Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 1 | #include "Python.h" |
| 2 | #include "pythread.h" |
| 3 | #include <signal.h> |
| 4 | #include <object.h> |
| 5 | #include <frameobject.h> |
| 6 | #include <signal.h> |
| 7 | |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 8 | /* Allocate at maximum 100 MB of the stack to raise the stack overflow */ |
| 9 | #define STACK_OVERFLOW_MAX_SIZE (100*1024*1024) |
| 10 | |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 11 | #ifdef WITH_THREAD |
| 12 | # define FAULTHANDLER_LATER |
| 13 | #endif |
| 14 | |
| 15 | #ifndef MS_WINDOWS |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 16 | /* register() is useless on Windows, because only SIGSEGV, SIGABRT and |
| 17 | SIGILL can be handled by the process, and these signals can only be used |
| 18 | with enable(), not using register() */ |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 19 | # define FAULTHANDLER_USER |
| 20 | #endif |
| 21 | |
| 22 | #define PUTS(fd, str) write(fd, str, strlen(str)) |
| 23 | |
| 24 | #ifdef HAVE_SIGACTION |
| 25 | typedef struct sigaction _Py_sighandler_t; |
| 26 | #else |
| 27 | typedef PyOS_sighandler_t _Py_sighandler_t; |
| 28 | #endif |
| 29 | |
| 30 | typedef struct { |
| 31 | int signum; |
| 32 | int enabled; |
| 33 | const char* name; |
| 34 | _Py_sighandler_t previous; |
| 35 | int all_threads; |
| 36 | } fault_handler_t; |
| 37 | |
| 38 | static struct { |
| 39 | int enabled; |
| 40 | PyObject *file; |
| 41 | int fd; |
| 42 | int all_threads; |
| 43 | } fatal_error = {0, NULL, -1, 0}; |
| 44 | |
| 45 | #ifdef FAULTHANDLER_LATER |
| 46 | static struct { |
| 47 | PyObject *file; |
| 48 | int fd; |
| 49 | PY_TIMEOUT_T timeout_ms; /* timeout in microseconds */ |
| 50 | int repeat; |
Victor Stinner | f309134 | 2011-04-01 03:16:51 +0200 | [diff] [blame] | 51 | int running; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 52 | PyInterpreterState *interp; |
| 53 | int exit; |
| 54 | /* released by parent thread when cancel request */ |
| 55 | PyThread_type_lock cancel_event; |
| 56 | /* released by child thread when joined */ |
| 57 | PyThread_type_lock join_event; |
| 58 | } thread; |
| 59 | #endif |
| 60 | |
| 61 | #ifdef FAULTHANDLER_USER |
| 62 | typedef struct { |
| 63 | int enabled; |
| 64 | PyObject *file; |
| 65 | int fd; |
| 66 | int all_threads; |
| 67 | _Py_sighandler_t previous; |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 68 | PyInterpreterState *interp; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 69 | } user_signal_t; |
| 70 | |
| 71 | static user_signal_t *user_signals; |
| 72 | |
| 73 | /* the following macros come from Python: Modules/signalmodule.c */ |
| 74 | #if defined(PYOS_OS2) && !defined(PYCC_GCC) |
| 75 | #define NSIG 12 |
| 76 | #endif |
| 77 | #ifndef NSIG |
| 78 | # if defined(_NSIG) |
| 79 | # define NSIG _NSIG /* For BSD/SysV */ |
| 80 | # elif defined(_SIGMAX) |
| 81 | # define NSIG (_SIGMAX + 1) /* For QNX */ |
| 82 | # elif defined(SIGMAX) |
| 83 | # define NSIG (SIGMAX + 1) /* For djgpp */ |
| 84 | # else |
| 85 | # define NSIG 64 /* Use a reasonable default value */ |
| 86 | # endif |
| 87 | #endif |
| 88 | |
| 89 | #endif /* FAULTHANDLER_USER */ |
| 90 | |
| 91 | |
| 92 | static fault_handler_t faulthandler_handlers[] = { |
| 93 | #ifdef SIGBUS |
| 94 | {SIGBUS, 0, "Bus error", }, |
| 95 | #endif |
| 96 | #ifdef SIGILL |
| 97 | {SIGILL, 0, "Illegal instruction", }, |
| 98 | #endif |
| 99 | {SIGFPE, 0, "Floating point exception", }, |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 100 | {SIGABRT, 0, "Aborted", }, |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 101 | /* define SIGSEGV at the end to make it the default choice if searching the |
| 102 | handler fails in faulthandler_fatal_error() */ |
| 103 | {SIGSEGV, 0, "Segmentation fault", } |
| 104 | }; |
| 105 | static const unsigned char faulthandler_nsignals = \ |
| 106 | sizeof(faulthandler_handlers) / sizeof(faulthandler_handlers[0]); |
| 107 | |
| 108 | #ifdef HAVE_SIGALTSTACK |
| 109 | static stack_t stack; |
| 110 | #endif |
| 111 | |
| 112 | |
| 113 | /* Get the file descriptor of a file by calling its fileno() method and then |
| 114 | call its flush() method. |
| 115 | |
| 116 | If file is NULL or Py_None, use sys.stderr as the new file. |
| 117 | |
| 118 | On success, return the new file and write the file descriptor into *p_fd. |
| 119 | On error, return NULL. */ |
| 120 | |
| 121 | static PyObject* |
| 122 | faulthandler_get_fileno(PyObject *file, int *p_fd) |
| 123 | { |
| 124 | PyObject *result; |
| 125 | long fd_long; |
| 126 | int fd; |
| 127 | |
| 128 | if (file == NULL || file == Py_None) { |
| 129 | file = PySys_GetObject("stderr"); |
| 130 | if (file == NULL) { |
| 131 | PyErr_SetString(PyExc_RuntimeError, "unable to get sys.stderr"); |
| 132 | return NULL; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | result = PyObject_CallMethod(file, "fileno", ""); |
| 137 | if (result == NULL) |
| 138 | return NULL; |
| 139 | |
| 140 | fd = -1; |
| 141 | if (PyLong_Check(result)) { |
