1 /*
2 * Copyright (c) 2001, 2014, 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/vmSymbols.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "os_windows.inline.hpp"
31 #include "runtime/handles.inline.hpp"
32 #include "runtime/os.hpp"
33 #include "runtime/perfMemory.hpp"
34 #include "services/memTracker.hpp"
35 #include "utilities/exceptions.hpp"
36
37 #include <windows.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <errno.h>
41 #include <lmcons.h>
42
43 typedef BOOL (WINAPI *SetSecurityDescriptorControlFnPtr)(
44 IN PSECURITY_DESCRIPTOR pSecurityDescriptor,
45 IN SECURITY_DESCRIPTOR_CONTROL ControlBitsOfInterest,
46 IN SECURITY_DESCRIPTOR_CONTROL ControlBitsToSet);
47
48 // Standard Memory Implementation Details
49
50 // create the PerfData memory region in standard memory.
51 //
52 static char* create_standard_memory(size_t size) {
53
54 // allocate an aligned chuck of memory
55 char* mapAddress = os::reserve_memory(size);
56
57 if (mapAddress == NULL) {
58 return NULL;
59 }
60
61 // commit memory
62 if (!os::commit_memory(mapAddress, size, !ExecMem)) {
63 if (PrintMiscellaneous && Verbose) {
64 warning("Could not commit PerfData memory\n");
65 }
66 os::release_memory(mapAddress, size);
67 return NULL;
68 }
69
70 return mapAddress;
71 }
72
73 // delete the PerfData memory region
74 //
75 static void delete_standard_memory(char* addr, size_t size) {
76
77 // there are no persistent external resources to cleanup for standard
78 // memory. since DestroyJavaVM does not support unloading of the JVM,
79 // cleanup of the memory resource is not performed. The memory will be
80 // reclaimed by the OS upon termination of the process.
81 //
82 return;
83
84 }
85
86 // save the specified memory region to the given file
87 //
88 static void save_memory_to_file(char* addr, size_t size) {
89
90 const char* destfile = PerfMemory::get_perfdata_file_path();
91 assert(destfile[0] != '\0', "invalid Perfdata file path");
92
93 int fd = ::_open(destfile, _O_BINARY|_O_CREAT|_O_WRONLY|_O_TRUNC,
94 _S_IREAD|_S_IWRITE);
95
96 if (fd == OS_ERR) {
97 if (PrintMiscellaneous && Verbose) {
98 warning("Could not create Perfdata save file: %s: %s\n",
99 destfile, strerror(errno));
100 }
101 } else {
102 for (size_t remaining = size; remaining > 0;) {
103
104 int nbytes = ::_write(fd, addr, (unsigned int)remaining);
105 if (nbytes == OS_ERR) {
106 if (PrintMiscellaneous && Verbose) {
107 warning("Could not write Perfdata save file: %s: %s\n",
108 destfile, strerror(errno));
109 }
110 break;
111 }
112
113 remaining -= (size_t)nbytes;
114 addr += nbytes;
115 }
116
117 int result = ::_close(fd);
118 if (PrintMiscellaneous && Verbose) {
119 if (result == OS_ERR) {
120 warning("Could not close %s: %s\n", destfile, strerror(errno));
121 }
122 }
123 }
124
125 FREE_C_HEAP_ARRAY(char, destfile);
126 }
127
128 // Shared Memory Implementation Details
129
130 // Note: the win32 shared memory implementation uses two objects to represent
131 // the shared memory: a windows kernel based file mapping object and a backing
132 // store file. On windows, the name space for shared memory is a kernel
133 // based name space that is disjoint from other win32 name spaces. Since Java
134 // is unaware of this name space, a parallel file system based name space is
135 // maintained, which provides a common file system based shared memory name
136 // space across the supported platforms and one that Java apps can deal with
137 // through simple file apis.
138 //
139 // For performance and resource cleanup reasons, it is recommended that the
140 // user specific directory and the backing store file be stored in either a
141 // RAM based file system or a local disk based file system. Network based
142 // file systems are not recommended for performance reasons. In addition,
143 // use of SMB network based file systems may result in unsuccesful cleanup
144 // of the disk based resource on exit of the VM. The Windows TMP and TEMP
145 // environement variables, as used by the GetTempPath() Win32 API (see
146 // os::get_temp_directory() in os_win32.cpp), control the location of the
147 // user specific directory and the shared memory backing store file.
148
149 static HANDLE sharedmem_fileMapHandle = NULL;
150 static HANDLE sharedmem_fileHandle = INVALID_HANDLE_VALUE;
151 static char* sharedmem_fileName = NULL;
152
153 // return the user specific temporary directory name.
154 //
155 // the caller is expected to free the allocated memory.
156 //
157 static char* get_user_tmp_dir(const char* user) {
158
159 const char* tmpdir = os::get_temp_directory();
160 const char* perfdir = PERFDATA_NAME;
161 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3;
162 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);
163
164 // construct the path name to user specific tmp directory
165 _snprintf(dirname, nbytes, "%s\\%s_%s", tmpdir, perfdir, user);
166
167 return dirname;
168 }
169
170 // convert the given file name into a process id. if the file
171 // does not meet the file naming constraints, return 0.
172 //
173 static int filename_to_pid(const char* filename) {
174
175 // a filename that doesn't begin with a digit is not a
176 // candidate for conversion.
177 //
178 if (!isdigit(*filename)) {
179 return 0;
180 }
181
182 // check if file name can be converted to an integer without
183 // any leftover characters.
184 //
185 char* remainder = NULL;
186 errno = 0;
187 int pid = (int)strtol(filename, &remainder, 10);
188
189 if (errno != 0) {
190 return 0;
191 }
192
193 // check for left over characters. If any, then the filename is
194 // not a candidate for conversion.
195 //
196 if (remainder != NULL && *remainder != '\0') {
197 return 0;
198 }
199
200 // successful conversion, return the pid
201 return pid;
202 }
203
204 // check if the given path is considered a secure directory for
205 // the backing store files. Returns true if the directory exists
206 // and is considered a secure location. Returns false if the path
207 // is a symbolic link or if an error occurred.
208 //
209 static bool is_directory_secure(const char* path) {
210
211 DWORD fa;
212
213 fa = GetFileAttributes(path);
214 if (fa == 0xFFFFFFFF) {
215 DWORD lasterror = GetLastError();
216 if (lasterror == ERROR_FILE_NOT_FOUND) {
217 return false;
218 }
219 else {
220 // unexpected error, declare the path insecure
221 if (PrintMiscellaneous && Verbose) {
222 warning("could not get attributes for file %s: ",
223 " lasterror = %d\n", path, lasterror);
224 }
225 return false;
226 }
227 }
228
229 if (fa & FILE_ATTRIBUTE_REPARSE_POINT) {
230 // we don't accept any redirection for the user specific directory
231 // so declare the path insecure. This may be too conservative,
232 // as some types of reparse points might be acceptable, but it
233 // is probably more secure to avoid these conditions.
234 //
235 if (PrintMiscellaneous && Verbose) {
236 warning("%s is a reparse point\n", path);
237 }
238 return false;
239 }
240
241 if (fa & FILE_ATTRIBUTE_DIRECTORY) {
242 // this is the expected case. Since windows supports symbolic
243 // links to directories only, not to files, there is no need
244 // to check for open write permissions on the directory. If the
245 // directory has open write permissions, any files deposited that
246 // are not expected will be removed by the cleanup code.
247 //
248 return true;
249 }
250 else {
251 // this is either a regular file or some other type of file,
252 // any of which are unexpected and therefore insecure.
253 //
254 if (PrintMiscellaneous && Verbose) {
255 warning("%s is not a directory, file attributes = "
256 INTPTR_FORMAT "\n", path, fa);
257 }
258 return false;
259 }
260 }
261
262 // return the user name for the owner of this process
263 //
264 // the caller is expected to free the allocated memory.
265 //
266 static char* get_user_name() {
267
268 /* get the user name. This code is adapted from code found in
269 * the jdk in src/windows/native/java/lang/java_props_md.c
270 * java_props_md.c 1.29 02/02/06. According to the original
271 * source, the call to GetUserName is avoided because of a resulting
272 * increase in footprint of 100K.
