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annotate src/os/solaris/vm/perfMemory_solaris.cpp @ 4992:f86ddbd42a7b
eclipse CDT project update
author | Lukas Stadler <lukas.stadler@jku.at> |
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date | Tue, 28 Feb 2012 17:53:07 +0100 |
parents | f95d63e2154a |
children | d2a62e0f25eb |
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_solaris.inline.hpp" | |
31 #include "runtime/handles.inline.hpp" | |
32 #include "runtime/perfMemory.hpp" | |
33 #include "utilities/exceptions.hpp" | |
0 | 34 |
35 // put OS-includes here | |
36 # include <sys/types.h> | |
37 # include <sys/mman.h> | |
38 # include <errno.h> | |
39 # include <stdio.h> | |
40 # include <unistd.h> | |
41 # include <sys/stat.h> | |
42 # include <signal.h> | |
43 # include <pwd.h> | |
44 # include <procfs.h> | |
45 | |
46 | |
47 static char* backing_store_file_name = NULL; // name of the backing store | |
48 // file, if successfully created. | |
49 | |
50 // Standard Memory Implementation Details | |
51 | |
52 // create the PerfData memory region in standard memory. | |
53 // | |
54 static char* create_standard_memory(size_t size) { | |
55 | |
56 // allocate an aligned chuck of memory | |
57 char* mapAddress = os::reserve_memory(size); | |
58 | |
59 if (mapAddress == NULL) { | |
60 return NULL; | |
61 } | |
62 | |
63 // commit memory | |
64 if (!os::commit_memory(mapAddress, size)) { | |
65 if (PrintMiscellaneous && Verbose) { | |
66 warning("Could not commit PerfData memory\n"); | |
67 } | |
68 os::release_memory(mapAddress, size); | |
69 return NULL; | |
70 } | |
71 | |
72 return mapAddress; | |
73 } | |
74 | |
75 // delete the PerfData memory region | |
76 // | |
77 static void delete_standard_memory(char* addr, size_t size) { | |
78 | |
79 // there are no persistent external resources to cleanup for standard | |
80 // memory. since DestroyJavaVM does not support unloading of the JVM, | |
81 // cleanup of the memory resource is not performed. The memory will be | |
82 // reclaimed by the OS upon termination of the process. | |
83 // | |
84 return; | |
85 } | |
86 | |
87 // save the specified memory region to the given file | |
88 // | |
89 // Note: this function might be called from signal handler (by os::abort()), | |
90 // don't allocate heap memory. | |
91 // | |
92 static void save_memory_to_file(char* addr, size_t size) { | |
93 | |
94 const char* destfile = PerfMemory::get_perfdata_file_path(); | |
95 assert(destfile[0] != '\0', "invalid PerfData file path"); | |
96 | |
97 int result; | |
98 | |
99 RESTARTABLE(::open(destfile, O_CREAT|O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE), | |
100 result);; | |
101 if (result == OS_ERR) { | |
102 if (PrintMiscellaneous && Verbose) { | |
103 warning("Could not create Perfdata save file: %s: %s\n", | |
104 destfile, strerror(errno)); | |
105 } | |
106 } else { | |
107 | |
108 int fd = result; | |
109 | |
110 for (size_t remaining = size; remaining > 0;) { | |
111 | |
112 RESTARTABLE(::write(fd, addr, remaining), result); | |
113 if (result == OS_ERR) { | |
114 if (PrintMiscellaneous && Verbose) { | |
115 warning("Could not write Perfdata save file: %s: %s\n", | |
116 destfile, strerror(errno)); | |
117 } | |
118 break; | |
119 } | |
120 remaining -= (size_t)result; | |
121 addr += result; | |
122 } | |
123 | |
124 RESTARTABLE(::close(fd), result); | |
125 if (PrintMiscellaneous && Verbose) { | |
126 if (result == OS_ERR) { | |
127 warning("Could not close %s: %s\n", destfile, strerror(errno)); | |
128 } | |
129 } | |
130 } | |
131 FREE_C_HEAP_ARRAY(char, destfile); | |
132 } | |
133 | |
134 | |
135 // Shared Memory Implementation Details | |
136 | |
137 // Note: the solaris and linux shared memory implementation uses the mmap | |
138 // interface with a backing store file to implement named shared memory. | |
139 // Using the file system as the name space for shared memory allows a | |
140 // common name space to be supported across a variety of platforms. It | |
141 // also provides a name space that Java applications can deal with through | |
142 // simple file apis. | |
143 // | |
144 // The solaris and linux implementations store the backing store file in | |
145 // a user specific temporary directory located in the /tmp file system, | |
146 // which is always a local file system and is sometimes a RAM based file | |
147 // system. | |
148 | |
149 // return the user specific temporary directory name. | |
150 // | |
151 // the caller is expected to free the allocated memory. | |
152 // | |
