1 /*
   2  * Copyright (c) 2003, 2019, 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 "jvm.h"
  27 #include "classfile/classFileStream.hpp"
  28 #include "classfile/classLoader.inline.hpp"
  29 #include "classfile/classLoaderData.inline.hpp"
  30 #include "classfile/classLoaderExt.hpp"
  31 #include "classfile/symbolTable.hpp"
  32 #include "classfile/systemDictionaryShared.hpp"
  33 #include "classfile/altHashing.hpp"
  34 #include "logging/log.hpp"
  35 #include "logging/logStream.hpp"
  36 #include "logging/logMessage.hpp"
  37 #include "memory/archiveUtils.hpp"
  38 #include "memory/dynamicArchive.hpp"
  39 #include "memory/filemap.hpp"
  40 #include "memory/heapShared.inline.hpp"
  41 #include "memory/iterator.inline.hpp"
  42 #include "memory/metadataFactory.hpp"
  43 #include "memory/metaspaceClosure.hpp"
  44 #include "memory/metaspaceShared.hpp"
  45 #include "memory/oopFactory.hpp"
  46 #include "memory/universe.hpp"
  47 #include "oops/compressedOops.hpp"
  48 #include "oops/compressedOops.inline.hpp"
  49 #include "oops/objArrayOop.hpp"
  50 #include "oops/oop.inline.hpp"
  51 #include "prims/jvmtiExport.hpp"
  52 #include "runtime/arguments.hpp"
  53 #include "runtime/java.hpp"
  54 #include "runtime/mutexLocker.hpp"
  55 #include "runtime/os.inline.hpp"
  56 #include "runtime/vm_version.hpp"
  57 #include "services/memTracker.hpp"
  58 #include "utilities/align.hpp"
  59 #include "utilities/bitMap.inline.hpp"
  60 #include "utilities/classpathStream.hpp"
  61 #include "utilities/defaultStream.hpp"
  62 #if INCLUDE_G1GC
  63 #include "gc/g1/g1CollectedHeap.hpp"
  64 #include "gc/g1/heapRegion.hpp"
  65 #endif
  66 
  67 # include <sys/stat.h>
  68 # include <errno.h>
  69 
  70 #ifndef O_BINARY       // if defined (Win32) use binary files.
  71 #define O_BINARY 0     // otherwise do nothing.
  72 #endif
  73 
  74 // Complain and stop. All error conditions occurring during the writing of
  75 // an archive file should stop the process.  Unrecoverable errors during
  76 // the reading of the archive file should stop the process.
  77 
  78 static void fail_exit(const char *msg, va_list ap) {
  79   // This occurs very early during initialization: tty is not initialized.
  80   jio_fprintf(defaultStream::error_stream(),
  81               "An error has occurred while processing the"
  82               " shared archive file.\n");
  83   jio_vfprintf(defaultStream::error_stream(), msg, ap);
  84   jio_fprintf(defaultStream::error_stream(), "\n");
  85   // Do not change the text of the below message because some tests check for it.
  86   vm_exit_during_initialization("Unable to use shared archive.", NULL);
  87 }
  88 
  89 
  90 void FileMapInfo::fail_stop(const char *msg, ...) {
  91         va_list ap;
  92   va_start(ap, msg);
  93   fail_exit(msg, ap);   // Never returns.
  94   va_end(ap);           // for completeness.
  95 }
  96 
  97 
  98 // Complain and continue.  Recoverable errors during the reading of the
  99 // archive file may continue (with sharing disabled).
 100 //
 101 // If we continue, then disable shared spaces and close the file.
 102 
 103 void FileMapInfo::fail_continue(const char *msg, ...) {
 104   va_list ap;
 105   va_start(ap, msg);
 106   if (PrintSharedArchiveAndExit && _validating_shared_path_table) {
 107     // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
 108     // do not validate, we can still continue "limping" to validate the remaining
 109     // entries. No need to quit.
 110     tty->print("[");
 111     tty->vprint(msg, ap);
 112     tty->print_cr("]");
 113   } else {
 114     if (RequireSharedSpaces) {
 115       fail_exit(msg, ap);
 116     } else {
 117       if (log_is_enabled(Info, cds)) {
 118         ResourceMark rm;
 119         LogStream ls(Log(cds)::info());
 120         ls.print("UseSharedSpaces: ");
 121         ls.vprint_cr(msg, ap);
 122       }
 123     }
 124   }
 125   va_end(ap);
 126 }
 127 
 128 // Fill in the fileMapInfo structure with data about this VM instance.
 129 
 130 // This method copies the vm version info into header_version.  If the version is too
 131 // long then a truncated version, which has a hash code appended to it, is copied.
 132 //
 133 // Using a template enables this method to verify that header_version is an array of
 134 // length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and
 135 // the code that reads the CDS file will both use the same size buffer.  Hence, will
 136 // use identical truncation.  This is necessary for matching of truncated versions.
 137 template <int N> static void get_header_version(char (&header_version) [N]) {
 138   assert(N == JVM_IDENT_MAX, "Bad header_version size");
 139 
 140   const char *vm_version = VM_Version::internal_vm_info_string();
 141   const int version_len = (int)strlen(vm_version);
 142 
 143   memset(header_version, 0, JVM_IDENT_MAX);
 144 
 145   if (version_len < (JVM_IDENT_MAX-1)) {
 146     strcpy(header_version, vm_version);
 147 
 148   } else {
 149     // Get the hash value.  Use a static seed because the hash needs to return the same
 150     // value over multiple jvm invocations.
 151     unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
 152 
 153     // Truncate the ident, saving room for the 8 hex character hash value.
 154     strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
 155 
 156     // Append the hash code as eight hex digits.
 157     sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
 158     header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.
 159   }
 160 
 161   assert(header_version[JVM_IDENT_MAX-1] == 0, "must be");
 162 }
 163 
 164 FileMapInfo::FileMapInfo(bool is_static) {
 165   memset((void*)this, 0, sizeof(FileMapInfo));
 166   _is_static = is_static;
 167   size_t header_size;
 168   if (is_static) {
 169     assert(_current_info == NULL, "must be singleton"); // not thread safe
 170     _current_info = this;
 171     header_size = sizeof(FileMapHeader);
 172   } else {
 173     assert(_dynamic_archive_info == NULL, "must be singleton"); // not thread safe
 174     _dynamic_archive_info = this;
 175     header_size = sizeof(DynamicArchiveHeader);
 176   }
 177   _header = (FileMapHeader*)os::malloc(header_size, mtInternal);
 178   memset((void*)_header, 0, header_size);
 179   _header->set_header_size(header_size);
 180   _header->set_version(INVALID_CDS_ARCHIVE_VERSION);
 181   _header->set_has_platform_or_app_classes(true);
 182   _file_offset = 0;
 183   _file_open = false;
 184 }
 185 
 186 FileMapInfo::~FileMapInfo() {
 187   if (_is_static) {
 188     assert(_current_info == this, "must be singleton"); // not thread safe
 189     _current_info = NULL;
 190   } else {
 191     assert(_dynamic_archive_info == this, "must be singleton"); // not thread safe
 192     _dynamic_archive_info = NULL;
 193   }
 194 }
 195 
 196 void FileMapInfo::populate_header(size_t alignment) {
 197   header()->populate(this, alignment);
 198 }
 199 
 200 void FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
 201   if (DynamicDumpSharedSpaces) {
 202     _magic = CDS_DYNAMIC_ARCHIVE_MAGIC;
 203   } else {
 204     _magic = CDS_ARCHIVE_MAGIC;
 205   }
 206   _version = CURRENT_CDS_ARCHIVE_VERSION;
 207   _alignment = alignment;
 208   _obj_alignment = ObjectAlignmentInBytes;
 209   _compact_strings = CompactStrings;
 210   _narrow_oop_mode = CompressedOops::mode();
 211   _narrow_oop_base = CompressedOops::base();
 212   _narrow_oop_shift = CompressedOops::shift();
 213   _max_heap_size = MaxHeapSize;
 214   _narrow_klass_shift = CompressedKlassPointers::shift();
 215   if (HeapShared::is_heap_object_archiving_allowed()) {
 216     _heap_end = CompressedOops::end();
 217   }
 218 
 219   // The following fields are for sanity checks for whether this archive
 220   // will function correctly with this JVM and the bootclasspath it's
 221   // invoked with.
 222 
 223   // JVM version string ... changes on each build.
 224   get_header_version(_jvm_ident);
 225 
 226   _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();
 227   _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();
 228   _num_module_paths = ClassLoader::num_module_path_entries();
 229   _max_used_path_index = ClassLoaderExt::max_used_path_index();
 230 
 231   _verify_local = BytecodeVerificationLocal;
 232   _verify_remote = BytecodeVerificationRemote;
 233   _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();
 234   _requested_base_address = (char*)SharedBaseAddress;
 235   _mapped_base_address = (char*)SharedBaseAddress;
 236   _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;
 237   // the following 2 fields will be set in write_header for dynamic archive header
 238   _base_archive_name_size = 0;
 239   _base_archive_is_default = false;
 240 
 241   if (!DynamicDumpSharedSpaces) {
 242     set_shared_path_table(mapinfo->_shared_path_table);
 243   }
 244 }
 245 
 246 void SharedClassPathEntry::init_as_non_existent(const char* path, TRAPS) {
 247   _type = non_existent_entry;
 248   set_name(path, THREAD);
 249 }
 250 
 251 void SharedClassPathEntry::init(bool is_modules_image,
 252                                 ClassPathEntry* cpe, TRAPS) {
 253   Arguments::assert_is_dumping_archive();
 254   _timestamp = 0;
 255   _filesize  = 0;
 256   _from_class_path_attr = false;
 257 
 258   struct stat st;
 259   if (os::stat(cpe->name(), &st) == 0) {
 260     if ((st.st_mode & S_IFMT) == S_IFDIR) {
 261       _type = dir_entry;
 262     } else {
 263       // The timestamp of the modules_image is not checked at runtime.
 264       if (is_modules_image) {
 265         _type = modules_image_entry;
 266       } else {
 267         _type = jar_entry;
 268         _timestamp = st.st_mtime;
 269         _from_class_path_attr = cpe->from_class_path_attr();
 270       }
 271       _filesize = st.st_size;
 272     }
 273   } else {
 274     // The file/dir must exist, or it would not have been added
 275     // into ClassLoader::classpath_entry().
 276     //
 277     // If we can't access a jar file in the boot path, then we can't
 278     // make assumptions about where classes get loaded from.
 279     FileMapInfo::fail_stop("Unable to open file %s.", cpe->name());
 280   }
 281 
 282   // No need to save the name of the module file, as it will be computed at run time
 283   // to allow relocation of the JDK directory.
