[GitHub/MotorolaMobilityLLC/kernel-slsi.git] / arch / mn10300 / kernel / module.c

/* 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;
}
Commit	Line	Data
b920de1b DH	1	/* MN10300 Kernel module helper routines
b920de1b DH	2	*
5ae8606d	3	* Copyright (C) 2007, 2008, 2009 Red Hat, Inc. All Rights Reserved.
b920de1b DH	4	* Written by Mark Salter (msalter@redhat.com)
	5	* - Derived from arch/i386/kernel/module.c
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public Licence as published by
	9	* the Free Software Foundation; either version 2 of the Licence, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public Licence for more details.
	16	*
	17	* You should have received a copy of the GNU General Public Licence
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21	#include <linux/moduleloader.h>
	22	#include <linux/elf.h>
	23	#include <linux/vmalloc.h>
	24	#include <linux/fs.h>
	25	#include <linux/string.h>
	26	#include <linux/kernel.h>
18f6db95	27	#include <linux/bug.h>
b920de1b DH	28
	29	#if 0
	30	#define DEBUGP printk
	31	#else
	32	#define DEBUGP(fmt, ...)
	33	#endif
	34
b920de1b DH	35	static void reloc_put16(uint8_t *p, uint32_t val)
	36	{
	37	p[0] = val & 0xff;
	38	p[1] = (val >> 8) & 0xff;
	39	}
	40
	41	static void reloc_put24(uint8_t *p, uint32_t val)
	42	{
	43	reloc_put16(p, val);
	44	p[2] = (val >> 16) & 0xff;
	45	}
	46
	47	static void reloc_put32(uint8_t *p, uint32_t val)
	48	{
	49	reloc_put16(p, val);
	50	reloc_put16(p+2, val >> 16);
	51	}
	52
b920de1b DH	53	/*
	54	* apply a RELA relocation
	55	*/
	56	int apply_relocate_add(Elf32_Shdr *sechdrs,
	57	const char *strtab,
	58	unsigned int symindex,
	59	unsigned int relsec,
	60	struct module *me)
	61	{
5ae8606d	62	unsigned int i, sym_diff_seen = 0;
b920de1b DH	63	Elf32_Rela rel = (void )sechdrs[relsec].sh_addr;
b920de1b DH	64	Elf32_Sym *sym;
5ae8606d	65	Elf32_Addr relocation, sym_diff_val = 0;
b920de1b DH	66	uint8_t *location;
	67	uint32_t value;
	68
	69	DEBUGP("Applying relocate section %u to %u\n",
	70	relsec, sechdrs[relsec].sh_info);
	71
	72	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	73	/* this is where to make the change */
	74	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	75	+ rel[i].r_offset;
	76
	77	/* this is the symbol the relocation is referring to (note that
	78	* all undefined symbols have been resolved by the caller) */
	79	sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
	80	+ ELF32_R_SYM(rel[i].r_info);
	81
	82	/* this is the adjustment to be made */
	83	relocation = sym->st_value + rel[i].r_addend;
	84
5ae8606d MS	85	if (sym_diff_seen) {
	86	switch (ELF32_R_TYPE(rel[i].r_info)) {
	87	case R_MN10300_32:
	88	case R_MN10300_24:
	89	case R_MN10300_16:
	90	case R_MN10300_8:
	91	relocation -= sym_diff_val;
	92	sym_diff_seen = 0;
	93	break;
	94	default:
	95	printk(KERN_ERR "module %s: Unexpected SYM_DIFF relocation: %u\n",
	96	me->name, ELF32_R_TYPE(rel[i].r_info));
	97	return -ENOEXEC;
	98	}
	99	}
	100
b920de1b	101	switch (ELF32_R_TYPE(rel[i].r_info)) {
1122b19b MS	102	/* for the first four relocation types, we simply
1122b19b MS	103	* store the adjustment at the location given */
b920de1b	104	case R_MN10300_32:
1122b19b	105	reloc_put32(location, relocation);
b920de1b DH	106	break;
b920de1b DH	107	case R_MN10300_24:
1122b19b	108	reloc_put24(location, relocation);
b920de1b DH	109	break;
b920de1b DH	110	case R_MN10300_16:
1122b19b	111	reloc_put16(location, relocation);
b920de1b DH	112	break;
b920de1b DH	113	case R_MN10300_8:
1122b19b	114	*location = relocation;
b920de1b DH	115	break;
	116
	117	/* for the next three relocation types, we write the
	118	* adjustment with the address subtracted over the
	119	* value at the location given */
	120	case R_MN10300_PCREL32:
	121	value = relocation - (uint32_t) location;
	122	reloc_put32(location, value);
	123	break;
	124	case R_MN10300_PCREL16:
	125	value = relocation - (uint32_t) location;
	126	reloc_put16(location, value);
	127	break;
	128	case R_MN10300_PCREL8:
	129	*location = relocation - (uint32_t) location;
	130	break;
	131
5ae8606d MS	132	case R_MN10300_SYM_DIFF:
	133	/* This is used to adjust the next reloc as required
	134	* by relaxation. */
	135	sym_diff_seen = 1;
	136	sym_diff_val = sym->st_value;
	137	break;
	138
	139	case R_MN10300_ALIGN:
	140	/* Just ignore the ALIGN relocs.
	141	* Only interesting if kernel performed relaxation. */
	142	continue;
	143
b920de1b DH	144	default:
	145	printk(KERN_ERR "module %s: Unknown relocation: %u\n",
	146	me->name, ELF32_R_TYPE(rel[i].r_info));
	147	return -ENOEXEC;
	148	}
	149	}
5ae8606d MS	150	if (sym_diff_seen) {
	151	printk(KERN_ERR "module %s: Nothing follows SYM_DIFF relocation: %u\n",
	152	me->name, ELF32_R_TYPE(rel[i].r_info));
	153	return -ENOEXEC;
	154	}
b920de1b DH	155	return 0;
b920de1b DH	156	}