Mercurial > hg > graal-compiler
annotate src/os/solaris/vm/perfMemory_solaris.cpp @ 1725:09cdb1e1c77b
Merge
author | trims |
---|---|
date | Fri, 20 Aug 2010 04:08:08 -0700 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
rev | line source |
---|---|
0 | 1 /* |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1353
diff
changeset
|
2 * Copyright (c) 2001, 2007, 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 * | |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1353
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1353
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1353
diff
changeset
|
21 * questions. |
0 | 22 * |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_perfMemory_solaris.cpp.incl" | |
27 | |
28 // put OS-includes here | |
29 # include <sys/types.h> | |
30 # include <sys/mman.h> | |
31 # include <errno.h> | |
32 # include <stdio.h> | |
33 # include <unistd.h> | |
34 # include <sys/stat.h> | |
35 # include <signal.h> | |
36 # include <pwd.h> | |
37 # include <procfs.h> | |
38 | |
39 | |
40 static char* backing_store_file_name = NULL; // name of the backing store | |
41 // file, if successfully created. | |
42 | |
43 // Standard Memory Implementation Details | |
44 | |
45 // create the PerfData memory region in standard memory. | |
46 // | |
47 static char* create_standard_memory(size_t size) { | |
48 | |
49 // allocate an aligned chuck of memory | |
50 char* mapAddress = os::reserve_memory(size); | |
51 | |
52 if (mapAddress == NULL) { | |
53 return NULL; | |
54 } | |
55 | |
56 // commit memory | |
57 if (!os::commit_memory(mapAddress, size)) { | |
58 if (PrintMiscellaneous && Verbose) { | |
59 warning("Could not commit PerfData memory\n"); | |
60 } | |
61 os::release_memory(mapAddress, size); | |
62 return NULL; | |
63 } | |
64 | |
65 return mapAddress; | |
66 } | |
67 | |
68 // delete the PerfData memory region | |
69 // | |
70 static void delete_standard_memory(char* addr, size_t size) { | |
71 | |
72 // there are no persistent external resources to cleanup for standard | |
73 // memory. since DestroyJavaVM does not support unloading of the JVM, | |
74 // cleanup of the memory resource is not performed. The memory will be | |
75 // reclaimed by the OS upon termination of the process. | |
76 // | |
77 return; | |
78 } | |
79 | |
80 // save the specified memory region to the given file | |
81 // | |
82 // Note: this function might be called from signal handler (by os::abort()), | |
83 // don't allocate heap memory. | |
84 // | |
85 static void save_memory_to_file(char* addr, size_t size) { | |
86 | |
87 const char* destfile = PerfMemory::get_perfdata_file_path(); | |
88 assert(destfile[0] != '\0', "invalid PerfData file path"); | |
89 | |
90 int result; | |
91 | |
92 RESTARTABLE(::open(destfile, O_CREAT|O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE), | |
93 result);; | |
94 if (result == 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 | |
101 int fd = result; | |
102 | |
103 for (size_t remaining = size; remaining > 0;) { | |
104 | |
105 RESTARTABLE(::write(fd, addr, remaining), result); | |
106 if (result == OS_ERR) { | |
107 if (PrintMiscellaneous && Verbose) { | |
108 warning("Could not write Perfdata save file: %s: %s\n", | |
109 destfile, strerror(errno)); | |
110 } | |
111 break; | |
112 } | |
113 remaining -= (size_t)result; | |
114 addr += result; | |
115 } | |
116 | |
117 RESTARTABLE(::close(fd), result); | |
118 if (PrintMiscellaneous && Verbose) { | |
119 if (result == OS_ERR) { | |
120 warning("Could not close %s: %s\n", destfile, strerror(errno)); | |
121 } | |
122 } | |
123 } | |
124 FREE_C_HEAP_ARRAY(char, destfile); | |
125 } | |
126 | |
127 | |
128 // Shared Memory Implementation Details | |
129 | |
130 // Note: the solaris and linux shared memory implementation uses the mmap | |
131 // interface with a backing store file to implement named shared memory. | |
132 // Using the file system as the name space for shared memory allows a | |
133 // common name space to be supported across a variety of platforms. It | |
134 // also provides a name space that Java applications can deal with through | |
135 // simple file apis. | |
136 // | |
137 // The solaris and linux implementations store the backing store file in | |
138 // a user specific temporary directory located in the /tmp file system, | |
139 // which is always a local file system and is sometimes a RAM based file | |
140 // system. | |
141 | |
