Mercurial > hg > graal-jvmci-8
annotate src/os/windows/vm/perfMemory_windows.cpp @ 2068:1e637defdda6
6961186: Better VM handling of unexpected exceptions from application native code
Summary: Trap uncaught C++ exception on Windows and Solaris and generate hs_err report.
Reviewed-by: coleenp, bobv, dholmes
author | zgu |
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date | Wed, 22 Dec 2010 11:24:21 -0500 |
parents | f95d63e2154a |
children | de14f1eee390 |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 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/perfMemory.hpp" | |
33 #include "utilities/exceptions.hpp" | |
0 | 34 |
35 #include <windows.h> | |
36 #include <sys/types.h> | |
37 #include <sys/stat.h> | |
38 #include <errno.h> | |
39 #include <lmcons.h> | |
40 | |
41 typedef BOOL (WINAPI *SetSecurityDescriptorControlFnPtr)( | |
42 IN PSECURITY_DESCRIPTOR pSecurityDescriptor, | |
43 IN SECURITY_DESCRIPTOR_CONTROL ControlBitsOfInterest, | |
44 IN SECURITY_DESCRIPTOR_CONTROL ControlBitsToSet); | |
45 | |
46 // Standard Memory Implementation Details | |
47 | |
48 // create the PerfData memory region in standard memory. | |
49 // | |
50 static char* create_standard_memory(size_t size) { | |
51 | |
52 // allocate an aligned chuck of memory | |
53 char* mapAddress = os::reserve_memory(size); | |
54 | |
55 if (mapAddress == NULL) { | |
56 return NULL; | |
57 } | |
58 | |
59 // commit memory | |
60 if (!os::commit_memory(mapAddress, size)) { | |
61 if (PrintMiscellaneous && Verbose) { | |
62 warning("Could not commit PerfData memory\n"); | |
63 } | |
64 os::release_memory(mapAddress, size); | |
65 return NULL; | |
66 } | |
67 | |
68 return mapAddress; | |
69 } | |
70 | |
71 // delete the PerfData memory region | |
72 // | |
73 static void delete_standard_memory(char* addr, size_t size) { | |
74 | |
75 // there are no persistent external resources to cleanup for standard | |
76 // memory. since DestroyJavaVM does not support unloading of the JVM, | |
77 // cleanup of the memory resource is not performed. The memory will be | |
78 // reclaimed by the OS upon termination of the process. | |
79 // | |
80 return; | |
81 | |
82 } | |
83 | |
84 // save the specified memory region to the given file | |
85 // | |
86 static void save_memory_to_file(char* addr, size_t size) { | |
87 | |
88 const char* destfile = PerfMemory::get_perfdata_file_path(); | |
89 assert(destfile[0] != '\0', "invalid Perfdata file path"); | |
90 | |
91 int fd = ::_open(destfile, _O_BINARY|_O_CREAT|_O_WRONLY|_O_TRUNC, | |
92 _S_IREAD|_S_IWRITE); | |
93 | |
94 if (fd == OS_ERR) { | |
95 if (PrintMiscellaneous && Verbose) { | |
96 warning("Could not create Perfdata save file: %s: %s\n", | |
97 destfile, strerror(errno)); | |
98 } | |
99 } else { | |
100 for (size_t remaining = size; remaining > 0;) { | |
101 | |
102 int nbytes = ::_write(fd, addr, (unsigned int)remaining); | |
103 if (nbytes == OS_ERR) { | |
104 if (PrintMiscellaneous && Verbose) { | |
105 warning("Could not write Perfdata save file: %s: %s\n", | |
106 destfile, strerror(errno)); | |
107 } | |
108 break; | |
109 } | |
110 | |
111 remaining -= (size_t)nbytes; | |
112 addr += nbytes; | |
113 } | |
114 | |
115 int result = ::_close(fd); | |
116 if (PrintMiscellaneous && Verbose) { | |
117 if (result == OS_ERR) { | |
118 warning("Could not close %s: %s\n", destfile, strerror(errno)); | |
119 } | |
120 } | |
121 } | |
122 | |
123 FREE_C_HEAP_ARRAY(char, destfile); | |
124 } | |
125 | |
126 // Shared Memory Implementation Details | |
127 | |
128 // Note: the win32 shared memory implementation uses two objects to represent | |
129 // the shared memory: a windows kernel based file mapping object and a backing | |
130 // store file. On windows, the name space for shared memory is a kernel | |
131 // based name space that is disjoint from other win32 name spaces. Since Java | |
132 // is unaware of this name space, a parallel file system based name space is | |
133 // maintained, which provides a common file system based shared memory name | |
134 // space across the supported platforms and one that Java apps can deal with | |
135 // through simple file apis. | |
136 // | |
137 // For performance and resource cleanup reasons, it is recommended that the | |
138 // user specific directory and the backing store file be stored in either a | |
139 // RAM based file system or a local disk based file system. Network based | |
140 // file systems are not recommended for performance reasons. In addition, | |
141 // use of SMB network based file systems may result in unsuccesful cleanup | |
142 // of the disk based resource on exit of the VM. The Windows TMP and TEMP | |
143 // environement variables, as used by the GetTempPath() Win32 API (see | |
144 // os::get_temp_directory() in os_win32.cpp), control the location of the | |
145 // user specific directory and the shared memory backing store file. | |
146 | |
147 static HANDLE sharedmem_fileMapHandle = NULL; | |
148 static HANDLE sharedmem_fileHandle = INVALID_HANDLE_VALUE; | |
149 static char* sharedmem_fileName = NULL; | |
150 | |
151 // return the user specific temporary directory name. | |
152 // | |
153 // the caller is expected to free the allocated memory. | |
154 // | |
155 static char* get_user_tmp_dir(const char* user) { | |
156 | |
157 const char* tmpdir = os::get_temp_directory(); | |
158 const char* perfdir = PERFDATA_NAME; | |
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159 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; |
0 | 160 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes); |
161 | |
162 // construct the path name to user specific tmp directory | |
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163 _snprintf(dirname, nbytes, "%s\\%s_%s", tmpdir, perfdir, user); |
0 | 164 |
165 return dirname; | |
166 } | |
167 | |
168 // convert the given file name into a process id. if the file | |
169 // does not meet the file naming constraints, return 0. | |
170 // | |
171 static int filename_to_pid(const char* filename) { | |
172 | |
173 // a filename that doesn't begin with a digit is not a | |
174 // candidate for conversion. | |
175 // | |
176 if (!isdigit(*filename)) { | |
177 return 0; | |
178 } | |
179 | |
180 // check if file name can be converted to an integer without | |
181 // any leftover characters. | |
182 // | |
183 char* remainder = NULL; | |
184 errno = 0; | |
185 int pid = (int)strtol(filename, &remainder, 10); | |
186 | |
187 if (errno != 0) { | |
188 return 0; | |
189 } | |
190 | |
191 // check for left over characters. If any, then the filename is | |
192 // not a candidate for conversion. | |
193 // | |
194 if (remainder != NULL && *remainder != '\0') { | |
195 return 0; | |
196 } | |
197 | |
198 // successful conversion, return the pid | |
199 return pid; | |
200 } | |
201 | |
202 // check if the given path is considered a secure directory for | |
203 // the backing store files. Returns true if the directory exists | |
204 // and is considered a secure location. Returns false if the path | |
605 | 205 // is a symbolic link or if an error occurred. |
0 | 206 // |
207 static bool is_directory_secure(const char* path) { | |
208 | |
209 DWORD fa; | |
210 | |
211 fa = GetFileAttributes(path); | |
212 if (fa == 0xFFFFFFFF) { | |
213 DWORD lasterror = GetLastError(); | |
214 if (lasterror == ERROR_FILE_NOT_FOUND) { | |
215 return false; | |
216 } | |
217 else { | |
218 // unexpected error, declare the path insecure | |
219 if (PrintMiscellaneous && Verbose) { | |
220 warning("could not get attributes for file %s: ", | |
221 " lasterror = %d\n", path, lasterror); | |
222 } | |
223 return false; | |
224 } | |
225 } | |
226 | |
227 if (fa & FILE_ATTRIBUTE_REPARSE_POINT) { | |
228 // we don't accept any redirection for the user specific directory | |
229 // so declare the path insecure. This may be too conservative, | |
230 // as some types of reparse points might be acceptable, but it | |
231 // is probably more secure to avoid these conditions. | |
232 // | |
233 if (PrintMiscellaneous && Verbose) { | |
234 warning("%s is a reparse point\n", path); | |
235 } | |
236 return false; | |
237 } | |
238 | |
239 if (fa & FILE_ATTRIBUTE_DIRECTORY) { | |
240 // this is the expected case. Since windows supports symbolic | |
241 // links to directories only, not to files, there is no need | |
