1 /*
   2  * Copyright (c) 2003, 2024, 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/archiveBuilder.hpp"
  27 #include "cds/archiveHeapLoader.inline.hpp"
  28 #include "cds/archiveHeapWriter.hpp"
  29 #include "cds/archiveUtils.inline.hpp"
  30 #include "cds/cds_globals.hpp"
  31 #include "cds/cdsConfig.hpp"
  32 #include "cds/dynamicArchive.hpp"
  33 #include "cds/filemap.hpp"
  34 #include "cds/heapShared.hpp"
  35 #include "cds/metaspaceShared.hpp"
  36 #include "classfile/altHashing.hpp"
  37 #include "classfile/classFileStream.hpp"
  38 #include "classfile/classLoader.hpp"
  39 #include "classfile/classLoader.inline.hpp"
  40 #include "classfile/classLoaderData.inline.hpp"
  41 #include "classfile/classLoaderExt.hpp"
  42 #include "classfile/symbolTable.hpp"
  43 #include "classfile/systemDictionaryShared.hpp"
  44 #include "classfile/vmClasses.hpp"
  45 #include "classfile/vmSymbols.hpp"
  46 #include "jvm.h"
  47 #include "logging/log.hpp"
  48 #include "logging/logMessage.hpp"
  49 #include "logging/logStream.hpp"
  50 #include "memory/iterator.inline.hpp"
  51 #include "memory/metadataFactory.hpp"
  52 #include "memory/metaspaceClosure.hpp"
  53 #include "memory/oopFactory.hpp"
  54 #include "memory/universe.hpp"
  55 #include "nmt/memTracker.hpp"
  56 #include "oops/compressedOops.hpp"
  57 #include "oops/compressedOops.inline.hpp"
  58 #include "oops/objArrayOop.hpp"
  59 #include "oops/oop.inline.hpp"
  60 #include "prims/jvmtiExport.hpp"
  61 #include "runtime/arguments.hpp"
  62 #include "runtime/globals_extension.hpp"
  63 #include "runtime/java.hpp"
  64 #include "runtime/mutexLocker.hpp"
  65 #include "runtime/os.hpp"
  66 #include "runtime/vm_version.hpp"
  67 #include "utilities/align.hpp"
  68 #include "utilities/bitMap.inline.hpp"
  69 #include "utilities/classpathStream.hpp"
  70 #include "utilities/defaultStream.hpp"
  71 #include "utilities/ostream.hpp"
  72 #if INCLUDE_G1GC
  73 #include "gc/g1/g1CollectedHeap.hpp"
  74 #include "gc/g1/g1HeapRegion.hpp"
  75 #endif
  76 
  77 # include <sys/stat.h>
  78 # include <errno.h>
  79 
  80 #ifndef O_BINARY       // if defined (Win32) use binary files.
  81 #define O_BINARY 0     // otherwise do nothing.
  82 #endif
  83 
  84 inline void CDSMustMatchFlags::do_print(outputStream* st, bool v) {
  85   st->print("%s", v ? "true" : "false");
  86 }
  87 
  88 inline void CDSMustMatchFlags::do_print(outputStream* st, intx v) {
  89   st->print(INTX_FORMAT, v);
  90 }
  91 
  92 inline void CDSMustMatchFlags::do_print(outputStream* st, uintx v) {
  93   st->print(UINTX_FORMAT, v);
  94 }
  95 
  96 inline void CDSMustMatchFlags::do_print(outputStream* st, double v) {
  97   st->print("%f", v);
  98 }
  99 
 100 void CDSMustMatchFlags::init() {
 101   assert(CDSConfig::is_dumping_archive(), "sanity");
 102   _max_name_width = 0;
 103 
 104 #define INIT_CDS_MUST_MATCH_FLAG(n) \
 105   _v_##n = n; \
 106   _max_name_width = MAX2(_max_name_width,strlen(#n));
 107   CDS_MUST_MATCH_FLAGS_DO(INIT_CDS_MUST_MATCH_FLAG);
 108 #undef INIT_CDS_MUST_MATCH_FLAG
 109 }
 110 
 111 bool CDSMustMatchFlags::runtime_check() const {
 112 #define CHECK_CDS_MUST_MATCH_FLAG(n) \
 113   if (_v_##n != n) { \
 114     ResourceMark rm; \
 115     stringStream ss; \
 116     ss.print("VM option %s is different between dumptime (", #n);  \
 117     do_print(&ss, _v_ ## n); \
 118     ss.print(") and runtime ("); \
 119     do_print(&ss, n); \
 120     ss.print(")"); \
 121     log_info(cds)("%s", ss.as_string()); \
 122     return false; \
 123   }
 124   CDS_MUST_MATCH_FLAGS_DO(CHECK_CDS_MUST_MATCH_FLAG);
 125 #undef CHECK_CDS_MUST_MATCH_FLAG
 126 
 127   return true;
 128 }
 129 
 130 void CDSMustMatchFlags::print_info() const {
 131   LogTarget(Info, cds) lt;
 132   if (lt.is_enabled()) {
 133     LogStream ls(lt);
 134     ls.print_cr("Recorded VM flags during dumptime:");
 135     print(&ls);
 136   }
 137 }
 138 
 139 void CDSMustMatchFlags::print(outputStream* st) const {
 140 #define PRINT_CDS_MUST_MATCH_FLAG(n) \
 141   st->print("- %-s ", #n);                   \
 142   st->sp(int(_max_name_width - strlen(#n))); \
 143   do_print(st, _v_##n);                      \
 144   st->cr();
 145   CDS_MUST_MATCH_FLAGS_DO(PRINT_CDS_MUST_MATCH_FLAG);
 146 #undef PRINT_CDS_MUST_MATCH_FLAG
 147 }
 148 
 149 // Fill in the fileMapInfo structure with data about this VM instance.
 150 
 151 // This method copies the vm version info into header_version.  If the version is too
 152 // long then a truncated version, which has a hash code appended to it, is copied.
 153 //
 154 // Using a template enables this method to verify that header_version is an array of
 155 // length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and
 156 // the code that reads the CDS file will both use the same size buffer.  Hence, will
 157 // use identical truncation.  This is necessary for matching of truncated versions.
 158 template <int N> static void get_header_version(char (&header_version) [N]) {
 159   assert(N == JVM_IDENT_MAX, "Bad header_version size");
 160 
 161   const char *vm_version = VM_Version::internal_vm_info_string();
 162   const int version_len = (int)strlen(vm_version);
 163 
 164   memset(header_version, 0, JVM_IDENT_MAX);
 165 
 166   if (version_len < (JVM_IDENT_MAX-1)) {
 167     strcpy(header_version, vm_version);
 168 
 169   } else {
 170     // Get the hash value.  Use a static seed because the hash needs to return the same
 171     // value over multiple jvm invocations.
 172     uint32_t hash = AltHashing::halfsiphash_32(8191, (const uint8_t*)vm_version, version_len);
 173 
 174     // Truncate the ident, saving room for the 8 hex character hash value.
 175     strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
 176 
 177     // Append the hash code as eight hex digits.
 178     os::snprintf_checked(&header_version[JVM_IDENT_MAX-9], 9, "%08x", hash);
 179     header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.
 180   }
 181 
 182   assert(header_version[JVM_IDENT_MAX-1] == 0, "must be");
 183 }
 184 
 185 FileMapInfo::FileMapInfo(const char* full_path, bool is_static) :
 186   _is_static(is_static), _file_open(false), _is_mapped(false), _fd(-1), _file_offset(0),
 187   _full_path(full_path), _base_archive_name(nullptr), _header(nullptr) {
 188   if (_is_static) {
 189     assert(_current_info == nullptr, "must be singleton"); // not thread safe
 190     _current_info = this;
 191   } else {
 192     assert(_dynamic_archive_info == nullptr, "must be singleton"); // not thread safe
 193     _dynamic_archive_info = this;
 194   }
 195 }
 196 
 197 FileMapInfo::~FileMapInfo() {
 198   if (_is_static) {
 199     assert(_current_info == this, "must be singleton"); // not thread safe
 200     _current_info = nullptr;
 201   } else {
 202     assert(_dynamic_archive_info == this, "must be singleton"); // not thread safe
 203     _dynamic_archive_info = nullptr;
 204   }
 205 
 206   if (_header != nullptr) {
 207     os::free(_header);
 208   }
 209 
 210   if (_file_open) {
 211     ::close(_fd);
 212   }
 213 }
 214 
 215 void FileMapInfo::populate_header(size_t core_region_alignment) {
 216   assert(_header == nullptr, "Sanity check");
 217   size_t c_header_size;
 218   size_t header_size;
 219   size_t base_archive_name_size = 0;
 220   size_t base_archive_name_offset = 0;
 221   size_t longest_common_prefix_size = 0;
 222   if (is_static()) {
 223     c_header_size = sizeof(FileMapHeader);
 224     header_size = c_header_size;
 225   } else {
 226     // dynamic header including base archive name for non-default base archive
 227     c_header_size = sizeof(DynamicArchiveHeader);
 228     header_size = c_header_size;
 229 
 230     const char* default_base_archive_name = CDSConfig::default_archive_path();
 231     const char* current_base_archive_name = CDSConfig::static_archive_path();
 232     if (!os::same_files(current_base_archive_name, default_base_archive_name)) {
 233       base_archive_name_size = strlen(current_base_archive_name) + 1;
 234       header_size += base_archive_name_size;
 235       base_archive_name_offset = c_header_size;
 236     }
 237   }
 238   ResourceMark rm;
 239   GrowableArray<const char*>* app_cp_array = create_dumptime_app_classpath_array();
 240   int len = app_cp_array->length();
 241   longest_common_prefix_size = longest_common_app_classpath_prefix_len(len, app_cp_array);
 242   _header = (FileMapHeader*)os::malloc(header_size, mtInternal);
 243   memset((void*)_header, 0, header_size);
 244   _header->populate(this,
 245                     core_region_alignment,
 246                     header_size,
 247                     base_archive_name_size,
 248                     base_archive_name_offset,
 249                     longest_common_prefix_size);
 250 }
 251 
 252 void FileMapHeader::populate(FileMapInfo *info, size_t core_region_alignment,
 253                              size_t header_size, size_t base_archive_name_size,
 254                              size_t base_archive_name_offset, size_t common_app_classpath_prefix_size) {
 255   // 1. We require _generic_header._magic to be at the beginning of the file
 256   // 2. FileMapHeader also assumes that _generic_header is at the beginning of the file
 257   assert(offset_of(FileMapHeader, _generic_header) == 0, "must be");
 258   set_header_size((unsigned int)header_size);
 259   set_base_archive_name_offset((unsigned int)base_archive_name_offset);
 260   set_base_archive_name_size((unsigned int)base_archive_name_size);
 261   set_common_app_classpath_prefix_size((unsigned int)common_app_classpath_prefix_size);
 262   set_magic(CDSConfig::is_dumping_dynamic_archive() ? CDS_DYNAMIC_ARCHIVE_MAGIC : CDS_ARCHIVE_MAGIC);
 263   set_version(CURRENT_CDS_ARCHIVE_VERSION);
 264 
 265   if (!info->is_static() && base_archive_name_size != 0) {
 266     // copy base archive name
 267     copy_base_archive_name(CDSConfig::static_archive_path());
 268   }
 269   _core_region_alignment = core_region_alignment;
 270   _obj_alignment = ObjectAlignmentInBytes;
 271   _compact_strings = CompactStrings;
 272   if (CDSConfig::is_dumping_heap()) {
 273     _narrow_oop_mode = CompressedOops::mode();
 274     _narrow_oop_base = CompressedOops::base();
 275     _narrow_oop_shift = CompressedOops::shift();
 276   }
 277   _compressed_oops = UseCompressedOops;
 278   _compressed_class_ptrs = UseCompressedClassPointers;
 279   _use_secondary_supers_table = UseSecondarySupersTable;
 280   _max_heap_size = MaxHeapSize;
 281   _use_optimized_module_handling = CDSConfig::is_using_optimized_module_handling();
 282   _has_full_module_graph = CDSConfig::is_dumping_full_module_graph();
 283   _has_valhalla_patched_classes = CDSConfig::is_valhalla_preview();
 284   // The following fields are for sanity checks for whether this archive
 285   // will function correctly with this JVM and the bootclasspath it's
 286   // invoked with.
 287 
 288   // JVM version string ... changes on each build.
