1 /*
2 * Copyright (c) 2003, 2010, 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 #ifdef TARGET_OS_FAMILY_linux
34 # include "hpi_linux.hpp"
35 #endif
36 #ifdef TARGET_OS_FAMILY_solaris
37 # include "hpi_solaris.hpp"
38 #endif
39 #ifdef TARGET_OS_FAMILY_windows
40 # include "hpi_windows.hpp"
41 #endif
42
43 # include <sys/stat.h>
44 # include <errno.h>
45
46 #ifndef O_BINARY // if defined (Win32) use binary files.
47 #define O_BINARY 0 // otherwise do nothing.
48 #endif
49
50
51 extern address JVM_FunctionAtStart();
52 extern address JVM_FunctionAtEnd();
53
54 // Complain and stop. All error conditions occurring during the writing of
55 // an archive file should stop the process. Unrecoverable errors during
56 // the reading of the archive file should stop the process.
57
58 static void fail(const char *msg, va_list ap) {
59 // This occurs very early during initialization: tty is not initialized.
60 jio_fprintf(defaultStream::error_stream(),
61 "An error has occurred while processing the"
62 " shared archive file.\n");
63 jio_vfprintf(defaultStream::error_stream(), msg, ap);
64 jio_fprintf(defaultStream::error_stream(), "\n");
65 vm_exit_during_initialization("Unable to use shared archive.", NULL);
66 }
67
68
69 void FileMapInfo::fail_stop(const char *msg, ...) {
70 va_list ap;
71 va_start(ap, msg);
72 fail(msg, ap); // Never returns.
73 va_end(ap); // for completeness.
74 }
75
76
77 // Complain and continue. Recoverable errors during the reading of the
78 // archive file may continue (with sharing disabled).
79 //
80 // If we continue, then disable shared spaces and close the file.
81
82 void FileMapInfo::fail_continue(const char *msg, ...) {
83 va_list ap;
84 va_start(ap, msg);
85 if (RequireSharedSpaces) {
86 fail(msg, ap);
87 }
88 va_end(ap);
89 UseSharedSpaces = false;
90 close();
91 }
92
93
94 // Fill in the fileMapInfo structure with data about this VM instance.
95
96 void FileMapInfo::populate_header(size_t alignment) {
97 _header._magic = 0xf00baba2;
98 _header._version = _current_version;
99 _header._alignment = alignment;
100
101 // The following fields are for sanity checks for whether this archive
102 // will function correctly with this JVM and the bootclasspath it's
103 // invoked with.
104
105 // JVM version string ... changes on each build.
106 const char *vm_version = VM_Version::internal_vm_info_string();
107 if (strlen(vm_version) < (JVM_IDENT_MAX-1)) {
108 strcpy(_header._jvm_ident, vm_version);
109 } else {
110 fail_stop("JVM Ident field for shared archive is too long"
111 " - truncated to <%s>", _header._jvm_ident);
112 }
113
114 // Build checks on classpath and jar files
115 _header._num_jars = 0;
116 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
117 for ( ; cpe != NULL; cpe = cpe->next()) {
118
119 if (cpe->is_jar_file()) {
120 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
121 fail_stop("Too many jar files to share.", NULL);
122 }
123
124 // Jar file - record timestamp and file size.
125 struct stat st;
126 const char *path = cpe->name();
127 if (os::stat(path, &st) != 0) {
128 // If we can't access a jar file in the boot path, then we can't
129 // make assumptions about where classes get loaded from.
130 fail_stop("Unable to open jar file %s.", path);
131 }
132 _header._jar[_header._num_jars]._timestamp = st.st_mtime;
133 _header._jar[_header._num_jars]._filesize = st.st_size;
134 _header._num_jars++;
135 } else {
136
137 // If directories appear in boot classpath, they must be empty to
138 // avoid having to verify each individual class file.
139 const char* name = ((ClassPathDirEntry*)cpe)->name();
140 if (!os::dir_is_empty(name)) {
141 fail_stop("Boot classpath directory %s is not empty.", name);
142 }
143 }
144 }
145 }
146
147
148 // Read the FileMapInfo information from the file.
149
150 bool FileMapInfo::init_from_file(int fd) {
151
152 size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
153 if (n != sizeof(struct FileMapHeader)) {
154 fail_continue("Unable to read the file header.");
155 return false;
156 }
157 if (_header._version != current_version()) {
158 fail_continue("The shared archive file has the wrong version.");
159 return false;
160 }
161 _file_offset = (long)n;
162 return true;
163 }
164
165
166 // Read the FileMapInfo information from the file.
167 bool FileMapInfo::open_for_read() {
168 _full_path = Arguments::GetSharedArchivePath();
169 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
170 if (fd < 0) {
171 if (errno == ENOENT) {
172 // Not locating the shared archive is ok.
173 fail_continue("Specified shared archive not found.");
174 } else {
175 fail_continue("Failed to open shared archive file (%s).",
176 strerror(errno));
177 }
178 return false;
179 }
180
181 _fd = fd;
182 _file_open = true;
183 return true;
184 }
185
186
187 // Write the FileMapInfo information to the file.
