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 = CDSConfig::is_using_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("- _heap_oopmap_start_pos:         " SIZE_FORMAT, _heap_oopmap_start_pos);
 293   st->print_cr("- _heap_ptrmap_start_pos:         " SIZE_FORMAT, _heap_ptrmap_start_pos);
 294   st->print_cr("- allow_archiving_with_java_agent:%d", _allow_archiving_with_java_agent);
 295   st->print_cr("- use_optimized_module_handling:  %d", _use_optimized_module_handling);
 296   st->print_cr("- has_full_module_graph           %d", _has_full_module_graph);


 297   st->print_cr("- ptrmap_size_in_bits:            " SIZE_FORMAT, _ptrmap_size_in_bits);
 298 }
 299 
 300 void SharedClassPathEntry::init_as_non_existent(const char* path, TRAPS) {
 301   _type = non_existent_entry;
 302   set_name(path, CHECK);
 303 }
 304 
 305 void SharedClassPathEntry::init(bool is_modules_image,
 306                                 bool is_module_path,
 307                                 ClassPathEntry* cpe, TRAPS) {
 308   assert(CDSConfig::is_dumping_archive(), "sanity");
 309   _timestamp = 0;
 310   _filesize  = 0;
 311   _from_class_path_attr = false;
 312 
 313   struct stat st;
 314   if (os::stat(cpe->name(), &st) == 0) {
 315     if ((st.st_mode & S_IFMT) == S_IFDIR) {
 316       _type = dir_entry;
 317     } else {
 318       // The timestamp of the modules_image is not checked at runtime.
 319       if (is_modules_image) {
 320         _type = modules_image_entry;
 321       } else {
 322         _type = jar_entry;
 323         _timestamp = st.st_mtime;
 324         _from_class_path_attr = cpe->from_class_path_attr();
 325       }
 326       _filesize = st.st_size;
 327       _is_module_path = is_module_path;
 328     }
 329   } else {
 330     // The file/dir must exist, or it would not have been added
 331     // into ClassLoader::classpath_entry().
 332     //
 333     // If we can't access a jar file in the boot path, then we can't
 334     // make assumptions about where classes get loaded from.
 335     log_error(cds)("Unable to open file %s.", cpe->name());
 336     MetaspaceShared::unrecoverable_loading_error();
 337   }
 338 
 339   // No need to save the name of the module file, as it will be computed at run time
 340   // to allow relocation of the JDK directory.
 341   const char* name = is_modules_image  ? "" : cpe->name();
 342   set_name(name, CHECK);
 343 }
 344 
 345 void SharedClassPathEntry::set_name(const char* name, TRAPS) {
 346   size_t len = strlen(name) + 1;
 347   _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, CHECK);
 348   strcpy(_name->data(), name);
 349 }
 350 
 351 void SharedClassPathEntry::copy_from(SharedClassPathEntry* ent, ClassLoaderData* loader_data, TRAPS) {
 352   assert(ent != nullptr, "sanity");
 353   _type = ent->_type;
 354   _is_module_path = ent->_is_module_path;
 355   _timestamp = ent->_timestamp;
 356   _filesize = ent->_filesize;
 357   _from_class_path_attr = ent->_from_class_path_attr;
 358   set_name(ent->name(), CHECK);
 359 
 360   if (ent->is_jar() && ent->manifest() != nullptr) {
 361     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 362                                                     ent->manifest_size(),
 363                                                     CHECK);
 364     char* p = (char*)(buf->data());
 365     memcpy(p, ent->manifest(), ent->manifest_size());
 366     set_manifest(buf);
 367   }
 368 }
 369 
 370 const char* SharedClassPathEntry::name() const {
 371   if (UseSharedSpaces && is_modules_image()) {
 372     // In order to validate the runtime modules image file size against the archived
 373     // size information, we need to obtain the runtime modules image path. The recorded
 374     // dump time modules image path in the archive may be different from the runtime path
 375     // if the JDK image has beed moved after generating the archive.
 376     return ClassLoader::get_jrt_entry()->name();
 377   } else {
 378     return _name->data();
 379   }
 380 }
 381 
 382 bool SharedClassPathEntry::validate(bool is_class_path) const {
 383   assert(UseSharedSpaces, "runtime only");
 384 
 385   struct stat st;
 386   const char* name = this->name();
 387 
 388   bool ok = true;
 389   log_info(class, path)("checking shared classpath entry: %s", name);
 390   if (os::stat(name, &st) != 0 && is_class_path) {
 391     // If the archived module path entry does not exist at runtime, it is not fatal
 392     // (no need to invalid the shared archive) because the shared runtime visibility check
 393     // filters out any archived module classes that do not have a matching runtime
 394     // module path location.
 395     log_warning(cds)("Required classpath entry does not exist: %s", name);
 396     ok = false;
 397   } else if (is_dir()) {
 398     if (!os::dir_is_empty(name)) {
 399       log_warning(cds)("directory is not empty: %s", name);
 400       ok = false;
 401     }
 402   } else {
 403     bool size_differs = _filesize != st.st_size;
 404     bool time_differs = has_timestamp() && _timestamp != st.st_mtime;
 405     if (time_differs || size_differs) {
 406       ok = false;
 407       if (PrintSharedArchiveAndExit) {
 408         log_warning(cds)(time_differs ? "Timestamp mismatch" : "File size mismatch");
 409       } else {
 410         const char* bad_file_msg = "This file is not the one used while building the shared archive file:";
 411         log_warning(cds)("%s %s", bad_file_msg, name);
 412         if (!log_is_enabled(Info, cds)) {
 413           log_warning(cds)("%s %s", bad_file_msg, name);
 414         }
 415         if (time_differs) {
 416           log_warning(cds)("%s timestamp has changed.", name);
 417         }
 418         if (size_differs) {
 419           log_warning(cds)("%s size has changed.", name);
 420         }
 421       }
 422     }
 423   }
 424 
 425   if (PrintSharedArchiveAndExit && !ok) {
 426     // If PrintSharedArchiveAndExit is enabled, don't report failure to the
 427     // caller. Please see above comments for more details.
 428     ok = true;
 429     MetaspaceShared::set_archive_loading_failed();
 430   }
 431   return ok;
 432 }
 433 
 434 bool SharedClassPathEntry::check_non_existent() const {
 435   assert(_type == non_existent_entry, "must be");
 436   log_info(class, path)("should be non-existent: %s", name());
 437   struct stat st;
 438   if (os::stat(name(), &st) != 0) {
 439     log_info(class, path)("ok");
 440     return true; // file doesn't exist
 441   } else {
 442     return false;
 443   }
 444 }
 445 
 446 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
 447   it->push(&_name);
 448   it->push(&_manifest);
 449 }
 450 
 451 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
 452   it->push(&_entries);
 453 }
 454 
 455 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, TRAPS) {
 456   const int num_entries =
 457     ClassLoader::num_boot_classpath_entries() +
 458     ClassLoader::num_app_classpath_entries() +
 459     ClassLoader::num_module_path_entries() +
 460     FileMapInfo::num_non_existent_class_paths();
 461   _entries = MetadataFactory::new_array<SharedClassPathEntry*>(loader_data, num_entries, CHECK);
 462   for (int i = 0; i < num_entries; i++) {
 463     SharedClassPathEntry* ent =
 464       new (loader_data, SharedClassPathEntry::size(), MetaspaceObj::SharedClassPathEntryType, THREAD) SharedClassPathEntry;
 465     _entries->at_put(i, ent);
 466   }
 467 }
 468 
 469 void FileMapInfo::allocate_shared_path_table(TRAPS) {
 470   assert(CDSConfig::is_dumping_archive(), "sanity");
 471 
 472   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 473   ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
 474 
 475   assert(jrt != nullptr,
 476          "No modular java runtime image present when allocating the CDS classpath entry table");
 477 
 478   _shared_path_table.dumptime_init(loader_data, CHECK);
 479 
 480   // 1. boot class path
 481   int i = 0;
 482   i = add_shared_classpaths(i, "boot",   jrt, CHECK);
 483   i = add_shared_classpaths(i, "app",    ClassLoader::app_classpath_entries(), CHECK);
 484   i = add_shared_classpaths(i, "module", ClassLoader::module_path_entries(), CHECK);
 485 
 486   for (int x = 0; x < num_non_existent_class_paths(); x++, i++) {
 487     const char* path = _non_existent_class_paths->at(x);
 488     shared_path(i)->init_as_non_existent(path, CHECK);
 489   }
 490 
 491   assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
 492 }
 493 
 494 int FileMapInfo::add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS) {
 495   while (cpe != nullptr) {
 496     bool is_jrt = (cpe == ClassLoader::get_jrt_entry());
 497     bool is_module_path = i >= ClassLoaderExt::app_module_paths_start_index();
 498     const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
 499     log_info(class, path)("add %s shared path (%s) %s", which, type, cpe->name());
 500     SharedClassPathEntry* ent = shared_path(i);
 501     ent->init(is_jrt, is_module_path, cpe, CHECK_0);
 502     if (cpe->is_jar_file()) {
 503       update_jar_manifest(cpe, ent, CHECK_0);
 504     }
 505     if (is_jrt) {
 506       cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
 507     } else {
 508       cpe = cpe->next();
 509     }
 510     i++;
 511   }
 512 
 513   return i;
 514 }
 515 
 516 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
 517   assert(CDSConfig::is_dumping_archive(), "sanity");
 518 
 519   bool has_nonempty_dir = false;
 520 
 521   int last = _shared_path_table.size() - 1;
 522   if (last > ClassLoaderExt::max_used_path_index()) {
 523      // no need to check any path beyond max_used_path_index
 524      last = ClassLoaderExt::max_used_path_index();
 525   }
 526 
 527   for (int i = 0; i <= last; i++) {
 528     SharedClassPathEntry *e = shared_path(i);
 529     if (e->is_dir()) {
 530       const char* path = e->name();
 531       if (!os::dir_is_empty(path)) {
 532         log_error(cds)("Error: non-empty directory '%s'", path);
 533         has_nonempty_dir = true;
 534       }
 535     }
 536   }
 537 
 538   if (has_nonempty_dir) {
 539     ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", nullptr);
 540   }
 541 }
 542 
 543 void FileMapInfo::record_non_existent_class_path_entry(const char* path) {
 544   assert(CDSConfig::is_dumping_archive(), "sanity");
 545   log_info(class, path)("non-existent Class-Path entry %s", path);
 546   if (_non_existent_class_paths == nullptr) {
 547     _non_existent_class_paths = new (mtClass) GrowableArray<const char*>(10, mtClass);
 548   }
 549   _non_existent_class_paths->append(os::strdup(path));
 550 }
 551 
 552 int FileMapInfo::num_non_existent_class_paths() {
 553   assert(CDSConfig::is_dumping_archive(), "sanity");
 554   if (_non_existent_class_paths != nullptr) {
 555     return _non_existent_class_paths->length();
 556   } else {
 557     return 0;
 558   }
 559 }
 560 
 561 int FileMapInfo::get_module_shared_path_index(Symbol* location) {



 562   if (location->starts_with("jrt:", 4) && get_number_of_shared_paths() > 0) {
 563     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 564     return 0;
 565   }
 566 
 567   if (ClassLoaderExt::app_module_paths_start_index() >= get_number_of_shared_paths()) {
 568     // The archive(s) were created without --module-path option
 569     return -1;
 570   }
 571 
 572   if (!location->starts_with("file:", 5)) {
 573     return -1;
 574   }
 575 
 576   // skip_uri_protocol was also called during dump time -- see ClassLoaderExt::process_module_table()
 577   ResourceMark rm;
 578   const char* file = ClassLoader::skip_uri_protocol(location->as_C_string());
 579   for (int i = ClassLoaderExt::app_module_paths_start_index(); i < get_number_of_shared_paths(); i++) {
 580     SharedClassPathEntry* ent = shared_path(i);
 581     if (!ent->is_non_existent()) {