142 // return the user specific temporary directory name. | |
143 // | |
144 // the caller is expected to free the allocated memory. | |
145 // | |
146 static char* get_user_tmp_dir(const char* user) { | |
147 | |
148 const char* tmpdir = os::get_temp_directory(); | |
149 const char* perfdir = PERFDATA_NAME; | |
1353
a2ea687fdc7c
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
605
diff
changeset
|
150 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; |
0 | 151 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes); |
152 | |
153 // construct the path name to user specific tmp directory | |
1353
a2ea687fdc7c
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
605
diff
changeset
|
154 snprintf(dirname, nbytes, "%s/%s_%s", tmpdir, perfdir, user); |
0 | 155 |
156 return dirname; | |
157 } | |
158 | |
159 // convert the given file name into a process id. if the file | |
160 // does not meet the file naming constraints, return 0. | |
161 // | |
162 static pid_t filename_to_pid(const char* filename) { | |
163 | |
164 // a filename that doesn't begin with a digit is not a | |
165 // candidate for conversion. | |
166 // | |
167 if (!isdigit(*filename)) { | |
168 return 0; | |
169 } | |
170 | |
171 // check if file name can be converted to an integer without | |
172 // any leftover characters. | |
173 // | |
174 char* remainder = NULL; | |
175 errno = 0; | |
176 pid_t pid = (pid_t)strtol(filename, &remainder, 10); | |
177 | |
178 if (errno != 0) { | |
179 return 0; | |
180 } | |
181 | |
182 // check for left over characters. If any, then the filename is | |
183 // not a candidate for conversion. | |
184 // | |
185 if (remainder != NULL && *remainder != '\0') { | |
186 return 0; | |
187 } | |
188 | |
189 // successful conversion, return the pid | |
190 return pid; | |
191 } | |
192 | |
193 | |
194 // check if the given path is considered a secure directory for | |
195 // the backing store files. Returns true if the directory exists | |
196 // and is considered a secure location. Returns false if the path | |
605 | 197 // is a symbolic link or if an error occurred. |
0 | 198 // |
199 static bool is_directory_secure(const char* path) { | |
200 struct stat statbuf; | |
201 int result = 0; | |
202 | |
203 RESTARTABLE(::lstat(path, &statbuf), result); | |
204 if (result == OS_ERR) { | |
205 return false; | |
206 } | |
207 | |
208 // the path exists, now check it's mode | |
209 if (S_ISLNK(statbuf.st_mode) || !S_ISDIR(statbuf.st_mode)) { | |
210 // the path represents a link or some non-directory file type, | |
211 // which is not what we expected. declare it insecure. | |
212 // | |
213 return false; | |
214 } | |
215 else { | |
216 // we have an existing directory, check if the permissions are safe. | |
217 // | |
218 if ((statbuf.st_mode & (S_IWGRP|S_IWOTH)) != 0) { | |
219 // the directory is open for writing and could be subjected | |
220 // to a symlnk attack. declare it insecure. | |
221 // | |
222 return false; | |
223 } | |
224 } | |
225 return true; | |
226 } | |
227 | |
228 | |
229 // return the user name for the given user id | |
230 // | |
231 // the caller is expected to free the allocated memory. | |
232 // | |
233 static char* get_user_name(uid_t uid) { | |
234 | |
235 struct passwd pwent; | |
236 | |
237 // determine the max pwbuf size from sysconf, and hardcode | |
238 // a default if this not available through sysconf. | |
239 // | |
240 long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
241 if (bufsize == -1) | |
242 bufsize = 1024; | |
243 | |
244 char* pwbuf = NEW_C_HEAP_ARRAY(char, bufsize); | |
245 | |
246 #ifdef _GNU_SOURCE | |
247 struct passwd* p = NULL; | |
248 int result = getpwuid_r(uid, &pwent, pwbuf, (size_t)bufsize, &p); | |
249 #else // _GNU_SOURCE | |
250 struct passwd* p = getpwuid_r(uid, &pwent, pwbuf, (int)bufsize); | |
251 #endif // _GNU_SOURCE | |
252 | |
253 if (p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') { | |
254 if (PrintMiscellaneous && Verbose) { | |
255 if (p == NULL) { | |
256 warning("Could not retrieve passwd entry: %s\n", | |
257 strerror(errno)); | |
258 } | |
259 else { | |
260 warning("Could not determine user name: %s\n", | |
261 p->pw_name == NULL ? "pw_name = NULL" : | |
262 "pw_name zero length"); | |
263 } | |
264 } | |
265 FREE_C_HEAP_ARRAY(char, pwbuf); | |
266 return NULL; | |
267 } | |
268 | |
269 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(p->pw_name) + 1); | |
270 strcpy(user_name, p->pw_name); | |
271 | |
