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 RedefineMethodUsedByMultipleMethodHandlesNoASM.java
29 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+EnableInvokeDynamic RedefineMethodUsedByMultipleMethodHandlesNoASM
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 public class RedefineMethodUsedByMultipleMethodHandlesNoASM {
45
46 static class Foo {
47 public static Object getName() {
48 int fooInt = 1;
49 if (true) {
50 // We "just know" that this creates bytecodes:
51 // bipush 0x7 0x10 0x7
52 // ishl 0x78
53 fooInt <<= 0x7;
54 }
55 return "foo" + fooInt;
56 }
57 }
58
59 public static void main(String[] args) throws Throwable {
60
61 Lookup lookup = MethodHandles.lookup();
62 Method fooMethod = Foo.class.getDeclaredMethod("getName");
63
64 // fooMH2 displaces fooMH1 from the MemberNamesTable
65 MethodHandle fooMH1 = lookup.unreflect(fooMethod);
66 MethodHandle fooMH2 = lookup.unreflect(fooMethod);
67
68 System.out.println("Foo.getName() = " + Foo.getName());
69 System.out.println("fooMH1.invoke = " + fooMH1.invokeExact());
70 System.out.println("fooMH2.invoke = " + fooMH2.invokeExact());
71
72 // Redefining Foo.getName() causes vmtarget to be updated
73 // in fooMH2 but not fooMH1
74 redefineFoo();
75
76 // Full GC causes fooMH1.vmtarget to be deallocated
77 System.gc();
78
79 // Calling fooMH1.vmtarget crashes the VM on JDK8, on JDK7 we see
80 // the wrong method invoked, we execute the old code.
81 Object newResult = fooMH1.invokeExact();
82 System.out.println("fooMH1.invoke = " + fooMH1.invokeExact());
83 if (!((String) newResult).equals("foo32")) {
84 throw new RuntimeException("failed, fooMH1 invoke gets '" + newResult + "'");
85 }
86 }
87
88 /**
89 * Adds the class file bytes for {@code c} to {@code jar}.
90 */
91 static void add(JarOutputStream jar, Class<?> c) throws IOException {
92 String classAsPath = c.getName().replace('.', '/') + ".class";
93 jar.putNextEntry(new JarEntry(classAsPath));
94 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath);
95
96 int b;
97 while ((b = stream.read()) != -1) {
98 jar.write(b);
99 }
100 }
101
102 static void redefineFoo() throws Exception {
103 Manifest manifest = new Manifest();
104 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
105 Attributes mainAttrs = manifest.getMainAttributes();
106 mainAttrs.putValue("Agent-Class", FooAgent.class.getName());
107 mainAttrs.putValue("Can-Redefine-Classes", "true");
108 mainAttrs.putValue("Can-Retransform-Classes", "true");
109
110 Path jar = Files.createTempFile("myagent", ".jar");
111 try {
112 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest);
113 add(jarStream, FooAgent.class);
114 add(jarStream, FooTransformer.class);
115 jarStream.close();
116 runAgent(jar);
117 } finally {
118 Files.deleteIfExists(jar);
119 }
120 }
121
122 public static void runAgent(Path agent) throws Exception {
123 String vmName = ManagementFactory.getRuntimeMXBean().getName();
124 int p = vmName.indexOf('@');
125 assert p != -1 : "VM name not in <pid>@<host> format: " + vmName;
126 String pid = vmName.substring(0, p);
127 ClassLoader cl = ToolProvider.getSystemToolClassLoader();
128 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl);
129 Method attach = c.getDeclaredMethod("attach", String.class);
130 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class);
131 Method detach = c.getDeclaredMethod("detach");
132 Object vm = attach.invoke(null, pid);
133 loadAgent.invoke(vm, agent.toString());
134 detach.invoke(vm);
135 }
136
137 public static class FooAgent {
138
139 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception {
140 assert inst.isRedefineClassesSupported();
141 assert inst.isRetransformClassesSupported();
142 inst.addTransformer(new FooTransformer(), true);
143 Class<?>[] classes = inst.getAllLoadedClasses();
144 for (int i = 0; i < classes.length; i++) {
145 Class<?> c = classes[i];
146 if (c == Foo.class) {
147 inst.retransformClasses(new Class[]{c});
148 }
149 }
150 }
151 }
152
153
154 /**
155 * This method will only be called on the class Foo, above, and that class
156 * only has the method getName().
157 * Avoid using the objectweb ASM library as we do in jdk8, by
158 * looking for a specific bytecode pattern (which this method does not really
159 * understand).
160 */
161 static class FooTransformer implements ClassFileTransformer {
162
163 @Override
164 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain,
165 byte[] classfileBuffer) throws IllegalClassFormatException {
166
167
168 if (Foo.class.equals(classBeingRedefined)) {
169
170 try {
171 System.out.println("redefining " + classBeingRedefined);
172 ByteArrayOutputStream baos = new ByteArrayOutputStream();
173 InputStream is = new ByteArrayInputStream(classfileBuffer);
174 copyWithSubstitution(is, new byte[] {(byte)0x10,(byte)0x07,(byte)0x78},
175 new byte[] {(byte)0x10,(byte)0x05,(byte)0x78},
176 baos);
177 return baos.toByteArray();
178 } catch(Exception e) {
179 e.printStackTrace();
180 }
181 }
182 return classfileBuffer;
183 }
184
185 /**
186 * Copy bytes from a Reader to an OutputStream. If a sequence of bytes
187 * matches the given oldBytes byte array, write the newBytes array instead.
188 */
189 public void copyWithSubstitution(InputStream is, byte[] oldBytes, byte [] newBytes, OutputStream out) throws Exception {
190
191 byte[] buffer = new byte[oldBytes.length];
192
193 while (is.available() > 0) {
194 int i = 0xff & is.read();
195 if (i != oldBytes[0]) {
196 out.write(i);
197 continue;
198 }
199 int pos = 0;
200 while (pos < oldBytes.length && oldBytes[pos] == (byte) i) {
201 buffer[pos] = (byte) i;
202 pos++;
203 i = is.read();
204 }
205 // We have read as much as matches oldBytes, plus one byte (now in i).
206 // Write out:
207 // buffer it if did not match fully
208 // new bytes if it was a full match
209 if (pos > 0) {
210 if (pos == oldBytes.length) {
211 System.out.println("copyWithSubstitution: replacing: ");
212 printBytesOn(System.out, buffer);
213 System.out.println("copyWithSubstitution: with:");
214 printBytesOn(System.out, newBytes);
215 out.write(newBytes, 0, newBytes.length);
216 } else {
217 out.write(buffer, 0, pos);
218 }
219 }
220 // Does not handle two sequential occurrences of oldBytes.
221 out.write(i);
222 }
223 out.close();
224 }
225
226
227 public static void printBytesOn(PrintStream out, byte[] bytes) {
228 int numColumns = 16;
229 int column = 0;
230 for (int i = 0; i < bytes.length; i++) {
231 if (column == 0) {
232 out.print(i);
233 out.print("\t");
234 }
235 out.print("0x" + Integer.toHexString(255 & bytes[i])
236 /* + " (" + (char) bytes[i] + */ + "\t");
237 column++;
238 if (column == numColumns) {
239 out.println();
240 column = 0;
241 }
242 }
243 out.println();
244 }
245 }
246 }