1 /*
2 * Copyright (c) 2015, 2018, 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, TRAPS) {
50 #if INCLUDE_CDS && INCLUDE_JVMTI
51 assert(ik != NULL, "sanity");
52 assert(ik->is_shared(), "expecting a shared class");
53
54 if (JvmtiExport::should_post_class_file_load_hook()) {
55 assert(THREAD->is_Java_thread(), "must be JavaThread");
56
57 // Post the CFLH
58 JvmtiCachedClassFileData* cached_class_file = NULL;
59 JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data();
60 assert(archived_class_data != NULL, "shared class has no archived class data");
61 unsigned char* ptr =
62 VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data);
63 unsigned char* end_ptr =
64 ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data);
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 const char* pathname;
79 if (path_index < 0) {
80 // shared classes loaded by user defined class loader
81 // do not have shared_classpath_index
82 ModuleEntry* mod_entry = ik->module();
83 if (mod_entry != NULL && (mod_entry->location() != NULL)) {
84 ResourceMark rm;
85 pathname = (const char*)(mod_entry->location()->as_C_string());
86 } else {
87 pathname = "";
88 }
89 } else {
90 SharedClassPathEntry* ent =
91 (SharedClassPathEntry*)FileMapInfo::shared_path(path_index);
92 pathname = ent == NULL ? NULL : ent->name();
93 }
94 ClassFileStream* stream = new ClassFileStream(ptr,
95 end_ptr - ptr,
96 pathname,
97 ClassFileStream::verify);
98 ClassFileParser parser(stream,
99 class_name,
100 loader_data,
101 protection_domain,
102 NULL, // unsafe_anonymous_host
103 NULL, // cp_patches
104 false, // is_nonfindable
105 ClassFileParser::BROADCAST, // publicity level
106 CHECK_NULL);
107 InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
108 CHECK_NULL);
109 if (cached_class_file != NULL) {
110 new_ik->set_cached_class_file(cached_class_file);
111 }
112
113 if (class_loader.is_null()) {
114 ResourceMark rm;
115 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
116 }
117
118 return new_ik;
119 }
120 }
121 #endif
122
123 return NULL;
124 }
125
126
127 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
128 Symbol* name,
129 ClassLoaderData* loader_data,
130 Handle protection_domain,
131 JvmtiCachedClassFileData** cached_class_file,
132 TRAPS) {
133
134 assert(stream != NULL, "invariant");
135
136 if (JvmtiExport::should_post_class_file_load_hook()) {
137 assert(THREAD->is_Java_thread(), "must be a JavaThread");
138 const JavaThread* jt = (JavaThread*)THREAD;
139
140 Handle class_loader(THREAD, loader_data->class_loader());
141
142 // Get the cached class file bytes (if any) from the class that
143 // is being redefined or retransformed. We use jvmti_thread_state()
144 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
145 // a JvmtiThreadState any earlier than necessary. This will help
146 // avoid the bug described by 7126851.
147
148 JvmtiThreadState* state = jt->jvmti_thread_state();
149
150 if (state != NULL) {
151 Klass* k = state->get_class_being_redefined();
152
153 if (k != NULL) {
154 InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
155 *cached_class_file = class_being_redefined->get_cached_class_file();
156 }
157 }
158
159 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
160 unsigned char* end_ptr = ptr + stream->length();
161
162 JvmtiExport::post_class_file_load_hook(name,
163 class_loader,
164 protection_domain,
165 &ptr,
166 &end_ptr,
167 cached_class_file);
168
169 if (ptr != stream->buffer()) {
170 // JVMTI agent has modified class file data.
171 // Set new class file stream using JVMTI agent modified class file data.
172 stream = new ClassFileStream(ptr,
173 end_ptr - ptr,
174 stream->source(),
175 stream->need_verify());
176 }
177 }
178
179 return stream;
180 }
181
182
183 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
184 Symbol* name,
185 ClassLoaderData* loader_data,
186 Handle protection_domain,
187 const InstanceKlass* unsafe_anonymous_host,
188 GrowableArray<Handle>* cp_patches,
189 bool is_nonfindable,
190 TRAPS) {
191 assert(stream != NULL, "invariant");
192 assert(loader_data != NULL, "invariant");
193 assert(THREAD->is_Java_thread(), "must be a JavaThread");
194
195 ResourceMark rm;
196 HandleMark hm;
197
198 JvmtiCachedClassFileData* cached_class_file = NULL;
199
200 ClassFileStream* old_stream = stream;
201
202 // increment counter
203 THREAD->statistical_info().incr_define_class_count();
204
205 // Skip this processing for VM nonfindable or anonymous classes
206 if (is_nonfindable || (unsafe_anonymous_host == NULL)) {
207 stream = check_class_file_load_hook(stream,
208 name,
209 loader_data,
210 protection_domain,
211 &cached_class_file,
212 CHECK_NULL);
213 }
214
215 ClassFileParser parser(stream,
216 name,
217 loader_data,
218 protection_domain,
219 unsafe_anonymous_host,
220 cp_patches,
221 is_nonfindable,
222 ClassFileParser::BROADCAST, // publicity level
223 CHECK_NULL);
224
225 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
226 assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
227
228 if (result == NULL) {
229 return NULL;
230 }
231
232 if (cached_class_file != NULL) {
233 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
234 result->set_cached_class_file(cached_class_file);
235 }
236
237 if (result->should_store_fingerprint()) {
238 result->store_fingerprint(stream->compute_fingerprint());
239 }
240
241 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);)
242
243 #if INCLUDE_CDS
244 if (DumpSharedSpaces) {
245 ClassLoader::record_result(result, stream, THREAD);
246 #if INCLUDE_JVMTI
247 assert(cached_class_file == NULL, "Sanity");
248 // Archive the class stream data into the optional data section
249 JvmtiCachedClassFileData *p;
250 int len;
251 const unsigned char *bytes;
252 // event based tracing might set cached_class_file
253 if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
254 len = result->get_cached_class_file_len();
255 } else {
256 len = stream->length();
257 bytes = stream->buffer();
258 }
259 p = (JvmtiCachedClassFileData*)os::malloc(offset_of(JvmtiCachedClassFileData, data) + len, mtInternal);
260 p->length = len;
261 memcpy(p->data, bytes, len);
262 result->set_archived_class_data(p);
263 #endif // INCLUDE_JVMTI
264 }
265 #endif // INCLUDE_CDS
266
267 return result;
268 }