272 FREE_C_HEAP_ARRAY(char, pwbuf); | |
273 return user_name; | |
274 } | |
275 | |
276 // return the name of the user that owns the process identified by vmid. | |
277 // | |
278 // This method uses a slow directory search algorithm to find the backing | |
279 // store file for the specified vmid and returns the user name, as determined | |
280 // by the user name suffix of the hsperfdata_<username> directory name. | |
281 // | |
282 // the caller is expected to free the allocated memory. | |
283 // | |
284 static char* get_user_name_slow(int vmid, TRAPS) { | |
285 | |
286 // short circuit the directory search if the process doesn't even exist. | |
287 if (kill(vmid, 0) == OS_ERR) { | |
288 if (errno == ESRCH) { | |
289 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
290 "Process not found"); | |
291 } | |
292 else /* EPERM */ { | |
293 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
294 } | |
295 } | |
296 | |
297 // directory search | |
298 char* oldest_user = NULL; | |
299 time_t oldest_ctime = 0; | |
300 | |
301 const char* tmpdirname = os::get_temp_directory(); | |
302 | |
303 DIR* tmpdirp = os::opendir(tmpdirname); | |
304 | |
305 if (tmpdirp == NULL) { | |
306 return NULL; | |
307 } | |
308 | |
309 // for each entry in the directory that matches the pattern hsperfdata_*, | |
310 // open the directory and check if the file for the given vmid exists. | |
311 // The file with the expected name and the latest creation date is used | |
312 // to determine the user name for the process id. | |
313 // | |
314 struct dirent* dentry; | |
315 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname)); | |
316 errno = 0; | |
317 while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { | |
318 | |
319 // check if the directory entry is a hsperfdata file | |
320 if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { | |
321 continue; | |
322 } | |
323 | |
324 char* usrdir_name = NEW_C_HEAP_ARRAY(char, | |
1353
a2ea687fdc7c
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
605
diff
changeset
|
325 strlen(tmpdirname) + strlen(dentry->d_name) + 2); |
0 | 326 strcpy(usrdir_name, tmpdirname); |
1353
a2ea687fdc7c
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
605
diff
changeset
|
327 strcat(usrdir_name, "/"); |
0 | 328 strcat(usrdir_name, dentry->d_name); |
329 | |
330 DIR* subdirp = os::opendir(usrdir_name); | |
331 | |
332 if (subdirp == NULL) { | |
333 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
334 continue; | |
335 } | |
336 | |
337 // Since we don't create the backing store files in directories | |
338 // pointed to by symbolic links, we also don't follow them when | |
339 // looking for the files. We check for a symbolic link after the | |
340 // call to opendir in order to eliminate a small window where the | |
341 // symlink can be exploited. | |
342 // | |
343 if (!is_directory_secure(usrdir_name)) { | |
344 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
345 os::closedir(subdirp); | |
346 continue; | |
347 } | |
348 | |
349 struct dirent* udentry; | |
350 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name)); | |
351 errno = 0; | |
352 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { | |
353 | |
354 if (filename_to_pid(udentry->d_name) == vmid) { | |
355 struct stat statbuf; | |
356 int result; | |
357 | |
358 char* filename = NEW_C_HEAP_ARRAY(char, | |
359 strlen(usrdir_name) + strlen(udentry->d_name) + 2); | |
360 | |
361 strcpy(filename, usrdir_name); | |
362 strcat(filename, "/"); | |
363 strcat(filename, udentry->d_name); | |
364 | |
365 // don't follow symbolic links for the file | |
366 RESTARTABLE(::lstat(filename, &statbuf), result); | |
367 if (result == OS_ERR) { | |
368 FREE_C_HEAP_ARRAY(char, filename); | |
369 continue; | |
370 } | |
371 | |
372 // skip over files that are not regular files. | |
373 if (!S_ISREG(statbuf.st_mode)) { | |
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 JVM indicated by the given vmid. | |
406 // | |
407 static char* get_user_name(int vmid, TRAPS) { | |
408 | |
409 char psinfo_name[PATH_MAX]; | |
410 int result; | |
411 | |
412 snprintf(psinfo_name, PATH_MAX, "/proc/%d/psinfo", vmid); | |
413 | |
414 RESTARTABLE(::open(psinfo_name, O_RDONLY), result); | |
415 | |
416 if (result != OS_ERR) { | |
417 int fd = result; | |
418 | |
419 psinfo_t psinfo; | |
420 char* addr = (char*)&psinfo; | |
421 | |
422 for (size_t remaining = sizeof(psinfo_t); remaining > 0;) { | |
423 | |
