1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/filemap.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,522 @@
1.4 +/*
1.5 + * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_filemap.cpp.incl"
1.30 +# include <sys/stat.h>
1.31 +# include <errno.h>
1.32 +
1.33 +#ifndef O_BINARY // if defined (Win32) use binary files.
1.34 +#define O_BINARY 0 // otherwise do nothing.
1.35 +#endif
1.36 +
1.37 +
1.38 +extern address JVM_FunctionAtStart();
1.39 +extern address JVM_FunctionAtEnd();
1.40 +
1.41 +// Complain and stop. All error conditions occuring during the writing of
1.42 +// an archive file should stop the process. Unrecoverable errors during
1.43 +// the reading of the archive file should stop the process.
1.44 +
1.45 +static void fail(const char *msg, va_list ap) {
1.46 + // This occurs very early during initialization: tty is not initialized.
1.47 + jio_fprintf(defaultStream::error_stream(),
1.48 + "An error has occured while processing the"
1.49 + " shared archive file.\n");
1.50 + jio_vfprintf(defaultStream::error_stream(), msg, ap);
1.51 + jio_fprintf(defaultStream::error_stream(), "\n");
1.52 + vm_exit_during_initialization("Unable to use shared archive.", NULL);
1.53 +}
1.54 +
1.55 +
1.56 +void FileMapInfo::fail_stop(const char *msg, ...) {
1.57 + va_list ap;
1.58 + va_start(ap, msg);
1.59 + fail(msg, ap); // Never returns.
1.60 + va_end(ap); // for completeness.
1.61 +}
1.62 +
1.63 +
1.64 +// Complain and continue. Recoverable errors during the reading of the
1.65 +// archive file may continue (with sharing disabled).
1.66 +//
1.67 +// If we continue, then disable shared spaces and close the file.
1.68 +
1.69 +void FileMapInfo::fail_continue(const char *msg, ...) {
1.70 + va_list ap;
1.71 + va_start(ap, msg);
1.72 + if (RequireSharedSpaces) {
1.73 + fail(msg, ap);
1.74 + }
1.75 + va_end(ap);
1.76 + UseSharedSpaces = false;
1.77 + close();
1.78 +}
1.79 +
1.80 +
1.81 +// Fill in the fileMapInfo structure with data about this VM instance.
1.82 +
1.83 +void FileMapInfo::populate_header(size_t alignment) {
1.84 + _header._magic = 0xf00baba2;
1.85 + _header._version = _current_version;
1.86 + _header._alignment = alignment;
1.87 +
1.88 + // The following fields are for sanity checks for whether this archive
1.89 + // will function correctly with this JVM and the bootclasspath it's
1.90 + // invoked with.
1.91 +
1.92 + // JVM version string ... changes on each build.
1.93 + const char *vm_version = VM_Version::internal_vm_info_string();
1.94 + if (strlen(vm_version) < (JVM_IDENT_MAX-1)) {
1.95 + strcpy(_header._jvm_ident, vm_version);
1.96 + } else {
1.97 + fail_stop("JVM Ident field for shared archive is too long"
1.98 + " - truncated to <%s>", _header._jvm_ident);
1.99 + }
1.100 +
1.101 + // Build checks on classpath and jar files
1.102 + _header._num_jars = 0;
1.103 + ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
1.104 + for ( ; cpe != NULL; cpe = cpe->next()) {
1.105 +
1.106 + if (cpe->is_jar_file()) {
1.107 + if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
1.108 + fail_stop("Too many jar files to share.", NULL);
1.109 + }
1.110 +
1.111 + // Jar file - record timestamp and file size.
1.112 + struct stat st;
1.113 + const char *path = cpe->name();
1.114 + if (os::stat(path, &st) != 0) {
1.115 + // If we can't access a jar file in the boot path, then we can't
1.116 + // make assumptions about where classes get loaded from.
1.117 + fail_stop("Unable to open jar file %s.", path);
1.118 + }
1.119 + _header._jar[_header._num_jars]._timestamp = st.st_mtime;
1.120 + _header._jar[_header._num_jars]._filesize = st.st_size;
1.121 + _header._num_jars++;
1.122 + } else {
1.123 +
1.124 + // If directories appear in boot classpath, they must be empty to
1.125 + // avoid having to verify each individual class file.
1.126 + const char* name = ((ClassPathDirEntry*)cpe)->name();
1.127 + if (!os::dir_is_empty(name)) {
1.128 + fail_stop("Boot classpath directory %s is not empty.", name);
1.129 + }
1.130 + }
1.131 + }
1.132 +}
1.133 +
1.134 +
1.135 +// Read the FileMapInfo information from the file.
