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.
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/classFileStream.hpp"
27 #include "classfile/classListParser.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/classLoaderData.inline.hpp"
30 #include "classfile/classLoaderExt.hpp"
31 #include "classfile/compactHashtable.inline.hpp"
32 #include "classfile/dictionary.hpp"
33 #include "classfile/javaClasses.hpp"
34 #include "classfile/sharedClassUtil.hpp"
35 #include "classfile/symbolTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/verificationType.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "logging/log.hpp"
41 #include "memory/allocation.hpp"
42 #include "memory/filemap.hpp"
43 #include "memory/metadataFactory.hpp"
44 #include "memory/metaspaceClosure.hpp"
45 #include "memory/oopFactory.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "oops/instanceKlass.hpp"
48 #include "oops/klass.inline.hpp"
49 #include "oops/objArrayOop.inline.hpp"
50 #include "oops/oop.inline.hpp"
51 #include "oops/typeArrayOop.inline.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/java.hpp"
54 #include "runtime/javaCalls.hpp"
55 #include "runtime/mutexLocker.hpp"
56 #include "utilities/hashtable.inline.hpp"
57 #include "utilities/stringUtils.hpp"
58
59
60 objArrayOop SystemDictionaryShared::_shared_protection_domains = NULL;
61 objArrayOop SystemDictionaryShared::_shared_jar_urls = NULL;
62 objArrayOop SystemDictionaryShared::_shared_jar_manifests = NULL;
63
64 static Mutex* SharedDictionary_lock = NULL;
65
66 void SystemDictionaryShared::initialize(TRAPS) {
67 if (_java_system_loader != NULL) {
68 SharedDictionary_lock = new Mutex(Mutex::leaf, "SharedDictionary_lock", true);
69
70 // These classes need to be initialized before calling get_shared_jar_manifest(), etc.
71 SystemDictionary::ByteArrayInputStream_klass()->initialize(CHECK);
72 SystemDictionary::File_klass()->initialize(CHECK);
73 SystemDictionary::Jar_Manifest_klass()->initialize(CHECK);
74 SystemDictionary::CodeSource_klass()->initialize(CHECK);
75 }
76 }
77
78 oop SystemDictionaryShared::shared_protection_domain(int index) {
79 return _shared_protection_domains->obj_at(index);
80 }
81
82 oop SystemDictionaryShared::shared_jar_url(int index) {
83 return _shared_jar_urls->obj_at(index);
84 }
85
86 oop SystemDictionaryShared::shared_jar_manifest(int index) {
87 return _shared_jar_manifests->obj_at(index);
88 }
89
90
91 Handle SystemDictionaryShared::get_shared_jar_manifest(int shared_path_index, TRAPS) {
92 Handle empty;
93 Handle manifest ;
94 if (shared_jar_manifest(shared_path_index) == NULL) {
95 SharedClassPathEntryExt* ent = (SharedClassPathEntryExt*)FileMapInfo::shared_path(shared_path_index);
96 long size = ent->manifest_size();
97 if (size <= 0) {
98 return empty; // No manifest - return NULL handle
99 }
100
101 // ByteArrayInputStream bais = new ByteArrayInputStream(buf);
102 InstanceKlass* bais_klass = SystemDictionary::ByteArrayInputStream_klass();
103 Handle bais = bais_klass->allocate_instance_handle(CHECK_(empty));
104 {
105 const char* src = ent->manifest();
106 assert(src != NULL, "No Manifest data");
107 typeArrayOop buf = oopFactory::new_byteArray(size, CHECK_(empty));
108 typeArrayHandle bufhandle(THREAD, buf);
109 char* dst = (char*)(buf->byte_at_addr(0));
110 memcpy(dst, src, (size_t)size);
111
112 JavaValue result(T_VOID);
113 JavaCalls::call_special(&result, bais, bais_klass,
114 vmSymbols::object_initializer_name(),
115 vmSymbols::byte_array_void_signature(),
116 bufhandle, CHECK_(empty));
117 }
118
119 // manifest = new Manifest(bais)
120 InstanceKlass* manifest_klass = SystemDictionary::Jar_Manifest_klass();
121 manifest = manifest_klass->allocate_instance_handle(CHECK_(empty));
122 {
123 JavaValue result(T_VOID);
124 JavaCalls::call_special(&result, manifest, manifest_klass,
125 vmSymbols::object_initializer_name(),
126 vmSymbols::input_stream_void_signature(),
127 bais, CHECK_(empty));
128 }
129 atomic_set_shared_jar_manifest(shared_path_index, manifest());
130 }
131
132 manifest = Handle(THREAD, shared_jar_manifest(shared_path_index));
133 assert(manifest.not_null(), "sanity");
134 return manifest;
135 }
136
137 Handle SystemDictionaryShared::get_shared_jar_url(int shared_path_index, TRAPS) {
138 Handle url_h;
139 if (shared_jar_url(shared_path_index) == NULL) {
140 JavaValue result(T_OBJECT);
141 const char* path = FileMapInfo::shared_path_name(shared_path_index);
142 Handle path_string = java_lang_String::create_from_str(path, CHECK_(url_h));
143 Klass* classLoaders_klass =
144 SystemDictionary::jdk_internal_loader_ClassLoaders_klass();
145 JavaCalls::call_static(&result, classLoaders_klass,
146 vmSymbols::toFileURL_name(),
147 vmSymbols::toFileURL_signature(),
148 path_string, CHECK_(url_h));
149
150 atomic_set_shared_jar_url(shared_path_index, (oop)result.get_jobject());
151 }
152
153 url_h = Handle(THREAD, shared_jar_url(shared_path_index));
154 assert(url_h.not_null(), "sanity");
155 return url_h;
156 }
157
158 Handle SystemDictionaryShared::get_package_name(Symbol* class_name, TRAPS) {
159 ResourceMark rm(THREAD);
160 Handle pkgname_string;
161 char* pkgname = (char*) ClassLoader::package_from_name((const char*) class_name->as_C_string());
162 if (pkgname != NULL) { // Package prefix found
163 StringUtils::replace_no_expand(pkgname, "/", ".");
164 pkgname_string = java_lang_String::create_from_str(pkgname,
165 CHECK_(pkgname_string));
166 }
167 return pkgname_string;
168 }
169
