1 /*
2 * Copyright (c) 2014, 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.
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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
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
27
28 #include "oops/klass.hpp"
29 #include "classfile/dictionary.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "memory/filemap.hpp"
32
33
34 /*===============================================================================
35
36 Handling of the classes in the AppCDS archive
37
38 To ensure safety and to simplify the implementation, archived classes are
39 "segregated" into several types. The following rules describe how they
40 are stored and looked up.
41
42 [1] Category of archived classes
43
44 There are 3 disjoint groups of classes stored in the AppCDS archive. They are
45 categorized as by their SharedDictionaryEntry::loader_type()
46
47 BUILTIN: These classes may be defined ONLY by the BOOT/PLATFORM/APP
48 loaders.
49
50 UNREGISTERED: These classes may be defined ONLY by a ClassLoader
51 instance that's not listed above (using fingerprint matching)
52
53 [2] How classes from different categories are specified in the classlist:
54
55 Starting from JDK9, each class in the classlist may be specified with
56 these keywords: "id", "super", "interfaces", "loader" and "source".
57
58
59 BUILTIN Only the "id" keyword may be (optionally) specified. All other
60 keywords are forbidden.
61
62 The named class is looked up from the jimage and from
63 Xbootclasspath/a and CLASSPATH.
64
65 UNREGISTERED: The "id", "super", and "source" keywords must all be
66 specified.
67
68 The "interfaces" keyword must be specified if the class implements
69 one or more local interfaces. The "interfaces" keyword must not be
70 specified if the class does not implement local interfaces.
71
72 The named class is looked up from the location specified in the
73 "source" keyword.
74
75 Example classlist:
76
77 # BUILTIN
78 java/lang/Object id: 0
79 java/lang/Cloneable id: 1
80 java/lang/String
81
82 # UNREGISTERED
83 Bar id: 3 super: 0 interfaces: 1 source: /foo.jar
84
85
86 [3] Identifying the loader_type of archived classes in the shared dictionary
87
88 Each archived Klass* C is associated with a SharedDictionaryEntry* E
89
90 BUILTIN: (C->shared_classpath_index() >= 0)
91 UNREGISTERED: (C->shared_classpath_index() < 0)
92
93 [4] Lookup of archived classes at run time:
94
95 (a) BUILTIN loaders:
96
97 Search the shared directory for a BUILTIN class with a matching name.
98
99 (b) UNREGISTERED loaders:
100
101 The search originates with SystemDictionaryShared::lookup_from_stream().
102
103 Search the shared directory for a UNREGISTERED class with a matching
104 (name, clsfile_len, clsfile_crc32) tuple.
105
106 ===============================================================================*/
107 #define UNREGISTERED_INDEX -9999
108
109 class ClassFileStream;
110
111 // Archived classes need extra information not needed by traditionally loaded classes.
112 // To keep footprint small, we add these in the dictionary entry instead of the InstanceKlass.
113 class SharedDictionaryEntry : public DictionaryEntry {
114
115 public:
116 enum LoaderType {
117 LT_BUILTIN,
118 LT_UNREGISTERED
119 };
120
121 enum {
122 FROM_FIELD_IS_PROTECTED = 1 << 0,
123 FROM_IS_ARRAY = 1 << 1,
124 FROM_IS_OBJECT = 1 << 2
125 };
126
127 int _id;
128 int _clsfile_size;
129 int _clsfile_crc32;
130 void* _verifier_constraints; // FIXME - use a union here to avoid type casting??
131 void* _verifier_constraint_flags;
132
133 // See "Identifying the loader_type of archived classes" comments above.