| 142 | fd_long = PyLong_AsLong(result); |
| 143 | if (0 <= fd_long && fd_long < INT_MAX) |
| 144 | fd = (int)fd_long; |
| 145 | } |
| 146 | Py_DECREF(result); |
| 147 | |
| 148 | if (fd == -1) { |
| 149 | PyErr_SetString(PyExc_RuntimeError, |
| 150 | "file.fileno() is not a valid file descriptor"); |
| 151 | return NULL; |
| 152 | } |
| 153 | |
| 154 | result = PyObject_CallMethod(file, "flush", ""); |
| 155 | if (result != NULL) |
| 156 | Py_DECREF(result); |
| 157 | else { |
| 158 | /* ignore flush() error */ |
| 159 | PyErr_Clear(); |
| 160 | } |
| 161 | *p_fd = fd; |
| 162 | return file; |
| 163 | } |
| 164 | |
| 165 | static PyObject* |
| 166 | faulthandler_dump_traceback_py(PyObject *self, |
| 167 | PyObject *args, PyObject *kwargs) |
| 168 | { |
| 169 | static char *kwlist[] = {"file", "all_threads", NULL}; |
| 170 | PyObject *file = NULL; |
| 171 | int all_threads = 0; |
| 172 | PyThreadState *tstate; |
| 173 | const char *errmsg; |
| 174 | int fd; |
| 175 | |
| 176 | if (!PyArg_ParseTupleAndKeywords(args, kwargs, |
| 177 | "|Oi:dump_traceback", kwlist, |
| 178 | &file, &all_threads)) |
| 179 | return NULL; |
| 180 | |
| 181 | file = faulthandler_get_fileno(file, &fd); |
| 182 | if (file == NULL) |
| 183 | return NULL; |
| 184 | |
| 185 | /* The caller holds the GIL and so PyThreadState_Get() can be used */ |
| 186 | tstate = PyThreadState_Get(); |
| 187 | if (tstate == NULL) { |
| 188 | PyErr_SetString(PyExc_RuntimeError, |
| 189 | "unable to get the current thread state"); |
| 190 | return NULL; |
| 191 | } |
| 192 | |
| 193 | if (all_threads) { |
| 194 | errmsg = _Py_DumpTracebackThreads(fd, tstate->interp, tstate); |
| 195 | if (errmsg != NULL) { |
| 196 | PyErr_SetString(PyExc_RuntimeError, errmsg); |
| 197 | return NULL; |
| 198 | } |
| 199 | } |
| 200 | else { |
| 201 | _Py_DumpTraceback(fd, tstate); |
| 202 | } |
| 203 | Py_RETURN_NONE; |
| 204 | } |
| 205 | |
| 206 | |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 207 | /* Handler of SIGSEGV, SIGFPE, SIGABRT, SIGBUS and SIGILL signals. |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 208 | |
| 209 | Display the current Python traceback, restore the previous handler and call |
| 210 | the previous handler. |
| 211 | |
| 212 | On Windows, don't call explictly the previous handler, because Windows |
| 213 | signal handler would not be called (for an unknown reason). The execution of |
| 214 | the program continues at faulthandler_fatal_error() exit, but the same |
| 215 | instruction will raise the same fault (signal), and so the previous handler |
| 216 | will be called. |
| 217 | |
| 218 | This function is signal safe and should only call signal safe functions. */ |
| 219 | |
| 220 | static void |
Victor Stinner | 44e31ba | 2011-04-07 11:39:03 +0200 | [diff] [blame^] | 221 | faulthandler_fatal_error(int signum) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 222 | { |
| 223 | const int fd = fatal_error.fd; |
| 224 | unsigned int i; |
| 225 | fault_handler_t *handler = NULL; |
| 226 | PyThreadState *tstate; |
| 227 | |
| 228 | if (!fatal_error.enabled) |
| 229 | return; |
| 230 | |
| 231 | for (i=0; i < faulthandler_nsignals; i++) { |
| 232 | handler = &faulthandler_handlers[i]; |
| 233 | if (handler->signum == signum) |
| 234 | break; |
| 235 | } |
| 236 | if (handler == NULL) { |
| 237 | /* faulthandler_nsignals == 0 (unlikely) */ |
| 238 | return; |
| 239 | } |
| 240 | |
| 241 | /* restore the previous handler */ |
| 242 | #ifdef HAVE_SIGACTION |
| 243 | (void)sigaction(handler->signum, &handler->previous, NULL); |
| 244 | #else |
| 245 | (void)signal(handler->signum, handler->previous); |
| 246 | #endif |
| 247 | handler->enabled = 0; |
| 248 | |
| 249 | PUTS(fd, "Fatal Python error: "); |
| 250 | PUTS(fd, handler->name); |
| 251 | PUTS(fd, "\n\n"); |
| 252 | |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 253 | /* SIGSEGV, SIGFPE, SIGABRT, SIGBUS and SIGILL are synchronous signals and |
| 254 | so are delivered to the thread that caused the fault. Get the Python |
| 255 | thread state of the current thread. |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 256 | |
| 257 | PyThreadState_Get() doesn't give the state of the thread that caused the |
| 258 | fault if the thread released the GIL, and so this function cannot be |
| 259 | used. Read the thread local storage (TLS) instead: call |
| 260 | PyGILState_GetThisThreadState(). */ |
| 261 | tstate = PyGILState_GetThisThreadState(); |
| 262 | if (tstate == NULL) |
| 263 | return; |
| 264 | |
| 265 | if (fatal_error.all_threads) |
| 266 | _Py_DumpTracebackThreads(fd, tstate->interp, tstate); |
| 267 | else |
| 268 | _Py_DumpTraceback(fd, tstate); |
| 269 | |
Victor Stinner | bc6a4db | 2011-04-01 12:08:57 +0200 | [diff] [blame] | 270 | #ifdef MS_WINDOWS |
| 271 | if (signum == SIGSEGV) { |
| 272 | /* don't call explictly the previous handler for SIGSEGV in this signal |
| 273 | handler, because the Windows signal handler would not be called */ |
| 274 | return; |
| 275 | } |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 276 | #endif |
