Mercurial > hg > graal-compiler
annotate src/os/linux/vm/perfMemory_linux.cpp @ 14909:4ca6dc0799b6
Backout jdk9 merge
| author | Gilles Duboscq <duboscq@ssw.jku.at> |
|---|---|
| date | Tue, 01 Apr 2014 13:57:07 +0200 |
| parents | 2c2a99f6cf83 |
| children | 52b4284cb496 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 14909 | 2 * Copyright (c) 2001, 2013, 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_linux.inline.hpp" | |
| 31 #include "runtime/handles.inline.hpp" | |
| 32 #include "runtime/perfMemory.hpp" | |
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33 #include "services/memTracker.hpp" |
| 1972 | 34 #include "utilities/exceptions.hpp" |
| 0 | 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 | |
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63 if (!os::commit_memory(mapAddress, size, !ExecMem)) { |
| 0 | 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 | |
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123 result = ::close(fd); |
| 0 | 124 if (PrintMiscellaneous && Verbose) { |
| 125 if (result == OS_ERR) { | |
| 126 warning("Could not close %s: %s\n", destfile, strerror(errno)); | |
| 127 } | |
| 128 } | |
| 129 } | |
| 6197 | 130 FREE_C_HEAP_ARRAY(char, destfile, mtInternal); |
| 0 | 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; | |
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156 size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; |
| 6197 | 157 char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| 0 | 158 |
| 159 // construct the path name to user specific tmp directory | |
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160 snprintf(dirname, nbytes, "%s/%s_%s", tmpdir, perfdir, user); |
| 0 | 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 | |
| 605 | 203 // is a symbolic link or if an error occurred. |
| 0 | 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 | |
| 6197 | 250 char* pwbuf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); |
| 0 | 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 } | |
| 6197 | 282 FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal); |
| 0 | 283 return NULL; |
| 284 } | |
| 285 | |
| 6197 | 286 char* user_name = NEW_C_HEAP_ARRAY(char, strlen(p->pw_name) + 1, mtInternal); |
| 0 | 287 strcpy(user_name, p->pw_name); |
| 288 | |
| 6197 | 289 FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal); |
| 0 | 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; | |
| 6197 | 332 char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal); |
| 0 | 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, | |
| 6197 | 342 strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal); |
| 0 | 343 strcpy(usrdir_name, tmpdirname); |
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344 strcat(usrdir_name, "/"); |
| 0 | 345 strcat(usrdir_name, dentry->d_name); |
| 346 | |
| 347 DIR* subdirp = os::opendir(usrdir_name); | |
| 348 | |
| 349 if (subdirp == NULL) { | |
| 6197 | 350 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); |
| 0 | 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)) { | |
| 6197 | 361 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); |
| 0 | 362 os::closedir(subdirp); |
| 363 continue; | |
| 364 } | |
| 365 | |
| 366 struct dirent* udentry; | |
| 6197 | 367 char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal); |
| 0 | 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, | |
| 6197 | 376 strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal); |
| 0 | 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) { | |
| 6197 | 385 FREE_C_HEAP_ARRAY(char, filename, mtInternal); |
| 0 | 386 continue; |
| 387 } | |
| 388 | |
| 389 // skip over files that are not regular files. | |
| 390 if (!S_ISREG(statbuf.st_mode)) { | |
| 6197 | 391 FREE_C_HEAP_ARRAY(char, filename, mtInternal); |
| 0 | 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 | |
| 6197 | 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); | |
| 0 | 403 |
| 404 strcpy(oldest_user, user); | |
| 405 oldest_ctime = statbuf.st_ctime; | |
| 406 } | |
| 407 } | |
| 408 | |
| 6197 | 409 FREE_C_HEAP_ARRAY(char, filename, mtInternal); |
| 0 | 410 } |
| 411 } | |
| 412 os::closedir(subdirp); | |
| 6197 | 413 FREE_C_HEAP_ARRAY(char, udbuf, mtInternal); |
| 414 FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal); | |
| 0 | 415 } |
| 416 os::closedir(tmpdirp); | |
| 6197 | 417 FREE_C_HEAP_ARRAY(char, tdbuf, mtInternal); |
| 0 | 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 | |
| 6197 | 438 char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| 0 | 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; | |
| 6197 | 476 char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| 0 | 477 |