273 */
274 char* user = getenv("USERNAME");
275 char buf[UNLEN+1];
276 DWORD buflen = sizeof(buf);
277 if (user == NULL || strlen(user) == 0) {
278 if (GetUserName(buf, &buflen)) {
279 user = buf;
280 }
281 else {
282 return NULL;
283 }
284 }
285
286 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal);
287 strcpy(user_name, user);
288
289 return user_name;
290 }
291
292 // return the name of the user that owns the process identified by vmid.
293 //
294 // This method uses a slow directory search algorithm to find the backing
295 // store file for the specified vmid and returns the user name, as determined
296 // by the user name suffix of the hsperfdata_<username> directory name.
297 //
298 // the caller is expected to free the allocated memory.
299 //
300 static char* get_user_name_slow(int vmid) {
301
302 // directory search
303 char* latest_user = NULL;
304 time_t latest_ctime = 0;
305
306 const char* tmpdirname = os::get_temp_directory();
307
308 DIR* tmpdirp = os::opendir(tmpdirname);
309
310 if (tmpdirp == NULL) {
311 return NULL;
312 }
313
314 // for each entry in the directory that matches the pattern hsperfdata_*,
315 // open the directory and check if the file for the given vmid exists.
316 // The file with the expected name and the latest creation date is used
317 // to determine the user name for the process id.
318 //
319 struct dirent* dentry;
320 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal);
321 errno = 0;
322 while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) {
323
324 // check if the directory entry is a hsperfdata file
325 if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) {
326 continue;
327 }
328
329 char* usrdir_name = NEW_C_HEAP_ARRAY(char,
330 strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal);
331 strcpy(usrdir_name, tmpdirname);
332 strcat(usrdir_name, "\\");
333 strcat(usrdir_name, dentry->d_name);
334
335 DIR* subdirp = os::opendir(usrdir_name);
336
337 if (subdirp == NULL) {
338 FREE_C_HEAP_ARRAY(char, usrdir_name);
339 continue;
340 }
341
342 // Since we don't create the backing store files in directories
343 // pointed to by symbolic links, we also don't follow them when
344 // looking for the files. We check for a symbolic link after the
345 // call to opendir in order to eliminate a small window where the
346 // symlink can be exploited.
347 //
348 if (!is_directory_secure(usrdir_name)) {
349 FREE_C_HEAP_ARRAY(char, usrdir_name);
350 os::closedir(subdirp);
351 continue;
352 }
353
354 struct dirent* udentry;
355 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal);
356 errno = 0;
357 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) {
358
359 if (filename_to_pid(udentry->d_name) == vmid) {
360 struct stat statbuf;
361
362 char* filename = NEW_C_HEAP_ARRAY(char,
363 strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal);
364
365 strcpy(filename, usrdir_name);
366 strcat(filename, "\\");
367 strcat(filename, udentry->d_name);
368
369 if (::stat(filename, &statbuf) == OS_ERR) {
370 FREE_C_HEAP_ARRAY(char, filename);
371 continue;
372 }
373
374 // skip over files that are not regular files.
375 if ((statbuf.st_mode & S_IFMT) != S_IFREG) {
376 FREE_C_HEAP_ARRAY(char, filename);
377 continue;
378 }
379
380 // If we found a matching file with a newer creation time, then
381 // save the user name. The newer creation time indicates that
382 // we found a newer incarnation of the process associated with
383 // vmid. Due to the way that Windows recycles pids and the fact
384 // that we can't delete the file from the file system namespace
385 // until last close, it is possible for there to be more than
386 // one hsperfdata file with a name matching vmid (diff users).
387 //
388 // We no longer ignore hsperfdata files where (st_size == 0).
389 // In this function, all we're trying to do is determine the
390 // name of the user that owns the process associated with vmid
391 // so the size doesn't matter. Very rarely, we have observed
392 // hsperfdata files where (st_size == 0) and the st_size field
393 // later becomes the expected value.
394 //
395 if (statbuf.st_ctime > latest_ctime) {
396 char* user = strchr(dentry->d_name, '_') + 1;
397
398 if (latest_user != NULL) FREE_C_HEAP_ARRAY(char, latest_user);
399 latest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal);
400
401 strcpy(latest_user, user);
402 latest_ctime = statbuf.st_ctime;
403 }
404
405 FREE_C_HEAP_ARRAY(char, filename);
406 }
407 }
408 os::closedir(subdirp);
409 FREE_C_HEAP_ARRAY(char, udbuf);
410 FREE_C_HEAP_ARRAY(char, usrdir_name);
411 }
412 os::closedir(tmpdirp);
413 FREE_C_HEAP_ARRAY(char, tdbuf);
414
415 return(latest_user);
416 }
417
418 // return the name of the user that owns the process identified by vmid.
419 //
420 // note: this method should only be used via the Perf native methods.
421 // There are various costs to this method and limiting its use to the
422 // Perf native methods limits the impact to monitoring applications only.
423 //
424 static char* get_user_name(int vmid) {
425
426 // A fast implementation is not provided at this time. It's possible
427 // to provide a fast process id to user name mapping function using
428 // the win32 apis, but the default ACL for the process object only
429 // allows processes with the same owner SID to acquire the process
430 // handle (via OpenProcess(PROCESS_QUERY_INFORMATION)). It's possible
431 // to have the JVM change the ACL for the process object to allow arbitrary
432 // users to access the process handle and the process security token.
433 // The security ramifications need to be studied before providing this
434 // mechanism.
435 //
436 return get_user_name_slow(vmid);
437 }
438
439 // return the name of the shared memory file mapping object for the
440 // named shared memory region for the given user name and vmid.
441 //
442 // The file mapping object's name is not the file name. It is a name
443 // in a separate name space.
444 //
445 // the caller is expected to free the allocated memory.
446 //
447 static char *get_sharedmem_objectname(const char* user, int vmid) {
448
449 // construct file mapping object's name, add 3 for two '_' and a
450 // null terminator.
451 int nbytes = (int)strlen(PERFDATA_NAME) + (int)strlen(user) + 3;
452
453 // the id is converted to an unsigned value here because win32 allows
454 // negative process ids. However, OpenFileMapping API complains
455 // about a name containing a '-' characters.
456 //
457 nbytes += UINT_CHARS;
458 char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);
459 _snprintf(name, nbytes, "%s_%s_%u", PERFDATA_NAME, user, vmid);
460
461 return name;
462 }
463
464 // return the file name of the backing store file for the named
465 // shared memory region for the given user name and vmid.
466 //
467 // the caller is expected to free the allocated memory.
468 //
469 static char* get_sharedmem_filename(const char* dirname, int vmid) {
470
471 // add 2 for the file separator and a null terminator.
472 size_t nbytes = strlen(dirname) + UINT_CHARS + 2;
473
474 char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);
475 _snprintf(name, nbytes, "%s\\%d", dirname, vmid);
476
477 return name;
478 }
479
480 // remove file
481 //
482 // this method removes the file with the given file name.
483 //
484 // Note: if the indicated file is on an SMB network file system, this
485 // method may be unsuccessful in removing the file.
486 //
487 static void remove_file(const char* dirname, const char* filename) {
488
489 size_t nbytes = strlen(dirname) + strlen(filename) + 2;
490 char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);
491
492 strcpy(path, dirname);
493 strcat(path, "\\");
494 strcat(path, filename);
495
496 if (::unlink(path) == OS_ERR) {
497 if (PrintMiscellaneous && Verbose) {
498 if (errno != ENOENT) {
499 warning("Could not unlink shared memory backing"
500 " store file %s : %s\n", path, strerror(errno));
501 }
502 }
503 }
504
505 FREE_C_HEAP_ARRAY(char, path);
506 }
507
508 // returns true if the process represented by pid is alive, otherwise
509 // returns false. the validity of the result is only accurate if the
510 // target process is owned by the same principal that owns this process.
