blob: 8fa36893df7af1f5f20bcfc379d88d40a1f61a49 [file] [log] [blame]
David Howellsb920de12008-02-08 04:19:31 -08001/* MN10300 Kernel module helper routines
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by Mark Salter (msalter@redhat.com)
5 * - Derived from arch/i386/kernel/module.c
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public Licence as published by
9 * the Free Software Foundation; either version 2 of the Licence, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public Licence for more details.
16 *
17 * You should have received a copy of the GNU General Public Licence
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21#include <linux/moduleloader.h>
22#include <linux/elf.h>
23#include <linux/vmalloc.h>
24#include <linux/fs.h>
25#include <linux/string.h>
26#include <linux/kernel.h>
Paul Mundt18f6db92008-08-04 11:21:23 +010027#include <linux/bug.h>
David Howellsb920de12008-02-08 04:19:31 -080028
29#if 0
30#define DEBUGP printk
31#else
32#define DEBUGP(fmt, ...)
33#endif
34
35/*
36 * allocate storage for a module
37 */
38void *module_alloc(unsigned long size)
39{
40 if (size == 0)
41 return NULL;
42 return vmalloc_exec(size);
43}
44
45/*
46 * free memory returned from module_alloc()
47 */
48void module_free(struct module *mod, void *module_region)
49{
50 vfree(module_region);
51 /* FIXME: If module_region == mod->init_region, trim exception
52 * table entries. */
53}
54
55/*
56 * allow the arch to fix up the section table
57 * - we don't need anything special
58 */
59int module_frob_arch_sections(Elf_Ehdr *hdr,
60 Elf_Shdr *sechdrs,
61 char *secstrings,
62 struct module *mod)
63{
64 return 0;
65}
66
67static uint32_t reloc_get16(uint8_t *p)
68{
69 return p[0] | (p[1] << 8);
70}
71
72static uint32_t reloc_get24(uint8_t *p)
73{
74 return reloc_get16(p) | (p[2] << 16);
75}
76
77static uint32_t reloc_get32(uint8_t *p)
78{
79 return reloc_get16(p) | (reloc_get16(p+2) << 16);
80}
81
82static void reloc_put16(uint8_t *p, uint32_t val)
83{
84 p[0] = val & 0xff;
85 p[1] = (val >> 8) & 0xff;
86}
87
88static void reloc_put24(uint8_t *p, uint32_t val)
89{
90 reloc_put16(p, val);
91 p[2] = (val >> 16) & 0xff;
92}
93
94static void reloc_put32(uint8_t *p, uint32_t val)
95{
96 reloc_put16(p, val);
97 reloc_put16(p+2, val >> 16);
98}
99
100/*
101 * apply a REL relocation
102 */
103int apply_relocate(Elf32_Shdr *sechdrs,
104 const char *strtab,
105 unsigned int symindex,
106 unsigned int relsec,
107 struct module *me)
108{
109 printk(KERN_ERR "module %s: RELOCATION unsupported\n",
110 me->name);
111 return -ENOEXEC;
112}
113
114/*
115 * apply a RELA relocation
116 */
117int apply_relocate_add(Elf32_Shdr *sechdrs,
118 const char *strtab,
119 unsigned int symindex,
120 unsigned int relsec,
121 struct module *me)
122{
123 unsigned int i;
124 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
125 Elf32_Sym *sym;
126 Elf32_Addr relocation;
127 uint8_t *location;
128 uint32_t value;
129
130 DEBUGP("Applying relocate section %u to %u\n",
131 relsec, sechdrs[relsec].sh_info);
132
133 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
134 /* this is where to make the change */
135 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
136 + rel[i].r_offset;
137
138 /* this is the symbol the relocation is referring to (note that
139 * all undefined symbols have been resolved by the caller) */
140 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
141 + ELF32_R_SYM(rel[i].r_info);
142
143 /* this is the adjustment to be made */
144 relocation = sym->st_value + rel[i].r_addend;
145
146 switch (ELF32_R_TYPE(rel[i].r_info)) {
147 /* for the first four relocation types, we add the
148 * adjustment into the value at the location given */
149 case R_MN10300_32:
150 value = reloc_get32(location);
151 value += relocation;
152 reloc_put32(location, value);
153 break;
154 case R_MN10300_24:
155 value = reloc_get24(location);
156 value += relocation;
157 reloc_put24(location, value);
158 break;
159 case R_MN10300_16:
160 value = reloc_get16(location);
161 value += relocation;
162 reloc_put16(location, value);
163 break;
164 case R_MN10300_8:
165 *location += relocation;
166 break;
167
168 /* for the next three relocation types, we write the
169 * adjustment with the address subtracted over the
170 * value at the location given */
171 case R_MN10300_PCREL32:
172 value = relocation - (uint32_t) location;
173 reloc_put32(location, value);
174 break;
175 case R_MN10300_PCREL16:
176 value = relocation - (uint32_t) location;
177 reloc_put16(location, value);
178 break;
179 case R_MN10300_PCREL8:
180 *location = relocation - (uint32_t) location;
181 break;
182
183 default:
184 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
185 me->name, ELF32_R_TYPE(rel[i].r_info));
186 return -ENOEXEC;
187 }
188 }
189 return 0;
190}
191
192/*
193 * finish loading the module
194 */
195int module_finalize(const Elf_Ehdr *hdr,
196 const Elf_Shdr *sechdrs,
197 struct module *me)
198{
Paul Mundt18f6db92008-08-04 11:21:23 +0100199 return module_bug_finalize(hdr, sechdrs, me);
David Howellsb920de12008-02-08 04:19:31 -0800200}
201
202/*
203 * finish clearing the module
204 */
205void module_arch_cleanup(struct module *mod)
206{
Paul Mundt18f6db92008-08-04 11:21:23 +0100207 module_bug_cleanup(mod);
David Howellsb920de12008-02-08 04:19:31 -0800208}