 582       assert(ent->in_named_module(), "must be");
 583       bool cond = strcmp(file, ent->name()) == 0;
 584       log_debug(class, path)("get_module_shared_path_index (%d) %s : %s = %s", i,
 585                              location->as_C_string(), ent->name(), cond ? "same" : "different");
 586       if (cond) {
 587         return i;
 588       }
 589     }
 590   }
 591 
 592   return -1;
 593 }
 594 
 595 class ManifestStream: public ResourceObj {
 596   private:
 597   u1*   _buffer_start; // Buffer bottom
 598   u1*   _buffer_end;   // Buffer top (one past last element)
 599   u1*   _current;      // Current buffer position
 600 
 601  public:
 602   // Constructor
 603   ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
 604                                            _current(buffer) {
 605     _buffer_end = buffer + length;
 606   }
 607 
 608   static bool is_attr(u1* attr, const char* name) {
 609     return strncmp((const char*)attr, name, strlen(name)) == 0;
 610   }
 611 
 612   static char* copy_attr(u1* value, size_t len) {
 613     char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
 614     strncpy(buf, (char*)value, len);
 615     buf[len] = 0;
 616     return buf;
 617   }
 618 };
 619 
 620 void FileMapInfo::update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
 621   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 622   ResourceMark rm(THREAD);
 623   jint manifest_size;
 624 
 625   assert(cpe->is_jar_file() && ent->is_jar(), "the shared class path entry is not a JAR file");
 626   char* manifest = ClassLoaderExt::read_manifest(THREAD, cpe, &manifest_size);
 627   if (manifest != nullptr) {
 628     ManifestStream* stream = new ManifestStream((u1*)manifest,
 629                                                 manifest_size);
 630     // Copy the manifest into the shared archive
 631     manifest = ClassLoaderExt::read_raw_manifest(THREAD, cpe, &manifest_size);
 632     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 633                                                     manifest_size,
 634                                                     CHECK);
 635     char* p = (char*)(buf->data());
 636     memcpy(p, manifest, manifest_size);
 637     ent->set_manifest(buf);
 638   }
 639 }
 640 
 641 char* FileMapInfo::skip_first_path_entry(const char* path) {
 642   size_t path_sep_len = strlen(os::path_separator());
 643   char* p = strstr((char*)path, os::path_separator());
 644   if (p != nullptr) {
 645     debug_only( {
 646       size_t image_name_len = strlen(MODULES_IMAGE_NAME);
 647       assert(strncmp(p - image_name_len, MODULES_IMAGE_NAME, image_name_len) == 0,
 648              "first entry must be the modules image");
 649     } );
 650     p += path_sep_len;
 651   } else {
 652     debug_only( {
 653       assert(ClassLoader::string_ends_with(path, MODULES_IMAGE_NAME),
 654              "first entry must be the modules image");
 655     } );
 656   }
 657   return p;
 658 }
 659 
 660 int FileMapInfo::num_paths(const char* path) {
 661   if (path == nullptr) {
 662     return 0;
 663   }
 664   int npaths = 1;
 665   char* p = (char*)path;
 666   while (p != nullptr) {
 667     char* prev = p;
 668     p = strstr((char*)p, os::path_separator());
 669     if (p != nullptr) {
 670       p++;
 671       // don't count empty path
 672       if ((p - prev) > 1) {
 673        npaths++;
 674       }
 675     }
 676   }
 677   return npaths;
 678 }
 679 
 680 // Returns true if a path within the paths exists and has non-zero size.
 681 bool FileMapInfo::check_paths_existence(const char* paths) {
 682   ClasspathStream cp_stream(paths);
 683   bool exist = false;
 684   struct stat st;
 685   while (cp_stream.has_next()) {
 686     const char* path = cp_stream.get_next();
 687     if (os::stat(path, &st) == 0 && st.st_size > 0) {
 688       exist = true;
 689       break;
 690     }
 691   }
 692   return exist;
 693 }
 694 
 695 GrowableArray<const char*>* FileMapInfo::create_dumptime_app_classpath_array() {
 696   assert(CDSConfig::is_dumping_archive(), "sanity");
 697   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 698   ClassPathEntry* cpe = ClassLoader::app_classpath_entries();
 699   while (cpe != nullptr) {
 700     path_array->append(cpe->name());
 701     cpe = cpe->next();
 702   }
 703   return path_array;
 704 }
 705 
 706 GrowableArray<const char*>* FileMapInfo::create_path_array(const char* paths) {
 707   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 708   JavaThread* current = JavaThread::current();
 709   ClasspathStream cp_stream(paths);
 710   bool non_jar_in_cp = header()->has_non_jar_in_classpath();
 711   while (cp_stream.has_next()) {
 712     const char* path = cp_stream.get_next();
 713     if (!non_jar_in_cp) {
 714       struct stat st;
 715       if (os::stat(path, &st) == 0) {
 716         path_array->append(path);
 717       }
 718     } else {
 719       const char* canonical_path = ClassLoader::get_canonical_path(path, current);
 720       if (canonical_path != nullptr) {
 721         char* error_msg = nullptr;
 722         jzfile* zip = ClassLoader::open_zip_file(canonical_path, &error_msg, current);
 723         if (zip != nullptr && error_msg == nullptr) {
 724           path_array->append(path);
 725         }
 726       }
 727     }
 728   }
 729   return path_array;
 730 }
 731 
 732 bool FileMapInfo::classpath_failure(const char* msg, const char* name) {
 733   ClassLoader::trace_class_path(msg, name);
 734   if (PrintSharedArchiveAndExit) {
 735     MetaspaceShared::set_archive_loading_failed();
 736   }
 737   return false;
 738 }
 739 
 740 unsigned int FileMapInfo::longest_common_app_classpath_prefix_len(int num_paths,
 741                                                                   GrowableArray<const char*>* rp_array) {
 742   if (num_paths == 0) {
 743     return 0;
 744   }
 745   unsigned int pos;
 746   for (pos = 0; ; pos++) {
 747     for (int i = 0; i < num_paths; i++) {
 748       if (rp_array->at(i)[pos] != '\0' && rp_array->at(i)[pos] == rp_array->at(0)[pos]) {
 749         continue;
 750       }
 751       // search backward for the pos before the file separator char
 752       while (pos > 0) {
 753         if (rp_array->at(0)[--pos] == *os::file_separator()) {
 754           return pos + 1;
 755         }
 756       }
 757       return 0;
 758     }
 759   }
 760   return 0;
 761 }
 762 
 763 bool FileMapInfo::check_paths(int shared_path_start_idx, int num_paths, GrowableArray<const char*>* rp_array,
 764                               unsigned int dumptime_prefix_len, unsigned int runtime_prefix_len) {
 765   int i = 0;
 766   int j = shared_path_start_idx;
 767   while (i < num_paths) {
 768     while (shared_path(j)->from_class_path_attr()) {
 769       // shared_path(j) was expanded from the JAR file attribute "Class-Path:"
 770       // during dump time. It's not included in the -classpath VM argument.
 771       j++;
 772     }
 773     assert(strlen(shared_path(j)->name()) > (size_t)dumptime_prefix_len, "sanity");
 774     const char* dumptime_path = shared_path(j)->name() + dumptime_prefix_len;
 775     assert(strlen(rp_array->at(i)) > (size_t)runtime_prefix_len, "sanity");
 776     const char* runtime_path = rp_array->at(i)  + runtime_prefix_len;
 777     if (!os::same_files(dumptime_path, runtime_path)) {
 778       return true;
 779     }
 780     i++;
 781     j++;
 782   }
 783   return false;
 784 }
 785 
 786 bool FileMapInfo::validate_boot_class_paths() {
 787   //
 788   // - Archive contains boot classes only - relaxed boot path check:
 789   //   Extra path elements appended to the boot path at runtime are allowed.
 790   //
 791   // - Archive contains application or platform classes - strict boot path check:
 792   //   Validate the entire runtime boot path, which must be compatible
 793   //   with the dump time boot path. Appending boot path at runtime is not
 794   //   allowed.
 795   //
 796 
 797   // The first entry in boot path is the modules_image (guaranteed by
 798   // ClassLoader::setup_boot_search_path()). Skip the first entry. The
 799   // path of the runtime modules_image may be different from the dump
 800   // time path (e.g. the JDK image is copied to a different location
 801   // after generating the shared archive), which is acceptable. For most
 802   // common cases, the dump time boot path might contain modules_image only.
 803   char* runtime_boot_path = Arguments::get_boot_class_path();
 804   char* rp = skip_first_path_entry(runtime_boot_path);
 805   assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 806   int dp_len = header()->app_class_paths_start_index() - 1; // ignore the first path to the module image
 807   bool mismatch = false;
 808 
 809   bool relaxed_check = !header()->has_platform_or_app_classes();
 810   if (dp_len == 0 && rp == nullptr) {
 811     return true;   // ok, both runtime and dump time boot paths have modules_images only
 812   } else if (dp_len == 0 && rp != nullptr) {
 813     if (relaxed_check) {
 814       return true;   // ok, relaxed check, runtime has extra boot append path entries
 815     } else {
 816       ResourceMark rm;
 817       if (check_paths_existence(rp)) {
 818         // If a path exists in the runtime boot paths, it is considered a mismatch
 819         // since there's no boot path specified during dump time.
 820         mismatch = true;
 821       }
 822     }
 823   } else if (dp_len > 0 && rp != nullptr) {
 824     int num;
 825     ResourceMark rm;
 826     GrowableArray<const char*>* rp_array = create_path_array(rp);
 827     int rp_len = rp_array->length();
 828     if (rp_len >= dp_len) {
 829       if (relaxed_check) {
 830         // only check the leading entries in the runtime boot path, up to
 831         // the length of the dump time boot path
 832         num = dp_len;
 833       } else {
 834         // check the full runtime boot path, must match with dump time
 835         num = rp_len;
 836       }
 837       mismatch = check_paths(1, num, rp_array, 0, 0);
 838     } else {
 839       // create_path_array() ignores non-existing paths. Although the dump time and runtime boot classpath lengths
 840       // are the same initially, after the call to create_path_array(), the runtime boot classpath length could become
 841       // shorter. We consider boot classpath mismatch in this case.
 842       mismatch = true;
 843     }
 844   }
 845 
 846   if (mismatch) {
 847     // The paths are different
 848     return classpath_failure("[BOOT classpath mismatch, actual =", runtime_boot_path);
 849   }
 850   return true;
 851 }
 852 
 853 bool FileMapInfo::validate_app_class_paths(int shared_app_paths_len) {
 854   const char *appcp = Arguments::get_appclasspath();
 855   assert(appcp != nullptr, "null app classpath");
 856   int rp_len = num_paths(appcp);
 857   bool mismatch = false;
 858   if (rp_len < shared_app_paths_len) {
 859     return classpath_failure("Run time APP classpath is shorter than the one at dump time: ", appcp);
 860   }
 861   if (shared_app_paths_len != 0 && rp_len != 0) {
 862     // Prefix is OK: E.g., dump with -cp foo.jar, but run with -cp foo.jar:bar.jar.
 863     ResourceMark rm;
 864     GrowableArray<const char*>* rp_array = create_path_array(appcp);
 865     if (rp_array->length() == 0) {
 866       // None of the jar file specified in the runtime -cp exists.
 867       return classpath_failure("None of the jar file specified in the runtime -cp exists: -Djava.class.path=", appcp);
 868     }
 869     if (rp_array->length() < shared_app_paths_len) {
 870       // create_path_array() ignores non-existing paths. Although the dump time and runtime app classpath lengths
 871       // are the same initially, after the call to create_path_array(), the runtime app classpath length could become
 872       // shorter. We consider app classpath mismatch in this case.