153 static char* get_user_tmp_dir(const char* user) { | |
154 | |
155 const char* tmpdir = os::get_temp_directory(); | |
156 const char* perfdir = PERFDATA_NAME; | |
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157 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; |
0 | 158 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes); |
159 | |
160 // construct the path name to user specific tmp directory | |
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161 snprintf(dirname, nbytes, "%s/%s_%s", tmpdir, perfdir, user); |
0 | 162 |
163 return dirname; | |
164 } | |
165 | |
166 // convert the given file name into a process id. if the file | |
167 // does not meet the file naming constraints, return 0. | |
168 // | |
169 static pid_t filename_to_pid(const char* filename) { | |
170 | |
171 // a filename that doesn't begin with a digit is not a | |
172 // candidate for conversion. | |
173 // | |
174 if (!isdigit(*filename)) { | |
175 return 0; | |
176 } | |
177 | |
178 // check if file name can be converted to an integer without | |
179 // any leftover characters. | |
180 // | |
181 char* remainder = NULL; | |
182 errno = 0; | |
183 pid_t pid = (pid_t)strtol(filename, &remainder, 10); | |
184 | |
185 if (errno != 0) { | |
186 return 0; | |
187 } | |
188 | |
189 // check for left over characters. If any, then the filename is | |
190 // not a candidate for conversion. | |
191 // | |
192 if (remainder != NULL && *remainder != '\0') { | |
193 return 0; | |
194 } | |
195 | |
196 // successful conversion, return the pid | |
197 return pid; | |
198 } | |
199 | |
200 | |
201 // check if the given path is considered a secure directory for | |
202 // the backing store files. Returns true if the directory exists | |
203 // and is considered a secure location. Returns false if the path | |
605 | 204 // is a symbolic link or if an error occurred. |
0 | 205 // |
206 static bool is_directory_secure(const char* path) { | |
207 struct stat statbuf; | |
208 int result = 0; | |
209 | |
210 RESTARTABLE(::lstat(path, &statbuf), result); | |
211 if (result == OS_ERR) { | |
212 return false; | |
213 } | |
214 | |
215 // the path exists, now check it's mode | |
216 if (S_ISLNK(statbuf.st_mode) || !S_ISDIR(statbuf.st_mode)) { | |
217 // the path represents a link or some non-directory file type, | |
218 // which is not what we expected. declare it insecure. | |
219 // | |
220 return false; | |
221 } | |
222 else { | |
223 // we have an existing directory, check if the permissions are safe. | |
224 // | |
225 if ((statbuf.st_mode & (S_IWGRP|S_IWOTH)) != 0) { | |
226 // the directory is open for writing and could be subjected | |
227 // to a symlnk attack. declare it insecure. | |
228 // | |
229 return false; | |
230 } | |
231 } | |
232 return true; | |
233 } | |
234 | |
235 | |
236 // return the user name for the given user id | |
237 // | |
238 // the caller is expected to free the allocated memory. | |
239 // | |
240 static char* get_user_name(uid_t uid) { | |
241 | |
242 struct passwd pwent; | |
243 | |
244 // determine the max pwbuf size from sysconf, and hardcode | |
245 // a default if this not available through sysconf. | |
246 // | |
247 long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
248 if (bufsize == -1) | |
249 bufsize = 1024; | |
250 | |
251 char* pwbuf = NEW_C_HEAP_ARRAY(char, bufsize); | |
252 | |
253 #ifdef _GNU_SOURCE | |
254 struct passwd* p = NULL; | |
255 int result = getpwuid_r(uid, &pwent, pwbuf, (size_t)bufsize, &p); | |
256 #else // _GNU_SOURCE | |
257 struct passwd* p = getpwuid_r(uid, &pwent, pwbuf, (int)bufsize); | |
258 #endif // _GNU_SOURCE | |
259 | |
260 if (p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') { | |
261 if (PrintMiscellaneous && Verbose) { | |
262 if (p == NULL) { | |
263 warning("Could not retrieve passwd entry: %s\n", | |
264 strerror(errno)); | |
265 } | |
266 else { | |
267 warning("Could not determine user name: %s\n", | |
268 p->pw_name == NULL ? "pw_name = NULL" : | |
269 "pw_name zero length"); | |
270 } | |
271 } | |
272 FREE_C_HEAP_ARRAY(char, pwbuf); | |
273 return NULL; | |
274 } | |
275 | |
276 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(p->pw_name) + 1); | |
277 strcpy(user_name, p->pw_name); | |
278 | |
279 FREE_C_HEAP_ARRAY(char, pwbuf); | |
280 return user_name; | |
281 } | |
282 | |
283 // return the name of the user that owns the process identified by vmid. | |
284 // | |
285 // This method uses a slow directory search algorithm to find the backing | |
