1 /*
   2  * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "cds/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/dynamicArchive.hpp"
  32 #include "cds/filemap.hpp"
  33 #include "cds/heapShared.hpp"
  34 #include "cds/metaspaceShared.hpp"
  35 #include "classfile/altHashing.hpp"
  36 #include "classfile/classFileStream.hpp"
  37 #include "classfile/classLoader.hpp"
  38 #include "classfile/classLoader.inline.hpp"
  39 #include "classfile/classLoaderData.inline.hpp"
  40 #include "classfile/classLoaderExt.hpp"
  41 #include "classfile/symbolTable.hpp"
  42 #include "classfile/systemDictionaryShared.hpp"
  43 #include "classfile/vmClasses.hpp"
  44 #include "classfile/vmSymbols.hpp"
  45 #include "jvm.h"
  46 #include "logging/log.hpp"
  47 #include "logging/logStream.hpp"
  48 #include "logging/logMessage.hpp"
  49 #include "memory/iterator.inline.hpp"
  50 #include "memory/metadataFactory.hpp"
  51 #include "memory/metaspaceClosure.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/universe.hpp"
  54 #include "oops/compressedOops.hpp"
  55 #include "oops/compressedOops.inline.hpp"
  56 #include "oops/objArrayOop.hpp"
  57 #include "oops/oop.inline.hpp"
  58 #include "prims/jvmtiExport.hpp"
  59 #include "runtime/arguments.hpp"
  60 #include "runtime/globals_extension.hpp"
  61 #include "runtime/java.hpp"
  62 #include "runtime/mutexLocker.hpp"
  63 #include "runtime/os.hpp"
  64 #include "runtime/vm_version.hpp"
  65 #include "services/memTracker.hpp"
  66 #include "utilities/align.hpp"
  67 #include "utilities/bitMap.inline.hpp"
  68 #include "utilities/classpathStream.hpp"
  69 #include "utilities/defaultStream.hpp"
  70 #include "utilities/ostream.hpp"
  71 #if INCLUDE_G1GC
  72 #include "gc/g1/g1CollectedHeap.hpp"
  73 #include "gc/g1/heapRegion.hpp"
  74 #endif
  75 
  76 # include <sys/stat.h>
  77 # include <errno.h>
  78 
  79 #ifndef O_BINARY       // if defined (Win32) use binary files.
  80 #define O_BINARY 0     // otherwise do nothing.
  81 #endif
  82 
  83 // Fill in the fileMapInfo structure with data about this VM instance.
  84 
  85 // This method copies the vm version info into header_version.  If the version is too
  86 // long then a truncated version, which has a hash code appended to it, is copied.
  87 //
  88 // Using a template enables this method to verify that header_version is an array of
  89 // length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and
  90 // the code that reads the CDS file will both use the same size buffer.  Hence, will
  91 // use identical truncation.  This is necessary for matching of truncated versions.
  92 template <int N> static void get_header_version(char (&header_version) [N]) {
  93   assert(N == JVM_IDENT_MAX, "Bad header_version size");
  94 
  95   const char *vm_version = VM_Version::internal_vm_info_string();
  96   const int version_len = (int)strlen(vm_version);
  97 
  98   memset(header_version, 0, JVM_IDENT_MAX);
  99 
 100   if (version_len < (JVM_IDENT_MAX-1)) {
 101     strcpy(header_version, vm_version);
 102 
 103   } else {
 104     // Get the hash value.  Use a static seed because the hash needs to return the same
 105     // value over multiple jvm invocations.
 106     uint32_t hash = AltHashing::halfsiphash_32(8191, (const uint8_t*)vm_version, version_len);
 107 
 108     // Truncate the ident, saving room for the 8 hex character hash value.
 109     strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
 110 
 111     // Append the hash code as eight hex digits.
 112     os::snprintf_checked(&header_version[JVM_IDENT_MAX-9], 9, "%08x", hash);
 113     header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.
 114   }
 115 
 116   assert(header_version[JVM_IDENT_MAX-1] == 0, "must be");
 117 }
 118 
 119 FileMapInfo::FileMapInfo(const char* full_path, bool is_static) :
 120   _is_static(is_static), _file_open(false), _is_mapped(false), _fd(-1), _file_offset(0),
 121   _full_path(full_path), _base_archive_name(nullptr), _header(nullptr) {
 122   if (_is_static) {
 123     assert(_current_info == nullptr, "must be singleton"); // not thread safe
 124     _current_info = this;
 125   } else {
 126     assert(_dynamic_archive_info == nullptr, "must be singleton"); // not thread safe
 127     _dynamic_archive_info = this;
 128   }
 129 }
 130 
 131 FileMapInfo::~FileMapInfo() {
 132   if (_is_static) {
 133     assert(_current_info == this, "must be singleton"); // not thread safe
 134     _current_info = nullptr;
 135   } else {
 136     assert(_dynamic_archive_info == this, "must be singleton"); // not thread safe
 137     _dynamic_archive_info = nullptr;
 138   }
 139 
 140   if (_header != nullptr) {
 141     os::free(_header);
 142   }
 143 
 144   if (_file_open) {
 145     ::close(_fd);
 146   }
 147 }
 148 
 149 void FileMapInfo::populate_header(size_t core_region_alignment) {
 150   assert(_header == nullptr, "Sanity check");
 151   size_t c_header_size;
 152   size_t header_size;
 153   size_t base_archive_name_size = 0;
 154   size_t base_archive_name_offset = 0;
 155   size_t longest_common_prefix_size = 0;
 156   if (is_static()) {
 157     c_header_size = sizeof(FileMapHeader);
 158     header_size = c_header_size;
 159   } else {
 160     // dynamic header including base archive name for non-default base archive
 161     c_header_size = sizeof(DynamicArchiveHeader);
 162     header_size = c_header_size;
 163 
 164     const char* default_base_archive_name = Arguments::get_default_shared_archive_path();
 165     const char* current_base_archive_name = Arguments::GetSharedArchivePath();
 166     if (!os::same_files(current_base_archive_name, default_base_archive_name)) {
 167       base_archive_name_size = strlen(current_base_archive_name) + 1;
 168       header_size += base_archive_name_size;
 169       base_archive_name_offset = c_header_size;
 170     }
 171   }
 172   ResourceMark rm;
 173   GrowableArray<const char*>* app_cp_array = create_dumptime_app_classpath_array();
 174   int len = app_cp_array->length();
 175   longest_common_prefix_size = longest_common_app_classpath_prefix_len(len, app_cp_array);
 176   _header = (FileMapHeader*)os::malloc(header_size, mtInternal);
 177   memset((void*)_header, 0, header_size);
 178   _header->populate(this,
 179                     core_region_alignment,
 180                     header_size,
 181                     base_archive_name_size,
 182                     base_archive_name_offset,
 183                     longest_common_prefix_size);
 184 }
 185 
 186 void FileMapHeader::populate(FileMapInfo *info, size_t core_region_alignment,
 187                              size_t header_size, size_t base_archive_name_size,
 188                              size_t base_archive_name_offset, size_t common_app_classpath_prefix_size) {
 189   // 1. We require _generic_header._magic to be at the beginning of the file
 190   // 2. FileMapHeader also assumes that _generic_header is at the beginning of the file
 191   assert(offset_of(FileMapHeader, _generic_header) == 0, "must be");
 192   set_header_size((unsigned int)header_size);
 193   set_base_archive_name_offset((unsigned int)base_archive_name_offset);
 194   set_base_archive_name_size((unsigned int)base_archive_name_size);
 195   set_common_app_classpath_prefix_size((unsigned int)common_app_classpath_prefix_size);
 196   set_magic(DynamicDumpSharedSpaces ? CDS_DYNAMIC_ARCHIVE_MAGIC : CDS_ARCHIVE_MAGIC);
 197   set_version(CURRENT_CDS_ARCHIVE_VERSION);
 198 
 199   if (!info->is_static() && base_archive_name_size != 0) {
 200     // copy base archive name
 201     copy_base_archive_name(Arguments::GetSharedArchivePath());
 202   }
 203   _core_region_alignment = core_region_alignment;
 204   _obj_alignment = ObjectAlignmentInBytes;
 205   _compact_strings = CompactStrings;
 206   _compact_headers = UseCompactObjectHeaders;
 207   if (DumpSharedSpaces && HeapShared::can_write()) {
 208     _narrow_oop_mode = CompressedOops::mode();
 209     _narrow_oop_base = CompressedOops::base();
 210     _narrow_oop_shift = CompressedOops::shift();
 211     if (UseCompressedOops) {
 212       _heap_begin = CompressedOops::begin();
 213       _heap_end = CompressedOops::end();
 214     } else {
 215 #if INCLUDE_G1GC
 216       address start = (address)G1CollectedHeap::heap()->reserved().start();
 217       address end = (address)G1CollectedHeap::heap()->reserved().end();
 218       _heap_begin = HeapShared::to_requested_address(start);
 219       _heap_end = HeapShared::to_requested_address(end);
 220 #endif
 221     }
 222   }
 223   _compressed_oops = UseCompressedOops;
 224   _compressed_class_ptrs = UseCompressedClassPointers;
 225   _max_heap_size = MaxHeapSize;
 226   _narrow_klass_shift = CompressedKlassPointers::shift();
 227   _use_optimized_module_handling = MetaspaceShared::use_optimized_module_handling();
 228   _use_full_module_graph = MetaspaceShared::use_full_module_graph();
 229 
 230   // The following fields are for sanity checks for whether this archive
 231   // will function correctly with this JVM and the bootclasspath it's
 232   // invoked with.
 233 
 234   // JVM version string ... changes on each build.
 235   get_header_version(_jvm_ident);
 236 
 237   _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();
 238   _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();
 239   _num_module_paths = ClassLoader::num_module_path_entries();
 240   _max_used_path_index = ClassLoaderExt::max_used_path_index();
 241 
 242   _verify_local = BytecodeVerificationLocal;
 243   _verify_remote = BytecodeVerificationRemote;
 244   _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();
 245   _has_non_jar_in_classpath = ClassLoaderExt::has_non_jar_in_classpath();
 246   _requested_base_address = (char*)SharedBaseAddress;
 247   _mapped_base_address = (char*)SharedBaseAddress;
 248   _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;
 249 
 250   if (!DynamicDumpSharedSpaces) {
 251     set_shared_path_table(info->_shared_path_table);
 252   }
 253 }
 254 
 255 void FileMapHeader::copy_base_archive_name(const char* archive) {
 256   assert(base_archive_name_size() != 0, "_base_archive_name_size not set");
 257   assert(base_archive_name_offset() != 0, "_base_archive_name_offset not set");
 258   assert(header_size() > sizeof(*this), "_base_archive_name_size not included in header size?");
 259   memcpy((char*)this + base_archive_name_offset(), archive, base_archive_name_size());
 260 }
 261 
 262 void FileMapHeader::print(outputStream* st) {
 263   ResourceMark rm;
 264 
 265   st->print_cr("- magic:                          0x%08x", magic());
 266   st->print_cr("- crc:                            0x%08x", crc());
 267   st->print_cr("- version:                        0x%x", version());
 268   st->print_cr("- header_size:                    " UINT32_FORMAT, header_size());
 269   st->print_cr("- common_app_classpath_size:      " UINT32_FORMAT, common_app_classpath_prefix_size());
 270   st->print_cr("- base_archive_name_offset:       " UINT32_FORMAT, base_archive_name_offset());
 271   st->print_cr("- base_archive_name_size:         " UINT32_FORMAT, base_archive_name_size());
 272 
 273   for (int i = 0; i < NUM_CDS_REGIONS; i++) {
 274     FileMapRegion* r = region_at(i);
 275     r->print(st, i);
 276   }
 277   st->print_cr("============ end regions ======== ");
 278 
 279   st->print_cr("- core_region_alignment:          " SIZE_FORMAT, _core_region_alignment);
 280   st->print_cr("- obj_alignment:                  %d", _obj_alignment);
 281   st->print_cr("- narrow_oop_base:                " INTPTR_FORMAT, p2i(_narrow_oop_base));
 282   st->print_cr("- narrow_oop_base:                " INTPTR_FORMAT, p2i(_narrow_oop_base));
 283   st->print_cr("- narrow_oop_shift                %d", _narrow_oop_shift);
 284   st->print_cr("- compact_strings:                %d", _compact_strings);
 285   st->print_cr("- compact_headers:                %d", _compact_headers);
 286   st->print_cr("- max_heap_size:                  " UINTX_FORMAT, _max_heap_size);
 287   st->print_cr("- narrow_oop_mode:                %d", _narrow_oop_mode);
 288   st->print_cr("- narrow_klass_shift:             %d", _narrow_klass_shift);
 289   st->print_cr("- compressed_oops:                %d", _compressed_oops);
 290   st->print_cr("- compressed_class_ptrs:          %d", _compressed_class_ptrs);
 291   st->print_cr("- cloned_vtables_offset:          " SIZE_FORMAT_X, _cloned_vtables_offset);
 292   st->print_cr("- serialized_data_offset:         " SIZE_FORMAT_X, _serialized_data_offset);
 293   st->print_cr("- heap_begin:                     " INTPTR_FORMAT, p2i(_heap_begin));
 294   st->print_cr("- heap_end:                       " INTPTR_FORMAT, p2i(_heap_end));
 295   st->print_cr("- jvm_ident:                      %s", _jvm_ident);
 296   st->print_cr("- shared_path_table_offset:       " SIZE_FORMAT_X, _shared_path_table_offset);
 297   st->print_cr("- app_class_paths_start_index:    %d", _app_class_paths_start_index);
 298   st->print_cr("- app_module_paths_start_index:   %d", _app_module_paths_start_index);
 299   st->print_cr("- num_module_paths:               %d", _num_module_paths);
 300   st->print_cr("- max_used_path_index:            %d", _max_used_path_index);
 301   st->print_cr("- verify_local:                   %d", _verify_local);
 302   st->print_cr("- verify_remote:                  %d", _verify_remote);
 303   st->print_cr("- has_platform_or_app_classes:    %d", _has_platform_or_app_classes);
 304   st->print_cr("- has_non_jar_in_classpath:       %d", _has_non_jar_in_classpath);
 305   st->print_cr("- requested_base_address:         " INTPTR_FORMAT, p2i(_requested_base_address));
 306   st->print_cr("- mapped_base_address:            " INTPTR_FORMAT, p2i(_mapped_base_address));
 307   st->print_cr("- allow_archiving_with_java_agent:%d", _allow_archiving_with_java_agent);
 308   st->print_cr("- use_optimized_module_handling:  %d", _use_optimized_module_handling);
 309   st->print_cr("- use_full_module_graph           %d", _use_full_module_graph);
 310   st->print_cr("- ptrmap_size_in_bits:            " SIZE_FORMAT, _ptrmap_size_in_bits);
 311 }
 312 
 313 void SharedClassPathEntry::init_as_non_existent(const char* path, TRAPS) {
 314   _type = non_existent_entry;
 315   set_name(path, CHECK);
 316 }
 317 
 318 void SharedClassPathEntry::init(bool is_modules_image,
 319                                 bool is_module_path,
 320                                 ClassPathEntry* cpe, TRAPS) {
 321   Arguments::assert_is_dumping_archive();
 322   _timestamp = 0;
 323   _filesize  = 0;
 324   _from_class_path_attr = false;
 325 
 326   struct stat st;
 327   if (os::stat(cpe->name(), &st) == 0) {
 328     if ((st.st_mode & S_IFMT) == S_IFDIR) {
 329       _type = dir_entry;
 330     } else {
 331       // The timestamp of the modules_image is not checked at runtime.