 873       return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 874     }
 875 
 876     // Handling of non-existent entries in the classpath: we eliminate all the non-existent
 877     // entries from both the dump time classpath (ClassLoader::update_class_path_entry_list)
 878     // and the runtime classpath (FileMapInfo::create_path_array), and check the remaining
 879     // entries. E.g.:
 880     //
 881     // dump : -cp a.jar:NE1:NE2:b.jar  -> a.jar:b.jar -> recorded in archive.
 882     // run 1: -cp NE3:a.jar:NE4:b.jar  -> a.jar:b.jar -> matched
 883     // run 2: -cp x.jar:NE4:b.jar      -> x.jar:b.jar -> mismatched
 884 
 885     int j = header()->app_class_paths_start_index();
 886     mismatch = check_paths(j, shared_app_paths_len, rp_array, 0, 0);
 887     if (mismatch) {
 888       // To facilitate app deployment, we allow the JAR files to be moved *together* to
 889       // a different location, as long as they are still stored under the same directory
 890       // structure. E.g., the following is OK.
 891       //     java -Xshare:dump -cp /a/Foo.jar:/a/b/Bar.jar  ...
 892       //     java -Xshare:auto -cp /x/y/Foo.jar:/x/y/b/Bar.jar  ...
 893       unsigned int dumptime_prefix_len = header()->common_app_classpath_prefix_size();
 894       unsigned int runtime_prefix_len = longest_common_app_classpath_prefix_len(shared_app_paths_len, rp_array);
 895       if (dumptime_prefix_len != 0 || runtime_prefix_len != 0) {
 896         log_info(class, path)("LCP length for app classpath (dumptime: %u, runtime: %u)",
 897                               dumptime_prefix_len, runtime_prefix_len);
 898         mismatch = check_paths(j, shared_app_paths_len, rp_array,
 899                                dumptime_prefix_len, runtime_prefix_len);
 900       }
 901       if (mismatch) {
 902         return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 903       }
 904     }
 905   }
 906   return true;
 907 }
 908 
 909 void FileMapInfo::log_paths(const char* msg, int start_idx, int end_idx) {
 910   LogTarget(Info, class, path) lt;
 911   if (lt.is_enabled()) {
 912     LogStream ls(lt);
 913     ls.print("%s", msg);
 914     const char* prefix = "";
 915     for (int i = start_idx; i < end_idx; i++) {
 916       ls.print("%s%s", prefix, shared_path(i)->name());
 917       prefix = os::path_separator();
 918     }
 919     ls.cr();
 920   }
 921 }
 922 
 923 bool FileMapInfo::check_module_paths() {
 924   const char* rp = Arguments::get_property("jdk.module.path");
 925   int num_paths = CDSConfig::num_archives(rp);
 926   if (num_paths != header()->num_module_paths()) {
 927     return false;
 928   }
 929   ResourceMark rm;
 930   GrowableArray<const char*>* rp_array = create_path_array(rp);
 931   return check_paths(header()->app_module_paths_start_index(), num_paths, rp_array, 0, 0);
 932 }
 933 
 934 bool FileMapInfo::validate_shared_path_table() {
 935   assert(UseSharedSpaces, "runtime only");
 936 
 937   _validating_shared_path_table = true;
 938 
 939   // Load the shared path table info from the archive header
 940   _shared_path_table = header()->shared_path_table();
 941   if (CDSConfig::is_dumping_dynamic_archive()) {
 942     // Only support dynamic dumping with the usage of the default CDS archive
 943     // or a simple base archive.
 944     // If the base layer archive contains additional path component besides
 945     // the runtime image and the -cp, dynamic dumping is disabled.
 946     //
 947     // When dynamic archiving is enabled, the _shared_path_table is overwritten
 948     // to include the application path and stored in the top layer archive.
 949     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 950     if (header()->app_class_paths_start_index() > 1) {
 951       CDSConfig::disable_dumping_dynamic_archive();
 952       log_warning(cds)(
 953         "Dynamic archiving is disabled because base layer archive has appended boot classpath");
 954     }
 955     if (header()->num_module_paths() > 0) {
 956       if (!check_module_paths()) {
 957         CDSConfig::disable_dumping_dynamic_archive();
 958         log_warning(cds)(
 959           "Dynamic archiving is disabled because base layer archive has a different module path");
 960       }
 961     }
 962   }
 963 
 964   log_paths("Expecting BOOT path=", 0, header()->app_class_paths_start_index());
 965   log_paths("Expecting -Djava.class.path=", header()->app_class_paths_start_index(), header()->app_module_paths_start_index());
 966 
 967   int module_paths_start_index = header()->app_module_paths_start_index();
 968   int shared_app_paths_len = 0;
 969 
 970   // validate the path entries up to the _max_used_path_index
 971   for (int i=0; i < header()->max_used_path_index() + 1; i++) {
 972     if (i < module_paths_start_index) {
 973       if (shared_path(i)->validate()) {
 974         // Only count the app class paths not from the "Class-path" attribute of a jar manifest.
 975         if (!shared_path(i)->from_class_path_attr() && i >= header()->app_class_paths_start_index()) {
 976           shared_app_paths_len++;
 977         }
 978         log_info(class, path)("ok");
 979       } else {
 980         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
 981           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 982         }
 983         return false;
 984       }
 985     } else if (i >= module_paths_start_index) {
 986       if (shared_path(i)->validate(false /* not a class path entry */)) {
 987         log_info(class, path)("ok");
 988       } else {
 989         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
 990           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 991         }
 992         return false;
 993       }
 994     }
 995   }
 996 
 997   if (header()->max_used_path_index() == 0) {
 998     // default archive only contains the module image in the bootclasspath
 999     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
1000   } else {
1001     if (!validate_boot_class_paths() || !validate_app_class_paths(shared_app_paths_len)) {
1002       const char* mismatch_msg = "shared class paths mismatch";
1003       const char* hint_msg = log_is_enabled(Info, class, path) ?
1004           "" : " (hint: enable -Xlog:class+path=info to diagnose the failure)";
1005       if (RequireSharedSpaces) {
1006         log_error(cds)("%s%s", mismatch_msg, hint_msg);
1007         MetaspaceShared::unrecoverable_loading_error();
1008       } else {
1009         log_warning(cds)("%s%s", mismatch_msg, hint_msg);
1010       }
1011       return false;
1012     }
1013   }
1014 
1015   validate_non_existent_class_paths();
1016 
1017   _validating_shared_path_table = false;
1018 
1019 #if INCLUDE_JVMTI
1020   if (_classpath_entries_for_jvmti != nullptr) {
1021     os::free(_classpath_entries_for_jvmti);
1022   }
1023   size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
1024   _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
1025   memset((void*)_classpath_entries_for_jvmti, 0, sz);
1026 #endif
1027 
1028   return true;
1029 }
1030 
1031 void FileMapInfo::validate_non_existent_class_paths() {
1032   // All of the recorded non-existent paths came from the Class-Path: attribute from the JAR
1033   // files on the app classpath. If any of these are found to exist during runtime,
1034   // it will change how classes are loading for the app loader. For safety, disable
1035   // loading of archived platform/app classes (currently there's no way to disable just the
1036   // app classes).
1037 
1038   assert(UseSharedSpaces, "runtime only");
1039   for (int i = header()->app_module_paths_start_index() + header()->num_module_paths();
1040        i < get_number_of_shared_paths();
1041        i++) {
1042     SharedClassPathEntry* ent = shared_path(i);
1043     if (!ent->check_non_existent()) {
1044       log_warning(cds)("Archived non-system classes are disabled because the "
1045               "file %s exists", ent->name());
1046       header()->set_has_platform_or_app_classes(false);
1047     }
1048   }
1049 }
1050 
1051 // A utility class for reading/validating the GenericCDSFileMapHeader portion of
1052 // a CDS archive's header. The file header of all CDS archives with versions from
1053 // CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION (12) are guaranteed to always start
1054 // with GenericCDSFileMapHeader. This makes it possible to read important information
1055 // from a CDS archive created by a different version of HotSpot, so that we can
1056 // automatically regenerate the archive as necessary (JDK-8261455).
1057 class FileHeaderHelper {
1058   int _fd;
1059   bool _is_valid;
1060   bool _is_static;
1061   GenericCDSFileMapHeader* _header;
1062   const char* _archive_name;
1063   const char* _base_archive_name;
1064 
1065 public:
1066   FileHeaderHelper(const char* archive_name, bool is_static) {
1067     _fd = -1;
1068     _is_valid = false;
1069     _header = nullptr;
1070     _base_archive_name = nullptr;
1071     _archive_name = archive_name;
1072     _is_static = is_static;
1073   }
1074 
1075   ~FileHeaderHelper() {
1076     if (_header != nullptr) {
1077       FREE_C_HEAP_ARRAY(char, _header);
1078     }
1079     if (_fd != -1) {
1080       ::close(_fd);
1081     }
1082   }
1083 
1084   bool initialize() {
1085     assert(_archive_name != nullptr, "Archive name is null");
1086     _fd = os::open(_archive_name, O_RDONLY | O_BINARY, 0);
1087     if (_fd < 0) {
1088       log_info(cds)("Specified shared archive not found (%s)", _archive_name);
1089       return false;
1090     }
1091     return initialize(_fd);
1092   }
1093 
1094   // for an already opened file, do not set _fd
1095   bool initialize(int fd) {
1096     assert(_archive_name != nullptr, "Archive name is null");
1097     assert(fd != -1, "Archive must be opened already");
1098     // First read the generic header so we know the exact size of the actual header.
1099     GenericCDSFileMapHeader gen_header;
1100     size_t size = sizeof(GenericCDSFileMapHeader);
1101     os::lseek(fd, 0, SEEK_SET);
1102     size_t n = ::read(fd, (void*)&gen_header, (unsigned int)size);
1103     if (n != size) {
1104       log_warning(cds)("Unable to read generic CDS file map header from shared archive");
1105       return false;
1106     }
1107 
1108     if (gen_header._magic != CDS_ARCHIVE_MAGIC &&
1109         gen_header._magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1110       log_warning(cds)("The shared archive file has a bad magic number: %#x", gen_header._magic);
1111       return false;
1112     }
1113 
1114     if (gen_header._version < CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION) {
1115       log_warning(cds)("Cannot handle shared archive file version 0x%x. Must be at least 0x%x.",
1116                                  gen_header._version, CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION);
1117       return false;
1118     }
1119 
1120     if (gen_header._version !=  CURRENT_CDS_ARCHIVE_VERSION) {
1121       log_warning(cds)("The shared archive file version 0x%x does not match the required version 0x%x.",
1122                                  gen_header._version, CURRENT_CDS_ARCHIVE_VERSION);
1123     }
1124 
1125     size_t filelen = os::lseek(fd, 0, SEEK_END);
1126     if (gen_header._header_size >= filelen) {
1127       log_warning(cds)("Archive file header larger than archive file");
1128       return false;
1129     }
1130 
1131     // Read the actual header and perform more checks
1132     size = gen_header._header_size;
1133     _header = (GenericCDSFileMapHeader*)NEW_C_HEAP_ARRAY(char, size, mtInternal);
1134     os::lseek(fd, 0, SEEK_SET);
1135     n = ::read(fd, (void*)_header, (unsigned int)size);
1136     if (n != size) {
1137       log_warning(cds)("Unable to read actual CDS file map header from shared archive");
1138       return false;
1139     }
1140 
1141     if (!check_header_crc()) {
1142       return false;
1143     }
1144 
1145     if (!check_and_init_base_archive_name()) {
1146       return false;
1147     }
1148 
1149     // All fields in the GenericCDSFileMapHeader has been validated.
