diff options
Diffstat (limited to 'arch/mn10300/kernel/module.c')
| -rw-r--r-- | arch/mn10300/kernel/module.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/module.c b/arch/mn10300/kernel/module.c new file mode 100644 index 000000000..216ad23c9 --- /dev/null +++ b/arch/mn10300/kernel/module.c @@ -0,0 +1,156 @@ +/* MN10300 Kernel module helper routines + * + * Copyright (C) 2007, 2008, 2009 Red Hat, Inc. All Rights Reserved. + * Written by Mark Salter (msalter@redhat.com) + * - Derived from arch/i386/kernel/module.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public Licence as published by + * the Free Software Foundation; either version 2 of the Licence, 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 Licence for more details. + * + * You should have received a copy of the GNU General Public Licence + * 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> +#include <linux/bug.h> + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(fmt, ...) +#endif + +static void reloc_put16(uint8_t *p, uint32_t val) +{ + p[0] = val & 0xff; + p[1] = (val >> 8) & 0xff; +} + +static void reloc_put24(uint8_t *p, uint32_t val) +{ + reloc_put16(p, val); + p[2] = (val >> 16) & 0xff; +} + +static void reloc_put32(uint8_t *p, uint32_t val) +{ + reloc_put16(p, val); + reloc_put16(p+2, val >> 16); +} + +/* + * apply a RELA relocation + */ +int apply_relocate_add(Elf32_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *me) +{ + unsigned int i, sym_diff_seen = 0; + Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; + Elf32_Sym *sym; + Elf32_Addr relocation, sym_diff_val = 0; + uint8_t *location; + uint32_t value; + + 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 the relocation is referring to (note that + * all undefined symbols have been resolved by the caller) */ + sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + + ELF32_R_SYM(rel[i].r_info); + + /* this is the adjustment to be made */ + relocation = sym->st_value + rel[i].r_addend; + + if (sym_diff_seen) { + switch (ELF32_R_TYPE(rel[i].r_info)) { + case R_MN10300_32: + case R_MN10300_24: + case R_MN10300_16: + case R_MN10300_8: + relocation -= sym_diff_val; + sym_diff_seen = 0; + break; + default: + printk(KERN_ERR "module %s: Unexpected SYM_DIFF relocation: %u\n", + me->name, ELF32_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + } + + switch (ELF32_R_TYPE(rel[i].r_info)) { + /* for the first four relocation types, we simply + * store the adjustment at the location given */ + case R_MN10300_32: + reloc_put32(location, relocation); + break; + case R_MN10300_24: + reloc_put24(location, relocation); + break; + case R_MN10300_16: + reloc_put16(location, relocation); + break; + case R_MN10300_8: + *location = relocation; + break; + + /* for the next three relocation types, we write the + * adjustment with the address subtracted over the + * value at the location given */ + case R_MN10300_PCREL32: + value = relocation - (uint32_t) location; + reloc_put32(location, value); + break; + case R_MN10300_PCREL16: + value = relocation - (uint32_t) location; + reloc_put16(location, value); + break; + case R_MN10300_PCREL8: + *location = relocation - (uint32_t) location; + break; + + case R_MN10300_SYM_DIFF: + /* This is used to adjust the next reloc as required + * by relaxation. */ + sym_diff_seen = 1; + sym_diff_val = sym->st_value; + break; + + case R_MN10300_ALIGN: + /* Just ignore the ALIGN relocs. + * Only interesting if kernel performed relaxation. */ + continue; + + default: + printk(KERN_ERR "module %s: Unknown relocation: %u\n", + me->name, ELF32_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + } + if (sym_diff_seen) { + printk(KERN_ERR "module %s: Nothing follows SYM_DIFF relocation: %u\n", + me->name, ELF32_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + return 0; +} |