1 /*
2 * Copyright (c) 2003, 2018, 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 "jvm.h"
27 #include "classfile/classLoader.inline.hpp"
28 #include "classfile/compactHashtable.inline.hpp"
29 #include "classfile/sharedClassUtil.hpp"
30 #include "classfile/stringTable.hpp"
31 #include "classfile/symbolTable.hpp"
32 #include "classfile/systemDictionaryShared.hpp"
33 #include "classfile/altHashing.hpp"
34 #include "logging/log.hpp"
35 #include "logging/logStream.hpp"
36 #include "logging/logMessage.hpp"
37 #include "memory/filemap.hpp"
38 #include "memory/metadataFactory.hpp"
39 #include "memory/metaspaceClosure.hpp"
40 #include "memory/metaspaceShared.hpp"
41 #include "memory/oopFactory.hpp"
42 #include "oops/compressedOops.inline.hpp"
43 #include "oops/objArrayOop.hpp"
44 #include "prims/jvmtiExport.hpp"
45 #include "runtime/arguments.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/os.hpp"
48 #include "runtime/vm_version.hpp"
49 #include "services/memTracker.hpp"
50 #include "utilities/align.hpp"
51 #include "utilities/defaultStream.hpp"
52 #if INCLUDE_ALL_GCS
53 #include "gc/g1/g1CollectedHeap.hpp"
54 #endif
55
56 # include <sys/stat.h>
57 # include <errno.h>
58
59 #ifndef O_BINARY // if defined (Win32) use binary files.
60 #define O_BINARY 0 // otherwise do nothing.
61 #endif
62
63 extern address JVM_FunctionAtStart();
64 extern address JVM_FunctionAtEnd();
65
66 // Complain and stop. All error conditions occurring during the writing of
67 // an archive file should stop the process. Unrecoverable errors during
68 // the reading of the archive file should stop the process.
69
70 static void fail(const char *msg, va_list ap) {
71 // This occurs very early during initialization: tty is not initialized.
72 jio_fprintf(defaultStream::error_stream(),
73 "An error has occurred while processing the"
74 " shared archive file.\n");
75 jio_vfprintf(defaultStream::error_stream(), msg, ap);
76 jio_fprintf(defaultStream::error_stream(), "\n");
77 // Do not change the text of the below message because some tests check for it.
78 vm_exit_during_initialization("Unable to use shared archive.", NULL);
79 }
80
81
82 void FileMapInfo::fail_stop(const char *msg, ...) {
83 va_list ap;
84 va_start(ap, msg);
85 fail(msg, ap); // Never returns.
86 va_end(ap); // for completeness.
87 }
88
89
90 // Complain and continue. Recoverable errors during the reading of the
91 // archive file may continue (with sharing disabled).
92 //
93 // If we continue, then disable shared spaces and close the file.
94
95 void FileMapInfo::fail_continue(const char *msg, ...) {
96 va_list ap;
97 va_start(ap, msg);
98 MetaspaceShared::set_archive_loading_failed();
99 if (PrintSharedArchiveAndExit && _validating_shared_path_table) {
100 // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
101 // do not validate, we can still continue "limping" to validate the remaining
102 // entries. No need to quit.
103 tty->print("[");
104 tty->vprint(msg, ap);
105 tty->print_cr("]");
106 } else {
107 if (RequireSharedSpaces) {
108 fail(msg, ap);
109 } else {
110 if (log_is_enabled(Info, cds)) {
111 ResourceMark rm;
112 LogStream ls(Log(cds)::info());
113 ls.print("UseSharedSpaces: ");
114 ls.vprint_cr(msg, ap);
115 }
116 }
117 UseSharedSpaces = false;
118 assert(current_info() != NULL, "singleton must be registered");
119 current_info()->close();
120 }
121 va_end(ap);
122 }
123
124 // Fill in the fileMapInfo structure with data about this VM instance.
125
126 // This method copies the vm version info into header_version. If the version is too
127 // long then a truncated version, which has a hash code appended to it, is copied.
128 //
129 // Using a template enables this method to verify that header_version is an array of
130 // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and
131 // the code that reads the CDS file will both use the same size buffer. Hence, will
132 // use identical truncation. This is necessary for matching of truncated versions.
133 template <int N> static void get_header_version(char (&header_version) [N]) {
134 assert(N == JVM_IDENT_MAX, "Bad header_version size");
135
136 const char *vm_version = VM_Version::internal_vm_info_string();
137 const int version_len = (int)strlen(vm_version);
138
139 if (version_len < (JVM_IDENT_MAX-1)) {
140 strcpy(header_version, vm_version);
141
142 } else {
143 // Get the hash value. Use a static seed because the hash needs to return the same
144 // value over multiple jvm invocations.
145 unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
146
147 // Truncate the ident, saving room for the 8 hex character hash value.
148 strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
149
150 // Append the hash code as eight hex digits.
151 sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
152 header_version[JVM_IDENT_MAX-1] = 0; // Null terminate.
