/* Kernel module help for M32R.
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
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt...)
#endif
#define COPY_UNALIGNED_WORD(sw, tw, align) \
{ \
void *__s = &(sw), *__t = &(tw); \
unsigned short *__s2 = __s, *__t2 =__t; \
unsigned char *__s1 = __s, *__t1 =__t; \
switch ((align)) \
{ \
case 0: \
*(unsigned long *) __t = *(unsigned long *) __s; \
break; \
case 2: \
*__t2++ = *__s2++; \
*__t2 = *__s2; \
break; \
default: \
*__t1++ = *__s1++; \
*__t1++ = *__s1++; \
*__t1++ = *__s1++; \
*__t1 = *__s1; \
break; \
} \
}
#define COPY_UNALIGNED_HWORD(sw, tw, align) \
{ \
void *__s = &(sw), *__t = &(tw); \
unsigned short *__s2 = __s, *__t2 =__t; \
unsigned char *__s1 = __s, *__t1 =__t; \
switch ((align)) \
{ \
case 0: \
*__t2 = *__s2; \
break; \
default: \
*__t1++ = *__s1++; \
*__t1 = *__s1; \
break; \
} \
}
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;
uint32_t *location;
uint32_t value;
unsigned short *hlocation;
unsigned short hvalue;
int svalue;
int align;
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 it is referring to. Note that all
undefined symbols have been resolved. */
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rel[i].r_info);
relocation = sym->st_value + rel[i].r_addend;
align = (int)location & 3;
switch (ELF32_R_TYPE(rel[i].r_info)) {
case R_M32R_32_RELA:
COPY_UNALIGNED_WORD (*location, value, align);
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_HI16_ULO_RELA:
COPY_UNALIGNED_WORD (*location, value, align);
relocation = (relocation >>16) & 0xffff;
/* RELA must has 0 at relocation field. */
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_HI16_SLO_RELA:
COPY_UNALIGNED_WORD (*location, value, align);
if (relocation & 0x8000) relocation += 0x10000;
relocation = (relocation >>16) & 0xffff;
/* RELA must has 0 at relocation field. */
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_16_RELA:
hlocation = (unsigned short *)location;
relocation = relocation & 0xffff;
/* RELA must has 0 at relocation field. */
hvalue = relocation;
COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
break;
case R_M32R_SDA16_RELA:
case R_M32R_LO16_RELA:
COPY_UNALIGNED_WORD (*location, value, align);
relocation = relocation & 0xffff;
/* RELA must has 0 at relocation field. */
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_24_RELA:
COPY_UNALIGNED_WORD (*location, value, align);
relocation = relocation & 0xffffff;
/* RELA must has 0 at relocation field. */
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_18_PCREL_RELA:
relocation = (relocation - (Elf32_Addr) location);
if (relocation < -0x20000 || 0x1fffc < relocation)
{
printk(KERN_ERR "module %s: relocation overflow: %u\n",
me->name, relocation);
return -ENOEXEC;
}
COPY_UNALIGNED_WORD (*location, value, align);
if (value & 0xffff)
{
/* RELA must has 0 at relocation field. */
printk(KERN_ERR "module %s: illegal relocation field: %u\n",
me->name, value);
return -ENOEXEC;
}
relocation = (relocation >> 2) & 0xffff;
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
case R_M32R_10_PCREL_RELA:
hlocation = (unsigned short *)location;
relocation = (relocation - (Elf32_Addr) location);
COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
svalue = (int)hvalue;
svalue = (signed char)svalue << 2;
relocation += svalue;
relocation = (relocation >> 2) & 0xff;
hvalue = hvalue & 0xff00;
hvalue += relocation;
COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
break;
case R_M32R_26_PCREL_RELA:
relocation = (relocation - (Elf32_Addr) location);
if (relocation < -0x2000000 || 0x1fffffc < relocation)
{
printk(KERN_ERR "module %s: relocation overflow: %u\n",
me->name, relocation);
return -ENOEXEC;
}
COPY_UNALIGNED_WORD (*location, value, align);
if (value & 0xffffff)
{
/* RELA must has 0 at relocation field. */
printk(KERN_ERR "module %s: illegal relocation field: %u\n",
me->name, value);
return -ENOEXEC;
}
relocation = (relocation >> 2) & 0xffffff;
value += relocation;
COPY_UNALIGNED_WORD (value, *location, align);
break;
default:
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
}