Victor Stinner | bc6a4db | 2011-04-01 12:08:57 +0200 | [diff] [blame] | 277 | /* call the previous signal handler: it is called immediatly if we use |
| 278 | sigaction() thanks to SA_NODEFER flag, otherwise it is deferred */ |
| 279 | raise(signum); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 280 | } |
| 281 | |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 282 | /* Install the handler for fatal signals, faulthandler_fatal_error(). */ |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 283 | |
| 284 | static PyObject* |
| 285 | faulthandler_enable(PyObject *self, PyObject *args, PyObject *kwargs) |
| 286 | { |
| 287 | static char *kwlist[] = {"file", "all_threads", NULL}; |
| 288 | PyObject *file = NULL; |
| 289 | int all_threads = 0; |
| 290 | unsigned int i; |
| 291 | fault_handler_t *handler; |
| 292 | #ifdef HAVE_SIGACTION |
| 293 | struct sigaction action; |
| 294 | #endif |
| 295 | int err; |
| 296 | int fd; |
| 297 | |
| 298 | if (!PyArg_ParseTupleAndKeywords(args, kwargs, |
| 299 | "|Oi:enable", kwlist, &file, &all_threads)) |
| 300 | return NULL; |
| 301 | |
| 302 | file = faulthandler_get_fileno(file, &fd); |
| 303 | if (file == NULL) |
| 304 | return NULL; |
| 305 | |
| 306 | Py_XDECREF(fatal_error.file); |
| 307 | Py_INCREF(file); |
| 308 | fatal_error.file = file; |
| 309 | fatal_error.fd = fd; |
| 310 | fatal_error.all_threads = all_threads; |
| 311 | |
| 312 | if (!fatal_error.enabled) { |
| 313 | fatal_error.enabled = 1; |
| 314 | |
| 315 | for (i=0; i < faulthandler_nsignals; i++) { |
| 316 | handler = &faulthandler_handlers[i]; |
| 317 | #ifdef HAVE_SIGACTION |
Victor Stinner | 44e31ba | 2011-04-07 11:39:03 +0200 | [diff] [blame^] | 318 | action.sa_handler = faulthandler_fatal_error; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 319 | sigemptyset(&action.sa_mask); |
| 320 | /* Do not prevent the signal from being received from within |
| 321 | its own signal handler */ |
| 322 | action.sa_flags = SA_NODEFER; |
| 323 | #ifdef HAVE_SIGALTSTACK |
| 324 | if (stack.ss_sp != NULL) { |
| 325 | /* Call the signal handler on an alternate signal stack |
| 326 | provided by sigaltstack() */ |
| 327 | action.sa_flags |= SA_ONSTACK; |
| 328 | } |
| 329 | #endif |
| 330 | err = sigaction(handler->signum, &action, &handler->previous); |
| 331 | #else |
| 332 | handler->previous = signal(handler->signum, |
| 333 | faulthandler_fatal_error); |
| 334 | err = (handler->previous == SIG_ERR); |
| 335 | #endif |
| 336 | if (err) { |
| 337 | PyErr_SetFromErrno(PyExc_RuntimeError); |
| 338 | return NULL; |
| 339 | } |
| 340 | handler->enabled = 1; |
| 341 | } |
| 342 | } |
| 343 | Py_RETURN_NONE; |
| 344 | } |
| 345 | |
| 346 | static void |
| 347 | faulthandler_disable(void) |
| 348 | { |
| 349 | unsigned int i; |
| 350 | fault_handler_t *handler; |
| 351 | |
| 352 | if (fatal_error.enabled) { |
| 353 | fatal_error.enabled = 0; |
| 354 | for (i=0; i < faulthandler_nsignals; i++) { |
| 355 | handler = &faulthandler_handlers[i]; |
| 356 | if (!handler->enabled) |
| 357 | continue; |
| 358 | #ifdef HAVE_SIGACTION |
| 359 | (void)sigaction(handler->signum, &handler->previous, NULL); |
| 360 | #else |
| 361 | (void)signal(handler->signum, handler->previous); |
| 362 | #endif |
| 363 | handler->enabled = 0; |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | Py_CLEAR(fatal_error.file); |
| 368 | } |
| 369 | |
| 370 | static PyObject* |
| 371 | faulthandler_disable_py(PyObject *self) |
| 372 | { |
| 373 | if (!fatal_error.enabled) { |
| 374 | Py_INCREF(Py_False); |
| 375 | return Py_False; |
| 376 | } |
| 377 | faulthandler_disable(); |
| 378 | Py_INCREF(Py_True); |
| 379 | return Py_True; |
| 380 | } |
| 381 | |
| 382 | static PyObject* |
| 383 | faulthandler_is_enabled(PyObject *self) |
| 384 | { |
| 385 | return PyBool_FromLong(fatal_error.enabled); |
| 386 | } |
| 387 | |
| 388 | #ifdef FAULTHANDLER_LATER |
| 389 | |
| 390 | static void |
| 391 | faulthandler_thread(void *unused) |
| 392 | { |
| 393 | PyLockStatus st; |
| 394 | const char* errmsg; |
| 395 | PyThreadState *current; |
| 396 | int ok; |
Victor Stinner | da9edae | 2011-04-04 11:05:21 +0200 | [diff] [blame] | 397 | #ifdef HAVE_PTHREAD_H |
| 398 | sigset_t set; |
| 399 | |
| 400 | /* we don't want to receive any signal */ |
| 401 | sigfillset(&set); |
| 402 | #if defined(HAVE_PTHREAD_SIGMASK) && !defined(HAVE_BROKEN_PTHREAD_SIGMASK) |
| 403 | pthread_sigmask(SIG_SETMASK, &set, NULL); |
| 404 | #else |
| 405 | sigprocmask(SIG_SETMASK, &set, NULL); |
| 406 | #endif |
| 407 | #endif |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 408 | |
| 409 | do { |
| 410 | st = PyThread_acquire_lock_timed(thread.cancel_event, |
| 411 | thread.timeout_ms, 0); |
| 412 | if (st == PY_LOCK_ACQUIRED) { |
| 413 | /* Cancelled by user */ |
| 414 | break; |
| 415 | } |
| 416 | /* Timeout => dump traceback */ |
| 417 | assert(st == PY_LOCK_FAILURE); |
| 418 | |
| 419 | /* get the thread holding the GIL, NULL if no thread hold the GIL */ |
| 420 | current = _Py_atomic_load_relaxed(&_PyThreadState_Current); |
