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 "runtime/arguments.hpp"
39 #include "runtime/java.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/vm_version.hpp"
42 #include "services/memTracker.hpp"
43 #include "utilities/defaultStream.hpp"
44
45 # include <sys/stat.h>
46 # include <errno.h>
47
48 #ifndef O_BINARY // if defined (Win32) use binary files.
49 #define O_BINARY 0 // otherwise do nothing.
50 #endif
51
52 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
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 _narrow_oop_mode = Universe::narrow_oop_mode();
172 _narrow_oop_shift = Universe::narrow_oop_shift();
173 _max_heap_size = MaxHeapSize;
174 _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;
175 _classpath_entry_table = mapinfo->_classpath_entry_table;
176 _classpath_entry_size = mapinfo->_classpath_entry_size;
177
178 // The following fields are for sanity checks for whether this archive
179 // will function correctly with this JVM and the bootclasspath it's
180 // invoked with.
181
182 // JVM version string ... changes on each build.
183 get_header_version(_jvm_ident);
184 }
185
186 void FileMapInfo::allocate_classpath_entry_table() {
187 int bytes = 0;
188 int count = 0;
189 char* strptr = NULL;
190 char* strptr_max = NULL;
191 Thread* THREAD = Thread::current();
192
193 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
194 size_t entry_size = SharedClassUtil::shared_class_path_entry_size();
195
196 for (int pass=0; pass<2; pass++) {
197 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
198
199 for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {
200 const char *name = cpe->name();
201 int name_bytes = (int)(strlen(name) + 1);
202
203 if (pass == 0) {
204 count ++;
205 bytes += (int)entry_size;
206 bytes += name_bytes;
207 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
208 tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name);
209 }
210 } else {
211 SharedClassPathEntry* ent = shared_classpath(cur_entry);
212 if (cpe->is_jar_file()) {
213 struct stat st;
214 if (os::stat(name, &st) != 0) {
215 // The file/dir must exist, or it would not have been added
216 // into ClassLoader::classpath_entry().
217 //
218 // If we can't access a jar file in the boot path, then we can't
219 // make assumptions about where classes get loaded from.
220 FileMapInfo::fail_stop("Unable to open jar file %s.", name);
221 }
222
223 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
224 SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);
225 } else {
226 struct stat st;
227 if ((os::stat(name, &st) == 0) && ((st.st_mode & S_IFDIR) == S_IFDIR)) {
228 if (!os::dir_is_empty(name)) {
229 ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);
230 }
231 ent->_filesize = -1;
232 } else {
233 ent->_filesize = -2;
234 }
235 }
236 ent->_name = strptr;
237 if (strptr + name_bytes <= strptr_max) {
238 strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
239 strptr += name_bytes;
240 } else {
241 assert(0, "miscalculated buffer size");
242 }
243 }
244 }
245
246 if (pass == 0) {
247 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
248 Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);
249 strptr = (char*)(arr->data());
250 strptr_max = strptr + bytes;
251 SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;
252 strptr += entry_size * count;
253
254 _classpath_entry_table_size = count;
255 _classpath_entry_table = table;
256 _classpath_entry_size = entry_size;
257 }
258 }
259 }
260
261 bool FileMapInfo::validate_classpath_entry_table() {
262 _validating_classpath_entry_table = true;
263
264 int count = _header->_classpath_entry_table_size;
265
266 _classpath_entry_table = _header->_classpath_entry_table;
267 _classpath_entry_size = _header->_classpath_entry_size;
268
269 for (int i=0; i<count; i++) {
270 SharedClassPathEntry* ent = shared_classpath(i);
271 struct stat st;
272 const char* name = ent->_name;
273 bool ok = true;
274 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
275 tty->print_cr("[Checking shared classpath entry: %s]", name);
276 }
277 if (os::stat(name, &st) != 0) {
278 fail_continue("Required classpath entry does not exist: %s", name);
279 ok = false;
280 } else if (ent->is_dir()) {
281 if (!os::dir_is_empty(name)) {
282 fail_continue("directory is not empty: %s", name);
283 ok = false;
284 }
285 } else if (ent->is_jar()) {
286 if (ent->_timestamp != st.st_mtime ||
287 ent->_filesize != st.st_size) {
288 ok = false;
289 if (PrintSharedArchiveAndExit) {
290 fail_continue(ent->_timestamp != st.st_mtime ?
