1 /*
2 * Copyright (c) 2003, 2016, 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/compactHashtable.inline.hpp"
28 #include "classfile/sharedClassUtil.hpp"
29 #include "classfile/symbolTable.hpp"
30 #include "classfile/systemDictionaryShared.hpp"
31 #include "classfile/altHashing.hpp"
32 #if INCLUDE_ALL_GCS
33 #include "gc/g1/g1CollectedHeap.hpp"
34 #endif
35 #include "memory/filemap.hpp"
36 #include "memory/metadataFactory.hpp"
37 #include "memory/oopFactory.hpp"
38 #include "oops/objArrayOop.hpp"
39 #include "prims/jvmtiExport.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/java.hpp"
42 #include "runtime/os.hpp"
43 #include "runtime/vm_version.hpp"
44 #include "services/memTracker.hpp"
45 #include "utilities/defaultStream.hpp"
46
47 # include <sys/stat.h>
48 # include <errno.h>
49
50 #ifndef O_BINARY // if defined (Win32) use binary files.
51 #define O_BINARY 0 // otherwise do nothing.
52 #endif
53
54 extern address JVM_FunctionAtStart();
55 extern address JVM_FunctionAtEnd();
56
57 // Complain and stop. All error conditions occurring during the writing of
58 // an archive file should stop the process. Unrecoverable errors during
59 // the reading of the archive file should stop the process.
60
61 static void fail(const char *msg, va_list ap) {
62 // This occurs very early during initialization: tty is not initialized.
63 jio_fprintf(defaultStream::error_stream(),
64 "An error has occurred while processing the"
65 " shared archive file.\n");
66 jio_vfprintf(defaultStream::error_stream(), msg, ap);
67 jio_fprintf(defaultStream::error_stream(), "\n");
68 // Do not change the text of the below message because some tests check for it.
69 vm_exit_during_initialization("Unable to use shared archive.", NULL);
70 }
71
72
73 void FileMapInfo::fail_stop(const char *msg, ...) {
74 va_list ap;
75 va_start(ap, msg);
76 fail(msg, ap); // Never returns.
77 va_end(ap); // for completeness.
78 }
79
80
81 // Complain and continue. Recoverable errors during the reading of the
82 // archive file may continue (with sharing disabled).
83 //
84 // If we continue, then disable shared spaces and close the file.
85
86 void FileMapInfo::fail_continue(const char *msg, ...) {
87 va_list ap;
88 va_start(ap, msg);
89 MetaspaceShared::set_archive_loading_failed();
90 if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) {
91 // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
92 // do not validate, we can still continue "limping" to validate the remaining
93 // entries. No need to quit.
94 tty->print("[");
95 tty->vprint(msg, ap);
96 tty->print_cr("]");
97 } else {
98 if (RequireSharedSpaces) {
99 fail(msg, ap);
100 } else {
101 if (PrintSharedSpaces) {
102 tty->print("UseSharedSpaces: ");
103 tty->vprint_cr(msg, ap);
104 }
105 }
106 UseSharedSpaces = false;
107 assert(current_info() != NULL, "singleton must be registered");
108 current_info()->close();
109 }
110 va_end(ap);
111 }
112
113 // Fill in the fileMapInfo structure with data about this VM instance.
114
115 // This method copies the vm version info into header_version. If the version is too
116 // long then a truncated version, which has a hash code appended to it, is copied.
117 //
118 // Using a template enables this method to verify that header_version is an array of
119 // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and
120 // the code that reads the CDS file will both use the same size buffer. Hence, will
121 // use identical truncation. This is necessary for matching of truncated versions.
122 template <int N> static void get_header_version(char (&header_version) [N]) {
123 assert(N == JVM_IDENT_MAX, "Bad header_version size");
124
125 const char *vm_version = VM_Version::internal_vm_info_string();
126 const int version_len = (int)strlen(vm_version);
127
128 if (version_len < (JVM_IDENT_MAX-1)) {
129 strcpy(header_version, vm_version);
130
131 } else {
132 // Get the hash value. Use a static seed because the hash needs to return the same
133 // value over multiple jvm invocations.
134 unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
135
136 // Truncate the ident, saving room for the 8 hex character hash value.
137 strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
138
139 // Append the hash code as eight hex digits.
140 sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
141 header_version[JVM_IDENT_MAX-1] = 0; // Null terminate.