511 // this method should not be used if to test the status of an otherwise
512 // arbitrary process unless it is know that this process has the appropriate
513 // privileges to guarantee a result valid.
514 //
515 static bool is_alive(int pid) {
516
517 HANDLE ph = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);
518 if (ph == NULL) {
519 // the process does not exist.
520 if (PrintMiscellaneous && Verbose) {
521 DWORD lastError = GetLastError();
522 if (lastError != ERROR_INVALID_PARAMETER) {
523 warning("OpenProcess failed: %d\n", GetLastError());
524 }
525 }
526 return false;
527 }
528
529 DWORD exit_status;
530 if (!GetExitCodeProcess(ph, &exit_status)) {
531 if (PrintMiscellaneous && Verbose) {
532 warning("GetExitCodeProcess failed: %d\n", GetLastError());
533 }
534 CloseHandle(ph);
535 return false;
536 }
537
538 CloseHandle(ph);
539 return (exit_status == STILL_ACTIVE) ? true : false;
540 }
541
542 // check if the file system is considered secure for the backing store files
543 //
544 static bool is_filesystem_secure(const char* path) {
545
546 char root_path[MAX_PATH];
547 char fs_type[MAX_PATH];
548
549 if (PerfBypassFileSystemCheck) {
550 if (PrintMiscellaneous && Verbose) {
551 warning("bypassing file system criteria checks for %s\n", path);
552 }
553 return true;
554 }
555
556 char* first_colon = strchr((char *)path, ':');
557 if (first_colon == NULL) {
558 if (PrintMiscellaneous && Verbose) {
559 warning("expected device specifier in path: %s\n", path);
560 }
561 return false;
562 }
563
564 size_t len = (size_t)(first_colon - path);
565 assert(len + 2 <= MAX_PATH, "unexpected device specifier length");
566 strncpy(root_path, path, len + 1);
567 root_path[len + 1] = '\\';
568 root_path[len + 2] = '\0';
569
570 // check that we have something like "C:\" or "AA:\"
571 assert(strlen(root_path) >= 3, "device specifier too short");
572 assert(strchr(root_path, ':') != NULL, "bad device specifier format");
573 assert(strchr(root_path, '\\') != NULL, "bad device specifier format");
574
575 DWORD maxpath;
576 DWORD flags;
577
578 if (!GetVolumeInformation(root_path, NULL, 0, NULL, &maxpath,
579 &flags, fs_type, MAX_PATH)) {
580 // we can't get information about the volume, so assume unsafe.
581 if (PrintMiscellaneous && Verbose) {
582 warning("could not get device information for %s: "
583 " path = %s: lasterror = %d\n",
584 root_path, path, GetLastError());
585 }
586 return false;
587 }
588
589 if ((flags & FS_PERSISTENT_ACLS) == 0) {
590 // file system doesn't support ACLs, declare file system unsafe
591 if (PrintMiscellaneous && Verbose) {
592 warning("file system type %s on device %s does not support"
593 " ACLs\n", fs_type, root_path);
594 }
595 return false;
596 }
597
598 if ((flags & FS_VOL_IS_COMPRESSED) != 0) {
599 // file system is compressed, declare file system unsafe
600 if (PrintMiscellaneous && Verbose) {
601 warning("file system type %s on device %s is compressed\n",
602 fs_type, root_path);
603 }
604 return false;
605 }
606
607 return true;
608 }
609
610 // cleanup stale shared memory resources
611 //
612 // This method attempts to remove all stale shared memory files in
613 // the named user temporary directory. It scans the named directory
614 // for files matching the pattern ^$[0-9]*$. For each file found, the
615 // process id is extracted from the file name and a test is run to
616 // determine if the process is alive. If the process is not alive,
617 // any stale file resources are removed.
618 //
619 static void cleanup_sharedmem_resources(const char* dirname) {
620
621 // open the user temp directory
622 DIR* dirp = os::opendir(dirname);
623
624 if (dirp == NULL) {
625 // directory doesn't exist, so there is nothing to cleanup
626 return;
627 }
628
629 if (!is_directory_secure(dirname)) {
630 // the directory is not secure, don't attempt any cleanup
631 return;
632 }
633
634 // for each entry in the directory that matches the expected file
635 // name pattern, determine if the file resources are stale and if
636 // so, remove the file resources. Note, instrumented HotSpot processes
637 // for this user may start and/or terminate during this search and
638 // remove or create new files in this directory. The behavior of this
639 // loop under these conditions is dependent upon the implementation of
640 // opendir/readdir.
641 //
642 struct dirent* entry;
643 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal);
644 errno = 0;
645 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) {
646
647 int pid = filename_to_pid(entry->d_name);
648
649 if (pid == 0) {
650
651 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) {
652
653 // attempt to remove all unexpected files, except "." and ".."
654 remove_file(dirname, entry->d_name);
655 }
656
657 errno = 0;
658 continue;
659 }
660
661 // we now have a file name that converts to a valid integer
662 // that could represent a process id . if this process id
663 // matches the current process id or the process is not running,
664 // then remove the stale file resources.
665 //
666 // process liveness is detected by checking the exit status
667 // of the process. if the process id is valid and the exit status
668 // indicates that it is still running, the file file resources
669 // are not removed. If the process id is invalid, or if we don't
670 // have permissions to check the process status, or if the process
671 // id is valid and the process has terminated, the the file resources
672 // are assumed to be stale and are removed.
673 //
674 if (pid == os::current_process_id() || !is_alive(pid)) {
675
676 // we can only remove the file resources. Any mapped views
677 // of the file can only be unmapped by the processes that
678 // opened those views and the file mapping object will not
679 // get removed until all views are unmapped.
680 //
681 remove_file(dirname, entry->d_name);
682 }
683 errno = 0;
684 }
685 os::closedir(dirp);
686 FREE_C_HEAP_ARRAY(char, dbuf);
687 }
688
689 // create a file mapping object with the requested name, and size
690 // from the file represented by the given Handle object
691 //
692 static HANDLE create_file_mapping(const char* name, HANDLE fh, LPSECURITY_ATTRIBUTES fsa, size_t size) {
693
694 DWORD lowSize = (DWORD)size;
695 DWORD highSize = 0;
696 HANDLE fmh = NULL;
697
698 // Create a file mapping object with the given name. This function
699 // will grow the file to the specified size.
700 //
701 fmh = CreateFileMapping(
702 fh, /* HANDLE file handle for backing store */
703 fsa, /* LPSECURITY_ATTRIBUTES Not inheritable */
704 PAGE_READWRITE, /* DWORD protections */
705 highSize, /* DWORD High word of max size */
706 lowSize, /* DWORD Low word of max size */
707 name); /* LPCTSTR name for object */
708
709 if (fmh == NULL) {
710 if (PrintMiscellaneous && Verbose) {
711 warning("CreateFileMapping failed, lasterror = %d\n", GetLastError());
712 }
713 return NULL;
714 }
715
716 if (GetLastError() == ERROR_ALREADY_EXISTS) {
717
718 // a stale file mapping object was encountered. This object may be
719 // owned by this or some other user and cannot be removed until
720 // the other processes either exit or close their mapping objects
721 // and/or mapped views of this mapping object.
722 //
723 if (PrintMiscellaneous && Verbose) {
724 warning("file mapping already exists, lasterror = %d\n", GetLastError());
725 }
726
727 CloseHandle(fmh);
728 return NULL;
729 }
730
731 return fmh;
732 }
733
734
735 // method to free the given security descriptor and the contained
736 // access control list.
737 //
738 static void free_security_desc(PSECURITY_DESCRIPTOR pSD) {
739
740 BOOL success, exists, isdefault;
741 PACL pACL;
742
743 if (pSD != NULL) {
744
745 // get the access control list from the security descriptor
746 success = GetSecurityDescriptorDacl(pSD, &exists, &pACL, &isdefault);
747
748 // if an ACL existed and it was not a default acl, then it must
749 // be an ACL we enlisted. free the resources.
