sysdeps/x86_64/dl-runtime.h

   1 /* Helpers for On-demand PLT fixup for shared objects.  x86_64 version.
   2    Copyright (C) 2020-2021 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* The ABI calls for the PLT stubs to pass the index of the relocation
  21    and not its offset.  In _dl_profile_fixup and _dl_call_pltexit we
  22    also use the index.  Therefore it is wasteful to compute the offset
  23    in the trampoline just to reverse the operation immediately
  24    afterwards.  */
  25 static inline uintptr_t
  26 reloc_offset (uintptr_t plt0, uintptr_t pltn)
  27 {
  28   return pltn * sizeof (ElfW(Rela));
  29 }
  30
  31 static inline uintptr_t
  32 reloc_index (uintptr_t plt0, uintptr_t pltn, size_t size)
  33 {
  34   return pltn;
  35 }