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