elf/do-rel.h

   1 /* Do relocations for ELF dynamic linking.
   2 Copyright (C) 1995 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 /* This file may be included twice, to define both
  21    `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.  */
  22
  23 #ifdef DO_RELA
  24 #define elf_dynamic_do_rel      elf_dynamic_do_rela
  25 #define Elf32_Rel               Elf32_Rela
  26 #define elf_machine_rel         elf_machine_rela
  27 #endif
  28
  29
  30 /* Perform the relocations in MAP on the running program image as specified
  31    by RELTAG, SZTAG.  *RESOLVE is called to resolve symbol values; it
  32    modifies its argument pointer to point to the defining symbol, and
  33    returns the base load address of the defining object.  */
  34
  35 static inline void
  36 elf_dynamic_do_rel (struct link_map *map,
  37                     int reltag, int sztag,
  38                     Elf32_Addr (*resolve) (const Elf32_Sym **))
  39 {
  40   const Elf32_Sym *const symtab
  41     = (const Elf32_Sym *) map->l_info[DT_SYMTAB]->d_un.d_ptr;
  42   const Elf32_Rel *r = (const Elf32_Rel *) map->l_info[reltag]->d_un.d_ptr;
  43   const Elf32_Rel *end = &r[map->l_info[sztag]->d_un.d_val / sizeof *r];
  44
  45   for (; r < end; ++r)
  46     {
  47       const Elf32_Sym *definer = &symtab[ELF32_R_SYM (r->r_info)];
  48       Elf32_Addr loadbase;
  49
  50       if (ELF32_R_SYM (r->r_info) == STN_UNDEF)
  51         loadbase = 0;           /* This value will not be consulted.  */
  52       else
  53         {
  54           if (resolve)
  55             loadbase = (*resolve) (&definer);
  56           else
  57             {
  58               assert (definer->st_shndx != SHN_UNDEF);
  59               loadbase = map->l_addr;
  60             }
  61         }
  62       elf_machine_rel (map, r, loadbase, definer);
  63     }
  64 }
  65
  66 #undef elf_dynamic_do_rel
  67 #undef Elf32_Rel
  68 #undef elf_machine_rel