1 /*
2 * Copyright (c) 2007, 2018, 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 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <jni.h>
27 #include <jvmti.h>
28 #include <aod.h>
29 #include <jvmti_aod.h>
30 #include "ExceptionCheckingJniEnv.hpp"
31
32 extern "C" {
33
34 /*
35 * Expected agent work scenario:
36 * - receive ClassFileLoadHook event for class 'ClassToRedefine'
37 * - receive ClassLoad event for class 'ClassToRedefine' and redefine class from ClassLoad event handler
38 * - receive one more ClassFileLoadHook event for class 'ClassToRedefine'
39 * - receive ClassPrepare event for class 'ClassToRedefine' and finish work
40 */
41
42 #define REDEFINED_CLASS_NAME "Lnsk/jvmti/AttachOnDemand/attach002/ClassToRedefine;"
43 #define REDEFINED_CLASS_FILE_NAME "nsk/jvmti/AttachOnDemand/attach002/ClassToRedefine"
44
45 // class name in the ClassFileLoadHook callback
46 #define REDEFINED_CLASS_NAME_INTERNAL "nsk/jvmti/AttachOnDemand/attach002/ClassToRedefine"
47
48 static Options* options = NULL;
49 static const char* agentName;
50
51 static volatile jboolean agentGotCapabilities = JNI_FALSE;
52
53 static jvmtiEvent testEvents[] = {
54 JVMTI_EVENT_CLASS_LOAD,
55 JVMTI_EVENT_CLASS_PREPARE,
56 JVMTI_EVENT_CLASS_FILE_LOAD_HOOK};
57
58 static const int testEventsNumber = 3;
59
60 static volatile int classLoadReceived = 0;
61 static volatile int classFileLoadHookReceived = 0;
62
63 JNIEXPORT jboolean JNICALL
64 Java_nsk_jvmti_AttachOnDemand_attach002_attach002Target_agentGotCapabilities(JNIEnv * jni,
65 jclass klass, jobject obj) {
66 return agentGotCapabilities;
67 }
68
69 #define ATTACH002_TARGET_APP_CLASS_NAME "nsk/jvmti/AttachOnDemand/attach002/attach002Target"
70
71 int registerNativeMethods(JNIEnv* jni_env) {
72 ExceptionCheckingJniEnvPtr jni(jni_env);
73 jclass appClass;
74 JNINativeMethod nativeMethods[] = {
75 {(char*) "agentGotCapabilities", (char*) "()Z", (void*) Java_nsk_jvmti_AttachOnDemand_attach002_attach002Target_agentGotCapabilities}};
76 jint nativeMethodsNumber = 1;
77
78 appClass = jni->FindClass(ATTACH002_TARGET_APP_CLASS_NAME, TRACE_JNI_CALL);
79 if (appClass == NULL) {
80 return NSK_FALSE;
81 }
82
83 if (jni->RegisterNatives(appClass, nativeMethods, nativeMethodsNumber, TRACE_JNI_CALL) != 0) {
84 return NSK_FALSE;
85 }
86
87 return NSK_TRUE;
88 }
89
90 void JNICALL classLoadHandler(
91 jvmtiEnv *jvmti,
92 JNIEnv* jni,
93 jthread thread,
94 jclass klass) {
95 char className[MAX_STRING_LENGTH];
96
97 if (!nsk_jvmti_aod_getClassName(jvmti, klass, className)) {
98 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
99 return;
100 }
101
102 NSK_DISPLAY2("%s: ClassLoad event was received for class '%s'\n", agentName, className);
103
104 if (!strcmp(className, REDEFINED_CLASS_NAME)) {
105
106 classLoadReceived = 1;
107
108 NSK_DISPLAY1("%s: redefining class\n", agentName);
109
110 if (!NSK_VERIFY(nsk_jvmti_aod_redefineClass(options, jvmti, klass, REDEFINED_CLASS_FILE_NAME))) {
111 NSK_COMPLAIN1("%s: failed to redefine class\n", agentName);
112 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
113 }
114 }
115 }
116
117 void JNICALL classPrepareHandler(
118 jvmtiEnv *jvmti,
119 JNIEnv* jni,
120 jthread thread,
121 jclass klass) {
122 char className[MAX_STRING_LENGTH];
123
124 if (!nsk_jvmti_aod_getClassName(jvmti, klass, className)) {
125 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
126 return;
127 }
128
129 NSK_DISPLAY2("%s: ClassPrepare event received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
130
131 if (!strcmp(className, REDEFINED_CLASS_NAME)) {