242 // to check for open write permissions on the directory. If the | |
243 // directory has open write permissions, any files deposited that | |
244 // are not expected will be removed by the cleanup code. | |
245 // | |
246 return true; | |
247 } | |
248 else { | |
249 // this is either a regular file or some other type of file, | |
250 // any of which are unexpected and therefore insecure. | |
251 // | |
252 if (PrintMiscellaneous && Verbose) { | |
253 warning("%s is not a directory, file attributes = " | |
254 INTPTR_FORMAT "\n", path, fa); | |
255 } | |
256 return false; | |
257 } | |
258 } | |
259 | |
260 // return the user name for the owner of this process | |
261 // | |
262 // the caller is expected to free the allocated memory. | |
263 // | |
264 static char* get_user_name() { | |
265 | |
266 /* get the user name. This code is adapted from code found in | |
267 * the jdk in src/windows/native/java/lang/java_props_md.c | |
268 * java_props_md.c 1.29 02/02/06. According to the original | |
269 * source, the call to GetUserName is avoided because of a resulting | |
270 * increase in footprint of 100K. | |
271 */ | |
272 char* user = getenv("USERNAME"); | |
273 char buf[UNLEN+1]; | |
274 DWORD buflen = sizeof(buf); | |
275 if (user == NULL || strlen(user) == 0) { | |
276 if (GetUserName(buf, &buflen)) { | |
277 user = buf; | |
278 } | |
279 else { | |
280 return NULL; | |
281 } | |
282 } | |
283 | |
284 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(user)+1); | |
285 strcpy(user_name, user); | |
286 | |
287 return user_name; | |
288 } | |
289 | |
290 // return the name of the user that owns the process identified by vmid. | |
291 // | |
292 // This method uses a slow directory search algorithm to find the backing | |
293 // store file for the specified vmid and returns the user name, as determined | |
294 // by the user name suffix of the hsperfdata_<username> directory name. | |
295 // | |
296 // the caller is expected to free the allocated memory. | |
297 // | |
298 static char* get_user_name_slow(int vmid) { | |
299 | |
300 // directory search | |
301 char* oldest_user = NULL; | |
302 time_t oldest_ctime = 0; | |
303 | |
304 const char* tmpdirname = os::get_temp_directory(); | |
305 | |
306 DIR* tmpdirp = os::opendir(tmpdirname); | |
307 | |
308 if (tmpdirp == NULL) { | |
309 return NULL; | |
310 } | |
311 | |
312 // for each entry in the directory that matches the pattern hsperfdata_*, | |
313 // open the directory and check if the file for the given vmid exists. | |
314 // The file with the expected name and the latest creation date is used | |
315 // to determine the user name for the process id. | |
316 // | |
317 struct dirent* dentry; | |
318 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname)); | |
319 errno = 0; | |
320 while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { | |
321 | |
322 // check if the directory entry is a hsperfdata file | |
323 if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { | |
324 continue; | |
325 } | |
326 | |
327 char* usrdir_name = NEW_C_HEAP_ARRAY(char, | |
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328 strlen(tmpdirname) + strlen(dentry->d_name) + 2); |
0 | 329 strcpy(usrdir_name, tmpdirname); |
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330 strcat(usrdir_name, "\\"); |
0 | 331 strcat(usrdir_name, dentry->d_name); |
332 | |
333 DIR* subdirp = os::opendir(usrdir_name); | |
334 | |
335 if (subdirp == NULL) { | |
336 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
337 continue; | |
338 } | |
339 | |
340 // Since we don't create the backing store files in directories | |
341 // pointed to by symbolic links, we also don't follow them when | |
342 // looking for the files. We check for a symbolic link after the | |
343 // call to opendir in order to eliminate a small window where the | |
344 // symlink can be exploited. | |
345 // | |
346 if (!is_directory_secure(usrdir_name)) { | |
347 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
348 os::closedir(subdirp); | |
349 continue; | |
350 } | |
351 | |
352 struct dirent* udentry; | |
353 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name)); | |
354 errno = 0; | |
355 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { | |
356 | |
357 if (filename_to_pid(udentry->d_name) == vmid) { | |
358 struct stat statbuf; | |
359 | |
360 char* filename = NEW_C_HEAP_ARRAY(char, | |
361 strlen(usrdir_name) + strlen(udentry->d_name) + 2); | |
362 | |
363 strcpy(filename, usrdir_name); | |
364 strcat(filename, "\\"); | |
365 strcat(filename, udentry->d_name); | |
366 | |
367 if (::stat(filename, &statbuf) == OS_ERR) { | |
368 FREE_C_HEAP_ARRAY(char, filename); | |
369 continue; | |
370 } | |
371 | |
372 // skip over files that are not regular files. | |
373 if ((statbuf.st_mode & S_IFMT) != S_IFREG) { | |
374 FREE_C_HEAP_ARRAY(char, filename); | |
375 continue; | |
376 } | |
377 | |
378 // compare and save filename with latest creation time | |
379 if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) { | |
380 | |
381 if (statbuf.st_ctime > oldest_ctime) { | |
382 char* user = strchr(dentry->d_name, '_') + 1; | |
383 | |
384 if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user); | |
385 oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1); | |
386 | |
387 strcpy(oldest_user, user); | |
388 oldest_ctime = statbuf.st_ctime; | |
389 } | |
390 } | |
391 | |
392 FREE_C_HEAP_ARRAY(char, filename); | |
393 } | |
394 } | |
395 os::closedir(subdirp); | |
396 FREE_C_HEAP_ARRAY(char, udbuf); | |
397 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
398 } | |
399 os::closedir(tmpdirp); | |
400 FREE_C_HEAP_ARRAY(char, tdbuf); | |
401 | |
402 return(oldest_user); | |
403 } | |
404 | |
405 // return the name of the user that owns the process identified by vmid. | |
406 // | |
407 // note: this method should only be used via the Perf native methods. | |
408 // There are various costs to this method and limiting its use to the | |
409 // Perf native methods limits the impact to monitoring applications only. | |
410 // | |
411 static char* get_user_name(int vmid) { | |
412 | |
413 // A fast implementation is not provided at this time. It's possible | |
414 // to provide a fast process id to user name mapping function using | |
415 // the win32 apis, but the default ACL for the process object only | |
416 // allows processes with the same owner SID to acquire the process | |
417 // handle (via OpenProcess(PROCESS_QUERY_INFORMATION)). It's possible | |
418 // to have the JVM change the ACL for the process object to allow arbitrary | |
419 // users to access the process handle and the process security token. | |
420 // The security ramifications need to be studied before providing this | |
421 // mechanism. | |
422 // | |
423 return get_user_name_slow(vmid); | |
424 } | |
425 | |
426 // return the name of the shared memory file mapping object for the | |
427 // named shared memory region for the given user name and vmid. | |
428 // | |
429 // The file mapping object's name is not the file name. It is a name | |
430 // in a separate name space. | |
431 // | |
432 // the caller is expected to free the allocated memory. | |
433 // | |
434 static char *get_sharedmem_objectname(const char* user, int vmid) { | |
435 | |
436 // construct file mapping object's name, add 3 for two '_' and a | |
437 // null terminator. | |
438 int nbytes = (int)strlen(PERFDATA_NAME) + (int)strlen(user) + 3; | |
439 | |
440 // the id is converted to an unsigned value here because win32 allows | |
441 // negative process ids. However, OpenFileMapping API complains | |
442 // about a name containing a '-' characters. | |
443 // | |
444 nbytes += UINT_CHARS; | |
445 char* name = NEW_C_HEAP_ARRAY(char, nbytes); | |
446 _snprintf(name, nbytes, "%s_%s_%u", PERFDATA_NAME, user, vmid); | |
447 | |
448 return name; | |
449 } | |
450 | |
451 // return the file name of the backing store file for the named | |
452 // shared memory region for the given user name and vmid. | |
453 // | |
454 // the caller is expected to free the allocated memory. | |
455 // | |
456 static char* get_sharedmem_filename(const char* dirname, int vmid) { | |
457 | |
458 // add 2 for the file separator and a null terminator. | |
459 size_t nbytes = strlen(dirname) + UINT_CHARS + 2; | |
