filemap.cpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 2003, 2012, 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/symbolTable.hpp" 28#include "memory/filemap.hpp" 29#include "runtime/arguments.hpp" 30#include "runtime/java.hpp" 31#include "runtime/os.hpp" 32#include "utilities/defaultStream.hpp" 33 34# include <sys/stat.h> 35# include <errno.h> 36 37#ifndef O_BINARY // if defined (Win32) use binary files. 38#define O_BINARY 0 // otherwise do nothing. 39#endif 40 41 42extern address JVM_FunctionAtStart(); 43extern address JVM_FunctionAtEnd(); 44 45// Complain and stop. All error conditions occurring during the writing of 46// an archive file should stop the process. Unrecoverable errors during 47// the reading of the archive file should stop the process. 48 49static void fail(const char *msg, va_list ap) { 50 // This occurs very early during initialization: tty is not initialized. 51 jio_fprintf(defaultStream::error_stream(), 52 "An error has occurred while processing the" 53 " shared archive file.\n"); 54 jio_vfprintf(defaultStream::error_stream(), msg, ap); 55 jio_fprintf(defaultStream::error_stream(), "\n"); 56 vm_exit_during_initialization("Unable to use shared archive.", NULL); 57} 58 59 60void FileMapInfo::fail_stop(const char *msg, ...) { 61 va_list ap; 62 va_start(ap, msg); 63 fail(msg, ap); // Never returns. 64 va_end(ap); // for completeness. 65} 66 67 68// Complain and continue. Recoverable errors during the reading of the 69// archive file may continue (with sharing disabled). 70// 71// If we continue, then disable shared spaces and close the file. 72 73void FileMapInfo::fail_continue(const char *msg, ...) { 74 va_list ap; 75 va_start(ap, msg); 76 if (RequireSharedSpaces) { 77 fail(msg, ap); 78 } 79 va_end(ap); 80 UseSharedSpaces = false; 81 close(); 82} 83 84 85// Fill in the fileMapInfo structure with data about this VM instance. 86 87void FileMapInfo::populate_header(size_t alignment) { 88 _header._magic = 0xf00baba2; 89 _header._version = _current_version; 90 _header._alignment = alignment; 91 92 // The following fields are for sanity checks for whether this archive 93 // will function correctly with this JVM and the bootclasspath it's 94 // invoked with. 95 96 // JVM version string ... changes on each build. 97 const char *vm_version = VM_Version::internal_vm_info_string(); 98 if (strlen(vm_version) < (JVM_IDENT_MAX-1)) { 99 strcpy(_header._jvm_ident, vm_version); 100 } else { 101 fail_stop("JVM Ident field for shared archive is too long" 102 " - truncated to <%s>", _header._jvm_ident); 103 } 104 105 // Build checks on classpath and jar files 106 _header._num_jars = 0; 107 ClassPathEntry *cpe = ClassLoader::classpath_entry(0); 108 for ( ; cpe != NULL; cpe = cpe->next()) { 109 110 if (cpe->is_jar_file()) { 111 if (_header._num_jars >= JVM_SHARED_JARS_MAX) { 112 fail_stop("Too many jar files to share.", NULL); 113 } 114 115 // Jar file - record timestamp and file size. 116 struct stat st; 117 const char *path = cpe->name(); 118 if (os::stat(path, &st) != 0) { 119 // If we can't access a jar file in the boot path, then we can't 120 // make assumptions about where classes get loaded from. 121 fail_stop("Unable to open jar file %s.", path); 122 } 123 _header._jar[_header._num_jars]._timestamp = st.st_mtime; 124 _header._jar[_header._num_jars]._filesize = st.st_size; 125 _header._num_jars++; 126 } else { 127 128 // If directories appear in boot classpath, they must be empty to 129 // avoid having to verify each individual class file. 130 const char* name = ((ClassPathDirEntry*)cpe)->name(); 131 if (!os::dir_is_empty(name)) { 132 fail_stop("Boot classpath directory %s is not empty.", name); 133 } 134 } 135 } 136} 137 138 139// Read the FileMapInfo information from the file. 140 141bool FileMapInfo::init_from_file(int fd) { 142 143 size_t n = read(fd, &_header, sizeof(struct FileMapHeader)); 144 if (n != sizeof(struct FileMapHeader)) { 145 fail_continue("Unable to read the file header."); 146 return false; 147 } 148 if (_header._version != current_version()) { 149 fail_continue("The shared archive file has the wrong version."); 150 return false; 151 } 152 _file_offset = (long)n; 153 return true; 154} 155 156 157// Read the FileMapInfo information from the file. 158bool FileMapInfo::open_for_read() { 159 _full_path = Arguments::GetSharedArchivePath(); 160 int fd = open(_full_path, O_RDONLY | O_BINARY, 0); 161 if (fd < 0) { 162 if (errno == ENOENT) { 163 // Not locating the shared archive is ok. 164 fail_continue("Specified shared archive not found."); 165 } else { 166 fail_continue("Failed to open shared archive file (%s).", 167 strerror(errno)); 168 } 169 return false; 170 } 171 172 _fd = fd; 173 _file_open = true; 174 return true; 175} 176 177 178// Write the FileMapInfo information to the file. 179 180void FileMapInfo::open_for_write() { 181 _full_path = Arguments::GetSharedArchivePath(); 182 if (PrintSharedSpaces) { 183 tty->print_cr("Dumping shared data to file: "); 184 tty->print_cr(" %s", _full_path); 185 } 186 187 // Remove the existing file in case another process has it open. 188 remove(_full_path); 189 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444); 190 if (fd < 0) { 191 fail_stop("Unable to create shared archive file %s.", _full_path); 192 } 193 _fd = fd; 194 _file_offset = 0; 195 _file_open = true; 196} 197 198 199// Write the header to the file, seek to the next allocation boundary. 200 201void FileMapInfo::write_header() { 202 write_bytes_aligned(&_header, sizeof(FileMapHeader)); 203} 204 205 206// Dump shared spaces to file. 207 208void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) { 209 align_file_position(); 210 size_t used = space->used_words(Metaspace::NonClassType) * BytesPerWord; 211 size_t capacity = space->capacity_words(Metaspace::NonClassType) * BytesPerWord; 212 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i]; 213 write_region(i, (char*)space->bottom(), used, capacity, read_only, false); 214} 215 216 217// Dump region to file. 218 219void FileMapInfo::write_region(int region, char* base, size_t size, 220 size_t capacity, bool read_only, 221 bool allow_exec) { 222 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region]; 223 224 if (_file_open) { 225 guarantee(si->_file_offset == _file_offset, "file offset mismatch."); 226 if (PrintSharedSpaces) { 227 tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT 228 " file offset 0x%6x", region, size, base, _file_offset); 229 } 230 } else { 231 si->_file_offset = _file_offset; 232 } 233 si->_base = base; 234 si->_used = size; 235 si->_capacity = capacity; 236 si->_read_only = read_only; 237 si->_allow_exec = allow_exec; 238 write_bytes_aligned(base, (int)size); 239} 240 241 242// Dump bytes to file -- at the current file position. 243 244void FileMapInfo::write_bytes(const void* buffer, int nbytes) { 245 if (_file_open) { 246 int n = ::write(_fd, buffer, nbytes); 247 if (n != nbytes) { 248 // It is dangerous to leave the corrupted shared archive file around, 249 // close and remove the file. See bug 6372906. 250 close(); 251 remove(_full_path); 252 fail_stop("Unable to write to shared archive file.", NULL); 253 } 254 } 255 _file_offset += nbytes; 256} 257 258 259// Align file position to an allocation unit boundary. 260 261void FileMapInfo::align_file_position() { 262 long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity()); 263 if (new_file_offset != _file_offset) { 264 _file_offset = new_file_offset; 265 if (_file_open) { 266 // Seek one byte back from the target and write a byte to insure 267 // that the written file is the correct length. 