sysdeps/generic/elf/backtracesymsfd.c

   1 /* Write formatted list with names for addresses in backtrace to a file.
   2    Copyright (C) 1998,2000,2003,2005,2009 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <execinfo.h>
  22 #include <string.h>
  23 #include <sys/uio.h>
  24
  25 #include <stdio-common/_itoa.h>
  26 #include <ldsodefs.h>
  27
  28 #if __ELF_NATIVE_CLASS == 32
  29 # define WORD_WIDTH 8
  30 #else
  31 /* We assyme 64bits.  */
  32 # define WORD_WIDTH 16
  33 #endif
  34
  35
  36 void
  37 __backtrace_symbols_fd (array, size, fd)
  38      void *const *array;
  39      int size;
  40      int fd;
  41 {
  42   struct iovec iov[9];
  43   int cnt;
  44
  45   for (cnt = 0; cnt < size; ++cnt)
  46     {
  47       char buf[WORD_WIDTH];
  48       Dl_info info;
  49       struct link_map *map;
  50       size_t last = 0;
  51
  52       if (_dl_addr (array[cnt], &info, &map, NULL)
  53           && info.dli_fname != NULL && info.dli_fname[0] != '\0')
  54         {
  55           /* Name of the file.  */
  56           iov[0].iov_base = (void *) info.dli_fname;
  57           iov[0].iov_len = strlen (info.dli_fname);
  58           last = 1;
  59
  60           if (info.dli_sname != NULL || map->l_addr != 0)
  61             {
  62               char buf2[WORD_WIDTH];
  63               size_t diff;
  64
  65               iov[last].iov_base = (void *) "(";
  66               iov[last].iov_len = 1;
  67               ++last;
  68
  69               if (info.dli_sname != NULL)
  70                 {
  71                   /* We have a symbol name.  */
  72                   iov[last].iov_base = (void *) info.dli_sname;
  73                   iov[last].iov_len = strlen (info.dli_sname);
  74                   ++last;
  75                 }
  76               else
  77                 /* We have no symbol, so describe it as relative to the file.
  78                    The load bias is more useful to the user than the load
  79                    address.  The use of these addresses is to calculate an
  80                    address in the ELF file, so its prelinked bias is not
  81                    something we want to subtract out.  */
  82                 info.dli_saddr = (void *) map->l_addr;
  83
  84               if (array[cnt] >= (void *) info.dli_saddr)
  85                 {
  86                   iov[last].iov_base = (void *) "+0x";
  87                   diff = array[cnt] - info.dli_saddr;
  88                 }
  89               else
  90                 {
  91                   iov[last].iov_base = (void *) "-0x";
  92                   diff = info.dli_saddr - array[cnt];
  93                 }
  94               iov[last].iov_len = 3;
  95               ++last;
  96
  97               iov[last].iov_base = _itoa_word ((unsigned long int) diff,
  98                                                &buf2[WORD_WIDTH], 16, 0);
  99               iov[last].iov_len = (&buf2[WORD_WIDTH]
 100                                    - (char *) iov[last].iov_base);
 101               ++last;
 102
 103               iov[last].iov_base = (void *) ")";
 104               iov[last].iov_len = 1;
 105               ++last;
 106             }
 107         }
 108
 109       iov[last].iov_base = (void *) "[0x";
 110       iov[last].iov_len = 3;
 111       ++last;
 112
 113       iov[last].iov_base = _itoa_word ((unsigned long int) array[cnt],
 114                                        &buf[WORD_WIDTH], 16, 0);
 115       iov[last].iov_len = &buf[WORD_WIDTH] - (char *) iov[last].iov_base;
 116       ++last;
 117
 118       iov[last].iov_base = (void *) "]\n";
 119       iov[last].iov_len = 2;
 120       ++last;
 121
 122       __writev (fd, iov, last);
 123     }
 124 }
 125 weak_alias (__backtrace_symbols_fd, backtrace_symbols_fd)
 126 libc_hidden_def (__backtrace_symbols_fd)