750 //
751 if (success && exists && pACL != NULL && !isdefault) {
752 FREE_C_HEAP_ARRAY(char, pACL);
753 }
754
755 // free the security descriptor
756 FREE_C_HEAP_ARRAY(char, pSD);
757 }
758 }
759
760 // method to free up a security attributes structure and any
761 // contained security descriptors and ACL
762 //
763 static void free_security_attr(LPSECURITY_ATTRIBUTES lpSA) {
764
765 if (lpSA != NULL) {
766 // free the contained security descriptor and the ACL
767 free_security_desc(lpSA->lpSecurityDescriptor);
768 lpSA->lpSecurityDescriptor = NULL;
769
770 // free the security attributes structure
771 FREE_C_HEAP_ARRAY(char, lpSA);
772 }
773 }
774
775 // get the user SID for the process indicated by the process handle
776 //
777 static PSID get_user_sid(HANDLE hProcess) {
778
779 HANDLE hAccessToken;
780 PTOKEN_USER token_buf = NULL;
781 DWORD rsize = 0;
782
783 if (hProcess == NULL) {
784 return NULL;
785 }
786
787 // get the process token
788 if (!OpenProcessToken(hProcess, TOKEN_READ, &hAccessToken)) {
789 if (PrintMiscellaneous && Verbose) {
790 warning("OpenProcessToken failure: lasterror = %d \n", GetLastError());
791 }
792 return NULL;
793 }
794
795 // determine the size of the token structured needed to retrieve
796 // the user token information from the access token.
797 //
798 if (!GetTokenInformation(hAccessToken, TokenUser, NULL, rsize, &rsize)) {
799 DWORD lasterror = GetLastError();
800 if (lasterror != ERROR_INSUFFICIENT_BUFFER) {
801 if (PrintMiscellaneous && Verbose) {
802 warning("GetTokenInformation failure: lasterror = %d,"
803 " rsize = %d\n", lasterror, rsize);
804 }
805 CloseHandle(hAccessToken);
806 return NULL;
807 }
808 }
809
810 token_buf = (PTOKEN_USER) NEW_C_HEAP_ARRAY(char, rsize, mtInternal);
811
812 // get the user token information
813 if (!GetTokenInformation(hAccessToken, TokenUser, token_buf, rsize, &rsize)) {
814 if (PrintMiscellaneous && Verbose) {
815 warning("GetTokenInformation failure: lasterror = %d,"
816 " rsize = %d\n", GetLastError(), rsize);
817 }
818 FREE_C_HEAP_ARRAY(char, token_buf);
819 CloseHandle(hAccessToken);
820 return NULL;
821 }
822
823 DWORD nbytes = GetLengthSid(token_buf->User.Sid);
824 PSID pSID = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);
825
826 if (!CopySid(nbytes, pSID, token_buf->User.Sid)) {
827 if (PrintMiscellaneous && Verbose) {
828 warning("GetTokenInformation failure: lasterror = %d,"
829 " rsize = %d\n", GetLastError(), rsize);
830 }
831 FREE_C_HEAP_ARRAY(char, token_buf);
832 FREE_C_HEAP_ARRAY(char, pSID);
833 CloseHandle(hAccessToken);
834 return NULL;
835 }
836
837 // close the access token.
838 CloseHandle(hAccessToken);
839 FREE_C_HEAP_ARRAY(char, token_buf);
840
841 return pSID;
842 }
843
844 // structure used to consolidate access control entry information
845 //
846 typedef struct ace_data {
847 PSID pSid; // SID of the ACE
848 DWORD mask; // mask for the ACE
849 } ace_data_t;
850
851
852 // method to add an allow access control entry with the access rights
853 // indicated in mask for the principal indicated in SID to the given
854 // security descriptor. Much of the DACL handling was adapted from
855 // the example provided here:
856 // http://support.microsoft.com/kb/102102/EN-US/
857 //
858
859 static bool add_allow_aces(PSECURITY_DESCRIPTOR pSD,
860 ace_data_t aces[], int ace_count) {
861 PACL newACL = NULL;
862 PACL oldACL = NULL;
863
864 if (pSD == NULL) {
865 return false;
866 }
867
868 BOOL exists, isdefault;
869
870 // retrieve any existing access control list.
871 if (!GetSecurityDescriptorDacl(pSD, &exists, &oldACL, &isdefault)) {
872 if (PrintMiscellaneous && Verbose) {
873 warning("GetSecurityDescriptor failure: lasterror = %d \n",
874 GetLastError());
875 }
876 return false;
877 }
878
879 // get the size of the DACL
880 ACL_SIZE_INFORMATION aclinfo;
881
882 // GetSecurityDescriptorDacl may return true value for exists (lpbDaclPresent)
883 // while oldACL is NULL for some case.
884 if (oldACL == NULL) {
885 exists = FALSE;
886 }
887
888 if (exists) {
889 if (!GetAclInformation(oldACL, &aclinfo,
890 sizeof(ACL_SIZE_INFORMATION),
891 AclSizeInformation)) {
892 if (PrintMiscellaneous && Verbose) {
893 warning("GetAclInformation failure: lasterror = %d \n", GetLastError());
894 return false;
895 }
896 }
897 } else {
898 aclinfo.AceCount = 0; // assume NULL DACL
899 aclinfo.AclBytesFree = 0;
900 aclinfo.AclBytesInUse = sizeof(ACL);
901 }
902
903 // compute the size needed for the new ACL
904 // initial size of ACL is sum of the following:
905 // * size of ACL structure.
906 // * size of each ACE structure that ACL is to contain minus the sid
907 // sidStart member (DWORD) of the ACE.
908 // * length of the SID that each ACE is to contain.
909 DWORD newACLsize = aclinfo.AclBytesInUse +
910 (sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count;
911 for (int i = 0; i < ace_count; i++) {
912 assert(aces[i].pSid != 0, "pSid should not be 0");
913 newACLsize += GetLengthSid(aces[i].pSid);
914 }
915
916 // create the new ACL
917 newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize, mtInternal);
918
919 if (!InitializeAcl(newACL, newACLsize, ACL_REVISION)) {
920 if (PrintMiscellaneous && Verbose) {
921 warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
922 }
923 FREE_C_HEAP_ARRAY(char, newACL);
924 return false;
925 }
926
927 unsigned int ace_index = 0;
928 // copy any existing ACEs from the old ACL (if any) to the new ACL.
929 if (aclinfo.AceCount != 0) {
930 while (ace_index < aclinfo.AceCount) {
931 LPVOID ace;
932 if (!GetAce(oldACL, ace_index, &ace)) {
933 if (PrintMiscellaneous && Verbose) {
934 warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
935 }
936 FREE_C_HEAP_ARRAY(char, newACL);
937 return false;
938 }
939 if (((ACCESS_ALLOWED_ACE *)ace)->Header.AceFlags && INHERITED_ACE) {
940 // this is an inherited, allowed ACE; break from loop so we can
941 // add the new access allowed, non-inherited ACE in the correct
942 // position, immediately following all non-inherited ACEs.
943 break;
944 }
945
946 // determine if the SID of this ACE matches any of the SIDs
947 // for which we plan to set ACEs.