1.136 +
1.137 +bool FileMapInfo::init_from_file(int fd) {
1.138 +
1.139 + size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
1.140 + if (n != sizeof(struct FileMapHeader)) {
1.141 + fail_continue("Unable to read the file header.");
1.142 + return false;
1.143 + }
1.144 + if (_header._version != current_version()) {
1.145 + fail_continue("The shared archive file has the wrong version.");
1.146 + return false;
1.147 + }
1.148 + _file_offset = (long)n;
1.149 + return true;
1.150 +}
1.151 +
1.152 +
1.153 +// Read the FileMapInfo information from the file.
1.154 +bool FileMapInfo::open_for_read() {
1.155 + _full_path = Arguments::GetSharedArchivePath();
1.156 + int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
1.157 + if (fd < 0) {
1.158 + if (errno == ENOENT) {
1.159 + // Not locating the shared archive is ok.
1.160 + fail_continue("Specified shared archive not found.");
1.161 + } else {
1.162 + fail_continue("Failed to open shared archive file (%s).",
1.163 + strerror(errno));
1.164 + }
1.165 + return false;
1.166 + }
1.167 +
1.168 + _fd = fd;
1.169 + _file_open = true;
1.170 + return true;
1.171 +}
1.172 +
1.173 +
1.174 +// Write the FileMapInfo information to the file.
1.175 +
1.176 +void FileMapInfo::open_for_write() {
1.177 + _full_path = Arguments::GetSharedArchivePath();
1.178 + if (PrintSharedSpaces) {
1.179 + tty->print_cr("Dumping shared data to file: ");
1.180 + tty->print_cr(" %s", _full_path);
1.181 + }
1.182 +
1.183 + // Remove the existing file in case another process has it open.
1.184 + remove(_full_path);
1.185 + int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
1.186 + if (fd < 0) {
1.187 + fail_stop("Unable to create shared archive file %s.", _full_path);
1.188 + }
1.189 + _fd = fd;
1.190 + _file_offset = 0;
1.191 + _file_open = true;
1.192 +}
1.193 +
1.194 +
1.195 +// Write the header to the file, seek to the next allocation boundary.
1.196 +
1.197 +void FileMapInfo::write_header() {
1.198 + write_bytes_aligned(&_header, sizeof(FileMapHeader));
1.199 +}
1.200 +
1.201 +
1.202 +// Dump shared spaces to file.
1.203 +
1.204 +void FileMapInfo::write_space(int i, CompactibleSpace* space, bool read_only) {
1.205 + align_file_position();
1.206 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
1.207 + write_region(i, (char*)space->bottom(), space->used(),
1.208 + space->capacity(), read_only, false);
1.209 +}
1.210 +
1.211 +
1.212 +// Dump region to file.
1.213 +
1.214 +void FileMapInfo::write_region(int region, char* base, size_t size,
1.215 + size_t capacity, bool read_only,
1.216 + bool allow_exec) {
1.217 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
1.218 +
1.219 + if (_file_open) {
1.220 + guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
1.221 + if (PrintSharedSpaces) {
1.222 + tty->print_cr("Shared file region %d: 0x%x bytes, addr 0x%x,"
1.223 + " file offset 0x%x", region, size, base, _file_offset);
1.224 + }
1.225 + } else {
1.226 + si->_file_offset = _file_offset;
1.227 + }
1.228 + si->_base = base;
1.229 + si->_used = size;
1.230 + si->_capacity = capacity;
1.231 + si->_read_only = read_only;
1.232 + si->_allow_exec = allow_exec;
1.233 + write_bytes_aligned(base, (int)size);
1.234 +}
1.235 +
1.236 +
1.237 +// Dump bytes to file -- at the current file position.
1.238 +
1.239 +void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
1.240 + if (_file_open) {
1.241 + int n = ::write(_fd, buffer, nbytes);
1.242 + if (n != nbytes) {
1.243 + // It is dangerous to leave the corrupted shared archive file around,
1.244 + // close and remove the file. See bug 6372906.
1.245 + close();
1.246 + remove(_full_path);
1.247 + fail_stop("Unable to write to shared archive file.", NULL);
1.248 + }
1.249 + }
1.250 + _file_offset += nbytes;
1.251 +}
1.252 +
1.253 +
1.254 +// Align file position to an allocation unit boundary.
1.255 +
1.256 +void FileMapInfo::align_file_position() {
1.257 + long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity());
1.258 + if (new_file_offset != _file_offset) {
1.259 + _file_offset = new_file_offset;
1.260 + if (_file_open) {
1.261 + // Seek one byte back from the target and write a byte to insure
1.262 + // that the written file is the correct length.