1150     _is_valid = true;
1151     return true;
1152   }
1153 
1154   GenericCDSFileMapHeader* get_generic_file_header() {
1155     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1156     return _header;
1157   }
1158 
1159   const char* base_archive_name() {
1160     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1161     return _base_archive_name;
1162   }
1163 
1164  private:
1165   bool check_header_crc() const {
1166     if (VerifySharedSpaces) {
1167       FileMapHeader* header = (FileMapHeader*)_header;
1168       int actual_crc = header->compute_crc();
1169       if (actual_crc != header->crc()) {
1170         log_info(cds)("_crc expected: %d", header->crc());
1171         log_info(cds)("       actual: %d", actual_crc);
1172         log_warning(cds)("Header checksum verification failed.");
1173         return false;
1174       }
1175     }
1176     return true;
1177   }
1178 
1179   bool check_and_init_base_archive_name() {
1180     unsigned int name_offset = _header->_base_archive_name_offset;
1181     unsigned int name_size   = _header->_base_archive_name_size;
1182     unsigned int header_size = _header->_header_size;
1183 
1184     if (name_offset + name_size < name_offset) {
1185       log_warning(cds)("base_archive_name offset/size overflow: " UINT32_FORMAT "/" UINT32_FORMAT,
1186                                  name_offset, name_size);
1187       return false;
1188     }
1189     if (_header->_magic == CDS_ARCHIVE_MAGIC) {
1190       if (name_offset != 0) {
1191         log_warning(cds)("static shared archive must have zero _base_archive_name_offset");
1192         return false;
1193       }
1194       if (name_size != 0) {
1195         log_warning(cds)("static shared archive must have zero _base_archive_name_size");
1196         return false;
1197       }
1198     } else {
1199       assert(_header->_magic == CDS_DYNAMIC_ARCHIVE_MAGIC, "must be");
1200       if ((name_size == 0 && name_offset != 0) ||
1201           (name_size != 0 && name_offset == 0)) {
1202         // If either is zero, both must be zero. This indicates that we are using the default base archive.
1203         log_warning(cds)("Invalid base_archive_name offset/size: " UINT32_FORMAT "/" UINT32_FORMAT,
1204                                    name_offset, name_size);
1205         return false;
1206       }
1207       if (name_size > 0) {
1208         if (name_offset + name_size > header_size) {
1209           log_warning(cds)("Invalid base_archive_name offset/size (out of range): "
1210                                      UINT32_FORMAT " + " UINT32_FORMAT " > " UINT32_FORMAT ,
1211                                      name_offset, name_size, header_size);
1212           return false;
1213         }
1214         const char* name = ((const char*)_header) + _header->_base_archive_name_offset;
1215         if (name[name_size - 1] != '\0' || strlen(name) != name_size - 1) {
1216           log_warning(cds)("Base archive name is damaged");
1217           return false;
1218         }
1219         if (!os::file_exists(name)) {
1220           log_warning(cds)("Base archive %s does not exist", name);
1221           return false;
1222         }
1223         _base_archive_name = name;
1224       }
1225     }
1226 
1227     return true;
1228   }
1229 };
1230 
1231 // Return value:
1232 // false:
1233 //      <archive_name> is not a valid archive. *base_archive_name is set to null.
1234 // true && (*base_archive_name) == nullptr:
1235 //      <archive_name> is a valid static archive.
1236 // true && (*base_archive_name) != nullptr:
1237 //      <archive_name> is a valid dynamic archive.
1238 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
1239                                                     char** base_archive_name) {
1240   FileHeaderHelper file_helper(archive_name, false);
1241   *base_archive_name = nullptr;
1242 
1243   if (!file_helper.initialize()) {
1244     return false;
1245   }
1246   GenericCDSFileMapHeader* header = file_helper.get_generic_file_header();
1247   if (header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1248     assert(header->_magic == CDS_ARCHIVE_MAGIC, "must be");
1249     if (AutoCreateSharedArchive) {
1250      log_warning(cds)("AutoCreateSharedArchive is ignored because %s is a static archive", archive_name);
1251     }
1252     return true;
1253   }
1254 
1255   const char* base = file_helper.base_archive_name();
1256   if (base == nullptr) {
1257     *base_archive_name = CDSConfig::default_archive_path();
1258   } else {
1259     *base_archive_name = os::strdup_check_oom(base);
1260   }
1261 
1262   return true;
1263 }
1264 
1265 // Read the FileMapInfo information from the file.
1266 
1267 bool FileMapInfo::init_from_file(int fd) {
1268   FileHeaderHelper file_helper(_full_path, _is_static);
1269   if (!file_helper.initialize(fd)) {
1270     log_warning(cds)("Unable to read the file header.");
1271     return false;
1272   }
1273   GenericCDSFileMapHeader* gen_header = file_helper.get_generic_file_header();
1274 
1275   if (_is_static) {
1276     if (gen_header->_magic != CDS_ARCHIVE_MAGIC) {
1277       log_warning(cds)("Not a base shared archive: %s", _full_path);
1278       return false;
1279     }
1280   } else {
1281     if (gen_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1282       log_warning(cds)("Not a top shared archive: %s", _full_path);
1283       return false;
1284     }
1285   }
1286 
1287   _header = (FileMapHeader*)os::malloc(gen_header->_header_size, mtInternal);
1288   os::lseek(fd, 0, SEEK_SET); // reset to begin of the archive
1289   size_t size = gen_header->_header_size;
1290   size_t n = ::read(fd, (void*)_header, (unsigned int)size);
1291   if (n != size) {
1292     log_warning(cds)("Failed to read file header from the top archive file\n");
1293     return false;
1294   }
1295 
1296   if (header()->version() != CURRENT_CDS_ARCHIVE_VERSION) {
1297     log_info(cds)("_version expected: 0x%x", CURRENT_CDS_ARCHIVE_VERSION);
1298     log_info(cds)("           actual: 0x%x", header()->version());
1299     log_warning(cds)("The shared archive file has the wrong version.");
1300     return false;
1301   }
1302 
1303   int common_path_size = header()->common_app_classpath_prefix_size();
1304   if (common_path_size < 0) {
1305       log_warning(cds)("common app classpath prefix len < 0");
1306       return false;
1307   }
1308 
1309   unsigned int base_offset = header()->base_archive_name_offset();
1310   unsigned int name_size = header()->base_archive_name_size();
1311   unsigned int header_size = header()->header_size();
1312   if (base_offset != 0 && name_size != 0) {
1313     if (header_size != base_offset + name_size) {
1314       log_info(cds)("_header_size: " UINT32_FORMAT, header_size);
1315       log_info(cds)("common_app_classpath_size: " UINT32_FORMAT, header()->common_app_classpath_prefix_size());
1316       log_info(cds)("base_archive_name_size: " UINT32_FORMAT, header()->base_archive_name_size());
1317       log_info(cds)("base_archive_name_offset: " UINT32_FORMAT, header()->base_archive_name_offset());
1318       log_warning(cds)("The shared archive file has an incorrect header size.");
1319       return false;
1320     }
1321   }
1322 
1323   const char* actual_ident = header()->jvm_ident();
1324 
1325   if (actual_ident[JVM_IDENT_MAX-1] != 0) {
1326     log_warning(cds)("JVM version identifier is corrupted.");
1327     return false;
1328   }
1329 
1330   char expected_ident[JVM_IDENT_MAX];
1331   get_header_version(expected_ident);
1332   if (strncmp(actual_ident, expected_ident, JVM_IDENT_MAX-1) != 0) {
1333     log_info(cds)("_jvm_ident expected: %s", expected_ident);
1334     log_info(cds)("             actual: %s", actual_ident);
1335     log_warning(cds)("The shared archive file was created by a different"
1336                   " version or build of HotSpot");
1337     return false;
1338   }
1339 
1340   _file_offset = header()->header_size(); // accounts for the size of _base_archive_name
1341 
1342   size_t len = os::lseek(fd, 0, SEEK_END);
1343 
1344   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1345     FileMapRegion* r = region_at(i);
1346     if (r->file_offset() > len || len - r->file_offset() < r->used()) {
1347       log_warning(cds)("The shared archive file has been truncated.");
1348       return false;
1349     }
1350   }
1351 
1352   return true;
1353 }
1354 
1355 void FileMapInfo::seek_to_position(size_t pos) {
1356   if (os::lseek(_fd, (long)pos, SEEK_SET) < 0) {
1357     log_error(cds)("Unable to seek to position " SIZE_FORMAT, pos);
1358     MetaspaceShared::unrecoverable_loading_error();
1359   }
1360 }
1361 
1362 // Read the FileMapInfo information from the file.
1363 bool FileMapInfo::open_for_read() {
1364   if (_file_open) {
1365     return true;
1366   }
1367   log_info(cds)("trying to map %s", _full_path);
1368   int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
1369   if (fd < 0) {
1370     if (errno == ENOENT) {
1371       log_info(cds)("Specified shared archive not found (%s)", _full_path);
1372     } else {
1373       log_warning(cds)("Failed to open shared archive file (%s)",
1374                     os::strerror(errno));
1375     }
1376     return false;
1377   } else {
1378     log_info(cds)("Opened archive %s.", _full_path);
1379   }
1380 
1381   _fd = fd;
1382   _file_open = true;
1383   return true;
1384 }
1385 
1386 // Write the FileMapInfo information to the file.
1387 
1388 void FileMapInfo::open_for_write() {
1389   LogMessage(cds) msg;
1390   if (msg.is_info()) {
1391     msg.info("Dumping shared data to file: ");
1392     msg.info("   %s", _full_path);
1393   }
1394 
1395 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
1396     chmod(_full_path, _S_IREAD | _S_IWRITE);
1397 #endif
1398 
1399   // Use remove() to delete the existing file because, on Unix, this will
1400   // allow processes that have it open continued access to the file.
1401   remove(_full_path);
1402   int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1403   if (fd < 0) {
1404     log_error(cds)("Unable to create shared archive file %s: (%s).", _full_path,
1405                    os::strerror(errno));
1406     MetaspaceShared::unrecoverable_writing_error();
1407   }
1408   _fd = fd;
1409   _file_open = true;
1410 
1411   // Seek past the header. We will write the header after all regions are written
1412   // and their CRCs computed.
1413   size_t header_bytes = header()->header_size();
1414 
1415   header_bytes = align_up(header_bytes, MetaspaceShared::core_region_alignment());
1416   _file_offset = header_bytes;
1417   seek_to_position(_file_offset);
1418 }
1419 
1420 // Write the header to the file, seek to the next allocation boundary.
1421 
1422 void FileMapInfo::write_header() {
1423   _file_offset = 0;
1424   seek_to_position(_file_offset);
1425   assert(is_file_position_aligned(), "must be");
1426   write_bytes(header(), header()->header_size());
1427 }
1428 
1429 size_t FileMapRegion::used_aligned() const {
1430   return align_up(used(), MetaspaceShared::core_region_alignment());
1431 }
1432 
1433 void FileMapRegion::init(int region_index, size_t mapping_offset, size_t size, bool read_only,
1434                          bool allow_exec, int crc) {
1435   _is_heap_region = HeapShared::is_heap_region(region_index);
1436   _is_bitmap_region = (region_index == MetaspaceShared::bm);
1437   _mapping_offset = mapping_offset;
1438   _used = size;
1439   _read_only = read_only;
1440   _allow_exec = allow_exec;
1441   _crc = crc;
1442   _mapped_from_file = false;
1443   _mapped_base = nullptr;
1444 }
1445 
1446 void FileMapRegion::init_oopmap(size_t offset, size_t size_in_bits) {
1447   _oopmap_offset = offset;
1448   _oopmap_size_in_bits = size_in_bits;
1449 }
1450 
1451 void FileMapRegion::init_ptrmap(size_t offset, size_t size_in_bits) {
1452   _ptrmap_offset = offset;
1453   _ptrmap_size_in_bits = size_in_bits;
1454 }
1455 
1456 BitMapView FileMapRegion::bitmap_view(bool is_oopmap) {
1457   char* bitmap_base = FileMapInfo::current_info()->map_bitmap_region();
1458   bitmap_base += is_oopmap ? _oopmap_offset : _ptrmap_offset;
1459   size_t size_in_bits = is_oopmap ? _oopmap_size_in_bits : _ptrmap_size_in_bits;
1460   return BitMapView((BitMap::bm_word_t*)(bitmap_base), size_in_bits);
1461 }
1462 
1463 BitMapView FileMapRegion::oopmap_view() {
1464   return bitmap_view(true);
1465 }
1466 
1467 BitMapView FileMapRegion::ptrmap_view() {
1468   assert(has_ptrmap(), "must be");
1469   return bitmap_view(false);
1470 }
1471 
1472 bool FileMapRegion::check_region_crc(char* base) const {
1473   // This function should be called after the region has been properly
1474   // loaded into memory via FileMapInfo::map_region() or FileMapInfo::read_region().
