1 /*
   2  * Copyright (c) 2003, 2016, 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 "classfile/classLoader.hpp"
  27 #include "classfile/compactHashtable.inline.hpp"
  28 #include "classfile/sharedClassUtil.hpp"
  29 #include "classfile/symbolTable.hpp"
  30 #include "classfile/systemDictionaryShared.hpp"
  31 #include "classfile/altHashing.hpp"
  32 #if INCLUDE_ALL_GCS
  33 #include "gc/g1/g1CollectedHeap.hpp"
  34 #endif
  35 #include "memory/filemap.hpp"
  36 #include "memory/metadataFactory.hpp"
  37 #include "memory/oopFactory.hpp"
  38 #include "oops/objArrayOop.hpp"
  39 #include "prims/jvmtiExport.hpp"
  40 #include "runtime/arguments.hpp"
  41 #include "runtime/java.hpp"
  42 #include "runtime/os.hpp"
  43 #include "runtime/vm_version.hpp"
  44 #include "services/memTracker.hpp"
  45 #include "utilities/defaultStream.hpp"
  46 
  47 # include <sys/stat.h>
  48 # include <errno.h>
  49 
  50 #ifndef O_BINARY       // if defined (Win32) use binary files.
  51 #define O_BINARY 0     // otherwise do nothing.
  52 #endif
  53 
  54 extern address JVM_FunctionAtStart();
  55 extern address JVM_FunctionAtEnd();
  56 
  57 // Complain and stop. All error conditions occurring during the writing of
  58 // an archive file should stop the process.  Unrecoverable errors during
  59 // the reading of the archive file should stop the process.
  60 
  61 static void fail(const char *msg, va_list ap) {
  62   // This occurs very early during initialization: tty is not initialized.
  63   jio_fprintf(defaultStream::error_stream(),
  64               "An error has occurred while processing the"
  65               " shared archive file.\n");
  66   jio_vfprintf(defaultStream::error_stream(), msg, ap);
  67   jio_fprintf(defaultStream::error_stream(), "\n");
  68   // Do not change the text of the below message because some tests check for it.
  69   vm_exit_during_initialization("Unable to use shared archive.", NULL);
  70 }
  71 
  72 
  73 void FileMapInfo::fail_stop(const char *msg, ...) {
  74         va_list ap;
  75   va_start(ap, msg);
  76   fail(msg, ap);        // Never returns.
  77   va_end(ap);           // for completeness.
  78 }
  79 
  80 
  81 // Complain and continue.  Recoverable errors during the reading of the
  82 // archive file may continue (with sharing disabled).
  83 //
  84 // If we continue, then disable shared spaces and close the file.
  85 
  86 void FileMapInfo::fail_continue(const char *msg, ...) {
  87   va_list ap;
  88   va_start(ap, msg);
  89   MetaspaceShared::set_archive_loading_failed();
  90   if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) {
  91     // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
  92     // do not validate, we can still continue "limping" to validate the remaining
  93     // entries. No need to quit.
  94     tty->print("[");
  95     tty->vprint(msg, ap);
  96     tty->print_cr("]");
  97   } else {
  98     if (RequireSharedSpaces) {
  99       fail(msg, ap);
 100     } else {
 101       if (PrintSharedSpaces) {
 102         tty->print_cr("UseSharedSpaces: %s", msg);
 103       }
 104     }
 105     UseSharedSpaces = false;
 106     assert(current_info() != NULL, "singleton must be registered");
 107     current_info()->close();
 108   }
 109   va_end(ap);
 110 }
 111 
 112 // Fill in the fileMapInfo structure with data about this VM instance.
 113 
 114 // This method copies the vm version info into header_version.  If the version is too
 115 // long then a truncated version, which has a hash code appended to it, is copied.
 116 //
 117 // Using a template enables this method to verify that header_version is an array of
 118 // length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and
 119 // the code that reads the CDS file will both use the same size buffer.  Hence, will
 120 // use identical truncation.  This is necessary for matching of truncated versions.
 121 template <int N> static void get_header_version(char (&header_version) [N]) {
 122   assert(N == JVM_IDENT_MAX, "Bad header_version size");
 123 
 124   const char *vm_version = VM_Version::internal_vm_info_string();
 125   const int version_len = (int)strlen(vm_version);
 126 
 127   if (version_len < (JVM_IDENT_MAX-1)) {
 128     strcpy(header_version, vm_version);
 129 
 130   } else {
 131     // Get the hash value.  Use a static seed because the hash needs to return the same
 132     // value over multiple jvm invocations.