 289   get_header_version(_jvm_ident);
 290 
 291   _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();
 292   _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();
 293   _max_used_path_index = ClassLoaderExt::max_used_path_index();
 294   _num_module_paths = ClassLoader::num_module_path_entries();
 295 
 296   _verify_local = BytecodeVerificationLocal;
 297   _verify_remote = BytecodeVerificationRemote;
 298   _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();
 299   _has_non_jar_in_classpath = ClassLoaderExt::has_non_jar_in_classpath();
 300   _requested_base_address = (char*)SharedBaseAddress;
 301   _mapped_base_address = (char*)SharedBaseAddress;
 302   _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;
 303   _must_match.init();
 304 
 305   if (!CDSConfig::is_dumping_dynamic_archive()) {
 306     set_shared_path_table(info->_shared_path_table);
 307   }
 308 }
 309 
 310 void FileMapHeader::copy_base_archive_name(const char* archive) {
 311   assert(base_archive_name_size() != 0, "_base_archive_name_size not set");
 312   assert(base_archive_name_offset() != 0, "_base_archive_name_offset not set");
 313   assert(header_size() > sizeof(*this), "_base_archive_name_size not included in header size?");
 314   memcpy((char*)this + base_archive_name_offset(), archive, base_archive_name_size());
 315 }
 316 
 317 void FileMapHeader::print(outputStream* st) {
 318   ResourceMark rm;
 319 
 320   st->print_cr("- magic:                          0x%08x", magic());
 321   st->print_cr("- crc:                            0x%08x", crc());
 322   st->print_cr("- version:                        0x%x", version());
 323   st->print_cr("- header_size:                    " UINT32_FORMAT, header_size());
 324   st->print_cr("- common_app_classpath_size:      " UINT32_FORMAT, common_app_classpath_prefix_size());
 325   st->print_cr("- base_archive_name_offset:       " UINT32_FORMAT, base_archive_name_offset());
 326   st->print_cr("- base_archive_name_size:         " UINT32_FORMAT, base_archive_name_size());
 327 
 328   for (int i = 0; i < NUM_CDS_REGIONS; i++) {
 329     FileMapRegion* r = region_at(i);
 330     r->print(st, i);
 331   }
 332   st->print_cr("============ end regions ======== ");
 333 
 334   st->print_cr("- core_region_alignment:          " SIZE_FORMAT, _core_region_alignment);
 335   st->print_cr("- obj_alignment:                  %d", _obj_alignment);
 336   st->print_cr("- narrow_oop_base:                " INTPTR_FORMAT, p2i(_narrow_oop_base));
 337   st->print_cr("- narrow_oop_base:                " INTPTR_FORMAT, p2i(_narrow_oop_base));
 338   st->print_cr("- narrow_oop_shift                %d", _narrow_oop_shift);
 339   st->print_cr("- compact_strings:                %d", _compact_strings);
 340   st->print_cr("- max_heap_size:                  " UINTX_FORMAT, _max_heap_size);
 341   st->print_cr("- narrow_oop_mode:                %d", _narrow_oop_mode);
 342   st->print_cr("- compressed_oops:                %d", _compressed_oops);
 343   st->print_cr("- compressed_class_ptrs:          %d", _compressed_class_ptrs);
 344   st->print_cr("- use_secondary_supers_table:     %d", _use_secondary_supers_table);
 345   st->print_cr("- cloned_vtables_offset:          " SIZE_FORMAT_X, _cloned_vtables_offset);
 346   st->print_cr("- serialized_data_offset:         " SIZE_FORMAT_X, _serialized_data_offset);
 347   st->print_cr("- jvm_ident:                      %s", _jvm_ident);
 348   st->print_cr("- shared_path_table_offset:       " SIZE_FORMAT_X, _shared_path_table_offset);
 349   st->print_cr("- app_class_paths_start_index:    %d", _app_class_paths_start_index);
 350   st->print_cr("- app_module_paths_start_index:   %d", _app_module_paths_start_index);
 351   st->print_cr("- num_module_paths:               %d", _num_module_paths);
 352   st->print_cr("- max_used_path_index:            %d", _max_used_path_index);
 353   st->print_cr("- verify_local:                   %d", _verify_local);
 354   st->print_cr("- verify_remote:                  %d", _verify_remote);
 355   st->print_cr("- has_platform_or_app_classes:    %d", _has_platform_or_app_classes);
 356   st->print_cr("- has_non_jar_in_classpath:       %d", _has_non_jar_in_classpath);
 357   st->print_cr("- requested_base_address:         " INTPTR_FORMAT, p2i(_requested_base_address));
 358   st->print_cr("- mapped_base_address:            " INTPTR_FORMAT, p2i(_mapped_base_address));
 359   st->print_cr("- heap_roots_offset:              " SIZE_FORMAT, _heap_roots_offset);
 360   st->print_cr("- _heap_oopmap_start_pos:         " SIZE_FORMAT, _heap_oopmap_start_pos);
 361   st->print_cr("- _heap_ptrmap_start_pos:         " SIZE_FORMAT, _heap_ptrmap_start_pos);
 362   st->print_cr("- _rw_ptrmap_start_pos:           " SIZE_FORMAT, _rw_ptrmap_start_pos);
 363   st->print_cr("- _ro_ptrmap_start_pos:           " SIZE_FORMAT, _ro_ptrmap_start_pos);
 364   st->print_cr("- allow_archiving_with_java_agent:%d", _allow_archiving_with_java_agent);
 365   st->print_cr("- use_optimized_module_handling:  %d", _use_optimized_module_handling);
 366   st->print_cr("- has_full_module_graph           %d", _has_full_module_graph);
 367   st->print_cr("- has_valhalla_patched_classes    %d", _has_valhalla_patched_classes);
 368   _must_match.print(st);
 369 }
 370 
 371 void SharedClassPathEntry::init_as_non_existent(const char* path, TRAPS) {
 372   _type = non_existent_entry;
 373   set_name(path, CHECK);
 374 }
 375 
 376 void SharedClassPathEntry::init(bool is_modules_image,
 377                                 bool is_module_path,
 378                                 ClassPathEntry* cpe, TRAPS) {
 379   assert(CDSConfig::is_dumping_archive(), "sanity");
 380   _timestamp = 0;
 381   _filesize  = 0;
 382   _from_class_path_attr = false;
 383 
 384   struct stat st;
 385   if (os::stat(cpe->name(), &st) == 0) {
 386     if ((st.st_mode & S_IFMT) == S_IFDIR) {
 387       _type = dir_entry;
 388     } else {
 389       // The timestamp of the modules_image is not checked at runtime.
 390       if (is_modules_image) {
 391         _type = modules_image_entry;
 392       } else {
 393         _type = jar_entry;
 394         _timestamp = st.st_mtime;
 395         _from_class_path_attr = cpe->from_class_path_attr();
 396       }
 397       _filesize = st.st_size;
 398       _is_module_path = is_module_path;
 399     }
 400   } else {
 401     // The file/dir must exist, or it would not have been added
 402     // into ClassLoader::classpath_entry().
 403     //
 404     // If we can't access a jar file in the boot path, then we can't
 405     // make assumptions about where classes get loaded from.
 406     log_error(cds)("Unable to open file %s.", cpe->name());
 407     MetaspaceShared::unrecoverable_loading_error();
 408   }
 409 
 410   // No need to save the name of the module file, as it will be computed at run time
 411   // to allow relocation of the JDK directory.
 412   const char* name = is_modules_image  ? "" : cpe->name();
 413   set_name(name, CHECK);
 414 }
 415 
 416 void SharedClassPathEntry::set_name(const char* name, TRAPS) {
 417   size_t len = strlen(name) + 1;
 418   _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, CHECK);
 419   strcpy(_name->data(), name);
 420 }
 421 
 422 void SharedClassPathEntry::copy_from(SharedClassPathEntry* ent, ClassLoaderData* loader_data, TRAPS) {
 423   assert(ent != nullptr, "sanity");
 424   _type = ent->_type;
 425   _is_module_path = ent->_is_module_path;
 426   _timestamp = ent->_timestamp;
 427   _filesize = ent->_filesize;
 428   _from_class_path_attr = ent->_from_class_path_attr;
 429   set_name(ent->name(), CHECK);
 430 
 431   if (ent->is_jar() && ent->manifest() != nullptr) {
 432     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 433                                                     ent->manifest_size(),
 434                                                     CHECK);
 435     char* p = (char*)(buf->data());
 436     memcpy(p, ent->manifest(), ent->manifest_size());
 437     set_manifest(buf);
 438   }
 439 }
 440 
 441 const char* SharedClassPathEntry::name() const {
 442   if (CDSConfig::is_using_archive() && is_modules_image()) {
 443     // In order to validate the runtime modules image file size against the archived
 444     // size information, we need to obtain the runtime modules image path. The recorded
 445     // dump time modules image path in the archive may be different from the runtime path
 446     // if the JDK image has beed moved after generating the archive.
 447     return ClassLoader::get_jrt_entry()->name();
 448   } else {
 449     return _name->data();
 450   }
 451 }
 452 
 453 bool SharedClassPathEntry::validate(bool is_class_path) const {
 454   assert(CDSConfig::is_using_archive(), "runtime only");
 455 
 456   struct stat st;
 457   const char* name = this->name();
 458 
 459   bool ok = true;
 460   log_info(class, path)("checking shared classpath entry: %s", name);
 461   if (os::stat(name, &st) != 0 && is_class_path) {
 462     // If the archived module path entry does not exist at runtime, it is not fatal
 463     // (no need to invalid the shared archive) because the shared runtime visibility check
 464     // filters out any archived module classes that do not have a matching runtime
 465     // module path location.
 466     log_warning(cds)("Required classpath entry does not exist: %s", name);
 467     ok = false;
 468   } else if (is_dir()) {
 469     if (!os::dir_is_empty(name)) {
 470       log_warning(cds)("directory is not empty: %s", name);
 471       ok = false;
 472     }
 473   } else {
 474     bool size_differs = _filesize != st.st_size;
 475     bool time_differs = has_timestamp() && _timestamp != st.st_mtime;
 476     if (time_differs || size_differs) {
 477       ok = false;
 478       if (PrintSharedArchiveAndExit) {
 479         log_warning(cds)(time_differs ? "Timestamp mismatch" : "File size mismatch");
 480       } else {
 481         const char* bad_file_msg = "This file is not the one used while building the shared archive file:";
 482         log_warning(cds)("%s %s", bad_file_msg, name);
 483         if (!log_is_enabled(Info, cds)) {
 484           log_warning(cds)("%s %s", bad_file_msg, name);
 485         }
 486         if (time_differs) {
 487           log_warning(cds)("%s timestamp has changed.", name);
 488         }
 489         if (size_differs) {
 490           log_warning(cds)("%s size has changed.", name);
 491         }
 492       }
 493     }
 494   }
 495 
 496   if (PrintSharedArchiveAndExit && !ok) {
 497     // If PrintSharedArchiveAndExit is enabled, don't report failure to the
 498     // caller. Please see above comments for more details.
 499     ok = true;
 500     MetaspaceShared::set_archive_loading_failed();
 501   }
 502   return ok;
 503 }
 504 
 505 bool SharedClassPathEntry::check_non_existent() const {
 506   assert(_type == non_existent_entry, "must be");
 507   log_info(class, path)("should be non-existent: %s", name());
 508   struct stat st;
 509   if (os::stat(name(), &st) != 0) {
 510     log_info(class, path)("ok");
 511     return true; // file doesn't exist
 512   } else {
 513     return false;
 514   }
 515 }
 516 
 517 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
 518   it->push(&_name);
 519   it->push(&_manifest);
 520 }
 521 
 522 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
 523   it->push(&_entries);
 524 }
 525 
 526 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, TRAPS) {
 527   const int num_entries =
 528     ClassLoader::num_boot_classpath_entries() +
 529     ClassLoader::num_app_classpath_entries() +
 530     ClassLoader::num_module_path_entries() +
 531     FileMapInfo::num_non_existent_class_paths();
 532   _entries = MetadataFactory::new_array<SharedClassPathEntry*>(loader_data, num_entries, CHECK);
 533   for (int i = 0; i < num_entries; i++) {
 534     SharedClassPathEntry* ent =
 535       new (loader_data, SharedClassPathEntry::size(), MetaspaceObj::SharedClassPathEntryType, THREAD) SharedClassPathEntry;
 536     _entries->at_put(i, ent);
 537   }
 538 }
 539 
 540 void FileMapInfo::allocate_shared_path_table(TRAPS) {
 541   assert(CDSConfig::is_dumping_archive(), "sanity");
 542 
 543   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 544   ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
 545 
 546   assert(jrt != nullptr,
 547          "No modular java runtime image present when allocating the CDS classpath entry table");
 548 
 549   _shared_path_table.dumptime_init(loader_data, CHECK);
 550 
 551   // 1. boot class path
 552   int i = 0;
 553   i = add_shared_classpaths(i, "boot",   jrt, CHECK);
 554   i = add_shared_classpaths(i, "app",    ClassLoader::app_classpath_entries(), CHECK);
 555   i = add_shared_classpaths(i, "module", ClassLoader::module_path_entries(), CHECK);
 556 
 557   for (int x = 0; x < num_non_existent_class_paths(); x++, i++) {
 558     const char* path = _non_existent_class_paths->at(x);
 559     shared_path(i)->init_as_non_existent(path, CHECK);
 560   }
 561 
 562   assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
 563 }
 564 
 565 int FileMapInfo::add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS) {
 566   while (cpe != nullptr) {
 567     bool is_jrt = (cpe == ClassLoader::get_jrt_entry());
 568     bool is_module_path = i >= ClassLoaderExt::app_module_paths_start_index();
 569     const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
 570     log_info(class, path)("add %s shared path (%s) %s", which, type, cpe->name());
 571     SharedClassPathEntry* ent = shared_path(i);
 572     ent->init(is_jrt, is_module_path, cpe, CHECK_0);
 573     if (cpe->is_jar_file()) {
 574       update_jar_manifest(cpe, ent, CHECK_0);
 575     }
 576     if (is_jrt) {
 577       cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
 578     } else {
 579       cpe = cpe->next();
 580     }
 581     i++;
 582   }
 583 
 584   return i;
 585 }
 586 
 587 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
 588   assert(CDSConfig::is_dumping_archive(), "sanity");
 589 
 590   bool has_nonempty_dir = false;
 591 
 592   int last = _shared_path_table.size() - 1;
 593   if (last > ClassLoaderExt::max_used_path_index()) {
 594      // no need to check any path beyond max_used_path_index
 595      last = ClassLoaderExt::max_used_path_index();
 596   }
 597 
 598   for (int i = 0; i <= last; i++) {
 599     SharedClassPathEntry *e = shared_path(i);
 600     if (e->is_dir()) {
 601       const char* path = e->name();
 602       if (!os::dir_is_empty(path)) {
 603         log_error(cds)("Error: non-empty directory '%s'", path);
 604         has_nonempty_dir = true;
 605       }
 606     }
 607   }
 608 
 609   if (has_nonempty_dir) {
 610     ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", nullptr);
 611   }
 612 }
 613 
 614 void FileMapInfo::record_non_existent_class_path_entry(const char* path) {
 615   assert(CDSConfig::is_dumping_archive(), "sanity");
 616   log_info(class, path)("non-existent Class-Path entry %s", path);
 617   if (_non_existent_class_paths == nullptr) {
 618     _non_existent_class_paths = new (mtClass) GrowableArray<const char*>(10, mtClass);
 619   }
 620   _non_existent_class_paths->append(os::strdup(path));
 621 }
 622 
 623 int FileMapInfo::num_non_existent_class_paths() {
 624   assert(CDSConfig::is_dumping_archive(), "sanity");
 625   if (_non_existent_class_paths != nullptr) {
 626     return _non_existent_class_paths->length();
 627   } else {
 628     return 0;
 629   }
 630 }
 631 
 632 int FileMapInfo::get_module_shared_path_index(Symbol* location) {
 633   if (location->starts_with("jrt:", 4) && get_number_of_shared_paths() > 0) {
 634     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 635     return 0;
 636   }
 637 
 638   if (ClassLoaderExt::app_module_paths_start_index() >= get_number_of_shared_paths()) {
 639     // The archive(s) were created without --module-path option
 640     return -1;
 641   }
 642 
 643   if (!location->starts_with("file:", 5)) {
 644     return -1;
 645   }
 646 
 647   // skip_uri_protocol was also called during dump time -- see ClassLoaderExt::process_module_table()
 648   ResourceMark rm;
 649   const char* file = ClassLoader::skip_uri_protocol(location->as_C_string());
 650   for (int i = ClassLoaderExt::app_module_paths_start_index(); i < get_number_of_shared_paths(); i++) {
 651     SharedClassPathEntry* ent = shared_path(i);
 652     if (!ent->is_non_existent()) {
 653       assert(ent->in_named_module(), "must be");
 654       bool cond = strcmp(file, ent->name()) == 0;
 655       log_debug(class, path)("get_module_shared_path_index (%d) %s : %s = %s", i,
 656                              location->as_C_string(), ent->name(), cond ? "same" : "different");
 657       if (cond) {
 658         return i;
 659       }
 660     }
 661   }
 662 
 663   return -1;
 664 }
 665 
 666 class ManifestStream: public ResourceObj {
 667   private:
 668   u1*   _buffer_start; // Buffer bottom
 669   u1*   _buffer_end;   // Buffer top (one past last element)
 670   u1*   _current;      // Current buffer position
 671 
 672  public:
 673   // Constructor
 674   ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
 675                                            _current(buffer) {
 676     _buffer_end = buffer + length;
 677   }
 678 
 679   static bool is_attr(u1* attr, const char* name) {
 680     return strncmp((const char*)attr, name, strlen(name)) == 0;
 681   }
 682 
 683   static char* copy_attr(u1* value, size_t len) {
 684     char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
 685     strncpy(buf, (char*)value, len);
 686     buf[len] = 0;
 687     return buf;
 688   }
 689 };
 690 
 691 void FileMapInfo::update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
 692   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 693   ResourceMark rm(THREAD);
 694   jint manifest_size;
 695 
 696   assert(cpe->is_jar_file() && ent->is_jar(), "the shared class path entry is not a JAR file");
 697   char* manifest = ClassLoaderExt::read_manifest(THREAD, cpe, &manifest_size);
 698   if (manifest != nullptr) {
 699     ManifestStream* stream = new ManifestStream((u1*)manifest,
 700                                                 manifest_size);
 701     // Copy the manifest into the shared archive
 702     manifest = ClassLoaderExt::read_raw_manifest(THREAD, cpe, &manifest_size);
 703     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 704                                                     manifest_size,
 705                                                     CHECK);
 706     char* p = (char*)(buf->data());
 707     memcpy(p, manifest, manifest_size);
 708     ent->set_manifest(buf);
 709   }
 710 }
 711 
 712 char* FileMapInfo::skip_first_path_entry(const char* path) {
 713   size_t path_sep_len = strlen(os::path_separator());
 714   char* p = strstr((char*)path, os::path_separator());
 715   if (p != nullptr) {
 716     debug_only( {
 717       size_t image_name_len = strlen(MODULES_IMAGE_NAME);
 718       assert(strncmp(p - image_name_len, MODULES_IMAGE_NAME, image_name_len) == 0,
 719              "first entry must be the modules image");
 720     } );
 721     p += path_sep_len;
 722   } else {
 723     debug_only( {
 724       assert(ClassLoader::string_ends_with(path, MODULES_IMAGE_NAME),
 725              "first entry must be the modules image");
 726     } );
 727   }
 728   return p;
 729 }
 730 
 731 int FileMapInfo::num_paths(const char* path) {
 732   if (path == nullptr) {
 733     return 0;
 734   }
 735   int npaths = 1;
 736   char* p = (char*)path;
 737   while (p != nullptr) {
 738     char* prev = p;
 739     p = strstr((char*)p, os::path_separator());
 740     if (p != nullptr) {
 741       p++;
 742       // don't count empty path
 743       if ((p - prev) > 1) {
 744        npaths++;
 745       }
 746     }
 747   }
 748   return npaths;
 749 }
 750 
 751 // Returns true if a path within the paths exists and has non-zero size.
