1 /*
2 * Copyright (c) 2015, 2021, 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 "cds/filemap.hpp"
27 #include "classfile/classFileParser.hpp"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/classLoaderData.hpp"
31 #include "classfile/classLoaderData.inline.hpp"
32 #include "classfile/classLoadInfo.hpp"
33 #include "classfile/klassFactory.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "prims/jvmtiEnvBase.hpp"
36 #include "prims/jvmtiRedefineClasses.hpp"
37 #include "runtime/arguments.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "utilities/macros.hpp"
40 #if INCLUDE_JFR
41 #include "jfr/support/jfrKlassExtension.hpp"
42 #endif
43
44
45 // called during initial loading of a shared class
check_shared_class_file_load_hook(InstanceKlass * ik,Symbol * class_name,Handle class_loader,Handle protection_domain,const ClassFileStream * cfs,TRAPS)46 InstanceKlass* KlassFactory::check_shared_class_file_load_hook(
47 InstanceKlass* ik,
48 Symbol* class_name,
49 Handle class_loader,
50 Handle protection_domain,
51 const ClassFileStream *cfs,
52 TRAPS) {
53 #if INCLUDE_CDS && INCLUDE_JVMTI
54 assert(ik != NULL, "sanity");
55 assert(ik->is_shared(), "expecting a shared class");
56 if (JvmtiExport::should_post_class_file_load_hook()) {
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 new_ik->set_classpath_index(path_index);
100 }
101
102 return new_ik;
103 }
104 }
105 #endif
106
107 return NULL;
108 }
109
110
check_class_file_load_hook(ClassFileStream * stream,Symbol * name,ClassLoaderData * loader_data,Handle protection_domain,JvmtiCachedClassFileData ** cached_class_file,TRAPS)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 const JavaThread* jt = THREAD;
122
123 Handle class_loader(THREAD, loader_data->class_loader());
124
125 // Get the cached class file bytes (if any) from the class that
126 // is being redefined or retransformed. We use jvmti_thread_state()
127 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
128 // a JvmtiThreadState any earlier than necessary. This will help
129 // avoid the bug described by 7126851.
130
131 JvmtiThreadState* state = jt->jvmti_thread_state();
132
133 if (state != NULL) {
134 Klass* k = state->get_class_being_redefined();
135
136 if (k != NULL) {
137 InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
138 *cached_class_file = class_being_redefined->get_cached_class_file();
139 }
140 }
141
142 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
143 unsigned char* end_ptr = ptr + stream->length();
144
145 JvmtiExport::post_class_file_load_hook(name,
146 class_loader,
147 protection_domain,
148 &ptr,
149 &end_ptr,
150 cached_class_file);
151
152 if (ptr != stream->buffer()) {
153 // JVMTI agent has modified class file data.
154 // Set new class file stream using JVMTI agent modified class file data.
155 stream = new ClassFileStream(ptr,
156 end_ptr - ptr,
157 stream->source(),
158 stream->need_verify());
159 }
160 }
161
162 return stream;
163 }
164
165
create_from_stream(ClassFileStream * stream,Symbol * name,ClassLoaderData * loader_data,const ClassLoadInfo & cl_info,TRAPS)166 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
167 Symbol* name,
168 ClassLoaderData* loader_data,
169 const ClassLoadInfo& cl_info,
170 TRAPS) {
171 assert(stream != NULL, "invariant");
172 assert(loader_data != NULL, "invariant");
173
174 ResourceMark rm(THREAD);
175 HandleMark hm(THREAD);
176
177 JvmtiCachedClassFileData* cached_class_file = NULL;
178
179 ClassFileStream* old_stream = stream;
180
181 // increment counter
182 THREAD->statistical_info().incr_define_class_count();
183
184 // Skip this processing for VM hidden classes
185 if (!cl_info.is_hidden()) {
186 stream = check_class_file_load_hook(stream,
187 name,
188 loader_data,
189 cl_info.protection_domain(),
190 &cached_class_file,
191 CHECK_NULL);
192 }
193
194 ClassFileParser parser(stream,
195 name,
196 loader_data,
197 &cl_info,
198 ClassFileParser::BROADCAST, // publicity level
199 CHECK_NULL);
200
201 const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr();
202 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, *cl_inst_info, CHECK_NULL);
203 assert(result != NULL, "result cannot be null with no pending exception");
204
205 if (cached_class_file != NULL) {
206 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
207 result->set_cached_class_file(cached_class_file);
208 }
209
210 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);)
211
212 #if INCLUDE_CDS
213 if (Arguments::is_dumping_archive()) {
214 ClassLoader::record_result(THREAD, result, stream);
215 }
216 #endif // INCLUDE_CDS
217
218 return result;
219 }
220