elf/dynamic-link.h

   1 /* Inline functions for dynamic linking.
   2    Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <elf.h>
  21 #include <dl-machine.h>
  22 #include <assert.h>
  23
  24
  25 /* Read the dynamic section at DYN and fill in INFO with indices DT_*.  */
  26
  27 static inline void __attribute__ ((unused))
  28 elf_get_dynamic_info (ElfW(Dyn) *dyn,
  29                       ElfW(Dyn) *info[DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM
  30                                      + DT_EXTRANUM])
  31 {
  32   unsigned int i;
  33
  34   for (i = 0; i < DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM + DT_EXTRANUM; ++i)
  35     info[i] = NULL;
  36
  37   if (! dyn)
  38     return;
  39
  40   while (dyn->d_tag != DT_NULL)
  41     {
  42       if (dyn->d_tag < DT_NUM)
  43         info[dyn->d_tag] = dyn;
  44       else if (dyn->d_tag >= DT_LOPROC &&
  45                dyn->d_tag < DT_LOPROC + DT_PROCNUM)
  46         info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
  47       else if ((Elf32_Word) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
  48         info[DT_VERSIONTAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM] = dyn;
  49       else if ((Elf32_Word) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
  50         info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM
  51              + DT_VERSIONTAGNUM] = dyn;
  52       else
  53         assert (! "bad dynamic tag");
  54       dyn++;
  55     }
  56
  57   if (info[DT_RELA])
  58     assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
  59   if (info[DT_REL])
  60     assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
  61   if (info[DT_PLTREL])
  62     assert (info[DT_PLTREL]->d_un.d_val == DT_REL ||
  63             info[DT_PLTREL]->d_un.d_val == DT_RELA);
  64 }
  65
  66 #ifdef RESOLVE
  67
  68 /* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
  69    These functions are almost identical, so we use cpp magic to avoid
  70    duplicating their code.  It cannot be done in a more general function
  71    because we must be able to completely inline.  */
  72
  73 #if ! ELF_MACHINE_NO_REL
  74 #include "do-rel.h"
  75 #define ELF_DYNAMIC_DO_REL(map, lazy)                                         \
  76   if ((map)->l_info[DT_REL])                                                  \
  77     elf_dynamic_do_rel ((map), DT_REL, DT_RELSZ, 0);                          \
  78   if ((map)->l_info[DT_PLTREL] &&                                             \
  79       (map)->l_info[DT_PLTREL]->d_un.d_val == DT_REL)                         \
  80     elf_dynamic_do_rel ((map), DT_JMPREL, DT_PLTRELSZ, (lazy));
  81 #else
  82 #define ELF_DYNAMIC_DO_REL(map, lazy) /* Nothing to do.  */
  83 #endif
  84
  85 #if ! ELF_MACHINE_NO_RELA
  86 #define DO_RELA
  87 #include "do-rel.h"
  88 #define ELF_DYNAMIC_DO_RELA(map, lazy)                                        \
  89   if ((map)->l_info[DT_RELA])                                                 \
  90     elf_dynamic_do_rela ((map), DT_RELA, DT_RELASZ, 0);                       \
  91   if ((map)->l_info[DT_PLTREL] &&                                             \
  92       (map)->l_info[DT_PLTREL]->d_un.d_val == DT_RELA)                        \
  93     elf_dynamic_do_rela ((map), DT_JMPREL, DT_PLTRELSZ, (lazy));
  94 #else
  95 #define ELF_DYNAMIC_DO_RELA(map, lazy) /* Nothing to do.  */
  96 #endif
  97
  98 /* This can't just be an inline function because GCC is too dumb
  99    to inline functions containing inlines themselves.  */
 100 #define ELF_DYNAMIC_RELOCATE(map, lazy)                         \
 101   do {                                                          \
 102     int edr_lazy = elf_machine_runtime_setup((map), (lazy));    \
 103     ELF_DYNAMIC_DO_REL ((map), edr_lazy);                       \
 104     ELF_DYNAMIC_DO_RELA ((map), edr_lazy);                      \
 105   } while (0)
 106
 107 #endif