1 /* 2 * Copyright (c) 2015, 2020, 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 #include "precompiled.hpp" 26 #include "classfile/classFileParser.hpp" 27 #include "classfile/classFileStream.hpp" 28 #include "classfile/classLoader.hpp" 29 #include "classfile/classLoaderData.hpp" 30 #include "classfile/classLoaderData.inline.hpp" 31 #include "classfile/klassFactory.hpp" 32 #include "memory/filemap.hpp" 33 #include "memory/metaspaceShared.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "prims/jvmtiEnvBase.hpp" 36 #include "prims/jvmtiRedefineClasses.hpp" 37 #include "runtime/handles.inline.hpp" 38 #include "utilities/macros.hpp" 39 #if INCLUDE_JFR 40 #include "jfr/support/jfrKlassExtension.hpp" 41 #endif 42 43 44 // called during initial loading of a shared class 45 InstanceKlass* KlassFactory::check_shared_class_file_load_hook( 46 InstanceKlass* ik, 47 Symbol* class_name, 48 Handle class_loader, 49 Handle protection_domain, 50 const ClassFileStream *cfs, 51 TRAPS) { 52 #if INCLUDE_CDS && INCLUDE_JVMTI 53 assert(ik != NULL, "sanity"); 54 assert(ik->is_shared(), "expecting a shared class"); 55 if (JvmtiExport::should_post_class_file_load_hook()) { 56 assert(THREAD->is_Java_thread(), "must be JavaThread"); 57 58 // Post the CFLH 59 JvmtiCachedClassFileData* cached_class_file = NULL; 60 if (cfs == NULL) { 61 cfs = FileMapInfo::open_stream_for_jvmti(ik, class_loader, CHECK_NULL); 62 } 63 unsigned char* ptr = (unsigned char*)cfs->buffer(); 64 unsigned char* end_ptr = ptr + cfs->length(); 65 unsigned char* old_ptr = ptr; 66 JvmtiExport::post_class_file_load_hook(class_name, 67 class_loader, 68 protection_domain, 69 &ptr, 70 &end_ptr, 71 &cached_class_file); 72 if (old_ptr != ptr) { 73 // JVMTI agent has modified class file data. 74 // Set new class file stream using JVMTI agent modified class file data. 75 ClassLoaderData* loader_data = 76 ClassLoaderData::class_loader_data(class_loader()); 77 int path_index = ik->shared_classpath_index(); 78 ClassFileStream* stream = new ClassFileStream(ptr, 79 end_ptr - ptr, 80 cfs->source(), 81 ClassFileStream::verify); 82 ClassLoadInfo cl_info(protection_domain); 83 ClassFileParser parser(stream, 84 class_name, 85 loader_data, 86 &cl_info, 87 ClassFileParser::BROADCAST, // publicity level 88 CHECK_NULL); 89 const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr(); 90 InstanceKlass* new_ik = parser.create_instance_klass(true, // changed_by_loadhook 91 *cl_inst_info, // dynamic_nest_host and classData 92 CHECK_NULL); 93 94 if (cached_class_file != NULL) { 95 new_ik->set_cached_class_file(cached_class_file); 96 } 97 98 if (class_loader.is_null()) { 99 ClassLoader::add_package(new_ik, path_index, THREAD); 100 } 101 102 return new_ik; 103 } 104 } 105 #endif 106 107 return NULL; 108 } 109 110 111 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream, 112 Symbol* name, 113 ClassLoaderData* loader_data, 114 Handle protection_domain, 115 JvmtiCachedClassFileData** cached_class_file, 116 TRAPS) { 117 118 assert(stream != NULL, "invariant"); 119 120 if (JvmtiExport::should_post_class_file_load_hook()) { 121 assert(THREAD->is_Java_thread(), "must be a JavaThread"); 122 const JavaThread* jt = (JavaThread*)THREAD; 123 124 Handle class_loader(THREAD, loader_data->class_loader()); 125 126 // Get the cached class file bytes (if any) from the class that 127 // is being redefined or retransformed. We use jvmti_thread_state() 128 // instead of JvmtiThreadState::state_for(jt) so we don't allocate 129 // a JvmtiThreadState any earlier than necessary. This will help 130 // avoid the bug described by 7126851. 131 132 JvmtiThreadState* state = jt->jvmti_thread_state(); 133 134 if (state != NULL) { 135 Klass* k = state->get_class_being_redefined(); 136 137 if (k != NULL) { 138 InstanceKlass* class_being_redefined = InstanceKlass::cast(k); 139 *cached_class_file = class_being_redefined->get_cached_class_file(); 140 } 141 } 142 143 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer()); 144 unsigned char* end_ptr = ptr + stream->length(); 145 146 JvmtiExport::post_class_file_load_hook(name, 147 class_loader, 148 protection_domain, 149 &ptr, 150 &end_ptr, 151 cached_class_file); 152 153 if (ptr != stream->buffer()) { 154 // JVMTI agent has modified class file data. 155 // Set new class file stream using JVMTI agent modified class file data. 156 stream = new ClassFileStream(ptr, 157 end_ptr - ptr, 158 stream->source(), 159 stream->need_verify()); 160 } 161 } 162 163 return stream; 164 } 165 166 167 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream, 168 Symbol* name, 169 ClassLoaderData* loader_data, 170 const ClassLoadInfo& cl_info, 171 TRAPS) { 172 assert(stream != NULL, "invariant"); 173 assert(loader_data != NULL, "invariant"); 174 assert(THREAD->is_Java_thread(), "must be a JavaThread"); 175 176 ResourceMark rm; 177 HandleMark hm; 178 179 JvmtiCachedClassFileData* cached_class_file = NULL; 180 181 ClassFileStream* old_stream = stream; 182 183 // increment counter 184 THREAD->statistical_info().incr_define_class_count(); 185 186 assert(!(cl_info.is_hidden() && (cl_info.unsafe_anonymous_host() != NULL)), 187 "hidden class has an anonymous host"); 188 189 // Skip this processing for VM hidden or anonymous classes 190 if (!cl_info.is_hidden() && (cl_info.unsafe_anonymous_host() == NULL)) { 191 stream = check_class_file_load_hook(stream, 192 name, 193 loader_data, 194 cl_info.protection_domain(), 195 &cached_class_file, 196 CHECK_NULL); 197 } 198 199 ClassFileParser parser(stream, 200 name, 201 loader_data, 202 &cl_info, 203 ClassFileParser::BROADCAST, // publicity level 204 CHECK_NULL); 205 206 const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr(); 207 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, *cl_inst_info, CHECK_NULL); 208 209 if (result == NULL) { 210 return NULL; 211 } 212 213 if (cached_class_file != NULL) { 214 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes 215 result->set_cached_class_file(cached_class_file); 216 } 217 218 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);) 219 220 #if INCLUDE_CDS 221 if (Arguments::is_dumping_archive()) { 222 ClassLoader::record_result(result, stream, THREAD); 223 } 224 #endif // INCLUDE_CDS 225 226 return result; 227 }