libelf/gelf_update_auxv.c

   1 /* Update information in dynamic table at the given index.
   2    Copyright (C) 2007, 2015 Red Hat, Inc.
   3    This file is part of elfutils.
   4
   5    This file is free software; you can redistribute it and/or modify
   6    it under the terms of either
   7
   8      * the GNU Lesser General Public License as published by the Free
   9        Software Foundation; either version 3 of the License, or (at
  10        your option) any later version
  11
  12    or
  13
  14      * the GNU General Public License as published by the Free
  15        Software Foundation; either version 2 of the License, or (at
  16        your option) any later version
  17
  18    or both in parallel, as here.
  19
  20    elfutils is distributed in the hope that it will be useful, but
  21    WITHOUT ANY WARRANTY; without even the implied warranty of
  22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23    General Public License for more details.
  24
  25    You should have received copies of the GNU General Public License and
  26    the GNU Lesser General Public License along with this program.  If
  27    not, see <http://www.gnu.org/licenses/>.  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include <config.h>
  31 #endif
  32
  33 #include <gelf.h>
  34 #include <string.h>
  35
  36 #include "libelfP.h"
  37
  38
  39 int
  40 gelf_update_auxv (Elf_Data *data, int ndx, GElf_auxv_t *src)
  41 {
  42   Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
  43   Elf_Scn *scn;
  44   int result = 0;
  45
  46   if (data == NULL)
  47     return 0;
  48
  49   if (unlikely (ndx < 0))
  50     {
  51       __libelf_seterrno (ELF_E_INVALID_INDEX);
  52       return 0;
  53     }
  54
  55   if (unlikely (data_scn->d.d_type != ELF_T_AUXV))
  56     {
  57       /* The type of the data better should match.  */
  58       __libelf_seterrno (ELF_E_DATA_MISMATCH);
  59       return 0;
  60     }
  61
  62   scn = data_scn->s;
  63   rwlock_wrlock (scn->elf->lock);
  64
  65   if (scn->elf->class == ELFCLASS32)
  66     {
  67       Elf32_auxv_t *auxv;
  68
  69       /* There is the possibility that the values in the input are
  70          too large.  */
  71       if (unlikely (src->a_type > 0xffffffffll)
  72           || unlikely (src->a_un.a_val > 0xffffffffull))
  73         {
  74           __libelf_seterrno (ELF_E_INVALID_DATA);
  75           goto out;
  76         }
  77
  78       /* Check whether we have to resize the data buffer.  */
  79       if (unlikely ((ndx + 1) * sizeof (Elf32_auxv_t) > data_scn->d.d_size))
  80         {
  81           __libelf_seterrno (ELF_E_INVALID_INDEX);
  82           goto out;
  83         }
  84
  85       auxv = &((Elf32_auxv_t *) data_scn->d.d_buf)[ndx];
  86
  87       auxv->a_type = src->a_type;
  88       auxv->a_un.a_val = src->a_un.a_val;
  89     }
  90   else
  91     {
  92       /* Check whether we have to resize the data buffer.  */
  93       if (unlikely ((ndx + 1) * sizeof (Elf64_auxv_t) > data_scn->d.d_size))
  94         {
  95           __libelf_seterrno (ELF_E_INVALID_INDEX);
  96           goto out;
  97         }
  98
  99       ((Elf64_auxv_t *) data_scn->d.d_buf)[ndx] = *src;
 100     }
 101
 102   result = 1;
 103
 104   /* Mark the section as modified.  */
 105   scn->flags |= ELF_F_DIRTY;
 106
 107  out:
 108   rwlock_unlock (scn->elf->lock);
 109
 110   return result;
 111 }