1 /*
   2  * Copyright (c) 2019, Red Hat, Inc. 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 8216549
  27  * @summary Mismatched unsafe access to non escaping object fails
  28  *
  29  * @modules java.base/jdk.internal.misc
  30  * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation MismatchedUnsafeLoadFromNewObject
  31  */
  32 
  33 import java.lang.reflect.Field;
  34 import jdk.internal.misc.Unsafe;
  35 
  36 public class MismatchedUnsafeLoadFromNewObject {
  37     public volatile int f_int = -1;
  38     public volatile int f_int2 = -1;
  39 
  40     public static Unsafe unsafe = Unsafe.getUnsafe();
  41     public static final long f_int_off;
  42     public static final long f_int2_off;
  43 
  44     static {
  45         Field f_int_field = null;
  46         Field f_int2_field = null;
  47         try {
  48             f_int_field = MismatchedUnsafeLoadFromNewObject.class.getField("f_int");
  49             f_int2_field = MismatchedUnsafeLoadFromNewObject.class.getField("f_int2");
  50         } catch (Exception e) {
  51             System.out.println("reflection failed " + e);
  52             e.printStackTrace();
  53         }
  54         f_int_off = unsafe.objectFieldOffset(f_int_field);
  55         f_int2_off = unsafe.objectFieldOffset(f_int2_field);
  56     }
  57 
  58     static public void main(String[] args) {
  59         for (int i = 0; i < 20_000; i++) {
  60             byte res = test1();
  61             if (res != -1) {
  62                 throw new RuntimeException("Incorrect result: " + res);
  63             }
  64             res = test2();
  65             if (res != -1) {
  66                 throw new RuntimeException("Incorrect result: " + res);
  67             }
  68             int res2 = test3();
  69             if (res2 != -1) {
  70                 throw new RuntimeException("Incorrect result: " + res2);
  71             }
  72         }
  73     }
  74 
  75     static byte test1() {
  76         MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
  77         return unsafe.getByte(t, f_int_off);
  78     }
  79 
  80     static byte test2() {
  81         MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
  82         return unsafe.getByte(t, f_int_off+1);
  83     }
  84 
  85     static int test3() {
  86         MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
  87         if (f_int_off < f_int2_off) {
  88             return unsafe.getIntUnaligned(t, f_int_off+1);
  89         } else {
  90             return unsafe.getIntUnaligned(t, f_int2_off+1);
  91         }
  92     }
  93 }