286 // store file for the specified vmid and returns the user name, as determined | |
287 // by the user name suffix of the hsperfdata_<username> directory name. | |
288 // | |
289 // the caller is expected to free the allocated memory. | |
290 // | |
291 static char* get_user_name_slow(int vmid, TRAPS) { | |
292 | |
293 // short circuit the directory search if the process doesn't even exist. | |
294 if (kill(vmid, 0) == OS_ERR) { | |
295 if (errno == ESRCH) { | |
296 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
297 "Process not found"); | |
298 } | |
299 else /* EPERM */ { | |
300 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
301 } | |
302 } | |
303 | |
304 // directory search | |
305 char* oldest_user = NULL; | |
306 time_t oldest_ctime = 0; | |
307 | |
308 const char* tmpdirname = os::get_temp_directory(); | |
309 | |
310 DIR* tmpdirp = os::opendir(tmpdirname); | |
311 | |
312 if (tmpdirp == NULL) { | |
313 return NULL; | |
314 } | |
315 | |
316 // for each entry in the directory that matches the pattern hsperfdata_*, | |
317 // open the directory and check if the file for the given vmid exists. | |
318 // The file with the expected name and the latest creation date is used | |
319 // to determine the user name for the process id. | |
320 // | |
321 struct dirent* dentry; | |
322 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname)); | |
323 errno = 0; | |
324 while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { | |
325 | |
326 // check if the directory entry is a hsperfdata file | |
327 if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { | |
328 continue; | |
329 } | |
330 | |
331 char* usrdir_name = NEW_C_HEAP_ARRAY(char, | |
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332 strlen(tmpdirname) + strlen(dentry->d_name) + 2); |
0 | 333 strcpy(usrdir_name, tmpdirname); |
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334 strcat(usrdir_name, "/"); |
0 | 335 strcat(usrdir_name, dentry->d_name); |
336 | |
337 DIR* subdirp = os::opendir(usrdir_name); | |
338 | |
339 if (subdirp == NULL) { | |
340 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
341 continue; | |
342 } | |
343 | |
344 // Since we don't create the backing store files in directories | |
345 // pointed to by symbolic links, we also don't follow them when | |
346 // looking for the files. We check for a symbolic link after the | |
347 // call to opendir in order to eliminate a small window where the | |
348 // symlink can be exploited. | |
349 // | |
350 if (!is_directory_secure(usrdir_name)) { | |
351 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
352 os::closedir(subdirp); | |
353 continue; | |
354 } | |
355 | |
356 struct dirent* udentry; | |
357 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name)); | |
358 errno = 0; | |
359 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { | |
360 | |
361 if (filename_to_pid(udentry->d_name) == vmid) { | |
362 struct stat statbuf; | |
363 int result; | |
364 | |
365 char* filename = NEW_C_HEAP_ARRAY(char, | |
366 strlen(usrdir_name) + strlen(udentry->d_name) + 2); | |
367 | |
368 strcpy(filename, usrdir_name); | |
369 strcat(filename, "/"); | |
370 strcat(filename, udentry->d_name); | |
371 | |
372 // don't follow symbolic links for the file | |
373 RESTARTABLE(::lstat(filename, &statbuf), result); | |
374 if (result == OS_ERR) { | |
375 FREE_C_HEAP_ARRAY(char, filename); | |
376 continue; | |
377 } | |
378 | |
379 // skip over files that are not regular files. | |
380 if (!S_ISREG(statbuf.st_mode)) { | |
381 FREE_C_HEAP_ARRAY(char, filename); | |
382 continue; | |
383 } | |
384 | |
385 // compare and save filename with latest creation time | |
386 if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) { | |
387 | |
388 if (statbuf.st_ctime > oldest_ctime) { | |
389 char* user = strchr(dentry->d_name, '_') + 1; | |
390 | |
391 if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user); | |
392 oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1); | |
393 | |
394 strcpy(oldest_user, user); | |
395 oldest_ctime = statbuf.st_ctime; | |
396 } | |
397 } | |
398 | |
399 FREE_C_HEAP_ARRAY(char, filename); | |
400 } | |
401 } | |
402 os::closedir(subdirp); | |
403 FREE_C_HEAP_ARRAY(char, udbuf); | |
404 FREE_C_HEAP_ARRAY(char, usrdir_name); | |
405 } | |
406 os::closedir(tmpdirp); | |
407 FREE_C_HEAP_ARRAY(char, tdbuf); | |
408 | |
409 return(oldest_user); | |
410 } | |
411 | |
412 // return the name of the user that owns the JVM indicated by the given vmid. | |
413 // | |
414 static char* get_user_name(int vmid, TRAPS) { | |
415 | |