 284   const char* name = is_modules_image  ? "" : cpe->name();
 285   set_name(name, THREAD);
 286 }
 287 
 288 void SharedClassPathEntry::set_name(const char* name, TRAPS) {
 289   size_t len = strlen(name) + 1;
 290   _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, THREAD);
 291   strcpy(_name->data(), name);
 292 }
 293 
 294 const char* SharedClassPathEntry::name() const {
 295   if (UseSharedSpaces && is_modules_image()) {
 296     // In order to validate the runtime modules image file size against the archived
 297     // size information, we need to obtain the runtime modules image path. The recorded
 298     // dump time modules image path in the archive may be different from the runtime path
 299     // if the JDK image has beed moved after generating the archive.
 300     return ClassLoader::get_jrt_entry()->name();
 301   } else {
 302     return _name->data();
 303   }
 304 }
 305 
 306 bool SharedClassPathEntry::validate(bool is_class_path) const {
 307   assert(UseSharedSpaces, "runtime only");
 308 
 309   struct stat st;
 310   const char* name = this->name();
 311 
 312   bool ok = true;
 313   log_info(class, path)("checking shared classpath entry: %s", name);
 314   if (os::stat(name, &st) != 0 && is_class_path) {
 315     // If the archived module path entry does not exist at runtime, it is not fatal
 316     // (no need to invalid the shared archive) because the shared runtime visibility check
 317     // filters out any archived module classes that do not have a matching runtime
 318     // module path location.
 319     FileMapInfo::fail_continue("Required classpath entry does not exist: %s", name);
 320     ok = false;
 321   } else if (is_dir()) {
 322     if (!os::dir_is_empty(name)) {
 323       FileMapInfo::fail_continue("directory is not empty: %s", name);
 324       ok = false;
 325     }
 326   } else if ((has_timestamp() && _timestamp != st.st_mtime) ||
 327              _filesize != st.st_size) {
 328     ok = false;
 329     if (PrintSharedArchiveAndExit) {
 330       FileMapInfo::fail_continue(_timestamp != st.st_mtime ?
 331                                  "Timestamp mismatch" :
 332                                  "File size mismatch");
 333     } else {
 334       FileMapInfo::fail_continue("A jar file is not the one used while building"
 335                                  " the shared archive file: %s", name);
 336     }
 337   }
 338 
 339   if (PrintSharedArchiveAndExit && !ok) {
 340     // If PrintSharedArchiveAndExit is enabled, don't report failure to the
 341     // caller. Please see above comments for more details.
 342     ok = true;
 343     MetaspaceShared::set_archive_loading_failed();
 344   }
 345   return ok;
 346 }
 347 
 348 bool SharedClassPathEntry::check_non_existent() const {
 349   assert(_type == non_existent_entry, "must be");
 350   log_info(class, path)("should be non-existent: %s", name());
 351   struct stat st;
 352   if (os::stat(name(), &st) != 0) {
 353     log_info(class, path)("ok");
 354     return true; // file doesn't exist
 355   } else {
 356     return false;
 357   }
 358 }
 359 
 360 
 361 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
 362   it->push(&_name);
 363   it->push(&_manifest);
 364 }
 365 
 366 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
 367   it->push(&_table);
 368   for (int i=0; i<_size; i++) {
 369     path_at(i)->metaspace_pointers_do(it);
 370   }
 371 }
 372 
 373 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, Thread* THREAD) {
 374   size_t entry_size = sizeof(SharedClassPathEntry);
 375   int num_entries = 0;
 376   num_entries += ClassLoader::num_boot_classpath_entries();
 377   num_entries += ClassLoader::num_app_classpath_entries();
 378   num_entries += ClassLoader::num_module_path_entries();
 379   num_entries += FileMapInfo::num_non_existent_class_paths();
 380   size_t bytes = entry_size * num_entries;
 381 
 382   _table = MetadataFactory::new_array<u8>(loader_data, (int)(bytes + 7 / 8), THREAD);
 383   _size = num_entries;
 384 }
 385 
 386 void FileMapInfo::allocate_shared_path_table() {
 387   Arguments::assert_is_dumping_archive();
 388 
 389   EXCEPTION_MARK; // The following calls should never throw, but would exit VM on error.
 390   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 391   ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
 392 
 393   assert(jrt != NULL,
 394          "No modular java runtime image present when allocating the CDS classpath entry table");
 395 
 396   _shared_path_table.dumptime_init(loader_data, THREAD);
 397 
 398   // 1. boot class path
 399   int i = 0;
 400   i = add_shared_classpaths(i, "boot",   jrt, THREAD);
 401   i = add_shared_classpaths(i, "app",    ClassLoader::app_classpath_entries(), THREAD);
 402   i = add_shared_classpaths(i, "module", ClassLoader::module_path_entries(), THREAD);
 403 
 404   for (int x = 0; x < num_non_existent_class_paths(); x++, i++) {
 405     const char* path = _non_existent_class_paths->at(x);
 406     shared_path(i)->init_as_non_existent(path, THREAD);
 407   }
 408 
 409   assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
 410 }
 411 
 412 int FileMapInfo::add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS) {
 413   while (cpe != NULL) {
 414     bool is_jrt = (cpe == ClassLoader::get_jrt_entry());
 415     const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
 416     log_info(class, path)("add %s shared path (%s) %s", which, type, cpe->name());
 417     SharedClassPathEntry* ent = shared_path(i);
 418     ent->init(is_jrt, cpe, THREAD);
 419     if (cpe->is_jar_file()) {
 420       update_jar_manifest(cpe, ent, THREAD);
 421     }
 422     if (is_jrt) {
 423       cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
 424     } else {
 425       cpe = cpe->next();
 426     }
 427     i++;
 428   }
 429 
 430   return i;
 431 }
 432 
 433 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
 434   Arguments::assert_is_dumping_archive();
 435 
 436   bool has_nonempty_dir = false;
 437 
 438   int last = _shared_path_table.size() - 1;
 439   if (last > ClassLoaderExt::max_used_path_index()) {
 440      // no need to check any path beyond max_used_path_index
 441      last = ClassLoaderExt::max_used_path_index();
 442   }
 443 
 444   for (int i = 0; i <= last; i++) {
 445     SharedClassPathEntry *e = shared_path(i);
 446     if (e->is_dir()) {
 447       const char* path = e->name();
 448       if (!os::dir_is_empty(path)) {
 449         log_error(cds)("Error: non-empty directory '%s'", path);
 450         has_nonempty_dir = true;
 451       }
 452     }
 453   }
 454 
 455   if (has_nonempty_dir) {
 456     ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", NULL);
 457   }
 458 }
 459 
 460 void FileMapInfo::record_non_existent_class_path_entry(const char* path) {
 461   Arguments::assert_is_dumping_archive();
 462   log_info(class, path)("non-existent Class-Path entry %s", path);
 463   if (_non_existent_class_paths == NULL) {
 464     _non_existent_class_paths = new (ResourceObj::C_HEAP, mtInternal)GrowableArray<const char*>(10, true);
 465   }
 466   _non_existent_class_paths->append(os::strdup(path));
 467 }
 468 
 469 int FileMapInfo::num_non_existent_class_paths() {
 470   Arguments::assert_is_dumping_archive();
 471   if (_non_existent_class_paths != NULL) {
 472     return _non_existent_class_paths->length();
 473   } else {
 474     return 0;
 475   }
 476 }
 477 
 478 class ManifestStream: public ResourceObj {
 479   private:
 480   u1*   _buffer_start; // Buffer bottom
 481   u1*   _buffer_end;   // Buffer top (one past last element)
 482   u1*   _current;      // Current buffer position
 483 
 484  public:
 485   // Constructor
 486   ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
 487                                            _current(buffer) {
 488     _buffer_end = buffer + length;
 489   }
 490 
 491   static bool is_attr(u1* attr, const char* name) {
 492     return strncmp((const char*)attr, name, strlen(name)) == 0;
 493   }
 494 
 495   static char* copy_attr(u1* value, size_t len) {
 496     char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
 497     strncpy(buf, (char*)value, len);
 498     buf[len] = 0;
 499     return buf;
 500   }
 501 
 502   // The return value indicates if the JAR is signed or not
 503   bool check_is_signed() {
 504     u1* attr = _current;
 505     bool isSigned = false;
 506     while (_current < _buffer_end) {
 507       if (*_current == '\n') {
 508         *_current = '\0';
 509         u1* value = (u1*)strchr((char*)attr, ':');
 510         if (value != NULL) {
 511           assert(*(value+1) == ' ', "Unrecognized format" );
 512           if (strstr((char*)attr, "-Digest") != NULL) {
 513             isSigned = true;
 514             break;
 515           }
 516         }
 517         *_current = '\n'; // restore
 518         attr = _current + 1;
 519       }
 520       _current ++;
 521     }
 522     return isSigned;
 523   }
 524 };
 525 
 526 void FileMapInfo::update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
 527   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 528   ResourceMark rm(THREAD);
 529   jint manifest_size;
 530 
 531   assert(cpe->is_jar_file() && ent->is_jar(), "the shared class path entry is not a JAR file");
 532   char* manifest = ClassLoaderExt::read_manifest(cpe, &manifest_size, CHECK);
 533   if (manifest != NULL) {
 534     ManifestStream* stream = new ManifestStream((u1*)manifest,
 535                                                 manifest_size);
 536     if (stream->check_is_signed()) {
 537       ent->set_is_signed();
 538     } else {
 539       // Copy the manifest into the shared archive
 540       manifest = ClassLoaderExt::read_raw_manifest(cpe, &manifest_size, CHECK);
 541       Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
 542                                                       manifest_size,
 543                                                       THREAD);
 544       char* p = (char*)(buf->data());
 545       memcpy(p, manifest, manifest_size);
 546       ent->set_manifest(buf);
 547     }
 548   }
 549 }
 550 
 551 char* FileMapInfo::skip_first_path_entry(const char* path) {
 552   size_t path_sep_len = strlen(os::path_separator());
 553   char* p = strstr((char*)path, os::path_separator());
 554   if (p != NULL) {
 555     debug_only( {
 556       size_t image_name_len = strlen(MODULES_IMAGE_NAME);
 557       assert(strncmp(p - image_name_len, MODULES_IMAGE_NAME, image_name_len) == 0,
 558              "first entry must be the modules image");
 559     } );
 560     p += path_sep_len;
 561   } else {
 562     debug_only( {
 563       assert(ClassLoader::string_ends_with(path, MODULES_IMAGE_NAME),
 564              "first entry must be the modules image");
 565     } );
 566   }
 567   return p;
 568 }
 569 
 570 int FileMapInfo::num_paths(const char* path) {
 571   if (path == NULL) {
 572     return 0;
 573   }
 574   int npaths = 1;
 575   char* p = (char*)path;
 576   while (p != NULL) {
 577     char* prev = p;
 578     p = strstr((char*)p, os::path_separator());
 579     if (p != NULL) {
 580       p++;
 581       // don't count empty path
 582       if ((p - prev) > 1) {
 583        npaths++;
 584       }
 585     }
 586   }
 587   return npaths;
 588 }
 589 
 590 GrowableArray<const char*>* FileMapInfo::create_path_array(const char* paths) {
 591   GrowableArray<const char*>* path_array =  new(ResourceObj::RESOURCE_AREA, mtInternal)
 592       GrowableArray<const char*>(10);
 593 
 594   ClasspathStream cp_stream(paths);
 595   while (cp_stream.has_next()) {
 596     const char* path = cp_stream.get_next();
 597     struct stat st;
 598     if (os::stat(path, &st) == 0) {
 599       path_array->append(path);
 600     }
 601   }
 602   return path_array;
 603 }
 604 
 605 bool FileMapInfo::fail(const char* msg, const char* name) {
 606   ClassLoader::trace_class_path(msg, name);
 607   return false;
 608 }
 609 
 610 bool FileMapInfo::check_paths(int shared_path_start_idx, int num_paths, GrowableArray<const char*>* rp_array) {
 611   int i = 0;
 612   int j = shared_path_start_idx;
 613   bool mismatch = false;
 614   while (i < num_paths && !mismatch) {
 615     while (shared_path(j)->from_class_path_attr()) {
 616       // shared_path(j) was expanded from the JAR file attribute "Class-Path:"
 617       // during dump time. It's not included in the -classpath VM argument.
