elf/do-rel.h

   1 /* Do relocations for ELF 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 /* 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 Rel                    Rela
  26 # define elf_machine_rel        elf_machine_rela
  27 #endif
  28
  29 #ifndef VERSYMIDX
  30 # define VERSYMIDX(sym) (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (sym))
  31 #endif
  32
  33 /* Perform the relocations in MAP on the running program image as specified
  34    by RELTAG, SZTAG.  If LAZY is nonzero, this is the first pass on PLT
  35    relocations; they should be set up to call _dl_runtime_resolve, rather
  36    than fully resolved now.  */
  37
  38 static inline void
  39 elf_dynamic_do_rel (struct link_map *map,
  40                     int reltag, int sztag,
  41                     int lazy)
  42 {
  43   const ElfW(Rel) *r
  44     = (const ElfW(Rel) *) (map->l_addr + map->l_info[reltag]->d_un.d_ptr);
  45   const ElfW(Rel) *end = &r[map->l_info[sztag]->d_un.d_val / sizeof *r];
  46
  47   if (lazy)
  48     /* Doing lazy PLT relocations; they need very little info.  */
  49     for (; r < end; ++r)
  50       elf_machine_lazy_rel (map, r);
  51   else
  52     {
  53       const ElfW(Sym) *const symtab =
  54         (const ElfW(Sym) *) (map->l_addr + map->l_info[DT_SYMTAB]->d_un.d_ptr);
  55
  56       if (map->l_info[VERSYMIDX (DT_VERNEEDNUM)])
  57         {
  58           const ElfW(Half) *const version =
  59             (const ElfW(Half) *) (map->l_addr
  60                                   + map->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr);
  61
  62           for (; r < end; ++r)
  63             {
  64               ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)];
  65               elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
  66                                &map->l_versions[ndx]);
  67             }
  68         }
  69       else
  70         for (; r < end; ++r)
  71           elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL);
  72     }
  73 }
  74
  75 #undef elf_dynamic_do_rel
  76 #undef Rel
  77 #undef elf_machine_rel