1 /*
2 * Copyright (c) 2015, 2016, 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 "classfile/sharedClassUtil.hpp"
33 #include "memory/metaspaceShared.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "prims/jvmtiEnvBase.hpp"
36 #include "prims/jvmtiRedefineClasses.hpp"
37 #include "trace/traceMacros.hpp"
38
39 // called during initial loading of a shared class
40 instanceKlassHandle KlassFactory::check_shared_class_file_load_hook(
41 instanceKlassHandle ik,
42 Symbol* class_name,
43 Handle class_loader,
44 Handle protection_domain, TRAPS) {
45 #if INCLUDE_CDS && INCLUDE_JVMTI
46 assert(ik.not_null(), "sanity");
47 assert(ik()->is_shared(), "expecting a shared class");
48
49 if (JvmtiExport::should_post_class_file_load_hook()) {
50 assert(THREAD->is_Java_thread(), "must be JavaThread");
51
52 // Post the CFLH
53 JvmtiCachedClassFileData* cached_class_file = NULL;
54 JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data();
55 assert(archived_class_data != NULL, "shared class has no archived class data");
56 unsigned char* ptr =
57 VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data);
58 unsigned char* end_ptr =
59 ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data);
60 unsigned char* old_ptr = ptr;
61 JvmtiExport::post_class_file_load_hook(class_name,
62 class_loader,
63 protection_domain,
64 &ptr,
65 &end_ptr,
66 &cached_class_file);
67 if (old_ptr != ptr) {
68 // JVMTI agent has modified class file data.
69 // Set new class file stream using JVMTI agent modified class file data.
70 ClassLoaderData* loader_data =
71 ClassLoaderData::class_loader_data(class_loader());
72 int path_index = ik->shared_classpath_index();
73 SharedClassPathEntry* ent =
74 (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
75 ClassFileStream* stream = new ClassFileStream(ptr,
76 end_ptr - ptr,
77 ent == NULL ? NULL : ent->_name,
78 ClassFileStream::verify);
79 ClassFileParser parser(stream,
80 class_name,
81 loader_data,
82 protection_domain,
83 NULL,
84 NULL,
85 ClassFileParser::BROADCAST, // publicity level
86 CHECK_NULL);
87 instanceKlassHandle new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
88 CHECK_NULL);
89 if (cached_class_file != NULL) {
90 new_ik->set_cached_class_file(cached_class_file);
91 }
92
93 if (class_loader.is_null()) {
94 ResourceMark rm;
95 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
96 }
97
98 return new_ik;
99 }
100 }
101 #endif
102
103 return NULL;
104 }
105
106
107 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
108 Symbol* name,
109 ClassLoaderData* loader_data,
110 Handle protection_domain,
111 JvmtiCachedClassFileData** cached_class_file,
112 TRAPS) {
113
114 assert(stream != NULL, "invariant");
115
116 if (JvmtiExport::should_post_class_file_load_hook()) {
117 assert(THREAD->is_Java_thread(), "must be a JavaThread");
118 const JavaThread* jt = (JavaThread*)THREAD;
119
120 Handle class_loader(THREAD, loader_data->class_loader());
121
122 // Get the cached class file bytes (if any) from the class that
123 // is being redefined or retransformed. We use jvmti_thread_state()
124 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
125 // a JvmtiThreadState any earlier than necessary. This will help
126 // avoid the bug described by 7126851.
127
128 JvmtiThreadState* state = jt->jvmti_thread_state();
129
130 if (state != NULL) {
131 KlassHandle* h_class_being_redefined =
132 state->get_class_being_redefined();
133
134 if (h_class_being_redefined != NULL) {
135 instanceKlassHandle ikh_class_being_redefined =
136 instanceKlassHandle(THREAD, (*h_class_being_redefined)());
137
138 *cached_class_file = ikh_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
166 instanceKlassHandle KlassFactory::create_from_stream(ClassFileStream* stream,
167 Symbol* name,
168 ClassLoaderData* loader_data,
169 Handle protection_domain,
170 const InstanceKlass* host_klass,
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 // Skip this processing for VM anonymous classes
185 if (host_klass == NULL) {
186 stream = check_class_file_load_hook(stream,
187 name,
188 loader_data,
189 protection_domain,
190 &cached_class_file,
191 CHECK_NULL);
192 }
193
194 ClassFileParser parser(stream,
195 name,
196 loader_data,
197 protection_domain,
198 host_klass,
199 cp_patches,
200 ClassFileParser::BROADCAST, // publicity level
201 CHECK_NULL);
202
203 instanceKlassHandle result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
204 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
205
206 if (result.is_null()) {
207 return NULL;
208 }
209
210 if (cached_class_file != NULL) {
211 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
212 result->set_cached_class_file(cached_class_file);
213 }
214
215 if (InstanceKlass::should_store_fingerprint()) {
216 result->store_fingerprint(!result->is_anonymous() ? stream->compute_fingerprint() : 0);
217 }
218
219 TRACE_KLASS_CREATION(result, parser, THREAD);
220
221 #if INCLUDE_CDS && INCLUDE_JVMTI
222 if (DumpSharedSpaces) {
223 assert(cached_class_file == NULL, "Sanity");
224 // Archive the class stream data into the optional data section
225 JvmtiCachedClassFileData *p;
226 int len;
227 const unsigned char *bytes;
228 // event based tracing might set cached_class_file
229 if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
230 len = result->get_cached_class_file_len();
231 } else {
232 len = stream->length();
233 bytes = stream->buffer();
234 }
235 p = (JvmtiCachedClassFileData*)MetaspaceShared::optional_data_space_alloc(
236 offset_of(JvmtiCachedClassFileData, data) + len);
237 p->length = len;
238 memcpy(p->data, bytes, len);
239 result->set_archived_class_data(p);
240 }
241 #endif
242
243 return result;
244 }