153 }
154 }
155
156 FileMapInfo::FileMapInfo() {
157 assert(_current_info == NULL, "must be singleton"); // not thread safe
158 _current_info = this;
159 memset((void*)this, 0, sizeof(FileMapInfo));
160 _file_offset = 0;
161 _file_open = false;
162 _header = SharedClassUtil::allocate_file_map_header();
163 _header->_version = _invalid_version;
164 }
165
166 FileMapInfo::~FileMapInfo() {
167 assert(_current_info == this, "must be singleton"); // not thread safe
168 _current_info = NULL;
169 }
170
171 void FileMapInfo::populate_header(size_t alignment) {
172 _header->populate(this, alignment);
173 }
174
175 size_t FileMapInfo::FileMapHeader::data_size() {
176 return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);
177 }
178
179 void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
180 _magic = 0xf00baba2;
181 _version = _current_version;
182 _alignment = alignment;
183 _obj_alignment = ObjectAlignmentInBytes;
184 _compact_strings = CompactStrings;
185 _narrow_oop_mode = Universe::narrow_oop_mode();
186 _narrow_oop_base = Universe::narrow_oop_base();
187 _narrow_oop_shift = Universe::narrow_oop_shift();
188 _max_heap_size = MaxHeapSize;
189 _narrow_klass_base = Universe::narrow_klass_base();
190 _narrow_klass_shift = Universe::narrow_klass_shift();
191 _shared_path_table_size = mapinfo->_shared_path_table_size;
192 _shared_path_table = mapinfo->_shared_path_table;
193 _shared_path_entry_size = mapinfo->_shared_path_entry_size;
194
195 // The following fields are for sanity checks for whether this archive
196 // will function correctly with this JVM and the bootclasspath it's
197 // invoked with.
198
199 // JVM version string ... changes on each build.
200 get_header_version(_jvm_ident);
201 }
202
203 void SharedClassPathEntry::init(const char* name, TRAPS) {
204 _timestamp = 0;
205 _filesize = 0;
206
207 struct stat st;
208 if (os::stat(name, &st) == 0) {
209 if ((st.st_mode & S_IFMT) == S_IFDIR) {
210 if (!os::dir_is_empty(name)) {
211 ClassLoader::exit_with_path_failure(
212 "Cannot have non-empty directory in archived classpaths", name);
213 }
214 _is_dir = true;
215 } else {
216 _is_dir = false;
217 _timestamp = st.st_mtime;
218 _filesize = st.st_size;
219 }
220 } else {
221 // The file/dir must exist, or it would not have been added
222 // into ClassLoader::classpath_entry().
223 //
224 // If we can't access a jar file in the boot path, then we can't
225 // make assumptions about where classes get loaded from.
226 FileMapInfo::fail_stop("Unable to open file %s.", name);
227 }
228
229 size_t len = strlen(name) + 1;
230 _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, THREAD);
231 strcpy(_name->data(), name);
232 }
233
234 bool SharedClassPathEntry::validate(bool is_class_path) {
235 struct stat st;
236 const char* name = this->name();
237 bool ok = true;
238 log_info(class, path)("checking shared classpath entry: %s", name);
239 if (os::stat(name, &st) != 0 && is_class_path) {
240 FileMapInfo::fail_continue("Required classpath entry does not exist: %s", name);
241 ok = false;
242 } else if (is_dir() && is_class_path) {
243 if (!os::dir_is_empty(name)) {
244 FileMapInfo::fail_continue("directory is not empty: %s", name);
245 ok = false;
246 }
247 } else if (is_jar_or_bootimage()) {
248 if (_timestamp != st.st_mtime ||
249 _filesize != st.st_size) {
250 ok = false;
251 if (PrintSharedArchiveAndExit) {
252 FileMapInfo::fail_continue(_timestamp != st.st_mtime ?
253 "Timestamp mismatch" :
254 "File size mismatch");
255 } else {
256 FileMapInfo::fail_continue("A jar/jimage file is not the one used while building"
257 " the shared archive file: %s", name);
258 }
259 }
260 }
261 return ok;
262 }
263
264 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
265 it->push(&_name);
266 it->push(&_manifest);
267 }
268
269 void FileMapInfo::allocate_shared_path_table() {
270 assert(DumpSharedSpaces, "Sanity");
271
272 Thread* THREAD = Thread::current();
273 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
274 ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
275
276 assert(jrt != NULL,
277 "No modular java runtime image present when allocating the CDS classpath entry table");
278
279 size_t entry_size = SharedClassUtil::shared_class_path_entry_size(); // assert ( should be 8 byte aligned??)