 618       j++;
 619     }
 620     if (!os::same_files(shared_path(j)->name(), rp_array->at(i))) {
 621       mismatch = true;
 622     }
 623     i++;
 624     j++;
 625   }
 626   return mismatch;
 627 }
 628 
 629 bool FileMapInfo::validate_boot_class_paths() {
 630   //
 631   // - Archive contains boot classes only - relaxed boot path check:
 632   //   Extra path elements appended to the boot path at runtime are allowed.
 633   //
 634   // - Archive contains application or platform classes - strict boot path check:
 635   //   Validate the entire runtime boot path, which must be compatible
 636   //   with the dump time boot path. Appending boot path at runtime is not
 637   //   allowed.
 638   //
 639 
 640   // The first entry in boot path is the modules_image (guaranteed by
 641   // ClassLoader::setup_boot_search_path()). Skip the first entry. The
 642   // path of the runtime modules_image may be different from the dump
 643   // time path (e.g. the JDK image is copied to a different location
 644   // after generating the shared archive), which is acceptable. For most
 645   // common cases, the dump time boot path might contain modules_image only.
 646   char* runtime_boot_path = Arguments::get_sysclasspath();
 647   char* rp = skip_first_path_entry(runtime_boot_path);
 648   assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 649   int dp_len = header()->app_class_paths_start_index() - 1; // ignore the first path to the module image
 650   bool mismatch = false;
 651 
 652   bool relaxed_check = !header()->has_platform_or_app_classes();
 653   if (dp_len == 0 && rp == NULL) {
 654     return true;   // ok, both runtime and dump time boot paths have modules_images only
 655   } else if (dp_len == 0 && rp != NULL) {
 656     if (relaxed_check) {
 657       return true;   // ok, relaxed check, runtime has extra boot append path entries
 658     } else {
 659       mismatch = true;
 660     }
 661   } else if (dp_len > 0 && rp != NULL) {
 662     int num;
 663     ResourceMark rm;
 664     GrowableArray<const char*>* rp_array = create_path_array(rp);
 665     int rp_len = rp_array->length();
 666     if (rp_len >= dp_len) {
 667       if (relaxed_check) {
 668         // only check the leading entries in the runtime boot path, up to
 669         // the length of the dump time boot path
 670         num = dp_len;
 671       } else {
 672         // check the full runtime boot path, must match with dump time
 673         num = rp_len;
 674       }
 675       mismatch = check_paths(1, num, rp_array);
 676     }
 677   }
 678 
 679   if (mismatch) {
 680     // The paths are different
 681     return fail("[BOOT classpath mismatch, actual =", runtime_boot_path);
 682   }
 683   return true;
 684 }
 685 
 686 bool FileMapInfo::validate_app_class_paths(int shared_app_paths_len) {
 687   const char *appcp = Arguments::get_appclasspath();
 688   assert(appcp != NULL, "NULL app classpath");
 689   int rp_len = num_paths(appcp);
 690   bool mismatch = false;
 691   if (rp_len < shared_app_paths_len) {
 692     return fail("Run time APP classpath is shorter than the one at dump time: ", appcp);
 693   }
 694   if (shared_app_paths_len != 0 && rp_len != 0) {
 695     // Prefix is OK: E.g., dump with -cp foo.jar, but run with -cp foo.jar:bar.jar.
 696     ResourceMark rm;
 697     GrowableArray<const char*>* rp_array = create_path_array(appcp);
 698     if (rp_array->length() == 0) {
 699       // None of the jar file specified in the runtime -cp exists.
 700       return fail("None of the jar file specified in the runtime -cp exists: -Djava.class.path=", appcp);
 701     }
 702 
 703     // Handling of non-existent entries in the classpath: we eliminate all the non-existent
 704     // entries from both the dump time classpath (ClassLoader::update_class_path_entry_list)
 705     // and the runtime classpath (FileMapInfo::create_path_array), and check the remaining
 706     // entries. E.g.:
 707     //
 708     // dump : -cp a.jar:NE1:NE2:b.jar  -> a.jar:b.jar -> recorded in archive.
 709     // run 1: -cp NE3:a.jar:NE4:b.jar  -> a.jar:b.jar -> matched
 710     // run 2: -cp x.jar:NE4:b.jar      -> x.jar:b.jar -> mismatched
 711 
 712     int j = header()->app_class_paths_start_index();
 713     mismatch = check_paths(j, shared_app_paths_len, rp_array);
 714     if (mismatch) {
 715       return fail("[APP classpath mismatch, actual: -Djava.class.path=", appcp);
 716     }
 717   }
 718   return true;
 719 }
 720 
 721 void FileMapInfo::log_paths(const char* msg, int start_idx, int end_idx) {
 722   LogTarget(Info, class, path) lt;
 723   if (lt.is_enabled()) {
 724     LogStream ls(lt);
 725     ls.print("%s", msg);
 726     const char* prefix = "";
 727     for (int i = start_idx; i < end_idx; i++) {
 728       ls.print("%s%s", prefix, shared_path(i)->name());
 729       prefix = os::path_separator();
 730     }
 731     ls.cr();
 732   }
 733 }
 734 
 735 bool FileMapInfo::validate_shared_path_table() {
 736   assert(UseSharedSpaces, "runtime only");
 737 
 738   _validating_shared_path_table = true;
 739 
 740   // Load the shared path table info from the archive header
 741   _shared_path_table = header()->shared_path_table();
 742   if (DynamicDumpSharedSpaces) {
 743     // Only support dynamic dumping with the usage of the default CDS archive
 744     // or a simple base archive.
 745     // If the base layer archive contains additional path component besides
 746     // the runtime image and the -cp, dynamic dumping is disabled.
 747     //
 748     // When dynamic archiving is enabled, the _shared_path_table is overwritten
 749     // to include the application path and stored in the top layer archive.
 750     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 751     if (header()->app_class_paths_start_index() > 1) {
 752       DynamicDumpSharedSpaces = false;
 753       warning(
 754         "Dynamic archiving is disabled because base layer archive has appended boot classpath");
 755     }
 756     if (header()->num_module_paths() > 0) {
 757       DynamicDumpSharedSpaces = false;
 758       warning(
 759         "Dynamic archiving is disabled because base layer archive has module path");
 760     }
 761   }
 762 
 763   log_paths("Expecting BOOT path=", 0, header()->app_class_paths_start_index());
 764   log_paths("Expecting -Djava.class.path=", header()->app_class_paths_start_index(), header()->app_module_paths_start_index());
 765 
 766   int module_paths_start_index = header()->app_module_paths_start_index();
 767   int shared_app_paths_len = 0;
 768 
 769   // validate the path entries up to the _max_used_path_index
 770   for (int i=0; i < header()->max_used_path_index() + 1; i++) {
 771     if (i < module_paths_start_index) {
 772       if (shared_path(i)->validate()) {
 773         // Only count the app class paths not from the "Class-path" attribute of a jar manifest.
 774         if (!shared_path(i)->from_class_path_attr() && i >= header()->app_class_paths_start_index()) {
 775           shared_app_paths_len++;
 776         }
 777         log_info(class, path)("ok");
 778       } else {
 779         if (_dynamic_archive_info != NULL && _dynamic_archive_info->_is_static) {
 780           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 781         }
 782         return false;
 783       }
 784     } else if (i >= module_paths_start_index) {
 785       if (shared_path(i)->validate(false /* not a class path entry */)) {
 786         log_info(class, path)("ok");
 787       } else {
 788         if (_dynamic_archive_info != NULL && _dynamic_archive_info->_is_static) {
 789           assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
 790         }
 791         return false;
 792       }
 793     }
 794   }
 795 
 796   if (header()->max_used_path_index() == 0) {
 797     // default archive only contains the module image in the bootclasspath
 798     assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
 799   } else {
 800     if (!validate_boot_class_paths() || !validate_app_class_paths(shared_app_paths_len)) {
 801       fail_continue("shared class paths mismatch (hint: enable -Xlog:class+path=info to diagnose the failure)");
 802       return false;
 803     }
 804   }
 805 
 806   validate_non_existent_class_paths();
 807 
 808   _validating_shared_path_table = false;
 809 
 810 #if INCLUDE_JVMTI
 811   if (_classpath_entries_for_jvmti != NULL) {
 812     os::free(_classpath_entries_for_jvmti);
 813   }
 814   size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
 815   _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
 816   memset((void*)_classpath_entries_for_jvmti, 0, sz);
 817 #endif
 818 
 819   return true;
 820 }
 821 
 822 void FileMapInfo::validate_non_existent_class_paths() {
 823   // All of the recorded non-existent paths came from the Class-Path: attribute from the JAR
 824   // files on the app classpath. If any of these are found to exist during runtime,
 825   // it will change how classes are loading for the app loader. For safety, disable
 826   // loading of archived platform/app classes (currently there's no way to disable just the
 827   // app classes).
 828 
 829   assert(UseSharedSpaces, "runtime only");
 830   for (int i = header()->app_module_paths_start_index() + header()->num_module_paths();
 831        i < get_number_of_shared_paths();
 832        i++) {
 833     SharedClassPathEntry* ent = shared_path(i);
 834     if (!ent->check_non_existent()) {
 835       warning("Archived non-system classes are disabled because the "
 836               "file %s exists", ent->name());
 837       header()->set_has_platform_or_app_classes(false);
 838     }
 839   }
 840 }
 841 
 842 bool FileMapInfo::check_archive(const char* archive_name, bool is_static) {
 843   int fd = os::open(archive_name, O_RDONLY | O_BINARY, 0);
 844   if (fd < 0) {
 845     // do not vm_exit_during_initialization here because Arguments::init_shared_archive_paths()
 846     // requires a shared archive name. The open_for_read() function will log a message regarding
 847     // failure in opening a shared archive.