 752 bool FileMapInfo::check_paths_existence(const char* paths) {
 753   ClasspathStream cp_stream(paths);
 754   bool exist = false;
 755   struct stat st;
 756   while (cp_stream.has_next()) {
 757     const char* path = cp_stream.get_next();
 758     if (os::stat(path, &st) == 0 && st.st_size > 0) {
 759       exist = true;
 760       break;
 761     }
 762   }
 763   return exist;
 764 }
 765 
 766 GrowableArray<const char*>* FileMapInfo::create_dumptime_app_classpath_array() {
 767   assert(CDSConfig::is_dumping_archive(), "sanity");
 768   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 769   ClassPathEntry* cpe = ClassLoader::app_classpath_entries();
 770   while (cpe != nullptr) {
 771     path_array->append(cpe->name());
 772     cpe = cpe->next();
 773   }
 774   return path_array;
 775 }
 776 
 777 GrowableArray<const char*>* FileMapInfo::create_path_array(const char* paths) {
 778   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 779   JavaThread* current = JavaThread::current();
 780   ClasspathStream cp_stream(paths);
 781   bool non_jar_in_cp = header()->has_non_jar_in_classpath();
 782   while (cp_stream.has_next()) {
 783     const char* path = cp_stream.get_next();
 784     if (!non_jar_in_cp) {
 785       struct stat st;
 786       if (os::stat(path, &st) == 0) {
 787         path_array->append(path);
 788       }
 789     } else {
 790       const char* canonical_path = ClassLoader::get_canonical_path(path, current);
 791       if (canonical_path != nullptr) {
 792         char* error_msg = nullptr;
 793         jzfile* zip = ClassLoader::open_zip_file(canonical_path, &error_msg, current);
 794         if (zip != nullptr && error_msg == nullptr) {
 795           path_array->append(path);
 796         }
 797       }
 798     }
 799   }
 800   return path_array;
 801 }
 802 
 803 bool FileMapInfo::classpath_failure(const char* msg, const char* name) {
 804   ClassLoader::trace_class_path(msg, name);
 805   if (PrintSharedArchiveAndExit) {
 806     MetaspaceShared::set_archive_loading_failed();
 807   }
 808   return false;
 809 }
 810 
 811 unsigned int FileMapInfo::longest_common_app_classpath_prefix_len(int num_paths,
 812                                                                   GrowableArray<const char*>* rp_array) {
 813   if (num_paths == 0) {
 814     return 0;
 815   }
 816   unsigned int pos;
 817   for (pos = 0; ; pos++) {
 818     for (int i = 0; i < num_paths; i++) {
 819       if (rp_array->at(i)[pos] != '\0' && rp_array->at(i)[pos] == rp_array->at(0)[pos]) {
 820         continue;
 821       }
 822       // search backward for the pos before the file separator char
 823       while (pos > 0) {
 824         if (rp_array->at(0)[--pos] == *os::file_separator()) {
 825           return pos + 1;
 826         }
 827       }
 828       return 0;
 829     }
 830   }
 831   return 0;
 832 }
 833 
 834 bool FileMapInfo::check_paths(int shared_path_start_idx, int num_paths, GrowableArray<const char*>* rp_array,
 835                               unsigned int dumptime_prefix_len, unsigned int runtime_prefix_len) {
 836   int i = 0;
 837   int j = shared_path_start_idx;
 838   while (i < num_paths) {
 839     while (shared_path(j)->from_class_path_attr()) {
 840       // shared_path(j) was expanded from the JAR file attribute "Class-Path:"
 841       // during dump time. It's not included in the -classpath VM argument.
 842       j++;
 843     }
 844     assert(strlen(shared_path(j)->name()) > (size_t)dumptime_prefix_len, "sanity");
 845     const char* dumptime_path = shared_path(j)->name() + dumptime_prefix_len;
 846     assert(strlen(rp_array->at(i)) > (size_t)runtime_prefix_len, "sanity");
 847     const char* runtime_path = rp_array->at(i)  + runtime_prefix_len;
 848     if (!os::same_files(dumptime_path, runtime_path)) {
 849       return true;
 850     }
 851     i++;
 852     j++;
 853   }
 854   return false;
 855 }
 856 
 857 bool FileMapInfo::validate_boot_class_paths() {
 858   //
 859   // - Archive contains boot classes only - relaxed boot path check:
 860   //   Extra path elements appended to the boot path at runtime are allowed.
 861   //
 862   // - Archive contains application or platform classes - strict boot path check:
 863   //   Validate the entire runtime boot path, which must be compatible
 864   //   with the dump time boot path. Appending boot path at runtime is not
 865   //   allowed.
 866   //
 867 
 868   // The first entry in boot path is the modules_image (guaranteed by
 869   // ClassLoader::setup_boot_search_path()). Skip the first entry. The
 870   // path of the runtime modules_image may be different from the dump
 871   // time path (e.g. the JDK image is copied to a different location
 872   // after generating the shared archive), which is acceptable. For most
 873   // common cases, the dump time boot path might contain modules_image only.
 874   char* runtime_boot_path = Arguments::get_boot_class_path();
 875   char* rp = skip_first_path_entry(runtime_boot_path);
 876   assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 877   int dp_len = header()->app_class_paths_start_index() - 1; // ignore the first path to the module image
 878   bool mismatch = false;
 879 
 880   bool relaxed_check = !header()->has_platform_or_app_classes();
 881   if (dp_len == 0 && rp == nullptr) {
 882     return true;   // ok, both runtime and dump time boot paths have modules_images only
 883   } else if (dp_len == 0 && rp != nullptr) {
 884     if (relaxed_check) {
 885       return true;   // ok, relaxed check, runtime has extra boot append path entries
 886     } else {
 887       ResourceMark rm;
 888       if (check_paths_existence(rp)) {
 889         // If a path exists in the runtime boot paths, it is considered a mismatch
 890         // since there's no boot path specified during dump time.
 891         mismatch = true;
 892       }
 893     }
 894   } else if (dp_len > 0 && rp != nullptr) {
 895     int num;
 896     ResourceMark rm;
 897     GrowableArray<const char*>* rp_array = create_path_array(rp);
 898     int rp_len = rp_array->length();
 899     if (rp_len >= dp_len) {
 900       if (relaxed_check) {
 901         // only check the leading entries in the runtime boot path, up to
 902         // the length of the dump time boot path
 903         num = dp_len;
 904       } else {
 905         // check the full runtime boot path, must match with dump time
 906         num = rp_len;
 907       }
 908       mismatch = check_paths(1, num, rp_array, 0, 0);
 909     } else {
 910       // create_path_array() ignores non-existing paths. Although the dump time and runtime boot classpath lengths
 911       // are the same initially, after the call to create_path_array(), the runtime boot classpath length could become
 912       // shorter. We consider boot classpath mismatch in this case.
 913       mismatch = true;
 914     }
 915   }
 916 
 917   if (mismatch) {
 918     // The paths are different
 919     return classpath_failure("[BOOT classpath mismatch, actual =", runtime_boot_path);
 920   }
 921   return true;
 922 }
 923 
 924 bool FileMapInfo::validate_app_class_paths(int shared_app_paths_len) {
 925   const char *appcp = Arguments::get_appclasspath();
 926   assert(appcp != nullptr, "null app classpath");
 927   int rp_len = num_paths(appcp);
 928   bool mismatch = false;
 929   if (rp_len < shared_app_paths_len) {
 930     return classpath_failure("Run time APP classpath is shorter than the one at dump time: ", appcp);
 931   }
 932   if (shared_app_paths_len != 0 && rp_len != 0) {
 933     // Prefix is OK: E.g., dump with -cp foo.jar, but run with -cp foo.jar:bar.jar.
 934     ResourceMark rm;
 935     GrowableArray<const char*>* rp_array = create_path_array(appcp);
 936     if (rp_array->length() == 0) {
 937       // None of the jar file specified in the runtime -cp exists.
 938       return classpath_failure("None of the jar file specified in the runtime -cp exists: -Djava.class.path=", appcp);
 939     }
 940     if (rp_array->length() < shared_app_paths_len) {
 941       // create_path_array() ignores non-existing paths. Although the dump time and runtime app classpath lengths
 942       // are the same initially, after the call to create_path_array(), the runtime app classpath length could become
 943       // shorter. We consider app classpath mismatch in this case.
 944       return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 945     }
 946 
 947     // Handling of non-existent entries in the classpath: we eliminate all the non-existent
 948     // entries from both the dump time classpath (ClassLoader::update_class_path_entry_list)
 949     // and the runtime classpath (FileMapInfo::create_path_array), and check the remaining
 950     // entries. E.g.:
 951     //
 952     // dump : -cp a.jar:NE1:NE2:b.jar  -> a.jar:b.jar -> recorded in archive.
 953     // run 1: -cp NE3:a.jar:NE4:b.jar  -> a.jar:b.jar -> matched
 954     // run 2: -cp x.jar:NE4:b.jar      -> x.jar:b.jar -> mismatched
 955 
 956     int j = header()->app_class_paths_start_index();
 957     mismatch = check_paths(j, shared_app_paths_len, rp_array, 0, 0);
 958     if (mismatch) {
 959       // To facilitate app deployment, we allow the JAR files to be moved *together* to
 960       // a different location, as long as they are still stored under the same directory
 961       // structure. E.g., the following is OK.
 962       //     java -Xshare:dump -cp /a/Foo.jar:/a/b/Bar.jar  ...
 963       //     java -Xshare:auto -cp /x/y/Foo.jar:/x/y/b/Bar.jar  ...
