1 /*

     2  * Copyright (c) 2013, 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  * @key regression

    27  * @bug 8012015

    28  * @summary Make sure reserved (but uncommitted) memory is not accessible

    29  * @library /testlibrary /testlibrary/whitebox

    30  * @build ReserveMemory

    31  * @run main ClassFileInstaller sun.hotspot.WhiteBox

    32  * @run main ReserveMemory

    33  */

    34 

    35 import com.oracle.java.testlibrary.*;

    36 

    37 import java.lang.reflect.Field;

    38 import sun.hotspot.WhiteBox;

    39 import sun.misc.Unsafe;

    40 

    41 public class ReserveMemory {

    42   private static Unsafe getUnsafe() throws Exception {

    43     Field f = Unsafe.class.getDeclaredField("theUnsafe");

    44     f.setAccessible(true);

    45     return (Unsafe)f.get(null);

    46   }

    47 

    48   private static boolean isWindows() {

    49     return System.getProperty("os.name").toLowerCase().startsWith("win");

    50   }

    51 

    52   public static void main(String args[]) throws Exception {

    53     if (args.length > 0) {

    54       long address = WhiteBox.getWhiteBox().reserveMemory(4096);

    55 

    56       System.out.println("Reserved memory at address: 0x" + Long.toHexString(address));

    57       System.out.println("Will now read from the address, expecting a crash!");

    58 

    59       int x = getUnsafe().getInt(address);

    60 

    61       throw new Exception("Read of reserved/uncommitted memory unexpectedly succeeded, expected crash!");

    62     }

    63 

    64     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(

    65           "-Xbootclasspath/a:.",

    66           "-XX:+UnlockDiagnosticVMOptions",

    67           "-XX:+WhiteBoxAPI",

    68           "ReserveMemory",

    69           "test");

    70 

    71     OutputAnalyzer output = new OutputAnalyzer(pb.start());

    72     if (isWindows()) {

    73       output.shouldContain("EXCEPTION_ACCESS_VIOLATION");

    74     } else {

    75       output.shouldContain("SIGSEGV");

    76     }

    77   }

    78 }