948 int matches = 0;
949 for (int i = 0; i < ace_count; i++) {
950 if (EqualSid(aces[i].pSid, &(((ACCESS_ALLOWED_ACE *)ace)->SidStart))) {
951 matches++;
952 break;
953 }
954 }
955
956 // if there are no SID matches, then add this existing ACE to the new ACL
957 if (matches == 0) {
958 if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace,
959 ((PACE_HEADER)ace)->AceSize)) {
960 if (PrintMiscellaneous && Verbose) {
961 warning("AddAce failure: lasterror = %d \n", GetLastError());
962 }
963 FREE_C_HEAP_ARRAY(char, newACL);
964 return false;
965 }
966 }
967 ace_index++;
968 }
969 }
970
971 // add the passed-in access control entries to the new ACL
972 for (int i = 0; i < ace_count; i++) {
973 if (!AddAccessAllowedAce(newACL, ACL_REVISION,
974 aces[i].mask, aces[i].pSid)) {
975 if (PrintMiscellaneous && Verbose) {
976 warning("AddAccessAllowedAce failure: lasterror = %d \n",
977 GetLastError());
978 }
979 FREE_C_HEAP_ARRAY(char, newACL);
980 return false;
981 }
982 }
983
984 // now copy the rest of the inherited ACEs from the old ACL
985 if (aclinfo.AceCount != 0) {
986 // picking up at ace_index, where we left off in the
987 // previous ace_index loop
988 while (ace_index < aclinfo.AceCount) {
989 LPVOID ace;
990 if (!GetAce(oldACL, ace_index, &ace)) {
991 if (PrintMiscellaneous && Verbose) {
992 warning("InitializeAcl failure: lasterror = %d \n", GetLastError());
993 }
994 FREE_C_HEAP_ARRAY(char, newACL);
995 return false;
996 }
997 if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace,
998 ((PACE_HEADER)ace)->AceSize)) {
999 if (PrintMiscellaneous && Verbose) {
1000 warning("AddAce failure: lasterror = %d \n", GetLastError());
1001 }
1002 FREE_C_HEAP_ARRAY(char, newACL);
1003 return false;
1004 }
1005 ace_index++;
1006 }
1007 }
1008
1009 // add the new ACL to the security descriptor.
1010 if (!SetSecurityDescriptorDacl(pSD, TRUE, newACL, FALSE)) {
1011 if (PrintMiscellaneous && Verbose) {
1012 warning("SetSecurityDescriptorDacl failure:"
1013 " lasterror = %d \n", GetLastError());
1014 }
1015 FREE_C_HEAP_ARRAY(char, newACL);
1016 return false;
1017 }
1018
1019 // if running on windows 2000 or later, set the automatic inheritance
1020 // control flags.
1021 SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl;
1022 _SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr)
1023 GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")),
1024 "SetSecurityDescriptorControl");
1025
1026 if (_SetSecurityDescriptorControl != NULL) {
1027 // We do not want to further propagate inherited DACLs, so making them
1028 // protected prevents that.
1029 if (!_SetSecurityDescriptorControl(pSD, SE_DACL_PROTECTED,
1030 SE_DACL_PROTECTED)) {
1031 if (PrintMiscellaneous && Verbose) {
1032 warning("SetSecurityDescriptorControl failure:"
1033 " lasterror = %d \n", GetLastError());
1034 }
1035 FREE_C_HEAP_ARRAY(char, newACL);
1036 return false;
1037 }
1038 }
1039 // Note, the security descriptor maintains a reference to the newACL, not
1040 // a copy of it. Therefore, the newACL is not freed here. It is freed when
1041 // the security descriptor containing its reference is freed.
1042 //
1043 return true;
1044 }
1045
1046 // method to create a security attributes structure, which contains a
1047 // security descriptor and an access control list comprised of 0 or more
1048 // access control entries. The method take an array of ace_data structures
1049 // that indicate the ACE to be added to the security descriptor.
1050 //
1051 // the caller must free the resources associated with the security
1052 // attributes structure created by this method by calling the
1053 // free_security_attr() method.
1054 //
1055 static LPSECURITY_ATTRIBUTES make_security_attr(ace_data_t aces[], int count) {
1056
1057 // allocate space for a security descriptor
1058 PSECURITY_DESCRIPTOR pSD = (PSECURITY_DESCRIPTOR)
1059 NEW_C_HEAP_ARRAY(char, SECURITY_DESCRIPTOR_MIN_LENGTH, mtInternal);
1060
1061 // initialize the security descriptor
1062 if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) {
1063 if (PrintMiscellaneous && Verbose) {
1064 warning("InitializeSecurityDescriptor failure: "
1065 "lasterror = %d \n", GetLastError());
1066 }
1067 free_security_desc(pSD);
1068 return NULL;
1069 }
1070
1071 // add the access control entries
1072 if (!add_allow_aces(pSD, aces, count)) {
1073 free_security_desc(pSD);
1074 return NULL;
1075 }
1076
1077 // allocate and initialize the security attributes structure and
1078 // return it to the caller.
1079 //
1080 LPSECURITY_ATTRIBUTES lpSA = (LPSECURITY_ATTRIBUTES)
1081 NEW_C_HEAP_ARRAY(char, sizeof(SECURITY_ATTRIBUTES), mtInternal);
1082 lpSA->nLength = sizeof(SECURITY_ATTRIBUTES);
1083 lpSA->lpSecurityDescriptor = pSD;
1084 lpSA->bInheritHandle = FALSE;
1085
1086 return(lpSA);
1087 }
1088
1089 // method to create a security attributes structure with a restrictive
1090 // access control list that creates a set access rights for the user/owner
1091 // of the securable object and a separate set access rights for everyone else.
1092 // also provides for full access rights for the administrator group.
1093 //
1094 // the caller must free the resources associated with the security
1095 // attributes structure created by this method by calling the
1096 // free_security_attr() method.
1097 //
1098
1099 static LPSECURITY_ATTRIBUTES make_user_everybody_admin_security_attr(
1100 DWORD umask, DWORD emask, DWORD amask) {
1101
1102 ace_data_t aces[3];
1103
1104 // initialize the user ace data
1105 aces[0].pSid = get_user_sid(GetCurrentProcess());
1106 aces[0].mask = umask;
1107
1108 if (aces[0].pSid == 0)
1109 return NULL;
1110
1111 // get the well known SID for BUILTIN\Administrators
1112 PSID administratorsSid = NULL;
1113 SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY;
1114
1115 if (!AllocateAndInitializeSid( &SIDAuthAdministrators, 2,
1116 SECURITY_BUILTIN_DOMAIN_RID,
1117 DOMAIN_ALIAS_RID_ADMINS,
1118 0, 0, 0, 0, 0, 0, &administratorsSid)) {
1119
1120 if (PrintMiscellaneous && Verbose) {
1121 warning("AllocateAndInitializeSid failure: "
1122 "lasterror = %d \n", GetLastError());
1123 }
1124 return NULL;
1125 }
1126
1127 // initialize the ace data for administrator group
1128 aces[1].pSid = administratorsSid;
1129 aces[1].mask = amask;
1130
1131 // get the well known SID for the universal Everybody
1132 PSID everybodySid = NULL;
1133 SID_IDENTIFIER_AUTHORITY SIDAuthEverybody = SECURITY_WORLD_SID_AUTHORITY;
1134
1135 if (!AllocateAndInitializeSid( &SIDAuthEverybody, 1, SECURITY_WORLD_RID,
1136 0, 0, 0, 0, 0, 0, 0, &everybodySid)) {
1137
1138 if (PrintMiscellaneous && Verbose) {
1139 warning("AllocateAndInitializeSid failure: "
1140 "lasterror = %d \n", GetLastError());
1141 }
1142 return NULL;
1143 }
1144
1145 // initialize the ace data for everybody else.
1146 aces[2].pSid = everybodySid;
1147 aces[2].mask = emask;
1148
1149 // create a security attributes structure with access control
1150 // entries as initialized above.
1151 LPSECURITY_ATTRIBUTES lpSA = make_security_attr(aces, 3);
1152 FREE_C_HEAP_ARRAY(char, aces[0].pSid);
1153 FreeSid(everybodySid);
1154 FreeSid(administratorsSid);
1155 return(lpSA);
1156 }
1157
1158
1159 // method to create the security attributes structure for restricting
1160 // access to the user temporary directory.
1161 //
1162 // the caller must free the resources associated with the security
1163 // attributes structure created by this method by calling the
1164 // free_security_attr() method.
1165 //
1166 static LPSECURITY_ATTRIBUTES make_tmpdir_security_attr() {
1167
1168 // create full access rights for the user/owner of the directory
1169 // and read-only access rights for everybody else. This is
1170 // effectively equivalent to UNIX 755 permissions on a directory.
1171 //
1172 DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_ALL_ACCESS;
1173 DWORD emask = GENERIC_READ | FILE_LIST_DIRECTORY | FILE_TRAVERSE;
1174 DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
1175
1176 return make_user_everybody_admin_security_attr(umask, emask, amask);
1177 }
1178
1179 // method to create the security attributes structure for restricting
1180 // access to the shared memory backing store file.