| 421 | |
| 422 | errmsg = _Py_DumpTracebackThreads(thread.fd, thread.interp, current); |
| 423 | ok = (errmsg == NULL); |
| 424 | |
| 425 | if (thread.exit) |
| 426 | _exit(1); |
| 427 | } while (ok && thread.repeat); |
| 428 | |
| 429 | /* The only way out */ |
Victor Stinner | a4d4f1b | 2011-04-01 03:00:05 +0200 | [diff] [blame] | 430 | PyThread_release_lock(thread.cancel_event); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 431 | PyThread_release_lock(thread.join_event); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 432 | } |
| 433 | |
| 434 | static void |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 435 | faulthandler_cancel_dump_tracebacks_later(void) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 436 | { |
| 437 | if (thread.running) { |
| 438 | /* Notify cancellation */ |
| 439 | PyThread_release_lock(thread.cancel_event); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 440 | } |
Victor Stinner | a4d4f1b | 2011-04-01 03:00:05 +0200 | [diff] [blame] | 441 | /* Wait for thread to join */ |
| 442 | PyThread_acquire_lock(thread.join_event, 1); |
Victor Stinner | a4d4f1b | 2011-04-01 03:00:05 +0200 | [diff] [blame] | 443 | PyThread_release_lock(thread.join_event); |
Victor Stinner | f309134 | 2011-04-01 03:16:51 +0200 | [diff] [blame] | 444 | thread.running = 0; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 445 | Py_CLEAR(thread.file); |
| 446 | } |
| 447 | |
| 448 | static PyObject* |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 449 | faulthandler_dump_tracebacks_later(PyObject *self, |
| 450 | PyObject *args, PyObject *kwargs) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 451 | { |
| 452 | static char *kwlist[] = {"timeout", "repeat", "file", "exit", NULL}; |
| 453 | double timeout; |
| 454 | PY_TIMEOUT_T timeout_ms; |
| 455 | int repeat = 0; |
| 456 | PyObject *file = NULL; |
| 457 | int fd; |
| 458 | int exit = 0; |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 459 | PyThreadState *tstate; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 460 | |
| 461 | if (!PyArg_ParseTupleAndKeywords(args, kwargs, |
| 462 | "d|iOi:dump_tracebacks_later", kwlist, |
| 463 | &timeout, &repeat, &file, &exit)) |
| 464 | return NULL; |
| 465 | timeout *= 1e6; |
| 466 | if (timeout >= (double) PY_TIMEOUT_MAX) { |
| 467 | PyErr_SetString(PyExc_OverflowError, "timeout value is too large"); |
| 468 | return NULL; |
| 469 | } |
| 470 | timeout_ms = (PY_TIMEOUT_T)timeout; |
| 471 | if (timeout_ms <= 0) { |
| 472 | PyErr_SetString(PyExc_ValueError, "timeout must be greater than 0"); |
| 473 | return NULL; |
| 474 | } |
| 475 | |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 476 | tstate = PyThreadState_Get(); |
| 477 | if (tstate == NULL) { |
| 478 | PyErr_SetString(PyExc_RuntimeError, |
| 479 | "unable to get the current thread state"); |
| 480 | return NULL; |
| 481 | } |
| 482 | |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 483 | file = faulthandler_get_fileno(file, &fd); |
| 484 | if (file == NULL) |
| 485 | return NULL; |
| 486 | |
| 487 | /* Cancel previous thread, if running */ |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 488 | faulthandler_cancel_dump_tracebacks_later(); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 489 | |
| 490 | Py_XDECREF(thread.file); |
| 491 | Py_INCREF(file); |
| 492 | thread.file = file; |
| 493 | thread.fd = fd; |
| 494 | thread.timeout_ms = timeout_ms; |
| 495 | thread.repeat = repeat; |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 496 | thread.interp = tstate->interp; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 497 | thread.exit = exit; |
| 498 | |
| 499 | /* Arm these locks to serve as events when released */ |
| 500 | PyThread_acquire_lock(thread.join_event, 1); |
| 501 | PyThread_acquire_lock(thread.cancel_event, 1); |
| 502 | |
| 503 | thread.running = 1; |
| 504 | if (PyThread_start_new_thread(faulthandler_thread, NULL) == -1) { |
| 505 | thread.running = 0; |
Victor Stinner | f309134 | 2011-04-01 03:16:51 +0200 | [diff] [blame] | 506 | PyThread_release_lock(thread.join_event); |
| 507 | PyThread_release_lock(thread.cancel_event); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 508 | Py_CLEAR(thread.file); |
| 509 | PyErr_SetString(PyExc_RuntimeError, |
| 510 | "unable to start watchdog thread"); |
| 511 | return NULL; |
| 512 | } |
| 513 | |
| 514 | Py_RETURN_NONE; |
| 515 | } |
| 516 | |
| 517 | static PyObject* |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 518 | faulthandler_cancel_dump_tracebacks_later_py(PyObject *self) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 519 | { |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 520 | faulthandler_cancel_dump_tracebacks_later(); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 521 | Py_RETURN_NONE; |
| 522 | } |
| 523 | #endif /* FAULTHANDLER_LATER */ |
| 524 | |
| 525 | #ifdef FAULTHANDLER_USER |
| 526 | /* Handler of user signals (e.g. SIGUSR1). |
| 527 | |
| 528 | Dump the traceback of the current thread, or of all threads if |
| 529 | thread.all_threads is true. |
