1 /*
  2  * Copyright (c) 2015, 2023, 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 "cds/cds_globals.hpp"
 27 #include "cds/cdsConfig.hpp"
 28 #include "cds/dynamicArchive.hpp"
 29 #include "cds/filemap.hpp"
 30 #include "cds/heapShared.hpp"
 31 #include "classfile/classFileParser.hpp"
 32 #include "classfile/classLoader.inline.hpp"
 33 #include "classfile/classLoaderExt.hpp"
 34 #include "classfile/classLoaderData.inline.hpp"
 35 #include "classfile/classLoadInfo.hpp"
 36 #include "classfile/klassFactory.hpp"
 37 #include "classfile/modules.hpp"
 38 #include "classfile/systemDictionary.hpp"
 39 #include "classfile/vmSymbols.hpp"
 40 #include "gc/shared/collectedHeap.hpp"
 41 #include "logging/log.hpp"
 42 #include "memory/allocation.inline.hpp"
 43 #include "memory/resourceArea.hpp"
 44 #include "oops/instanceKlass.hpp"
 45 #include "oops/klass.inline.hpp"
 46 #include "oops/oop.inline.hpp"
 47 #include "oops/symbol.hpp"
 48 #include "runtime/arguments.hpp"
 49 #include "runtime/handles.inline.hpp"
 50 #include "runtime/java.hpp"
 51 #include "runtime/os.hpp"
 52 #include "utilities/checkedCast.hpp"
 53 #include "utilities/stringUtils.hpp"
 54 
 55 jshort ClassLoaderExt::_app_class_paths_start_index = ClassLoaderExt::max_classpath_index;
 56 jshort ClassLoaderExt::_app_module_paths_start_index = ClassLoaderExt::max_classpath_index;
 57 jshort ClassLoaderExt::_max_used_path_index = 0;
 58 bool ClassLoaderExt::_has_app_classes = false;
 59 bool ClassLoaderExt::_has_platform_classes = false;
 60 bool ClassLoaderExt::_has_non_jar_in_classpath = false;
 61 
 62 void ClassLoaderExt::append_boot_classpath(ClassPathEntry* new_entry) {
 63   if (UseSharedSpaces) {
 64     warning("Sharing is only supported for boot loader classes because bootstrap classpath has been appended");
 65     FileMapInfo::current_info()->set_has_platform_or_app_classes(false);
 66     if (DynamicArchive::is_mapped()) {
 67       FileMapInfo::dynamic_info()->set_has_platform_or_app_classes(false);
 68     }
 69   }
 70   ClassLoader::add_to_boot_append_entries(new_entry);
 71 }
 72 
 73 void ClassLoaderExt::setup_app_search_path(JavaThread* current) {
 74   assert(CDSConfig::is_dumping_archive(), "sanity");
 75   int start_index = ClassLoader::num_boot_classpath_entries();
 76   _app_class_paths_start_index = checked_cast<jshort>(start_index);
 77   char* app_class_path = os::strdup_check_oom(Arguments::get_appclasspath(), mtClass);
 78 
 79   if (strcmp(app_class_path, ".") == 0) {
 80     // This doesn't make any sense, even for AppCDS, so let's skip it. We
 81     // don't want to throw an error here because -cp "." is usually assigned
 82     // by the launcher when classpath is not specified.
