/* * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "cds/cdsConfig.hpp" #include "cds/filemap.hpp" #include "classfile/classFileParser.hpp" #include "classfile/classFileStream.hpp" #include "classfile/classLoader.hpp" #include "classfile/classLoaderData.hpp" #include "classfile/classLoaderData.inline.hpp" #include "classfile/classLoadInfo.hpp" #include "classfile/klassFactory.hpp" #include "classfile/systemDictionaryShared.hpp" #include "memory/resourceArea.hpp" #include "prims/jvmtiEnvBase.hpp" #include "prims/jvmtiRedefineClasses.hpp" #include "runtime/handles.inline.hpp" #include "utilities/macros.hpp" #if INCLUDE_JFR #include "jfr/support/jfrKlassExtension.hpp" #endif // called during initial loading of a shared class InstanceKlass* KlassFactory::check_shared_class_file_load_hook( InstanceKlass* ik, Symbol* class_name, Handle class_loader, Handle protection_domain, const ClassFileStream *cfs, TRAPS) { #if INCLUDE_CDS && INCLUDE_JVMTI assert(ik != nullptr, "sanity"); assert(ik->is_shared(), "expecting a shared class"); if (JvmtiExport::should_post_class_file_load_hook()) { ResourceMark rm(THREAD); // Post the CFLH JvmtiCachedClassFileData* cached_class_file = nullptr; if (cfs == nullptr) { cfs = FileMapInfo::open_stream_for_jvmti(ik, class_loader, CHECK_NULL); } unsigned char* ptr = (unsigned char*)cfs->buffer(); unsigned char* end_ptr = ptr + cfs->length(); unsigned char* old_ptr = ptr; JvmtiExport::post_class_file_load_hook(class_name, class_loader, protection_domain, &ptr, &end_ptr, &cached_class_file); if (old_ptr != ptr) { // JVMTI agent has modified class file data. // Set new class file stream using JVMTI agent modified class file data. ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader()); s2 path_index = ik->shared_classpath_index(); ClassFileStream* stream = new ClassFileStream(ptr, pointer_delta_as_int(end_ptr, ptr), cfs->source(), /* from_boot_loader_modules_image */ false, /* from_class_file_load_hook */ true); ClassLoadInfo cl_info(protection_domain); ClassFileParser parser(stream, class_name, loader_data, &cl_info, ClassFileParser::BROADCAST, // publicity level CHECK_NULL); const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr(); InstanceKlass* new_ik = parser.create_instance_klass(true, // changed_by_loadhook *cl_inst_info, // dynamic_nest_host and classData CHECK_NULL); if (cached_class_file != nullptr) { new_ik->set_cached_class_file(cached_class_file); } if (class_loader.is_null()) { new_ik->set_classpath_index(path_index); } return new_ik; } } #endif return nullptr; } static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream, Symbol* name, ClassLoaderData* loader_data, Handle protection_domain, JvmtiCachedClassFileData** cached_class_file, TRAPS) { assert(stream != nullptr, "invariant"); if (JvmtiExport::should_post_class_file_load_hook()) { const JavaThread* jt = THREAD; Handle class_loader(THREAD, loader_data->class_loader()); // Get the cached class file bytes (if any) from the class that // is being retransformed. If class file load hook provides // modified class data during class loading or redefinition, // new cached class file buffer should be allocated. // We use jvmti_thread_state() // instead of JvmtiThreadState::state_for(jt) so we don't allocate // a JvmtiThreadState any earlier than necessary. This will help // avoid the bug described by 7126851. JvmtiThreadState* state = jt->jvmti_thread_state(); if (state != nullptr) { Klass* k = state->get_class_being_redefined(); if (k != nullptr && state->get_class_load_kind() == jvmti_class_load_kind_retransform) { InstanceKlass* class_being_redefined = InstanceKlass::cast(k); *cached_class_file = class_being_redefined->get_cached_class_file(); } } unsigned char* ptr = const_cast(stream->buffer()); unsigned char* end_ptr = ptr + stream->length(); JvmtiExport::post_class_file_load_hook(name, class_loader, protection_domain, &ptr, &end_ptr, cached_class_file); if (ptr != stream->buffer()) { // JVMTI agent has modified class file data. // Set new class file stream using JVMTI agent modified class file data. stream = new ClassFileStream(ptr, pointer_delta_as_int(end_ptr, ptr), stream->source(), /* from_boot_loader_modules_image */ false, /* from_class_file_load_hook */ true); } } return stream; } InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream, Symbol* name, ClassLoaderData* loader_data, const ClassLoadInfo& cl_info, TRAPS) { assert(stream != nullptr, "invariant"); assert(loader_data != nullptr, "invariant"); ResourceMark rm(THREAD); HandleMark hm(THREAD); JvmtiCachedClassFileData* cached_class_file = nullptr; ClassFileStream* old_stream = stream; // increment counter THREAD->statistical_info().incr_define_class_count(); // Skip this processing for VM hidden classes if (!cl_info.is_hidden()) { stream = check_class_file_load_hook(stream, name, loader_data, cl_info.protection_domain(), &cached_class_file, CHECK_NULL); } ClassFileParser parser(stream, name, loader_data, &cl_info, ClassFileParser::BROADCAST, // publicity level CHECK_NULL); const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr(); InstanceKlass* result = parser.create_instance_klass(old_stream != stream, *cl_inst_info, CHECK_NULL); assert(result != nullptr, "result cannot be null with no pending exception"); if (CDSConfig::is_dumping_archive() && stream->from_class_file_load_hook()) { SystemDictionaryShared::set_from_class_file_load_hook(result); } if (cached_class_file != nullptr) { // JVMTI: we have an InstanceKlass now, tell it about the cached bytes result->set_cached_class_file(cached_class_file); } JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);) #if INCLUDE_CDS if (CDSConfig::is_dumping_archive()) { ClassLoader::record_result(THREAD, result, stream, old_stream != stream); } #endif // INCLUDE_CDS return result; }