 964       unsigned int dumptime_prefix_len = header()->common_app_classpath_prefix_size();
 965       unsigned int runtime_prefix_len = longest_common_app_classpath_prefix_len(shared_app_paths_len, rp_array);
 966       if (dumptime_prefix_len != 0 || runtime_prefix_len != 0) {
 967         log_info(class, path)("LCP length for app classpath (dumptime: %u, runtime: %u)",
 968                               dumptime_prefix_len, runtime_prefix_len);
 969         mismatch = check_paths(j, shared_app_paths_len, rp_array,
 970                                dumptime_prefix_len, runtime_prefix_len);
 971       }
 972       if (mismatch) {
 973         return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 974       }
 975     }
 976   }
 977   return true;
 978 }
 979 
 980 void FileMapInfo::log_paths(const char* msg, int start_idx, int end_idx) {
 981   LogTarget(Info, class, path) lt;
 982   if (lt.is_enabled()) {
 983     LogStream ls(lt);
 984     ls.print("%s", msg);
 985     const char* prefix = "";
 986     for (int i = start_idx; i < end_idx; i++) {
 987       ls.print("%s%s", prefix, shared_path(i)->name());
 988       prefix = os::path_separator();
 989     }
 990     ls.cr();
 991   }
 992 }
 993 
 994 bool FileMapInfo::check_module_paths() {
 995   const char* rp = Arguments::get_property("jdk.module.path");
 996   int num_paths = CDSConfig::num_archives(rp);
 997   if (num_paths != header()->num_module_paths()) {
 998     return false;
 999   }
1000   ResourceMark rm;
1001   GrowableArray<const char*>* rp_array = create_path_array(rp);
1002   return check_paths(header()->app_module_paths_start_index(), num_paths, rp_array, 0, 0);
1003 }
1004 
1005 bool FileMapInfo::validate_shared_path_table() {
1006   assert(CDSConfig::is_using_archive(), "runtime only");
1007 
1008   _validating_shared_path_table = true;
1009 
1010   // Load the shared path table info from the archive header
1011   _shared_path_table = header()->shared_path_table();
1012   if (CDSConfig::is_dumping_dynamic_archive()) {
1013     // Only support dynamic dumping with the usage of the default CDS archive
1014     // or a simple base archive.
1015     // If the base layer archive contains additional path component besides
1016     // the runtime image and the -cp, dynamic dumping is disabled.
1017     //
1018     // When dynamic archiving is enabled, the _shared_path_table is overwritten
1019     // to include the application path and stored in the top layer archive.
1020     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
1021     if (header()->app_class_paths_start_index() > 1) {
1022       CDSConfig::disable_dumping_dynamic_archive();
1023       log_warning(cds)(
1024         "Dynamic archiving is disabled because base layer archive has appended boot classpath");
1025     }
1026     if (header()->num_module_paths() > 0) {
1027       if (!check_module_paths()) {
1028         CDSConfig::disable_dumping_dynamic_archive();
1029         log_warning(cds)(
1030           "Dynamic archiving is disabled because base layer archive has a different module path");
1031       }
1032     }
1033   }
1034 
1035   log_paths("Expecting BOOT path=", 0, header()->app_class_paths_start_index());
1036   log_paths("Expecting -Djava.class.path=", header()->app_class_paths_start_index(), header()->app_module_paths_start_index());
1037 
1038   int module_paths_start_index = header()->app_module_paths_start_index();
1039   int shared_app_paths_len = 0;
1040 
1041   // validate the path entries up to the _max_used_path_index
1042   for (int i=0; i < header()->max_used_path_index() + 1; i++) {
1043     if (i < module_paths_start_index) {
1044       if (shared_path(i)->validate()) {
1045         // Only count the app class paths not from the "Class-path" attribute of a jar manifest.
1046         if (!shared_path(i)->from_class_path_attr() && i >= header()->app_class_paths_start_index()) {
1047           shared_app_paths_len++;
1048         }
1049         log_info(class, path)("ok");
1050       } else {
1051         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
1052           assert(!CDSConfig::is_using_archive(), "UseSharedSpaces should be disabled");
1053         }
1054         return false;
1055       }
1056     } else if (i >= module_paths_start_index) {
1057       if (shared_path(i)->validate(false /* not a class path entry */)) {
1058         log_info(class, path)("ok");
1059       } else {
1060         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
1061           assert(!CDSConfig::is_using_archive(), "UseSharedSpaces should be disabled");
1062         }
1063         return false;
1064       }
1065     }
1066   }
1067 
1068   if (header()->max_used_path_index() == 0) {
1069     // default archive only contains the module image in the bootclasspath
1070     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
1071   } else {
1072     if (!validate_boot_class_paths() || !validate_app_class_paths(shared_app_paths_len)) {
1073       const char* mismatch_msg = "shared class paths mismatch";
1074       const char* hint_msg = log_is_enabled(Info, class, path) ?
1075           "" : " (hint: enable -Xlog:class+path=info to diagnose the failure)";
1076       if (RequireSharedSpaces) {
1077         log_error(cds)("%s%s", mismatch_msg, hint_msg);
1078         MetaspaceShared::unrecoverable_loading_error();
1079       } else {
1080         log_warning(cds)("%s%s", mismatch_msg, hint_msg);
1081       }
1082       return false;
1083     }
1084   }
1085 
1086   validate_non_existent_class_paths();
1087 
1088   _validating_shared_path_table = false;
1089 
1090 #if INCLUDE_JVMTI
1091   if (_classpath_entries_for_jvmti != nullptr) {
1092     os::free(_classpath_entries_for_jvmti);
1093   }
1094   size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
1095   _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
1096   memset((void*)_classpath_entries_for_jvmti, 0, sz);
1097 #endif
1098 
1099   return true;
1100 }
1101 
1102 void FileMapInfo::validate_non_existent_class_paths() {
1103   // All of the recorded non-existent paths came from the Class-Path: attribute from the JAR
1104   // files on the app classpath. If any of these are found to exist during runtime,
1105   // it will change how classes are loading for the app loader. For safety, disable
1106   // loading of archived platform/app classes (currently there's no way to disable just the
1107   // app classes).
1108 
1109   assert(CDSConfig::is_using_archive(), "runtime only");
1110   for (int i = header()->app_module_paths_start_index() + header()->num_module_paths();
1111        i < get_number_of_shared_paths();
1112        i++) {
1113     SharedClassPathEntry* ent = shared_path(i);
1114     if (!ent->check_non_existent()) {
1115       log_warning(cds)("Archived non-system classes are disabled because the "
1116               "file %s exists", ent->name());
1117       header()->set_has_platform_or_app_classes(false);
1118     }
1119   }
1120 }
1121 
1122 // A utility class for reading/validating the GenericCDSFileMapHeader portion of
1123 // a CDS archive's header. The file header of all CDS archives with versions from
1124 // CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION (12) are guaranteed to always start
1125 // with GenericCDSFileMapHeader. This makes it possible to read important information
1126 // from a CDS archive created by a different version of HotSpot, so that we can
1127 // automatically regenerate the archive as necessary (JDK-8261455).
1128 class FileHeaderHelper {
1129   int _fd;
1130   bool _is_valid;
1131   bool _is_static;
1132   GenericCDSFileMapHeader* _header;
1133   const char* _archive_name;
1134   const char* _base_archive_name;
1135 
1136 public:
1137   FileHeaderHelper(const char* archive_name, bool is_static) {
1138     _fd = -1;
1139     _is_valid = false;
1140     _header = nullptr;
1141     _base_archive_name = nullptr;
1142     _archive_name = archive_name;
1143     _is_static = is_static;
1144   }
1145 
1146   ~FileHeaderHelper() {
1147     if (_header != nullptr) {
1148       FREE_C_HEAP_ARRAY(char, _header);
1149     }
1150     if (_fd != -1) {
1151       ::close(_fd);
1152     }
1153   }
1154 
1155   bool initialize() {
1156     assert(_archive_name != nullptr, "Archive name is null");
1157     _fd = os::open(_archive_name, O_RDONLY | O_BINARY, 0);
1158     if (_fd < 0) {
1159       log_info(cds)("Specified shared archive not found (%s)", _archive_name);
1160       return false;
1161     }
1162     return initialize(_fd);
1163   }
1164 
1165   // for an already opened file, do not set _fd
1166   bool initialize(int fd) {
1167     assert(_archive_name != nullptr, "Archive name is null");
1168     assert(fd != -1, "Archive must be opened already");
1169     // First read the generic header so we know the exact size of the actual header.
1170     GenericCDSFileMapHeader gen_header;
1171     size_t size = sizeof(GenericCDSFileMapHeader);
1172     os::lseek(fd, 0, SEEK_SET);
1173     size_t n = ::read(fd, (void*)&gen_header, (unsigned int)size);
1174     if (n != size) {
1175       log_warning(cds)("Unable to read generic CDS file map header from shared archive");
1176       return false;
1177     }
1178 
1179     if (gen_header._magic != CDS_ARCHIVE_MAGIC &&
1180         gen_header._magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1181       log_warning(cds)("The shared archive file has a bad magic number: %#x", gen_header._magic);
1182       return false;
1183     }
1184 
1185     if (gen_header._version < CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION) {
1186       log_warning(cds)("Cannot handle shared archive file version 0x%x. Must be at least 0x%x.",
1187                                  gen_header._version, CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION);
1188       return false;
1189     }
1190 
1191     if (gen_header._version !=  CURRENT_CDS_ARCHIVE_VERSION) {
1192       log_warning(cds)("The shared archive file version 0x%x does not match the required version 0x%x.",
1193                                  gen_header._version, CURRENT_CDS_ARCHIVE_VERSION);
1194     }
1195 
1196     size_t filelen = os::lseek(fd, 0, SEEK_END);
1197     if (gen_header._header_size >= filelen) {
1198       log_warning(cds)("Archive file header larger than archive file");
1199       return false;
1200     }
1201 
1202     // Read the actual header and perform more checks
1203     size = gen_header._header_size;
1204     _header = (GenericCDSFileMapHeader*)NEW_C_HEAP_ARRAY(char, size, mtInternal);
1205     os::lseek(fd, 0, SEEK_SET);
1206     n = ::read(fd, (void*)_header, (unsigned int)size);
1207     if (n != size) {
1208       log_warning(cds)("Unable to read actual CDS file map header from shared archive");
1209       return false;
1210     }
1211 
1212     if (!check_header_crc()) {
1213       return false;
1214     }
1215 
1216     if (!check_and_init_base_archive_name()) {
1217       return false;
1218     }
1219 
1220     // All fields in the GenericCDSFileMapHeader has been validated.
1221     _is_valid = true;
1222     return true;
1223   }
1224 
1225   GenericCDSFileMapHeader* get_generic_file_header() {
1226     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1227     return _header;
1228   }
1229 
1230   const char* base_archive_name() {
1231     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1232     return _base_archive_name;
1233   }
1234 
1235  private:
1236   bool check_header_crc() const {
1237     if (VerifySharedSpaces) {
1238       FileMapHeader* header = (FileMapHeader*)_header;
1239       int actual_crc = header->compute_crc();
1240       if (actual_crc != header->crc()) {
1241         log_info(cds)("_crc expected: %d", header->crc());
1242         log_info(cds)("       actual: %d", actual_crc);
1243         log_warning(cds)("Header checksum verification failed.");
1244         return false;
1245       }
1246     }
1247     return true;
1248   }
1249 
1250   bool check_and_init_base_archive_name() {
1251     unsigned int name_offset = _header->_base_archive_name_offset;
1252     unsigned int name_size   = _header->_base_archive_name_size;
1253     unsigned int header_size = _header->_header_size;
1254 
1255     if (name_offset + name_size < name_offset) {
1256       log_warning(cds)("base_archive_name offset/size overflow: " UINT32_FORMAT "/" UINT32_FORMAT,
1257                                  name_offset, name_size);
1258       return false;
1259     }
1260     if (_header->_magic == CDS_ARCHIVE_MAGIC) {
1261       if (name_offset != 0) {
1262         log_warning(cds)("static shared archive must have zero _base_archive_name_offset");
1263         return false;
1264       }
1265       if (name_size != 0) {
1266         log_warning(cds)("static shared archive must have zero _base_archive_name_size");
1267         return false;
1268       }
1269     } else {
1270       assert(_header->_magic == CDS_DYNAMIC_ARCHIVE_MAGIC, "must be");
1271       if ((name_size == 0 && name_offset != 0) ||
1272           (name_size != 0 && name_offset == 0)) {
1273         // If either is zero, both must be zero. This indicates that we are using the default base archive.
1274         log_warning(cds)("Invalid base_archive_name offset/size: " UINT32_FORMAT "/" UINT32_FORMAT,
1275                                    name_offset, name_size);
1276         return false;
1277       }
1278       if (name_size > 0) {
1279         if (name_offset + name_size > header_size) {
1280           log_warning(cds)("Invalid base_archive_name offset/size (out of range): "
1281                                      UINT32_FORMAT " + " UINT32_FORMAT " > " UINT32_FORMAT ,
1282                                      name_offset, name_size, header_size);
1283           return false;
1284         }
1285         const char* name = ((const char*)_header) + _header->_base_archive_name_offset;
1286         if (name[name_size - 1] != '\0' || strlen(name) != name_size - 1) {
1287           log_warning(cds)("Base archive name is damaged");
1288           return false;
1289         }
1290         if (!os::file_exists(name)) {
1291           log_warning(cds)("Base archive %s does not exist", name);
1292           return false;
1293         }
1294         _base_archive_name = name;
1295       }
1296     }
1297 
1298     return true;
1299   }
1300 };
1301 
1302 // Return value:
1303 // false:
1304 //      <archive_name> is not a valid archive. *base_archive_name is set to null.
1305 // true && (*base_archive_name) == nullptr:
1306 //      <archive_name> is a valid static archive.
1307 // true && (*base_archive_name) != nullptr:
1308 //      <archive_name> is a valid dynamic archive.
1309 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
1310                                                     char** base_archive_name) {
1311   FileHeaderHelper file_helper(archive_name, false);
1312   *base_archive_name = nullptr;
1313 
1314   if (!file_helper.initialize()) {
1315     return false;
1316   }
1317   GenericCDSFileMapHeader* header = file_helper.get_generic_file_header();
1318   if (header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1319     assert(header->_magic == CDS_ARCHIVE_MAGIC, "must be");
1320     if (AutoCreateSharedArchive) {
1321      log_warning(cds)("AutoCreateSharedArchive is ignored because %s is a static archive", archive_name);
1322     }
1323     return true;
1324   }
1325 
1326   const char* base = file_helper.base_archive_name();
1327   if (base == nullptr) {
1328     *base_archive_name = CDSConfig::default_archive_path();
1329   } else {
1330     *base_archive_name = os::strdup_check_oom(base);
1331   }
1332 
1333   return true;
1334 }
1335 
1336 // Read the FileMapInfo information from the file.
