Mercurial > hg > graal-jvmci-8
comparison src/os/solaris/vm/perfMemory_solaris.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 98cb887364d3 |
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1 /* | |
2 * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
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; | |
150 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 2; | |
151 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes); | |
152 | |
153 // construct the path name to user specific tmp directory | |
154 snprintf(dirname, nbytes, "%s%s_%s", tmpdir, perfdir, user); | |
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 | |
197 // is a symbolic link or if an error occured. | |
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, | |
325 strlen(tmpdirname) + strlen(dentry->d_name) + 1); | |
326 strcpy(usrdir_name, tmpdirname); | |
327 strcat(usrdir_name, dentry->d_name); | |
328 | |
329 DIR* subdirp = os::opendir(usrdir_name); | |
330 | |
331 if (subdirp == NULL) { | |
332 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
333 continue; | |
334 } | |
335 | |
336 // Since we don't create the backing store files in directories | |
337 // pointed to by symbolic links, we also don't follow them when | |
338 // looking for the files. We check for a symbolic link after the | |
339 // call to opendir in order to eliminate a small window where the | |
340 // symlink can be exploited. | |
341 // | |
342 if (!is_directory_secure(usrdir_name)) { | |
343 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
344 os::closedir(subdirp); | |
345 continue; | |
346 } | |
347 | |
348 struct dirent* udentry; | |
349 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name)); | |
350 errno = 0; | |
351 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { | |
352 | |
353 if (filename_to_pid(udentry->d_name) == vmid) { | |
354 struct stat statbuf; | |
355 int result; | |
356 | |
357 char* filename = NEW_C_HEAP_ARRAY(char, | |
358 strlen(usrdir_name) + strlen(udentry->d_name) + 2); | |
359 | |
360 strcpy(filename, usrdir_name); | |
361 strcat(filename, "/"); | |
362 strcat(filename, udentry->d_name); | |
363 | |
364 // don't follow symbolic links for the file | |
365 RESTARTABLE(::lstat(filename, &statbuf), result); | |
366 if (result == OS_ERR) { | |
367 FREE_C_HEAP_ARRAY(char, filename); | |
368 continue; | |
369 } | |
370 | |
371 // skip over files that are not regular files. | |
372 if (!S_ISREG(statbuf.st_mode)) { | |
373 FREE_C_HEAP_ARRAY(char, filename); | |
374 continue; | |
375 } | |
376 | |
377 // compare and save filename with latest creation time | |
378 if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) { | |
379 | |
380 if (statbuf.st_ctime > oldest_ctime) { | |
381 char* user = strchr(dentry->d_name, '_') + 1; | |
382 | |
383 if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user); | |
384 oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1); | |
385 | |
386 strcpy(oldest_user, user); | |
387 oldest_ctime = statbuf.st_ctime; | |
388 } | |
389 } | |
390 | |
391 FREE_C_HEAP_ARRAY(char, filename); | |
392 } | |
393 } | |
394 os::closedir(subdirp); | |
395 FREE_C_HEAP_ARRAY(char, udbuf); | |
396 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
397 } | |
398 os::closedir(tmpdirp); | |
399 FREE_C_HEAP_ARRAY(char, tdbuf); | |
400 | |
401 return(oldest_user); | |
402 } | |
403 | |
404 // return the name of the user that owns the JVM indicated by the given vmid. | |
405 // | |
406 static char* get_user_name(int vmid, TRAPS) { | |
407 | |
408 char psinfo_name[PATH_MAX]; | |
409 int result; | |
410 | |
411 snprintf(psinfo_name, PATH_MAX, "/proc/%d/psinfo", vmid); | |
412 | |
413 RESTARTABLE(::open(psinfo_name, O_RDONLY), result); | |
414 | |
415 if (result != OS_ERR) { | |
416 int fd = result; | |
417 | |
418 psinfo_t psinfo; | |
419 char* addr = (char*)&psinfo; | |
420 | |
421 for (size_t remaining = sizeof(psinfo_t); remaining > 0;) { | |
422 | |
423 RESTARTABLE(::read(fd, addr, remaining), result); | |
424 if (result == OS_ERR) { | |
425 THROW_MSG_0(vmSymbols::java_io_IOException(), "Read error"); | |
426 } | |
427 remaining-=result; | |
428 addr+=result; | |
429 } | |
430 | |
431 RESTARTABLE(::close(fd), result); | |
432 | |
433 // get the user name for the effective user id of the process | |
434 char* user_name = get_user_name(psinfo.pr_euid); | |
435 | |
