1 /*
   2  * Copyright (c) 2003, 2015, 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/sharedClassUtil.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "classfile/systemDictionaryShared.hpp"
  30 #include "classfile/altHashing.hpp"
  31 #if INCLUDE_ALL_GCS
  32 #include "gc/g1/g1CollectedHeap.hpp"
  33 #endif
  34 #include "memory/filemap.hpp"
  35 #include "memory/metadataFactory.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "oops/objArrayOop.hpp"
  38 #include "prims/jvmtiExport.hpp"
  39 #include "runtime/arguments.hpp"
  40 #include "runtime/java.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/vm_version.hpp"
  43 #include "services/memTracker.hpp"
  44 #include "utilities/defaultStream.hpp"
  45 
  46 # include <sys/stat.h>
  47 # include <errno.h>
  48 
  49 #ifndef O_BINARY       // if defined (Win32) use binary files.
  50 #define O_BINARY 0     // otherwise do nothing.
  51 #endif
  52 
  53 extern address JVM_FunctionAtStart();
  54 extern address JVM_FunctionAtEnd();
  55 
  56 // Complain and stop. All error conditions occurring during the writing of
  57 // an archive file should stop the process.  Unrecoverable errors during
  58 // the reading of the archive file should stop the process.
  59 
  60 static void fail(const char *msg, va_list ap) {
  61   // This occurs very early during initialization: tty is not initialized.
  62   jio_fprintf(defaultStream::error_stream(),
  63               "An error has occurred while processing the"
  64               " shared archive file.\n");
  65   jio_vfprintf(defaultStream::error_stream(), msg, ap);
  66   jio_fprintf(defaultStream::error_stream(), "\n");
  67   // Do not change the text of the below message because some tests check for it.
  68   vm_exit_during_initialization("Unable to use shared archive.", NULL);
  69 }
  70 
  71 
  72 void FileMapInfo::fail_stop(const char *msg, ...) {
  73         va_list ap;
  74   va_start(ap, msg);
  75   fail(msg, ap);        // Never returns.
  76   va_end(ap);           // for completeness.
  77 }
  78 
  79 
  80 // Complain and continue.  Recoverable errors during the reading of the
  81 // archive file may continue (with sharing disabled).
  82 //
  83 // If we continue, then disable shared spaces and close the file.
  84 
  85 void FileMapInfo::fail_continue(const char *msg, ...) {
  86   va_list ap;
  87   va_start(ap, msg);
  88   MetaspaceShared::set_archive_loading_failed();
  89   if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) {
  90     // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
  91     // do not validate, we can still continue "limping" to validate the remaining
  92     // entries. No need to quit.
  93     tty->print("[");
  94     tty->vprint(msg, ap);
  95     tty->print_cr("]");
  96   } else {
  97     if (RequireSharedSpaces) {
  98       fail(msg, ap);
  99     } else {
 100       if (PrintSharedSpaces) {
 101         tty->print_cr("UseSharedSpaces: %s", msg);
 102       }
 103     }
 104     UseSharedSpaces = false;
 105     assert(current_info() != NULL, "singleton must be registered");
 106     current_info()->close();
 107   }
 108   va_end(ap);
 109 }
 110 
 111 // Fill in the fileMapInfo structure with data about this VM instance.
 112 
 113 // This method copies the vm version info into header_version.  If the version is too
 114 // long then a truncated version, which has a hash code appended to it, is copied.
 115 //
 116 // Using a template enables this method to verify that header_version is an array of
 117 // length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and
 118 // the code that reads the CDS file will both use the same size buffer.  Hence, will
 119 // use identical truncation.  This is necessary for matching of truncated versions.
 120 template <int N> static void get_header_version(char (&header_version) [N]) {
 121   assert(N == JVM_IDENT_MAX, "Bad header_version size");
 122 
 123   const char *vm_version = VM_Version::internal_vm_info_string();
 124   const int version_len = (int)strlen(vm_version);
 125 
 126   if (version_len < (JVM_IDENT_MAX-1)) {
 127     strcpy(header_version, vm_version);
 128 
 129   } else {
 130     // Get the hash value.  Use a static seed because the hash needs to return the same
 131     // value over multiple jvm invocations.
 132     unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
 133 
 134     // Truncate the ident, saving room for the 8 hex character hash value.
 135     strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
 136 
 137     // Append the hash code as eight hex digits.