142 }
143 }
144
145 FileMapInfo::FileMapInfo() {
146 assert(_current_info == NULL, "must be singleton"); // not thread safe
147 _current_info = this;
148 memset(this, 0, sizeof(FileMapInfo));
149 _file_offset = 0;
150 _file_open = false;
151 _header = SharedClassUtil::allocate_file_map_header();
152 _header->_version = _invalid_version;
153 }
154
155 FileMapInfo::~FileMapInfo() {
156 assert(_current_info == this, "must be singleton"); // not thread safe
157 _current_info = NULL;
158 }
159
160 void FileMapInfo::populate_header(size_t alignment) {
161 _header->populate(this, alignment);
162 }
163
164 size_t FileMapInfo::FileMapHeader::data_size() {
165 return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);
166 }
167
168 void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
169 _magic = 0xf00baba2;
170 _version = _current_version;
171 _alignment = alignment;
172 _obj_alignment = ObjectAlignmentInBytes;
173 _compact_strings = CompactStrings;
174 _narrow_oop_mode = Universe::narrow_oop_mode();
175 _narrow_oop_shift = Universe::narrow_oop_shift();
176 _max_heap_size = MaxHeapSize;
177 _narrow_klass_base = Universe::narrow_klass_base();
178 _narrow_klass_shift = Universe::narrow_klass_shift();
179 _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;
180 _classpath_entry_table = mapinfo->_classpath_entry_table;
181 _classpath_entry_size = mapinfo->_classpath_entry_size;
182 _num_patch_mod_prefixes = ClassLoader::num_patch_mod_prefixes();
183
184 // The following fields are for sanity checks for whether this archive
185 // will function correctly with this JVM and the bootclasspath it's
186 // invoked with.
187
188 // JVM version string ... changes on each build.
189 get_header_version(_jvm_ident);
190 }
191
192 void FileMapInfo::allocate_classpath_entry_table() {
193 int bytes = 0;
194 int count = 0;
195 char* strptr = NULL;
196 char* strptr_max = NULL;
197 Thread* THREAD = Thread::current();
198
199 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
200 size_t entry_size = SharedClassUtil::shared_class_path_entry_size();
201
202 for (int pass=0; pass<2; pass++) {
203
204 // Process the modular java runtime image first
205 ClassPathEntry* jrt_entry = ClassLoader::get_jrt_entry();
206 assert(jrt_entry != NULL,
207 "No modular java runtime image present when allocating the CDS classpath entry table");
208 const char *name = jrt_entry->name();
209 int name_bytes = (int)(strlen(name) + 1);
210 if (pass == 0) {
211 count++;
212 bytes += (int)entry_size;
213 bytes += name_bytes;
214 log_info(class, path)("add main shared path for modular java runtime image %s", name);
215 } else {
216 // The java runtime image is always in slot 0 on the shared class path.
217 SharedClassPathEntry* ent = shared_classpath(0);
218 struct stat st;
219 if (os::stat(name, &st) == 0) {
220 ent->_timestamp = st.st_mtime;
221 ent->_filesize = st.st_size;
222 }
223 if (ent->_filesize == 0) {
224 // unknown
225 ent->_filesize = -2;
226 }
227 ent->_name = strptr;
228 assert(strptr + name_bytes <= strptr_max, "miscalculated buffer size");
229 strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
230 strptr += name_bytes;
231 }
232
233 // Walk the appended entries, which includes the entries added for the classpath.
234 ClassPathEntry *cpe = ClassLoader::classpath_entry(1);
235
236 // Since the java runtime image is always in slot 0 on the shared class path, the
237 // appended entries are started at slot 1 immediately after.
238 for (int cur_entry = 1 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {
239 const char *name = cpe->name();
240 int name_bytes = (int)(strlen(name) + 1);
241 assert(!cpe->is_jrt(), "A modular java runtime image is present on the list of appended entries");
242
243 if (pass == 0) {
244 count ++;
245 bytes += (int)entry_size;
246 bytes += name_bytes;
247 log_info(class, path)("add main shared path (%s) %s", (cpe->is_jar_file() ? "jar" : "dir"), name);
248 } else {
249 SharedClassPathEntry* ent = shared_classpath(cur_entry);
250 if (cpe->is_jar_file()) {
251 struct stat st;
252 if (os::stat(name, &st) != 0) {
253 // The file/dir must exist, or it would not have been added
254 // into ClassLoader::classpath_entry().