1337 
1338 bool FileMapInfo::init_from_file(int fd) {
1339   FileHeaderHelper file_helper(_full_path, _is_static);
1340   if (!file_helper.initialize(fd)) {
1341     log_warning(cds)("Unable to read the file header.");
1342     return false;
1343   }
1344   GenericCDSFileMapHeader* gen_header = file_helper.get_generic_file_header();
1345 
1346   if (_is_static) {
1347     if (gen_header->_magic != CDS_ARCHIVE_MAGIC) {
1348       log_warning(cds)("Not a base shared archive: %s", _full_path);
1349       return false;
1350     }
1351   } else {
1352     if (gen_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1353       log_warning(cds)("Not a top shared archive: %s", _full_path);
1354       return false;
1355     }
1356   }
1357 
1358   _header = (FileMapHeader*)os::malloc(gen_header->_header_size, mtInternal);
1359   os::lseek(fd, 0, SEEK_SET); // reset to begin of the archive
1360   size_t size = gen_header->_header_size;
1361   size_t n = ::read(fd, (void*)_header, (unsigned int)size);
1362   if (n != size) {
1363     log_warning(cds)("Failed to read file header from the top archive file\n");
1364     return false;
1365   }
1366 
1367   if (header()->version() != CURRENT_CDS_ARCHIVE_VERSION) {
1368     log_info(cds)("_version expected: 0x%x", CURRENT_CDS_ARCHIVE_VERSION);
1369     log_info(cds)("           actual: 0x%x", header()->version());
1370     log_warning(cds)("The shared archive file has the wrong version.");
1371     return false;
1372   }
1373 
1374   int common_path_size = header()->common_app_classpath_prefix_size();
1375   if (common_path_size < 0) {
1376       log_warning(cds)("common app classpath prefix len < 0");
1377       return false;
1378   }
1379 
1380   unsigned int base_offset = header()->base_archive_name_offset();
1381   unsigned int name_size = header()->base_archive_name_size();
1382   unsigned int header_size = header()->header_size();
1383   if (base_offset != 0 && name_size != 0) {
1384     if (header_size != base_offset + name_size) {
1385       log_info(cds)("_header_size: " UINT32_FORMAT, header_size);
1386       log_info(cds)("common_app_classpath_size: " UINT32_FORMAT, header()->common_app_classpath_prefix_size());
1387       log_info(cds)("base_archive_name_size: " UINT32_FORMAT, header()->base_archive_name_size());
1388       log_info(cds)("base_archive_name_offset: " UINT32_FORMAT, header()->base_archive_name_offset());
1389       log_warning(cds)("The shared archive file has an incorrect header size.");
1390       return false;
1391     }
1392   }
1393 
1394   const char* actual_ident = header()->jvm_ident();
1395 
1396   if (actual_ident[JVM_IDENT_MAX-1] != 0) {
1397     log_warning(cds)("JVM version identifier is corrupted.");
1398     return false;
1399   }
1400 
1401   char expected_ident[JVM_IDENT_MAX];
1402   get_header_version(expected_ident);
1403   if (strncmp(actual_ident, expected_ident, JVM_IDENT_MAX-1) != 0) {
1404     log_info(cds)("_jvm_ident expected: %s", expected_ident);
1405     log_info(cds)("             actual: %s", actual_ident);
1406     log_warning(cds)("The shared archive file was created by a different"
1407                   " version or build of HotSpot");
1408     return false;
1409   }
1410 
1411   _file_offset = header()->header_size(); // accounts for the size of _base_archive_name
1412 
1413   size_t len = os::lseek(fd, 0, SEEK_END);
1414 
1415   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1416     FileMapRegion* r = region_at(i);
1417     if (r->file_offset() > len || len - r->file_offset() < r->used()) {
1418       log_warning(cds)("The shared archive file has been truncated.");
1419       return false;
1420     }
1421   }
1422 
1423   if (!header()->check_must_match_flags()) {
1424     return false;
1425   }
1426 
1427   return true;
1428 }
1429 
1430 void FileMapInfo::seek_to_position(size_t pos) {
1431   if (os::lseek(_fd, (long)pos, SEEK_SET) < 0) {
1432     log_error(cds)("Unable to seek to position " SIZE_FORMAT, pos);
1433     MetaspaceShared::unrecoverable_loading_error();
1434   }
1435 }
1436 
1437 // Read the FileMapInfo information from the file.
1438 bool FileMapInfo::open_for_read() {
1439   if (_file_open) {
1440     return true;
1441   }
1442   log_info(cds)("trying to map %s", _full_path);
1443   int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
1444   if (fd < 0) {
1445     if (errno == ENOENT) {
1446       log_info(cds)("Specified shared archive not found (%s)", _full_path);
1447     } else {
1448       log_warning(cds)("Failed to open shared archive file (%s)",
1449                     os::strerror(errno));
1450     }
1451     return false;
1452   } else {
1453     log_info(cds)("Opened archive %s.", _full_path);
1454   }
1455 
1456   _fd = fd;
1457   _file_open = true;
1458   return true;
1459 }
1460 
1461 // Write the FileMapInfo information to the file.
1462 
1463 void FileMapInfo::open_for_write() {
1464   LogMessage(cds) msg;
1465   if (msg.is_info()) {
1466     msg.info("Dumping shared data to file: ");
1467     msg.info("   %s", _full_path);
1468   }
1469 
1470 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
1471     chmod(_full_path, _S_IREAD | _S_IWRITE);
1472 #endif
1473 
1474   // Use remove() to delete the existing file because, on Unix, this will
1475   // allow processes that have it open continued access to the file.
1476   remove(_full_path);
1477   int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1478   if (fd < 0) {
1479     log_error(cds)("Unable to create shared archive file %s: (%s).", _full_path,
1480                    os::strerror(errno));
1481     MetaspaceShared::unrecoverable_writing_error();
1482   }
1483   _fd = fd;
1484   _file_open = true;
1485 
1486   // Seek past the header. We will write the header after all regions are written
1487   // and their CRCs computed.
1488   size_t header_bytes = header()->header_size();
1489 
1490   header_bytes = align_up(header_bytes, MetaspaceShared::core_region_alignment());
1491   _file_offset = header_bytes;
1492   seek_to_position(_file_offset);
1493 }
1494 
1495 // Write the header to the file, seek to the next allocation boundary.
1496 
1497 void FileMapInfo::write_header() {
1498   _file_offset = 0;
1499   seek_to_position(_file_offset);
1500   assert(is_file_position_aligned(), "must be");
1501   write_bytes(header(), header()->header_size());
1502 }
1503 
1504 size_t FileMapRegion::used_aligned() const {
1505   return align_up(used(), MetaspaceShared::core_region_alignment());
1506 }
1507 
1508 void FileMapRegion::init(int region_index, size_t mapping_offset, size_t size, bool read_only,
1509                          bool allow_exec, int crc) {
1510   _is_heap_region = HeapShared::is_heap_region(region_index);
1511   _is_bitmap_region = (region_index == MetaspaceShared::bm);
1512   _mapping_offset = mapping_offset;
1513   _used = size;
1514   _read_only = read_only;
1515   _allow_exec = allow_exec;
1516   _crc = crc;
1517   _mapped_from_file = false;
1518   _mapped_base = nullptr;
1519 }
1520 
1521 void FileMapRegion::init_oopmap(size_t offset, size_t size_in_bits) {
1522   _oopmap_offset = offset;
1523   _oopmap_size_in_bits = size_in_bits;
1524 }
1525 
1526 void FileMapRegion::init_ptrmap(size_t offset, size_t size_in_bits) {
1527   _ptrmap_offset = offset;
1528   _ptrmap_size_in_bits = size_in_bits;
1529 }
1530 
1531 bool FileMapRegion::check_region_crc(char* base) const {
1532   // This function should be called after the region has been properly
1533   // loaded into memory via FileMapInfo::map_region() or FileMapInfo::read_region().
1534   // I.e., this->mapped_base() must be valid.
1535   size_t sz = used();
1536   if (sz == 0) {
1537     return true;
1538   }
1539 
1540   assert(base != nullptr, "must be initialized");
1541   int crc = ClassLoader::crc32(0, base, (jint)sz);
1542   if (crc != this->crc()) {
1543     log_warning(cds)("Checksum verification failed.");
1544     return false;
1545   }
1546   return true;
1547 }
1548 
1549 static const char* region_name(int region_index) {
1550   static const char* names[] = {
1551     "rw", "ro", "bm", "hp"
1552   };
1553   const int num_regions = sizeof(names)/sizeof(names[0]);
1554   assert(0 <= region_index && region_index < num_regions, "sanity");
1555 
1556   return names[region_index];
1557 }
1558 
1559 BitMapView FileMapInfo::bitmap_view(int region_index, bool is_oopmap) {
1560   FileMapRegion* r = region_at(region_index);
1561   char* bitmap_base = is_static() ? FileMapInfo::current_info()->map_bitmap_region() : FileMapInfo::dynamic_info()->map_bitmap_region();
1562   bitmap_base += is_oopmap ? r->oopmap_offset() : r->ptrmap_offset();
1563   size_t size_in_bits = is_oopmap ? r->oopmap_size_in_bits() : r->ptrmap_size_in_bits();
1564 
1565   log_debug(cds, reloc)("mapped %s relocation %smap @ " INTPTR_FORMAT " (" SIZE_FORMAT " bits)",
1566                         region_name(region_index), is_oopmap ? "oop" : "ptr",
1567                         p2i(bitmap_base), size_in_bits);
1568 
1569   return BitMapView((BitMap::bm_word_t*)(bitmap_base), size_in_bits);
1570 }
1571 
1572 BitMapView FileMapInfo::oopmap_view(int region_index) {
1573     return bitmap_view(region_index, /*is_oopmap*/true);
1574   }
1575 
1576 BitMapView FileMapInfo::ptrmap_view(int region_index) {
1577   return bitmap_view(region_index, /*is_oopmap*/false);
1578 }
1579 
1580 void FileMapRegion::print(outputStream* st, int region_index) {
1581   st->print_cr("============ region ============= %d \"%s\"", region_index, region_name(region_index));
1582   st->print_cr("- crc:                            0x%08x", _crc);
1583   st->print_cr("- read_only:                      %d", _read_only);
1584   st->print_cr("- allow_exec:                     %d", _allow_exec);
1585   st->print_cr("- is_heap_region:                 %d", _is_heap_region);
1586   st->print_cr("- is_bitmap_region:               %d", _is_bitmap_region);
1587   st->print_cr("- mapped_from_file:               %d", _mapped_from_file);
1588   st->print_cr("- file_offset:                    " SIZE_FORMAT_X, _file_offset);
1589   st->print_cr("- mapping_offset:                 " SIZE_FORMAT_X, _mapping_offset);
1590   st->print_cr("- used:                           " SIZE_FORMAT, _used);
1591   st->print_cr("- oopmap_offset:                  " SIZE_FORMAT_X, _oopmap_offset);
1592   st->print_cr("- oopmap_size_in_bits:            " SIZE_FORMAT, _oopmap_size_in_bits);
1593   st->print_cr("- ptrmap_offset:                  " SIZE_FORMAT_X, _ptrmap_offset);
1594   st->print_cr("- ptrmap_size_in_bits:            " SIZE_FORMAT, _ptrmap_size_in_bits);
1595   st->print_cr("- mapped_base:                    " INTPTR_FORMAT, p2i(_mapped_base));
1596 }
1597 
1598 void FileMapInfo::write_region(int region, char* base, size_t size,
1599                                bool read_only, bool allow_exec) {
1600   assert(CDSConfig::is_dumping_archive(), "sanity");
1601 
1602   FileMapRegion* r = region_at(region);
1603   char* requested_base;
1604   size_t mapping_offset = 0;
1605 
1606   if (region == MetaspaceShared::bm) {
1607     requested_base = nullptr; // always null for bm region
1608   } else if (size == 0) {
1609     // This is an unused region (e.g., a heap region when !INCLUDE_CDS_JAVA_HEAP)
1610     requested_base = nullptr;
1611   } else if (HeapShared::is_heap_region(region)) {
1612     assert(HeapShared::can_write(), "sanity");
1613 #if INCLUDE_CDS_JAVA_HEAP
1614     assert(!CDSConfig::is_dumping_dynamic_archive(), "must be");
1615     requested_base = (char*)ArchiveHeapWriter::requested_address();
1616     if (UseCompressedOops) {
1617       mapping_offset = (size_t)((address)requested_base - CompressedOops::base());
1618       assert((mapping_offset >> CompressedOops::shift()) << CompressedOops::shift() == mapping_offset, "must be");
1619     } else {
1620       mapping_offset = 0; // not used with !UseCompressedOops
1621     }
1622 #endif // INCLUDE_CDS_JAVA_HEAP
1623   } else {
1624     char* requested_SharedBaseAddress = (char*)MetaspaceShared::requested_base_address();
1625     requested_base = ArchiveBuilder::current()->to_requested(base);
1626     assert(requested_base >= requested_SharedBaseAddress, "must be");
1627     mapping_offset = requested_base - requested_SharedBaseAddress;
1628   }
1629 
1630   r->set_file_offset(_file_offset);
1631   int crc = ClassLoader::crc32(0, base, (jint)size);
1632   if (size > 0) {
1633     log_info(cds)("Shared file region (%s) %d: " SIZE_FORMAT_W(8)
1634                    " bytes, addr " INTPTR_FORMAT " file offset 0x%08" PRIxPTR
1635                    " crc 0x%08x",
1636                    region_name(region), region, size, p2i(requested_base), _file_offset, crc);
1637   }
1638 
1639   r->init(region, mapping_offset, size, read_only, allow_exec, crc);
1640 
1641   if (base != nullptr) {
1642     write_bytes_aligned(base, size);
1643   }
1644 }
1645 
1646 static size_t write_bitmap(const CHeapBitMap* map, char* output, size_t offset) {
1647   size_t size_in_bytes = map->size_in_bytes();
1648   map->write_to((BitMap::bm_word_t*)(output + offset), size_in_bytes);
1649   return offset + size_in_bytes;
1650 }
1651 
1652 // The start of the archived heap has many primitive arrays (String
1653 // bodies) that are not marked by the oop/ptr maps. So we must have
1654 // lots of leading zeros.