 138     sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
 139     header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.
 140   }
 141 }
 142 
 143 FileMapInfo::FileMapInfo() {
 144   assert(_current_info == NULL, "must be singleton"); // not thread safe
 145   _current_info = this;
 146   memset(this, 0, sizeof(FileMapInfo));
 147   _file_offset = 0;
 148   _file_open = false;
 149   _header = SharedClassUtil::allocate_file_map_header();
 150   _header->_version = _invalid_version;
 151 }
 152 
 153 FileMapInfo::~FileMapInfo() {
 154   assert(_current_info == this, "must be singleton"); // not thread safe
 155   _current_info = NULL;
 156 }
 157 
 158 void FileMapInfo::populate_header(size_t alignment) {
 159   _header->populate(this, alignment);
 160 }
 161 
 162 size_t FileMapInfo::FileMapHeader::data_size() {
 163   return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);
 164 }
 165 
 166 void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
 167   _magic = 0xf00baba2;
 168   _version = _current_version;
 169   _alignment = alignment;
 170   _obj_alignment = ObjectAlignmentInBytes;
 171   _compact_strings = CompactStrings;
 172   _narrow_oop_mode = Universe::narrow_oop_mode();
 173   _narrow_oop_shift = Universe::narrow_oop_shift();
 174   _max_heap_size = MaxHeapSize;
 175   _narrow_klass_base = Universe::narrow_klass_base();
 176   _narrow_klass_shift = Universe::narrow_klass_shift();
 177   _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;
 178   _classpath_entry_table = mapinfo->_classpath_entry_table;
 179   _classpath_entry_size = mapinfo->_classpath_entry_size;
 180 
 181   // The following fields are for sanity checks for whether this archive
 182   // will function correctly with this JVM and the bootclasspath it's
 183   // invoked with.
 184 
 185   // JVM version string ... changes on each build.
 186   get_header_version(_jvm_ident);
 187 }
 188 
 189 void FileMapInfo::allocate_classpath_entry_table() {
 190   int bytes = 0;
 191   int count = 0;
 192   char* strptr = NULL;
 193   char* strptr_max = NULL;
 194   Thread* THREAD = Thread::current();
 195 
 196   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
 197   size_t entry_size = SharedClassUtil::shared_class_path_entry_size();
 198 
 199   for (int pass=0; pass<2; pass++) {
 200     ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
 201 
 202     for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {
 203       const char *name = cpe->name();
 204       int name_bytes = (int)(strlen(name) + 1);
 205 
 206       if (pass == 0) {
 207         count ++;
 208         bytes += (int)entry_size;
 209         bytes += name_bytes;
 210         if (TraceClassPaths || (TraceClassLoading && Verbose)) {
 211           tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name);
 212         }
 213       } else {
 214         SharedClassPathEntry* ent = shared_classpath(cur_entry);
 215         if (cpe->is_jar_file()) {
 216           struct stat st;
 217           if (os::stat(name, &st) != 0) {
 218             // The file/dir must exist, or it would not have been added
 219             // into ClassLoader::classpath_entry().
 220             //
 221             // If we can't access a jar file in the boot path, then we can't
 222             // make assumptions about where classes get loaded from.
