager security = System.getSecurityManager();
+        this(checkCreateClassLoader(), parent);
-        if (security != null) {
-            security.checkCreateClassLoader();
-        }
-        this.parent = parent;
-        if (parallelLoaders.contains(this.getClass())) {
-            parallelLockMap = new ConcurrentHashMap<String, Object>();
-            package2certs = new ConcurrentHashMap<String, Certificate[]>();
-            domains =
-                Collections.synchronizedSet(new HashSet<ProtectionDomain>());
-            assertionLock = new Object();
-        } else {
-            // no finer-grained lock; lock on the classloader instance
-            parallelLockMap = null;
-            package2certs = new Hashtable<String, Certificate[]>();
-            domains = new HashSet<ProtectionDomain>();
-            assertionLock = this;
-        }
-        initialized = true;
     }
 
     /**
@@ -289,25 +291,7 @@ public abstract class ClassLoader {
      *          of a new class loader.
      */
     protected ClassLoader() {
-        SecurityManager security = System.getSecurityManager();
+        this(checkCreateClassLoader(), getSystemClassLoader());
-        if (security != null) {
-            security.checkCreateClassLoader();
-        }
-        this.parent = getSystemClassLoader();
-        if (parallelLoaders.contains(this.getClass())) {
-            parallelLockMap = new ConcurrentHashMap<String, Object>();
-            package2certs = new ConcurrentHashMap<String, Certificate[]>();
-            domains =
-                Collections.synchronizedSet(new HashSet<ProtectionDomain>());
-            assertionLock = new Object();
-        } else {
-            // no finer-grained lock; lock on the classloader instance
-            parallelLockMap = null;
-            package2certs = new Hashtable<String, Certificate[]>();
-            domains = new HashSet<ProtectionDomain>();
-            assertionLock = this;
-        }
-        initialized = true;
     }
 
     // -- Class --
@@ -742,7 +726,6 @@ public abstract class ClassLoader {
                                          ProtectionDomain protectionDomain)
         throws ClassFormatError
     {
-        check();
         protectionDomain = preDefineClass(name, protectionDomain);
 
         Class c = null;
@@ -826,8 +809,6 @@ public abstract class ClassLoader {
                                          ProtectionDomain protectionDomain)
         throws ClassFormatError
     {
-        check();
-
         int len = b.remaining();
 
         // Use byte[] if not a direct ByteBufer:
@@ -972,7 +953,6 @@ public abstract class ClassLoader {
      * @see  #defineClass(String, byte[], int, int)
      */
     protected final void resolveClass(Class<?> c) {
-        check();
         resolveClass0(c);
     }
 
@@ -1003,7 +983,6 @@ public abstract class ClassLoader {
     protected final Class<?> findSystemClass(String name)
         throws ClassNotFoundException
     {
-        check();
         ClassLoader system = getSystemClassLoader();
         if (system == null) {
             if (!checkName(name))
@@ -1016,7 +995,6 @@ public abstract class ClassLoader {
     private Class findBootstrapClass0(String name)
         throws ClassNotFoundException
     {
-        check();
         if (!checkName(name))
             throw new ClassNotFoundException(name);
         return findBootstrapClass(name);
@@ -1025,13 +1003,6 @@ public abstract class ClassLoader {
     private native Class findBootstrapClass(String name)
         throws ClassNotFoundException;
 
-    // Check to make sure the class loader has been initialized.
-    private void check() {
-        if (!initialized) {
-            throw new SecurityException("ClassLoader object not initialized");
-        }
-    }
-
     /**
      * Returns the class with the given <a href="#name">binary name</a> if this
      * loader has been recorded by the Java virtual machine as an initiating
@@ -1047,7 +1018,6 @@ public abstract class ClassLoader {
      * @since  1.1
      */
     protected final Class<?> findLoadedClass(String name) {
-        check();
         if (!checkName(name))
             return null;
         return findLoadedClass0(name);
@@ -1068,7 +1038,6 @@ public abstract class ClassLoader {
      * @since  1.1
      */
     protected final void setSigners(Class<?> c, Object[] signers) {
-        check();
         c.setSigners(signers);
     }