424 RESTARTABLE(::read(fd, addr, remaining), result); | |
425 if (result == OS_ERR) { | |
426 THROW_MSG_0(vmSymbols::java_io_IOException(), "Read error"); | |
427 } | |
428 remaining-=result; | |
429 addr+=result; | |
430 } | |
431 | |
432 RESTARTABLE(::close(fd), result); | |
433 | |
434 // get the user name for the effective user id of the process | |
435 char* user_name = get_user_name(psinfo.pr_euid); | |
436 | |
437 return user_name; | |
438 } | |
439 | |
440 if (result == OS_ERR && errno == EACCES) { | |
441 | |
442 // In this case, the psinfo file for the process id existed, | |
443 // but we didn't have permission to access it. | |
444 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
445 strerror(errno)); | |
446 } | |
447 | |
448 // at this point, we don't know if the process id itself doesn't | |
449 // exist or if the psinfo file doesn't exit. If the psinfo file | |
450 // doesn't exist, then we are running on Solaris 2.5.1 or earlier. | |
451 // since the structured procfs and old procfs interfaces can't be | |
452 // mixed, we attempt to find the file through a directory search. | |
453 | |
454 return get_user_name_slow(vmid, CHECK_NULL); | |
455 } | |
456 | |
457 // return the file name of the backing store file for the named | |
458 // shared memory region for the given user name and vmid. | |
459 // | |
460 // the caller is expected to free the allocated memory. | |
461 // | |
462 static char* get_sharedmem_filename(const char* dirname, int vmid) { | |
463 | |
464 // add 2 for the file separator and a NULL terminator. | |
465 size_t nbytes = strlen(dirname) + UINT_CHARS + 2; | |
466 | |
467 char* name = NEW_C_HEAP_ARRAY(char, nbytes); | |
468 snprintf(name, nbytes, "%s/%d", dirname, vmid); | |
469 | |
470 return name; | |
471 } | |
472 | |
473 | |
474 // remove file | |
475 // | |
476 // this method removes the file specified by the given path | |
477 // | |
478 static void remove_file(const char* path) { | |
479 | |
480 int result; | |
481 | |
482 // if the file is a directory, the following unlink will fail. since | |
483 // we don't expect to find directories in the user temp directory, we | |
484 // won't try to handle this situation. even if accidentially or | |
485 // maliciously planted, the directory's presence won't hurt anything. | |
486 // | |
487 RESTARTABLE(::unlink(path), result); | |
488 if (PrintMiscellaneous && Verbose && result == OS_ERR) { | |
489 if (errno != ENOENT) { | |
490 warning("Could not unlink shared memory backing" | |
491 " store file %s : %s\n", path, strerror(errno)); | |
492 } | |
493 } | |
494 } | |
495 | |
496 | |
497 // remove file | |
498 // | |
499 // this method removes the file with the given file name in the | |
500 // named directory. | |
501 // | |
502 static void remove_file(const char* dirname, const char* filename) { | |
503 | |
504 size_t nbytes = strlen(dirname) + strlen(filename) + 2; | |
505 char* path = NEW_C_HEAP_ARRAY(char, nbytes); | |
506 | |
507 strcpy(path, dirname); | |
508 strcat(path, "/"); | |
509 strcat(path, filename); | |
510 | |
511 remove_file(path); | |
512 | |
513 FREE_C_HEAP_ARRAY(char, path); | |
514 } | |
515 | |
516 | |
517 // cleanup stale shared memory resources | |
518 // | |
519 // This method attempts to remove all stale shared memory files in | |
520 // the named user temporary directory. It scans the named directory | |
521 // for files matching the pattern ^$[0-9]*$. For each file found, the | |
522 // process id is extracted from the file name and a test is run to | |
523 // determine if the process is alive. If the process is not alive, | |
524 // any stale file resources are removed. | |
525 // | |
526 static void cleanup_sharedmem_resources(const char* dirname) { | |
527 | |
528 // open the user temp directory | |
529 DIR* dirp = os::opendir(dirname); | |
530 | |
531 if (dirp == NULL) { | |
532 // directory doesn't exist, so there is nothing to cleanup | |
533 return; | |
534 } | |
535 | |
536 if (!is_directory_secure(dirname)) { | |
537 // the directory is not a secure directory | |
538 return; | |
539 } | |
540 | |
541 // for each entry in the directory that matches the expected file | |
542 // name pattern, determine if the file resources are stale and if | |
543 // so, remove the file resources. Note, instrumented HotSpot processes | |
544 // for this user may start and/or terminate during this search and | |
545 // remove or create new files in this directory. The behavior of this | |