 223             FileMapInfo::fail_stop("Unable to open jar file %s.", name);
 224           }
 225 
 226           EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
 227           SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);
 228         } else {
 229           struct stat st;
 230           if ((os::stat(name, &st) == 0) && ((st.st_mode & S_IFDIR) == S_IFDIR)) {
 231             if (!os::dir_is_empty(name)) {
 232               ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);
 233             }
 234             ent->_filesize = -1;
 235           } else {
 236             ent->_filesize = -2;
 237           }
 238         }
 239         ent->_name = strptr;
 240         if (strptr + name_bytes <= strptr_max) {
 241           strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
 242           strptr += name_bytes;
 243         } else {
 244           assert(0, "miscalculated buffer size");
 245         }
 246       }
 247     }
 248 
 249     if (pass == 0) {
 250       EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
 251       Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);
 252       strptr = (char*)(arr->data());
 253       strptr_max = strptr + bytes;
 254       SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;
 255       strptr += entry_size * count;
 256 
 257       _classpath_entry_table_size = count;
 258       _classpath_entry_table = table;
 259       _classpath_entry_size = entry_size;
 260     }
 261   }
 262 }
 263 
 264 bool FileMapInfo::validate_classpath_entry_table() {
 265   _validating_classpath_entry_table = true;
 266 
 267   int count = _header->_classpath_entry_table_size;
 268 
 269   _classpath_entry_table = _header->_classpath_entry_table;
 270   _classpath_entry_size = _header->_classpath_entry_size;
 271 
 272   for (int i=0; i<count; i++) {
 273     SharedClassPathEntry* ent = shared_classpath(i);
 274     struct stat st;
 275     const char* name = ent->_name;
 276     bool ok = true;
 277     if (TraceClassPaths || (TraceClassLoading && Verbose)) {
 278       tty->print_cr("[Checking shared classpath entry: %s]", name);
 279     }
 280     if (os::stat(name, &st) != 0) {
 281       fail_continue("Required classpath entry does not exist: %s", name);
 282       ok = false;
 283     } else if (ent->is_dir()) {
 284       if (!os::dir_is_empty(name)) {
 285         fail_continue("directory is not empty: %s", name);
 286         ok = false;
 287       }
 288     } else if (ent->is_jar()) {
 289       if (ent->_timestamp != st.st_mtime ||
 290           ent->_filesize != st.st_size) {
 291         ok = false;
 292         if (PrintSharedArchiveAndExit) {
 293           fail_continue(ent->_timestamp != st.st_mtime ?
 294                         "Timestamp mismatch" :
 295                         "File size mismatch");
 296         } else {
 297           fail_continue("A jar file is not the one used while building"
 298                         " the shared archive file: %s", name);
 299         }
 300       }
 301     }
 302     if (ok) {
 303       if (TraceClassPaths || (TraceClassLoading && Verbose)) {
 304         tty->print_cr("[ok]");
 305       }
 306     } else if (!PrintSharedArchiveAndExit) {
 307       _validating_classpath_entry_table = false;
 308       return false;
 309     }
 310   }
 311 
 312   _classpath_entry_table_size = _header->_classpath_entry_table_size;
 313   _validating_classpath_entry_table = false;
 314   return true;
 315 }
 316 
 317 
 318 // Read the FileMapInfo information from the file.
 319 
 320 bool FileMapInfo::init_from_file(int fd) {
 321   size_t sz = _header->data_size();
 322   char* addr = _header->data();
 323   size_t n = os::read(fd, addr, (unsigned int)sz);
 324   if (n != sz) {
 325     fail_continue("Unable to read the file header.");
 326     return false;
 327   }
 328   if (_header->_version != current_version()) {
 329     fail_continue("The shared archive file has the wrong version.");
 330     return false;
 331   }
 332   _file_offset = (long)n;
 333 
 334   size_t info_size = _header->_paths_misc_info_size;
 335   _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
 336   if (_paths_misc_info == NULL) {
 337     fail_continue("Unable to read the file header.");
 338     return false;
 339   }
 340   n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
 341   if (n != info_size) {
 342     fail_continue("Unable to read the shared path info header.");
 343     FREE_C_HEAP_ARRAY(char, _paths_misc_info);
 344     _paths_misc_info = NULL;
 345     return false;
 346   }
 347 
 348   size_t len = lseek(fd, 0, SEEK_END);
 349   struct FileMapInfo::FileMapHeader::space_info* si =
 350     &_header->_space[MetaspaceShared::mc];
 351   if (si->_file_offset >= len || len - si->_file_offset < si->_used) {
 352     fail_continue("The shared archive file has been truncated.");
 353     return false;
 354   }
 355 
 356   _file_offset += (long)n;
 357   return true;
 358 }
 359 
 360 
 361 // Read the FileMapInfo information from the file.
 362 bool FileMapInfo::open_for_read() {
 363   _full_path = Arguments::GetSharedArchivePath();
 364   int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
 365   if (fd < 0) {
 366     if (errno == ENOENT) {
 367       // Not locating the shared archive is ok.
 368       fail_continue("Specified shared archive not found.");
 369     } else {
 370       fail_continue("Failed to open shared archive file (%s).",
 371                     strerror(errno));
 372     }
 373     return false;
 374   }
 375 
 376   _fd = fd;
 377   _file_open = true;
 378   return true;
 379 }
 380 
 381 
 382 // Write the FileMapInfo information to the file.