1.263 + _file_offset -= 1;
1.264 + if (lseek(_fd, _file_offset, SEEK_SET) < 0) {
1.265 + fail_stop("Unable to seek.", NULL);
1.266 + }
1.267 + char zero = 0;
1.268 + write_bytes(&zero, 1);
1.269 + }
1.270 + }
1.271 +}
1.272 +
1.273 +
1.274 +// Dump bytes to file -- at the current file position.
1.275 +
1.276 +void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
1.277 + align_file_position();
1.278 + write_bytes(buffer, nbytes);
1.279 + align_file_position();
1.280 +}
1.281 +
1.282 +
1.283 +// Close the shared archive file. This does NOT unmap mapped regions.
1.284 +
1.285 +void FileMapInfo::close() {
1.286 + if (_file_open) {
1.287 + if (::close(_fd) < 0) {
1.288 + fail_stop("Unable to close the shared archive file.");
1.289 + }
1.290 + _file_open = false;
1.291 + _fd = -1;
1.292 + }
1.293 +}
1.294 +
1.295 +
1.296 +// Memory map a shared space from the archive file.
1.297 +
1.298 +bool FileMapInfo::map_space(int i, ReservedSpace rs, ContiguousSpace* space) {
1.299 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
1.300 + if (space != NULL) {
1.301 + if (si->_base != (char*)space->bottom() ||
1.302 + si->_capacity != space->capacity()) {
1.303 + fail_continue("Shared space base address does not match.");
1.304 + return false;
1.305 + }
1.306 + }
1.307 + bool result = (map_region(i, rs) != NULL);
1.308 + if (space != NULL && result) {
1.309 + space->set_top((HeapWord*)(si->_base + si->_used));
1.310 + space->set_saved_mark();
1.311 + }
1.312 + return result;
1.313 +}
1.314 +
1.315 +
1.316 +// JVM/TI RedefineClasses() support:
1.317 +// Remap the shared readonly space to shared readwrite, private.
1.318 +bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1.319 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
1.320 + if (!si->_read_only) {
1.321 + // the space is already readwrite so we are done
1.322 + return true;
1.323 + }
1.324 + size_t used = si->_used;
1.325 + size_t size = align_size_up(used, os::vm_allocation_granularity());
1.326 + if (!open_for_read()) {
1.327 + return false;
1.328 + }
1.329 + char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
1.330 + si->_base, size, false /* !read_only */,
1.331 + si->_allow_exec);
1.332 + close();
1.333 + if (base == NULL) {
1.334 + fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
1.335 + return false;
1.336 + }
1.337 + if (base != si->_base) {
1.338 + fail_continue("Unable to remap shared readonly space at required address.");
1.339 + return false;
1.340 + }
1.341 + si->_read_only = false;
1.342 + return true;
1.343 +}
1.344 +
1.345 +
1.346 +// Memory map a region in the address space.
1.347 +
1.348 +char* FileMapInfo::map_region(int i, ReservedSpace rs) {
1.349 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
1.350 + size_t used = si->_used;
1.351 + size_t size = align_size_up(used, os::vm_allocation_granularity());
1.352 +
1.353 + ReservedSpace mapped_rs = rs.first_part(size, true, true);
1.354 + ReservedSpace unmapped_rs = rs.last_part(size);
1.355 + mapped_rs.release();
1.356 +
1.357 + return map_region(i, true);
1.358 +}
1.359 +
1.360 +
1.361 +// Memory map a region in the address space.
1.362 +
1.363 +char* FileMapInfo::map_region(int i, bool address_must_match) {
1.364 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
1.365 + size_t used = si->_used;
1.366 + size_t size = align_size_up(used, os::vm_allocation_granularity());
1.367 + char *requested_addr = 0;
1.368 + if (address_must_match) {
1.369 + requested_addr = si->_base;
1.370 + }
1.371 + char *base = os::map_memory(_fd, _full_path, si->_file_offset,
1.372 + requested_addr, size, si->_read_only,
1.373 + si->_allow_exec);
1.374 + if (base == NULL) {
1.375 + fail_continue("Unable to map shared space.");
1.376 + return NULL;
1.377 + }
1.378 + if (address_must_match) {
1.379 + if (base != si->_base) {
1.380 + fail_continue("Unable to map shared space at required address.");
1.381 + return NULL;
1.382 + }
1.383 + } else {
1.384 + si->_base = base; // save mapped address for unmapping.
1.385 + }
1.386 + return base;
1.387 +}
1.388 +
1.389 +
1.390 +// Unmap a memory region in the address space.