170 // Define Package for shared app classes from JAR file and also checks for
171 // package sealing (all done in Java code)
172 // See http://docs.oracle.com/javase/tutorial/deployment/jar/sealman.html
173 void SystemDictionaryShared::define_shared_package(Symbol* class_name,
174 Handle class_loader,
175 Handle manifest,
176 Handle url,
177 TRAPS) {
178 assert(class_loader == _java_system_loader, "unexpected class loader");
179 // get_package_name() returns a NULL handle if the class is in unnamed package
180 Handle pkgname_string = get_package_name(class_name, CHECK);
181 if (pkgname_string.not_null()) {
182 Klass* app_classLoader_klass = SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass();
183 JavaValue result(T_OBJECT);
184 JavaCallArguments args(3);
185 args.set_receiver(class_loader);
186 args.push_oop(pkgname_string);
187 args.push_oop(manifest);
188 args.push_oop(url);
189 JavaCalls::call_virtual(&result, app_classLoader_klass,
190 vmSymbols::defineOrCheckPackage_name(),
191 vmSymbols::defineOrCheckPackage_signature(),
192 &args,
193 CHECK);
194 }
195 }
196
197 // Define Package for shared app/platform classes from named module
198 void SystemDictionaryShared::define_shared_package(Symbol* class_name,
199 Handle class_loader,
200 ModuleEntry* mod_entry,
201 TRAPS) {
202 assert(mod_entry != NULL, "module_entry should not be NULL");
203 Handle module_handle(THREAD, mod_entry->module());
204
205 Handle pkg_name = get_package_name(class_name, CHECK);
206 assert(pkg_name.not_null(), "Package should not be null for class in named module");
207
208 Klass* classLoader_klass;
209 if (SystemDictionary::is_system_class_loader(class_loader())) {
210 classLoader_klass = SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass();
211 } else {
212 assert(SystemDictionary::is_platform_class_loader(class_loader()), "unexpected classloader");
213 classLoader_klass = SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass();
214 }
215
216 JavaValue result(T_OBJECT);
217 JavaCallArguments args(2);
218 args.set_receiver(class_loader);
219 args.push_oop(pkg_name);
220 args.push_oop(module_handle);
221 JavaCalls::call_virtual(&result, classLoader_klass,
222 vmSymbols::definePackage_name(),
223 vmSymbols::definePackage_signature(),
224 &args,
225 CHECK);
226 }
227
228 // Get the ProtectionDomain associated with the CodeSource from the classloader.
229 Handle SystemDictionaryShared::get_protection_domain_from_classloader(Handle class_loader,
230 Handle url, TRAPS) {
231 // CodeSource cs = new CodeSource(url, null);
232 InstanceKlass* cs_klass = SystemDictionary::CodeSource_klass();
233 Handle cs = cs_klass->allocate_instance_handle(CHECK_NH);
234 JavaValue void_result(T_VOID);
235 JavaCalls::call_special(&void_result, cs, cs_klass,
236 vmSymbols::object_initializer_name(),
237 vmSymbols::url_code_signer_array_void_signature(),
238 url, Handle(), CHECK_NH);
239
240 // protection_domain = SecureClassLoader.getProtectionDomain(cs);
241 Klass* secureClassLoader_klass = SystemDictionary::SecureClassLoader_klass();
242 JavaValue obj_result(T_OBJECT);
243 JavaCalls::call_virtual(&obj_result, class_loader, secureClassLoader_klass,
244 vmSymbols::getProtectionDomain_name(),
245 vmSymbols::getProtectionDomain_signature(),
246 cs, CHECK_NH);
247 return Handle(THREAD, (oop)obj_result.get_jobject());
248 }
249
250 // Returns the ProtectionDomain associated with the JAR file identified by the url.
251 Handle SystemDictionaryShared::get_shared_protection_domain(Handle class_loader,
252 int shared_path_index,
253 Handle url,
254 TRAPS) {
255 Handle protection_domain;
256 if (shared_protection_domain(shared_path_index) == NULL) {
257 Handle pd = get_protection_domain_from_classloader(class_loader, url, THREAD);
258 atomic_set_shared_protection_domain(shared_path_index, pd());
259 }
260
261 // Acquire from the cache because if another thread beats the current one to
262 // set the shared protection_domain and the atomic_set fails, the current thread
263 // needs to get the updated protection_domain from the cache.
264 protection_domain = Handle(THREAD, shared_protection_domain(shared_path_index));
265 assert(protection_domain.not_null(), "sanity");
266 return protection_domain;
267 }
268
269 // Returns the ProtectionDomain associated with the moduleEntry.
270 Handle SystemDictionaryShared::get_shared_protection_domain(Handle class_loader,
271 ModuleEntry* mod, TRAPS) {
272 ClassLoaderData *loader_data = mod->loader_data();
273 Handle protection_domain;
274 if (mod->shared_protection_domain() == NULL) {
275 Symbol* location = mod->location();
276 if (location != NULL) {
277 Handle url_string = java_lang_String::create_from_symbol(
278 location, CHECK_(protection_domain));
279 JavaValue result(T_OBJECT);
280 Klass* classLoaders_klass =
281 SystemDictionary::jdk_internal_loader_ClassLoaders_klass();
282 JavaCalls::call_static(&result, classLoaders_klass, vmSymbols::toFileURL_name(),
283 vmSymbols::toFileURL_signature(),
284 url_string, CHECK_(protection_domain));
285 Handle url = Handle(THREAD, (oop)result.get_jobject());
286
287 Handle pd = get_protection_domain_from_classloader(class_loader, url, THREAD);
288 mod->set_shared_protection_domain(loader_data, pd);
289 }
290 }
291
292 protection_domain = Handle(THREAD, mod->shared_protection_domain());
293 assert(protection_domain.not_null(), "sanity");
294 return protection_domain;
295 }
296
297 // Initializes the java.lang.Package and java.security.ProtectionDomain objects associated with
298 // the given InstanceKlass.
