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 void 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 jni->RegisterNatives(appClass, nativeMethods, nativeMethodsNumber, TRACE_JNI_CALL);
80 }
81
82 void JNICALL classLoadHandler(
83 jvmtiEnv *jvmti,
84 JNIEnv* jni,
85 jthread thread,
86 jclass klass) {
87 char className[MAX_STRING_LENGTH];
88
89 if (!nsk_jvmti_aod_getClassName(jvmti, klass, className)) {
90 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
91 return;
92 }
93
94 NSK_DISPLAY2("%s: ClassLoad event was received for class '%s'\n", agentName, className);
95
96 if (!strcmp(className, REDEFINED_CLASS_NAME)) {
97
98 classLoadReceived = 1;
99
100 NSK_DISPLAY1("%s: redefining class\n", agentName);
101
102 if (!NSK_VERIFY(nsk_jvmti_aod_redefineClass(options, jvmti, klass, REDEFINED_CLASS_FILE_NAME))) {
103 NSK_COMPLAIN1("%s: failed to redefine class\n", agentName);
104 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
105 }
106 }
107 }
108
109 void JNICALL classPrepareHandler(
110 jvmtiEnv *jvmti,
111 JNIEnv* jni,
112 jthread thread,
113 jclass klass) {
114 char className[MAX_STRING_LENGTH];
115
116 if (!nsk_jvmti_aod_getClassName(jvmti, klass, className)) {
117 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
118 return;
119 }
120
121 NSK_DISPLAY2("%s: ClassPrepare event received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
122
123 if (!strcmp(className, REDEFINED_CLASS_NAME)) {
124 int success = 1;
125
126 if (!classLoadReceived) {
127 success = 0;
128 NSK_COMPLAIN2("%s: expected ClassLoad event wasn't received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
129 }
130
131 /*
132 * ClassFileLoadHook event should be received twice - when class is loaded and when class is redefined
133 */
134 if (classFileLoadHookReceived != 2) {
135 success = 0;
136 NSK_COMPLAIN2("%s: expected ClassFileLoadHook event wasn't received for class '%s'\n", agentName, REDEFINED_CLASS_NAME);
137 }
138
139 nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, success, jvmti, jni);
140 }
141 }
142
143 void JNICALL classFileLoadHoockHandler(
144 jvmtiEnv * jvmti,
145 JNIEnv * jni,
146 jclass class_beeing_redefined,
147 jobject loader,
148 const char * name,
149 jobject protection_domain,
150 jint class_data_len,
151 const unsigned char * class_data,
152 jint * new_class_data_len,
153 unsigned char** new_class_data) {
154
155 if (name != NULL) {
156 NSK_DISPLAY2("%s: ClassFileLoadHook event received for class '%s'\n", agentName, name);
157 if (!strcmp(name, REDEFINED_CLASS_NAME_INTERNAL)) {
158 classFileLoadHookReceived++;
159 }
160 } else {
161 NSK_DISPLAY1("%s: ClassFileLoadHook event received for class with NULL name\n", agentName);
162 }
163 }
164
165 #ifdef STATIC_BUILD
166 JNIEXPORT jint JNI_OnLoad_attach002Agent00(JavaVM *jvm, char *options, void *reserved) {
167 return JNI_VERSION_1_8;
168 }
169 #endif
170
171 JNIEXPORT jint JNICALL
172 #ifdef STATIC_BUILD
173 Agent_OnAttach_attach002Agent00(JavaVM *vm, char *optionsString, void *reserved)
174 #else
175 Agent_OnAttach(JavaVM *vm, char *optionsString, void *reserved)
176 #endif
177 {
178 jvmtiEventCallbacks eventCallbacks;
179 jvmtiCapabilities caps;
180 jvmtiEnv* jvmti = NULL;
181 JNIEnv* jni = NULL;
182
183 options = (Options*) nsk_aod_createOptions(optionsString);
184 if (!NSK_VERIFY(options != NULL))
185 return JNI_ERR;
186
187 agentName = nsk_aod_getOptionValue(options, NSK_AOD_AGENT_NAME_OPTION);
188
189 jni = (JNIEnv*) nsk_aod_createJNIEnv(vm);
190 if (jni == NULL)
191 return NSK_FALSE;
192
193 jvmti = nsk_jvmti_createJVMTIEnv(vm, reserved);
194 if (!NSK_VERIFY(jvmti != NULL))
195 return JNI_ERR;
196
197 registerNativeMethods(jni);
198
199 memset(&caps, 0, sizeof(caps));
200 caps.can_generate_all_class_hook_events = 1;
201 caps.can_redefine_classes = 1;
202 if (!NSK_JVMTI_VERIFY(jvmti->AddCapabilities(&caps))) {
203 /*
204 * If VM is run with -Xshare:on agent can't get required capabilities (see 6718407)
205 */
206 NSK_DISPLAY1("%s: warning: agent failed to get required capabilities, agent finishing\n", agentName);
207
208 if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
209 return JNI_ERR;
210
211 nsk_aod_agentFinished(jni, agentName, 1);
212 } else {
213 agentGotCapabilities = JNI_TRUE;
214
215 memset(&eventCallbacks,0, sizeof(eventCallbacks));
216 eventCallbacks.ClassLoad = classLoadHandler;
217 eventCallbacks.ClassPrepare = classPrepareHandler;
218 eventCallbacks.ClassFileLoadHook = classFileLoadHoockHandler;
219 if (!NSK_JVMTI_VERIFY(jvmti->SetEventCallbacks(&eventCallbacks, sizeof(eventCallbacks)))) {
220 return JNI_ERR;
221 }
222
223 if (!(nsk_jvmti_aod_enableEvents(jvmti, testEvents, testEventsNumber))) {
224 return JNI_ERR;
225 }
226
227 NSK_DISPLAY1("%s: initialization was done\n", agentName);
228
229 if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
230 return JNI_ERR;
231 }
232
233 return JNI_OK;
234 }
235
236 }