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
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)16 int 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