| /* Copyright (C) 1991-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <libc-lock.h> |
| #include <signal.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <sigsetops.h> |
| |
| /* Try to get a machine dependent instruction which will make the |
| program crash. This is used in case everything else fails. */ |
| #include <abort-instr.h> |
| #ifndef ABORT_INSTRUCTION |
| /* No such instruction is available. */ |
| # define ABORT_INSTRUCTION |
| #endif |
| |
| /* Exported variable to locate abort message in core files etc. */ |
| struct abort_msg_s *__abort_msg __attribute__ ((nocommon)); |
| libc_hidden_def (__abort_msg) |
| |
| /* We must avoid to run in circles. Therefore we remember how far we |
| already got. */ |
| static int stage; |
| |
| /* We should be prepared for multiple threads trying to run abort. */ |
| __libc_lock_define_initialized_recursive (static, lock); |
| |
| |
| /* Cause an abnormal program termination with core-dump. */ |
| void |
| abort (void) |
| { |
| struct sigaction act; |
| sigset_t sigs; |
| |
| /* First acquire the lock. */ |
| __libc_lock_lock_recursive (lock); |
| |
| /* Now it's for sure we are alone. But recursive calls are possible. */ |
| |
| /* Unblock SIGABRT. */ |
| if (stage == 0) |
| { |
| ++stage; |
| __sigemptyset (&sigs); |
| __sigaddset (&sigs, SIGABRT); |
| __sigprocmask (SIG_UNBLOCK, &sigs, 0); |
| } |
| |
| /* Send signal which possibly calls a user handler. */ |
| if (stage == 1) |
| { |
| /* This stage is special: we must allow repeated calls of |
| `abort' when a user defined handler for SIGABRT is installed. |
| This is risky since the `raise' implementation might also |
| fail but I don't see another possibility. */ |
| int save_stage = stage; |
| |
| stage = 0; |
| __libc_lock_unlock_recursive (lock); |
| |
| raise (SIGABRT); |
| |
| __libc_lock_lock_recursive (lock); |
| stage = save_stage + 1; |
| } |
| |
| /* There was a handler installed. Now remove it. */ |
| if (stage == 2) |
| { |
| ++stage; |
| memset (&act, '\0', sizeof (struct sigaction)); |
| act.sa_handler = SIG_DFL; |
| __sigfillset (&act.sa_mask); |
| act.sa_flags = 0; |
| __sigaction (SIGABRT, &act, NULL); |
| } |
| |
| /* Try again. */ |
| if (stage == 3) |
| { |
| ++stage; |
| raise (SIGABRT); |
| } |
| |
| /* Now try to abort using the system specific command. */ |
| if (stage == 4) |
| { |
| ++stage; |
| ABORT_INSTRUCTION; |
| } |
| |
| /* If we can't signal ourselves and the abort instruction failed, exit. */ |
| if (stage == 5) |
| { |
| ++stage; |
| _exit (127); |
| } |
| |
| /* If even this fails try to use the provided instruction to crash |
| or otherwise make sure we never return. */ |
| while (1) |
| /* Try for ever and ever. */ |
| ABORT_INSTRUCTION; |
| } |
| libc_hidden_def (abort) |