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   _max_heap_size = MaxHeapSize;
 215   _use_optimized_module_handling = MetaspaceShared::use_optimized_module_handling();
 216   _has_full_module_graph = CDSConfig::is_dumping_full_module_graph();
 217 
 218   // The following fields are for sanity checks for whether this archive
 219   // will function correctly with this JVM and the bootclasspath it's
 220   // invoked with.
 221 
 222   // JVM version string ... changes on each build.
 223   get_header_version(_jvm_ident);
 224 
 225   _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();
 226   _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();
 227   _max_used_path_index = ClassLoaderExt::max_used_path_index();
 228   _num_module_paths = ClassLoader::num_module_path_entries();
 229 
 230   _verify_local = BytecodeVerificationLocal;
 231   _verify_remote = BytecodeVerificationRemote;
 232   _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();
 233   _has_non_jar_in_classpath = ClassLoaderExt::has_non_jar_in_classpath();
 234   _requested_base_address = (char*)SharedBaseAddress;
 235   _mapped_base_address = (char*)SharedBaseAddress;
 236   _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;
 237 
 238   if (!CDSConfig::is_dumping_dynamic_archive()) {
 239     set_shared_path_table(info->_shared_path_table);
 240   }
 241 }
 242 
 243 void FileMapHeader::copy_base_archive_name(const char* archive) {
 244   assert(base_archive_name_size() != 0, "_base_archive_name_size not set");
 245   assert(base_archive_name_offset() != 0, "_base_archive_name_offset not set");
 246   assert(header_size() > sizeof(*this), "_base_archive_name_size not included in header size?");
 247   memcpy((char*)this + base_archive_name_offset(), archive, base_archive_name_size());
 248 }
 249 
 250 void FileMapHeader::print(outputStream* st) {
 251   ResourceMark rm;
 252 
 253   st->print_cr("- magic:                          0x%08x", magic());
 254   st->print_cr("- crc:                            0x%08x", crc());
 255   st->print_cr("- version:                        0x%x", version());
 256   st->print_cr("- header_size:                    " UINT32_FORMAT, header_size());
 257   st->print_cr("- common_app_classpath_size:      " UINT32_FORMAT, common_app_classpath_prefix_size());
 258   st->print_cr("- base_archive_name_offset:       " UINT32_FORMAT, base_archive_name_offset());
 259   st->print_cr("- base_archive_name_size:         " UINT32_FORMAT, base_archive_name_size());
 260 
 261   for (int i = 0; i < NUM_CDS_REGIONS; i++) {
 262     FileMapRegion* r = region_at(i);
 263     r->print(st, i);
 264   }
 265   st->print_cr("============ end regions ======== ");
 266 
 267   st->print_cr("- core_region_alignment:          " SIZE_FORMAT, _core_region_alignment);
 268   st->print_cr("- obj_alignment:                  %d", _obj_alignment);
 269   st->print_cr("- narrow_oop_base:                " INTPTR_FORMAT, p2i(_narrow_oop_base));
 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("- cloned_vtables_offset:          " SIZE_FORMAT_X, _cloned_vtables_offset);
 278   st->print_cr("- serialized_data_offset:         " SIZE_FORMAT_X, _serialized_data_offset);
 279   st->print_cr("- jvm_ident:                      %s", _jvm_ident);
 280   st->print_cr("- shared_path_table_offset:       " SIZE_FORMAT_X, _shared_path_table_offset);
 281   st->print_cr("- app_class_paths_start_index:    %d", _app_class_paths_start_index);
 282   st->print_cr("- app_module_paths_start_index:   %d", _app_module_paths_start_index);
 283   st->print_cr("- num_module_paths:               %d", _num_module_paths);
 284   st->print_cr("- max_used_path_index:            %d", _max_used_path_index);
 285   st->print_cr("- verify_local:                   %d", _verify_local);
 286   st->print_cr("- verify_remote:                  %d", _verify_remote);
 287   st->print_cr("- has_platform_or_app_classes:    %d", _has_platform_or_app_classes);
 288   st->print_cr("- has_non_jar_in_classpath:       %d", _has_non_jar_in_classpath);
 289   st->print_cr("- requested_base_address:         " INTPTR_FORMAT, p2i(_requested_base_address));
 290   st->print_cr("- mapped_base_address:            " INTPTR_FORMAT, p2i(_mapped_base_address));
 291   st->print_cr("- heap_roots_offset:              " SIZE_FORMAT, _heap_roots_offset);
 292   st->print_cr("- allow_archiving_with_java_agent:%d", _allow_archiving_with_java_agent);
 293   st->print_cr("- use_optimized_module_handling:  %d", _use_optimized_module_handling);
 294   st->print_cr("- has_full_module_graph           %d", _has_full_module_graph);
 295   st->print_cr("- ptrmap_size_in_bits:            " SIZE_FORMAT, _ptrmap_size_in_bits);
 296 }
 297 
 298 void SharedClassPathEntry::init_as_non_existent(const char* path, TRAPS) {
 299   _type = non_existent_entry;
 300   set_name(path, CHECK);
 301 }
 302 
 303 void SharedClassPathEntry::init(bool is_modules_image,
 304                                 bool is_module_path,
 305                                 ClassPathEntry* cpe, TRAPS) {
 306   assert(CDSConfig::is_dumping_archive(), "sanity");
 307   _timestamp = 0;
 308   _filesize  = 0;
 309   _from_class_path_attr = false;
 310 
 311   struct stat st;
 312   if (os::stat(cpe->name(), &st) == 0) {
 313     if ((st.st_mode & S_IFMT) == S_IFDIR) {
 314       _type = dir_entry;
 315     } else {
 316       // The timestamp of the modules_image is not checked at runtime.
 317       if (is_modules_image) {
 318         _type = modules_image_entry;
 319       } else {
 320         _type = jar_entry;
 321         _timestamp = st.st_mtime;
 322         _from_class_path_attr = cpe->from_class_path_attr();
 323       }
 324       _filesize = st.st_size;
 325       _is_module_path = is_module_path;
 326     }
 327   } else {
 328     // The file/dir must exist, or it would not have been added
 329     // into ClassLoader::classpath_entry().
 330     //
 331     // If we can't access a jar file in the boot path, then we can't
 332     // make assumptions about where classes get loaded from.
 333     log_error(cds)("Unable to open file %s.", cpe->name());
 334     MetaspaceShared::unrecoverable_loading_error();
 335   }
 336 
 337   // No need to save the name of the module file, as it will be computed at run time
 338   // to allow relocation of the JDK directory.
 339   const char* name = is_modules_image  ? "" : cpe->name();
 340   set_name(name, CHECK);
 341 }
 342 
 343 void SharedClassPathEntry::set_name(const char* name, TRAPS) {
 344   size_t len = strlen(name) + 1;
 345   _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, CHECK);
 346   strcpy(_name->data(), name);
 347 }
 348 
 349 void SharedClassPathEntry::copy_from(SharedClassPathEntry* ent, ClassLoaderData* loader_data, TRAPS) {
 350   assert(ent != nullptr, "sanity");
 351   _type = ent->_type;
 352   _is_module_path = ent->_is_module_path;
 353   _timestamp = ent->_timestamp;
 354   _filesize = ent->_filesize;
 355   _from_class_path_attr = ent->_from_class_path_attr;
 356   set_name(ent->name(), CHECK);
 357 
 358   if (ent->is_jar() && ent->manifest() != nullptr) {
 359     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 360                                                     ent->manifest_size(),
 361                                                     CHECK);
 362     char* p = (char*)(buf->data());
 363     memcpy(p, ent->manifest(), ent->manifest_size());
 364     set_manifest(buf);
 365   }
 366 }
 367 
 368 const char* SharedClassPathEntry::name() const {
 369   if (UseSharedSpaces && is_modules_image()) {
 370     // In order to validate the runtime modules image file size against the archived
 371     // size information, we need to obtain the runtime modules image path. The recorded
 372     // dump time modules image path in the archive may be different from the runtime path
 373     // if the JDK image has beed moved after generating the archive.
 374     return ClassLoader::get_jrt_entry()->name();
 375   } else {
 376     return _name->data();
 377   }
 378 }
 379 
 380 bool SharedClassPathEntry::validate(bool is_class_path) const {
 381   assert(UseSharedSpaces, "runtime only");
 382 
 383   struct stat st;
 384   const char* name = this->name();
 385 
 386   bool ok = true;
 387   log_info(class, path)("checking shared classpath entry: %s", name);
 388   if (os::stat(name, &st) != 0 && is_class_path) {
 389     // If the archived module path entry does not exist at runtime, it is not fatal
 390     // (no need to invalid the shared archive) because the shared runtime visibility check
 391     // filters out any archived module classes that do not have a matching runtime
 392     // module path location.
 393     log_warning(cds)("Required classpath entry does not exist: %s", name);
 394     ok = false;
 395   } else if (is_dir()) {
 396     if (!os::dir_is_empty(name)) {
 397       log_warning(cds)("directory is not empty: %s", name);
 398       ok = false;
 399     }
 400   } else {
 401     bool size_differs = _filesize != st.st_size;
 402     bool time_differs = has_timestamp() && _timestamp != st.st_mtime;
 403     if (time_differs || size_differs) {
 404       ok = false;
 405       if (PrintSharedArchiveAndExit) {
 406         log_warning(cds)(time_differs ? "Timestamp mismatch" : "File size mismatch");
 407       } else {
 408         const char* bad_file_msg = "This file is not the one used while building the shared archive file:";
 409         log_warning(cds)("%s %s", bad_file_msg, name);
 410         if (!log_is_enabled(Info, cds)) {
 411           log_warning(cds)("%s %s", bad_file_msg, name);
 412         }
 413         if (time_differs) {
 414           log_warning(cds)("%s timestamp has changed.", name);
 415         }
 416         if (size_differs) {
 417           log_warning(cds)("%s size has changed.", name);
 418         }
 419       }
 420     }
 421   }
 422 
 423   if (PrintSharedArchiveAndExit && !ok) {
 424     // If PrintSharedArchiveAndExit is enabled, don't report failure to the
 425     // caller. Please see above comments for more details.
