1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test 26 * @bug 8042235 27 * @summary redefining method used by multiple MethodHandles crashes VM 28 * @compile -XDignore.symbol.file RedefineMethodUsedByMultipleMethodHandles.java 29 * @run main/othervm RedefineMethodUsedByMultipleMethodHandles 30 */ 31 32 import java.io.*; 33 import java.lang.instrument.*; 34 import java.lang.invoke.*; 35 import java.lang.invoke.MethodHandles.Lookup; 36 import java.lang.management.*; 37 import java.lang.reflect.*; 38 import java.nio.file.*; 39 import java.security.*; 40 import java.util.jar.*; 41 42 import javax.tools.*; 43 44 import jdk.internal.org.objectweb.asm.*; 45 46 public class RedefineMethodUsedByMultipleMethodHandles { 47 48 static class Foo { 49 public static Object getName() { 50 return "foo"; 51 } 52 } 53 54 public static void main(String[] args) throws Throwable { 55 56 Lookup lookup = MethodHandles.lookup(); 57 Method fooMethod = Foo.class.getDeclaredMethod("getName"); 58 59 // fooMH2 displaces fooMH1 from the MemberNamesTable 60 MethodHandle fooMH1 = lookup.unreflect(fooMethod); 61 MethodHandle fooMH2 = lookup.unreflect(fooMethod); 62 63 System.out.println("fooMH1.invoke = " + fooMH1.invokeExact()); 64 System.out.println("fooMH2.invoke = " + fooMH2.invokeExact()); 65 66 // Redefining Foo.getName() causes vmtarget to be updated 67 // in fooMH2 but not fooMH1 68 redefineFoo(); 69 70 // Full GC causes fooMH1.vmtarget to be deallocated 71 System.gc(); 72 73 // Calling fooMH1.vmtarget crashes the VM 74 System.out.println("fooMH1.invoke = " + fooMH1.invokeExact()); 75 } 76 77 /** 78 * Adds the class file bytes for {@code c} to {@code jar}. 79 */ 80 static void add(JarOutputStream jar, Class<?> c) throws IOException { 81 String classAsPath = c.getName().replace('.', '/') + ".class"; 82 jar.putNextEntry(new JarEntry(classAsPath)); 83 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath); 84 85 int b; 86 while ((b = stream.read()) != -1) { 87 jar.write(b); 88 } 89 } 90 91 static void redefineFoo() throws Exception { 92 Manifest manifest = new Manifest(); 93 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0"); 94 Attributes mainAttrs = manifest.getMainAttributes(); 95 mainAttrs.putValue("Agent-Class", FooAgent.class.getName()); 96 mainAttrs.putValue("Can-Redefine-Classes", "true"); 97 mainAttrs.putValue("Can-Retransform-Classes", "true"); 98 99 Path jar = Files.createTempFile("myagent", ".jar"); 100 try { 101 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest); 102 add(jarStream, FooAgent.class); 103 add(jarStream, FooTransformer.class); 104 jarStream.close(); 105 runAgent(jar); 106 } finally { 107 Files.deleteIfExists(jar); 108 } 109 } 110 111 public static void runAgent(Path agent) throws Exception { 112 String vmName = ManagementFactory.getRuntimeMXBean().getName(); 113 int p = vmName.indexOf('@'); 114 assert p != -1 : "VM name not in <pid>@<host> format: " + vmName; 115 String pid = vmName.substring(0, p); 116 ClassLoader cl = ToolProvider.getSystemToolClassLoader(); 117 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl); 118 Method attach = c.getDeclaredMethod("attach", String.class); 119 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class); 120 Method detach = c.getDeclaredMethod("detach"); 121 Object vm = attach.invoke(null, pid); 122 loadAgent.invoke(vm, agent.toString()); 123 detach.invoke(vm); 124 } 125 126 public static class FooAgent { 127 128 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception { 129 assert inst.isRedefineClassesSupported(); 130 assert inst.isRetransformClassesSupported(); 131 inst.addTransformer(new FooTransformer(), true); 132 Class<?>[] classes = inst.getAllLoadedClasses(); 133 for (int i = 0; i < classes.length; i++) { 134 Class<?> c = classes[i]; 135 if (c == Foo.class) { 136 inst.retransformClasses(new Class[]{c}); 137 } 138 } 139 } 140 } 141 142 static class FooTransformer implements ClassFileTransformer { 143 144 @Override 145 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException { 146 if (Foo.class.equals(classBeingRedefined)) { 147 System.out.println("redefining " + classBeingRedefined); 148 ClassReader cr = new ClassReader(classfileBuffer); 149 ClassWriter cw = new ClassWriter(cr, ClassWriter.COMPUTE_FRAMES); 150 ClassVisitor adapter = new ClassVisitor(Opcodes.ASM5, cw) { 151 @Override 152 public MethodVisitor visitMethod(int access, String base, String desc, String signature, String[] exceptions) { 153 MethodVisitor mv = cv.visitMethod(access, base, desc, signature, exceptions); 154 if (mv != null) { 155 mv = new MethodVisitor(Opcodes.ASM5, mv) { 156 @Override 157 public void visitLdcInsn(Object cst) { 158 System.out.println("replacing \"" + cst + "\" with \"bar\""); 159 mv.visitLdcInsn("bar"); 160 } 161 }; 162 } 163 return mv; 164 } 165 }; 166 167 cr.accept(adapter, ClassReader.SKIP_FRAMES); 168 cw.visitEnd(); 169 return cw.toByteArray(); 170 } 171 return classfileBuffer; 172 } 173 } 174 }