 133     unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
 134 
 135     // Truncate the ident, saving room for the 8 hex character hash value.
 136     strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
 137 
 138     // Append the hash code as eight hex digits.
 139     sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
 140     header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.
 141   }
 142 }
 143 
 144 FileMapInfo::FileMapInfo() {
 145   assert(_current_info == NULL, "must be singleton"); // not thread safe
 146   _current_info = this;
 147   memset(this, 0, sizeof(FileMapInfo));
 148   _file_offset = 0;
 149   _file_open = false;
 150   _header = SharedClassUtil::allocate_file_map_header();
 151   _header->_version = _invalid_version;
 152 }
 153 
 154 FileMapInfo::~FileMapInfo() {
 155   assert(_current_info == this, "must be singleton"); // not thread safe
 156   _current_info = NULL;
 157 }
 158 
 159 void FileMapInfo::populate_header(size_t alignment) {
 160   _header->populate(this, alignment);
 161 }
 162 
 163 size_t FileMapInfo::FileMapHeader::data_size() {
 164   return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);
 165 }
 166 
 167 void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
 168   _magic = 0xf00baba2;
 169   _version = _current_version;
 170   _alignment = alignment;
 171   _obj_alignment = ObjectAlignmentInBytes;
 172   _compact_strings = CompactStrings;
 173   _narrow_oop_mode = Universe::narrow_oop_mode();
 174   _narrow_oop_shift = Universe::narrow_oop_shift();
 175   _max_heap_size = MaxHeapSize;
 176   _narrow_klass_base = Universe::narrow_klass_base();
 177   _narrow_klass_shift = Universe::narrow_klass_shift();
 178   _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;
 179   _classpath_entry_table = mapinfo->_classpath_entry_table;
 180   _classpath_entry_size = mapinfo->_classpath_entry_size;
 181 
 182   // The following fields are for sanity checks for whether this archive
 183   // will function correctly with this JVM and the bootclasspath it's
 184   // invoked with.
 185 
 186   // JVM version string ... changes on each build.
 187   get_header_version(_jvm_ident);
 188 }
 189 
 190 void FileMapInfo::allocate_classpath_entry_table() {
 191   int bytes = 0;
 192   int count = 0;
 193   char* strptr = NULL;
 194   char* strptr_max = NULL;
 195   Thread* THREAD = Thread::current();
 196 
 197   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 198   size_t entry_size = SharedClassUtil::shared_class_path_entry_size();
 199 
 200   for (int pass=0; pass<2; pass++) {
 201     ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
 202 
 203     for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {
 204       const char *name = cpe->name();
 205       int name_bytes = (int)(strlen(name) + 1);
 206 
 207       if (pass == 0) {
 208         count ++;
 209         bytes += (int)entry_size;
 210         bytes += name_bytes;
 211         if (TraceClassPaths) {
 212           tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name);
 213         }
 214       } else {
 215         SharedClassPathEntry* ent = shared_classpath(cur_entry);
 216         if (cpe->is_jar_file()) {
 217           struct stat st;
 218           if (os::stat(name, &st) != 0) {
 219             // The file/dir must exist, or it would not have been added
 220             // into ClassLoader::classpath_entry().
 221             //
 222             // If we can't access a jar file in the boot path, then we can't
 223             // make assumptions about where classes get loaded from.