 426     ok = true;
 427     MetaspaceShared::set_archive_loading_failed();
 428   }
 429   return ok;
 430 }
 431 
 432 bool SharedClassPathEntry::check_non_existent() const {
 433   assert(_type == non_existent_entry, "must be");
 434   log_info(class, path)("should be non-existent: %s", name());
 435   struct stat st;
 436   if (os::stat(name(), &st) != 0) {
 437     log_info(class, path)("ok");
 438     return true; // file doesn't exist
 439   } else {
 440     return false;
 441   }
 442 }
 443 
 444 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
 445   it->push(&_name);
 446   it->push(&_manifest);
 447 }
 448 
 449 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
 450   it->push(&_entries);
 451 }
 452 
 453 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, TRAPS) {
 454   const int num_entries =
 455     ClassLoader::num_boot_classpath_entries() +
 456     ClassLoader::num_app_classpath_entries() +
 457     ClassLoader::num_module_path_entries() +
 458     FileMapInfo::num_non_existent_class_paths();
 459   _entries = MetadataFactory::new_array<SharedClassPathEntry*>(loader_data, num_entries, CHECK);
 460   for (int i = 0; i < num_entries; i++) {
 461     SharedClassPathEntry* ent =
 462       new (loader_data, SharedClassPathEntry::size(), MetaspaceObj::SharedClassPathEntryType, THREAD) SharedClassPathEntry;
 463     _entries->at_put(i, ent);
 464   }
 465 }
 466 
 467 void FileMapInfo::allocate_shared_path_table(TRAPS) {
 468   assert(CDSConfig::is_dumping_archive(), "sanity");
 469 
 470   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 471   ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
 472 
 473   assert(jrt != nullptr,
 474          "No modular java runtime image present when allocating the CDS classpath entry table");
 475 
 476   _shared_path_table.dumptime_init(loader_data, CHECK);
 477 
 478   // 1. boot class path
 479   int i = 0;
 480   i = add_shared_classpaths(i, "boot",   jrt, CHECK);
 481   i = add_shared_classpaths(i, "app",    ClassLoader::app_classpath_entries(), CHECK);
 482   i = add_shared_classpaths(i, "module", ClassLoader::module_path_entries(), CHECK);
 483 
 484   for (int x = 0; x < num_non_existent_class_paths(); x++, i++) {
 485     const char* path = _non_existent_class_paths->at(x);
 486     shared_path(i)->init_as_non_existent(path, CHECK);
 487   }
 488 
 489   assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
 490 }
 491 
 492 int FileMapInfo::add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS) {
 493   while (cpe != nullptr) {
 494     bool is_jrt = (cpe == ClassLoader::get_jrt_entry());
 495     bool is_module_path = i >= ClassLoaderExt::app_module_paths_start_index();
 496     const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
 497     log_info(class, path)("add %s shared path (%s) %s", which, type, cpe->name());
 498     SharedClassPathEntry* ent = shared_path(i);
 499     ent->init(is_jrt, is_module_path, cpe, CHECK_0);
 500     if (cpe->is_jar_file()) {
 501       update_jar_manifest(cpe, ent, CHECK_0);
 502     }
 503     if (is_jrt) {
 504       cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
 505     } else {
 506       cpe = cpe->next();
 507     }
 508     i++;
 509   }
 510 
 511   return i;
 512 }
 513 
 514 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
 515   assert(CDSConfig::is_dumping_archive(), "sanity");
 516 
 517   bool has_nonempty_dir = false;
 518 
 519   int last = _shared_path_table.size() - 1;
 520   if (last > ClassLoaderExt::max_used_path_index()) {
 521      // no need to check any path beyond max_used_path_index
 522      last = ClassLoaderExt::max_used_path_index();
 523   }
 524 
 525   for (int i = 0; i <= last; i++) {
 526     SharedClassPathEntry *e = shared_path(i);
 527     if (e->is_dir()) {
 528       const char* path = e->name();
 529       if (!os::dir_is_empty(path)) {
 530         log_error(cds)("Error: non-empty directory '%s'", path);
 531         has_nonempty_dir = true;
 532       }
 533     }
 534   }
 535 
 536   if (has_nonempty_dir) {
 537     ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", nullptr);
 538   }
 539 }
 540 
 541 void FileMapInfo::record_non_existent_class_path_entry(const char* path) {
 542   assert(CDSConfig::is_dumping_archive(), "sanity");
 543   log_info(class, path)("non-existent Class-Path entry %s", path);
 544   if (_non_existent_class_paths == nullptr) {
 545     _non_existent_class_paths = new (mtClass) GrowableArray<const char*>(10, mtClass);
 546   }
 547   _non_existent_class_paths->append(os::strdup(path));
 548 }
 549 
 550 int FileMapInfo::num_non_existent_class_paths() {
 551   assert(CDSConfig::is_dumping_archive(), "sanity");
 552   if (_non_existent_class_paths != nullptr) {
 553     return _non_existent_class_paths->length();
 554   } else {
 555     return 0;
 556   }
 557 }
 558 
 559 int FileMapInfo::get_module_shared_path_index(Symbol* location) {
 560   if (location->starts_with("jrt:", 4) && get_number_of_shared_paths() > 0) {
 561     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 562     return 0;
 563   }
 564 
 565   if (ClassLoaderExt::app_module_paths_start_index() >= get_number_of_shared_paths()) {
 566     // The archive(s) were created without --module-path option
 567     return -1;
 568   }
 569 
 570   if (!location->starts_with("file:", 5)) {
 571     return -1;
 572   }
 573 
 574   // skip_uri_protocol was also called during dump time -- see ClassLoaderExt::process_module_table()
 575   ResourceMark rm;
 576   const char* file = ClassLoader::skip_uri_protocol(location->as_C_string());
 577   for (int i = ClassLoaderExt::app_module_paths_start_index(); i < get_number_of_shared_paths(); i++) {
 578     SharedClassPathEntry* ent = shared_path(i);
 579     if (!ent->is_non_existent()) {
 580       assert(ent->in_named_module(), "must be");
 581       bool cond = strcmp(file, ent->name()) == 0;
 582       log_debug(class, path)("get_module_shared_path_index (%d) %s : %s = %s", i,
 583                              location->as_C_string(), ent->name(), cond ? "same" : "different");
 584       if (cond) {
 585         return i;
 586       }
 587     }
 588   }
 589 
 590   return -1;
 591 }
 592 
 593 class ManifestStream: public ResourceObj {
 594   private:
 595   u1*   _buffer_start; // Buffer bottom
 596   u1*   _buffer_end;   // Buffer top (one past last element)
 597   u1*   _current;      // Current buffer position
 598 
 599  public:
 600   // Constructor
 601   ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
 602                                            _current(buffer) {
 603     _buffer_end = buffer + length;
 604   }
 605 
 606   static bool is_attr(u1* attr, const char* name) {
 607     return strncmp((const char*)attr, name, strlen(name)) == 0;
 608   }
 609 
 610   static char* copy_attr(u1* value, size_t len) {
 611     char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
 612     strncpy(buf, (char*)value, len);
 613     buf[len] = 0;
 614     return buf;
 615   }
 616 };
 617 
 618 void FileMapInfo::update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
 619   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 620   ResourceMark rm(THREAD);
 621   jint manifest_size;
 622 
 623   assert(cpe->is_jar_file() && ent->is_jar(), "the shared class path entry is not a JAR file");
 624   char* manifest = ClassLoaderExt::read_manifest(THREAD, cpe, &manifest_size);
 625   if (manifest != nullptr) {
 626     ManifestStream* stream = new ManifestStream((u1*)manifest,
 627                                                 manifest_size);
 628     // Copy the manifest into the shared archive
 629     manifest = ClassLoaderExt::read_raw_manifest(THREAD, cpe, &manifest_size);
 630     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 631                                                     manifest_size,
 632                                                     CHECK);
 633     char* p = (char*)(buf->data());
 634     memcpy(p, manifest, manifest_size);
 635     ent->set_manifest(buf);
 636   }
 637 }
 638 
 639 char* FileMapInfo::skip_first_path_entry(const char* path) {
 640   size_t path_sep_len = strlen(os::path_separator());
 641   char* p = strstr((char*)path, os::path_separator());
 642   if (p != nullptr) {
 643     debug_only( {
 644       size_t image_name_len = strlen(MODULES_IMAGE_NAME);
 645       assert(strncmp(p - image_name_len, MODULES_IMAGE_NAME, image_name_len) == 0,
 646              "first entry must be the modules image");
 647     } );
 648     p += path_sep_len;
 649   } else {
 650     debug_only( {
 651       assert(ClassLoader::string_ends_with(path, MODULES_IMAGE_NAME),
 652              "first entry must be the modules image");
 653     } );
 654   }
 655   return p;
 656 }
 657 
 658 int FileMapInfo::num_paths(const char* path) {
 659   if (path == nullptr) {
 660     return 0;
 661   }
 662   int npaths = 1;
 663   char* p = (char*)path;
 664   while (p != nullptr) {
 665     char* prev = p;
 666     p = strstr((char*)p, os::path_separator());
 667     if (p != nullptr) {
 668       p++;
 669       // don't count empty path
 670       if ((p - prev) > 1) {
 671        npaths++;
 672       }
 673     }
 674   }
 675   return npaths;
 676 }
 677 
 678 // Returns true if a path within the paths exists and has non-zero size.
 679 bool FileMapInfo::check_paths_existence(const char* paths) {
 680   ClasspathStream cp_stream(paths);
 681   bool exist = false;
 682   struct stat st;
 683   while (cp_stream.has_next()) {
 684     const char* path = cp_stream.get_next();
 685     if (os::stat(path, &st) == 0 && st.st_size > 0) {
 686       exist = true;
 687       break;
 688     }
 689   }
 690   return exist;
 691 }
 692 
 693 GrowableArray<const char*>* FileMapInfo::create_dumptime_app_classpath_array() {
 694   assert(CDSConfig::is_dumping_archive(), "sanity");
 695   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 696   ClassPathEntry* cpe = ClassLoader::app_classpath_entries();
 697   while (cpe != nullptr) {
 698     path_array->append(cpe->name());
 699     cpe = cpe->next();
 700   }
 701   return path_array;
 702 }
 703 
 704 GrowableArray<const char*>* FileMapInfo::create_path_array(const char* paths) {
 705   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 706   JavaThread* current = JavaThread::current();
 707   ClasspathStream cp_stream(paths);
 708   bool non_jar_in_cp = header()->has_non_jar_in_classpath();
 709   while (cp_stream.has_next()) {
 710     const char* path = cp_stream.get_next();
 711     if (!non_jar_in_cp) {
 712       struct stat st;
 713       if (os::stat(path, &st) == 0) {
 714         path_array->append(path);
 715       }
 716     } else {
 717       const char* canonical_path = ClassLoader::get_canonical_path(path, current);
 718       if (canonical_path != nullptr) {
 719         char* error_msg = nullptr;
 720         jzfile* zip = ClassLoader::open_zip_file(canonical_path, &error_msg, current);
 721         if (zip != nullptr && error_msg == nullptr) {
 722           path_array->append(path);
 723         }
 724       }
 725     }
 726   }
 727   return path_array;
 728 }
 729 
 730 bool FileMapInfo::classpath_failure(const char* msg, const char* name) {
 731   ClassLoader::trace_class_path(msg, name);
 732   if (PrintSharedArchiveAndExit) {
 733     MetaspaceShared::set_archive_loading_failed();
 734   }
 735   return false;
 736 }
 737 
 738 unsigned int FileMapInfo::longest_common_app_classpath_prefix_len(int num_paths,
 739                                                                   GrowableArray<const char*>* rp_array) {
 740   if (num_paths == 0) {
 741     return 0;
 742   }
 743   unsigned int pos;
 744   for (pos = 0; ; pos++) {
 745     for (int i = 0; i < num_paths; i++) {
 746       if (rp_array->at(i)[pos] != '\0' && rp_array->at(i)[pos] == rp_array->at(0)[pos]) {
 747         continue;
 748       }
 749       // search backward for the pos before the file separator char
 750       while (pos > 0) {
 751         if (rp_array->at(0)[--pos] == *os::file_separator()) {
 752           return pos + 1;
 753         }
 754       }
 755       return 0;
 756     }
 757   }
 758   return 0;
 759 }
 760 
 761 bool FileMapInfo::check_paths(int shared_path_start_idx, int num_paths, GrowableArray<const char*>* rp_array,
 762                               unsigned int dumptime_prefix_len, unsigned int runtime_prefix_len) {
 763   int i = 0;
 764   int j = shared_path_start_idx;
 765   while (i < num_paths) {
 766     while (shared_path(j)->from_class_path_attr()) {
 767       // shared_path(j) was expanded from the JAR file attribute "Class-Path:"
 768       // during dump time. It's not included in the -classpath VM argument.
 769       j++;
 770     }
 771     assert(strlen(shared_path(j)->name()) > (size_t)dumptime_prefix_len, "sanity");
 772     const char* dumptime_path = shared_path(j)->name() + dumptime_prefix_len;
 773     assert(strlen(rp_array->at(i)) > (size_t)runtime_prefix_len, "sanity");
 774     const char* runtime_path = rp_array->at(i)  + runtime_prefix_len;
 775     if (!os::same_files(dumptime_path, runtime_path)) {
 776       return true;
 777     }
 778     i++;
 779     j++;
 780   }
 781   return false;
 782 }
 783 
 784 bool FileMapInfo::validate_boot_class_paths() {
 785   //
 786   // - Archive contains boot classes only - relaxed boot path check:
 787   //   Extra path elements appended to the boot path at runtime are allowed.
 788   //
 789   // - Archive contains application or platform classes - strict boot path check:
 790   //   Validate the entire runtime boot path, which must be compatible
 791   //   with the dump time boot path. Appending boot path at runtime is not
 792   //   allowed.
 793   //
 794 
 795   // The first entry in boot path is the modules_image (guaranteed by
 796   // ClassLoader::setup_boot_search_path()). Skip the first entry. The
 797   // path of the runtime modules_image may be different from the dump
 798   // time path (e.g. the JDK image is copied to a different location
 799   // after generating the shared archive), which is acceptable. For most
 800   // common cases, the dump time boot path might contain modules_image only.
