[linux.git] / arch / avr32 / kernel / module.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;
}
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* AVR32-specific kernel module loader
	3	*
	4	* Copyright (C) 2005-2006 Atmel Corporation
	5	*
	6	* GOT initialization parts are based on the s390 version
	7	* Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH,
	8	* IBM Corporation
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
623b0355	15	#include <linux/bug.h>
5f97f7f9	16	#include <linux/elf.h>
623b0355 HS	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/moduleloader.h>
5f97f7f9 HS	20	#include <linux/vmalloc.h>
5f97f7f9 HS	21
d453cded	22	void module_arch_freeing_init(struct module *mod)
5f97f7f9 HS	23	{
	24	vfree(mod->arch.syminfo);
	25	mod->arch.syminfo = NULL;
5f97f7f9 HS	26	}
	27
	28	static inline int check_rela(Elf32_Rela rela, struct module module,
	29	char strings, Elf32_Sym symbols)
	30	{
	31	struct mod_arch_syminfo *info;
	32
	33	info = module->arch.syminfo + ELF32_R_SYM(rela->r_info);
	34	switch (ELF32_R_TYPE(rela->r_info)) {
	35	case R_AVR32_GOT32:
	36	case R_AVR32_GOT16:
	37	case R_AVR32_GOT8:
	38	case R_AVR32_GOT21S:
	39	case R_AVR32_GOT18SW: /* mcall */
	40	case R_AVR32_GOT16S: /* ld.w */
	41	if (rela->r_addend != 0) {
	42	printk(KERN_ERR
	43	"GOT relocation against %s at offset %u with addend\n",
	44	strings + symbols[ELF32_R_SYM(rela->r_info)].st_name,
	45	rela->r_offset);
	46	return -ENOEXEC;
	47	}
	48	if (info->got_offset == -1UL) {
	49	info->got_offset = module->arch.got_size;
	50	module->arch.got_size += sizeof(void *);
	51	}
	52	pr_debug("GOT[%3lu] %s\n", info->got_offset,
	53	strings + symbols[ELF32_R_SYM(rela->r_info)].st_name);
	54	break;
	55	}
	56
	57	return 0;
	58	}
	59
	60	int module_frob_arch_sections(Elf_Ehdr hdr, Elf_Shdr sechdrs,
	61	char secstrings, struct module module)
	62	{
	63	Elf32_Shdr *symtab;
	64	Elf32_Sym *symbols;
	65	Elf32_Rela *rela;
	66	char *strings;
	67	int nrela, i, j;
	68	int ret;
	69
	70	/* Find the symbol table */
	71	symtab = NULL;
	72	for (i = 0; i < hdr->e_shnum; i++)
	73	switch (sechdrs[i].sh_type) {
	74	case SHT_SYMTAB:
	75	symtab = &sechdrs[i];
	76	break;
	77	}
	78	if (!symtab) {
	79	printk(KERN_ERR "module %s: no symbol table\n", module->name);
	80	return -ENOEXEC;
	81	}
	82
	83	/* Allocate room for one syminfo structure per symbol. */
	84	module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
	85	module->arch.syminfo = vmalloc(module->arch.nsyms
	86	* sizeof(struct mod_arch_syminfo));
	87	if (!module->arch.syminfo)
	88	return -ENOMEM;
	89
90	symbols = (void *)hdr + symtab->sh_offset;
91	strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset;
92	for (i = 0; i < module->arch.nsyms; i++) {
93	if (symbols[i].st_shndx == SHN_UNDEF &&
94	strcmp(strings + symbols[i].st_name,
95	"_GLOBAL_OFFSET_TABLE_") == 0)
96	/* "Define" it as absolute. */
97	symbols[i].st_shndx = SHN_ABS;
98	module->arch.syminfo[i].got_offset = -1UL;
99	module->arch.syminfo[i].got_initialized = 0;
100	}
101
102	/* Allocate GOT entries for symbols that need it. */
103	module->arch.got_size = 0;
104	for (i = 0; i < hdr->e_shnum; i++) {
105	if (sechdrs[i].sh_type != SHT_RELA)
106	continue;
107	nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela);
108	rela = (void *)hdr + sechdrs[i].sh_offset;
109	for (j = 0; j < nrela; j++) {
110	ret = check_rela(rela + j, module,
111	strings, symbols);
112	if (ret)
113	goto out_free_syminfo;
114	}
115	}
116
117	/*
118	* Increase core size to make room for GOT and set start
119	* offset for GOT.
