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