Mercurial > hg > truffle
comparison src/os/aix/vm/perfMemory_aix.cpp @ 14415:666e6ce3976c
8023038: PPC64 (part 15): Platform files for AIX/PPC64 support
Reviewed-by: kvn
author | simonis |
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date | Fri, 06 Sep 2013 20:16:09 +0200 |
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children | b9c06f87e476 |
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1 /* | |
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. | |
3 * Copyright 2012, 2013 SAP AG. All rights reserved. | |
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
5 * | |
6 * This code is free software; you can redistribute it and/or modify it | |
7 * under the terms of the GNU General Public License version 2 only, as | |
8 * published by the Free Software Foundation. | |
9 * | |
10 * This code is distributed in the hope that it will be useful, but WITHOUT | |
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
13 * version 2 for more details (a copy is included in the LICENSE file that | |
14 * accompanied this code). | |
15 * | |
16 * You should have received a copy of the GNU General Public License version | |
17 * 2 along with this work; if not, write to the Free Software Foundation, | |
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
19 * | |
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
21 * or visit www.oracle.com if you need additional information or have any | |
22 * questions. | |
23 * | |
24 */ | |
25 | |
26 #include "precompiled.hpp" | |
27 #include "classfile/vmSymbols.hpp" | |
28 #include "memory/allocation.inline.hpp" | |
29 #include "memory/resourceArea.hpp" | |
30 #include "oops/oop.inline.hpp" | |
31 #include "os_aix.inline.hpp" | |
32 #include "runtime/handles.inline.hpp" | |
33 #include "runtime/perfMemory.hpp" | |
34 #include "utilities/exceptions.hpp" | |
35 | |
36 // put OS-includes here | |
37 # include <sys/types.h> | |
38 # include <sys/mman.h> | |
39 # include <errno.h> | |
40 # include <stdio.h> | |
41 # include <unistd.h> | |
42 # include <sys/stat.h> | |
43 # include <signal.h> | |
44 # include <pwd.h> | |
45 | |
46 static char* backing_store_file_name = NULL; // name of the backing store | |
47 // file, if successfully created. | |
48 | |
49 // Standard Memory Implementation Details | |
50 | |
51 // create the PerfData memory region in standard memory. | |
52 // | |
53 static char* create_standard_memory(size_t size) { | |
54 | |
55 // allocate an aligned chuck of memory | |
56 char* mapAddress = os::reserve_memory(size); | |
57 | |
58 if (mapAddress == NULL) { | |
59 return NULL; | |
60 } | |
61 | |
62 // commit memory | |
63 if (!os::commit_memory(mapAddress, size, !ExecMem)) { | |
64 if (PrintMiscellaneous && Verbose) { | |
65 warning("Could not commit PerfData memory\n"); | |
66 } | |
67 os::release_memory(mapAddress, size); | |
68 return NULL; | |
69 } | |
70 | |
71 return mapAddress; | |
72 } | |
73 | |
74 // delete the PerfData memory region | |
75 // | |
76 static void delete_standard_memory(char* addr, size_t size) { | |
77 | |
78 // there are no persistent external resources to cleanup for standard | |
79 // memory. since DestroyJavaVM does not support unloading of the JVM, | |
80 // cleanup of the memory resource is not performed. The memory will be | |
81 // reclaimed by the OS upon termination of the process. | |
82 // | |
83 return; | |
84 } | |
85 | |
86 // save the specified memory region to the given file | |
87 // | |
88 // Note: this function might be called from signal handler (by os::abort()), | |
89 // don't allocate heap memory. | |
90 // | |
91 static void save_memory_to_file(char* addr, size_t size) { | |
92 | |
93 const char* destfile = PerfMemory::get_perfdata_file_path(); | |
94 assert(destfile[0] != '\0', "invalid PerfData file path"); | |
95 | |
96 int result; | |
97 | |
98 RESTARTABLE(::open(destfile, O_CREAT|O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE), | |
99 result);; | |
100 if (result == OS_ERR) { | |
101 if (PrintMiscellaneous && Verbose) { | |
102 warning("Could not create Perfdata save file: %s: %s\n", | |
103 destfile, strerror(errno)); | |
104 } | |
105 } else { | |
106 int fd = result; | |
107 | |
108 for (size_t remaining = size; remaining > 0;) { | |
109 | |
110 RESTARTABLE(::write(fd, addr, remaining), result); | |
111 if (result == OS_ERR) { | |
112 if (PrintMiscellaneous && Verbose) { | |
113 warning("Could not write Perfdata save file: %s: %s\n", | |
114 destfile, strerror(errno)); | |
115 } | |
116 break; | |
117 } | |
118 | |
119 remaining -= (size_t)result; | |
120 addr += result; | |
121 } | |
122 | |
123 RESTARTABLE(::close(fd), result); | |