| 530 | |
| 531 | This function is signal safe and should only call signal safe functions. */ |
| 532 | |
| 533 | static void |
| 534 | faulthandler_user(int signum) |
| 535 | { |
| 536 | user_signal_t *user; |
| 537 | PyThreadState *tstate; |
| 538 | |
| 539 | user = &user_signals[signum]; |
| 540 | if (!user->enabled) |
| 541 | return; |
| 542 | |
| 543 | /* PyThreadState_Get() doesn't give the state of the current thread if |
| 544 | the thread doesn't hold the GIL. Read the thread local storage (TLS) |
| 545 | instead: call PyGILState_GetThisThreadState(). */ |
| 546 | tstate = PyGILState_GetThisThreadState(); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 547 | |
| 548 | if (user->all_threads) |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 549 | _Py_DumpTracebackThreads(user->fd, user->interp, tstate); |
| 550 | else { |
| 551 | if (tstate == NULL) |
| 552 | return; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 553 | _Py_DumpTraceback(user->fd, tstate); |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 554 | } |
| 555 | } |
| 556 | |
| 557 | static int |
| 558 | check_signum(int signum) |
| 559 | { |
| 560 | unsigned int i; |
| 561 | |
| 562 | for (i=0; i < faulthandler_nsignals; i++) { |
| 563 | if (faulthandler_handlers[i].signum == signum) { |
| 564 | PyErr_Format(PyExc_RuntimeError, |
| 565 | "signal %i cannot be registered, " |
| 566 | "use enable() instead", |
| 567 | signum); |
| 568 | return 0; |
| 569 | } |
| 570 | } |
| 571 | if (signum < 1 || NSIG <= signum) { |
| 572 | PyErr_SetString(PyExc_ValueError, "signal number out of range"); |
| 573 | return 0; |
| 574 | } |
| 575 | return 1; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 576 | } |
| 577 | |
| 578 | static PyObject* |
| 579 | faulthandler_register(PyObject *self, |
| 580 | PyObject *args, PyObject *kwargs) |
| 581 | { |
| 582 | static char *kwlist[] = {"signum", "file", "all_threads", NULL}; |
| 583 | int signum; |
| 584 | PyObject *file = NULL; |
| 585 | int all_threads = 0; |
| 586 | int fd; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 587 | user_signal_t *user; |
| 588 | _Py_sighandler_t previous; |
| 589 | #ifdef HAVE_SIGACTION |
| 590 | struct sigaction action; |
| 591 | #endif |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 592 | PyThreadState *tstate; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 593 | int err; |
| 594 | |
| 595 | if (!PyArg_ParseTupleAndKeywords(args, kwargs, |
| 596 | "i|Oi:register", kwlist, |
| 597 | &signum, &file, &all_threads)) |
| 598 | return NULL; |
| 599 | |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 600 | if (!check_signum(signum)) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 601 | return NULL; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 602 | |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 603 | /* The caller holds the GIL and so PyThreadState_Get() can be used */ |
| 604 | tstate = PyThreadState_Get(); |
| 605 | if (tstate == NULL) { |
| 606 | PyErr_SetString(PyExc_RuntimeError, |
| 607 | "unable to get the current thread state"); |
| 608 | return NULL; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 609 | } |
| 610 | |
| 611 | file = faulthandler_get_fileno(file, &fd); |
| 612 | if (file == NULL) |
| 613 | return NULL; |
| 614 | |
| 615 | if (user_signals == NULL) { |
| 616 | user_signals = calloc(NSIG, sizeof(user_signal_t)); |
| 617 | if (user_signals == NULL) |
| 618 | return PyErr_NoMemory(); |
| 619 | } |
| 620 | user = &user_signals[signum]; |
| 621 | |
| 622 | if (!user->enabled) { |
| 623 | #ifdef HAVE_SIGACTION |
| 624 | action.sa_handler = faulthandler_user; |
| 625 | sigemptyset(&action.sa_mask); |
| 626 | /* if the signal is received while the kernel is executing a system |
| 627 | call, try to restart the system call instead of interrupting it and |
| 628 | return EINTR */ |
| 629 | action.sa_flags = SA_RESTART; |
| 630 | #ifdef HAVE_SIGALTSTACK |
| 631 | if (stack.ss_sp != NULL) { |
| 632 | /* Call the signal handler on an alternate signal stack |
| 633 | provided by sigaltstack() */ |
| 634 | action.sa_flags |= SA_ONSTACK; |
| 635 | } |
| 636 | #endif |
| 637 | err = sigaction(signum, &action, &previous); |
| 638 | #else |
| 639 | previous = signal(signum, faulthandler_user); |
| 640 | err = (previous == SIG_ERR); |
| 641 | #endif |
| 642 | if (err) { |
| 643 | PyErr_SetFromErrno(PyExc_OSError); |
| 644 | return NULL; |
| 645 | } |
| 646 | } |
| 647 | |
| 648 | Py_XDECREF(user->file); |
| 649 | Py_INCREF(file); |
| 650 | user->file = file; |
| 651 | user->fd = fd; |
| 652 | user->all_threads = all_threads; |
| 653 | user->previous = previous; |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 654 | user->interp = tstate->interp; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 655 | user->enabled = 1; |
| 656 | |
| 657 | Py_RETURN_NONE; |
| 658 | } |
| 659 | |
| 660 | static int |
| 661 | faulthandler_unregister(user_signal_t *user, int signum) |
| 662 | { |