546 // loop under these conditions is dependent upon the implementation of | |
547 // opendir/readdir. | |
548 // | |
549 struct dirent* entry; | |
550 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname)); | |
551 errno = 0; | |
552 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { | |
553 | |
554 pid_t pid = filename_to_pid(entry->d_name); | |
555 | |
556 if (pid == 0) { | |
557 | |
558 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { | |
559 | |
560 // attempt to remove all unexpected files, except "." and ".." | |
561 remove_file(dirname, entry->d_name); | |
562 } | |
563 | |
564 errno = 0; | |
565 continue; | |
566 } | |
567 | |
568 // we now have a file name that converts to a valid integer | |
569 // that could represent a process id . if this process id | |
570 // matches the current process id or the process is not running, | |
571 // then remove the stale file resources. | |
572 // | |
573 // process liveness is detected by sending signal number 0 to | |
574 // the process id (see kill(2)). if kill determines that the | |
575 // process does not exist, then the file resources are removed. | |
576 // if kill determines that that we don't have permission to | |
577 // signal the process, then the file resources are assumed to | |
578 // be stale and are removed because the resources for such a | |
579 // process should be in a different user specific directory. | |
580 // | |
581 if ((pid == os::current_process_id()) || | |
582 (kill(pid, 0) == OS_ERR && (errno == ESRCH || errno == EPERM))) { | |
583 | |
584 remove_file(dirname, entry->d_name); | |
585 } | |
586 errno = 0; | |
587 } | |
588 os::closedir(dirp); | |
589 FREE_C_HEAP_ARRAY(char, dbuf); | |
590 } | |
591 | |
592 // make the user specific temporary directory. Returns true if | |
593 // the directory exists and is secure upon return. Returns false | |
594 // if the directory exists but is either a symlink, is otherwise | |
595 // insecure, or if an error occurred. | |
596 // | |
597 static bool make_user_tmp_dir(const char* dirname) { | |
598 | |
599 // create the directory with 0755 permissions. note that the directory | |
600 // will be owned by euid::egid, which may not be the same as uid::gid. | |
601 // | |
602 if (mkdir(dirname, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) == OS_ERR) { | |
603 if (errno == EEXIST) { | |
604 // The directory already exists and was probably created by another | |
605 // JVM instance. However, this could also be the result of a | |
606 // deliberate symlink. Verify that the existing directory is safe. | |
607 // | |
608 if (!is_directory_secure(dirname)) { | |
609 // directory is not secure | |
610 if (PrintMiscellaneous && Verbose) { | |
611 warning("%s directory is insecure\n", dirname); | |
612 } | |
613 return false; | |
614 } | |
615 } | |
616 else { | |
617 // we encountered some other failure while attempting | |
618 // to create the directory | |
619 // | |
620 if (PrintMiscellaneous && Verbose) { | |
621 warning("could not create directory %s: %s\n", | |
622 dirname, strerror(errno)); | |
623 } | |
624 return false; | |
625 } | |
626 } | |
627 return true; | |
628 } | |
629 | |
630 // create the shared memory file resources | |
631 // | |
632 // This method creates the shared memory file with the given size | |
633 // This method also creates the user specific temporary directory, if | |
634 // it does not yet exist. | |
635 // | |
636 static int create_sharedmem_resources(const char* dirname, const char* filename, size_t size) { | |
637 | |
638 // make the user temporary directory | |
639 if (!make_user_tmp_dir(dirname)) { | |
640 // could not make/find the directory or the found directory | |
641 // was not secure | |
642 return -1; | |
643 } | |
644 | |
645 int result; | |
646 | |
647 RESTARTABLE(::open(filename, O_RDWR|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE), result); | |
648 if (result == OS_ERR) { | |
649 if (PrintMiscellaneous && Verbose) { | |
650 warning("could not create file %s: %s\n", filename, strerror(errno)); | |
651 } | |
652 return -1; | |
653 } | |
654 | |
655 // save the file descriptor | |
656 int fd = result; | |
657 | |
658 // set the file size | |
659 RESTARTABLE(::ftruncate(fd, (off_t)size), result); | |
660 if (result == OS_ERR) { | |
661 if (PrintMiscellaneous && Verbose) { | |
662 warning("could not set shared memory file size: %s\n", strerror(errno)); | |
663 } | |
664 RESTARTABLE(::close(fd), result); | |