124 if (PrintMiscellaneous && Verbose) { | |
125 if (result == OS_ERR) { | |
126 warning("Could not close %s: %s\n", destfile, strerror(errno)); | |
127 } | |
128 } | |
129 } | |
130 FREE_C_HEAP_ARRAY(char, destfile, mtInternal); | |
131 } | |
132 | |
133 | |
134 // Shared Memory Implementation Details | |
135 | |
136 // Note: the solaris and linux shared memory implementation uses the mmap | |
137 // interface with a backing store file to implement named shared memory. | |
138 // Using the file system as the name space for shared memory allows a | |
139 // common name space to be supported across a variety of platforms. It | |
140 // also provides a name space that Java applications can deal with through | |
141 // simple file apis. | |
142 // | |
143 // The solaris and linux implementations store the backing store file in | |
144 // a user specific temporary directory located in the /tmp file system, | |
145 // which is always a local file system and is sometimes a RAM based file | |
146 // system. | |
147 | |
148 // return the user specific temporary directory name. | |
149 // | |
150 // the caller is expected to free the allocated memory. | |
151 // | |
152 static char* get_user_tmp_dir(const char* user) { | |
153 | |
154 const char* tmpdir = os::get_temp_directory(); | |
155 const char* perfdir = PERFDATA_NAME; | |
156 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; | |
157 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); | |
158 | |
159 // construct the path name to user specific tmp directory | |
160 snprintf(dirname, nbytes, "%s/%s_%s", tmpdir, perfdir, user); | |
161 | |
162 return dirname; | |
163 } | |
164 | |
165 // convert the given file name into a process id. if the file | |
166 // does not meet the file naming constraints, return 0. | |
167 // | |
168 static pid_t filename_to_pid(const char* filename) { | |
169 | |
170 // a filename that doesn't begin with a digit is not a | |
171 // candidate for conversion. | |
172 // | |
173 if (!isdigit(*filename)) { | |
174 return 0; | |
175 } | |
176 | |
177 // check if file name can be converted to an integer without | |
178 // any leftover characters. | |
179 // | |
180 char* remainder = NULL; | |
181 errno = 0; | |
182 pid_t pid = (pid_t)strtol(filename, &remainder, 10); | |
183 | |
184 if (errno != 0) { | |
185 return 0; | |
186 } | |
187 | |
188 // check for left over characters. If any, then the filename is | |
189 // not a candidate for conversion. | |
190 // | |
191 if (remainder != NULL && *remainder != '\0') { | |
192 return 0; | |
193 } | |
194 | |
195 // successful conversion, return the pid | |
196 return pid; | |
197 } | |
198 | |
199 | |
200 // check if the given path is considered a secure directory for | |
201 // the backing store files. Returns true if the directory exists | |
202 // and is considered a secure location. Returns false if the path | |
203 // is a symbolic link or if an error occurred. | |
204 // | |
205 static bool is_directory_secure(const char* path) { | |
206 struct stat statbuf; | |
207 int result = 0; | |
208 | |
209 RESTARTABLE(::lstat(path, &statbuf), result); | |
210 if (result == OS_ERR) { | |
211 return false; | |
212 } | |
213 | |
214 // the path exists, now check it's mode | |
215 if (S_ISLNK(statbuf.st_mode) || !S_ISDIR(statbuf.st_mode)) { | |
216 // the path represents a link or some non-directory file type, | |
217 // which is not what we expected. declare it insecure. | |
218 // | |
219 return false; | |
220 } | |
221 else { | |
222 // we have an existing directory, check if the permissions are safe. | |
223 // | |
224 if ((statbuf.st_mode & (S_IWGRP|S_IWOTH)) != 0) { | |
225 // the directory is open for writing and could be subjected | |
226 // to a symlnk attack. declare it insecure. | |
227 // | |
228 return false; | |
229 } | |
230 } | |
231 return true; | |
232 } | |
233 | |
234 | |
235 // return the user name for the given user id | |
236 // | |
237 // the caller is expected to free the allocated memory. | |
238 // | |
239 static char* get_user_name(uid_t uid) { | |
240 | |
241 struct passwd pwent; | |
242 | |
243 // determine the max pwbuf size from sysconf, and hardcode | |
244 // a default if this not available through sysconf. | |
245 // | |
246 long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
247 if (bufsize == -1) | |
248 bufsize = 1024; | |
249 | |
250 char* pwbuf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); | |
251 | |
252 // POSIX interface to getpwuid_r is used on LINUX | |
253 struct passwd* p; | |
254 int result = getpwuid_r(uid, &pwent, pwbuf, (size_t)bufsize, &p); | |
255 | |
256 if (result != 0 || p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') { | |