 801   char* runtime_boot_path = Arguments::get_boot_class_path();
 802   char* rp = skip_first_path_entry(runtime_boot_path);
 803   assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 804   int dp_len = header()->app_class_paths_start_index() - 1; // ignore the first path to the module image
 805   bool mismatch = false;
 806 
 807   bool relaxed_check = !header()->has_platform_or_app_classes();
 808   if (dp_len == 0 && rp == nullptr) {
 809     return true;   // ok, both runtime and dump time boot paths have modules_images only
 810   } else if (dp_len == 0 && rp != nullptr) {
 811     if (relaxed_check) {
 812       return true;   // ok, relaxed check, runtime has extra boot append path entries
 813     } else {
 814       ResourceMark rm;
 815       if (check_paths_existence(rp)) {
 816         // If a path exists in the runtime boot paths, it is considered a mismatch
 817         // since there's no boot path specified during dump time.
 818         mismatch = true;
 819       }
 820     }
 821   } else if (dp_len > 0 && rp != nullptr) {
 822     int num;
 823     ResourceMark rm;
 824     GrowableArray<const char*>* rp_array = create_path_array(rp);
 825     int rp_len = rp_array->length();
 826     if (rp_len >= dp_len) {
 827       if (relaxed_check) {
 828         // only check the leading entries in the runtime boot path, up to
 829         // the length of the dump time boot path
 830         num = dp_len;
 831       } else {
 832         // check the full runtime boot path, must match with dump time
 833         num = rp_len;
 834       }
 835       mismatch = check_paths(1, num, rp_array, 0, 0);
 836     } else {
 837       // create_path_array() ignores non-existing paths. Although the dump time and runtime boot classpath lengths
 838       // are the same initially, after the call to create_path_array(), the runtime boot classpath length could become
 839       // shorter. We consider boot classpath mismatch in this case.
 840       mismatch = true;
 841     }
 842   }
 843 
 844   if (mismatch) {
 845     // The paths are different
 846     return classpath_failure("[BOOT classpath mismatch, actual =", runtime_boot_path);
 847   }
 848   return true;
 849 }
 850 
 851 bool FileMapInfo::validate_app_class_paths(int shared_app_paths_len) {
 852   const char *appcp = Arguments::get_appclasspath();
 853   assert(appcp != nullptr, "null app classpath");
 854   int rp_len = num_paths(appcp);
 855   bool mismatch = false;
 856   if (rp_len < shared_app_paths_len) {
 857     return classpath_failure("Run time APP classpath is shorter than the one at dump time: ", appcp);
 858   }
 859   if (shared_app_paths_len != 0 && rp_len != 0) {
 860     // Prefix is OK: E.g., dump with -cp foo.jar, but run with -cp foo.jar:bar.jar.
 861     ResourceMark rm;
 862     GrowableArray<const char*>* rp_array = create_path_array(appcp);
 863     if (rp_array->length() == 0) {
 864       // None of the jar file specified in the runtime -cp exists.
 865       return classpath_failure("None of the jar file specified in the runtime -cp exists: -Djava.class.path=", appcp);
 866     }
 867     if (rp_array->length() < shared_app_paths_len) {
 868       // create_path_array() ignores non-existing paths. Although the dump time and runtime app classpath lengths
 869       // are the same initially, after the call to create_path_array(), the runtime app classpath length could become
 870       // shorter. We consider app classpath mismatch in this case.
 871       return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 872     }
 873 
 874     // Handling of non-existent entries in the classpath: we eliminate all the non-existent
 875     // entries from both the dump time classpath (ClassLoader::update_class_path_entry_list)
 876     // and the runtime classpath (FileMapInfo::create_path_array), and check the remaining
 877     // entries. E.g.:
 878     //
 879     // dump : -cp a.jar:NE1:NE2:b.jar  -> a.jar:b.jar -> recorded in archive.
 880     // run 1: -cp NE3:a.jar:NE4:b.jar  -> a.jar:b.jar -> matched
 881     // run 2: -cp x.jar:NE4:b.jar      -> x.jar:b.jar -> mismatched
 882 
 883     int j = header()->app_class_paths_start_index();
 884     mismatch = check_paths(j, shared_app_paths_len, rp_array, 0, 0);
 885     if (mismatch) {
 886       // To facilitate app deployment, we allow the JAR files to be moved *together* to
 887       // a different location, as long as they are still stored under the same directory
 888       // structure. E.g., the following is OK.
 889       //     java -Xshare:dump -cp /a/Foo.jar:/a/b/Bar.jar  ...
 890       //     java -Xshare:auto -cp /x/y/Foo.jar:/x/y/b/Bar.jar  ...
 891       unsigned int dumptime_prefix_len = header()->common_app_classpath_prefix_size();
 892       unsigned int runtime_prefix_len = longest_common_app_classpath_prefix_len(shared_app_paths_len, rp_array);
 893       if (dumptime_prefix_len != 0 || runtime_prefix_len != 0) {
 894         log_info(class, path)("LCP length for app classpath (dumptime: %u, runtime: %u)",
 895                               dumptime_prefix_len, runtime_prefix_len);
 896         mismatch = check_paths(j, shared_app_paths_len, rp_array,
 897                                dumptime_prefix_len, runtime_prefix_len);
 898       }
 899       if (mismatch) {
 900         return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 901       }
 902     }
 903   }
 904   return true;
 905 }
 906 
 907 void FileMapInfo::log_paths(const char* msg, int start_idx, int end_idx) {
 908   LogTarget(Info, class, path) lt;
 909   if (lt.is_enabled()) {
 910     LogStream ls(lt);
 911     ls.print("%s", msg);
 912     const char* prefix = "";
 913     for (int i = start_idx; i < end_idx; i++) {
 914       ls.print("%s%s", prefix, shared_path(i)->name());
 915       prefix = os::path_separator();
 916     }
 917     ls.cr();
 918   }
 919 }
 920 
 921 bool FileMapInfo::check_module_paths() {
 922   const char* rp = Arguments::get_property("jdk.module.path");
 923   int num_paths = CDSConfig::num_archives(rp);
 924   if (num_paths != header()->num_module_paths()) {
 925     return false;
 926   }
 927   ResourceMark rm;
 928   GrowableArray<const char*>* rp_array = create_path_array(rp);
 929   return check_paths(header()->app_module_paths_start_index(), num_paths, rp_array, 0, 0);
 930 }
 931 
 932 bool FileMapInfo::validate_shared_path_table() {
 933   assert(UseSharedSpaces, "runtime only");
 934 
 935   _validating_shared_path_table = true;
 936 
 937   // Load the shared path table info from the archive header
 938   _shared_path_table = header()->shared_path_table();
 939   if (CDSConfig::is_dumping_dynamic_archive()) {
 940     // Only support dynamic dumping with the usage of the default CDS archive
 941     // or a simple base archive.
 942     // If the base layer archive contains additional path component besides
 943     // the runtime image and the -cp, dynamic dumping is disabled.
 944     //
 945     // When dynamic archiving is enabled, the _shared_path_table is overwritten
 946     // to include the application path and stored in the top layer archive.
 947     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 948     if (header()->app_class_paths_start_index() > 1) {
 949       CDSConfig::disable_dumping_dynamic_archive();
 950       log_warning(cds)(
 951         "Dynamic archiving is disabled because base layer archive has appended boot classpath");
 952     }
 953     if (header()->num_module_paths() > 0) {
 954       if (!check_module_paths()) {
 955         CDSConfig::disable_dumping_dynamic_archive();
 956         log_warning(cds)(
 957           "Dynamic archiving is disabled because base layer archive has a different module path");
 958       }
 959     }
 960   }
 961 
 962   log_paths("Expecting BOOT path=", 0, header()->app_class_paths_start_index());
 963   log_paths("Expecting -Djava.class.path=", header()->app_class_paths_start_index(), header()->app_module_paths_start_index());
 964 
 965   int module_paths_start_index = header()->app_module_paths_start_index();
 966   int shared_app_paths_len = 0;
 967 
 968   // validate the path entries up to the _max_used_path_index
 969   for (int i=0; i < header()->max_used_path_index() + 1; i++) {
 970     if (i < module_paths_start_index) {
 971       if (shared_path(i)->validate()) {
 972         // Only count the app class paths not from the "Class-path" attribute of a jar manifest.
 973         if (!shared_path(i)->from_class_path_attr() && i >= header()->app_class_paths_start_index()) {
 974           shared_app_paths_len++;
 975         }
 976         log_info(class, path)("ok");
 977       } else {
 978         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
 979           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 980         }
 981         return false;
 982       }
 983     } else if (i >= module_paths_start_index) {
 984       if (shared_path(i)->validate(false /* not a class path entry */)) {
 985         log_info(class, path)("ok");
 986       } else {
 987         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
 988           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 989         }
 990         return false;
 991       }
 992     }
 993   }
 994 
 995   if (header()->max_used_path_index() == 0) {
 996     // default archive only contains the module image in the bootclasspath
 997     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 998   } else {
 999     if (!validate_boot_class_paths() || !validate_app_class_paths(shared_app_paths_len)) {
1000       const char* mismatch_msg = "shared class paths mismatch";
1001       const char* hint_msg = log_is_enabled(Info, class, path) ?
1002           "" : " (hint: enable -Xlog:class+path=info to diagnose the failure)";
1003       if (RequireSharedSpaces) {
1004         log_error(cds)("%s%s", mismatch_msg, hint_msg);
1005         MetaspaceShared::unrecoverable_loading_error();
1006       } else {
1007         log_warning(cds)("%s%s", mismatch_msg, hint_msg);
1008       }
1009       return false;
1010     }
1011   }
1012 
1013   validate_non_existent_class_paths();
1014 
1015   _validating_shared_path_table = false;
1016 
1017 #if INCLUDE_JVMTI
1018   if (_classpath_entries_for_jvmti != nullptr) {
1019     os::free(_classpath_entries_for_jvmti);
1020   }
1021   size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
1022   _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
1023   memset((void*)_classpath_entries_for_jvmti, 0, sz);
1024 #endif
1025 
1026   return true;
1027 }
1028 
1029 void FileMapInfo::validate_non_existent_class_paths() {
1030   // All of the recorded non-existent paths came from the Class-Path: attribute from the JAR
1031   // files on the app classpath. If any of these are found to exist during runtime,
1032   // it will change how classes are loading for the app loader. For safety, disable
1033   // loading of archived platform/app classes (currently there's no way to disable just the
1034   // app classes).
1035 
1036   assert(UseSharedSpaces, "runtime only");
1037   for (int i = header()->app_module_paths_start_index() + header()->num_module_paths();
1038        i < get_number_of_shared_paths();
1039        i++) {
1040     SharedClassPathEntry* ent = shared_path(i);
1041     if (!ent->check_non_existent()) {
1042       log_warning(cds)("Archived non-system classes are disabled because the "
1043               "file %s exists", ent->name());
1044       header()->set_has_platform_or_app_classes(false);
1045     }
1046   }
1047 }
1048 
1049 // A utility class for reading/validating the GenericCDSFileMapHeader portion of
1050 // a CDS archive's header. The file header of all CDS archives with versions from
1051 // CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION (12) are guaranteed to always start
1052 // with GenericCDSFileMapHeader. This makes it possible to read important information
1053 // from a CDS archive created by a different version of HotSpot, so that we can
1054 // automatically regenerate the archive as necessary (JDK-8261455).
