1 /* 2 * Copyright (c) 2011, 2016, 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 * @requires vm.jvmci 27 * @library ../../../../../ 28 * @modules jdk.internal.vm.ci/jdk.vm.ci.meta 29 * jdk.internal.vm.ci/jdk.vm.ci.runtime 30 * jdk.attach 31 * java.base/jdk.internal.misc 32 * @run junit/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -Djvmci.Compiler=null jdk.vm.ci.runtime.test.RedefineClassTest 33 */ 34 35 package jdk.vm.ci.runtime.test; 36 37 import jdk.vm.ci.meta.ResolvedJavaMethod; 38 import org.junit.Assert; 39 import org.junit.Test; 40 41 import java.io.FileOutputStream; 42 import java.io.IOException; 43 import java.io.InputStream; 44 import java.lang.instrument.ClassFileTransformer; 45 import java.lang.instrument.IllegalClassFormatException; 46 import java.lang.instrument.Instrumentation; 47 import java.lang.management.ManagementFactory; 48 import java.lang.reflect.Method; 49 import java.nio.file.Files; 50 import java.nio.file.Path; 51 import java.security.ProtectionDomain; 52 import java.util.Arrays; 53 import java.util.jar.Attributes; 54 import java.util.jar.JarEntry; 55 import java.util.jar.JarOutputStream; 56 import java.util.jar.Manifest; 57 58 import static org.junit.Assume.assumeTrue; 59 60 /** 61 * Tests that {@link ResolvedJavaMethod}s are safe in the context of class redefinition being used 62 * to redefine the method to which they refer. 63 */ 64 public class RedefineClassTest extends TypeUniverse { 65 66 static class Foo { 67 public static Object getName() { 68 return "foo"; 69 } 70 } 71 72 @Test 73 public void test() throws Throwable { 74 75 Method fooMethod = Foo.class.getDeclaredMethod("getName"); 76 77 ResolvedJavaMethod foo1 = metaAccess.lookupJavaMethod(fooMethod); 78 ResolvedJavaMethod foo2 = metaAccess.lookupJavaMethod(fooMethod); 79 80 String foo1Code = Arrays.toString(foo1.getCode()); 81 String foo2Code = Arrays.toString(foo2.getCode()); 82 83 Assert.assertEquals("foo", Foo.getName()); 84 85 redefineFoo(); 86 System.gc(); 87 88 // Make sure the transformation happened 89 Assert.assertEquals("bar", Foo.getName()); 90 91 Assert.assertEquals(foo1Code, Arrays.toString(foo1.getCode())); 92 Assert.assertEquals(foo2Code, Arrays.toString(foo1.getCode())); 93 } 94 95 /** 96 * Adds the class file bytes for a given class to a JAR stream. 97 */ 98 static void add(JarOutputStream jar, Class<?> c) throws IOException { 99 String name = c.getName(); 100 String classAsPath = name.replace('.', '/') + ".class"; 101 jar.putNextEntry(new JarEntry(classAsPath)); 102 103 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath); 104 105 int nRead; 106 byte[] buf = new byte[1024]; 107 while ((nRead = stream.read(buf, 0, buf.length)) != -1) { 108 jar.write(buf, 0, nRead); 109 } 110 111 jar.closeEntry(); 112 } 113 114 protected void redefineFoo() throws Exception { 115 Manifest manifest = new Manifest(); 116 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0"); 117 Attributes mainAttrs = manifest.getMainAttributes(); 118 mainAttrs.putValue("Agent-Class", FooAgent.class.getName()); 119 mainAttrs.putValue("Can-Redefine-Classes", "true"); 120 mainAttrs.putValue("Can-Retransform-Classes", "true"); 121 122 Path jar = Files.createTempFile("myagent", ".jar"); 123 try { 124 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest); 125 add(jarStream, FooAgent.class); 126 add(jarStream, FooTransformer.class); 127 jarStream.close(); 128 129 loadAgent(jar); 130 } finally { 131 Files.deleteIfExists(jar); 132 } 133 } 134 135 public static void loadAgent(Path agent) throws Exception { 136 String vmName = ManagementFactory.getRuntimeMXBean().getName(); 137 int p = vmName.indexOf('@'); 138 assumeTrue(p != -1); 139 String pid = vmName.substring(0, p); 140 ClassLoader cl = ClassLoader.getSystemClassLoader(); 141 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl); 142 Method attach = c.getDeclaredMethod("attach", String.class); 143 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class, String.class); 144 Method detach = c.getDeclaredMethod("detach"); 145 Object vm = attach.invoke(null, pid); 146 loadAgent.invoke(vm, agent.toString(), ""); 147 detach.invoke(vm); 148 } 149 150 public static class FooAgent { 151 152 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception { 153 if (inst.isRedefineClassesSupported() && inst.isRetransformClassesSupported()) { 154 inst.addTransformer(new FooTransformer(), true); 155 Class<?>[] allClasses = inst.getAllLoadedClasses(); 156 for (int i = 0; i < allClasses.length; i++) { 157 Class<?> c = allClasses[i]; 158 if (c == Foo.class) { 159 inst.retransformClasses(new Class<?>[]{c}); 160 } 161 } 162 } 163 } 164 } 165 166 /** 167 * This transformer replaces the first instance of the constant "foo" in the class file for 168 * {@link Foo} with "bar". 169 */ 170 static class FooTransformer implements ClassFileTransformer { 171 172 @Override 173 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException { 174 if (Foo.class.equals(classBeingRedefined)) { 175 String cf = new String(classfileBuffer); 176 int i = cf.indexOf("foo"); 177 Assert.assertTrue("cannot find \"foo\" constant in " + Foo.class.getSimpleName() + "'s class file", i > 0); 178 classfileBuffer[i] = 'b'; 179 classfileBuffer[i + 1] = 'a'; 180 classfileBuffer[i + 2] = 'r'; 181 } 182 return classfileBuffer; 183 } 184 } 185 }