292 lines
8.0 KiB
C
292 lines
8.0 KiB
C
/*
|
|
* AVR32-specific kernel module loader
|
|
*
|
|
* Copyright (C) 2005-2006 Atmel Corporation
|
|
*
|
|
* GOT initialization parts are based on the s390 version
|
|
* Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH,
|
|
* IBM Corporation
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/bug.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleloader.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
void module_arch_freeing_init(struct module *mod)
|
|
{
|
|
vfree(mod->arch.syminfo);
|
|
mod->arch.syminfo = NULL;
|
|
}
|
|
|
|
static inline int check_rela(Elf32_Rela *rela, struct module *module,
|
|
char *strings, Elf32_Sym *symbols)
|
|
{
|
|
struct mod_arch_syminfo *info;
|
|
|
|
info = module->arch.syminfo + ELF32_R_SYM(rela->r_info);
|
|
switch (ELF32_R_TYPE(rela->r_info)) {
|
|
case R_AVR32_GOT32:
|
|
case R_AVR32_GOT16:
|
|
case R_AVR32_GOT8:
|
|
case R_AVR32_GOT21S:
|
|
case R_AVR32_GOT18SW: /* mcall */
|
|
case R_AVR32_GOT16S: /* ld.w */
|
|
if (rela->r_addend != 0) {
|
|
printk(KERN_ERR
|
|
"GOT relocation against %s at offset %u with addend\n",
|
|
strings + symbols[ELF32_R_SYM(rela->r_info)].st_name,
|
|
rela->r_offset);
|
|
return -ENOEXEC;
|
|
}
|
|
if (info->got_offset == -1UL) {
|
|
info->got_offset = module->arch.got_size;
|
|
module->arch.got_size += sizeof(void *);
|
|
}
|
|
pr_debug("GOT[%3lu] %s\n", info->got_offset,
|
|
strings + symbols[ELF32_R_SYM(rela->r_info)].st_name);
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
|
|
char *secstrings, struct module *module)
|
|
{
|
|
Elf32_Shdr *symtab;
|
|
Elf32_Sym *symbols;
|
|
Elf32_Rela *rela;
|
|
char *strings;
|
|
int nrela, i, j;
|
|
int ret;
|
|
|
|
/* Find the symbol table */
|
|
symtab = NULL;
|
|
for (i = 0; i < hdr->e_shnum; i++)
|
|
switch (sechdrs[i].sh_type) {
|
|
case SHT_SYMTAB:
|
|
symtab = &sechdrs[i];
|
|
break;
|
|
}
|
|
if (!symtab) {
|
|
printk(KERN_ERR "module %s: no symbol table\n", module->name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* Allocate room for one syminfo structure per symbol. */
|
|
module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
|
|
module->arch.syminfo = vmalloc(module->arch.nsyms
|
|
* sizeof(struct mod_arch_syminfo));
|
|
if (!module->arch.syminfo)
|
|
return -ENOMEM;
|
|
|
|
symbols = (void *)hdr + symtab->sh_offset;
|
|
strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset;
|
|
for (i = 0; i < module->arch.nsyms; i++) {
|
|
if (symbols[i].st_shndx == SHN_UNDEF &&
|
|
strcmp(strings + symbols[i].st_name,
|
|
"_GLOBAL_OFFSET_TABLE_") == 0)
|
|
/* "Define" it as absolute. */
|
|
symbols[i].st_shndx = SHN_ABS;
|
|
module->arch.syminfo[i].got_offset = -1UL;
|
|
module->arch.syminfo[i].got_initialized = 0;
|
|
}
|
|
|
|
/* Allocate GOT entries for symbols that need it. */
|
|
module->arch.got_size = 0;
|
|
for (i = 0; i < hdr->e_shnum; i++) {
|
|
if (sechdrs[i].sh_type != SHT_RELA)
|
|
continue;
|
|
nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela);
|
|
rela = (void *)hdr + sechdrs[i].sh_offset;
|
|
for (j = 0; j < nrela; j++) {
|
|
ret = check_rela(rela + j, module,
|
|
strings, symbols);
|
|
if (ret)
|
|
goto out_free_syminfo;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Increase core size to make room for GOT and set start
|
|
* offset for GOT.
