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linux/arch/avr32/kernel/module.c
Rusty Russell 7523e4dc50 module: use a structure to encapsulate layout. 
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:25 +01:00

292 lines
8.0 KiB
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/*
* 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;
}
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