1 /*
   2  * Copyright (c) 2003, 2018, 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 #ifndef SHARE_VM_MEMORY_FILEMAP_HPP
  26 #define SHARE_VM_MEMORY_FILEMAP_HPP
  27 
  28 #include "classfile/classLoader.hpp"
  29 #include "include/cds.h"
  30 #include "memory/metaspaceShared.hpp"
  31 #include "memory/metaspace.hpp"
  32 #include "memory/universe.hpp"
  33 #include "utilities/align.hpp"
  34 
  35 // Layout of the file:
  36 //  header: dump of archive instance plus versioning info, datestamp, etc.
  37 //   [magic # = 0xF00BABA2]
  38 //  ... padding to align on page-boundary
  39 //  read-write space
  40 //  read-only space
  41 //  misc data (block offset table, string table, symbols, dictionary, etc.)
  42 //  tag(666)
  43 
  44 static const int JVM_IDENT_MAX = 256;
  45 
  46 class SharedClassPathEntry {
  47   enum {
  48     modules_image_entry,
  49     jar_entry,
  50     signed_jar_entry,
  51     dir_entry,
  52     unknown_entry
  53   };
  54 protected:
  55   u1     _type;
  56   time_t _timestamp;          // jar timestamp,  0 if is directory, modules image or other
  57   long   _filesize;           // jar/jimage file size, -1 if is directory, -2 if other
  58   Array<char>* _name;
  59   Array<u1>*   _manifest;
  60 
  61 public:
  62   void init(const char* name, bool is_modules_image, TRAPS);
  63   void metaspace_pointers_do(MetaspaceClosure* it);
  64   bool validate(bool is_class_path = true);
  65 
  66   // The _timestamp only gets set for jar files.
  67   bool has_timestamp() {
  68     return _timestamp != 0;
  69   }
  70   bool is_dir()            { return _type == dir_entry; }
  71   bool is_modules_image()  { return _type == modules_image_entry; }
  72   bool is_jar()            { return _type == jar_entry; }
  73   bool is_signed()         { return _type == signed_jar_entry; }
  74   void set_is_signed()     {
  75     _type = signed_jar_entry;
  76   }
  77   time_t timestamp() const { return _timestamp; }
  78   long   filesize()  const { return _filesize; }
  79   const char* name() const { return _name->data(); }
  80   const char* manifest() const {
  81     return (_manifest == NULL) ? NULL : (const char*)_manifest->data();
  82   }
  83   int manifest_size() const {
  84     return (_manifest == NULL) ? 0 : _manifest->length();
  85   }
  86   void set_manifest(Array<u1>* manifest) {
  87     _manifest = manifest;
  88   }
  89 };
  90 
  91 struct ArchiveHeapOopmapInfo {
  92   address _oopmap;               // bitmap for relocating embedded oops
  93   size_t  _oopmap_size_in_bits;
  94 };
  95 
  96 struct FileMapHeader : public CDSFileMapHeaderBase {
  97   size_t _alignment;                // how shared archive should be aligned
  98   int    _obj_alignment;            // value of ObjectAlignmentInBytes
  99   address _narrow_oop_base;         // compressed oop encoding base
 100   int    _narrow_oop_shift;         // compressed oop encoding shift
 101   bool    _compact_strings;         // value of CompactStrings
 102   uintx  _max_heap_size;            // java max heap size during dumping
 103   Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode
 104   int     _narrow_klass_shift;      // save narrow klass base and shift
 105   address _narrow_klass_base;
 106   char*   _misc_data_patching_start;
 107   char*   _read_only_tables_start;
 108   address _cds_i2i_entry_code_buffers;
 109   size_t  _cds_i2i_entry_code_buffers_size;
 110   size_t  _core_spaces_size;        // number of bytes allocated by the core spaces
 111                                     // (mc, md, ro, rw and od).
 112   MemRegion _heap_reserved;         // reserved region for the entire heap at dump time.
 113 
 114   // The following fields are all sanity checks for whether this archive
 115   // will function correctly with this JVM and the bootclasspath it's
 116   // invoked with.
 117   char  _jvm_ident[JVM_IDENT_MAX];      // identifier for jvm
 118 
 119   // The _paths_misc_info is a variable-size structure that records "miscellaneous"
 120   // information during dumping. It is generated and validated by the
 121   // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp for
 122   // detailed description.
 123   //
 124   // The _paths_misc_info data is stored as a byte array in the archive file header,
 125   // immediately after the _header field. This information is used only when
 126   // checking the validity of the archive and is deallocated after the archive is loaded.
 127   //
 128   // Note that the _paths_misc_info does NOT include information for JAR files
 129   // that existed during dump time. Their information is stored in _shared_path_table.
 130   int _paths_misc_info_size;
 131 
 132   // The following is a table of all the class path entries that were used
 133   // during dumping. At run time, we require these files to exist and have the same
 134   // size/modification time, or else the archive will refuse to load.
