1 /*
2  * Copyright (c) 2019, 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  * @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 
main(String[] args)41     public static void main(String[] args) {
42         System.err.close();
43         int count = 0;
44         while (count++ < 120000) {
45           test();
46         }
47     }
48 
test()49     public static void test() {
50         byte[] newBufb = serByte(397);
51         short[] newBufs = serShort(397);
52         int[] newBufi = serInt(397);
53         long[] newBufl = serLong(397);
54         if (newBufb.length != 397 || newBufs.length != 397
55             || newBufi.length != 397 || newBufl.length != 397) {
56             System.out.println("array length internal error");
57             throw new RuntimeException("Test failed");
58         }
59 
60     }
61 
serByte(int bufLen)62     public static byte[] serByte(int bufLen) {
63         byte[] buf = new byte[bufLen];
64         THE_UNSAFE.putByte(buf, BYTE_ARRAY_BASE_OFFSET + 1, (byte) buf.length);
65         System.err.println("ref " + buf);
66         return buf;
67     }
68 
serShort(int bufLen)69     public static short[] serShort(int bufLen) {
70         short[] buf = new short[bufLen];
71         THE_UNSAFE.putShort(buf, SHORT_ARRAY_BASE_OFFSET + 1, (short) buf.length);
72         System.err.println("ref " + buf);
73         return buf;
74     }
75 
serInt(int bufLen)76     public static int[] serInt(int bufLen) {
77         int[] buf = new int[bufLen];
78         THE_UNSAFE.putInt(buf, INT_ARRAY_BASE_OFFSET + 1, buf.length);
79         System.err.println("ref " + buf);
80         return buf;
81     }
82 
serLong(int bufLen)83     public static long[] serLong(int bufLen) {
84         long[] buf = new long[bufLen];
85         THE_UNSAFE.putLong(buf, LONG_ARRAY_BASE_OFFSET + 1, buf.length);
86         System.err.println("ref " + buf);
87         return buf;
88     }
89 
90     /* Unsafe fields and initialization
91      */
92     static final Unsafe THE_UNSAFE;
93     static final long BYTE_ARRAY_BASE_OFFSET;
94     static final long SHORT_ARRAY_BASE_OFFSET;
95     static final long INT_ARRAY_BASE_OFFSET;
96     static final long LONG_ARRAY_BASE_OFFSET;
97     static {
98         THE_UNSAFE = (Unsafe) AccessController.doPrivileged (
99             new PrivilegedAction<Object>() {
100                 @Override
101                 public Object run() {
102                     try {
103                         Field f = Unsafe.class.getDeclaredField("theUnsafe");
104                         f.setAccessible(true);
105                         return f.get(null);
106                     } catch (NoSuchFieldException | IllegalAccessException e) {
107                         throw new Error();
108                     }
109                 }
110             }
111         );
112         BYTE_ARRAY_BASE_OFFSET = THE_UNSAFE.arrayBaseOffset(byte[].class);
113         SHORT_ARRAY_BASE_OFFSET = THE_UNSAFE.arrayBaseOffset(short[].class);
114         INT_ARRAY_BASE_OFFSET = THE_UNSAFE.arrayBaseOffset(int[].class);
115         LONG_ARRAY_BASE_OFFSET = THE_UNSAFE.arrayBaseOffset(long[].class);
116     }
117 }
118