460 | |
461 char* name = NEW_C_HEAP_ARRAY(char, nbytes); | |
462 _snprintf(name, nbytes, "%s\\%d", dirname, vmid); | |
463 | |
464 return name; | |
465 } | |
466 | |
467 // remove file | |
468 // | |
469 // this method removes the file with the given file name. | |
470 // | |
471 // Note: if the indicated file is on an SMB network file system, this | |
472 // method may be unsuccessful in removing the file. | |
473 // | |
474 static void remove_file(const char* dirname, const char* filename) { | |
475 | |
476 size_t nbytes = strlen(dirname) + strlen(filename) + 2; | |
477 char* path = NEW_C_HEAP_ARRAY(char, nbytes); | |
478 | |
479 strcpy(path, dirname); | |
480 strcat(path, "\\"); | |
481 strcat(path, filename); | |
482 | |
483 if (::unlink(path) == OS_ERR) { | |
484 if (PrintMiscellaneous && Verbose) { | |
485 if (errno != ENOENT) { | |
486 warning("Could not unlink shared memory backing" | |
487 " store file %s : %s\n", path, strerror(errno)); | |
488 } | |
489 } | |
490 } | |
491 | |
492 FREE_C_HEAP_ARRAY(char, path); | |
493 } | |
494 | |
495 // returns true if the process represented by pid is alive, otherwise | |
496 // returns false. the validity of the result is only accurate if the | |
497 // target process is owned by the same principal that owns this process. | |
498 // this method should not be used if to test the status of an otherwise | |
499 // arbitrary process unless it is know that this process has the appropriate | |
500 // privileges to guarantee a result valid. | |
501 // | |
502 static bool is_alive(int pid) { | |
503 | |
504 HANDLE ph = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid); | |
505 if (ph == NULL) { | |
506 // the process does not exist. | |
507 if (PrintMiscellaneous && Verbose) { | |
508 DWORD lastError = GetLastError(); | |
509 if (lastError != ERROR_INVALID_PARAMETER) { | |
510 warning("OpenProcess failed: %d\n", GetLastError()); | |
511 } | |
512 } | |
513 return false; | |
514 } | |
515 | |
516 DWORD exit_status; | |
517 if (!GetExitCodeProcess(ph, &exit_status)) { | |
518 if (PrintMiscellaneous && Verbose) { | |
519 warning("GetExitCodeProcess failed: %d\n", GetLastError()); | |
520 } | |
521 CloseHandle(ph); | |
522 return false; | |
523 } | |
524 | |
525 CloseHandle(ph); | |
526 return (exit_status == STILL_ACTIVE) ? true : false; | |
527 } | |
528 | |
529 // check if the file system is considered secure for the backing store files | |
530 // | |
531 static bool is_filesystem_secure(const char* path) { | |
532 | |
533 char root_path[MAX_PATH]; | |
534 char fs_type[MAX_PATH]; | |
535 | |
536 if (PerfBypassFileSystemCheck) { | |
537 if (PrintMiscellaneous && Verbose) { | |
538 warning("bypassing file system criteria checks for %s\n", path); | |
539 } | |
540 return true; | |
541 } | |
542 | |
543 char* first_colon = strchr((char *)path, ':'); | |
544 if (first_colon == NULL) { | |
545 if (PrintMiscellaneous && Verbose) { | |
546 warning("expected device specifier in path: %s\n", path); | |
547 } | |
548 return false; | |
549 } | |
550 | |
551 size_t len = (size_t)(first_colon - path); | |
552 assert(len + 2 <= MAX_PATH, "unexpected device specifier length"); | |
553 strncpy(root_path, path, len + 1); | |
554 root_path[len + 1] = '\\'; | |
555 root_path[len + 2] = '\0'; | |
556 | |
557 // check that we have something like "C:\" or "AA:\" | |
558 assert(strlen(root_path) >= 3, "device specifier too short"); | |
559 assert(strchr(root_path, ':') != NULL, "bad device specifier format"); | |
560 assert(strchr(root_path, '\\') != NULL, "bad device specifier format"); | |
561 | |
562 DWORD maxpath; | |
563 DWORD flags; | |
564 | |
565 if (!GetVolumeInformation(root_path, NULL, 0, NULL, &maxpath, | |
566 &flags, fs_type, MAX_PATH)) { | |
567 // we can't get information about the volume, so assume unsafe. | |
568 if (PrintMiscellaneous && Verbose) { | |
569 warning("could not get device information for %s: " | |
570 " path = %s: lasterror = %d\n", | |
571 root_path, path, GetLastError()); | |
572 } | |
573 return false; | |
574 } | |
575 | |
576 if ((flags & FS_PERSISTENT_ACLS) == 0) { | |
577 // file system doesn't support ACLs, declare file system unsafe | |
578 if (PrintMiscellaneous && Verbose) { | |
579 warning("file system type %s on device %s does not support" | |
580 " ACLs\n", fs_type, root_path); | |
581 } | |
582 return false; | |
583 } | |
584 | |
585 if ((flags & FS_VOL_IS_COMPRESSED) != 0) { | |
586 // file system is compressed, declare file system unsafe | |
587 if (PrintMiscellaneous && Verbose) { | |
588 warning("file system type %s on device %s is compressed\n", | |
589 fs_type, root_path); | |
590 } | |
591 return false; | |
592 } | |
593 | |
594 return true; | |
595 } | |
596 | |
597 // cleanup stale shared memory resources | |
598 // | |
599 // This method attempts to remove all stale shared memory files in | |
600 // the named user temporary directory. It scans the named directory | |
601 // for files matching the pattern ^$[0-9]*$. For each file found, the | |
602 // process id is extracted from the file name and a test is run to | |
603 // determine if the process is alive. If the process is not alive, | |
604 // any stale file resources are removed. | |
605 // | |
606 static void cleanup_sharedmem_resources(const char* dirname) { | |
607 | |
608 // open the user temp directory | |
609 DIR* dirp = os::opendir(dirname); | |
610 | |
611 if (dirp == NULL) { | |
612 // directory doesn't exist, so there is nothing to cleanup | |
613 return; | |
614 } | |
615 | |
616 if (!is_directory_secure(dirname)) { | |
617 // the directory is not secure, don't attempt any cleanup | |
618 return; | |
619 } | |
620 | |
621 // for each entry in the directory that matches the expected file | |
622 // name pattern, determine if the file resources are stale and if | |
623 // so, remove the file resources. Note, instrumented HotSpot processes | |
624 // for this user may start and/or terminate during this search and | |
625 // remove or create new files in this directory. The behavior of this | |
626 // loop under these conditions is dependent upon the implementation of | |
627 // opendir/readdir. | |
628 // | |
629 struct dirent* entry; | |
630 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname)); | |
631 errno = 0; | |
632 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { | |
633 | |
634 int pid = filename_to_pid(entry->d_name); | |
635 | |
636 if (pid == 0) { | |
637 | |
638 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { | |
639 | |
640 // attempt to remove all unexpected files, except "." and ".." | |
641 remove_file(dirname, entry->d_name); | |
642 } | |
643 | |
644 errno = 0; | |
645 continue; | |
646 } | |
647 | |
648 // we now have a file name that converts to a valid integer | |
649 // that could represent a process id . if this process id | |
650 // matches the current process id or the process is not running, | |
651 // then remove the stale file resources. | |
652 // | |
653 // process liveness is detected by checking the exit status | |
654 // of the process. if the process id is valid and the exit status | |
655 // indicates that it is still running, the file file resources | |
656 // are not removed. If the process id is invalid, or if we don't | |
657 // have permissions to check the process status, or if the process | |
658 // id is valid and the process has terminated, the the file resources | |
659 // are assumed to be stale and are removed. | |
660 // | |
661 if (pid == os::current_process_id() || !is_alive(pid)) { | |
662 | |
663 // we can only remove the file resources. Any mapped views | |
664 // of the file can only be unmapped by the processes that | |
665 // opened those views and the file mapping object will not | |
666 // get removed until all views are unmapped. | |
667 // | |
668 remove_file(dirname, entry->d_name); | |
669 } | |
670 errno = 0; | |
671 } | |
672 os::closedir(dirp); | |
673 FREE_C_HEAP_ARRAY(char, dbuf); | |
674 } | |
675 | |
676 // create a file mapping object with the requested name, and size | |
677 // from the file represented by the given Handle object | |
678 // | |
679 static HANDLE create_file_mapping(const char* name, HANDLE fh, LPSECURITY_ATTRIBUTES fsa, size_t size) { | |
680 | |
681 DWORD lowSize = (DWORD)size; | |
682 DWORD highSize = 0; | |
683 HANDLE fmh = NULL; | |