 332       if (is_modules_image) {
 333         _type = modules_image_entry;
 334       } else {
 335         _type = jar_entry;
 336         _timestamp = st.st_mtime;
 337         _from_class_path_attr = cpe->from_class_path_attr();
 338       }
 339       _filesize = st.st_size;
 340       _is_module_path = is_module_path;
 341     }
 342   } else {
 343     // The file/dir must exist, or it would not have been added
 344     // into ClassLoader::classpath_entry().
 345     //
 346     // If we can't access a jar file in the boot path, then we can't
 347     // make assumptions about where classes get loaded from.
 348     log_error(cds)("Unable to open file %s.", cpe->name());
 349     MetaspaceShared::unrecoverable_loading_error();
 350   }
 351 
 352   // No need to save the name of the module file, as it will be computed at run time
 353   // to allow relocation of the JDK directory.
 354   const char* name = is_modules_image  ? "" : cpe->name();
 355   set_name(name, CHECK);
 356 }
 357 
 358 void SharedClassPathEntry::set_name(const char* name, TRAPS) {
 359   size_t len = strlen(name) + 1;
 360   _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, CHECK);
 361   strcpy(_name->data(), name);
 362 }
 363 
 364 void SharedClassPathEntry::copy_from(SharedClassPathEntry* ent, ClassLoaderData* loader_data, TRAPS) {
 365   assert(ent != nullptr, "sanity");
 366   _type = ent->_type;
 367   _is_module_path = ent->_is_module_path;
 368   _timestamp = ent->_timestamp;
 369   _filesize = ent->_filesize;
 370   _from_class_path_attr = ent->_from_class_path_attr;
 371   set_name(ent->name(), CHECK);
 372 
 373   if (ent->is_jar() && !ent->is_signed() && ent->manifest() != nullptr) {
 374     Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 375                                                     ent->manifest_size(),
 376                                                     CHECK);
 377     char* p = (char*)(buf->data());
 378     memcpy(p, ent->manifest(), ent->manifest_size());
 379     set_manifest(buf);
 380   }
 381 }
 382 
 383 const char* SharedClassPathEntry::name() const {
 384   if (UseSharedSpaces && is_modules_image()) {
 385     // In order to validate the runtime modules image file size against the archived
 386     // size information, we need to obtain the runtime modules image path. The recorded
 387     // dump time modules image path in the archive may be different from the runtime path
 388     // if the JDK image has beed moved after generating the archive.
 389     return ClassLoader::get_jrt_entry()->name();
 390   } else {
 391     return _name->data();
 392   }
 393 }
 394 
 395 bool SharedClassPathEntry::validate(bool is_class_path) const {
 396   assert(UseSharedSpaces, "runtime only");
 397 
 398   struct stat st;
 399   const char* name = this->name();
 400 
 401   bool ok = true;
 402   log_info(class, path)("checking shared classpath entry: %s", name);
 403   if (os::stat(name, &st) != 0 && is_class_path) {
 404     // If the archived module path entry does not exist at runtime, it is not fatal
 405     // (no need to invalid the shared archive) because the shared runtime visibility check
 406     // filters out any archived module classes that do not have a matching runtime
 407     // module path location.
 408     log_warning(cds)("Required classpath entry does not exist: %s", name);
 409     ok = false;
 410   } else if (is_dir()) {
 411     if (!os::dir_is_empty(name)) {
 412       log_warning(cds)("directory is not empty: %s", name);
 413       ok = false;
 414     }
 415   } else if ((has_timestamp() && _timestamp != st.st_mtime) ||
 416              _filesize != st.st_size) {
 417     ok = false;
 418     if (PrintSharedArchiveAndExit) {
 419       log_warning(cds)(_timestamp != st.st_mtime ?
 420                                  "Timestamp mismatch" :
 421                                  "File size mismatch");
 422     } else {
 423       const char* bad_jar_msg = "A jar file is not the one used while building the shared archive file:";
 424       log_warning(cds)("%s %s", bad_jar_msg, name);
 425       if (!log_is_enabled(Info, cds)) {
 426         log_warning(cds)("%s %s", bad_jar_msg, name);
 427       }
 428       if (_timestamp != st.st_mtime) {
 429         log_warning(cds)("%s timestamp has changed.", name);
 430       } else {
 431         log_warning(cds)("%s size has changed.", name);
 432       }
 433     }
 434   }
 435 
 436   if (PrintSharedArchiveAndExit && !ok) {
 437     // If PrintSharedArchiveAndExit is enabled, don't report failure to the
 438     // caller. Please see above comments for more details.
 439     ok = true;
 440     MetaspaceShared::set_archive_loading_failed();
 441   }
 442   return ok;
 443 }
 444 
 445 bool SharedClassPathEntry::check_non_existent() const {
 446   assert(_type == non_existent_entry, "must be");
 447   log_info(class, path)("should be non-existent: %s", name());
 448   struct stat st;
 449   if (os::stat(name(), &st) != 0) {
 450     log_info(class, path)("ok");
 451     return true; // file doesn't exist
 452   } else {
 453     return false;
 454   }
 455 }
 456 
 457 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
 458   it->push(&_name);
 459   it->push(&_manifest);
 460 }
 461 
 462 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
 463   it->push(&_entries);
 464 }
 465 
 466 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, TRAPS) {
 467   const int num_entries =
 468     ClassLoader::num_boot_classpath_entries() +
 469     ClassLoader::num_app_classpath_entries() +
 470     ClassLoader::num_module_path_entries() +
 471     FileMapInfo::num_non_existent_class_paths();
 472   _entries = MetadataFactory::new_array<SharedClassPathEntry*>(loader_data, num_entries, CHECK);
 473   for (int i = 0; i < num_entries; i++) {
 474     SharedClassPathEntry* ent =
 475       new (loader_data, SharedClassPathEntry::size(), MetaspaceObj::SharedClassPathEntryType, THREAD) SharedClassPathEntry;
 476     _entries->at_put(i, ent);
 477   }
 478 }
 479 
 480 void FileMapInfo::allocate_shared_path_table(TRAPS) {
 481   Arguments::assert_is_dumping_archive();
 482 
 483   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 484   ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
 485 
 486   assert(jrt != nullptr,
 487          "No modular java runtime image present when allocating the CDS classpath entry table");
 488 
 489   _shared_path_table.dumptime_init(loader_data, CHECK);
 490 
 491   // 1. boot class path
 492   int i = 0;
 493   i = add_shared_classpaths(i, "boot",   jrt, CHECK);
 494   i = add_shared_classpaths(i, "app",    ClassLoader::app_classpath_entries(), CHECK);
 495   i = add_shared_classpaths(i, "module", ClassLoader::module_path_entries(), CHECK);
 496 
 497   for (int x = 0; x < num_non_existent_class_paths(); x++, i++) {
 498     const char* path = _non_existent_class_paths->at(x);
 499     shared_path(i)->init_as_non_existent(path, CHECK);
 500   }
 501 
 502   assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
 503 }
 504 
 505 int FileMapInfo::add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS) {
 506   while (cpe != nullptr) {
 507     bool is_jrt = (cpe == ClassLoader::get_jrt_entry());
 508     bool is_module_path = i >= ClassLoaderExt::app_module_paths_start_index();
 509     const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
 510     log_info(class, path)("add %s shared path (%s) %s", which, type, cpe->name());
 511     SharedClassPathEntry* ent = shared_path(i);
 512     ent->init(is_jrt, is_module_path, cpe, CHECK_0);
 513     if (cpe->is_jar_file()) {
 514       update_jar_manifest(cpe, ent, CHECK_0);
 515     }
 516     if (is_jrt) {
 517       cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
 518     } else {
 519       cpe = cpe->next();
 520     }
 521     i++;
 522   }
 523 
 524   return i;
 525 }
 526 
 527 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
 528   Arguments::assert_is_dumping_archive();
 529 
 530   bool has_nonempty_dir = false;
 531 
 532   int last = _shared_path_table.size() - 1;
 533   if (last > ClassLoaderExt::max_used_path_index()) {
 534      // no need to check any path beyond max_used_path_index
 535      last = ClassLoaderExt::max_used_path_index();
 536   }
 537 
 538   for (int i = 0; i <= last; i++) {
 539     SharedClassPathEntry *e = shared_path(i);
 540     if (e->is_dir()) {
 541       const char* path = e->name();
 542       if (!os::dir_is_empty(path)) {
 543         log_error(cds)("Error: non-empty directory '%s'", path);
 544         has_nonempty_dir = true;
 545       }
 546     }
 547   }
 548 
 549   if (has_nonempty_dir) {
 550     ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", nullptr);
 551   }
 552 }
 553 
 554 void FileMapInfo::record_non_existent_class_path_entry(const char* path) {
 555   Arguments::assert_is_dumping_archive();
 556   log_info(class, path)("non-existent Class-Path entry %s", path);
 557   if (_non_existent_class_paths == nullptr) {
 558     _non_existent_class_paths = new (mtClass) GrowableArray<const char*>(10, mtClass);
 559   }
 560   _non_existent_class_paths->append(os::strdup(path));
 561 }
 562 
 563 int FileMapInfo::num_non_existent_class_paths() {
 564   Arguments::assert_is_dumping_archive();
 565   if (_non_existent_class_paths != nullptr) {
 566     return _non_existent_class_paths->length();
 567   } else {
 568     return 0;
 569   }
 570 }
 571 
 572 int FileMapInfo::get_module_shared_path_index(Symbol* location) {
 573   if (location->starts_with("jrt:", 4) && get_number_of_shared_paths() > 0) {
 574     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 575     return 0;
 576   }
 577 
 578   if (ClassLoaderExt::app_module_paths_start_index() >= get_number_of_shared_paths()) {
 579     // The archive(s) were created without --module-path option
 580     return -1;
 581   }
 582 
 583   if (!location->starts_with("file:", 5)) {
 584     return -1;
 585   }
 586 
 587   // skip_uri_protocol was also called during dump time -- see ClassLoaderExt::process_module_table()
 588   ResourceMark rm;
 589   const char* file = ClassLoader::skip_uri_protocol(location->as_C_string());
 590   for (int i = ClassLoaderExt::app_module_paths_start_index(); i < get_number_of_shared_paths(); i++) {
 591     SharedClassPathEntry* ent = shared_path(i);
 592     assert(ent->in_named_module(), "must be");
 593     bool cond = strcmp(file, ent->name()) == 0;
 594     log_debug(class, path)("get_module_shared_path_index (%d) %s : %s = %s", i,
 595                            location->as_C_string(), ent->name(), cond ? "same" : "different");
 596     if (cond) {
 597       return i;
 598     }
 599   }
 600 
 601   return -1;
 602 }
 603 
 604 class ManifestStream: public ResourceObj {
 605   private:
 606   u1*   _buffer_start; // Buffer bottom
 607   u1*   _buffer_end;   // Buffer top (one past last element)
 608   u1*   _current;      // Current buffer position
 609 
 610  public:
 611   // Constructor
 612   ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
 613                                            _current(buffer) {
 614     _buffer_end = buffer + length;
 615   }
 616 
 617   static bool is_attr(u1* attr, const char* name) {
 618     return strncmp((const char*)attr, name, strlen(name)) == 0;
 619   }
 620 
 621   static char* copy_attr(u1* value, size_t len) {
 622     char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
 623     strncpy(buf, (char*)value, len);
 624     buf[len] = 0;
 625     return buf;
 626   }
 627 
 628   // The return value indicates if the JAR is signed or not
 629   bool check_is_signed() {
 630     u1* attr = _current;
 631     bool isSigned = false;
 632     while (_current < _buffer_end) {
 633       if (*_current == '\n') {
 634         *_current = '\0';
 635         u1* value = (u1*)strchr((char*)attr, ':');
 636         if (value != nullptr) {
 637           assert(*(value+1) == ' ', "Unrecognized format" );
 638           if (strstr((char*)attr, "-Digest") != nullptr) {
 639             isSigned = true;
 640             break;
 641           }
 642         }
 643         *_current = '\n'; // restore
 644         attr = _current + 1;
 645       }
 646       _current ++;
 647     }
 648     return isSigned;
 649   }
 650 };
 651 
 652 void FileMapInfo::update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
 653   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 654   ResourceMark rm(THREAD);
 655   jint manifest_size;
 656 
 657   assert(cpe->is_jar_file() && ent->is_jar(), "the shared class path entry is not a JAR file");
 658   char* manifest = ClassLoaderExt::read_manifest(THREAD, cpe, &manifest_size);
 659   if (manifest != nullptr) {
 660     ManifestStream* stream = new ManifestStream((u1*)manifest,
 661                                                 manifest_size);
 662     if (stream->check_is_signed()) {
 663       ent->set_is_signed();
 664     } else {
 665       // Copy the manifest into the shared archive
 666       manifest = ClassLoaderExt::read_raw_manifest(THREAD, cpe, &manifest_size);
 667       Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 668                                                       manifest_size,
 669                                                       CHECK);
 670       char* p = (char*)(buf->data());
 671       memcpy(p, manifest, manifest_size);
 672       ent->set_manifest(buf);
 673     }
 674   }
 675 }
 676 
 677 char* FileMapInfo::skip_first_path_entry(const char* path) {
 678   size_t path_sep_len = strlen(os::path_separator());
 679   char* p = strstr((char*)path, os::path_separator());
 680   if (p != nullptr) {
 681     debug_only( {
 682       size_t image_name_len = strlen(MODULES_IMAGE_NAME);
 683       assert(strncmp(p - image_name_len, MODULES_IMAGE_NAME, image_name_len) == 0,
 684              "first entry must be the modules image");
 685     } );
 686     p += path_sep_len;
 687   } else {
 688     debug_only( {
 689       assert(ClassLoader::string_ends_with(path, MODULES_IMAGE_NAME),
 690              "first entry must be the modules image");
 691     } );
 692   }
 693   return p;
 694 }
 695 
 696 int FileMapInfo::num_paths(const char* path) {
 697   if (path == nullptr) {
 698     return 0;
 699   }
 700   int npaths = 1;
 701   char* p = (char*)path;
 702   while (p != nullptr) {
 703     char* prev = p;
 704     p = strstr((char*)p, os::path_separator());
 705     if (p != nullptr) {
 706       p++;
 707       // don't count empty path
 708       if ((p - prev) > 1) {
 709        npaths++;
 710       }
 711     }
 712   }
 713   return npaths;
 714 }
 715 
 716 // Returns true if a path within the paths exists and has non-zero size.
