7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "classfile/altHashing.hpp"
29 #include "memory/filemap.hpp"
30 #include "runtime/arguments.hpp"
31 #include "runtime/java.hpp"
32 #include "runtime/os.hpp"
33 #include "runtime/vm_version.hpp"
34 #include "services/memTracker.hpp"
35 #include "utilities/defaultStream.hpp"
36
37 # include <sys/stat.h>
38 # include <errno.h>
39
40 #ifndef O_BINARY // if defined (Win32) use binary files.
41 #define O_BINARY 0 // otherwise do nothing.
42 #endif
43
44 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
45
46 extern address JVM_FunctionAtStart();
47 extern address JVM_FunctionAtEnd();
48
49 // Complain and stop. All error conditions occurring during the writing of
50 // an archive file should stop the process. Unrecoverable errors during
51 // the reading of the archive file should stop the process.
52
53 static void fail(const char *msg, va_list ap) {
54 // This occurs very early during initialization: tty is not initialized.
55 jio_fprintf(defaultStream::error_stream(),
56 "An error has occurred while processing the"
57 " shared archive file.\n");
58 jio_vfprintf(defaultStream::error_stream(), msg, ap);
59 jio_fprintf(defaultStream::error_stream(), "\n");
60 // Do not change the text of the below message because some tests check for it.
61 vm_exit_during_initialization("Unable to use shared archive.", NULL);
62 }
63
64
65 void FileMapInfo::fail_stop(const char *msg, ...) {
66 va_list ap;
67 va_start(ap, msg);
68 fail(msg, ap); // Never returns.
69 va_end(ap); // for completeness.
70 }
71
72
73 // Complain and continue. Recoverable errors during the reading of the
74 // archive file may continue (with sharing disabled).
75 //
76 // If we continue, then disable shared spaces and close the file.
77
78 void FileMapInfo::fail_continue(const char *msg, ...) {
79 va_list ap;
80 va_start(ap, msg);
81 if (RequireSharedSpaces) {
82 fail(msg, ap);
83 } else {
84 if (PrintSharedSpaces) {
85 tty->print_cr("UseSharedSpaces: %s", msg);
86 }
87 }
88 va_end(ap);
89 UseSharedSpaces = false;
90 close();
91 }
92
93 // Fill in the fileMapInfo structure with data about this VM instance.
94
95 // This method copies the vm version info into header_version. If the version is too
96 // long then a truncated version, which has a hash code appended to it, is copied.
97 //
98 // Using a template enables this method to verify that header_version is an array of
99 // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and
100 // the code that reads the CDS file will both use the same size buffer. Hence, will
101 // use identical truncation. This is necessary for matching of truncated versions.
102 template <int N> static void get_header_version(char (&header_version) [N]) {
103 assert(N == JVM_IDENT_MAX, "Bad header_version size");
104
105 const char *vm_version = VM_Version::internal_vm_info_string();
106 const int version_len = (int)strlen(vm_version);
107
108 if (version_len < (JVM_IDENT_MAX-1)) {
109 strcpy(header_version, vm_version);
110
111 } else {
112 // Get the hash value. Use a static seed because the hash needs to return the same
113 // value over multiple jvm invocations.
114 unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
115
116 // Truncate the ident, saving room for the 8 hex character hash value.
117 strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
118
119 // Append the hash code as eight hex digits.
120 sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
121 header_version[JVM_IDENT_MAX-1] = 0; // Null terminate.
122 }
123 }
124
125 void FileMapInfo::populate_header(size_t alignment) {
126 _header._magic = 0xf00baba2;
127 _header._version = _current_version;
128 _header._alignment = alignment;
129 _header._obj_alignment = ObjectAlignmentInBytes;
130
131 // The following fields are for sanity checks for whether this archive
132 // will function correctly with this JVM and the bootclasspath it's
133 // invoked with.
134
135 // JVM version string ... changes on each build.
136 get_header_version(_header._jvm_ident);
137
138 // Build checks on classpath and jar files
139 _header._num_jars = 0;
140 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
141 for ( ; cpe != NULL; cpe = cpe->next()) {
142
143 if (cpe->is_jar_file()) {
144 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
145 fail_stop("Too many jar files to share.", NULL);
146 }
147
148 // Jar file - record timestamp and file size.