684 | |
685 // Create a file mapping object with the given name. This function | |
686 // will grow the file to the specified size. | |
687 // | |
688 fmh = CreateFileMapping( | |
689 fh, /* HANDLE file handle for backing store */ | |
690 fsa, /* LPSECURITY_ATTRIBUTES Not inheritable */ | |
691 PAGE_READWRITE, /* DWORD protections */ | |
692 highSize, /* DWORD High word of max size */ | |
693 lowSize, /* DWORD Low word of max size */ | |
694 name); /* LPCTSTR name for object */ | |
695 | |
696 if (fmh == NULL) { | |
697 if (PrintMiscellaneous && Verbose) { | |
698 warning("CreateFileMapping failed, lasterror = %d\n", GetLastError()); | |
699 } | |
700 return NULL; | |
701 } | |
702 | |
703 if (GetLastError() == ERROR_ALREADY_EXISTS) { | |
704 | |
705 // a stale file mapping object was encountered. This object may be | |
706 // owned by this or some other user and cannot be removed until | |
707 // the other processes either exit or close their mapping objects | |
708 // and/or mapped views of this mapping object. | |
709 // | |
710 if (PrintMiscellaneous && Verbose) { | |
711 warning("file mapping already exists, lasterror = %d\n", GetLastError()); | |
712 } | |
713 | |
714 CloseHandle(fmh); | |
715 return NULL; | |
716 } | |
717 | |
718 return fmh; | |
719 } | |
720 | |
721 | |
722 // method to free the given security descriptor and the contained | |
723 // access control list. | |
724 // | |
725 static void free_security_desc(PSECURITY_DESCRIPTOR pSD) { | |
726 | |
727 BOOL success, exists, isdefault; | |
728 PACL pACL; | |
729 | |
730 if (pSD != NULL) { | |
731 | |
732 // get the access control list from the security descriptor | |
733 success = GetSecurityDescriptorDacl(pSD, &exists, &pACL, &isdefault); | |
734 | |
735 // if an ACL existed and it was not a default acl, then it must | |
736 // be an ACL we enlisted. free the resources. | |
737 // | |
738 if (success && exists && pACL != NULL && !isdefault) { | |
739 FREE_C_HEAP_ARRAY(char, pACL); | |
740 } | |
741 | |
742 // free the security descriptor | |
743 FREE_C_HEAP_ARRAY(char, pSD); | |
744 } | |
745 } | |
746 | |
747 // method to free up a security attributes structure and any | |
748 // contained security descriptors and ACL | |
749 // | |
750 static void free_security_attr(LPSECURITY_ATTRIBUTES lpSA) { | |
751 | |
752 if (lpSA != NULL) { | |
753 // free the contained security descriptor and the ACL | |
754 free_security_desc(lpSA->lpSecurityDescriptor); | |
755 lpSA->lpSecurityDescriptor = NULL; | |
756 | |
757 // free the security attributes structure | |
758 FREE_C_HEAP_ARRAY(char, lpSA); | |
759 } | |
760 } | |
761 | |
762 // get the user SID for the process indicated by the process handle | |
763 // | |
764 static PSID get_user_sid(HANDLE hProcess) { | |
765 | |
766 HANDLE hAccessToken; | |
767 PTOKEN_USER token_buf = NULL; | |
768 DWORD rsize = 0; | |
769 | |
770 if (hProcess == NULL) { | |
771 return NULL; | |
772 } | |
773 | |
774 // get the process token | |
775 if (!OpenProcessToken(hProcess, TOKEN_READ, &hAccessToken)) { | |
776 if (PrintMiscellaneous && Verbose) { | |
777 warning("OpenProcessToken failure: lasterror = %d \n", GetLastError()); | |
778 } | |
779 return NULL; | |
780 } | |
781 | |
782 // determine the size of the token structured needed to retrieve | |
783 // the user token information from the access token. | |
784 // | |
785 if (!GetTokenInformation(hAccessToken, TokenUser, NULL, rsize, &rsize)) { | |
786 DWORD lasterror = GetLastError(); | |
787 if (lasterror != ERROR_INSUFFICIENT_BUFFER) { | |
788 if (PrintMiscellaneous && Verbose) { | |
789 warning("GetTokenInformation failure: lasterror = %d," | |
790 " rsize = %d\n", lasterror, rsize); | |
791 } | |
792 CloseHandle(hAccessToken); | |
793 return NULL; | |
794 } | |
795 } | |
796 | |
797 token_buf = (PTOKEN_USER) NEW_C_HEAP_ARRAY(char, rsize); | |
798 | |
799 // get the user token information | |
800 if (!GetTokenInformation(hAccessToken, TokenUser, token_buf, rsize, &rsize)) { | |
801 if (PrintMiscellaneous && Verbose) { | |
802 warning("GetTokenInformation failure: lasterror = %d," | |
803 " rsize = %d\n", GetLastError(), rsize); | |
804 } | |
805 FREE_C_HEAP_ARRAY(char, token_buf); | |
806 CloseHandle(hAccessToken); | |
807 return NULL; | |
808 } | |
809 | |
810 DWORD nbytes = GetLengthSid(token_buf->User.Sid); | |
811 PSID pSID = NEW_C_HEAP_ARRAY(char, nbytes); | |
812 | |
813 if (!CopySid(nbytes, pSID, token_buf->User.Sid)) { | |
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 FREE_C_HEAP_ARRAY(char, pSID); | |
820 CloseHandle(hAccessToken); | |
821 return NULL; | |
822 } | |
823 | |
824 // close the access token. | |
825 CloseHandle(hAccessToken); | |
826 FREE_C_HEAP_ARRAY(char, token_buf); | |
827 | |
828 return pSID; | |
829 } | |
830 | |
831 // structure used to consolidate access control entry information | |
832 // | |
833 typedef struct ace_data { | |
834 PSID pSid; // SID of the ACE | |
835 DWORD mask; // mask for the ACE | |
836 } ace_data_t; | |
837 | |
838 | |
839 // method to add an allow access control entry with the access rights | |
840 // indicated in mask for the principal indicated in SID to the given | |
841 // security descriptor. Much of the DACL handling was adapted from | |
842 // the example provided here: | |
843 // http://support.microsoft.com/kb/102102/EN-US/ | |
844 // | |
845 | |
846 static bool add_allow_aces(PSECURITY_DESCRIPTOR pSD, | |
847 ace_data_t aces[], int ace_count) { | |
848 PACL newACL = NULL; | |
849 PACL oldACL = NULL; | |
850 | |
851 if (pSD == NULL) { | |
852 return false; | |
853 } | |
854 | |
855 BOOL exists, isdefault; | |
856 | |
857 // retrieve any existing access control list. | |
858 if (!GetSecurityDescriptorDacl(pSD, &exists, &oldACL, &isdefault)) { | |
859 if (PrintMiscellaneous && Verbose) { | |
860 warning("GetSecurityDescriptor failure: lasterror = %d \n", | |
861 GetLastError()); | |
862 } | |
863 return false; | |
864 } | |
865 | |
866 // get the size of the DACL | |
867 ACL_SIZE_INFORMATION aclinfo; | |
868 | |
869 // GetSecurityDescriptorDacl may return true value for exists (lpbDaclPresent) | |
870 // while oldACL is NULL for some case. | |
871 if (oldACL == NULL) { | |
872 exists = FALSE; | |
873 } | |
874 | |
875 if (exists) { | |
876 if (!GetAclInformation(oldACL, &aclinfo, | |
877 sizeof(ACL_SIZE_INFORMATION), | |
878 AclSizeInformation)) { | |
879 if (PrintMiscellaneous && Verbose) { | |
880 warning("GetAclInformation failure: lasterror = %d \n", GetLastError()); | |
881 return false; | |
882 } | |
883 } | |
884 } else { | |
885 aclinfo.AceCount = 0; // assume NULL DACL | |
886 aclinfo.AclBytesFree = 0; | |
887 aclinfo.AclBytesInUse = sizeof(ACL); | |
888 } | |
889 | |
890 // compute the size needed for the new ACL | |
891 // initial size of ACL is sum of the following: | |
892 // * size of ACL structure. | |
893 // * size of each ACE structure that ACL is to contain minus the sid | |
894 // sidStart member (DWORD) of the ACE. | |
895 // * length of the SID that each ACE is to contain. | |
896 DWORD newACLsize = aclinfo.AclBytesInUse + | |
897 (sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count; | |
898 for (int i = 0; i < ace_count; i++) { | |
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899 assert(aces[i].pSid != 0, "pSid should not be 0"); |
0 | 900 newACLsize += GetLengthSid(aces[i].pSid); |
901 } | |
902 | |
903 // create the new ACL | |
904 newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize); | |
905 | |
906 if (!InitializeAcl(newACL, newACLsize, ACL_REVISION)) { | |
907 if (PrintMiscellaneous && Verbose) { | |
908 warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); | |
909 } | |
910 FREE_C_HEAP_ARRAY(char, newACL); | |
911 return false; | |
912 } | |
913 | |
914 unsigned int ace_index = 0; | |
915 // copy any existing ACEs from the old ACL (if any) to the new ACL. | |
916 if (aclinfo.AceCount != 0) { | |
917 while (ace_index < aclinfo.AceCount) { | |
918 LPVOID ace; | |
919 if (!GetAce(oldACL, ace_index, &ace)) { | |
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 if (((ACCESS_ALLOWED_ACE *)ace)->Header.AceFlags && INHERITED_ACE) { | |
927 // this is an inherited, allowed ACE; break from loop so we can | |
928 // add the new access allowed, non-inherited ACE in the correct | |
929 // position, immediately following all non-inherited ACEs. | |