280 int num_boot_classpath_entries = ClassLoader::num_boot_classpath_entries();
281 int num_app_classpath_entries = ClassLoader::num_app_classpath_entries();
282 int num_module_path_entries = ClassLoader::num_module_path_entries();
283 int num_entries = num_boot_classpath_entries + num_app_classpath_entries + num_module_path_entries;
284 size_t bytes = entry_size * num_entries;
285
286 _shared_path_table = MetadataFactory::new_array<u8>(loader_data, (int)(bytes + 7 / 8), THREAD);
287 _shared_path_table_size = num_entries;
288 _shared_path_entry_size = entry_size;
289
290 // 1. boot class path
291 int i = 0;
292 ClassPathEntry* cpe = jrt;
293 while (cpe != NULL) {
294 const char* type = ((cpe == jrt) ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
295 log_info(class, path)("add main shared path (%s) %s", type, cpe->name());
296 SharedClassPathEntry* ent = shared_path(i);
297 ent->init(cpe->name(), THREAD);
298 if (cpe != jrt) { // No need to do jimage.
299 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
300 SharedClassUtil::update_shared_classpath(cpe, ent, THREAD);
301 }
302 cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
303 i++;
304 }
305 assert(i == num_boot_classpath_entries,
306 "number of boot class path entry mismatch");
307
308 // 2. app class path
309 ClassPathEntry *acpe = ClassLoader::app_classpath_entries();
310 while (acpe != NULL) {
311 log_info(class, path)("add app shared path %s", acpe->name());
312 SharedClassPathEntry* ent = shared_path(i);
313 ent->init(acpe->name(), THREAD);
314 EXCEPTION_MARK;
315 SharedClassUtil::update_shared_classpath(acpe, ent, THREAD);
316 acpe = acpe->next();
317 i++;
318 }
319
320 // 3. module path
321 ClassPathEntry *mpe = ClassLoader::module_path_entries();
322 while (mpe != NULL) {
323 log_info(class, path)("add module path %s",mpe->name());
324 SharedClassPathEntry* ent = shared_path(i);
325 ent->init(mpe->name(), THREAD);
326 EXCEPTION_MARK;
327 SharedClassUtil::update_shared_classpath(mpe, ent, THREAD);
328 mpe = mpe->next();
329 i++;
330 }
331 assert(i == num_entries, "number of shared path entry mismatch");
332 }
333
334 bool FileMapInfo::validate_shared_path_table() {
335 _validating_shared_path_table = true;
336
337 _shared_path_table = _header->_shared_path_table;
338 _shared_path_entry_size = _header->_shared_path_entry_size;
339 _shared_path_table_size = _header->_shared_path_table_size;
340
341 // Note: _app_module_paths_start_index may not have a valid value if the UseAppCDS flag
342 // wasn't enabled during dump time. Therefore, we need to use the smaller of
343 // _shared_path_table_size and _app_module_paths_start_index for the _app_module_paths_start_index.
344 FileMapHeaderExt* header = (FileMapHeaderExt*)FileMapInfo::current_info()->header();
345 int module_paths_start_index = (header->_app_module_paths_start_index >= _shared_path_table_size) ?
346 _shared_path_table_size : header->_app_module_paths_start_index;
347
348 int count = _shared_path_table_size;
349
350 for (int i=0; i<count; i++) {
351 if (i < module_paths_start_index) {
352 if (shared_path(i)->validate()) {
353 log_info(class, path)("ok");
354 }
355 } else if (i >= module_paths_start_index) {
356 if (shared_path(i)->validate(false /* not a class path entry */)) {
357 log_info(class, path)("ok");
358 }
359 } else if (!PrintSharedArchiveAndExit) {
360 _validating_shared_path_table = false;
361 _shared_path_table = NULL;
362 _shared_path_table_size = 0;
363 return false;
364 }
365 }
366
367 _validating_shared_path_table = false;
368 return true;
369 }
370
371 // Read the FileMapInfo information from the file.
372
373 bool FileMapInfo::init_from_file(int fd) {
374 size_t sz = _header->data_size();
375 char* addr = _header->data();
376 size_t n = os::read(fd, addr, (unsigned int)sz);
377 if (n != sz) {
378 fail_continue("Unable to read the file header.");
379 return false;
380 }
381 if (_header->_version != current_version()) {
382 fail_continue("The shared archive file has the wrong version.");
383 return false;
384 }
385 _file_offset = (long)n;
386
387 size_t info_size = _header->_paths_misc_info_size;
388 _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
389 if (_paths_misc_info == NULL) {
390 fail_continue("Unable to read the file header.");
391 return false;
392 }
393 n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
394 if (n != info_size) {
395 fail_continue("Unable to read the shared path info header.");
396 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
397 _paths_misc_info = NULL;
398 return false;
399 }
400
401 size_t len = lseek(fd, 0, SEEK_END);
402 struct FileMapInfo::FileMapHeader::space_info* si =
403 &_header->_space[MetaspaceShared::last_valid_region];
404 // The last space might be empty
405 if (si->_file_offset > len || len - si->_file_offset < si->_used) {
406 fail_continue("The shared archive file has been truncated.");
407 return false;
408 }
409
410 _file_offset += (long)n;
411 return true;
412 }
413
414
415 // Read the FileMapInfo information from the file.
416 bool FileMapInfo::open_for_read() {
417 _full_path = Arguments::GetSharedArchivePath();
418 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
419 if (fd < 0) {
420 if (errno == ENOENT) {
421 // Not locating the shared archive is ok.