149 struct stat st;
150 const char *path = cpe->name();
151 if (os::stat(path, &st) != 0) {
152 // If we can't access a jar file in the boot path, then we can't
153 // make assumptions about where classes get loaded from.
154 fail_stop("Unable to open jar file %s.", path);
155 }
156 _header._jar[_header._num_jars]._timestamp = st.st_mtime;
157 _header._jar[_header._num_jars]._filesize = st.st_size;
158 _header._num_jars++;
159 } else {
160
161 // If directories appear in boot classpath, they must be empty to
162 // avoid having to verify each individual class file.
163 const char* name = ((ClassPathDirEntry*)cpe)->name();
164 if (!os::dir_is_empty(name)) {
165 fail_stop("Boot classpath directory %s is not empty.", name);
166 }
167 }
168 }
169 }
170
171
172 // Read the FileMapInfo information from the file.
173
174 bool FileMapInfo::init_from_file(int fd) {
175
176 size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
177 if (n != sizeof(struct FileMapHeader)) {
178 fail_continue("Unable to read the file header.");
179 return false;
180 }
181 if (_header._version != current_version()) {
182 fail_continue("The shared archive file has the wrong version.");
183 return false;
184 }
185 _file_offset = (long)n;
186 return true;
187 }
188
189
190 // Read the FileMapInfo information from the file.
191 bool FileMapInfo::open_for_read() {
192 _full_path = Arguments::GetSharedArchivePath();
193 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
194 if (fd < 0) {
195 if (errno == ENOENT) {
196 // Not locating the shared archive is ok.
197 fail_continue("Specified shared archive not found.");
198 } else {
199 fail_continue("Failed to open shared archive file (%s).",
200 strerror(errno));
201 }
202 return false;
203 }
204
205 _fd = fd;
220 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
221 chmod(_full_path, _S_IREAD | _S_IWRITE);
222 #endif
223
224 // Use remove() to delete the existing file because, on Unix, this will
225 // allow processes that have it open continued access to the file.
226 remove(_full_path);
227 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
228 if (fd < 0) {
229 fail_stop("Unable to create shared archive file %s.", _full_path);
230 }
231 _fd = fd;
232 _file_offset = 0;
233 _file_open = true;
234 }
235
236
237 // Write the header to the file, seek to the next allocation boundary.
238
239 void FileMapInfo::write_header() {
240 write_bytes_aligned(&_header, sizeof(FileMapHeader));
241 }
242
243
244 // Dump shared spaces to file.
245
246 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
247 align_file_position();
248 size_t used = space->used_bytes_slow(Metaspace::NonClassType);
249 size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
250 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
251 write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
252 }
253
254
255 // Dump region to file.
256
257 void FileMapInfo::write_region(int region, char* base, size_t size,
258 size_t capacity, bool read_only,
259 bool allow_exec) {
260 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
261
262 if (_file_open) {
263 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
264 if (PrintSharedSpaces) {
265 tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT
266 " file offset 0x%6x", region, size, base, _file_offset);
267 }
268 } else {
269 si->_file_offset = _file_offset;
270 }
271 si->_base = base;
272 si->_used = size;
273 si->_capacity = capacity;
274 si->_read_only = read_only;
275 si->_allow_exec = allow_exec;
276 write_bytes_aligned(base, (int)size);
277 }
278
279
280 // Dump bytes to file -- at the current file position.
322 align_file_position();
323 }
324
325
326 // Close the shared archive file. This does NOT unmap mapped regions.
327
328 void FileMapInfo::close() {
329 if (_file_open) {
330 if (::close(_fd) < 0) {
331 fail_stop("Unable to close the shared archive file.");
332 }
333 _file_open = false;
334 _fd = -1;
335 }
336 }
337
338
339 // JVM/TI RedefineClasses() support:
340 // Remap the shared readonly space to shared readwrite, private.
341 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
342 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
343 if (!si->_read_only) {
344 // the space is already readwrite so we are done
345 return true;
346 }
347 size_t used = si->_used;
348 size_t size = align_size_up(used, os::vm_allocation_granularity());
349 if (!open_for_read()) {
350 return false;
351 }
352 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
353 si->_base, size, false /* !read_only */,
354 si->_allow_exec);
355 close();
356 if (base == NULL) {
357 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
358 return false;
359 }
360 if (base != si->_base) {
361 fail_continue("Unable to remap shared readonly space at required address.");
362 return false;
363 }
364 si->_read_only = false;
365 return true;
366 }
367
368 // Map the whole region at once, assumed to be allocated contiguously.