1475   // I.e., this->mapped_base() must be valid.
1476   size_t sz = used();
1477   if (sz == 0) {
1478     return true;
1479   }
1480 
1481   assert(base != nullptr, "must be initialized");
1482   int crc = ClassLoader::crc32(0, base, (jint)sz);
1483   if (crc != this->crc()) {
1484     log_warning(cds)("Checksum verification failed.");
1485     return false;
1486   }
1487   return true;
1488 }
1489 
1490 static const char* region_name(int region_index) {
1491   static const char* names[] = {
1492     "rw", "ro", "bm", "hp"
1493   };
1494   const int num_regions = sizeof(names)/sizeof(names[0]);
1495   assert(0 <= region_index && region_index < num_regions, "sanity");
1496 
1497   return names[region_index];
1498 }
1499 
1500 void FileMapRegion::print(outputStream* st, int region_index) {
1501   st->print_cr("============ region ============= %d \"%s\"", region_index, region_name(region_index));
1502   st->print_cr("- crc:                            0x%08x", _crc);
1503   st->print_cr("- read_only:                      %d", _read_only);
1504   st->print_cr("- allow_exec:                     %d", _allow_exec);
1505   st->print_cr("- is_heap_region:                 %d", _is_heap_region);
1506   st->print_cr("- is_bitmap_region:               %d", _is_bitmap_region);
1507   st->print_cr("- mapped_from_file:               %d", _mapped_from_file);
1508   st->print_cr("- file_offset:                    " SIZE_FORMAT_X, _file_offset);
1509   st->print_cr("- mapping_offset:                 " SIZE_FORMAT_X, _mapping_offset);
1510   st->print_cr("- used:                           " SIZE_FORMAT, _used);
1511   st->print_cr("- oopmap_offset:                  " SIZE_FORMAT_X, _oopmap_offset);
1512   st->print_cr("- oopmap_size_in_bits:            " SIZE_FORMAT, _oopmap_size_in_bits);
1513   st->print_cr("- mapped_base:                    " INTPTR_FORMAT, p2i(_mapped_base));
1514 }
1515 
1516 void FileMapInfo::write_region(int region, char* base, size_t size,
1517                                bool read_only, bool allow_exec) {
1518   assert(CDSConfig::is_dumping_archive(), "sanity");
1519 
1520   FileMapRegion* r = region_at(region);
1521   char* requested_base;
1522   size_t mapping_offset = 0;
1523 
1524   if (region == MetaspaceShared::bm) {
1525     requested_base = nullptr; // always null for bm region
1526   } else if (size == 0) {
1527     // This is an unused region (e.g., a heap region when !INCLUDE_CDS_JAVA_HEAP)
1528     requested_base = nullptr;
1529   } else if (HeapShared::is_heap_region(region)) {
1530     assert(HeapShared::can_write(), "sanity");
1531 #if INCLUDE_CDS_JAVA_HEAP
1532     assert(!CDSConfig::is_dumping_dynamic_archive(), "must be");
1533     requested_base = (char*)ArchiveHeapWriter::requested_address();
1534     if (UseCompressedOops) {
1535       mapping_offset = (size_t)((address)requested_base - CompressedOops::base());
1536       assert((mapping_offset >> CompressedOops::shift()) << CompressedOops::shift() == mapping_offset, "must be");
1537     } else {
1538       mapping_offset = 0; // not used with !UseCompressedOops
1539     }
1540 #endif // INCLUDE_CDS_JAVA_HEAP
1541   } else {
1542     char* requested_SharedBaseAddress = (char*)MetaspaceShared::requested_base_address();
1543     requested_base = ArchiveBuilder::current()->to_requested(base);
1544     assert(requested_base >= requested_SharedBaseAddress, "must be");
1545     mapping_offset = requested_base - requested_SharedBaseAddress;
1546   }
1547 
1548   r->set_file_offset(_file_offset);
1549   int crc = ClassLoader::crc32(0, base, (jint)size);
1550   if (size > 0) {
1551     log_info(cds)("Shared file region (%s) %d: " SIZE_FORMAT_W(8)
1552                    " bytes, addr " INTPTR_FORMAT " file offset 0x%08" PRIxPTR
1553                    " crc 0x%08x",
1554                    region_name(region), region, size, p2i(requested_base), _file_offset, crc);



1555   }
1556 
1557   r->init(region, mapping_offset, size, read_only, allow_exec, crc);
1558 
1559   if (base != nullptr) {
1560     write_bytes_aligned(base, size);
1561   }
1562 }
1563 
1564 static size_t write_bitmap(const CHeapBitMap* map, char* output, size_t offset) {
1565   size_t size_in_bytes = map->size_in_bytes();
1566   map->write_to((BitMap::bm_word_t*)(output + offset), size_in_bytes);
1567   return offset + size_in_bytes;
1568 }
1569 
1570 // The start of the archived heap has many primitive arrays (String
1571 // bodies) that are not marked by the oop/ptr maps. So we must have
1572 // lots of leading zeros.
1573 size_t FileMapInfo::remove_bitmap_leading_zeros(CHeapBitMap* map) {
1574   size_t old_zeros = map->find_first_set_bit(0);
1575   size_t old_size = map->size_in_bytes();
1576 
1577   // Slice and resize bitmap
1578   map->truncate(old_zeros, map->size());
1579 
1580   DEBUG_ONLY(
1581     size_t new_zeros = map->find_first_set_bit(0);
1582     assert(new_zeros == 0, "Should have removed leading zeros");
1583   )
1584 
1585   assert(map->size_in_bytes() < old_size, "Map size should have decreased");
1586   return old_zeros;
1587 }
1588 
1589 char* FileMapInfo::write_bitmap_region(const CHeapBitMap* ptrmap, ArchiveHeapInfo* heap_info,
1590                                        size_t &size_in_bytes) {
1591   size_in_bytes = ptrmap->size_in_bytes();
1592 
1593   if (heap_info->is_used()) {
1594     // Remove leading zeros
1595     size_t removed_oop_zeros = remove_bitmap_leading_zeros(heap_info->oopmap());
1596     size_t removed_ptr_zeros = remove_bitmap_leading_zeros(heap_info->ptrmap());
1597 
1598     header()->set_heap_oopmap_start_pos(removed_oop_zeros);
1599     header()->set_heap_ptrmap_start_pos(removed_ptr_zeros);
1600 
1601     size_in_bytes += heap_info->oopmap()->size_in_bytes();
1602     size_in_bytes += heap_info->ptrmap()->size_in_bytes();
1603   }
1604 
1605   // The bitmap region contains up to 3 parts:
1606   // ptrmap:              metaspace pointers inside the ro/rw regions
1607   // heap_info->oopmap(): Java oop pointers in the heap region
1608   // heap_info->ptrmap(): metaspace pointers in the heap region
1609   char* buffer = NEW_C_HEAP_ARRAY(char, size_in_bytes, mtClassShared);
1610   size_t written = 0;
1611   written = write_bitmap(ptrmap, buffer, written);
1612   header()->set_ptrmap_size_in_bits(ptrmap->size());
1613 
1614   if (heap_info->is_used()) {
1615     FileMapRegion* r = region_at(MetaspaceShared::hp);
1616 
1617     r->init_oopmap(written, heap_info->oopmap()->size());
1618     written = write_bitmap(heap_info->oopmap(), buffer, written);
1619 
1620     r->init_ptrmap(written, heap_info->ptrmap()->size());
1621     written = write_bitmap(heap_info->ptrmap(), buffer, written);
1622   }
1623 
1624   write_region(MetaspaceShared::bm, (char*)buffer, size_in_bytes, /*read_only=*/true, /*allow_exec=*/false);
1625   return buffer;
1626 }
1627 
1628 size_t FileMapInfo::write_heap_region(ArchiveHeapInfo* heap_info) {
1629   char* buffer_start = heap_info->buffer_start();
1630   size_t buffer_size = heap_info->buffer_byte_size();
1631   write_region(MetaspaceShared::hp, buffer_start, buffer_size, false, false);
1632   header()->set_heap_roots_offset(heap_info->heap_roots_offset());
1633   return buffer_size;
1634 }
1635 
1636 // Dump bytes to file -- at the current file position.
1637 
1638 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1639   assert(_file_open, "must be");
1640   if (!os::write(_fd, buffer, nbytes)) {
1641     // If the shared archive is corrupted, close it and remove it.
1642     close();
1643     remove(_full_path);
1644     MetaspaceShared::unrecoverable_writing_error("Unable to write to shared archive file.");
1645   }
1646   _file_offset += nbytes;
1647 }
1648 
1649 bool FileMapInfo::is_file_position_aligned() const {
1650   return _file_offset == align_up(_file_offset,
1651                                   MetaspaceShared::core_region_alignment());
1652 }
1653 
1654 // Align file position to an allocation unit boundary.
1655 
1656 void FileMapInfo::align_file_position() {
1657   assert(_file_open, "must be");
1658   size_t new_file_offset = align_up(_file_offset,
1659                                     MetaspaceShared::core_region_alignment());
1660   if (new_file_offset != _file_offset) {
1661     _file_offset = new_file_offset;
1662     // Seek one byte back from the target and write a byte to insure
1663     // that the written file is the correct length.
1664     _file_offset -= 1;
1665     seek_to_position(_file_offset);
1666     char zero = 0;
1667     write_bytes(&zero, 1);
1668   }
1669 }
1670 
1671 
1672 // Dump bytes to file -- at the current file position.
1673 
1674 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1675   align_file_position();
1676   write_bytes(buffer, nbytes);
1677   align_file_position();
1678 }
1679 
1680 // Close the shared archive file.  This does NOT unmap mapped regions.
1681 
1682 void FileMapInfo::close() {
1683   if (_file_open) {
1684     if (::close(_fd) < 0) {
1685       MetaspaceShared::unrecoverable_loading_error("Unable to close the shared archive file.");
1686     }
1687     _file_open = false;
1688     _fd = -1;
1689   }
1690 }
1691 
1692 /*
1693  * Same as os::map_memory() but also pretouches if AlwaysPreTouch is enabled.
1694  */
1695 static char* map_memory(int fd, const char* file_name, size_t file_offset,
1696                         char *addr, size_t bytes, bool read_only,
1697                         bool allow_exec, MEMFLAGS flags = mtNone) {
1698   char* mem = os::map_memory(fd, file_name, file_offset, addr, bytes,
1699                              AlwaysPreTouch ? false : read_only,
1700                              allow_exec, flags);
1701   if (mem != nullptr && AlwaysPreTouch) {
1702     os::pretouch_memory(mem, mem + bytes);
1703   }
1704   return mem;
1705 }
1706 
1707 // JVM/TI RedefineClasses() support:
1708 // Remap the shared readonly space to shared readwrite, private.
