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 }