 224             FileMapInfo::fail_stop("Unable to open jar file %s.", name);
 225           }
 226 
 227           EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
 228           SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);
 229         } else {
 230           struct stat st;
 231           if ((os::stat(name, &st) == 0) && ((st.st_mode & S_IFDIR) == S_IFDIR)) {
 232             if (!os::dir_is_empty(name)) {
 233               ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);
 234             }
 235             ent->_filesize = -1;
 236           } else {
 237             ent->_filesize = -2;
 238           }
 239         }
 240         ent->_name = strptr;
 241         if (strptr + name_bytes <= strptr_max) {
 242           strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
 243           strptr += name_bytes;
 244         } else {
 245           assert(0, "miscalculated buffer size");
 246         }
 247       }
 248     }
 249 
 250     if (pass == 0) {
 251       EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
 252       Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);
 253       strptr = (char*)(arr->data());
 254       strptr_max = strptr + bytes;
 255       SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;
 256       strptr += entry_size * count;
 257 
 258       _classpath_entry_table_size = count;
 259       _classpath_entry_table = table;
 260       _classpath_entry_size = entry_size;
 261     }
 262   }
 263 }
 264 
 265 bool FileMapInfo::validate_classpath_entry_table() {
 266   _validating_classpath_entry_table = true;
 267 
 268   int count = _header->_classpath_entry_table_size;
 269 
 270   _classpath_entry_table = _header->_classpath_entry_table;
 271   _classpath_entry_size = _header->_classpath_entry_size;
 272 
 273   for (int i=0; i<count; i++) {
 274     SharedClassPathEntry* ent = shared_classpath(i);
 275     struct stat st;
 276     const char* name = ent->_name;
 277     bool ok = true;
 278     if (TraceClassPaths) {
 279       tty->print_cr("[Checking shared classpath entry: %s]", name);
 280     }
 281     if (os::stat(name, &st) != 0) {
 282       fail_continue("Required classpath entry does not exist: %s", name);
 283       ok = false;
 284     } else if (ent->is_dir()) {
 285       if (!os::dir_is_empty(name)) {
 286         fail_continue("directory is not empty: %s", name);
 287         ok = false;
 288       }
 289     } else if (ent->is_jar()) {
 290       if (ent->_timestamp != st.st_mtime ||
 291           ent->_filesize != st.st_size) {
 292         ok = false;
 293         if (PrintSharedArchiveAndExit) {
 294           fail_continue(ent->_timestamp != st.st_mtime ?
 295                         "Timestamp mismatch" :
 296                         "File size mismatch");
 297         } else {
 298           fail_continue("A jar file is not the one used while building"
 299                         " the shared archive file: %s", name);
 300         }
 301       }
 302     }
 303     if (ok) {
 304       if (TraceClassPaths) {
 305         tty->print_cr("[ok]");
 306       }
 307     } else if (!PrintSharedArchiveAndExit) {
 308       _validating_classpath_entry_table = false;
 309       return false;
 310     }
 311   }
 312 
 313   _classpath_entry_table_size = _header->_classpath_entry_table_size;
 314   _validating_classpath_entry_table = false;
 315   return true;
 316 }
 317 
 318 
 319 // Read the FileMapInfo information from the file.
 320 
 321 bool FileMapInfo::init_from_file(int fd) {
 322   size_t sz = _header->data_size();
 323   char* addr = _header->data();
 324   size_t n = os::read(fd, addr, (unsigned int)sz);
 325   if (n != sz) {
 326     fail_continue("Unable to read the file header.");
 327     return false;
 328   }
 329   if (_header->_version != current_version()) {
 330     fail_continue("The shared archive file has the wrong version.");
 331     return false;
 332   }
 333   _file_offset = (long)n;
 334 
 335   size_t info_size = _header->_paths_misc_info_size;
 336   _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
 337   if (_paths_misc_info == NULL) {
 338     fail_continue("Unable to read the file header.");
 339     return false;
 340   }
 341   n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
 342   if (n != info_size) {
 343     fail_continue("Unable to read the shared path info header.");
 344     FREE_C_HEAP_ARRAY(char, _paths_misc_info);
 345     _paths_misc_info = NULL;
 346     return false;
 347   }
 348 
 349   size_t len = lseek(fd, 0, SEEK_END);
 350   struct FileMapInfo::FileMapHeader::space_info* si =
 351     &_header->_space[MetaspaceShared::mc];
 352   if (si->_file_offset >= len || len - si->_file_offset < si->_used) {
 353     fail_continue("The shared archive file has been truncated.");
 354     return false;
 355   }
 356 
 357   _file_offset += (long)n;
 358   return true;
 359 }
 360 
 361 
 362 // Read the FileMapInfo information from the file.
 363 bool FileMapInfo::open_for_read() {
 364   _full_path = Arguments::GetSharedArchivePath();
 365   int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
 366   if (fd < 0) {
 367     if (errno == ENOENT) {
 368       // Not locating the shared archive is ok.
 369       fail_continue("Specified shared archive not found.");
 370     } else {
 371       fail_continue("Failed to open shared archive file (%s).",
 372                     strerror(errno));
 373     }
 374     return false;
 375   }
 376 
 377   _fd = fd;
 378   _file_open = true;
 379   return true;
 380 }
 381 
 382 
 383 // Write the FileMapInfo information to the file.
