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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 | /* MN10300 Kernel module helper routines
*
* Copyright (C) 2007, 2008, 2009 Red Hat, Inc. All Rights Reserved.
* Written by Mark Salter (msalter@redhat.com)
* - Derived from arch/i386/kernel/module.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public Licence as published by
* the Free Software Foundation; either version 2 of the Licence, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public Licence for more details.
*
* You should have received a copy of the GNU General Public Licence
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt, ...)
#endif
/*
* allocate storage for a module
*/
void *module_alloc(unsigned long size)
{
if (size == 0)
return NULL;
return vmalloc_exec(size);
}
/*
* free memory returned from module_alloc()
*/
void module_free(struct module *mod, void *module_region)
{
vfree(module_region);
}
/*
* allow the arch to fix up the section table
* - we don't need anything special
*/
int module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
char *secstrings,
struct module *mod)
{
return 0;
}
static void reloc_put16(uint8_t *p, uint32_t val)
{
p[0] = val & 0xff;
p[1] = (val >> 8) & 0xff;
}
static void reloc_put24(uint8_t *p, uint32_t val)
{
reloc_put16(p, val);
p[2] = (val >> 16) & 0xff;
}
static void reloc_put32(uint8_t *p, uint32_t val)
{
reloc_put16(p, val);
reloc_put16(p+2, val >> 16);
}
/*
* apply a REL relocation
*/
int apply_relocate(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
printk(KERN_ERR "module %s: RELOCATION unsupported\n",
me->name);
return -ENOEXEC;
}
/*
* apply a RELA relocation
*/
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
unsigned int i, sym_diff_seen = 0;
Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
Elf32_Addr relocation, sym_diff_val = 0;
uint8_t *location;
uint32_t value;
DEBUGP("Applying relocate section %u to %u\n",
relsec, sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* this is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[i].r_offset;
/* this is the symbol the relocation is referring to (note that
* all undefined symbols have been resolved by the caller) */
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rel[i].r_info);
/* this is the adjustment to be made */
relocation = sym->st_value + rel[i].r_addend;
if (sym_diff_seen) {
switch (ELF32_R_TYPE(rel[i].r_info)) {
case R_MN10300_32:
case R_MN10300_24:
case R_MN10300_16:
case R_MN10300_8:
relocation -= sym_diff_val;
sym_diff_seen = 0;
break;
default:
printk(KERN_ERR "module %s: Unexpected SYM_DIFF relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
switch (ELF32_R_TYPE(rel[i].r_info)) {
/* for the first four relocation types, we simply
* store the adjustment at the location given */
case R_MN10300_32:
reloc_put32(location, relocation);
break;
case R_MN10300_24:
reloc_put24(location, relocation);
break;
case R_MN10300_16:
reloc_put16(location, relocation);
break;
case R_MN10300_8:
*location = relocation;
break;
/* for the next three relocation types, we write the
* adjustment with the address subtracted over the
* value at the location given */
case R_MN10300_PCREL32:
value = relocation - (uint32_t) location;
reloc_put32(location, value);
break;
case R_MN10300_PCREL16:
value = relocation - (uint32_t) location;
reloc_put16(location, value);
break;
case R_MN10300_PCREL8:
*location = relocation - (uint32_t) location;
break;
case R_MN10300_SYM_DIFF:
/* This is used to adjust the next reloc as required
* by relaxation. */
sym_diff_seen = 1;
sym_diff_val = sym->st_value;
break;
case R_MN10300_ALIGN:
/* Just ignore the ALIGN relocs.
* Only interesting if kernel performed relaxation. */
continue;
default:
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
if (sym_diff_seen) {
printk(KERN_ERR "module %s: Nothing follows SYM_DIFF relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
return 0;
}
/*
* finish loading the module
*/
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
return 0;
}
/*
* finish clearing the module
*/
void module_arch_cleanup(struct module *mod)
{
}
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