1// SPDX-License-Identifier: GPL-2.0+
2/* Kernel module help for SH.
3
4 SHcompact version by Kaz Kojima and Paul Mundt.
5
6 SHmedia bits:
7
8 Copyright 2004 SuperH (UK) Ltd
9 Author: Richard Curnow
10
11 Based on the sh version, and on code from the sh64-specific parts of
12 modutils, originally written by Richard Curnow and Ben Gaster.
13*/
14#include <linux/moduleloader.h>
15#include <linux/elf.h>
16#include <linux/vmalloc.h>
17#include <linux/bug.h>
18#include <linux/fs.h>
19#include <linux/string.h>
20#include <linux/kernel.h>
21#include <asm/unaligned.h>
22#include <asm/dwarf.h>
23
24int apply_relocate_add(Elf32_Shdr *sechdrs,
25 const char *strtab,
26 unsigned int symindex,
27 unsigned int relsec,
28 struct module *me)
29{
30 unsigned int i;
31 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
32 Elf32_Sym *sym;
33 Elf32_Addr relocation;
34 uint32_t *location;
35 uint32_t value;
36
37 pr_debug("Applying relocate section %u to %u\n", relsec,
38 sechdrs[relsec].sh_info);
39 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
40 /* This is where to make the change */
41 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
42 + rel[i].r_offset;
43 /* This is the symbol it is referring to. Note that all
44 undefined symbols have been resolved. */
45 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
46 + ELF32_R_SYM(rel[i].r_info);
47 relocation = sym->st_value + rel[i].r_addend;
48
49 switch (ELF32_R_TYPE(rel[i].r_info)) {
50 case R_SH_NONE:
51 break;
52 case R_SH_DIR32:
53 value = get_unaligned(location);
54 value += relocation;
55 put_unaligned(value, location);
56 break;
57 case R_SH_REL32:
58 relocation = (relocation - (Elf32_Addr) location);
59 value = get_unaligned(location);
60 value += relocation;
61 put_unaligned(value, location);
62 break;
63 case R_SH_IMM_LOW16:
64 *location = (*location & ~0x3fffc00) |
65 ((relocation & 0xffff) << 10);
66 break;
67 case R_SH_IMM_MEDLOW16:
68 *location = (*location & ~0x3fffc00) |
69 (((relocation >> 16) & 0xffff) << 10);
70 break;
71 case R_SH_IMM_LOW16_PCREL:
72 relocation -= (Elf32_Addr) location;
73 *location = (*location & ~0x3fffc00) |
74 ((relocation & 0xffff) << 10);
75 break;
76 case R_SH_IMM_MEDLOW16_PCREL:
77 relocation -= (Elf32_Addr) location;
78 *location = (*location & ~0x3fffc00) |
79 (((relocation >> 16) & 0xffff) << 10);
80 break;
81 default:
82 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
83 me->name, ELF32_R_TYPE(rel[i].r_info));
84 return -ENOEXEC;
85 }
86 }
87 return 0;
88}
89
90int module_finalize(const Elf_Ehdr *hdr,
91 const Elf_Shdr *sechdrs,
92 struct module *me)
93{
94 int ret = 0;
95
96 ret |= module_dwarf_finalize(hdr, sechdrs, me);
97
98 return ret;
99}
100
101void module_arch_cleanup(struct module *mod)
102{
103 module_dwarf_cleanup(mod);
104}
105

source code of linux/arch/sh/kernel/module.c