416 char psinfo_name[PATH_MAX]; | |
417 int result; | |
418 | |
419 snprintf(psinfo_name, PATH_MAX, "/proc/%d/psinfo", vmid); | |
420 | |
421 RESTARTABLE(::open(psinfo_name, O_RDONLY), result); | |
422 | |
423 if (result != OS_ERR) { | |
424 int fd = result; | |
425 | |
426 psinfo_t psinfo; | |
427 char* addr = (char*)&psinfo; | |
428 | |
429 for (size_t remaining = sizeof(psinfo_t); remaining > 0;) { | |
430 | |
431 RESTARTABLE(::read(fd, addr, remaining), result); | |
432 if (result == OS_ERR) { | |
433 THROW_MSG_0(vmSymbols::java_io_IOException(), "Read error"); | |
434 } | |
435 remaining-=result; | |
436 addr+=result; | |
437 } | |
438 | |
439 RESTARTABLE(::close(fd), result); | |
440 | |
441 // get the user name for the effective user id of the process | |
442 char* user_name = get_user_name(psinfo.pr_euid); | |
443 | |
444 return user_name; | |
445 } | |
446 | |
447 if (result == OS_ERR && errno == EACCES) { | |
448 | |
449 // In this case, the psinfo file for the process id existed, | |
450 // but we didn't have permission to access it. | |
451 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
452 strerror(errno)); | |
453 } | |
454 | |
455 // at this point, we don't know if the process id itself doesn't | |
456 // exist or if the psinfo file doesn't exit. If the psinfo file | |
457 // doesn't exist, then we are running on Solaris 2.5.1 or earlier. | |
458 // since the structured procfs and old procfs interfaces can't be | |
459 // mixed, we attempt to find the file through a directory search. | |
460 | |
461 return get_user_name_slow(vmid, CHECK_NULL); | |
462 } | |
463 | |
464 // return the file name of the backing store file for the named | |
465 // shared memory region for the given user name and vmid. | |
466 // | |
467 // the caller is expected to free the allocated memory. | |
468 // | |
469 static char* get_sharedmem_filename(const char* dirname, int vmid) { | |
470 | |
471 // add 2 for the file separator and a NULL terminator. | |
472 size_t nbytes = strlen(dirname) + UINT_CHARS + 2; | |
473 | |
474 char* name = NEW_C_HEAP_ARRAY(char, nbytes); | |
475 snprintf(name, nbytes, "%s/%d", dirname, vmid); | |
476 | |
477 return name; | |
478 } | |
479 | |
480 | |
481 // remove file | |
482 // | |
483 // this method removes the file specified by the given path | |
484 // | |
485 static void remove_file(const char* path) { | |
486 | |
487 int result; | |
488 | |
489 // if the file is a directory, the following unlink will fail. since | |
490 // we don't expect to find directories in the user temp directory, we | |
491 // won't try to handle this situation. even if accidentially or | |
492 // maliciously planted, the directory's presence won't hurt anything. | |
493 // | |
494 RESTARTABLE(::unlink(path), result); | |
495 if (PrintMiscellaneous && Verbose && result == OS_ERR) { | |
496 if (errno != ENOENT) { | |
497 warning("Could not unlink shared memory backing" | |
498 " store file %s : %s\n", path, strerror(errno)); | |
499 } | |
500 } | |
501 } | |
502 | |
503 | |
504 // remove file | |
505 // | |
506 // this method removes the file with the given file name in the | |
507 // named directory. | |
508 // | |
509 static void remove_file(const char* dirname, const char* filename) { | |
510 | |
511 size_t nbytes = strlen(dirname) + strlen(filename) + 2; | |
512 char* path = NEW_C_HEAP_ARRAY(char, nbytes); | |
513 | |
514 strcpy(path, dirname); | |
515 strcat(path, "/"); | |
516 strcat(path, filename); | |
517 | |
518 remove_file(path); | |
519 | |
520 FREE_C_HEAP_ARRAY(char, path); | |
521 } | |
522 | |
523 | |
524 // cleanup stale shared memory resources | |
525 // | |
526 // This method attempts to remove all stale shared memory files in | |
527 // the named user temporary directory. It scans the named directory | |
528 // for files matching the pattern ^$[0-9]*$. For each file found, the | |
529 // process id is extracted from the file name and a test is run to | |
530 // determine if the process is alive. If the process is not alive, | |
531 // any stale file resources are removed. | |
532 // | |
533 static void cleanup_sharedmem_resources(const char* dirname) { | |
534 | |
535 // open the user temp directory | |
536 DIR* dirp = os::opendir(dirname); | |
537 | |
538 if (dirp == NULL) { | |
539 // directory doesn't exist, so there is nothing to cleanup | |
540 return; | |
541 } | |
542 | |
543 if (!is_directory_secure(dirname)) { | |
544 // the directory is not a secure directory | |
545 return; | |
546 } | |
547 | |
548 // for each entry in the directory that matches the expected file | |
