1 /*
2 * Copyright (c) 2014, 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
40 public class TooSmallStackSize extends TestHelper {
41 /* for debugging. Normally false. */
42 static final boolean verbose = false;
43
44 static void printTestOutput(TestResult tr) {
45 System.out.println("*** exitValue = " + tr.exitValue);
46 for (String x : tr.testOutput) {
47 System.out.println(x);
48 }
49 }
50
51 /*
52 * Returns the minimum stack size this platform will allowed based on the
53 * contents of the error message the JVM outputs when too small of a
54 * -Xss size was used.
55 *
56 * The TestResult argument must contain the result of having already run
57 * the JVM with too small of a stack size.
58 */
59 static String getMinStackAllowed(TestResult tr) {
60 /*
61 * The JVM output will contain in one of the lines:
62 * "The stack size specified is too small, Specify at least 100k"
63 * Although the actual size will vary. We need to extract this size
64 * string from the output and return it.
65 */
66 String matchStr = "Specify at least ";
67 for (String x : tr.testOutput) {
68 int match_idx = x.indexOf(matchStr);
69 if (match_idx >= 0) {
70 int size_start_idx = match_idx + matchStr.length();
71 int k_start_idx = x.indexOf("k", size_start_idx);
72 return x.substring(size_start_idx, k_start_idx + 1); // include the "k"
73 }
74 }
75
76 System.out.println("FAILED: Could not get the stack size from the output");
77 throw new RuntimeException("test fails");
78 }
79
80 /*
81 * Run the JVM with the specified stack size.
82 *
83 * Returns the minimum allowed stack size gleaned from the error message,
84 * if there is an error message. Otherwise returns the stack size passed in.
85 */
86 static String checkStack(String stackSize) {
87 String min_stack_allowed;
88
89 if (verbose)
90 System.out.println("*** Testing " + stackSize);
91 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
92 if (verbose)
93 printTestOutput(tr);
94
95 if (tr.isOK()) {
96 System.out.println("PASSED: got no error message with stack size of " + stackSize);
97 min_stack_allowed = stackSize;
98 } else {
99 if (tr.contains("The stack size specified is too small")) {
100 System.out.println("PASSED: got expected error message with stack size of " + stackSize);
101 min_stack_allowed = getMinStackAllowed(tr);
102 } else {
103 // Likely a crash
104 System.out.println("FAILED: Did not get expected error message with stack size of " + stackSize);
105 throw new RuntimeException("test fails");
106 }
107 }
108
109 return min_stack_allowed;
110 }
111
112 /*
113 * Run the JVM with the minimum allowed stack size. This should always succeed.
114 */
115 static void checkMinStackAllowed(String stackSize) {
116 if (verbose)
117 System.out.println("*** Testing " + stackSize);
118 TestResult tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
119 if (verbose)
120 printTestOutput(tr);
121
122 if (tr.isOK()) {
123 System.out.println("PASSED: VM launched with minimum allowed stack size of " + stackSize);
124 } else {
125 // Likely a crash
126 System.out.println("FAILED: VM failed to launch with minimum allowed stack size of " + stackSize);
127 throw new RuntimeException("test fails");
128 }
129 }
130
131 public static void main(String... args) {
132 /*
133 * The result of a 16k stack size should be a quick exit with a complaint
134 * that the stack size is too small. However, for some win32 builds, the
135 * stack is always at least 64k, and this also sometimes is the minimum
136 * allowed size, so we won't see an error in this case.
137 *
138 * This test case will also produce a crash on some platforms if the fix
139 * for 6762191 is not yet in place.
140 */
141 checkStack("16k");
142
143 /*
144 * Try with a 32k stack size, which is the size that the launcher will
145 * set to if you try setting to anything smaller. This should produce the same
146 * result as setting to 16k if the fix for 6762191 is in place.
147 */
148 String min_stack_allowed = checkStack("32k");
149
150 /*
151 * Try again with a the minimum stack size that was given in the error message
152 */
153 checkMinStackAllowed(min_stack_allowed);
154 }
155 }