436 return user_name; | |
437 } | |
438 | |
439 if (result == OS_ERR && errno == EACCES) { | |
440 | |
441 // In this case, the psinfo file for the process id existed, | |
442 // but we didn't have permission to access it. | |
443 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
444 strerror(errno)); | |
445 } | |
446 | |
447 // at this point, we don't know if the process id itself doesn't | |
448 // exist or if the psinfo file doesn't exit. If the psinfo file | |
449 // doesn't exist, then we are running on Solaris 2.5.1 or earlier. | |
450 // since the structured procfs and old procfs interfaces can't be | |
451 // mixed, we attempt to find the file through a directory search. | |
452 | |
453 return get_user_name_slow(vmid, CHECK_NULL); | |
454 } | |
455 | |
456 // return the file name of the backing store file for the named | |
457 // shared memory region for the given user name and vmid. | |
458 // | |
459 // the caller is expected to free the allocated memory. | |
460 // | |
461 static char* get_sharedmem_filename(const char* dirname, int vmid) { | |
462 | |
463 // add 2 for the file separator and a NULL terminator. | |
464 size_t nbytes = strlen(dirname) + UINT_CHARS + 2; | |
465 | |
466 char* name = NEW_C_HEAP_ARRAY(char, nbytes); | |
467 snprintf(name, nbytes, "%s/%d", dirname, vmid); | |
468 | |
469 return name; | |
470 } | |
471 | |
472 | |
473 // remove file | |
474 // | |
475 // this method removes the file specified by the given path | |
476 // | |
477 static void remove_file(const char* path) { | |
478 | |
479 int result; | |
480 | |
481 // if the file is a directory, the following unlink will fail. since | |
482 // we don't expect to find directories in the user temp directory, we | |
483 // won't try to handle this situation. even if accidentially or | |
484 // maliciously planted, the directory's presence won't hurt anything. | |
485 // | |
486 RESTARTABLE(::unlink(path), result); | |
487 if (PrintMiscellaneous && Verbose && result == OS_ERR) { | |
488 if (errno != ENOENT) { | |
489 warning("Could not unlink shared memory backing" | |
490 " store file %s : %s\n", path, strerror(errno)); | |
491 } | |
492 } | |
493 } | |
494 | |
495 | |
496 // remove file | |
497 // | |
498 // this method removes the file with the given file name in the | |
499 // named directory. | |
500 // | |
501 static void remove_file(const char* dirname, const char* filename) { | |
502 | |
503 size_t nbytes = strlen(dirname) + strlen(filename) + 2; | |
504 char* path = NEW_C_HEAP_ARRAY(char, nbytes); | |
505 | |
506 strcpy(path, dirname); | |
507 strcat(path, "/"); | |
508 strcat(path, filename); | |
509 | |
510 remove_file(path); | |
511 | |
512 FREE_C_HEAP_ARRAY(char, path); | |
513 } | |
514 | |
515 | |
516 // cleanup stale shared memory resources | |
517 // | |
518 // This method attempts to remove all stale shared memory files in | |
519 // the named user temporary directory. It scans the named directory | |
520 // for files matching the pattern ^$[0-9]*$. For each file found, the | |
521 // process id is extracted from the file name and a test is run to | |
522 // determine if the process is alive. If the process is not alive, | |
523 // any stale file resources are removed. | |
524 // | |
525 static void cleanup_sharedmem_resources(const char* dirname) { | |
526 | |
527 // open the user temp directory | |
528 DIR* dirp = os::opendir(dirname); | |
529 | |
530 if (dirp == NULL) { | |
531 // directory doesn't exist, so there is nothing to cleanup | |
532 return; | |
533 } | |
534 | |
535 if (!is_directory_secure(dirname)) { | |
536 // the directory is not a secure directory | |
537 return; | |
538 } | |
539 | |
540 // for each entry in the directory that matches the expected file | |
541 // name pattern, determine if the file resources are stale and if | |
542 // so, remove the file resources. Note, instrumented HotSpot processes | |
543 // for this user may start and/or terminate during this search and | |
544 // remove or create new files in this directory. The behavior of this | |
545 // loop under these conditions is dependent upon the implementation of | |
546 // opendir/readdir. | |
547 // | |
548 struct dirent* entry; | |
549 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname)); | |
550 errno = 0; | |
551 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { | |
552 | |
553 pid_t pid = filename_to_pid(entry->d_name); | |
