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
45InstanceKlass* 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 ResourceMark rm;
98 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
99 }
100
101 return new_ik;
102 }
103 }
104#endif
105
106 return NULL;
107}
108
109
110static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
111 Symbol* name,
112 ClassLoaderData* loader_data,
113 Handle protection_domain,
114 JvmtiCachedClassFileData** cached_class_file,
115 TRAPS) {
116
117 assert(stream != NULL, "invariant");
118
119 if (JvmtiExport::should_post_class_file_load_hook()) {
120 assert(THREAD->is_Java_thread(), "must be a JavaThread");
121 const JavaThread* jt = (JavaThread*)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
166InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
167 Symbol* name,
168 ClassLoaderData* loader_data,
169 Handle protection_domain,
170 const InstanceKlass* unsafe_anonymous_host,
171 GrowableArray<Handle>* cp_patches,
172 TRAPS) {
173 assert(stream != NULL, "invariant");
174 assert(loader_data != NULL, "invariant");
175 assert(THREAD->is_Java_thread(), "must be a JavaThread");
176
177 ResourceMark rm;
178 HandleMark hm;
179
180 JvmtiCachedClassFileData* cached_class_file = NULL;
181
182 ClassFileStream* old_stream = stream;
183
184 // increment counter
185 THREAD->statistical_info().incr_define_class_count();
186
187 // Skip this processing for VM anonymous classes
188 if (unsafe_anonymous_host == NULL) {
189 stream = check_class_file_load_hook(stream,
190 name,
191 loader_data,
192 protection_domain,
193 &cached_class_file,
194 CHECK_NULL);
195 }
196
197 ClassFileParser parser(stream,
198 name,
199 loader_data,
200 protection_domain,
201 unsafe_anonymous_host,
202 cp_patches,
203 ClassFileParser::BROADCAST, // publicity level
204 CHECK_NULL);
205
206 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
207 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
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 (DumpSharedSpaces || DynamicDumpSharedSpaces) {
222 ClassLoader::record_result(result, stream, THREAD);
223 }
224#endif // INCLUDE_CDS
225
226 return result;
227}
228