1181 //
1182 // the caller must free the resources associated with the security
1183 // attributes structure created by this method by calling the
1184 // free_security_attr() method.
1185 //
1186 static LPSECURITY_ATTRIBUTES make_file_security_attr() {
1187
1188 // create extensive access rights for the user/owner of the file
1189 // and attribute read-only access rights for everybody else. This
1190 // is effectively equivalent to UNIX 600 permissions on a file.
1191 //
1192 DWORD umask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
1193 DWORD emask = STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES |
1194 FILE_READ_EA | FILE_LIST_DIRECTORY | FILE_TRAVERSE;
1195 DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS;
1196
1197 return make_user_everybody_admin_security_attr(umask, emask, amask);
1198 }
1199
1200 // method to create the security attributes structure for restricting
1201 // access to the name shared memory file mapping object.
1202 //
1203 // the caller must free the resources associated with the security
1204 // attributes structure created by this method by calling the
1205 // free_security_attr() method.
1206 //
1207 static LPSECURITY_ATTRIBUTES make_smo_security_attr() {
1208
1209 // create extensive access rights for the user/owner of the shared
1210 // memory object and attribute read-only access rights for everybody
1211 // else. This is effectively equivalent to UNIX 600 permissions on
1212 // on the shared memory object.
1213 //
1214 DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_MAP_ALL_ACCESS;
1215 DWORD emask = STANDARD_RIGHTS_READ; // attributes only
1216 DWORD amask = STANDARD_RIGHTS_ALL | FILE_MAP_ALL_ACCESS;
1217
1218 return make_user_everybody_admin_security_attr(umask, emask, amask);
1219 }
1220
1221 // make the user specific temporary directory
1222 //
1223 static bool make_user_tmp_dir(const char* dirname) {
1224
1225
1226 LPSECURITY_ATTRIBUTES pDirSA = make_tmpdir_security_attr();
1227 if (pDirSA == NULL) {
1228 return false;
1229 }
1230
1231
1232 // create the directory with the given security attributes
1233 if (!CreateDirectory(dirname, pDirSA)) {
1234 DWORD lasterror = GetLastError();
1235 if (lasterror == ERROR_ALREADY_EXISTS) {
1236 // The directory already exists and was probably created by another
1237 // JVM instance. However, this could also be the result of a
1238 // deliberate symlink. Verify that the existing directory is safe.
1239 //
1240 if (!is_directory_secure(dirname)) {
1241 // directory is not secure
1242 if (PrintMiscellaneous && Verbose) {
1243 warning("%s directory is insecure\n", dirname);
1244 }
1245 return false;
1246 }
1247 // The administrator should be able to delete this directory.
1248 // But the directory created by previous version of JVM may not
1249 // have permission for administrators to delete this directory.
1250 // So add full permission to the administrator. Also setting new
1251 // DACLs might fix the corrupted the DACLs.
1252 SECURITY_INFORMATION secInfo = DACL_SECURITY_INFORMATION;
1253 if (!SetFileSecurity(dirname, secInfo, pDirSA->lpSecurityDescriptor)) {
1254 if (PrintMiscellaneous && Verbose) {
1255 lasterror = GetLastError();
1256 warning("SetFileSecurity failed for %s directory. lasterror %d \n",
1257 dirname, lasterror);
1258 }
1259 }
1260 }
1261 else {
1262 if (PrintMiscellaneous && Verbose) {
1263 warning("CreateDirectory failed: %d\n", GetLastError());
1264 }
1265 return false;
1266 }
1267 }
1268
1269 // free the security attributes structure
1270 free_security_attr(pDirSA);
1271
1272 return true;
1273 }
1274
1275 // create the shared memory resources
1276 //
1277 // This function creates the shared memory resources. This includes
1278 // the backing store file and the file mapping shared memory object.
1279 //
1280 static HANDLE create_sharedmem_resources(const char* dirname, const char* filename, const char* objectname, size_t size) {
1281
1282 HANDLE fh = INVALID_HANDLE_VALUE;
1283 HANDLE fmh = NULL;
1284
1285
1286 // create the security attributes for the backing store file
1287 LPSECURITY_ATTRIBUTES lpFileSA = make_file_security_attr();
1288 if (lpFileSA == NULL) {
1289 return NULL;
1290 }
1291
1292 // create the security attributes for the shared memory object
1293 LPSECURITY_ATTRIBUTES lpSmoSA = make_smo_security_attr();
1294 if (lpSmoSA == NULL) {
1295 free_security_attr(lpFileSA);
1296 return NULL;
1297 }
1298
1299 // create the user temporary directory
1300 if (!make_user_tmp_dir(dirname)) {
1301 // could not make/find the directory or the found directory
1302 // was not secure
1303 return NULL;
1304 }
1305
1306 // Create the file - the FILE_FLAG_DELETE_ON_CLOSE flag allows the
1307 // file to be deleted by the last process that closes its handle to
1308 // the file. This is important as the apis do not allow a terminating
1309 // JVM being monitored by another process to remove the file name.
1310 //
1311 fh = CreateFile(
1312 filename, /* LPCTSTR file name */
1313
1314 GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */
1315 FILE_SHARE_DELETE|FILE_SHARE_READ, /* DWORD share mode, future READONLY
1316 * open operations allowed
1317 */
1318 lpFileSA, /* LPSECURITY security attributes */
1319 CREATE_ALWAYS, /* DWORD creation disposition
1320 * create file, if it already
1321 * exists, overwrite it.
1322 */
1323 FILE_FLAG_DELETE_ON_CLOSE, /* DWORD flags and attributes */
1324
1325 NULL); /* HANDLE template file access */
1326
1327 free_security_attr(lpFileSA);
1328
1329 if (fh == INVALID_HANDLE_VALUE) {
1330 DWORD lasterror = GetLastError();
1331 if (PrintMiscellaneous && Verbose) {
1332 warning("could not create file %s: %d\n", filename, lasterror);
1333 }
1334 return NULL;
1335 }
1336
1337 // try to create the file mapping
1338 fmh = create_file_mapping(objectname, fh, lpSmoSA, size);
1339
1340 free_security_attr(lpSmoSA);
1341
1342 if (fmh == NULL) {
1343 // closing the file handle here will decrement the reference count
1344 // on the file. When all processes accessing the file close their
1345 // handle to it, the reference count will decrement to 0 and the
1346 // OS will delete the file. These semantics are requested by the
1347 // FILE_FLAG_DELETE_ON_CLOSE flag in CreateFile call above.
1348 CloseHandle(fh);
1349 fh = NULL;
1350 return NULL;
1351 } else {
1352 // We created the file mapping, but rarely the size of the
1353 // backing store file is reported as zero (0) which can cause
1354 // failures when trying to use the hsperfdata file.
1355 struct stat statbuf;
1356 int ret_code = ::stat(filename, &statbuf);
1357 if (ret_code == OS_ERR) {
1358 if (PrintMiscellaneous && Verbose) {
1359 warning("Could not get status information from file %s: %s\n",
1360 filename, strerror(errno));
1361 }
1362 CloseHandle(fmh);
1363 CloseHandle(fh);
1364 fh = NULL;
1365 fmh = NULL;
1366 return NULL;
1367 }
1368
1369 // We could always call FlushFileBuffers() but the Microsoft
1370 // docs indicate that it is considered expensive so we only
1371 // call it when we observe the size as zero (0).
1372 if (statbuf.st_size == 0 && FlushFileBuffers(fh) != TRUE) {
1373 DWORD lasterror = GetLastError();
1374 if (PrintMiscellaneous && Verbose) {
1375 warning("could not flush file %s: %d\n", filename, lasterror);
1376 }
1377 CloseHandle(fmh);
1378 CloseHandle(fh);
1379 fh = NULL;
1380 fmh = NULL;
1381 return NULL;
1382 }
1383 }
1384
1385 // the file has been successfully created and the file mapping
1386 // object has been created.