132 int success = 1;
133
134 if (!classLoadReceived) {
135 success = 0;
136 NSK_COMPLAIN2("%s: expected ClassLoad event wasn't received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
137 }
138
139 /*
140 * ClassFileLoadHook event should be received twice - when class is loaded and when class is redefined
141 */
142 if (classFileLoadHookReceived != 2) {
143 success = 0;
144 NSK_COMPLAIN2("%s: expected ClassFileLoadHook event wasn't received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
145 }
146
147 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, success, jvmti, jni);
148 }
149 }
150
151 void JNICALL classFileLoadHoockHandler(
152 jvmtiEnv * jvmti,
153 JNIEnv * jni,
154 jclass class_beeing_redefined,
155 jobject loader,
156 const char * name,
157 jobject protection_domain,
158 jint class_data_len,
159 const unsigned char * class_data,
160 jint * new_class_data_len,
161 unsigned char** new_class_data) {
162
163 if (name != NULL) {
164 NSK_DISPLAY2("%s: ClassFileLoadHook event received for class '%s'\n", agentName, name);
165 if (!strcmp(name, REDEFINED_CLASS_NAME_INTERNAL)) {
166 classFileLoadHookReceived++;
167 }
168 } else {
169 NSK_DISPLAY1("%s: ClassFileLoadHook event received for class with NULL name\n", agentName);
170 }
171 }
172
173 #ifdef STATIC_BUILD
174 JNIEXPORT jint JNI_OnLoad_attach002Agent00(JavaVM *jvm, char *options, void *reserved) {
175 return JNI_VERSION_1_8;
176 }
177 #endif
178
179 JNIEXPORT jint JNICALL
180 #ifdef STATIC_BUILD
181 Agent_OnAttach_attach002Agent00(JavaVM *vm, char *optionsString, void *reserved)
182 #else
183 Agent_OnAttach(JavaVM *vm, char *optionsString, void *reserved)
184 #endif
185 {
186 jvmtiEventCallbacks eventCallbacks;
187 jvmtiCapabilities caps;
188 jvmtiEnv* jvmti = NULL;
189 JNIEnv* jni = NULL;
190
191 options = (Options*) nsk_aod_createOptions(optionsString);
192 if (!NSK_VERIFY(options != NULL))
193 return JNI_ERR;
194
195 agentName = nsk_aod_getOptionValue(options, NSK_AOD_AGENT_NAME_OPTION);
196
197 jni = (JNIEnv*) nsk_aod_createJNIEnv(vm);
198 if (jni == NULL)
199 return NSK_FALSE;
200
201 jvmti = nsk_jvmti_createJVMTIEnv(vm, reserved);
202 if (!NSK_VERIFY(jvmti != NULL))
203 return JNI_ERR;
204
205 if (!NSK_VERIFY(registerNativeMethods(jni))) {
206 return JNI_ERR;
207 }
208
209 memset(&caps, 0, sizeof(caps));
210 caps.can_generate_all_class_hook_events = 1;
211 caps.can_redefine_classes = 1;
212 if (!NSK_JVMTI_VERIFY(jvmti->AddCapabilities(&caps))) {
213 /*
214 * If VM is run with -Xshare:on agent can't get required capabilities (see 6718407)
215 */
216 NSK_DISPLAY1("%s: warning: agent failed to get required capabilities, agent finishing\n", agentName);
217
218 if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
219 return JNI_ERR;
220
221 nsk_aod_agentFinished(jni, agentName, 1);
222 } else {
223 agentGotCapabilities = JNI_TRUE;
224
225 memset(&eventCallbacks,0, sizeof(eventCallbacks));
226 eventCallbacks.ClassLoad = classLoadHandler;
227 eventCallbacks.ClassPrepare = classPrepareHandler;
228 eventCallbacks.ClassFileLoadHook = classFileLoadHoockHandler;
229 if (!NSK_JVMTI_VERIFY(jvmti->SetEventCallbacks(&eventCallbacks, sizeof(eventCallbacks)))) {
230 return JNI_ERR;
231 }
232
233 if (!(nsk_jvmti_aod_enableEvents(jvmti, testEvents, testEventsNumber))) {
234 return JNI_ERR;
235 }
236
237 NSK_DISPLAY1("%s: initialization was done\n", agentName);
238
239 if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
240 return JNI_ERR;
241 }
242
243 return JNI_OK;
244 }
245
246 }