 848     return false;
 849   }
 850 
 851   size_t sz = is_static ? sizeof(FileMapHeader) : sizeof(DynamicArchiveHeader);
 852   void* header = os::malloc(sz, mtInternal);
 853   memset(header, 0, sz);
 854   size_t n = os::read(fd, header, (unsigned int)sz);
 855   if (n != sz) {
 856     os::free(header);
 857     os::close(fd);
 858     vm_exit_during_initialization("Unable to read header from shared archive", archive_name);
 859     return false;
 860   }
 861   if (is_static) {
 862     FileMapHeader* static_header = (FileMapHeader*)header;
 863     if (static_header->magic() != CDS_ARCHIVE_MAGIC) {
 864       os::free(header);
 865       os::close(fd);
 866       vm_exit_during_initialization("Not a base shared archive", archive_name);
 867       return false;
 868     }
 869   } else {
 870     DynamicArchiveHeader* dynamic_header = (DynamicArchiveHeader*)header;
 871     if (dynamic_header->magic() != CDS_DYNAMIC_ARCHIVE_MAGIC) {
 872       os::free(header);
 873       os::close(fd);
 874       vm_exit_during_initialization("Not a top shared archive", archive_name);
 875       return false;
 876     }
 877   }
 878   os::free(header);
 879   os::close(fd);
 880   return true;
 881 }
 882 
 883 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
 884                                                     int* size, char** base_archive_name) {
 885   int fd = os::open(archive_name, O_RDONLY | O_BINARY, 0);
 886   if (fd < 0) {
 887     *size = 0;
 888     return false;
 889   }
 890 
 891   // read the header as a dynamic archive header
 892   size_t sz = sizeof(DynamicArchiveHeader);
 893   DynamicArchiveHeader* dynamic_header = (DynamicArchiveHeader*)os::malloc(sz, mtInternal);
 894   size_t n = os::read(fd, dynamic_header, (unsigned int)sz);
 895   if (n != sz) {
 896     fail_continue("Unable to read the file header.");
 897     os::free(dynamic_header);
 898     os::close(fd);
 899     return false;
 900   }
 901   if (dynamic_header->magic() != CDS_DYNAMIC_ARCHIVE_MAGIC) {
 902     // Not a dynamic header, no need to proceed further.
 903     *size = 0;
 904     os::free(dynamic_header);
 905     os::close(fd);
 906     return false;
 907   }
 908   if (dynamic_header->base_archive_is_default()) {
 909     *base_archive_name = Arguments::get_default_shared_archive_path();
 910   } else {
 911     // read the base archive name
 912     size_t name_size = dynamic_header->base_archive_name_size();
 913     if (name_size == 0) {
 914       os::free(dynamic_header);
 915       os::close(fd);
 916       return false;
 917     }
 918     *base_archive_name = NEW_C_HEAP_ARRAY(char, name_size, mtInternal);
 919     n = os::read(fd, *base_archive_name, (unsigned int)name_size);
 920     if (n != name_size) {
 921       fail_continue("Unable to read the base archive name from the header.");
 922       FREE_C_HEAP_ARRAY(char, *base_archive_name);
 923       *base_archive_name = NULL;
 924       os::free(dynamic_header);
 925       os::close(fd);
 926       return false;
 927     }
 928   }
 929 
 930   os::free(dynamic_header);
 931   os::close(fd);
 932   return true;
 933 }
 934 
 935 void FileMapInfo::restore_shared_path_table() {
 936   _shared_path_table = _current_info->header()->shared_path_table();
 937 }
 938 
 939 // Read the FileMapInfo information from the file.
 940 
 941 bool FileMapInfo::init_from_file(int fd) {
 942   size_t sz = is_static() ? sizeof(FileMapHeader) : sizeof(DynamicArchiveHeader);
 943   size_t n = os::read(fd, header(), (unsigned int)sz);
 944   if (n != sz) {
 945     fail_continue("Unable to read the file header.");
 946     return false;
 947   }
 948 
 949   if (!Arguments::has_jimage()) {
 950     FileMapInfo::fail_continue("The shared archive file cannot be used with an exploded module build.");
 951     return false;
 952   }
 953 
 954   unsigned int expected_magic = is_static() ? CDS_ARCHIVE_MAGIC : CDS_DYNAMIC_ARCHIVE_MAGIC;
 955   if (header()->magic() != expected_magic) {
 956     log_info(cds)("_magic expected: 0x%08x", expected_magic);
 957     log_info(cds)("         actual: 0x%08x", header()->magic());
 958     FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
 959     return false;
 960   }
 961 
 962   if (header()->version() != CURRENT_CDS_ARCHIVE_VERSION) {
 963     log_info(cds)("_version expected: %d", CURRENT_CDS_ARCHIVE_VERSION);
 964     log_info(cds)("           actual: %d", header()->version());
 965     fail_continue("The shared archive file has the wrong version.");
 966     return false;
 967   }
 968 
 969   if (header()->header_size() != sz) {
 970     log_info(cds)("_header_size expected: " SIZE_FORMAT, sz);
 971     log_info(cds)("               actual: " SIZE_FORMAT, header()->header_size());
 972     FileMapInfo::fail_continue("The shared archive file has an incorrect header size.");
 973     return false;
 974   }
 975 
 976   const char* actual_ident = header()->jvm_ident();
 977 
 978   if (actual_ident[JVM_IDENT_MAX-1] != 0) {
 979     FileMapInfo::fail_continue("JVM version identifier is corrupted.");
 980     return false;
 981   }
 982 
 983   char expected_ident[JVM_IDENT_MAX];
 984   get_header_version(expected_ident);
 985   if (strncmp(actual_ident, expected_ident, JVM_IDENT_MAX-1) != 0) {
 986     log_info(cds)("_jvm_ident expected: %s", expected_ident);
 987     log_info(cds)("             actual: %s", actual_ident);
 988     FileMapInfo::fail_continue("The shared archive file was created by a different"
 989                   " version or build of HotSpot");
 990     return false;
 991   }
 992 
 993   if (VerifySharedSpaces) {
 994     int expected_crc = header()->compute_crc();
 995     if (expected_crc != header()->crc()) {
 996       log_info(cds)("_crc expected: %d", expected_crc);
 997       log_info(cds)("       actual: %d", header()->crc());
 998       FileMapInfo::fail_continue("Header checksum verification failed.");
 999       return false;
1000     }
1001   }
1002 
1003   _file_offset = n + header()->base_archive_name_size(); // accounts for the size of _base_archive_name
1004 
1005   if (is_static()) {
1006     // just checking the last region is sufficient since the archive is written
1007     // in sequential order
1008     size_t len = lseek(fd, 0, SEEK_END);
1009     FileMapRegion* si = space_at(MetaspaceShared::last_valid_region);
1010     // The last space might be empty
1011     if (si->file_offset() > len || len - si->file_offset() < si->used()) {
1012       fail_continue("The shared archive file has been truncated.");
1013       return false;
1014     }
1015   }
1016 
1017   return true;
1018 }
1019 
1020 void FileMapInfo::seek_to_position(size_t pos) {
1021   if (lseek(_fd, (long)pos, SEEK_SET) < 0) {
1022     fail_stop("Unable to seek to position " SIZE_FORMAT, pos);
1023   }
1024 }
1025 
1026 // Read the FileMapInfo information from the file.
1027 bool FileMapInfo::open_for_read() {
1028   if (_file_open) {
1029     return true;
1030   }
1031   if (is_static()) {
1032     _full_path = Arguments::GetSharedArchivePath();
1033   } else {
1034     _full_path = Arguments::GetSharedDynamicArchivePath();
1035   }
1036   int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
1037   if (fd < 0) {
1038     if (is_static()) {
1039       if (errno == ENOENT) {
1040         // Not locating the shared archive is ok.
1041         fail_continue("Specified shared archive not found (%s).", _full_path);
1042       } else {
1043         fail_continue("Failed to open shared archive file (%s).",
1044                       os::strerror(errno));
1045       }
1046     } else {
1047       log_warning(cds, dynamic)("specified dynamic archive doesn't exist: %s", _full_path);
1048     }
1049     return false;
1050   }
1051 
1052   _fd = fd;
1053   _file_open = true;
1054   return true;
1055 }
1056 
1057 // Write the FileMapInfo information to the file.
1058 
1059 void FileMapInfo::open_for_write(const char* path) {
1060   if (path == NULL) {
1061     _full_path = Arguments::GetSharedArchivePath();
1062   } else {
1063     _full_path = path;
1064   }
1065   LogMessage(cds) msg;
1066   if (msg.is_info()) {
1067     msg.info("Dumping shared data to file: ");
1068     msg.info("   %s", _full_path);
1069   }
1070 
1071 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
1072     chmod(_full_path, _S_IREAD | _S_IWRITE);
1073 #endif
1074 
1075   // Use remove() to delete the existing file because, on Unix, this will
1076   // allow processes that have it open continued access to the file.
1077   remove(_full_path);
1078   int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1079   if (fd < 0) {
1080     fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
1081               os::strerror(errno));
1082   }
1083   _fd = fd;
1084   _file_open = true;
1085 
1086   // Seek past the header. We will write the header after all regions are written
1087   // and their CRCs computed.
1088   size_t header_bytes = header()->header_size();
1089   if (header()->magic() == CDS_DYNAMIC_ARCHIVE_MAGIC) {
1090     header_bytes += strlen(Arguments::GetSharedArchivePath()) + 1;
1091   }
1092 
1093   header_bytes = align_up(header_bytes, os::vm_allocation_granularity());
1094   _file_offset = header_bytes;
1095   seek_to_position(_file_offset);
1096 }
1097 
1098 
1099 // Write the header to the file, seek to the next allocation boundary.
