elf/dynamic-link.h

   1 /* Inline functions for dynamic linking.
   2 Copyright (C) 1995, 1996 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
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, 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
  28 elf_get_dynamic_info (ElfW(Dyn) *dyn, ElfW(Dyn) *info[DT_NUM + DT_PROCNUM])
  29 {
  30   unsigned int i;
  31
  32   for (i = 0; i < DT_NUM + DT_PROCNUM; ++i)
  33     info[i] = NULL;
  34
  35   if (! dyn)
  36     return;
  37
  38   while (dyn->d_tag != DT_NULL)
  39     {
  40       if (dyn->d_tag < DT_NUM)
  41         info[dyn->d_tag] = dyn;
  42       else if (dyn->d_tag >= DT_LOPROC &&
  43                dyn->d_tag < DT_LOPROC + DT_PROCNUM)
  44         info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
  45       else
  46         assert (! "bad dynamic tag");
  47       dyn++;
  48     }
  49
  50   if (info[DT_RELA])
  51     assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
  52   if (info[DT_REL])
  53     assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
  54   if (info[DT_PLTREL])
  55     assert (info[DT_PLTREL]->d_un.d_val == DT_REL ||
  56             info[DT_PLTREL]->d_un.d_val == DT_RELA);
  57 }
  58
  59 /* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
  60    These functions are almost identical, so we use cpp magic to avoid
  61    duplicating their code.  It cannot be done in a more general function
  62    because we must be able to completely inline.  */
  63
  64 #if ! ELF_MACHINE_NO_REL
  65 #include "do-rel.h"
  66 #define ELF_DYNAMIC_DO_REL(map, lazy, resolve)                                \
  67   if ((map)->l_info[DT_REL])                                                  \
  68     elf_dynamic_do_rel ((map), DT_REL, DT_RELSZ, (resolve), 0);               \
  69   if ((map)->l_info[DT_PLTREL] &&                                             \
  70       (map)->l_info[DT_PLTREL]->d_un.d_val == DT_REL)                         \
  71     elf_dynamic_do_rel ((map), DT_JMPREL, DT_PLTRELSZ, (resolve), (lazy));
  72 #else
  73 #define ELF_DYNAMIC_DO_REL(map, lazy, resolve) /* Nothing to do.  */
  74 #endif
  75
  76 #if ! ELF_MACHINE_NO_RELA
  77 #define DO_RELA
  78 #include "do-rel.h"
  79 #define ELF_DYNAMIC_DO_RELA(map, lazy, resolve)                               \
  80   if ((map)->l_info[DT_RELA])                                                 \
  81     elf_dynamic_do_rela ((map), DT_RELA, DT_RELASZ, (resolve), 0);            \
  82   if ((map)->l_info[DT_PLTREL] &&                                             \
  83       (map)->l_info[DT_PLTREL]->d_un.d_val == DT_RELA)                        \
  84     elf_dynamic_do_rela ((map), DT_JMPREL, DT_PLTRELSZ, (resolve), (lazy));
  85 #else
  86 #define ELF_DYNAMIC_DO_RELA(map, lazy, resolve) /* Nothing to do.  */
  87 #endif
  88
  89 /* This can't just be an inline function because GCC is too dumb
  90    to inline functions containing inlines themselves.  */
  91 #define ELF_DYNAMIC_RELOCATE(map, lazy, resolve) \
  92   do { ELF_DYNAMIC_DO_REL ((map), (lazy), (resolve)); \
  93        ELF_DYNAMIC_DO_RELA ((map), (lazy), (resolve)); } while (0)