 717 bool FileMapInfo::check_paths_existence(const char* paths) {
 718   ClasspathStream cp_stream(paths);
 719   bool exist = false;
 720   struct stat st;
 721   while (cp_stream.has_next()) {
 722     const char* path = cp_stream.get_next();
 723     if (os::stat(path, &st) == 0 && st.st_size > 0) {
 724       exist = true;
 725       break;
 726     }
 727   }
 728   return exist;
 729 }
 730 
 731 GrowableArray<const char*>* FileMapInfo::create_dumptime_app_classpath_array() {
 732   Arguments::assert_is_dumping_archive();
 733   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 734   ClassPathEntry* cpe = ClassLoader::app_classpath_entries();
 735   while (cpe != nullptr) {
 736     path_array->append(cpe->name());
 737     cpe = cpe->next();
 738   }
 739   return path_array;
 740 }
 741 
 742 GrowableArray<const char*>* FileMapInfo::create_path_array(const char* paths) {
 743   GrowableArray<const char*>* path_array = new GrowableArray<const char*>(10);
 744   JavaThread* current = JavaThread::current();
 745   ClasspathStream cp_stream(paths);
 746   bool non_jar_in_cp = header()->has_non_jar_in_classpath();
 747   while (cp_stream.has_next()) {
 748     const char* path = cp_stream.get_next();
 749     if (!non_jar_in_cp) {
 750       struct stat st;
 751       if (os::stat(path, &st) == 0) {
 752         path_array->append(path);
 753       }
 754     } else {
 755       const char* canonical_path = ClassLoader::get_canonical_path(path, current);
 756       if (canonical_path != nullptr) {
 757         char* error_msg = nullptr;
 758         jzfile* zip = ClassLoader::open_zip_file(canonical_path, &error_msg, current);
 759         if (zip != nullptr && error_msg == nullptr) {
 760           path_array->append(path);
 761         }
 762       }
 763     }
 764   }
 765   return path_array;
 766 }
 767 
 768 bool FileMapInfo::classpath_failure(const char* msg, const char* name) {
 769   ClassLoader::trace_class_path(msg, name);
 770   if (PrintSharedArchiveAndExit) {
 771     MetaspaceShared::set_archive_loading_failed();
 772   }
 773   return false;
 774 }
 775 
 776 unsigned int FileMapInfo::longest_common_app_classpath_prefix_len(int num_paths,
 777                                                                   GrowableArray<const char*>* rp_array) {
 778   if (num_paths == 0) {
 779     return 0;
 780   }
 781   unsigned int pos;
 782   for (pos = 0; ; pos++) {
 783     for (int i = 0; i < num_paths; i++) {
 784       if (rp_array->at(i)[pos] != '\0' && rp_array->at(i)[pos] == rp_array->at(0)[pos]) {
 785         continue;
 786       }
 787       // search backward for the pos before the file separator char
 788       while (pos > 0) {
 789         if (rp_array->at(0)[--pos] == *os::file_separator()) {
 790           return pos + 1;
 791         }
 792       }
 793       return 0;
 794     }
 795   }
 796   return 0;
 797 }
 798 
 799 bool FileMapInfo::check_paths(int shared_path_start_idx, int num_paths, GrowableArray<const char*>* rp_array,
 800                               unsigned int dumptime_prefix_len, unsigned int runtime_prefix_len) {
 801   int i = 0;
 802   int j = shared_path_start_idx;
 803   while (i < num_paths) {
 804     while (shared_path(j)->from_class_path_attr()) {
 805       // shared_path(j) was expanded from the JAR file attribute "Class-Path:"
 806       // during dump time. It's not included in the -classpath VM argument.
 807       j++;
 808     }
 809     assert(strlen(shared_path(j)->name()) > (size_t)dumptime_prefix_len, "sanity");
 810     const char* dumptime_path = shared_path(j)->name() + dumptime_prefix_len;
 811     assert(strlen(rp_array->at(i)) > (size_t)runtime_prefix_len, "sanity");
 812     const char* runtime_path = rp_array->at(i)  + runtime_prefix_len;
 813     if (!os::same_files(dumptime_path, runtime_path)) {
 814       return true;
 815     }
 816     i++;
 817     j++;
 818   }
 819   return false;
 820 }
 821 
 822 bool FileMapInfo::validate_boot_class_paths() {
 823   //
 824   // - Archive contains boot classes only - relaxed boot path check:
 825   //   Extra path elements appended to the boot path at runtime are allowed.
 826   //
 827   // - Archive contains application or platform classes - strict boot path check:
 828   //   Validate the entire runtime boot path, which must be compatible
 829   //   with the dump time boot path. Appending boot path at runtime is not
 830   //   allowed.
 831   //
 832 
 833   // The first entry in boot path is the modules_image (guaranteed by
 834   // ClassLoader::setup_boot_search_path()). Skip the first entry. The
 835   // path of the runtime modules_image may be different from the dump
 836   // time path (e.g. the JDK image is copied to a different location
 837   // after generating the shared archive), which is acceptable. For most
 838   // common cases, the dump time boot path might contain modules_image only.
 839   char* runtime_boot_path = Arguments::get_boot_class_path();
 840   char* rp = skip_first_path_entry(runtime_boot_path);
 841   assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 842   int dp_len = header()->app_class_paths_start_index() - 1; // ignore the first path to the module image
 843   bool mismatch = false;
 844 
 845   bool relaxed_check = !header()->has_platform_or_app_classes();
 846   if (dp_len == 0 && rp == nullptr) {
 847     return true;   // ok, both runtime and dump time boot paths have modules_images only
 848   } else if (dp_len == 0 && rp != nullptr) {
 849     if (relaxed_check) {
 850       return true;   // ok, relaxed check, runtime has extra boot append path entries
 851     } else {
 852       ResourceMark rm;
 853       if (check_paths_existence(rp)) {
 854         // If a path exists in the runtime boot paths, it is considered a mismatch
 855         // since there's no boot path specified during dump time.
 856         mismatch = true;
 857       }
 858     }
 859   } else if (dp_len > 0 && rp != nullptr) {
 860     int num;
 861     ResourceMark rm;
 862     GrowableArray<const char*>* rp_array = create_path_array(rp);
 863     int rp_len = rp_array->length();
 864     if (rp_len >= dp_len) {
 865       if (relaxed_check) {
 866         // only check the leading entries in the runtime boot path, up to
 867         // the length of the dump time boot path
 868         num = dp_len;
 869       } else {
 870         // check the full runtime boot path, must match with dump time
 871         num = rp_len;
 872       }
 873       mismatch = check_paths(1, num, rp_array, 0, 0);
 874     } else {
 875       // create_path_array() ignores non-existing paths. Although the dump time and runtime boot classpath lengths
 876       // are the same initially, after the call to create_path_array(), the runtime boot classpath length could become
 877       // shorter. We consider boot classpath mismatch in this case.
 878       mismatch = true;
 879     }
 880   }
 881 
 882   if (mismatch) {
 883     // The paths are different
 884     return classpath_failure("[BOOT classpath mismatch, actual =", runtime_boot_path);
 885   }
 886   return true;
 887 }
 888 
 889 bool FileMapInfo::validate_app_class_paths(int shared_app_paths_len) {
 890   const char *appcp = Arguments::get_appclasspath();
 891   assert(appcp != nullptr, "null app classpath");
 892   int rp_len = num_paths(appcp);
 893   bool mismatch = false;
 894   if (rp_len < shared_app_paths_len) {
 895     return classpath_failure("Run time APP classpath is shorter than the one at dump time: ", appcp);
 896   }
 897   if (shared_app_paths_len != 0 && rp_len != 0) {
 898     // Prefix is OK: E.g., dump with -cp foo.jar, but run with -cp foo.jar:bar.jar.
 899     ResourceMark rm;
 900     GrowableArray<const char*>* rp_array = create_path_array(appcp);
 901     if (rp_array->length() == 0) {
 902       // None of the jar file specified in the runtime -cp exists.
 903       return classpath_failure("None of the jar file specified in the runtime -cp exists: -Djava.class.path=", appcp);
 904     }
 905     if (rp_array->length() < shared_app_paths_len) {
 906       // create_path_array() ignores non-existing paths. Although the dump time and runtime app classpath lengths
 907       // are the same initially, after the call to create_path_array(), the runtime app classpath length could become
 908       // shorter. We consider app classpath mismatch in this case.
 909       return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 910     }
 911 
 912     // Handling of non-existent entries in the classpath: we eliminate all the non-existent
 913     // entries from both the dump time classpath (ClassLoader::update_class_path_entry_list)
 914     // and the runtime classpath (FileMapInfo::create_path_array), and check the remaining
 915     // entries. E.g.:
 916     //
 917     // dump : -cp a.jar:NE1:NE2:b.jar  -> a.jar:b.jar -> recorded in archive.
 918     // run 1: -cp NE3:a.jar:NE4:b.jar  -> a.jar:b.jar -> matched
 919     // run 2: -cp x.jar:NE4:b.jar      -> x.jar:b.jar -> mismatched
 920 
 921     int j = header()->app_class_paths_start_index();
 922     mismatch = check_paths(j, shared_app_paths_len, rp_array, 0, 0);
 923     if (mismatch) {
 924       // To facilitate app deployment, we allow the JAR files to be moved *together* to
 925       // a different location, as long as they are still stored under the same directory
 926       // structure. E.g., the following is OK.
 927       //     java -Xshare:dump -cp /a/Foo.jar:/a/b/Bar.jar  ...
 928       //     java -Xshare:auto -cp /x/y/Foo.jar:/x/y/b/Bar.jar  ...