422 fail_continue("Specified shared archive not found.");
423 } else {
424 fail_continue("Failed to open shared archive file (%s).",
425 os::strerror(errno));
426 }
427 return false;
428 }
429
430 _fd = fd;
431 _file_open = true;
432 return true;
433 }
434
435
436 // Write the FileMapInfo information to the file.
437
438 void FileMapInfo::open_for_write() {
439 _full_path = Arguments::GetSharedArchivePath();
440 LogMessage(cds) msg;
441 if (msg.is_info()) {
442 msg.info("Dumping shared data to file: ");
443 msg.info(" %s", _full_path);
444 }
445
446 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
447 chmod(_full_path, _S_IREAD | _S_IWRITE);
448 #endif
449
450 // Use remove() to delete the existing file because, on Unix, this will
451 // allow processes that have it open continued access to the file.
452 remove(_full_path);
453 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
454 if (fd < 0) {
455 fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
456 os::strerror(errno));
457 }
458 _fd = fd;
459 _file_offset = 0;
460 _file_open = true;
461 }
462
463
464 // Write the header to the file, seek to the next allocation boundary.
465
466 void FileMapInfo::write_header() {
467 int info_size = ClassLoader::get_shared_paths_misc_info_size();
468
469 _header->_paths_misc_info_size = info_size;
470
471 align_file_position();
472 size_t sz = _header->data_size();
473 char* addr = _header->data();
474 write_bytes(addr, (int)sz); // skip the C++ vtable
475 write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
476 align_file_position();
477 }
478
479
480 // Dump region to file.
481
482 void FileMapInfo::write_region(int region, char* base, size_t size,
483 bool read_only, bool allow_exec) {
484 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
485
486 if (_file_open) {
487 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
488 log_info(cds)("Shared file region %d: " SIZE_FORMAT_HEX_W(08)
489 " bytes, addr " INTPTR_FORMAT " file offset " SIZE_FORMAT_HEX_W(08),
490 region, size, p2i(base), _file_offset);
491 } else {
492 si->_file_offset = _file_offset;
493 }
494 if (MetaspaceShared::is_heap_region(region)) {
495 assert((base - (char*)Universe::narrow_oop_base()) % HeapWordSize == 0, "Sanity");
496 if (base != NULL) {
497 si->_addr._offset = (intx)CompressedOops::encode_not_null((oop)base);
498 } else {
499 si->_addr._offset = 0;
500 }
501 } else {
502 si->_addr._base = base;
503 }
504 si->_used = size;
505 si->_read_only = read_only;
506 si->_allow_exec = allow_exec;
507 si->_crc = ClassLoader::crc32(0, base, (jint)size);
508 write_bytes_aligned(base, (int)size);
509 }
510
511 // Write out the given archive heap memory regions. GC code combines multiple
512 // consecutive archive GC regions into one MemRegion whenever possible and
513 // produces the 'heap_mem' array.
514 //
515 // If the archive heap memory size is smaller than a single dump time GC region
516 // size, there is only one MemRegion in the array.
517 //
518 // If the archive heap memory size is bigger than one dump time GC region size,
519 // the 'heap_mem' array may contain more than one consolidated MemRegions. When
520 // the first/bottom archive GC region is a partial GC region (with the empty
521 // portion at the higher address within the region), one MemRegion is used for
522 // the bottom partial archive GC region. The rest of the consecutive archive
523 // GC regions are combined into another MemRegion.
524 //
525 // Here's the mapping from (archive heap GC regions) -> (GrowableArray<MemRegion> *regions).
526 // + We have 1 or more archive heap regions: ah0, ah1, ah2 ..... ahn
527 // + We have 1 or 2 consolidated heap memory regions: r0 and r1
528 //
529 // If there's a single archive GC region (ah0), then r0 == ah0, and r1 is empty.
530 // Otherwise:
531 //
532 // "X" represented space that's occupied by heap objects.
533 // "_" represented unused spaced in the heap region.
534 //
535 //
536 // |ah0 | ah1 | ah2| ...... | ahn |
537 // |XXXXXX|__ |XXXXX|XXXX|XXXXXXXX|XXXX|
538 // |<-r0->| |<- r1 ----------------->|
539 // ^^^
540 // |
541 // +-- gap
542 size_t FileMapInfo::write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,
543 int first_region_id, int max_num_regions) {
544 assert(max_num_regions <= 2, "Only support maximum 2 memory regions");
545
546 int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
547 if(arr_len > max_num_regions) {
548 fail_stop("Unable to write archive heap memory regions: "
549 "number of memory regions exceeds maximum due to fragmentation");
550 }
551
552 size_t total_size = 0;
553 for (int i = first_region_id, arr_idx = 0;
554 i < first_region_id + max_num_regions;
555 i++, arr_idx++) {
556 char* start = NULL;
557 size_t size = 0;
558 if (arr_idx < arr_len) {
559 start = (char*)heap_mem->at(arr_idx).start();
560 size = heap_mem->at(arr_idx).byte_size();
561 total_size += size;
562 }
563
564 log_info(cds)("Archive heap region %d " INTPTR_FORMAT " - " INTPTR_FORMAT " = " SIZE_FORMAT_W(8) " bytes",
565 i, p2i(start), p2i(start + size), size);
566 write_region(i, start, size, false, false);
567 }
568 return total_size;
569 }
570
571 // Dump bytes to file -- at the current file position.
