/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, 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 License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright (C) 2001 Rusty Russell.
* Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
*/
#undef DEBUG
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
struct mips_hi16 {
struct mips_hi16 *next;
Elf32_Addr *addr;
Elf32_Addr value;
};
static struct mips_hi16 *mips_hi16_list;
void *module_alloc(unsigned long size)
{
if (size == 0)
return NULL;
return vmalloc(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. */
}
int module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
char *secstrings,
struct module *mod)
{
return 0;
}
static int apply_r_mips_none(struct module *me, uint32_t *location,
Elf32_Addr v)
{
return 0;
}
static int apply_r_mips_32(struct module *me, uint32_t *location,
Elf32_Addr v)
{
*location += v;
return 0;
}
static int apply_r_mips_26(struct module *me, uint32_t *location,
Elf32_Addr v)
{
if (v % 4) {
printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
return -ENOEXEC;
}
if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
printk(KERN_ERR
"module %s: relocation overflow\n",
me->name);
return -ENOEXEC;
}
*location = (*location & ~0x03ffffff) |
((*location + (v >> 2)) & 0x03ffffff);
return 0;
}
static int apply_r_mips_hi16(struct module *me, uint32_t *location,
Elf32_Addr v)
{
struct mips_hi16 *n;
/*
* We cannot relocate this one now because we don't know the value of
* the carry we need to add. Save the information, and let LO16 do the
* actual relocation.
*/
n = kmalloc(sizeof *n, GFP_KERNEL);
if (!n)
return -ENOMEM;
n->addr = location;
n->value = v;
n->next = mips_hi16_list;
mips_hi16_list = n;
return 0;
}
static int apply_r_mips_lo16(struct module *me, uint32_t *location,
Elf32_Addr v)
{
unsigned long insnlo = *location;
Elf32_Addr val, vallo;
/* Sign extend the addend we extract from the lo insn. */
vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
if (mips_hi16_list != NULL) {
struct mips_hi16 *l;
l = mips_hi16_list;
while (l != NULL) {
struct mips_hi16 *next;
unsigned long insn;
/*
* The value for the HI16 had best be the same.
*/
if (v != l->value)
goto out_danger;
/*
* Do the HI16 relocation. Note that we actually don't
* need to know anything about the LO16 itself, except
* where to find the low 16 bits of the addend needed
* by the LO16.
*/
insn = *l->addr;
val = ((insn & 0xffff) << 16) + vallo;
val += v;
/*
* Account for the sign extension that will happen in
* the low bits.
*/
val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
insn = (insn & ~0xffff) | val;
*l->addr = insn;
next = l->next;
kfree(l);
l = next;
}
mips_hi16_list = NULL;
}
/*
* Ok, we're done with the HI16 relocs. Now deal with the LO16.
*/
val = v + vallo;
insnlo = (insnlo & ~0xffff) | (val & 0xffff);
*location = insnlo;
return 0;
out_danger:
printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name);
return -ENOEXEC;
}
static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
Elf32_Addr v) = {
[R_MIPS_NONE] = apply_r_mips_none,
[R_MIPS_32] = apply_r_mips_32,
[R_MIPS_26] = apply_r_mips_26,
[R_MIPS_HI16] = apply_r_mips_hi16,
[R_MIPS_LO16] = apply_r_mips_lo16
};
int apply_relocate(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
uint32_t *location;
unsigned int i;
Elf32_Addr v;
int res;
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
Elf32_Word r_info = rel[i].r_info;
/* This is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[i].r_offset;
/* This is the symbol it is referring to */
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(r_info);
if (!sym->st_value) {
printk(KERN_WARNING "%s: Unknown symbol %s\n",
me->name, strtab + sym->st_name);
return -ENOENT;
}
v = sym->st_value;
res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
if (res)
return res;
}
return 0;
}
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
/*
* Current binutils always generate .rela relocations. Keep smiling
* if it's empty, abort otherwise.
*/
if (!sechdrs[relsec].sh_size)
return 0;
printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
me->name);
return -ENOEXEC;
}