369 ReservedSpace FileMapInfo::reserve_shared_memory() {
370 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
371 char* requested_addr = si->_base;
372
373 size_t size = FileMapInfo::shared_spaces_size();
374
375 // Reserve the space first, then map otherwise map will go right over some
376 // other reserved memory (like the code cache).
377 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
378 if (!rs.is_reserved()) {
379 fail_continue(err_msg("Unable to reserve shared space at required address " INTPTR_FORMAT, requested_addr));
380 return rs;
381 }
382 // the reserved virtual memory is for mapping class data sharing archive
383 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
384
385 return rs;
386 }
387
388 // Memory map a region in the address space.
389 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode"};
390
391 char* FileMapInfo::map_region(int i) {
392 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
393 size_t used = si->_used;
394 size_t alignment = os::vm_allocation_granularity();
395 size_t size = align_size_up(used, alignment);
396 char *requested_addr = si->_base;
397
398 // map the contents of the CDS archive in this memory
399 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
400 requested_addr, size, si->_read_only,
401 si->_allow_exec);
402 if (base == NULL || base != si->_base) {
403 fail_continue(err_msg("Unable to map %s shared space at required address.", shared_region_name[i]));
404 return NULL;
405 }
406 #ifdef _WINDOWS
407 // This call is Windows-only because the memory_type gets recorded for the other platforms
408 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
409 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
410 #endif
411 return base;
412 }
413
414
415 // Unmap a memory region in the address space.
416
417 void FileMapInfo::unmap_region(int i) {
418 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
419 size_t used = si->_used;
420 size_t size = align_size_up(used, os::vm_allocation_granularity());
421 if (!os::unmap_memory(si->_base, size)) {
422 fail_stop("Unable to unmap shared space.");
423 }
424 }
425
426
427 void FileMapInfo::assert_mark(bool check) {
428 if (!check) {
429 fail_stop("Mark mismatch while restoring from shared file.", NULL);
430 }
431 }
432
433
434 FileMapInfo* FileMapInfo::_current_info = NULL;
435
436
437 // Open the shared archive file, read and validate the header
438 // information (version, boot classpath, etc.). If initialization
439 // fails, shared spaces are disabled and the file is closed. [See
440 // fail_continue.]
441 bool FileMapInfo::initialize() {
442 assert(UseSharedSpaces, "UseSharedSpaces expected.");
443
444 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
445 fail_continue("Tool agent requires sharing to be disabled.");
446 return false;
447 }
448
449 if (!open_for_read()) {
450 return false;
451 }
452
453 init_from_file(_fd);
454 if (!validate()) {
455 return false;
456 }
457
458 SharedReadOnlySize = _header._space[0]._capacity;
459 SharedReadWriteSize = _header._space[1]._capacity;
460 SharedMiscDataSize = _header._space[2]._capacity;
461 SharedMiscCodeSize = _header._space[3]._capacity;
462 return true;
463 }
464
465
466 bool FileMapInfo::validate() {
467 if (_header._version != current_version()) {
468 fail_continue("The shared archive file is the wrong version.");
469 return false;
470 }
471 if (_header._magic != (int)0xf00baba2) {
472 fail_continue("The shared archive file has a bad magic number.");
473 return false;
474 }
475 char header_version[JVM_IDENT_MAX];
476 get_header_version(header_version);
477 if (strncmp(_header._jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
478 fail_continue("The shared archive file was created by a different"
479 " version or build of HotSpot.");
480 return false;
481 }
482 if (_header._obj_alignment != ObjectAlignmentInBytes) {
483 fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
484 " does not equal the current ObjectAlignmentInBytes of %d.",
485 _header._obj_alignment, ObjectAlignmentInBytes);
486 return false;
487 }
488
489 // Cannot verify interpreter yet, as it can only be created after the GC
490 // heap has been initialized.
491
492 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
493 fail_continue("Too many jar files to share.");
494 return false;
495 }
496
497 // Build checks on classpath and jar files
498 int num_jars_now = 0;
499 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
500 for ( ; cpe != NULL; cpe = cpe->next()) {
501
502 if (cpe->is_jar_file()) {
503 if (num_jars_now < _header._num_jars) {
504
505 // Jar file - verify timestamp and file size.