1709 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1710   int idx = MetaspaceShared::ro;
1711   FileMapRegion* r = region_at(idx);
1712   if (!r->read_only()) {
1713     // the space is already readwrite so we are done
1714     return true;
1715   }
1716   size_t size = r->used_aligned();
1717   if (!open_for_read()) {
1718     return false;
1719   }
1720   char *addr = r->mapped_base();
1721   // This path should not be reached for Windows; see JDK-8222379.
1722   assert(WINDOWS_ONLY(false) NOT_WINDOWS(true), "Don't call on Windows");
1723   // Replace old mapping with new one that is writable.
1724   char *base = os::map_memory(_fd, _full_path, r->file_offset(),
1725                               addr, size, false /* !read_only */,
1726                               r->allow_exec());
1727   close();
1728   // These have to be errors because the shared region is now unmapped.
1729   if (base == nullptr) {
1730     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1731     vm_exit(1);
1732   }
1733   if (base != addr) {
1734     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1735     vm_exit(1);
1736   }
1737   r->set_read_only(false);
1738   return true;
1739 }
1740 
1741 // Memory map a region in the address space.
1742 static const char* shared_region_name[] = { "ReadWrite", "ReadOnly", "Bitmap", "Heap" };
1743 
1744 MapArchiveResult FileMapInfo::map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs) {
1745   DEBUG_ONLY(FileMapRegion* last_region = nullptr);
1746   intx addr_delta = mapped_base_address - header()->requested_base_address();
1747 
1748   // Make sure we don't attempt to use header()->mapped_base_address() unless
1749   // it's been successfully mapped.
1750   DEBUG_ONLY(header()->set_mapped_base_address((char*)(uintptr_t)0xdeadbeef);)
1751 
1752   for (int i = 0; i < num_regions; i++) {
1753     int idx = regions[i];
1754     MapArchiveResult result = map_region(idx, addr_delta, mapped_base_address, rs);
1755     if (result != MAP_ARCHIVE_SUCCESS) {
1756       return result;
1757     }
1758     FileMapRegion* r = region_at(idx);
1759     DEBUG_ONLY(if (last_region != nullptr) {
1760         // Ensure that the OS won't be able to allocate new memory spaces between any mapped
1761         // regions, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1762         assert(r->mapped_base() == last_region->mapped_end(), "must have no gaps");
1763       }
1764       last_region = r;)
1765     log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)", is_static() ? "static " : "dynamic",
1766                   idx, p2i(r->mapped_base()), p2i(r->mapped_end()),
1767                   shared_region_name[idx]);
1768 
1769   }
1770 
1771   header()->set_mapped_base_address(header()->requested_base_address() + addr_delta);
1772   if (addr_delta != 0 && !relocate_pointers_in_core_regions(addr_delta)) {
1773     return MAP_ARCHIVE_OTHER_FAILURE;
1774   }
1775 
1776   return MAP_ARCHIVE_SUCCESS;
1777 }
1778 
1779 bool FileMapInfo::read_region(int i, char* base, size_t size, bool do_commit) {
1780   FileMapRegion* r = region_at(i);
1781   if (do_commit) {
1782     log_info(cds)("Commit %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)%s",
1783                   is_static() ? "static " : "dynamic", i, p2i(base), p2i(base + size),
1784                   shared_region_name[i], r->allow_exec() ? " exec" : "");
1785     if (!os::commit_memory(base, size, r->allow_exec())) {
1786       log_error(cds)("Failed to commit %s region #%d (%s)", is_static() ? "static " : "dynamic",
1787                      i, shared_region_name[i]);
1788       return false;
1789     }
1790   }
1791   if (os::lseek(_fd, (long)r->file_offset(), SEEK_SET) != (int)r->file_offset() ||
1792       read_bytes(base, size) != size) {
1793     return false;
1794   }
1795 
1796   if (VerifySharedSpaces && !r->check_region_crc(base)) {
1797     return false;
1798   }
1799 
1800   r->set_mapped_from_file(false);
1801   r->set_mapped_base(base);
1802 
1803   return true;
1804 }
1805 
1806 MapArchiveResult FileMapInfo::map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs) {
1807   assert(!HeapShared::is_heap_region(i), "sanity");
1808   FileMapRegion* r = region_at(i);
1809   size_t size = r->used_aligned();
1810   char *requested_addr = mapped_base_address + r->mapping_offset();
1811   assert(r->mapped_base() == nullptr, "must be not mapped yet");
1812   assert(requested_addr != nullptr, "must be specified");
1813 
1814   r->set_mapped_from_file(false);
1815 
1816   if (MetaspaceShared::use_windows_memory_mapping()) {
1817     // Windows cannot remap read-only shared memory to read-write when required for
1818     // RedefineClasses, which is also used by JFR.  Always map windows regions as RW.
1819     r->set_read_only(false);
1820   } else if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1821              Arguments::has_jfr_option()) {
1822     // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW
1823     r->set_read_only(false);
1824   } else if (addr_delta != 0) {
1825     r->set_read_only(false); // Need to patch the pointers
1826   }
1827 
1828   if (MetaspaceShared::use_windows_memory_mapping() && rs.is_reserved()) {
1829     // This is the second time we try to map the archive(s). We have already created a ReservedSpace
1830     // that covers all the FileMapRegions to ensure all regions can be mapped. However, Windows
1831     // can't mmap into a ReservedSpace, so we just ::read() the data. We're going to patch all the
1832     // regions anyway, so there's no benefit for mmap anyway.
1833     if (!read_region(i, requested_addr, size, /* do_commit = */ true)) {
1834       log_info(cds)("Failed to read %s shared space into reserved space at " INTPTR_FORMAT,
1835                     shared_region_name[i], p2i(requested_addr));
1836       return MAP_ARCHIVE_OTHER_FAILURE; // oom or I/O error.
1837     } else {
1838       assert(r->mapped_base() != nullptr, "must be initialized");
1839       return MAP_ARCHIVE_SUCCESS;
1840     }
1841   } else {
1842     // Note that this may either be a "fresh" mapping into unreserved address
1843     // space (Windows, first mapping attempt), or a mapping into pre-reserved
1844     // space (Posix). See also comment in MetaspaceShared::map_archives().

1845     char* base = map_memory(_fd, _full_path, r->file_offset(),
1846                             requested_addr, size, r->read_only(),
1847                             r->allow_exec(), mtClassShared);
1848     if (base != requested_addr) {
1849       log_info(cds)("Unable to map %s shared space at " INTPTR_FORMAT,
1850                     shared_region_name[i], p2i(requested_addr));
1851       _memory_mapping_failed = true;
1852       return MAP_ARCHIVE_MMAP_FAILURE;
1853     }
1854 
1855     if (VerifySharedSpaces && !r->check_region_crc(requested_addr)) {
1856       return MAP_ARCHIVE_OTHER_FAILURE;
1857     }
1858 
1859     r->set_mapped_from_file(true);
1860     r->set_mapped_base(requested_addr);
1861 
1862     return MAP_ARCHIVE_SUCCESS;
1863   }
1864 }
1865 
1866 // The return value is the location of the archive relocation bitmap.
1867 char* FileMapInfo::map_bitmap_region() {
1868   FileMapRegion* r = region_at(MetaspaceShared::bm);
1869   if (r->mapped_base() != nullptr) {
1870     return r->mapped_base();
1871   }
1872   bool read_only = true, allow_exec = false;
1873   char* requested_addr = nullptr; // allow OS to pick any location
1874   char* bitmap_base = map_memory(_fd, _full_path, r->file_offset(),
1875                                  requested_addr, r->used_aligned(), read_only, allow_exec, mtClassShared);
1876   if (bitmap_base == nullptr) {
1877     log_info(cds)("failed to map relocation bitmap");
1878     return nullptr;
1879   }
1880 
1881   if (VerifySharedSpaces && !r->check_region_crc(bitmap_base)) {
1882     log_error(cds)("relocation bitmap CRC error");
1883     if (!os::unmap_memory(bitmap_base, r->used_aligned())) {
1884       fatal("os::unmap_memory of relocation bitmap failed");
1885     }
1886     return nullptr;
1887   }
1888 
1889   r->set_mapped_from_file(true);
1890   r->set_mapped_base(bitmap_base);
1891   log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)",
1892                 is_static() ? "static " : "dynamic",
1893                 MetaspaceShared::bm, p2i(r->mapped_base()), p2i(r->mapped_end()),
1894                 shared_region_name[MetaspaceShared::bm]);
1895   return bitmap_base;
1896 }
1897 
















































































1898 // This is called when we cannot map the archive at the requested[ base address (usually 0x800000000).
1899 // We relocate all pointers in the 2 core regions (ro, rw).
1900 bool FileMapInfo::relocate_pointers_in_core_regions(intx addr_delta) {
1901   log_debug(cds, reloc)("runtime archive relocation start");
1902   char* bitmap_base = map_bitmap_region();
1903 
1904   if (bitmap_base == nullptr) {
1905     return false; // OOM, or CRC check failure
1906   } else {
1907     size_t ptrmap_size_in_bits = header()->ptrmap_size_in_bits();
1908     log_debug(cds, reloc)("mapped relocation bitmap @ " INTPTR_FORMAT " (" SIZE_FORMAT " bits)",
1909                           p2i(bitmap_base), ptrmap_size_in_bits);
1910 
1911     BitMapView ptrmap((BitMap::bm_word_t*)bitmap_base, ptrmap_size_in_bits);
1912 
1913     // Patch all pointers in the mapped region that are marked by ptrmap.
1914     address patch_base = (address)mapped_base();
1915     address patch_end  = (address)mapped_end();
1916 




1917     // the current value of the pointers to be patched must be within this
1918     // range (i.e., must be between the requested base address and the address of the current archive).
1919     // Note: top archive may point to objects in the base archive, but not the other way around.
1920     address valid_old_base = (address)header()->requested_base_address();
1921     address valid_old_end  = valid_old_base + mapping_end_offset();
1922 
1923     // after patching, the pointers must point inside this range
1924     // (the requested location of the archive, as mapped at runtime).
1925     address valid_new_base = (address)header()->mapped_base_address();
1926     address valid_new_end  = (address)mapped_end();
1927 




1928     SharedDataRelocator patcher((address*)patch_base, (address*)patch_end, valid_old_base, valid_old_end,
1929                                 valid_new_base, valid_new_end, addr_delta);
1930     ptrmap.iterate(&patcher);
1931 
1932     // The MetaspaceShared::bm region will be unmapped in MetaspaceShared::initialize_shared_spaces().
1933 
1934     log_debug(cds, reloc)("runtime archive relocation done");
1935     return true;
1936   }
1937 }
1938 
1939 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
1940   assert(_file_open, "Archive file is not open");
1941   size_t n = ::read(_fd, buffer, (unsigned int)count);
1942   if (n != count) {
1943     // Close the file if there's a problem reading it.
1944     close();
1945     return 0;
1946   }
1947   _file_offset += count;
1948   return count;
1949 }
1950 
1951 // Get the total size in bytes of a read only region
1952 size_t FileMapInfo::readonly_total() {
1953   size_t total = 0;
1954   if (current_info() != nullptr) {
1955     FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::ro);
1956     if (r->read_only()) total += r->used();
1957   }
1958   if (dynamic_info() != nullptr) {
1959     FileMapRegion* r = FileMapInfo::dynamic_info()->region_at(MetaspaceShared::ro);
1960     if (r->read_only()) total += r->used();
1961   }
1962   return total;
1963 }
1964 
1965 #if INCLUDE_CDS_JAVA_HEAP
1966 MemRegion FileMapInfo::_mapped_heap_memregion;
1967 
1968 bool FileMapInfo::has_heap_region() {
1969   return (region_at(MetaspaceShared::hp)->used() > 0);
1970 }
1971 
1972 // Returns the address range of the archived heap region computed using the
1973 // current oop encoding mode. This range may be different than the one seen at
1974 // dump time due to encoding mode differences. The result is used in determining
1975 // if/how these regions should be relocated at run time.