 383 
 384 void FileMapInfo::open_for_write() {
 385  _full_path = Arguments::GetSharedArchivePath();
 386   if (PrintSharedSpaces) {
 387     tty->print_cr("Dumping shared data to file: ");
 388     tty->print_cr("   %s", _full_path);
 389   }
 390 
 391 #ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.
 392   chmod(_full_path, _S_IREAD | _S_IWRITE);
 393 #endif
 394 
 395   // Use remove() to delete the existing file because, on Unix, this will
 396   // allow processes that have it open continued access to the file.
 397   remove(_full_path);
 398   int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
 399   if (fd < 0) {
 400     fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
 401               strerror(errno));
 402   }
 403   _fd = fd;
 404   _file_offset = 0;
 405   _file_open = true;
 406 }
 407 
 408 
 409 // Write the header to the file, seek to the next allocation boundary.
 410 
 411 void FileMapInfo::write_header() {
 412   int info_size = ClassLoader::get_shared_paths_misc_info_size();
 413 
 414   _header->_paths_misc_info_size = info_size;
 415 
 416   align_file_position();
 417   size_t sz = _header->data_size();
 418   char* addr = _header->data();
 419   write_bytes(addr, (int)sz); // skip the C++ vtable
 420   write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
 421   align_file_position();
 422 }
 423 
 424 
 425 // Dump shared spaces to file.
 426 
 427 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
 428   align_file_position();
 429   size_t used = space->used_bytes_slow(Metaspace::NonClassType);
 430   size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
 431   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 432   write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
 433 }
 434 
 435 
 436 // Dump region to file.
 437 
 438 void FileMapInfo::write_region(int region, char* base, size_t size,
 439                                size_t capacity, bool read_only,
 440                                bool allow_exec) {
 441   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
 442 
 443   if (_file_open) {
 444     guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
 445     if (PrintSharedSpaces) {
 446       tty->print_cr("Shared file region %d: " SIZE_FORMAT_HEX_W(6) " bytes, addr " INTPTR_FORMAT
 447                     " file offset " SIZE_FORMAT_HEX_W(6), region, size, p2i(base), _file_offset);
 448     }
 449   } else {
 450     si->_file_offset = _file_offset;
 451   }
 452   if (MetaspaceShared::is_string_region(region)) {
 453     assert((base - (char*)Universe::narrow_oop_base()) % HeapWordSize == 0, "Sanity");
 454     if (base != NULL) {
 455       si->_addr._offset = (intx)oopDesc::encode_heap_oop_not_null((oop)base);
 456     } else {
 457       si->_addr._offset = 0;
 458     }
 459   } else {
 460     si->_addr._base = base;
 461   }
 462   si->_used = size;
 463   si->_capacity = capacity;
 464   si->_read_only = read_only;
 465   si->_allow_exec = allow_exec;
 466   si->_crc = ClassLoader::crc32(0, base, (jint)size);
 467   write_bytes_aligned(base, (int)size);
 468 }
 469 
 470 // Write the string space. The string space contains one or multiple GC(G1) regions.
 471 // When the total string space size is smaller than one GC region of the dump time,
 472 // only one string region is used for shared strings.
 473 //
 474 // If the total string space size is bigger than one GC region, there would be more
 475 // than one GC regions allocated for shared strings. The first/bottom GC region might
 476 // be a partial GC region with the empty portion at the higher address within that region.
 477 // The non-empty portion of the first region is written into the archive as one string
 478 // region. The rest are consecutive full GC regions if they exist, which can be written
 479 // out in one chunk as another string region.
 480 void FileMapInfo::write_string_regions(GrowableArray<MemRegion> *regions) {
 481   for (int i = MetaspaceShared::first_string;
 482            i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 483     char* start = NULL;
 484     size_t size = 0;
 485     if (regions->is_nonempty()) {
 486       if (i == MetaspaceShared::first_string) {
 487         MemRegion first = regions->first();
 488         start = (char*)first.start();
 489         size = first.byte_size();
 490       } else {
 491         int len = regions->length();
 492         if (len > 1) {
 493           start = (char*)regions->at(1).start();
 494           size = (char*)regions->at(len - 1).end() - start;
 495         }
 496       }
 497     }
 498     write_region(i, start, size, size, false, false);
 499   }
 500 }
 501 
 502 
 503 // Dump bytes to file -- at the current file position.
