libc/stdlib/abort.c

   1 /* Copyright (C) 1991 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Hacked up for uClibc by Erik Andersen */
  19
  20 #include <features.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <signal.h>
  26 #include <errno.h>
  27
  28
  29
  30 /* Defeat compiler optimization which assumes function addresses are never NULL */
  31 static __always_inline int not_null_ptr(const void *p)
  32 {
  33         const void *q;
  34         __asm__ (""
  35                 : "=r" (q) /* output */
  36                 : "0" (p) /* input */
  37         );
  38         return q != 0;
  39 }
  40
  41 /* Our last ditch effort to commit suicide */
  42 #ifdef __UCLIBC_ABORT_INSTRUCTION__
  43 # define ABORT_INSTRUCTION __asm__(__UCLIBC_ABORT_INSTRUCTION__)
  44 #else
  45 # define ABORT_INSTRUCTION
  46 # warning "no abort instruction defined for your arch"
  47 #endif
  48
  49 static smallint been_there_done_that = 0;
  50
  51 /* Be prepared in case multiple threads try to abort() */
  52 #include <bits/uClibc_mutex.h>
  53 __UCLIBC_MUTEX_STATIC(mylock, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP);
  54
  55 /* Cause an abnormal program termination with core-dump */
  56 void abort(void)
  57 {
  58         sigset_t sigs;
  59
  60         /* Make sure we acquire the lock before proceeding */
  61         __UCLIBC_MUTEX_LOCK_CANCEL_UNSAFE(mylock);
  62
  63         /* Unmask SIGABRT to be sure we can get it */
  64         __sigemptyset(&sigs);
  65         __sigaddset(&sigs, SIGABRT);
  66         sigprocmask(SIG_UNBLOCK, &sigs, NULL);
  67
  68         while (1) {
  69                 /* Try to suicide with a SIGABRT */
  70                 if (been_there_done_that == 0) {
  71                         been_there_done_that++;
  72
  73 #ifdef __UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT__
  74                         /* If we are using stdio, try to shut it down.  At the very least,
  75                          * this will attempt to commit all buffered writes.  It may also
  76                          * unbuffer all writable files, or close them outright.
  77                          * Check the stdio routines for details. */
  78                         if (not_null_ptr(_stdio_term)) {
  79                                 _stdio_term();
  80                         }
  81 #endif
  82
  83 abort_it:
  84                         __UCLIBC_MUTEX_UNLOCK_CANCEL_UNSAFE(mylock);
  85                         raise(SIGABRT);
  86                         __UCLIBC_MUTEX_LOCK_CANCEL_UNSAFE(mylock);
  87                 }
  88
  89                 /* Still here?  Try to remove any signal handlers */
  90                 if (been_there_done_that == 1) {
  91                         struct sigaction act;
  92
  93                         been_there_done_that++;
  94                         memset(&act, '\0', sizeof(struct sigaction));
  95                         if (SIG_DFL) /* if it's constant zero, already done */
  96                                 act.sa_handler = SIG_DFL;
  97                         __sigfillset(&act.sa_mask);
  98                         sigaction(SIGABRT, &act, NULL);
  99
 100                         goto abort_it;
 101                 }
 102
 103                 /* Still here?  Try to suicide with an illegal instruction */
 104                 if (been_there_done_that == 2) {
 105                         been_there_done_that++;
 106                         ABORT_INSTRUCTION;
 107                 }
 108
 109                 /* Still here?  Try to at least exit */
 110                 if (been_there_done_that == 3) {
 111                         been_there_done_that++;
 112                         _exit(127);
 113                 }
 114
 115                 /* Still here?  We're screwed.  Sleepy time.  Good night. */
 116                 while (1)
 117                         /* Try for ever and ever */
 118                         ABORT_INSTRUCTION;
 119         }
 120 }
 121 libc_hidden_def(abort)