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, // unsafe_anonymous_host
87 NULL, // cp_patches
88 false, // is_hidden
89 false, // can_access_vm_annotations
90 ClassFileParser::BROADCAST, // publicity level
91 CHECK_NULL);
92 ClassInstanceInfo cl_inst_info;
93 InstanceKlass* new_ik = parser.create_instance_klass(true, // changed_by_loadhook
94 cl_inst_info, // dynamic_nest_host and classData
95 CHECK_NULL);
96
97 if (cached_class_file != NULL) {
98 new_ik->set_cached_class_file(cached_class_file);
99 }
100
101 if (class_loader.is_null()) {
102 ResourceMark rm;
103 ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
104 }
105
106 return new_ik;
107 }
108 }
109 #endif
110
111 return NULL;
112 }
113
114
115 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
116 Symbol* name,
117 ClassLoaderData* loader_data,
118 Handle protection_domain,
119 JvmtiCachedClassFileData** cached_class_file,
120 TRAPS) {
121
122 assert(stream != NULL, "invariant");
123
124 if (JvmtiExport::should_post_class_file_load_hook()) {
125 assert(THREAD->is_Java_thread(), "must be a JavaThread");
126 const JavaThread* jt = (JavaThread*)THREAD;
127
128 Handle class_loader(THREAD, loader_data->class_loader());
129
130 // Get the cached class file bytes (if any) from the class that
131 // is being redefined or retransformed. We use jvmti_thread_state()
132 // instead of JvmtiThreadState::state_for(jt) so we don't allocate
133 // a JvmtiThreadState any earlier than necessary. This will help
134 // avoid the bug described by 7126851.
135
136 JvmtiThreadState* state = jt->jvmti_thread_state();
137
138 if (state != NULL) {
139 Klass* k = state->get_class_being_redefined();
140
141 if (k != NULL) {
142 InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
143 *cached_class_file = class_being_redefined->get_cached_class_file();
144 }
145 }
146
147 unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
148 unsigned char* end_ptr = ptr + stream->length();
149
150 JvmtiExport::post_class_file_load_hook(name,
151 class_loader,
152 protection_domain,
153 &ptr,
154 &end_ptr,
155 cached_class_file);
156
157 if (ptr != stream->buffer()) {
158 // JVMTI agent has modified class file data.
159 // Set new class file stream using JVMTI agent modified class file data.
160 stream = new ClassFileStream(ptr,
161 end_ptr - ptr,
162 stream->source(),
163 stream->need_verify());
164 }
165 }
166
167 return stream;
168 }
169
170
171 InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
172 Symbol* name,
173 ClassLoaderData* loader_data,
174 const ClassLoadInfo& cl_info,
175 TRAPS) {
176 assert(stream != NULL, "invariant");
177 assert(loader_data != NULL, "invariant");
178 assert(THREAD->is_Java_thread(), "must be a JavaThread");
179
180 ResourceMark rm;
181 HandleMark hm;
182
183 JvmtiCachedClassFileData* cached_class_file = NULL;
184
185 ClassFileStream* old_stream = stream;
186
187 // increment counter
188 THREAD->statistical_info().incr_define_class_count();
189
190 assert(!(cl_info.is_hidden() && (cl_info.unsafe_anonymous_host() != NULL)),
191 "hidden class has an anonymous host");
192
193 // Skip this processing for VM hidden or anonymous classes
194 if (!cl_info.is_hidden() && (cl_info.unsafe_anonymous_host() == NULL)) {
195 stream = check_class_file_load_hook(stream,
196 name,
197 loader_data,
198 cl_info.protection_domain(),
199 &cached_class_file,
200 CHECK_NULL);
201 }
202
203 ClassFileParser parser(stream,
204 name,
205 loader_data,
206 cl_info.protection_domain(),
207 cl_info.unsafe_anonymous_host(),
208 cl_info.cp_patches(),
209 cl_info.is_hidden(),
210 cl_info.can_access_vm_annotations(),
211 ClassFileParser::BROADCAST, // publicity level
212 CHECK_NULL);
213
214 const ClassInstanceInfo* cl_inst_info = cl_info.class_hidden_info_ptr();
215 InstanceKlass* result = parser.create_instance_klass(old_stream != stream, *cl_inst_info, CHECK_NULL);
216 #ifdef ASSERT
217 // Need a NULL dynamic_nest_host here otherwise set_nest_host() may assert.
218 ClassInstanceInfo cl_inst_info_null(NULL, cl_inst_info->class_data());
219 assert(result == parser.create_instance_klass(old_stream != stream, cl_inst_info_null, THREAD), "invariant");
220 #endif
221
222 if (result == NULL) {
223 return NULL;
224 }
225
226 if (cached_class_file != NULL) {
227 // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
228 result->set_cached_class_file(cached_class_file);
229 }
230
231 JFR_ONLY(ON_KLASS_CREATION(result, parser, THREAD);)
232
233 #if INCLUDE_CDS
234 if (Arguments::is_dumping_archive()) {
235 ClassLoader::record_result(result, stream, THREAD);
236 }
237 #endif // INCLUDE_CDS
238
239 return result;
240 }