/* MN10300 Kernel module helper routines
*
* Copyright (C) 2007 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);
/* FIXME: If module_region == mod->init_region, trim exception
* table entries. */
}
/*
* 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 uint32_t reloc_get16(uint8_t *p)
{
return p[0] | (p[1] << 8);
}
static uint32_t reloc_get24(uint8_t *p)
{
return reloc_get16(p) | (p[2] << 16);
}
static uint32_t reloc_get32(uint8_t *p)
{
return reloc_get16(p) | (reloc_get16(p+2) << 16);
}
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;
Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
Elf32_Addr relocation;
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;
switch (ELF32_R_TYPE(rel[i].r_info)) {
/* for the first four relocation types, we add the
* adjustment into the value at the location given */
case R_MN10300_32:
value = reloc_get32(location);
value += relocation;
reloc_put32(location, value);
break;
case R_MN10300_24:
value = reloc_get24(location);
value += relocation;
reloc_put24(location, value);
break;
case R_MN10300_16:
value = reloc_get16(location);
value += relocation;
reloc_put16(location, value);
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;
default:
printk(KERN_ERR "module %s: Unknown 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 module_bug_finalize(hdr, sechdrs, me);
}
/*
* finish clearing the module
*/
void module_arch_cleanup(struct module *mod)
{
module_bug_cleanup(mod);
}