 504 
 505 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
 506   if (_file_open) {
 507     int n = ::write(_fd, buffer, nbytes);
 508     if (n != nbytes) {
 509       // It is dangerous to leave the corrupted shared archive file around,
 510       // close and remove the file. See bug 6372906.
 511       close();
 512       remove(_full_path);
 513       fail_stop("Unable to write to shared archive file.");
 514     }
 515   }
 516   _file_offset += nbytes;
 517 }
 518 
 519 
 520 // Align file position to an allocation unit boundary.
 521 
 522 void FileMapInfo::align_file_position() {
 523   size_t new_file_offset = align_size_up(_file_offset,
 524                                          os::vm_allocation_granularity());
 525   if (new_file_offset != _file_offset) {
 526     _file_offset = new_file_offset;
 527     if (_file_open) {
 528       // Seek one byte back from the target and write a byte to insure
 529       // that the written file is the correct length.
 530       _file_offset -= 1;
 531       if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
 532         fail_stop("Unable to seek.");
 533       }
 534       char zero = 0;
 535       write_bytes(&zero, 1);
 536     }
 537   }
 538 }
 539 
 540 
 541 // Dump bytes to file -- at the current file position.
 542 
 543 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
 544   align_file_position();
 545   write_bytes(buffer, nbytes);
 546   align_file_position();
 547 }
 548 
 549 
 550 // Close the shared archive file.  This does NOT unmap mapped regions.
 551 
 552 void FileMapInfo::close() {
 553   if (_file_open) {
 554     if (::close(_fd) < 0) {
 555       fail_stop("Unable to close the shared archive file.");
 556     }
 557     _file_open = false;
 558     _fd = -1;
 559   }
 560 }
 561 
 562 
 563 // JVM/TI RedefineClasses() support:
 564 // Remap the shared readonly space to shared readwrite, private.
 565 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
 566   int idx = 0;
 567   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[idx];
 568   if (!si->_read_only) {
 569     // the space is already readwrite so we are done
 570     return true;
 571   }
 572   size_t used = si->_used;
 573   size_t size = align_size_up(used, os::vm_allocation_granularity());
 574   if (!open_for_read()) {
 575     return false;
 576   }
 577   char *addr = _header->region_addr(idx);
 578   char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
 579                                 addr, size, false /* !read_only */,
 580                                 si->_allow_exec);
 581   close();
 582   if (base == NULL) {
 583     fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
 584     return false;
 585   }
 586   if (base != addr) {
 587     fail_continue("Unable to remap shared readonly space at required address.");
 588     return false;
 589   }
 590   si->_read_only = false;
 591   return true;
 592 }
 593 
 594 // Map the whole region at once, assumed to be allocated contiguously.
 595 ReservedSpace FileMapInfo::reserve_shared_memory() {
 596   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
 597   char* requested_addr = _header->region_addr(0);
 598 
 599   size_t size = FileMapInfo::shared_spaces_size();
 600 
 601   // Reserve the space first, then map otherwise map will go right over some
 602   // other reserved memory (like the code cache).
 603   ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
 604   if (!rs.is_reserved()) {
 605     fail_continue("Unable to reserve shared space at required address "
 606                   INTPTR_FORMAT, p2i(requested_addr));
 607     return rs;
 608   }
 609   // the reserved virtual memory is for mapping class data sharing archive
 610   MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
 611 
 612   return rs;
 613 }
 614 
 615 // Memory map a region in the address space.