257 if (PrintMiscellaneous && Verbose) { | |
258 if (result != 0) { | |
259 warning("Could not retrieve passwd entry: %s\n", | |
260 strerror(result)); | |
261 } | |
262 else if (p == NULL) { | |
263 // this check is added to protect against an observed problem | |
264 // with getpwuid_r() on RedHat 9 where getpwuid_r returns 0, | |
265 // indicating success, but has p == NULL. This was observed when | |
266 // inserting a file descriptor exhaustion fault prior to the call | |
267 // getpwuid_r() call. In this case, error is set to the appropriate | |
268 // error condition, but this is undocumented behavior. This check | |
269 // is safe under any condition, but the use of errno in the output | |
270 // message may result in an erroneous message. | |
271 // Bug Id 89052 was opened with RedHat. | |
272 // | |
273 warning("Could not retrieve passwd entry: %s\n", | |
274 strerror(errno)); | |
275 } | |
276 else { | |
277 warning("Could not determine user name: %s\n", | |
278 p->pw_name == NULL ? "pw_name = NULL" : | |
279 "pw_name zero length"); | |
280 } | |
281 } | |
282 FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal); | |
283 return NULL; | |
284 } | |
285 | |
286 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(p->pw_name) + 1, mtInternal); | |
287 strcpy(user_name, p->pw_name); | |
288 | |
289 FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal); | |
290 return user_name; | |
291 } | |
292 | |
293 // return the name of the user that owns the process identified by vmid. | |
294 // | |
295 // This method uses a slow directory search algorithm to find the backing | |
296 // store file for the specified vmid and returns the user name, as determined | |
297 // by the user name suffix of the hsperfdata_<username> directory name. | |
298 // | |
299 // the caller is expected to free the allocated memory. | |
300 // | |
301 static char* get_user_name_slow(int vmid, TRAPS) { | |
302 | |
303 // short circuit the directory search if the process doesn't even exist. | |
304 if (kill(vmid, 0) == OS_ERR) { | |
305 if (errno == ESRCH) { | |
306 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
307 "Process not found"); | |
308 } | |
309 else /* EPERM */ { | |
310 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
311 } | |
312 } | |
313 | |
314 // directory search | |
315 char* oldest_user = NULL; | |
316 time_t oldest_ctime = 0; | |
317 | |
318 const char* tmpdirname = os::get_temp_directory(); | |
319 | |
320 DIR* tmpdirp = os::opendir(tmpdirname); | |
321 | |
322 if (tmpdirp == NULL) { | |
323 return NULL; | |
324 } | |
325 | |
326 // for each entry in the directory that matches the pattern hsperfdata_*, | |
327 // open the directory and check if the file for the given vmid exists. | |
328 // The file with the expected name and the latest creation date is used | |
329 // to determine the user name for the process id. | |
330 // | |
331 struct dirent* dentry; | |
332 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal); | |
333 errno = 0; | |
334 while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { | |
335 | |
336 // check if the directory entry is a hsperfdata file | |
337 if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { | |
338 continue; | |
339 } | |
340 | |
341 char* usrdir_name = NEW_C_HEAP_ARRAY(char, | |
342 strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal); | |
343 strcpy(usrdir_name, tmpdirname); | |
344 strcat(usrdir_name, "/"); | |
345 strcat(usrdir_name, dentry->d_name); | |
346 | |
347 DIR* subdirp = os::opendir(usrdir_name); | |
348 | |
349 if (subdirp == NULL) { | |
350 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); | |
351 continue; | |
352 } | |
353 | |
354 // Since we don't create the backing store files in directories | |
355 // pointed to by symbolic links, we also don't follow them when | |
356 // looking for the files. We check for a symbolic link after the | |
357 // call to opendir in order to eliminate a small window where the | |
358 // symlink can be exploited. | |
359 // | |
360 if (!is_directory_secure(usrdir_name)) { | |
361 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); | |
362 os::closedir(subdirp); | |
363 continue; | |
364 } | |
365 | |
366 struct dirent* udentry; | |
367 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal); | |
368 errno = 0; | |
369 while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { | |
370 | |
371 if (filename_to_pid(udentry->d_name) == vmid) { | |
372 struct stat statbuf; | |
373 int result; | |
374 | |
375 char* filename = NEW_C_HEAP_ARRAY(char, | |
376 strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal); | |
