105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Emergency actions in case of a fatal signal. 205436638acc7c010349a69c3395f1a57c642dc62Ying Wang Copyright (C) 2003-2004, 2006-2012 Free Software Foundation, Inc. 305436638acc7c010349a69c3395f1a57c642dc62Ying Wang Written by Bruno Haible <bruno@clisp.org>, 2003. 405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 505436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is free software: you can redistribute it and/or modify 605436638acc7c010349a69c3395f1a57c642dc62Ying Wang it under the terms of the GNU General Public License as published by 705436638acc7c010349a69c3395f1a57c642dc62Ying Wang the Free Software Foundation; either version 3 of the License, or 805436638acc7c010349a69c3395f1a57c642dc62Ying Wang (at your option) any later version. 905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1005436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is distributed in the hope that it will be useful, 1105436638acc7c010349a69c3395f1a57c642dc62Ying Wang but WITHOUT ANY WARRANTY; without even the implied warranty of 1205436638acc7c010349a69c3395f1a57c642dc62Ying Wang MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1305436638acc7c010349a69c3395f1a57c642dc62Ying Wang GNU General Public License for more details. 1405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1505436638acc7c010349a69c3395f1a57c642dc62Ying Wang You should have received a copy of the GNU General Public License 1605436638acc7c010349a69c3395f1a57c642dc62Ying Wang along with this program. If not, see <http://www.gnu.org/licenses/>. */ 1705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1905436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <config.h> 2005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Specification. */ 2205436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "fatal-signal.h" 2305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2405436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <stdbool.h> 2505436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <stdlib.h> 2605436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <signal.h> 2705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <unistd.h> 2805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2905436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "sig-handler.h" 3005436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "xalloc.h" 3105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3205436638acc7c010349a69c3395f1a57c642dc62Ying Wang#define SIZEOF(a) (sizeof(a) / sizeof(a[0])) 3305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3405436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* ========================================================================= */ 3505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3705436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* The list of fatal signals. 3805436638acc7c010349a69c3395f1a57c642dc62Ying Wang These are those signals whose default action is to terminate the process 3905436638acc7c010349a69c3395f1a57c642dc62Ying Wang without a core dump, except 4005436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGKILL - because it cannot be caught, 4105436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGALRM SIGUSR1 SIGUSR2 SIGPOLL SIGIO SIGLOST - because applications 4205436638acc7c010349a69c3395f1a57c642dc62Ying Wang often use them for their own purpose, 4305436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGPROF SIGVTALRM - because they are used for profiling, 4405436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGSTKFLT - because it is more similar to SIGFPE, SIGSEGV, SIGBUS, 4505436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGSYS - because it is more similar to SIGABRT, SIGSEGV, 4605436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGPWR - because it of too special use, 4705436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGRTMIN...SIGRTMAX - because they are reserved for application use. 4805436638acc7c010349a69c3395f1a57c642dc62Ying Wang plus 4905436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGXCPU, SIGXFSZ - because they are quite similar to SIGTERM. */ 5005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 5105436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic int fatal_signals[] = 5205436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 5305436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* ISO C 99 signals. */ 5405436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGINT 5505436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGINT, 5605436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 5705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGTERM 5805436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGTERM, 5905436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 6005436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* POSIX:2001 signals. */ 6105436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGHUP 6205436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGHUP, 6305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 6405436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGPIPE 6505436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGPIPE, 6605436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 6705436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* BSD signals. */ 6805436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGXCPU 6905436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGXCPU, 7005436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 7105436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGXFSZ 7205436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGXFSZ, 7305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 7405436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Native Windows signals. */ 7505436638acc7c010349a69c3395f1a57c642dc62Ying Wang#ifdef SIGBREAK 7605436638acc7c010349a69c3395f1a57c642dc62Ying Wang SIGBREAK, 7705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 7805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 0 7905436638acc7c010349a69c3395f1a57c642dc62Ying Wang }; 8005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 8105436638acc7c010349a69c3395f1a57c642dc62Ying Wang#define num_fatal_signals (SIZEOF (fatal_signals) - 1) 8205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 8305436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Eliminate signals whose signal handler is SIG_IGN. */ 8405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 8505436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void 8605436638acc7c010349a69c3395f1a57c642dc62Ying Wanginit_fatal_signals (void) 8705436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 8805436638acc7c010349a69c3395f1a57c642dc62Ying Wang static bool fatal_signals_initialized = false; 8905436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (!fatal_signals_initialized) 9005436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 9105436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t i; 9205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 9305436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (i = 0; i < num_fatal_signals; i++) 9405436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 9505436638acc7c010349a69c3395f1a57c642dc62Ying Wang struct sigaction action; 9605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 9705436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (sigaction (fatal_signals[i], NULL, &action) >= 0 9805436638acc7c010349a69c3395f1a57c642dc62Ying Wang && get_handler (&action) == SIG_IGN) 9905436638acc7c010349a69c3395f1a57c642dc62Ying Wang fatal_signals[i] = -1; 10005436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 10105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 10205436638acc7c010349a69c3395f1a57c642dc62Ying Wang fatal_signals_initialized = true; 10305436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 10405436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 10505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 10605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 10705436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* ========================================================================= */ 10805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 10905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 11005436638acc7c010349a69c3395f1a57c642dc62Ying Wangtypedef void (*action_t) (void); 11105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 11205436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Type of an entry in the actions array. 