| 478 strcpy(path, dirname); | |
| 479 strcat(path, "/"); | |
| 480 strcat(path, filename); | |
| 481 | |
| 482 remove_file(path); | |
| 483 | |
| 6197 | 484 FREE_C_HEAP_ARRAY(char, path, mtInternal); |
| 0 | 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; | |
| 6197 | 521 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal); |
| 0 | 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); | |
| 6197 | 560 FREE_C_HEAP_ARRAY(char, dbuf, mtInternal); |
| 0 | 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 } | |
|
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635 ::close(fd); |
| 0 | 636 return -1; |
| 637 } | |
| 638 | |
|
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639 // Verify that we have enough disk space for this file. |
|
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640 // We'll get random SIGBUS crashes on memory accesses if |
|
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641 // we don't. |
|
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|
642 |
|
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|
643 for (size_t seekpos = 0; seekpos < size; seekpos += os::vm_page_size()) { |
|
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|
644 int zero_int = 0; |
|
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645 result = (int)os::seek_to_file_offset(fd, (jlong)(seekpos)); |
|
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646 if (result == -1 ) break; |
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647 RESTARTABLE(::write(fd, &zero_int, 1), result); |
|
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648 if (result != 1) { |
|
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649 if (errno == ENOSPC) { |
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650 warning("Insufficient space for shared memory file:\n %s\nTry using the -Djava.io.tmpdir= option to select an alternate temp location.\n", filename); |
|
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|
651 } |
|
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|
652 break; |
|
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|
653 } |
|
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|
654 } |
|
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diff
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|
655 |
|
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|
656 if (result != -1) { |
|
02895c6a2f82
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|
657 return fd; |
|
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diff
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|
658 } else { |
|
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659 ::close(fd); |
|
2066
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660 return -1; |
|
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|
661 } |
| 0 | 662 } |
| 663 | |
| 664 // open the shared memory file for the given user and vmid. returns | |
| 665 // the file descriptor for the open file or -1 if the file could not | |
| 666 // be opened. | |
| 667 // | |
| 668 static int open_sharedmem_file(const char* filename, int oflags, TRAPS) { | |
| 669 | |
| 670 // open the file | |
| 671 int result; | |
| 672 RESTARTABLE(::open(filename, oflags), result); | |
| 673 if (result == OS_ERR) { | |
| 674 if (errno == ENOENT) { | |
|
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675 THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), |
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|
676 "Process not found", OS_ERR); |
| 0 | 677 } |
| 678 else if (errno == EACCES) { | |
|
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|
679 THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), |
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|
680 "Permission denied", OS_ERR); |
| 0 | 681 } |
| 682 else { | |
|
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|
683 THROW_MSG_(vmSymbols::java_io_IOException(), strerror(errno), OS_ERR); |
| 0 | 684 } |
| 685 } | |
| 686 | |
| 687 return result; | |
| 688 } | |
| 689 | |
| 690 // create a named shared memory region. returns the address of the | |
| 691 // memory region on success or NULL on failure. A return value of | |
| 692 // NULL will ultimately disable the shared memory feature. | |
| 693 // | |
| 694 // On Solaris and Linux, the name space for shared memory objects | |
| 695 // is the file system name space. | |
| 696 // | |
| 697 // A monitoring application attaching to a JVM does not need to know | |
| 698 // the file system name of the shared memory object. However, it may | |
| 699 // be convenient for applications to discover the existence of newly | |
| 700 // created and terminating JVMs by watching the file system name space | |
