sysdeps/arm/eabi/find_exidx.c

   1 /* Copyright (C) 2005 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 <link.h>
  20 #include <unwind.h>
  21
  22 struct unw_eh_callback_data
  23 {
  24   _Unwind_Ptr pc;
  25   _Unwind_Ptr exidx_start;
  26   int exidx_len;
  27 };
  28
  29
  30 /* Callback to determins if the PC lies within an object, and remember the
  31    location of the exception index table if it does.  */
  32
  33 static int
  34 find_exidx_callback (struct dl_phdr_info * info, size_t size, void * ptr)
  35 {
  36   struct unw_eh_callback_data * data;
  37   const ElfW(Phdr) *phdr;
  38   int i;
  39   int match;
  40   _Unwind_Ptr load_base;
  41
  42   data = (struct unw_eh_callback_data *) ptr;
  43   load_base = info->dlpi_addr;
  44   phdr = info->dlpi_phdr;
  45
  46   match = 0;
  47   for (i = info->dlpi_phnum; i > 0; i--, phdr++)
  48     {
  49       if (phdr->p_type == PT_LOAD)
  50         {
  51           _Unwind_Ptr vaddr = phdr->p_vaddr + load_base;
  52           if (data->pc >= vaddr && data->pc < vaddr + phdr->p_memsz)
  53             match = 1;
  54         }
  55       else if (phdr->p_type == PT_ARM_EXIDX)
  56         {
  57           data->exidx_start = (_Unwind_Ptr) (phdr->p_vaddr + load_base);
  58           data->exidx_len = phdr->p_memsz;
  59         }
  60     }
  61
  62   return match;
  63 }
  64
  65
  66 /* Find the exception index table containing PC.  */
  67
  68 _Unwind_Ptr
  69 __gnu_Unwind_Find_exidx (_Unwind_Ptr pc, int * pcount)
  70 {
  71   struct unw_eh_callback_data data;
  72
  73   data.pc = pc;
  74   data.exidx_start = 0;
  75   if (dl_iterate_phdr (find_exidx_callback, &data) <= 0)
  76     return 0;
  77
  78   *pcount = data.exidx_len / 8;
  79   return data.exidx_start;
  80 }