930 break; | |
931 } | |
932 | |
933 // determine if the SID of this ACE matches any of the SIDs | |
934 // for which we plan to set ACEs. | |
935 int matches = 0; | |
936 for (int i = 0; i < ace_count; i++) { | |
937 if (EqualSid(aces[i].pSid, &(((ACCESS_ALLOWED_ACE *)ace)->SidStart))) { | |
938 matches++; | |
939 break; | |
940 } | |
941 } | |
942 | |
943 // if there are no SID matches, then add this existing ACE to the new ACL | |
944 if (matches == 0) { | |
945 if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, | |
946 ((PACE_HEADER)ace)->AceSize)) { | |
947 if (PrintMiscellaneous && Verbose) { | |
948 warning("AddAce failure: lasterror = %d \n", GetLastError()); | |
949 } | |
950 FREE_C_HEAP_ARRAY(char, newACL); | |
951 return false; | |
952 } | |
953 } | |
954 ace_index++; | |
955 } | |
956 } | |
957 | |
958 // add the passed-in access control entries to the new ACL | |
959 for (int i = 0; i < ace_count; i++) { | |
960 if (!AddAccessAllowedAce(newACL, ACL_REVISION, | |
961 aces[i].mask, aces[i].pSid)) { | |
962 if (PrintMiscellaneous && Verbose) { | |
963 warning("AddAccessAllowedAce failure: lasterror = %d \n", | |
964 GetLastError()); | |
965 } | |
966 FREE_C_HEAP_ARRAY(char, newACL); | |
967 return false; | |
968 } | |
969 } | |
970 | |
971 // now copy the rest of the inherited ACEs from the old ACL | |
972 if (aclinfo.AceCount != 0) { | |
973 // picking up at ace_index, where we left off in the | |
974 // previous ace_index loop | |
975 while (ace_index < aclinfo.AceCount) { | |
976 LPVOID ace; | |
977 if (!GetAce(oldACL, ace_index, &ace)) { | |
978 if (PrintMiscellaneous && Verbose) { | |
979 warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); | |
980 } | |
981 FREE_C_HEAP_ARRAY(char, newACL); | |
982 return false; | |
983 } | |
984 if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, | |
985 ((PACE_HEADER)ace)->AceSize)) { | |
986 if (PrintMiscellaneous && Verbose) { | |
987 warning("AddAce failure: lasterror = %d \n", GetLastError()); | |
988 } | |
989 FREE_C_HEAP_ARRAY(char, newACL); | |
990 return false; | |
991 } | |
992 ace_index++; | |
993 } | |
994 } | |
995 | |
996 // add the new ACL to the security descriptor. | |
997 if (!SetSecurityDescriptorDacl(pSD, TRUE, newACL, FALSE)) { | |
998 if (PrintMiscellaneous && Verbose) { | |
999 warning("SetSecurityDescriptorDacl failure:" | |
1000 " lasterror = %d \n", GetLastError()); | |
1001 } | |
1002 FREE_C_HEAP_ARRAY(char, newACL); | |
1003 return false; | |
1004 } | |
1005 | |
605 | 1006 // if running on windows 2000 or later, set the automatic inheritance |
0 | 1007 // control flags. |
1008 SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl; | |
1009 _SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr) | |
1010 GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")), | |
1011 "SetSecurityDescriptorControl"); | |
1012 | |
1013 if (_SetSecurityDescriptorControl != NULL) { | |
605 | 1014 // We do not want to further propagate inherited DACLs, so making them |
0 | 1015 // protected prevents that. |
1016 if (!_SetSecurityDescriptorControl(pSD, SE_DACL_PROTECTED, | |
1017 SE_DACL_PROTECTED)) { | |
1018 if (PrintMiscellaneous && Verbose) { | |
1019 warning("SetSecurityDescriptorControl failure:" | |
1020 " lasterror = %d \n", GetLastError()); | |
1021 } | |
1022 FREE_C_HEAP_ARRAY(char, newACL); | |
1023 return false; | |
1024 } | |
1025 } | |
1026 // Note, the security descriptor maintains a reference to the newACL, not | |
1027 // a copy of it. Therefore, the newACL is not freed here. It is freed when | |
1028 // the security descriptor containing its reference is freed. | |
1029 // | |
1030 return true; | |
1031 } | |
1032 | |
1033 // method to create a security attributes structure, which contains a | |
1034 // security descriptor and an access control list comprised of 0 or more | |
1035 // access control entries. The method take an array of ace_data structures | |
1036 // that indicate the ACE to be added to the security descriptor. | |
1037 // | |
1038 // the caller must free the resources associated with the security | |
1039 // attributes structure created by this method by calling the | |
1040 // free_security_attr() method. | |
1041 // | |
1042 static LPSECURITY_ATTRIBUTES make_security_attr(ace_data_t aces[], int count) { | |
1043 | |
1044 // allocate space for a security descriptor | |
1045 PSECURITY_DESCRIPTOR pSD = (PSECURITY_DESCRIPTOR) | |
1046 NEW_C_HEAP_ARRAY(char, SECURITY_DESCRIPTOR_MIN_LENGTH); | |
1047 | |
1048 // initialize the security descriptor | |
1049 if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) { | |
1050 if (PrintMiscellaneous && Verbose) { | |
1051 warning("InitializeSecurityDescriptor failure: " | |
1052 "lasterror = %d \n", GetLastError()); | |
1053 } | |
1054 free_security_desc(pSD); | |
1055 return NULL; | |
1056 } | |
1057 | |
1058 // add the access control entries | |
1059 if (!add_allow_aces(pSD, aces, count)) { | |
1060 free_security_desc(pSD); | |
1061 return NULL; | |
1062 } | |
1063 | |
1064 // allocate and initialize the security attributes structure and | |
1065 // return it to the caller. | |
1066 // | |
1067 LPSECURITY_ATTRIBUTES lpSA = (LPSECURITY_ATTRIBUTES) | |
1068 NEW_C_HEAP_ARRAY(char, sizeof(SECURITY_ATTRIBUTES)); | |
1069 lpSA->nLength = sizeof(SECURITY_ATTRIBUTES); | |
1070 lpSA->lpSecurityDescriptor = pSD; | |
1071 lpSA->bInheritHandle = FALSE; | |
1072 | |
1073 return(lpSA); | |
1074 } | |
1075 | |
1076 // method to create a security attributes structure with a restrictive | |
1077 // access control list that creates a set access rights for the user/owner | |
1078 // of the securable object and a separate set access rights for everyone else. | |
1079 // also provides for full access rights for the administrator group. | |
1080 // | |
1081 // the caller must free the resources associated with the security | |
1082 // attributes structure created by this method by calling the | |
1083 // free_security_attr() method. | |
1084 // | |
1085 | |
1086 static LPSECURITY_ATTRIBUTES make_user_everybody_admin_security_attr( | |
1087 DWORD umask, DWORD emask, DWORD amask) { | |
1088 | |
1089 ace_data_t aces[3]; | |
1090 | |
1091 // initialize the user ace data | |
1092 aces[0].pSid = get_user_sid(GetCurrentProcess()); | |
1093 aces[0].mask = umask; | |
1094 | |
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1095 if (aces[0].pSid == 0) |
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1096 return NULL; |
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1097 |
0 | 1098 // get the well known SID for BUILTIN\Administrators |
1099 PSID administratorsSid = NULL; | |
1100 SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY; | |
1101 | |
1102 if (!AllocateAndInitializeSid( &SIDAuthAdministrators, 2, | |
1103 SECURITY_BUILTIN_DOMAIN_RID, | |
1104 DOMAIN_ALIAS_RID_ADMINS, | |
1105 0, 0, 0, 0, 0, 0, &administratorsSid)) { | |
1106 | |
1107 if (PrintMiscellaneous && Verbose) { | |
1108 warning("AllocateAndInitializeSid failure: " | |
1109 "lasterror = %d \n", GetLastError()); | |
1110 } | |
1111 return NULL; | |
1112 } | |
1113 | |
1114 // initialize the ace data for administrator group | |
1115 aces[1].pSid = administratorsSid; | |
1116 aces[1].mask = amask; | |
1117 | |
1118 // get the well known SID for the universal Everybody | |
1119 PSID everybodySid = NULL; | |
1120 SID_IDENTIFIER_AUTHORITY SIDAuthEverybody = SECURITY_WORLD_SID_AUTHORITY; | |
1121 | |
1122 if (!AllocateAndInitializeSid( &SIDAuthEverybody, 1, SECURITY_WORLD_RID, | |
1123 0, 0, 0, 0, 0, 0, 0, &everybodySid)) { | |
1124 | |
1125 if (PrintMiscellaneous && Verbose) { | |
1126 warning("AllocateAndInitializeSid failure: " | |
1127 "lasterror = %d \n", GetLastError()); | |
1128 } | |
1129 return NULL; | |
1130 } | |
1131 | |
1132 // initialize the ace data for everybody else. | |
1133 aces[2].pSid = everybodySid; | |
1134 aces[2].mask = emask; | |
1135 | |
1136 // create a security attributes structure with access control | |
1137 // entries as initialized above. | |
1138 LPSECURITY_ATTRIBUTES lpSA = make_security_attr(aces, 3); | |
1139 FREE_C_HEAP_ARRAY(char, aces[0].pSid); | |
1140 FreeSid(everybodySid); | |
1141 FreeSid(administratorsSid); | |
1142 return(lpSA); | |
1143 } | |
1144 | |
1145 | |