1.391 +
1.392 +void FileMapInfo::unmap_region(int i) {
1.393 + struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
1.394 + size_t used = si->_used;
1.395 + size_t size = align_size_up(used, os::vm_allocation_granularity());
1.396 + if (!os::unmap_memory(si->_base, size)) {
1.397 + fail_stop("Unable to unmap shared space.");
1.398 + }
1.399 +}
1.400 +
1.401 +
1.402 +void FileMapInfo::assert_mark(bool check) {
1.403 + if (!check) {
1.404 + fail_stop("Mark mismatch while restoring from shared file.", NULL);
1.405 + }
1.406 +}
1.407 +
1.408 +
1.409 +FileMapInfo* FileMapInfo::_current_info = NULL;
1.410 +
1.411 +
1.412 +// Open the shared archive file, read and validate the header
1.413 +// information (version, boot classpath, etc.). If initialization
1.414 +// fails, shared spaces are disabled and the file is closed. [See
1.415 +// fail_continue.]
1.416 +
1.417 +
1.418 +bool FileMapInfo::initialize() {
1.419 + assert(UseSharedSpaces, "UseSharedSpaces expected.");
1.420 +
1.421 + if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
1.422 + fail_continue("Tool agent requires sharing to be disabled.");
1.423 + return false;
1.424 + }
1.425 +
1.426 + if (!open_for_read()) {
1.427 + return false;
1.428 + }
1.429 +
1.430 + init_from_file(_fd);
1.431 + if (!validate()) {
1.432 + return false;
1.433 + }
1.434 +
1.435 + SharedReadOnlySize = _header._space[0]._capacity;
1.436 + SharedReadWriteSize = _header._space[1]._capacity;
1.437 + SharedMiscDataSize = _header._space[2]._capacity;
1.438 + SharedMiscCodeSize = _header._space[3]._capacity;
1.439 + return true;
1.440 +}
1.441 +
1.442 +
1.443 +bool FileMapInfo::validate() {
1.444 + if (_header._version != current_version()) {
1.445 + fail_continue("The shared archive file is the wrong version.");
1.446 + return false;
1.447 + }
1.448 + if (_header._magic != (int)0xf00baba2) {
1.449 + fail_continue("The shared archive file has a bad magic number.");
1.450 + return false;
1.451 + }
1.452 + if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(),
1.453 + JVM_IDENT_MAX-1) != 0) {
1.454 + fail_continue("The shared archive file was created by a different"
1.455 + " version or build of HotSpot.");
1.456 + return false;
1.457 + }
1.458 +
1.459 + // Cannot verify interpreter yet, as it can only be created after the GC
1.460 + // heap has been initialized.
1.461 +
1.462 + if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
1.463 + fail_continue("Too many jar files to share.");
1.464 + return false;
1.465 + }
1.466 +
1.467 + // Build checks on classpath and jar files
1.468 + int num_jars_now = 0;
1.469 + ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
1.470 + for ( ; cpe != NULL; cpe = cpe->next()) {
1.471 +
1.472 + if (cpe->is_jar_file()) {
1.473 + if (num_jars_now < _header._num_jars) {
1.474 +
1.475 + // Jar file - verify timestamp and file size.
1.476 + struct stat st;
1.477 + const char *path = cpe->name();
1.478 + if (os::stat(path, &st) != 0) {
1.479 + fail_continue("Unable to open jar file %s.", path);
1.480 + return false;
1.481 + }
1.482 + if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
1.483 + _header._jar[num_jars_now]._filesize != st.st_size) {
1.484 + fail_continue("A jar file is not the one used while building"
1.485 + " the shared archive file.");
1.486 + return false;
1.487 + }
1.488 + }
1.489 + ++num_jars_now;
1.490 + } else {
1.491 +
1.492 + // If directories appear in boot classpath, they must be empty to
1.493 + // avoid having to verify each individual class file.
1.494 + const char* name = ((ClassPathDirEntry*)cpe)->name();
1.495 + if (!os::dir_is_empty(name)) {
1.496 + fail_continue("Boot classpath directory %s is not empty.", name);
1.497 + return false;
1.498 + }
1.499 + }
1.500 + }
1.501 + if (num_jars_now < _header._num_jars) {
1.502 + fail_continue("The number of jar files in the boot classpath is"
1.503 + " less than the number the shared archive was created with.");
1.504 + return false;
1.505 + }
1.506 +
1.507 + return true;
1.508 +}
1.509 +
1.510 +// The following method is provided to see whether a given pointer
1.511 +// falls in the mapped shared space.
1.512 +// Param:
1.513 +// p, The given pointer
1.514 +// Return:
1.515 +// True if the p is within the mapped shared space, otherwise, false.
1.516 +bool FileMapInfo::is_in_shared_space(const void* p) {
1.517 + for (int i = 0; i < CompactingPermGenGen::n_regions; i++) {
1.518 + if (p >= _header._space[i]._base &&
1.519 + p < _header._space[i]._base + _header._space[i]._used) {
1.520 + return true;
1.521 + }
1.522 + }
1.523 +
1.524 + return false;
1.525 +}