554 | |
555 if (pid == 0) { | |
556 | |
557 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { | |
558 | |
559 // attempt to remove all unexpected files, except "." and ".." | |
560 remove_file(dirname, entry->d_name); | |
561 } | |
562 | |
563 errno = 0; | |
564 continue; | |
565 } | |
566 | |
567 // we now have a file name that converts to a valid integer | |
568 // that could represent a process id . if this process id | |
569 // matches the current process id or the process is not running, | |
570 // then remove the stale file resources. | |
571 // | |
572 // process liveness is detected by sending signal number 0 to | |
573 // the process id (see kill(2)). if kill determines that the | |
574 // process does not exist, then the file resources are removed. | |
575 // if kill determines that that we don't have permission to | |
576 // signal the process, then the file resources are assumed to | |
577 // be stale and are removed because the resources for such a | |
578 // process should be in a different user specific directory. | |
579 // | |
580 if ((pid == os::current_process_id()) || | |
581 (kill(pid, 0) == OS_ERR && (errno == ESRCH || errno == EPERM))) { | |
582 | |
583 remove_file(dirname, entry->d_name); | |
584 } | |
585 errno = 0; | |
586 } | |
587 os::closedir(dirp); | |
588 FREE_C_HEAP_ARRAY(char, dbuf); | |
589 } | |
590 | |
591 // make the user specific temporary directory. Returns true if | |
592 // the directory exists and is secure upon return. Returns false | |
593 // if the directory exists but is either a symlink, is otherwise | |
594 // insecure, or if an error occurred. | |
595 // | |
596 static bool make_user_tmp_dir(const char* dirname) { | |
597 | |
598 // create the directory with 0755 permissions. note that the directory | |
599 // will be owned by euid::egid, which may not be the same as uid::gid. | |
600 // | |
601 if (mkdir(dirname, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) == OS_ERR) { | |
602 if (errno == EEXIST) { | |
603 // The directory already exists and was probably created by another | |
604 // JVM instance. However, this could also be the result of a | |
605 // deliberate symlink. Verify that the existing directory is safe. | |
606 // | |
607 if (!is_directory_secure(dirname)) { | |
608 // directory is not secure | |
609 if (PrintMiscellaneous && Verbose) { | |
610 warning("%s directory is insecure\n", dirname); | |
611 } | |
612 return false; | |
613 } | |
614 } | |
615 else { | |
616 // we encountered some other failure while attempting | |
617 // to create the directory | |
618 // | |
619 if (PrintMiscellaneous && Verbose) { | |
620 warning("could not create directory %s: %s\n", | |
621 dirname, strerror(errno)); | |
622 } | |
623 return false; | |
624 } | |
625 } | |
626 return true; | |
627 } | |
628 | |
629 // create the shared memory file resources | |
630 // | |
631 // This method creates the shared memory file with the given size | |
632 // This method also creates the user specific temporary directory, if | |
633 // it does not yet exist. | |
634 // | |
635 static int create_sharedmem_resources(const char* dirname, const char* filename, size_t size) { | |
636 | |
637 // make the user temporary directory | |
638 if (!make_user_tmp_dir(dirname)) { | |
639 // could not make/find the directory or the found directory | |
640 // was not secure | |
641 return -1; | |
642 } | |
643 | |
644 int result; | |
645 | |
646 RESTARTABLE(::open(filename, O_RDWR|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE), result); | |
647 if (result == OS_ERR) { | |
648 if (PrintMiscellaneous && Verbose) { | |
649 warning("could not create file %s: %s\n", filename, strerror(errno)); | |
650 } | |
651 return -1; | |
652 } | |
653 | |
654 // save the file descriptor | |
655 int fd = result; | |
656 | |
657 // set the file size | |
658 RESTARTABLE(::ftruncate(fd, (off_t)size), result); | |
659 if (result == OS_ERR) { | |
660 if (PrintMiscellaneous && Verbose) { | |
661 warning("could not set shared memory file size: %s\n", strerror(errno)); | |
662 } | |
663 RESTARTABLE(::close(fd), result); | |
664 return -1; | |
665 } | |
666 | |
667 return fd; | |
668 } | |
669 | |
670 // open the shared memory file for the given user and vmid. returns | |
671 // the file descriptor for the open file or -1 if the file could not | |
672 // be opened. | |
673 // | |