1055 class FileHeaderHelper {
1056   int _fd;
1057   bool _is_valid;
1058   bool _is_static;
1059   GenericCDSFileMapHeader* _header;
1060   const char* _archive_name;
1061   const char* _base_archive_name;
1062 
1063 public:
1064   FileHeaderHelper(const char* archive_name, bool is_static) {
1065     _fd = -1;
1066     _is_valid = false;
1067     _header = nullptr;
1068     _base_archive_name = nullptr;
1069     _archive_name = archive_name;
1070     _is_static = is_static;
1071   }
1072 
1073   ~FileHeaderHelper() {
1074     if (_header != nullptr) {
1075       FREE_C_HEAP_ARRAY(char, _header);
1076     }
1077     if (_fd != -1) {
1078       ::close(_fd);
1079     }
1080   }
1081 
1082   bool initialize() {
1083     assert(_archive_name != nullptr, "Archive name is null");
1084     _fd = os::open(_archive_name, O_RDONLY | O_BINARY, 0);
1085     if (_fd < 0) {
1086       log_info(cds)("Specified shared archive not found (%s)", _archive_name);
1087       return false;
1088     }
1089     return initialize(_fd);
1090   }
1091 
1092   // for an already opened file, do not set _fd
1093   bool initialize(int fd) {
1094     assert(_archive_name != nullptr, "Archive name is null");
1095     assert(fd != -1, "Archive must be opened already");
1096     // First read the generic header so we know the exact size of the actual header.
1097     GenericCDSFileMapHeader gen_header;
1098     size_t size = sizeof(GenericCDSFileMapHeader);
1099     os::lseek(fd, 0, SEEK_SET);
1100     size_t n = ::read(fd, (void*)&gen_header, (unsigned int)size);
1101     if (n != size) {
1102       log_warning(cds)("Unable to read generic CDS file map header from shared archive");
1103       return false;
1104     }
1105 
1106     if (gen_header._magic != CDS_ARCHIVE_MAGIC &&
1107         gen_header._magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1108       log_warning(cds)("The shared archive file has a bad magic number: %#x", gen_header._magic);
1109       return false;
1110     }
1111 
1112     if (gen_header._version < CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION) {
1113       log_warning(cds)("Cannot handle shared archive file version 0x%x. Must be at least 0x%x.",
1114                                  gen_header._version, CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION);
1115       return false;
1116     }
1117 
1118     if (gen_header._version !=  CURRENT_CDS_ARCHIVE_VERSION) {
1119       log_warning(cds)("The shared archive file version 0x%x does not match the required version 0x%x.",
1120                                  gen_header._version, CURRENT_CDS_ARCHIVE_VERSION);
1121     }
1122 
1123     size_t filelen = os::lseek(fd, 0, SEEK_END);
1124     if (gen_header._header_size >= filelen) {
1125       log_warning(cds)("Archive file header larger than archive file");
1126       return false;
1127     }
1128 
1129     // Read the actual header and perform more checks
1130     size = gen_header._header_size;
1131     _header = (GenericCDSFileMapHeader*)NEW_C_HEAP_ARRAY(char, size, mtInternal);
1132     os::lseek(fd, 0, SEEK_SET);
1133     n = ::read(fd, (void*)_header, (unsigned int)size);
1134     if (n != size) {
1135       log_warning(cds)("Unable to read actual CDS file map header from shared archive");
1136       return false;
1137     }
1138 
1139     if (!check_header_crc()) {
1140       return false;
1141     }
1142 
1143     if (!check_and_init_base_archive_name()) {
1144       return false;
1145     }
1146 
1147     // All fields in the GenericCDSFileMapHeader has been validated.
1148     _is_valid = true;
1149     return true;
1150   }
1151 
1152   GenericCDSFileMapHeader* get_generic_file_header() {
1153     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1154     return _header;
1155   }
1156 
1157   const char* base_archive_name() {
1158     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1159     return _base_archive_name;
1160   }
1161 
1162  private:
1163   bool check_header_crc() const {
1164     if (VerifySharedSpaces) {
1165       FileMapHeader* header = (FileMapHeader*)_header;
1166       int actual_crc = header->compute_crc();
1167       if (actual_crc != header->crc()) {
1168         log_info(cds)("_crc expected: %d", header->crc());
1169         log_info(cds)("       actual: %d", actual_crc);
1170         log_warning(cds)("Header checksum verification failed.");
1171         return false;
1172       }
1173     }
1174     return true;
1175   }
1176 
1177   bool check_and_init_base_archive_name() {
1178     unsigned int name_offset = _header->_base_archive_name_offset;
1179     unsigned int name_size   = _header->_base_archive_name_size;
1180     unsigned int header_size = _header->_header_size;
1181 
1182     if (name_offset + name_size < name_offset) {
1183       log_warning(cds)("base_archive_name offset/size overflow: " UINT32_FORMAT "/" UINT32_FORMAT,
1184                                  name_offset, name_size);
1185       return false;
1186     }
1187     if (_header->_magic == CDS_ARCHIVE_MAGIC) {
1188       if (name_offset != 0) {
1189         log_warning(cds)("static shared archive must have zero _base_archive_name_offset");
1190         return false;
1191       }
1192       if (name_size != 0) {
1193         log_warning(cds)("static shared archive must have zero _base_archive_name_size");
1194         return false;
1195       }
1196     } else {
1197       assert(_header->_magic == CDS_DYNAMIC_ARCHIVE_MAGIC, "must be");
1198       if ((name_size == 0 && name_offset != 0) ||
1199           (name_size != 0 && name_offset == 0)) {
1200         // If either is zero, both must be zero. This indicates that we are using the default base archive.
1201         log_warning(cds)("Invalid base_archive_name offset/size: " UINT32_FORMAT "/" UINT32_FORMAT,
1202                                    name_offset, name_size);
1203         return false;
1204       }
1205       if (name_size > 0) {
1206         if (name_offset + name_size > header_size) {
1207           log_warning(cds)("Invalid base_archive_name offset/size (out of range): "
1208                                      UINT32_FORMAT " + " UINT32_FORMAT " > " UINT32_FORMAT ,
1209                                      name_offset, name_size, header_size);
1210           return false;
1211         }
1212         const char* name = ((const char*)_header) + _header->_base_archive_name_offset;
1213         if (name[name_size - 1] != '\0' || strlen(name) != name_size - 1) {
1214           log_warning(cds)("Base archive name is damaged");
1215           return false;
1216         }
1217         if (!os::file_exists(name)) {
1218           log_warning(cds)("Base archive %s does not exist", name);
1219           return false;
1220         }
1221         _base_archive_name = name;
1222       }
1223     }
1224 
1225     return true;
1226   }
1227 };
1228 
1229 // Return value:
1230 // false:
1231 //      <archive_name> is not a valid archive. *base_archive_name is set to null.
1232 // true && (*base_archive_name) == nullptr:
1233 //      <archive_name> is a valid static archive.
1234 // true && (*base_archive_name) != nullptr:
1235 //      <archive_name> is a valid dynamic archive.
1236 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
1237                                                     char** base_archive_name) {
1238   FileHeaderHelper file_helper(archive_name, false);
1239   *base_archive_name = nullptr;
1240 
1241   if (!file_helper.initialize()) {
1242     return false;
1243   }
1244   GenericCDSFileMapHeader* header = file_helper.get_generic_file_header();
1245   if (header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1246     assert(header->_magic == CDS_ARCHIVE_MAGIC, "must be");
1247     if (AutoCreateSharedArchive) {
1248      log_warning(cds)("AutoCreateSharedArchive is ignored because %s is a static archive", archive_name);
1249     }
1250     return true;
1251   }
1252 
1253   const char* base = file_helper.base_archive_name();
1254   if (base == nullptr) {
1255     *base_archive_name = CDSConfig::default_archive_path();
1256   } else {
1257     *base_archive_name = os::strdup_check_oom(base);
1258   }
1259 
1260   return true;
1261 }
1262 
1263 // Read the FileMapInfo information from the file.
1264 
1265 bool FileMapInfo::init_from_file(int fd) {
1266   FileHeaderHelper file_helper(_full_path, _is_static);
1267   if (!file_helper.initialize(fd)) {
1268     log_warning(cds)("Unable to read the file header.");
1269     return false;
1270   }
1271   GenericCDSFileMapHeader* gen_header = file_helper.get_generic_file_header();
1272 
1273   if (_is_static) {
1274     if (gen_header->_magic != CDS_ARCHIVE_MAGIC) {
1275       log_warning(cds)("Not a base shared archive: %s", _full_path);
1276       return false;
1277     }
1278   } else {
1279     if (gen_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1280       log_warning(cds)("Not a top shared archive: %s", _full_path);
1281       return false;
1282     }
1283   }
1284 
1285   _header = (FileMapHeader*)os::malloc(gen_header->_header_size, mtInternal);
1286   os::lseek(fd, 0, SEEK_SET); // reset to begin of the archive
1287   size_t size = gen_header->_header_size;
1288   size_t n = ::read(fd, (void*)_header, (unsigned int)size);
1289   if (n != size) {
1290     log_warning(cds)("Failed to read file header from the top archive file\n");
1291     return false;
1292   }
1293 
1294   if (header()->version() != CURRENT_CDS_ARCHIVE_VERSION) {
1295     log_info(cds)("_version expected: 0x%x", CURRENT_CDS_ARCHIVE_VERSION);
1296     log_info(cds)("           actual: 0x%x", header()->version());
1297     log_warning(cds)("The shared archive file has the wrong version.");
1298     return false;
1299   }
1300 
1301   int common_path_size = header()->common_app_classpath_prefix_size();
1302   if (common_path_size < 0) {
1303       log_warning(cds)("common app classpath prefix len < 0");
1304       return false;
1305   }
1306 
1307   unsigned int base_offset = header()->base_archive_name_offset();
1308   unsigned int name_size = header()->base_archive_name_size();
1309   unsigned int header_size = header()->header_size();
1310   if (base_offset != 0 && name_size != 0) {
1311     if (header_size != base_offset + name_size) {
1312       log_info(cds)("_header_size: " UINT32_FORMAT, header_size);
1313       log_info(cds)("common_app_classpath_size: " UINT32_FORMAT, header()->common_app_classpath_prefix_size());
1314       log_info(cds)("base_archive_name_size: " UINT32_FORMAT, header()->base_archive_name_size());
1315       log_info(cds)("base_archive_name_offset: " UINT32_FORMAT, header()->base_archive_name_offset());
1316       log_warning(cds)("The shared archive file has an incorrect header size.");
1317       return false;
1318     }
1319   }
1320 
1321   const char* actual_ident = header()->jvm_ident();
1322 
1323   if (actual_ident[JVM_IDENT_MAX-1] != 0) {
1324     log_warning(cds)("JVM version identifier is corrupted.");
1325     return false;
1326   }
1327 
1328   char expected_ident[JVM_IDENT_MAX];
1329   get_header_version(expected_ident);
1330   if (strncmp(actual_ident, expected_ident, JVM_IDENT_MAX-1) != 0) {
1331     log_info(cds)("_jvm_ident expected: %s", expected_ident);
1332     log_info(cds)("             actual: %s", actual_ident);
1333     log_warning(cds)("The shared archive file was created by a different"
1334                   " version or build of HotSpot");
1335     return false;
1336   }
1337 
1338   _file_offset = header()->header_size(); // accounts for the size of _base_archive_name
1339 
1340   size_t len = os::lseek(fd, 0, SEEK_END);
1341 
1342   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1343     FileMapRegion* r = region_at(i);
1344     if (r->file_offset() > len || len - r->file_offset() < r->used()) {
1345       log_warning(cds)("The shared archive file has been truncated.");
1346       return false;
1347     }
1348   }
1349 
1350   return true;
1351 }
1352 
1353 void FileMapInfo::seek_to_position(size_t pos) {
1354   if (os::lseek(_fd, (long)pos, SEEK_SET) < 0) {
1355     log_error(cds)("Unable to seek to position " SIZE_FORMAT, pos);
1356     MetaspaceShared::unrecoverable_loading_error();
1357   }
1358 }
1359 
1360 // Read the FileMapInfo information from the file.
1361 bool FileMapInfo::open_for_read() {
1362   if (_file_open) {
1363     return true;
1364   }
1365   log_info(cds)("trying to map %s", _full_path);
1366   int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
1367   if (fd < 0) {
1368     if (errno == ENOENT) {
1369       log_info(cds)("Specified shared archive not found (%s)", _full_path);
1370     } else {
1371       log_warning(cds)("Failed to open shared archive file (%s)",
1372                     os::strerror(errno));
1373     }
1374     return false;
1375   } else {
1376     log_info(cds)("Opened archive %s.", _full_path);
1377   }
1378 
1379   _fd = fd;
1380   _file_open = true;
1381   return true;
1382 }
1383 
1384 // Write the FileMapInfo information to the file.
