1 /*
   2  * Copyright (c) 2013, 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 
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <jvmti.h>
  27 
  28 #include "jni_tools.h"
  29 #include "nsk_tools.h"
  30 #include "JVMTITools.h"
  31 #include "jvmti_tools.h"
  32 
  33 extern "C" {
  34 
  35 
  36 static jvmtiEnv *test_jvmti = NULL;
  37 static jvmtiCapabilities caps;
  38 
  39 /*
  40  * Redefine a class with a new version (class file in byte array).
  41  *
  42  * native static public boolean redefineClassIntl(Class<?> clz, byte[] classFile);
  43  *
  44  * @param clz class for redefinition
  45  * @param classFile new version as a byte array
  46  * @return false if any errors occurred during class redefinition
  47  */
  48 JNIEXPORT jboolean JNICALL
  49 Java_vm_runtime_defmeth_shared_Util_redefineClassIntl(JNIEnv *env, jclass clazz, jclass clazzToRedefine, jbyteArray bytecodeArray) {
  50     jvmtiClassDefinition classDef;
  51     jboolean result = JNI_TRUE;
  52 
  53     if (!NSK_VERIFY(env != NULL) || !NSK_VERIFY(clazzToRedefine != NULL) || !NSK_VERIFY(bytecodeArray != NULL)) {
  54         return JNI_FALSE;
  55     }
  56 
  57     classDef.klass = clazzToRedefine;
  58     if (!NSK_JNI_VERIFY(env,
  59             (classDef.class_byte_count = /* jsize */ NSK_CPP_STUB2(GetArrayLength, env, bytecodeArray)) > 0)) {
  60         return JNI_FALSE;
  61     }
  62 
  63     if (!NSK_JNI_VERIFY(env,
  64             (classDef.class_bytes = (const unsigned char *) /* jbyte* */ NSK_CPP_STUB3(GetByteArrayElements, env, bytecodeArray, NULL)) != NULL)) {
  65         return JNI_FALSE;
  66     }
  67 
  68     if (!NSK_JVMTI_VERIFY(
  69             NSK_CPP_STUB3(RedefineClasses, test_jvmti, 1, &classDef))) {
  70         result = JNI_FALSE;
  71     }
  72 
  73     // Need to cleanup reference to byte[] whether RedefineClasses succeeded or not
  74     if (!NSK_JNI_VERIFY_VOID(env,
  75             NSK_CPP_STUB4(ReleaseByteArrayElements, env, bytecodeArray, (jbyte*)classDef.class_bytes, JNI_ABORT))) {
  76         return JNI_FALSE;
  77     }
  78 
  79     return result;
  80 }
  81 
  82 jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {
  83     /* init framework and parse options */
  84     if (!NSK_VERIFY(nsk_jvmti_parseOptions(options)))
  85         return JNI_ERR;
  86 
  87     /* create JVMTI environment */
  88     if (!NSK_VERIFY((test_jvmti =
  89             nsk_jvmti_createJVMTIEnv(jvm, reserved)) != NULL))
  90         return JNI_ERR;
  91 
  92     memset(&caps, 0, sizeof(jvmtiCapabilities));
  93     caps.can_redefine_classes = 1;
  94     if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(AddCapabilities,
  95             test_jvmti, &caps)))
  96         return JNI_ERR;
  97 
  98     if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(GetCapabilities,
  99             test_jvmti, &caps)))
 100         return JNI_ERR;
 101 
 102     if (!caps.can_redefine_classes)
 103         printf("Warning: RedefineClasses is not implemented\n");
 104 
 105     return JNI_OK;
 106 }
 107 
 108 JNIEXPORT jint JNICALL Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {
 109     return Agent_Initialize(jvm, options, reserved);
 110 }
 111 
 112 JNIEXPORT jint JNICALL Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {
 113     return Agent_Initialize(jvm, options, reserved);
 114 }
 115 
 116 }