506 struct stat st;
507 const char *path = cpe->name();
508 if (os::stat(path, &st) != 0) {
509 fail_continue("Unable to open jar file %s.", path);
510 return false;
511 }
512 if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
513 _header._jar[num_jars_now]._filesize != st.st_size) {
514 fail_continue("A jar file is not the one used while building"
515 " the shared archive file.");
516 return false;
517 }
518 }
519 ++num_jars_now;
520 } else {
521
522 // If directories appear in boot classpath, they must be empty to
523 // avoid having to verify each individual class file.
524 const char* name = ((ClassPathDirEntry*)cpe)->name();
525 if (!os::dir_is_empty(name)) {
526 fail_continue("Boot classpath directory %s is not empty.", name);
527 return false;
528 }
529 }
530 }
531 if (num_jars_now < _header._num_jars) {
532 fail_continue("The number of jar files in the boot classpath is"
533 " less than the number the shared archive was created with.");
534 return false;
535 }
536
537 return true;
538 }
539
540 // The following method is provided to see whether a given pointer
541 // falls in the mapped shared space.
542 // Param:
543 // p, The given pointer
544 // Return:
545 // True if the p is within the mapped shared space, otherwise, false.
546 bool FileMapInfo::is_in_shared_space(const void* p) {
547 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
548 if (p >= _header._space[i]._base &&
549 p < _header._space[i]._base + _header._space[i]._used) {
550 return true;
551 }
552 }
553
554 return false;
555 }
556
557 void FileMapInfo::print_shared_spaces() {
558 gclog_or_tty->print_cr("Shared Spaces:");
559 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
560 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
561 gclog_or_tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
562 shared_region_name[i],
563 si->_base, si->_base + si->_used);
564 }
565 }
566
567 // Unmap mapped regions of shared space.
568 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
569 FileMapInfo *map_info = FileMapInfo::current_info();
570 if (map_info) {
571 map_info->fail_continue(msg);
572 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
573 if (map_info->_header._space[i]._base != NULL) {
574 map_info->unmap_region(i);
575 map_info->_header._space[i]._base = NULL;
576 }
577 }
578 } else if (DumpSharedSpaces) {
579 fail_stop(msg, NULL);
580 }
581 }
|
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 #include "memory/filemap.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/oopFactory.hpp"
34 #include "oops/objArrayOop.hpp"
35 #include "runtime/arguments.hpp"
36 #include "runtime/java.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/vm_version.hpp"
39 #include "services/memTracker.hpp"
40 #include "utilities/defaultStream.hpp"
41
42 # include <sys/stat.h>
43 # include <errno.h>
44
45 #ifndef O_BINARY // if defined (Win32) use binary files.
46 #define O_BINARY 0 // otherwise do nothing.
47 #endif
48
49 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
50 extern address JVM_FunctionAtStart();
51 extern address JVM_FunctionAtEnd();
52
53 // Complain and stop. All error conditions occurring during the writing of
54 // an archive file should stop the process. Unrecoverable errors during
55 // the reading of the archive file should stop the process.
56
57 static void fail(const char *msg, va_list ap) {
58 // This occurs very early during initialization: tty is not initialized.
59 jio_fprintf(defaultStream::error_stream(),
60 "An error has occurred while processing the"
61 " shared archive file.\n");
62 jio_vfprintf(defaultStream::error_stream(), msg, ap);
63 jio_fprintf(defaultStream::error_stream(), "\n");
64 // Do not change the text of the below message because some tests check for it.
65 vm_exit_during_initialization("Unable to use shared archive.", NULL);
66 }
67
68
69 void FileMapInfo::fail_stop(const char *msg, ...) {
70 va_list ap;
71 va_start(ap, msg);
72 fail(msg, ap); // Never returns.
73 va_end(ap); // for completeness.
74 }
75
76
77 // Complain and continue. Recoverable errors during the reading of the
78 // archive file may continue (with sharing disabled).
79 //
80 // If we continue, then disable shared spaces and close the file.
81
82 void FileMapInfo::fail_continue(const char *msg, ...) {
83 va_list ap;
84 va_start(ap, msg);
85 MetaspaceShared::set_archive_loading_failed();
86 if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) {
87 // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
88 // do not validate, we can still continue "limping" to validate the remaining
89 // entries. No need to quit.