 929       unsigned int dumptime_prefix_len = header()->common_app_classpath_prefix_size();
 930       unsigned int runtime_prefix_len = longest_common_app_classpath_prefix_len(shared_app_paths_len, rp_array);
 931       if (dumptime_prefix_len != 0 || runtime_prefix_len != 0) {
 932         log_info(class, path)("LCP length for app classpath (dumptime: %u, runtime: %u)",
 933                               dumptime_prefix_len, runtime_prefix_len);
 934         mismatch = check_paths(j, shared_app_paths_len, rp_array,
 935                                dumptime_prefix_len, runtime_prefix_len);
 936       }
 937       if (mismatch) {
 938         return classpath_failure("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 939       }
 940     }
 941   }
 942   return true;
 943 }
 944 
 945 void FileMapInfo::log_paths(const char* msg, int start_idx, int end_idx) {
 946   LogTarget(Info, class, path) lt;
 947   if (lt.is_enabled()) {
 948     LogStream ls(lt);
 949     ls.print("%s", msg);
 950     const char* prefix = "";
 951     for (int i = start_idx; i < end_idx; i++) {
 952       ls.print("%s%s", prefix, shared_path(i)->name());
 953       prefix = os::path_separator();
 954     }
 955     ls.cr();
 956   }
 957 }
 958 
 959 bool FileMapInfo::check_module_paths() {
 960   const char* rp = Arguments::get_property("jdk.module.path");
 961   int num_paths = Arguments::num_archives(rp);
 962   if (num_paths != header()->num_module_paths()) {
 963     return false;
 964   }
 965   ResourceMark rm;
 966   GrowableArray<const char*>* rp_array = create_path_array(rp);
 967   return check_paths(header()->app_module_paths_start_index(), num_paths, rp_array, 0, 0);
 968 }
 969 
 970 bool FileMapInfo::validate_shared_path_table() {
 971   assert(UseSharedSpaces, "runtime only");
 972 
 973   _validating_shared_path_table = true;
 974 
 975   // Load the shared path table info from the archive header
 976   _shared_path_table = header()->shared_path_table();
 977   if (DynamicDumpSharedSpaces) {
 978     // Only support dynamic dumping with the usage of the default CDS archive
 979     // or a simple base archive.
 980     // If the base layer archive contains additional path component besides
 981     // the runtime image and the -cp, dynamic dumping is disabled.
 982     //
 983     // When dynamic archiving is enabled, the _shared_path_table is overwritten
 984     // to include the application path and stored in the top layer archive.
 985     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 986     if (header()->app_class_paths_start_index() > 1) {
 987       DynamicDumpSharedSpaces = false;
 988       log_warning(cds)(
 989         "Dynamic archiving is disabled because base layer archive has appended boot classpath");
 990     }
 991     if (header()->num_module_paths() > 0) {
 992       if (!check_module_paths()) {
 993         DynamicDumpSharedSpaces = false;
 994         log_warning(cds)(
 995           "Dynamic archiving is disabled because base layer archive has a different module path");
 996       }
 997     }
 998   }
 999 
1000   log_paths("Expecting BOOT path=", 0, header()->app_class_paths_start_index());
1001   log_paths("Expecting -Djava.class.path=", header()->app_class_paths_start_index(), header()->app_module_paths_start_index());
1002 
1003   int module_paths_start_index = header()->app_module_paths_start_index();
1004   int shared_app_paths_len = 0;
1005 
1006   // validate the path entries up to the _max_used_path_index
1007   for (int i=0; i < header()->max_used_path_index() + 1; i++) {
1008     if (i < module_paths_start_index) {
1009       if (shared_path(i)->validate()) {
1010         // Only count the app class paths not from the "Class-path" attribute of a jar manifest.
1011         if (!shared_path(i)->from_class_path_attr() && i >= header()->app_class_paths_start_index()) {
1012           shared_app_paths_len++;
1013         }
1014         log_info(class, path)("ok");
1015       } else {
1016         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
1017           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
1018         }
1019         return false;
1020       }
1021     } else if (i >= module_paths_start_index) {
1022       if (shared_path(i)->validate(false /* not a class path entry */)) {
1023         log_info(class, path)("ok");
1024       } else {
1025         if (_dynamic_archive_info != nullptr && _dynamic_archive_info->_is_static) {
1026           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
1027         }
1028         return false;
1029       }
1030     }
1031   }
1032 
1033   if (header()->max_used_path_index() == 0) {
1034     // default archive only contains the module image in the bootclasspath
1035     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
1036   } else {
1037     if (!validate_boot_class_paths() || !validate_app_class_paths(shared_app_paths_len)) {
1038       const char* mismatch_msg = "shared class paths mismatch";
1039       const char* hint_msg = log_is_enabled(Info, class, path) ?
1040           "" : " (hint: enable -Xlog:class+path=info to diagnose the failure)";
1041       if (RequireSharedSpaces) {
1042         log_error(cds)("%s%s", mismatch_msg, hint_msg);
1043         MetaspaceShared::unrecoverable_loading_error();
1044       } else {
1045         log_warning(cds)("%s%s", mismatch_msg, hint_msg);
1046       }
1047       return false;
1048     }
1049   }
1050 
1051   validate_non_existent_class_paths();
1052 
1053   _validating_shared_path_table = false;
1054 
1055 #if INCLUDE_JVMTI
1056   if (_classpath_entries_for_jvmti != nullptr) {
1057     os::free(_classpath_entries_for_jvmti);
1058   }
1059   size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
1060   _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
1061   memset((void*)_classpath_entries_for_jvmti, 0, sz);
1062 #endif
1063 
1064   return true;
1065 }
1066 
1067 void FileMapInfo::validate_non_existent_class_paths() {
1068   // All of the recorded non-existent paths came from the Class-Path: attribute from the JAR
1069   // files on the app classpath. If any of these are found to exist during runtime,
1070   // it will change how classes are loading for the app loader. For safety, disable
1071   // loading of archived platform/app classes (currently there's no way to disable just the
1072   // app classes).
1073 
1074   assert(UseSharedSpaces, "runtime only");
1075   for (int i = header()->app_module_paths_start_index() + header()->num_module_paths();
1076        i < get_number_of_shared_paths();
1077        i++) {
1078     SharedClassPathEntry* ent = shared_path(i);
1079     if (!ent->check_non_existent()) {
1080       log_warning(cds)("Archived non-system classes are disabled because the "
1081               "file %s exists", ent->name());
1082       header()->set_has_platform_or_app_classes(false);
1083     }
1084   }
1085 }
1086 
1087 // A utility class for reading/validating the GenericCDSFileMapHeader portion of
1088 // a CDS archive's header. The file header of all CDS archives with versions from
1089 // CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION (12) are guaranteed to always start
1090 // with GenericCDSFileMapHeader. This makes it possible to read important information
1091 // from a CDS archive created by a different version of HotSpot, so that we can
1092 // automatically regenerate the archive as necessary (JDK-8261455).
1093 class FileHeaderHelper {
1094   int _fd;
1095   bool _is_valid;
1096   bool _is_static;
1097   GenericCDSFileMapHeader* _header;
1098   const char* _archive_name;
1099   const char* _base_archive_name;
1100 
1101 public:
1102   FileHeaderHelper(const char* archive_name, bool is_static) {
1103     _fd = -1;
1104     _is_valid = false;
1105     _header = nullptr;
1106     _base_archive_name = nullptr;
1107     _archive_name = archive_name;
1108     _is_static = is_static;
1109   }
1110 
1111   ~FileHeaderHelper() {
1112     if (_header != nullptr) {
1113       FREE_C_HEAP_ARRAY(char, _header);
1114     }
1115     if (_fd != -1) {
1116       ::close(_fd);
1117     }
1118   }
1119 
1120   bool initialize() {
1121     assert(_archive_name != nullptr, "Archive name is null");
1122     _fd = os::open(_archive_name, O_RDONLY | O_BINARY, 0);
1123     if (_fd < 0) {
1124       log_info(cds)("Specified shared archive not found (%s)", _archive_name);
1125       return false;
1126     }
1127     return initialize(_fd);
1128   }
1129 
1130   // for an already opened file, do not set _fd
1131   bool initialize(int fd) {
1132     assert(_archive_name != nullptr, "Archive name is null");
1133     assert(fd != -1, "Archive must be opened already");
1134     // First read the generic header so we know the exact size of the actual header.
1135     GenericCDSFileMapHeader gen_header;
1136     size_t size = sizeof(GenericCDSFileMapHeader);
1137     os::lseek(fd, 0, SEEK_SET);
1138     size_t n = ::read(fd, (void*)&gen_header, (unsigned int)size);
1139     if (n != size) {
1140       log_warning(cds)("Unable to read generic CDS file map header from shared archive");
1141       return false;
1142     }
1143 
1144     if (gen_header._magic != CDS_ARCHIVE_MAGIC &&
1145         gen_header._magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1146       log_warning(cds)("The shared archive file has a bad magic number: %#x", gen_header._magic);
1147       return false;
1148     }
1149 
1150     if (gen_header._version < CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION) {
1151       log_warning(cds)("Cannot handle shared archive file version 0x%x. Must be at least 0x%x.",
1152                                  gen_header._version, CDS_GENERIC_HEADER_SUPPORTED_MIN_VERSION);
1153       return false;
1154     }
1155 
1156     if (gen_header._version !=  CURRENT_CDS_ARCHIVE_VERSION) {
1157       log_warning(cds)("The shared archive file version 0x%x does not match the required version 0x%x.",
1158                                  gen_header._version, CURRENT_CDS_ARCHIVE_VERSION);
1159     }
1160 
1161     size_t filelen = os::lseek(fd, 0, SEEK_END);
1162     if (gen_header._header_size >= filelen) {
1163       log_warning(cds)("Archive file header larger than archive file");
1164       return false;
1165     }
1166 
1167     // Read the actual header and perform more checks
1168     size = gen_header._header_size;
1169     _header = (GenericCDSFileMapHeader*)NEW_C_HEAP_ARRAY(char, size, mtInternal);
1170     os::lseek(fd, 0, SEEK_SET);
1171     n = ::read(fd, (void*)_header, (unsigned int)size);
1172     if (n != size) {
1173       log_warning(cds)("Unable to read actual CDS file map header from shared archive");
1174       return false;
1175     }
1176 
1177     if (!check_header_crc()) {
1178       return false;
1179     }
1180 
1181     if (!check_and_init_base_archive_name()) {
1182       return false;
1183     }
1184 
1185     // All fields in the GenericCDSFileMapHeader has been validated.
1186     _is_valid = true;
1187     return true;
1188   }
1189 
1190   GenericCDSFileMapHeader* get_generic_file_header() {
1191     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1192     return _header;
1193   }
1194 
1195   const char* base_archive_name() {
1196     assert(_header != nullptr && _is_valid, "must be a valid archive file");
1197     return _base_archive_name;
1198   }
1199 
1200  private:
1201   bool check_header_crc() const {
1202     if (VerifySharedSpaces) {
1203       FileMapHeader* header = (FileMapHeader*)_header;
1204       int actual_crc = header->compute_crc();
1205       if (actual_crc != header->crc()) {
1206         log_info(cds)("_crc expected: %d", header->crc());
1207         log_info(cds)("       actual: %d", actual_crc);
1208         log_warning(cds)("Header checksum verification failed.");
1209         return false;
1210       }
1211     }
1212     return true;
1213   }
1214 
1215   bool check_and_init_base_archive_name() {
1216     unsigned int name_offset = _header->_base_archive_name_offset;
1217     unsigned int name_size   = _header->_base_archive_name_size;
1218     unsigned int header_size = _header->_header_size;
1219 
1220     if (name_offset + name_size < name_offset) {
1221       log_warning(cds)("base_archive_name offset/size overflow: " UINT32_FORMAT "/" UINT32_FORMAT,
1222                                  name_offset, name_size);
1223       return false;
1224     }
1225     if (_header->_magic == CDS_ARCHIVE_MAGIC) {
1226       if (name_offset != 0) {
1227         log_warning(cds)("static shared archive must have zero _base_archive_name_offset");
1228         return false;
1229       }
1230       if (name_size != 0) {
1231         log_warning(cds)("static shared archive must have zero _base_archive_name_size");
1232         return false;
1233       }
1234     } else {
1235       assert(_header->_magic == CDS_DYNAMIC_ARCHIVE_MAGIC, "must be");
1236       if ((name_size == 0 && name_offset != 0) ||
1237           (name_size != 0 && name_offset == 0)) {
1238         // If either is zero, both must be zero. This indicates that we are using the default base archive.
1239         log_warning(cds)("Invalid base_archive_name offset/size: " UINT32_FORMAT "/" UINT32_FORMAT,
1240                                    name_offset, name_size);
1241         return false;
1242       }
1243       if (name_size > 0) {
1244         if (name_offset + name_size > header_size) {
1245           log_warning(cds)("Invalid base_archive_name offset/size (out of range): "
1246                                      UINT32_FORMAT " + " UINT32_FORMAT " > " UINT32_FORMAT ,
1247                                      name_offset, name_size, header_size);
1248           return false;
1249         }
1250         const char* name = ((const char*)_header) + _header->_base_archive_name_offset;
1251         if (name[name_size - 1] != '\0' || strlen(name) != name_size - 1) {
1252           log_warning(cds)("Base archive name is damaged");
1253           return false;
1254         }
1255         if (!os::file_exists(name)) {
1256           log_warning(cds)("Base archive %s does not exist", name);
1257           return false;
1258         }
1259         _base_archive_name = name;
1260       }
1261     }
1262 
1263     return true;
1264   }
1265 };
1266 
1267 // Return value:
1268 // false:
1269 //      <archive_name> is not a valid archive. *base_archive_name is set to null.
1270 // true && (*base_archive_name) == nullptr:
1271 //      <archive_name> is a valid static archive.
1272 // true && (*base_archive_name) != nullptr:
1273 //      <archive_name> is a valid dynamic archive.
