1 /*
2 * Copyright (c) 2010, 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 /* This code tests the fact that we actually remove stack guard page when calling
26 * JavaThread::exit() i.e. when detaching from current thread.
27 * We overflow the stack and check that we get access error because of a guard page.
28 * than detaching from vm thread and overflow stack once again. This time we shouldn't
29 * get access error because stack guard page is removed
30 *
31 * Notice: due a complicated interaction of signal handlers, the test may crash.
32 * It's OK - don't file a bug.
33 */
34
35 #include <assert.h>
36 #include <jni.h>
37 #include <alloca.h>
38 #include <signal.h>
39 #include <sys/mman.h>
40 #include <stdlib.h>
41 #include <sys/ucontext.h>
42 #include <setjmp.h>
43 #include <unistd.h>
44 #include <sys/syscall.h>
45 #include <errno.h>
46
47 #include <pthread.h>
48
49 JavaVM* _jvm;
50
51 static jmp_buf context;
52
53 static int _last_si_code;
54 static int _failures = 0;
55
56 pid_t gettid() {
57 return (pid_t) syscall(SYS_gettid);
58 }
59
60 static void handler(int sig, siginfo_t *si, void *unused) {
61 _last_si_code = si->si_code;
62 printf("Got SIGSEGV(%d) at address: 0x%lx\n",si->si_code, (long) si->si_addr);
63 longjmp(context, 1);
64 }
65
66 void set_signal_handler() {
67 static char altstack[SIGSTKSZ];
68
69 stack_t ss = {
70 .ss_size = SIGSTKSZ,
71 .ss_flags = 0,
72 .ss_sp = altstack
73 };
74
75 struct sigaction sa = {
76 .sa_sigaction = handler,
77 .sa_flags = SA_ONSTACK | SA_SIGINFO | SA_RESETHAND
78 };
79
80 sigaltstack(&ss, 0);
81 sigemptyset(&sa.sa_mask);
82 if (sigaction(SIGSEGV, &sa, NULL) == -1) {
83 perror("sigaction");
84 }
85 }
86
87 void *run_java_overflow (void *p) {
88 JNIEnv *env;
89 jclass class_id;
90 jmethodID method_id;
91
92 (*_jvm)->AttachCurrentThread(_jvm, (void**)&env, NULL);
93
94 class_id = (*env)->FindClass (env, "DoOverflow");
95 if (class_id == NULL) {
96 printf("Test ERROR. Can't load class DoOverflow\n");
97 exit(7);
98 }
99
100 method_id = (*env)->GetStaticMethodID(env, class_id, "printIt", "()V");
101 if (method_id == NULL) {
102 printf("Test ERROR. Can't find method DoOverflow.printIt\n");
103 exit(7);
104 }
105
106 (*env)->CallStaticVoidMethod(env, class_id, method_id, NULL);
107
108 (*_jvm)->DetachCurrentThread(_jvm);
109 }
110
111 void do_overflow(){
112 int *p = alloca(sizeof(int));
113 do_overflow();
114 }
115
116 void *run_native_overflow(void *p) {
117 // Test that stack guard page is correctly set for initial and non initial thread
118 // and correctly removed for the initial thread
119 JNIEnv *env;
120 jclass class_id;
121 jmethodID method_id;
122
123 printf("run_native_overflow %ld\n", (long) gettid());
124
125 (*_jvm)->AttachCurrentThread(_jvm, (void **)&env, NULL);
126
127 class_id = (*env)->FindClass (env, "DoOverflow");
128 if (class_id == NULL) {
129 printf("Test ERROR. Can't load class DoOverflow\n");
130 exit(7);
131 }
132
133 method_id = (*env)->GetStaticMethodID (env, class_id, "printAlive", "()V");
134 if (method_id == NULL) {
135 printf("Test ERROR. Can't find method DoOverflow.printAlive\n");
136 exit(7);
137 }
138
139 (*env)->CallStaticVoidMethod (env, class_id, method_id, NULL);
140
141 set_signal_handler();
142 if (! setjmp(context)) {
143 do_overflow();
144 }
145
146 if (_last_si_code == SEGV_ACCERR) {
147 printf("Test OK. Got access violation accessing guard page\n");
148 }
149
150 (*_jvm)->DetachCurrentThread(_jvm);
151
152 if (getpid() != gettid()) {
153 // For non-initial thread we doesn't unmap the region but call os::uncommit_memory and keep PROT_NONE
154 // so if host has enough swap space we will get the same SEGV_ACCERR tring to access it
155 // as if the guard page is present.
156 // We have no ways to check this, so bail out, marking test as succeded
157 printf("Test OK. Not initial thread\n");
158 return NULL;
159 }
160
161 set_signal_handler();
162 if (! setjmp(context)) {
163 do_overflow();
164 }
165
166 if (_last_si_code == SEGV_ACCERR) {
167 ++ _failures;
168 printf("Test FAILED. Stack guard page is still there\n");
169 }
170 else {
171 printf("Test OK. No stack guard page is present\n");
172 }
173
174 return NULL;
175 }
176
177 int main (int argc, const char** argv) {
178 JavaVMInitArgs vm_args;
179 JavaVMOption options[1];
180 JNIEnv* env;
181
182 printf("Test started with pid: %ld\n", (long) getpid());
183
184 options[0].optionString = "-Xss320k";
185
186 vm_args.version = JNI_VERSION_1_2;
187 vm_args.ignoreUnrecognized = JNI_TRUE;
188 vm_args.options = options;
189 vm_args.nOptions = 1;
190
191 if (JNI_CreateJavaVM (&_jvm, (void **)&env, &vm_args) < 0 ) {
192 printf("Test ERROR. Can't create JavaVM\n");
193 exit(7);
194 }
195
196 pthread_t thr;
197
198 if (argc > 1 && strcmp(argv[1], "test_java_overflow") == 0) {
199 printf("\nTesting JAVA_OVERFLOW\n");
200
201 printf("Testing stack guard page behaviour for other thread\n");
202 pthread_create (&thr, NULL, run_java_overflow, NULL);
203 pthread_join (thr, NULL);
204
205 printf("Testing stack guard page behaviour for initial thread\n");
206 run_java_overflow(NULL);
207 // This test crash on error
208 return 0;
209 }
210
211 if (argc > 1 && strcmp(argv[1], "test_native_overflow") == 0) {
212 printf("\nTesting NATIVE_OVERFLOW\n");
213
214 printf("Testing stack guard page behaviour for other thread\n");
215 pthread_create (&thr, NULL, run_native_overflow, NULL);
216 pthread_join (thr, NULL);
217
218 printf("Testing stack guard page behaviour for initial thread\n");
219 run_native_overflow(NULL);
220
221 return (_failures > 0) ? 1 : 0;
222 }
223
224 printf("Test ERROR. Unknown parameter should be test_java_overflow or test_native_overflow\n");
225 exit(7);
226
227 }