1387 sharedmem_fileHandle = fh;
1388 sharedmem_fileName = os::strdup(filename);
1389
1390 return fmh;
1391 }
1392
1393 // open the shared memory object for the given vmid.
1394 //
1395 static HANDLE open_sharedmem_object(const char* objectname, DWORD ofm_access, TRAPS) {
1396
1397 HANDLE fmh;
1398
1399 // open the file mapping with the requested mode
1400 fmh = OpenFileMapping(
1401 ofm_access, /* DWORD access mode */
1402 FALSE, /* BOOL inherit flag - Do not allow inherit */
1403 objectname); /* name for object */
1404
1405 if (fmh == NULL) {
1406 if (PrintMiscellaneous && Verbose) {
1407 warning("OpenFileMapping failed for shared memory object %s:"
1408 " lasterror = %d\n", objectname, GetLastError());
1409 }
1410 THROW_MSG_(vmSymbols::java_lang_Exception(),
1411 "Could not open PerfMemory", INVALID_HANDLE_VALUE);
1412 }
1413
1414 return fmh;;
1415 }
1416
1417 // create a named shared memory region
1418 //
1419 // On Win32, a named shared memory object has a name space that
1420 // is independent of the file system name space. Shared memory object,
1421 // or more precisely, file mapping objects, provide no mechanism to
1422 // inquire the size of the memory region. There is also no api to
1423 // enumerate the memory regions for various processes.
1424 //
1425 // This implementation utilizes the shared memory name space in parallel
1426 // with the file system name space. This allows us to determine the
1427 // size of the shared memory region from the size of the file and it
1428 // allows us to provide a common, file system based name space for
1429 // shared memory across platforms.
1430 //
1431 static char* mapping_create_shared(size_t size) {
1432
1433 void *mapAddress;
1434 int vmid = os::current_process_id();
1435
1436 // get the name of the user associated with this process
1437 char* user = get_user_name();
1438
1439 if (user == NULL) {
1440 return NULL;
1441 }
1442
1443 // construct the name of the user specific temporary directory
1444 char* dirname = get_user_tmp_dir(user);
1445
1446 // check that the file system is secure - i.e. it supports ACLs.
1447 if (!is_filesystem_secure(dirname)) {
1448 return NULL;
1449 }
1450
1451 // create the names of the backing store files and for the
1452 // share memory object.
1453 //
1454 char* filename = get_sharedmem_filename(dirname, vmid);
1455 char* objectname = get_sharedmem_objectname(user, vmid);
1456
1457 // cleanup any stale shared memory resources
1458 cleanup_sharedmem_resources(dirname);
1459
1460 assert(((size != 0) && (size % os::vm_page_size() == 0)),
1461 "unexpected PerfMemry region size");
1462
1463 FREE_C_HEAP_ARRAY(char, user);
1464
1465 // create the shared memory resources
1466 sharedmem_fileMapHandle =
1467 create_sharedmem_resources(dirname, filename, objectname, size);
1468
1469 FREE_C_HEAP_ARRAY(char, filename);
1470 FREE_C_HEAP_ARRAY(char, objectname);
1471 FREE_C_HEAP_ARRAY(char, dirname);
1472
1473 if (sharedmem_fileMapHandle == NULL) {
1474 return NULL;
1475 }
1476
1477 // map the file into the address space
1478 mapAddress = MapViewOfFile(
1479 sharedmem_fileMapHandle, /* HANDLE = file mapping object */
1480 FILE_MAP_ALL_ACCESS, /* DWORD access flags */
1481 0, /* DWORD High word of offset */
1482 0, /* DWORD Low word of offset */
1483 (DWORD)size); /* DWORD Number of bytes to map */
1484
1485 if (mapAddress == NULL) {
1486 if (PrintMiscellaneous && Verbose) {
1487 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError());
1488 }
1489 CloseHandle(sharedmem_fileMapHandle);
1490 sharedmem_fileMapHandle = NULL;
1491 return NULL;
1492 }
1493
1494 // clear the shared memory region
1495 (void)memset(mapAddress, '\0', size);
1496
1497 // it does not go through os api, the operation has to record from here
1498 MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress,
1499 size, CURRENT_PC, mtInternal);
1500
1501 return (char*) mapAddress;
1502 }
1503
1504 // this method deletes the file mapping object.
1505 //
1506 static void delete_file_mapping(char* addr, size_t size) {
1507
1508 // cleanup the persistent shared memory resources. since DestroyJavaVM does
1509 // not support unloading of the JVM, unmapping of the memory resource is not
1510 // performed. The memory will be reclaimed by the OS upon termination of all
1511 // processes mapping the resource. The file mapping handle and the file
1512 // handle are closed here to expedite the remove of the file by the OS. The
1513 // file is not removed directly because it was created with
1514 // FILE_FLAG_DELETE_ON_CLOSE semantics and any attempt to remove it would
1515 // be unsuccessful.
1516
1517 // close the fileMapHandle. the file mapping will still be retained
1518 // by the OS as long as any other JVM processes has an open file mapping
1519 // handle or a mapped view of the file.
1520 //
1521 if (sharedmem_fileMapHandle != NULL) {
1522 CloseHandle(sharedmem_fileMapHandle);
1523 sharedmem_fileMapHandle = NULL;
1524 }
1525
1526 // close the file handle. This will decrement the reference count on the
1527 // backing store file. When the reference count decrements to 0, the OS
1528 // will delete the file. These semantics apply because the file was
1529 // created with the FILE_FLAG_DELETE_ON_CLOSE flag.
1530 //
1531 if (sharedmem_fileHandle != INVALID_HANDLE_VALUE) {
1532 CloseHandle(sharedmem_fileHandle);
1533 sharedmem_fileHandle = INVALID_HANDLE_VALUE;
1534 }
1535 }
1536
1537 // this method determines the size of the shared memory file
1538 //
1539 static size_t sharedmem_filesize(const char* filename, TRAPS) {
1540
1541 struct stat statbuf;
1542
1543 // get the file size
1544 //
1545 // on win95/98/me, _stat returns a file size of 0 bytes, but on
1546 // winnt/2k the appropriate file size is returned. support for
1547 // the sharable aspects of performance counters was abandonded
1548 // on the non-nt win32 platforms due to this and other api
1549 // inconsistencies
1550 //
1551 if (::stat(filename, &statbuf) == OS_ERR) {
1552 if (PrintMiscellaneous && Verbose) {
1553 warning("stat %s failed: %s\n", filename, strerror(errno));
1554 }
1555 THROW_MSG_0(vmSymbols::java_io_IOException(),
1556 "Could not determine PerfMemory size");
1557 }
1558
1559 if ((statbuf.st_size == 0) || (statbuf.st_size % os::vm_page_size() != 0)) {
1560 if (PrintMiscellaneous && Verbose) {
1561 warning("unexpected file size: size = " SIZE_FORMAT "\n",
1562 statbuf.st_size);
1563 }
1564 THROW_MSG_0(vmSymbols::java_lang_Exception(),
1565 "Invalid PerfMemory size");
1566 }
1567
1568 return statbuf.st_size;
1569 }
1570
1571 // this method opens a file mapping object and maps the object
1572 // into the address space of the process
1573 //
1574 static void open_file_mapping(const char* user, int vmid,
1575 PerfMemory::PerfMemoryMode mode,
1576 char** addrp, size_t* sizep, TRAPS) {
1577
1578 ResourceMark rm;
1579
1580 void *mapAddress = 0;
1581 size_t size = 0;
1582 HANDLE fmh;
1583 DWORD ofm_access;
1584 DWORD mv_access;
1585 const char* luser = NULL;
1586
1587 if (mode == PerfMemory::PERF_MODE_RO) {
1588 ofm_access = FILE_MAP_READ;
1589 mv_access = FILE_MAP_READ;
1590 }
1591 else if (mode == PerfMemory::PERF_MODE_RW) {
1592 #ifdef LATER
1593 ofm_access = FILE_MAP_READ | FILE_MAP_WRITE;
1594 mv_access = FILE_MAP_READ | FILE_MAP_WRITE;
1595 #else
1596 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1597 "Unsupported access mode");
1598 #endif
1599 }
1600 else {
1601 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1602 "Illegal access mode");
1603 }
1604
1605 // if a user name wasn't specified, then find the user name for
1606 // the owner of the target vm.