120	*/
7523e4dc RR	121	module->core_layout.size = ALIGN(module->core_layout.size, 4);
	122	module->arch.got_offset = module->core_layout.size;
	123	module->core_layout.size += module->arch.got_size;
5f97f7f9 HS	124
	125	return 0;
	126
	127	out_free_syminfo:
	128	vfree(module->arch.syminfo);
	129	module->arch.syminfo = NULL;
	130
	131	return ret;
	132	}
	133
	134	static inline int reloc_overflow(struct module module, const char reloc_name,
	135	Elf32_Addr relocation)
	136	{
	137	printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n",
	138	module->name, (unsigned long)relocation, reloc_name);
	139	return -ENOEXEC;
	140	}
	141
	142	#define get_u16(loc) (((uint16_t )loc))
	143	#define put_u16(loc, val) (((uint16_t )loc) = (val))
	144
	145	int apply_relocate_add(Elf32_Shdr sechdrs, const char strtab,
	146	unsigned int symindex, unsigned int relindex,
	147	struct module *module)
	148	{
	149	Elf32_Shdr *symsec = sechdrs + symindex;
	150	Elf32_Shdr *relsec = sechdrs + relindex;
	151	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
	152	Elf32_Rela rel = (void )relsec->sh_addr;
	153	unsigned int i;
	154	int ret = 0;
	155
	156	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) {
	157	struct mod_arch_syminfo *info;
	158	Elf32_Sym *sym;
	159	Elf32_Addr relocation;
	160	uint32_t *location;
	161	uint32_t value;
	162
	163	location = (void *)dstsec->sh_addr + rel->r_offset;
	164	sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info);
	165	relocation = sym->st_value + rel->r_addend;
	166
	167	info = module->arch.syminfo + ELF32_R_SYM(rel->r_info);
	168
	169	/* Initialize GOT entry if necessary */
	170	switch (ELF32_R_TYPE(rel->r_info)) {
	171	case R_AVR32_GOT32:
	172	case R_AVR32_GOT16:
	173	case R_AVR32_GOT8:
	174	case R_AVR32_GOT21S:
	175	case R_AVR32_GOT18SW:
	176	case R_AVR32_GOT16S:
	177	if (!info->got_initialized) {
	178	Elf32_Addr *gotent;
	179
7523e4dc	180	gotent = (module->core_layout.base
5f97f7f9 HS	181	+ module->arch.got_offset
	182	+ info->got_offset);
	183	*gotent = relocation;
	184	info->got_initialized = 1;
	185	}
	186
	187	relocation = info->got_offset;
	188	break;
	189	}
	190
	191	switch (ELF32_R_TYPE(rel->r_info)) {
	192	case R_AVR32_32:
	193	case R_AVR32_32_CPENT:
	194	*location = relocation;
	195	break;
	196	case R_AVR32_22H_PCREL:
	197	relocation -= (Elf32_Addr)location;
	198	if ((relocation & 0xffe00001) != 0
	199	&& (relocation & 0xffc00001) != 0xffc00000)
	200	return reloc_overflow(module,
	201	"R_AVR32_22H_PCREL",
	202	relocation);
	203	relocation >>= 1;
	204
	205	value = *location;
	206	value = ((value & 0xe1ef0000)
	207	\| (relocation & 0xffff)
	208	\| ((relocation & 0x10000) << 4)
	209	\| ((relocation & 0x1e0000) << 8));
	210	*location = value;
	211	break;
	212	case R_AVR32_11H_PCREL:
	213	relocation -= (Elf32_Addr)location;
	214	if ((relocation & 0xfffffc01) != 0
	215	&& (relocation & 0xfffff801) != 0xfffff800)
	216	return reloc_overflow(module,
	217	"R_AVR32_11H_PCREL",
	218	relocation);
	219	value = get_u16(location);
	220	value = ((value & 0xf00c)
	221	\| ((relocation & 0x1fe) << 3)
	222	\| ((relocation & 0x600) >> 9));
	223	put_u16(location, value);
	224	break;
	225	case R_AVR32_9H_PCREL:
	226	relocation -= (Elf32_Addr)location;
	227	if ((relocation & 0xffffff01) != 0
	228	&& (relocation & 0xfffffe01) != 0xfffffe00)
	229	return reloc_overflow(module,
	230	"R_AVR32_9H_PCREL",
	231	relocation);
	232	value = get_u16(location);
	233	value = ((value & 0xf00f)
	234	\| ((relocation & 0x1fe) << 3));
	235	put_u16(location, value);
	236	break;
	237	case R_AVR32_9UW_PCREL:
	238	relocation -= ((Elf32_Addr)location) & 0xfffffffc;
	239	if ((relocation & 0xfffffc03) != 0)
	240	return reloc_overflow(module,
	241	"R_AVR32_9UW_PCREL",
	242	relocation);
	243	value = get_u16(location);
	244	value = ((value & 0xf80f)
245	\| ((relocation & 0x1fc) << 2));
246	put_u16(location, value);
247	break;
248	case R_AVR32_GOTPC:
249	/*
250	* R6 = PC - (PC - GOT)
251	*
252	* At this point, relocation contains the
253	* value of PC. Just subtract the value of
254	* GOT, and we're done.
255	*/
6ea850b5	256	pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n",
5f97f7f9	257	relocation, module->arch.got_offset,
7523e4dc RR	258	module->core_layout.base);
7523e4dc RR	259	relocation -= ((unsigned long)module->core_layout.base
5f97f7f9 HS	260	+ module->arch.got_offset);
	261	*location = relocation;
	262	break;
	263	case R_AVR32_GOT18SW:
	264	if ((relocation & 0xfffe0003) != 0
e68c636d	265	&& (relocation & 0xfffc0000) != 0xfffc0000)
5f97f7f9 HS	266	return reloc_overflow(module, "R_AVR32_GOT18SW",
	267	relocation);
	268	relocation >>= 2;
	269	/* fall through */
	270	case R_AVR32_GOT16S:
	271	if ((relocation & 0xffff8000) != 0
	272	&& (relocation & 0xffff0000) != 0xffff0000)
	273	return reloc_overflow(module, "R_AVR32_GOT16S",
	274	relocation);
6ea850b5	275	pr_debug("GOT reloc @ 0x%x -> %u\n",
5f97f7f9 HS	276	rel->r_offset, relocation);
	277	value = *location;
	278	value = ((value & 0xffff0000)
	279	\| (relocation & 0xffff));
	280	*location = value;
	281	break;
	282
	283	default:
	284	printk(KERN_ERR "module %s: Unknown relocation: %u\n",
	285	module->name, ELF32_R_TYPE(rel->r_info));
	286	return -ENOEXEC;
	287	}
	288	}
	289
	290	return ret;
	291	}