Victor Stinner | a01ca12 | 2011-04-01 12:56:17 +0200 | [diff] [blame] | 663 | if (!user->enabled) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 664 | return 0; |
| 665 | user->enabled = 0; |
| 666 | #ifdef HAVE_SIGACTION |
| 667 | (void)sigaction(signum, &user->previous, NULL); |
| 668 | #else |
| 669 | (void)signal(signum, user->previous); |
| 670 | #endif |
| 671 | Py_CLEAR(user->file); |
| 672 | user->fd = -1; |
| 673 | return 1; |
| 674 | } |
| 675 | |
| 676 | static PyObject* |
| 677 | faulthandler_unregister_py(PyObject *self, PyObject *args) |
| 678 | { |
| 679 | int signum; |
| 680 | user_signal_t *user; |
| 681 | int change; |
| 682 | |
| 683 | if (!PyArg_ParseTuple(args, "i:unregister", &signum)) |
| 684 | return NULL; |
| 685 | |
Victor Stinner | 44378d4 | 2011-04-01 15:37:12 +0200 | [diff] [blame] | 686 | if (!check_signum(signum)) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 687 | return NULL; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 688 | |
| 689 | user = &user_signals[signum]; |
| 690 | change = faulthandler_unregister(user, signum); |
| 691 | return PyBool_FromLong(change); |
| 692 | } |
| 693 | #endif /* FAULTHANDLER_USER */ |
| 694 | |
| 695 | |
| 696 | static PyObject * |
| 697 | faulthandler_read_null(PyObject *self, PyObject *args) |
| 698 | { |
| 699 | int *x = NULL, y; |
| 700 | int release_gil = 0; |
| 701 | if (!PyArg_ParseTuple(args, "|i:_read_null", &release_gil)) |
| 702 | return NULL; |
| 703 | if (release_gil) { |
| 704 | Py_BEGIN_ALLOW_THREADS |
| 705 | y = *x; |
| 706 | Py_END_ALLOW_THREADS |
| 707 | } else |
| 708 | y = *x; |
| 709 | return PyLong_FromLong(y); |
| 710 | |
| 711 | } |
| 712 | |
| 713 | static PyObject * |
| 714 | faulthandler_sigsegv(PyObject *self, PyObject *args) |
| 715 | { |
| 716 | #if defined(MS_WINDOWS) |
Victor Stinner | bc6a4db | 2011-04-01 12:08:57 +0200 | [diff] [blame] | 717 | /* For SIGSEGV, faulthandler_fatal_error() restores the previous signal |
| 718 | handler and then gives back the execution flow to the program (without |
| 719 | calling explicitly the previous error handler). In a normal case, the |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 720 | SIGSEGV was raised by the kernel because of a fault, and so if the |
| 721 | program retries to execute the same instruction, the fault will be |
| 722 | raised again. |
| 723 | |
| 724 | Here the fault is simulated by a fake SIGSEGV signal raised by the |
| 725 | application. We have to raise SIGSEGV at lease twice: once for |
| 726 | faulthandler_fatal_error(), and one more time for the previous signal |
| 727 | handler. */ |
| 728 | while(1) |
| 729 | raise(SIGSEGV); |
| 730 | #else |
| 731 | raise(SIGSEGV); |
| 732 | #endif |
| 733 | Py_RETURN_NONE; |
| 734 | } |
| 735 | |
| 736 | static PyObject * |
| 737 | faulthandler_sigfpe(PyObject *self, PyObject *args) |
| 738 | { |
| 739 | /* Do an integer division by zero: raise a SIGFPE on Intel CPU, but not on |
| 740 | PowerPC. Use volatile to disable compile-time optimizations. */ |
| 741 | volatile int x = 1, y = 0, z; |
| 742 | z = x / y; |
| 743 | /* if the division by zero didn't raise a SIGFPE, raise it manually */ |
| 744 | raise(SIGFPE); |
| 745 | Py_RETURN_NONE; |
| 746 | } |
| 747 | |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 748 | static PyObject * |
| 749 | faulthandler_sigabrt(PyObject *self, PyObject *args) |
| 750 | { |
| 751 | #if _MSC_VER |
| 752 | /* If Python is compiled in debug mode with Visual Studio, abort() opens |
| 753 | a popup asking the user how to handle the assertion. Use raise(SIGABRT) |
| 754 | instead. */ |
| 755 | raise(SIGABRT); |
| 756 | #else |
| 757 | abort(); |
| 758 | #endif |
| 759 | Py_RETURN_NONE; |
| 760 | } |
| 761 | |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 762 | #ifdef SIGBUS |
| 763 | static PyObject * |
| 764 | faulthandler_sigbus(PyObject *self, PyObject *args) |
| 765 | { |
| 766 | raise(SIGBUS); |
| 767 | Py_RETURN_NONE; |
| 768 | } |
| 769 | #endif |
| 770 | |
| 771 | #ifdef SIGILL |
| 772 | static PyObject * |
| 773 | faulthandler_sigill(PyObject *self, PyObject *args) |
| 774 | { |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 775 | raise(SIGILL); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 776 | Py_RETURN_NONE; |
| 777 | } |
| 778 | #endif |
| 779 | |
| 780 | static PyObject * |
| 781 | faulthandler_fatal_error_py(PyObject *self, PyObject *args) |
| 782 | { |
| 783 | char *message; |
| 784 | if (!PyArg_ParseTuple(args, "y:fatal_error", &message)) |
| 785 | return NULL; |
| 786 | Py_FatalError(message); |
| 787 | Py_RETURN_NONE; |
| 788 | } |
| 789 | |
| 790 | #if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION) |
Victor Stinner | f048075 | 2011-03-31 11:34:08 +0200 | [diff] [blame] | 791 | void* |
| 792 | stack_overflow(void *min_sp, void *max_sp, size_t *depth) |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 793 | { |
| 794 | /* allocate 4096 bytes on the stack at each call */ |
| 795 | unsigned char buffer[4096]; |
Victor Stinner | f048075 | 2011-03-31 11:34:08 +0200 | [diff] [blame] | 796 | void *sp = &buffer; |
| 797 | *depth += 1; |