549 // name pattern, determine if the file resources are stale and if | |
550 // so, remove the file resources. Note, instrumented HotSpot processes | |
551 // for this user may start and/or terminate during this search and | |
552 // remove or create new files in this directory. The behavior of this | |
553 // loop under these conditions is dependent upon the implementation of | |
554 // opendir/readdir. | |
555 // | |
556 struct dirent* entry; | |
557 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname)); | |
558 errno = 0; | |
559 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { | |
560 | |
561 pid_t pid = filename_to_pid(entry->d_name); | |
562 | |
563 if (pid == 0) { | |
564 | |
565 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { | |
566 | |
567 // attempt to remove all unexpected files, except "." and ".." | |
568 remove_file(dirname, entry->d_name); | |
569 } | |
570 | |
571 errno = 0; | |
572 continue; | |
573 } | |
574 | |
575 // we now have a file name that converts to a valid integer | |
576 // that could represent a process id . if this process id | |
577 // matches the current process id or the process is not running, | |
578 // then remove the stale file resources. | |
579 // | |
580 // process liveness is detected by sending signal number 0 to | |
581 // the process id (see kill(2)). if kill determines that the | |
582 // process does not exist, then the file resources are removed. | |
583 // if kill determines that that we don't have permission to | |
584 // signal the process, then the file resources are assumed to | |
585 // be stale and are removed because the resources for such a | |
586 // process should be in a different user specific directory. | |
587 // | |
588 if ((pid == os::current_process_id()) || | |
589 (kill(pid, 0) == OS_ERR && (errno == ESRCH || errno == EPERM))) { | |
590 | |
591 remove_file(dirname, entry->d_name); | |
592 } | |
593 errno = 0; | |
594 } | |
595 os::closedir(dirp); | |
596 FREE_C_HEAP_ARRAY(char, dbuf); | |
597 } | |
598 | |
599 // make the user specific temporary directory. Returns true if | |
600 // the directory exists and is secure upon return. Returns false | |
601 // if the directory exists but is either a symlink, is otherwise | |
602 // insecure, or if an error occurred. | |
603 // | |
604 static bool make_user_tmp_dir(const char* dirname) { | |
605 | |
606 // create the directory with 0755 permissions. note that the directory | |
607 // will be owned by euid::egid, which may not be the same as uid::gid. | |
608 // | |
609 if (mkdir(dirname, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) == OS_ERR) { | |
610 if (errno == EEXIST) { | |
611 // The directory already exists and was probably created by another | |
612 // JVM instance. However, this could also be the result of a | |
613 // deliberate symlink. Verify that the existing directory is safe. | |
614 // | |
615 if (!is_directory_secure(dirname)) { | |
616 // directory is not secure | |
617 if (PrintMiscellaneous && Verbose) { | |
618 warning("%s directory is insecure\n", dirname); | |
619 } | |
620 return false; | |
621 } | |
622 } | |
623 else { | |
624 // we encountered some other failure while attempting | |
625 // to create the directory | |
626 // | |
627 if (PrintMiscellaneous && Verbose) { | |
628 warning("could not create directory %s: %s\n", | |
629 dirname, strerror(errno)); | |
630 } | |
631 return false; | |
632 } | |
633 } | |
634 return true; | |
635 } | |
636 | |
637 // create the shared memory file resources | |
638 // | |
639 // This method creates the shared memory file with the given size | |
640 // This method also creates the user specific temporary directory, if | |
641 // it does not yet exist. | |
642 // | |
643 static int create_sharedmem_resources(const char* dirname, const char* filename, size_t size) { | |
644 | |
645 // make the user temporary directory | |
646 if (!make_user_tmp_dir(dirname)) { | |
647 // could not make/find the directory or the found directory | |
648 // was not secure | |
649 return -1; | |
650 } | |
651 | |
652 int result; | |
653 | |
654 RESTARTABLE(::open(filename, O_RDWR|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE), result); | |
655 if (result == OS_ERR) { | |
656 if (PrintMiscellaneous && Verbose) { | |
657 warning("could not create file %s: %s\n", filename, strerror(errno)); | |
658 } | |
659 return -1; | |
660 } | |
661 | |
662 // save the file descriptor | |
663 int fd = result; | |
664 | |
665 // set the file size | |
