1 /*
   2  * Copyright (c) 2010, 2018, 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 /*
  26  * @test
  27  * @modules java.base/jdk.internal.misc
  28  *
  29  * @summary converted from VM Testbase vm/mlvm/anonloader/stress/randomBytecodes.
  30  * VM Testbase keywords: [feature_mlvm, nonconcurrent]
  31  *
  32  * @library /vmTestbase
  33  *          /test/lib
  34  * @run driver jdk.test.lib.FileInstaller . .
  35  *
  36  * @comment build test class and indify classes
  37  * @build vm.mlvm.anonloader.stress.randomBytecodes.Test
  38  * @run driver vm.mlvm.share.IndifiedClassesBuilder
  39  *
  40  * @run main/othervm vm.mlvm.anonloader.stress.randomBytecodes.Test -stressIterationsFactor 100000
  41  */
  42 
  43 package vm.mlvm.anonloader.stress.randomBytecodes;
  44 
  45 import java.util.Arrays;
  46 import vm.mlvm.anonloader.share.StressClassLoadingTest;
  47 
  48 /**
  49  * The test does the following in a cycle:
  50  * <ol>
  51  * <li>Creates a class bytecodes that has a valid 12-byte header
  52  *     and has totally random bytes after the header
  53  * <li>Tries to load such class using:
  54  *     <ul>
  55  *       <li>a custom class loader, or
  56  *       <li>{@link sun.misc.Unsafe#defineAnonymousClass}
  57  *           when {@code -unsafeLoad true} is set.
  58  *     </ul>
  59  * </ol>
  60  *
  61  * <p>In most cases the resulting class file is invalid and rejected by
  62  * the VM verifier. But this test is looking for pathological cases
  63  * such as infinite loops in the verifier or VM crashes.
  64  *
  65  * <p>NB: There is a tool to load invalid classes saved by this test.
  66  * Please see tool documentation at {@link vm.mlvm.tools.LoadClass}.
  67  *
  68  */
  69 public class Test extends StressClassLoadingTest {
  70     private static final Class<?> HOST_CLASS = Test.class;
  71     private static final int MAX_SIZE = 0xFFF7;
  72     private static final byte[] CLASS_HEADER = new byte[] {
  73         (byte)0xCA, (byte)0xFE, (byte)0xBA, (byte)0xBE,
  74         0x00, 0x00, 0x00, 0x32
  75     };
  76 
  77     /**
  78      * Returns {@link vm.mlvm.anonloader.share.AnonkTestee01} class to the
  79      * parent.
  80      * @return {@link vm.mlvm.anonloader.share.AnonkTestee01} class.
  81      */
  82     @Override
  83     protected Class<?> getHostClass() {
  84         return HOST_CLASS;
  85     }
  86 
  87     /**
  88      * Generates a class with valid header (magic and version fields) and
  89      * random bytes after the header.
  90      * <p>Class size is random ([8..65527]).
  91      * Byte values are limited to [0..11] range in order to increase
  92      * possiblity that the random class passes the initial (dead-on-arrival)
  93      * stages of the verifier and is rejected
  94      * in more interesting ones, like method bytecode verification.
  95      * Class version is 52.
  96      *
  97      * @return Class with valid Java header (8 bytes) and totally random bytes
  98      * after the header
  99      */
 100     @Override
 101     protected byte[] generateClassBytes() {
 102         final byte[] classBytes = Arrays.copyOf(CLASS_HEADER,
 103                 CLASS_HEADER.length + getRNG().nextInt(MAX_SIZE));
 104         for (int j = CLASS_HEADER.length; j < classBytes.length; j++) {
 105             classBytes[j] = (byte) getRNG().nextInt(12);
 106         }
 107 
 108         return classBytes;
 109     }
 110 
 111     /**
 112      * Runs the test.
 113      * @param args Test arguments.
 114      */
 115     public static void main(String[] args) {
 116         StressClassLoadingTest.launch(args);
 117     }
 118 }