674 static int open_sharedmem_file(const char* filename, int oflags, TRAPS) { | |
675 | |
676 // open the file | |
677 int result; | |
678 RESTARTABLE(::open(filename, oflags), result); | |
679 if (result == OS_ERR) { | |
680 if (errno == ENOENT) { | |
681 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
682 "Process not found"); | |
683 } | |
684 else if (errno == EACCES) { | |
685 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
686 "Permission denied"); | |
687 } | |
688 else { | |
689 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
690 } | |
691 } | |
692 | |
693 return result; | |
694 } | |
695 | |
696 // create a named shared memory region. returns the address of the | |
697 // memory region on success or NULL on failure. A return value of | |
698 // NULL will ultimately disable the shared memory feature. | |
699 // | |
700 // On Solaris and Linux, the name space for shared memory objects | |
701 // is the file system name space. | |
702 // | |
703 // A monitoring application attaching to a JVM does not need to know | |
704 // the file system name of the shared memory object. However, it may | |
705 // be convenient for applications to discover the existence of newly | |
706 // created and terminating JVMs by watching the file system name space | |
707 // for files being created or removed. | |
708 // | |
709 static char* mmap_create_shared(size_t size) { | |
710 | |
711 int result; | |
712 int fd; | |
713 char* mapAddress; | |
714 | |
715 int vmid = os::current_process_id(); | |
716 | |
717 char* user_name = get_user_name(geteuid()); | |
718 | |
719 if (user_name == NULL) | |
720 return NULL; | |
721 | |
722 char* dirname = get_user_tmp_dir(user_name); | |
723 char* filename = get_sharedmem_filename(dirname, vmid); | |
724 | |
725 // cleanup any stale shared memory files | |
726 cleanup_sharedmem_resources(dirname); | |
727 | |
728 assert(((size > 0) && (size % os::vm_page_size() == 0)), | |
729 "unexpected PerfMemory region size"); | |
730 | |
731 fd = create_sharedmem_resources(dirname, filename, size); | |
732 | |
733 FREE_C_HEAP_ARRAY(char, user_name); | |
734 FREE_C_HEAP_ARRAY(char, dirname); | |
735 | |
736 if (fd == -1) { | |
737 FREE_C_HEAP_ARRAY(char, filename); | |
738 return NULL; | |
739 } | |
740 | |
741 mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
742 | |
743 // attempt to close the file - restart it if it was interrupted, | |
744 // but ignore other failures | |
745 RESTARTABLE(::close(fd), result); | |
746 assert(result != OS_ERR, "could not close file"); | |
747 | |
748 if (mapAddress == MAP_FAILED) { | |
749 if (PrintMiscellaneous && Verbose) { | |
750 warning("mmap failed - %s\n", strerror(errno)); | |
751 } | |
752 remove_file(filename); | |
753 FREE_C_HEAP_ARRAY(char, filename); | |
754 return NULL; | |
755 } | |
756 | |
757 // save the file name for use in delete_shared_memory() | |
758 backing_store_file_name = filename; | |
759 | |
760 // clear the shared memory region | |
761 (void)::memset((void*) mapAddress, 0, size); | |
762 | |
763 return mapAddress; | |
764 } | |
765 | |
766 // release a named shared memory region | |
767 // | |
768 static void unmap_shared(char* addr, size_t bytes) { | |
769 os::release_memory(addr, bytes); | |
770 } | |
771 | |
772 // create the PerfData memory region in shared memory. | |
773 // | |
774 static char* create_shared_memory(size_t size) { | |
775 | |
776 // create the shared memory region. | |
777 return mmap_create_shared(size); | |
778 } | |
779 | |
780 // delete the shared PerfData memory region | |
781 // | |
782 static void delete_shared_memory(char* addr, size_t size) { | |
783 | |
784 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
785 // not support unloading of the JVM, unmapping of the memory resource is | |
786 // not performed. The memory will be reclaimed by the OS upon termination of | |
787 // the process. The backing store file is deleted from the file system. | |
788 | |
789 assert(!PerfDisableSharedMem, "shouldn't be here"); | |
790 | |
791 if (backing_store_file_name != NULL) { | |
792 remove_file(backing_store_file_name); | |
793 // Don't.. Free heap memory could deadlock os::abort() if it is called | |
794 // from signal handler. OS will reclaim the heap memory. | |
795 // FREE_C_HEAP_ARRAY(char, backing_store_file_name); | |
796 backing_store_file_name = NULL; | |
797 } | |