1385 
1386 void FileMapInfo::open_for_write() {
1387   LogMessage(cds) msg;
1388   if (msg.is_info()) {
1389     msg.info("Dumping shared data to file: ");
1390     msg.info("   %s", _full_path);
1391   }
1392 
1393 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
1394     chmod(_full_path, _S_IREAD | _S_IWRITE);
1395 #endif
1396 
1397   // Use remove() to delete the existing file because, on Unix, this will
1398   // allow processes that have it open continued access to the file.
1399   remove(_full_path);
1400   int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1401   if (fd < 0) {
1402     log_error(cds)("Unable to create shared archive file %s: (%s).", _full_path,
1403                    os::strerror(errno));
1404     MetaspaceShared::unrecoverable_writing_error();
1405   }
1406   _fd = fd;
1407   _file_open = true;
1408 
1409   // Seek past the header. We will write the header after all regions are written
1410   // and their CRCs computed.
1411   size_t header_bytes = header()->header_size();
1412 
1413   header_bytes = align_up(header_bytes, MetaspaceShared::core_region_alignment());
1414   _file_offset = header_bytes;
1415   seek_to_position(_file_offset);
1416 }
1417 
1418 // Write the header to the file, seek to the next allocation boundary.
1419 
1420 void FileMapInfo::write_header() {
1421   _file_offset = 0;
1422   seek_to_position(_file_offset);
1423   assert(is_file_position_aligned(), "must be");
1424   write_bytes(header(), header()->header_size());
1425 }
1426 
1427 size_t FileMapRegion::used_aligned() const {
1428   return align_up(used(), MetaspaceShared::core_region_alignment());
1429 }
1430 
1431 void FileMapRegion::init(int region_index, size_t mapping_offset, size_t size, bool read_only,
1432                          bool allow_exec, int crc) {
1433   _is_heap_region = HeapShared::is_heap_region(region_index);
1434   _is_bitmap_region = (region_index == MetaspaceShared::bm);
1435   _mapping_offset = mapping_offset;
1436   _used = size;
1437   _read_only = read_only;
1438   _allow_exec = allow_exec;
1439   _crc = crc;
1440   _mapped_from_file = false;
1441   _mapped_base = nullptr;
1442 }
1443 
1444 void FileMapRegion::init_oopmap(size_t offset, size_t size_in_bits) {
1445   _oopmap_offset = offset;
1446   _oopmap_size_in_bits = size_in_bits;
1447 }
1448 
1449 void FileMapRegion::init_ptrmap(size_t offset, size_t size_in_bits) {
1450   _ptrmap_offset = offset;
1451   _ptrmap_size_in_bits = size_in_bits;
1452 }
1453 
1454 BitMapView FileMapRegion::bitmap_view(bool is_oopmap) {
1455   char* bitmap_base = FileMapInfo::current_info()->map_bitmap_region();
1456   bitmap_base += is_oopmap ? _oopmap_offset : _ptrmap_offset;
1457   size_t size_in_bits = is_oopmap ? _oopmap_size_in_bits : _ptrmap_size_in_bits;
1458   return BitMapView((BitMap::bm_word_t*)(bitmap_base), size_in_bits);
1459 }
1460 
1461 BitMapView FileMapRegion::oopmap_view() {
1462   return bitmap_view(true);
1463 }
1464 
1465 BitMapView FileMapRegion::ptrmap_view() {
1466   assert(has_ptrmap(), "must be");
1467   return bitmap_view(false);
1468 }
1469 
1470 bool FileMapRegion::check_region_crc(char* base) const {
1471   // This function should be called after the region has been properly
1472   // loaded into memory via FileMapInfo::map_region() or FileMapInfo::read_region().
1473   // I.e., this->mapped_base() must be valid.
1474   size_t sz = used();
1475   if (sz == 0) {
1476     return true;
1477   }
1478 
1479   assert(base != nullptr, "must be initialized");
1480   int crc = ClassLoader::crc32(0, base, (jint)sz);
1481   if (crc != this->crc()) {
1482     log_warning(cds)("Checksum verification failed.");
1483     return false;
1484   }
1485   return true;
1486 }
1487 
1488 static const char* region_name(int region_index) {
1489   static const char* names[] = {
1490     "rw", "ro", "bm", "hp"
1491   };
1492   const int num_regions = sizeof(names)/sizeof(names[0]);
1493   assert(0 <= region_index && region_index < num_regions, "sanity");
1494 
1495   return names[region_index];
1496 }
1497 
1498 void FileMapRegion::print(outputStream* st, int region_index) {
1499   st->print_cr("============ region ============= %d \"%s\"", region_index, region_name(region_index));
1500   st->print_cr("- crc:                            0x%08x", _crc);
1501   st->print_cr("- read_only:                      %d", _read_only);
1502   st->print_cr("- allow_exec:                     %d", _allow_exec);
1503   st->print_cr("- is_heap_region:                 %d", _is_heap_region);
1504   st->print_cr("- is_bitmap_region:               %d", _is_bitmap_region);
1505   st->print_cr("- mapped_from_file:               %d", _mapped_from_file);
1506   st->print_cr("- file_offset:                    " SIZE_FORMAT_X, _file_offset);
1507   st->print_cr("- mapping_offset:                 " SIZE_FORMAT_X, _mapping_offset);
1508   st->print_cr("- used:                           " SIZE_FORMAT, _used);
1509   st->print_cr("- oopmap_offset:                  " SIZE_FORMAT_X, _oopmap_offset);
1510   st->print_cr("- oopmap_size_in_bits:            " SIZE_FORMAT, _oopmap_size_in_bits);
1511   st->print_cr("- mapped_base:                    " INTPTR_FORMAT, p2i(_mapped_base));
1512 }
1513 
1514 void FileMapInfo::write_region(int region, char* base, size_t size,
1515                                bool read_only, bool allow_exec) {
1516   assert(CDSConfig::is_dumping_archive(), "sanity");
1517 
1518   FileMapRegion* r = region_at(region);
1519   char* requested_base;
1520   size_t mapping_offset = 0;
1521 
1522   if (region == MetaspaceShared::bm) {
1523     requested_base = nullptr; // always null for bm region
1524   } else if (size == 0) {
1525     // This is an unused region (e.g., a heap region when !INCLUDE_CDS_JAVA_HEAP)
1526     requested_base = nullptr;
1527   } else if (HeapShared::is_heap_region(region)) {
1528     assert(HeapShared::can_write(), "sanity");
1529 #if INCLUDE_CDS_JAVA_HEAP
1530     assert(!CDSConfig::is_dumping_dynamic_archive(), "must be");
1531     requested_base = (char*)ArchiveHeapWriter::requested_address();
1532     if (UseCompressedOops) {
1533       mapping_offset = (size_t)((address)requested_base - CompressedOops::base());
1534       assert((mapping_offset >> CompressedOops::shift()) << CompressedOops::shift() == mapping_offset, "must be");
1535     } else {
1536       mapping_offset = 0; // not used with !UseCompressedOops
1537     }
1538 #endif // INCLUDE_CDS_JAVA_HEAP
1539   } else {
1540     char* requested_SharedBaseAddress = (char*)MetaspaceShared::requested_base_address();
1541     requested_base = ArchiveBuilder::current()->to_requested(base);
1542     assert(requested_base >= requested_SharedBaseAddress, "must be");
1543     mapping_offset = requested_base - requested_SharedBaseAddress;
1544   }
1545 
1546   r->set_file_offset(_file_offset);
1547   int crc = ClassLoader::crc32(0, base, (jint)size);
1548   if (size > 0) {
1549     log_info(cds)("Shared file region (%s) %d: " SIZE_FORMAT_W(8)
1550                    " bytes, addr " INTPTR_FORMAT " file offset 0x%08" PRIxPTR
1551                    " crc 0x%08x",
1552                    region_name(region), region, size, p2i(requested_base), _file_offset, crc);
1553   }
1554 
1555   r->init(region, mapping_offset, size, read_only, allow_exec, crc);
1556 
1557   if (base != nullptr) {
1558     write_bytes_aligned(base, size);
1559   }
1560 }
1561 
1562 static size_t write_bitmap(const CHeapBitMap* map, char* output, size_t offset) {
1563   size_t size_in_bytes = map->size_in_bytes();
1564   map->write_to((BitMap::bm_word_t*)(output + offset), size_in_bytes);
1565   return offset + size_in_bytes;
1566 }
1567 
1568 char* FileMapInfo::write_bitmap_region(const CHeapBitMap* ptrmap, ArchiveHeapInfo* heap_info,
1569                                        size_t &size_in_bytes) {
1570   size_in_bytes = ptrmap->size_in_bytes();
1571 
1572   if (heap_info->is_used()) {
1573     size_in_bytes += heap_info->oopmap()->size_in_bytes();
1574     size_in_bytes += heap_info->ptrmap()->size_in_bytes();
1575   }
1576 
1577   // The bitmap region contains up to 3 parts:
1578   // ptrmap:              metaspace pointers inside the ro/rw regions
1579   // heap_info->oopmap(): Java oop pointers in the heap region
1580   // heap_info->ptrmap(): metaspace pointers in the heap region
1581   char* buffer = NEW_C_HEAP_ARRAY(char, size_in_bytes, mtClassShared);
1582   size_t written = 0;
1583   written = write_bitmap(ptrmap, buffer, written);
1584   header()->set_ptrmap_size_in_bits(ptrmap->size());
1585 
1586   if (heap_info->is_used()) {
1587     FileMapRegion* r = region_at(MetaspaceShared::hp);
1588 
1589     r->init_oopmap(written, heap_info->oopmap()->size());
1590     written = write_bitmap(heap_info->oopmap(), buffer, written);
1591 
1592     r->init_ptrmap(written, heap_info->ptrmap()->size());
1593     written = write_bitmap(heap_info->ptrmap(), buffer, written);
1594   }
1595 
1596   write_region(MetaspaceShared::bm, (char*)buffer, size_in_bytes, /*read_only=*/true, /*allow_exec=*/false);
1597   return buffer;
1598 }
1599 
1600 size_t FileMapInfo::write_heap_region(ArchiveHeapInfo* heap_info) {
1601   char* buffer_start = heap_info->buffer_start();
1602   size_t buffer_size = heap_info->buffer_byte_size();
1603   write_region(MetaspaceShared::hp, buffer_start, buffer_size, false, false);
1604   header()->set_heap_roots_offset(heap_info->heap_roots_offset());
1605   return buffer_size;
1606 }
1607 
1608 // Dump bytes to file -- at the current file position.
1609 
1610 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1611   assert(_file_open, "must be");
1612   if (!os::write(_fd, buffer, nbytes)) {
1613     // If the shared archive is corrupted, close it and remove it.
1614     close();
1615     remove(_full_path);
1616     MetaspaceShared::unrecoverable_writing_error("Unable to write to shared archive file.");
1617   }
1618   _file_offset += nbytes;
1619 }
1620 
1621 bool FileMapInfo::is_file_position_aligned() const {
1622   return _file_offset == align_up(_file_offset,
1623                                   MetaspaceShared::core_region_alignment());
1624 }
1625 
1626 // Align file position to an allocation unit boundary.
1627 
1628 void FileMapInfo::align_file_position() {
1629   assert(_file_open, "must be");
1630   size_t new_file_offset = align_up(_file_offset,
1631                                     MetaspaceShared::core_region_alignment());
1632   if (new_file_offset != _file_offset) {
1633     _file_offset = new_file_offset;
1634     // Seek one byte back from the target and write a byte to insure
1635     // that the written file is the correct length.
1636     _file_offset -= 1;
1637     seek_to_position(_file_offset);
1638     char zero = 0;
1639     write_bytes(&zero, 1);
1640   }
1641 }
1642 
1643 
1644 // Dump bytes to file -- at the current file position.