 384 
 385 void FileMapInfo::open_for_write() {
 386  _full_path = Arguments::GetSharedArchivePath();
 387   if (PrintSharedSpaces) {
 388     tty->print_cr("Dumping shared data to file: ");
 389     tty->print_cr("   %s", _full_path);
 390   }
 391 
 392 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
 393   chmod(_full_path, _S_IREAD | _S_IWRITE);
 394 #endif
 395 
 396   // Use remove() to delete the existing file because, on Unix, this will
 397   // allow processes that have it open continued access to the file.
 398   remove(_full_path);
 399   int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
 400   if (fd < 0) {
 401     fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
 402               strerror(errno));
 403   }
 404   _fd = fd;
 405   _file_offset = 0;
 406   _file_open = true;
 407 }
 408 
 409 
 410 // Write the header to the file, seek to the next allocation boundary.
 411 
 412 void FileMapInfo::write_header() {
 413   int info_size = ClassLoader::get_shared_paths_misc_info_size();
 414 
 415   _header->_paths_misc_info_size = info_size;
 416 
 417   align_file_position();
 418   size_t sz = _header->data_size();
 419   char* addr = _header->data();
 420   write_bytes(addr, (int)sz); // skip the C++ vtable
 421   write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
 422   align_file_position();
 423 }
 424 
 425 
 426 // Dump shared spaces to file.
 427 
 428 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
 429   align_file_position();
 430   size_t used = space->used_bytes_slow(Metaspace::NonClassType);
 431   size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
 432   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 433   write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
 434 }
 435 
 436 
 437 // Dump region to file.
 438 
 439 void FileMapInfo::write_region(int region, char* base, size_t size,
 440                                size_t capacity, bool read_only,
 441                                bool allow_exec) {
 442   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
 443 
 444   if (_file_open) {
 445     guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
 446     if (PrintSharedSpaces) {
 447       tty->print_cr("Shared file region %d: " SIZE_FORMAT_HEX_W(6) " bytes, addr " INTPTR_FORMAT
 448                     " file offset " SIZE_FORMAT_HEX_W(6), region, size, p2i(base), _file_offset);
 449     }
 450   } else {
 451     si->_file_offset = _file_offset;
 452   }
 453   if (MetaspaceShared::is_string_region(region)) {
 454     assert((base - (char*)Universe::narrow_oop_base()) % HeapWordSize == 0, "Sanity");
 455     if (base != NULL) {
 456       si->_addr._offset = (intx)oopDesc::encode_heap_oop_not_null((oop)base);
 457     } else {
 458       si->_addr._offset = 0;
 459     }
 460   } else {
 461     si->_addr._base = base;
 462   }
 463   si->_used = size;
 464   si->_capacity = capacity;
 465   si->_read_only = read_only;
 466   si->_allow_exec = allow_exec;
 467   si->_crc = ClassLoader::crc32(0, base, (jint)size);
 468   write_bytes_aligned(base, (int)size);
 469 }
 470 
 471 // Write the string space. The string space contains one or multiple GC(G1) regions.
 472 // When the total string space size is smaller than one GC region of the dump time,
 473 // only one string region is used for shared strings.
 474 //
 475 // If the total string space size is bigger than one GC region, there would be more
 476 // than one GC regions allocated for shared strings. The first/bottom GC region might
 477 // be a partial GC region with the empty portion at the higher address within that region.
 478 // The non-empty portion of the first region is written into the archive as one string
 479 // region. The rest are consecutive full GC regions if they exist, which can be written
 480 // out in one chunk as another string region.
 481 void FileMapInfo::write_string_regions(GrowableArray<MemRegion> *regions) {
 482   for (int i = MetaspaceShared::first_string;
 483            i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 484     char* start = NULL;
 485     size_t size = 0;
 486     if (regions->is_nonempty()) {
 487       if (i == MetaspaceShared::first_string) {
 488         MemRegion first = regions->first();
 489         start = (char*)first.start();
 490         size = first.byte_size();
 491       } else {
 492         int len = regions->length();
 493         if (len > 1) {
 494           start = (char*)regions->at(1).start();
 495           size = (char*)regions->at(len - 1).end() - start;
 496         }
 497       }
 498     }
 499     write_region(i, start, size, size, false, false);
 500   }
 501 }
 502 
 503 
 504 // Dump bytes to file -- at the current file position.