1274 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
1275                                                     char** base_archive_name) {
1276   FileHeaderHelper file_helper(archive_name, false);
1277   *base_archive_name = nullptr;
1278 
1279   if (!file_helper.initialize()) {
1280     return false;
1281   }
1282   GenericCDSFileMapHeader* header = file_helper.get_generic_file_header();
1283   if (header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1284     assert(header->_magic == CDS_ARCHIVE_MAGIC, "must be");
1285     if (AutoCreateSharedArchive) {
1286      log_warning(cds)("AutoCreateSharedArchive is ignored because %s is a static archive", archive_name);
1287     }
1288     return true;
1289   }
1290 
1291   const char* base = file_helper.base_archive_name();
1292   if (base == nullptr) {
1293     *base_archive_name = Arguments::get_default_shared_archive_path();
1294   } else {
1295     *base_archive_name = os::strdup_check_oom(base);
1296   }
1297 
1298   return true;
1299 }
1300 
1301 // Read the FileMapInfo information from the file.
1302 
1303 bool FileMapInfo::init_from_file(int fd) {
1304   FileHeaderHelper file_helper(_full_path, _is_static);
1305   if (!file_helper.initialize(fd)) {
1306     log_warning(cds)("Unable to read the file header.");
1307     return false;
1308   }
1309   GenericCDSFileMapHeader* gen_header = file_helper.get_generic_file_header();
1310 
1311   if (_is_static) {
1312     if (gen_header->_magic != CDS_ARCHIVE_MAGIC) {
1313       log_warning(cds)("Not a base shared archive: %s", _full_path);
1314       return false;
1315     }
1316   } else {
1317     if (gen_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
1318       log_warning(cds)("Not a top shared archive: %s", _full_path);
1319       return false;
1320     }
1321   }
1322 
1323   _header = (FileMapHeader*)os::malloc(gen_header->_header_size, mtInternal);
1324   os::lseek(fd, 0, SEEK_SET); // reset to begin of the archive
1325   size_t size = gen_header->_header_size;
1326   size_t n = ::read(fd, (void*)_header, (unsigned int)size);
1327   if (n != size) {
1328     log_warning(cds)("Failed to read file header from the top archive file\n");
1329     return false;
1330   }
1331 
1332   if (header()->version() != CURRENT_CDS_ARCHIVE_VERSION) {
1333     log_info(cds)("_version expected: 0x%x", CURRENT_CDS_ARCHIVE_VERSION);
1334     log_info(cds)("           actual: 0x%x", header()->version());
1335     log_warning(cds)("The shared archive file has the wrong version.");
1336     return false;
1337   }
1338 
1339   int common_path_size = header()->common_app_classpath_prefix_size();
1340   if (common_path_size < 0) {
1341       log_warning(cds)("common app classpath prefix len < 0");
1342       return false;
1343   }
1344 
1345   unsigned int base_offset = header()->base_archive_name_offset();
1346   unsigned int name_size = header()->base_archive_name_size();
1347   unsigned int header_size = header()->header_size();
1348   if (base_offset != 0 && name_size != 0) {
1349     if (header_size != base_offset + name_size) {
1350       log_info(cds)("_header_size: " UINT32_FORMAT, header_size);
1351       log_info(cds)("common_app_classpath_size: " UINT32_FORMAT, header()->common_app_classpath_prefix_size());
1352       log_info(cds)("base_archive_name_size: " UINT32_FORMAT, header()->base_archive_name_size());
1353       log_info(cds)("base_archive_name_offset: " UINT32_FORMAT, header()->base_archive_name_offset());
1354       log_warning(cds)("The shared archive file has an incorrect header size.");
1355       return false;
1356     }
1357   }
1358 
1359   const char* actual_ident = header()->jvm_ident();
1360 
1361   if (actual_ident[JVM_IDENT_MAX-1] != 0) {
1362     log_warning(cds)("JVM version identifier is corrupted.");
1363     return false;
1364   }
1365 
1366   char expected_ident[JVM_IDENT_MAX];
1367   get_header_version(expected_ident);
1368   if (strncmp(actual_ident, expected_ident, JVM_IDENT_MAX-1) != 0) {
1369     log_info(cds)("_jvm_ident expected: %s", expected_ident);
1370     log_info(cds)("             actual: %s", actual_ident);
1371     log_warning(cds)("The shared archive file was created by a different"
1372                   " version or build of HotSpot");
1373     return false;
1374   }
1375 
1376   _file_offset = header()->header_size(); // accounts for the size of _base_archive_name
1377 
1378   size_t len = os::lseek(fd, 0, SEEK_END);
1379 
1380   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1381     FileMapRegion* r = region_at(i);
1382     if (r->file_offset() > len || len - r->file_offset() < r->used()) {
1383       log_warning(cds)("The shared archive file has been truncated.");
1384       return false;
1385     }
1386   }
1387 
1388   return true;
1389 }
1390 
1391 void FileMapInfo::seek_to_position(size_t pos) {
1392   if (os::lseek(_fd, (long)pos, SEEK_SET) < 0) {
1393     log_error(cds)("Unable to seek to position " SIZE_FORMAT, pos);
1394     MetaspaceShared::unrecoverable_loading_error();
1395   }
1396 }
1397 
1398 // Read the FileMapInfo information from the file.
1399 bool FileMapInfo::open_for_read() {
1400   if (_file_open) {
1401     return true;
1402   }
1403   log_info(cds)("trying to map %s", _full_path);
1404   int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
1405   if (fd < 0) {
1406     if (errno == ENOENT) {
1407       log_info(cds)("Specified shared archive not found (%s)", _full_path);
1408     } else {
1409       log_warning(cds)("Failed to open shared archive file (%s)",
1410                     os::strerror(errno));
1411     }
1412     return false;
1413   } else {
1414     log_info(cds)("Opened archive %s.", _full_path);
1415   }
1416 
1417   _fd = fd;
1418   _file_open = true;
1419   return true;
1420 }
1421 
1422 // Write the FileMapInfo information to the file.
1423 
1424 void FileMapInfo::open_for_write() {
1425   LogMessage(cds) msg;
1426   if (msg.is_info()) {
1427     msg.info("Dumping shared data to file: ");
1428     msg.info("   %s", _full_path);
1429   }
1430 
1431 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
1432     chmod(_full_path, _S_IREAD | _S_IWRITE);
1433 #endif
1434 
1435   // Use remove() to delete the existing file because, on Unix, this will
1436   // allow processes that have it open continued access to the file.
1437   remove(_full_path);
1438   int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1439   if (fd < 0) {
1440     log_error(cds)("Unable to create shared archive file %s: (%s).", _full_path,
1441                    os::strerror(errno));
1442     MetaspaceShared::unrecoverable_writing_error();
1443   }
1444   _fd = fd;
1445   _file_open = true;
1446 
1447   // Seek past the header. We will write the header after all regions are written
1448   // and their CRCs computed.
1449   size_t header_bytes = header()->header_size();
1450 
1451   header_bytes = align_up(header_bytes, MetaspaceShared::core_region_alignment());
1452   _file_offset = header_bytes;
1453   seek_to_position(_file_offset);
1454 }
1455 
1456 // Write the header to the file, seek to the next allocation boundary.
1457 
1458 void FileMapInfo::write_header() {
1459   _file_offset = 0;
1460   seek_to_position(_file_offset);
1461   assert(is_file_position_aligned(), "must be");
1462   write_bytes(header(), header()->header_size());
1463 }
1464 
1465 size_t FileMapRegion::used_aligned() const {
1466   return align_up(used(), MetaspaceShared::core_region_alignment());
1467 }
1468 
1469 void FileMapRegion::init(int region_index, size_t mapping_offset, size_t size, bool read_only,
1470                          bool allow_exec, int crc) {
1471   _is_heap_region = HeapShared::is_heap_region(region_index);
1472   _is_bitmap_region = (region_index == MetaspaceShared::bm);
1473   _mapping_offset = mapping_offset;
1474   _used = size;
1475   _read_only = read_only;
1476   _allow_exec = allow_exec;
1477   _crc = crc;
1478   _mapped_from_file = false;
1479   _mapped_base = nullptr;
1480 }
1481 
1482 void FileMapRegion::init_oopmap(size_t offset, size_t size_in_bits) {
1483   _oopmap_offset = offset;
1484   _oopmap_size_in_bits = size_in_bits;
1485 }
1486 
1487 void FileMapRegion::init_ptrmap(size_t offset, size_t size_in_bits) {
1488   _ptrmap_offset = offset;
1489   _ptrmap_size_in_bits = size_in_bits;
1490 }
1491 
1492 BitMapView FileMapRegion::bitmap_view(bool is_oopmap) {
1493   char* bitmap_base = FileMapInfo::current_info()->map_bitmap_region();
1494   bitmap_base += is_oopmap ? _oopmap_offset : _ptrmap_offset;
1495   size_t size_in_bits = is_oopmap ? _oopmap_size_in_bits : _ptrmap_size_in_bits;
1496   return BitMapView((BitMap::bm_word_t*)(bitmap_base), size_in_bits);
1497 }
1498 
1499 BitMapView FileMapRegion::oopmap_view() {
1500   return bitmap_view(true);
1501 }
1502 
1503 BitMapView FileMapRegion::ptrmap_view() {
1504   assert(has_ptrmap(), "must be");
1505   return bitmap_view(false);
1506 }
1507 
1508 bool FileMapRegion::check_region_crc() const {
1509   // This function should be called after the region has been properly
1510   // loaded into memory via FileMapInfo::map_region() or FileMapInfo::read_region().
1511   // I.e., this->mapped_base() must be valid.
1512   size_t sz = used();
1513   if (sz == 0) {
1514     return true;
1515   }
1516 
1517   assert(mapped_base() != nullptr, "must be initialized");
1518   int crc = ClassLoader::crc32(0, mapped_base(), (jint)sz);
1519   if (crc != this->crc()) {
1520     log_warning(cds)("Checksum verification failed.");
1521     return false;
1522   }
1523   return true;
1524 }
1525 
1526 static const char* region_name(int region_index) {
1527   static const char* names[] = {
1528     "rw", "ro", "bm", "hp"
1529   };
1530   const int num_regions = sizeof(names)/sizeof(names[0]);
1531   assert(0 <= region_index && region_index < num_regions, "sanity");
1532 
1533   return names[region_index];
1534 }
1535 
1536 void FileMapRegion::print(outputStream* st, int region_index) {
1537   st->print_cr("============ region ============= %d \"%s\"", region_index, region_name(region_index));
1538   st->print_cr("- crc:                            0x%08x", _crc);
1539   st->print_cr("- read_only:                      %d", _read_only);
1540   st->print_cr("- allow_exec:                     %d", _allow_exec);
1541   st->print_cr("- is_heap_region:                 %d", _is_heap_region);
1542   st->print_cr("- is_bitmap_region:               %d", _is_bitmap_region);
1543   st->print_cr("- mapped_from_file:               %d", _mapped_from_file);
1544   st->print_cr("- file_offset:                    " SIZE_FORMAT_X, _file_offset);
1545   st->print_cr("- mapping_offset:                 " SIZE_FORMAT_X, _mapping_offset);
1546   st->print_cr("- used:                           " SIZE_FORMAT, _used);
1547   st->print_cr("- oopmap_offset:                  " SIZE_FORMAT_X, _oopmap_offset);
1548   st->print_cr("- oopmap_size_in_bits:            " SIZE_FORMAT, _oopmap_size_in_bits);
1549   st->print_cr("- mapped_base:                    " INTPTR_FORMAT, p2i(_mapped_base));
1550 }
1551 
1552 void FileMapInfo::write_region(int region, char* base, size_t size,
1553                                bool read_only, bool allow_exec) {
1554   Arguments::assert_is_dumping_archive();
1555 
1556   FileMapRegion* r = region_at(region);
1557   char* requested_base;
1558   size_t mapping_offset = 0;
1559 
1560   if (region == MetaspaceShared::bm) {
1561     requested_base = nullptr; // always null for bm region
1562   } else if (size == 0) {
1563     // This is an unused region (e.g., a heap region when !INCLUDE_CDS_JAVA_HEAP)
1564     requested_base = nullptr;
1565   } else if (HeapShared::is_heap_region(region)) {
1566     assert(HeapShared::can_write(), "sanity");
1567 #if INCLUDE_CDS_JAVA_HEAP
1568     assert(!DynamicDumpSharedSpaces, "must be");
1569     requested_base = (char*)ArchiveHeapWriter::requested_address();
1570     if (UseCompressedOops) {
1571       mapping_offset = (size_t)((address)requested_base - CompressedOops::base());
1572       assert((mapping_offset >> CompressedOops::shift()) << CompressedOops::shift() == mapping_offset, "must be");
1573     } else {
1574 #if INCLUDE_G1GC
1575       mapping_offset = requested_base - (char*)G1CollectedHeap::heap()->reserved().start();
1576 #endif
1577     }
1578 #endif // INCLUDE_CDS_JAVA_HEAP
1579   } else {
1580     char* requested_SharedBaseAddress = (char*)MetaspaceShared::requested_base_address();
1581     requested_base = ArchiveBuilder::current()->to_requested(base);
1582     assert(requested_base >= requested_SharedBaseAddress, "must be");
1583     mapping_offset = requested_base - requested_SharedBaseAddress;
1584   }
1585 
1586   r->set_file_offset(_file_offset);
1587   int crc = ClassLoader::crc32(0, base, (jint)size);
1588   if (size > 0) {
1589     log_info(cds)("Shared file region (%s) %d: " SIZE_FORMAT_W(8)
1590                    " bytes, addr " INTPTR_FORMAT " file offset 0x%08" PRIxPTR
1591                    " crc 0x%08x",
1592                    region_name(region), region, size, p2i(requested_base), _file_offset, crc);
1593   }
1594 
1595   r->init(region, mapping_offset, size, read_only, allow_exec, crc);
1596 
1597   if (base != nullptr) {
1598     write_bytes_aligned(base, size);
1599   }
1600 }
1601 
1602 static size_t write_bitmap(const CHeapBitMap* map, char* output, size_t offset) {
1603   size_t size_in_bytes = map->size_in_bytes();
1604   map->write_to((BitMap::bm_word_t*)(output + offset), size_in_bytes);
1605   return offset + size_in_bytes;
1606 }
1607 
1608 char* FileMapInfo::write_bitmap_region(const CHeapBitMap* ptrmap, ArchiveHeapInfo* heap_info,
1609                                        size_t &size_in_bytes) {
1610   size_in_bytes = ptrmap->size_in_bytes();
1611 
1612   if (heap_info->is_used()) {
1613     size_in_bytes += heap_info->oopmap()->size_in_bytes();
1614     size_in_bytes += heap_info->ptrmap()->size_in_bytes();
1615   }
1616 
1617   // The bitmap region contains up to 3 parts:
1618   // ptrmap:              metaspace pointers inside the ro/rw regions
1619   // heap_info->oopmap(): Java oop pointers in the heap region
1620   // heap_info->ptrmap(): metaspace pointers in the heap region
1621   char* buffer = NEW_C_HEAP_ARRAY(char, size_in_bytes, mtClassShared);
1622   size_t written = 0;
1623   written = write_bitmap(ptrmap, buffer, written);
1624   header()->set_ptrmap_size_in_bits(ptrmap->size());
1625 
1626   if (heap_info->is_used()) {
1627     FileMapRegion* r = region_at(MetaspaceShared::hp);
1628 
1629     r->init_oopmap(written, heap_info->oopmap()->size());
1630     written = write_bitmap(heap_info->oopmap(), buffer, written);
1631 
1632     r->init_ptrmap(written, heap_info->ptrmap()->size());
1633     written = write_bitmap(heap_info->ptrmap(), buffer, written);
1634   }
1635 
1636   write_region(MetaspaceShared::bm, (char*)buffer, size_in_bytes, /*read_only=*/true, /*allow_exec=*/false);
1637   return buffer;
1638 }
1639 
1640 size_t FileMapInfo::write_heap_region(ArchiveHeapInfo* heap_info) {
1641   char* start = heap_info->start();
1642   size_t size = heap_info->byte_size();
1643   write_region(MetaspaceShared::hp, start, size, false, false);
1644   return size;
1645 }
1646 
1647 // Dump bytes to file -- at the current file position.