666 RESTARTABLE(::ftruncate(fd, (off_t)size), result); | |
667 if (result == OS_ERR) { | |
668 if (PrintMiscellaneous && Verbose) { | |
669 warning("could not set shared memory file size: %s\n", strerror(errno)); | |
670 } | |
671 RESTARTABLE(::close(fd), result); | |
672 return -1; | |
673 } | |
674 | |
675 return fd; | |
676 } | |
677 | |
678 // open the shared memory file for the given user and vmid. returns | |
679 // the file descriptor for the open file or -1 if the file could not | |
680 // be opened. | |
681 // | |
682 static int open_sharedmem_file(const char* filename, int oflags, TRAPS) { | |
683 | |
684 // open the file | |
685 int result; | |
686 RESTARTABLE(::open(filename, oflags), result); | |
687 if (result == OS_ERR) { | |
688 if (errno == ENOENT) { | |
689 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
690 "Process not found"); | |
691 } | |
692 else if (errno == EACCES) { | |
693 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
694 "Permission denied"); | |
695 } | |
696 else { | |
697 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
698 } | |
699 } | |
700 | |
701 return result; | |
702 } | |
703 | |
704 // create a named shared memory region. returns the address of the | |
705 // memory region on success or NULL on failure. A return value of | |
706 // NULL will ultimately disable the shared memory feature. | |
707 // | |
708 // On Solaris and Linux, the name space for shared memory objects | |
709 // is the file system name space. | |
710 // | |
711 // A monitoring application attaching to a JVM does not need to know | |
712 // the file system name of the shared memory object. However, it may | |
713 // be convenient for applications to discover the existence of newly | |
714 // created and terminating JVMs by watching the file system name space | |
715 // for files being created or removed. | |
716 // | |
717 static char* mmap_create_shared(size_t size) { | |
718 | |
719 int result; | |
720 int fd; | |
721 char* mapAddress; | |
722 | |
723 int vmid = os::current_process_id(); | |
724 | |
725 char* user_name = get_user_name(geteuid()); | |
726 | |
727 if (user_name == NULL) | |
728 return NULL; | |
729 | |
730 char* dirname = get_user_tmp_dir(user_name); | |
731 char* filename = get_sharedmem_filename(dirname, vmid); | |
732 | |
733 // cleanup any stale shared memory files | |
734 cleanup_sharedmem_resources(dirname); | |
735 | |
736 assert(((size > 0) && (size % os::vm_page_size() == 0)), | |
737 "unexpected PerfMemory region size"); | |
738 | |
739 fd = create_sharedmem_resources(dirname, filename, size); | |
740 | |
741 FREE_C_HEAP_ARRAY(char, user_name); | |
742 FREE_C_HEAP_ARRAY(char, dirname); | |
743 | |
744 if (fd == -1) { | |
745 FREE_C_HEAP_ARRAY(char, filename); | |
746 return NULL; | |
747 } | |
748 | |
749 mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
750 | |
751 // attempt to close the file - restart it if it was interrupted, | |
752 // but ignore other failures | |
753 RESTARTABLE(::close(fd), result); | |
754 assert(result != OS_ERR, "could not close file"); | |
755 | |
756 if (mapAddress == MAP_FAILED) { | |
757 if (PrintMiscellaneous && Verbose) { | |
758 warning("mmap failed - %s\n", strerror(errno)); | |
759 } | |
760 remove_file(filename); | |
761 FREE_C_HEAP_ARRAY(char, filename); | |
762 return NULL; | |
763 } | |
764 | |
765 // save the file name for use in delete_shared_memory() | |
766 backing_store_file_name = filename; | |
767 | |
768 // clear the shared memory region | |
769 (void)::memset((void*) mapAddress, 0, size); | |
770 | |
771 return mapAddress; | |
772 } | |
773 | |
774 // release a named shared memory region | |
775 // | |
776 static void unmap_shared(char* addr, size_t bytes) { | |
777 os::release_memory(addr, bytes); | |
778 } | |
779 | |
780 // create the PerfData memory region in shared memory. | |
781 // | |
782 static char* create_shared_memory(size_t size) { | |
783 | |
784 // create the shared memory region. | |
785 return mmap_create_shared(size); | |
786 } | |
787 | |
788 // delete the shared PerfData memory region | |
789 // | |
790 static void delete_shared_memory(char* addr, size_t size) { | |
791 | |
792 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
793 // not support unloading of the JVM, unmapping of the memory resource is | |
794 // not performed. The memory will be reclaimed by the OS upon termination of | |
795 // the process. The backing store file is deleted from the file system. | |
796 | |
797 assert(!PerfDisableSharedMem, "shouldn't be here"); | |
798 | |