134 LoaderType loader_type() const {
135 Klass* k = (Klass*)literal();
136
137 if ((k->shared_classpath_index() != UNREGISTERED_INDEX)) {
138 return LT_BUILTIN;
139 } else {
140 return LT_UNREGISTERED;
141 }
142 }
143
144 SharedDictionaryEntry* next() {
145 return (SharedDictionaryEntry*)(DictionaryEntry::next());
146 }
147
148 bool is_builtin() const {
149 return loader_type() == LT_BUILTIN;
150 }
151 bool is_unregistered() const {
152 return loader_type() == LT_UNREGISTERED;
153 }
154
155 void add_verification_constraint(Symbol* name,
156 Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object);
157 int finalize_verification_constraints();
158 void check_verification_constraints(InstanceKlass* klass, TRAPS);
159 void metaspace_pointers_do(MetaspaceClosure* it) NOT_CDS_RETURN;
160 };
161
162 class SharedDictionary : public Dictionary {
163 SharedDictionaryEntry* get_entry_for_builtin_loader(const Symbol* name) const;
164 SharedDictionaryEntry* get_entry_for_unregistered_loader(const Symbol* name,
165 int clsfile_size,
166 int clsfile_crc32) const;
167
168 // Convenience functions
169 SharedDictionaryEntry* bucket(int index) const {
170 return (SharedDictionaryEntry*)(Dictionary::bucket(index));
171 }
172
173 public:
174 SharedDictionaryEntry* find_entry_for(Klass* klass);
175 void finalize_verification_constraints();
176
177 bool add_non_builtin_klass(const Symbol* class_name,
178 ClassLoaderData* loader_data,
179 InstanceKlass* obj);
180
181 void update_entry(Klass* klass, int id);
182
183 Klass* find_class_for_builtin_loader(const Symbol* name) const;
184 Klass* find_class_for_unregistered_loader(const Symbol* name,
185 int clsfile_size,
186 int clsfile_crc32) const;
187 bool class_exists_for_unregistered_loader(const Symbol* name) {
188 return (get_entry_for_unregistered_loader(name, -1, -1) != NULL);
189 }
190 };
191
192 class SystemDictionaryShared: public SystemDictionary {
193 private:
194 // These _shared_xxxs arrays are used to initialize the java.lang.Package and
195 // java.security.ProtectionDomain objects associated with each shared class.
196 //
197 // See SystemDictionaryShared::init_security_info for more info.
198 static objArrayOop _shared_protection_domains;
199 static objArrayOop _shared_jar_urls;
200 static objArrayOop _shared_jar_manifests;
201
202 static InstanceKlass* load_shared_class_for_builtin_loader(
203 Symbol* class_name,
204 Handle class_loader,
205 TRAPS);
206 static Handle get_package_name(Symbol* class_name, TRAPS);
207
208
209 // Package handling:
210 //
211 // 1. For named modules in the runtime image
212 // BOOT classes: Reuses the existing JVM_GetSystemPackage(s) interfaces
213 // to get packages in named modules for shared classes.
214 // Package for non-shared classes in named module is also
215 // handled using JVM_GetSystemPackage(s).
216 //
217 // APP classes: VM calls ClassLoaders.AppClassLoader::definePackage(String, Module)
218 // to define package for shared app classes from named
219 // modules.
220 //
221 // PLATFORM classes: VM calls ClassLoaders.PlatformClassLoader::definePackage(String, Module)
222 // to define package for shared platform classes from named
223 // modules.
224 //
225 // 2. For unnamed modules
226 // BOOT classes: Reuses the existing JVM_GetSystemPackage(s) interfaces to
227 // get packages for shared boot classes in unnamed modules.
228 //
229 // APP classes: VM calls ClassLoaders.AppClassLoader::defineOrCheckPackage()
230 // with with the manifest and url from archived data.
231 //
232 // PLATFORM classes: No package is defined.
233 //
234 // The following two define_shared_package() functions are used to define
235 // package for shared APP and PLATFORM classes.
236 static void define_shared_package(Symbol* class_name,
237 Handle class_loader,
238 Handle manifest,
239 Handle url,
240 TRAPS);
241 static void define_shared_package(Symbol* class_name,
242 Handle class_loader,
243 ModuleEntry* mod_entry,
244 TRAPS);
245
246 static Handle get_shared_jar_manifest(int shared_path_index, TRAPS);
247 static Handle get_shared_jar_url(int shared_path_index, TRAPS);
248 static Handle get_protection_domain_from_classloader(Handle class_loader,
249 Handle url, TRAPS);
250 static Handle get_shared_protection_domain(Handle class_loader,
251 int shared_path_index,
252 Handle url,
253 TRAPS);
254 static Handle get_shared_protection_domain(Handle class_loader,
255 ModuleEntry* mod, TRAPS);
256 static Handle init_security_info(Handle class_loader, InstanceKlass* ik, TRAPS);
257
258 static void atomic_set_array_index(objArrayOop array, int index, oop o) {
259 // Benign race condition: array.obj_at(index) may already be filled in.
260 // The important thing here is that all threads pick up the same result.
261 // It doesn't matter which racing thread wins, as long as only one
262 // result is used by all threads, and all future queries.