299 // Returns the ProtectionDomain for the InstanceKlass.
300 Handle SystemDictionaryShared::init_security_info(Handle class_loader, InstanceKlass* ik, TRAPS) {
301 Handle pd;
302
303 if (ik != NULL) {
304 int index = ik->shared_classpath_index();
305 assert(index >= 0, "Sanity");
306 SharedClassPathEntryExt* ent =
307 (SharedClassPathEntryExt*)FileMapInfo::shared_path(index);
308 Symbol* class_name = ik->name();
309
310 if (ent->is_modules_image()) {
311 // For shared app/platform classes originated from the run-time image:
312 // The ProtectionDomains are cached in the corresponding ModuleEntries
313 // for fast access by the VM.
314 ResourceMark rm;
315 ClassLoaderData *loader_data =
316 ClassLoaderData::class_loader_data(class_loader());
317 PackageEntryTable* pkgEntryTable = loader_data->packages();
318 TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK_(pd));
319 if (pkg_name != NULL) {
320 PackageEntry* pkg_entry = pkgEntryTable->lookup_only(pkg_name);
321 if (pkg_entry != NULL) {
322 ModuleEntry* mod_entry = pkg_entry->module();
323 pd = get_shared_protection_domain(class_loader, mod_entry, THREAD);
324 define_shared_package(class_name, class_loader, mod_entry, CHECK_(pd));
325 }
326 }
327 } else {
328 // For shared app/platform classes originated from JAR files on the class path:
329 // Each of the 3 SystemDictionaryShared::_shared_xxx arrays has the same length
330 // as the shared classpath table in the shared archive (see
331 // FileMap::_shared_path_table in filemap.hpp for details).
332 //
333 // If a shared InstanceKlass k is loaded from the class path, let
334 //
335 // index = k->shared_classpath_index():
336 //
337 // FileMap::_shared_path_table[index] identifies the JAR file that contains k.
338 //
339 // k's protection domain is:
340 //
341 // ProtectionDomain pd = _shared_protection_domains[index];
342 //
343 // and k's Package is initialized using
344 //
345 // manifest = _shared_jar_manifests[index];
346 // url = _shared_jar_urls[index];
347 // define_shared_package(class_name, class_loader, manifest, url, CHECK_(pd));
348 //
349 // Note that if an element of these 3 _shared_xxx arrays is NULL, it will be initialized by
350 // the corresponding SystemDictionaryShared::get_shared_xxx() function.
351 Handle manifest = get_shared_jar_manifest(index, CHECK_(pd));
352 Handle url = get_shared_jar_url(index, CHECK_(pd));
353 define_shared_package(class_name, class_loader, manifest, url, CHECK_(pd));
354 pd = get_shared_protection_domain(class_loader, index, url, CHECK_(pd));
355 }
356 }
357 return pd;
358 }
359
360 bool SystemDictionaryShared::is_sharing_possible(ClassLoaderData* loader_data) {
361 oop class_loader = loader_data->class_loader();
362 return (class_loader == NULL ||
363 SystemDictionary::is_system_class_loader(class_loader) ||
364 SystemDictionary::is_platform_class_loader(class_loader));
365 }
366
367 // Currently AppCDS only archives classes from the run-time image, the
368 // -Xbootclasspath/a path, the class path, and the module path.
369 //
370 // Check if a shared class can be loaded by the specific classloader. Following
371 // are the "visible" archived classes for different classloaders.
372 //
373 // NULL classloader:
374 // - see SystemDictionary::is_shared_class_visible()
375 // Platform classloader:
376 // - Module class from runtime image. ModuleEntry must be defined in the
377 // classloader.
378 // App classloader:
379 // - Module Class from runtime image and module path. ModuleEntry must be defined in the
380 // classloader.
381 // - Class from -cp. The class must have no PackageEntry defined in any of the
382 // boot/platform/app classloader, or must be in the unnamed module defined in the
383 // AppClassLoader.
384 bool SystemDictionaryShared::is_shared_class_visible_for_classloader(
385 InstanceKlass* ik,
386 Handle class_loader,
387 const char* pkg_string,
388 Symbol* pkg_name,
389 PackageEntry* pkg_entry,
390 ModuleEntry* mod_entry,
391 TRAPS) {
392 assert(class_loader.not_null(), "Class loader should not be NULL");
393 assert(Universe::is_module_initialized(), "Module system is not initialized");
394 ResourceMark rm(THREAD);
395
396 int path_index = ik->shared_classpath_index();
397 SharedClassPathEntry* ent =
398 (SharedClassPathEntry*)FileMapInfo::shared_path(path_index);
399
400 if (SystemDictionary::is_platform_class_loader(class_loader())) {
401 assert(ent != NULL, "shared class for PlatformClassLoader should have valid SharedClassPathEntry");
402 // The PlatformClassLoader can only load archived class originated from the
403 // run-time image. The class' PackageEntry/ModuleEntry must be
404 // defined by the PlatformClassLoader.
405 if (mod_entry != NULL) {
406 // PackageEntry/ModuleEntry is found in the classloader. Check if the
407 // ModuleEntry's location agrees with the archived class' origination.
408 if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
409 return true; // Module class from the runtime image
410 }
411 }
412 } else if (SystemDictionary::is_system_class_loader(class_loader())) {
413 assert(ent != NULL, "shared class for system loader should have valid SharedClassPathEntry");
414 if (pkg_string == NULL) {
415 // The archived class is in the unnamed package. Currently, the boot image
416 // does not contain any class in the unnamed package.