1648 
1649 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1650   assert(_file_open, "must be");
1651   if (!os::write(_fd, buffer, nbytes)) {
1652     // If the shared archive is corrupted, close it and remove it.
1653     close();
1654     remove(_full_path);
1655     MetaspaceShared::unrecoverable_writing_error("Unable to write to shared archive file.");
1656   }
1657   _file_offset += nbytes;
1658 }
1659 
1660 bool FileMapInfo::is_file_position_aligned() const {
1661   return _file_offset == align_up(_file_offset,
1662                                   MetaspaceShared::core_region_alignment());
1663 }
1664 
1665 // Align file position to an allocation unit boundary.
1666 
1667 void FileMapInfo::align_file_position() {
1668   assert(_file_open, "must be");
1669   size_t new_file_offset = align_up(_file_offset,
1670                                     MetaspaceShared::core_region_alignment());
1671   if (new_file_offset != _file_offset) {
1672     _file_offset = new_file_offset;
1673     // Seek one byte back from the target and write a byte to insure
1674     // that the written file is the correct length.
1675     _file_offset -= 1;
1676     seek_to_position(_file_offset);
1677     char zero = 0;
1678     write_bytes(&zero, 1);
1679   }
1680 }
1681 
1682 
1683 // Dump bytes to file -- at the current file position.
1684 
1685 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1686   align_file_position();
1687   write_bytes(buffer, nbytes);
1688   align_file_position();
1689 }
1690 
1691 // Close the shared archive file.  This does NOT unmap mapped regions.
1692 
1693 void FileMapInfo::close() {
1694   if (_file_open) {
1695     if (::close(_fd) < 0) {
1696       MetaspaceShared::unrecoverable_loading_error("Unable to close the shared archive file.");
1697     }
1698     _file_open = false;
1699     _fd = -1;
1700   }
1701 }
1702 
1703 
1704 // JVM/TI RedefineClasses() support:
1705 // Remap the shared readonly space to shared readwrite, private.
1706 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1707   int idx = MetaspaceShared::ro;
1708   FileMapRegion* r = region_at(idx);
1709   if (!r->read_only()) {
1710     // the space is already readwrite so we are done
1711     return true;
1712   }
1713   size_t size = r->used_aligned();
1714   if (!open_for_read()) {
1715     return false;
1716   }
1717   char *addr = r->mapped_base();
1718   char *base = os::remap_memory(_fd, _full_path, r->file_offset(),
1719                                 addr, size, false /* !read_only */,
1720                                 r->allow_exec());
1721   close();
1722   // These have to be errors because the shared region is now unmapped.
1723   if (base == nullptr) {
1724     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1725     vm_exit(1);
1726   }
1727   if (base != addr) {
1728     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1729     vm_exit(1);
1730   }
1731   r->set_read_only(false);
1732   return true;
1733 }
1734 
1735 // Memory map a region in the address space.
1736 static const char* shared_region_name[] = { "ReadWrite", "ReadOnly", "Bitmap", "Heap" };
1737 
1738 MapArchiveResult FileMapInfo::map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs) {
1739   DEBUG_ONLY(FileMapRegion* last_region = nullptr);
1740   intx addr_delta = mapped_base_address - header()->requested_base_address();
1741 
1742   // Make sure we don't attempt to use header()->mapped_base_address() unless
1743   // it's been successfully mapped.
1744   DEBUG_ONLY(header()->set_mapped_base_address((char*)(uintptr_t)0xdeadbeef);)
1745 
1746   for (int i = 0; i < num_regions; i++) {
1747     int idx = regions[i];
1748     MapArchiveResult result = map_region(idx, addr_delta, mapped_base_address, rs);
1749     if (result != MAP_ARCHIVE_SUCCESS) {
1750       return result;
1751     }
1752     FileMapRegion* r = region_at(idx);
1753     DEBUG_ONLY(if (last_region != nullptr) {
1754         // Ensure that the OS won't be able to allocate new memory spaces between any mapped
1755         // regions, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1756         assert(r->mapped_base() == last_region->mapped_end(), "must have no gaps");
1757       }
1758       last_region = r;)
1759     log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)", is_static() ? "static " : "dynamic",
1760                   idx, p2i(r->mapped_base()), p2i(r->mapped_end()),
1761                   shared_region_name[idx]);
1762 
1763   }
1764 
1765   header()->set_mapped_base_address(header()->requested_base_address() + addr_delta);
1766   if (addr_delta != 0 && !relocate_pointers_in_core_regions(addr_delta)) {
1767     return MAP_ARCHIVE_OTHER_FAILURE;
1768   }
1769 
1770   return MAP_ARCHIVE_SUCCESS;
1771 }
1772 
1773 bool FileMapInfo::read_region(int i, char* base, size_t size, bool do_commit) {
1774   FileMapRegion* r = region_at(i);
1775   if (do_commit) {
1776     log_info(cds)("Commit %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)%s",
1777                   is_static() ? "static " : "dynamic", i, p2i(base), p2i(base + size),
1778                   shared_region_name[i], r->allow_exec() ? " exec" : "");
1779     if (!os::commit_memory(base, size, r->allow_exec())) {
1780       log_error(cds)("Failed to commit %s region #%d (%s)", is_static() ? "static " : "dynamic",
1781                      i, shared_region_name[i]);
1782       return false;
1783     }
1784   }
1785   if (os::lseek(_fd, (long)r->file_offset(), SEEK_SET) != (int)r->file_offset() ||
1786       read_bytes(base, size) != size) {
1787     return false;
1788   }
1789 
1790   r->set_mapped_from_file(false);
1791   r->set_mapped_base(base);
1792 
1793   if (VerifySharedSpaces && !r->check_region_crc()) {
1794     return false;
1795   }
1796 
1797   return true;
1798 }
1799 
1800 MapArchiveResult FileMapInfo::map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs) {
1801   assert(!HeapShared::is_heap_region(i), "sanity");
1802   FileMapRegion* r = region_at(i);
1803   size_t size = r->used_aligned();
1804   char *requested_addr = mapped_base_address + r->mapping_offset();
1805   assert(r->mapped_base() == nullptr, "must be not mapped yet");
1806   assert(requested_addr != nullptr, "must be specified");
1807 
1808   r->set_mapped_from_file(false);
1809 
1810   if (MetaspaceShared::use_windows_memory_mapping()) {
1811     // Windows cannot remap read-only shared memory to read-write when required for
1812     // RedefineClasses, which is also used by JFR.  Always map windows regions as RW.
1813     r->set_read_only(false);
1814   } else if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1815              Arguments::has_jfr_option()) {
1816     // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW
1817     r->set_read_only(false);
1818   } else if (addr_delta != 0) {
1819     r->set_read_only(false); // Need to patch the pointers
1820   }
1821 
1822   if (MetaspaceShared::use_windows_memory_mapping() && rs.is_reserved()) {
1823     // This is the second time we try to map the archive(s). We have already created a ReservedSpace
1824     // that covers all the FileMapRegions to ensure all regions can be mapped. However, Windows
1825     // can't mmap into a ReservedSpace, so we just ::read() the data. We're going to patch all the
1826     // regions anyway, so there's no benefit for mmap anyway.
1827     if (!read_region(i, requested_addr, size, /* do_commit = */ true)) {
1828       log_info(cds)("Failed to read %s shared space into reserved space at " INTPTR_FORMAT,
1829                     shared_region_name[i], p2i(requested_addr));
1830       return MAP_ARCHIVE_OTHER_FAILURE; // oom or I/O error.
1831     } else {
1832       assert(r->mapped_base() != nullptr, "must be initialized");
1833     }
1834   } else {
1835     // Note that this may either be a "fresh" mapping into unreserved address
1836     // space (Windows, first mapping attempt), or a mapping into pre-reserved
1837     // space (Posix). See also comment in MetaspaceShared::map_archives().
1838     char* base = os::map_memory(_fd, _full_path, r->file_offset(),
1839                                 requested_addr, size, r->read_only(),
1840                                 r->allow_exec(), mtClassShared);
1841     if (base != requested_addr) {
1842       log_info(cds)("Unable to map %s shared space at " INTPTR_FORMAT,
1843                     shared_region_name[i], p2i(requested_addr));
1844       _memory_mapping_failed = true;
1845       return MAP_ARCHIVE_MMAP_FAILURE;
1846     }
1847     r->set_mapped_from_file(true);
1848     r->set_mapped_base(requested_addr);
1849   }
1850 
1851   if (VerifySharedSpaces && !r->check_region_crc()) {
1852     return MAP_ARCHIVE_OTHER_FAILURE;
1853   }
1854 
1855   return MAP_ARCHIVE_SUCCESS;
1856 }
1857 
1858 // The return value is the location of the archive relocation bitmap.
1859 char* FileMapInfo::map_bitmap_region() {
1860   FileMapRegion* r = region_at(MetaspaceShared::bm);
1861   if (r->mapped_base() != nullptr) {
1862     return r->mapped_base();
1863   }
1864   bool read_only = true, allow_exec = false;
1865   char* requested_addr = nullptr; // allow OS to pick any location
1866   char* bitmap_base = os::map_memory(_fd, _full_path, r->file_offset(),
1867                                      requested_addr, r->used_aligned(), read_only, allow_exec, mtClassShared);
1868   if (bitmap_base == nullptr) {
1869     log_info(cds)("failed to map relocation bitmap");
1870     return nullptr;
1871   }
1872 
1873   r->set_mapped_base(bitmap_base);
1874   if (VerifySharedSpaces && !r->check_region_crc()) {
1875     log_error(cds)("relocation bitmap CRC error");
1876     if (!os::unmap_memory(bitmap_base, r->used_aligned())) {
1877       fatal("os::unmap_memory of relocation bitmap failed");
1878     }
1879     return nullptr;
1880   }
1881 
1882   r->set_mapped_from_file(true);
1883   log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)",
1884                 is_static() ? "static " : "dynamic",
1885                 MetaspaceShared::bm, p2i(r->mapped_base()), p2i(r->mapped_end()),
1886                 shared_region_name[MetaspaceShared::bm]);
1887   return bitmap_base;
1888 }
1889 
1890 // This is called when we cannot map the archive at the requested[ base address (usually 0x800000000).
1891 // We relocate all pointers in the 2 core regions (ro, rw).
1892 bool FileMapInfo::relocate_pointers_in_core_regions(intx addr_delta) {
1893   log_debug(cds, reloc)("runtime archive relocation start");
1894   char* bitmap_base = map_bitmap_region();
1895 
1896   if (bitmap_base == nullptr) {
1897     return false; // OOM, or CRC check failure
1898   } else {
1899     size_t ptrmap_size_in_bits = header()->ptrmap_size_in_bits();
1900     log_debug(cds, reloc)("mapped relocation bitmap @ " INTPTR_FORMAT " (" SIZE_FORMAT " bits)",
1901                           p2i(bitmap_base), ptrmap_size_in_bits);
1902 
1903     BitMapView ptrmap((BitMap::bm_word_t*)bitmap_base, ptrmap_size_in_bits);
1904 
1905     // Patch all pointers in the mapped region that are marked by ptrmap.
