1 /* 2 * Copyright (c) 2014, 2016, 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 6762191 27 * @summary Setting stack size to 16K causes segmentation fault 28 * @compile TooSmallStackSize.java 29 * @run main TooSmallStackSize 30 */ 31 32 /* 33 * The primary purpose of this test is to make sure we can run with a 16k stack 34 * size without crashing. Also this test will determine the minimum allowed 35 * stack size for the platform (as provided by the JVM error message when a very 36 * small stack is used), and then verify that the JVM can be launched with that stack 37 * size without a crash or any error messages. 38 * 39 * Note: This repo's version of the test uses the '-Xss' option. The 40 * hotspot repo's version of the test uses the '-XX:ThreadStackSize=n' 41 * VM option. 42 */ 43 44 public class TooSmallStackSize extends TestHelper { 45 /* for debugging. Normally false. */ 46 static final boolean verbose = false; 47 48 static void printTestOutput(TestResult tr) { 49 System.out.println("*** exitValue = " + tr.exitValue); 50 for (String x : tr.testOutput) { 51 System.out.println(x); 52 } 53 } 54 55 /* 56 * Returns the minimum stack size this platform will allowed based on the 57 * contents of the error message the JVM outputs when too small of a 58 * -Xss size was used. 59 * 60 * The TestResult argument must contain the result of having already run 61 * the JVM with too small of a stack size. 62 */ 63 static String getMinStackAllowed(TestResult tr) { 64 /* 65 * The JVM output will contain in one of the lines: 66 * "The Java thread stack size specified is too small. Specify at least 100k" 67 * Although the actual size will vary. We need to extract this size 68 * string from the output and return it. 69 */ 70 String matchStr = "Specify at least "; 71 for (String x : tr.testOutput) { 72 int match_idx = x.indexOf(matchStr); 73 if (match_idx >= 0) { 74 int size_start_idx = match_idx + matchStr.length(); 75 int k_start_idx = x.indexOf("k", size_start_idx); 76 return x.substring(size_start_idx, k_start_idx + 1); // include the "k" 77 } 78 } 79 80 System.out.println("FAILED: Could not get the stack size from the output"); 81 throw new RuntimeException("test fails"); 82 } 83 84 /* 85 * Run the JVM with the specified stack size. 86 * 87 * Returns the minimum allowed stack size gleaned from the error message, 88 * if there is an error message. Otherwise returns the stack size passed in. 89 */ 90 static String checkStack(String stackSize) { 91 String min_stack_allowed; 92 93 if (verbose) 94 System.out.println("*** Testing " + stackSize); 95 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version"); 96 if (verbose) 97 printTestOutput(tr); 98 99 if (tr.isOK()) { 100 System.out.println("PASSED: got no error message with stack size of " + stackSize); 101 min_stack_allowed = stackSize; 102 } else { 103 if (tr.contains("The Java thread stack size specified is too small")) { 104 System.out.println("PASSED: got expected error message with stack size of " + stackSize); 105 min_stack_allowed = getMinStackAllowed(tr); 106 } else { 107 // Likely a crash 108 System.out.println("FAILED: Did not get expected error message with stack size of " + stackSize); 109 throw new RuntimeException("test fails"); 110 } 111 } 112 113 return min_stack_allowed; 114 } 115 116 /* 117 * Run the JVM with the minimum allowed stack size. This should always succeed. 118 */ 119 static void checkMinStackAllowed(String stackSize) { 120 if (verbose) 121 System.out.println("*** Testing " + stackSize); 122 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version"); 123 if (verbose) 124 printTestOutput(tr); 125 126 if (tr.isOK()) { 127 System.out.println("PASSED: VM launched with minimum allowed stack size of " + stackSize); 128 } else { 129 // Likely a crash 130 System.out.println("FAILED: VM failed to launch with minimum allowed stack size of " + stackSize); 131 throw new RuntimeException("test fails"); 132 } 133 } 134 135 public static void main(String... args) { 136 /* 137 * The result of a 16k stack size should be a quick exit with a complaint 138 * that the stack size is too small. However, for some win32 builds, the 139 * stack is always at least 64k, and this also sometimes is the minimum 140 * allowed size, so we won't see an error in this case. 141 * 142 * This test case will also produce a crash on some platforms if the fix 143 * for 6762191 is not yet in place. 144 */ 145 checkStack("16k"); 146 147 /* 148 * Try with a 32k stack size, which is the size that the launcher will 149 * set to if you try setting to anything smaller. This should produce the same 150 * result as setting to 16k if the fix for 6762191 is in place. 151 */ 152 String min_stack_allowed = checkStack("32k"); 153 154 /* 155 * Try again with a the minimum stack size that was given in the error message 156 */ 157 checkMinStackAllowed(min_stack_allowed); 158 } 159 }