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