1 /* 2 * Copyright (c) 2015, 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 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, TRAPS) { 50 #if INCLUDE_CDS && INCLUDE_JVMTI 51 assert(ik != NULL, "sanity"); 52 assert(ik->is_shared(), "expecting a shared class"); 53 54 if (JvmtiExport::should_post_class_file_load_hook()) { 55 assert(THREAD->is_Java_thread(), "must be JavaThread"); 56 57 // Post the CFLH 58 JvmtiCachedClassFileData* cached_class_file = NULL; 59 JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data(); 60 assert(archived_class_data != NULL, "shared class has no archived class data"); 61 unsigned char* ptr = 62 VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data); 63 unsigned char* end_ptr = 64 ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data); 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 const char* pathname; 79 if (path_index < 0) { 80 // shared classes loaded by user defined class loader 81 // do not have shared_classpath_index 82 ModuleEntry* mod_entry = ik->module(); 83 if (mod_entry != NULL && (mod_entry->location() != NULL)) { 84 ResourceMark rm; 85 pathname = (const char*)(mod_entry->location()->as_C_string()); 86 } else { 87 pathname = ""; 88 } 89 } else { 90 SharedClassPathEntry* ent = 91 (SharedClassPathEntry*)FileMapInfo::shared_path(path_index); 92 pathname = ent == NULL ? NULL : ent->name(); 93 } 94 ClassFileStream* stream = new ClassFileStream(ptr, 95 end_ptr - ptr, 96 pathname, 97 ClassFileStream::verify); 98 ClassFileParser parser(stream, 99 class_name, 100 loader_data, 101 protection_domain, 102 NULL, 103 NULL, 104 ClassFileParser::BROADCAST, // publicity level 105 CHECK_NULL); 106 InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */, 107 CHECK_NULL); 108 if (cached_class_file != NULL) { 109 new_ik->set_cached_class_file(cached_class_file); 110 } 111 112 if (class_loader.is_null()) { 113 ResourceMark rm; 114 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD); 115 } 116 117 return new_ik; 118 } 119 } 120 #endif 121 122 return NULL; 123 } 124 125 126 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream, 127 Symbol* name, 128 ClassLoaderData* loader_data, 129 Handle protection_domain, 130 JvmtiCachedClassFileData** cached_class_file, 131 TRAPS) { 132 133 assert(stream != NULL, "invariant"); 134 135 if (JvmtiExport::should_post_class_file_load_hook()) { 136 assert(THREAD->is_Java_thread(), "must be a JavaThread"); 137 const JavaThread* jt = (JavaThread*)THREAD; 138 139 Handle class_loader(THREAD, loader_data->class_loader()); 140 141 // Get the cached class file bytes (if any) from the class that 142 // is being redefined or retransformed. We use jvmti_thread_state() 143 // instead of JvmtiThreadState::state_for(jt) so we don't allocate 144 // a JvmtiThreadState any earlier than necessary. This will help 145 // avoid the bug described by 7126851. 146 147 JvmtiThreadState* state = jt->jvmti_thread_state(); 148 149 if (state != NULL) { 150 Klass* k = state->get_class_being_redefined(); 151 152 if (k != NULL) { 153 InstanceKlass* class_being_redefined = InstanceKlass::cast(k); 154 *cached_class_file = class_being_redefined->get_cached_class_file(); 155 } 156 } 157 158 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer()); 159 unsigned char* end_ptr = ptr + stream->length(); 160 161 JvmtiExport::post_class_file_load_hook(name, 162 class_loader, 163 protection_domain, 164 &ptr, 165 &end_ptr, 166 cached_class_file); 167 168 if (ptr != stream->buffer()) { 169 // JVMTI agent has modified class file data. 170 // Set new class file stream using JVMTI agent modified class file data. 171 stream = new ClassFileStream(ptr, 172 end_ptr - ptr, 173 stream->source(), 174 stream->need_verify()); 175 } 176 } 177 178 return stream; 179 } 180 181 182 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream, 183 Symbol* name, 184 ClassLoaderData* loader_data, 185 Handle protection_domain, 186 const InstanceKlass* host_klass, 187 GrowableArray<Handle>* cp_patches, 188 TRAPS) { 189 assert(stream != NULL, "invariant"); 190 assert(loader_data != NULL, "invariant"); 191 assert(THREAD->is_Java_thread(), "must be a JavaThread"); 192 193 ResourceMark rm; 194 HandleMark hm; 195 196 JvmtiCachedClassFileData* cached_class_file = NULL; 197 198 ClassFileStream* old_stream = stream; 199 200 // Skip this processing for VM anonymous classes 201 if (host_klass == NULL) { 202 stream = check_class_file_load_hook(stream, 203 name, 204 loader_data, 205 protection_domain, 206 &cached_class_file, 207 CHECK_NULL); 208 } 209 210 ClassFileParser parser(stream, 211 name, 212 loader_data, 213 protection_domain, 214 host_klass, 215 cp_patches, 216 ClassFileParser::BROADCAST, // publicity level 217 CHECK_NULL); 218 219 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL); 220 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant"); 221 222 if (result == NULL) { 223 return NULL; 224 } 225 226 if (cached_class_file != NULL) { 227 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes 228 result->set_cached_class_file(cached_class_file); 229 } 230 231 if (result->should_store_fingerprint()) { 232 result->store_fingerprint(stream->compute_fingerprint()); 233 } 234 235 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);) 236 237 #if INCLUDE_CDS 238 if (DumpSharedSpaces) { 239 ClassLoader::record_result(result, stream, THREAD); 240 #if INCLUDE_JVMTI 241 assert(cached_class_file == NULL, "Sanity"); 242 // Archive the class stream data into the optional data section 243 JvmtiCachedClassFileData *p; 244 int len; 245 const unsigned char *bytes; 246 // event based tracing might set cached_class_file 247 if ((bytes = result->get_cached_class_file_bytes()) != NULL) { 248 len = result->get_cached_class_file_len(); 249 } else { 250 len = stream->length(); 251 bytes = stream->buffer(); 252 } 253 p = (JvmtiCachedClassFileData*)os::malloc(offset_of(JvmtiCachedClassFileData, data) + len, mtInternal); 254 p->length = len; 255 memcpy(p->data, bytes, len); 256 result->set_archived_class_data(p); 257 #endif // INCLUDE_JVMTI 258 } 259 #endif // INCLUDE_CDS 260 261 return result; 262 }