572
573 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
574 if (_file_open) {
575 int n = ::write(_fd, buffer, nbytes);
576 if (n != nbytes) {
577 // It is dangerous to leave the corrupted shared archive file around,
578 // close and remove the file. See bug 6372906.
579 close();
580 remove(_full_path);
581 fail_stop("Unable to write to shared archive file.");
582 }
583 }
584 _file_offset += nbytes;
585 }
586
587
588 // Align file position to an allocation unit boundary.
589
590 void FileMapInfo::align_file_position() {
591 size_t new_file_offset = align_up(_file_offset,
592 os::vm_allocation_granularity());
593 if (new_file_offset != _file_offset) {
594 _file_offset = new_file_offset;
595 if (_file_open) {
596 // Seek one byte back from the target and write a byte to insure
597 // that the written file is the correct length.
598 _file_offset -= 1;
599 if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
600 fail_stop("Unable to seek.");
601 }
602 char zero = 0;
603 write_bytes(&zero, 1);
604 }
605 }
606 }
607
608
609 // Dump bytes to file -- at the current file position.
610
611 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
612 align_file_position();
613 write_bytes(buffer, nbytes);
614 align_file_position();
615 }
616
617
618 // Close the shared archive file. This does NOT unmap mapped regions.
619
620 void FileMapInfo::close() {
621 if (_file_open) {
622 if (::close(_fd) < 0) {
623 fail_stop("Unable to close the shared archive file.");
624 }
625 _file_open = false;
626 _fd = -1;
627 }
628 }
629
630
631 // JVM/TI RedefineClasses() support:
632 // Remap the shared readonly space to shared readwrite, private.
633 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
634 int idx = MetaspaceShared::ro;
635 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[idx];
636 if (!si->_read_only) {
637 // the space is already readwrite so we are done
638 return true;
639 }
640 size_t used = si->_used;
641 size_t size = align_up(used, os::vm_allocation_granularity());
642 if (!open_for_read()) {
643 return false;
644 }
645 char *addr = _header->region_addr(idx);
646 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
647 addr, size, false /* !read_only */,
648 si->_allow_exec);
649 close();
650 if (base == NULL) {
651 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
652 return false;
653 }
654 if (base != addr) {
655 fail_continue("Unable to remap shared readonly space at required address.");
656 return false;
657 }
658 si->_read_only = false;
659 return true;
660 }
661
662 // Map the whole region at once, assumed to be allocated contiguously.
663 ReservedSpace FileMapInfo::reserve_shared_memory() {
664 char* requested_addr = _header->region_addr(0);
665 size_t size = FileMapInfo::core_spaces_size();
666
667 // Reserve the space first, then map otherwise map will go right over some
668 // other reserved memory (like the code cache).
669 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
670 if (!rs.is_reserved()) {
671 fail_continue("Unable to reserve shared space at required address "
672 INTPTR_FORMAT, p2i(requested_addr));
673 return rs;
674 }
675 // the reserved virtual memory is for mapping class data sharing archive
676 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
677
678 return rs;
679 }
680
681 // Memory map a region in the address space.
682 static const char* shared_region_name[] = { "MiscData", "ReadWrite", "ReadOnly", "MiscCode", "OptionalData",
683 "String1", "String2", "OpenArchive1", "OpenArchive2" };
684
685 char* FileMapInfo::map_region(int i, char** top_ret) {
686 assert(!MetaspaceShared::is_heap_region(i), "sanity");
687 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
688 size_t used = si->_used;
689 size_t alignment = os::vm_allocation_granularity();
690 size_t size = align_up(used, alignment);
691 char *requested_addr = _header->region_addr(i);
692
693 // If a tool agent is in use (debugging enabled), we must map the address space RW
694 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
695 si->_read_only = false;
696 }
697
698 // map the contents of the CDS archive in this memory
699 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
700 requested_addr, size, si->_read_only,
701 si->_allow_exec);
702 if (base == NULL || base != requested_addr) {
703 fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
704 return NULL;
705 }
706 #ifdef _WINDOWS
707 // This call is Windows-only because the memory_type gets recorded for the other platforms
708 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
709 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
710 #endif
711
712
713 if (!verify_region_checksum(i)) {
714 return NULL;
715 }
716
717 *top_ret = base + size;
718 return base;
719 }
720
721 static MemRegion *string_ranges = NULL;
722 static MemRegion *open_archive_heap_ranges = NULL;
723 static int num_string_ranges = 0;
724 static int num_open_archive_heap_ranges = 0;
725
726 #if INCLUDE_CDS_JAVA_HEAP
727 //
728 // Map the shared string objects and open archive heap objects to the runtime
729 // java heap.