 616 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode",
 617                                             "String1", "String2" };
 618 
 619 char* FileMapInfo::map_region(int i) {
 620   assert(!MetaspaceShared::is_string_region(i), "sanity");
 621   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 622   size_t used = si->_used;
 623   size_t alignment = os::vm_allocation_granularity();
 624   size_t size = align_size_up(used, alignment);
 625   char *requested_addr = _header->region_addr(i);
 626 
 627   // If a tool agent is in use (debugging enabled), we must map the address space RW
 628   if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
 629     si->_read_only = false;
 630   }
 631 
 632   // map the contents of the CDS archive in this memory
 633   char *base = os::map_memory(_fd, _full_path, si->_file_offset,
 634                               requested_addr, size, si->_read_only,
 635                               si->_allow_exec);
 636   if (base == NULL || base != requested_addr) {
 637     fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
 638     return NULL;
 639   }
 640 #ifdef _WINDOWS
 641   // This call is Windows-only because the memory_type gets recorded for the other platforms
 642   // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
 643   MemTracker::record_virtual_memory_type((address)base, mtClassShared);
 644 #endif
 645 
 646   return base;
 647 }
 648 
 649 static MemRegion *string_ranges = NULL;
 650 static int num_ranges = 0;
 651 bool FileMapInfo::map_string_regions() {
 652 #if INCLUDE_ALL_GCS
 653   if (UseG1GC && UseCompressedOops && UseCompressedClassPointers) {
 654     // Check that all the narrow oop and klass encodings match the archive
 655     if (narrow_oop_mode() != Universe::narrow_oop_mode() ||
 656         narrow_oop_shift() != Universe::narrow_oop_shift() ||
 657         narrow_klass_base() != Universe::narrow_klass_base() ||
 658         narrow_klass_shift() != Universe::narrow_klass_shift()) {
 659       if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
 660         tty->print_cr("Shared string data from the CDS archive is being ignored. "
 661                      "The current CompressedOops/CompressedClassPointers encoding differs from "
 662                      "that archived due to heap size change. The archive was dumped using max heap "
 663                      "size " UINTX_FORMAT "M.", max_heap_size()/M);
 664       }
 665     } else {
 666       string_ranges = new MemRegion[MetaspaceShared::max_strings];
 667       struct FileMapInfo::FileMapHeader::space_info* si;
 668 
 669       for (int i = MetaspaceShared::first_string;
 670                i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 671         si = &_header->_space[i];
 672         size_t used = si->_used;
 673         if (used > 0) {
 674           size_t size = used;
 675           char* requested_addr = (char*)((void*)oopDesc::decode_heap_oop_not_null(
 676                                                  (narrowOop)si->_addr._offset));
 677           string_ranges[num_ranges] = MemRegion((HeapWord*)requested_addr, size / HeapWordSize);
 678           num_ranges ++;
 679         }
 680       }
 681 
 682       if (num_ranges == 0) {
 683         StringTable::ignore_shared_strings(true);
 684         return true; // no shared string data
 685       }
 686 
 687       // Check that ranges are within the java heap
 688       if (!G1CollectedHeap::heap()->check_archive_addresses(string_ranges, num_ranges)) {
 689         fail_continue("Unable to allocate shared string space: range is not "
 690                       "within java heap.");
 691         return false;
 692       }
 693 
 694       // allocate from java heap
 695       if (!G1CollectedHeap::heap()->alloc_archive_regions(string_ranges, num_ranges)) {
 696         fail_continue("Unable to allocate shared string space: range is "
 697                       "already in use.");
 698         return false;
 699       }
 700 
 701       // Map the string data. No need to call MemTracker::record_virtual_memory_type()
 702       // for mapped string regions as they are part of the reserved java heap, which
 703       // is already recorded.
 704       for (int i = 0; i < num_ranges; i++) {
 705         si = &_header->_space[MetaspaceShared::first_string + i];
 706         char* addr = (char*)string_ranges[i].start();
 707         char* base = os::map_memory(_fd, _full_path, si->_file_offset,
 708                                     addr, string_ranges[i].byte_size(), si->_read_only,
 709                                     si->_allow_exec);
 710         if (base == NULL || base != addr) {
 711           // dealloc the string regions from java heap
 712           dealloc_string_regions();
 713           fail_continue("Unable to map shared string space at required address.");
 714           return false;
 715         }
 716       }
 717 
 718       if (!verify_string_regions()) {
 719         // dealloc the string regions from java heap
 720         dealloc_string_regions();
 721         fail_continue("Shared string regions are corrupt");
 722         return false;
 723       }
 724 
 725       // the shared string data is mapped successfully
 726       return true;
 727     }
 728   } else {
 729     if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
 730       tty->print_cr("Shared string data from the CDS archive is being ignored. UseG1GC, "
 731                     "UseCompressedOops and UseCompressedClassPointers are required.");
 732     }
 733   }
 734 
 735   // if we get here, the shared string data is not mapped
 736   assert(string_ranges == NULL && num_ranges == 0, "sanity");
 737   StringTable::ignore_shared_strings(true);
 738 #endif
 739   return true;
 740 }
 741 
 742 bool FileMapInfo::verify_string_regions() {
 743   for (int i = MetaspaceShared::first_string;
 744            i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
 745     if (!verify_region_checksum(i)) {
 746       return false;
 747     }
 748   }
 749   return true;
 750 }
 751 
 752 void FileMapInfo::fixup_string_regions() {
 753 #if INCLUDE_ALL_GCS
 754   // If any string regions were found, call the fill routine to make them parseable.