 83     trace_class_path("app loader class path (skipped)=", app_class_path);
 84   } else {
 85     trace_class_path("app loader class path=", app_class_path);
 86     ClassLoader::setup_app_search_path(current, app_class_path);
 87   }
 88 
 89   os::free(app_class_path);
 90 }
 91 
 92 void ClassLoaderExt::process_module_table(JavaThread* current, ModuleEntryTable* met) {
 93   ResourceMark rm(current);
 94   GrowableArray<char*>* module_paths = new GrowableArray<char*>(5);
 95 
 96   class ModulePathsGatherer : public ModuleClosure {
 97     JavaThread* _current;
 98     GrowableArray<char*>* _module_paths;
 99    public:
100     ModulePathsGatherer(JavaThread* current, GrowableArray<char*>* module_paths) :
101       _current(current), _module_paths(module_paths) {}
102     void do_module(ModuleEntry* m) {
103       char* path = m->location()->as_C_string();
104       if (strncmp(path, "file:", 5) == 0) {
105         path = ClassLoader::skip_uri_protocol(path);
106         char* path_copy = NEW_RESOURCE_ARRAY(char, strlen(path) + 1);
107         strcpy(path_copy, path);
108         _module_paths->append(path_copy);
109       }
110     }
111   };
112 
113   ModulePathsGatherer gatherer(current, module_paths);
114   {
115     MutexLocker ml(Module_lock);
116     met->modules_do(&gatherer);
117   }
118 
119   for (int i = 0; i < module_paths->length(); i++) {
120     ClassLoader::setup_module_search_path(current, module_paths->at(i));
121   }
122 }
123 
124 void ClassLoaderExt::setup_module_paths(JavaThread* current) {
125   assert(CDSConfig::is_dumping_archive(), "sanity");
126   int start_index = ClassLoader::num_boot_classpath_entries() +
127                     ClassLoader::num_app_classpath_entries();
128   _app_module_paths_start_index = checked_cast<jshort>(start_index);
129   Handle system_class_loader (current, SystemDictionary::java_system_loader());
130   ModuleEntryTable* met = Modules::get_module_entry_table(system_class_loader);
131   process_module_table(current, met);
132 }
133 
134 char* ClassLoaderExt::read_manifest(JavaThread* current, ClassPathEntry* entry,
135                                     jint *manifest_size, bool clean_text) {
136   const char* name = "META-INF/MANIFEST.MF";
137   char* manifest;
138   jint size;
139 
140   assert(entry->is_jar_file(), "must be");
141   manifest = (char*) ((ClassPathZipEntry*)entry )->open_entry(current, name, &size, true);
142 
143   if (manifest == nullptr) { // No Manifest
144     *manifest_size = 0;
145     return nullptr;
146   }
147 
148 
149   if (clean_text) {
150     // See http://docs.oracle.com/javase/6/docs/technotes/guides/jar/jar.html#JAR%20Manifest
151     // (1): replace all CR/LF and CR with LF
152     StringUtils::replace_no_expand(manifest, "\r\n", "\n");
153 
154     // (2) remove all new-line continuation (remove all "\n " substrings)
155     StringUtils::replace_no_expand(manifest, "\n ", "");
156   }
157 
158   *manifest_size = (jint)strlen(manifest);
159   return manifest;
160 }
161 
162 char* ClassLoaderExt::get_class_path_attr(const char* jar_path, char* manifest, jint manifest_size) {
163   const char* tag = "Class-Path: ";
164   const int tag_len = (int)strlen(tag);
165   char* found = nullptr;
166   char* line_start = manifest;
167   char* end = manifest + manifest_size;
168 
169   assert(*end == 0, "must be nul-terminated");
170 
171   while (line_start < end) {
172     char* line_end = strchr(line_start, '\n');
173     if (line_end == nullptr) {
174       // JAR spec require the manifest file to be terminated by a new line.
175       break;
176     }
177     if (strncmp(tag, line_start, tag_len) == 0) {
178       if (found != nullptr) {
179         // Same behavior as jdk/src/share/classes/java/util/jar/Attributes.java
180         // If duplicated entries are found, the last one is used.