255 //
256 // If we can't access a jar file in the boot path, then we can't
257 // make assumptions about where classes get loaded from.
258 FileMapInfo::fail_stop("Unable to open jar file %s.", name);
259 }
260
261 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
262 SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);
263 } else {
264 struct stat st;
265 if (os::stat(name, &st) == 0) {
266 if ((st.st_mode & S_IFDIR) == S_IFDIR) {
267 if (!os::dir_is_empty(name)) {
268 ClassLoader::exit_with_path_failure(
269 "Cannot have non-empty directory in archived classpaths", name);
270 }
271 ent->_filesize = -1;
272 }
273 }
274 if (ent->_filesize == 0) {
275 // unknown
276 ent->_filesize = -2;
277 }
278 }
279 ent->_name = strptr;
280 if (strptr + name_bytes <= strptr_max) {
281 strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
282 strptr += name_bytes;
283 } else {
284 assert(0, "miscalculated buffer size");
285 }
286 }
287 }
288
289 if (pass == 0) {
290 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
291 Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);
292 strptr = (char*)(arr->data());
293 strptr_max = strptr + bytes;
294 SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;
295 strptr += entry_size * count;
296
297 _classpath_entry_table_size = count;
298 _classpath_entry_table = table;
299 _classpath_entry_size = entry_size;
300 }
301 }
302 }
303
304 bool FileMapInfo::validate_classpath_entry_table() {
305 _validating_classpath_entry_table = true;
306
307 int count = _header->_classpath_entry_table_size;
308
309 _classpath_entry_table = _header->_classpath_entry_table;
310 _classpath_entry_size = _header->_classpath_entry_size;
311
312 for (int i=0; i<count; i++) {
313 SharedClassPathEntry* ent = shared_classpath(i);
314 struct stat st;
315 const char* name = ent->_name;
316 bool ok = true;
317 log_info(class, path)("checking shared classpath entry: %s", name);
318 if (os::stat(name, &st) != 0) {
319 fail_continue("Required classpath entry does not exist: %s", name);
320 ok = false;
321 } else if (ent->is_dir()) {
322 if (!os::dir_is_empty(name)) {
323 fail_continue("directory is not empty: %s", name);
324 ok = false;
325 }
326 } else if (ent->is_jar_or_bootimage()) {
327 if (ent->_timestamp != st.st_mtime ||
328 ent->_filesize != st.st_size) {
329 ok = false;
330 if (PrintSharedArchiveAndExit) {
331 fail_continue(ent->_timestamp != st.st_mtime ?
332 "Timestamp mismatch" :
333 "File size mismatch");
334 } else {
335 fail_continue("A jar/jimage file is not the one used while building"
336 " the shared archive file: %s", name);
337 }
338 }
339 }
340 if (ok) {
341 log_info(class, path)("ok");
342 } else if (!PrintSharedArchiveAndExit) {
343 _validating_classpath_entry_table = false;
344 return false;
345 }
346 }
347
348 _classpath_entry_table_size = _header->_classpath_entry_table_size;
349 _validating_classpath_entry_table = false;
350 return true;
351 }
352
353
354 // Read the FileMapInfo information from the file.
355
356 bool FileMapInfo::init_from_file(int fd) {
357 size_t sz = _header->data_size();
358 char* addr = _header->data();
359 size_t n = os::read(fd, addr, (unsigned int)sz);
360 if (n != sz) {
361 fail_continue("Unable to read the file header.");
362 return false;
363 }
364 if (_header->_version != current_version()) {
365 fail_continue("The shared archive file has the wrong version.");
366 return false;
367 }
368 _file_offset = (long)n;
369
370 size_t info_size = _header->_paths_misc_info_size;
371 _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
372 if (_paths_misc_info == NULL) {
373 fail_continue("Unable to read the file header.");
374 return false;
375 }
376 n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
377 if (n != info_size) {
378 fail_continue("Unable to read the shared path info header.");
379 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
380 _paths_misc_info = NULL;
381 return false;
382 }
383
384 size_t len = lseek(fd, 0, SEEK_END);
385 struct FileMapInfo::FileMapHeader::space_info* si =
386 &_header->_space[MetaspaceShared::mc];
387 if (si->_file_offset >= len || len - si->_file_offset < si->_used) {
388 fail_continue("The shared archive file has been truncated.");
389 return false;
390 }
391
392 _file_offset += (long)n;
393 return true;
394 }
395
396
397 // Read the FileMapInfo information from the file.