 755   // Note that string_ranges may be non-NULL even if no ranges were found.
 756   if (num_ranges != 0) {
 757     assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
 758     G1CollectedHeap::heap()->fill_archive_regions(string_ranges, num_ranges);
 759   }
 760 #endif
 761 }
 762 
 763 bool FileMapInfo::verify_region_checksum(int i) {
 764   if (!VerifySharedSpaces) {
 765     return true;
 766   }
 767 
 768   size_t sz = _header->_space[i]._used;
 769 
 770   if (sz == 0) {
 771     return true; // no data
 772   }
 773   if (MetaspaceShared::is_string_region(i) && StringTable::shared_string_ignored()) {
 774     return true; // shared string data are not mapped
 775   }
 776   const char* buf = _header->region_addr(i);
 777   int crc = ClassLoader::crc32(0, buf, (jint)sz);
 778   if (crc != _header->_space[i]._crc) {
 779     fail_continue("Checksum verification failed.");
 780     return false;
 781   }
 782   return true;
 783 }
 784 
 785 // Unmap a memory region in the address space.
 786 
 787 void FileMapInfo::unmap_region(int i) {
 788   assert(!MetaspaceShared::is_string_region(i), "sanity");
 789   struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 790   size_t used = si->_used;
 791   size_t size = align_size_up(used, os::vm_allocation_granularity());
 792 
 793   if (used == 0) {
 794     return;
 795   }
 796 
 797   char* addr = _header->region_addr(i);
 798   if (!os::unmap_memory(addr, size)) {
 799     fail_stop("Unable to unmap shared space.");
 800   }
 801 }
 802 
 803 // dealloc the archived string region from java heap
 804 void FileMapInfo::dealloc_string_regions() {
 805 #if INCLUDE_ALL_GCS
 806   if (num_ranges > 0) {
 807     assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
 808     G1CollectedHeap::heap()->dealloc_archive_regions(string_ranges, num_ranges);
 809   }
 810 #endif
 811 }
 812 
 813 void FileMapInfo::assert_mark(bool check) {
 814   if (!check) {
 815     fail_stop("Mark mismatch while restoring from shared file.");
 816   }
 817 }
 818 
 819 
 820 FileMapInfo* FileMapInfo::_current_info = NULL;
 821 SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL;
 822 int FileMapInfo::_classpath_entry_table_size = 0;
 823 size_t FileMapInfo::_classpath_entry_size = 0x1234baad;
 824 bool FileMapInfo::_validating_classpath_entry_table = false;
 825 
 826 // Open the shared archive file, read and validate the header
 827 // information (version, boot classpath, etc.).  If initialization
 828 // fails, shared spaces are disabled and the file is closed. [See
 829 // fail_continue.]
 830 //
 831 // Validation of the archive is done in two steps:
 832 //
 833 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
 834 // [2] validate_classpath_entry_table - this is done later, because the table is in the RW
 835 //     region of the archive, which is not mapped yet.
