diff -r b09e56145e11 test/jdk/java/lang/instrument/NamedBuffer.java
--- a/test/jdk/java/lang/instrument/NamedBuffer.java	Thu Mar 08 04:23:31 2018 +0000
+++ b/test/jdk/java/lang/instrument/NamedBuffer.java	Mon Jan 07 18:16:52 2019 -0800
@@ -64,7 +64,7 @@
     public static byte[]
     loadBufferFromStream(InputStream stream)
         throws IOException
-        {
+    {
         // hack for now, just assume the stream will fit in our reasonable size buffer.
         // if not, panic
         int bufferLimit = 200 * 1024;
@@ -83,5 +83,53 @@
                             0,
                             actualSize);
         return resultBuffer;
+    }
+
+    static final String DEST = System.getProperty("test.classes");
+    static final boolean VERBOSE = false;
+
+    static boolean checkMatch(byte[] buf, byte[] name, int begIdx) {
+        for (int i = 0; i < name.length; i++) {
+            if (buf[i + begIdx] != name[i]) {
+                return false;
+            }
         }
+        return true;
+    }
+
+    static byte[]
+    bytesForHostClass(char replace, String className) throws Throwable {
+        String tail = className.substring(1);
+        String origClassName = "" + replace + tail;
+        File clsfile = new File(DEST + "/" + origClassName + ".class");
+
+        if (VERBOSE) {
+            System.out.println("   Reading bytes from " + clsfile);
+        }
+        byte[] buf = null;
+        try (FileInputStream str = new FileInputStream(clsfile)) {
+            buf = loadBufferFromStream(str);
+        }
+        System.out.println("\n    Changing name of " + origClassName + " to " + className + " in bytes");
+
+        boolean found = false;
+        int dollarSignIdx = className.indexOf('$');
+        int ptrnLen = (dollarSignIdx == -1) ? className.length() : dollarSignIdx;
+        byte[] ptrnBytes = origClassName.substring(0, ptrnLen).getBytes();
+        final byte FirstByte = className.getBytes()[0];
+
+        for (int i = 0; i < buf.length - ptrnLen; i++) {
+            if(checkMatch(buf, ptrnBytes, i)) {
+                if (VERBOSE) {
+                    System.out.println("Appear to have found " + origClassName + " starting at " + i);
+                }
+                buf[i] = FirstByte;
+                found = true;
+            }
+        }
+        if (!found) {
+            throw new Error("Could not locate '" + ptrnBytes + "' name in byte array");
+        }
+        return buf;
+    }
 }
diff -r b09e56145e11 test/jdk/java/lang/instrument/RedefineInterfaceMethods/RedefineInterfaceMethods.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/lang/instrument/RedefineInterfaceMethods/RedefineInterfaceMethods.java	Mon Jan 07 18:16:52 2019 -0800
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8191496
+ * @summary Crash in JVM_GetClassModifiers when redefining a class' private method during resolution of the bootstrap specifier
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ * @modules java.compiler
+ *          java.instrument
+ *          jdk.jartool/sun.tools.jar
+ * @compile ../NamedBuffer.java
+ * @compile redef/Xost.java
+ * @run main RedefineClassHelper
+ * @run main/othervm -javaagent:redefineagent.jar -Xlog:redefine+class*=trace RedefineInterfaceMethods
+ */ 
+
+class Host {
+    static void log(String msg) { System.out.println(msg); }
+
+    static interface B {
+        int ORIGINAL_RETURN = 1;
+        int NEW_RETURN = 2;
+
+        private int privateMethod() {
+            Runnable race1 = () -> log("Hello from inside privateMethod");
+            race1.run();
+            return ORIGINAL_RETURN;
+        }
+
+        public default int defaultMethod(String p) {
+            log(p + "from interface B's defaultMethod");
+            return privateMethod();
+        }
+    }
+
+    static class Impl implements B {
+    }
+}
+
+public class RedefineInterfaceMethods {
+    private static byte[] bytesForHostClass(char replace) throws Throwable {
+        return NamedBuffer.bytesForHostClass(replace, "Host$B");
+    }
+
+    public static void main(String[] args) throws Throwable {
