1 /*
2 * Copyright (c) 2014, 2017, 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: The '-Xss<size>' and '-XX:ThreadStackSize=<k-bytes>' options
40 * both control Java thread stack size. This repo's version of the test
41 * exercises the '-Xss' option. The hotspot repo's version of the test
42 * exercises the '-XX:ThreadStackSize' VM option.
43 */
44
45 public class TooSmallStackSize extends TestHelper {
46 /* for debugging. Normally false. */
47 static final boolean verbose = false;
48
49 static void printTestOutput(TestResult tr) {
50 System.out.println("*** exitValue = " + tr.exitValue);
51 for (String x : tr.testOutput) {
52 System.out.println(x);
53 }
54 }
55
56 /*
57 * Returns the minimum stack size this platform will allowed based on the
58 * contents of the error message the JVM outputs when too small of a
59 * -Xss size was used.
60 *
61 * The TestResult argument must contain the result of having already run
62 * the JVM with too small of a stack size.
63 */
64 static String getMinStackAllowed(TestResult tr) {
65 /*
66 * The JVM output will contain in one of the lines:
67 * "The Java thread stack size specified is too small. Specify at least 100k"
68 * Although the actual size will vary. We need to extract this size
69 * string from the output and return it.
70 */
71 String matchStr = "Specify at least ";
72 for (String x : tr.testOutput) {
73 int match_idx = x.indexOf(matchStr);
74 if (match_idx >= 0) {
75 int size_start_idx = match_idx + matchStr.length();
76 int k_start_idx = x.indexOf("k", size_start_idx);
77 return x.substring(size_start_idx, k_start_idx + 1); // include the "k"
78 }
79 }
80
81 System.out.println("Expect='" + matchStr + "'");
82 System.out.println("Actual:");
83 printTestOutput(tr);
84 System.out.println("FAILED: Could not get the stack size from the output");
85 throw new RuntimeException("test fails");
86 }
87
88 /*
89 * Run the JVM with the specified stack size.
90 *
91 * Returns the minimum allowed stack size gleaned from the error message,
92 * if there is an error message. Otherwise returns the stack size passed in.
93 */
94 static String checkStack(String stackSize) {
95 String min_stack_allowed;
96
97 if (verbose)
98 System.out.println("*** Testing " + stackSize);
99 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
100 if (verbose)
101 printTestOutput(tr);
102
103 if (tr.isOK()) {
104 System.out.println("PASSED: got no error message with stack size of " + stackSize);
105 min_stack_allowed = stackSize;
106 } else {
107 String matchStr = "The Java thread stack size specified is too small";
108 if (tr.contains(matchStr)) {
109 System.out.println("PASSED: got expected error message with stack size of " + stackSize);
110 min_stack_allowed = getMinStackAllowed(tr);
111 } else {
112 // Likely a crash
113 System.out.println("Expect='" + matchStr + "'");
114 System.out.println("Actual:");
115 printTestOutput(tr);
116 System.out.println("FAILED: Did not get expected error message with stack size of " + stackSize);
117 throw new RuntimeException("test fails");
118 }
119 }
120
121 return min_stack_allowed;
122 }
123
124 /*
125 * Run the JVM with the minimum allowed stack size. This should always succeed.
126 */
127 static void checkMinStackAllowed(String stackSize) {
128 if (verbose)
129 System.out.println("*** Testing " + stackSize);
130 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
131 if (verbose)
132 printTestOutput(tr);
133
134 if (tr.isOK()) {
135 System.out.println("PASSED: VM launched with minimum allowed stack size of " + stackSize);
136 } else {
137 // Likely a crash
138 System.out.println("Test output:");
139 printTestOutput(tr);
140 System.out.println("FAILED: VM failed to launch with minimum allowed stack size of " + stackSize);
141 throw new RuntimeException("test fails");
142 }
143 }
144
145 public static void main(String... args) {
146 /*
147 * The result of a 16k stack size should be a quick exit with a complaint
148 * that the stack size is too small. However, for some win32 builds, the
149 * stack is always at least 64k, and this also sometimes is the minimum
150 * allowed size, so we won't see an error in this case.
151 *
152 * This test case will also produce a crash on some platforms if the fix
153 * for 6762191 is not yet in place.
154 */
155 checkStack("16k");
156
157 /*
158 * Try with a 64k stack size, which is the size that the launcher will
159 * set to if you try setting to anything smaller. This should produce the same
160 * result as setting to 16k if the fix for 6762191 is in place.
161 */
162 String min_stack_allowed = checkStack("64k");
163
164 /*
165 * Try again with a the minimum stack size that was given in the error message
166 */
167 checkMinStackAllowed(min_stack_allowed);
168
169 /*
170 * Try again with a size that is not OS page aligned. This is to help test that
171 * asserts added for 8176768 are not triggered.
172 */
173 checkMinStackAllowed("513k");
174
175 /*
176 * Try with 0k which indicates that the default thread stack size either from JVM or system
177 * will be used, this should always succeed. It can verify the issue fixed in 8222334.
178 */
179 checkMinStackAllowed("0k");
180 }
181 }