377 | |
378 strcpy(filename, usrdir_name); | |
379 strcat(filename, "/"); | |
380 strcat(filename, udentry->d_name); | |
381 | |
382 // don't follow symbolic links for the file | |
383 RESTARTABLE(::lstat(filename, &statbuf), result); | |
384 if (result == OS_ERR) { | |
385 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
386 continue; | |
387 } | |
388 | |
389 // skip over files that are not regular files. | |
390 if (!S_ISREG(statbuf.st_mode)) { | |
391 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
392 continue; | |
393 } | |
394 | |
395 // compare and save filename with latest creation time | |
396 if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) { | |
397 | |
398 if (statbuf.st_ctime > oldest_ctime) { | |
399 char* user = strchr(dentry->d_name, '_') + 1; | |
400 | |
401 if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user, mtInternal); | |
402 oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal); | |
403 | |
404 strcpy(oldest_user, user); | |
405 oldest_ctime = statbuf.st_ctime; | |
406 } | |
407 } | |
408 | |
409 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
410 } | |
411 } | |
412 os::closedir(subdirp); | |
413 FREE_C_HEAP_ARRAY(char, udbuf, mtInternal); | |
414 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); | |
415 } | |
416 os::closedir(tmpdirp); | |
417 FREE_C_HEAP_ARRAY(char, tdbuf, mtInternal); | |
418 | |
419 return(oldest_user); | |
420 } | |
421 | |
422 // return the name of the user that owns the JVM indicated by the given vmid. | |
423 // | |
424 static char* get_user_name(int vmid, TRAPS) { | |
425 return get_user_name_slow(vmid, CHECK_NULL); | |
426 } | |
427 | |
428 // return the file name of the backing store file for the named | |
429 // shared memory region for the given user name and vmid. | |
430 // | |
431 // the caller is expected to free the allocated memory. | |
432 // | |
433 static char* get_sharedmem_filename(const char* dirname, int vmid) { | |
434 | |
435 // add 2 for the file separator and a null terminator. | |
436 size_t nbytes = strlen(dirname) + UINT_CHARS + 2; | |
437 | |
438 char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); | |
439 snprintf(name, nbytes, "%s/%d", dirname, vmid); | |
440 | |
441 return name; | |
442 } | |
443 | |
444 | |
445 // remove file | |
446 // | |
447 // this method removes the file specified by the given path | |
448 // | |
449 static void remove_file(const char* path) { | |
450 | |
451 int result; | |
452 | |
453 // if the file is a directory, the following unlink will fail. since | |
454 // we don't expect to find directories in the user temp directory, we | |
455 // won't try to handle this situation. even if accidentially or | |
456 // maliciously planted, the directory's presence won't hurt anything. | |
457 // | |
458 RESTARTABLE(::unlink(path), result); | |
459 if (PrintMiscellaneous && Verbose && result == OS_ERR) { | |
460 if (errno != ENOENT) { | |
461 warning("Could not unlink shared memory backing" | |
462 " store file %s : %s\n", path, strerror(errno)); | |
463 } | |
464 } | |
465 } | |
466 | |
467 | |
468 // remove file | |
469 // | |
470 // this method removes the file with the given file name in the | |
471 // named directory. | |
472 // | |
473 static void remove_file(const char* dirname, const char* filename) { | |
474 | |
475 size_t nbytes = strlen(dirname) + strlen(filename) + 2; | |
476 char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); | |
477 | |
478 strcpy(path, dirname); | |
479 strcat(path, "/"); | |
480 strcat(path, filename); | |
481 | |
482 remove_file(path); | |
483 | |
484 FREE_C_HEAP_ARRAY(char, path, mtInternal); | |
485 } | |
486 | |
487 | |
488 // cleanup stale shared memory resources | |
489 // | |
490 // This method attempts to remove all stale shared memory files in | |
491 // the named user temporary directory. It scans the named directory | |
492 // for files matching the pattern ^$[0-9]*$. For each file found, the | |
493 // process id is extracted from the file name and a test is run to | |
494 // determine if the process is alive. If the process is not alive, | |
495 // any stale file resources are removed. | |
496 // | |
497 static void cleanup_sharedmem_resources(const char* dirname) { | |
498 | |
499 // open the user temp directory | |
500 DIR* dirp = os::opendir(dirname); | |
501 | |
502 if (dirp == NULL) { | |
503 // directory doesn't exist, so there is nothing to cleanup | |
504 return; | |
505 } | |
506 | |
507 if (!is_directory_secure(dirname)) { | |
508 // the directory is not a secure directory | |
509 return; | |
510 } | |
511 | |
512 // for each entry in the directory that matches the expected file | |
