arch/avr32/kernel/module.c - arm/linux - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}