398 bool FileMapInfo::open_for_read() {
399 _full_path = Arguments::GetSharedArchivePath();
400 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
401 if (fd < 0) {
402 if (errno == ENOENT) {
403 // Not locating the shared archive is ok.
404 fail_continue("Specified shared archive not found.");
405 } else {
406 fail_continue("Failed to open shared archive file (%s).",
407 os::strerror(errno));
408 }
409 return false;
410 }
411
412 _fd = fd;
413 _file_open = true;
414 return true;
415 }
416
417
418 // Write the FileMapInfo information to the file.
419
420 void FileMapInfo::open_for_write() {
421 _full_path = Arguments::GetSharedArchivePath();
422 if (PrintSharedSpaces) {
423 tty->print_cr("Dumping shared data to file: ");
424 tty->print_cr(" %s", _full_path);
425 }
426
427 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
428 chmod(_full_path, _S_IREAD | _S_IWRITE);
429 #endif
430
431 // Use remove() to delete the existing file because, on Unix, this will
432 // allow processes that have it open continued access to the file.
433 remove(_full_path);
434 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
435 if (fd < 0) {
436 fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
437 os::strerror(errno));
438 }
439 _fd = fd;
440 _file_offset = 0;
441 _file_open = true;
442 }
443
444
445 // Write the header to the file, seek to the next allocation boundary.
446
447 void FileMapInfo::write_header() {
448 int info_size = ClassLoader::get_shared_paths_misc_info_size();
449
450 _header->_paths_misc_info_size = info_size;
451
452 align_file_position();
453 size_t sz = _header->data_size();
454 char* addr = _header->data();
455 write_bytes(addr, (int)sz); // skip the C++ vtable
456 write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
457 align_file_position();
458 }
459
460
461 // Dump shared spaces to file.
462
463 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
464 align_file_position();
465 size_t used = space->used_bytes_slow(Metaspace::NonClassType);
466 size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
467 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
468 write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
469 }
470
471
472 // Dump region to file.
473
474 void FileMapInfo::write_region(int region, char* base, size_t size,
475 size_t capacity, bool read_only,
476 bool allow_exec) {
477 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
478
479 if (_file_open) {
480 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
481 if (PrintSharedSpaces) {
482 tty->print_cr("Shared file region %d: " SIZE_FORMAT_HEX_W(6) " bytes, addr " INTPTR_FORMAT
483 " file offset " SIZE_FORMAT_HEX_W(6), region, size, p2i(base), _file_offset);
484 }
485 } else {
486 si->_file_offset = _file_offset;
487 }
488 if (MetaspaceShared::is_string_region(region)) {
489 assert((base - (char*)Universe::narrow_oop_base()) % HeapWordSize == 0, "Sanity");
490 if (base != NULL) {
491 si->_addr._offset = (intx)oopDesc::encode_heap_oop_not_null((oop)base);
492 } else {
493 si->_addr._offset = 0;
494 }
495 } else {
496 si->_addr._base = base;
497 }
498 si->_used = size;
499 si->_capacity = capacity;
500 si->_read_only = read_only;
501 si->_allow_exec = allow_exec;
502 si->_crc = ClassLoader::crc32(0, base, (jint)size);
503 write_bytes_aligned(base, (int)size);
504 }
505
506 // Write the string space. The string space contains one or multiple GC(G1) regions.
507 // When the total string space size is smaller than one GC region of the dump time,
508 // only one string region is used for shared strings.
509 //
510 // If the total string space size is bigger than one GC region, there would be more
511 // than one GC regions allocated for shared strings. The first/bottom GC region might
512 // be a partial GC region with the empty portion at the higher address within that region.
513 // The non-empty portion of the first region is written into the archive as one string
514 // region. The rest are consecutive full GC regions if they exist, which can be written
515 // out in one chunk as another string region.
516 void FileMapInfo::write_string_regions(GrowableArray<MemRegion> *regions) {
517 for (int i = MetaspaceShared::first_string;
518 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
519 char* start = NULL;
520 size_t size = 0;
521 if (regions->is_nonempty()) {
522 if (i == MetaspaceShared::first_string) {
523 MemRegion first = regions->first();
524 start = (char*)first.start();
525 size = first.byte_size();
526 } else {
527 int len = regions->length();
528 if (len > 1) {
529 start = (char*)regions->at(1).start();
530 size = (char*)regions->at(len - 1).end() - start;
531 }
532 }
533 }
534 write_region(i, start, size, size, false, false);
535 }
536 }
537
538
539 // Dump bytes to file -- at the current file position.