665 return -1; | |
666 } | |
667 | |
668 return fd; | |
669 } | |
670 | |
671 // open the shared memory file for the given user and vmid. returns | |
672 // the file descriptor for the open file or -1 if the file could not | |
673 // be opened. | |
674 // | |
675 static int open_sharedmem_file(const char* filename, int oflags, TRAPS) { | |
676 | |
677 // open the file | |
678 int result; | |
679 RESTARTABLE(::open(filename, oflags), result); | |
680 if (result == OS_ERR) { | |
681 if (errno == ENOENT) { | |
682 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
683 "Process not found"); | |
684 } | |
685 else if (errno == EACCES) { | |
686 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
687 "Permission denied"); | |
688 } | |
689 else { | |
690 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
691 } | |
692 } | |
693 | |
694 return result; | |
695 } | |
696 | |
697 // create a named shared memory region. returns the address of the | |
698 // memory region on success or NULL on failure. A return value of | |
699 // NULL will ultimately disable the shared memory feature. | |
700 // | |
701 // On Solaris and Linux, the name space for shared memory objects | |
702 // is the file system name space. | |
703 // | |
704 // A monitoring application attaching to a JVM does not need to know | |
705 // the file system name of the shared memory object. However, it may | |
706 // be convenient for applications to discover the existence of newly | |
707 // created and terminating JVMs by watching the file system name space | |
708 // for files being created or removed. | |
709 // | |
710 static char* mmap_create_shared(size_t size) { | |
711 | |
712 int result; | |
713 int fd; | |
714 char* mapAddress; | |
715 | |
716 int vmid = os::current_process_id(); | |
717 | |
718 char* user_name = get_user_name(geteuid()); | |
719 | |
720 if (user_name == NULL) | |
721 return NULL; | |
722 | |
723 char* dirname = get_user_tmp_dir(user_name); | |
724 char* filename = get_sharedmem_filename(dirname, vmid); | |
725 | |
726 // cleanup any stale shared memory files | |
727 cleanup_sharedmem_resources(dirname); | |
728 | |
729 assert(((size > 0) && (size % os::vm_page_size() == 0)), | |
730 "unexpected PerfMemory region size"); | |
731 | |
732 fd = create_sharedmem_resources(dirname, filename, size); | |
733 | |
734 FREE_C_HEAP_ARRAY(char, user_name); | |
735 FREE_C_HEAP_ARRAY(char, dirname); | |
736 | |
737 if (fd == -1) { | |
738 FREE_C_HEAP_ARRAY(char, filename); | |
739 return NULL; | |
740 } | |
741 | |
742 mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
743 | |
744 // attempt to close the file - restart it if it was interrupted, | |
745 // but ignore other failures | |
746 RESTARTABLE(::close(fd), result); | |
747 assert(result != OS_ERR, "could not close file"); | |
748 | |
749 if (mapAddress == MAP_FAILED) { | |
750 if (PrintMiscellaneous && Verbose) { | |
751 warning("mmap failed - %s\n", strerror(errno)); | |
752 } | |
753 remove_file(filename); | |
754 FREE_C_HEAP_ARRAY(char, filename); | |
755 return NULL; | |
756 } | |
757 | |
758 // save the file name for use in delete_shared_memory() | |
759 backing_store_file_name = filename; | |
760 | |
761 // clear the shared memory region | |
762 (void)::memset((void*) mapAddress, 0, size); | |
763 | |
764 return mapAddress; | |
765 } | |
766 | |
767 // release a named shared memory region | |
768 // | |
769 static void unmap_shared(char* addr, size_t bytes) { | |
770 os::release_memory(addr, bytes); | |
771 } | |
772 | |
773 // create the PerfData memory region in shared memory. | |
774 // | |
775 static char* create_shared_memory(size_t size) { | |
776 | |
777 // create the shared memory region. | |
778 return mmap_create_shared(size); | |
779 } | |
780 | |
781 // delete the shared PerfData memory region | |
782 // | |
783 static void delete_shared_memory(char* addr, size_t size) { | |
784 | |
785 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
786 // not support unloading of the JVM, unmapping of the memory resource is | |
787 // not performed. The memory will be reclaimed by the OS upon termination of | |
788 // the process. The backing store file is deleted from the file system. | |
789 | |
790 assert(!PerfDisableSharedMem, "shouldn't be here"); | |
791 | |
792 if (backing_store_file_name != NULL) { | |
793 remove_file(backing_store_file_name); | |
794 // Don't.. Free heap memory could deadlock os::abort() if it is called | |