798 } | |
799 | |
800 // return the size of the file for the given file descriptor | |
801 // or 0 if it is not a valid size for a shared memory file | |
802 // | |
803 static size_t sharedmem_filesize(int fd, TRAPS) { | |
804 | |
805 struct stat statbuf; | |
806 int result; | |
807 | |
808 RESTARTABLE(::fstat(fd, &statbuf), result); | |
809 if (result == OS_ERR) { | |
810 if (PrintMiscellaneous && Verbose) { | |
811 warning("fstat failed: %s\n", strerror(errno)); | |
812 } | |
813 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
814 "Could not determine PerfMemory size"); | |
815 } | |
816 | |
817 if ((statbuf.st_size == 0) || | |
818 ((size_t)statbuf.st_size % os::vm_page_size() != 0)) { | |
819 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
820 "Invalid PerfMemory size"); | |
821 } | |
822 | |
823 return (size_t)statbuf.st_size; | |
824 } | |
825 | |
826 // attach to a named shared memory region. | |
827 // | |
828 static void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) { | |
829 | |
830 char* mapAddress; | |
831 int result; | |
832 int fd; | |
833 size_t size; | |
834 const char* luser = NULL; | |
835 | |
836 int mmap_prot; | |
837 int file_flags; | |
838 | |
839 ResourceMark rm; | |
840 | |
841 // map the high level access mode to the appropriate permission | |
842 // constructs for the file and the shared memory mapping. | |
843 if (mode == PerfMemory::PERF_MODE_RO) { | |
844 mmap_prot = PROT_READ; | |
845 file_flags = O_RDONLY; | |
846 } | |
847 else if (mode == PerfMemory::PERF_MODE_RW) { | |
848 #ifdef LATER | |
849 mmap_prot = PROT_READ | PROT_WRITE; | |
850 file_flags = O_RDWR; | |
851 #else | |
852 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
853 "Unsupported access mode"); | |
854 #endif | |
855 } | |
856 else { | |
857 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
858 "Illegal access mode"); | |
859 } | |
860 | |
861 if (user == NULL || strlen(user) == 0) { | |
862 luser = get_user_name(vmid, CHECK); | |
863 } | |
864 else { | |
865 luser = user; | |
866 } | |
867 | |
868 if (luser == NULL) { | |
869 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
870 "Could not map vmid to user Name"); | |
871 } | |
872 | |
873 char* dirname = get_user_tmp_dir(luser); | |
874 | |
875 // since we don't follow symbolic links when creating the backing | |
876 // store file, we don't follow them when attaching either. | |
877 // | |
878 if (!is_directory_secure(dirname)) { | |
879 FREE_C_HEAP_ARRAY(char, dirname); | |
880 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
881 "Process not found"); | |
882 } | |
883 | |
884 char* filename = get_sharedmem_filename(dirname, vmid); | |
885 | |
886 // copy heap memory to resource memory. the open_sharedmem_file | |
887 // method below need to use the filename, but could throw an | |
888 // exception. using a resource array prevents the leak that | |
889 // would otherwise occur. | |
890 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
891 strcpy(rfilename, filename); | |
892 | |
893 // free the c heap resources that are no longer needed | |
894 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); | |
895 FREE_C_HEAP_ARRAY(char, dirname); | |
896 FREE_C_HEAP_ARRAY(char, filename); | |
897 | |
898 // open the shared memory file for the give vmid | |
899 fd = open_sharedmem_file(rfilename, file_flags, CHECK); | |
900 assert(fd != OS_ERR, "unexpected value"); | |
901 | |
902 if (*sizep == 0) { | |
903 size = sharedmem_filesize(fd, CHECK); | |
904 assert(size != 0, "unexpected size"); | |
905 } | |
906 | |
907 mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0); | |
908 | |
909 // attempt to close the file - restart if it gets interrupted, | |
910 // but ignore other failures | |
911 RESTARTABLE(::close(fd), result); | |
912 assert(result != OS_ERR, "could not close file"); | |
913 | |
914 if (mapAddress == MAP_FAILED) { | |
915 if (PrintMiscellaneous && Verbose) { | |
916 warning("mmap failed: %s\n", strerror(errno)); | |
917 } | |
918 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
919 "Could not map PerfMemory"); | |
920 } | |
921 | |
922 *addr = mapAddress; | |
923 *sizep = size; | |
924 | |
925 if (PerfTraceMemOps) { | |
926 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
927 INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress); | |
928 } | |
929 } | |
930 | |
931 | |
932 | |
933 | |