 836 bool FileMapInfo::initialize() {
 837   assert(UseSharedSpaces, "UseSharedSpaces expected.");
 838 
 839   if (!open_for_read()) {
 840     return false;
 841   }
 842 
 843   init_from_file(_fd);
 844   if (!validate_header()) {
 845     return false;
 846   }
 847 
 848   SharedReadOnlySize =  _header->_space[0]._capacity;
 849   SharedReadWriteSize = _header->_space[1]._capacity;
 850   SharedMiscDataSize =  _header->_space[2]._capacity;
 851   SharedMiscCodeSize =  _header->_space[3]._capacity;
 852   return true;
 853 }
 854 
 855 char* FileMapInfo::FileMapHeader::region_addr(int idx) {
 856   if (MetaspaceShared::is_string_region(idx)) {
 857     return (char*)((void*)oopDesc::decode_heap_oop_not_null(
 858               (narrowOop)_space[idx]._addr._offset));
 859   } else {
 860     return _space[idx]._addr._base;
 861   }
 862 }
 863 
 864 int FileMapInfo::FileMapHeader::compute_crc() {
 865   char* header = data();
 866   // start computing from the field after _crc
 867   char* buf = (char*)&_crc + sizeof(int);
 868   size_t sz = data_size() - (buf - header);
 869   int crc = ClassLoader::crc32(0, buf, (jint)sz);
 870   return crc;
 871 }
 872 
 873 bool FileMapInfo::FileMapHeader::validate() {
 874   if (VerifySharedSpaces && compute_crc() != _crc) {
 875     fail_continue("Header checksum verification failed.");
 876     return false;
 877   }
 878 
 879   if (_version != current_version()) {
 880     FileMapInfo::fail_continue("The shared archive file is the wrong version.");
 881     return false;
 882   }
 883   if (_magic != (int)0xf00baba2) {
 884     FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
 885     return false;
 886   }
 887   char header_version[JVM_IDENT_MAX];
 888   get_header_version(header_version);
 889   if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
 890     if (TraceClassPaths) {
 891       tty->print_cr("Expected: %s", header_version);
 892       tty->print_cr("Actual:   %s", _jvm_ident);
 893     }
 894     FileMapInfo::fail_continue("The shared archive file was created by a different"
 895                   " version or build of HotSpot");
 896     return false;
 897   }
 898   if (_obj_alignment != ObjectAlignmentInBytes) {
 899     FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
 900                   " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
 901                   _obj_alignment, ObjectAlignmentInBytes);
 902     return false;
 903   }
 904   if (_compact_strings != CompactStrings) {
 905     FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
 906                   " does not equal the current CompactStrings setting (%s).",
 907                   _compact_strings ? "enabled" : "disabled",
 908                   CompactStrings   ? "enabled" : "disabled");
 909     return false;
 910   }
 911 
 912   return true;
 913 }
 914 
 915 bool FileMapInfo::validate_header() {
 916   bool status = _header->validate();
 917 
 918   if (status) {
 919     if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
 920       if (!PrintSharedArchiveAndExit) {
 921         fail_continue("shared class paths mismatch (hint: enable -XX:+TraceClassPaths to diagnose the failure)");
 922         status = false;
 923       }
 924     }
 925   }
 926 
 927   if (_paths_misc_info != NULL) {
 928     FREE_C_HEAP_ARRAY(char, _paths_misc_info);
 929     _paths_misc_info = NULL;
 930   }
 931   return status;
 932 }
 933 
 934 // The following method is provided to see whether a given pointer
 935 // falls in the mapped shared space.
 936 // Param:
 937 // p, The given pointer
 938 // Return:
 939 // True if the p is within the mapped shared space, otherwise, false.
 940 bool FileMapInfo::is_in_shared_space(const void* p) {
 941   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
 942     char *base;
 943     if (MetaspaceShared::is_string_region(i) && _header->_space[i]._used == 0) {
 944       continue;
 945     }
 946     base = _header->region_addr(i);
 947     if (p >= base && p < base + _header->_space[i]._used) {
 948       return true;
 949     }
 950   }
 951 
 952   return false;
 953 }
 954 
 955 void FileMapInfo::print_shared_spaces() {
 956   gclog_or_tty->print_cr("Shared Spaces:");
 957   for (int i = 0; i < MetaspaceShared::n_regions; i++) {
 958     struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
 959     char *base = _header->region_addr(i);
 960     gclog_or_tty->print("  %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
 961                         shared_region_name[i],
 962                         p2i(base), p2i(base + si->_used));
 963   }
 964 }
 965 
 966 // Unmap mapped regions of shared space.
 967 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
 968   FileMapInfo *map_info = FileMapInfo::current_info();
 969   if (map_info) {
 970     map_info->fail_continue("%s", msg);
 971     for (int i = 0; i < MetaspaceShared::num_non_strings; i++) {
 972       char *addr = map_info->_header->region_addr(i);
 973       if (addr != NULL && !MetaspaceShared::is_string_region(i)) {
 974         map_info->unmap_region(i);
 975         map_info->_header->_space[i]._addr._base = NULL;
 976       }
 977     }
 978     // Dealloc the string regions only without unmapping. The string regions are part
 979     // of the java heap. Unmapping of the heap regions are managed by GC.
 980     map_info->dealloc_string_regions();
 981   } else if (DumpSharedSpaces) {
 982     fail_stop("%s", msg);
 983   }
 984 }