1655 size_t FileMapInfo::remove_bitmap_leading_zeros(CHeapBitMap* map) {
1656   size_t old_zeros = map->find_first_set_bit(0);
1657   size_t old_size = map->size();
1658 
1659   // Slice and resize bitmap
1660   map->truncate(old_zeros, map->size());
1661 
1662   DEBUG_ONLY(
1663     size_t new_zeros = map->find_first_set_bit(0);
1664     assert(new_zeros == 0, "Should have removed leading zeros");
1665   )
1666   assert(map->size() <= old_size, "sanity");
1667   return old_zeros;
1668 }
1669 
1670 char* FileMapInfo::write_bitmap_region(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap, ArchiveHeapInfo* heap_info,
1671                                        size_t &size_in_bytes) {
1672   size_t removed_rw_zeros = remove_bitmap_leading_zeros(rw_ptrmap);
1673   size_t removed_ro_zeros = remove_bitmap_leading_zeros(ro_ptrmap);
1674   header()->set_rw_ptrmap_start_pos(removed_rw_zeros);
1675   header()->set_ro_ptrmap_start_pos(removed_ro_zeros);
1676   size_in_bytes = rw_ptrmap->size_in_bytes() + ro_ptrmap->size_in_bytes();
1677 
1678   if (heap_info->is_used()) {
1679     // Remove leading zeros
1680     size_t removed_oop_zeros = remove_bitmap_leading_zeros(heap_info->oopmap());
1681     size_t removed_ptr_zeros = remove_bitmap_leading_zeros(heap_info->ptrmap());
1682 
1683     header()->set_heap_oopmap_start_pos(removed_oop_zeros);
1684     header()->set_heap_ptrmap_start_pos(removed_ptr_zeros);
1685 
1686     size_in_bytes += heap_info->oopmap()->size_in_bytes();
1687     size_in_bytes += heap_info->ptrmap()->size_in_bytes();
1688   }
1689 
1690   // The bitmap region contains up to 4 parts:
1691   // rw_ptrmap:           metaspace pointers inside the read-write region
1692   // ro_ptrmap:           metaspace pointers inside the read-only region
1693   // heap_info->oopmap(): Java oop pointers in the heap region
1694   // heap_info->ptrmap(): metaspace pointers in the heap region
1695   char* buffer = NEW_C_HEAP_ARRAY(char, size_in_bytes, mtClassShared);
1696   size_t written = 0;
1697 
1698   region_at(MetaspaceShared::rw)->init_ptrmap(0, rw_ptrmap->size());
1699   written = write_bitmap(rw_ptrmap, buffer, written);
1700 
1701   region_at(MetaspaceShared::ro)->init_ptrmap(written, ro_ptrmap->size());
1702   written = write_bitmap(ro_ptrmap, buffer, written);
1703 
1704   if (heap_info->is_used()) {
1705     FileMapRegion* r = region_at(MetaspaceShared::hp);
1706 
1707     r->init_oopmap(written, heap_info->oopmap()->size());
1708     written = write_bitmap(heap_info->oopmap(), buffer, written);
1709 
1710     r->init_ptrmap(written, heap_info->ptrmap()->size());
1711     written = write_bitmap(heap_info->ptrmap(), buffer, written);
1712   }
1713 
1714   write_region(MetaspaceShared::bm, (char*)buffer, size_in_bytes, /*read_only=*/true, /*allow_exec=*/false);
1715   return buffer;
1716 }
1717 
1718 size_t FileMapInfo::write_heap_region(ArchiveHeapInfo* heap_info) {
1719   char* buffer_start = heap_info->buffer_start();
1720   size_t buffer_size = heap_info->buffer_byte_size();
1721   write_region(MetaspaceShared::hp, buffer_start, buffer_size, false, false);
1722   header()->set_heap_roots_offset(heap_info->heap_roots_offset());
1723   return buffer_size;
1724 }
1725 
1726 // Dump bytes to file -- at the current file position.
1727 
1728 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1729   assert(_file_open, "must be");
1730   if (!os::write(_fd, buffer, nbytes)) {
1731     // If the shared archive is corrupted, close it and remove it.
1732     close();
1733     remove(_full_path);
1734     MetaspaceShared::unrecoverable_writing_error("Unable to write to shared archive file.");
1735   }
1736   _file_offset += nbytes;
1737 }
1738 
1739 bool FileMapInfo::is_file_position_aligned() const {
1740   return _file_offset == align_up(_file_offset,
1741                                   MetaspaceShared::core_region_alignment());
1742 }
1743 
1744 // Align file position to an allocation unit boundary.
1745 
1746 void FileMapInfo::align_file_position() {
1747   assert(_file_open, "must be");
1748   size_t new_file_offset = align_up(_file_offset,
1749                                     MetaspaceShared::core_region_alignment());
1750   if (new_file_offset != _file_offset) {
1751     _file_offset = new_file_offset;
1752     // Seek one byte back from the target and write a byte to insure
1753     // that the written file is the correct length.
1754     _file_offset -= 1;
1755     seek_to_position(_file_offset);
1756     char zero = 0;
1757     write_bytes(&zero, 1);
1758   }
1759 }
1760 
1761 
1762 // Dump bytes to file -- at the current file position.
1763 
1764 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1765   align_file_position();
1766   write_bytes(buffer, nbytes);
1767   align_file_position();
1768 }
1769 
1770 // Close the shared archive file.  This does NOT unmap mapped regions.
1771 
1772 void FileMapInfo::close() {
1773   if (_file_open) {
1774     if (::close(_fd) < 0) {
1775       MetaspaceShared::unrecoverable_loading_error("Unable to close the shared archive file.");
1776     }
1777     _file_open = false;
1778     _fd = -1;
1779   }
1780 }
1781 
1782 /*
1783  * Same as os::map_memory() but also pretouches if AlwaysPreTouch is enabled.
1784  */
1785 static char* map_memory(int fd, const char* file_name, size_t file_offset,
1786                         char *addr, size_t bytes, bool read_only,
1787                         bool allow_exec, MEMFLAGS flags = mtNone) {
1788   char* mem = os::map_memory(fd, file_name, file_offset, addr, bytes,
1789                              AlwaysPreTouch ? false : read_only,
1790                              allow_exec, flags);
1791   if (mem != nullptr && AlwaysPreTouch) {
1792     os::pretouch_memory(mem, mem + bytes);
1793   }
1794   return mem;
1795 }
1796 
1797 // JVM/TI RedefineClasses() support:
1798 // Remap the shared readonly space to shared readwrite, private.
1799 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1800   int idx = MetaspaceShared::ro;
1801   FileMapRegion* r = region_at(idx);
1802   if (!r->read_only()) {
1803     // the space is already readwrite so we are done
1804     return true;
1805   }
1806   size_t size = r->used_aligned();
1807   if (!open_for_read()) {
1808     return false;
1809   }
1810   char *addr = r->mapped_base();
1811   // This path should not be reached for Windows; see JDK-8222379.
1812   assert(WINDOWS_ONLY(false) NOT_WINDOWS(true), "Don't call on Windows");
1813   // Replace old mapping with new one that is writable.
1814   char *base = os::map_memory(_fd, _full_path, r->file_offset(),
1815                               addr, size, false /* !read_only */,
1816                               r->allow_exec());
1817   close();
1818   // These have to be errors because the shared region is now unmapped.
1819   if (base == nullptr) {
1820     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1821     vm_exit(1);
1822   }
1823   if (base != addr) {
1824     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1825     vm_exit(1);
1826   }
1827   r->set_read_only(false);
1828   return true;
1829 }
1830 
1831 // Memory map a region in the address space.
1832 static const char* shared_region_name[] = { "ReadWrite", "ReadOnly", "Bitmap", "Heap" };
1833 
1834 MapArchiveResult FileMapInfo::map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs) {
1835   DEBUG_ONLY(FileMapRegion* last_region = nullptr);
1836   intx addr_delta = mapped_base_address - header()->requested_base_address();
1837 
1838   // Make sure we don't attempt to use header()->mapped_base_address() unless
1839   // it's been successfully mapped.
1840   DEBUG_ONLY(header()->set_mapped_base_address((char*)(uintptr_t)0xdeadbeef);)
1841 
1842   for (int i = 0; i < num_regions; i++) {
1843     int idx = regions[i];
1844     MapArchiveResult result = map_region(idx, addr_delta, mapped_base_address, rs);
1845     if (result != MAP_ARCHIVE_SUCCESS) {
1846       return result;
1847     }
1848     FileMapRegion* r = region_at(idx);
1849     DEBUG_ONLY(if (last_region != nullptr) {
1850         // Ensure that the OS won't be able to allocate new memory spaces between any mapped
1851         // regions, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1852         assert(r->mapped_base() == last_region->mapped_end(), "must have no gaps");
1853       }
1854       last_region = r;)
1855     log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)", is_static() ? "static " : "dynamic",
1856                   idx, p2i(r->mapped_base()), p2i(r->mapped_end()),
1857                   shared_region_name[idx]);
1858 
1859   }
1860 
1861   header()->set_mapped_base_address(header()->requested_base_address() + addr_delta);
1862   if (addr_delta != 0 && !relocate_pointers_in_core_regions(addr_delta)) {
1863     return MAP_ARCHIVE_OTHER_FAILURE;
1864   }
1865 
1866   return MAP_ARCHIVE_SUCCESS;
1867 }
1868 
1869 bool FileMapInfo::read_region(int i, char* base, size_t size, bool do_commit) {
1870   FileMapRegion* r = region_at(i);
1871   if (do_commit) {
1872     log_info(cds)("Commit %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)%s",
1873                   is_static() ? "static " : "dynamic", i, p2i(base), p2i(base + size),
1874                   shared_region_name[i], r->allow_exec() ? " exec" : "");
1875     if (!os::commit_memory(base, size, r->allow_exec())) {
1876       log_error(cds)("Failed to commit %s region #%d (%s)", is_static() ? "static " : "dynamic",
1877                      i, shared_region_name[i]);
1878       return false;
1879     }
1880   }
1881   if (os::lseek(_fd, (long)r->file_offset(), SEEK_SET) != (int)r->file_offset() ||
1882       read_bytes(base, size) != size) {
1883     return false;
1884   }
1885 
1886   if (VerifySharedSpaces && !r->check_region_crc(base)) {
1887     return false;
1888   }
1889 
1890   r->set_mapped_from_file(false);
1891   r->set_mapped_base(base);
1892 
1893   return true;
1894 }
1895 
1896 MapArchiveResult FileMapInfo::map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs) {
1897   assert(!HeapShared::is_heap_region(i), "sanity");
1898   FileMapRegion* r = region_at(i);
1899   size_t size = r->used_aligned();
1900   char *requested_addr = mapped_base_address + r->mapping_offset();
1901   assert(r->mapped_base() == nullptr, "must be not mapped yet");
1902   assert(requested_addr != nullptr, "must be specified");
1903 
1904   r->set_mapped_from_file(false);
1905 
1906   if (MetaspaceShared::use_windows_memory_mapping()) {
1907     // Windows cannot remap read-only shared memory to read-write when required for
1908     // RedefineClasses, which is also used by JFR.  Always map windows regions as RW.
1909     r->set_read_only(false);
1910   } else if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1911              Arguments::has_jfr_option()) {
1912     // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW
1913     r->set_read_only(false);
1914   } else if (addr_delta != 0) {
1915     r->set_read_only(false); // Need to patch the pointers
1916   }
1917 
1918   if (MetaspaceShared::use_windows_memory_mapping() && rs.is_reserved()) {
1919     // This is the second time we try to map the archive(s). We have already created a ReservedSpace
1920     // that covers all the FileMapRegions to ensure all regions can be mapped. However, Windows
1921     // can't mmap into a ReservedSpace, so we just ::read() the data. We're going to patch all the
1922     // regions anyway, so there's no benefit for mmap anyway.
1923     if (!read_region(i, requested_addr, size, /* do_commit = */ true)) {
1924       log_info(cds)("Failed to read %s shared space into reserved space at " INTPTR_FORMAT,
1925                     shared_region_name[i], p2i(requested_addr));
1926       return MAP_ARCHIVE_OTHER_FAILURE; // oom or I/O error.
1927     } else {
1928       assert(r->mapped_base() != nullptr, "must be initialized");
1929       return MAP_ARCHIVE_SUCCESS;
1930     }
1931   } else {
1932     // Note that this may either be a "fresh" mapping into unreserved address
1933     // space (Windows, first mapping attempt), or a mapping into pre-reserved
1934     // space (Posix). See also comment in MetaspaceShared::map_archives().
1935     char* base = map_memory(_fd, _full_path, r->file_offset(),
1936                             requested_addr, size, r->read_only(),
1937                             r->allow_exec(), mtClassShared);
1938     if (base != requested_addr) {
1939       log_info(cds)("Unable to map %s shared space at " INTPTR_FORMAT,
1940                     shared_region_name[i], p2i(requested_addr));
1941       _memory_mapping_failed = true;
1942       return MAP_ARCHIVE_MMAP_FAILURE;
1943     }
1944 
1945     if (VerifySharedSpaces && !r->check_region_crc(requested_addr)) {
1946       return MAP_ARCHIVE_OTHER_FAILURE;
1947     }
1948 
1949     r->set_mapped_from_file(true);
1950     r->set_mapped_base(requested_addr);
1951 
1952     return MAP_ARCHIVE_SUCCESS;
1953   }
1954 }
1955 
1956 // The return value is the location of the archive relocation bitmap.