 505 
 506 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
 507   if (_file_open) {
 508     int n = ::write(_fd, buffer, nbytes);
 509     if (n != nbytes) {
 510       // It is dangerous to leave the corrupted shared archive file around,
 511       // close and remove the file. See bug 6372906.
 512       close();
 513       remove(_full_path);
 514       fail_stop("Unable to write to shared archive file.");
 515     }
 516   }
 517   _file_offset += nbytes;
 518 }
 519 
 520 
 521 // Align file position to an allocation unit boundary.
 522 
 523 void FileMapInfo::align_file_position() {
 524   size_t new_file_offset = align_size_up(_file_offset,
 525                                          os::vm_allocation_granularity());
 526   if (new_file_offset != _file_offset) {
 527     _file_offset = new_file_offset;
 528     if (_file_open) {
 529       // Seek one byte back from the target and write a byte to insure
 530       // that the written file is the correct length.
 531       _file_offset -= 1;
 532       if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
 533         fail_stop("Unable to seek.");
 534       }
 535       char zero = 0;
 536       write_bytes(&zero, 1);
 537     }
 538   }
 539 }
 540 
 541 
 542 // Dump bytes to file -- at the current file position.
 543 
 544 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
 545   align_file_position();
 546   write_bytes(buffer, nbytes);
 547   align_file_position();
 548 }
 549 
 550 
 551 // Close the shared archive file.  This does NOT unmap mapped regions.
 552 
 553 void FileMapInfo::close() {
 554   if (_file_open) {
 555     if (::close(_fd) < 0) {
 556       fail_stop("Unable to close the shared archive file.");
 557     }
 558     _file_open = false;
 559     _fd = -1;
 560   }
 561 }
 562 
 563 
 564 // JVM/TI RedefineClasses() support:
 565 // Remap the shared readonly space to shared readwrite, private.
 566 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
 567   int idx = 0;
 568   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[idx];
 569   if (!si->_read_only) {
 570     // the space is already readwrite so we are done
 571     return true;
 572   }
 573   size_t used = si->_used;
 574   size_t size = align_size_up(used, os::vm_allocation_granularity());
 575   if (!open_for_read()) {
 576     return false;
 577   }
 578   char *addr = _header->region_addr(idx);
 579   char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
 580                                 addr, size, false /* !read_only */,
 581                                 si->_allow_exec);
 582   close();
 583   if (base == NULL) {
 584     fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
 585     return false;
 586   }
 587   if (base != addr) {
 588     fail_continue("Unable to remap shared readonly space at required address.");
 589     return false;
 590   }
 591   si->_read_only = false;
 592   return true;
 593 }
 594 
 595 // Map the whole region at once, assumed to be allocated contiguously.
 596 ReservedSpace FileMapInfo::reserve_shared_memory() {
 597   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
 598   char* requested_addr = _header->region_addr(0);
 599 
 600   size_t size = FileMapInfo::shared_spaces_size();
 601 
 602   // Reserve the space first, then map otherwise map will go right over some
 603   // other reserved memory (like the code cache).
 604   ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
 605   if (!rs.is_reserved()) {
 606     fail_continue("Unable to reserve shared space at required address "
 607                   INTPTR_FORMAT, p2i(requested_addr));
 608     return rs;
 609   }
 610   // the reserved virtual memory is for mapping class data sharing archive
 611   MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
 612 
 613   return rs;
 614 }
 615 
 616 // Memory map a region in the address space.
