LXR linux/arch/openrisc/kernel/module.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * OpenRISC module.c
   4 *
   5 * Linux architectural port borrowing liberally from similar works of
   6 * others.  All original copyrights apply as per the original source
   7 * declaration.
   8 *
   9 * Modifications for the OpenRISC architecture:
  10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  11 */
  12
  13#include <linux/moduleloader.h>
  14#include <linux/elf.h>
  15
  16int apply_relocate_add(Elf32_Shdr *sechdrs,
  17                       const char *strtab,
  18                       unsigned int symindex,
  19                       unsigned int relsec,
  20                       struct module *me)
  21{
  22        unsigned int i;
  23        Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  24        Elf32_Sym *sym;
  25        uint32_t *location;
  26        uint32_t value;
  27
  28        pr_debug("Applying relocate section %u to %u\n", relsec,
  29                 sechdrs[relsec].sh_info);
  30        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  31                /* This is where to make the change */
  32                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  33                        + rel[i].r_offset;
  34
  35                /* This is the symbol it is referring to.  Note that all
  36                   undefined symbols have been resolved.  */
  37                sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  38                        + ELF32_R_SYM(rel[i].r_info);
  39                value = sym->st_value + rel[i].r_addend;
  40
  41                switch (ELF32_R_TYPE(rel[i].r_info)) {
  42                case R_OR32_32:
  43                        *location = value;
  44                        break;
  45                case R_OR32_CONST:
  46                        *((uint16_t *)location + 1) = value;
  47                        break;
  48                case R_OR32_CONSTH:
  49                        *((uint16_t *)location + 1) = value >> 16;
  50                        break;
  51                case R_OR32_JUMPTARG:
  52                        value -= (uint32_t)location;
  53                        value >>= 2;
  54                        value &= 0x03ffffff;
  55                        value |= *location & 0xfc000000;
  56                        *location = value;
  57                        break;
  58                default:
  59                        pr_err("module %s: Unknown relocation: %u\n",
  60                               me->name, ELF32_R_TYPE(rel[i].r_info));
  61                        break;
  62                }
  63        }
  64
  65        return 0;
  66}
  67