1100 
1101 void FileMapInfo::write_header() {
1102   _file_offset = 0;
1103   seek_to_position(_file_offset);
1104   char* base_archive_name = NULL;
1105   if (header()->magic() == CDS_DYNAMIC_ARCHIVE_MAGIC) {
1106     base_archive_name = (char*)Arguments::GetSharedArchivePath();
1107     header()->set_base_archive_name_size(strlen(base_archive_name) + 1);
1108     header()->set_base_archive_is_default(FLAG_IS_DEFAULT(SharedArchiveFile));
1109   }
1110 
1111   assert(is_file_position_aligned(), "must be");
1112   write_bytes(header(), header()->header_size());
1113   if (base_archive_name != NULL) {
1114     write_bytes(base_archive_name, header()->base_archive_name_size());
1115   }
1116 }
1117 
1118 size_t FileMapRegion::used_aligned() const {
1119   return align_up(used(), os::vm_allocation_granularity());
1120 }
1121 
1122 void FileMapRegion::init(bool is_heap_region, char* base, size_t size, bool read_only,
1123                          bool allow_exec, int crc) {
1124   _is_heap_region = is_heap_region;
1125   _mapping_offset = 0;
1126 
1127   if (is_heap_region) {
1128     assert(!DynamicDumpSharedSpaces, "must be");
1129     assert((base - (char*)CompressedKlassPointers::base()) % HeapWordSize == 0, "Sanity");
1130     if (base != NULL) {
1131       _mapping_offset = (size_t)CompressedOops::encode_not_null((oop)base);
1132       assert(_mapping_offset >> 32 == 0, "must be 32-bit only");
1133     }
1134   } else {
1135     if (base != NULL) {
1136       assert(base >= (char*)SharedBaseAddress, "must be");
1137       _mapping_offset = base - (char*)SharedBaseAddress;
1138     } 
1139   }
1140   _used = size;
1141   _read_only = read_only;
1142   _allow_exec = allow_exec;
1143   _crc = crc;
1144   _mapped_from_file = false;
1145   _mapped_base = NULL;
1146 }
1147 
1148 void FileMapInfo::write_region(int region, char* base, size_t size,
1149                                bool read_only, bool allow_exec) {
1150   Arguments::assert_is_dumping_archive();
1151 
1152   FileMapRegion* si = space_at(region);
1153   char* target_base = base;
1154 
1155   if (region == MetaspaceShared::bm) {
1156     target_base = NULL;
1157   } else if (DynamicDumpSharedSpaces) {
1158     assert(!HeapShared::is_heap_region(region), "dynamic archive doesn't support heap regions");
1159     target_base = DynamicArchive::buffer_to_target(base);
1160   }
1161 
1162   si->set_file_offset(_file_offset);
1163   char* requested_base = (target_base == NULL) ? NULL : target_base + MetaspaceShared::final_delta();
1164   log_info(cds)("Shared file region  %d: " SIZE_FORMAT_HEX_W(08)
1165                 " bytes, addr " INTPTR_FORMAT " file offset " SIZE_FORMAT_HEX_W(08),
1166                 region, size, p2i(requested_base), _file_offset);
1167 
1168   int crc = ClassLoader::crc32(0, base, (jint)size);
1169   si->init(HeapShared::is_heap_region(region), target_base, size, read_only, allow_exec, crc);
1170 
1171   if (base != NULL) {
1172     write_bytes_aligned(base, size);
1173   }
1174 }
1175 
1176 
1177 void FileMapInfo::write_bitmap_region(const CHeapBitMap* ptrmap) {
1178   ResourceMark rm;
1179   size_t size_in_bits = ptrmap->size();
1180   size_t size_in_bytes = ptrmap->size_in_bytes();
1181   uintptr_t* buffer = (uintptr_t*)NEW_RESOURCE_ARRAY(char, size_in_bytes);
1182   ptrmap->write_to(buffer, size_in_bytes);
1183   header()->set_ptrmap_size_in_bits(size_in_bits);
1184 
1185   log_info(cds)("ptrmap = " INTPTR_FORMAT " (" SIZE_FORMAT " bytes)",
1186                 p2i(buffer), size_in_bytes);
1187   write_region(MetaspaceShared::bm, (char*)buffer, size_in_bytes, /*read_only=*/true, /*allow_exec=*/false);
1188 }
1189 
1190 // Write out the given archive heap memory regions.  GC code combines multiple
1191 // consecutive archive GC regions into one MemRegion whenever possible and
1192 // produces the 'heap_mem' array.
1193 //
1194 // If the archive heap memory size is smaller than a single dump time GC region
1195 // size, there is only one MemRegion in the array.
1196 //
1197 // If the archive heap memory size is bigger than one dump time GC region size,
1198 // the 'heap_mem' array may contain more than one consolidated MemRegions. When
1199 // the first/bottom archive GC region is a partial GC region (with the empty
1200 // portion at the higher address within the region), one MemRegion is used for
1201 // the bottom partial archive GC region. The rest of the consecutive archive
1202 // GC regions are combined into another MemRegion.
1203 //
1204 // Here's the mapping from (archive heap GC regions) -> (GrowableArray<MemRegion> *regions).
1205 //   + We have 1 or more archive heap regions: ah0, ah1, ah2 ..... ahn
1206 //   + We have 1 or 2 consolidated heap memory regions: r0 and r1
1207 //
1208 // If there's a single archive GC region (ah0), then r0 == ah0, and r1 is empty.
1209 // Otherwise:
1210 //
1211 // "X" represented space that's occupied by heap objects.
1212 // "_" represented unused spaced in the heap region.
1213 //
1214 //
1215 //    |ah0       | ah1 | ah2| ...... | ahn|
1216 //    |XXXXXX|__ |XXXXX|XXXX|XXXXXXXX|XXXX|
1217 //    |<-r0->|   |<- r1 ----------------->|
1218 //            ^^^
1219 //             |
1220 //             +-- gap
1221 size_t FileMapInfo::write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,
1222                                                GrowableArray<ArchiveHeapOopmapInfo> *oopmaps,
1223                                                int first_region_id, int max_num_regions) {
1224   assert(max_num_regions <= 2, "Only support maximum 2 memory regions");
1225 
1226   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1227   if(arr_len > max_num_regions) {
1228     fail_stop("Unable to write archive heap memory regions: "
1229               "number of memory regions exceeds maximum due to fragmentation. "
1230               "Please increase java heap size "
1231               "(current MaxHeapSize is " SIZE_FORMAT ", InitialHeapSize is " SIZE_FORMAT ").",
1232               MaxHeapSize, InitialHeapSize);
1233   }
1234 
1235   size_t total_size = 0;
1236   for (int i = first_region_id, arr_idx = 0;
1237            i < first_region_id + max_num_regions;
1238            i++, arr_idx++) {
1239     char* start = NULL;
1240     size_t size = 0;
1241     if (arr_idx < arr_len) {
1242       start = (char*)heap_mem->at(arr_idx).start();
1243       size = heap_mem->at(arr_idx).byte_size();
1244       total_size += size;
1245     }
1246 
1247     log_info(cds)("Archive heap region %d: " INTPTR_FORMAT " - " INTPTR_FORMAT " = " SIZE_FORMAT_W(8) " bytes",
1248                   i, p2i(start), p2i(start + size), size);
1249     write_region(i, start, size, false, false);
1250     if (size > 0) {
1251       address oopmap = oopmaps->at(arr_idx)._oopmap;
1252       assert(oopmap >= (address)SharedBaseAddress, "must be");
1253       space_at(i)->init_oopmap(oopmap - (address)SharedBaseAddress,
1254                                oopmaps->at(arr_idx)._oopmap_size_in_bits);
1255     }
1256   }
1257   return total_size;
1258 }
1259 
1260 // Dump bytes to file -- at the current file position.
1261 
1262 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1263   assert(_file_open, "must be");
1264   size_t n = os::write(_fd, buffer, (unsigned int)nbytes);
1265   if (n != nbytes) {
1266     // If the shared archive is corrupted, close it and remove it.
1267     close();
1268     remove(_full_path);
1269     fail_stop("Unable to write to shared archive file.");
1270   }
1271   _file_offset += nbytes;
1272 }
1273 
1274 bool FileMapInfo::is_file_position_aligned() const {
1275   return _file_offset == align_up(_file_offset,
1276                                   os::vm_allocation_granularity());
1277 }
1278 
1279 // Align file position to an allocation unit boundary.
1280 
1281 void FileMapInfo::align_file_position() {
1282   assert(_file_open, "must be");
1283   size_t new_file_offset = align_up(_file_offset,
1284                                     os::vm_allocation_granularity());
1285   if (new_file_offset != _file_offset) {
1286     _file_offset = new_file_offset;
1287     // Seek one byte back from the target and write a byte to insure
1288     // that the written file is the correct length.
1289     _file_offset -= 1;
1290     seek_to_position(_file_offset);
1291     char zero = 0;
1292     write_bytes(&zero, 1);
1293   }
1294 }
1295 
1296 
1297 // Dump bytes to file -- at the current file position.
1298 
1299 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1300   align_file_position();
1301   write_bytes(buffer, nbytes);
1302   align_file_position();
1303 }
1304 
1305 void FileMapInfo::set_final_requested_base(char* b) {
1306   header()->set_final_requested_base(b);
1307 }
1308 
1309 // Close the shared archive file.  This does NOT unmap mapped regions.
1310 
1311 void FileMapInfo::close() {
1312   if (_file_open) {
1313     if (::close(_fd) < 0) {
1314       fail_stop("Unable to close the shared archive file.");
1315     }
1316     _file_open = false;
1317     _fd = -1;
1318   }
1319 }
1320 
1321 
1322 // JVM/TI RedefineClasses() support:
1323 // Remap the shared readonly space to shared readwrite, private.
1324 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1325   int idx = MetaspaceShared::ro;
1326   FileMapRegion* si = space_at(idx);
1327   if (!si->read_only()) {
1328     // the space is already readwrite so we are done
1329     return true;
1330   }
1331   size_t used = si->used();
1332   size_t size = align_up(used, os::vm_allocation_granularity());
1333   if (!open_for_read()) {
1334     return false;
1335   }
1336   char *addr = region_addr(idx);
1337   char *base = os::remap_memory(_fd, _full_path, si->file_offset(),
1338                                 addr, size, false /* !read_only */,
1339                                 si->allow_exec());
1340   close();
1341   // These have to be errors because the shared region is now unmapped.
1342   if (base == NULL) {
1343     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1344     vm_exit(1);
1345   }
1346   if (base != addr) {
1347     log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1348     vm_exit(1);
1349   }
1350   si->set_read_only(false);
1351   return true;
1352 }
1353 
1354 // Memory map a region in the address space.
1355 static const char* shared_region_name[] = { "MiscData", "ReadWrite", "ReadOnly", "MiscCode", "Bitmap",
1356                                             "String1", "String2", "OpenArchive1", "OpenArchive2" };
1357 
1358 MapArchiveResult FileMapInfo::map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs) {
1359   FileMapRegion* last_region = NULL;
1360   intx addr_delta = mapped_base_address - header()->requested_base_address();
1361 
1362   DEBUG_ONLY(header()->set_mapped_base_address((char*)(uintptr_t)0xdeadbeef);)
1363 
1364   for (int r = 0; r < num_regions; r++) {
1365     int idx = regions[r];
1366     MapArchiveResult result = map_region(idx, addr_delta, mapped_base_address, rs);
1367     if (result != MAP_ARCHIVE_SUCCESS) {
1368       return result;
1369     }
1370     FileMapRegion* si = space_at(idx);
1371     if (last_region != NULL) {
1372       // Ensure that the OS won't be able to allocate new memory spaces between any mapped
1373       // regions, or else it would mess up the simple comparision in MetaspaceObj::is_shared().
1374       assert(si->mapped_base() == last_region->mapped_end(), "must have no gaps");
1375     }
1376     log_info(cds)("Mapped %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)", is_static() ? "static " : "dynamic",
1377                   idx, p2i(si->mapped_base()), p2i(si->mapped_end()),
1378                   shared_region_name[idx]);
1379     last_region = si;
1380   }
1381 
1382   DEBUG_ONLY(if (addr_delta == 0 && SharedBaseAddress == 0) {
1383       // This is for simulating mmap failures at the requested location, so we can thoroughly
1384       // test the code for failure handling (releasing all allocated resource) and retry mapping
1385       // at an alternative address picked by the OS.