291 "Timestamp mismatch" :
292 "File size mismatch");
293 } else {
294 fail_continue("A jar file is not the one used while building"
295 " the shared archive file: %s", name);
296 }
297 }
298 }
299 if (ok) {
300 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
301 tty->print_cr("[ok]");
302 }
303 } else if (!PrintSharedArchiveAndExit) {
304 _validating_classpath_entry_table = false;
305 return false;
306 }
307 }
308
309 _classpath_entry_table_size = _header->_classpath_entry_table_size;
310 _validating_classpath_entry_table = false;
311 return true;
312 }
313
314
315 // Read the FileMapInfo information from the file.
316
317 bool FileMapInfo::init_from_file(int fd) {
318 size_t sz = _header->data_size();
319 char* addr = _header->data();
320 size_t n = os::read(fd, addr, (unsigned int)sz);
321 if (n != sz) {
322 fail_continue("Unable to read the file header.");
323 return false;
324 }
325 if (_header->_version != current_version()) {
326 fail_continue("The shared archive file has the wrong version.");
327 return false;
328 }
329 _file_offset = (long)n;
330
331 size_t info_size = _header->_paths_misc_info_size;
332 _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
333 if (_paths_misc_info == NULL) {
334 fail_continue("Unable to read the file header.");
335 return false;
336 }
337 n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
338 if (n != info_size) {
339 fail_continue("Unable to read the shared path info header.");
340 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
341 _paths_misc_info = NULL;
342 return false;
343 }
344
345 size_t len = lseek(fd, 0, SEEK_END);
346 struct FileMapInfo::FileMapHeader::space_info* si =
347 &_header->_space[MetaspaceShared::mc];
348 if (si->_file_offset >= len || len - si->_file_offset < si->_used) {
349 fail_continue("The shared archive file has been truncated.");
350 return false;
351 }
352
353 _file_offset += (long)n;
354 return true;
355 }
356
357
358 // Read the FileMapInfo information from the file.
359 bool FileMapInfo::open_for_read() {
360 _full_path = Arguments::GetSharedArchivePath();
361 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
362 if (fd < 0) {
363 if (errno == ENOENT) {
364 // Not locating the shared archive is ok.
365 fail_continue("Specified shared archive not found.");
366 } else {
367 fail_continue("Failed to open shared archive file (%s).",
368 strerror(errno));
369 }
370 return false;
371 }
372
373 _fd = fd;
374 _file_open = true;
375 return true;
376 }
377
378
379 // Write the FileMapInfo information to the file.
380
381 void FileMapInfo::open_for_write() {
382 _full_path = Arguments::GetSharedArchivePath();
383 if (PrintSharedSpaces) {
384 tty->print_cr("Dumping shared data to file: ");
385 tty->print_cr(" %s", _full_path);
386 }
387
388 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
389 chmod(_full_path, _S_IREAD | _S_IWRITE);
390 #endif
391
392 // Use remove() to delete the existing file because, on Unix, this will
393 // allow processes that have it open continued access to the file.
394 remove(_full_path);
395 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
396 if (fd < 0) {
397 fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
398 strerror(errno));
399 }
400 _fd = fd;
401 _file_offset = 0;
402 _file_open = true;
403 }
404
405
406 // Write the header to the file, seek to the next allocation boundary.
407
408 void FileMapInfo::write_header() {
409 int info_size = ClassLoader::get_shared_paths_misc_info_size();
410
411 _header->_paths_misc_info_size = info_size;
412
413 align_file_position();
414 size_t sz = _header->data_size();
415 char* addr = _header->data();
416 write_bytes(addr, (int)sz); // skip the C++ vtable
417 write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
418 align_file_position();
419 }
420
421
422 // Dump shared spaces to file.
423
424 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
425 align_file_position();
426 size_t used = space->used_bytes_slow(Metaspace::NonClassType);
427 size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
428 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
429 write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
430 }
431
432
433 // Dump region to file.