1976 MemRegion FileMapInfo::get_heap_region_requested_range() {
1977   FileMapRegion* r = region_at(MetaspaceShared::hp);
1978   size_t size = r->used();
1979   assert(size > 0, "must have non-empty heap region");
1980 
1981   address start = heap_region_requested_address();
1982   address end = start + size;
1983   log_info(cds)("Requested heap region [" INTPTR_FORMAT " - " INTPTR_FORMAT "] = "  SIZE_FORMAT_W(8) " bytes",
1984                 p2i(start), p2i(end), size);
1985 
1986   return MemRegion((HeapWord*)start, (HeapWord*)end);
1987 }
1988 
1989 void FileMapInfo::map_or_load_heap_region() {
1990   bool success = false;
1991 
1992   if (can_use_heap_region()) {
1993     if (ArchiveHeapLoader::can_map()) {
1994       success = map_heap_region();
1995     } else if (ArchiveHeapLoader::can_load()) {
1996       success = ArchiveHeapLoader::load_heap_region(this);
1997     } else {
1998       if (!UseCompressedOops && !ArchiveHeapLoader::can_map()) {
1999         // TODO - remove implicit knowledge of G1
2000         log_info(cds)("Cannot use CDS heap data. UseG1GC is required for -XX:-UseCompressedOops");
2001       } else {
2002         log_info(cds)("Cannot use CDS heap data. UseEpsilonGC, UseG1GC, UseSerialGC or UseParallelGC are required.");
2003       }
2004     }
2005   }
2006 
2007   if (!success) {
2008     CDSConfig::stop_using_full_module_graph();
2009   }
2010 }
2011 
2012 bool FileMapInfo::can_use_heap_region() {
2013   if (!has_heap_region()) {
2014     return false;
2015   }
2016   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2017     ShouldNotReachHere(); // CDS should have been disabled.
2018     // The archived objects are mapped at JVM start-up, but we don't know if
2019     // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
2020     // which would make the archived String or mirror objects invalid. Let's be safe and not
2021     // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
2022     //
2023     // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
2024     // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
2025     // because we won't install an archived object subgraph if the klass of any of the
2026     // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
2027   }
2028 
2029   // We pre-compute narrow Klass IDs with the runtime mapping start intended to be the base, and a shift of
2030   // ArchiveHeapWriter::precomputed_narrow_klass_shift. We enforce this encoding at runtime (see
2031   // CompressedKlassPointers::initialize_for_given_encoding()). Therefore, the following assertions must
2032   // hold:
2033   address archive_narrow_klass_base = (address)header()->mapped_base_address();
2034   const int archive_narrow_klass_shift = ArchiveHeapWriter::precomputed_narrow_klass_shift;
2035 
2036   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
2037                 max_heap_size()/M);
2038   log_info(cds)("    narrow_klass_base at mapping start address, narrow_klass_shift = %d",
2039                 archive_narrow_klass_shift);
2040   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2041                 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
2042   log_info(cds)("The current max heap size = " SIZE_FORMAT "M, HeapRegion::GrainBytes = " SIZE_FORMAT,
2043                 MaxHeapSize/M, HeapRegion::GrainBytes);
2044   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
2045                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
2046   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2047                 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
2048   log_info(cds)("    heap range = [" PTR_FORMAT " - "  PTR_FORMAT "]",
2049                 UseCompressedOops ? p2i(CompressedOops::begin()) :
2050                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().start()) : 0L,
2051                 UseCompressedOops ? p2i(CompressedOops::end()) :
2052                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().end()) : 0L);
2053 
2054   assert(archive_narrow_klass_base == CompressedKlassPointers::base(), "Unexpected encoding base encountered "
2055          "(" PTR_FORMAT ", expected " PTR_FORMAT ")", p2i(CompressedKlassPointers::base()), p2i(archive_narrow_klass_base));
2056   assert(archive_narrow_klass_shift == CompressedKlassPointers::shift(), "Unexpected encoding shift encountered "
2057          "(%d, expected %d)", CompressedKlassPointers::shift(), archive_narrow_klass_shift);
2058 
2059   return true;
2060 }
2061 
2062 // The actual address of this region during dump time.
2063 address FileMapInfo::heap_region_dumptime_address() {
2064   FileMapRegion* r = region_at(MetaspaceShared::hp);
2065   assert(UseSharedSpaces, "runtime only");
2066   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2067   if (UseCompressedOops) {
2068     return /*dumptime*/ narrow_oop_base() + r->mapping_offset();
2069   } else {
2070     return heap_region_requested_address();
2071   }
2072 }
2073 
2074 // The address where this region can be mapped into the runtime heap without
2075 // patching any of the pointers that are embedded in this region.
2076 address FileMapInfo::heap_region_requested_address() {
2077   assert(UseSharedSpaces, "runtime only");
2078   FileMapRegion* r = region_at(MetaspaceShared::hp);
2079   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2080   assert(ArchiveHeapLoader::can_map(), "cannot be used by ArchiveHeapLoader::can_load() mode");
2081   if (UseCompressedOops) {
2082     // We can avoid relocation if each region's offset from the runtime CompressedOops::base()
2083     // is the same as its offset from the CompressedOops::base() during dumptime.
2084     // Note that CompressedOops::base() may be different between dumptime and runtime.
2085     //
2086     // Example:
2087     // Dumptime base = 0x1000 and shift is 0. We have a region at address 0x2000. There's a
2088     // narrowOop P stored in this region that points to an object at address 0x2200.
2089     // P's encoded value is 0x1200.
2090     //
2091     // Runtime base = 0x4000 and shift is also 0. If we map this region at 0x5000, then
2092     // the value P can remain 0x1200. The decoded address = (0x4000 + (0x1200 << 0)) = 0x5200,
2093     // which is the runtime location of the referenced object.
2094     return /*runtime*/ CompressedOops::base() + r->mapping_offset();
2095   } else {
2096     // This was the hard-coded requested base address used at dump time. With uncompressed oops,
2097     // the heap range is assigned by the OS so we will most likely have to relocate anyway, no matter
2098     // what base address was picked at duump time.
2099     return (address)ArchiveHeapWriter::NOCOOPS_REQUESTED_BASE;
2100   }
2101 }
2102 
2103 bool FileMapInfo::map_heap_region() {
2104   if (map_heap_region_impl()) {
2105 #ifdef ASSERT
2106     // The "old" regions must be parsable -- we cannot have any unused space
2107     // at the start of the lowest G1 region that contains archived objects.
2108     assert(is_aligned(_mapped_heap_memregion.start(), HeapRegion::GrainBytes), "must be");
2109 
2110     // Make sure we map at the very top of the heap - see comments in
2111     // init_heap_region_relocation().
2112     MemRegion heap_range = G1CollectedHeap::heap()->reserved();
2113     assert(heap_range.contains(_mapped_heap_memregion), "must be");
2114 
2115     address heap_end = (address)heap_range.end();
2116     address mapped_heap_region_end = (address)_mapped_heap_memregion.end();
2117     assert(heap_end >= mapped_heap_region_end, "must be");
2118     assert(heap_end - mapped_heap_region_end < (intx)(HeapRegion::GrainBytes),
2119            "must be at the top of the heap to avoid fragmentation");
2120 #endif
2121 
2122     ArchiveHeapLoader::set_mapped();
2123     return true;
2124   } else {
2125     return false;
2126   }
2127 }
2128 
2129 bool FileMapInfo::map_heap_region_impl() {
2130   assert(UseG1GC, "the following code assumes G1");
2131 
2132   FileMapRegion* r = region_at(MetaspaceShared::hp);
2133   size_t size = r->used();
2134   if (size == 0) {
2135     return false; // no archived java heap data
2136   }
2137 
2138   size_t word_size = size / HeapWordSize;
2139   address requested_start = heap_region_requested_address();
2140 
2141   log_info(cds)("Preferred address to map heap data (to avoid relocation) is " INTPTR_FORMAT, p2i(requested_start));
2142 
2143   // allocate from java heap
2144   HeapWord* start = G1CollectedHeap::heap()->alloc_archive_region(word_size, (HeapWord*)requested_start);
2145   if (start == nullptr) {
2146     log_info(cds)("UseSharedSpaces: Unable to allocate java heap region for archive heap.");
2147     return false;
2148   }
2149 
2150   _mapped_heap_memregion = MemRegion(start, word_size);
2151 
2152   // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
2153   // for mapped region as it is part of the reserved java heap, which is already recorded.
2154   char* addr = (char*)_mapped_heap_memregion.start();
2155   char* base = map_memory(_fd, _full_path, r->file_offset(),
2156                           addr, _mapped_heap_memregion.byte_size(), r->read_only(),
2157                           r->allow_exec());
2158   if (base == nullptr || base != addr) {
2159     dealloc_heap_region();
2160     log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
2161                   INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
2162                   p2i(addr), _mapped_heap_memregion.byte_size());
2163     return false;
2164   }
2165 
2166   if (VerifySharedSpaces && !r->check_region_crc(base)) {
2167     dealloc_heap_region();
2168     log_info(cds)("UseSharedSpaces: mapped heap region is corrupt");
2169     return false;
2170   }
2171 
2172   r->set_mapped_base(base);
2173 
2174   // If the requested range is different from the range allocated by GC, then
2175   // the pointers need to be patched.
2176   address mapped_start = (address) _mapped_heap_memregion.start();
2177   ptrdiff_t delta = mapped_start - requested_start;
2178   if (UseCompressedOops &&
2179       (narrow_oop_mode() != CompressedOops::mode() ||
2180        narrow_oop_shift() != CompressedOops::shift())) {
2181     _heap_pointers_need_patching = true;
2182   }
2183   if (delta != 0) {
2184     _heap_pointers_need_patching = true;
2185   }
2186   ArchiveHeapLoader::init_mapped_heap_info(mapped_start, delta, narrow_oop_shift());
2187 
2188   if (_heap_pointers_need_patching) {
2189     char* bitmap_base = map_bitmap_region();
2190     if (bitmap_base == nullptr) {
2191       log_info(cds)("CDS heap cannot be used because bitmap region cannot be mapped");
2192       dealloc_heap_region();
2193       unmap_region(MetaspaceShared::hp);
2194       _heap_pointers_need_patching = false;
2195       return false;
2196     }
2197   }
2198   log_info(cds)("Heap data mapped at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
2199                 p2i(mapped_start), _mapped_heap_memregion.byte_size());
2200   log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
2201   return true;
2202 }
2203 
2204 narrowOop FileMapInfo::encoded_heap_region_dumptime_address() {
2205   assert(UseSharedSpaces, "runtime only");
2206   assert(UseCompressedOops, "sanity");
2207   FileMapRegion* r = region_at(MetaspaceShared::hp);
2208   return CompressedOops::narrow_oop_cast(r->mapping_offset() >> narrow_oop_shift());
2209 }
2210 
2211 void FileMapInfo::patch_heap_embedded_pointers() {
2212   if (!ArchiveHeapLoader::is_mapped() || !_heap_pointers_need_patching) {
2213     return;
2214   }
2215 
2216   char* bitmap_base = map_bitmap_region();
2217   assert(bitmap_base != nullptr, "must have already been mapped");
2218 
2219   FileMapRegion* r = region_at(MetaspaceShared::hp);
2220   ArchiveHeapLoader::patch_embedded_pointers(
2221       this, _mapped_heap_memregion,
2222       (address)(region_at(MetaspaceShared::bm)->mapped_base()) + r->oopmap_offset(),
2223       r->oopmap_size_in_bits());
2224 }
2225 
2226 void FileMapInfo::fixup_mapped_heap_region() {
2227   if (ArchiveHeapLoader::is_mapped()) {
2228     assert(!_mapped_heap_memregion.is_empty(), "sanity");
2229 
2230     // Populate the archive regions' G1BlockOffsetTableParts. That ensures
2231     // fast G1BlockOffsetTablePart::block_start operations for any given address
2232     // within the archive regions when trying to find start of an object
2233     // (e.g. during card table scanning).