795 // from signal handler. OS will reclaim the heap memory. | |
796 // FREE_C_HEAP_ARRAY(char, backing_store_file_name); | |
797 backing_store_file_name = NULL; | |
798 } | |
799 } | |
800 | |
801 // return the size of the file for the given file descriptor | |
802 // or 0 if it is not a valid size for a shared memory file | |
803 // | |
804 static size_t sharedmem_filesize(int fd, TRAPS) { | |
805 | |
806 struct stat statbuf; | |
807 int result; | |
808 | |
809 RESTARTABLE(::fstat(fd, &statbuf), result); | |
810 if (result == OS_ERR) { | |
811 if (PrintMiscellaneous && Verbose) { | |
812 warning("fstat failed: %s\n", strerror(errno)); | |
813 } | |
814 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
815 "Could not determine PerfMemory size"); | |
816 } | |
817 | |
818 if ((statbuf.st_size == 0) || | |
819 ((size_t)statbuf.st_size % os::vm_page_size() != 0)) { | |
820 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
821 "Invalid PerfMemory size"); | |
822 } | |
823 | |
824 return (size_t)statbuf.st_size; | |
825 } | |
826 | |
827 // attach to a named shared memory region. | |
828 // | |
829 static void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) { | |
830 | |
831 char* mapAddress; | |
832 int result; | |
833 int fd; | |
834 size_t size; | |
835 const char* luser = NULL; | |
836 | |
837 int mmap_prot; | |
838 int file_flags; | |
839 | |
840 ResourceMark rm; | |
841 | |
842 // map the high level access mode to the appropriate permission | |
843 // constructs for the file and the shared memory mapping. | |
844 if (mode == PerfMemory::PERF_MODE_RO) { | |
845 mmap_prot = PROT_READ; | |
846 file_flags = O_RDONLY; | |
847 } | |
848 else if (mode == PerfMemory::PERF_MODE_RW) { | |
849 #ifdef LATER | |
850 mmap_prot = PROT_READ | PROT_WRITE; | |
851 file_flags = O_RDWR; | |
852 #else | |
853 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
854 "Unsupported access mode"); | |
855 #endif | |
856 } | |
857 else { | |
858 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
859 "Illegal access mode"); | |
860 } | |
861 | |
862 if (user == NULL || strlen(user) == 0) { | |
863 luser = get_user_name(vmid, CHECK); | |
864 } | |
865 else { | |
866 luser = user; | |
867 } | |
868 | |
869 if (luser == NULL) { | |
870 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
871 "Could not map vmid to user Name"); | |
872 } | |
873 | |
874 char* dirname = get_user_tmp_dir(luser); | |
875 | |
876 // since we don't follow symbolic links when creating the backing | |
877 // store file, we don't follow them when attaching either. | |
878 // | |
879 if (!is_directory_secure(dirname)) { | |
880 FREE_C_HEAP_ARRAY(char, dirname); | |
881 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
882 "Process not found"); | |
883 } | |
884 | |
885 char* filename = get_sharedmem_filename(dirname, vmid); | |
886 | |
887 // copy heap memory to resource memory. the open_sharedmem_file | |
888 // method below need to use the filename, but could throw an | |
889 // exception. using a resource array prevents the leak that | |
890 // would otherwise occur. | |
891 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
892 strcpy(rfilename, filename); | |
893 | |
894 // free the c heap resources that are no longer needed | |
895 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); | |
896 FREE_C_HEAP_ARRAY(char, dirname); | |
897 FREE_C_HEAP_ARRAY(char, filename); | |
898 | |
899 // open the shared memory file for the give vmid | |
900 fd = open_sharedmem_file(rfilename, file_flags, CHECK); | |
901 assert(fd != OS_ERR, "unexpected value"); | |
902 | |
903 if (*sizep == 0) { | |
904 size = sharedmem_filesize(fd, CHECK); | |
905 assert(size != 0, "unexpected size"); | |
906 } | |
907 | |
908 mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0); | |
909 | |
910 // attempt to close the file - restart if it gets interrupted, | |
911 // but ignore other failures | |
912 RESTARTABLE(::close(fd), result); | |
913 assert(result != OS_ERR, "could not close file"); | |
914 | |
915 if (mapAddress == MAP_FAILED) { | |
916 if (PrintMiscellaneous && Verbose) { | |
917 warning("mmap failed: %s\n", strerror(errno)); | |
918 } | |
919 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
920 "Could not map PerfMemory"); | |
921 } | |
922 | |
923 *addr = mapAddress; | |
924 *sizep = size; | |
925 | |
926 if (PerfTraceMemOps) { | |
927 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
928 INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress); | |