11305436638acc7c010349a69c3395f1a57c642dc62Ying Wang The 'action' field is accessed from within the fatal_signal_handler(), 11405436638acc7c010349a69c3395f1a57c642dc62Ying Wang therefore we mark it as 'volatile'. */ 11505436638acc7c010349a69c3395f1a57c642dc62Ying Wangtypedef struct 11605436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 11705436638acc7c010349a69c3395f1a57c642dc62Ying Wang volatile action_t action; 11805436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 11905436638acc7c010349a69c3395f1a57c642dc62Ying Wangactions_entry_t; 12005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 12105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* The registered cleanup actions. */ 12205436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic actions_entry_t static_actions[32]; 12305436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic actions_entry_t * volatile actions = static_actions; 12405436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic sig_atomic_t volatile actions_count = 0; 12505436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic size_t actions_allocated = SIZEOF (static_actions); 12605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 12705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 12805436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* The saved signal handlers. 12905436638acc7c010349a69c3395f1a57c642dc62Ying Wang Size 32 would not be sufficient: On HP-UX, SIGXCPU = 33, SIGXFSZ = 34. */ 13005436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic struct sigaction saved_sigactions[64]; 13105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 13205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 13305436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Uninstall the handlers. */ 13405436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void 13505436638acc7c010349a69c3395f1a57c642dc62Ying Wanguninstall_handlers (void) 13605436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 13705436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t i; 13805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 13905436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (i = 0; i < num_fatal_signals; i++) 14005436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fatal_signals[i] >= 0) 14105436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 14205436638acc7c010349a69c3395f1a57c642dc62Ying Wang int sig = fatal_signals[i]; 14305436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (saved_sigactions[sig].sa_handler == SIG_IGN) 14405436638acc7c010349a69c3395f1a57c642dc62Ying Wang saved_sigactions[sig].sa_handler = SIG_DFL; 14505436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigaction (sig, &saved_sigactions[sig], NULL); 14605436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 14705436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 14805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 14905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 15005436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* The signal handler. It gets called asynchronously. */ 15105436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void 15205436638acc7c010349a69c3395f1a57c642dc62Ying Wangfatal_signal_handler (int sig) 15305436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 15405436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (;;) 15505436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 15605436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Get the last registered cleanup action, in a reentrant way. */ 15705436638acc7c010349a69c3395f1a57c642dc62Ying Wang action_t action; 15805436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t n = actions_count; 15905436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (n == 0) 16005436638acc7c010349a69c3395f1a57c642dc62Ying Wang break; 16105436638acc7c010349a69c3395f1a57c642dc62Ying Wang n--; 16205436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions_count = n; 16305436638acc7c010349a69c3395f1a57c642dc62Ying Wang action = actions[n].action; 16405436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Execute the action. */ 16505436638acc7c010349a69c3395f1a57c642dc62Ying Wang action (); 16605436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 16705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 16805436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Now execute the signal's default action. 16905436638acc7c010349a69c3395f1a57c642dc62Ying Wang If the signal being delivered was blocked, the re-raised signal would be 17005436638acc7c010349a69c3395f1a57c642dc62Ying Wang delivered when this handler returns. But the way we install this handler, 17105436638acc7c010349a69c3395f1a57c642dc62Ying Wang no signal is blocked, and the re-raised signal is delivered already 17205436638acc7c010349a69c3395f1a57c642dc62Ying Wang during raise(). */ 17305436638acc7c010349a69c3395f1a57c642dc62Ying Wang uninstall_handlers (); 17405436638acc7c010349a69c3395f1a57c642dc62Ying Wang raise (sig); 17505436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 17605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 17705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 17805436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Install the handlers. */ 17905436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void 18005436638acc7c010349a69c3395f1a57c642dc62Ying Wanginstall_handlers (void) 18105436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 18205436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t i; 18305436638acc7c010349a69c3395f1a57c642dc62Ying Wang struct sigaction action; 18405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 18505436638acc7c010349a69c3395f1a57c642dc62Ying Wang action.sa_handler = &fatal_signal_handler; 18605436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* If we get a fatal signal while executing fatal_signal_handler, enter 18705436638acc7c010349a69c3395f1a57c642dc62Ying Wang fatal_signal_handler recursively, since it is reentrant. Hence no 18805436638acc7c010349a69c3395f1a57c642dc62Ying Wang SA_RESETHAND. */ 18905436638acc7c010349a69c3395f1a57c642dc62Ying Wang action.sa_flags = SA_NODEFER; 19005436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigemptyset (&action.sa_mask); 19105436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (i = 0; i < num_fatal_signals; i++) 19205436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fatal_signals[i] >= 0) 19305436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 19405436638acc7c010349a69c3395f1a57c642dc62Ying Wang int sig = fatal_signals[i]; 19505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 19605436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (!(sig < sizeof (saved_sigactions) / sizeof (saved_sigactions[0]))) 19705436638acc7c010349a69c3395f1a57c642dc62Ying Wang abort (); 19805436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigaction (sig, &action, &saved_sigactions[sig]); 19905436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 20005436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 20105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 20205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 20305436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Register a cleanup function to be executed when a catchable fatal signal 20405436638acc7c010349a69c3395f1a57c642dc62Ying Wang occurs. */ 20505436638acc7c010349a69c3395f1a57c642dc62Ying Wangvoid 20605436638acc7c010349a69c3395f1a57c642dc62Ying Wangat_fatal_signal (action_t action) 20705436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 20805436638acc7c010349a69c3395f1a57c642dc62Ying Wang static bool cleanup_initialized = false; 20905436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (!cleanup_initialized) 21005436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 21105436638acc7c010349a69c3395f1a57c642dc62Ying Wang init_fatal_signals (); 21205436638acc7c010349a69c3395f1a57c642dc62Ying Wang install_handlers (); 21305436638acc7c010349a69c3395f1a57c642dc62Ying Wang cleanup_initialized = true; 21405436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 21505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 21605436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (actions_count == actions_allocated) 21705436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 21805436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Extend the actions array. Note that we cannot use xrealloc(), 21905436638acc7c010349a69c3395f1a57c642dc62Ying Wang because then the cleanup() function could access an already 22005436638acc7c010349a69c3395f1a57c642dc62Ying Wang deallocated array. */ 22105436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions_entry_t *old_actions = actions; 22205436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t old_actions_allocated = actions_allocated; 22305436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t new_actions_allocated = 2 * actions_allocated; 22405436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions_entry_t *new_actions = 22505436638acc7c010349a69c3395f1a57c642dc62Ying Wang XNMALLOC (new_actions_allocated, actions_entry_t); 22605436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t k; 22705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 22805436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Don't use memcpy() here, because memcpy takes non-volatile arguments 22905436638acc7c010349a69c3395f1a57c642dc62Ying Wang and is therefore not guaranteed to complete all memory stores before 23005436638acc7c010349a69c3395f1a57c642dc62Ying Wang the next statement. */ 23105436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (k = 0; k < old_actions_allocated; k++) 23205436638acc7c010349a69c3395f1a57c642dc62Ying Wang new_actions[k] = old_actions[k]; 23305436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions = new_actions; 23405436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions_allocated = new_actions_allocated; 23505436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* Now we can free the old actions array. */ 23605436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (old_actions != static_actions) 23705436638acc7c010349a69c3395f1a57c642dc62Ying Wang free (old_actions); 23805436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 23905436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* The two uses of 'volatile' in the types above (and ISO C 99 section 24005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 5.1.2.3.(5)) ensure that we increment the actions_count only after 24105436638acc7c010349a69c3395f1a57c642dc62Ying Wang the new action has been written to the memory location 24205436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions[actions_count]. */ 24305436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions[actions_count].action = action; 24405436638acc7c010349a69c3395f1a57c642dc62Ying Wang actions_count++; 24505436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 24605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 24705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 24805436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* ========================================================================= */ 24905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 25005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 25105436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic sigset_t fatal_signal_set; 25205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 25305436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void 25405436638acc7c010349a69c3395f1a57c642dc62Ying Wanginit_fatal_signal_set (void) 25505436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 25605436638acc7c010349a69c3395f1a57c642dc62Ying Wang static bool fatal_signal_set_initialized = false; 25705436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (!fatal_signal_set_initialized) 25805436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 25905436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t i; 26005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 26105436638acc7c010349a69c3395f1a57c642dc62Ying Wang init_fatal_signals (); 26205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 26305436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigemptyset (&fatal_signal_set); 26405436638acc7c010349a69c3395f1a57c642dc62Ying Wang for (i = 0; i < num_fatal_signals; i++) 26505436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fatal_signals[i] >= 0) 26605436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigaddset (&fatal_signal_set, fatal_signals[i]); 26705436638acc7c010349a69c3395f1a57c642dc62Ying Wang 26805436638acc7c010349a69c3395f1a57c642dc62Ying Wang fatal_signal_set_initialized = true; 26905436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 27005436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 27105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 27205436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Temporarily delay the catchable fatal signals. */ 27305436638acc7c010349a69c3395f1a57c642dc62Ying Wangvoid 27405436638acc7c010349a69c3395f1a57c642dc62Ying Wangblock_fatal_signals (void) 27505436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 27605436638acc7c010349a69c3395f1a57c642dc62Ying Wang init_fatal_signal_set (); 27705436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL); 27805436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 27905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 28005436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Stop delaying the catchable fatal signals. */ 28105436638acc7c010349a69c3395f1a57c642dc62Ying Wangvoid 28205436638acc7c010349a69c3395f1a57c642dc62Ying Wangunblock_fatal_signals (void) 28305436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 28405436638acc7c010349a69c3395f1a57c642dc62Ying Wang init_fatal_signal_set (); 28505436638acc7c010349a69c3395f1a57c642dc62Ying Wang sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL); 28605436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 287