1 /*
2 * Copyright (c) 2015, 2019, 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 ClassFileParser parser(stream,
83 class_name,
84 loader_data,
85 protection_domain,
86 NULL,
87 NULL,
88 ClassFileParser::BROADCAST, // publicity level
89 CHECK_NULL);
90 InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
91 CHECK_NULL);
92 if (cached_class_file != NULL) {
93 new_ik->set_cached_class_file(cached_class_file);
94 }
95
96 if (class_loader.is_null()) {
97 ClassLoader::add_package(new_ik, path_index, THREAD);
98 }
99
100 return new_ik;
101 }
102 }
103 #endif
104
105 return NULL;
106 }
107
108
109 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
110 Symbol* name,
111 ClassLoaderData* loader_data,
112 Handle protection_domain,
113 JvmtiCachedClassFileData** cached_class_file,
114 TRAPS) {
115
116 assert(stream != NULL, "invariant");
117
118 if (JvmtiExport::should_post_class_file_load_hook()) {
119 assert(THREAD->is_Java_thread(), "must be a JavaThread");
120 const JavaThread* jt = (JavaThread*)THREAD;
121
122 Handle class_loader(THREAD, loader_data->class_loader());
123
124 // Get the cached class file bytes (if any) from the class that
125 // is being redefined or retransformed. We use jvmti_thread_state()
126 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
127 // a JvmtiThreadState any earlier than necessary. This will help
128 // avoid the bug described by 7126851.
129
130 JvmtiThreadState* state = jt->jvmti_thread_state();
131
132 if (state != NULL) {
133 Klass* k = state->get_class_being_redefined();
134
135 if (k != NULL) {
136 InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
137 *cached_class_file = class_being_redefined->get_cached_class_file();
138 }
139 }
140
141 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
142 unsigned char* end_ptr = ptr + stream->length();
143
144 JvmtiExport::post_class_file_load_hook(name,
145 class_loader,
146 protection_domain,
147 &ptr,
148 &end_ptr,
149 cached_class_file);
150
151 if (ptr != stream->buffer()) {
152 // JVMTI agent has modified class file data.
153 // Set new class file stream using JVMTI agent modified class file data.
154 stream = new ClassFileStream(ptr,
155 end_ptr - ptr,
156 stream->source(),
157 stream->need_verify());
158 }
159 }
160
161 return stream;
162 }
163
164
165 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
166 Symbol* name,
167 ClassLoaderData* loader_data,
168 Handle protection_domain,
169 const InstanceKlass* unsafe_anonymous_host,
170 GrowableArray<Handle>* cp_patches,
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 // Skip this processing for VM anonymous classes
187 if (unsafe_anonymous_host == NULL) {
188 stream = check_class_file_load_hook(stream,
189 name,
190 loader_data,
191 protection_domain,
192 &cached_class_file,
193 CHECK_NULL);
194 }
195
196 ClassFileParser parser(stream,
197 name,
198 loader_data,
199 protection_domain,
200 unsafe_anonymous_host,
201 cp_patches,
202 ClassFileParser::BROADCAST, // publicity level
203 CHECK_NULL);
204
205 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
206 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
207
208 if (result == NULL) {
209 return NULL;
210 }
211
212 if (cached_class_file != NULL) {
213 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
214 result->set_cached_class_file(cached_class_file);
215 }
216
217 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);)
218
219 #if INCLUDE_CDS
220 if (Arguments::is_dumping_archive()) {
221 ClassLoader::record_result(result, stream, THREAD);
222 }
223 #endif // INCLUDE_CDS
224
225 return result;
226 }