513 // name pattern, determine if the file resources are stale and if | |
514 // so, remove the file resources. Note, instrumented HotSpot processes | |
515 // for this user may start and/or terminate during this search and | |
516 // remove or create new files in this directory. The behavior of this | |
517 // loop under these conditions is dependent upon the implementation of | |
518 // opendir/readdir. | |
519 // | |
520 struct dirent* entry; | |
521 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal); | |
522 errno = 0; | |
523 while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { | |
524 | |
525 pid_t pid = filename_to_pid(entry->d_name); | |
526 | |
527 if (pid == 0) { | |
528 | |
529 if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { | |
530 | |
531 // attempt to remove all unexpected files, except "." and ".." | |
532 remove_file(dirname, entry->d_name); | |
533 } | |
534 | |
535 errno = 0; | |
536 continue; | |
537 } | |
538 | |
539 // we now have a file name that converts to a valid integer | |
540 // that could represent a process id . if this process id | |
541 // matches the current process id or the process is not running, | |
542 // then remove the stale file resources. | |
543 // | |
544 // process liveness is detected by sending signal number 0 to | |
545 // the process id (see kill(2)). if kill determines that the | |
546 // process does not exist, then the file resources are removed. | |
547 // if kill determines that that we don't have permission to | |
548 // signal the process, then the file resources are assumed to | |
549 // be stale and are removed because the resources for such a | |
550 // process should be in a different user specific directory. | |
551 // | |
552 if ((pid == os::current_process_id()) || | |
553 (kill(pid, 0) == OS_ERR && (errno == ESRCH || errno == EPERM))) { | |
554 | |
555 remove_file(dirname, entry->d_name); | |
556 } | |
557 errno = 0; | |
558 } | |
559 os::closedir(dirp); | |
560 FREE_C_HEAP_ARRAY(char, dbuf, mtInternal); | |
561 } | |
562 | |
563 // make the user specific temporary directory. Returns true if | |
564 // the directory exists and is secure upon return. Returns false | |
565 // if the directory exists but is either a symlink, is otherwise | |
566 // insecure, or if an error occurred. | |
567 // | |
568 static bool make_user_tmp_dir(const char* dirname) { | |
569 | |
570 // create the directory with 0755 permissions. note that the directory | |
571 // will be owned by euid::egid, which may not be the same as uid::gid. | |
572 // | |
573 if (mkdir(dirname, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) == OS_ERR) { | |
574 if (errno == EEXIST) { | |
575 // The directory already exists and was probably created by another | |
576 // JVM instance. However, this could also be the result of a | |
577 // deliberate symlink. Verify that the existing directory is safe. | |
578 // | |
579 if (!is_directory_secure(dirname)) { | |
580 // directory is not secure | |
581 if (PrintMiscellaneous && Verbose) { | |
582 warning("%s directory is insecure\n", dirname); | |
583 } | |
584 return false; | |
585 } | |
586 } | |
587 else { | |
588 // we encountered some other failure while attempting | |
589 // to create the directory | |
590 // | |
591 if (PrintMiscellaneous && Verbose) { | |
592 warning("could not create directory %s: %s\n", | |
593 dirname, strerror(errno)); | |
594 } | |
595 return false; | |
596 } | |
597 } | |
598 return true; | |
599 } | |
600 | |
601 // create the shared memory file resources | |
602 // | |
603 // This method creates the shared memory file with the given size | |
604 // This method also creates the user specific temporary directory, if | |
605 // it does not yet exist. | |
606 // | |
607 static int create_sharedmem_resources(const char* dirname, const char* filename, size_t size) { | |
608 | |
609 // make the user temporary directory | |
610 if (!make_user_tmp_dir(dirname)) { | |
611 // could not make/find the directory or the found directory | |
612 // was not secure | |
613 return -1; | |
614 } | |
615 | |
616 int result; | |
617 | |
618 RESTARTABLE(::open(filename, O_RDWR|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE), result); | |
619 if (result == OS_ERR) { | |
620 if (PrintMiscellaneous && Verbose) { | |
621 warning("could not create file %s: %s\n", filename, strerror(errno)); | |
622 } | |
623 return -1; | |
624 } | |
625 | |
626 // save the file descriptor | |
627 int fd = result; | |
628 | |
629 // set the file size | |
630 RESTARTABLE(::ftruncate(fd, (off_t)size), result); | |
631 if (result == OS_ERR) { | |
632 if (PrintMiscellaneous && Verbose) { | |