929 } | |
930 } | |
931 | |
932 | |
933 | |
934 | |
935 // create the PerfData memory region | |
936 // | |
937 // This method creates the memory region used to store performance | |
938 // data for the JVM. The memory may be created in standard or | |
939 // shared memory. | |
940 // | |
941 void PerfMemory::create_memory_region(size_t size) { | |
942 | |
943 if (PerfDisableSharedMem) { | |
944 // do not share the memory for the performance data. | |
945 _start = create_standard_memory(size); | |
946 } | |
947 else { | |
948 _start = create_shared_memory(size); | |
949 if (_start == NULL) { | |
950 | |
951 // creation of the shared memory region failed, attempt | |
952 // to create a contiguous, non-shared memory region instead. | |
953 // | |
954 if (PrintMiscellaneous && Verbose) { | |
955 warning("Reverting to non-shared PerfMemory region.\n"); | |
956 } | |
957 PerfDisableSharedMem = true; | |
958 _start = create_standard_memory(size); | |
959 } | |
960 } | |
961 | |
962 if (_start != NULL) _capacity = size; | |
963 | |
964 } | |
965 | |
966 // delete the PerfData memory region | |
967 // | |
968 // This method deletes the memory region used to store performance | |
969 // data for the JVM. The memory region indicated by the <address, size> | |
970 // tuple will be inaccessible after a call to this method. | |
971 // | |
972 void PerfMemory::delete_memory_region() { | |
973 | |
974 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
975 | |
976 // If user specifies PerfDataSaveFile, it will save the performance data | |
977 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
978 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
979 // -XX:+PerfDataSaveToFile. | |
980 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
981 save_memory_to_file(start(), capacity()); | |
982 } | |
983 | |
984 if (PerfDisableSharedMem) { | |
985 delete_standard_memory(start(), capacity()); | |
986 } | |
987 else { | |
988 delete_shared_memory(start(), capacity()); | |
989 } | |
990 } | |
991 | |
992 // attach to the PerfData memory region for another JVM | |
993 // | |
994 // This method returns an <address, size> tuple that points to | |
995 // a memory buffer that is kept reasonably synchronized with | |
996 // the PerfData memory region for the indicated JVM. This | |
997 // buffer may be kept in synchronization via shared memory | |
998 // or some other mechanism that keeps the buffer updated. | |
999 // | |
1000 // If the JVM chooses not to support the attachability feature, | |
1001 // this method should throw an UnsupportedOperation exception. | |
1002 // | |
1003 // This implementation utilizes named shared memory to map | |
1004 // the indicated process's PerfData memory region into this JVMs | |
1005 // address space. | |
1006 // | |
1007 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) { | |
1008 | |
1009 if (vmid == 0 || vmid == os::current_process_id()) { | |
1010 *addrp = start(); | |
1011 *sizep = capacity(); | |
1012 return; | |
1013 } | |
1014 | |
1015 mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK); | |
1016 } | |
1017 | |
1018 // detach from the PerfData memory region of another JVM | |
1019 // | |
1020 // This method detaches the PerfData memory region of another | |
1021 // JVM, specified as an <address, size> tuple of a buffer | |
1022 // in this process's address space. This method may perform | |
1023 // arbitrary actions to accomplish the detachment. The memory | |
1024 // region specified by <address, size> will be inaccessible after | |
1025 // a call to this method. | |
1026 // | |
1027 // If the JVM chooses not to support the attachability feature, | |
1028 // this method should throw an UnsupportedOperation exception. | |
1029 // | |
1030 // This implementation utilizes named shared memory to detach | |
1031 // the indicated process's PerfData memory region from this | |
1032 // process's address space. | |
1033 // | |
1034 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
1035 | |
1036 assert(addr != 0, "address sanity check"); | |
1037 assert(bytes > 0, "capacity sanity check"); | |
1038 | |
1039 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
1040 // prevent accidental detachment of this process's PerfMemory region | |
1041 return; | |
1042 } | |
1043 | |
1044 unmap_shared(addr, bytes); | |
1045 } | |
1046 | |
1047 char* PerfMemory::backing_store_filename() { | |
1048 return backing_store_file_name; | |
1049 } |