730 //
731 // The shared strings are mapped near the runtime java heap top. The
732 // mapped strings contain no out-going references to any other java heap
733 // regions. GC does not write into the mapped shared strings.
734 //
735 // The open archive heap objects are mapped below the shared strings in
736 // the runtime java heap. The mapped open archive heap data only contain
737 // references to the shared strings and open archive objects initially.
738 // During runtime execution, out-going references to any other java heap
739 // regions may be added. GC may mark and update references in the mapped
740 // open archive objects.
741 void FileMapInfo::map_heap_regions() {
742 if (MetaspaceShared::is_heap_object_archiving_allowed()) {
743 log_info(cds)("Archived narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
744 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
745 log_info(cds)("Archived narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
746 p2i(narrow_klass_base()), narrow_klass_shift());
747
748 // Check that all the narrow oop and klass encodings match the archive
749 if (narrow_oop_mode() != Universe::narrow_oop_mode() ||
750 narrow_oop_base() != Universe::narrow_oop_base() ||
751 narrow_oop_shift() != Universe::narrow_oop_shift() ||
752 narrow_klass_base() != Universe::narrow_klass_base() ||
753 narrow_klass_shift() != Universe::narrow_klass_shift()) {
754 if (log_is_enabled(Info, cds) && _header->_space[MetaspaceShared::first_string]._used > 0) {
755 log_info(cds)("Cached heap data from the CDS archive is being ignored. "
756 "The current CompressedOops/CompressedClassPointers encoding differs from "
757 "that archived due to heap size change. The archive was dumped using max heap "
758 "size " UINTX_FORMAT "M.", max_heap_size()/M);
759 log_info(cds)("Current narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
760 Universe::narrow_oop_mode(), p2i(Universe::narrow_oop_base()),
761 Universe::narrow_oop_shift());
762 log_info(cds)("Current narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
763 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
764 }
765 } else {
766 // First, map string regions as closed archive heap regions.
767 // GC does not write into the regions.
768 if (map_heap_data(&string_ranges,
769 MetaspaceShared::first_string,
770 MetaspaceShared::max_strings,
771 &num_string_ranges)) {
772 StringTable::set_shared_string_mapped();
773
774 // Now, map open_archive heap regions, GC can write into the regions.
775 if (map_heap_data(&open_archive_heap_ranges,
776 MetaspaceShared::first_open_archive_heap_region,
777 MetaspaceShared::max_open_archive_heap_region,
778 &num_open_archive_heap_ranges,
779 true /* open */)) {
780 MetaspaceShared::set_open_archive_heap_region_mapped();
781 }
782 }
783 }
784 } else {
785 if (log_is_enabled(Info, cds) && _header->_space[MetaspaceShared::first_string]._used > 0) {
786 log_info(cds)("Cached heap data from the CDS archive is being ignored. UseG1GC, "
787 "UseCompressedOops and UseCompressedClassPointers are required.");
788 }
789 }
790
791 if (!StringTable::shared_string_mapped()) {
792 assert(string_ranges == NULL && num_string_ranges == 0, "sanity");
793 }
794
795 if (!MetaspaceShared::open_archive_heap_region_mapped()) {
796 assert(open_archive_heap_ranges == NULL && num_open_archive_heap_ranges == 0, "sanity");
797 }
798 }
799
800 bool FileMapInfo::map_heap_data(MemRegion **heap_mem, int first,
801 int max, int* num, bool is_open_archive) {
802 MemRegion * regions = new MemRegion[max];
803 struct FileMapInfo::FileMapHeader::space_info* si;
804 int region_num = 0;
805
806 for (int i = first;
807 i < first + max; i++) {
808 si = &_header->_space[i];
809 size_t used = si->_used;
810 if (used > 0) {
811 size_t size = used;
812 char* requested_addr = (char*)((void*)CompressedOops::decode_not_null(
813 (narrowOop)si->_addr._offset));
814 regions[region_num] = MemRegion((HeapWord*)requested_addr, size / HeapWordSize);
815 region_num ++;
816 }
817 }
818
819 if (region_num == 0) {
820 return false; // no archived java heap data
821 }
822
823 // Check that ranges are within the java heap
824 if (!G1CollectedHeap::heap()->check_archive_addresses(regions, region_num)) {
825 log_info(cds)("UseSharedSpaces: Unable to allocate region, "
826 "range is not within java heap.");
827 return false;
828 }
829
830 // allocate from java heap
831 if (!G1CollectedHeap::heap()->alloc_archive_regions(
832 regions, region_num, is_open_archive)) {
833 log_info(cds)("UseSharedSpaces: Unable to allocate region, "
834 "java heap range is already in use.");
835 return false;
836 }
837
838 // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
839 // for mapped regions as they are part of the reserved java heap, which is
840 // already recorded.