1146 // method to create the security attributes structure for restricting | |
1147 // access to the user temporary directory. | |
1148 // | |
1149 // the caller must free the resources associated with the security | |
1150 // attributes structure created by this method by calling the | |
1151 // free_security_attr() method. | |
1152 // | |
1153 static LPSECURITY_ATTRIBUTES make_tmpdir_security_attr() { | |
1154 | |
1155 // create full access rights for the user/owner of the directory | |
1156 // and read-only access rights for everybody else. This is | |
1157 // effectively equivalent to UNIX 755 permissions on a directory. | |
1158 // | |
1159 DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_ALL_ACCESS; | |
1160 DWORD emask = GENERIC_READ | FILE_LIST_DIRECTORY | FILE_TRAVERSE; | |
1161 DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; | |
1162 | |
1163 return make_user_everybody_admin_security_attr(umask, emask, amask); | |
1164 } | |
1165 | |
1166 // method to create the security attributes structure for restricting | |
1167 // access to the shared memory backing store file. | |
1168 // | |
1169 // the caller must free the resources associated with the security | |
1170 // attributes structure created by this method by calling the | |
1171 // free_security_attr() method. | |
1172 // | |
1173 static LPSECURITY_ATTRIBUTES make_file_security_attr() { | |
1174 | |
1175 // create extensive access rights for the user/owner of the file | |
1176 // and attribute read-only access rights for everybody else. This | |
1177 // is effectively equivalent to UNIX 600 permissions on a file. | |
1178 // | |
1179 DWORD umask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; | |
1180 DWORD emask = STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES | | |
1181 FILE_READ_EA | FILE_LIST_DIRECTORY | FILE_TRAVERSE; | |
1182 DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; | |
1183 | |
1184 return make_user_everybody_admin_security_attr(umask, emask, amask); | |
1185 } | |
1186 | |
1187 // method to create the security attributes structure for restricting | |
1188 // access to the name shared memory file mapping object. | |
1189 // | |
1190 // the caller must free the resources associated with the security | |
1191 // attributes structure created by this method by calling the | |
1192 // free_security_attr() method. | |
1193 // | |
1194 static LPSECURITY_ATTRIBUTES make_smo_security_attr() { | |
1195 | |
1196 // create extensive access rights for the user/owner of the shared | |
1197 // memory object and attribute read-only access rights for everybody | |
1198 // else. This is effectively equivalent to UNIX 600 permissions on | |
1199 // on the shared memory object. | |
1200 // | |
1201 DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_MAP_ALL_ACCESS; | |
1202 DWORD emask = STANDARD_RIGHTS_READ; // attributes only | |
1203 DWORD amask = STANDARD_RIGHTS_ALL | FILE_MAP_ALL_ACCESS; | |
1204 | |
1205 return make_user_everybody_admin_security_attr(umask, emask, amask); | |
1206 } | |
1207 | |
1208 // make the user specific temporary directory | |
1209 // | |
1210 static bool make_user_tmp_dir(const char* dirname) { | |
1211 | |
1212 | |
1213 LPSECURITY_ATTRIBUTES pDirSA = make_tmpdir_security_attr(); | |
1214 if (pDirSA == NULL) { | |
1215 return false; | |
1216 } | |
1217 | |
1218 | |
1219 // create the directory with the given security attributes | |
1220 if (!CreateDirectory(dirname, pDirSA)) { | |
1221 DWORD lasterror = GetLastError(); | |
1222 if (lasterror == ERROR_ALREADY_EXISTS) { | |
1223 // The directory already exists and was probably created by another | |
1224 // JVM instance. However, this could also be the result of a | |
1225 // deliberate symlink. Verify that the existing directory is safe. | |
1226 // | |
1227 if (!is_directory_secure(dirname)) { | |
1228 // directory is not secure | |
1229 if (PrintMiscellaneous && Verbose) { | |
1230 warning("%s directory is insecure\n", dirname); | |
1231 } | |
1232 return false; | |
1233 } | |
1234 // The administrator should be able to delete this directory. | |
1235 // But the directory created by previous version of JVM may not | |
1236 // have permission for administrators to delete this directory. | |
1237 // So add full permission to the administrator. Also setting new | |
1238 // DACLs might fix the corrupted the DACLs. | |
1239 SECURITY_INFORMATION secInfo = DACL_SECURITY_INFORMATION; | |
1240 if (!SetFileSecurity(dirname, secInfo, pDirSA->lpSecurityDescriptor)) { | |
1241 if (PrintMiscellaneous && Verbose) { | |
1242 lasterror = GetLastError(); | |
1243 warning("SetFileSecurity failed for %s directory. lasterror %d \n", | |
1244 dirname, lasterror); | |
1245 } | |
1246 } | |
1247 } | |
1248 else { | |
1249 if (PrintMiscellaneous && Verbose) { | |
1250 warning("CreateDirectory failed: %d\n", GetLastError()); | |
1251 } | |
1252 return false; | |
1253 } | |
1254 } | |
1255 | |
1256 // free the security attributes structure | |
1257 free_security_attr(pDirSA); | |
1258 | |
1259 return true; | |
1260 } | |
1261 | |
1262 // create the shared memory resources | |
1263 // | |
1264 // This function creates the shared memory resources. This includes | |
1265 // the backing store file and the file mapping shared memory object. | |
1266 // | |
1267 static HANDLE create_sharedmem_resources(const char* dirname, const char* filename, const char* objectname, size_t size) { | |
1268 | |
1269 HANDLE fh = INVALID_HANDLE_VALUE; | |
1270 HANDLE fmh = NULL; | |
1271 | |
1272 | |
1273 // create the security attributes for the backing store file | |
1274 LPSECURITY_ATTRIBUTES lpFileSA = make_file_security_attr(); | |
1275 if (lpFileSA == NULL) { | |
1276 return NULL; | |
1277 } | |
1278 | |
1279 // create the security attributes for the shared memory object | |
1280 LPSECURITY_ATTRIBUTES lpSmoSA = make_smo_security_attr(); | |
1281 if (lpSmoSA == NULL) { | |
1282 free_security_attr(lpFileSA); | |
1283 return NULL; | |
1284 } | |
1285 | |
1286 // create the user temporary directory | |
1287 if (!make_user_tmp_dir(dirname)) { | |
1288 // could not make/find the directory or the found directory | |
1289 // was not secure | |
1290 return NULL; | |
1291 } | |
1292 | |
1293 // Create the file - the FILE_FLAG_DELETE_ON_CLOSE flag allows the | |
1294 // file to be deleted by the last process that closes its handle to | |
1295 // the file. This is important as the apis do not allow a terminating | |
1296 // JVM being monitored by another process to remove the file name. | |
1297 // | |
1298 // the FILE_SHARE_DELETE share mode is valid only in winnt | |
1299 // | |
1300 fh = CreateFile( | |
1301 filename, /* LPCTSTR file name */ | |
1302 | |
1303 GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */ | |
1304 | |
1305 (os::win32::is_nt() ? FILE_SHARE_DELETE : 0)| | |
1306 FILE_SHARE_READ, /* DWORD share mode, future READONLY | |
1307 * open operations allowed | |
1308 */ | |
1309 lpFileSA, /* LPSECURITY security attributes */ | |
1310 CREATE_ALWAYS, /* DWORD creation disposition | |
1311 * create file, if it already | |
1312 * exists, overwrite it. | |
1313 */ | |
1314 FILE_FLAG_DELETE_ON_CLOSE, /* DWORD flags and attributes */ | |
1315 | |
1316 NULL); /* HANDLE template file access */ | |
1317 | |
1318 free_security_attr(lpFileSA); | |
1319 | |
1320 if (fh == INVALID_HANDLE_VALUE) { | |
1321 DWORD lasterror = GetLastError(); | |
1322 if (PrintMiscellaneous && Verbose) { | |
1323 warning("could not create file %s: %d\n", filename, lasterror); | |
1324 } | |
1325 return NULL; | |
1326 } | |
1327 | |
1328 // try to create the file mapping | |
1329 fmh = create_file_mapping(objectname, fh, lpSmoSA, size); | |
1330 | |
1331 free_security_attr(lpSmoSA); | |
1332 | |
1333 if (fmh == NULL) { | |
1334 // closing the file handle here will decrement the reference count | |
1335 // on the file. When all processes accessing the file close their | |
1336 // handle to it, the reference count will decrement to 0 and the | |
1337 // OS will delete the file. These semantics are requested by the | |
1338 // FILE_FLAG_DELETE_ON_CLOSE flag in CreateFile call above. | |
1339 CloseHandle(fh); | |
1340 fh = NULL; | |
1341 return NULL; | |
1342 } | |
1343 | |
1344 // the file has been successfully created and the file mapping | |
1345 // object has been created. | |
1346 sharedmem_fileHandle = fh; | |
