1 /*
2 * Copyright (c) 2015, 2017, 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 InstanceKlass* KlassFactory::check_shared_class_file_load_hook(
41 InstanceKlass* ik,
42 Symbol* class_name,
43 Handle class_loader,
44 Handle protection_domain, TRAPS) {
45 #if INCLUDE_CDS && INCLUDE_JVMTI
46 assert(ik != 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 const char* pathname;
74 if (path_index < 0) {
75 // shared classes loaded by user defined class loader
76 // do not have shared_classpath_index
77 ModuleEntry* mod_entry = ik->module();
78 if (mod_entry != NULL && (mod_entry->location() != NULL)) {
79 ResourceMark rm;
80 pathname = (const char*)(mod_entry->location()->as_C_string());
81 } else {
82 pathname = "";
83 }
84 } else {
85 SharedClassPathEntry* ent =
86 (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
87 pathname = ent == NULL ? NULL : ent->name();
88 }
89 ClassFileStream* stream = new ClassFileStream(ptr,
90 end_ptr - ptr,
91 pathname,
92 ClassFileStream::verify);
93 ClassFileParser parser(stream,
94 class_name,
95 loader_data,
96 protection_domain,
97 NULL,
98 NULL,
99 ClassFileParser::BROADCAST, // publicity level
100 CHECK_NULL);
101 InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
102 CHECK_NULL);
103 if (cached_class_file != NULL) {
104 new_ik->set_cached_class_file(cached_class_file);
105 }
106
107 if (class_loader.is_null()) {
108 ResourceMark rm;
109 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
110 }
111
112 return new_ik;
113 }
114 }
115 #endif
116
117 return NULL;
118 }
119
120
121 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
122 Symbol* name,
123 ClassLoaderData* loader_data,
124 Handle protection_domain,
125 JvmtiCachedClassFileData** cached_class_file,
126 TRAPS) {
127
128 assert(stream != NULL, "invariant");
129
130 if (JvmtiExport::should_post_class_file_load_hook()) {
131 assert(THREAD->is_Java_thread(), "must be a JavaThread");
132 const JavaThread* jt = (JavaThread*)THREAD;
133
134 Handle class_loader(THREAD, loader_data->class_loader());
135
136 // Get the cached class file bytes (if any) from the class that
137 // is being redefined or retransformed. We use jvmti_thread_state()
138 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
139 // a JvmtiThreadState any earlier than necessary. This will help
140 // avoid the bug described by 7126851.
141
142 JvmtiThreadState* state = jt->jvmti_thread_state();
143
144 if (state != NULL) {
145 Klass* k = state->get_class_being_redefined();
146
147 if (k != NULL) {
148 InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
149 *cached_class_file = class_being_redefined->get_cached_class_file();
150 }
151 }
152
153 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
154 unsigned char* end_ptr = ptr + stream->length();
155
156 JvmtiExport::post_class_file_load_hook(name,
157 class_loader,
158 protection_domain,
159 &ptr,
160 &end_ptr,
161 cached_class_file);
162
163 if (ptr != stream->buffer()) {
164 // JVMTI agent has modified class file data.
165 // Set new class file stream using JVMTI agent modified class file data.
166 stream = new ClassFileStream(ptr,
167 end_ptr - ptr,
168 stream->source(),
169 stream->need_verify());
170 }
171 }
172
173 return stream;
174 }
175
176
177 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
178 Symbol* name,
179 ClassLoaderData* loader_data,
180 Handle protection_domain,
181 const InstanceKlass* host_klass,
182 GrowableArray<Handle>* cp_patches,
183 TRAPS) {
184 assert(stream != NULL, "invariant");
185 assert(loader_data != NULL, "invariant");
186 assert(THREAD->is_Java_thread(), "must be a JavaThread");
187
188 ResourceMark rm;
189 HandleMark hm;
190
191 JvmtiCachedClassFileData* cached_class_file = NULL;
192
193 ClassFileStream* old_stream = stream;
194
195 // Skip this processing for VM anonymous classes
196 if (host_klass == NULL) {
197 stream = check_class_file_load_hook(stream,
198 name,
199 loader_data,
200 protection_domain,
201 &cached_class_file,
202 CHECK_NULL);
203 }
204
205 ClassFileParser parser(stream,
206 name,
207 loader_data,
208 protection_domain,
209 host_klass,
210 cp_patches,
211 ClassFileParser::BROADCAST, // publicity level
212 CHECK_NULL);
213
214 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
215 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
216
217 if (result == NULL) {
218 return NULL;
219 }
220
221 if (cached_class_file != NULL) {
222 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
223 result->set_cached_class_file(cached_class_file);
224 }
225
226 if (result->should_store_fingerprint()) {
227 result->store_fingerprint(stream->compute_fingerprint());
228 }
229
230 TRACE_KLASS_CREATION(result, parser, THREAD);
231
232 #if INCLUDE_CDS
233 if (DumpSharedSpaces) {
234 ClassLoader::record_shared_class_loader_type(result, stream);
235 #if INCLUDE_JVMTI
236 assert(cached_class_file == NULL, "Sanity");
237 // Archive the class stream data into the optional data section
238 JvmtiCachedClassFileData *p;
239 int len;
240 const unsigned char *bytes;
241 // event based tracing might set cached_class_file
242 if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
243 len = result->get_cached_class_file_len();
244 } else {
245 len = stream->length();
246 bytes = stream->buffer();
247 }
248 p = (JvmtiCachedClassFileData*)os::malloc(offset_of(JvmtiCachedClassFileData, data) + len, mtInternal);
249 p->length = len;
250 memcpy(p->data, bytes, len);
251 result->set_archived_class_data(p);
252 #endif // INCLUDE_JVMTI
253 }
254 #endif // INCLUDE_CDS
255
256 return result;
257 }