+        Host.Impl impl = new Host.Impl();
+
+        int res = impl.defaultMethod("Hello ");
+        if (res != Host.B.ORIGINAL_RETURN)
+            throw new Error("defaultMethod returned " + res +
+                            " expected " + Host.B.ORIGINAL_RETURN);
+
+        byte[] buf = bytesForHostClass('X');
+        RedefineClassHelper.redefineClass(Host.B.class, buf);
+
+        res = impl.defaultMethod("Goodbye ");
+        if (res != Host.B.NEW_RETURN)
+            throw new Error("defaultMethod returned " + res +
+                            " expected " + Host.B.NEW_RETURN);
+    }
+} 
diff -r b09e56145e11 test/jdk/java/lang/instrument/RedefineInterfaceMethods/redef/Xost.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/lang/instrument/RedefineInterfaceMethods/redef/Xost.java	Mon Jan 07 18:16:52 2019 -0800
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+class Xost {
+    static void log(String msg) { System.out.println(msg); }
+
+    static interface B {
+        int ORIGINAL_RETURN = 1;
+        int NEW_RETURN = 2;
+
+        private int privateMethod() {
+            Runnable race1 = () -> log("Hello from inside privateMethod");
+            race1.run();
+            return NEW_RETURN;
+        }
+        public default int defaultMethod(String p) {
+            log(p + "from interface B's defaultMethod");
+             return privateMethod();
+        }
+    }
+
+    static class Impl implements B {
+    }
+}
diff -r b09e56145e11 test/jdk/java/lang/instrument/RedefineMathTesterMethods/RedefineMathTesterMethods.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/lang/instrument/RedefineMathTesterMethods/RedefineMathTesterMethods.java	Mon Jan 07 18:16:52 2019 -0800
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8191496
+ * @summary Crash in JVM_GetClassModifiers when redefining a class' private method during resolution of the bootstrap specifier
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ * @modules java.compiler
+ *          java.instrument
+ *          jdk.jartool/sun.tools.jar
+ * @compile ../NamedBuffer.java
+ * @compile redef/Xost.java
+ * @run main RedefineClassHelper
+ * @run main/othervm -javaagent:redefineagent.jar -Xlog:redefine+class*=trace RedefineMathTesterMethods
+ */ 
+
+interface MathOperation {
+    public int operation(int a, int b);
+}
+
+class Host {
+    static class B {
+        public static int operate(int a, int b, MathOperation mathOperation) {
+            return mathOperation.operation(a, b);
+        }
+
+        static int test_math() {
+            MathOperation addition = (int a, int b) -> a + b;
+            return operate(10, 5, addition);
+        }
+    }
+}
+
+public class RedefineMathTesterMethods {
+    private static byte[] bytesForHostClass(char replace) throws Throwable {
+        return NamedBuffer.bytesForHostClass(replace, "Host$B");
+    }
+
+    public static void main(String[] args) throws Throwable {
+        int res = Host.B.test_math();
+        System.out.println("Result = " + res);
+        if (res != 15) {
+            throw new Error("test_math returned " + res + " expected " + 15);
+        }
+
+        byte[] buf = bytesForHostClass('X');
+        RedefineClassHelper.redefineClass(Host.B.class, buf);
+
+        res = Host.B.test_math();
+        if (res != 5)
+            throw new Error("test_math returned " + res + " expected " + 5);
+    }
+} 
diff -r b09e56145e11 test/jdk/java/lang/instrument/RedefineMathTesterMethods/redef/Xost.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/lang/instrument/RedefineMathTesterMethods/redef/Xost.java	Mon Jan 07 18:16:52 2019 -0800
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+interface MathOperation {
+    public int operation(int a, int b);
+}
+
+class Xost {
+    static class B {
+        public static int operate(int a, int b, MathOperation mathOperation) {
+            return mathOperation.operation(a, b);
+        }
+
+        static int test_math() {
+            MathOperation subtraction = (int a, int b) -> a - b;
+            return operate(10, 5, subtraction);
+        }
+    }
+}