|
|
*/
|
|
module->core_layout.size = ALIGN(module->core_layout.size, 4);
|
|
module->arch.got_offset = module->core_layout.size;
|
|
module->core_layout.size += module->arch.got_size;
|
|
|
|
return 0;
|
|
|
|
out_free_syminfo:
|
|
vfree(module->arch.syminfo);
|
|
module->arch.syminfo = NULL;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline int reloc_overflow(struct module *module, const char *reloc_name,
|
|
Elf32_Addr relocation)
|
|
{
|
|
printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n",
|
|
module->name, (unsigned long)relocation, reloc_name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
#define get_u16(loc) (*((uint16_t *)loc))
|
|
#define put_u16(loc, val) (*((uint16_t *)loc) = (val))
|
|
|
|
int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
|
|
unsigned int symindex, unsigned int relindex,
|
|
struct module *module)
|
|
{
|
|
Elf32_Shdr *symsec = sechdrs + symindex;
|
|
Elf32_Shdr *relsec = sechdrs + relindex;
|
|
Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
|
|
Elf32_Rela *rel = (void *)relsec->sh_addr;
|
|
unsigned int i;
|
|
int ret = 0;
|
|
|
|
for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) {
|
|
struct mod_arch_syminfo *info;
|
|
Elf32_Sym *sym;
|
|
Elf32_Addr relocation;
|
|
uint32_t *location;
|
|
uint32_t value;
|
|
|
|
location = (void *)dstsec->sh_addr + rel->r_offset;
|
|
sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info);
|
|
relocation = sym->st_value + rel->r_addend;
|
|
|
|
info = module->arch.syminfo + ELF32_R_SYM(rel->r_info);
|
|
|
|
/* Initialize GOT entry if necessary */
|
|
switch (ELF32_R_TYPE(rel->r_info)) {
|
|
case R_AVR32_GOT32:
|
|
case R_AVR32_GOT16:
|
|
case R_AVR32_GOT8:
|
|
case R_AVR32_GOT21S:
|
|
case R_AVR32_GOT18SW:
|
|
case R_AVR32_GOT16S:
|
|
if (!info->got_initialized) {
|
|
Elf32_Addr *gotent;
|
|
|
|
gotent = (module->core_layout.base
|
|
+ module->arch.got_offset
|
|
+ info->got_offset);
|
|
*gotent = relocation;
|
|
info->got_initialized = 1;
|
|
}
|
|
|
|
relocation = info->got_offset;
|
|
break;
|
|
}
|
|
|
|
switch (ELF32_R_TYPE(rel->r_info)) {
|
|
case R_AVR32_32:
|
|
case R_AVR32_32_CPENT:
|
|
*location = relocation;
|
|
break;
|
|
case R_AVR32_22H_PCREL:
|
|
relocation -= (Elf32_Addr)location;
|
|
if ((relocation & 0xffe00001) != 0
|
|
&& (relocation & 0xffc00001) != 0xffc00000)
|
|
return reloc_overflow(module,
|
|
"R_AVR32_22H_PCREL",
|
|
relocation);
|
|
relocation >>= 1;
|
|
|
|
value = *location;
|
|
value = ((value & 0xe1ef0000)
|
|
| (relocation & 0xffff)
|
|
| ((relocation & 0x10000) << 4)
|
|
| ((relocation & 0x1e0000) << 8));
|
|
*location = value;
|
|
break;
|
|
case R_AVR32_11H_PCREL:
|
|
relocation -= (Elf32_Addr)location;
|
|
if ((relocation & 0xfffffc01) != 0
|
|
&& (relocation & 0xfffff801) != 0xfffff800)
|
|
return reloc_overflow(module,
|
|
"R_AVR32_11H_PCREL",
|
|
relocation);
|
|
value = get_u16(location);
|
|
value = ((value & 0xf00c)
|
|
| ((relocation & 0x1fe) << 3)
|
|
| ((relocation & 0x600) >> 9));
|
|
put_u16(location, value);
|
|
break;
|
|
case R_AVR32_9H_PCREL:
|
|
relocation -= (Elf32_Addr)location;
|
|
if ((relocation & 0xffffff01) != 0
|
|
&& (relocation & 0xfffffe01) != 0xfffffe00)
|
|
return reloc_overflow(module,
|
|
"R_AVR32_9H_PCREL",
|
|
relocation);
|
|
value = get_u16(location);
|
|
value = ((value & 0xf00f)
|
|
| ((relocation & 0x1fe) << 3));
|
|
put_u16(location, value);
|
|
break;
|
|
case R_AVR32_9UW_PCREL:
|
|
relocation -= ((Elf32_Addr)location) & 0xfffffffc;
|
|
if ((relocation & 0xfffffc03) != 0)
|
|
return reloc_overflow(module,
|
|
"R_AVR32_9UW_PCREL",
|
|
relocation);
|
|
value = get_u16(location);
|
|
value = ((value & 0xf80f)
|
|
| ((relocation & 0x1fc) << 2));
|
|
put_u16(location, value);
|
|
break;
|
|
case R_AVR32_GOTPC:
|
|
/*
|
|
* R6 = PC - (PC - GOT)
|
|
*
|
|
* At this point, relocation contains the
|
|
* value of PC. Just subtract the value of
|
|
* GOT, and we're done.
|
|
*/
|
|
pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n",
|
|
relocation, module->arch.got_offset,
|
|
module->core_layout.base);
|
|
relocation -= ((unsigned long)module->core_layout.base
|
|
+ module->arch.got_offset);
|
|
*location = relocation;
|
|
break;
|
|
case R_AVR32_GOT18SW:
|
|
if ((relocation & 0xfffe0003) != 0
|
|
&& (relocation & 0xfffc0000) != 0xfffc0000)
|
|
return reloc_overflow(module, "R_AVR32_GOT18SW",
|
|
relocation);
|
|
relocation >>= 2;
|
|
/* fall through */
|
|
case R_AVR32_GOT16S:
|
|
if ((relocation & 0xffff8000) != 0
|
|
&& (relocation & 0xffff0000) != 0xffff0000)
|
|
return reloc_overflow(module, "R_AVR32_GOT16S",
|
|
relocation);
|
|
pr_debug("GOT reloc @ 0x%x -> %u\n",
|
|
rel->r_offset, relocation);
|
|
value = *location;
|
|
value = ((value & 0xffff0000)
|
|
| (relocation & 0xffff));
|
|
*location = value;
|
|
break;
|
|
|
|
default:
|
|
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
|
|
module->name, ELF32_R_TYPE(rel->r_info));
|
|
return -ENOEXEC;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|