1386       log_info(cds)("SharedBaseAddress == 0: always map archive(s) at an alternative address");
1387       return MAP_ARCHIVE_MMAP_FAILURE;
1388     });
1389 
1390   header()->set_mapped_base_address(header()->requested_base_address() + addr_delta);
1391   if (addr_delta != 0 && !relocate_pointers(addr_delta)) {
1392     return MAP_ARCHIVE_OTHER_FAILURE;
1393   }
1394 
1395   return MAP_ARCHIVE_SUCCESS;
1396 }
1397 
1398 bool FileMapInfo::read_region(int i, char* base, size_t size) {
1399   assert(MetaspaceShared::use_windows_memory_mapping(), "used by windows only");
1400   FileMapRegion* si = space_at(i);
1401   log_info(cds)("Commit %s region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT " (%s)%s",
1402                 is_static() ? "static " : "dynamic", i, p2i(base), p2i(base + size),
1403                 shared_region_name[i], si->allow_exec() ? " exec" : "");
1404   if (!os::commit_memory(base, size, si->allow_exec())) {
1405     log_error(cds)("Failed to commit %s region #%d (%s)", is_static() ? "static " : "dynamic",
1406                    i, shared_region_name[i]);
1407     return false;
1408   }
1409   if (lseek(_fd, (long)si->file_offset(), SEEK_SET) != (int)si->file_offset() ||
1410       read_bytes(base, size) != size) {
1411     return false;
1412   }
1413   return true;
1414 }
1415 
1416 MapArchiveResult FileMapInfo::map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs) {
1417   assert(!HeapShared::is_heap_region(i), "sanity");
1418   FileMapRegion* si = space_at(i);
1419   size_t size = si->used_aligned();
1420   char *requested_addr = mapped_base_address + si->mapping_offset();
1421   assert(si->mapped_base() == NULL, "must be not mapped yet");
1422   assert(requested_addr != NULL, "must be specified");
1423 
1424   si->set_mapped_from_file(false);
1425 
1426   if (MetaspaceShared::use_windows_memory_mapping()) {
1427     // Windows cannot remap read-only shared memory to read-write when required for
1428     // RedefineClasses, which is also used by JFR.  Always map windows regions as RW.
1429     si->set_read_only(false);
1430   } else if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1431              Arguments::has_jfr_option()) {
1432     // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW    
1433     si->set_read_only(false);
1434   } else if (addr_delta != 0) {
1435     si->set_read_only(false); // Need to patch the pointers
1436   }
1437 
1438   if (rs.is_reserved()) {
1439     assert(rs.contains(requested_addr) && rs.contains(requested_addr + size - 1), "must be");
1440     MemTracker::record_virtual_memory_type((address)requested_addr, mtClassShared);
1441   }
1442 
1443   if (MetaspaceShared::use_windows_memory_mapping() && addr_delta != 0) {
1444     // This is the second time we try to map the archive(s). We have already created a ReservedSpace
1445     // that covers all the FileMapRegions to ensure all regions can be mapped. However, Windows
1446     // can't mmap into a ReservedSpace, so we just os::read() the data. We're going to patch all the
1447     // regions anyway, so there's no benefit for mmap anyway.
1448     if (!read_region(i, requested_addr, size)) {
1449       return MAP_ARCHIVE_OTHER_FAILURE; // oom or I/O error.
1450     }
1451   } else {
1452     char* base = os::map_memory(_fd, _full_path, si->file_offset(),
1453                                 requested_addr, size, si->read_only(),
1454                                 si->allow_exec());
1455     if (base != requested_addr) {
1456       log_info(cds)("Unable to map %s shared space at required address.", shared_region_name[i]);
1457       _memory_mapping_failed = true;
1458       return MAP_ARCHIVE_MMAP_FAILURE;
1459     }
1460     si->set_mapped_from_file(true);
1461   }
1462   si->set_mapped_base(requested_addr);
1463 
1464   if (!rs.is_reserved()) {
1465     // When mapping on Windows with (addr_delta == 0), we don't reserve the address space for the regions
1466     // (Windows can't mmap into a ReservedSpace). In this case, NMT requires we call it after
1467     // os::map_memory has succeeded.
1468     MemTracker::record_virtual_memory_type((address)requested_addr, mtClassShared);
1469   }
1470 
1471   if (VerifySharedSpaces && !verify_region_checksum(i)) {
1472     return MAP_ARCHIVE_OTHER_FAILURE;
1473   }
1474 
1475   return MAP_ARCHIVE_SUCCESS;
1476 }
1477 
1478 char* FileMapInfo::map_relocation_bitmap(size_t& bitmap_size) {
1479   FileMapRegion* si = space_at(MetaspaceShared::bm);
1480   bitmap_size = si->used_aligned();
1481   bool read_only = true, allow_exec = false;
1482   char* requested_addr = NULL; // allow OS to pick any location
1483   char* bitmap_base = os::map_memory(_fd, _full_path, si->file_offset(),
1484                                      requested_addr, bitmap_size, read_only, allow_exec);
1485 
1486   if (VerifySharedSpaces && bitmap_base != NULL && !region_crc_check(bitmap_base, bitmap_size, si->crc())) {
1487     log_error(cds)("relocation bitmap CRC error");
1488     if (!os::unmap_memory(bitmap_base, bitmap_size)) {
1489       fatal("os::unmap_memory of relocation bitmap failed");
1490     }
1491     return NULL;
1492   }
1493   return bitmap_base;
1494 }
1495 
1496 bool FileMapInfo::relocate_pointers(intx addr_delta) {
1497   log_debug(cds, reloc)("runtime archive relocation start");
1498   size_t bitmap_size;
1499   char* bitmap_base = map_relocation_bitmap(bitmap_size);
1500 
1501   if (bitmap_base != NULL) {
1502     size_t ptrmap_size_in_bits = header()->ptrmap_size_in_bits();
1503     log_debug(cds, reloc)("mapped relocation bitmap @ " INTPTR_FORMAT " (" SIZE_FORMAT
1504                           " bytes = " SIZE_FORMAT " bits)",
1505                           p2i(bitmap_base), bitmap_size, ptrmap_size_in_bits);
1506 
1507     BitMapView ptrmap((BitMap::bm_word_t*)bitmap_base, ptrmap_size_in_bits);
1508 
1509     // Patch all pointers in the the mapped region that are marked by ptrmap.
1510     address patch_base = (address)mapped_base();
1511     address patch_end  = (address)mapped_end();
1512 
1513     // debug only -- the current value of the pointers to be patched must be within this
1514     // range (i.e., must be between the requesed base address, and the of the current archive).
1515     // Note: top archive may point to objects in the base archive, but not the other way around.
1516     address valid_old_base = (address)header()->requested_base_address();
1517     address valid_old_end  = valid_old_base + mapping_end_offset();
1518 
1519     // debug only -- after patching, the pointers must point inside this range
1520     // (the requested location of the archive, as mapped at runtime).
1521     address valid_new_base = (address)header()->mapped_base_address();
1522     address valid_new_end  = (address)mapped_end();
1523 
1524     SharedDataRelocator patcher((address*)patch_base, (address*)patch_end, valid_old_base, valid_old_end,
1525                                 valid_new_base, valid_new_end, addr_delta);
1526     ptrmap.iterate(&patcher);
1527 
1528     if (!os::unmap_memory(bitmap_base, bitmap_size)) {
1529       fatal("os::unmap_memory of relocation bitmap failed");
1530     }
1531     log_debug(cds, reloc)("runtime archive relocation done");
1532     return true;
1533   } else {
1534     log_error(cds)("failed to map relocation bitmap");
1535     return false;
1536   }
1537 }
1538 
1539 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
1540   assert(_file_open, "Archive file is not open");
1541   size_t n = os::read(_fd, buffer, (unsigned int)count);
1542   if (n != count) {
1543     // Close the file if there's a problem reading it.
1544     close();
1545     return 0;
1546   }
1547   _file_offset += count;
1548   return count;
1549 }
1550 
1551 address FileMapInfo::decode_start_address(FileMapRegion* spc, bool with_current_oop_encoding_mode) {
1552   size_t offset = spc->mapping_offset();
1553   assert((offset >> 32) == 0, "must be 32-bit only");
1554   uint n = (uint)offset;
1555   if (with_current_oop_encoding_mode) {
1556     return (address)CompressedOops::decode_not_null(n);
1557   } else {
1558     return (address)HeapShared::decode_from_archive(n);
1559   }
1560 }
1561 
1562 static MemRegion *closed_archive_heap_ranges = NULL;
1563 static MemRegion *open_archive_heap_ranges = NULL;
1564 static int num_closed_archive_heap_ranges = 0;
1565 static int num_open_archive_heap_ranges = 0;
1566 
1567 #if INCLUDE_CDS_JAVA_HEAP
1568 bool FileMapInfo::has_heap_regions() {
1569   return (space_at(MetaspaceShared::first_closed_archive_heap_region)->used() > 0);
1570 }
1571 
1572 // Returns the address range of the archived heap regions computed using the
1573 // current oop encoding mode. This range may be different than the one seen at
1574 // dump time due to encoding mode differences. The result is used in determining
1575 // if/how these regions should be relocated at run time.
1576 MemRegion FileMapInfo::get_heap_regions_range_with_current_oop_encoding_mode() {
1577   address start = (address) max_uintx;
1578   address end   = NULL;
1579 
1580   for (int i = MetaspaceShared::first_closed_archive_heap_region;
1581            i <= MetaspaceShared::last_valid_region;
1582            i++) {
1583     FileMapRegion* si = space_at(i);
1584     size_t size = si->used();
1585     if (size > 0) {
1586       address s = start_address_as_decoded_with_current_oop_encoding_mode(si);
1587       address e = s + size;
1588       if (start > s) {
1589         start = s;
1590       }
1591       if (end < e) {
1592         end = e;
1593       }
1594     }
1595   }
1596   assert(end != NULL, "must have at least one used heap region");
1597   return MemRegion((HeapWord*)start, (HeapWord*)end);
1598 }
1599 
1600 //
1601 // Map the closed and open archive heap objects to the runtime java heap.
1602 //
1603 // The shared objects are mapped at (or close to ) the java heap top in
1604 // closed archive regions. The mapped objects contain no out-going
1605 // references to any other java heap regions. GC does not write into the
1606 // mapped closed archive heap region.
1607 //
1608 // The open archive heap objects are mapped below the shared objects in
1609 // the runtime java heap. The mapped open archive heap data only contains
1610 // references to the shared objects and open archive objects initially.
1611 // During runtime execution, out-going references to any other java heap
1612 // regions may be added. GC may mark and update references in the mapped
1613 // open archive objects.