90 tty->print("[");
91 tty->vprint(msg, ap);
92 tty->print_cr("]");
93 } else {
94 if (RequireSharedSpaces) {
95 fail(msg, ap);
96 } else {
97 if (PrintSharedSpaces) {
98 tty->print_cr("UseSharedSpaces: %s", msg);
99 }
100 }
101 }
102 va_end(ap);
103 UseSharedSpaces = false;
104 assert(current_info() != NULL, "singleton must be registered");
105 current_info()->close();
106 }
107
108 // Fill in the fileMapInfo structure with data about this VM instance.
109
110 // This method copies the vm version info into header_version. If the version is too
111 // long then a truncated version, which has a hash code appended to it, is copied.
112 //
113 // Using a template enables this method to verify that header_version is an array of
114 // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and
115 // the code that reads the CDS file will both use the same size buffer. Hence, will
116 // use identical truncation. This is necessary for matching of truncated versions.
117 template <int N> static void get_header_version(char (&header_version) [N]) {
118 assert(N == JVM_IDENT_MAX, "Bad header_version size");
119
120 const char *vm_version = VM_Version::internal_vm_info_string();
121 const int version_len = (int)strlen(vm_version);
122
123 if (version_len < (JVM_IDENT_MAX-1)) {
124 strcpy(header_version, vm_version);
125
126 } else {
127 // Get the hash value. Use a static seed because the hash needs to return the same
128 // value over multiple jvm invocations.
129 unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
130
131 // Truncate the ident, saving room for the 8 hex character hash value.
132 strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
133
134 // Append the hash code as eight hex digits.
135 sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
136 header_version[JVM_IDENT_MAX-1] = 0; // Null terminate.
137 }
138 }
139
140 FileMapInfo::FileMapInfo() {
141 assert(_current_info == NULL, "must be singleton"); // not thread safe
142 _current_info = this;
143 memset(this, 0, sizeof(FileMapInfo));
144 _file_offset = 0;
145 _file_open = false;
146 _header = SharedClassUtil::allocate_file_map_header();
147 _header->_version = _invalid_version;
148 }
149
150 FileMapInfo::~FileMapInfo() {
151 assert(_current_info == this, "must be singleton"); // not thread safe
152 _current_info = NULL;
153 }
154
155 void FileMapInfo::populate_header(size_t alignment) {
156 _header->populate(this, alignment);
157 }
158
159 size_t FileMapInfo::FileMapHeader::data_size() {
160 return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);
161 }
162
163 void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
164 _magic = 0xf00baba2;
165 _version = _current_version;
166 _alignment = alignment;
167 _obj_alignment = ObjectAlignmentInBytes;
168 _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;
169 _classpath_entry_table = mapinfo->_classpath_entry_table;
170 _classpath_entry_size = mapinfo->_classpath_entry_size;
171
172 // The following fields are for sanity checks for whether this archive
173 // will function correctly with this JVM and the bootclasspath it's
174 // invoked with.
175
176 // JVM version string ... changes on each build.
177 get_header_version(_jvm_ident);
178 }
179
180 void FileMapInfo::allocate_classpath_entry_table() {
181 int bytes = 0;
182 int count = 0;
183 char* strptr = NULL;
184 char* strptr_max = NULL;
185 Thread* THREAD = Thread::current();
186
187 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
188 size_t entry_size = SharedClassUtil::shared_class_path_entry_size();
189
190 for (int pass=0; pass<2; pass++) {
191 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
192
193 for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {
194 const char *name = cpe->name();
195 int name_bytes = (int)(strlen(name) + 1);
196
197 if (pass == 0) {
198 count ++;
199 bytes += (int)entry_size;
200 bytes += name_bytes;
201 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
202 tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name);
203 }
204 } else {
205 SharedClassPathEntry* ent = shared_classpath(cur_entry);
206 if (cpe->is_jar_file()) {
207 struct stat st;
208 if (os::stat(name, &st) != 0) {
209 // The file/dir must exist, or else it would not have been added
210 // into ClassLoader::classpath_entry().
211 //
212 // If we can't access a jar file in the boot path, then we can't
213 // make assumptions about where classes get loaded from.
214 FileMapInfo::fail_stop("Unable to open jar file %s.", name);
215 }
216
217 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
218 SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);
219 } else {
220 ent->_filesize = -1;
221 if (!os::dir_is_empty(name)) {
222 ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);
223 }
224 }
225 ent->_name = strptr;
226 if (strptr + name_bytes <= strptr_max) {
227 strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.