1645 
1646 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1647   align_file_position();
1648   write_bytes(buffer, nbytes);
1649   align_file_position();
1650 }
1651 
1652 // Close the shared archive file.  This does NOT unmap mapped regions.
1653 
1654 void FileMapInfo::close() {
1655   if (_file_open) {
1656     if (::close(_fd) < 0) {
1657       MetaspaceShared::unrecoverable_loading_error("Unable to close the shared archive file.");
1658     }
1659     _file_open = false;
1660     _fd = -1;
1661   }
1662 }
1663 
1664 /*
1665  * Same as os::map_memory() but also pretouches if AlwaysPreTouch is enabled.
1666  */
1667 static char* map_memory(int fd, const char* file_name, size_t file_offset,
1668                         char *addr, size_t bytes, bool read_only,
1669                         bool allow_exec, MEMFLAGS flags = mtNone) {
1670   char* mem = os::map_memory(fd, file_name, file_offset, addr, bytes,
1671                              AlwaysPreTouch ? false : read_only,
1672                              allow_exec, flags);
1673   if (mem != nullptr && AlwaysPreTouch) {
1674     os::pretouch_memory(mem, mem + bytes);
1675   }
1676   return mem;
1677 }
1678 
1679 // JVM/TI RedefineClasses() support:
1680 // Remap the shared readonly space to shared readwrite, private.
1681 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1682   int idx = MetaspaceShared::ro;
1683   FileMapRegion* r = region_at(idx);
1684   if (!r->read_only()) {
1685     // the space is already readwrite so we are done
1686     return true;
1687   }
1688   size_t size = r->used_aligned();
1689   if (!open_for_read()) {
1690     return false;
1691   }
1692   char *addr = r->mapped_base();
1693   // This path should not be reached for Windows; see JDK-8222379.
1694   assert(WINDOWS_ONLY(false) NOT_WINDOWS(true), "Don't call on Windows");
1695   // Replace old mapping with new one that is writable.
1696   char *base = os::map_memory(_fd, _full_path, r->file_offset(),
1697                               addr, size, false /* !read_only */,
1698                               r->allow_exec());
1699   close();
1700   // These have to be errors because the shared region is now unmapped.
1701   if (base == nullptr) {
1702     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1703     vm_exit(1);
1704   }
1705   if (base != addr) {
1706     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1707     vm_exit(1);
1708   }
1709   r->set_read_only(false);
1710   return true;
1711 }
1712 
1713 // Memory map a region in the address space.
1714 static const char* shared_region_name[] = { "ReadWrite", "ReadOnly", "Bitmap", "Heap" };
1715 
1716 MapArchiveResult FileMapInfo::map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs) {
1717   DEBUG_ONLY(FileMapRegion* last_region = nullptr);
1718   intx addr_delta = mapped_base_address - header()->requested_base_address();
1719 
1720   // Make sure we don't attempt to use header()->mapped_base_address() unless
1721   // it's been successfully mapped.
1722   DEBUG_ONLY(header()->set_mapped_base_address((char*)(uintptr_t)0xdeadbeef);)
1723 
1724   for (int i = 0; i < num_regions; i++) {
1725     int idx = regions[i];
1726     MapArchiveResult result = map_region(idx, addr_delta, mapped_base_address, rs);
1727     if (result != MAP_ARCHIVE_SUCCESS) {
1728       return result;
1729     }
1730     FileMapRegion* r = region_at(idx);
1731     DEBUG_ONLY(if (last_region != nullptr) {
1732         // Ensure that the OS won't be able to allocate new memory spaces between any mapped
1733         // regions, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1734         assert(r->mapped_base() == last_region->mapped_end(), "must have no gaps");
1735       }
1736       last_region = r;)
1737     log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)", is_static() ? "static " : "dynamic",
1738                   idx, p2i(r->mapped_base()), p2i(r->mapped_end()),
1739                   shared_region_name[idx]);
1740 
1741   }
1742 
1743   header()->set_mapped_base_address(header()->requested_base_address() + addr_delta);
1744   if (addr_delta != 0 && !relocate_pointers_in_core_regions(addr_delta)) {
1745     return MAP_ARCHIVE_OTHER_FAILURE;
1746   }
1747 
1748   return MAP_ARCHIVE_SUCCESS;
1749 }
1750 
1751 bool FileMapInfo::read_region(int i, char* base, size_t size, bool do_commit) {
1752   FileMapRegion* r = region_at(i);
1753   if (do_commit) {
1754     log_info(cds)("Commit %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)%s",
1755                   is_static() ? "static " : "dynamic", i, p2i(base), p2i(base + size),
1756                   shared_region_name[i], r->allow_exec() ? " exec" : "");
1757     if (!os::commit_memory(base, size, r->allow_exec())) {
1758       log_error(cds)("Failed to commit %s region #%d (%s)", is_static() ? "static " : "dynamic",
1759                      i, shared_region_name[i]);
1760       return false;
1761     }
1762   }
1763   if (os::lseek(_fd, (long)r->file_offset(), SEEK_SET) != (int)r->file_offset() ||
1764       read_bytes(base, size) != size) {
1765     return false;
1766   }
1767 
1768   if (VerifySharedSpaces && !r->check_region_crc(base)) {
1769     return false;
1770   }
1771 
1772   r->set_mapped_from_file(false);
1773   r->set_mapped_base(base);
1774 
1775   return true;
1776 }
1777 
1778 MapArchiveResult FileMapInfo::map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs) {
1779   assert(!HeapShared::is_heap_region(i), "sanity");
1780   FileMapRegion* r = region_at(i);
1781   size_t size = r->used_aligned();
1782   char *requested_addr = mapped_base_address + r->mapping_offset();
1783   assert(r->mapped_base() == nullptr, "must be not mapped yet");
1784   assert(requested_addr != nullptr, "must be specified");
1785 
1786   r->set_mapped_from_file(false);
1787 
1788   if (MetaspaceShared::use_windows_memory_mapping()) {
1789     // Windows cannot remap read-only shared memory to read-write when required for
1790     // RedefineClasses, which is also used by JFR.  Always map windows regions as RW.
1791     r->set_read_only(false);
1792   } else if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1793              Arguments::has_jfr_option()) {
1794     // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW
1795     r->set_read_only(false);
1796   } else if (addr_delta != 0) {
1797     r->set_read_only(false); // Need to patch the pointers
1798   }
1799 
1800   if (MetaspaceShared::use_windows_memory_mapping() && rs.is_reserved()) {
1801     // This is the second time we try to map the archive(s). We have already created a ReservedSpace
1802     // that covers all the FileMapRegions to ensure all regions can be mapped. However, Windows
1803     // can't mmap into a ReservedSpace, so we just ::read() the data. We're going to patch all the
1804     // regions anyway, so there's no benefit for mmap anyway.
1805     if (!read_region(i, requested_addr, size, /* do_commit = */ true)) {
1806       log_info(cds)("Failed to read %s shared space into reserved space at " INTPTR_FORMAT,
1807                     shared_region_name[i], p2i(requested_addr));
1808       return MAP_ARCHIVE_OTHER_FAILURE; // oom or I/O error.
1809     } else {
1810       assert(r->mapped_base() != nullptr, "must be initialized");
1811       return MAP_ARCHIVE_SUCCESS;
1812     }
1813   } else {
1814     // Note that this may either be a "fresh" mapping into unreserved address
1815     // space (Windows, first mapping attempt), or a mapping into pre-reserved
1816     // space (Posix). See also comment in MetaspaceShared::map_archives().
1817     char* base = map_memory(_fd, _full_path, r->file_offset(),
1818                             requested_addr, size, r->read_only(),
1819                             r->allow_exec(), mtClassShared);
1820     if (base != requested_addr) {
1821       log_info(cds)("Unable to map %s shared space at " INTPTR_FORMAT,
1822                     shared_region_name[i], p2i(requested_addr));
1823       _memory_mapping_failed = true;
1824       return MAP_ARCHIVE_MMAP_FAILURE;
1825     }
1826 
1827     if (VerifySharedSpaces && !r->check_region_crc(requested_addr)) {
1828       return MAP_ARCHIVE_OTHER_FAILURE;
1829     }
1830 
1831     r->set_mapped_from_file(true);
1832     r->set_mapped_base(requested_addr);
1833 
1834     return MAP_ARCHIVE_SUCCESS;
1835   }
1836 }
1837 
1838 // The return value is the location of the archive relocation bitmap.
1839 char* FileMapInfo::map_bitmap_region() {
1840   FileMapRegion* r = region_at(MetaspaceShared::bm);
1841   if (r->mapped_base() != nullptr) {
1842     return r->mapped_base();
1843   }
1844   bool read_only = true, allow_exec = false;
1845   char* requested_addr = nullptr; // allow OS to pick any location
1846   char* bitmap_base = map_memory(_fd, _full_path, r->file_offset(),
1847                                  requested_addr, r->used_aligned(), read_only, allow_exec, mtClassShared);
1848   if (bitmap_base == nullptr) {
1849     log_info(cds)("failed to map relocation bitmap");
1850     return nullptr;
1851   }
1852 
1853   if (VerifySharedSpaces && !r->check_region_crc(bitmap_base)) {
1854     log_error(cds)("relocation bitmap CRC error");
1855     if (!os::unmap_memory(bitmap_base, r->used_aligned())) {
1856       fatal("os::unmap_memory of relocation bitmap failed");
1857     }
1858     return nullptr;
1859   }
1860 
1861   r->set_mapped_from_file(true);
1862   r->set_mapped_base(bitmap_base);
1863   log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)",
1864                 is_static() ? "static " : "dynamic",
1865                 MetaspaceShared::bm, p2i(r->mapped_base()), p2i(r->mapped_end()),
1866                 shared_region_name[MetaspaceShared::bm]);
1867   return bitmap_base;
1868 }
1869 
1870 // This is called when we cannot map the archive at the requested[ base address (usually 0x800000000).
1871 // We relocate all pointers in the 2 core regions (ro, rw).
1872 bool FileMapInfo::relocate_pointers_in_core_regions(intx addr_delta) {
1873   log_debug(cds, reloc)("runtime archive relocation start");
1874   char* bitmap_base = map_bitmap_region();
1875 
1876   if (bitmap_base == nullptr) {
1877     return false; // OOM, or CRC check failure
1878   } else {
1879     size_t ptrmap_size_in_bits = header()->ptrmap_size_in_bits();
1880     log_debug(cds, reloc)("mapped relocation bitmap @ " INTPTR_FORMAT " (" SIZE_FORMAT " bits)",
1881                           p2i(bitmap_base), ptrmap_size_in_bits);
1882 
1883     BitMapView ptrmap((BitMap::bm_word_t*)bitmap_base, ptrmap_size_in_bits);
1884 
1885     // Patch all pointers in the mapped region that are marked by ptrmap.
1886     address patch_base = (address)mapped_base();
1887     address patch_end  = (address)mapped_end();
1888 
1889     // the current value of the pointers to be patched must be within this
1890     // range (i.e., must be between the requested base address and the address of the current archive).
1891     // Note: top archive may point to objects in the base archive, but not the other way around.
1892     address valid_old_base = (address)header()->requested_base_address();
1893     address valid_old_end  = valid_old_base + mapping_end_offset();
1894 
1895     // after patching, the pointers must point inside this range
1896     // (the requested location of the archive, as mapped at runtime).
1897     address valid_new_base = (address)header()->mapped_base_address();
1898     address valid_new_end  = (address)mapped_end();
1899 
1900     SharedDataRelocator patcher((address*)patch_base, (address*)patch_end, valid_old_base, valid_old_end,
1901                                 valid_new_base, valid_new_end, addr_delta);
1902     ptrmap.iterate(&patcher);
1903 
1904     // The MetaspaceShared::bm region will be unmapped in MetaspaceShared::initialize_shared_spaces().
1905 
1906     log_debug(cds, reloc)("runtime archive relocation done");
1907     return true;
1908   }
1909 }
1910 
1911 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
1912   assert(_file_open, "Archive file is not open");
1913   size_t n = ::read(_fd, buffer, (unsigned int)count);
1914   if (n != count) {
1915     // Close the file if there's a problem reading it.
