1 /*
2 * Copyright (c) 2015, 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 ReservedStackTest
26 * @library /testlibrary
27 * @build jdk.test.lib.*
28 * @run main/othervm -XX:-Inline -XX:CompileCommand=exclude,java/util/concurrent/locks/AbstractOwnableSynchronizer.setExclusiveOwnerThread ReservedStackTest
29 */
30
31 /* The exclusion of java.util.concurrent.locks.AbstractOwnableSynchronizer.setExclusiveOwnerThread()
32 * from the compilable methods is required to ensure that the test will be able
33 * to trigger a StackOverflowError on the right method.
34 */
35
36
37 /*
38 * Notes about this test:
39 * This test tries to reproduce a rare but nasty corruption bug that
40 * occurs when a StackOverflowError is thrown in some critical sections
41 * of the ReentrantLock implementation.
42 *
43 * Here's the critical section where a corruption could occur
44 * (from java.util.concurrent.ReentrantLock.java)
45 *
46 * final void lock() {
47 * if (compareAndSetState(0, 1))
48 * setExclusiveOwnerThread(Thread.currentThread());
49 * else
50 * acquire(1);
51 * }
52 *
53 * The corruption occurs when the compareAndSetState(0, 1)
54 * successfully updates the status of the lock but the method
55 * fails to set the owner because of a stack overflow.
56 * HotSpot checks for stack overflow on method invocations.
57 * The test must trigger a stack overflow either when
58 * Thread.currentThread() or setExclusiveOwnerThread() is
59 * invoked.
60 *
61 * The test starts with a recursive invocation loop until a
62 * first StackOverflowError is thrown, the Error is caught
63 * and a few dozen frames are exited. Now the thread has
64 * little free space on its execution stack and will try
65 * to trigger a stack overflow in the critical section.
66 * The test has a huge array of ReentrantLocks instances.
67 * The thread invokes a recursive method which, at each
68 * of its invocations, tries to acquire the next lock
69 * in the array. The execution continues until a
70 * StackOverflowError is thrown or the end of the array
71 * is reached.
72 * If no StackOverflowError has been thrown, the test
73 * is non conclusive (recommendation: increase the size
74 * of the ReentrantLock array).
75 * The status of all Reentrant locks in the array is checked,
76 * if a corruption is detected, the test failed, otherwise
77 * the test passed.
78 *
79 * To have a chance that the stack overflow occurs on one
80 * of the two targeted method invocations, the test is
81 * repeated in different threads. Each Java thread has a
82 * random size area allocated at the beginning of its
83 * stack to prevent false sharing. The test relies on this
84 * to have different stack alignments when it hits the targeted
85 * methods (the test could have been written with a native
86 * method with alloca, but using different Java threads makes
87 * the test 100% Java).
88 *
89 * One additional trick is required to ensure that the stack
90 * overflow will occur on the Thread.currentThread() getter
91 * or the setExclusiveOwnerThread() setter.
92 *
93 * Potential stack overflows are detected by stack banging,
94 * at method invocation time.
95 * In interpreted code, the stack banging performed for the
96 * lock() method goes further than the stack banging performed
97 * for the getter or the setter method, so the potential stack
98 * overflow is detected before entering the critical section.
99 * In compiled code, the getter and the setter are in-lined,
100 * so the stack banging is only performed before entering the
101 * critical section.
102 * In order to have a stack banging that goes further for the
103 * getter/setter methods than for the lock() method, the test
104 * exploits the property that interpreter frames are (much)
105 * bigger than compiled code frames. When the test is run,
106 * a compiler option disables the compilation of the
107 * setExclusiveOwnerThread() method.
108 *
109 */
110
111 import java.util.concurrent.locks.ReentrantLock;
112 import jdk.test.lib.Platform;
113
114 public class ReservedStackTest {
115
116 static class ReentrantLockTest {
117
118 private ReentrantLock lockArray[];
119 // Frame sizes vary a lot between interpreted code and compiled code
120 // so the lock array has to be big enough to cover all cases.