1347 sharedmem_fileName = strdup(filename); | |
1348 | |
1349 return fmh; | |
1350 } | |
1351 | |
1352 // open the shared memory object for the given vmid. | |
1353 // | |
1354 static HANDLE open_sharedmem_object(const char* objectname, DWORD ofm_access, TRAPS) { | |
1355 | |
1356 HANDLE fmh; | |
1357 | |
1358 // open the file mapping with the requested mode | |
1359 fmh = OpenFileMapping( | |
1360 ofm_access, /* DWORD access mode */ | |
1361 FALSE, /* BOOL inherit flag - Do not allow inherit */ | |
1362 objectname); /* name for object */ | |
1363 | |
1364 if (fmh == NULL) { | |
1365 if (PrintMiscellaneous && Verbose) { | |
1366 warning("OpenFileMapping failed for shared memory object %s:" | |
1367 " lasterror = %d\n", objectname, GetLastError()); | |
1368 } | |
1369 THROW_MSG_(vmSymbols::java_lang_Exception(), | |
1370 "Could not open PerfMemory", INVALID_HANDLE_VALUE); | |
1371 } | |
1372 | |
1373 return fmh;; | |
1374 } | |
1375 | |
1376 // create a named shared memory region | |
1377 // | |
1378 // On Win32, a named shared memory object has a name space that | |
1379 // is independent of the file system name space. Shared memory object, | |
1380 // or more precisely, file mapping objects, provide no mechanism to | |
1381 // inquire the size of the memory region. There is also no api to | |
1382 // enumerate the memory regions for various processes. | |
1383 // | |
1384 // This implementation utilizes the shared memory name space in parallel | |
1385 // with the file system name space. This allows us to determine the | |
1386 // size of the shared memory region from the size of the file and it | |
1387 // allows us to provide a common, file system based name space for | |
1388 // shared memory across platforms. | |
1389 // | |
1390 static char* mapping_create_shared(size_t size) { | |
1391 | |
1392 void *mapAddress; | |
1393 int vmid = os::current_process_id(); | |
1394 | |
1395 // get the name of the user associated with this process | |
1396 char* user = get_user_name(); | |
1397 | |
1398 if (user == NULL) { | |
1399 return NULL; | |
1400 } | |
1401 | |
1402 // construct the name of the user specific temporary directory | |
1403 char* dirname = get_user_tmp_dir(user); | |
1404 | |
1405 // check that the file system is secure - i.e. it supports ACLs. | |
1406 if (!is_filesystem_secure(dirname)) { | |
1407 return NULL; | |
1408 } | |
1409 | |
1410 // create the names of the backing store files and for the | |
1411 // share memory object. | |
1412 // | |
1413 char* filename = get_sharedmem_filename(dirname, vmid); | |
1414 char* objectname = get_sharedmem_objectname(user, vmid); | |
1415 | |
1416 // cleanup any stale shared memory resources | |
1417 cleanup_sharedmem_resources(dirname); | |
1418 | |
1419 assert(((size != 0) && (size % os::vm_page_size() == 0)), | |
1420 "unexpected PerfMemry region size"); | |
1421 | |
1422 FREE_C_HEAP_ARRAY(char, user); | |
1423 | |
1424 // create the shared memory resources | |
1425 sharedmem_fileMapHandle = | |
1426 create_sharedmem_resources(dirname, filename, objectname, size); | |
1427 | |
1428 FREE_C_HEAP_ARRAY(char, filename); | |
1429 FREE_C_HEAP_ARRAY(char, objectname); | |
1430 FREE_C_HEAP_ARRAY(char, dirname); | |
1431 | |
1432 if (sharedmem_fileMapHandle == NULL) { | |
1433 return NULL; | |
1434 } | |
1435 | |
1436 // map the file into the address space | |
1437 mapAddress = MapViewOfFile( | |
1438 sharedmem_fileMapHandle, /* HANDLE = file mapping object */ | |
1439 FILE_MAP_ALL_ACCESS, /* DWORD access flags */ | |
1440 0, /* DWORD High word of offset */ | |
1441 0, /* DWORD Low word of offset */ | |
1442 (DWORD)size); /* DWORD Number of bytes to map */ | |
1443 | |
1444 if (mapAddress == NULL) { | |
1445 if (PrintMiscellaneous && Verbose) { | |
1446 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); | |
1447 } | |
1448 CloseHandle(sharedmem_fileMapHandle); | |
1449 sharedmem_fileMapHandle = NULL; | |
1450 return NULL; | |
1451 } | |
1452 | |
1453 // clear the shared memory region | |
1454 (void)memset(mapAddress, '\0', size); | |
1455 | |
1456 return (char*) mapAddress; | |
1457 } | |
1458 | |
1459 // this method deletes the file mapping object. | |
1460 // | |
1461 static void delete_file_mapping(char* addr, size_t size) { | |
1462 | |
1463 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
1464 // not support unloading of the JVM, unmapping of the memory resource is not | |
1465 // performed. The memory will be reclaimed by the OS upon termination of all | |
1466 // processes mapping the resource. The file mapping handle and the file | |
1467 // handle are closed here to expedite the remove of the file by the OS. The | |
1468 // file is not removed directly because it was created with | |
1469 // FILE_FLAG_DELETE_ON_CLOSE semantics and any attempt to remove it would | |
1470 // be unsuccessful. | |
1471 | |
1472 // close the fileMapHandle. the file mapping will still be retained | |
1473 // by the OS as long as any other JVM processes has an open file mapping | |
1474 // handle or a mapped view of the file. | |
1475 // | |
1476 if (sharedmem_fileMapHandle != NULL) { | |
1477 CloseHandle(sharedmem_fileMapHandle); | |
1478 sharedmem_fileMapHandle = NULL; | |
1479 } | |
1480 | |
1481 // close the file handle. This will decrement the reference count on the | |
1482 // backing store file. When the reference count decrements to 0, the OS | |
1483 // will delete the file. These semantics apply because the file was | |
1484 // created with the FILE_FLAG_DELETE_ON_CLOSE flag. | |
1485 // | |
1486 if (sharedmem_fileHandle != INVALID_HANDLE_VALUE) { | |
1487 CloseHandle(sharedmem_fileHandle); | |
1488 sharedmem_fileHandle = INVALID_HANDLE_VALUE; | |
1489 } | |
1490 } | |
1491 | |
1492 // this method determines the size of the shared memory file | |
1493 // | |
1494 static size_t sharedmem_filesize(const char* filename, TRAPS) { | |
1495 | |
1496 struct stat statbuf; | |
1497 | |
1498 // get the file size | |
1499 // | |
1500 // on win95/98/me, _stat returns a file size of 0 bytes, but on | |
1501 // winnt/2k the appropriate file size is returned. support for | |
1502 // the sharable aspects of performance counters was abandonded | |
1503 // on the non-nt win32 platforms due to this and other api | |
1504 // inconsistencies | |
1505 // | |
1506 if (::stat(filename, &statbuf) == OS_ERR) { | |
1507 if (PrintMiscellaneous && Verbose) { | |
1508 warning("stat %s failed: %s\n", filename, strerror(errno)); | |
1509 } | |
1510 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
1511 "Could not determine PerfMemory size"); | |
1512 } | |
1513 | |
1514 if ((statbuf.st_size == 0) || (statbuf.st_size % os::vm_page_size() != 0)) { | |
1515 if (PrintMiscellaneous && Verbose) { | |
1516 warning("unexpected file size: size = " SIZE_FORMAT "\n", | |
1517 statbuf.st_size); | |
1518 } | |
1519 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
1520 "Invalid PerfMemory size"); | |
1521 } | |
1522 | |
1523 return statbuf.st_size; | |
1524 } | |
1525 | |
1526 // this method opens a file mapping object and maps the object | |
1527 // into the address space of the process | |
1528 // | |
1529 static void open_file_mapping(const char* user, int vmid, | |
1530 PerfMemory::PerfMemoryMode mode, | |
1531 char** addrp, size_t* sizep, TRAPS) { | |
1532 | |
1533 ResourceMark rm; | |
1534 | |
1535 void *mapAddress = 0; | |
1536 size_t size; | |
1537 HANDLE fmh; | |
1538 DWORD ofm_access; | |
1539 DWORD mv_access; | |
1540 const char* luser = NULL; | |
1541 | |
1542 if (mode == PerfMemory::PERF_MODE_RO) { | |
1543 ofm_access = FILE_MAP_READ; | |
1544 mv_access = FILE_MAP_READ; | |
1545 } | |
1546 else if (mode == PerfMemory::PERF_MODE_RW) { | |
1547 #ifdef LATER | |
1548 ofm_access = FILE_MAP_READ | FILE_MAP_WRITE; | |
1549 mv_access = FILE_MAP_READ | FILE_MAP_WRITE; | |
1550 #else | |
1551 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
1552 "Unsupported access mode"); | |
1553 #endif | |
1554 } | |
1555 else { | |
1556 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
1557 "Illegal access mode"); | |
1558 } | |
1559 | |
1560 // if a user name wasn't specified, then find the user name for | |
1561 // the owner of the target vm. | |
1562 if (user == NULL || strlen(user) == 0) { | |
1563 luser = get_user_name(vmid); | |
1564 } | |
1565 else { | |
