module.c (1740B)
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}