1 /*
   2  * Copyright (c) 2010, 2015, 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  * @bug 6968348
  28  * @summary Byteswapped memory access can point to wrong location after JIT
  29  *
  30  * @modules java.base/jdk.internal.misc
  31  * @run main Test6968348
  32  */
  33 
  34 import jdk.internal.misc.Unsafe;
  35 import java.lang.reflect.*;
  36 
  37 public class Test6968348 {
  38     static Unsafe unsafe;
  39     static final long[] buffer = new long[4096];
  40     static int array_long_base_offset;
  41 
  42     public static void main(String[] args) throws Exception {
  43         Class c = Test6968348.class.getClassLoader().loadClass("jdk.internal.misc.Unsafe");
  44         Field f = c.getDeclaredField("theUnsafe");
  45         f.setAccessible(true);
  46         unsafe = (Unsafe)f.get(c);
  47         array_long_base_offset = unsafe.arrayBaseOffset(long[].class);
  48 
  49         for (int n = 0; n < 100000; n++) {
  50             test();
  51         }
  52     }
  53 
  54     public static void test() {
  55         for (long i = array_long_base_offset; i < 4096; i += 8) {
  56             unsafe.putLong(buffer, i, Long.reverseBytes(i));
  57         }
  58     }
  59 }