1566 luser = user; | |
1567 } | |
1568 | |
1569 if (luser == NULL) { | |
1570 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
1571 "Could not map vmid to user name"); | |
1572 } | |
1573 | |
1574 // get the names for the resources for the target vm | |
1575 char* dirname = get_user_tmp_dir(luser); | |
1576 | |
1577 // since we don't follow symbolic links when creating the backing | |
1578 // store file, we also don't following them when attaching | |
1579 // | |
1580 if (!is_directory_secure(dirname)) { | |
1581 FREE_C_HEAP_ARRAY(char, dirname); | |
1582 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
1583 "Process not found"); | |
1584 } | |
1585 | |
1586 char* filename = get_sharedmem_filename(dirname, vmid); | |
1587 char* objectname = get_sharedmem_objectname(luser, vmid); | |
1588 | |
1589 // copy heap memory to resource memory. the objectname and | |
1590 // filename are passed to methods that may throw exceptions. | |
1591 // using resource arrays for these names prevents the leaks | |
1592 // that would otherwise occur. | |
1593 // | |
1594 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
1595 char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1); | |
1596 strcpy(rfilename, filename); | |
1597 strcpy(robjectname, objectname); | |
1598 | |
1599 // free the c heap resources that are no longer needed | |
1600 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); | |
1601 FREE_C_HEAP_ARRAY(char, dirname); | |
1602 FREE_C_HEAP_ARRAY(char, filename); | |
1603 FREE_C_HEAP_ARRAY(char, objectname); | |
1604 | |
1605 if (*sizep == 0) { | |
1606 size = sharedmem_filesize(rfilename, CHECK); | |
1607 assert(size != 0, "unexpected size"); | |
1608 } | |
1609 | |
1610 // Open the file mapping object with the given name | |
1611 fmh = open_sharedmem_object(robjectname, ofm_access, CHECK); | |
1612 | |
1613 assert(fmh != INVALID_HANDLE_VALUE, "unexpected handle value"); | |
1614 | |
1615 // map the entire file into the address space | |
1616 mapAddress = MapViewOfFile( | |
1617 fmh, /* HANDLE Handle of file mapping object */ | |
1618 mv_access, /* DWORD access flags */ | |
1619 0, /* DWORD High word of offset */ | |
1620 0, /* DWORD Low word of offset */ | |
1621 size); /* DWORD Number of bytes to map */ | |
1622 | |
1623 if (mapAddress == NULL) { | |
1624 if (PrintMiscellaneous && Verbose) { | |
1625 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); | |
1626 } | |
1627 CloseHandle(fmh); | |
1628 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
1629 "Could not map PerfMemory"); | |
1630 } | |
1631 | |
1632 *addrp = (char*)mapAddress; | |
1633 *sizep = size; | |
1634 | |
1635 // File mapping object can be closed at this time without | |
1636 // invalidating the mapped view of the file | |
1637 CloseHandle(fmh); | |
1638 | |
1639 if (PerfTraceMemOps) { | |
1640 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
1641 INTPTR_FORMAT "\n", size, vmid, mapAddress); | |
1642 } | |
1643 } | |
1644 | |
1645 // this method unmaps the the mapped view of the the | |
1646 // file mapping object. | |
1647 // | |
1648 static void remove_file_mapping(char* addr) { | |
1649 | |
1650 // the file mapping object was closed in open_file_mapping() | |
1651 // after the file map view was created. We only need to | |
1652 // unmap the file view here. | |
1653 UnmapViewOfFile(addr); | |
1654 } | |
1655 | |
1656 // create the PerfData memory region in shared memory. | |
1657 static char* create_shared_memory(size_t size) { | |
1658 | |
1659 return mapping_create_shared(size); | |
1660 } | |
1661 | |
1662 // release a named, shared memory region | |
1663 // | |
1664 void delete_shared_memory(char* addr, size_t size) { | |
1665 | |
1666 delete_file_mapping(addr, size); | |
1667 } | |
1668 | |
1669 | |
1670 | |
1671 | |
1672 // create the PerfData memory region | |
1673 // | |
1674 // This method creates the memory region used to store performance | |
1675 // data for the JVM. The memory may be created in standard or | |
1676 // shared memory. | |
1677 // | |
1678 void PerfMemory::create_memory_region(size_t size) { | |
1679 | |
1680 if (PerfDisableSharedMem || !os::win32::is_nt()) { | |
1681 // do not share the memory for the performance data. | |
1682 PerfDisableSharedMem = true; | |
1683 _start = create_standard_memory(size); | |
1684 } | |
1685 else { | |
1686 _start = create_shared_memory(size); | |
1687 if (_start == NULL) { | |
1688 | |
1689 // creation of the shared memory region failed, attempt | |
1690 // to create a contiguous, non-shared memory region instead. | |
1691 // | |
1692 if (PrintMiscellaneous && Verbose) { | |
1693 warning("Reverting to non-shared PerfMemory region.\n"); | |
1694 } | |
1695 PerfDisableSharedMem = true; | |
1696 _start = create_standard_memory(size); | |
1697 } | |
1698 } | |
1699 | |
1700 if (_start != NULL) _capacity = size; | |
1701 | |
1702 } | |
1703 | |
1704 // delete the PerfData memory region | |
1705 // | |
1706 // This method deletes the memory region used to store performance | |
1707 // data for the JVM. The memory region indicated by the <address, size> | |
1708 // tuple will be inaccessible after a call to this method. | |
1709 // | |
1710 void PerfMemory::delete_memory_region() { | |
1711 | |
1712 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
1713 | |
1714 // If user specifies PerfDataSaveFile, it will save the performance data | |
1715 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
1716 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
1717 // -XX:+PerfDataSaveToFile. | |
1718 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
1719 save_memory_to_file(start(), capacity()); | |
1720 } | |
1721 | |
1722 if (PerfDisableSharedMem) { | |
1723 delete_standard_memory(start(), capacity()); | |
1724 } | |
1725 else { | |
1726 delete_shared_memory(start(), capacity()); | |
1727 } | |
1728 } | |
1729 | |
1730 // attach to the PerfData memory region for another JVM | |
1731 // | |
1732 // This method returns an <address, size> tuple that points to | |
1733 // a memory buffer that is kept reasonably synchronized with | |
1734 // the PerfData memory region for the indicated JVM. This | |
1735 // buffer may be kept in synchronization via shared memory | |
1736 // or some other mechanism that keeps the buffer updated. | |
1737 // | |
1738 // If the JVM chooses not to support the attachability feature, | |
1739 // this method should throw an UnsupportedOperation exception. | |
1740 // | |
1741 // This implementation utilizes named shared memory to map | |
1742 // the indicated process's PerfData memory region into this JVMs | |
1743 // address space. | |
1744 // | |
1745 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, | |
1746 char** addrp, size_t* sizep, TRAPS) { | |
1747 | |
1748 if (vmid == 0 || vmid == os::current_process_id()) { | |
1749 *addrp = start(); | |
1750 *sizep = capacity(); | |
1751 return; | |
1752 } | |
1753 | |
1754 open_file_mapping(user, vmid, mode, addrp, sizep, CHECK); | |
1755 } | |
1756 | |
1757 // detach from the PerfData memory region of another JVM | |
1758 // | |
1759 // This method detaches the PerfData memory region of another | |
1760 // JVM, specified as an <address, size> tuple of a buffer | |
1761 // in this process's address space. This method may perform | |
1762 // arbitrary actions to accomplish the detachment. The memory | |
1763 // region specified by <address, size> will be inaccessible after | |
1764 // a call to this method. | |
1765 // | |
1766 // If the JVM chooses not to support the attachability feature, | |
1767 // this method should throw an UnsupportedOperation exception. | |
1768 // | |
1769 // This implementation utilizes named shared memory to detach | |
1770 // the indicated process's PerfData memory region from this | |
1771 // process's address space. | |
1772 // | |
1773 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
1774 | |
1775 assert(addr != 0, "address sanity check"); | |
1776 assert(bytes > 0, "capacity sanity check"); | |
1777 | |
1778 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
1779 // prevent accidental detachment of this process's PerfMemory region | |
1780 return; | |
1781 } | |
1782 | |
1783 remove_file_mapping(addr); | |
1784 } | |
1785 | |
1786 char* PerfMemory::backing_store_filename() { | |
1787 return sharedmem_fileName; | |
1788 } |