417 assert(!ent->is_modules_image(), "Class in the unnamed package must be from the classpath");
418 if (path_index >= ClassLoaderExt::app_class_paths_start_index()) {
419 assert(path_index < ClassLoaderExt::app_module_paths_start_index(), "invalid path_index");
420 return true;
421 }
422 } else {
423 // Check if this is from a PackageEntry/ModuleEntry defined in the AppClassloader.
424 if (pkg_entry == NULL) {
425 // It's not guaranteed that the class is from the classpath if the
426 // PackageEntry cannot be found from the AppClassloader. Need to check
427 // the boot and platform classloader as well.
428 if (get_package_entry(pkg_name, ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_platform_loader())) == NULL &&
429 get_package_entry(pkg_name, ClassLoaderData::the_null_class_loader_data()) == NULL) {
430 // The PackageEntry is not defined in any of the boot/platform/app classloaders.
431 // The archived class must from -cp path and not from the runtime image.
432 if (!ent->is_modules_image() && path_index >= ClassLoaderExt::app_class_paths_start_index() &&
433 path_index < ClassLoaderExt::app_module_paths_start_index()) {
434 return true;
435 }
436 }
437 } else if (mod_entry != NULL) {
438 // The package/module is defined in the AppClassLoader. We support
439 // archiving application module class from the runtime image or from
440 // a named module from a module path.
441 // Packages from the -cp path are in the unnamed_module.
442 if (ent->is_modules_image() && mod_entry->location()->starts_with("jrt:")) {
443 // shared module class from runtime image
444 return true;
445 } else if (pkg_entry->in_unnamed_module() && path_index >= ClassLoaderExt::app_class_paths_start_index() &&
446 path_index < ClassLoaderExt::app_module_paths_start_index()) {
447 // shared class from -cp
448 DEBUG_ONLY( \
449 ClassLoaderData* loader_data = class_loader_data(class_loader); \
450 assert(mod_entry == loader_data->unnamed_module(), "the unnamed module is not defined in the classloader");)
451 return true;
452 } else {
453 if(!pkg_entry->in_unnamed_module() &&
454 (path_index >= ClassLoaderExt::app_module_paths_start_index())&&
455 (path_index < FileMapInfo::get_number_of_shared_paths()) &&
456 (strcmp(ent->name(), ClassLoader::skip_uri_protocol(mod_entry->location()->as_C_string())) == 0)) {
457 // shared module class from module path
458 return true;
459 } else {
460 assert(path_index < FileMapInfo::get_number_of_shared_paths(), "invalid path_index");
461 }
462 }
463 }
464 }
465 } else {
466 // TEMP: if a shared class can be found by a custom loader, consider it visible now.
467 // FIXME: is this actually correct?
468 return true;
469 }
470 return false;
471 }
472
473 // The following stack shows how this code is reached:
474 //
475 // [0] SystemDictionaryShared::find_or_load_shared_class()
476 // [1] JVM_FindLoadedClass
477 // [2] java.lang.ClassLoader.findLoadedClass0()
478 // [3] java.lang.ClassLoader.findLoadedClass()
479 // [4] java.lang.ClassLoader.loadClass()
480 // [5] jdk.internal.loader.ClassLoaders$AppClassLoader_klass.loadClass()
481 //
482 // Because AppCDS supports only the PlatformClassLoader and AppClassLoader, we make the following
483 // assumptions (based on the JDK 8.0 source code):
484 //
485 // [a] these two loaders use the default implementation of
486 // ClassLoader.loadClass(String name, boolean resolve), which
487 // [b] calls findLoadedClass(name), immediately followed by parent.loadClass(),
488 // immediately followed by findClass(name).
489 // [c] If the requested class is a shared class of the current class loader, parent.loadClass()
490 // always returns null, and
491 // [d] if AppCDS is not enabled, the class would be loaded by findClass() by decoding it from a
492 // JAR file and then parsed.
493 //
494 // Given these assumptions, we intercept the findLoadedClass() call to invoke
495 // SystemDictionaryShared::find_or_load_shared_class() to load the shared class from
496 // the archive. The reasons are:
497 //
498 // + Because AppCDS is a commercial feature, we want to hide the implementation. There
499 // is currently no easy way to hide Java code, so we did it with native code.
500 // + Start-up is improved because we avoid decoding the JAR file, and avoid delegating
501 // to the parent (since we know the parent will not find this class).
502 //
503 // NOTE: there's a lot of assumption about the Java code. If any of that change, this
504 // needs to be redesigned.
505 //
506 // An alternative is to modify the Java code of AppClassLoader.loadClass().
507 //
508 InstanceKlass* SystemDictionaryShared::find_or_load_shared_class(
509 Symbol* name, Handle class_loader, TRAPS) {
510 InstanceKlass* k = NULL;
511 if (UseSharedSpaces) {
512 FileMapHeaderExt* header = (FileMapHeaderExt*)FileMapInfo::current_info()->header();
513 if (!header->has_platform_or_app_classes()) {
514 return NULL;
515 }
516
517 if (shared_dictionary() != NULL &&
518 (SystemDictionary::is_system_class_loader(class_loader()) ||
519 SystemDictionary::is_platform_class_loader(class_loader()))) {
520 // Fix for 4474172; see evaluation for more details
521 class_loader = Handle(
522 THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
523 ClassLoaderData *loader_data = register_loader(class_loader);
524 Dictionary* dictionary = loader_data->dictionary();
525
526 unsigned int d_hash = dictionary->compute_hash(name);
527
528 bool DoObjectLock = true;
529 if (is_parallelCapable(class_loader)) {
530 DoObjectLock = false;
531 }
532
533 // Make sure we are synchronized on the class loader before we proceed
534 //
535 // Note: currently, find_or_load_shared_class is called only from
536 // JVM_FindLoadedClass and used for PlatformClassLoader and AppClassLoader,
537 // which are parallel-capable loaders, so this lock is NOT taken.