1607 if (user == NULL || strlen(user) == 0) {
1608 luser = get_user_name(vmid);
1609 }
1610 else {
1611 luser = user;
1612 }
1613
1614 if (luser == NULL) {
1615 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1616 "Could not map vmid to user name");
1617 }
1618
1619 // get the names for the resources for the target vm
1620 char* dirname = get_user_tmp_dir(luser);
1621
1622 // since we don't follow symbolic links when creating the backing
1623 // store file, we also don't following them when attaching
1624 //
1625 if (!is_directory_secure(dirname)) {
1626 FREE_C_HEAP_ARRAY(char, dirname);
1627 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
1628 "Process not found");
1629 }
1630
1631 char* filename = get_sharedmem_filename(dirname, vmid);
1632 char* objectname = get_sharedmem_objectname(luser, vmid);
1633
1634 // copy heap memory to resource memory. the objectname and
1635 // filename are passed to methods that may throw exceptions.
1636 // using resource arrays for these names prevents the leaks
1637 // that would otherwise occur.
1638 //
1639 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1);
1640 char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1);
1641 strcpy(rfilename, filename);
1642 strcpy(robjectname, objectname);
1643
1644 // free the c heap resources that are no longer needed
1645 if (luser != user) FREE_C_HEAP_ARRAY(char, luser);
1646 FREE_C_HEAP_ARRAY(char, dirname);
1647 FREE_C_HEAP_ARRAY(char, filename);
1648 FREE_C_HEAP_ARRAY(char, objectname);
1649
1650 if (*sizep == 0) {
1651 size = sharedmem_filesize(rfilename, CHECK);
1652 } else {
1653 size = *sizep;
1654 }
1655
1656 assert(size > 0, "unexpected size <= 0");
1657
1658 // Open the file mapping object with the given name
1659 fmh = open_sharedmem_object(robjectname, ofm_access, CHECK);
1660
1661 assert(fmh != INVALID_HANDLE_VALUE, "unexpected handle value");
1662
1663 // map the entire file into the address space
1664 mapAddress = MapViewOfFile(
1665 fmh, /* HANDLE Handle of file mapping object */
1666 mv_access, /* DWORD access flags */
1667 0, /* DWORD High word of offset */
1668 0, /* DWORD Low word of offset */
1669 size); /* DWORD Number of bytes to map */
1670
1671 if (mapAddress == NULL) {
1672 if (PrintMiscellaneous && Verbose) {
1673 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError());
1674 }
1675 CloseHandle(fmh);
1676 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(),
1677 "Could not map PerfMemory");
1678 }
1679
1680 // it does not go through os api, the operation has to record from here
1681 MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress, size,
1682 CURRENT_PC, mtInternal);
1683
1684
1685 *addrp = (char*)mapAddress;
1686 *sizep = size;
1687
1688 // File mapping object can be closed at this time without
1689 // invalidating the mapped view of the file
1690 CloseHandle(fmh);
1691
1692 if (PerfTraceMemOps) {
1693 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at "
1694 INTPTR_FORMAT "\n", size, vmid, mapAddress);
1695 }
1696 }
1697
1698 // this method unmaps the the mapped view of the the
1699 // file mapping object.
1700 //
1701 static void remove_file_mapping(char* addr) {
1702
1703 // the file mapping object was closed in open_file_mapping()
1704 // after the file map view was created. We only need to
1705 // unmap the file view here.
1706 UnmapViewOfFile(addr);
1707 }
1708
1709 // create the PerfData memory region in shared memory.
1710 static char* create_shared_memory(size_t size) {
1711
1712 return mapping_create_shared(size);
1713 }
1714
1715 // release a named, shared memory region
1716 //
1717 void delete_shared_memory(char* addr, size_t size) {
1718
1719 delete_file_mapping(addr, size);
1720 }
1721
1722
1723
1724
1725 // create the PerfData memory region
1726 //
1727 // This method creates the memory region used to store performance
1728 // data for the JVM. The memory may be created in standard or
1729 // shared memory.
1730 //
1731 void PerfMemory::create_memory_region(size_t size) {
1732
1733 if (PerfDisableSharedMem) {
1734 // do not share the memory for the performance data.
1735 PerfDisableSharedMem = true;
1736 _start = create_standard_memory(size);
1737 }
1738 else {
1739 _start = create_shared_memory(size);
1740 if (_start == NULL) {
1741
1742 // creation of the shared memory region failed, attempt
1743 // to create a contiguous, non-shared memory region instead.
1744 //
1745 if (PrintMiscellaneous && Verbose) {
1746 warning("Reverting to non-shared PerfMemory region.\n");
1747 }
1748 PerfDisableSharedMem = true;
1749 _start = create_standard_memory(size);
1750 }
1751 }
1752
1753 if (_start != NULL) _capacity = size;
1754
1755 }
1756
1757 // delete the PerfData memory region
1758 //
1759 // This method deletes the memory region used to store performance
1760 // data for the JVM. The memory region indicated by the <address, size>
1761 // tuple will be inaccessible after a call to this method.
1762 //
1763 void PerfMemory::delete_memory_region() {
1764
1765 assert((start() != NULL && capacity() > 0), "verify proper state");
1766
1767 // If user specifies PerfDataSaveFile, it will save the performance data
1768 // to the specified file name no matter whether PerfDataSaveToFile is specified
1769 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag
1770 // -XX:+PerfDataSaveToFile.
1771 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) {
1772 save_memory_to_file(start(), capacity());
1773 }
1774
1775 if (PerfDisableSharedMem) {
1776 delete_standard_memory(start(), capacity());
1777 }
1778 else {
1779 delete_shared_memory(start(), capacity());
1780 }
1781 }
1782
1783 // attach to the PerfData memory region for another JVM
1784 //
1785 // This method returns an <address, size> tuple that points to
1786 // a memory buffer that is kept reasonably synchronized with
1787 // the PerfData memory region for the indicated JVM. This
1788 // buffer may be kept in synchronization via shared memory
1789 // or some other mechanism that keeps the buffer updated.
1790 //
1791 // If the JVM chooses not to support the attachability feature,
1792 // this method should throw an UnsupportedOperation exception.
1793 //
1794 // This implementation utilizes named shared memory to map
1795 // the indicated process's PerfData memory region into this JVMs
1796 // address space.
1797 //
1798 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode,
1799 char** addrp, size_t* sizep, TRAPS) {
1800
1801 if (vmid == 0 || vmid == os::current_process_id()) {
1802 *addrp = start();
1803 *sizep = capacity();
1804 return;
1805 }
1806
1807 open_file_mapping(user, vmid, mode, addrp, sizep, CHECK);
1808 }
1809
1810 // detach from the PerfData memory region of another JVM
1811 //
1812 // This method detaches the PerfData memory region of another
1813 // JVM, specified as an <address, size> tuple of a buffer
1814 // in this process's address space. This method may perform
1815 // arbitrary actions to accomplish the detachment. The memory
1816 // region specified by <address, size> will be inaccessible after
1817 // a call to this method.
1818 //
1819 // If the JVM chooses not to support the attachability feature,
1820 // this method should throw an UnsupportedOperation exception.
1821 //
1822 // This implementation utilizes named shared memory to detach
1823 // the indicated process's PerfData memory region from this
1824 // process's address space.
1825 //
1826 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) {
1827
1828 assert(addr != 0, "address sanity check");
1829 assert(bytes > 0, "capacity sanity check");
1830
1831 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) {
1832 // prevent accidental detachment of this process's PerfMemory region
1833 return;
1834 }
1835
1836 if (MemTracker::tracking_level() > NMT_minimal) {
1837 // it does not go through os api, the operation has to record from here
1838 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1839 remove_file_mapping(addr);
1840 tkr.record((address)addr, bytes);
1841 } else {
1842 remove_file_mapping(addr);
1843 }
1844 }