540
541 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
542 if (_file_open) {
543 int n = ::write(_fd, buffer, nbytes);
544 if (n != nbytes) {
545 // It is dangerous to leave the corrupted shared archive file around,
546 // close and remove the file. See bug 6372906.
547 close();
548 remove(_full_path);
549 fail_stop("Unable to write to shared archive file.");
550 }
551 }
552 _file_offset += nbytes;
553 }
554
555
556 // Align file position to an allocation unit boundary.
557
558 void FileMapInfo::align_file_position() {
559 size_t new_file_offset = align_size_up(_file_offset,
560 os::vm_allocation_granularity());
561 if (new_file_offset != _file_offset) {
562 _file_offset = new_file_offset;
563 if (_file_open) {
564 // Seek one byte back from the target and write a byte to insure
565 // that the written file is the correct length.
566 _file_offset -= 1;
567 if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
568 fail_stop("Unable to seek.");
569 }
570 char zero = 0;
571 write_bytes(&zero, 1);
572 }
573 }
574 }
575
576
577 // Dump bytes to file -- at the current file position.
578
579 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
580 align_file_position();
581 write_bytes(buffer, nbytes);
582 align_file_position();
583 }
584
585
586 // Close the shared archive file. This does NOT unmap mapped regions.
587
588 void FileMapInfo::close() {
589 if (_file_open) {
590 if (::close(_fd) < 0) {
591 fail_stop("Unable to close the shared archive file.");
592 }
593 _file_open = false;
594 _fd = -1;
595 }
596 }
597
598
599 // JVM/TI RedefineClasses() support:
600 // Remap the shared readonly space to shared readwrite, private.
601 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
602 int idx = 0;
603 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[idx];
604 if (!si->_read_only) {
605 // the space is already readwrite so we are done
606 return true;
607 }
608 size_t used = si->_used;
609 size_t size = align_size_up(used, os::vm_allocation_granularity());
610 if (!open_for_read()) {
611 return false;
612 }
613 char *addr = _header->region_addr(idx);
614 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
615 addr, size, false /* !read_only */,
616 si->_allow_exec);
617 close();
618 if (base == NULL) {
619 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
620 return false;
621 }
622 if (base != addr) {
623 fail_continue("Unable to remap shared readonly space at required address.");
624 return false;
625 }
626 si->_read_only = false;
627 return true;
628 }
629
630 // Map the whole region at once, assumed to be allocated contiguously.
631 ReservedSpace FileMapInfo::reserve_shared_memory() {
632 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
633 char* requested_addr = _header->region_addr(0);
634
635 size_t size = FileMapInfo::shared_spaces_size();
636
637 // Reserve the space first, then map otherwise map will go right over some
638 // other reserved memory (like the code cache).
639 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
640 if (!rs.is_reserved()) {
641 fail_continue("Unable to reserve shared space at required address "
642 INTPTR_FORMAT, p2i(requested_addr));
643 return rs;
644 }
645 // the reserved virtual memory is for mapping class data sharing archive
646 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
647
648 return rs;
649 }
650
651 // Memory map a region in the address space.
652 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode",
653 "String1", "String2" };
654
655 char* FileMapInfo::map_region(int i) {
656 assert(!MetaspaceShared::is_string_region(i), "sanity");
657 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
658 size_t used = si->_used;
659 size_t alignment = os::vm_allocation_granularity();
660 size_t size = align_size_up(used, alignment);
661 char *requested_addr = _header->region_addr(i);
662
663 // If a tool agent is in use (debugging enabled), we must map the address space RW
664 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
665 si->_read_only = false;
666 }
667
668 // map the contents of the CDS archive in this memory
669 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
670 requested_addr, size, si->_read_only,
671 si->_allow_exec);
672 if (base == NULL || base != requested_addr) {
673 fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
674 return NULL;
675 }
676 #ifdef _WINDOWS
677 // This call is Windows-only because the memory_type gets recorded for the other platforms
678 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
679 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
680 #endif
681
682 return base;
683 }
684
685 static MemRegion *string_ranges = NULL;
686 static int num_ranges = 0;
687 bool FileMapInfo::map_string_regions() {
688 #if INCLUDE_ALL_GCS
689 if (UseG1GC && UseCompressedOops && UseCompressedClassPointers) {
690 // Check that all the narrow oop and klass encodings match the archive
691 if (narrow_oop_mode() != Universe::narrow_oop_mode() ||
692 narrow_oop_shift() != Universe::narrow_oop_shift() ||
693 narrow_klass_base() != Universe::narrow_klass_base() ||
694 narrow_klass_shift() != Universe::narrow_klass_shift()) {
695 if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
696 tty->print_cr("Shared string data from the CDS archive is being ignored. "
697 "The current CompressedOops/CompressedClassPointers encoding differs from "
698 "that archived due to heap size change. The archive was dumped using max heap "
699 "size " UINTX_FORMAT "M.", max_heap_size()/M);
700 }
701 } else {
702 string_ranges = new MemRegion[MetaspaceShared::max_strings];
703 struct FileMapInfo::FileMapHeader::space_info* si;
704
705 for (int i = MetaspaceShared::first_string;
706 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
707 si = &_header->_space[i];
708 size_t used = si->_used;
709 if (used > 0) {
710 size_t size = used;
711 char* requested_addr = (char*)((void*)oopDesc::decode_heap_oop_not_null(
712 (narrowOop)si->_addr._offset));
713 string_ranges[num_ranges] = MemRegion((HeapWord*)requested_addr, size / HeapWordSize);
714 num_ranges ++;
715 }
716 }
717
718 if (num_ranges == 0) {
719 StringTable::ignore_shared_strings(true);
720 return true; // no shared string data
721 }
722
723 // Check that ranges are within the java heap
724 if (!G1CollectedHeap::heap()->check_archive_addresses(string_ranges, num_ranges)) {
725 fail_continue("Unable to allocate shared string space: range is not "
726 "within java heap.");
727 return false;
728 }
729
730 // allocate from java heap
731 if (!G1CollectedHeap::heap()->alloc_archive_regions(string_ranges, num_ranges)) {
732 fail_continue("Unable to allocate shared string space: range is "
733 "already in use.");
734 return false;
735 }
736
737 // Map the string data. No need to call MemTracker::record_virtual_memory_type()
738 // for mapped string regions as they are part of the reserved java heap, which
739 // is already recorded.
740 for (int i = 0; i < num_ranges; i++) {
741 si = &_header->_space[MetaspaceShared::first_string + i];
742 char* addr = (char*)string_ranges[i].start();
743 char* base = os::map_memory(_fd, _full_path, si->_file_offset,
744 addr, string_ranges[i].byte_size(), si->_read_only,
745 si->_allow_exec);
746 if (base == NULL || base != addr) {
747 // dealloc the string regions from java heap
748 dealloc_string_regions();
749 fail_continue("Unable to map shared string space at required address.");
750 return false;
751 }
752 }
753
754 if (!verify_string_regions()) {
755 // dealloc the string regions from java heap
756 dealloc_string_regions();
757 fail_continue("Shared string regions are corrupt");
758 return false;
759 }
760
761 // the shared string data is mapped successfully
762 return true;
763 }
764 } else {
765 if (PrintSharedSpaces && _header->_space[MetaspaceShared::first_string]._used > 0) {
766 tty->print_cr("Shared string data from the CDS archive is being ignored. UseG1GC, "
767 "UseCompressedOops and UseCompressedClassPointers are required.");
768 }
769 }
770
771 // if we get here, the shared string data is not mapped
772 assert(string_ranges == NULL && num_ranges == 0, "sanity");
773 StringTable::ignore_shared_strings(true);
774 #endif
775 return true;
776 }
777
778 bool FileMapInfo::verify_string_regions() {
779 for (int i = MetaspaceShared::first_string;
780 i < MetaspaceShared::first_string + MetaspaceShared::max_strings; i++) {
781 if (!verify_region_checksum(i)) {
782 return false;
783 }
784 }
785 return true;
786 }
787
788 void FileMapInfo::fixup_string_regions() {
789 #if INCLUDE_ALL_GCS
790 // If any string regions were found, call the fill routine to make them parseable.
791 // Note that string_ranges may be non-NULL even if no ranges were found.
