src/jdk.jfr/share/classes/jdk/jfr/internal/SecuritySupport.java

@@ -29,10 +29,11 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.RandomAccessFile;
 import java.io.Reader;
+import java.lang.invoke.MethodHandles;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.ReflectPermission;
 import java.nio.channels.FileChannel;

@@ -69,10 +70,11 @@
  * Contains JFR code that does
  * {@link AccessController#doPrivileged(PrivilegedAction)}
  */
 public final class SecuritySupport {
     private final static Unsafe unsafe = Unsafe.getUnsafe();
+    private final static MethodHandles.Lookup LOOKUP = MethodHandles.lookup();
     private final static Module JFR_MODULE = Event.class.getModule();
     public  final static SafePath JFC_DIRECTORY = getPathInProperty("java.home", "lib/jfr");
 
     static final SafePath USER_HOME = getPathInProperty("user.home", null);
     static final SafePath JAVA_IO_TMPDIR = getPathInProperty("java.io.tmpdir", null);

@@ -379,12 +381,21 @@
 
     static void ensureClassIsInitialized(Class<?> clazz) {
         unsafe.ensureClassInitialized(clazz);
     }
 
-    static Class<?> defineClass(String name, byte[] bytes, ClassLoader classLoader) {
-        return unsafe.defineClass(name, bytes, 0, bytes.length, classLoader, null);
+    static Class<?> defineClass(Class<?> lookupClass, byte[] bytes) {
+        return AccessController.doPrivileged(new PrivilegedAction<>() {
+            @Override
+            public Class<?> run() {
+                try {
+                    return MethodHandles.privateLookupIn(lookupClass, LOOKUP).defineClass(bytes);
+                } catch (IllegalAccessException e) {
+                    throw new InternalError(e);
+                }
+            }
+        });
     }
 
     static Thread createThreadWitNoPermissions(String threadName, Runnable runnable) {
         return doPrivilegedWithReturn(() -> new Thread(runnable, threadName), new Permission[0]);
     }