1614 void FileMapInfo::map_heap_regions_impl() {
1615   if (!HeapShared::is_heap_object_archiving_allowed()) {
1616     log_info(cds)("CDS heap data is being ignored. UseG1GC, "
1617                   "UseCompressedOops and UseCompressedClassPointers are required.");
1618     return;
1619   }
1620 
1621   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
1622     ShouldNotReachHere(); // CDS should have been disabled.
1623     // The archived objects are mapped at JVM start-up, but we don't know if
1624     // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
1625     // which would make the archived String or mirror objects invalid. Let's be safe and not
1626     // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
1627     //
1628     // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
1629     // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
1630     // because we won't install an archived object subgraph if the klass of any of the
1631     // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
1632   }
1633 
1634   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
1635                 max_heap_size()/M);
1636   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
1637                 p2i(narrow_klass_base()), narrow_klass_shift());
1638   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
1639                 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
1640 
1641   log_info(cds)("The current max heap size = " SIZE_FORMAT "M, HeapRegion::GrainBytes = " SIZE_FORMAT,
1642                 MaxHeapSize/M, HeapRegion::GrainBytes);
1643   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
1644                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
1645   log_info(cds)("    narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
1646                 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
1647 
1648   if (narrow_klass_base() != CompressedKlassPointers::base() ||
1649       narrow_klass_shift() != CompressedKlassPointers::shift()) {
1650     log_info(cds)("CDS heap data cannot be used because the archive was created with an incompatible narrow klass encoding mode.");
1651     return;
1652   }
1653 
1654   if (narrow_oop_mode() != CompressedOops::mode() ||
1655       narrow_oop_base() != CompressedOops::base() ||
1656       narrow_oop_shift() != CompressedOops::shift()) {
1657     log_info(cds)("CDS heap data need to be relocated because the archive was created with an incompatible oop encoding mode.");
1658     _heap_pointers_need_patching = true;
1659   } else {
1660     MemRegion range = get_heap_regions_range_with_current_oop_encoding_mode();
1661     if (!CompressedOops::is_in(range)) {
1662       log_info(cds)("CDS heap data need to be relocated because");
1663       log_info(cds)("the desired range " PTR_FORMAT " - "  PTR_FORMAT, p2i(range.start()), p2i(range.end()));
1664       log_info(cds)("is outside of the heap " PTR_FORMAT " - "  PTR_FORMAT, p2i(CompressedOops::begin()), p2i(CompressedOops::end()));
1665       _heap_pointers_need_patching = true;
1666     }
1667   }
1668 
1669   ptrdiff_t delta = 0;
1670   if (_heap_pointers_need_patching) {
1671     //   dumptime heap end  ------------v
1672     //   [      |archived heap regions| ]         runtime heap end ------v
1673     //                                       [   |archived heap regions| ]
1674     //                                  |<-----delta-------------------->|
1675     //
1676     // At dump time, the archived heap regions were near the top of the heap.
1677     // At run time, they may not be inside the heap, so we move them so
1678     // that they are now near the top of the runtime time. This can be done by
1679     // the simple math of adding the delta as shown above.
1680     address dumptime_heap_end = header()->heap_end();
1681     address runtime_heap_end = (address)CompressedOops::end();
1682     delta = runtime_heap_end - dumptime_heap_end;
1683   }
1684 
1685   log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
1686   HeapShared::init_narrow_oop_decoding(narrow_oop_base() + delta, narrow_oop_shift());
1687 
1688   FileMapRegion* si = space_at(MetaspaceShared::first_closed_archive_heap_region);
1689   address relocated_closed_heap_region_bottom = start_address_as_decoded_from_archive(si);
1690   if (!is_aligned(relocated_closed_heap_region_bottom, HeapRegion::GrainBytes)) {
1691     // Align the bottom of the closed archive heap regions at G1 region boundary.
1692     // This will avoid the situation where the highest open region and the lowest
1693     // closed region sharing the same G1 region. Otherwise we will fail to map the
1694     // open regions.
1695     size_t align = size_t(relocated_closed_heap_region_bottom) % HeapRegion::GrainBytes;
1696     delta -= align;
1697     log_info(cds)("CDS heap data need to be relocated lower by a further " SIZE_FORMAT
1698                   " bytes to " INTX_FORMAT " to be aligned with HeapRegion::GrainBytes",
1699                   align, delta);
1700     HeapShared::init_narrow_oop_decoding(narrow_oop_base() + delta, narrow_oop_shift());
1701     _heap_pointers_need_patching = true;
1702     relocated_closed_heap_region_bottom = start_address_as_decoded_from_archive(si);
1703   }
1704   assert(is_aligned(relocated_closed_heap_region_bottom, HeapRegion::GrainBytes),
1705          "must be");
1706 
1707   // Map the closed_archive_heap regions, GC does not write into the regions.
1708   if (map_heap_data(&closed_archive_heap_ranges,
1709                     MetaspaceShared::first_closed_archive_heap_region,
1710                     MetaspaceShared::max_closed_archive_heap_region,
1711                     &num_closed_archive_heap_ranges)) {
1712     HeapShared::set_closed_archive_heap_region_mapped();
1713 
1714     // Now, map open_archive heap regions, GC can write into the regions.
1715     if (map_heap_data(&open_archive_heap_ranges,
1716                       MetaspaceShared::first_open_archive_heap_region,
1717                       MetaspaceShared::max_open_archive_heap_region,
1718                       &num_open_archive_heap_ranges,
1719                       true /* open */)) {
1720       HeapShared::set_open_archive_heap_region_mapped();
1721     }
1722   }
1723 }
1724 
1725 void FileMapInfo::map_heap_regions() {
1726   if (has_heap_regions()) {
1727     map_heap_regions_impl();
1728   }
1729 
1730   if (!HeapShared::closed_archive_heap_region_mapped()) {
1731     assert(closed_archive_heap_ranges == NULL &&
1732            num_closed_archive_heap_ranges == 0, "sanity");
1733   }
1734 
1735   if (!HeapShared::open_archive_heap_region_mapped()) {
1736     assert(open_archive_heap_ranges == NULL && num_open_archive_heap_ranges == 0, "sanity");
1737   }
1738 }
1739 
1740 bool FileMapInfo::map_heap_data(MemRegion **heap_mem, int first,
1741                                 int max, int* num, bool is_open_archive) {
1742   MemRegion * regions = new MemRegion[max];
1743   FileMapRegion* si;
1744   int region_num = 0;
1745 
1746   for (int i = first;
1747            i < first + max; i++) {
1748     si = space_at(i);
1749     size_t size = si->used();
1750     if (size > 0) {
1751       HeapWord* start = (HeapWord*)start_address_as_decoded_from_archive(si);
1752       regions[region_num] = MemRegion(start, size / HeapWordSize);
1753       region_num ++;
1754       log_info(cds)("Trying to map heap data: region[%d] at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
1755                     i, p2i(start), size);
1756     }
1757   }
1758 
1759   if (region_num == 0) {
1760     return false; // no archived java heap data
1761   }
1762 
1763   // Check that ranges are within the java heap
1764   if (!G1CollectedHeap::heap()->check_archive_addresses(regions, region_num)) {
1765     log_info(cds)("UseSharedSpaces: Unable to allocate region, range is not within java heap.");
1766     return false;
1767   }
1768 
1769   // allocate from java heap
1770   if (!G1CollectedHeap::heap()->alloc_archive_regions(
1771              regions, region_num, is_open_archive)) {
1772     log_info(cds)("UseSharedSpaces: Unable to allocate region, java heap range is already in use.");
1773     return false;
1774   }
1775 
1776   // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
1777   // for mapped regions as they are part of the reserved java heap, which is
1778   // already recorded.
1779   for (int i = 0; i < region_num; i++) {
1780     si = space_at(first + i);
1781     char* addr = (char*)regions[i].start();
1782     char* base = os::map_memory(_fd, _full_path, si->file_offset(),
1783                                 addr, regions[i].byte_size(), si->read_only(),
1784                                 si->allow_exec());
1785     if (base == NULL || base != addr) {
1786       // dealloc the regions from java heap
1787       dealloc_archive_heap_regions(regions, region_num, is_open_archive);
1788       log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
1789                     INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
1790                     p2i(addr), regions[i].byte_size());
1791       return false;
1792     }
1793 
1794     if (VerifySharedSpaces && !region_crc_check(addr, regions[i].byte_size(), si->crc())) {
1795       // dealloc the regions from java heap
1796       dealloc_archive_heap_regions(regions, region_num, is_open_archive);
1797       log_info(cds)("UseSharedSpaces: mapped heap regions are corrupt");
1798       return false;
1799     }
1800   }
1801 
1802   // the shared heap data is mapped successfully
1803   *heap_mem = regions;
1804   *num = region_num;
1805   return true;
1806 }
1807 
1808 void FileMapInfo::patch_archived_heap_embedded_pointers() {
1809   if (!_heap_pointers_need_patching) {
1810     return;
1811   }
1812 
1813   patch_archived_heap_embedded_pointers(closed_archive_heap_ranges,
1814                                         num_closed_archive_heap_ranges,
1815                                         MetaspaceShared::first_closed_archive_heap_region);
1816 
1817   patch_archived_heap_embedded_pointers(open_archive_heap_ranges,
1818                                         num_open_archive_heap_ranges,
1819                                         MetaspaceShared::first_open_archive_heap_region);
1820 }
1821 
1822 void FileMapInfo::patch_archived_heap_embedded_pointers(MemRegion* ranges, int num_ranges,
1823                                                         int first_region_idx) {
1824   for (int i=0; i<num_ranges; i++) {
1825     FileMapRegion* si = space_at(i + first_region_idx);
1826     HeapShared::patch_archived_heap_embedded_pointers(ranges[i], (address)(SharedBaseAddress + si->oopmap_offset()),
1827                                                       si->oopmap_size_in_bits());
1828   }
1829 }
1830 
1831 // This internally allocates objects using SystemDictionary::Object_klass(), so it
1832 // must be called after the well-known classes are resolved.
1833 void FileMapInfo::fixup_mapped_heap_regions() {
1834   // If any closed regions were found, call the fill routine to make them parseable.
1835   // Note that closed_archive_heap_ranges may be non-NULL even if no ranges were found.
1836   if (num_closed_archive_heap_ranges != 0) {
1837     assert(closed_archive_heap_ranges != NULL,
1838            "Null closed_archive_heap_ranges array with non-zero count");
1839     G1CollectedHeap::heap()->fill_archive_regions(closed_archive_heap_ranges,
1840                                                   num_closed_archive_heap_ranges);
1841   }
1842 
1843   // do the same for mapped open archive heap regions
1844   if (num_open_archive_heap_ranges != 0) {
1845     assert(open_archive_heap_ranges != NULL, "NULL open_archive_heap_ranges array with non-zero count");
1846     G1CollectedHeap::heap()->fill_archive_regions(open_archive_heap_ranges,
1847                                                   num_open_archive_heap_ranges);
1848   }
1849 }
1850 
1851 // dealloc the archive regions from java heap
1852 void FileMapInfo::dealloc_archive_heap_regions(MemRegion* regions, int num, bool is_open) {
1853   if (num > 0) {
1854     assert(regions != NULL, "Null archive ranges array with non-zero count");
1855     G1CollectedHeap::heap()->dealloc_archive_regions(regions, num, is_open);
1856   }
1857 }
1858 #endif // INCLUDE_CDS_JAVA_HEAP
1859 
1860 bool FileMapInfo::region_crc_check(char* buf, size_t size, int expected_crc) {
1861   int crc = ClassLoader::crc32(0, buf, (jint)size);
1862   if (crc != expected_crc) {
1863     fail_continue("Checksum verification failed.");
1864     return false;
1865   }
1866   return true;
1867 }
1868 
1869 bool FileMapInfo::verify_region_checksum(int i) {
1870   assert(VerifySharedSpaces, "sanity");
1871   size_t sz = space_at(i)->used();
1872 
1873   if (sz == 0) {
1874     return true; // no data
1875   } else {
1876     return region_crc_check(region_addr(i), sz, space_at(i)->crc());
1877   }
1878 }
1879 
1880 void FileMapInfo::unmap_regions(int regions[], int num_regions) {
1881   for (int r = 0; r < num_regions; r++) {
1882     int idx = regions[r];
1883     unmap_region(idx);
1884   }
1885 }
1886 
1887 // Unmap a memory region in the address space.