1957 char* FileMapInfo::map_bitmap_region() {
1958   FileMapRegion* r = region_at(MetaspaceShared::bm);
1959   if (r->mapped_base() != nullptr) {
1960     return r->mapped_base();
1961   }
1962   bool read_only = true, allow_exec = false;
1963   char* requested_addr = nullptr; // allow OS to pick any location
1964   char* bitmap_base = map_memory(_fd, _full_path, r->file_offset(),
1965                                  requested_addr, r->used_aligned(), read_only, allow_exec, mtClassShared);
1966   if (bitmap_base == nullptr) {
1967     log_info(cds)("failed to map relocation bitmap");
1968     return nullptr;
1969   }
1970 
1971   if (VerifySharedSpaces && !r->check_region_crc(bitmap_base)) {
1972     log_error(cds)("relocation bitmap CRC error");
1973     if (!os::unmap_memory(bitmap_base, r->used_aligned())) {
1974       fatal("os::unmap_memory of relocation bitmap failed");
1975     }
1976     return nullptr;
1977   }
1978 
1979   r->set_mapped_from_file(true);
1980   r->set_mapped_base(bitmap_base);
1981   log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)",
1982                 is_static() ? "static " : "dynamic",
1983                 MetaspaceShared::bm, p2i(r->mapped_base()), p2i(r->mapped_end()),
1984                 shared_region_name[MetaspaceShared::bm]);
1985   return bitmap_base;
1986 }
1987 
1988 // This is called when we cannot map the archive at the requested[ base address (usually 0x800000000).
1989 // We relocate all pointers in the 2 core regions (ro, rw).
1990 bool FileMapInfo::relocate_pointers_in_core_regions(intx addr_delta) {
1991   log_debug(cds, reloc)("runtime archive relocation start");
1992   char* bitmap_base = map_bitmap_region();
1993 
1994   if (bitmap_base == nullptr) {
1995     return false; // OOM, or CRC check failure
1996   } else {
1997     BitMapView rw_ptrmap = ptrmap_view(MetaspaceShared::rw);
1998     BitMapView ro_ptrmap = ptrmap_view(MetaspaceShared::ro);
1999 
2000     FileMapRegion* rw_region = first_core_region();
2001     FileMapRegion* ro_region = last_core_region();
2002 
2003     // Patch all pointers inside the RW region
2004     address rw_patch_base = (address)rw_region->mapped_base();
2005     address rw_patch_end  = (address)rw_region->mapped_end();
2006 
2007     // Patch all pointers inside the RO region
2008     address ro_patch_base = (address)ro_region->mapped_base();
2009     address ro_patch_end  = (address)ro_region->mapped_end();
2010 
2011     // the current value of the pointers to be patched must be within this
2012     // range (i.e., must be between the requested base address and the address of the current archive).
2013     // Note: top archive may point to objects in the base archive, but not the other way around.
2014     address valid_old_base = (address)header()->requested_base_address();
2015     address valid_old_end  = valid_old_base + mapping_end_offset();
2016 
2017     // after patching, the pointers must point inside this range
2018     // (the requested location of the archive, as mapped at runtime).
2019     address valid_new_base = (address)header()->mapped_base_address();
2020     address valid_new_end  = (address)mapped_end();
2021 
2022     SharedDataRelocator rw_patcher((address*)rw_patch_base + header()->rw_ptrmap_start_pos(), (address*)rw_patch_end, valid_old_base, valid_old_end,
2023                                 valid_new_base, valid_new_end, addr_delta);
2024     SharedDataRelocator ro_patcher((address*)ro_patch_base + header()->ro_ptrmap_start_pos(), (address*)ro_patch_end, valid_old_base, valid_old_end,
2025                                 valid_new_base, valid_new_end, addr_delta);
2026     rw_ptrmap.iterate(&rw_patcher);
2027     ro_ptrmap.iterate(&ro_patcher);
2028 
2029     // The MetaspaceShared::bm region will be unmapped in MetaspaceShared::initialize_shared_spaces().
2030 
2031     log_debug(cds, reloc)("runtime archive relocation done");
2032     return true;
2033   }
2034 }
2035 
2036 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
2037   assert(_file_open, "Archive file is not open");
2038   size_t n = ::read(_fd, buffer, (unsigned int)count);
2039   if (n != count) {
2040     // Close the file if there's a problem reading it.
2041     close();
2042     return 0;
2043   }
2044   _file_offset += count;
2045   return count;
2046 }
2047 
2048 // Get the total size in bytes of a read only region
2049 size_t FileMapInfo::readonly_total() {
2050   size_t total = 0;
2051   if (current_info() != nullptr) {
2052     FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::ro);
2053     if (r->read_only()) total += r->used();
2054   }
2055   if (dynamic_info() != nullptr) {
2056     FileMapRegion* r = FileMapInfo::dynamic_info()->region_at(MetaspaceShared::ro);
2057     if (r->read_only()) total += r->used();
2058   }
2059   return total;
2060 }
2061 
2062 #if INCLUDE_CDS_JAVA_HEAP
2063 MemRegion FileMapInfo::_mapped_heap_memregion;
2064 
2065 bool FileMapInfo::has_heap_region() {
2066   return (region_at(MetaspaceShared::hp)->used() > 0);
2067 }
2068 
2069 // Returns the address range of the archived heap region computed using the
2070 // current oop encoding mode. This range may be different than the one seen at
2071 // dump time due to encoding mode differences. The result is used in determining
2072 // if/how these regions should be relocated at run time.
2073 MemRegion FileMapInfo::get_heap_region_requested_range() {
2074   FileMapRegion* r = region_at(MetaspaceShared::hp);
2075   size_t size = r->used();
2076   assert(size > 0, "must have non-empty heap region");
2077 
2078   address start = heap_region_requested_address();
2079   address end = start + size;
2080   log_info(cds)("Requested heap region [" INTPTR_FORMAT " - " INTPTR_FORMAT "] = "  SIZE_FORMAT_W(8) " bytes",
2081                 p2i(start), p2i(end), size);
2082 
2083   return MemRegion((HeapWord*)start, (HeapWord*)end);
2084 }
2085 
2086 void FileMapInfo::map_or_load_heap_region() {
2087   bool success = false;
2088 
2089   if (can_use_heap_region()) {
2090     if (ArchiveHeapLoader::can_map()) {
2091       success = map_heap_region();
2092     } else if (ArchiveHeapLoader::can_load()) {
2093       success = ArchiveHeapLoader::load_heap_region(this);
2094     } else {
2095       if (!UseCompressedOops && !ArchiveHeapLoader::can_map()) {
2096         // TODO - remove implicit knowledge of G1
2097         log_info(cds)("Cannot use CDS heap data. UseG1GC is required for -XX:-UseCompressedOops");
2098       } else {
2099         log_info(cds)("Cannot use CDS heap data. UseEpsilonGC, UseG1GC, UseSerialGC or UseParallelGC are required.");
2100       }
2101     }
2102   }
2103 
2104   if (!success) {
2105     CDSConfig::stop_using_full_module_graph();
2106   }
2107 }
2108 
2109 bool FileMapInfo::can_use_heap_region() {
2110   if (!has_heap_region()) {
2111     return false;
2112   }
2113   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2114     ShouldNotReachHere(); // CDS should have been disabled.
2115     // The archived objects are mapped at JVM start-up, but we don't know if
2116     // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
2117     // which would make the archived String or mirror objects invalid. Let's be safe and not
2118     // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
2119     //
2120     // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
2121     // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
2122     // because we won't install an archived object subgraph if the klass of any of the
2123     // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
2124   }
2125 
2126   // We pre-compute narrow Klass IDs with the runtime mapping start intended to be the base, and a shift of
2127   // ArchiveHeapWriter::precomputed_narrow_klass_shift. We enforce this encoding at runtime (see
2128   // CompressedKlassPointers::initialize_for_given_encoding()). Therefore, the following assertions must
2129   // hold:
2130   address archive_narrow_klass_base = (address)header()->mapped_base_address();
2131   const int archive_narrow_klass_shift = ArchiveHeapWriter::precomputed_narrow_klass_shift;
2132 
2133   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
2134                 max_heap_size()/M);
2135   log_info(cds)("    narrow_klass_base at mapping start address, narrow_klass_shift = %d",
2136                 archive_narrow_klass_shift);
2137   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2138                 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
2139   log_info(cds)("The current max heap size = " SIZE_FORMAT "M, G1HeapRegion::GrainBytes = " SIZE_FORMAT,
2140                 MaxHeapSize/M, G1HeapRegion::GrainBytes);
2141   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
2142                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
2143   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2144                 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
2145   log_info(cds)("    heap range = [" PTR_FORMAT " - "  PTR_FORMAT "]",
2146                 UseCompressedOops ? p2i(CompressedOops::begin()) :
2147                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().start()) : 0L,
2148                 UseCompressedOops ? p2i(CompressedOops::end()) :
2149                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().end()) : 0L);
2150 
2151   assert(archive_narrow_klass_base == CompressedKlassPointers::base(), "Unexpected encoding base encountered "
2152          "(" PTR_FORMAT ", expected " PTR_FORMAT ")", p2i(CompressedKlassPointers::base()), p2i(archive_narrow_klass_base));
2153   assert(archive_narrow_klass_shift == CompressedKlassPointers::shift(), "Unexpected encoding shift encountered "
2154          "(%d, expected %d)", CompressedKlassPointers::shift(), archive_narrow_klass_shift);
2155 
2156   return true;
2157 }
2158 
2159 // The actual address of this region during dump time.
2160 address FileMapInfo::heap_region_dumptime_address() {
2161   FileMapRegion* r = region_at(MetaspaceShared::hp);
2162   assert(CDSConfig::is_using_archive(), "runtime only");
2163   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2164   if (UseCompressedOops) {
2165     return /*dumptime*/ narrow_oop_base() + r->mapping_offset();
2166   } else {
2167     return heap_region_requested_address();
2168   }
2169 }
2170 
2171 // The address where this region can be mapped into the runtime heap without
2172 // patching any of the pointers that are embedded in this region.
2173 address FileMapInfo::heap_region_requested_address() {
2174   assert(CDSConfig::is_using_archive(), "runtime only");
2175   FileMapRegion* r = region_at(MetaspaceShared::hp);
2176   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2177   assert(ArchiveHeapLoader::can_map(), "cannot be used by ArchiveHeapLoader::can_load() mode");
2178   if (UseCompressedOops) {
2179     // We can avoid relocation if each region's offset from the runtime CompressedOops::base()
2180     // is the same as its offset from the CompressedOops::base() during dumptime.
2181     // Note that CompressedOops::base() may be different between dumptime and runtime.
2182     //
2183     // Example:
2184     // Dumptime base = 0x1000 and shift is 0. We have a region at address 0x2000. There's a
2185     // narrowOop P stored in this region that points to an object at address 0x2200.
2186     // P's encoded value is 0x1200.
2187     //
2188     // Runtime base = 0x4000 and shift is also 0. If we map this region at 0x5000, then
2189     // the value P can remain 0x1200. The decoded address = (0x4000 + (0x1200 << 0)) = 0x5200,
2190     // which is the runtime location of the referenced object.
2191     return /*runtime*/ CompressedOops::base() + r->mapping_offset();
2192   } else {
2193     // This was the hard-coded requested base address used at dump time. With uncompressed oops,
2194     // the heap range is assigned by the OS so we will most likely have to relocate anyway, no matter
2195     // what base address was picked at duump time.
2196     return (address)ArchiveHeapWriter::NOCOOPS_REQUESTED_BASE;
2197   }
2198 }
2199 
2200 bool FileMapInfo::map_heap_region() {
2201   if (map_heap_region_impl()) {
2202 #ifdef ASSERT
2203     // The "old" regions must be parsable -- we cannot have any unused space
2204     // at the start of the lowest G1 region that contains archived objects.
2205     assert(is_aligned(_mapped_heap_memregion.start(), G1HeapRegion::GrainBytes), "must be");
2206 
2207     // Make sure we map at the very top of the heap - see comments in
2208     // init_heap_region_relocation().
2209     MemRegion heap_range = G1CollectedHeap::heap()->reserved();
2210     assert(heap_range.contains(_mapped_heap_memregion), "must be");
2211 
2212     address heap_end = (address)heap_range.end();
2213     address mapped_heap_region_end = (address)_mapped_heap_memregion.end();
2214     assert(heap_end >= mapped_heap_region_end, "must be");
2215     assert(heap_end - mapped_heap_region_end < (intx)(G1HeapRegion::GrainBytes),
2216            "must be at the top of the heap to avoid fragmentation");
2217 #endif
2218 
2219     ArchiveHeapLoader::set_mapped();
2220     return true;
2221   } else {
2222     return false;
2223   }
2224 }
2225 
2226 bool FileMapInfo::map_heap_region_impl() {
2227   assert(UseG1GC, "the following code assumes G1");
2228 
2229   FileMapRegion* r = region_at(MetaspaceShared::hp);
2230   size_t size = r->used();
2231   if (size == 0) {
2232     return false; // no archived java heap data
2233   }
2234 
2235   size_t word_size = size / HeapWordSize;
2236   address requested_start = heap_region_requested_address();
2237 
2238   log_info(cds)("Preferred address to map heap data (to avoid relocation) is " INTPTR_FORMAT, p2i(requested_start));
2239 
2240   // allocate from java heap
2241   HeapWord* start = G1CollectedHeap::heap()->alloc_archive_region(word_size, (HeapWord*)requested_start);
2242   if (start == nullptr) {
2243     log_info(cds)("UseSharedSpaces: Unable to allocate java heap region for archive heap.");
2244     return false;
2245   }
2246 
2247   _mapped_heap_memregion = MemRegion(start, word_size);
2248 
2249   // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
2250   // for mapped region as it is part of the reserved java heap, which is already recorded.
2251   char* addr = (char*)_mapped_heap_memregion.start();
2252   char* base = map_memory(_fd, _full_path, r->file_offset(),
2253                           addr, _mapped_heap_memregion.byte_size(), r->read_only(),
2254                           r->allow_exec());
2255   if (base == nullptr || base != addr) {
2256     dealloc_heap_region();
2257     log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
2258                   INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
2259                   p2i(addr), _mapped_heap_memregion.byte_size());
2260     return false;
2261   }
2262 
2263   if (VerifySharedSpaces && !r->check_region_crc(base)) {
2264     dealloc_heap_region();
2265     log_info(cds)("UseSharedSpaces: mapped heap region is corrupt");
2266     return false;
2267   }
2268 
2269   r->set_mapped_base(base);
2270 
2271   // If the requested range is different from the range allocated by GC, then
2272   // the pointers need to be patched.