1916     close();
1917     return 0;
1918   }
1919   _file_offset += count;
1920   return count;
1921 }
1922 
1923 // Get the total size in bytes of a read only region
1924 size_t FileMapInfo::readonly_total() {
1925   size_t total = 0;
1926   if (current_info() != nullptr) {
1927     FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::ro);
1928     if (r->read_only()) total += r->used();
1929   }
1930   if (dynamic_info() != nullptr) {
1931     FileMapRegion* r = FileMapInfo::dynamic_info()->region_at(MetaspaceShared::ro);
1932     if (r->read_only()) total += r->used();
1933   }
1934   return total;
1935 }
1936 
1937 #if INCLUDE_CDS_JAVA_HEAP
1938 MemRegion FileMapInfo::_mapped_heap_memregion;
1939 
1940 bool FileMapInfo::has_heap_region() {
1941   return (region_at(MetaspaceShared::hp)->used() > 0);
1942 }
1943 
1944 // Returns the address range of the archived heap region computed using the
1945 // current oop encoding mode. This range may be different than the one seen at
1946 // dump time due to encoding mode differences. The result is used in determining
1947 // if/how these regions should be relocated at run time.
1948 MemRegion FileMapInfo::get_heap_region_requested_range() {
1949   FileMapRegion* r = region_at(MetaspaceShared::hp);
1950   size_t size = r->used();
1951   assert(size > 0, "must have non-empty heap region");
1952 
1953   address start = heap_region_requested_address();
1954   address end = start + size;
1955   log_info(cds)("Requested heap region [" INTPTR_FORMAT " - " INTPTR_FORMAT "] = "  SIZE_FORMAT_W(8) " bytes",
1956                 p2i(start), p2i(end), size);
1957 
1958   return MemRegion((HeapWord*)start, (HeapWord*)end);
1959 }
1960 
1961 void FileMapInfo::map_or_load_heap_region() {
1962   bool success = false;
1963 
1964   if (can_use_heap_region()) {
1965     if (ArchiveHeapLoader::can_map()) {
1966       success = map_heap_region();
1967     } else if (ArchiveHeapLoader::can_load()) {
1968       success = ArchiveHeapLoader::load_heap_region(this);
1969     } else {
1970       if (!UseCompressedOops && !ArchiveHeapLoader::can_map()) {
1971         // TODO - remove implicit knowledge of G1
1972         log_info(cds)("Cannot use CDS heap data. UseG1GC is required for -XX:-UseCompressedOops");
1973       } else {
1974         log_info(cds)("Cannot use CDS heap data. UseEpsilonGC, UseG1GC, UseSerialGC or UseParallelGC are required.");
1975       }
1976     }
1977   }
1978 
1979   if (!success) {
1980     CDSConfig::disable_loading_full_module_graph();
1981   }
1982 }
1983 
1984 bool FileMapInfo::can_use_heap_region() {
1985   if (!has_heap_region()) {
1986     return false;
1987   }
1988   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
1989     ShouldNotReachHere(); // CDS should have been disabled.
1990     // The archived objects are mapped at JVM start-up, but we don't know if
1991     // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
1992     // which would make the archived String or mirror objects invalid. Let's be safe and not
1993     // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
1994     //
1995     // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
1996     // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
1997     // because we won't install an archived object subgraph if the klass of any of the
1998     // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
1999   }
2000 
2001   // We pre-compute narrow Klass IDs with the runtime mapping start intended to be the base, and a shift of
2002   // ArchiveHeapWriter::precomputed_narrow_klass_shift. We enforce this encoding at runtime (see
2003   // CompressedKlassPointers::initialize_for_given_encoding()). Therefore, the following assertions must
2004   // hold:
2005   address archive_narrow_klass_base = (address)header()->mapped_base_address();
2006   const int archive_narrow_klass_shift = ArchiveHeapWriter::precomputed_narrow_klass_shift;
2007 
2008   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
2009                 max_heap_size()/M);
2010   log_info(cds)("    narrow_klass_base at mapping start address, narrow_klass_shift = %d",
2011                 archive_narrow_klass_shift);
2012   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2013                 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
2014   log_info(cds)("The current max heap size = " SIZE_FORMAT "M, HeapRegion::GrainBytes = " SIZE_FORMAT,
2015                 MaxHeapSize/M, HeapRegion::GrainBytes);
2016   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
2017                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
2018   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2019                 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
2020   log_info(cds)("    heap range = [" PTR_FORMAT " - "  PTR_FORMAT "]",
2021                 UseCompressedOops ? p2i(CompressedOops::begin()) :
2022                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().start()) : 0L,
2023                 UseCompressedOops ? p2i(CompressedOops::end()) :
2024                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().end()) : 0L);
2025 
2026   assert(archive_narrow_klass_base == CompressedKlassPointers::base(), "Unexpected encoding base encountered "
2027          "(" PTR_FORMAT ", expected " PTR_FORMAT ")", p2i(CompressedKlassPointers::base()), p2i(archive_narrow_klass_base));
2028   assert(archive_narrow_klass_shift == CompressedKlassPointers::shift(), "Unexpected encoding shift encountered "
2029          "(%d, expected %d)", CompressedKlassPointers::shift(), archive_narrow_klass_shift);
2030 
2031   return true;
2032 }
2033 
2034 // The actual address of this region during dump time.
2035 address FileMapInfo::heap_region_dumptime_address() {
2036   FileMapRegion* r = region_at(MetaspaceShared::hp);
2037   assert(UseSharedSpaces, "runtime only");
2038   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2039   if (UseCompressedOops) {
2040     return /*dumptime*/ narrow_oop_base() + r->mapping_offset();
2041   } else {
2042     return heap_region_requested_address();
2043   }
2044 }
2045 
2046 // The address where this region can be mapped into the runtime heap without
2047 // patching any of the pointers that are embedded in this region.
2048 address FileMapInfo::heap_region_requested_address() {
2049   assert(UseSharedSpaces, "runtime only");
2050   FileMapRegion* r = region_at(MetaspaceShared::hp);
2051   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2052   assert(ArchiveHeapLoader::can_map(), "cannot be used by ArchiveHeapLoader::can_load() mode");
2053   if (UseCompressedOops) {
2054     // We can avoid relocation if each region's offset from the runtime CompressedOops::base()
2055     // is the same as its offset from the CompressedOops::base() during dumptime.
2056     // Note that CompressedOops::base() may be different between dumptime and runtime.
2057     //
2058     // Example:
2059     // Dumptime base = 0x1000 and shift is 0. We have a region at address 0x2000. There's a
2060     // narrowOop P stored in this region that points to an object at address 0x2200.
2061     // P's encoded value is 0x1200.
2062     //
2063     // Runtime base = 0x4000 and shift is also 0. If we map this region at 0x5000, then
2064     // the value P can remain 0x1200. The decoded address = (0x4000 + (0x1200 << 0)) = 0x5200,
2065     // which is the runtime location of the referenced object.
2066     return /*runtime*/ CompressedOops::base() + r->mapping_offset();
2067   } else {
2068     // This was the hard-coded requested base address used at dump time. With uncompressed oops,
2069     // the heap range is assigned by the OS so we will most likely have to relocate anyway, no matter
2070     // what base address was picked at duump time.
2071     return (address)ArchiveHeapWriter::NOCOOPS_REQUESTED_BASE;
2072   }
2073 }
2074 
2075 bool FileMapInfo::map_heap_region() {
2076   if (map_heap_region_impl()) {
2077 #ifdef ASSERT
2078     // The "old" regions must be parsable -- we cannot have any unused space
2079     // at the start of the lowest G1 region that contains archived objects.
2080     assert(is_aligned(_mapped_heap_memregion.start(), HeapRegion::GrainBytes), "must be");
2081 
2082     // Make sure we map at the very top of the heap - see comments in
2083     // init_heap_region_relocation().
2084     MemRegion heap_range = G1CollectedHeap::heap()->reserved();
2085     assert(heap_range.contains(_mapped_heap_memregion), "must be");
2086 
2087     address heap_end = (address)heap_range.end();
2088     address mapped_heap_region_end = (address)_mapped_heap_memregion.end();
2089     assert(heap_end >= mapped_heap_region_end, "must be");
2090     assert(heap_end - mapped_heap_region_end < (intx)(HeapRegion::GrainBytes),
2091            "must be at the top of the heap to avoid fragmentation");
2092 #endif
2093 
2094     ArchiveHeapLoader::set_mapped();
2095     return true;
2096   } else {
2097     return false;
2098   }
2099 }
2100 
2101 bool FileMapInfo::map_heap_region_impl() {
2102   assert(UseG1GC, "the following code assumes G1");
2103 
2104   FileMapRegion* r = region_at(MetaspaceShared::hp);
2105   size_t size = r->used();
2106   if (size == 0) {
2107     return false; // no archived java heap data
2108   }
2109 
2110   size_t word_size = size / HeapWordSize;
2111   address requested_start = heap_region_requested_address();
2112 
2113   log_info(cds)("Preferred address to map heap data (to avoid relocation) is " INTPTR_FORMAT, p2i(requested_start));
2114 
2115   // allocate from java heap
2116   HeapWord* start = G1CollectedHeap::heap()->alloc_archive_region(word_size, (HeapWord*)requested_start);
2117   if (start == nullptr) {
2118     log_info(cds)("UseSharedSpaces: Unable to allocate java heap region for archive heap.");
2119     return false;
2120   }
2121 
2122   _mapped_heap_memregion = MemRegion(start, word_size);
2123 
2124   // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
2125   // for mapped region as it is part of the reserved java heap, which is already recorded.
2126   char* addr = (char*)_mapped_heap_memregion.start();
2127   char* base = map_memory(_fd, _full_path, r->file_offset(),
2128                           addr, _mapped_heap_memregion.byte_size(), r->read_only(),
2129                           r->allow_exec());
2130   if (base == nullptr || base != addr) {
2131     dealloc_heap_region();
2132     log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
2133                   INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
2134                   p2i(addr), _mapped_heap_memregion.byte_size());
2135     return false;
2136   }
2137 
2138   if (VerifySharedSpaces && !r->check_region_crc(base)) {
2139     dealloc_heap_region();
2140     log_info(cds)("UseSharedSpaces: mapped heap region is corrupt");
2141     return false;
2142   }
2143 
2144   r->set_mapped_base(base);
2145 
2146   // If the requested range is different from the range allocated by GC, then
2147   // the pointers need to be patched.
2148   address mapped_start = (address) _mapped_heap_memregion.start();
2149   ptrdiff_t delta = mapped_start - requested_start;
2150   if (UseCompressedOops &&
2151       (narrow_oop_mode() != CompressedOops::mode() ||
2152        narrow_oop_shift() != CompressedOops::shift())) {
2153     _heap_pointers_need_patching = true;
2154   }
2155   if (delta != 0) {
2156     _heap_pointers_need_patching = true;
2157   }
2158   ArchiveHeapLoader::init_mapped_heap_info(mapped_start, delta, narrow_oop_shift());
2159 
2160   if (_heap_pointers_need_patching) {
2161     char* bitmap_base = map_bitmap_region();
2162     if (bitmap_base == nullptr) {
2163       log_info(cds)("CDS heap cannot be used because bitmap region cannot be mapped");
2164       dealloc_heap_region();
2165       unmap_region(MetaspaceShared::hp);
2166       _heap_pointers_need_patching = false;
2167       return false;
2168     }
2169   }
2170   log_info(cds)("Heap data mapped at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
2171                 p2i(mapped_start), _mapped_heap_memregion.byte_size());
2172   log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
2173   return true;
2174 }
2175 
2176 narrowOop FileMapInfo::encoded_heap_region_dumptime_address() {
2177   assert(UseSharedSpaces, "runtime only");
2178   assert(UseCompressedOops, "sanity");
2179   FileMapRegion* r = region_at(MetaspaceShared::hp);
2180   return CompressedOops::narrow_oop_cast(r->mapping_offset() >> narrow_oop_shift());
2181 }
2182 
2183 void FileMapInfo::patch_heap_embedded_pointers() {
2184   if (!ArchiveHeapLoader::is_mapped() || !_heap_pointers_need_patching) {
2185     return;
2186   }
2187 
2188   char* bitmap_base = map_bitmap_region();
2189   assert(bitmap_base != nullptr, "must have already been mapped");
2190 
2191   FileMapRegion* r = region_at(MetaspaceShared::hp);
2192   ArchiveHeapLoader::patch_embedded_pointers(
2193       this, _mapped_heap_memregion,
2194       (address)(region_at(MetaspaceShared::bm)->mapped_base()) + r->oopmap_offset(),
2195       r->oopmap_size_in_bits());
2196 }
2197 
2198 void FileMapInfo::fixup_mapped_heap_region() {
2199   if (ArchiveHeapLoader::is_mapped()) {
2200     assert(!_mapped_heap_memregion.is_empty(), "sanity");
2201 
2202     // Populate the archive regions' G1BlockOffsetTableParts. That ensures
2203     // fast G1BlockOffsetTablePart::block_start operations for any given address
2204     // within the archive regions when trying to find start of an object
2205     // (e.g. during card table scanning).