1888 
1889 void FileMapInfo::unmap_region(int i) {
1890   assert(!HeapShared::is_heap_region(i), "sanity");
1891   FileMapRegion* si = space_at(i);
1892   char* mapped_base = si->mapped_base();
1893   size_t used = si->used();
1894   size_t size = align_up(used, os::vm_allocation_granularity());
1895 
1896   if (mapped_base != NULL && size > 0 && si->mapped_from_file()) {
1897     log_info(cds)("Unmapping region #%d at base " INTPTR_FORMAT " (%s)", i, p2i(mapped_base),
1898                   shared_region_name[i]);
1899     if (!os::unmap_memory(mapped_base, size)) {
1900       fatal("os::unmap_memory failed");
1901     }
1902     si->set_mapped_base(NULL);
1903   }
1904 }
1905 
1906 void FileMapInfo::assert_mark(bool check) {
1907   if (!check) {
1908     fail_stop("Mark mismatch while restoring from shared file.");
1909   }
1910 }
1911 
1912 void FileMapInfo::metaspace_pointers_do(MetaspaceClosure* it) {
1913   _shared_path_table.metaspace_pointers_do(it);
1914 }
1915 
1916 FileMapInfo* FileMapInfo::_current_info = NULL;
1917 FileMapInfo* FileMapInfo::_dynamic_archive_info = NULL;
1918 bool FileMapInfo::_heap_pointers_need_patching = false;
1919 SharedPathTable FileMapInfo::_shared_path_table;
1920 bool FileMapInfo::_validating_shared_path_table = false;
1921 bool FileMapInfo::_memory_mapping_failed = false;
1922 GrowableArray<const char*>* FileMapInfo::_non_existent_class_paths = NULL;
1923 
1924 // Open the shared archive file, read and validate the header
1925 // information (version, boot classpath, etc.).  If initialization
1926 // fails, shared spaces are disabled and the file is closed. [See
1927 // fail_continue.]
1928 //
1929 // Validation of the archive is done in two steps:
1930 //
1931 // [1] validate_header() - done here.
1932 // [2] validate_shared_path_table - this is done later, because the table is in the RW
1933 //     region of the archive, which is not mapped yet.
1934 bool FileMapInfo::initialize() {
1935   assert(UseSharedSpaces, "UseSharedSpaces expected.");
1936 
1937   if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
1938     // CDS assumes that no classes resolved in SystemDictionary::resolve_well_known_classes
1939     // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
1940     // during the JVMTI "early" stage, so we can still use CDS if
1941     // JvmtiExport::has_early_class_hook_env() is false.
1942     FileMapInfo::fail_continue("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
1943     return false;
1944   }
1945 
1946   if (!open_for_read()) {
1947     return false;
1948   }
1949   if (!init_from_file(_fd)) {
1950     return false;
1951   }
1952   if (!validate_header()) {
1953     return false;
1954   }
1955   return true;
1956 }
1957 
1958 char* FileMapInfo::region_addr(int idx) {
1959   FileMapRegion* si = space_at(idx);
1960   if (HeapShared::is_heap_region(idx)) {
1961     assert(DumpSharedSpaces, "The following doesn't work at runtime");
1962     return si->used() > 0 ?
1963           (char*)start_address_as_decoded_with_current_oop_encoding_mode(si) : NULL;
1964   } else {
1965     return si->mapped_base();
1966   }
1967 }
1968 
1969 FileMapRegion* FileMapInfo::first_core_space() const {
1970   return is_static() ? space_at(MetaspaceShared::mc) : space_at(MetaspaceShared::rw);
1971 }
1972 
1973 FileMapRegion* FileMapInfo::last_core_space() const {
1974   return is_static() ? space_at(MetaspaceShared::md) : space_at(MetaspaceShared::mc);
1975 }
1976 
1977 int FileMapHeader::compute_crc() {
1978   char* start = (char*)this;
1979   // start computing from the field after _crc
1980   char* buf = (char*)&_crc + sizeof(_crc);
1981   size_t sz = _header_size - (buf - start);
1982   int crc = ClassLoader::crc32(0, buf, (jint)sz);
1983   return crc;
1984 }
1985 
1986 // This function should only be called during run time with UseSharedSpaces enabled.
1987 bool FileMapHeader::validate() {
1988   if (_obj_alignment != ObjectAlignmentInBytes) {
1989     FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
1990                   " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
1991                   _obj_alignment, ObjectAlignmentInBytes);
1992     return false;
1993   }
1994   if (_compact_strings != CompactStrings) {
1995     FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
1996                   " does not equal the current CompactStrings setting (%s).",
1997                   _compact_strings ? "enabled" : "disabled",
1998                   CompactStrings   ? "enabled" : "disabled");
1999     return false;
2000   }
2001 
2002   // This must be done after header validation because it might change the
2003   // header data
2004   const char* prop = Arguments::get_property("java.system.class.loader");
2005   if (prop != NULL) {
2006     warning("Archived non-system classes are disabled because the "
2007             "java.system.class.loader property is specified (value = \"%s\"). "
2008             "To use archived non-system classes, this property must not be set", prop);
2009     _has_platform_or_app_classes = false;
2010   }
2011 
2012   // For backwards compatibility, we don't check the verification setting
2013   // if the archive only contains system classes.
2014   if (_has_platform_or_app_classes &&
2015       ((!_verify_local && BytecodeVerificationLocal) ||
2016        (!_verify_remote && BytecodeVerificationRemote))) {
2017     FileMapInfo::fail_continue("The shared archive file was created with less restrictive "
2018                   "verification setting than the current setting.");
2019     return false;
2020   }
2021 
2022   // Java agents are allowed during run time. Therefore, the following condition is not
2023   // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
2024   // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
2025   // while AllowArchivingWithJavaAgent is set during the current run.
2026   if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
2027     FileMapInfo::fail_continue("The setting of the AllowArchivingWithJavaAgent is different "
2028                                "from the setting in the shared archive.");
2029     return false;
2030   }
2031 
2032   if (_allow_archiving_with_java_agent) {
2033     warning("This archive was created with AllowArchivingWithJavaAgent. It should be used "
2034             "for testing purposes only and should not be used in a production environment");
2035   }
2036 
2037   return true;
2038 }
2039 
2040 bool FileMapInfo::validate_header() {
2041   return header()->validate();
2042 }
2043 
2044 // Check if a given address is within one of the shared regions
2045 bool FileMapInfo::is_in_shared_region(const void* p, int idx) {
2046   assert(idx == MetaspaceShared::ro ||
2047          idx == MetaspaceShared::rw ||
2048          idx == MetaspaceShared::mc ||
2049          idx == MetaspaceShared::md, "invalid region index");
2050   char* base = region_addr(idx);
2051   if (p >= base && p < base + space_at(idx)->used()) {
2052     return true;
2053   }
2054   return false;
2055 }
2056 
2057 // Unmap mapped regions of shared space.
2058 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
2059   MetaspaceShared::set_shared_metaspace_range(NULL, NULL, NULL);
2060 
2061   FileMapInfo *map_info = FileMapInfo::current_info();
2062   if (map_info) {
2063     map_info->fail_continue("%s", msg);
2064     for (int i = 0; i < MetaspaceShared::num_non_heap_spaces; i++) {
2065       if (!HeapShared::is_heap_region(i)) {
2066         map_info->unmap_region(i);
2067       }
2068     }
2069     // Dealloc the archive heap regions only without unmapping. The regions are part
2070     // of the java heap. Unmapping of the heap regions are managed by GC.
2071     map_info->dealloc_archive_heap_regions(open_archive_heap_ranges,
2072                                            num_open_archive_heap_ranges,
2073                                            true);
2074     map_info->dealloc_archive_heap_regions(closed_archive_heap_ranges,
2075                                            num_closed_archive_heap_ranges,
2076                                            false);
2077   } else if (DumpSharedSpaces) {
2078     fail_stop("%s", msg);
2079   }
2080 }
2081 
2082 #if INCLUDE_JVMTI
2083 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = NULL;
2084 
2085 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
2086   ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
2087   if (ent == NULL) {
2088     if (i == 0) {
2089       ent = ClassLoader::get_jrt_entry();
2090       assert(ent != NULL, "must be");
2091     } else {
2092       SharedClassPathEntry* scpe = shared_path(i);
2093       assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
2094 
2095       const char* path = scpe->name();
2096       struct stat st;
2097       if (os::stat(path, &st) != 0) {
2098         char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128); ;
2099         jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
2100         THROW_MSG_(vmSymbols::java_io_IOException(), msg, NULL);
2101       } else {
2102         ent = ClassLoader::create_class_path_entry(path, &st, /*throw_exception=*/true, false, false, CHECK_NULL);
2103       }
2104     }
2105 
2106     MutexLocker mu(CDSClassFileStream_lock, THREAD);
2107     if (_classpath_entries_for_jvmti[i] == NULL) {
2108       _classpath_entries_for_jvmti[i] = ent;
2109     } else {
2110       // Another thread has beat me to creating this entry
2111       delete ent;
2112       ent = _classpath_entries_for_jvmti[i];
2113     }
2114   }
2115 
2116   return ent;
2117 }
2118 
2119 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
2120   int path_index = ik->shared_classpath_index();
2121   assert(path_index >= 0, "should be called for shared built-in classes only");
2122   assert(path_index < (int)get_number_of_shared_paths(), "sanity");
2123 
2124   ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
2125   assert(cpe != NULL, "must be");
2126 
2127   Symbol* name = ik->name();
2128   const char* const class_name = name->as_C_string();
2129   const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
2130                                                                       name->utf8_length());
2131   ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
2132   ClassFileStream* cfs = cpe->open_stream_for_loader(file_name, loader_data, THREAD);
2133   assert(cfs != NULL, "must be able to read the classfile data of shared classes for built-in loaders.");
2134   log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
2135                         cfs->source(), cfs->length());
2136   return cfs;
2137 }
2138 
2139 #endif