181         log_warning(cds)("Warning: Duplicate name in Manifest: %s.\n"
182                       "Ensure that the manifest does not have duplicate entries, and\n"
183                       "that blank lines separate individual sections in both your\n"
184                       "manifest and in the META-INF/MANIFEST.MF entry in the jar file:\n%s\n", tag, jar_path);
185       }
186       found = line_start + tag_len;
187       assert(found <= line_end, "sanity");
188       *line_end = '\0';
189     }
190     line_start = line_end + 1;
191   }
192   return found;
193 }
194 
195 void ClassLoaderExt::process_jar_manifest(JavaThread* current, ClassPathEntry* entry) {
196   ResourceMark rm(current);
197   jint manifest_size;
198   char* manifest = read_manifest(current, entry, &manifest_size);
199 
200   if (manifest == nullptr) {
201     return;
202   }
203 
204   if (strstr(manifest, "Extension-List:") != nullptr) {
205     vm_exit_during_cds_dumping(err_msg("-Xshare:dump does not support Extension-List in JAR manifest: %s", entry->name()));
206   }
207 
208   char* cp_attr = get_class_path_attr(entry->name(), manifest, manifest_size);
209 
210   if (cp_attr != nullptr && strlen(cp_attr) > 0) {
211     trace_class_path("found Class-Path: ", cp_attr);
212 
213     char sep = os::file_separator()[0];
214     const char* dir_name = entry->name();
215     const char* dir_tail = strrchr(dir_name, sep);
216     int dir_len;
217     if (dir_tail == nullptr) {
218       dir_len = 0;
219     } else {
220       dir_len = pointer_delta_as_int(dir_tail, dir_name) + 1;
221     }
222 
223     // Split the cp_attr by spaces, and add each file
224     char* file_start = cp_attr;
225     char* end = file_start + strlen(file_start);
226 
227     while (file_start < end) {
228       char* file_end = strchr(file_start, ' ');
229       if (file_end != nullptr) {
230         *file_end = 0;
231         file_end += 1;
232       } else {
233         file_end = end;
234       }
235 
236       size_t name_len = strlen(file_start);
237       if (name_len > 0) {
238         ResourceMark rm(current);
239         size_t libname_len = dir_len + name_len;
240         char* libname = NEW_RESOURCE_ARRAY(char, libname_len + 1);
241         int n = os::snprintf(libname, libname_len + 1, "%.*s%s", dir_len, dir_name, file_start);
242         assert((size_t)n == libname_len, "Unexpected number of characters in string");
243         if (ClassLoader::update_class_path_entry_list(current, libname, true, false, true /* from_class_path_attr */)) {
244           trace_class_path("library = ", libname);
245         } else {
246           trace_class_path("library (non-existent) = ", libname);
247           FileMapInfo::record_non_existent_class_path_entry(libname);
248         }
249       }
250 
251       file_start = file_end;
252     }
253   }
254 }
255 
256 void ClassLoaderExt::setup_search_paths(JavaThread* current) {
257   ClassLoaderExt::setup_app_search_path(current);
258 }
259 
260 void ClassLoaderExt::record_result(const s2 classpath_index, InstanceKlass* result, bool redefined) {
261   assert(CDSConfig::is_dumping_archive(), "sanity");
262 
263   // We need to remember where the class comes from during dumping.
264   oop loader = result->class_loader();
265   s2 classloader_type = ClassLoader::BOOT_LOADER;
266   if (SystemDictionary::is_system_class_loader(loader)) {
267     classloader_type = ClassLoader::APP_LOADER;
268     ClassLoaderExt::set_has_app_classes();
269   } else if (SystemDictionary::is_platform_class_loader(loader)) {
270     classloader_type = ClassLoader::PLATFORM_LOADER;
271     ClassLoaderExt::set_has_platform_classes();
272   }
273   if (classpath_index > ClassLoaderExt::max_used_path_index()) {
274     ClassLoaderExt::set_max_used_path_index(classpath_index);
275   }
276   result->set_shared_classpath_index(classpath_index);
277   result->set_shared_class_loader_type(classloader_type);
278 #if INCLUDE_CDS_JAVA_HEAP
279   if (CDSConfig::is_dumping_heap() && AllowArchivingWithJavaAgent && classloader_type == ClassLoader::BOOT_LOADER &&
280       classpath_index < 0 && redefined) {
281     // When dumping the heap (which happens only during static dump), classes for the built-in
282     // loaders are always loaded from known locations (jimage, classpath or modulepath),
283     // so classpath_index should always be >= 0.
284     // The only exception is when a java agent is used during dump time (for testing
285     // purposes only). If a class is transformed by the agent, the CodeSource of
286     // this class may point to an unknown location. This may break heap object archiving,
287     // which requires all the boot classes to be from known locations. This is an
288     // uncommon scenario (even in test cases). Let's simply disable heap object archiving.
289     ResourceMark rm;
290     log_warning(cds)("CDS heap objects cannot be written because class %s maybe modified by ClassFileLoadHook.",
291                      result->external_name());
292     HeapShared::disable_writing();
293   }
294 #endif // INCLUDE_CDS_JAVA_HEAP
295 }