1906     address patch_base = (address)mapped_base();
1907     address patch_end  = (address)mapped_end();
1908 
1909     // the current value of the pointers to be patched must be within this
1910     // range (i.e., must be between the requested base address and the address of the current archive).
1911     // Note: top archive may point to objects in the base archive, but not the other way around.
1912     address valid_old_base = (address)header()->requested_base_address();
1913     address valid_old_end  = valid_old_base + mapping_end_offset();
1914 
1915     // after patching, the pointers must point inside this range
1916     // (the requested location of the archive, as mapped at runtime).
1917     address valid_new_base = (address)header()->mapped_base_address();
1918     address valid_new_end  = (address)mapped_end();
1919 
1920     SharedDataRelocator patcher((address*)patch_base, (address*)patch_end, valid_old_base, valid_old_end,
1921                                 valid_new_base, valid_new_end, addr_delta);
1922     ptrmap.iterate(&patcher);
1923 
1924     // The MetaspaceShared::bm region will be unmapped in MetaspaceShared::initialize_shared_spaces().
1925 
1926     log_debug(cds, reloc)("runtime archive relocation done");
1927     return true;
1928   }
1929 }
1930 
1931 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
1932   assert(_file_open, "Archive file is not open");
1933   size_t n = ::read(_fd, buffer, (unsigned int)count);
1934   if (n != count) {
1935     // Close the file if there's a problem reading it.
1936     close();
1937     return 0;
1938   }
1939   _file_offset += count;
1940   return count;
1941 }
1942 
1943 // Get the total size in bytes of a read only region
1944 size_t FileMapInfo::readonly_total() {
1945   size_t total = 0;
1946   if (current_info() != nullptr) {
1947     FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::ro);
1948     if (r->read_only()) total += r->used();
1949   }
1950   if (dynamic_info() != nullptr) {
1951     FileMapRegion* r = FileMapInfo::dynamic_info()->region_at(MetaspaceShared::ro);
1952     if (r->read_only()) total += r->used();
1953   }
1954   return total;
1955 }
1956 
1957 #if INCLUDE_CDS_JAVA_HEAP
1958 MemRegion FileMapInfo::_mapped_heap_memregion;
1959 
1960 bool FileMapInfo::has_heap_region() {
1961   return (region_at(MetaspaceShared::hp)->used() > 0);
1962 }
1963 
1964 // Returns the address range of the archived heap region computed using the
1965 // current oop encoding mode. This range may be different than the one seen at
1966 // dump time due to encoding mode differences. The result is used in determining
1967 // if/how these regions should be relocated at run time.
1968 MemRegion FileMapInfo::get_heap_region_requested_range() {
1969   FileMapRegion* r = region_at(MetaspaceShared::hp);
1970   size_t size = r->used();
1971   assert(size > 0, "must have non-empty heap region");
1972 
1973   address start = heap_region_requested_address();
1974   address end = start + size;
1975   log_info(cds)("Requested heap region [" INTPTR_FORMAT " - " INTPTR_FORMAT "] = "  SIZE_FORMAT_W(8) " bytes",
1976                 p2i(start), p2i(end), size);
1977 
1978   return MemRegion((HeapWord*)start, (HeapWord*)end);
1979 }
1980 
1981 void FileMapInfo::map_or_load_heap_region() {
1982   bool success = false;
1983 
1984   if (can_use_heap_region()) {
1985     if (ArchiveHeapLoader::can_map()) {
1986       success = map_heap_region();
1987     } else if (ArchiveHeapLoader::can_load()) {
1988       success = ArchiveHeapLoader::load_heap_region(this);
1989     } else {
1990       if (!UseCompressedOops && !ArchiveHeapLoader::can_map()) {
1991         // TODO - remove implicit knowledge of G1
1992         log_info(cds)("Cannot use CDS heap data. UseG1GC is required for -XX:-UseCompressedOops");
1993       } else {
1994         log_info(cds)("Cannot use CDS heap data. UseEpsilonGC, UseG1GC, UseSerialGC or UseParallelGC are required.");
1995       }
1996     }
1997   }
1998 
1999   if (!success) {
2000     MetaspaceShared::disable_full_module_graph();
2001   }
2002 }
2003 
2004 bool FileMapInfo::can_use_heap_region() {
2005   if (!has_heap_region()) {
2006     return false;
2007   }
2008   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2009     ShouldNotReachHere(); // CDS should have been disabled.
2010     // The archived objects are mapped at JVM start-up, but we don't know if
2011     // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
2012     // which would make the archived String or mirror objects invalid. Let's be safe and not
2013     // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
2014     //
2015     // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
2016     // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
2017     // because we won't install an archived object subgraph if the klass of any of the
2018     // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
2019   }
2020 
2021   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
2022                 max_heap_size()/M);
2023   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
2024                 p2i(narrow_klass_base()), narrow_klass_shift());
2025   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2026                 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
2027   log_info(cds)("    heap range = [" PTR_FORMAT " - "  PTR_FORMAT "]",
2028                 p2i(header()->heap_begin()), p2i(header()->heap_end()));
2029 
2030   log_info(cds)("The current max heap size = " SIZE_FORMAT "M, HeapRegion::GrainBytes = " SIZE_FORMAT,
2031                 MaxHeapSize/M, HeapRegion::GrainBytes);
2032   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
2033                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
2034   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
2035                 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
2036   log_info(cds)("    heap range = [" PTR_FORMAT " - "  PTR_FORMAT "]",
2037                 UseCompressedOops ? p2i(CompressedOops::begin()) :
2038                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().start()) : 0L,
2039                 UseCompressedOops ? p2i(CompressedOops::end()) :
2040                                     UseG1GC ? p2i((address)G1CollectedHeap::heap()->reserved().end()) : 0L);
2041 
2042   if (narrow_klass_base() != CompressedKlassPointers::base() ||
2043       narrow_klass_shift() != CompressedKlassPointers::shift()) {
2044     log_info(cds)("CDS heap data cannot be used because the archive was created with an incompatible narrow klass encoding mode.");
2045     return false;
2046   }
2047   return true;
2048 }
2049 
2050 // The actual address of this region during dump time.
2051 address FileMapInfo::heap_region_dumptime_address() {
2052   FileMapRegion* r = region_at(MetaspaceShared::hp);
2053   assert(UseSharedSpaces, "runtime only");
2054   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2055   if (UseCompressedOops) {
2056     return /*dumptime*/ narrow_oop_base() + r->mapping_offset();
2057   } else {
2058     return heap_region_requested_address();
2059   }
2060 }
2061 
2062 // The address where this region can be mapped into the runtime heap without
2063 // patching any of the pointers that are embedded in this region.
2064 address FileMapInfo::heap_region_requested_address() {
2065   assert(UseSharedSpaces, "runtime only");
2066   FileMapRegion* r = region_at(MetaspaceShared::hp);
2067   assert(is_aligned(r->mapping_offset(), sizeof(HeapWord)), "must be");
2068   assert(ArchiveHeapLoader::can_map(), "cannot be used by ArchiveHeapLoader::can_load() mode");
2069   if (UseCompressedOops) {
2070     // We can avoid relocation if each region's offset from the runtime CompressedOops::base()
2071     // is the same as its offset from the CompressedOops::base() during dumptime.
2072     // Note that CompressedOops::base() may be different between dumptime and runtime.
2073     //
2074     // Example:
2075     // Dumptime base = 0x1000 and shift is 0. We have a region at address 0x2000. There's a
2076     // narrowOop P stored in this region that points to an object at address 0x2200.
2077     // P's encoded value is 0x1200.
2078     //
2079     // Runtime base = 0x4000 and shift is also 0. If we map this region at 0x5000, then
2080     // the value P can remain 0x1200. The decoded address = (0x4000 + (0x1200 << 0)) = 0x5200,
2081     // which is the runtime location of the referenced object.
2082     return /*runtime*/ CompressedOops::base() + r->mapping_offset();
2083   } else {
2084     // We can avoid relocation if each region is mapped into the exact same address
2085     // where it was at dump time.
2086     return /*dumptime*/header()->heap_begin() + r->mapping_offset();
2087   }
2088 }
2089 
2090 // The address where this shared heap region is actually mapped at runtime. This function
2091 // can be called only after we have determined the value for ArchiveHeapLoader::mapped_heap_delta().
2092 address FileMapInfo::heap_region_mapped_address() {
2093   assert(UseSharedSpaces, "runtime only");
2094   assert(ArchiveHeapLoader::can_map(), "cannot be used by ArchiveHeapLoader::can_load() mode");
2095   return heap_region_requested_address() + ArchiveHeapLoader::mapped_heap_delta();
2096 }
2097 
2098 bool FileMapInfo::map_heap_region() {
2099   init_heap_region_relocation();
2100 
2101   if (_heap_pointers_need_patching) {
2102     char* bitmap_base = map_bitmap_region();
2103     if (bitmap_base == nullptr) {
2104       log_info(cds)("CDS heap cannot be used because bitmap region cannot be mapped");
2105       _heap_pointers_need_patching = false;
2106       return false;
2107     }
2108   }
2109 
2110   if (map_heap_region_impl()) {
2111 #ifdef ASSERT
2112     // The "old" regions must be parsable -- we cannot have any unused space
2113     // at the start of the lowest G1 region that contains archived objects.
2114     assert(is_aligned(_mapped_heap_memregion.start(), HeapRegion::GrainBytes), "must be");
2115 
2116     // Make sure we map at the very top of the heap - see comments in
2117     // init_heap_region_relocation().
2118     MemRegion heap_range = G1CollectedHeap::heap()->reserved();
2119     assert(heap_range.contains(_mapped_heap_memregion), "must be");
2120 
2121     address heap_end = (address)heap_range.end();
2122     address mapped_heap_region_end = (address)_mapped_heap_memregion.end();
2123     assert(heap_end >= mapped_heap_region_end, "must be");
2124     assert(heap_end - mapped_heap_region_end < (intx)(HeapRegion::GrainBytes),
2125            "must be at the top of the heap to avoid fragmentation");
2126 #endif
2127 
2128     ArchiveHeapLoader::set_mapped();
2129     return true;
2130   } else {
2131     return false;
2132   }
2133 }
2134 
2135 void FileMapInfo::init_heap_region_relocation() {
2136   assert(UseG1GC, "the following code assumes G1");
2137   _heap_pointers_need_patching = false;
2138 
2139   MemRegion heap_range = G1CollectedHeap::heap()->reserved();
2140   MemRegion archive_range = get_heap_region_requested_range();
2141 
2142   address requested_bottom = (address)archive_range.start();
2143   address heap_end = (address)heap_range.end();
2144   assert(is_aligned(heap_end, HeapRegion::GrainBytes), "must be");
2145 
2146   // We map the archive heap region at the very top of the heap to avoid fragmentation.
2147   // To do that, we make sure that the bottom of the archived region is at the same
2148   // address as the bottom of the highest possible G1 region.
2149   address mapped_bottom = heap_end - align_up(archive_range.byte_size(), HeapRegion::GrainBytes);
2150 
2151   if (UseCompressedOops &&
2152       (narrow_oop_mode() != CompressedOops::mode() ||
2153        narrow_oop_shift() != CompressedOops::shift())) {
2154     log_info(cds)("CDS heap data needs to be relocated because the archive was created with an incompatible oop encoding mode.");
2155     _heap_pointers_need_patching = true;
2156   } else if (requested_bottom != mapped_bottom) {
2157     log_info(cds)("CDS heap data needs to be relocated because it is mapped at a different address @ " INTPTR_FORMAT,
2158                   p2i(mapped_bottom));
2159     _heap_pointers_need_patching = true;
2160   }
2161 
2162   ptrdiff_t delta = 0;
2163   if (_heap_pointers_need_patching) {
2164     delta = mapped_bottom - requested_bottom;
2165   }
2166 
2167   log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
2168   ArchiveHeapLoader::init_mapped_heap_relocation(delta, narrow_oop_shift());
2169 }
2170 
2171 bool FileMapInfo::map_heap_region_impl() {
2172   FileMapRegion* r = region_at(MetaspaceShared::hp);
2173   size_t size = r->used();
2174 
2175   if (size > 0) {
2176     HeapWord* start = (HeapWord*)heap_region_mapped_address();
2177     _mapped_heap_memregion = MemRegion(start, size / HeapWordSize);
2178     log_info(cds)("Trying to map heap data at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
2179                   p2i(start), size);
2180   } else {
2181     return false; // no archived java heap data
2182   }
2183 
2184   // Check that the region is within the java heap
2185   if (!G1CollectedHeap::heap()->check_archive_addresses(_mapped_heap_memregion)) {
2186     log_info(cds)("Unable to allocate region, range is not within java heap.");
2187     return false;
2188   }
2189 
2190   // allocate from java heap
2191   if (!G1CollectedHeap::heap()->alloc_archive_regions(_mapped_heap_memregion)) {
2192     log_info(cds)("Unable to allocate region, java heap range is already in use.");
2193     return false;
2194   }
2195 
2196   // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
2197   // for mapped region as it is part of the reserved java heap, which is already recorded.