934 // create the PerfData memory region | |
935 // | |
936 // This method creates the memory region used to store performance | |
937 // data for the JVM. The memory may be created in standard or | |
938 // shared memory. | |
939 // | |
940 void PerfMemory::create_memory_region(size_t size) { | |
941 | |
942 if (PerfDisableSharedMem) { | |
943 // do not share the memory for the performance data. | |
944 _start = create_standard_memory(size); | |
945 } | |
946 else { | |
947 _start = create_shared_memory(size); | |
948 if (_start == NULL) { | |
949 | |
950 // creation of the shared memory region failed, attempt | |
951 // to create a contiguous, non-shared memory region instead. | |
952 // | |
953 if (PrintMiscellaneous && Verbose) { | |
954 warning("Reverting to non-shared PerfMemory region.\n"); | |
955 } | |
956 PerfDisableSharedMem = true; | |
957 _start = create_standard_memory(size); | |
958 } | |
959 } | |
960 | |
961 if (_start != NULL) _capacity = size; | |
962 | |
963 } | |
964 | |
965 // delete the PerfData memory region | |
966 // | |
967 // This method deletes the memory region used to store performance | |
968 // data for the JVM. The memory region indicated by the <address, size> | |
969 // tuple will be inaccessible after a call to this method. | |
970 // | |
971 void PerfMemory::delete_memory_region() { | |
972 | |
973 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
974 | |
975 // If user specifies PerfDataSaveFile, it will save the performance data | |
976 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
977 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
978 // -XX:+PerfDataSaveToFile. | |
979 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
980 save_memory_to_file(start(), capacity()); | |
981 } | |
982 | |
983 if (PerfDisableSharedMem) { | |
984 delete_standard_memory(start(), capacity()); | |
985 } | |
986 else { | |
987 delete_shared_memory(start(), capacity()); | |
988 } | |
989 } | |
990 | |
991 // attach to the PerfData memory region for another JVM | |
992 // | |
993 // This method returns an <address, size> tuple that points to | |
994 // a memory buffer that is kept reasonably synchronized with | |
995 // the PerfData memory region for the indicated JVM. This | |
996 // buffer may be kept in synchronization via shared memory | |
997 // or some other mechanism that keeps the buffer updated. | |
998 // | |
999 // If the JVM chooses not to support the attachability feature, | |
1000 // this method should throw an UnsupportedOperation exception. | |
1001 // | |
1002 // This implementation utilizes named shared memory to map | |
1003 // the indicated process's PerfData memory region into this JVMs | |
1004 // address space. | |
1005 // | |
1006 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) { | |
1007 | |
1008 if (vmid == 0 || vmid == os::current_process_id()) { | |
1009 *addrp = start(); | |
1010 *sizep = capacity(); | |
1011 return; | |
1012 } | |
1013 | |
1014 mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK); | |
1015 } | |
1016 | |
1017 // detach from the PerfData memory region of another JVM | |
1018 // | |
1019 // This method detaches the PerfData memory region of another | |
1020 // JVM, specified as an <address, size> tuple of a buffer | |
1021 // in this process's address space. This method may perform | |
1022 // arbitrary actions to accomplish the detachment. The memory | |
1023 // region specified by <address, size> will be inaccessible after | |
1024 // a call to this method. | |
1025 // | |
1026 // If the JVM chooses not to support the attachability feature, | |
1027 // this method should throw an UnsupportedOperation exception. | |
1028 // | |
1029 // This implementation utilizes named shared memory to detach | |
1030 // the indicated process's PerfData memory region from this | |
1031 // process's address space. | |
1032 // | |
1033 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
1034 | |
1035 assert(addr != 0, "address sanity check"); | |
1036 assert(bytes > 0, "capacity sanity check"); | |
1037 | |
1038 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
1039 // prevent accidental detachment of this process's PerfMemory region | |
1040 return; | |
1041 } | |
1042 | |
1043 unmap_shared(addr, bytes); | |
1044 } | |
1045 | |
1046 char* PerfMemory::backing_store_filename() { | |
1047 return backing_store_file_name; | |
1048 } |