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
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)24 int 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 #ifdef CONFIG_SUPERH64
50 /* For text addresses, bit2 of the st_other field indicates
51 * whether the symbol is SHmedia (1) or SHcompact (0). If
52 * SHmedia, the LSB of the symbol needs to be asserted
53 * for the CPU to be in SHmedia mode when it starts executing
54 * the branch target. */
55 relocation |= !!(sym->st_other & 4);
56 #endif
57
58 switch (ELF32_R_TYPE(rel[i].r_info)) {
59 case R_SH_NONE:
60 break;
61 case R_SH_DIR32:
62 value = get_unaligned(location);
63 value += relocation;
64 put_unaligned(value, location);
65 break;
66 case R_SH_REL32:
67 relocation = (relocation - (Elf32_Addr) location);
68 value = get_unaligned(location);
69 value += relocation;
70 put_unaligned(value, location);
71 break;
72 case R_SH_IMM_LOW16:
73 *location = (*location & ~0x3fffc00) |
74 ((relocation & 0xffff) << 10);
75 break;
76 case R_SH_IMM_MEDLOW16:
77 *location = (*location & ~0x3fffc00) |
78 (((relocation >> 16) & 0xffff) << 10);
79 break;
80 case R_SH_IMM_LOW16_PCREL:
81 relocation -= (Elf32_Addr) location;
82 *location = (*location & ~0x3fffc00) |
83 ((relocation & 0xffff) << 10);
84 break;
85 case R_SH_IMM_MEDLOW16_PCREL:
86 relocation -= (Elf32_Addr) location;
87 *location = (*location & ~0x3fffc00) |
88 (((relocation >> 16) & 0xffff) << 10);
89 break;
90 default:
91 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
92 me->name, ELF32_R_TYPE(rel[i].r_info));
93 return -ENOEXEC;
94 }
95 }
96 return 0;
97 }
98
module_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * me)99 int module_finalize(const Elf_Ehdr *hdr,
100 const Elf_Shdr *sechdrs,
101 struct module *me)
102 {
103 int ret = 0;
104
105 ret |= module_dwarf_finalize(hdr, sechdrs, me);
106
107 return ret;
108 }
109
module_arch_cleanup(struct module * mod)110 void module_arch_cleanup(struct module *mod)
111 {
112 module_dwarf_cleanup(mod);
113 }
114