188
189 void FileMapInfo::open_for_write() {
190 _full_path = Arguments::GetSharedArchivePath();
191 if (PrintSharedSpaces) {
192 tty->print_cr("Dumping shared data to file: ");
193 tty->print_cr(" %s", _full_path);
194 }
195
196 // Remove the existing file in case another process has it open.
197 remove(_full_path);
198 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
199 if (fd < 0) {
200 fail_stop("Unable to create shared archive file %s.", _full_path);
201 }
202 _fd = fd;
203 _file_offset = 0;
204 _file_open = true;
205 }
206
207
208 // Write the header to the file, seek to the next allocation boundary.
209
210 void FileMapInfo::write_header() {
211 write_bytes_aligned(&_header, sizeof(FileMapHeader));
212 }
213
214
215 // Dump shared spaces to file.
216
217 void FileMapInfo::write_space(int i, CompactibleSpace* space, bool read_only) {
218 align_file_position();
219 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
220 write_region(i, (char*)space->bottom(), space->used(),
221 space->capacity(), read_only, false);
222 }
223
224
225 // Dump region to file.
226
227 void FileMapInfo::write_region(int region, char* base, size_t size,
228 size_t capacity, bool read_only,
229 bool allow_exec) {
230 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
231
232 if (_file_open) {
233 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
234 if (PrintSharedSpaces) {
235 tty->print_cr("Shared file region %d: 0x%x bytes, addr 0x%x,"
236 " file offset 0x%x", region, size, base, _file_offset);
237 }
238 } else {
239 si->_file_offset = _file_offset;
240 }
241 si->_base = base;
242 si->_used = size;
243 si->_capacity = capacity;
244 si->_read_only = read_only;
245 si->_allow_exec = allow_exec;
246 write_bytes_aligned(base, (int)size);
247 }
248
249
250 // Dump bytes to file -- at the current file position.
251
252 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
253 if (_file_open) {
254 int n = ::write(_fd, buffer, nbytes);
255 if (n != nbytes) {
256 // It is dangerous to leave the corrupted shared archive file around,
257 // close and remove the file. See bug 6372906.
258 close();
259 remove(_full_path);
260 fail_stop("Unable to write to shared archive file.", NULL);
261 }
262 }
263 _file_offset += nbytes;
264 }
265
266
267 // Align file position to an allocation unit boundary.
268
269 void FileMapInfo::align_file_position() {
270 long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity());
271 if (new_file_offset != _file_offset) {
272 _file_offset = new_file_offset;
273 if (_file_open) {
274 // Seek one byte back from the target and write a byte to insure
275 // that the written file is the correct length.
276 _file_offset -= 1;
277 if (lseek(_fd, _file_offset, SEEK_SET) < 0) {
278 fail_stop("Unable to seek.", NULL);
279 }
280 char zero = 0;
281 write_bytes(&zero, 1);
282 }
283 }
284 }
285
286
287 // Dump bytes to file -- at the current file position.
288
289 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
290 align_file_position();
291 write_bytes(buffer, nbytes);
292 align_file_position();
293 }
294
295
296 // Close the shared archive file. This does NOT unmap mapped regions.
297
298 void FileMapInfo::close() {
299 if (_file_open) {
300 if (::close(_fd) < 0) {
301 fail_stop("Unable to close the shared archive file.");
302 }
303 _file_open = false;
304 _fd = -1;
305 }
306 }
307
308
309 // Memory map a shared space from the archive file.
310
311 bool FileMapInfo::map_space(int i, ReservedSpace rs, ContiguousSpace* space) {
312 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
313 if (space != NULL) {
314 if (si->_base != (char*)space->bottom() ||
315 si->_capacity != space->capacity()) {
316 fail_continue("Shared space base address does not match.");
317 return false;
318 }
319 }
320 bool result = (map_region(i, rs) != NULL);
321 if (space != NULL && result) {
322 space->set_top((HeapWord*)(si->_base + si->_used));
323 space->set_saved_mark();
324 }
325 return result;
326 }
327
328
329 // JVM/TI RedefineClasses() support:
330 // Remap the shared readonly space to shared readwrite, private.
331 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
332 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
333 if (!si->_read_only) {
334 // the space is already readwrite so we are done
335 return true;
336 }
337 size_t used = si->_used;
338 size_t size = align_size_up(used, os::vm_allocation_granularity());
339 if (!open_for_read()) {
340 return false;
341 }
342 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
343 si->_base, size, false /* !read_only */,
344 si->_allow_exec);
345 close();
346 if (base == NULL) {
347 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
348 return false;
349 }
350 if (base != si->_base) {
351 fail_continue("Unable to remap shared readonly space at required address.");
352 return false;
353 }
354 si->_read_only = false;
355 return true;
356 }
357
358
359 // Memory map a region in the address space.