2234     G1CollectedHeap::heap()->populate_archive_regions_bot_part(_mapped_heap_memregion);
2235   }
2236 }
2237 
2238 // dealloc the archive regions from java heap
2239 void FileMapInfo::dealloc_heap_region() {
2240   G1CollectedHeap::heap()->dealloc_archive_regions(_mapped_heap_memregion);
2241 }
2242 #endif // INCLUDE_CDS_JAVA_HEAP
2243 
2244 void FileMapInfo::unmap_regions(int regions[], int num_regions) {
2245   for (int r = 0; r < num_regions; r++) {
2246     int idx = regions[r];
2247     unmap_region(idx);
2248   }
2249 }
2250 
2251 // Unmap a memory region in the address space.
2252 
2253 void FileMapInfo::unmap_region(int i) {
2254   FileMapRegion* r = region_at(i);
2255   char* mapped_base = r->mapped_base();
2256   size_t size = r->used_aligned();
2257 
2258   if (mapped_base != nullptr) {
2259     if (size > 0 && r->mapped_from_file()) {
2260       log_info(cds)("Unmapping region #%d at base " INTPTR_FORMAT " (%s)", i, p2i(mapped_base),
2261                     shared_region_name[i]);
2262       if (!os::unmap_memory(mapped_base, size)) {
2263         fatal("os::unmap_memory failed");
2264       }
2265     }
2266     r->set_mapped_base(nullptr);
2267   }
2268 }
2269 
2270 void FileMapInfo::assert_mark(bool check) {
2271   if (!check) {
2272     MetaspaceShared::unrecoverable_loading_error("Mark mismatch while restoring from shared file.");
2273   }
2274 }
2275 
2276 FileMapInfo* FileMapInfo::_current_info = nullptr;
2277 FileMapInfo* FileMapInfo::_dynamic_archive_info = nullptr;
2278 bool FileMapInfo::_heap_pointers_need_patching = false;
2279 SharedPathTable FileMapInfo::_shared_path_table;
2280 bool FileMapInfo::_validating_shared_path_table = false;
2281 bool FileMapInfo::_memory_mapping_failed = false;
2282 GrowableArray<const char*>* FileMapInfo::_non_existent_class_paths = nullptr;
2283 
2284 // Open the shared archive file, read and validate the header
2285 // information (version, boot classpath, etc.). If initialization
2286 // fails, shared spaces are disabled and the file is closed.
2287 //
2288 // Validation of the archive is done in two steps:
2289 //
2290 // [1] validate_header() - done here.
2291 // [2] validate_shared_path_table - this is done later, because the table is in the RW
2292 //     region of the archive, which is not mapped yet.
2293 bool FileMapInfo::initialize() {
2294   assert(UseSharedSpaces, "UseSharedSpaces expected.");
2295   assert(Arguments::has_jimage(), "The shared archive file cannot be used with an exploded module build.");
2296 
2297   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2298     // CDS assumes that no classes resolved in vmClasses::resolve_all()
2299     // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
2300     // during the JVMTI "early" stage, so we can still use CDS if
2301     // JvmtiExport::has_early_class_hook_env() is false.
2302     log_info(cds)("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
2303     return false;
2304   }
2305 
2306   if (!open_for_read() || !init_from_file(_fd) || !validate_header()) {
2307     if (_is_static) {
2308       log_info(cds)("Initialize static archive failed.");
2309       return false;
2310     } else {
2311       log_info(cds)("Initialize dynamic archive failed.");
2312       if (AutoCreateSharedArchive) {
2313         CDSConfig::enable_dumping_dynamic_archive();
2314         ArchiveClassesAtExit = CDSConfig::dynamic_archive_path();
2315       }
2316       return false;
2317     }
2318   }
2319 











2320   return true;
2321 }
2322 
2323 // The 2 core spaces are RW->RO
2324 FileMapRegion* FileMapInfo::first_core_region() const {
2325   return region_at(MetaspaceShared::rw);
2326 }
2327 
2328 FileMapRegion* FileMapInfo::last_core_region() const {
2329   return region_at(MetaspaceShared::ro);
2330 }
2331 
2332 void FileMapInfo::print(outputStream* st) const {
2333   header()->print(st);
2334   if (!is_static()) {
2335     dynamic_header()->print(st);
2336   }
2337 }
2338 
2339 void FileMapHeader::set_as_offset(char* p, size_t *offset) {
2340   *offset = ArchiveBuilder::current()->any_to_offset((address)p);
2341 }
2342 
2343 int FileMapHeader::compute_crc() {
2344   char* start = (char*)this;
2345   // start computing from the field after _header_size to end of base archive name.
2346   char* buf = (char*)&(_generic_header._header_size) + sizeof(_generic_header._header_size);
2347   size_t sz = header_size() - (buf - start);
2348   int crc = ClassLoader::crc32(0, buf, (jint)sz);
2349   return crc;
2350 }
2351 
2352 // This function should only be called during run time with UseSharedSpaces enabled.
2353 bool FileMapHeader::validate() {
2354   if (_obj_alignment != ObjectAlignmentInBytes) {
2355     log_info(cds)("The shared archive file's ObjectAlignmentInBytes of %d"
2356                   " does not equal the current ObjectAlignmentInBytes of %d.",
2357                   _obj_alignment, ObjectAlignmentInBytes);
2358     return false;
2359   }
2360   if (_compact_strings != CompactStrings) {
2361     log_info(cds)("The shared archive file's CompactStrings setting (%s)"
2362                   " does not equal the current CompactStrings setting (%s).",
2363                   _compact_strings ? "enabled" : "disabled",
2364                   CompactStrings   ? "enabled" : "disabled");
2365     return false;
2366   }
2367 
2368   // This must be done after header validation because it might change the
2369   // header data
2370   const char* prop = Arguments::get_property("java.system.class.loader");
2371   if (prop != nullptr) {
2372     log_warning(cds)("Archived non-system classes are disabled because the "
2373             "java.system.class.loader property is specified (value = \"%s\"). "
2374             "To use archived non-system classes, this property must not be set", prop);
2375     _has_platform_or_app_classes = false;
2376   }
2377 
2378 
2379   if (!_verify_local && BytecodeVerificationLocal) {
2380     //  we cannot load boot classes, so there's no point of using the CDS archive
2381     log_info(cds)("The shared archive file's BytecodeVerificationLocal setting (%s)"
2382                                " does not equal the current BytecodeVerificationLocal setting (%s).",
2383                                _verify_local ? "enabled" : "disabled",
2384                                BytecodeVerificationLocal ? "enabled" : "disabled");
2385     return false;
2386   }
2387 
2388   // For backwards compatibility, we don't check the BytecodeVerificationRemote setting
2389   // if the archive only contains system classes.
2390   if (_has_platform_or_app_classes
2391       && !_verify_remote // we didn't verify the archived platform/app classes
2392       && BytecodeVerificationRemote) { // but we want to verify all loaded platform/app classes
2393     log_info(cds)("The shared archive file was created with less restrictive "
2394                                "verification setting than the current setting.");
2395     // Pretend that we didn't have any archived platform/app classes, so they won't be loaded
2396     // by SystemDictionaryShared.
2397     _has_platform_or_app_classes = false;
2398   }
2399 
2400   // Java agents are allowed during run time. Therefore, the following condition is not
2401   // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
2402   // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
2403   // while AllowArchivingWithJavaAgent is set during the current run.
2404   if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
2405     log_warning(cds)("The setting of the AllowArchivingWithJavaAgent is different "
2406                                "from the setting in the shared archive.");
2407     return false;
2408   }
2409 
2410   if (_allow_archiving_with_java_agent) {
2411     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
2412             "for testing purposes only and should not be used in a production environment");
2413   }
2414 
2415   log_info(cds)("Archive was created with UseCompressedOops = %d, UseCompressedClassPointers = %d",
2416                           compressed_oops(), compressed_class_pointers());
2417   if (compressed_oops() != UseCompressedOops || compressed_class_pointers() != UseCompressedClassPointers) {
2418     log_info(cds)("Unable to use shared archive.\nThe saved state of UseCompressedOops and UseCompressedClassPointers is "
2419                                "different from runtime, CDS will be disabled.");
2420     return false;
2421   }
2422 
2423   if (!_use_optimized_module_handling) {
2424     CDSConfig::stop_using_optimized_module_handling();
2425     log_info(cds)("optimized module handling: disabled because archive was created without optimized module handling");
2426   }
2427 
2428   if (is_static() && !_has_full_module_graph) {
2429     // Only the static archive can contain the full module graph.
2430     CDSConfig::stop_using_full_module_graph("archive was created without full module graph");









2431   }
2432 
2433   return true;
2434 }
2435 
2436 bool FileMapInfo::validate_header() {
2437   if (!header()->validate()) {
2438     return false;
2439   }
2440   if (_is_static) {
2441     return true;
2442   } else {
2443     return DynamicArchive::validate(this);
2444   }
2445 }
2446 
2447 #if INCLUDE_JVMTI
2448 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = nullptr;
2449 
2450 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
2451   if (i == 0) {
2452     // index 0 corresponds to the ClassPathImageEntry which is a globally shared object
2453     // and should never be deleted.
2454     return ClassLoader::get_jrt_entry();
2455   }
2456   ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
2457   if (ent == nullptr) {
2458     SharedClassPathEntry* scpe = shared_path(i);
2459     assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
2460 
2461     const char* path = scpe->name();
2462     struct stat st;
2463     if (os::stat(path, &st) != 0) {
2464       char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2465       jio_snprintf(msg, strlen(path) + 127, "error in finding JAR file %s", path);
2466       THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2467     } else {
2468       ent = ClassLoader::create_class_path_entry(THREAD, path, &st, false, false);
2469       if (ent == nullptr) {
2470         char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2471         jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
2472         THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2473       }
2474     }
2475 
2476     MutexLocker mu(THREAD, CDSClassFileStream_lock);
2477     if (_classpath_entries_for_jvmti[i] == nullptr) {
2478       _classpath_entries_for_jvmti[i] = ent;
2479     } else {
2480       // Another thread has beat me to creating this entry
2481       delete ent;
2482       ent = _classpath_entries_for_jvmti[i];
2483     }
2484   }
2485 
2486   return ent;
2487 }
2488 
2489 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
2490   int path_index = ik->shared_classpath_index();
2491   assert(path_index >= 0, "should be called for shared built-in classes only");
2492   assert(path_index < (int)get_number_of_shared_paths(), "sanity");
2493 
2494   ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
2495   assert(cpe != nullptr, "must be");
2496 
2497   Symbol* name = ik->name();
2498   const char* const class_name = name->as_C_string();
2499   const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
2500                                                                       name->utf8_length());
2501   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
2502   ClassFileStream* cfs = cpe->open_stream_for_loader(THREAD, file_name, loader_data);
2503   assert(cfs != nullptr, "must be able to read the classfile data of shared classes for built-in loaders.");
2504   log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
2505                         cfs->source(), cfs->length());
2506   return cfs;
2507 }
2508 
2509 #endif
--- EOF ---