1 /*
   2  * Copyright (c) 2019, Huawei Technologies Co. Ltd. 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 8202414
  27  * @summary Unsafe write after primitive array creation may result in array length change
  28  * @requires (os.arch != "sparc") & (os.arch != "sparcv9")
  29  * @run main/othervm compiler.c2.Test8202414
  30  */
  31 
  32 package compiler.c2;
  33 
  34 import sun.misc.Unsafe;
  35 import java.lang.reflect.Field;
  36 import java.security.AccessController;
  37 import java.security.PrivilegedAction;
  38 
  39 public class Test8202414 {
  40 
  41     public static void main(String[] args) {
  42         System.err.close();
  43         int count = 0;
  44         while (count++ < 120000) {
  45           test();
  46         }
  47     }
  48 
  49     public static void test() {
  50         byte[] newBuf = serBytes(397);
  51 
  52         if (newBuf.length != 397) {
  53             System.out.println("array length internal error, expected: "
  54               + 397 + " (0x" + Integer.toHexString(397) + ")"
  55               + " actual: " + newBuf.length
  56               + " (0x" + Integer.toHexString(newBuf.length) + ")");
  57             throw new RuntimeException("Test failed");
  58         }
  59     }
  60 
  61     public static byte[] serBytes(int bufLen) {
  62         byte[] buf = new byte[bufLen];
  63         THE_UNSAFE.putInt(buf, BYTE_ARRAY_BASE_OFFSET + 1, buf.length);
  64         System.err.println("ref " + buf);
  65         return buf;
  66     }
  67 
  68     /* Unsafe fields and initialization
  69      */
  70     static final Unsafe THE_UNSAFE;
  71     static final long BYTE_ARRAY_BASE_OFFSET;
  72     static {
  73         THE_UNSAFE = (Unsafe) AccessController.doPrivileged (
  74             new PrivilegedAction<Object>() {
  75                 @Override
  76                 public Object run() {
  77                     try {
  78                         Field f = Unsafe.class.getDeclaredField("theUnsafe");
  79                         f.setAccessible(true);
  80                         return f.get(null);
  81                     } catch (NoSuchFieldException | IllegalAccessException e) {
  82                         throw new Error();
  83                     }
  84                 }
  85             }
  86         );
  87         BYTE_ARRAY_BASE_OFFSET = THE_UNSAFE.arrayBaseOffset(byte[].class);
  88     }
  89 }