434
435 void FileMapInfo::write_region(int region, char* base, size_t size,
436 size_t capacity, bool read_only,
437 bool allow_exec) {
438 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
439
440 if (_file_open) {
441 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
442 if (PrintSharedSpaces) {
443 tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT
444 " file offset 0x%6x", region, size, base, _file_offset);
445 }
446 } else {
447 si->_file_offset = _file_offset;
448 }
449 if (MetaspaceShared::is_string_region(region)) {
450 assert((base - (char*)Universe::narrow_oop_base()) % HeapWordSize == 0, "Sanity");
451 if (base != NULL) {
452 si->_addr._offset = (intx)oopDesc::encode_heap_oop_not_null((oop)base);
453 } else {
454 si->_addr._offset = 0;
455 }
456 } else {
457 si->_addr._base = base;
458 }
459 si->_used = size;
460 si->_capacity = capacity;
461 si->_read_only = read_only;
462 si->_allow_exec = allow_exec;
463 si->_crc = ClassLoader::crc32(0, base, (jint)size);
464 write_bytes_aligned(base, (int)size);
465 }
466
467 // Write the string space. The string space contains one or multiple GC(G1) regions.
468 // When the total string space size is smaller than one GC region of the dump time,
469 // only one string region is used for shared strings.
470 //
471 // If the total string space size is bigger than one GC region, there would be more
472 // than one GC regions allocated for shared strings. The first/bottom GC region might
473 // be a partial GC region with the empty portion at the higher address within that region.
474 // The non-empty portion of the first region is written into the archive as one string
475 // region. The rest are consecutive full GC regions if they exist, which can be written
476 // out in one chunk as another string region.
477 void FileMapInfo::write_string_regions(GrowableArray<MemRegion> *regions) {
478 for (int i = MetaspaceShared::first_string;
479 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
480 char* start = NULL;
481 size_t size = 0;
482 if (regions->is_nonempty()) {
483 if (i == MetaspaceShared::first_string) {
484 MemRegion first = regions->first();
485 start = (char*)first.start();
486 size = first.byte_size();
487 } else {
488 int len = regions->length();
489 if (len > 1) {
490 start = (char*)regions->at(1).start();
491 size = (char*)regions->at(len - 1).end() - start;
492 }
493 }
494 }
495 write_region(i, start, size, size, false, false);
496 }
497 }
498
499
500 // Dump bytes to file -- at the current file position.
501
502 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
503 if (_file_open) {
504 int n = ::write(_fd, buffer, nbytes);
505 if (n != nbytes) {
506 // It is dangerous to leave the corrupted shared archive file around,
507 // close and remove the file. See bug 6372906.
508 close();
509 remove(_full_path);
510 fail_stop("Unable to write to shared archive file.");
511 }
512 }
513 _file_offset += nbytes;
514 }
515
516
517 // Align file position to an allocation unit boundary.
518
519 void FileMapInfo::align_file_position() {
520 size_t new_file_offset = align_size_up(_file_offset,
521 os::vm_allocation_granularity());
522 if (new_file_offset != _file_offset) {
523 _file_offset = new_file_offset;
524 if (_file_open) {
525 // Seek one byte back from the target and write a byte to insure
526 // that the written file is the correct length.
527 _file_offset -= 1;
528 if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
529 fail_stop("Unable to seek.");
530 }
531 char zero = 0;
532 write_bytes(&zero, 1);
533 }
534 }
535 }
536
537
538 // Dump bytes to file -- at the current file position.
539
540 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
541 align_file_position();
542 write_bytes(buffer, nbytes);
543 align_file_position();
544 }
545
546
547 // Close the shared archive file. This does NOT unmap mapped regions.
548
549 void FileMapInfo::close() {
550 if (_file_open) {
551 if (::close(_fd) < 0) {
552 fail_stop("Unable to close the shared archive file.");
553 }
554 _file_open = false;
555 _fd = -1;
556 }
557 }
558
559
560 // JVM/TI RedefineClasses() support:
561 // Remap the shared readonly space to shared readwrite, private.