 135   //
 136   // All of these entries must be JAR files. The dumping process would fail if a non-empty
 137   // directory was specified in the classpaths. If an empty directory was specified
 138   // it is checked by the _paths_misc_info as described above.
 139   //
 140   // FIXME -- if JAR files in the tail of the list were specified but not used during dumping,
 141   // they should be removed from this table, to save space and to avoid spurious
 142   // loading failures during runtime.
 143   int _shared_path_table_size;
 144   size_t _shared_path_entry_size;
 145   Array<u8>* _shared_path_table;
 146 
 147   jshort _app_class_paths_start_index;  // Index of first app classpath entry
 148   jshort _app_module_paths_start_index; // Index of first module path entry
 149   jshort _max_used_path_index;          // max path index referenced during CDS dump
 150   bool   _verify_local;                 // BytecodeVerificationLocal setting
 151   bool   _verify_remote;                // BytecodeVerificationRemote setting
 152   bool   _has_platform_or_app_classes;  // Archive contains app classes
 153 
 154   void set_has_platform_or_app_classes(bool v) {
 155     _has_platform_or_app_classes = v;
 156   }
 157   bool has_platform_or_app_classes() { return _has_platform_or_app_classes; }
 158   jshort max_used_path_index()       { return _max_used_path_index; }
 159   jshort app_module_paths_start_index() { return _app_module_paths_start_index; }
 160 
 161   bool validate();
 162   void populate(FileMapInfo* info, size_t alignment);
 163   int compute_crc();
 164 
 165   CDSFileMapRegion* space_at(int i) {
 166     assert(i >= 0 && i < NUM_CDS_REGIONS, "invalid region");
 167     return &_space[i];
 168   }
 169 };
 170 
 171 class FileMapInfo : public CHeapObj<mtInternal> {
 172 private:
 173   friend class ManifestStream;
 174   friend class VMStructs;
 175   friend struct FileMapHeader;
 176 
 177   bool    _file_open;
 178   int     _fd;
 179   size_t  _file_offset;
 180 
 181 private:
 182   static Array<u8>*            _shared_path_table;
 183   static int                   _shared_path_table_size;
 184   static size_t                _shared_path_entry_size;
 185   static bool                  _validating_shared_path_table;
 186 
 187   // FileMapHeader describes the shared space data in the file to be
 188   // mapped.  This structure gets written to a file.  It is not a class, so
 189   // that the compilers don't add any compiler-private data to it.
 190 
 191 public:
 192   struct FileMapHeaderBase : public CHeapObj<mtClass> {
 193     // Need to put something here. Otherwise, in product build, because CHeapObj has no virtual
 194     // methods, we would get sizeof(FileMapHeaderBase) == 1 with gcc.
 195     intx _dummy;
 196   };
 197 
 198 
 199   FileMapHeader * _header;
 200 
 201   const char* _full_path;
 202   char* _paths_misc_info;
 203 
 204   static FileMapInfo* _current_info;
 205   static bool _heap_pointers_need_patching;
 206 
 207   bool  init_from_file(int fd);
 208   void  align_file_position();
 209   bool  validate_header_impl();
 210   static void metaspace_pointers_do(MetaspaceClosure* it);
 211 
 212 public:
 213   FileMapInfo();
 214   ~FileMapInfo();
 215 
 216   int    compute_header_crc()         { return _header->compute_crc(); }
 217   void   set_header_crc(int crc)      { _header->_crc = crc; }
 218   void   populate_header(size_t alignment);
 219   bool   validate_header();
 220   void   invalidate();
 221   int    version()                    { return _header->_version; }
 222   size_t alignment()                  { return _header->_alignment; }
 223   Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; }
 224   address narrow_oop_base()    const  { return _header->_narrow_oop_base; }
 225   int     narrow_oop_shift()   const  { return _header->_narrow_oop_shift; }
 226   uintx   max_heap_size()      const  { return _header->_max_heap_size; }
 227   address narrow_klass_base()  const  { return _header->_narrow_klass_base; }
 228   int     narrow_klass_shift() const  { return _header->_narrow_klass_shift; }
 229   struct  FileMapHeader* header()     { return _header; }
 230   char*   misc_data_patching_start()          { return _header->_misc_data_patching_start; }
 231   void set_misc_data_patching_start(char* p)  { _header->_misc_data_patching_start = p; }
 232   char* read_only_tables_start()              { return _header->_read_only_tables_start; }
 233   void set_read_only_tables_start(char* p)    { _header->_read_only_tables_start = p; }
 234 
 235   address cds_i2i_entry_code_buffers() {
 236     return _header->_cds_i2i_entry_code_buffers;
 237   }
 238   void set_cds_i2i_entry_code_buffers(address addr) {
 239     _header->_cds_i2i_entry_code_buffers = addr;
 240   }
 241   size_t cds_i2i_entry_code_buffers_size() {
 242     return _header->_cds_i2i_entry_code_buffers_size;
 243   }
 244   void set_cds_i2i_entry_code_buffers_size(size_t s) {
 245     _header->_cds_i2i_entry_code_buffers_size = s;
 246   }
 247   void set_core_spaces_size(size_t s)    {  _header->_core_spaces_size = s; }
 248   size_t core_spaces_size()              { return _header->_core_spaces_size; }
 249 
 250   static FileMapInfo* current_info() {
 251     CDS_ONLY(return _current_info;)
 252     NOT_CDS(return NULL;)
 253   }
 254 
 255   static void assert_mark(bool check);
 256 
 257   // File manipulation.