| 701 // for files being created or removed. | |
| 702 // | |
| 703 static char* mmap_create_shared(size_t size) { | |
| 704 | |
| 705 int result; | |
| 706 int fd; | |
| 707 char* mapAddress; | |
| 708 | |
| 709 int vmid = os::current_process_id(); | |
| 710 | |
| 711 char* user_name = get_user_name(geteuid()); | |
| 712 | |
| 713 if (user_name == NULL) | |
| 714 return NULL; | |
| 715 | |
| 716 char* dirname = get_user_tmp_dir(user_name); | |
| 717 char* filename = get_sharedmem_filename(dirname, vmid); | |
| 718 | |
| 719 // cleanup any stale shared memory files | |
| 720 cleanup_sharedmem_resources(dirname); | |
| 721 | |
| 722 assert(((size > 0) && (size % os::vm_page_size() == 0)), | |
| 723 "unexpected PerfMemory region size"); | |
| 724 | |
| 725 fd = create_sharedmem_resources(dirname, filename, size); | |
| 726 | |
| 6197 | 727 FREE_C_HEAP_ARRAY(char, user_name, mtInternal); |
| 728 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); | |
| 0 | 729 |
| 730 if (fd == -1) { | |
| 6197 | 731 FREE_C_HEAP_ARRAY(char, filename, mtInternal); |
| 0 | 732 return NULL; |
| 733 } | |
| 734 | |
| 735 mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); | |
| 736 | |
|
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|
737 result = ::close(fd); |
| 0 | 738 assert(result != OS_ERR, "could not close file"); |
| 739 | |
| 740 if (mapAddress == MAP_FAILED) { | |
| 741 if (PrintMiscellaneous && Verbose) { | |
| 742 warning("mmap failed - %s\n", strerror(errno)); | |
| 743 } | |
| 744 remove_file(filename); | |
| 6197 | 745 FREE_C_HEAP_ARRAY(char, filename, mtInternal); |
| 0 | 746 return NULL; |
| 747 } | |
| 748 | |
| 749 // save the file name for use in delete_shared_memory() | |
| 750 backing_store_file_name = filename; | |
| 751 | |
| 752 // clear the shared memory region | |
| 753 (void)::memset((void*) mapAddress, 0, size); | |
| 754 | |
|
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755 // it does not go through os api, the operation has to record from here |
|
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756 MemTracker::record_virtual_memory_reserve((address)mapAddress, size, mtInternal, CURRENT_PC); |
|
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757 |
| 0 | 758 return mapAddress; |
| 759 } | |
| 760 | |
| 761 // release a named shared memory region | |
| 762 // | |
| 763 static void unmap_shared(char* addr, size_t bytes) { | |
| 764 os::release_memory(addr, bytes); | |
| 765 } | |
| 766 | |
| 767 // create the PerfData memory region in shared memory. | |
| 768 // | |
| 769 static char* create_shared_memory(size_t size) { | |
| 770 | |
| 771 // create the shared memory region. | |
| 772 return mmap_create_shared(size); | |
| 773 } | |
| 774 | |
| 775 // delete the shared PerfData memory region | |
| 776 // | |
| 777 static void delete_shared_memory(char* addr, size_t size) { | |
| 778 | |
| 779 // cleanup the persistent shared memory resources. since DestroyJavaVM does | |
| 780 // not support unloading of the JVM, unmapping of the memory resource is | |
| 781 // not performed. The memory will be reclaimed by the OS upon termination of | |
| 782 // the process. The backing store file is deleted from the file system. | |
| 783 | |
| 784 assert(!PerfDisableSharedMem, "shouldn't be here"); | |
| 785 | |
| 786 if (backing_store_file_name != NULL) { | |
| 787 remove_file(backing_store_file_name); | |
| 788 // Don't.. Free heap memory could deadlock os::abort() if it is called | |
| 789 // from signal handler. OS will reclaim the heap memory. | |
| 790 // FREE_C_HEAP_ARRAY(char, backing_store_file_name); | |
| 791 backing_store_file_name = NULL; | |
| 792 } | |
| 793 } | |
| 794 | |
| 795 // return the size of the file for the given file descriptor | |
| 796 // or 0 if it is not a valid size for a shared memory file | |
| 797 // | |
| 798 static size_t sharedmem_filesize(int fd, TRAPS) { | |
| 799 | |
| 800 struct stat statbuf; | |
| 801 int result; | |
| 802 | |
| 803 RESTARTABLE(::fstat(fd, &statbuf), result); | |
| 804 if (result == OS_ERR) { | |
| 805 if (PrintMiscellaneous && Verbose) { | |
| 806 warning("fstat failed: %s\n", strerror(errno)); | |
| 807 } | |
| 808 THROW_MSG_0(vmSymbols::java_io_IOException(), | |
| 809 "Could not determine PerfMemory size"); | |
| 810 } | |
| 811 | |
| 812 if ((statbuf.st_size == 0) || | |
| 813 ((size_t)statbuf.st_size % os::vm_page_size() != 0)) { | |
| 814 THROW_MSG_0(vmSymbols::java_lang_Exception(), | |
| 815 "Invalid PerfMemory size"); | |
| 816 } | |
| 817 | |
| 818 return (size_t)statbuf.st_size; | |
| 819 } | |
| 820 | |
| 821 // attach to a named shared memory region. | |
| 822 // | |
