arch/x86/lib/reloc_x86_64_efi.c

   1 // SPDX-License-Identifier: BSD-3-Clause
   2 /*
   3  * reloc_x86_64.c - position independent x86_64 ELF shared object relocator
   4  * Copyright (C) 1999 Hewlett-Packard Co.
   5  * Contributed by David Mosberger <davidm@hpl.hp.com>.
   6  * Copyright (C) 2005 Intel Co.
   7  * Contributed by Fenghua Yu <fenghua.yu@intel.com>.
   8  *
   9  * All rights reserved.
  10  */
  11
  12 #include <common.h>
  13 #include <efi.h>
  14 #include <elf.h>
  15
  16 efi_status_t EFIAPI _relocate(long ldbase, Elf64_Dyn *dyn)
  17 {
  18         long relsz = 0, relent = 0;
  19         Elf64_Rel *rel = 0;
  20         unsigned long *addr;
  21         int i;
  22
  23         for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
  24                 switch (dyn[i].d_tag) {
  25                 case DT_RELA:
  26                         rel = (Elf64_Rel *)
  27                                 ((unsigned long)dyn[i].d_un.d_ptr + ldbase);
  28                         break;
  29                 case DT_RELASZ:
  30                         relsz = dyn[i].d_un.d_val;
  31                         break;
  32                 case DT_RELAENT:
  33                         relent = dyn[i].d_un.d_val;
  34                         break;
  35                 default:
  36                         break;
  37                 }
  38         }
  39
  40         if (!rel && relent == 0)
  41                 return EFI_SUCCESS;
  42
  43         if (!rel || relent == 0)
  44                 return EFI_LOAD_ERROR;
  45
  46         while (relsz > 0) {
  47                 /* apply the relocs */
  48                 switch (ELF64_R_TYPE(rel->r_info)) {
  49                 case R_X86_64_NONE:
  50                         break;
  51                 case R_X86_64_RELATIVE:
  52                         addr = (unsigned long *)(ldbase + rel->r_offset);
  53                         *addr += ldbase;
  54                         break;
  55                 default:
  56                         break;
  57                 }
  58                 rel = (Elf64_Rel *)((char *)rel + relent);
  59                 relsz -= relent;
  60         }
  61
  62         return EFI_SUCCESS;
  63 }