562 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
563 int idx = 0;
564 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[idx];
565 if (!si->_read_only) {
566 // the space is already readwrite so we are done
567 return true;
568 }
569 size_t used = si->_used;
570 size_t size = align_size_up(used, os::vm_allocation_granularity());
571 if (!open_for_read()) {
572 return false;
573 }
574 char *addr = _header->region_addr(idx);
575 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
576 addr, size, false /* !read_only */,
577 si->_allow_exec);
578 close();
579 if (base == NULL) {
580 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
581 return false;
582 }
583 if (base != addr) {
584 fail_continue("Unable to remap shared readonly space at required address.");
585 return false;
586 }
587 si->_read_only = false;
588 return true;
589 }
590
591 // Map the whole region at once, assumed to be allocated contiguously.
592 ReservedSpace FileMapInfo::reserve_shared_memory() {
593 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
594 char* requested_addr = _header->region_addr(0);
595
596 size_t size = FileMapInfo::shared_spaces_size();
597
598 // Reserve the space first, then map otherwise map will go right over some
599 // other reserved memory (like the code cache).
600 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
601 if (!rs.is_reserved()) {
602 fail_continue("Unable to reserve shared space at required address " INTPTR_FORMAT, requested_addr);
603 return rs;
604 }
605 // the reserved virtual memory is for mapping class data sharing archive
606 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
607
608 return rs;
609 }
610
611 // Memory map a region in the address space.
612 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode",
613 "String1", "String2"};
614
615 char* FileMapInfo::map_region(int i) {
616 assert(!MetaspaceShared::is_string_region(i), "sanity");
617 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
618 size_t used = si->_used;
619 size_t alignment = os::vm_allocation_granularity();
620 size_t size = align_size_up(used, alignment);
621 char *requested_addr = _header->region_addr(i);
622
623 // map the contents of the CDS archive in this memory
624 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
625 requested_addr, size, si->_read_only,
626 si->_allow_exec);
627 if (base == NULL || base != requested_addr) {
628 fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
629 return NULL;
630 }
631 #ifdef _WINDOWS
632 // This call is Windows-only because the memory_type gets recorded for the other platforms
633 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
634 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
635 #endif
636
637 return base;
638 }
639
640 MemRegion *string_ranges = NULL;
641 int num_ranges = 0;
642 bool FileMapInfo::map_string_regions() {
643 #if INCLUDE_ALL_GCS
644 if (UseG1GC && UseCompressedOops && UseCompressedClassPointers) {
645 if (narrow_oop_mode() == Universe::narrow_oop_mode() &&
646 narrow_oop_shift() == Universe::narrow_oop_shift()) {
647 string_ranges = new MemRegion[MetaspaceShared::max_strings];
648 struct FileMapInfo::FileMapHeader::space_info* si;
649
650 for (int i = MetaspaceShared::first_string;
651 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
652 si = &_header->_space[i];
653 size_t used = si->_used;
654 if (used > 0) {
655 size_t size = used;
656 char* requested_addr = (char*)((void*)oopDesc::decode_heap_oop_not_null(
657 (narrowOop)si->_addr._offset));
658 string_ranges[num_ranges] = MemRegion((HeapWord*)requested_addr, size / HeapWordSize);
659 num_ranges ++;
660 }
661 }
662
663 // Check that ranges are within the java heap
664 if (!G1CollectedHeap::heap()->check_archive_addresses(string_ranges, num_ranges)) {
665 fail_continue("Unable to allocate shared string space: range is not "
666 "within java heap.");
667 return false;
668 }
669
670 // allocate from java heap
671 if (!G1CollectedHeap::heap()->alloc_archive_regions(string_ranges, num_ranges)) {
672 fail_continue("Unable to allocate shared string space: range is "
673 "already in use.");
674 return false;
675 }
676
677 // Map the string data. No need to call MemTracker::record_virtual_memory_type()
678 // for mapped string regions as they are part of the reserved java heap, which
679 // is already recorded.