2206     G1CollectedHeap::heap()->populate_archive_regions_bot_part(_mapped_heap_memregion);
2207   }
2208 }
2209 
2210 // dealloc the archive regions from java heap
2211 void FileMapInfo::dealloc_heap_region() {
2212   G1CollectedHeap::heap()->dealloc_archive_regions(_mapped_heap_memregion);
2213 }
2214 #endif // INCLUDE_CDS_JAVA_HEAP
2215 
2216 void FileMapInfo::unmap_regions(int regions[], int num_regions) {
2217   for (int r = 0; r < num_regions; r++) {
2218     int idx = regions[r];
2219     unmap_region(idx);
2220   }
2221 }
2222 
2223 // Unmap a memory region in the address space.
2224 
2225 void FileMapInfo::unmap_region(int i) {
2226   FileMapRegion* r = region_at(i);
2227   char* mapped_base = r->mapped_base();
2228   size_t size = r->used_aligned();
2229 
2230   if (mapped_base != nullptr) {
2231     if (size > 0 && r->mapped_from_file()) {
2232       log_info(cds)("Unmapping region #%d at base " INTPTR_FORMAT " (%s)", i, p2i(mapped_base),
2233                     shared_region_name[i]);
2234       if (!os::unmap_memory(mapped_base, size)) {
2235         fatal("os::unmap_memory failed");
2236       }
2237     }
2238     r->set_mapped_base(nullptr);
2239   }
2240 }
2241 
2242 void FileMapInfo::assert_mark(bool check) {
2243   if (!check) {
2244     MetaspaceShared::unrecoverable_loading_error("Mark mismatch while restoring from shared file.");
2245   }
2246 }
2247 
2248 FileMapInfo* FileMapInfo::_current_info = nullptr;
2249 FileMapInfo* FileMapInfo::_dynamic_archive_info = nullptr;
2250 bool FileMapInfo::_heap_pointers_need_patching = false;
2251 SharedPathTable FileMapInfo::_shared_path_table;
2252 bool FileMapInfo::_validating_shared_path_table = false;
2253 bool FileMapInfo::_memory_mapping_failed = false;
2254 GrowableArray<const char*>* FileMapInfo::_non_existent_class_paths = nullptr;
2255 
2256 // Open the shared archive file, read and validate the header
2257 // information (version, boot classpath, etc.). If initialization
2258 // fails, shared spaces are disabled and the file is closed.
2259 //
2260 // Validation of the archive is done in two steps:
2261 //
2262 // [1] validate_header() - done here.
2263 // [2] validate_shared_path_table - this is done later, because the table is in the RW
2264 //     region of the archive, which is not mapped yet.
2265 bool FileMapInfo::initialize() {
2266   assert(UseSharedSpaces, "UseSharedSpaces expected.");
2267   assert(Arguments::has_jimage(), "The shared archive file cannot be used with an exploded module build.");
2268 
2269   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2270     // CDS assumes that no classes resolved in vmClasses::resolve_all()
2271     // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
2272     // during the JVMTI "early" stage, so we can still use CDS if
2273     // JvmtiExport::has_early_class_hook_env() is false.
2274     log_info(cds)("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
2275     return false;
2276   }
2277 
2278   if (!open_for_read() || !init_from_file(_fd) || !validate_header()) {
2279     if (_is_static) {
2280       log_info(cds)("Initialize static archive failed.");
2281       return false;
2282     } else {
2283       log_info(cds)("Initialize dynamic archive failed.");
2284       if (AutoCreateSharedArchive) {
2285         CDSConfig::enable_dumping_dynamic_archive();
2286         ArchiveClassesAtExit = CDSConfig::dynamic_archive_path();
2287       }
2288       return false;
2289     }
2290   }
2291 
2292   return true;
2293 }
2294 
2295 // The 2 core spaces are RW->RO
2296 FileMapRegion* FileMapInfo::first_core_region() const {
2297   return region_at(MetaspaceShared::rw);
2298 }
2299 
2300 FileMapRegion* FileMapInfo::last_core_region() const {
2301   return region_at(MetaspaceShared::ro);
2302 }
2303 
2304 void FileMapInfo::print(outputStream* st) const {
2305   header()->print(st);
2306   if (!is_static()) {
2307     dynamic_header()->print(st);
2308   }
2309 }
2310 
2311 void FileMapHeader::set_as_offset(char* p, size_t *offset) {
2312   *offset = ArchiveBuilder::current()->any_to_offset((address)p);
2313 }
2314 
2315 int FileMapHeader::compute_crc() {
2316   char* start = (char*)this;
2317   // start computing from the field after _header_size to end of base archive name.
2318   char* buf = (char*)&(_generic_header._header_size) + sizeof(_generic_header._header_size);
2319   size_t sz = header_size() - (buf - start);
2320   int crc = ClassLoader::crc32(0, buf, (jint)sz);
2321   return crc;
2322 }
2323 
2324 // This function should only be called during run time with UseSharedSpaces enabled.
2325 bool FileMapHeader::validate() {
2326   if (_obj_alignment != ObjectAlignmentInBytes) {
2327     log_info(cds)("The shared archive file's ObjectAlignmentInBytes of %d"
2328                   " does not equal the current ObjectAlignmentInBytes of %d.",
2329                   _obj_alignment, ObjectAlignmentInBytes);
2330     return false;
2331   }
2332   if (_compact_strings != CompactStrings) {
2333     log_info(cds)("The shared archive file's CompactStrings setting (%s)"
2334                   " does not equal the current CompactStrings setting (%s).",
2335                   _compact_strings ? "enabled" : "disabled",
2336                   CompactStrings   ? "enabled" : "disabled");
2337     return false;
2338   }
2339 
2340   // This must be done after header validation because it might change the
2341   // header data
2342   const char* prop = Arguments::get_property("java.system.class.loader");
2343   if (prop != nullptr) {
2344     log_warning(cds)("Archived non-system classes are disabled because the "
2345             "java.system.class.loader property is specified (value = \"%s\"). "
2346             "To use archived non-system classes, this property must not be set", prop);
2347     _has_platform_or_app_classes = false;
2348   }
2349 
2350 
2351   if (!_verify_local && BytecodeVerificationLocal) {
2352     //  we cannot load boot classes, so there's no point of using the CDS archive
2353     log_info(cds)("The shared archive file's BytecodeVerificationLocal setting (%s)"
2354                                " does not equal the current BytecodeVerificationLocal setting (%s).",
2355                                _verify_local ? "enabled" : "disabled",
2356                                BytecodeVerificationLocal ? "enabled" : "disabled");
2357     return false;
2358   }
2359 
2360   // For backwards compatibility, we don't check the BytecodeVerificationRemote setting
2361   // if the archive only contains system classes.
2362   if (_has_platform_or_app_classes
2363       && !_verify_remote // we didn't verify the archived platform/app classes
2364       && BytecodeVerificationRemote) { // but we want to verify all loaded platform/app classes
2365     log_info(cds)("The shared archive file was created with less restrictive "
2366                                "verification setting than the current setting.");
2367     // Pretend that we didn't have any archived platform/app classes, so they won't be loaded
2368     // by SystemDictionaryShared.
2369     _has_platform_or_app_classes = false;
2370   }
2371 
2372   // Java agents are allowed during run time. Therefore, the following condition is not
2373   // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
2374   // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
2375   // while AllowArchivingWithJavaAgent is set during the current run.
2376   if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
2377     log_warning(cds)("The setting of the AllowArchivingWithJavaAgent is different "
2378                                "from the setting in the shared archive.");
2379     return false;
2380   }
2381 
2382   if (_allow_archiving_with_java_agent) {
2383     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
2384             "for testing purposes only and should not be used in a production environment");
2385   }
2386 
2387   log_info(cds)("Archive was created with UseCompressedOops = %d, UseCompressedClassPointers = %d",
2388                           compressed_oops(), compressed_class_pointers());
2389   if (compressed_oops() != UseCompressedOops || compressed_class_pointers() != UseCompressedClassPointers) {
2390     log_info(cds)("Unable to use shared archive.\nThe saved state of UseCompressedOops and UseCompressedClassPointers is "
2391                                "different from runtime, CDS will be disabled.");
2392     return false;
2393   }
2394 
2395   if (!_use_optimized_module_handling) {
2396     MetaspaceShared::disable_optimized_module_handling();
2397     log_info(cds)("optimized module handling: disabled because archive was created without optimized module handling");
2398   }
2399 
2400   if (is_static() && !_has_full_module_graph) {
2401     // Only the static archive can contain the full module graph.
2402     CDSConfig::disable_loading_full_module_graph("archive was created without full module graph");
2403   }
2404 
2405   return true;
2406 }
2407 
2408 bool FileMapInfo::validate_header() {
2409   if (!header()->validate()) {
2410     return false;
2411   }
2412   if (_is_static) {
2413     return true;
2414   } else {
2415     return DynamicArchive::validate(this);
2416   }
2417 }
2418 
2419 #if INCLUDE_JVMTI
2420 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = nullptr;
2421 
2422 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
2423   if (i == 0) {
2424     // index 0 corresponds to the ClassPathImageEntry which is a globally shared object
2425     // and should never be deleted.
2426     return ClassLoader::get_jrt_entry();
2427   }
2428   ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
2429   if (ent == nullptr) {
2430     SharedClassPathEntry* scpe = shared_path(i);
2431     assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
2432 
2433     const char* path = scpe->name();
2434     struct stat st;
2435     if (os::stat(path, &st) != 0) {
2436       char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2437       jio_snprintf(msg, strlen(path) + 127, "error in finding JAR file %s", path);
2438       THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2439     } else {
2440       ent = ClassLoader::create_class_path_entry(THREAD, path, &st, false, false);
2441       if (ent == nullptr) {
2442         char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2443         jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
2444         THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2445       }
2446     }
2447 
2448     MutexLocker mu(THREAD, CDSClassFileStream_lock);
2449     if (_classpath_entries_for_jvmti[i] == nullptr) {
2450       _classpath_entries_for_jvmti[i] = ent;
2451     } else {
2452       // Another thread has beat me to creating this entry
2453       delete ent;
2454       ent = _classpath_entries_for_jvmti[i];
2455     }
2456   }
2457 
2458   return ent;
2459 }
2460 
2461 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
2462   int path_index = ik->shared_classpath_index();
2463   assert(path_index >= 0, "should be called for shared built-in classes only");
2464   assert(path_index < (int)get_number_of_shared_paths(), "sanity");
2465 
2466   ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
2467   assert(cpe != nullptr, "must be");
2468 
2469   Symbol* name = ik->name();
2470   const char* const class_name = name->as_C_string();
2471   const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
2472                                                                       name->utf8_length());
2473   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
2474   ClassFileStream* cfs = cpe->open_stream_for_loader(THREAD, file_name, loader_data);
2475   assert(cfs != nullptr, "must be able to read the classfile data of shared classes for built-in loaders.");
2476   log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
2477                         cfs->source(), cfs->length());
2478   return cfs;
2479 }
2480 
2481 #endif