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/*
* arch/xtensa/kernel/module.c
*
* Module support.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2006 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
*
*/
#include <linux/module.h>
#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/cache.h>
static int
decode_calln_opcode (unsigned char *location)
{
#ifdef __XTENSA_EB__
return (location[0] & 0xf0) == 0x50;
#endif
#ifdef __XTENSA_EL__
return (location[0] & 0xf) == 0x5;
#endif
}
static int
decode_l32r_opcode (unsigned char *location)
{
#ifdef __XTENSA_EB__
return (location[0] & 0xf0) == 0x10;
#endif
#ifdef __XTENSA_EL__
return (location[0] & 0xf) == 0x1;
#endif
}
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *mod)
{
unsigned int i;
Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
unsigned char *location;
uint32_t value;
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
location = (char *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rela[i].r_offset;
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rela[i].r_info);
value = sym->st_value + rela[i].r_addend;
switch (ELF32_R_TYPE(rela[i].r_info)) {
case R_XTENSA_NONE:
case R_XTENSA_DIFF8:
case R_XTENSA_DIFF16:
case R_XTENSA_DIFF32:
case R_XTENSA_ASM_EXPAND:
break;
case R_XTENSA_32:
case R_XTENSA_PLT:
*(uint32_t *)location += value;
break;
case R_XTENSA_SLOT0_OP:
if (decode_calln_opcode(location)) {
value -= ((unsigned long)location & -4) + 4;
if ((value & 3) != 0 ||
((value + (1 << 19)) >> 20) != 0) {
pr_err("%s: relocation out of range, "
"section %d reloc %d "
"sym '%s'\n",
mod->name, relsec, i,
strtab + sym->st_name);
return -ENOEXEC;
}
value = (signed int)value >> 2;
#ifdef __XTENSA_EB__
location[0] = ((location[0] & ~0x3) |
((value >> 16) & 0x3));
location[1] = (value >> 8) & 0xff;
location[2] = value & 0xff;
#endif
#ifdef __XTENSA_EL__
location[0] = ((location[0] & ~0xc0) |
((value << 6) & 0xc0));
location[1] = (value >> 2) & 0xff;
location[2] = (value >> 10) & 0xff;
#endif
} else if (decode_l32r_opcode(location)) {
value -= (((unsigned long)location + 3) & -4);
if ((value & 3) != 0 ||
(signed int)value >> 18 != -1) {
pr_err("%s: relocation out of range, "
"section %d reloc %d "
"sym '%s'\n",
mod->name, relsec, i,
strtab + sym->st_name);
return -ENOEXEC;
}
value = (signed int)value >> 2;
#ifdef __XTENSA_EB__
location[1] = (value >> 8) & 0xff;
location[2] = value & 0xff;
#endif
#ifdef __XTENSA_EL__
location[1] = value & 0xff;
location[2] = (value >> 8) & 0xff;
#endif
}
/* FIXME: Ignore any other opcodes. The Xtensa
assembler currently assumes that the linker will
always do relaxation and so all PC-relative
operands need relocations. (The assembler also
writes out the tentative PC-relative values,
assuming no link-time relaxation, so it is usually
safe to ignore the relocations.) If the
assembler's "--no-link-relax" flag can be made to
work, and if all kernel modules can be assembled
with that flag, then unexpected relocations could
be detected here. */
break;
case R_XTENSA_SLOT1_OP:
case R_XTENSA_SLOT2_OP:
case R_XTENSA_SLOT3_OP:
case R_XTENSA_SLOT4_OP:
case R_XTENSA_SLOT5_OP:
case R_XTENSA_SLOT6_OP:
case R_XTENSA_SLOT7_OP:
case R_XTENSA_SLOT8_OP:
case R_XTENSA_SLOT9_OP:
case R_XTENSA_SLOT10_OP:
case R_XTENSA_SLOT11_OP:
case R_XTENSA_SLOT12_OP:
case R_XTENSA_SLOT13_OP:
case R_XTENSA_SLOT14_OP:
pr_err("%s: unexpected FLIX relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
case R_XTENSA_SLOT0_ALT:
case R_XTENSA_SLOT1_ALT:
case R_XTENSA_SLOT2_ALT:
case R_XTENSA_SLOT3_ALT:
case R_XTENSA_SLOT4_ALT:
case R_XTENSA_SLOT5_ALT:
case R_XTENSA_SLOT6_ALT:
case R_XTENSA_SLOT7_ALT:
case R_XTENSA_SLOT8_ALT:
case R_XTENSA_SLOT9_ALT:
case R_XTENSA_SLOT10_ALT:
case R_XTENSA_SLOT11_ALT:
case R_XTENSA_SLOT12_ALT:
case R_XTENSA_SLOT13_ALT:
case R_XTENSA_SLOT14_ALT:
pr_err("%s: unexpected ALT relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
default:
pr_err("%s: unexpected relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
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