792 if (num_ranges != 0) {
793 assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
794 G1CollectedHeap::heap()->fill_archive_regions(string_ranges, num_ranges);
795 }
796 #endif
797 }
798
799 bool FileMapInfo::verify_region_checksum(int i) {
800 if (!VerifySharedSpaces) {
801 return true;
802 }
803
804 size_t sz = _header->_space[i]._used;
805
806 if (sz == 0) {
807 return true; // no data
808 }
809 if (MetaspaceShared::is_string_region(i) && StringTable::shared_string_ignored()) {
810 return true; // shared string data are not mapped
811 }
812 const char* buf = _header->region_addr(i);
813 int crc = ClassLoader::crc32(0, buf, (jint)sz);
814 if (crc != _header->_space[i]._crc) {
815 fail_continue("Checksum verification failed.");
816 return false;
817 }
818 return true;
819 }
820
821 // Unmap a memory region in the address space.
822
823 void FileMapInfo::unmap_region(int i) {
824 assert(!MetaspaceShared::is_string_region(i), "sanity");
825 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
826 size_t used = si->_used;
827 size_t size = align_size_up(used, os::vm_allocation_granularity());
828
829 if (used == 0) {
830 return;
831 }
832
833 char* addr = _header->region_addr(i);
834 if (!os::unmap_memory(addr, size)) {
835 fail_stop("Unable to unmap shared space.");
836 }
837 }
838
839 // dealloc the archived string region from java heap
840 void FileMapInfo::dealloc_string_regions() {
841 #if INCLUDE_ALL_GCS
842 if (num_ranges > 0) {
843 assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
844 G1CollectedHeap::heap()->dealloc_archive_regions(string_ranges, num_ranges);
845 }
846 #endif
847 }
848
849 void FileMapInfo::assert_mark(bool check) {
850 if (!check) {
851 fail_stop("Mark mismatch while restoring from shared file.");
852 }
853 }
854
855
856 FileMapInfo* FileMapInfo::_current_info = NULL;
857 SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL;
858 int FileMapInfo::_classpath_entry_table_size = 0;
859 size_t FileMapInfo::_classpath_entry_size = 0x1234baad;
860 bool FileMapInfo::_validating_classpath_entry_table = false;
861
862 // Open the shared archive file, read and validate the header
863 // information (version, boot classpath, etc.). If initialization
864 // fails, shared spaces are disabled and the file is closed. [See
865 // fail_continue.]
866 //
867 // Validation of the archive is done in two steps:
868 //
869 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
870 // [2] validate_classpath_entry_table - this is done later, because the table is in the RW
871 // region of the archive, which is not mapped yet.
872 bool FileMapInfo::initialize() {
873 assert(UseSharedSpaces, "UseSharedSpaces expected.");
874
875 if (!open_for_read()) {
876 return false;
877 }
878
879 init_from_file(_fd);
880 if (!validate_header()) {
881 return false;
882 }
883
884 SharedReadOnlySize = _header->_space[0]._capacity;
885 SharedReadWriteSize = _header->_space[1]._capacity;
886 SharedMiscDataSize = _header->_space[2]._capacity;
887 SharedMiscCodeSize = _header->_space[3]._capacity;
888 return true;
889 }
890
891 char* FileMapInfo::FileMapHeader::region_addr(int idx) {
892 if (MetaspaceShared::is_string_region(idx)) {
893 return (char*)((void*)oopDesc::decode_heap_oop_not_null(
894 (narrowOop)_space[idx]._addr._offset));
895 } else {
896 return _space[idx]._addr._base;
897 }
898 }
899
900 int FileMapInfo::FileMapHeader::compute_crc() {
901 char* header = data();
902 // start computing from the field after _crc
903 char* buf = (char*)&_crc + sizeof(int);
904 size_t sz = data_size() - (buf - header);
905 int crc = ClassLoader::crc32(0, buf, (jint)sz);
906 return crc;
907 }
908
909 bool FileMapInfo::FileMapHeader::validate() {
910 if (VerifySharedSpaces && compute_crc() != _crc) {
911 fail_continue("Header checksum verification failed.");
912 return false;
913 }
914
915 if (!Arguments::has_jimage()) {
916 FileMapInfo::fail_continue("The shared archive file cannot be used with an exploded module build.");
917 return false;
918 }
919
920 if (_version != current_version()) {
921 FileMapInfo::fail_continue("The shared archive file is the wrong version.");
922 return false;
923 }
924 if (_magic != (int)0xf00baba2) {
925 FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
926 return false;
927 }
928 char header_version[JVM_IDENT_MAX];
929 get_header_version(header_version);
930 if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
931 log_info(class, path)("expected: %s", header_version);
932 log_info(class, path)("actual: %s", _jvm_ident);
933 FileMapInfo::fail_continue("The shared archive file was created by a different"
934 " version or build of HotSpot");
935 return false;
936 }
937 if (_obj_alignment != ObjectAlignmentInBytes) {
938 FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
939 " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
940 _obj_alignment, ObjectAlignmentInBytes);
941 return false;
942 }
943 if (_compact_strings != CompactStrings) {
944 FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
945 " does not equal the current CompactStrings setting (%s).",
946 _compact_strings ? "enabled" : "disabled",
947 CompactStrings ? "enabled" : "disabled");
948 return false;
949 }
950
951 // Check if there is a mismatch in --patch-module entry counts between dump time and run time.