 617 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode",
 618                                             "String1", "String2" };
 619 
 620 char* FileMapInfo::map_region(int i) {
 621   assert(!MetaspaceShared::is_string_region(i), "sanity");
 622   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 623   size_t used = si->_used;
 624   size_t alignment = os::vm_allocation_granularity();
 625   size_t size = align_size_up(used, alignment);
 626   char *requested_addr = _header->region_addr(i);
 627 
 628   // If a tool agent is in use (debugging enabled), we must map the address space RW
 629   if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
 630     si->_read_only = false;
 631   }
 632 
 633   // map the contents of the CDS archive in this memory
 634   char *base = os::map_memory(_fd, _full_path, si->_file_offset,
 635                               requested_addr, size, si->_read_only,
 636                               si->_allow_exec);
 637   if (base == NULL || base != requested_addr) {
 638     fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
 639     return NULL;
 640   }
 641 #ifdef _WINDOWS
 642   // This call is Windows-only because the memory_type gets recorded for the other platforms
 643   // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
 644   MemTracker::record_virtual_memory_type((address)base, mtClassShared);
 645 #endif
 646 
 647   return base;
 648 }
 649 
 650 static MemRegion *string_ranges = NULL;
 651 static int num_ranges = 0;
 652 bool FileMapInfo::map_string_regions() {
 653 #if INCLUDE_ALL_GCS
 654   if (UseG1GC && UseCompressedOops && UseCompressedClassPointers) {
 655     // Check that all the narrow oop and klass encodings match the archive
 656     if (narrow_oop_mode() != Universe::narrow_oop_mode() ||
 657         narrow_oop_shift() != Universe::narrow_oop_shift() ||
 658         narrow_klass_base() != Universe::narrow_klass_base() ||
 659         narrow_klass_shift() != Universe::narrow_klass_shift()) {
 660       if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
 661         tty->print_cr("Shared string data from the CDS archive is being ignored. "
 662                      "The current CompressedOops/CompressedClassPointers encoding differs from "
 663                      "that archived due to heap size change. The archive was dumped using max heap "
 664                      "size " UINTX_FORMAT "M.", max_heap_size()/M);
 665       }
 666     } else {
 667       string_ranges = new MemRegion[MetaspaceShared::max_strings];
 668       struct FileMapInfo::FileMapHeader::space_info* si;
 669 
 670       for (int i = MetaspaceShared::first_string;
 671                i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 672         si = &_header->_space[i];
 673         size_t used = si->_used;
 674         if (used > 0) {
 675           size_t size = used;
 676           char* requested_addr = (char*)((void*)oopDesc::decode_heap_oop_not_null(
 677                                                  (narrowOop)si->_addr._offset));
 678           string_ranges[num_ranges] = MemRegion((HeapWord*)requested_addr, size / HeapWordSize);
 679           num_ranges ++;
 680         }
 681       }
 682 
 683       if (num_ranges == 0) {
 684         StringTable::ignore_shared_strings(true);
 685         return true; // no shared string data
 686       }
 687 
 688       // Check that ranges are within the java heap
 689       if (!G1CollectedHeap::heap()->check_archive_addresses(string_ranges, num_ranges)) {
 690         fail_continue("Unable to allocate shared string space: range is not "
 691                       "within java heap.");
 692         return false;
 693       }
 694 
 695       // allocate from java heap
 696       if (!G1CollectedHeap::heap()->alloc_archive_regions(string_ranges, num_ranges)) {
 697         fail_continue("Unable to allocate shared string space: range is "
 698                       "already in use.");
 699         return false;
 700       }
 701 
 702       // Map the string data. No need to call MemTracker::record_virtual_memory_type()
 703       // for mapped string regions as they are part of the reserved java heap, which
 704       // is already recorded.
 705       for (int i = 0; i < num_ranges; i++) {
 706         si = &_header->_space[MetaspaceShared::first_string + i];
 707         char* addr = (char*)string_ranges[i].start();
 708         char* base = os::map_memory(_fd, _full_path, si->_file_offset,
 709                                     addr, string_ranges[i].byte_size(), si->_read_only,
 710                                     si->_allow_exec);
 711         if (base == NULL || base != addr) {
 712           // dealloc the string regions from java heap
 713           dealloc_string_regions();
 714           fail_continue("Unable to map shared string space at required address.");
 715           return false;
 716         }
 717       }
 718 
 719       if (!verify_string_regions()) {
 720         // dealloc the string regions from java heap
 721         dealloc_string_regions();
 722         fail_continue("Shared string regions are corrupt");
 723         return false;
 724       }
 725 
 726       // the shared string data is mapped successfully
 727       return true;
 728     }
 729   } else {
 730     if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
 731       tty->print_cr("Shared string data from the CDS archive is being ignored. UseG1GC, "
 732                     "UseCompressedOops and UseCompressedClassPointers are required.");
 733     }
 734   }
 735 
 736   // if we get here, the shared string data is not mapped
 737   assert(string_ranges == NULL && num_ranges == 0, "sanity");
 738   StringTable::ignore_shared_strings(true);
 739 #endif
 740   return true;
 741 }
 742 
 743 bool FileMapInfo::verify_string_regions() {
 744   for (int i = MetaspaceShared::first_string;
 745            i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 746     if (!verify_region_checksum(i)) {
 747       return false;
 748     }
 749   }
 750   return true;
 751 }
 752 
 753 void FileMapInfo::fixup_string_regions() {
 754 #if INCLUDE_ALL_GCS
 755   // If any string regions were found, call the fill routine to make them parseable.