268 _file_offset -= 1; 269 if (lseek(_fd, _file_offset, SEEK_SET) < 0) { 270 fail_stop("Unable to seek.", NULL); 271 } 272 char zero = 0; 273 write_bytes(&zero, 1); 274 } 275 } 276} 277 278 279// Dump bytes to file -- at the current file position. 280 281void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) { 282 align_file_position(); 283 write_bytes(buffer, nbytes); 284 align_file_position(); 285} 286 287 288// Close the shared archive file. This does NOT unmap mapped regions. 289 290void FileMapInfo::close() { 291 if (_file_open) { 292 if (::close(_fd) < 0) { 293 fail_stop("Unable to close the shared archive file."); 294 } 295 _file_open = false; 296 _fd = -1; 297 } 298} 299 300 301// JVM/TI RedefineClasses() support: 302// Remap the shared readonly space to shared readwrite, private. 303bool FileMapInfo::remap_shared_readonly_as_readwrite() { 304 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0]; 305 if (!si->_read_only) { 306 // the space is already readwrite so we are done 307 return true; 308 } 309 size_t used = si->_used; 310 size_t size = align_size_up(used, os::vm_allocation_granularity()); 311 if (!open_for_read()) { 312 return false; 313 } 314 char *base = os::remap_memory(_fd, _full_path, si->_file_offset, 315 si->_base, size, false /* !read_only */, 316 si->_allow_exec); 317 close(); 318 if (base == NULL) { 319 fail_continue("Unable to remap shared readonly space (errno=%d).", errno); 320 return false; 321 } 322 if (base != si->_base) { 323 fail_continue("Unable to remap shared readonly space at required address."); 324 return false; 325 } 326 si->_read_only = false; 327 return true; 328} 329 330// Map the whole region at once, assumed to be allocated contiguously. 331ReservedSpace FileMapInfo::reserve_shared_memory() { 332 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0]; 333 char* requested_addr = si->_base; 334 size_t alignment = os::vm_allocation_granularity(); 335 336 size_t size = align_size_up(SharedReadOnlySize + SharedReadWriteSize + 337 SharedMiscDataSize + SharedMiscCodeSize, 338 alignment); 339 340 // Reserve the space first, then map otherwise map will go right over some 341 // other reserved memory (like the code cache). 342 ReservedSpace rs(size, alignment, false, requested_addr); 343 if (!rs.is_reserved()) { 344 fail_continue(err_msg("Unable to reserved shared space at required address " INTPTR_FORMAT, requested_addr)); 345 return rs; 346 } 347 return rs; 348} 349 350// Memory map a region in the address space. 351 352char* FileMapInfo::map_region(int i, ReservedSpace rs) { 353 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i]; 354 size_t used = si->_used; 355 size_t size = align_size_up(used, os::vm_allocation_granularity()); 356 357 ReservedSpace mapped_rs = rs.first_part(size, true, true); 358 ReservedSpace unmapped_rs = rs.last_part(size); 359 mapped_rs.release(); 360 361 return map_region(i); 362} 363 364 365// Memory map a region in the address space. 366static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode"}; 367 368char* FileMapInfo::map_region(int i) { 369 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i]; 370 size_t used = si->_used; 371 size_t alignment = os::vm_allocation_granularity(); 372 size_t size = align_size_up(used, alignment); 373 char *requested_addr = si->_base; 374 375 // map the contents of the CDS archive in this memory 376 char *base = os::map_memory(_fd, _full_path, si->_file_offset, 377 requested_addr, size, si->_read_only, 378 si->_allow_exec); 379 if (base == NULL || base != si->_base) { 380 fail_continue(err_msg("Unable to map %s shared space at required address.", shared_region_name[i])); 381 return NULL; 382 } 383 return base; 384} 385 386 387// Unmap a memory region in the address space. 