799 if (backing_store_file_name != NULL) { | |
800 remove_file(backing_store_file_name); | |
801 // Don't.. Free heap memory could deadlock os::abort() if it is called | |
802 // from signal handler. OS will reclaim the heap memory. | |
803 // FREE_C_HEAP_ARRAY(char, backing_store_file_name); | |
804 backing_store_file_name = NULL; | |
805 } | |
806 } | |
807 | |
808 // return the size of the file for the given file descriptor | |
809 // or 0 if it is not a valid size for a shared memory file | |
810 // | |
811 static size_t sharedmem_filesize(int fd, TRAPS) { | |
812 | |
813 struct stat statbuf; | |
814 int result; | |
815 | |
816 RESTARTABLE(::fstat(fd, &statbuf), result); | |
817 if (result == OS_ERR) { | |
818 if (PrintMiscellaneous && Verbose) { | |
819 warning("fstat failed: %s\n", strerror(errno)); | |
820 } | |
821 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
822 "Could not determine PerfMemory size"); | |
823 } | |
824 | |
825 if ((statbuf.st_size == 0) || | |
826 ((size_t)statbuf.st_size % os::vm_page_size() != 0)) { | |
827 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
828 "Invalid PerfMemory size"); | |
829 } | |
830 | |
831 return (size_t)statbuf.st_size; | |
832 } | |
833 | |
834 // attach to a named shared memory region. | |
835 // | |
836 static void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) { | |
837 | |
838 char* mapAddress; | |
839 int result; | |
840 int fd; | |
841 size_t size; | |
842 const char* luser = NULL; | |
843 | |
844 int mmap_prot; | |
845 int file_flags; | |
846 | |
847 ResourceMark rm; | |
848 | |
849 // map the high level access mode to the appropriate permission | |
850 // constructs for the file and the shared memory mapping. | |
851 if (mode == PerfMemory::PERF_MODE_RO) { | |
852 mmap_prot = PROT_READ; | |
853 file_flags = O_RDONLY; | |
854 } | |
855 else if (mode == PerfMemory::PERF_MODE_RW) { | |
856 #ifdef LATER | |
857 mmap_prot = PROT_READ | PROT_WRITE; | |
858 file_flags = O_RDWR; | |
859 #else | |
860 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
861 "Unsupported access mode"); | |
862 #endif | |
863 } | |
864 else { | |
865 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
866 "Illegal access mode"); | |
867 } | |
868 | |
869 if (user == NULL || strlen(user) == 0) { | |
870 luser = get_user_name(vmid, CHECK); | |
871 } | |
872 else { | |
873 luser = user; | |
874 } | |
875 | |
876 if (luser == NULL) { | |
877 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
878 "Could not map vmid to user Name"); | |
879 } | |
880 | |
881 char* dirname = get_user_tmp_dir(luser); | |
882 | |
883 // since we don't follow symbolic links when creating the backing | |
884 // store file, we don't follow them when attaching either. | |
885 // | |
886 if (!is_directory_secure(dirname)) { | |
887 FREE_C_HEAP_ARRAY(char, dirname); | |
888 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
889 "Process not found"); | |
890 } | |
891 | |
892 char* filename = get_sharedmem_filename(dirname, vmid); | |
893 | |
894 // copy heap memory to resource memory. the open_sharedmem_file | |
895 // method below need to use the filename, but could throw an | |
896 // exception. using a resource array prevents the leak that | |
897 // would otherwise occur. | |
898 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
899 strcpy(rfilename, filename); | |
900 | |
901 // free the c heap resources that are no longer needed | |
902 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); | |
903 FREE_C_HEAP_ARRAY(char, dirname); | |
904 FREE_C_HEAP_ARRAY(char, filename); | |
905 | |
906 // open the shared memory file for the give vmid | |
907 fd = open_sharedmem_file(rfilename, file_flags, CHECK); | |
908 assert(fd != OS_ERR, "unexpected value"); | |
909 | |
910 if (*sizep == 0) { | |
911 size = sharedmem_filesize(fd, CHECK); | |
912 assert(size != 0, "unexpected size"); | |
913 } | |
914 | |
915 mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0); | |
916 | |
917 // attempt to close the file - restart if it gets interrupted, | |
918 // but ignore other failures | |
919 RESTARTABLE(::close(fd), result); | |
920 assert(result != OS_ERR, "could not close file"); | |
921 | |
922 if (mapAddress == MAP_FAILED) { | |
923 if (PrintMiscellaneous && Verbose) { | |
924 warning("mmap failed: %s\n", strerror(errno)); | |
925 } | |
926 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
927 "Could not map PerfMemory"); | |
928 } | |
929 | |
930 *addr = mapAddress; | |
931 *sizep = size; | |
932 | |
933 if (PerfTraceMemOps) { | |
