sysdeps/x86_64/dl-irel.h

   1 /* Machine-dependent ELF indirect relocation inline functions.
   2    x86-64 version.
   3    Copyright (C) 2009-2023 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _DL_IREL_H
  21 #define _DL_IREL_H
  22
  23 #include <stdio.h>
  24 #include <unistd.h>
  25
  26 #define ELF_MACHINE_IRELA       1
  27
  28 static inline ElfW(Addr)
  29 __attribute ((always_inline))
  30 elf_ifunc_invoke (ElfW(Addr) addr)
  31 {
  32   return ((ElfW(Addr) (*) (void)) (addr)) ();
  33 }
  34
  35 static inline void
  36 __attribute ((always_inline))
  37 elf_irela (const ElfW(Rela) *reloc)
  38 {
  39   ElfW(Addr) *const reloc_addr = (void *) reloc->r_offset;
  40   const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
  41
  42   if (__glibc_likely (r_type == R_X86_64_IRELATIVE))
  43     {
  44       ElfW(Addr) value = elf_ifunc_invoke(reloc->r_addend);
  45       *reloc_addr = value;
  46     }
  47   else
  48     __libc_fatal ("Unexpected reloc type in static binary.\n");
  49 }
  50
  51 #endif /* dl-irel.h */