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 package jdk.vm.ci.hotspot;
24
25 import static java.lang.String.format;
26
27 import java.io.IOException;
28 import java.io.InputStream;
29 import java.lang.reflect.Constructor;
30 import java.lang.reflect.Executable;
31 import java.lang.reflect.Method;
32 import java.lang.reflect.Modifier;
33 import java.util.Arrays;
34 import java.util.Objects;
35
36 import jdk.internal.misc.Unsafe;
37 import jdk.internal.org.objectweb.asm.ClassReader;
38 import jdk.internal.org.objectweb.asm.ClassVisitor;
39 import jdk.internal.org.objectweb.asm.Label;
40 import jdk.internal.org.objectweb.asm.MethodVisitor;
41 import jdk.internal.org.objectweb.asm.Opcodes;
42 import jdk.internal.org.objectweb.asm.Type;
43
44 /**
45 * A {@link ClassVisitor} that verifies {@link HotSpotVMConfig} does not access {@link Unsafe} from
46 * any of its non-static, non-constructor methods. This ensures that a deserialized
47 * {@link HotSpotVMConfig} object does not perform any unsafe reads on addresses that are only valid
48 * in the context in which the object was serialized. Note that this does not catch cases where a
49 * client uses an address stored in a {@link HotSpotVMConfig} field.
50 */
51 final class HotSpotVMConfigVerifier extends ClassVisitor {
52
53 public static boolean check() {
54 Class<?> cls = HotSpotVMConfig.class;
55 String classFilePath = "/" + cls.getName().replace('.', '/') + ".class";
56 try {
57 InputStream classfile = cls.getResourceAsStream(classFilePath);
58 ClassReader cr = new ClassReader(Objects.requireNonNull(classfile, "Could not find class file for " + cls.getName()));
59 ClassVisitor cv = new HotSpotVMConfigVerifier();
60 cr.accept(cv, 0);
61 return true;
62 } catch (IOException e) {
63 throw new InternalError(e);
64 }
65 }
66
67 /**
68 * Source file context for error reporting.
69 */
70 String sourceFile = null;
71
72 /**
73 * Line number for error reporting.
74 */
75 int lineNo = -1;
76
77 private static Class<?> resolve(String name) {
78 try {
79 return Class.forName(name.replace('/', '.'));
80 } catch (ClassNotFoundException e) {
81 throw new InternalError(e);
82 }
83 }
84
85 HotSpotVMConfigVerifier() {
86 super(Opcodes.ASM5);
87 }
88
89 @Override
90 public void visitSource(String source, String debug) {
91 this.sourceFile = source;
92 }
93
94 void verify(boolean condition, String message) {
95 if (!condition) {
96 error(message);
97 }
98 }
99
100 void error(String message) {
101 String errorMessage = format("%s:%d: %s is not allowed in the context of compilation replay. The unsafe access should be moved into the %s constructor and the result cached in a field",
102 sourceFile, lineNo, message, HotSpotVMConfig.class.getSimpleName());
103 throw new InternalError(errorMessage);
104
105 }
106
107 @Override
108 public MethodVisitor visitMethod(int access, String name, String d, String signature, String[] exceptions) {
109 if (!Modifier.isStatic(access) && Modifier.isPublic(access) && !name.equals("<init>")) {
110 return new MethodVisitor(Opcodes.ASM5) {
111
112 @Override
113 public void visitLineNumber(int line, Label start) {
114 lineNo = line;
115 }
116
117 private Executable resolveMethod(String owner, String methodName, String methodDesc) {
118 Class<?> declaringClass = resolve(owner);
119 while (declaringClass != null) {
120 if (methodName.equals("<init>")) {
121 for (Constructor<?> c : declaringClass.getDeclaredConstructors()) {
122 if (methodDesc.equals(Type.getConstructorDescriptor(c))) {
123 return c;
124 }
125 }
126 } else {
127 Type[] argumentTypes = Type.getArgumentTypes(methodDesc);
128 for (Method m : declaringClass.getDeclaredMethods()) {
129 if (m.getName().equals(methodName)) {
130 if (Arrays.equals(argumentTypes, Type.getArgumentTypes(m))) {
131 if (Type.getReturnType(methodDesc).equals(Type.getReturnType(m))) {
132 return m;
133 }
134 }
135 }
136 }
137 }
138 declaringClass = declaringClass.getSuperclass();
139 }
140 throw new NoSuchMethodError(owner + "." + methodName + methodDesc);
141 }
142
143 /**
144 * Checks whether a given method is allowed to be called.
145 */
146 private boolean checkInvokeTarget(Executable method) {
147 if (method.getDeclaringClass().equals(Unsafe.class)) {
148 return false;
149 }
150 return true;
151 }
152
153 @Override
154 public void visitMethodInsn(int opcode, String owner, String methodName, String methodDesc, boolean itf) {
155 Executable callee = resolveMethod(owner, methodName, methodDesc);
156 verify(checkInvokeTarget(callee), "invocation of " + callee);
157 }
158 };
159 } else {
160 return null;
161 }
162 }
163 }