538 Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
539 check_loader_lock_contention(lockObject, THREAD);
540 ObjectLocker ol(lockObject, THREAD, DoObjectLock);
541
542 {
543 MutexLocker mu(SystemDictionary_lock, THREAD);
544 Klass* check = find_class(d_hash, name, dictionary);
545 if (check != NULL) {
546 return InstanceKlass::cast(check);
547 }
548 }
549
550 k = load_shared_class_for_builtin_loader(name, class_loader, THREAD);
551 if (k != NULL) {
552 define_instance_class(k, CHECK_NULL);
553 }
554 }
555 }
556 return k;
557 }
558
559 InstanceKlass* SystemDictionaryShared::load_shared_class_for_builtin_loader(
560 Symbol* class_name, Handle class_loader, TRAPS) {
561 assert(UseSharedSpaces, "must be");
562 assert(shared_dictionary() != NULL, "already checked");
563 Klass* k = shared_dictionary()->find_class_for_builtin_loader(class_name);
564
565 if (k != NULL) {
566 InstanceKlass* ik = InstanceKlass::cast(k);
567 if ((ik->is_shared_app_class() &&
568 SystemDictionary::is_system_class_loader(class_loader())) ||
569 (ik->is_shared_platform_class() &&
570 SystemDictionary::is_platform_class_loader(class_loader()))) {
571 Handle protection_domain =
572 SystemDictionaryShared::init_security_info(class_loader, ik, CHECK_NULL);
573 return load_shared_class(ik, class_loader, protection_domain, THREAD);
574 }
575 }
576
577 return NULL;
578 }
579
580 void SystemDictionaryShared::oops_do(OopClosure* f) {
581 f->do_oop((oop*)&_shared_protection_domains);
582 f->do_oop((oop*)&_shared_jar_urls);
583 f->do_oop((oop*)&_shared_jar_manifests);
584 }
585
586 void SystemDictionaryShared::allocate_shared_protection_domain_array(int size, TRAPS) {
587 if (_shared_protection_domains == NULL) {
588 _shared_protection_domains = oopFactory::new_objArray(
589 SystemDictionary::ProtectionDomain_klass(), size, CHECK);
590 }
591 }
592
593 void SystemDictionaryShared::allocate_shared_jar_url_array(int size, TRAPS) {
594 if (_shared_jar_urls == NULL) {
595 _shared_jar_urls = oopFactory::new_objArray(
596 SystemDictionary::URL_klass(), size, CHECK);
597 }
598 }
599
600 void SystemDictionaryShared::allocate_shared_jar_manifest_array(int size, TRAPS) {
601 if (_shared_jar_manifests == NULL) {
602 _shared_jar_manifests = oopFactory::new_objArray(
603 SystemDictionary::Jar_Manifest_klass(), size, CHECK);
604 }
605 }
606
607 void SystemDictionaryShared::allocate_shared_data_arrays(int size, TRAPS) {
608 allocate_shared_protection_domain_array(size, CHECK);
609 allocate_shared_jar_url_array(size, CHECK);
610 allocate_shared_jar_manifest_array(size, CHECK);
611 }
612
613 // This function is called for loading only UNREGISTERED classes
614 InstanceKlass* SystemDictionaryShared::lookup_from_stream(const Symbol* class_name,
615 Handle class_loader,
616 Handle protection_domain,
617 const ClassFileStream* cfs,
618 TRAPS) {
619 if (shared_dictionary() == NULL) {
620 return NULL;
621 }
622 if (class_name == NULL) { // don't do this for anonymous classes
623 return NULL;
624 }
625 if (class_loader.is_null() ||
626 SystemDictionary::is_system_class_loader(class_loader()) ||
627 SystemDictionary::is_platform_class_loader(class_loader())) {
628 // Do nothing for the BUILTIN loaders.
629 return NULL;
630 }
631
632 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
633 Klass* k;
634
635 { // UNREGISTERED loader
636 if (!shared_dictionary()->class_exists_for_unregistered_loader(class_name)) {
637 // No classes of this name for unregistered loaders.
638 return NULL;
639 }
640
641 int clsfile_size = cfs->length();
642 int clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
643
644 k = shared_dictionary()->find_class_for_unregistered_loader(class_name,
645 clsfile_size, clsfile_crc32);
646 }
647
648 if (k == NULL) { // not archived
649 return NULL;
650 }
651
652 return acquire_class_for_current_thread(InstanceKlass::cast(k), class_loader,
653 protection_domain, THREAD);
654 }
655
656 InstanceKlass* SystemDictionaryShared::acquire_class_for_current_thread(
657 InstanceKlass *ik,
658 Handle class_loader,
659 Handle protection_domain,
660 TRAPS) {
661 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
662
663 {
664 MutexLocker mu(SharedDictionary_lock, THREAD);
665 if (ik->class_loader_data() != NULL) {
666 // ik is already loaded (by this loader or by a different loader)
667 // or ik is being loaded by a different thread (by this loader or by a different loader)
668 return NULL;
669 }
670
671 // No other thread has acquired this yet, so give it to *this thread*
672 ik->set_class_loader_data(loader_data);
673 }
674
675 // No longer holding SharedDictionary_lock
676 // No need to lock, as <ik> can be held only by a single thread.