934 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
935 INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress); | |
936 } | |
937 } | |
938 | |
939 | |
940 | |
941 | |
942 // create the PerfData memory region | |
943 // | |
944 // This method creates the memory region used to store performance | |
945 // data for the JVM. The memory may be created in standard or | |
946 // shared memory. | |
947 // | |
948 void PerfMemory::create_memory_region(size_t size) { | |
949 | |
950 if (PerfDisableSharedMem) { | |
951 // do not share the memory for the performance data. | |
952 _start = create_standard_memory(size); | |
953 } | |
954 else { | |
955 _start = create_shared_memory(size); | |
956 if (_start == NULL) { | |
957 | |
958 // creation of the shared memory region failed, attempt | |
959 // to create a contiguous, non-shared memory region instead. | |
960 // | |
961 if (PrintMiscellaneous && Verbose) { | |
962 warning("Reverting to non-shared PerfMemory region.\n"); | |
963 } | |
964 PerfDisableSharedMem = true; | |
965 _start = create_standard_memory(size); | |
966 } | |
967 } | |
968 | |
969 if (_start != NULL) _capacity = size; | |
970 | |
971 } | |
972 | |
973 // delete the PerfData memory region | |
974 // | |
975 // This method deletes the memory region used to store performance | |
976 // data for the JVM. The memory region indicated by the <address, size> | |
977 // tuple will be inaccessible after a call to this method. | |
978 // | |
979 void PerfMemory::delete_memory_region() { | |
980 | |
981 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
982 | |
983 // If user specifies PerfDataSaveFile, it will save the performance data | |
984 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
985 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
986 // -XX:+PerfDataSaveToFile. | |
987 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
988 save_memory_to_file(start(), capacity()); | |
989 } | |
990 | |
991 if (PerfDisableSharedMem) { | |
992 delete_standard_memory(start(), capacity()); | |
993 } | |
994 else { | |
995 delete_shared_memory(start(), capacity()); | |
996 } | |
997 } | |
998 | |
999 // attach to the PerfData memory region for another JVM | |
1000 // | |
1001 // This method returns an <address, size> tuple that points to | |
1002 // a memory buffer that is kept reasonably synchronized with | |
1003 // the PerfData memory region for the indicated JVM. This | |
1004 // buffer may be kept in synchronization via shared memory | |
1005 // or some other mechanism that keeps the buffer updated. | |
1006 // | |
1007 // If the JVM chooses not to support the attachability feature, | |
1008 // this method should throw an UnsupportedOperation exception. | |
1009 // | |
1010 // This implementation utilizes named shared memory to map | |
1011 // the indicated process's PerfData memory region into this JVMs | |
1012 // address space. | |
1013 // | |
1014 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) { | |
1015 | |
1016 if (vmid == 0 || vmid == os::current_process_id()) { | |
1017 *addrp = start(); | |
1018 *sizep = capacity(); | |
1019 return; | |
1020 } | |
1021 | |
1022 mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK); | |
1023 } | |
1024 | |
1025 // detach from the PerfData memory region of another JVM | |
1026 // | |
1027 // This method detaches the PerfData memory region of another | |
1028 // JVM, specified as an <address, size> tuple of a buffer | |
1029 // in this process's address space. This method may perform | |
1030 // arbitrary actions to accomplish the detachment. The memory | |
1031 // region specified by <address, size> will be inaccessible after | |
1032 // a call to this method. | |
1033 // | |
1034 // If the JVM chooses not to support the attachability feature, | |
1035 // this method should throw an UnsupportedOperation exception. | |
1036 // | |
1037 // This implementation utilizes named shared memory to detach | |
1038 // the indicated process's PerfData memory region from this | |
1039 // process's address space. | |
1040 // | |
1041 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
1042 | |
1043 assert(addr != 0, "address sanity check"); | |
1044 assert(bytes > 0, "capacity sanity check"); | |
1045 | |
1046 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
1047 // prevent accidental detachment of this process's PerfMemory region | |
1048 return; | |
1049 } | |
1050 | |
1051 unmap_shared(addr, bytes); | |
1052 } | |
1053 | |
1054 char* PerfMemory::backing_store_filename() { | |
1055 return backing_store_file_name; | |
1056 } |