841 for (int i = 0; i < region_num; i++) {
842 si = &_header->_space[first + i];
843 char* addr = (char*)regions[i].start();
844 char* base = os::map_memory(_fd, _full_path, si->_file_offset,
845 addr, regions[i].byte_size(), si->_read_only,
846 si->_allow_exec);
847 if (base == NULL || base != addr) {
848 // dealloc the regions from java heap
849 dealloc_archive_heap_regions(regions, region_num);
850 log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap.");
851 return false;
852 }
853 }
854
855 if (!verify_mapped_heap_regions(first, region_num)) {
856 // dealloc the regions from java heap
857 dealloc_archive_heap_regions(regions, region_num);
858 log_info(cds)("UseSharedSpaces: mapped heap regions are corrupt");
859 return false;
860 }
861
862 // the shared heap data is mapped successfully
863 *heap_mem = regions;
864 *num = region_num;
865 return true;
866 }
867
868 bool FileMapInfo::verify_mapped_heap_regions(int first, int num) {
869 for (int i = first;
870 i <= first + num; i++) {
871 if (!verify_region_checksum(i)) {
872 return false;
873 }
874 }
875 return true;
876 }
877
878 void FileMapInfo::fixup_mapped_heap_regions() {
879 // If any string regions were found, call the fill routine to make them parseable.
880 // Note that string_ranges may be non-NULL even if no ranges were found.
881 if (num_string_ranges != 0) {
882 assert(string_ranges != NULL, "Null string_ranges array with non-zero count");
883 G1CollectedHeap::heap()->fill_archive_regions(string_ranges, num_string_ranges);
884 }
885
886 // do the same for mapped open archive heap regions
887 if (num_open_archive_heap_ranges != 0) {
888 assert(open_archive_heap_ranges != NULL, "NULL open_archive_heap_ranges array with non-zero count");
889 G1CollectedHeap::heap()->fill_archive_regions(open_archive_heap_ranges,
890 num_open_archive_heap_ranges);
891 }
892 }
893
894 // dealloc the archive regions from java heap
895 void FileMapInfo::dealloc_archive_heap_regions(MemRegion* regions, int num) {
896 if (num > 0) {
897 assert(regions != NULL, "Null archive ranges array with non-zero count");
898 G1CollectedHeap::heap()->dealloc_archive_regions(regions, num);
899 }
900 }
901 #endif // INCLUDE_CDS_JAVA_HEAP
902
903 bool FileMapInfo::verify_region_checksum(int i) {
904 if (!VerifySharedSpaces) {
905 return true;
906 }
907
908 size_t sz = _header->_space[i]._used;
909
910 if (sz == 0) {
911 return true; // no data
912 }
913 if ((MetaspaceShared::is_string_region(i) &&
914 !StringTable::shared_string_mapped()) ||
915 (MetaspaceShared::is_open_archive_heap_region(i) &&
916 !MetaspaceShared::open_archive_heap_region_mapped())) {
917 return true; // archived heap data is not mapped
918 }
919 const char* buf = _header->region_addr(i);
920 int crc = ClassLoader::crc32(0, buf, (jint)sz);
921 if (crc != _header->_space[i]._crc) {
922 fail_continue("Checksum verification failed.");
923 return false;
924 }
925 return true;
926 }
927
928 // Unmap a memory region in the address space.
929
930 void FileMapInfo::unmap_region(int i) {
931 assert(!MetaspaceShared::is_heap_region(i), "sanity");
932 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
933 size_t used = si->_used;
934 size_t size = align_up(used, os::vm_allocation_granularity());
935
936 if (used == 0) {
937 return;
938 }
939
940 char* addr = _header->region_addr(i);
941 if (!os::unmap_memory(addr, size)) {
942 fail_stop("Unable to unmap shared space.");
943 }
944 }
945
946 void FileMapInfo::assert_mark(bool check) {
947 if (!check) {
948 fail_stop("Mark mismatch while restoring from shared file.");
949 }
950 }
951
952 void FileMapInfo::metaspace_pointers_do(MetaspaceClosure* it) {
953 it->push(&_shared_path_table);
954 for (int i=0; i<_shared_path_table_size; i++) {
955 shared_path(i)->metaspace_pointers_do(it);
956 }
957 }
958
959
960 FileMapInfo* FileMapInfo::_current_info = NULL;
961 Array<u8>* FileMapInfo::_shared_path_table = NULL;
962 int FileMapInfo::_shared_path_table_size = 0;
963 size_t FileMapInfo::_shared_path_entry_size = 0x1234baad;
964 bool FileMapInfo::_validating_shared_path_table = false;
965
966 // Open the shared archive file, read and validate the header
967 // information (version, boot classpath, etc.). If initialization
968 // fails, shared spaces are disabled and the file is closed. [See
969 // fail_continue.]
970 //
971 // Validation of the archive is done in two steps:
972 //
973 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
974 // [2] validate_shared_path_table - this is done later, because the table is in the RW
975 // region of the archive, which is not mapped yet.