677 loader_data->add_class(ik);
678
679 // Load and check super/interfaces, restore unsharable info
680 InstanceKlass* shared_klass = load_shared_class(ik, class_loader, protection_domain, THREAD);
681 if (shared_klass == NULL || HAS_PENDING_EXCEPTION) {
682 // TODO: clean up <ik> so it can be used again
683 return NULL;
684 }
685
686 return shared_klass;
687 }
688
689 bool SystemDictionaryShared::add_non_builtin_klass(Symbol* name,
690 ClassLoaderData* loader_data,
691 InstanceKlass* k,
692 TRAPS) {
693 assert(DumpSharedSpaces, "only when dumping");
694 assert(boot_loader_dictionary() != NULL, "must be");
695
696 if (boot_loader_dictionary()->add_non_builtin_klass(name, loader_data, k)) {
697 MutexLocker mu_r(Compile_lock, THREAD); // not really necessary, but add_to_hierarchy asserts this.
698 add_to_hierarchy(k, CHECK_0);
699 return true;
700 }
701 return false;
702 }
703
704 // This function is called to resolve the super/interfaces of shared classes for
705 // non-built-in loaders. E.g., ChildClass in the below example
706 // where "super:" (and optionally "interface:") have been specified.
707 //
708 // java/lang/Object id: 0
709 // Interface id: 2 super: 0 source: cust.jar
710 // ChildClass id: 4 super: 0 interfaces: 2 source: cust.jar
711 Klass* SystemDictionaryShared::dump_time_resolve_super_or_fail(
712 Symbol* child_name, Symbol* class_name, Handle class_loader,
713 Handle protection_domain, bool is_superclass, TRAPS) {
714
715 assert(DumpSharedSpaces, "only when dumping");
716
717 ClassListParser* parser = ClassListParser::instance();
718 if (parser == NULL) {
719 // We're still loading the well-known classes, before the ClassListParser is created.
720 return NULL;
721 }
722 if (child_name->equals(parser->current_class_name())) {
723 // When this function is called, all the numbered super and interface types
724 // must have already been loaded. Hence this function is never recursively called.
725 if (is_superclass) {
726 return parser->lookup_super_for_current_class(class_name);
727 } else {
728 return parser->lookup_interface_for_current_class(class_name);
729 }
730 } else {
731 // The VM is not trying to resolve a super type of parser->current_class_name().
732 // Instead, it's resolving an error class (because parser->current_class_name() has
733 // failed parsing or verification). Don't do anything here.
734 return NULL;
735 }
736 }
737
738 struct SharedMiscInfo {
739 Klass* _klass;
740 int _clsfile_size;
741 int _clsfile_crc32;
742 };
743
744 static GrowableArray<SharedMiscInfo>* misc_info_array = NULL;
745
746 void SystemDictionaryShared::set_shared_class_misc_info(Klass* k, ClassFileStream* cfs) {
747 assert(DumpSharedSpaces, "only when dumping");
748 int clsfile_size = cfs->length();
749 int clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
750
751 if (misc_info_array == NULL) {
752 misc_info_array = new (ResourceObj::C_HEAP, mtClass) GrowableArray<SharedMiscInfo>(20, /*c heap*/ true);
753 }
754
755 SharedMiscInfo misc_info;
756 DEBUG_ONLY({
757 for (int i=0; i<misc_info_array->length(); i++) {
758 misc_info = misc_info_array->at(i);
759 assert(misc_info._klass != k, "cannot call set_shared_class_misc_info twice for the same class");
760 }
761 });
762
763 misc_info._klass = k;
764 misc_info._clsfile_size = clsfile_size;
765 misc_info._clsfile_crc32 = clsfile_crc32;
766
767 misc_info_array->append(misc_info);
768 }
769
770 void SystemDictionaryShared::init_shared_dictionary_entry(Klass* k, DictionaryEntry* ent) {
771 SharedDictionaryEntry* entry = (SharedDictionaryEntry*)ent;
772 entry->_id = -1;
773 entry->_clsfile_size = -1;
774 entry->_clsfile_crc32 = -1;
775 entry->_verifier_constraints = NULL;
776 entry->_verifier_constraint_flags = NULL;
777
778 if (misc_info_array != NULL) {
779 for (int i=0; i<misc_info_array->length(); i++) {
780 SharedMiscInfo misc_info = misc_info_array->at(i);
781 if (misc_info._klass == k) {
782 entry->_clsfile_size = misc_info._clsfile_size;
783 entry->_clsfile_crc32 = misc_info._clsfile_crc32;
784 misc_info_array->remove_at(i);
785 return;
786 }
787 }
788 }
789 }
790
791 bool SystemDictionaryShared::add_verification_constraint(Klass* k, Symbol* name,
792 Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object) {
793 assert(DumpSharedSpaces, "called at dump time only");
794
795 // Skip anonymous classes, which are not archived as they are not in
796 // dictionary (see assert_no_anonymoys_classes_in_dictionaries() in
797 // VM_PopulateDumpSharedSpace::doit()).
798 if (k->class_loader_data()->is_anonymous()) {
799 return true; // anonymous classes are not archived, skip
800 }
801
802 SharedDictionaryEntry* entry = ((SharedDictionary*)(k->class_loader_data()->dictionary()))->find_entry_for(k);
803 ResourceMark rm;
804 // Lambda classes are not archived and will be regenerated at runtime.
805 if (entry == NULL && strstr(k->name()->as_C_string(), "Lambda$") != NULL) {
806 return true;
807 }
808 assert(entry != NULL, "class should be in dictionary before being verified");
809 entry->add_verification_constraint(name, from_name, from_field_is_protected,
810 from_is_array, from_is_object);
811 if (entry->is_builtin()) {
812 // For builtin class loaders, we can try to complete the verification check at dump time,
813 // because we can resolve all the constraint classes.
814 return false;
815 } else {
816 // For non-builtin class loaders, we cannot complete the verification check at dump time,
817 // because at dump time we don't know how to resolve classes for such loaders.
