1/* 2 * Copyright (c) 2017, 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 8181742 27 * @summary Loads that bypass arraycopy ends up with wrong memory state 28 * 29 * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:+UnlockDiagnosticVMOptions -XX:+IgnoreUnrecognizedVMOptions -XX:+StressGCM -XX:+StressLCM TestLoadBypassACWithWrongMem 30 * 31 */ 32 33import java.util.Arrays; 34 35public class TestLoadBypassACWithWrongMem { 36 37 static int test1(int[] src) { 38 int[] dst = new int[10]; 39 System.arraycopy(src, 0, dst, 0, 10); 40 src[1] = 0x42; 41 // dst[1] is transformed to src[1], src[1] must use the 42 // correct memory state (not the store above). 43 return dst[1]; 44 } 45 46 static int test2(int[] src) { 47 int[] dst = (int[])src.clone(); 48 src[1] = 0x42; 49 // Same as above for clone 50 return dst[1]; 51 } 52 53 static Object test5_src = null; 54 static int test3() { 55 int[] dst = new int[10]; 56 System.arraycopy(test5_src, 0, dst, 0, 10); 57 ((int[])test5_src)[1] = 0x42; 58 System.arraycopy(test5_src, 0, dst, 0, 10); 59 // dst[1] is transformed to test5_src[1]. test5_src is Object 60 // but test5_src[1] must be on the slice for int[] not 61 // Object+some offset. 62 return dst[1]; 63 } 64 65 static public void main(String[] args) { 66 int[] src = new int[10]; 67 for (int i = 0; i < 20000; i++) { 68 Arrays.fill(src, 0); 69 int res = test1(src); 70 if (res != 0) { 71 throw new RuntimeException("bad result: " + res + " != " + 0); 72 } 73 Arrays.fill(src, 0); 74 res = test2(src); 75 if (res != 0) { 76 throw new RuntimeException("bad result: " + res + " != " + 0); 77 } 78 Arrays.fill(src, 0); 79 test5_src = src; 80 res = test3(); 81 if (res != 0x42) { 82 throw new RuntimeException("bad result: " + res + " != " + 0x42); 83 } 84 } 85 } 86} 87