976 bool FileMapInfo::initialize() {
977 assert(UseSharedSpaces, "UseSharedSpaces expected.");
978
979 if (!open_for_read()) {
980 return false;
981 }
982
983 init_from_file(_fd);
984 if (!validate_header()) {
985 return false;
986 }
987 return true;
988 }
989
990 char* FileMapInfo::FileMapHeader::region_addr(int idx) {
991 if (MetaspaceShared::is_heap_region(idx)) {
992 return _space[idx]._used > 0 ?
993 (char*)((void*)CompressedOops::decode_not_null((narrowOop)_space[idx]._addr._offset)) : NULL;
994 } else {
995 return _space[idx]._addr._base;
996 }
997 }
998
999 int FileMapInfo::FileMapHeader::compute_crc() {
1000 char* header = data();
1001 // start computing from the field after _crc
1002 char* buf = (char*)&_crc + sizeof(int);
1003 size_t sz = data_size() - (buf - header);
1004 int crc = ClassLoader::crc32(0, buf, (jint)sz);
1005 return crc;
1006 }
1007
1008 bool FileMapInfo::FileMapHeader::validate() {
1009 if (VerifySharedSpaces && compute_crc() != _crc) {
1010 fail_continue("Header checksum verification failed.");
1011 return false;
1012 }
1013
1014 if (!Arguments::has_jimage()) {
1015 FileMapInfo::fail_continue("The shared archive file cannot be used with an exploded module build.");
1016 return false;
1017 }
1018
1019 if (_version != current_version()) {
1020 FileMapInfo::fail_continue("The shared archive file is the wrong version.");
1021 return false;
1022 }
1023 if (_magic != (int)0xf00baba2) {
1024 FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
1025 return false;
1026 }
1027 char header_version[JVM_IDENT_MAX];
1028 get_header_version(header_version);
1029 if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
1030 log_info(class, path)("expected: %s", header_version);
1031 log_info(class, path)("actual: %s", _jvm_ident);
1032 FileMapInfo::fail_continue("The shared archive file was created by a different"
1033 " version or build of HotSpot");
1034 return false;
1035 }
1036 if (_obj_alignment != ObjectAlignmentInBytes) {
1037 FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
1038 " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
1039 _obj_alignment, ObjectAlignmentInBytes);
1040 return false;
1041 }
1042 if (_compact_strings != CompactStrings) {
1043 FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
1044 " does not equal the current CompactStrings setting (%s).",
1045 _compact_strings ? "enabled" : "disabled",
1046 CompactStrings ? "enabled" : "disabled");
1047 return false;
1048 }
1049
1050 return true;
1051 }
1052
1053 bool FileMapInfo::validate_header() {
1054 bool status = _header->validate();
1055
1056 if (status) {
1057 if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
1058 if (!PrintSharedArchiveAndExit) {
1059 fail_continue("shared class paths mismatch (hint: enable -Xlog:class+path=info to diagnose the failure)");
1060 status = false;
1061 }
1062 }
1063 }
1064
1065 if (_paths_misc_info != NULL) {
1066 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
1067 _paths_misc_info = NULL;
1068 }
1069 return status;
1070 }
1071
1072 // Check if a given address is within one of the shared regions
1073 bool FileMapInfo::is_in_shared_region(const void* p, int idx) {
1074 assert(idx == MetaspaceShared::ro ||
1075 idx == MetaspaceShared::rw ||
1076 idx == MetaspaceShared::mc ||
1077 idx == MetaspaceShared::md, "invalid region index");
1078 char* base = _header->region_addr(idx);
1079 if (p >= base && p < base + _header->_space[idx]._used) {
1080 return true;
1081 }
1082 return false;
1083 }
1084
1085 void FileMapInfo::print_shared_spaces() {
1086 tty->print_cr("Shared Spaces:");
1087 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
1088 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
1089 char *base = _header->region_addr(i);
1090 tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
1091 shared_region_name[i],
1092 p2i(base), p2i(base + si->_used));
1093 }
1094 }
1095
1096 // Unmap mapped regions of shared space.
1097 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
1098 FileMapInfo *map_info = FileMapInfo::current_info();
1099 if (map_info) {
1100 map_info->fail_continue("%s", msg);
1101 for (int i = 0; i < MetaspaceShared::num_non_heap_spaces; i++) {
1102 char *addr = map_info->_header->region_addr(i);
1103 if (addr != NULL && !MetaspaceShared::is_heap_region(i)) {
1104 map_info->unmap_region(i);
1105 map_info->_header->_space[i]._addr._base = NULL;
1106 }
1107 }
1108 // Dealloc the archive heap regions only without unmapping. The regions are part
1109 // of the java heap. Unmapping of the heap regions are managed by GC.
1110 map_info->dealloc_archive_heap_regions(open_archive_heap_ranges,
1111 num_open_archive_heap_ranges);
1112 map_info->dealloc_archive_heap_regions(string_ranges, num_string_ranges);
1113 } else if (DumpSharedSpaces) {
1114 fail_stop("%s", msg);
1115 }
1116 }