 756   // Note that string_ranges may be non-NULL even if no ranges were found.
 757   if (num_ranges != 0) {
 758     assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
 759     G1CollectedHeap::heap()->fill_archive_regions(string_ranges, num_ranges);
 760   }
 761 #endif
 762 }
 763 
 764 bool FileMapInfo::verify_region_checksum(int i) {
 765   if (!VerifySharedSpaces) {
 766     return true;
 767   }
 768 
 769   size_t sz = _header->_space[i]._used;
 770 
 771   if (sz == 0) {
 772     return true; // no data
 773   }
 774   if (MetaspaceShared::is_string_region(i) && StringTable::shared_string_ignored()) {
 775     return true; // shared string data are not mapped
 776   }
 777   const char* buf = _header->region_addr(i);
 778   int crc = ClassLoader::crc32(0, buf, (jint)sz);
 779   if (crc != _header->_space[i]._crc) {
 780     fail_continue("Checksum verification failed.");
 781     return false;
 782   }
 783   return true;
 784 }
 785 
 786 // Unmap a memory region in the address space.
 787 
 788 void FileMapInfo::unmap_region(int i) {
 789   assert(!MetaspaceShared::is_string_region(i), "sanity");
 790   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 791   size_t used = si->_used;
 792   size_t size = align_size_up(used, os::vm_allocation_granularity());
 793 
 794   if (used == 0) {
 795     return;
 796   }
 797 
 798   char* addr = _header->region_addr(i);
 799   if (!os::unmap_memory(addr, size)) {
 800     fail_stop("Unable to unmap shared space.");
 801   }
 802 }
 803 
 804 // dealloc the archived string region from java heap
 805 void FileMapInfo::dealloc_string_regions() {
 806 #if INCLUDE_ALL_GCS
 807   if (num_ranges > 0) {
 808     assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
 809     G1CollectedHeap::heap()->dealloc_archive_regions(string_ranges, num_ranges);
 810   }
 811 #endif
 812 }
 813 
 814 void FileMapInfo::assert_mark(bool check) {
 815   if (!check) {
 816     fail_stop("Mark mismatch while restoring from shared file.");
 817   }
 818 }
 819 
 820 
 821 FileMapInfo* FileMapInfo::_current_info = NULL;
 822 SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL;
 823 int FileMapInfo::_classpath_entry_table_size = 0;
 824 size_t FileMapInfo::_classpath_entry_size = 0x1234baad;
 825 bool FileMapInfo::_validating_classpath_entry_table = false;
 826 
 827 // Open the shared archive file, read and validate the header
 828 // information (version, boot classpath, etc.).  If initialization
 829 // fails, shared spaces are disabled and the file is closed. [See
 830 // fail_continue.]
 831 //
 832 // Validation of the archive is done in two steps:
 833 //
 834 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
 835 // [2] validate_classpath_entry_table - this is done later, because the table is in the RW
 836 //     region of the archive, which is not mapped yet.