360
361 char* FileMapInfo::map_region(int i, ReservedSpace rs) {
362 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
363 size_t used = si->_used;
364 size_t size = align_size_up(used, os::vm_allocation_granularity());
365
366 ReservedSpace mapped_rs = rs.first_part(size, true, true);
367 ReservedSpace unmapped_rs = rs.last_part(size);
368 mapped_rs.release();
369
370 return map_region(i, true);
371 }
372
373
374 // Memory map a region in the address space.
375
376 char* FileMapInfo::map_region(int i, bool address_must_match) {
377 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
378 size_t used = si->_used;
379 size_t size = align_size_up(used, os::vm_allocation_granularity());
380 char *requested_addr = 0;
381 if (address_must_match) {
382 requested_addr = si->_base;
383 }
384 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
385 requested_addr, size, si->_read_only,
386 si->_allow_exec);
387 if (base == NULL) {
388 fail_continue("Unable to map shared space.");
389 return NULL;
390 }
391 if (address_must_match) {
392 if (base != si->_base) {
393 fail_continue("Unable to map shared space at required address.");
394 return NULL;
395 }
396 } else {
397 si->_base = base; // save mapped address for unmapping.
398 }
399 return base;
400 }
401
402
403 // Unmap a memory region in the address space.
404
405 void FileMapInfo::unmap_region(int i) {
406 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
407 size_t used = si->_used;
408 size_t size = align_size_up(used, os::vm_allocation_granularity());
409 if (!os::unmap_memory(si->_base, size)) {
410 fail_stop("Unable to unmap shared space.");
411 }
412 }
413
414
415 void FileMapInfo::assert_mark(bool check) {
416 if (!check) {
417 fail_stop("Mark mismatch while restoring from shared file.", NULL);
418 }
419 }
420
421
422 FileMapInfo* FileMapInfo::_current_info = NULL;
423
424
425 // Open the shared archive file, read and validate the header
426 // information (version, boot classpath, etc.). If initialization
427 // fails, shared spaces are disabled and the file is closed. [See
428 // fail_continue.]
429
430
431 bool FileMapInfo::initialize() {
432 assert(UseSharedSpaces, "UseSharedSpaces expected.");
433
434 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
435 fail_continue("Tool agent requires sharing to be disabled.");
436 return false;
437 }
438
439 if (!open_for_read()) {
440 return false;
441 }
442
443 init_from_file(_fd);
444 if (!validate()) {
445 return false;
446 }
447
448 SharedReadOnlySize = _header._space[0]._capacity;
449 SharedReadWriteSize = _header._space[1]._capacity;
450 SharedMiscDataSize = _header._space[2]._capacity;
451 SharedMiscCodeSize = _header._space[3]._capacity;
452 return true;
453 }
454
455
456 bool FileMapInfo::validate() {
457 if (_header._version != current_version()) {
458 fail_continue("The shared archive file is the wrong version.");
459 return false;
460 }
461 if (_header._magic != (int)0xf00baba2) {
462 fail_continue("The shared archive file has a bad magic number.");
463 return false;
464 }
465 if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(),
466 JVM_IDENT_MAX-1) != 0) {
467 fail_continue("The shared archive file was created by a different"
468 " version or build of HotSpot.");
469 return false;
470 }
471
472 // Cannot verify interpreter yet, as it can only be created after the GC
473 // heap has been initialized.
474
475 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
476 fail_continue("Too many jar files to share.");
477 return false;
478 }
479
480 // Build checks on classpath and jar files
481 int num_jars_now = 0;
482 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
483 for ( ; cpe != NULL; cpe = cpe->next()) {
484
485 if (cpe->is_jar_file()) {
486 if (num_jars_now < _header._num_jars) {
487
488 // Jar file - verify timestamp and file size.
489 struct stat st;
490 const char *path = cpe->name();
491 if (os::stat(path, &st) != 0) {
492 fail_continue("Unable to open jar file %s.", path);
493 return false;
494 }
495 if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
496 _header._jar[num_jars_now]._filesize != st.st_size) {
497 fail_continue("A jar file is not the one used while building"
498 " the shared archive file.");
499 return false;
500 }
501 }
502 ++num_jars_now;
503 } else {
504
505 // If directories appear in boot classpath, they must be empty to
506 // avoid having to verify each individual class file.
507 const char* name = ((ClassPathDirEntry*)cpe)->name();
508 if (!os::dir_is_empty(name)) {
509 fail_continue("Boot classpath directory %s is not empty.", name);
510 return false;
511 }
512 }
513 }
514 if (num_jars_now < _header._num_jars) {
515 fail_continue("The number of jar files in the boot classpath is"
516 " less than the number the shared archive was created with.");
517 return false;
518 }
519
520 return true;
521 }
522
523 // The following method is provided to see whether a given pointer
524 // falls in the mapped shared space.
525 // Param:
526 // p, The given pointer
527 // Return:
528 // True if the p is within the mapped shared space, otherwise, false.
529 bool FileMapInfo::is_in_shared_space(const void* p) {
530 for (int i = 0; i < CompactingPermGenGen::n_regions; i++) {
531 if (p >= _header._space[i]._base &&
532 p < _header._space[i]._base + _header._space[i]._used) {
533 return true;
534 }
535 }
536
537 return false;
538 }