| 798 | if (sp < min_sp || max_sp < sp) |
| 799 | return sp; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 800 | buffer[0] = 1; |
Victor Stinner | f048075 | 2011-03-31 11:34:08 +0200 | [diff] [blame] | 801 | buffer[4095] = 0; |
| 802 | return stack_overflow(min_sp, max_sp, depth); |
| 803 | } |
| 804 | |
| 805 | static PyObject * |
| 806 | faulthandler_stack_overflow(PyObject *self) |
| 807 | { |
| 808 | size_t depth, size; |
| 809 | void *sp = &depth, *stop; |
| 810 | |
| 811 | depth = 0; |
| 812 | stop = stack_overflow(sp - STACK_OVERFLOW_MAX_SIZE, |
| 813 | sp + STACK_OVERFLOW_MAX_SIZE, |
| 814 | &depth); |
| 815 | if (sp < stop) |
| 816 | size = stop - sp; |
| 817 | else |
| 818 | size = sp - stop; |
| 819 | PyErr_Format(PyExc_RuntimeError, |
| 820 | "unable to raise a stack overflow (allocated %zu bytes " |
| 821 | "on the stack, %zu recursive calls)", |
| 822 | size, depth); |
| 823 | return NULL; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 824 | } |
| 825 | #endif |
| 826 | |
| 827 | |
| 828 | static int |
| 829 | faulthandler_traverse(PyObject *module, visitproc visit, void *arg) |
| 830 | { |
| 831 | #ifdef FAULTHANDLER_USER |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 832 | unsigned int signum; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 833 | #endif |
| 834 | |
| 835 | #ifdef FAULTHANDLER_LATER |
| 836 | Py_VISIT(thread.file); |
| 837 | #endif |
| 838 | #ifdef FAULTHANDLER_USER |
| 839 | if (user_signals != NULL) { |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 840 | for (signum=0; signum < NSIG; signum++) |
| 841 | Py_VISIT(user_signals[signum].file); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 842 | } |
| 843 | #endif |
| 844 | Py_VISIT(fatal_error.file); |
| 845 | return 0; |
| 846 | } |
| 847 | |
| 848 | PyDoc_STRVAR(module_doc, |
| 849 | "faulthandler module."); |
| 850 | |
| 851 | static PyMethodDef module_methods[] = { |
| 852 | {"enable", |
| 853 | (PyCFunction)faulthandler_enable, METH_VARARGS|METH_KEYWORDS, |
| 854 | PyDoc_STR("enable(file=sys.stderr, all_threads=False): " |
| 855 | "enable the fault handler")}, |
| 856 | {"disable", (PyCFunction)faulthandler_disable_py, METH_NOARGS, |
| 857 | PyDoc_STR("disable(): disable the fault handler")}, |
| 858 | {"is_enabled", (PyCFunction)faulthandler_is_enabled, METH_NOARGS, |
| 859 | PyDoc_STR("is_enabled()->bool: check if the handler is enabled")}, |
| 860 | {"dump_traceback", |
| 861 | (PyCFunction)faulthandler_dump_traceback_py, METH_VARARGS|METH_KEYWORDS, |
| 862 | PyDoc_STR("dump_traceback(file=sys.stderr, all_threads=False): " |
| 863 | "dump the traceback of the current thread, or of all threads " |
| 864 | "if all_threads is True, into file")}, |
| 865 | #ifdef FAULTHANDLER_LATER |
| 866 | {"dump_tracebacks_later", |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 867 | (PyCFunction)faulthandler_dump_tracebacks_later, METH_VARARGS|METH_KEYWORDS, |
| 868 | PyDoc_STR("dump_tracebacks_later(timeout, repeat=False, file=sys.stderrn, exit=False):\n" |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 869 | "dump the traceback of all threads in timeout seconds,\n" |
Victor Stinner | 9699440 | 2011-04-07 11:37:19 +0200 | [diff] [blame] | 870 | "or each timeout seconds if repeat is True. If exit is True, " |
| 871 | "call _exit(1) which is not safe.")}, |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 872 | {"cancel_dump_tracebacks_later", |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 873 | (PyCFunction)faulthandler_cancel_dump_tracebacks_later_py, METH_NOARGS, |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 874 | PyDoc_STR("cancel_dump_tracebacks_later():\ncancel the previous call " |
| 875 | "to dump_tracebacks_later().")}, |
| 876 | #endif |
| 877 | |
| 878 | #ifdef FAULTHANDLER_USER |
| 879 | {"register", |
| 880 | (PyCFunction)faulthandler_register, METH_VARARGS|METH_KEYWORDS, |
| 881 | PyDoc_STR("register(signum, file=sys.stderr, all_threads=False): " |
| 882 | "register an handler for the signal 'signum': dump the " |
| 883 | "traceback of the current thread, or of all threads if " |
| 884 | "all_threads is True, into file")}, |
| 885 | {"unregister", |
| 886 | faulthandler_unregister_py, METH_VARARGS|METH_KEYWORDS, |
| 887 | PyDoc_STR("unregister(signum): unregister the handler of the signal " |
| 888 | "'signum' registered by register()")}, |
| 889 | #endif |
| 890 | |
| 891 | {"_read_null", faulthandler_read_null, METH_VARARGS, |
| 892 | PyDoc_STR("_read_null(release_gil=False): read from NULL, raise " |
| 893 | "a SIGSEGV or SIGBUS signal depending on the platform")}, |
| 894 | {"_sigsegv", faulthandler_sigsegv, METH_VARARGS, |
| 895 | PyDoc_STR("_sigsegv(): raise a SIGSEGV signal")}, |
Victor Stinner | d727e23 | 2011-04-01 12:13:55 +0200 | [diff] [blame] | 896 | {"_sigabrt", faulthandler_sigabrt, METH_VARARGS, |
| 897 | PyDoc_STR("_sigabrt(): raise a SIGABRT signal")}, |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 898 | {"_sigfpe", (PyCFunction)faulthandler_sigfpe, METH_NOARGS, |
| 899 | PyDoc_STR("_sigfpe(): raise a SIGFPE signal")}, |