818 return true;
819 }
820 }
821
822 void SystemDictionaryShared::finalize_verification_constraints() {
823 boot_loader_dictionary()->finalize_verification_constraints();
824 }
825
826 void SystemDictionaryShared::check_verification_constraints(InstanceKlass* klass,
827 TRAPS) {
828 assert(!DumpSharedSpaces && UseSharedSpaces, "called at run time with CDS enabled only");
829 SharedDictionaryEntry* entry = shared_dictionary()->find_entry_for(klass);
830 assert(entry != NULL, "call this only for shared classes");
831 entry->check_verification_constraints(klass, THREAD);
832 }
833
834 SharedDictionaryEntry* SharedDictionary::find_entry_for(Klass* klass) {
835 Symbol* class_name = klass->name();
836 unsigned int hash = compute_hash(class_name);
837 int index = hash_to_index(hash);
838
839 for (SharedDictionaryEntry* entry = bucket(index);
840 entry != NULL;
841 entry = entry->next()) {
842 if (entry->hash() == hash && entry->literal() == klass) {
843 return entry;
844 }
845 }
846
847 return NULL;
848 }
849
850 void SharedDictionary::finalize_verification_constraints() {
851 int bytes = 0, count = 0;
852 for (int index = 0; index < table_size(); index++) {
853 for (SharedDictionaryEntry *probe = bucket(index);
854 probe != NULL;
855 probe = probe->next()) {
856 int n = probe->finalize_verification_constraints();
857 if (n > 0) {
858 bytes += n;
859 count ++;
860 }
861 }
862 }
863 if (log_is_enabled(Info, cds, verification)) {
864 double avg = 0;
865 if (count > 0) {
866 avg = double(bytes) / double(count);
867 }
868 log_info(cds, verification)("Recorded verification constraints for %d classes = %d bytes (avg = %.2f bytes) ", count, bytes, avg);
869 }
870 }
871
872 void SharedDictionaryEntry::add_verification_constraint(Symbol* name,
873 Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object) {
874 if (_verifier_constraints == NULL) {
875 _verifier_constraints = new(ResourceObj::C_HEAP, mtClass) GrowableArray<Symbol*>(8, true, mtClass);
876 }
877 if (_verifier_constraint_flags == NULL) {
878 _verifier_constraint_flags = new(ResourceObj::C_HEAP, mtClass) GrowableArray<char>(4, true, mtClass);
879 }
880 GrowableArray<Symbol*>* vc_array = (GrowableArray<Symbol*>*)_verifier_constraints;
881 for (int i=0; i<vc_array->length(); i+= 2) {
882 if (name == vc_array->at(i) &&
883 from_name == vc_array->at(i+1)) {
884 return;
885 }
886 }
887 vc_array->append(name);
888 vc_array->append(from_name);
889
890 GrowableArray<char>* vcflags_array = (GrowableArray<char>*)_verifier_constraint_flags;
891 char c = 0;
892 c |= from_field_is_protected ? FROM_FIELD_IS_PROTECTED : 0;
893 c |= from_is_array ? FROM_IS_ARRAY : 0;
894 c |= from_is_object ? FROM_IS_OBJECT : 0;
895 vcflags_array->append(c);
896
897 if (log_is_enabled(Trace, cds, verification)) {
898 ResourceMark rm;
899 log_trace(cds, verification)("add_verification_constraint: %s: %s must be subclass of %s",
900 instance_klass()->external_name(), from_name->as_klass_external_name(),
901 name->as_klass_external_name());
902 }
903 }
904
905 int SharedDictionaryEntry::finalize_verification_constraints() {
906 assert(DumpSharedSpaces, "called at dump time only");
907 Thread* THREAD = Thread::current();
908 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
909 GrowableArray<Symbol*>* vc_array = (GrowableArray<Symbol*>*)_verifier_constraints;
910 GrowableArray<char>* vcflags_array = (GrowableArray<char>*)_verifier_constraint_flags;
911
912 if (vc_array != NULL) {
913 if (log_is_enabled(Trace, cds, verification)) {
914 ResourceMark rm;
915 log_trace(cds, verification)("finalize_verification_constraint: %s",
916 literal()->external_name());
917 }
918
919 // Copy the constraints from C_HEAP-alloced GrowableArrays to Metaspace-alloced
920 // Arrays
921 int size = 0;
922 {
923 // FIXME: change this to be done after relocation, so we can use symbol offset??
924 int length = vc_array->length();
925 Array<Symbol*>* out = MetadataFactory::new_array<Symbol*>(loader_data, length, 0, THREAD);
926 assert(out != NULL, "Dump time allocation failure would have aborted VM");
927 for (int i=0; i<length; i++) {
928 out->at_put(i, vc_array->at(i));
929 }
930 _verifier_constraints = out;
931 size += out->size() * BytesPerWord;
932 delete vc_array;
933 }
934 {
935 int length = vcflags_array->length();
936 Array<char>* out = MetadataFactory::new_array<char>(loader_data, length, 0, THREAD);
937 assert(out != NULL, "Dump time allocation failure would have aborted VM");
938 for (int i=0; i<length; i++) {
939 out->at_put(i, vcflags_array->at(i));
940 }
941 _verifier_constraint_flags = out;
942 size += out->size() * BytesPerWord;
943 delete vcflags_array;
944 }
945
946 return size;
947 }
948 return 0;
949 }
950
951 void SharedDictionaryEntry::check_verification_constraints(InstanceKlass* klass, TRAPS) {
952 Array<Symbol*>* vc_array = (Array<Symbol*>*)_verifier_constraints;
953 Array<char>* vcflags_array = (Array<char>*)_verifier_constraint_flags;
954
955 if (vc_array != NULL) {
956 int length = vc_array->length();
957 for (int i=0; i<length; i+=2) {
958 Symbol* name = vc_array->at(i);
959 Symbol* from_name = vc_array->at(i+1);
960 char c = vcflags_array->at(i/2);
961
962 bool from_field_is_protected = (c & FROM_FIELD_IS_PROTECTED) ? true : false;
963 bool from_is_array = (c & FROM_IS_ARRAY) ? true : false;
964 bool from_is_object = (c & FROM_IS_OBJECT) ? true : false;
965
966 bool ok = VerificationType::resolve_and_check_assignability(klass, name,
967 from_name, from_field_is_protected, from_is_array, from_is_object, CHECK);
968 if (!ok) {
969 ResourceMark rm(THREAD);
970 stringStream ss;
971
972 ss.print_cr("Bad type on operand stack");
973 ss.print_cr("Exception Details:");
974 ss.print_cr(" Location:\n %s", klass->name()->as_C_string());
975 ss.print_cr(" Reason:\n Type '%s' is not assignable to '%s'",
976 from_name->as_quoted_ascii(), name->as_quoted_ascii());
977 THROW_MSG(vmSymbols::java_lang_VerifyError(), ss.as_string());
978 }
979 }
980 }
981 }
982
983 void SharedDictionaryEntry::metaspace_pointers_do(MetaspaceClosure* it) {
984 it->push((Array<Symbol*>**)&_verifier_constraints);
985 it->push((Array<char>**)&_verifier_constraint_flags);
986 }
987
988 bool SharedDictionary::add_non_builtin_klass(const Symbol* class_name,
989 ClassLoaderData* loader_data,
990 InstanceKlass* klass) {
991
992 assert(DumpSharedSpaces, "supported only when dumping");
993 assert(klass != NULL, "adding NULL klass");
994 assert(klass->name() == class_name, "sanity check on name");
995 assert(klass->shared_classpath_index() < 0,
996 "the shared classpath index should not be set for shared class loaded by the custom loaders");
997
998 // Add an entry for a non-builtin class.