680 for (int i = 0; i < num_ranges; i++) {
681 si = &_header->_space[MetaspaceShared::first_string + i];
682 char* addr = (char*)string_ranges[i].start();
683 char* base = os::map_memory(_fd, _full_path, si->_file_offset,
684 addr, string_ranges[i].byte_size(), si->_read_only,
685 si->_allow_exec);
686 if (base == NULL || base != addr) {
687 fail_continue("Unable to map shared string space at required address.");
688 return false;
689 }
690 }
691 return true; // the shared string data is mapped successfuly
692 } else {
693 // narrow oop encoding differ, the shared string data are not used
694 if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
695 tty->print_cr("Shared string data from the CDS archive is being ignored. "
696 "The current CompressedOops encoding differs from that archived "
697 "due to heap size change. The archive was dumped using max heap "
698 "size %dM.", max_heap_size() >> 20);
699 }
700 }
701 } else {
702 if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
703 tty->print_cr("Shared string data from the CDS archive is being ignored. UseG1GC, "
704 "UseCompressedOops and UseCompressedClassPointers are required.");
705 }
706 }
707
708 // if we get here, the shared string data is not mapped
709 assert(string_ranges == NULL && num_ranges == 0, "sanity");
710 StringTable::ignore_shared_strings(true);
711 #endif
712 return true;
713 }
714
715 bool FileMapInfo::verify_string_regions() {
716 for (int i = MetaspaceShared::first_string;
717 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
718 if (!verify_region_checksum(i)) {
719 return false;
720 }
721 }
722 return true;
723 }
724
725 void FileMapInfo::fixup_string_regions() {
726 if (string_ranges != NULL) {
727 G1CollectedHeap::heap()->fill_archive_regions(string_ranges, num_ranges);
728 }
729 }
730
731 bool FileMapInfo::verify_region_checksum(int i) {
732 if (!VerifySharedSpaces) {
733 return true;
734 }
735
736 const char* buf;
737 size_t sz = _header->_space[i]._used;
738
739 if (sz == 0) {
740 return true; // no data
741 }
742 if (MetaspaceShared::is_string_region(i) && StringTable::shared_string_ignored()) {
743 return true; // shared string data are not mapped
744 }
745 buf = _header->region_addr(i);
746 int crc = ClassLoader::crc32(0, buf, (jint)sz);
747 if (crc != _header->_space[i]._crc) {
748 fail_continue("Checksum verification failed.");
749 return false;
750 }
751 return true;
752 }
753
754 // Unmap a memory region in the address space.
755
756 void FileMapInfo::unmap_region(int i) {
757 assert(!MetaspaceShared::is_string_region(i), "sanity");
758 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
759 size_t used = si->_used;
760 size_t size = align_size_up(used, os::vm_allocation_granularity());
761 char* addr;
762
763 if (used == 0) {
764 return;
765 }
766
767 addr = _header->region_addr(i);
768 if (!os::unmap_memory(addr, size)) {
769 fail_stop("Unable to unmap shared space.");
770 }
771 }
772
773 void FileMapInfo::unmap_string_regions() {
774 for (int i = MetaspaceShared::first_string;
775 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
776 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
777 size_t used = si->_used;
778 if (used > 0) {
779 size_t size = align_size_up(used, os::vm_allocation_granularity());
780 char* addr = (char*)((void*)oopDesc::decode_heap_oop_not_null(
781 (narrowOop)si->_addr._offset));
782 if (!os::unmap_memory(addr, size)) {
783 fail_stop("Unable to unmap shared space.");
784 }
785 }
786 }
787 }
788
789 void FileMapInfo::assert_mark(bool check) {
790 if (!check) {
791 fail_stop("Mark mismatch while restoring from shared file.");
792 }
793 }
794
795
796 FileMapInfo* FileMapInfo::_current_info = NULL;
797 SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL;
798 int FileMapInfo::_classpath_entry_table_size = 0;
799 size_t FileMapInfo::_classpath_entry_size = 0x1234baad;
800 bool FileMapInfo::_validating_classpath_entry_table = false;
801
802 // Open the shared archive file, read and validate the header
803 // information (version, boot classpath, etc.). If initialization
804 // fails, shared spaces are disabled and the file is closed. [See
805 // fail_continue.]
806 //
807 // Validation of the archive is done in two steps:
808 //
809 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
810 // [2] validate_classpath_entry_table - this is done later, because the table is in the RW
811 // region of the archive, which is not mapped yet.