388 389void FileMapInfo::unmap_region(int i) { 390 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i]; 391 size_t used = si->_used; 392 size_t size = align_size_up(used, os::vm_allocation_granularity()); 393 if (!os::unmap_memory(si->_base, size)) { 394 fail_stop("Unable to unmap shared space."); 395 } 396} 397 398 399void FileMapInfo::assert_mark(bool check) { 400 if (!check) { 401 fail_stop("Mark mismatch while restoring from shared file.", NULL); 402 } 403} 404 405 406FileMapInfo* FileMapInfo::_current_info = NULL; 407 408 409// Open the shared archive file, read and validate the header 410// information (version, boot classpath, etc.). If initialization 411// fails, shared spaces are disabled and the file is closed. [See 412// fail_continue.] 413bool FileMapInfo::initialize() { 414 assert(UseSharedSpaces, "UseSharedSpaces expected."); 415 416 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) { 417 fail_continue("Tool agent requires sharing to be disabled."); 418 return false; 419 } 420 421 if (!open_for_read()) { 422 return false; 423 } 424 425 init_from_file(_fd); 426 if (!validate()) { 427 return false; 428 } 429 430 SharedReadOnlySize = _header._space[0]._capacity; 431 SharedReadWriteSize = _header._space[1]._capacity; 432 SharedMiscDataSize = _header._space[2]._capacity; 433 SharedMiscCodeSize = _header._space[3]._capacity; 434 return true; 435} 436 437 438bool FileMapInfo::validate() { 439 if (_header._version != current_version()) { 440 fail_continue("The shared archive file is the wrong version."); 441 return false; 442 } 443 if (_header._magic != (int)0xf00baba2) { 444 fail_continue("The shared archive file has a bad magic number."); 445 return false; 446 } 447 if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(), 448 JVM_IDENT_MAX-1) != 0) { 449 fail_continue("The shared archive file was created by a different" 450 " version or build of HotSpot."); 451 return false; 452 } 453 454 // Cannot verify interpreter yet, as it can only be created after the GC 455 // heap has been initialized. 456 457 if (_header._num_jars >= JVM_SHARED_JARS_MAX) { 458 fail_continue("Too many jar files to share."); 459 return false; 460 } 461 462 // Build checks on classpath and jar files 463 int num_jars_now = 0; 464 ClassPathEntry *cpe = ClassLoader::classpath_entry(0); 465 for ( ; cpe != NULL; cpe = cpe->next()) { 466 467 if (cpe->is_jar_file()) { 468 if (num_jars_now < _header._num_jars) { 469 470 // Jar file - verify timestamp and file size. 471 struct stat st; 472 const char *path = cpe->name(); 473 if (os::stat(path, &st) != 0) { 474 fail_continue("Unable to open jar file %s.", path); 475 return false; 476 } 477 if (_header._jar[num_jars_now]._timestamp != st.st_mtime || 478 _header._jar[num_jars_now]._filesize != st.st_size) { 479 fail_continue("A jar file is not the one used while building" 480 " the shared archive file."); 481 return false; 482 } 483 } 484 ++num_jars_now; 485 } else { 486 487 // If directories appear in boot classpath, they must be empty to 488 // avoid having to verify each individual class file. 489 const char* name = ((ClassPathDirEntry*)cpe)->name(); 490 if (!os::dir_is_empty(name)) { 491 fail_continue("Boot classpath directory %s is not empty.", name); 492 return false; 493 } 494 } 495 } 496 if (num_jars_now < _header._num_jars) { 497 fail_continue("The number of jar files in the boot classpath is" 498 " less than the number the shared archive was created with."); 499 return false; 500 } 501 502 return true; 503} 504 505// The following method is provided to see whether a given pointer 506// falls in the mapped shared space. 507// Param: 508// p, The given pointer 509// Return: 510// True if the p is within the mapped shared space, otherwise, false. 511bool FileMapInfo::is_in_shared_space(const void* p) { 512 for (int i = 0; i < MetaspaceShared::n_regions; i++) { 513 if (p >= _header._space[i]._base && 514 p < _header._space[i]._base + _header._space[i]._used) { 515 return true; 516 } 517 } 518 519 return false; 520} 521