952 // More checks will be performed on individual --patch-module entry in the
953 // SharedPathsMiscInfo::check() function.
954 GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
955 if (patch_mod_args != NULL) {
956 if (_num_patch_mod_prefixes == 0) {
957 FileMapInfo::fail_stop("--patch-module found in run time but none was specified in dump time");
958 }
959 if (patch_mod_args->length() != _num_patch_mod_prefixes) {
960 FileMapInfo::fail_stop("mismatched --patch-module entry counts between dump time and run time");
961 }
962 } else {
963 if (_num_patch_mod_prefixes > 0) {
964 FileMapInfo::fail_stop("--patch-module specified in dump time but none was specified in run time");
965 }
966 }
967
968 return true;
969 }
970
971 bool FileMapInfo::validate_header() {
972 bool status = _header->validate();
973
974 if (status) {
975 if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
976 if (!PrintSharedArchiveAndExit) {
977 fail_continue("shared class paths mismatch (hint: enable -Xlog:class+path=info to diagnose the failure)");
978 status = false;
979 }
980 }
981 }
982
983 if (_paths_misc_info != NULL) {
984 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
985 _paths_misc_info = NULL;
986 }
987 return status;
988 }
989
990 // The following method is provided to see whether a given pointer
991 // falls in the mapped shared space.
992 // Param:
993 // p, The given pointer
994 // Return:
995 // True if the p is within the mapped shared space, otherwise, false.
996 bool FileMapInfo::is_in_shared_space(const void* p) {
997 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
998 char *base;
999 if (MetaspaceShared::is_string_region(i) && _header->_space[i]._used == 0) {
1000 continue;
1001 }
1002 base = _header->region_addr(i);
1003 if (p >= base && p < base + _header->_space[i]._used) {
1004 return true;
1005 }
1006 }
1007
1008 return false;
1009 }
1010
1011 // Check if a given address is within one of the shared regions (ro, rw, md, mc)
1012 bool FileMapInfo::is_in_shared_region(const void* p, int idx) {
1013 assert((idx >= MetaspaceShared::ro) && (idx <= MetaspaceShared::mc), "invalid region index");
1014 char* base = _header->region_addr(idx);
1015 if (p >= base && p < base + _header->_space[idx]._used) {
1016 return true;
1017 }
1018 return false;
1019 }
1020
1021 void FileMapInfo::print_shared_spaces() {
1022 tty->print_cr("Shared Spaces:");
1023 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1024 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
1025 char *base = _header->region_addr(i);
1026 tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
1027 shared_region_name[i],
1028 p2i(base), p2i(base + si->_used));
1029 }
1030 }
1031
1032 // Unmap mapped regions of shared space.
1033 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
1034 FileMapInfo *map_info = FileMapInfo::current_info();
1035 if (map_info) {
1036 map_info->fail_continue("%s", msg);
1037 for (int i = 0; i < MetaspaceShared::num_non_strings; i++) {
1038 char *addr = map_info->_header->region_addr(i);
1039 if (addr != NULL && !MetaspaceShared::is_string_region(i)) {
1040 map_info->unmap_region(i);
1041 map_info->_header->_space[i]._addr._base = NULL;
1042 }
1043 }
1044 // Dealloc the string regions only without unmapping. The string regions are part
1045 // of the java heap. Unmapping of the heap regions are managed by GC.
1046 map_info->dealloc_string_regions();
1047 } else if (DumpSharedSpaces) {
1048 fail_stop("%s", msg);
1049 }
1050 }