812 bool FileMapInfo::initialize() {
813 assert(UseSharedSpaces, "UseSharedSpaces expected.");
814
815 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
816 fail_continue("Tool agent requires sharing to be disabled.");
817 return false;
818 }
819
820 if (!open_for_read()) {
821 return false;
822 }
823
824 init_from_file(_fd);
825 if (!validate_header()) {
826 return false;
827 }
828
829 SharedReadOnlySize = _header->_space[0]._capacity;
830 SharedReadWriteSize = _header->_space[1]._capacity;
831 SharedMiscDataSize = _header->_space[2]._capacity;
832 SharedMiscCodeSize = _header->_space[3]._capacity;
833 return true;
834 }
835
836 char* FileMapInfo::FileMapHeader::region_addr(int idx) {
837 if (MetaspaceShared::is_string_region(idx)) {
838 return (char*)((void*)oopDesc::decode_heap_oop_not_null(
839 (narrowOop)_space[idx]._addr._offset));
840 } else {
841 return _space[idx]._addr._base;
842 }
843 }
844
845 int FileMapInfo::FileMapHeader::compute_crc() {
846 char* header = data();
847 // start computing from the field after _crc
848 char* buf = (char*)&_crc + sizeof(int);
849 size_t sz = data_size() - (buf - header);
850 int crc = ClassLoader::crc32(0, buf, (jint)sz);
851 return crc;
852 }
853
854 bool FileMapInfo::FileMapHeader::validate() {
855 if (VerifySharedSpaces && compute_crc() != _crc) {
856 fail_continue("Header checksum verification failed.");
857 return false;
858 }
859
860 if (_version != current_version()) {
861 FileMapInfo::fail_continue("The shared archive file is the wrong version.");
862 return false;
863 }
864 if (_magic != (int)0xf00baba2) {
865 FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
866 return false;
867 }
868 char header_version[JVM_IDENT_MAX];
869 get_header_version(header_version);
870 if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
871 if (TraceClassPaths) {
872 tty->print_cr("Expected: %s", header_version);
873 tty->print_cr("Actual: %s", _jvm_ident);
874 }
875 FileMapInfo::fail_continue("The shared archive file was created by a different"
876 " version or build of HotSpot");
877 return false;
878 }
879 if (_obj_alignment != ObjectAlignmentInBytes) {
880 FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
881 " does not equal the current ObjectAlignmentInBytes of %d.",
882 _obj_alignment, ObjectAlignmentInBytes);
883 return false;
884 }
885
886 return true;
887 }
888
889 bool FileMapInfo::validate_header() {
890 bool status = _header->validate();
891
892 if (status) {
893 if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
894 if (!PrintSharedArchiveAndExit) {
895 fail_continue("shared class paths mismatch (hint: enable -XX:+TraceClassPaths to diagnose the failure)");
896 status = false;
897 }
898 }
899 }
900
901 if (_paths_misc_info != NULL) {
902 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
903 _paths_misc_info = NULL;
904 }
905 return status;
906 }
907
908 // The following method is provided to see whether a given pointer
909 // falls in the mapped shared space.
910 // Param:
911 // p, The given pointer
912 // Return:
913 // True if the p is within the mapped shared space, otherwise, false.
914 bool FileMapInfo::is_in_shared_space(const void* p) {
915 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
916 char *base;
917 if (MetaspaceShared::is_string_region(i) && _header->_space[i]._used == 0) {
918 continue;
919 }
920 base = _header->region_addr(i);
921 if (p >= base && p < base + _header->_space[i]._used) {
922 return true;
923 }
924 }
925
926 return false;
927 }
928
929 void FileMapInfo::print_shared_spaces() {
930 gclog_or_tty->print_cr("Shared Spaces:");
931 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
932 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
933 char *base = _header->region_addr(i);
934 gclog_or_tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
935 shared_region_name[i],
936 base, base + si->_used);
937 }
938 }
939
940 // Unmap mapped regions of shared space.
941 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
942 FileMapInfo *map_info = FileMapInfo::current_info();
943 if (map_info) {
944 map_info->fail_continue("%s", msg);
945 for (int i = 0; i < MetaspaceShared::num_non_strings; i++) {
946 char *addr = map_info->_header->region_addr(i);
947 if (addr != NULL && !MetaspaceShared::is_string_region(i)) {
948 map_info->unmap_region(i);
949 map_info->_header->_space[i]._addr._base = NULL;
950 }
951 }
952 map_info->unmap_string_regions();
953 } else if (DumpSharedSpaces) {
954 fail_stop("%s", msg);
955 }
956 }