2273   address mapped_start = (address) _mapped_heap_memregion.start();
2274   ptrdiff_t delta = mapped_start - requested_start;
2275   if (UseCompressedOops &&
2276       (narrow_oop_mode() != CompressedOops::mode() ||
2277        narrow_oop_shift() != CompressedOops::shift())) {
2278     _heap_pointers_need_patching = true;
2279   }
2280   if (delta != 0) {
2281     _heap_pointers_need_patching = true;
2282   }
2283   ArchiveHeapLoader::init_mapped_heap_info(mapped_start, delta, narrow_oop_shift());
2284 
2285   if (_heap_pointers_need_patching) {
2286     char* bitmap_base = map_bitmap_region();
2287     if (bitmap_base == nullptr) {
2288       log_info(cds)("CDS heap cannot be used because bitmap region cannot be mapped");
2289       dealloc_heap_region();
2290       unmap_region(MetaspaceShared::hp);
2291       _heap_pointers_need_patching = false;
2292       return false;
2293     }
2294   }
2295   log_info(cds)("Heap data mapped at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
2296                 p2i(mapped_start), _mapped_heap_memregion.byte_size());
2297   log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
2298   return true;
2299 }
2300 
2301 narrowOop FileMapInfo::encoded_heap_region_dumptime_address() {
2302   assert(CDSConfig::is_using_archive(), "runtime only");
2303   assert(UseCompressedOops, "sanity");
2304   FileMapRegion* r = region_at(MetaspaceShared::hp);
2305   return CompressedOops::narrow_oop_cast(r->mapping_offset() >> narrow_oop_shift());
2306 }
2307 
2308 void FileMapInfo::patch_heap_embedded_pointers() {
2309   if (!ArchiveHeapLoader::is_mapped() || !_heap_pointers_need_patching) {
2310     return;
2311   }
2312 
2313   char* bitmap_base = map_bitmap_region();
2314   assert(bitmap_base != nullptr, "must have already been mapped");
2315 
2316   FileMapRegion* r = region_at(MetaspaceShared::hp);
2317   ArchiveHeapLoader::patch_embedded_pointers(
2318       this, _mapped_heap_memregion,
2319       (address)(region_at(MetaspaceShared::bm)->mapped_base()) + r->oopmap_offset(),
2320       r->oopmap_size_in_bits());
2321 }
2322 
2323 void FileMapInfo::fixup_mapped_heap_region() {
2324   if (ArchiveHeapLoader::is_mapped()) {
2325     assert(!_mapped_heap_memregion.is_empty(), "sanity");
2326 
2327     // Populate the archive regions' G1BlockOffsetTables. That ensures
2328     // fast G1BlockOffsetTable::block_start operations for any given address
2329     // within the archive regions when trying to find start of an object
2330     // (e.g. during card table scanning).
2331     G1CollectedHeap::heap()->populate_archive_regions_bot(_mapped_heap_memregion);
2332   }
2333 }
2334 
2335 // dealloc the archive regions from java heap
2336 void FileMapInfo::dealloc_heap_region() {
2337   G1CollectedHeap::heap()->dealloc_archive_regions(_mapped_heap_memregion);
2338 }
2339 #endif // INCLUDE_CDS_JAVA_HEAP
2340 
2341 void FileMapInfo::unmap_regions(int regions[], int num_regions) {
2342   for (int r = 0; r < num_regions; r++) {
2343     int idx = regions[r];
2344     unmap_region(idx);
2345   }
2346 }
2347 
2348 // Unmap a memory region in the address space.
2349 
2350 void FileMapInfo::unmap_region(int i) {
2351   FileMapRegion* r = region_at(i);
2352   char* mapped_base = r->mapped_base();
2353   size_t size = r->used_aligned();
2354 
2355   if (mapped_base != nullptr) {
2356     if (size > 0 && r->mapped_from_file()) {
2357       log_info(cds)("Unmapping region #%d at base " INTPTR_FORMAT " (%s)", i, p2i(mapped_base),
2358                     shared_region_name[i]);
2359       if (!os::unmap_memory(mapped_base, size)) {
2360         fatal("os::unmap_memory failed");
2361       }
2362     }
2363     r->set_mapped_base(nullptr);
2364   }
2365 }
2366 
2367 void FileMapInfo::assert_mark(bool check) {
2368   if (!check) {
2369     MetaspaceShared::unrecoverable_loading_error("Mark mismatch while restoring from shared file.");
2370   }
2371 }
2372 
2373 FileMapInfo* FileMapInfo::_current_info = nullptr;
2374 FileMapInfo* FileMapInfo::_dynamic_archive_info = nullptr;
2375 bool FileMapInfo::_heap_pointers_need_patching = false;
2376 SharedPathTable FileMapInfo::_shared_path_table;
2377 bool FileMapInfo::_validating_shared_path_table = false;
2378 bool FileMapInfo::_memory_mapping_failed = false;
2379 GrowableArray<const char*>* FileMapInfo::_non_existent_class_paths = nullptr;
2380 
2381 // Open the shared archive file, read and validate the header
2382 // information (version, boot classpath, etc.). If initialization
2383 // fails, shared spaces are disabled and the file is closed.
2384 //
2385 // Validation of the archive is done in two steps:
2386 //
2387 // [1] validate_header() - done here.
2388 // [2] validate_shared_path_table - this is done later, because the table is in the RW
2389 //     region of the archive, which is not mapped yet.
2390 bool FileMapInfo::initialize() {
2391   assert(CDSConfig::is_using_archive(), "UseSharedSpaces expected.");
2392   assert(Arguments::has_jimage(), "The shared archive file cannot be used with an exploded module build.");
2393 
2394   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2395     // CDS assumes that no classes resolved in vmClasses::resolve_all()
2396     // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
2397     // during the JVMTI "early" stage, so we can still use CDS if
2398     // JvmtiExport::has_early_class_hook_env() is false.
2399     log_info(cds)("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
2400     return false;
2401   }
2402 
2403   if (!open_for_read() || !init_from_file(_fd) || !validate_header()) {
2404     if (_is_static) {
2405       log_info(cds)("Initialize static archive failed.");
2406       return false;
2407     } else {
2408       log_info(cds)("Initialize dynamic archive failed.");
2409       if (AutoCreateSharedArchive) {
2410         CDSConfig::enable_dumping_dynamic_archive();
2411         ArchiveClassesAtExit = CDSConfig::dynamic_archive_path();
2412       }
2413       return false;
2414     }
2415   }
2416 
2417   return true;
2418 }
2419 
2420 // The 2 core spaces are RW->RO
2421 FileMapRegion* FileMapInfo::first_core_region() const {
2422   return region_at(MetaspaceShared::rw);
2423 }
2424 
2425 FileMapRegion* FileMapInfo::last_core_region() const {
2426   return region_at(MetaspaceShared::ro);
2427 }
2428 
2429 void FileMapInfo::print(outputStream* st) const {
2430   header()->print(st);
2431   if (!is_static()) {
2432     dynamic_header()->print(st);
2433   }
2434 }
2435 
2436 void FileMapHeader::set_as_offset(char* p, size_t *offset) {
2437   *offset = ArchiveBuilder::current()->any_to_offset((address)p);
2438 }
2439 
2440 int FileMapHeader::compute_crc() {
2441   char* start = (char*)this;
2442   // start computing from the field after _header_size to end of base archive name.
2443   char* buf = (char*)&(_generic_header._header_size) + sizeof(_generic_header._header_size);
2444   size_t sz = header_size() - (buf - start);
2445   int crc = ClassLoader::crc32(0, buf, (jint)sz);
2446   return crc;
2447 }
2448 
2449 // This function should only be called during run time with UseSharedSpaces enabled.
2450 bool FileMapHeader::validate() {
2451   if (_obj_alignment != ObjectAlignmentInBytes) {
2452     log_info(cds)("The shared archive file's ObjectAlignmentInBytes of %d"
2453                   " does not equal the current ObjectAlignmentInBytes of %d.",
2454                   _obj_alignment, ObjectAlignmentInBytes);
2455     return false;
2456   }
2457   if (_compact_strings != CompactStrings) {
2458     log_info(cds)("The shared archive file's CompactStrings setting (%s)"
2459                   " does not equal the current CompactStrings setting (%s).",
2460                   _compact_strings ? "enabled" : "disabled",
2461                   CompactStrings   ? "enabled" : "disabled");
2462     return false;
2463   }
2464 
2465   // This must be done after header validation because it might change the
2466   // header data
2467   const char* prop = Arguments::get_property("java.system.class.loader");
2468   if (prop != nullptr) {
2469     log_warning(cds)("Archived non-system classes are disabled because the "
2470             "java.system.class.loader property is specified (value = \"%s\"). "
2471             "To use archived non-system classes, this property must not be set", prop);
2472     _has_platform_or_app_classes = false;
2473   }
2474 
2475 
2476   if (!_verify_local && BytecodeVerificationLocal) {
2477     //  we cannot load boot classes, so there's no point of using the CDS archive
2478     log_info(cds)("The shared archive file's BytecodeVerificationLocal setting (%s)"
2479                                " does not equal the current BytecodeVerificationLocal setting (%s).",
2480                                _verify_local ? "enabled" : "disabled",
2481                                BytecodeVerificationLocal ? "enabled" : "disabled");
2482     return false;
2483   }
2484 
2485   // For backwards compatibility, we don't check the BytecodeVerificationRemote setting
2486   // if the archive only contains system classes.
2487   if (_has_platform_or_app_classes
2488       && !_verify_remote // we didn't verify the archived platform/app classes
2489       && BytecodeVerificationRemote) { // but we want to verify all loaded platform/app classes
2490     log_info(cds)("The shared archive file was created with less restrictive "
2491                                "verification setting than the current setting.");
2492     // Pretend that we didn't have any archived platform/app classes, so they won't be loaded
2493     // by SystemDictionaryShared.
2494     _has_platform_or_app_classes = false;
2495   }
2496 
2497   // Java agents are allowed during run time. Therefore, the following condition is not
2498   // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
2499   // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
2500   // while AllowArchivingWithJavaAgent is set during the current run.
2501   if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
2502     log_warning(cds)("The setting of the AllowArchivingWithJavaAgent is different "
2503                                "from the setting in the shared archive.");
2504     return false;
2505   }
2506 
2507   if (_allow_archiving_with_java_agent) {
2508     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
2509             "for testing purposes only and should not be used in a production environment");
2510   }
2511 
2512   log_info(cds)("Archive was created with UseCompressedOops = %d, UseCompressedClassPointers = %d",
2513                           compressed_oops(), compressed_class_pointers());
2514   if (compressed_oops() != UseCompressedOops || compressed_class_pointers() != UseCompressedClassPointers) {
2515     log_info(cds)("Unable to use shared archive.\nThe saved state of UseCompressedOops and UseCompressedClassPointers is "
2516                                "different from runtime, CDS will be disabled.");
2517     return false;
2518   }
2519 
2520   if (is_static()) {
2521     const char* err = nullptr;
2522     if (CDSConfig::is_valhalla_preview()) {
2523       if (!_has_valhalla_patched_classes) {
2524         err = "not created";
2525       }
2526     } else {
2527       if (_has_valhalla_patched_classes) {
2528         err = "created";
2529       }
2530     }
2531     if (err != nullptr) {
2532       log_warning(cds)("This archive was %s with --enable-preview -XX:+EnableValhalla. It is "
2533                          "incompatible with the current JVM setting", err);
2534       return false;
2535     }
2536   }
2537 
2538   if (! _use_secondary_supers_table && UseSecondarySupersTable) {
2539     log_warning(cds)("The shared archive was created without UseSecondarySupersTable.");
2540     return false;
2541   }
2542 
2543   if (!_use_optimized_module_handling) {
2544     CDSConfig::stop_using_optimized_module_handling();
2545     log_info(cds)("optimized module handling: disabled because archive was created without optimized module handling");
2546   }
2547 
2548   if (is_static() && !_has_full_module_graph) {
2549     // Only the static archive can contain the full module graph.
2550     CDSConfig::stop_using_full_module_graph("archive was created without full module graph");
2551   }
2552 
2553   return true;
2554 }
2555 
2556 bool FileMapInfo::validate_header() {
2557   if (!header()->validate()) {
2558     return false;
2559   }
2560   if (_is_static) {
2561     return true;
2562   } else {
2563     return DynamicArchive::validate(this);
2564   }
2565 }
2566 
2567 #if INCLUDE_JVMTI
2568 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = nullptr;
2569 
2570 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
2571   if (i == 0) {
2572     // index 0 corresponds to the ClassPathImageEntry which is a globally shared object
2573     // and should never be deleted.
2574     return ClassLoader::get_jrt_entry();
2575   }
2576   ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
2577   if (ent == nullptr) {
2578     SharedClassPathEntry* scpe = shared_path(i);
2579     assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
2580 
2581     const char* path = scpe->name();
2582     struct stat st;
2583     if (os::stat(path, &st) != 0) {
2584       char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2585       jio_snprintf(msg, strlen(path) + 127, "error in finding JAR file %s", path);
2586       THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2587     } else {
2588       ent = ClassLoader::create_class_path_entry(THREAD, path, &st, false, false);
2589       if (ent == nullptr) {
2590         char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2591         jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
2592         THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2593       }
2594     }
2595 
2596     MutexLocker mu(THREAD, CDSClassFileStream_lock);
2597     if (_classpath_entries_for_jvmti[i] == nullptr) {
2598       _classpath_entries_for_jvmti[i] = ent;
2599     } else {
2600       // Another thread has beat me to creating this entry
2601       delete ent;
2602       ent = _classpath_entries_for_jvmti[i];
2603     }
2604   }
2605 
2606   return ent;
2607 }
2608 
2609 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
2610   int path_index = ik->shared_classpath_index();
2611   assert(path_index >= 0, "should be called for shared built-in classes only");
2612   assert(path_index < (int)get_number_of_shared_paths(), "sanity");
2613 
2614   ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
2615   assert(cpe != nullptr, "must be");
2616 
2617   Symbol* name = ik->name();
2618   const char* const class_name = name->as_C_string();
2619   const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
2620                                                                       name->utf8_length());
2621   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
2622   ClassFileStream* cfs = cpe->open_stream_for_loader(THREAD, file_name, loader_data);
2623   assert(cfs != nullptr, "must be able to read the classfile data of shared classes for built-in loaders.");
2624   log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
2625                         cfs->source(), cfs->length());
2626   return cfs;
2627 }
2628 
2629 #endif