sysdeps/posix/libc_fatal.c

   1 /* Copyright (C) 1993,1994,1995,1997,2000,2004 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <paths.h>
  22 #include <stdarg.h>
  23 #include <stdbool.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sysdep.h>
  28 #include <unistd.h>
  29 #include <sys/syslog.h>
  30 #include <sys/uio.h>
  31 #include <not-cancel.h>
  32
  33 #ifdef FATAL_PREPARE_INCLUDE
  34 #include FATAL_PREPARE_INCLUDE
  35 #endif
  36
  37 struct str_list
  38 {
  39   const char *str;
  40   size_t len;
  41   struct str_list *next;
  42 };
  43
  44
  45 /* Abort with an error message.  */
  46 void
  47 __libc_message (int do_abort, const char *fmt, ...)
  48 {
  49   va_list ap;
  50   va_list ap_copy;
  51   int fd = -1;
  52
  53   va_start (ap, fmt);
  54   va_copy (ap_copy, ap);
  55
  56 #ifdef FATAL_PREPARE
  57   FATAL_PREPARE;
  58 #endif
  59
  60   /* Open a descriptor for /dev/tty unless the user explicitly
  61      requests errors on standard error.  */
  62   const char *on_2 = __secure_getenv ("LIBC_FATAL_STDERR_");
  63   if (on_2 == NULL || *on_2 == '\0')
  64     fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY);
  65
  66   if (fd == -1)
  67     fd = STDERR_FILENO;
  68
  69   struct str_list *list = NULL;
  70   int nlist = 0;
  71
  72   const char *cp = fmt;
  73   while (*cp != '\0')
  74     {
  75       /* Find the next "%s" or the end of the string.  */
  76       char *next = cp;
  77       while (next[0] != '%' || next[1] != 's')
  78         {
  79           next = __strchrnul (next + 1, '%');
  80
  81           if (next[0] == '\0')
  82             break;
  83         }
  84
  85       /* Determine what to print.  */
  86       const char *str;
  87       size_t len;
  88       if (cp[0] == '%' && cp[1] == 's')
  89         {
  90           str = va_arg (ap, const char *);
  91           len = strlen (str);
  92           cp += 2;
  93         }
  94       else
  95         {
  96           str = cp;
  97           len = next - cp;
  98           cp = next;
  99         }
 100
 101       struct str_list *newp = alloca (sizeof (struct str_list));
 102       newp->str = str;
 103       newp->len = len;
 104       newp->next = list;
 105       list = newp;
 106       ++nlist;
 107     }
 108
 109   bool written = false;
 110   if (nlist > 0)
 111     {
 112       struct iovec *iov = alloca (nlist * sizeof (struct iovec));
 113       ssize_t total = 0;
 114
 115       for (int cnt = nlist - 1; cnt >= 0; --cnt)
 116         {
 117           iov[cnt].iov_base = list->str;
 118           iov[cnt].iov_len = list->len;
 119           total += list->len;
 120           list = list->next;
 121         }
 122
 123       if (TEMP_FAILURE_RETRY (__writev (fd, iov, nlist)) == total)
 124         written = true;
 125     }
 126
 127   va_end (ap);
 128
 129   /* If we  had no success writing the message, use syslog.  */
 130   if (! written)
 131     vsyslog (LOG_ERR, fmt, ap_copy);
 132
 133   va_end (ap_copy);
 134
 135   if (do_abort)
 136     /* Kill the application.  */
 137     abort ();
 138 }
 139
 140
 141 void
 142 __libc_fatal (message)
 143      const char *message;
 144 {
 145   /* The loop is added only to keep gcc happy.  */
 146   while (1)
 147     __libc_message (1, "%s", message);
 148 }
 149 libc_hidden_def (__libc_fatal)