| 823 static void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) { | |
| 824 | |
| 825 char* mapAddress; | |
| 826 int result; | |
| 827 int fd; | |
|
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ccheung
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6882
diff
changeset
|
828 size_t size = 0; |
| 0 | 829 const char* luser = NULL; |
| 830 | |
| 831 int mmap_prot; | |
| 832 int file_flags; | |
| 833 | |
| 834 ResourceMark rm; | |
| 835 | |
| 836 // map the high level access mode to the appropriate permission | |
| 837 // constructs for the file and the shared memory mapping. | |
| 838 if (mode == PerfMemory::PERF_MODE_RO) { | |
| 839 mmap_prot = PROT_READ; | |
| 840 file_flags = O_RDONLY; | |
| 841 } | |
| 842 else if (mode == PerfMemory::PERF_MODE_RW) { | |
| 843 #ifdef LATER | |
| 844 mmap_prot = PROT_READ | PROT_WRITE; | |
| 845 file_flags = O_RDWR; | |
| 846 #else | |
| 847 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
| 848 "Unsupported access mode"); | |
| 849 #endif | |
| 850 } | |
| 851 else { | |
| 852 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
| 853 "Illegal access mode"); | |
| 854 } | |
| 855 | |
| 856 if (user == NULL || strlen(user) == 0) { | |
| 857 luser = get_user_name(vmid, CHECK); | |
| 858 } | |
| 859 else { | |
| 860 luser = user; | |
| 861 } | |
| 862 | |
| 863 if (luser == NULL) { | |
| 864 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), | |
| 865 "Could not map vmid to user Name"); | |
| 866 } | |
| 867 | |
| 868 char* dirname = get_user_tmp_dir(luser); | |
| 869 | |
| 870 // since we don't follow symbolic links when creating the backing | |
| 871 // store file, we don't follow them when attaching either. | |
| 872 // | |
| 873 if (!is_directory_secure(dirname)) { | |
| 6197 | 874 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); |
| 0 | 875 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), |
| 876 "Process not found"); | |
| 877 } | |
| 878 | |
| 879 char* filename = get_sharedmem_filename(dirname, vmid); | |
| 880 | |
| 881 // copy heap memory to resource memory. the open_sharedmem_file | |
| 882 // method below need to use the filename, but could throw an | |
| 883 // exception. using a resource array prevents the leak that | |
| 884 // would otherwise occur. | |
| 885 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); | |
| 886 strcpy(rfilename, filename); | |
| 887 | |
| 888 // free the c heap resources that are no longer needed | |
| 6197 | 889 if (luser != user) FREE_C_HEAP_ARRAY(char, luser, mtInternal); |
| 890 FREE_C_HEAP_ARRAY(char, dirname, mtInternal); | |
| 891 FREE_C_HEAP_ARRAY(char, filename, mtInternal); | |
| 0 | 892 |
| 893 // open the shared memory file for the give vmid | |
| 14909 | 894 fd = open_sharedmem_file(rfilename, file_flags, CHECK); |
| 895 assert(fd != OS_ERR, "unexpected value"); | |
| 0 | 896 |
| 897 if (*sizep == 0) { | |
| 898 size = sharedmem_filesize(fd, CHECK); | |
|
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6882
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changeset
|
899 } else { |
|
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|
900 size = *sizep; |
| 0 | 901 } |
| 902 | |
|
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ccheung
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changeset
|
903 assert(size > 0, "unexpected size <= 0"); |
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ccheung
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6882
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|
904 |
| 0 | 905 mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0); |
| 906 | |
|
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|
907 result = ::close(fd); |
| 0 | 908 assert(result != OS_ERR, "could not close file"); |
| 909 | |
| 910 if (mapAddress == MAP_FAILED) { | |
| 911 if (PrintMiscellaneous && Verbose) { | |
| 912 warning("mmap failed: %s\n", strerror(errno)); | |
| 913 } | |
| 914 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), | |
| 915 "Could not map PerfMemory"); | |
| 916 } | |
| 917 | |
|
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|
918 // it does not go through os api, the operation has to record from here |
|
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919 MemTracker::record_virtual_memory_reserve((address)mapAddress, size, mtInternal, CURRENT_PC); |
|
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920 |
| 0 | 921 *addr = mapAddress; |
| 922 *sizep = size; | |
| 923 | |
| 924 if (PerfTraceMemOps) { | |
| 925 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " | |
| 926 INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress); | |
| 927 } | |
| 928 } | |
| 929 | |
| 930 | |
| 931 | |
| 932 | |