228 strptr += name_bytes;
229 } else {
230 assert(0, "miscalculated buffer size");
231 }
232 }
233 }
234
235 if (pass == 0) {
236 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
237 Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);
238 strptr = (char*)(arr->data());
239 strptr_max = strptr + bytes;
240 SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;
241 strptr += entry_size * count;
242
243 _classpath_entry_table_size = count;
244 _classpath_entry_table = table;
245 _classpath_entry_size = entry_size;
246 }
247 }
248 }
249
250 bool FileMapInfo::validate_classpath_entry_table() {
251 _validating_classpath_entry_table = true;
252
253 int count = _header->_classpath_entry_table_size;
254
255 _classpath_entry_table = _header->_classpath_entry_table;
256 _classpath_entry_size = _header->_classpath_entry_size;
257
258 for (int i=0; i<count; i++) {
259 SharedClassPathEntry* ent = shared_classpath(i);
260 struct stat st;
261 const char* name = ent->_name;
262 bool ok = true;
263 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
264 tty->print_cr("[Checking shared classpath entry: %s]", name);
265 }
266 if (os::stat(name, &st) != 0) {
267 fail_continue("Required classpath entry does not exist: %s", name);
268 ok = false;
269 } else if (ent->is_dir()) {
270 if (!os::dir_is_empty(name)) {
271 fail_continue("directory is not empty: %s", name);
272 ok = false;
273 }
274 } else {
275 if (ent->_timestamp != st.st_mtime ||
276 ent->_filesize != st.st_size) {
277 ok = false;
278 if (PrintSharedArchiveAndExit) {
279 fail_continue(ent->_timestamp != st.st_mtime ?
280 "Timestamp mismatch" :
281 "File size mismatch");
282 } else {
283 fail_continue("A jar file is not the one used while building"
284 " the shared archive file: %s", name);
285 }
286 }
287 }
288 if (ok) {
289 if (TraceClassPaths || (TraceClassLoading && Verbose)) {
290 tty->print_cr("[ok]");
291 }
292 } else if (!PrintSharedArchiveAndExit) {
293 _validating_classpath_entry_table = false;
294 return false;
295 }
296 }
297
298 _classpath_entry_table_size = _header->_classpath_entry_table_size;
299 _validating_classpath_entry_table = false;
300 return true;
301 }
302
303
304 // Read the FileMapInfo information from the file.
305
306 bool FileMapInfo::init_from_file(int fd) {
307 size_t sz = _header->data_size();
308 char* addr = _header->data();
309 size_t n = os::read(fd, addr, (unsigned int)sz);
310 if (n != sz) {
311 fail_continue("Unable to read the file header.");
312 return false;
313 }
314 if (_header->_version != current_version()) {
315 fail_continue("The shared archive file has the wrong version.");
316 return false;
317 }
318 _file_offset = (long)n;
319
320 size_t info_size = _header->_paths_misc_info_size;
321 _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);
322 if (_paths_misc_info == NULL) {
323 fail_continue("Unable to read the file header.");
324 return false;
325 }
326 n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
327 if (n != info_size) {
328 fail_continue("Unable to read the shared path info header.");
329 FREE_C_HEAP_ARRAY(char, _paths_misc_info, mtClass);
330 _paths_misc_info = NULL;
331 return false;
332 }
333
334 _file_offset += (long)n;
335 return true;
336 }
337
338
339 // Read the FileMapInfo information from the file.
340 bool FileMapInfo::open_for_read() {
341 _full_path = Arguments::GetSharedArchivePath();
342 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
343 if (fd < 0) {
344 if (errno == ENOENT) {
345 // Not locating the shared archive is ok.
346 fail_continue("Specified shared archive not found.");
347 } else {
348 fail_continue("Failed to open shared archive file (%s).",
349 strerror(errno));
350 }
351 return false;
352 }
353
354 _fd = fd;
369 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
370 chmod(_full_path, _S_IREAD | _S_IWRITE);
371 #endif
372
373 // Use remove() to delete the existing file because, on Unix, this will
374 // allow processes that have it open continued access to the file.
375 remove(_full_path);
376 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
377 if (fd < 0) {
378 fail_stop("Unable to create shared archive file %s.", _full_path);
379 }
380 _fd = fd;
381 _file_offset = 0;
382 _file_open = true;
383 }
384
385
386 // Write the header to the file, seek to the next allocation boundary.
