Line data    Source code

       1             : /* Get REL relocation information at given index.
       2             :    Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             :    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
       5             : 
       6             :    This file is free software; you can redistribute it and/or modify
       7             :    it under the terms of either
       8             : 
       9             :      * the GNU Lesser General Public License as published by the Free
      10             :        Software Foundation; either version 3 of the License, or (at
      11             :        your option) any later version
      12             : 
      13             :    or
      14             : 
      15             :      * the GNU General Public License as published by the Free
      16             :        Software Foundation; either version 2 of the License, or (at
      17             :        your option) any later version
      18             : 
      19             :    or both in parallel, as here.
      20             : 
      21             :    elfutils is distributed in the hope that it will be useful, but
      22             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24             :    General Public License for more details.
      25             : 
      26             :    You should have received copies of the GNU General Public License and
      27             :    the GNU Lesser General Public License along with this program.  If
      28             :    not, see <http://www.gnu.org/licenses/>.  */
      29             : 
      30             : #ifdef HAVE_CONFIG_H
      31             : # include <config.h>
      32             : #endif
      33             : 
      34             : #include <gelf.h>
      35             : #include <string.h>
      36             : 
      37             : #include "libelfP.h"
      38             : 
      39             : 
      40             : GElf_Rel *
      41       37921 : gelf_getrel (Elf_Data *data, int ndx, GElf_Rel *dst)
      42             : {
      43       37921 :   Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
      44             :   Elf_Scn *scn;
      45             :   GElf_Rel *result;
      46             : 
      47       37921 :   if (data_scn == NULL)
      48             :     return NULL;
      49             : 
      50       37921 :   if (unlikely (data_scn->d.d_type != ELF_T_REL))
      51             :     {
      52           0 :       __libelf_seterrno (ELF_E_INVALID_HANDLE);
      53           0 :       return NULL;
      54             :     }
      55             : 
      56             :   /* This is the one place where we have to take advantage of the fact
      57             :      that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
      58             :      The interface is broken so that it requires this hack.  */
      59       37921 :   scn = data_scn->s;
      60             : 
      61       37921 :   rwlock_rdlock (scn->elf->lock);
      62             : 
      63       37921 :   if (scn->elf->class == ELFCLASS32)
      64             :     {
      65             :       /* We have to convert the data.  */
      66       37903 :       if (INVALID_NDX (ndx, Elf32_Rel, &data_scn->d))
      67             :         {
      68           0 :           __libelf_seterrno (ELF_E_INVALID_INDEX);
      69           0 :           result = NULL;
      70             :         }
      71             :       else
      72             :         {
      73       37903 :           Elf32_Rel *src = &((Elf32_Rel *) data_scn->d.d_buf)[ndx];
      74             : 
      75       37903 :           dst->r_offset = src->r_offset;
      76       37903 :           dst->r_info = GELF_R_INFO (ELF32_R_SYM (src->r_info),
      77             :                                      ELF32_R_TYPE (src->r_info));
      78             : 
      79       37903 :           result = dst;
      80             :         }
      81             :     }
      82             :   else
      83             :     {
      84             :       /* Simply copy the data after we made sure we are actually getting
      85             :          correct data.  */
      86          18 :       if (INVALID_NDX (ndx, Elf64_Rel, &data_scn->d))
      87             :         {
      88           0 :           __libelf_seterrno (ELF_E_INVALID_INDEX);
      89           0 :           result = NULL;
      90             :         }
      91             :       else
      92          36 :         result = memcpy (dst, &((Elf64_Rel *) data_scn->d.d_buf)[ndx],
      93             :                          sizeof (Elf64_Rel));
      94             :     }
      95             : 
      96             :   rwlock_unlock (scn->elf->lock);
      97             : 
      98       37921 :   return result;
      99             : }