633 warning("could not set shared memory file size: %s\n", strerror(errno)); | |
634 } | |
635 RESTARTABLE(::close(fd), result); | |
636 return -1; | |
637 } | |
638 | |
639 return fd; | |
640 } | |
641 | |
642 // open the shared memory file for the given user and vmid. returns | |
643 // the file descriptor for the open file or -1 if the file could not | |
644 // be opened. | |
645 // | |
646 static int open_sharedmem_file(const char* filename, int oflags, TRAPS) { | |
647 | |
648 // open the file | |
649 int result; | |
650 RESTARTABLE(::open(filename, oflags), result); | |
651 if (result == OS_ERR) { | |
652 if (errno == ENOENT) { | |
653 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
654 "Process not found"); | |
655 } | |
656 else if (errno == EACCES) { | |
657 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), | |
658 "Permission denied"); | |
659 } | |
660 else { | |
661 THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno)); | |
662 } | |
663 } | |
664 | |
665 return result; | |
666 } | |
667 | |
668 // create a named shared memory region. returns the address of the | |
669 // memory region on success or NULL on failure. A return value of | |
670 // NULL will ultimately disable the shared memory feature. | |
671 // | |
672 // On Solaris and Linux, the name space for shared memory objects | |
673 // is the file system name space. | |
674 // | |
675 // A monitoring application attaching to a JVM does not need to know | |
676 // the file system name of the shared memory object. However, it may | |
677 // be convenient for applications to discover the existence of newly | |
678 // created and terminating JVMs by watching the file system name space | |
679 // for files being created or removed. | |
680 // | |
681 static char* mmap_create_shared(size_t size) { | |
682 | |
683 int result; | |
684 int fd; | |
685 char* mapAddress; | |
686 | |
687 int vmid = os::current_process_id(); | |
688 | |
689 char* user_name = get_user_name(geteuid()); | |
690 | |
691 if (user_name == NULL) | |
692 return NULL; | |
693 | |
694 char* dirname = get_user_tmp_dir(user_name); | |
695 char* filename = get_sharedmem_filename(dirname, vmid); | |
696 | |
697 // cleanup any stale shared memory files | |
698 cleanup_sharedmem_resources(dirname); | |
699 | |
700 assert(((size > 0) && (size % os::vm_page_size() == 0)), | |
701 "unexpected PerfMemory region size"); | |
702 | |
703 fd = create_sharedmem_resources(dirname, filename, size); | |
704 | |
705 FREE_C_HEAP_ARRAY(char, user_name, mtInternal); | |
706 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); | |
707 | |
708 if (fd == -1) { | |
709 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
710 return NULL; | |
711 } | |
712 | |
713 mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
714 | |
715 // attempt to close the file - restart it if it was interrupted, | |
716 // but ignore other failures | |
717 RESTARTABLE(::close(fd), result); | |
718 assert(result != OS_ERR, "could not close file"); | |
719 | |
720 if (mapAddress == MAP_FAILED) { | |
721 if (PrintMiscellaneous && Verbose) { | |
722 warning("mmap failed - %s\n", strerror(errno)); | |
723 } | |
724 remove_file(filename); | |
725 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
726 return NULL; | |
727 } | |
728 | |
729 // save the file name for use in delete_shared_memory() | |
730 backing_store_file_name = filename; | |
731 | |
732 // clear the shared memory region | |
733 (void)::memset((void*) mapAddress, 0, size); | |
734 | |
735 return mapAddress; | |
736 } | |
737 | |
738 // release a named shared memory region | |
739 // | |
740 static void unmap_shared(char* addr, size_t bytes) { | |
741 // Do not rely on os::reserve_memory/os::release_memory to use mmap. | |
742 // Use os::reserve_memory/os::release_memory for PerfDisableSharedMem=1, mmap/munmap for PerfDisableSharedMem=0 | |
743 if (::munmap(addr, bytes) == -1) { | |
744 warning("perfmemory: munmap failed (%d)\n", errno); | |
745 } | |
746 } | |
747 | |
748 // create the PerfData memory region in shared memory. | |
749 // | |
750 static char* create_shared_memory(size_t size) { | |
751 | |
752 // create the shared memory region. | |
753 return mmap_create_shared(size); | |
754 } | |
755 | |
756 // delete the shared PerfData memory region | |
757 // | |
758 static void delete_shared_memory(char* addr, size_t size) { | |
759 | |
760 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
761 // not support unloading of the JVM, unmapping of the memory resource is | |
762 // not performed. The memory will be reclaimed by the OS upon termination of | |
763 // the process. The backing store file is deleted from the file system. | |