387
388 void FileMapInfo::write_header() {
389 int info_size = ClassLoader::get_shared_paths_misc_info_size();
390
391 _header->_paths_misc_info_size = info_size;
392
393 align_file_position();
394 size_t sz = _header->data_size();
395 char* addr = _header->data();
396 write_bytes(addr, (int)sz); // skip the C++ vtable
397 write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);
398 align_file_position();
399 }
400
401
402 // Dump shared spaces to file.
403
404 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
405 align_file_position();
406 size_t used = space->used_bytes_slow(Metaspace::NonClassType);
407 size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
408 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
409 write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
410 }
411
412
413 // Dump region to file.
414
415 void FileMapInfo::write_region(int region, char* base, size_t size,
416 size_t capacity, bool read_only,
417 bool allow_exec) {
418 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];
419
420 if (_file_open) {
421 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
422 if (PrintSharedSpaces) {
423 tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT
424 " file offset 0x%6x", region, size, base, _file_offset);
425 }
426 } else {
427 si->_file_offset = _file_offset;
428 }
429 si->_base = base;
430 si->_used = size;
431 si->_capacity = capacity;
432 si->_read_only = read_only;
433 si->_allow_exec = allow_exec;
434 write_bytes_aligned(base, (int)size);
435 }
436
437
438 // Dump bytes to file -- at the current file position.
480 align_file_position();
481 }
482
483
484 // Close the shared archive file. This does NOT unmap mapped regions.
485
486 void FileMapInfo::close() {
487 if (_file_open) {
488 if (::close(_fd) < 0) {
489 fail_stop("Unable to close the shared archive file.");
490 }
491 _file_open = false;
492 _fd = -1;
493 }
494 }
495
496
497 // JVM/TI RedefineClasses() support:
498 // Remap the shared readonly space to shared readwrite, private.
499 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
500 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
501 if (!si->_read_only) {
502 // the space is already readwrite so we are done
503 return true;
504 }
505 size_t used = si->_used;
506 size_t size = align_size_up(used, os::vm_allocation_granularity());
507 if (!open_for_read()) {
508 return false;
509 }
510 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
511 si->_base, size, false /* !read_only */,
512 si->_allow_exec);
513 close();
514 if (base == NULL) {
515 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
516 return false;
517 }
518 if (base != si->_base) {
519 fail_continue("Unable to remap shared readonly space at required address.");
520 return false;
521 }
522 si->_read_only = false;
523 return true;
524 }
525
526 // Map the whole region at once, assumed to be allocated contiguously.
527 ReservedSpace FileMapInfo::reserve_shared_memory() {
528 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0];
529 char* requested_addr = si->_base;
530
531 size_t size = FileMapInfo::shared_spaces_size();
532
533 // Reserve the space first, then map otherwise map will go right over some
534 // other reserved memory (like the code cache).
535 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
536 if (!rs.is_reserved()) {
537 fail_continue(err_msg("Unable to reserve shared space at required address " INTPTR_FORMAT, requested_addr));
538 return rs;
539 }
540 // the reserved virtual memory is for mapping class data sharing archive
541 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
542
543 return rs;
544 }
545
546 // Memory map a region in the address space.
547 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode"};
548
549 char* FileMapInfo::map_region(int i) {
550 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
551 size_t used = si->_used;
552 size_t alignment = os::vm_allocation_granularity();
553 size_t size = align_size_up(used, alignment);
554 char *requested_addr = si->_base;
555
556 // map the contents of the CDS archive in this memory
557 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
558 requested_addr, size, si->_read_only,
559 si->_allow_exec);
560 if (base == NULL || base != si->_base) {
561 fail_continue(err_msg("Unable to map %s shared space at required address.", shared_region_name[i]));
562 return NULL;
563 }
564 #ifdef _WINDOWS
565 // This call is Windows-only because the memory_type gets recorded for the other platforms
566 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
567 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
568 #endif
569 return base;
570 }
571
572
573 // Unmap a memory region in the address space.
