1 /*
2 * Kernel module support for Nios II.
3 *
4 * Copyright (C) 2004 Microtronix Datacom Ltd.
5 * Written by Wentao Xu <xuwentao@microtronix.com>
6 * Copyright (C) 2001, 2003 Rusty Russell
7 *
8 * This file is subject to the terms and conditions of the GNU General
9 * Public License. See the file COPYING in the main directory of this
10 * archive for more details.
11 */
12
13 #include <linux/moduleloader.h>
14 #include <linux/elf.h>
15 #include <linux/mm.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/string.h>
19 #include <linux/kernel.h>
20
21 #include <asm/cacheflush.h>
22
23 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
24 unsigned int symindex, unsigned int relsec,
25 struct module *mod)
26 {
27 unsigned int i;
28 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
29
30 pr_debug("Applying relocate section %u to %u\n", relsec,
31 sechdrs[relsec].sh_info);
32
33 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
34 /* This is where to make the change */
35 uint32_t word;
36 uint32_t *loc
37 = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
38 + rela[i].r_offset);
39 /* This is the symbol it is referring to. Note that all
40 undefined symbols have been resolved. */
41 Elf32_Sym *sym
42 = ((Elf32_Sym *)sechdrs[symindex].sh_addr
43 + ELF32_R_SYM(rela[i].r_info));
44 uint32_t v = sym->st_value + rela[i].r_addend;
45
46 pr_debug("reltype %d 0x%x name:<%s>\n",
47 ELF32_R_TYPE(rela[i].r_info),
48 rela[i].r_offset, strtab + sym->st_name);
49
50 switch (ELF32_R_TYPE(rela[i].r_info)) {
51 case R_NIOS2_NONE:
52 break;
53 case R_NIOS2_BFD_RELOC_32:
54 *loc += v;
55 break;
56 case R_NIOS2_PCREL16:
57 v -= (uint32_t)loc + 4;
58 if ((int32_t)v > 0x7fff ||
59 (int32_t)v < -(int32_t)0x8000) {
60 pr_err("module %s: relocation overflow\n",
61 mod->name);
62 return -ENOEXEC;
63 }
64 word = *loc;
65 *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
66 (word & 0x3f);
67 break;
68 case R_NIOS2_CALL26:
69 if (v & 3) {
70 pr_err("module %s: dangerous relocation\n",
71 mod->name);
72 return -ENOEXEC;
73 }
74 if ((v >> 28) != ((uint32_t)loc >> 28)) {
75 pr_err("module %s: relocation overflow\n",
76 mod->name);
77 return -ENOEXEC;
78 }
79 *loc = (*loc & 0x3f) | ((v >> 2) << 6);
80 break;
81 case R_NIOS2_HI16:
82 word = *loc;
83 *loc = ((((word >> 22) << 16) |
84 ((v >> 16) & 0xffff)) << 6) | (word & 0x3f);
85 break;
86 case R_NIOS2_LO16:
87 word = *loc;
88 *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
89 (word & 0x3f);
90 break;
91 case R_NIOS2_HIADJ16:
92 {
93 Elf32_Addr word2;
94
95 word = *loc;
96 word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff;
97 *loc = ((((word >> 22) << 16) | word2) << 6) |
98 (word & 0x3f);
99 }
100 break;
101
102 default:
103 pr_err("module %s: Unknown reloc: %u\n",
104 mod->name, ELF32_R_TYPE(rela[i].r_info));
105 return -ENOEXEC;
106 }
107 }
108
109 return 0;
110 }
111
112 int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
113 struct module *me)
114 {
115 flush_cache_all();
116 return 0;
117 }
118
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