764 | |
765 assert(!PerfDisableSharedMem, "shouldn't be here"); | |
766 | |
767 if (backing_store_file_name != NULL) { | |
768 remove_file(backing_store_file_name); | |
769 // Don't.. Free heap memory could deadlock os::abort() if it is called | |
770 // from signal handler. OS will reclaim the heap memory. | |
771 // FREE_C_HEAP_ARRAY(char, backing_store_file_name, mtInternal); | |
772 backing_store_file_name = NULL; | |
773 } | |
774 } | |
775 | |
776 // return the size of the file for the given file descriptor | |
777 // or 0 if it is not a valid size for a shared memory file | |
778 // | |
779 static size_t sharedmem_filesize(int fd, TRAPS) { | |
780 | |
781 struct stat statbuf; | |
782 int result; | |
783 | |
784 RESTARTABLE(::fstat(fd, &statbuf), result); | |
785 if (result == OS_ERR) { | |
786 if (PrintMiscellaneous && Verbose) { | |
787 warning("fstat failed: %s\n", strerror(errno)); | |
788 } | |
789 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
790 "Could not determine PerfMemory size"); | |
791 } | |
792 | |
793 if ((statbuf.st_size == 0) || | |
794 ((size_t)statbuf.st_size % os::vm_page_size() != 0)) { | |
795 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
796 "Invalid PerfMemory size"); | |
797 } | |
798 | |
799 return (size_t)statbuf.st_size; | |
800 } | |
801 | |
802 // attach to a named shared memory region. | |
803 // | |
804 static void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) { | |
805 | |
806 char* mapAddress; | |
807 int result; | |
808 int fd; | |
809 size_t size; | |
810 const char* luser = NULL; | |
811 | |
812 int mmap_prot; | |
813 int file_flags; | |
814 | |
815 ResourceMark rm; | |
816 | |
817 // map the high level access mode to the appropriate permission | |
818 // constructs for the file and the shared memory mapping. | |
819 if (mode == PerfMemory::PERF_MODE_RO) { | |
820 mmap_prot = PROT_READ; | |
821 file_flags = O_RDONLY; | |
822 } | |
823 else if (mode == PerfMemory::PERF_MODE_RW) { | |
824 #ifdef LATER | |
825 mmap_prot = PROT_READ | PROT_WRITE; | |
826 file_flags = O_RDWR; | |
827 #else | |
828 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
829 "Unsupported access mode"); | |
830 #endif | |
831 } | |
832 else { | |
833 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
834 "Illegal access mode"); | |
835 } | |
836 | |
837 if (user == NULL || strlen(user) == 0) { | |
838 luser = get_user_name(vmid, CHECK); | |
839 } | |
840 else { | |
841 luser = user; | |
842 } | |
843 | |
844 if (luser == NULL) { | |
845 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
846 "Could not map vmid to user Name"); | |
847 } | |
848 | |
849 char* dirname = get_user_tmp_dir(luser); | |
850 | |
851 // since we don't follow symbolic links when creating the backing | |
852 // store file, we don't follow them when attaching either. | |
853 // | |
854 if (!is_directory_secure(dirname)) { | |
855 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); | |
856 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
857 "Process not found"); | |
858 } | |
859 | |
860 char* filename = get_sharedmem_filename(dirname, vmid); | |
861 | |
862 // copy heap memory to resource memory. the open_sharedmem_file | |
863 // method below need to use the filename, but could throw an | |
864 // exception. using a resource array prevents the leak that | |
865 // would otherwise occur. | |
866 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
867 strcpy(rfilename, filename); | |
868 | |
869 // free the c heap resources that are no longer needed | |
870 if (luser != user) FREE_C_HEAP_ARRAY(char, luser, mtInternal); | |
871 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); | |
872 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
873 | |
874 // open the shared memory file for the give vmid | |
875 fd = open_sharedmem_file(rfilename, file_flags, CHECK); | |
876 assert(fd != OS_ERR, "unexpected value"); | |
877 | |
878 if (*sizep == 0) { | |
879 size = sharedmem_filesize(fd, CHECK); | |
880 assert(size != 0, "unexpected size"); | |
881 } else { | |
882 size = *sizep; | |
883 } | |
884 | |
885 mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0); | |
886 | |
887 // attempt to close the file - restart if it gets interrupted, | |
888 // but ignore other failures | |
889 RESTARTABLE(::close(fd), result); | |
890 assert(result != OS_ERR, "could not close file"); | |
891 | |
892 if (mapAddress == MAP_FAILED) { | |
893 if (PrintMiscellaneous && Verbose) { | |
894 warning("mmap failed: %s\n", strerror(errno)); | |
895 } | |
896 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
897 "Could not map PerfMemory"); | |