121 // If test fails with message "Not conclusive test", try to increase
122 // LOCK_ARRAY_SIZE value
123 private static final int LOCK_ARRAY_SIZE = 8192;
124 private boolean stackOverflowErrorReceived;
125 StackOverflowError soe = null;
126 private int index = -1;
127
128 public void initialize() {
129 lockArray = new ReentrantLock[LOCK_ARRAY_SIZE];
130 for (int i = 0; i < LOCK_ARRAY_SIZE; i++) {
131 lockArray[i] = new ReentrantLock();
132 }
133 stackOverflowErrorReceived = false;
134 }
135
136 public String getResult() {
137 if (!stackOverflowErrorReceived) {
138 return "ERROR: Not conclusive test: no StackOverflowError received";
139 }
140 for (int i = 0; i < LOCK_ARRAY_SIZE; i++) {
141 if (lockArray[i].isLocked()) {
142 if (!lockArray[i].isHeldByCurrentThread()) {
143 StringBuilder s = new StringBuilder();
144 s.append("FAILED: ReentrantLock ");
145 s.append(i);
146 s.append(" looks corrupted");
147 return s.toString();
148 }
149 }
150 }
151 return "PASSED";
152 }
153
154 public void run() {
155 try {
156 lockAndCall(0);
157 } catch (StackOverflowError e) {
158 soe = e;
159 stackOverflowErrorReceived = true;
160 }
161 }
162
163 private void lockAndCall(int i) {
164 index = i;
165 if (i < LOCK_ARRAY_SIZE) {
166 lockArray[i].lock();
167 lockAndCall(i + 1);
168 }
169 }
170 }
171
172 static class RunWithSOEContext implements Runnable {
173
174 int counter;
175 int deframe;
176 int decounter;
177 int setupSOEFrame;
178 int testStartFrame;
179 ReentrantLockTest test;
180
181 public RunWithSOEContext(ReentrantLockTest test, int deframe) {
182 this.test = test;
183 this.deframe = deframe;
184 }
185
186 @Override
187 @jdk.internal.vm.annotation.ReservedStackAccess
188 public void run() {
189 counter = 0;
190 decounter = deframe;
191 test.initialize();
192 recursiveCall();
193 System.out.println("Framework got StackOverflowError at frame = " + counter);
194 System.out.println("Test started execution at frame = " + (counter - deframe));
195 String result = test.getResult();
196 // The feature is not fully implemented on all platforms,
197 // corruptions are still possible
198 boolean supportedPlatform = Platform.isSolaris() || Platform.isOSX()
199 || (Platform.isLinux() && (Platform.isX86() || Platform.isX64()));
200 if (supportedPlatform && !result.contains("PASSED")) {
201 System.out.println(result);
202 throw new Error(result);
203 } else {
204 // Either the test passed or this platform is not supported.
205 // On not supported platforms, we only expect the VM to
206 // not crash during the test. This is especially important
207 // on Windows where the detection of SOE in annotated
208 // sections is implemented but the reserved zone mechanism
209 // to avoid the corruption cannot be implemented yet
210 // because of JDK-8067946
211 System.out.println("PASSED");
212 }
213 }
214
215 void recursiveCall() {
216 // Unused local variables to increase the frame size
217 long l1, l2, l3, l4, l5, l6, l7, l8, l9, l10, l11, l12, l13, l14, l15, l16, l17, l18, l19;
218 long l20, l21, l22, l23, l24, l25, l26, l27, l28, l30, l31, l32, l33, l34, l35, l36, l37;
219 counter++;
220 try {
221 recursiveCall();
222 } catch (StackOverflowError e) {
223 }
224 decounter--;
225 if (decounter == 0) {
226 setupSOEFrame = counter;
227 testStartFrame = counter - deframe;
228 test.run();
229 }
230 }
231 }
232
233 public static void main(String[] args) {
234 for (int i = 0; i < 1000; i++) {
235 // Each iteration has to be executed by a new thread. The test
236 // relies on the random size area pushed by the VM at the beginning
237 // of the stack of each Java thread it creates.
238 Thread thread = new Thread(new RunWithSOEContext(new ReentrantLockTest(), 256));
239 thread.start();
240 try {
241 thread.join();
242 } catch (InterruptedException ex) { }
243 }
244 }
245 }