| 933 // create the PerfData memory region | |
| 934 // | |
| 935 // This method creates the memory region used to store performance | |
| 936 // data for the JVM. The memory may be created in standard or | |
| 937 // shared memory. | |
| 938 // | |
| 939 void PerfMemory::create_memory_region(size_t size) { | |
| 940 | |
| 941 if (PerfDisableSharedMem) { | |
| 942 // do not share the memory for the performance data. | |
| 943 _start = create_standard_memory(size); | |
| 944 } | |
| 945 else { | |
| 946 _start = create_shared_memory(size); | |
| 947 if (_start == NULL) { | |
| 948 | |
| 949 // creation of the shared memory region failed, attempt | |
| 950 // to create a contiguous, non-shared memory region instead. | |
| 951 // | |
| 952 if (PrintMiscellaneous && Verbose) { | |
| 953 warning("Reverting to non-shared PerfMemory region.\n"); | |
| 954 } | |
| 955 PerfDisableSharedMem = true; | |
| 956 _start = create_standard_memory(size); | |
| 957 } | |
| 958 } | |
| 959 | |
| 960 if (_start != NULL) _capacity = size; | |
| 961 | |
| 962 } | |
| 963 | |
| 964 // delete the PerfData memory region | |
| 965 // | |
| 966 // This method deletes the memory region used to store performance | |
| 967 // data for the JVM. The memory region indicated by the <address, size> | |
| 968 // tuple will be inaccessible after a call to this method. | |
| 969 // | |
| 970 void PerfMemory::delete_memory_region() { | |
| 971 | |
| 972 assert((start() != NULL && capacity() > 0), "verify proper state"); | |
| 973 | |
| 974 // If user specifies PerfDataSaveFile, it will save the performance data | |
| 975 // to the specified file name no matter whether PerfDataSaveToFile is specified | |
| 976 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag | |
| 977 // -XX:+PerfDataSaveToFile. | |
| 978 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { | |
| 979 save_memory_to_file(start(), capacity()); | |
| 980 } | |
| 981 | |
| 982 if (PerfDisableSharedMem) { | |
| 983 delete_standard_memory(start(), capacity()); | |
| 984 } | |
| 985 else { | |
| 986 delete_shared_memory(start(), capacity()); | |
| 987 } | |
| 988 } | |
| 989 | |
| 990 // attach to the PerfData memory region for another JVM | |
| 991 // | |
| 992 // This method returns an <address, size> tuple that points to | |
| 993 // a memory buffer that is kept reasonably synchronized with | |
| 994 // the PerfData memory region for the indicated JVM. This | |
| 995 // buffer may be kept in synchronization via shared memory | |
| 996 // or some other mechanism that keeps the buffer updated. | |
| 997 // | |
| 998 // If the JVM chooses not to support the attachability feature, | |
| 999 // this method should throw an UnsupportedOperation exception. | |
| 1000 // | |
| 1001 // This implementation utilizes named shared memory to map | |
| 1002 // the indicated process's PerfData memory region into this JVMs | |
| 1003 // address space. | |
| 1004 // | |
| 1005 void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) { | |
| 1006 | |
| 1007 if (vmid == 0 || vmid == os::current_process_id()) { | |
| 1008 *addrp = start(); | |
| 1009 *sizep = capacity(); | |
| 1010 return; | |
| 1011 } | |
| 1012 | |
| 1013 mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK); | |
| 1014 } | |
| 1015 | |
| 1016 // detach from the PerfData memory region of another JVM | |
| 1017 // | |
| 1018 // This method detaches the PerfData memory region of another | |
| 1019 // JVM, specified as an <address, size> tuple of a buffer | |
| 1020 // in this process's address space. This method may perform | |
| 1021 // arbitrary actions to accomplish the detachment. The memory | |
| 1022 // region specified by <address, size> will be inaccessible after | |
| 1023 // a call to this method. | |
| 1024 // | |
| 1025 // If the JVM chooses not to support the attachability feature, | |
| 1026 // this method should throw an UnsupportedOperation exception. | |
| 1027 // | |
| 1028 // This implementation utilizes named shared memory to detach | |
| 1029 // the indicated process's PerfData memory region from this | |
| 1030 // process's address space. | |
| 1031 // | |
| 1032 void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { | |
| 1033 | |
| 1034 assert(addr != 0, "address sanity check"); | |
| 1035 assert(bytes > 0, "capacity sanity check"); | |
| 1036 | |
| 1037 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { | |
| 1038 // prevent accidental detachment of this process's PerfMemory region | |
| 1039 return; | |
| 1040 } | |
| 1041 | |
| 1042 unmap_shared(addr, bytes); | |
| 1043 } | |
| 1044 | |
| 1045 char* PerfMemory::backing_store_filename() { | |
| 1046 return backing_store_file_name; | |
| 1047 } |