898 } | |
899 | |
900 *addr = mapAddress; | |
901 *sizep = size; | |
902 | |
903 if (PerfTraceMemOps) { | |
904 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
905 INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress); | |
906 } | |
907 } | |
908 | |
909 | |
910 | |
911 | |
912 // create the PerfData memory region | |
913 // | |
914 // This method creates the memory region used to store performance | |
915 // data for the JVM. The memory may be created in standard or | |
916 // shared memory. | |
917 // | |
918 void PerfMemory::create_memory_region(size_t size) { | |
919 | |
920 if (PerfDisableSharedMem) { | |
921 // do not share the memory for the performance data. | |
922 _start = create_standard_memory(size); | |
923 } | |
924 else { | |
925 _start = create_shared_memory(size); | |
926 if (_start == NULL) { | |
927 | |
928 // creation of the shared memory region failed, attempt | |
929 // to create a contiguous, non-shared memory region instead. | |
930 // | |
931 if (PrintMiscellaneous && Verbose) { | |
932 warning("Reverting to non-shared PerfMemory region.\n"); | |
933 } | |
934 PerfDisableSharedMem = true; | |
935 _start = create_standard_memory(size); | |
936 } | |
937 } | |
938 | |
939 if (_start != NULL) _capacity = size; | |
940 | |
941 } | |
942 | |
943 // delete the PerfData memory region | |
944 // | |
945 // This method deletes the memory region used to store performance | |
946 // data for the JVM. The memory region indicated by the <address, size> | |
947 // tuple will be inaccessible after a call to this method. | |
948 // | |
949 void PerfMemory::delete_memory_region() { | |
950 | |
951 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
952 | |
953 // If user specifies PerfDataSaveFile, it will save the performance data | |
954 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
955 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
956 // -XX:+PerfDataSaveToFile. | |
957 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
958 save_memory_to_file(start(), capacity()); | |
959 } | |
960 | |
961 if (PerfDisableSharedMem) { | |
962 delete_standard_memory(start(), capacity()); | |
963 } | |
964 else { | |
965 delete_shared_memory(start(), capacity()); | |
966 } | |
967 } | |
968 | |
969 // attach to the PerfData memory region for another JVM | |
970 // | |
971 // This method returns an <address, size> tuple that points to | |
972 // a memory buffer that is kept reasonably synchronized with | |
973 // the PerfData memory region for the indicated JVM. This | |
974 // buffer may be kept in synchronization via shared memory | |
975 // or some other mechanism that keeps the buffer updated. | |
976 // | |
977 // If the JVM chooses not to support the attachability feature, | |
978 // this method should throw an UnsupportedOperation exception. | |
979 // | |
980 // This implementation utilizes named shared memory to map | |
981 // the indicated process's PerfData memory region into this JVMs | |
982 // address space. | |
983 // | |
984 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) { | |
985 | |
986 if (vmid == 0 || vmid == os::current_process_id()) { | |
987 *addrp = start(); | |
988 *sizep = capacity(); | |
989 return; | |
990 } | |
991 | |
992 mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK); | |
993 } | |
994 | |
995 // detach from the PerfData memory region of another JVM | |
996 // | |
997 // This method detaches the PerfData memory region of another | |
998 // JVM, specified as an <address, size> tuple of a buffer | |
999 // in this process's address space. This method may perform | |
1000 // arbitrary actions to accomplish the detachment. The memory | |
1001 // region specified by <address, size> will be inaccessible after | |
1002 // a call to this method. | |
1003 // | |
1004 // If the JVM chooses not to support the attachability feature, | |
1005 // this method should throw an UnsupportedOperation exception. | |
1006 // | |
1007 // This implementation utilizes named shared memory to detach | |
1008 // the indicated process's PerfData memory region from this | |
1009 // process's address space. | |
1010 // | |
1011 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
1012 | |
1013 assert(addr != 0, "address sanity check"); | |
1014 assert(bytes > 0, "capacity sanity check"); | |
1015 | |
1016 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
1017 // prevent accidental detachment of this process's PerfMemory region | |
1018 return; | |
1019 } | |
1020 | |
1021 unmap_shared(addr, bytes); | |
1022 } | |
1023 | |
1024 char* PerfMemory::backing_store_filename() { | |
1025 return backing_store_file_name; | |
1026 } |