| 900 | #ifdef SIGBUS |
| 901 | {"_sigbus", (PyCFunction)faulthandler_sigbus, METH_NOARGS, |
| 902 | PyDoc_STR("_sigbus(): raise a SIGBUS signal")}, |
| 903 | #endif |
| 904 | #ifdef SIGILL |
| 905 | {"_sigill", (PyCFunction)faulthandler_sigill, METH_NOARGS, |
| 906 | PyDoc_STR("_sigill(): raise a SIGILL signal")}, |
| 907 | #endif |
| 908 | {"_fatal_error", faulthandler_fatal_error_py, METH_VARARGS, |
| 909 | PyDoc_STR("_fatal_error(message): call Py_FatalError(message)")}, |
| 910 | #if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION) |
| 911 | {"_stack_overflow", (PyCFunction)faulthandler_stack_overflow, METH_NOARGS, |
| 912 | PyDoc_STR("_stack_overflow(): recursive call to raise a stack overflow")}, |
| 913 | #endif |
| 914 | {NULL, NULL} /* terminator */ |
| 915 | }; |
| 916 | |
| 917 | static struct PyModuleDef module_def = { |
| 918 | PyModuleDef_HEAD_INIT, |
| 919 | "faulthandler", |
| 920 | module_doc, |
| 921 | 0, /* non negative size to be able to unload the module */ |
| 922 | module_methods, |
| 923 | NULL, |
| 924 | faulthandler_traverse, |
| 925 | NULL, |
| 926 | NULL |
| 927 | }; |
| 928 | |
| 929 | PyMODINIT_FUNC |
| 930 | PyInit_faulthandler(void) |
| 931 | { |
| 932 | return PyModule_Create(&module_def); |
| 933 | } |
| 934 | |
| 935 | /* Call faulthandler.enable() if PYTHONFAULTHANDLER environment variable is |
| 936 | defined, or if sys._xoptions has a 'faulthandler' key. */ |
| 937 | |
| 938 | static int |
| 939 | faulthandler_env_options(void) |
| 940 | { |
| 941 | PyObject *xoptions, *key, *module, *res; |
| 942 | int enable; |
| 943 | |
| 944 | if (!Py_GETENV("PYTHONFAULTHANDLER")) { |
| 945 | xoptions = PySys_GetXOptions(); |
| 946 | if (xoptions == NULL) |
| 947 | return -1; |
| 948 | |
| 949 | key = PyUnicode_FromString("faulthandler"); |
| 950 | if (key == NULL) |
| 951 | return -1; |
| 952 | |
| 953 | enable = PyDict_Contains(xoptions, key); |
| 954 | Py_DECREF(key); |
| 955 | if (!enable) |
| 956 | return 0; |
| 957 | } |
| 958 | else |
| 959 | enable = 1; |
| 960 | |
| 961 | module = PyImport_ImportModule("faulthandler"); |
| 962 | if (module == NULL) { |
| 963 | return -1; |
| 964 | } |
| 965 | res = PyObject_CallMethod(module, "enable", ""); |
| 966 | Py_DECREF(module); |
| 967 | if (res == NULL) |
| 968 | return -1; |
| 969 | Py_DECREF(res); |
| 970 | return 0; |
| 971 | } |
| 972 | |
| 973 | int _PyFaulthandler_Init(void) |
| 974 | { |
| 975 | #ifdef HAVE_SIGALTSTACK |
| 976 | int err; |
| 977 | |
| 978 | /* Try to allocate an alternate stack for faulthandler() signal handler to |
| 979 | * be able to allocate memory on the stack, even on a stack overflow. If it |
| 980 | * fails, ignore the error. */ |
| 981 | stack.ss_flags = 0; |
| 982 | stack.ss_size = SIGSTKSZ; |
| 983 | stack.ss_sp = PyMem_Malloc(stack.ss_size); |
| 984 | if (stack.ss_sp != NULL) { |
| 985 | err = sigaltstack(&stack, NULL); |
| 986 | if (err) { |
| 987 | PyMem_Free(stack.ss_sp); |
| 988 | stack.ss_sp = NULL; |
| 989 | } |
| 990 | } |
| 991 | #endif |
| 992 | #ifdef FAULTHANDLER_LATER |
| 993 | thread.running = 0; |
| 994 | thread.file = NULL; |
| 995 | thread.cancel_event = PyThread_allocate_lock(); |
| 996 | thread.join_event = PyThread_allocate_lock(); |
| 997 | if (!thread.cancel_event || !thread.join_event) { |
| 998 | PyErr_SetString(PyExc_RuntimeError, |
| 999 | "could not allocate locks for faulthandler"); |
| 1000 | return -1; |
| 1001 | } |
| 1002 | #endif |
| 1003 | |
| 1004 | return faulthandler_env_options(); |
| 1005 | } |
| 1006 | |
| 1007 | void _PyFaulthandler_Fini(void) |
| 1008 | { |
| 1009 | #ifdef FAULTHANDLER_USER |
Victor Stinner | a01ca12 | 2011-04-01 12:56:17 +0200 | [diff] [blame] | 1010 | unsigned int signum; |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 1011 | #endif |
| 1012 | |
| 1013 | #ifdef FAULTHANDLER_LATER |
| 1014 | /* later */ |
Victor Stinner | 702624e | 2011-03-31 03:42:34 +0200 | [diff] [blame] | 1015 | faulthandler_cancel_dump_tracebacks_later(); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 1016 | if (thread.cancel_event) { |
| 1017 | PyThread_free_lock(thread.cancel_event); |
| 1018 | thread.cancel_event = NULL; |
| 1019 | } |
| 1020 | if (thread.join_event) { |
| 1021 | PyThread_free_lock(thread.join_event); |
| 1022 | thread.join_event = NULL; |
| 1023 | } |
| 1024 | #endif |
| 1025 | |
| 1026 | #ifdef FAULTHANDLER_USER |
| 1027 | /* user */ |
| 1028 | if (user_signals != NULL) { |
Victor Stinner | a01ca12 | 2011-04-01 12:56:17 +0200 | [diff] [blame] | 1029 | for (signum=0; signum < NSIG; signum++) |
| 1030 | faulthandler_unregister(&user_signals[signum], signum); |
Victor Stinner | 024e37a | 2011-03-31 01:31:06 +0200 | [diff] [blame] | 1031 | free(user_signals); |
| 1032 | user_signals = NULL; |
| 1033 | } |
| 1034 | #endif |
| 1035 | |
| 1036 | /* fatal */ |
| 1037 | faulthandler_disable(); |
| 1038 | #ifdef HAVE_SIGALTSTACK |
| 1039 | if (stack.ss_sp != NULL) { |
| 1040 | PyMem_Free(stack.ss_sp); |
| 1041 | stack.ss_sp = NULL; |
| 1042 | } |
| 1043 | #endif |
| 1044 | } |