 258   bool  initialize() NOT_CDS_RETURN_(false);
 259   bool  open_for_read();
 260   void  open_for_write();
 261   void  write_header();
 262   void  write_region(int region, char* base, size_t size,
 263                      bool read_only, bool allow_exec);
 264   size_t write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,
 265                                     GrowableArray<ArchiveHeapOopmapInfo> *oopmaps,
 266                                     int first_region_id, int max_num_regions);
 267   void  write_bytes(const void* buffer, size_t count);
 268   void  write_bytes_aligned(const void* buffer, size_t count);
 269   char* map_region(int i, char** top_ret);
 270   void  map_heap_regions_impl() NOT_CDS_JAVA_HEAP_RETURN;
 271   void  map_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;
 272   void  fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;
 273   void  patch_archived_heap_embedded_pointers() NOT_CDS_JAVA_HEAP_RETURN;
 274   void  patch_archived_heap_embedded_pointers(MemRegion* ranges, int num_ranges,
 275                                               int first_region_idx) NOT_CDS_JAVA_HEAP_RETURN;
 276   bool  has_heap_regions()  NOT_CDS_JAVA_HEAP_RETURN_(false);
 277   MemRegion get_heap_regions_range_with_current_oop_encoding_mode() NOT_CDS_JAVA_HEAP_RETURN_(MemRegion());
 278   void  unmap_region(int i);
 279   bool  verify_region_checksum(int i);
 280   void  close();
 281   bool  is_open() { return _file_open; }
 282   ReservedSpace reserve_shared_memory();
 283 
 284   // JVM/TI RedefineClasses() support:
 285   // Remap the shared readonly space to shared readwrite, private.
 286   bool  remap_shared_readonly_as_readwrite();
 287 
 288   // Errors.
 289   static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);
 290   static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);
 291 
 292   bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false);
 293 
 294   // Stop CDS sharing and unmap CDS regions.
 295   static void stop_sharing_and_unmap(const char* msg);
 296 
 297   static void allocate_shared_path_table();
 298   static void check_nonempty_dir_in_shared_path_table();
 299   bool validate_shared_path_table();
 300   static void update_shared_classpath(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS);
 301 
 302   static SharedClassPathEntry* shared_path(int index) {
 303     if (index < 0) {
 304       return NULL;
 305     }
 306     assert(index < _shared_path_table_size, "sanity");
 307     char* p = (char*)_shared_path_table->data();
 308     p += _shared_path_entry_size * index;
 309     return (SharedClassPathEntry*)p;
 310   }
 311 
 312   static const char* shared_path_name(int index) {
 313     assert(index >= 0, "Sanity");
 314     return shared_path(index)->name();
 315   }
 316 
 317   static int get_number_of_shared_paths() {
 318     return _shared_path_table_size;
 319   }
 320 
 321   char* region_addr(int idx);
 322 
 323  private:
 324   bool  map_heap_data(MemRegion **heap_mem, int first, int max, int* num,
 325                       bool is_open = false) NOT_CDS_JAVA_HEAP_RETURN_(false);
 326   bool  verify_mapped_heap_regions(int first, int num) NOT_CDS_JAVA_HEAP_RETURN_(false);
 327   void  dealloc_archive_heap_regions(MemRegion* regions, int num) NOT_CDS_JAVA_HEAP_RETURN;
 328 
 329   CDSFileMapRegion* space_at(int i) {
 330     return _header->space_at(i);
 331   }
 332 
 333   narrowOop offset_of_space(CDSFileMapRegion* spc) {
 334     return (narrowOop)(spc->_addr._offset);
 335   }
 336 
 337   // The starting address of spc, as calculated with CompressedOop::decode_non_null()
 338   address start_address_as_decoded_with_current_oop_encoding_mode(CDSFileMapRegion* spc) {
 339     return decode_start_address(spc, true);
 340   }
 341 
 342   // The starting address of spc, as calculated with HeapShared::decode_from_archive()
 343   address start_address_as_decoded_from_archive(CDSFileMapRegion* spc) {
 344     return decode_start_address(spc, false);
 345   }
 346 
 347   address decode_start_address(CDSFileMapRegion* spc, bool with_current_oop_encoding_mode);
 348 };
 349 
 350 #endif // SHARE_VM_MEMORY_FILEMAP_HPP