 837 bool FileMapInfo::initialize() {
 838   assert(UseSharedSpaces, "UseSharedSpaces expected.");
 839 
 840   if (!open_for_read()) {
 841     return false;
 842   }
 843 
 844   init_from_file(_fd);
 845   if (!validate_header()) {
 846     return false;
 847   }
 848 
 849   SharedReadOnlySize =  _header->_space[0]._capacity;
 850   SharedReadWriteSize = _header->_space[1]._capacity;
 851   SharedMiscDataSize =  _header->_space[2]._capacity;
 852   SharedMiscCodeSize =  _header->_space[3]._capacity;
 853   return true;
 854 }
 855 
 856 char* FileMapInfo::FileMapHeader::region_addr(int idx) {
 857   if (MetaspaceShared::is_string_region(idx)) {
 858     return (char*)((void*)oopDesc::decode_heap_oop_not_null(
 859               (narrowOop)_space[idx]._addr._offset));
 860   } else {
 861     return _space[idx]._addr._base;
 862   }
 863 }
 864 
 865 int FileMapInfo::FileMapHeader::compute_crc() {
 866   char* header = data();
 867   // start computing from the field after _crc
 868   char* buf = (char*)&_crc + sizeof(int);
 869   size_t sz = data_size() - (buf - header);
 870   int crc = ClassLoader::crc32(0, buf, (jint)sz);
 871   return crc;
 872 }
 873 
 874 bool FileMapInfo::FileMapHeader::validate() {
 875   if (VerifySharedSpaces && compute_crc() != _crc) {
 876     fail_continue("Header checksum verification failed.");
 877     return false;
 878   }
 879 
 880   if (_version != current_version()) {
 881     FileMapInfo::fail_continue("The shared archive file is the wrong version.");
 882     return false;
 883   }
 884   if (_magic != (int)0xf00baba2) {
 885     FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
 886     return false;
 887   }
 888   char header_version[JVM_IDENT_MAX];
 889   get_header_version(header_version);
 890   if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
 891     if (TraceClassPaths) {
 892       tty->print_cr("Expected: %s", header_version);
 893       tty->print_cr("Actual:   %s", _jvm_ident);
 894     }
 895     FileMapInfo::fail_continue("The shared archive file was created by a different"
 896                   " version or build of HotSpot");
 897     return false;
 898   }
 899   if (_obj_alignment != ObjectAlignmentInBytes) {
 900     FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
 901                   " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
 902                   _obj_alignment, ObjectAlignmentInBytes);
 903     return false;
 904   }
 905   if (_compact_strings != CompactStrings) {
 906     FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
 907                   " does not equal the current CompactStrings setting (%s).",
 908                   _compact_strings ? "enabled" : "disabled",
 909                   CompactStrings   ? "enabled" : "disabled");
 910     return false;
 911   }
 912 
 913   return true;
 914 }
 915 
 916 bool FileMapInfo::validate_header() {
 917   bool status = _header->validate();
 918 
 919   if (status) {
 920     if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
 921       if (!PrintSharedArchiveAndExit) {
 922         fail_continue("shared class paths mismatch (hint: enable -XX:+TraceClassPaths to diagnose the failure)");
 923         status = false;
 924       }
 925     }
 926   }
 927 
 928   if (_paths_misc_info != NULL) {
 929     FREE_C_HEAP_ARRAY(char, _paths_misc_info);
 930     _paths_misc_info = NULL;
 931   }
 932   return status;
 933 }
 934 
 935 // The following method is provided to see whether a given pointer
 936 // falls in the mapped shared space.
 937 // Param:
 938 // p, The given pointer
 939 // Return:
 940 // True if the p is within the mapped shared space, otherwise, false.
 941 bool FileMapInfo::is_in_shared_space(const void* p) {
 942   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
 943     char *base;
 944     if (MetaspaceShared::is_string_region(i) && _header->_space[i]._used == 0) {
 945       continue;
 946     }
 947     base = _header->region_addr(i);
 948     if (p >= base && p < base + _header->_space[i]._used) {
 949       return true;
 950     }
 951   }
 952 
 953   return false;
 954 }
 955 
 956 void FileMapInfo::print_shared_spaces() {
 957   tty->print_cr("Shared Spaces:");
 958   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
 959     struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 960     char *base = _header->region_addr(i);
 961     tty->print("  %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
 962                         shared_region_name[i],
 963                         p2i(base), p2i(base + si->_used));
 964   }
 965 }
 966 
 967 // Unmap mapped regions of shared space.
 968 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
 969   FileMapInfo *map_info = FileMapInfo::current_info();
 970   if (map_info) {
 971     map_info->fail_continue("%s", msg);
 972     for (int i = 0; i < MetaspaceShared::num_non_strings; i++) {
 973       char *addr = map_info->_header->region_addr(i);
 974       if (addr != NULL && !MetaspaceShared::is_string_region(i)) {
 975         map_info->unmap_region(i);
 976         map_info->_header->_space[i]._addr._base = NULL;
 977       }
 978     }
 979     // Dealloc the string regions only without unmapping. The string regions are part
 980     // of the java heap. Unmapping of the heap regions are managed by GC.
 981     map_info->dealloc_string_regions();
 982   } else if (DumpSharedSpaces) {
 983     fail_stop("%s", msg);
 984   }
 985 }