999 // For a shared class for custom class loaders, SystemDictionary::resolve_or_null will
1000 // not find this class, because is_builtin() is false.
1001 unsigned int hash = compute_hash(class_name);
1002 int index = hash_to_index(hash);
1003
1004 for (SharedDictionaryEntry* entry = bucket(index);
1005 entry != NULL;
1006 entry = entry->next()) {
1007 if (entry->hash() == hash) {
1008 Klass* klass = (Klass*)entry->literal();
1009 if (klass->name() == class_name && klass->class_loader_data() == loader_data) {
1010 // There is already a class defined with the same name
1011 return false;
1012 }
1013 }
1014 }
1015
1016 assert(Dictionary::entry_size() >= sizeof(SharedDictionaryEntry), "must be big enough");
1017 SharedDictionaryEntry* entry = (SharedDictionaryEntry*)new_entry(hash, klass);
1018 add_entry(index, entry);
1019
1020 assert(entry->is_unregistered(), "sanity");
1021 assert(!entry->is_builtin(), "sanity");
1022 return true;
1023 }
1024
1025
1026 //-----------------
1027 // SharedDictionary
1028 //-----------------
1029
1030
1031 Klass* SharedDictionary::find_class_for_builtin_loader(const Symbol* name) const {
1032 SharedDictionaryEntry* entry = get_entry_for_builtin_loader(name);
1033 return entry != NULL ? entry->instance_klass() : (Klass*)NULL;
1034 }
1035
1036 Klass* SharedDictionary::find_class_for_unregistered_loader(const Symbol* name,
1037 int clsfile_size,
1038 int clsfile_crc32) const {
1039
1040 const SharedDictionaryEntry* entry = get_entry_for_unregistered_loader(name,
1041 clsfile_size,
1042 clsfile_crc32);
1043 return entry != NULL ? entry->instance_klass() : (Klass*)NULL;
1044 }
1045
1046 void SharedDictionary::update_entry(Klass* klass, int id) {
1047 assert(DumpSharedSpaces, "supported only when dumping");
1048 Symbol* class_name = klass->name();
1049 unsigned int hash = compute_hash(class_name);
1050 int index = hash_to_index(hash);
1051
1052 for (SharedDictionaryEntry* entry = bucket(index);
1053 entry != NULL;
1054 entry = entry->next()) {
1055 if (entry->hash() == hash && entry->literal() == klass) {
1056 entry->_id = id;
1057 return;
1058 }
1059 }
1060
1061 ShouldNotReachHere();
1062 }
1063
1064 SharedDictionaryEntry* SharedDictionary::get_entry_for_builtin_loader(const Symbol* class_name) const {
1065 assert(!DumpSharedSpaces, "supported only when at runtime");
1066 unsigned int hash = compute_hash(class_name);
1067 const int index = hash_to_index(hash);
1068
1069 for (SharedDictionaryEntry* entry = bucket(index);
1070 entry != NULL;
1071 entry = entry->next()) {
1072 if (entry->hash() == hash && entry->equals(class_name)) {
1073 if (entry->is_builtin()) {
1074 return entry;
1075 }
1076 }
1077 }
1078 return NULL;
1079 }
1080
1081 SharedDictionaryEntry* SharedDictionary::get_entry_for_unregistered_loader(const Symbol* class_name,
1082 int clsfile_size,
1083 int clsfile_crc32) const {
1084 assert(!DumpSharedSpaces, "supported only when at runtime");
1085 unsigned int hash = compute_hash(class_name);
1086 int index = hash_to_index(hash);
1087
1088 for (SharedDictionaryEntry* entry = bucket(index);
1089 entry != NULL;
1090 entry = entry->next()) {
1091 if (entry->hash() == hash && entry->equals(class_name)) {
1092 if (entry->is_unregistered()) {
1093 if (clsfile_size == -1) {
1094 // We're called from class_exists_for_unregistered_loader. At run time, we want to
1095 // compute the CRC of a ClassFileStream only if there is an UNREGISTERED class
1096 // with the matching name.
1097 return entry;
1098 } else {
1099 // We're called from find_class_for_unregistered_loader
1100 if (entry->_clsfile_size && clsfile_crc32 == entry->_clsfile_crc32) {
1101 return entry;
1102 }
1103 }
1104
1105 // There can be only 1 class with this name for unregistered loaders.
1106 return NULL;
1107 }
1108 }
1109 }
1110 return NULL;
1111 }