574
575 void FileMapInfo::unmap_region(int i) {
576 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
577 size_t used = si->_used;
578 size_t size = align_size_up(used, os::vm_allocation_granularity());
579 if (!os::unmap_memory(si->_base, size)) {
580 fail_stop("Unable to unmap shared space.");
581 }
582 }
583
584
585 void FileMapInfo::assert_mark(bool check) {
586 if (!check) {
587 fail_stop("Mark mismatch while restoring from shared file.", NULL);
588 }
589 }
590
591
592 FileMapInfo* FileMapInfo::_current_info = NULL;
593 SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL;
594 int FileMapInfo::_classpath_entry_table_size = 0;
595 size_t FileMapInfo::_classpath_entry_size = 0x1234baad;
596 bool FileMapInfo::_validating_classpath_entry_table = false;
597
598 // Open the shared archive file, read and validate the header
599 // information (version, boot classpath, etc.). If initialization
600 // fails, shared spaces are disabled and the file is closed. [See
601 // fail_continue.]
602 //
603 // Validation of the archive is done in two steps:
604 //
605 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
606 // [2] validate_classpath_entry_table - this is done later, because the table is in the RW
607 // region of the archive, which is not mapped yet.
608 bool FileMapInfo::initialize() {
609 assert(UseSharedSpaces, "UseSharedSpaces expected.");
610
611 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
612 fail_continue("Tool agent requires sharing to be disabled.");
613 return false;
614 }
615
616 if (!open_for_read()) {
617 return false;
618 }
619
620 init_from_file(_fd);
621 if (!validate_header()) {
622 return false;
623 }
624
625 SharedReadOnlySize = _header->_space[0]._capacity;
626 SharedReadWriteSize = _header->_space[1]._capacity;
627 SharedMiscDataSize = _header->_space[2]._capacity;
628 SharedMiscCodeSize = _header->_space[3]._capacity;
629 return true;
630 }
631
632 bool FileMapInfo::FileMapHeader::validate() {
633 if (_version != current_version()) {
634 FileMapInfo::fail_continue("The shared archive file is the wrong version.");
635 return false;
636 }
637 if (_magic != (int)0xf00baba2) {
638 FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
639 return false;
640 }
641 char header_version[JVM_IDENT_MAX];
642 get_header_version(header_version);
643 if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
644 if (TraceClassPaths) {
645 tty->print_cr("Expected: %s", header_version);
646 tty->print_cr("Actual: %s", _jvm_ident);
647 }
648 FileMapInfo::fail_continue("The shared archive file was created by a different"
649 " version or build of HotSpot");
650 return false;
651 }
652 if (_obj_alignment != ObjectAlignmentInBytes) {
653 FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
654 " does not equal the current ObjectAlignmentInBytes of %d.",
655 _obj_alignment, ObjectAlignmentInBytes);
656 return false;
657 }
658
659 return true;
660 }
661
662 bool FileMapInfo::validate_header() {
663 bool status = _header->validate();
664
665 if (status) {
666 if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) {
667 if (!PrintSharedArchiveAndExit) {
668 fail_continue("shared class paths mismatch (hint: enable -XX:+TraceClassPaths to diagnose the failure)");
669 status = false;
670 }
671 }
672 }
673
674 if (_paths_misc_info != NULL) {
675 FREE_C_HEAP_ARRAY(char, _paths_misc_info, mtClass);
676 _paths_misc_info = NULL;
677 }
678 return status;
679 }
680
681 // The following method is provided to see whether a given pointer
682 // falls in the mapped shared space.
683 // Param:
684 // p, The given pointer
685 // Return:
686 // True if the p is within the mapped shared space, otherwise, false.
687 bool FileMapInfo::is_in_shared_space(const void* p) {
688 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
689 if (p >= _header->_space[i]._base &&
690 p < _header->_space[i]._base + _header->_space[i]._used) {
691 return true;
692 }
693 }
694
695 return false;
696 }
697
698 void FileMapInfo::print_shared_spaces() {
699 gclog_or_tty->print_cr("Shared Spaces:");
700 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
701 struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];
702 gclog_or_tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT,
703 shared_region_name[i],
704 si->_base, si->_base + si->_used);
705 }
706 }
707
708 // Unmap mapped regions of shared space.
709 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
710 FileMapInfo *map_info = FileMapInfo::current_info();
711 if (map_info) {
712 map_info->fail_continue(msg);
713 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
714 if (map_info->_header->_space[i]._base != NULL) {
715 map_info->unmap_region(i);
716 map_info->_header->_space[i]._base = NULL;
717 }
718 }
719 } else if (DumpSharedSpaces) {
720 fail_stop(msg, NULL);
721 }
722 }
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