2198   char* addr = (char*)_mapped_heap_memregion.start();
2199   char* base = os::map_memory(_fd, _full_path, r->file_offset(),
2200                               addr, _mapped_heap_memregion.byte_size(), r->read_only(),
2201                               r->allow_exec());
2202   if (base == nullptr || base != addr) {
2203     dealloc_heap_region();
2204     log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
2205                   INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
2206                   p2i(addr), _mapped_heap_memregion.byte_size());
2207     return false;
2208   }
2209 
2210   r->set_mapped_base(base);
2211   if (VerifySharedSpaces && !r->check_region_crc()) {
2212     dealloc_heap_region();
2213     log_info(cds)("mapped heap region is corrupt");
2214     return false;
2215   }
2216 
2217   return true;
2218 }
2219 
2220 narrowOop FileMapInfo::encoded_heap_region_dumptime_address() {
2221   assert(UseSharedSpaces, "runtime only");
2222   assert(UseCompressedOops, "sanity");
2223   FileMapRegion* r = region_at(MetaspaceShared::hp);
2224   return CompressedOops::narrow_oop_cast(r->mapping_offset() >> narrow_oop_shift());
2225 }
2226 
2227 void FileMapInfo::patch_heap_embedded_pointers() {
2228   if (!ArchiveHeapLoader::is_mapped() || !_heap_pointers_need_patching) {
2229     return;
2230   }
2231 
2232   char* bitmap_base = map_bitmap_region();
2233   assert(bitmap_base != nullptr, "must have already been mapped");
2234 
2235   FileMapRegion* r = region_at(MetaspaceShared::hp);
2236   ArchiveHeapLoader::patch_embedded_pointers(
2237       this, _mapped_heap_memregion,
2238       (address)(region_at(MetaspaceShared::bm)->mapped_base()) + r->oopmap_offset(),
2239       r->oopmap_size_in_bits());
2240 }
2241 
2242 void FileMapInfo::fixup_mapped_heap_region() {
2243   if (ArchiveHeapLoader::is_mapped()) {
2244     assert(!_mapped_heap_memregion.is_empty(), "sanity");
2245 
2246     // Populate the archive regions' G1BlockOffsetTableParts. That ensures
2247     // fast G1BlockOffsetTablePart::block_start operations for any given address
2248     // within the archive regions when trying to find start of an object
2249     // (e.g. during card table scanning).
2250     G1CollectedHeap::heap()->populate_archive_regions_bot_part(_mapped_heap_memregion);
2251   }
2252 }
2253 
2254 // dealloc the archive regions from java heap
2255 void FileMapInfo::dealloc_heap_region() {
2256   G1CollectedHeap::heap()->dealloc_archive_regions(_mapped_heap_memregion);
2257 }
2258 #endif // INCLUDE_CDS_JAVA_HEAP
2259 
2260 void FileMapInfo::unmap_regions(int regions[], int num_regions) {
2261   for (int r = 0; r < num_regions; r++) {
2262     int idx = regions[r];
2263     unmap_region(idx);
2264   }
2265 }
2266 
2267 // Unmap a memory region in the address space.
2268 
2269 void FileMapInfo::unmap_region(int i) {
2270   assert(!HeapShared::is_heap_region(i), "sanity");
2271   FileMapRegion* r = region_at(i);
2272   char* mapped_base = r->mapped_base();
2273   size_t size = r->used_aligned();
2274 
2275   if (mapped_base != nullptr) {
2276     if (size > 0 && r->mapped_from_file()) {
2277       log_info(cds)("Unmapping region #%d at base " INTPTR_FORMAT " (%s)", i, p2i(mapped_base),
2278                     shared_region_name[i]);
2279       if (!os::unmap_memory(mapped_base, size)) {
2280         fatal("os::unmap_memory failed");
2281       }
2282     }
2283     r->set_mapped_base(nullptr);
2284   }
2285 }
2286 
2287 void FileMapInfo::assert_mark(bool check) {
2288   if (!check) {
2289     MetaspaceShared::unrecoverable_loading_error("Mark mismatch while restoring from shared file.");
2290   }
2291 }
2292 
2293 FileMapInfo* FileMapInfo::_current_info = nullptr;
2294 FileMapInfo* FileMapInfo::_dynamic_archive_info = nullptr;
2295 bool FileMapInfo::_heap_pointers_need_patching = false;
2296 SharedPathTable FileMapInfo::_shared_path_table;
2297 bool FileMapInfo::_validating_shared_path_table = false;
2298 bool FileMapInfo::_memory_mapping_failed = false;
2299 GrowableArray<const char*>* FileMapInfo::_non_existent_class_paths = nullptr;
2300 
2301 // Open the shared archive file, read and validate the header
2302 // information (version, boot classpath, etc.). If initialization
2303 // fails, shared spaces are disabled and the file is closed.
2304 //
2305 // Validation of the archive is done in two steps:
2306 //
2307 // [1] validate_header() - done here.
2308 // [2] validate_shared_path_table - this is done later, because the table is in the RW
2309 //     region of the archive, which is not mapped yet.
2310 bool FileMapInfo::initialize() {
2311   assert(UseSharedSpaces, "UseSharedSpaces expected.");
2312   assert(Arguments::has_jimage(), "The shared archive file cannot be used with an exploded module build.");
2313 
2314   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
2315     // CDS assumes that no classes resolved in vmClasses::resolve_all()
2316     // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
2317     // during the JVMTI "early" stage, so we can still use CDS if
2318     // JvmtiExport::has_early_class_hook_env() is false.
2319     log_info(cds)("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
2320     return false;
2321   }
2322 
2323   if (!open_for_read() || !init_from_file(_fd) || !validate_header()) {
2324     if (_is_static) {
2325       log_info(cds)("Initialize static archive failed.");
2326       return false;
2327     } else {
2328       log_info(cds)("Initialize dynamic archive failed.");
2329       if (AutoCreateSharedArchive) {
2330         DynamicDumpSharedSpaces = true;
2331         ArchiveClassesAtExit = Arguments::GetSharedDynamicArchivePath();
2332       }
2333       return false;
2334     }
2335   }
2336 
2337   return true;
2338 }
2339 
2340 // The 2 core spaces are RW->RO
2341 FileMapRegion* FileMapInfo::first_core_region() const {
2342   return region_at(MetaspaceShared::rw);
2343 }
2344 
2345 FileMapRegion* FileMapInfo::last_core_region() const {
2346   return region_at(MetaspaceShared::ro);
2347 }
2348 
2349 void FileMapInfo::print(outputStream* st) const {
2350   header()->print(st);
2351   if (!is_static()) {
2352     dynamic_header()->print(st);
2353   }
2354 }
2355 
2356 void FileMapHeader::set_as_offset(char* p, size_t *offset) {
2357   *offset = ArchiveBuilder::current()->any_to_offset((address)p);
2358 }
2359 
2360 int FileMapHeader::compute_crc() {
2361   char* start = (char*)this;
2362   // start computing from the field after _header_size to end of base archive name.
2363   char* buf = (char*)&(_generic_header._header_size) + sizeof(_generic_header._header_size);
2364   size_t sz = header_size() - (buf - start);
2365   int crc = ClassLoader::crc32(0, buf, (jint)sz);
2366   return crc;
2367 }
2368 
2369 // This function should only be called during run time with UseSharedSpaces enabled.
2370 bool FileMapHeader::validate() {
2371   if (_obj_alignment != ObjectAlignmentInBytes) {
2372     log_info(cds)("The shared archive file's ObjectAlignmentInBytes of %d"
2373                   " does not equal the current ObjectAlignmentInBytes of %d.",
2374                   _obj_alignment, ObjectAlignmentInBytes);
2375     return false;
2376   }
2377   if (_compact_strings != CompactStrings) {
2378     log_info(cds)("The shared archive file's CompactStrings setting (%s)"
2379                   " does not equal the current CompactStrings setting (%s).",
2380                   _compact_strings ? "enabled" : "disabled",
2381                   CompactStrings   ? "enabled" : "disabled");
2382     return false;
2383   }
2384 
2385   // This must be done after header validation because it might change the
2386   // header data
2387   const char* prop = Arguments::get_property("java.system.class.loader");
2388   if (prop != nullptr) {
2389     log_warning(cds)("Archived non-system classes are disabled because the "
2390             "java.system.class.loader property is specified (value = \"%s\"). "
2391             "To use archived non-system classes, this property must not be set", prop);
2392     _has_platform_or_app_classes = false;
2393   }
2394 
2395 
2396   if (!_verify_local && BytecodeVerificationLocal) {
2397     //  we cannot load boot classes, so there's no point of using the CDS archive
2398     log_info(cds)("The shared archive file's BytecodeVerificationLocal setting (%s)"
2399                                " does not equal the current BytecodeVerificationLocal setting (%s).",
2400                                _verify_local ? "enabled" : "disabled",
2401                                BytecodeVerificationLocal ? "enabled" : "disabled");
2402     return false;
2403   }
2404 
2405   // For backwards compatibility, we don't check the BytecodeVerificationRemote setting
2406   // if the archive only contains system classes.
2407   if (_has_platform_or_app_classes
2408       && !_verify_remote // we didn't verify the archived platform/app classes
2409       && BytecodeVerificationRemote) { // but we want to verify all loaded platform/app classes
2410     log_info(cds)("The shared archive file was created with less restrictive "
2411                                "verification setting than the current setting.");
2412     // Pretend that we didn't have any archived platform/app classes, so they won't be loaded
2413     // by SystemDictionaryShared.
2414     _has_platform_or_app_classes = false;
2415   }
2416 
2417   // Java agents are allowed during run time. Therefore, the following condition is not
2418   // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
2419   // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
2420   // while AllowArchivingWithJavaAgent is set during the current run.
2421   if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
2422     log_warning(cds)("The setting of the AllowArchivingWithJavaAgent is different "
2423                                "from the setting in the shared archive.");
2424     return false;
2425   }
2426 
2427   if (_allow_archiving_with_java_agent) {
2428     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
2429             "for testing purposes only and should not be used in a production environment");
2430   }
2431 
2432   log_info(cds)("Archive was created with UseCompressedOops = %d, UseCompressedClassPointers = %d",
2433                           compressed_oops(), compressed_class_pointers());
2434   if (compressed_oops() != UseCompressedOops || compressed_class_pointers() != UseCompressedClassPointers) {
2435     log_info(cds)("Unable to use shared archive.\nThe saved state of UseCompressedOops and UseCompressedClassPointers is "
2436                                "different from runtime, CDS will be disabled.");
2437     return false;
2438   }
2439 
2440   if (compact_headers() != UseCompactObjectHeaders) {
2441     log_info(cds)("The shared archive file's UseCompactObjectHeaders setting (%s)"
2442                   " does not equal the current UseCompactObjectHeaders setting (%s).",
2443                   _compact_headers          ? "enabled" : "disabled",
2444                   UseCompactObjectHeaders   ? "enabled" : "disabled");
2445     return false;
2446   }
2447 
2448   if (!_use_optimized_module_handling) {
2449     MetaspaceShared::disable_optimized_module_handling();
2450     log_info(cds)("optimized module handling: disabled because archive was created without optimized module handling");
2451   }
2452 
2453   if (!_use_full_module_graph) {
2454     MetaspaceShared::disable_full_module_graph();
2455     log_info(cds)("full module graph: disabled because archive was created without full module graph");
2456   }
2457 
2458   return true;
2459 }
2460 
2461 bool FileMapInfo::validate_header() {
2462   if (!header()->validate()) {
2463     return false;
2464   }
2465   if (_is_static) {
2466     return true;
2467   } else {
2468     return DynamicArchive::validate(this);
2469   }
2470 }
2471 
2472 #if INCLUDE_JVMTI
2473 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = nullptr;
2474 
2475 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
2476   if (i == 0) {
2477     // index 0 corresponds to the ClassPathImageEntry which is a globally shared object
2478     // and should never be deleted.
2479     return ClassLoader::get_jrt_entry();
2480   }
2481   ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
2482   if (ent == nullptr) {
2483     SharedClassPathEntry* scpe = shared_path(i);
2484     assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
2485 
2486     const char* path = scpe->name();
2487     struct stat st;
2488     if (os::stat(path, &st) != 0) {
2489       char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2490       jio_snprintf(msg, strlen(path) + 127, "error in finding JAR file %s", path);
2491       THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2492     } else {
2493       ent = ClassLoader::create_class_path_entry(THREAD, path, &st, false, false);
2494       if (ent == nullptr) {
2495         char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128);
2496         jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
2497         THROW_MSG_(vmSymbols::java_io_IOException(), msg, nullptr);
2498       }
2499     }
2500 
2501     MutexLocker mu(THREAD, CDSClassFileStream_lock);
2502     if (_classpath_entries_for_jvmti[i] == nullptr) {
2503       _classpath_entries_for_jvmti[i] = ent;
2504     } else {
2505       // Another thread has beat me to creating this entry
2506       delete ent;
2507       ent = _classpath_entries_for_jvmti[i];
2508     }
2509   }
2510 
2511   return ent;
2512 }
2513 
2514 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
2515   int path_index = ik->shared_classpath_index();
2516   assert(path_index >= 0, "should be called for shared built-in classes only");
2517   assert(path_index < (int)get_number_of_shared_paths(), "sanity");
2518 
2519   ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
2520   assert(cpe != nullptr, "must be");
2521 
2522   Symbol* name = ik->name();
2523   const char* const class_name = name->as_C_string();
2524   const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
2525                                                                       name->utf8_length());
2526   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
2527   ClassFileStream* cfs = cpe->open_stream_for_loader(THREAD, file_name, loader_data);
2528   assert(cfs != nullptr, "must be able to read the classfile data of shared classes for built-in loaders.");
2529   log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
2530                         cfs->source(), cfs->length());
2531   return cfs;
2532 }
2533 
2534 #endif