263 array->atomic_compare_exchange_oop(index, o, NULL);
264 }
265
266 static oop shared_protection_domain(int index);
267 static void atomic_set_shared_protection_domain(int index, oop pd) {
268 atomic_set_array_index(_shared_protection_domains, index, pd);
269 }
270 static void allocate_shared_protection_domain_array(int size, TRAPS);
271 static oop shared_jar_url(int index);
272 static void atomic_set_shared_jar_url(int index, oop url) {
273 atomic_set_array_index(_shared_jar_urls, index, url);
274 }
275 static void allocate_shared_jar_url_array(int size, TRAPS);
276 static oop shared_jar_manifest(int index);
277 static void atomic_set_shared_jar_manifest(int index, oop man) {
278 atomic_set_array_index(_shared_jar_manifests, index, man);
279 }
280 static void allocate_shared_jar_manifest_array(int size, TRAPS);
281 static InstanceKlass* acquire_class_for_current_thread(
282 InstanceKlass *ik,
283 Handle class_loader,
284 Handle protection_domain,
285 TRAPS);
286
287 public:
288 static void initialize(TRAPS);
289
290 // Called by PLATFORM/APP loader only
291 static InstanceKlass* find_or_load_shared_class(Symbol* class_name,
292 Handle class_loader,
293 TRAPS);
294
295
296 static void allocate_shared_data_arrays(int size, TRAPS);
297 static void oops_do(OopClosure* f);
298 static void roots_oops_do(OopClosure* f) {
299 oops_do(f);
300 }
301
302 // Check if sharing is supported for the class loader.
303 static bool is_sharing_possible(ClassLoaderData* loader_data);
304 static bool is_shared_class_visible_for_classloader(InstanceKlass* ik,
305 Handle class_loader,
306 const char* pkg_string,
307 Symbol* pkg_name,
308 PackageEntry* pkg_entry,
309 ModuleEntry* mod_entry,
310 TRAPS);
311 static PackageEntry* get_package_entry(Symbol* pkg,
312 ClassLoaderData *loader_data) {
313 if (loader_data != NULL) {
314 PackageEntryTable* pkgEntryTable = loader_data->packages();
315 return pkgEntryTable->lookup_only(pkg);
316 }
317 return NULL;
318 }
319
320 static bool add_non_builtin_klass(Symbol* class_name, ClassLoaderData* loader_data,
321 InstanceKlass* k, TRAPS);
322 static Klass* dump_time_resolve_super_or_fail(Symbol* child_name,
323 Symbol* class_name,
324 Handle class_loader,
325 Handle protection_domain,
326 bool is_superclass,
327 TRAPS);
328
329 static size_t dictionary_entry_size() {
330 return (DumpSharedSpaces) ? sizeof(SharedDictionaryEntry) : sizeof(DictionaryEntry);
331 }
332 static void init_shared_dictionary_entry(Klass* k, DictionaryEntry* entry) NOT_CDS_RETURN;
333 static bool is_builtin(DictionaryEntry* ent) {
334 // Can't use virtual function is_builtin because DictionaryEntry doesn't initialize
335 // vtable because it's not constructed properly.
336 SharedDictionaryEntry* entry = (SharedDictionaryEntry*)ent;
337 return entry->is_builtin();
338 }
339
340 // For convenient access to the SharedDictionaryEntry's of the archived classes.
341 static SharedDictionary* shared_dictionary() {
342 assert(!DumpSharedSpaces, "not for dumping");
343 return (SharedDictionary*)SystemDictionary::shared_dictionary();
344 }
345
346 static SharedDictionary* boot_loader_dictionary() {
347 return (SharedDictionary*)ClassLoaderData::the_null_class_loader_data()->dictionary();
348 }
349
350 static void update_shared_entry(Klass* klass, int id) {
351 assert(DumpSharedSpaces, "sanity");
352 assert((SharedDictionary*)(klass->class_loader_data()->dictionary()) != NULL, "sanity");
353 ((SharedDictionary*)(klass->class_loader_data()->dictionary()))->update_entry(klass, id);
354 }
355
356 static void set_shared_class_misc_info(Klass* k, ClassFileStream* cfs);
357
358 static InstanceKlass* lookup_from_stream(const Symbol* class_name,
359 Handle class_loader,
360 Handle protection_domain,
361 const ClassFileStream* st,
362 TRAPS);
363 // "verification_constraints" are a set of checks performed by
364 // VerificationType::is_reference_assignable_from when verifying a shared class during
365 // dump time.
366 //
367 // With AppCDS, it is possible to override archived classes by calling
368 // ClassLoader.defineClass() directly. SystemDictionary::load_shared_class() already
369 // ensures that you cannot load a shared class if its super type(s) are changed. However,
370 // we need an additional check to ensure that the verification_constraints did not change
371 // between dump time and runtime.
372 static bool add_verification_constraint(Klass* k, Symbol* name,
373 Symbol* from_name, bool from_field_is_protected,
374 bool from_is_array, bool from_is_object) NOT_CDS_RETURN_(false);
375 static void finalize_verification_constraints() NOT_CDS_RETURN;
376 static void check_verification_constraints(InstanceKlass* klass,
377 TRAPS) NOT_CDS_RETURN;
378 };
379
380 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP