Fri, 08 May 2009 15:20:10 -0700
6838842: NUMA allocator: Segfault during startup on Linux
Summary: Restored os::free_memory() semantics
Reviewed-by: apetrusenko
duke@435 | 1 | /* |
xdono@631 | 2 | * Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_attachListener_linux.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | #include <unistd.h> |
duke@435 | 29 | #include <signal.h> |
duke@435 | 30 | #include <sys/types.h> |
duke@435 | 31 | #include <sys/socket.h> |
duke@435 | 32 | #include <sys/un.h> |
duke@435 | 33 | #include <sys/stat.h> |
duke@435 | 34 | |
duke@435 | 35 | // The attach mechanism on Linux uses a UNIX domain socket. An attach listener |
duke@435 | 36 | // thread is created at startup or is created on-demand via a signal from |
duke@435 | 37 | // the client tool. The attach listener creates a socket and binds it to a file |
duke@435 | 38 | // in the filesystem. The attach listener then acts as a simple (single- |
duke@435 | 39 | // threaded) server - tt waits for a client to connect, reads the request, |
duke@435 | 40 | // executes it, and returns the response to the client via the socket |
duke@435 | 41 | // connection. |
duke@435 | 42 | // |
duke@435 | 43 | // As the socket is a UNIX domain socket it means that only clients on the |
duke@435 | 44 | // local machine can connect. In addition there are two other aspects to |
duke@435 | 45 | // the security: |
duke@435 | 46 | // 1. The well known file that the socket is bound to has permission 400 |
duke@435 | 47 | // 2. When a client connect, the SO_PEERCRED socket option is used to |
duke@435 | 48 | // obtain the credentials of client. We check that the effective uid |
duke@435 | 49 | // of the client matches this process. |
duke@435 | 50 | |
duke@435 | 51 | // forward reference |
duke@435 | 52 | class LinuxAttachOperation; |
duke@435 | 53 | |
duke@435 | 54 | class LinuxAttachListener: AllStatic { |
duke@435 | 55 | private: |
duke@435 | 56 | // the path to which we bind the UNIX domain socket |
duke@435 | 57 | static char _path[PATH_MAX+1]; |
duke@435 | 58 | static bool _has_path; |
duke@435 | 59 | |
duke@435 | 60 | // the file descriptor for the listening socket |
duke@435 | 61 | static int _listener; |
duke@435 | 62 | |
duke@435 | 63 | static void set_path(char* path) { |
duke@435 | 64 | if (path == NULL) { |
duke@435 | 65 | _has_path = false; |
duke@435 | 66 | } else { |
duke@435 | 67 | strncpy(_path, path, PATH_MAX); |
duke@435 | 68 | _path[PATH_MAX] = '\0'; |
duke@435 | 69 | _has_path = true; |
duke@435 | 70 | } |
duke@435 | 71 | } |
duke@435 | 72 | |
duke@435 | 73 | static void set_listener(int s) { _listener = s; } |
duke@435 | 74 | |
duke@435 | 75 | // reads a request from the given connected socket |
duke@435 | 76 | static LinuxAttachOperation* read_request(int s); |
duke@435 | 77 | |
duke@435 | 78 | public: |
duke@435 | 79 | enum { |
duke@435 | 80 | ATTACH_PROTOCOL_VER = 1 // protocol version |
duke@435 | 81 | }; |
duke@435 | 82 | enum { |
duke@435 | 83 | ATTACH_ERROR_BADVERSION = 101 // error codes |
duke@435 | 84 | }; |
duke@435 | 85 | |
duke@435 | 86 | // initialize the listener, returns 0 if okay |
duke@435 | 87 | static int init(); |
duke@435 | 88 | |
duke@435 | 89 | static char* path() { return _path; } |
duke@435 | 90 | static bool has_path() { return _has_path; } |
duke@435 | 91 | static int listener() { return _listener; } |
duke@435 | 92 | |
duke@435 | 93 | // write the given buffer to a socket |
duke@435 | 94 | static int write_fully(int s, char* buf, int len); |
duke@435 | 95 | |
duke@435 | 96 | static LinuxAttachOperation* dequeue(); |
duke@435 | 97 | }; |
duke@435 | 98 | |
duke@435 | 99 | class LinuxAttachOperation: public AttachOperation { |
duke@435 | 100 | private: |
duke@435 | 101 | // the connection to the client |
duke@435 | 102 | int _socket; |
duke@435 | 103 | |
duke@435 | 104 | public: |
duke@435 | 105 | void complete(jint res, bufferedStream* st); |
duke@435 | 106 | |
duke@435 | 107 | void set_socket(int s) { _socket = s; } |
duke@435 | 108 | int socket() const { return _socket; } |
duke@435 | 109 | |
duke@435 | 110 | LinuxAttachOperation(char* name) : AttachOperation(name) { |
duke@435 | 111 | set_socket(-1); |
duke@435 | 112 | } |
duke@435 | 113 | }; |
duke@435 | 114 | |
duke@435 | 115 | // statics |
duke@435 | 116 | char LinuxAttachListener::_path[PATH_MAX+1]; |
duke@435 | 117 | bool LinuxAttachListener::_has_path; |
duke@435 | 118 | int LinuxAttachListener::_listener = -1; |
duke@435 | 119 | |
duke@435 | 120 | // Supporting class to help split a buffer into individual components |
duke@435 | 121 | class ArgumentIterator : public StackObj { |
duke@435 | 122 | private: |
duke@435 | 123 | char* _pos; |
duke@435 | 124 | char* _end; |
duke@435 | 125 | public: |
duke@435 | 126 | ArgumentIterator(char* arg_buffer, size_t arg_size) { |
duke@435 | 127 | _pos = arg_buffer; |
duke@435 | 128 | _end = _pos + arg_size - 1; |
duke@435 | 129 | } |
duke@435 | 130 | char* next() { |
duke@435 | 131 | if (*_pos == '\0') { |
duke@435 | 132 | return NULL; |
duke@435 | 133 | } |
duke@435 | 134 | char* res = _pos; |
duke@435 | 135 | char* next_pos = strchr(_pos, '\0'); |
duke@435 | 136 | if (next_pos < _end) { |
duke@435 | 137 | next_pos++; |
duke@435 | 138 | } |
duke@435 | 139 | _pos = next_pos; |
duke@435 | 140 | return res; |
duke@435 | 141 | } |
duke@435 | 142 | }; |
duke@435 | 143 | |
duke@435 | 144 | |
duke@435 | 145 | // atexit hook to stop listener and unlink the file that it is |
duke@435 | 146 | // bound too. |
duke@435 | 147 | extern "C" { |
duke@435 | 148 | static void listener_cleanup() { |
duke@435 | 149 | static int cleanup_done; |
duke@435 | 150 | if (!cleanup_done) { |
duke@435 | 151 | cleanup_done = 1; |
duke@435 | 152 | int s = LinuxAttachListener::listener(); |
duke@435 | 153 | if (s != -1) { |
duke@435 | 154 | ::close(s); |
duke@435 | 155 | } |
duke@435 | 156 | if (LinuxAttachListener::has_path()) { |
duke@435 | 157 | ::unlink(LinuxAttachListener::path()); |
duke@435 | 158 | } |
duke@435 | 159 | } |
duke@435 | 160 | } |
duke@435 | 161 | } |
duke@435 | 162 | |
duke@435 | 163 | // Initialization - create a listener socket and bind it to a file |
duke@435 | 164 | |
duke@435 | 165 | int LinuxAttachListener::init() { |
duke@435 | 166 | char path[PATH_MAX+1]; // socket file |
duke@435 | 167 | int listener; // listener socket (file descriptor) |
duke@435 | 168 | |
duke@435 | 169 | // register function to cleanup |
duke@435 | 170 | ::atexit(listener_cleanup); |
duke@435 | 171 | |
duke@435 | 172 | // create the listener socket |
duke@435 | 173 | listener = ::socket(PF_UNIX, SOCK_STREAM, 0); |
duke@435 | 174 | if (listener == -1) { |
duke@435 | 175 | return -1; |
duke@435 | 176 | } |
duke@435 | 177 | |
duke@435 | 178 | int res = -1; |
duke@435 | 179 | struct sockaddr_un addr; |
duke@435 | 180 | addr.sun_family = AF_UNIX; |
duke@435 | 181 | |
duke@435 | 182 | // FIXME: Prior to b39 the tool-side API expected to find the well |
duke@435 | 183 | // known file in the working directory. To allow this libjvm.so work with |
duke@435 | 184 | // a pre-b39 SDK we create it in the working directory if |
duke@435 | 185 | // +StartAttachListener is used is used. All unit tests for this feature |
duke@435 | 186 | // currently used this flag. Once b39 SDK has been promoted we can remove |
duke@435 | 187 | // this code. |
duke@435 | 188 | if (StartAttachListener) { |
duke@435 | 189 | sprintf(path, ".java_pid%d", os::current_process_id()); |
duke@435 | 190 | strcpy(addr.sun_path, path); |
duke@435 | 191 | ::unlink(path); |
duke@435 | 192 | res = ::bind(listener, (struct sockaddr*)&addr, sizeof(addr)); |
duke@435 | 193 | } |
duke@435 | 194 | if (res == -1) { |
duke@435 | 195 | sprintf(path, "%s/.java_pid%d", os::get_temp_directory(), os::current_process_id()); |
duke@435 | 196 | strcpy(addr.sun_path, path); |
duke@435 | 197 | ::unlink(path); |
duke@435 | 198 | res = ::bind(listener, (struct sockaddr*)&addr, sizeof(addr)); |
duke@435 | 199 | } |
duke@435 | 200 | if (res == -1) { |
duke@435 | 201 | RESTARTABLE(::close(listener), res); |
duke@435 | 202 | return -1; |
duke@435 | 203 | } |
duke@435 | 204 | set_path(path); |
duke@435 | 205 | |
duke@435 | 206 | // put in listen mode and set permission |
duke@435 | 207 | if ((::listen(listener, 5) == -1) || (::chmod(path, S_IREAD|S_IWRITE) == -1)) { |
duke@435 | 208 | RESTARTABLE(::close(listener), res); |
duke@435 | 209 | ::unlink(path); |
duke@435 | 210 | set_path(NULL); |
duke@435 | 211 | return -1; |
duke@435 | 212 | } |
duke@435 | 213 | set_listener(listener); |
duke@435 | 214 | |
duke@435 | 215 | return 0; |
duke@435 | 216 | } |
duke@435 | 217 | |
duke@435 | 218 | // Given a socket that is connected to a peer we read the request and |
duke@435 | 219 | // create an AttachOperation. As the socket is blocking there is potential |
duke@435 | 220 | // for a denial-of-service if the peer does not response. However this happens |
duke@435 | 221 | // after the peer credentials have been checked and in the worst case it just |
duke@435 | 222 | // means that the attach listener thread is blocked. |
duke@435 | 223 | // |
duke@435 | 224 | LinuxAttachOperation* LinuxAttachListener::read_request(int s) { |
duke@435 | 225 | char ver_str[8]; |
duke@435 | 226 | sprintf(ver_str, "%d", ATTACH_PROTOCOL_VER); |
duke@435 | 227 | |
duke@435 | 228 | // The request is a sequence of strings so we first figure out the |
duke@435 | 229 | // expected count and the maximum possible length of the request. |
duke@435 | 230 | // The request is: |
duke@435 | 231 | // <ver>0<cmd>0<arg>0<arg>0<arg>0 |
duke@435 | 232 | // where <ver> is the protocol version (1), <cmd> is the command |
duke@435 | 233 | // name ("load", "datadump", ...), and <arg> is an argument |
duke@435 | 234 | int expected_str_count = 2 + AttachOperation::arg_count_max; |
dcubed@485 | 235 | const int max_len = (sizeof(ver_str) + 1) + (AttachOperation::name_length_max + 1) + |
duke@435 | 236 | AttachOperation::arg_count_max*(AttachOperation::arg_length_max + 1); |
duke@435 | 237 | |
duke@435 | 238 | char buf[max_len]; |
duke@435 | 239 | int str_count = 0; |
duke@435 | 240 | |
duke@435 | 241 | // Read until all (expected) strings have been read, the buffer is |
duke@435 | 242 | // full, or EOF. |
duke@435 | 243 | |
duke@435 | 244 | int off = 0; |
duke@435 | 245 | int left = max_len; |
duke@435 | 246 | |
duke@435 | 247 | do { |
duke@435 | 248 | int n; |
duke@435 | 249 | RESTARTABLE(read(s, buf+off, left), n); |
duke@435 | 250 | if (n == -1) { |
duke@435 | 251 | return NULL; // reset by peer or other error |
duke@435 | 252 | } |
duke@435 | 253 | if (n == 0) { |
duke@435 | 254 | break; |
duke@435 | 255 | } |
duke@435 | 256 | for (int i=0; i<n; i++) { |
duke@435 | 257 | if (buf[off+i] == 0) { |
duke@435 | 258 | // EOS found |
duke@435 | 259 | str_count++; |
duke@435 | 260 | |
duke@435 | 261 | // The first string is <ver> so check it now to |
duke@435 | 262 | // check for protocol mis-match |
duke@435 | 263 | if (str_count == 1) { |
duke@435 | 264 | if ((strlen(buf) != strlen(ver_str)) || |
duke@435 | 265 | (atoi(buf) != ATTACH_PROTOCOL_VER)) { |
duke@435 | 266 | char msg[32]; |
duke@435 | 267 | sprintf(msg, "%d\n", ATTACH_ERROR_BADVERSION); |
duke@435 | 268 | write_fully(s, msg, strlen(msg)); |
duke@435 | 269 | return NULL; |
duke@435 | 270 | } |
duke@435 | 271 | } |
duke@435 | 272 | } |
duke@435 | 273 | } |
duke@435 | 274 | off += n; |
duke@435 | 275 | left -= n; |
duke@435 | 276 | } while (left > 0 && str_count < expected_str_count); |
duke@435 | 277 | |
duke@435 | 278 | if (str_count != expected_str_count) { |
duke@435 | 279 | return NULL; // incomplete request |
duke@435 | 280 | } |
duke@435 | 281 | |
duke@435 | 282 | // parse request |
duke@435 | 283 | |
duke@435 | 284 | ArgumentIterator args(buf, (max_len)-left); |
duke@435 | 285 | |
duke@435 | 286 | // version already checked |
duke@435 | 287 | char* v = args.next(); |
duke@435 | 288 | |
duke@435 | 289 | char* name = args.next(); |
duke@435 | 290 | if (name == NULL || strlen(name) > AttachOperation::name_length_max) { |
duke@435 | 291 | return NULL; |
duke@435 | 292 | } |
duke@435 | 293 | |
duke@435 | 294 | LinuxAttachOperation* op = new LinuxAttachOperation(name); |
duke@435 | 295 | |
duke@435 | 296 | for (int i=0; i<AttachOperation::arg_count_max; i++) { |
duke@435 | 297 | char* arg = args.next(); |
duke@435 | 298 | if (arg == NULL) { |
duke@435 | 299 | op->set_arg(i, NULL); |
duke@435 | 300 | } else { |
duke@435 | 301 | if (strlen(arg) > AttachOperation::arg_length_max) { |
duke@435 | 302 | delete op; |
duke@435 | 303 | return NULL; |
duke@435 | 304 | } |
duke@435 | 305 | op->set_arg(i, arg); |
duke@435 | 306 | } |
duke@435 | 307 | } |
duke@435 | 308 | |
duke@435 | 309 | op->set_socket(s); |
duke@435 | 310 | return op; |
duke@435 | 311 | } |
duke@435 | 312 | |
duke@435 | 313 | |
duke@435 | 314 | // Dequeue an operation |
duke@435 | 315 | // |
duke@435 | 316 | // In the Linux implementation there is only a single operation and clients |
duke@435 | 317 | // cannot queue commands (except at the socket level). |
duke@435 | 318 | // |
duke@435 | 319 | LinuxAttachOperation* LinuxAttachListener::dequeue() { |
duke@435 | 320 | for (;;) { |
duke@435 | 321 | int s; |
duke@435 | 322 | |
duke@435 | 323 | // wait for client to connect |
duke@435 | 324 | struct sockaddr addr; |
duke@435 | 325 | socklen_t len = sizeof(addr); |
duke@435 | 326 | RESTARTABLE(::accept(listener(), &addr, &len), s); |
duke@435 | 327 | if (s == -1) { |
duke@435 | 328 | return NULL; // log a warning? |
duke@435 | 329 | } |
duke@435 | 330 | |
duke@435 | 331 | // get the credentials of the peer and check the effective uid/guid |
duke@435 | 332 | // - check with jeff on this. |
duke@435 | 333 | struct ucred cred_info; |
duke@435 | 334 | socklen_t optlen = sizeof(cred_info); |
duke@435 | 335 | if (::getsockopt(s, SOL_SOCKET, SO_PEERCRED, (void*)&cred_info, &optlen) == -1) { |
duke@435 | 336 | int res; |
duke@435 | 337 | RESTARTABLE(::close(s), res); |
duke@435 | 338 | continue; |
duke@435 | 339 | } |
duke@435 | 340 | uid_t euid = geteuid(); |
duke@435 | 341 | gid_t egid = getegid(); |
duke@435 | 342 | |
duke@435 | 343 | if (cred_info.uid != euid || cred_info.gid != egid) { |
duke@435 | 344 | int res; |
duke@435 | 345 | RESTARTABLE(::close(s), res); |
duke@435 | 346 | continue; |
duke@435 | 347 | } |
duke@435 | 348 | |
duke@435 | 349 | // peer credential look okay so we read the request |
duke@435 | 350 | LinuxAttachOperation* op = read_request(s); |
duke@435 | 351 | if (op == NULL) { |
duke@435 | 352 | int res; |
duke@435 | 353 | RESTARTABLE(::close(s), res); |
duke@435 | 354 | continue; |
duke@435 | 355 | } else { |
duke@435 | 356 | return op; |
duke@435 | 357 | } |
duke@435 | 358 | } |
duke@435 | 359 | } |
duke@435 | 360 | |
duke@435 | 361 | // write the given buffer to the socket |
duke@435 | 362 | int LinuxAttachListener::write_fully(int s, char* buf, int len) { |
duke@435 | 363 | do { |
duke@435 | 364 | int n = ::write(s, buf, len); |
duke@435 | 365 | if (n == -1) { |
duke@435 | 366 | if (errno != EINTR) return -1; |
duke@435 | 367 | } else { |
duke@435 | 368 | buf += n; |
duke@435 | 369 | len -= n; |
duke@435 | 370 | } |
duke@435 | 371 | } |
duke@435 | 372 | while (len > 0); |
duke@435 | 373 | return 0; |
duke@435 | 374 | } |
duke@435 | 375 | |
duke@435 | 376 | // Complete an operation by sending the operation result and any result |
duke@435 | 377 | // output to the client. At this time the socket is in blocking mode so |
duke@435 | 378 | // potentially we can block if there is a lot of data and the client is |
duke@435 | 379 | // non-responsive. For most operations this is a non-issue because the |
duke@435 | 380 | // default send buffer is sufficient to buffer everything. In the future |
duke@435 | 381 | // if there are operations that involves a very big reply then it the |
duke@435 | 382 | // socket could be made non-blocking and a timeout could be used. |
duke@435 | 383 | |
duke@435 | 384 | void LinuxAttachOperation::complete(jint result, bufferedStream* st) { |
duke@435 | 385 | JavaThread* thread = JavaThread::current(); |
duke@435 | 386 | ThreadBlockInVM tbivm(thread); |
duke@435 | 387 | |
duke@435 | 388 | thread->set_suspend_equivalent(); |
duke@435 | 389 | // cleared by handle_special_suspend_equivalent_condition() or |
duke@435 | 390 | // java_suspend_self() via check_and_wait_while_suspended() |
duke@435 | 391 | |
duke@435 | 392 | // write operation result |
duke@435 | 393 | char msg[32]; |
duke@435 | 394 | sprintf(msg, "%d\n", result); |
duke@435 | 395 | int rc = LinuxAttachListener::write_fully(this->socket(), msg, strlen(msg)); |
duke@435 | 396 | |
duke@435 | 397 | // write any result data |
duke@435 | 398 | if (rc == 0) { |
duke@435 | 399 | LinuxAttachListener::write_fully(this->socket(), (char*) st->base(), st->size()); |
duke@435 | 400 | ::shutdown(this->socket(), 2); |
duke@435 | 401 | } |
duke@435 | 402 | |
duke@435 | 403 | // done |
duke@435 | 404 | RESTARTABLE(::close(this->socket()), rc); |
duke@435 | 405 | |
duke@435 | 406 | // were we externally suspended while we were waiting? |
duke@435 | 407 | thread->check_and_wait_while_suspended(); |
duke@435 | 408 | |
duke@435 | 409 | delete this; |
duke@435 | 410 | } |
duke@435 | 411 | |
duke@435 | 412 | |
duke@435 | 413 | // AttachListener functions |
duke@435 | 414 | |
duke@435 | 415 | AttachOperation* AttachListener::dequeue() { |
duke@435 | 416 | JavaThread* thread = JavaThread::current(); |
duke@435 | 417 | ThreadBlockInVM tbivm(thread); |
duke@435 | 418 | |
duke@435 | 419 | thread->set_suspend_equivalent(); |
duke@435 | 420 | // cleared by handle_special_suspend_equivalent_condition() or |
duke@435 | 421 | // java_suspend_self() via check_and_wait_while_suspended() |
duke@435 | 422 | |
duke@435 | 423 | AttachOperation* op = LinuxAttachListener::dequeue(); |
duke@435 | 424 | |
duke@435 | 425 | // were we externally suspended while we were waiting? |
duke@435 | 426 | thread->check_and_wait_while_suspended(); |
duke@435 | 427 | |
duke@435 | 428 | return op; |
duke@435 | 429 | } |
duke@435 | 430 | |
duke@435 | 431 | int AttachListener::pd_init() { |
duke@435 | 432 | JavaThread* thread = JavaThread::current(); |
duke@435 | 433 | ThreadBlockInVM tbivm(thread); |
duke@435 | 434 | |
duke@435 | 435 | thread->set_suspend_equivalent(); |
duke@435 | 436 | // cleared by handle_special_suspend_equivalent_condition() or |
duke@435 | 437 | // java_suspend_self() via check_and_wait_while_suspended() |
duke@435 | 438 | |
duke@435 | 439 | int ret_code = LinuxAttachListener::init(); |
duke@435 | 440 | |
duke@435 | 441 | // were we externally suspended while we were waiting? |
duke@435 | 442 | thread->check_and_wait_while_suspended(); |
duke@435 | 443 | |
duke@435 | 444 | return ret_code; |
duke@435 | 445 | } |
duke@435 | 446 | |
duke@435 | 447 | // Attach Listener is started lazily except in the case when |
duke@435 | 448 | // +ReduseSignalUsage is used |
duke@435 | 449 | bool AttachListener::init_at_startup() { |
duke@435 | 450 | if (ReduceSignalUsage) { |
duke@435 | 451 | return true; |
duke@435 | 452 | } else { |
duke@435 | 453 | return false; |
duke@435 | 454 | } |
duke@435 | 455 | } |
duke@435 | 456 | |
duke@435 | 457 | // If the file .attach_pid<pid> exists in the working directory |
duke@435 | 458 | // or /tmp then this is the trigger to start the attach mechanism |
duke@435 | 459 | bool AttachListener::is_init_trigger() { |
duke@435 | 460 | if (init_at_startup() || is_initialized()) { |
duke@435 | 461 | return false; // initialized at startup or already initialized |
duke@435 | 462 | } |
duke@435 | 463 | char fn[32]; |
duke@435 | 464 | sprintf(fn, ".attach_pid%d", os::current_process_id()); |
duke@435 | 465 | int ret; |
duke@435 | 466 | struct stat64 st; |
duke@435 | 467 | RESTARTABLE(::stat64(fn, &st), ret); |
duke@435 | 468 | if (ret == -1) { |
duke@435 | 469 | sprintf(fn, "/tmp/.attach_pid%d", os::current_process_id()); |
duke@435 | 470 | RESTARTABLE(::stat64(fn, &st), ret); |
duke@435 | 471 | } |
duke@435 | 472 | if (ret == 0) { |
duke@435 | 473 | // simple check to avoid starting the attach mechanism when |
duke@435 | 474 | // a bogus user creates the file |
duke@435 | 475 | if (st.st_uid == geteuid()) { |
duke@435 | 476 | init(); |
duke@435 | 477 | return true; |
duke@435 | 478 | } |
duke@435 | 479 | } |
duke@435 | 480 | return false; |
duke@435 | 481 | } |
duke@435 | 482 | |
duke@435 | 483 | // if VM aborts then remove listener |
duke@435 | 484 | void AttachListener::abort() { |
duke@435 | 485 | listener_cleanup(); |
duke@435 | 486 | } |
duke@435 | 487 | |
duke@435 | 488 | void AttachListener::pd_data_dump() { |
duke@435 | 489 | os::signal_notify(SIGQUIT); |
duke@435 | 490 | } |
duke@435 | 491 | |
duke@435 | 492 | AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* n) { |
duke@435 | 493 | return NULL; |
duke@435 | 494 | } |
duke@435 | 495 | |
duke@435 | 496 | jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) { |
duke@435 | 497 | out->print_cr("flag '%s' cannot be changed", op->arg(0)); |
duke@435 | 498 | return JNI_ERR; |
duke@435 | 499 | } |
duke@435 | 500 | |
duke@435 | 501 | void AttachListener::pd_detachall() { |
duke@435 | 502 | // do nothing for now |
duke@435 | 503 | } |