/* * arch/xtensa/kernel/module.c * * Module support. * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2006 Tensilica Inc. * * Chris Zankel <chris@zankel.net> * */ #include <linux/module.h>#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/cache.h> #undef DEBUG_RELOCATE static intdecode_calln_opcode (unsigned char *location){#ifdef __XTENSA_EB__	return (location[0] & 0xf0) == 0x50;#endif#ifdef __XTENSA_EL__	return (location[0] & 0xf) == 0x5;#endif} static intdecode_l32r_opcode (unsigned char *location){#ifdef __XTENSA_EB__	return (location[0] & 0xf0) == 0x10;#endif#ifdef __XTENSA_EL__	return (location[0] & 0xf) == 0x1;#endif} int apply_relocate_add(Elf32_Shdr *sechdrs,		       const char *strtab,		       unsigned int symindex,		       unsigned int relsec,		       struct module *mod){	unsigned int i;	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;	Elf32_Sym *sym;	unsigned char *location;	uint32_t value; #ifdef DEBUG_RELOCATE	printk("Applying relocate section %u to %u\n", relsec,	       sechdrs[relsec].sh_info);#endif	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {		location = (char *)sechdrs[sechdrs[relsec].sh_info].sh_addr			+ rela[i].r_offset;		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr			+ ELF32_R_SYM(rela[i].r_info);		value = sym->st_value + rela[i].r_addend; 		switch (ELF32_R_TYPE(rela[i].r_info)) {		case R_XTENSA_NONE:		case R_XTENSA_DIFF8:		case R_XTENSA_DIFF16:		case R_XTENSA_DIFF32:		case R_XTENSA_ASM_EXPAND:			break; 		case R_XTENSA_32:		case R_XTENSA_PLT:			*(uint32_t *)location += value;			break; 		case R_XTENSA_SLOT0_OP:			if (decode_calln_opcode(location)) {				value -= ((unsigned long)location & -4) + 4;				if ((value & 3) != 0 ||				    ((value + (1 << 19)) >> 20) != 0) {					printk("%s: relocation out of range, "					       "section %d reloc %d "					       "sym '%s'\n",					       mod->name, relsec, i,					       strtab + sym->st_name);					return -ENOEXEC;				}				value = (signed int)value >> 2;#ifdef __XTENSA_EB__				location[0] = ((location[0] & ~0x3) |					    ((value >> 16) & 0x3));				location[1] = (value >> 8) & 0xff;				location[2] = value & 0xff;#endif#ifdef __XTENSA_EL__				location[0] = ((location[0] & ~0xc0) |					    ((value << 6) & 0xc0));				location[1] = (value >> 2) & 0xff;				location[2] = (value >> 10) & 0xff;#endif			} else if (decode_l32r_opcode(location)) {				value -= (((unsigned long)location + 3) & -4);				if ((value & 3) != 0 ||				    (signed int)value >> 18 != -1) {					printk("%s: relocation out of range, "					       "section %d reloc %d "					       "sym '%s'\n",					       mod->name, relsec, i,					       strtab + sym->st_name);					return -ENOEXEC;				}				value = (signed int)value >> 2; #ifdef __XTENSA_EB__				location[1] = (value >> 8) & 0xff;				location[2] = value & 0xff;#endif#ifdef __XTENSA_EL__				location[1] = value & 0xff;				location[2] = (value >> 8) & 0xff;#endif			}			/* FIXME: Ignore any other opcodes.  The Xtensa			   assembler currently assumes that the linker will			   always do relaxation and so all PC-relative			   operands need relocations.  (The assembler also			   writes out the tentative PC-relative values,			   assuming no link-time relaxation, so it is usually			   safe to ignore the relocations.)  If the			   assembler's "--no-link-relax" flag can be made to			   work, and if all kernel modules can be assembled			   with that flag, then unexpected relocations could			   be detected here.  */			break; 		case R_XTENSA_SLOT1_OP:		case R_XTENSA_SLOT2_OP:		case R_XTENSA_SLOT3_OP:		case R_XTENSA_SLOT4_OP:		case R_XTENSA_SLOT5_OP:		case R_XTENSA_SLOT6_OP:		case R_XTENSA_SLOT7_OP:		case R_XTENSA_SLOT8_OP:		case R_XTENSA_SLOT9_OP:		case R_XTENSA_SLOT10_OP:		case R_XTENSA_SLOT11_OP:		case R_XTENSA_SLOT12_OP:		case R_XTENSA_SLOT13_OP:		case R_XTENSA_SLOT14_OP:			printk("%s: unexpected FLIX relocation: %u\n",			       mod->name,			       ELF32_R_TYPE(rela[i].r_info));			return -ENOEXEC; 		case R_XTENSA_SLOT0_ALT:		case R_XTENSA_SLOT1_ALT:		case R_XTENSA_SLOT2_ALT:		case R_XTENSA_SLOT3_ALT:		case R_XTENSA_SLOT4_ALT:		case R_XTENSA_SLOT5_ALT:		case R_XTENSA_SLOT6_ALT:		case R_XTENSA_SLOT7_ALT:		case R_XTENSA_SLOT8_ALT:		case R_XTENSA_SLOT9_ALT:		case R_XTENSA_SLOT10_ALT:		case R_XTENSA_SLOT11_ALT:		case R_XTENSA_SLOT12_ALT:		case R_XTENSA_SLOT13_ALT:		case R_XTENSA_SLOT14_ALT:			printk("%s: unexpected ALT relocation: %u\n",			       mod->name,			       ELF32_R_TYPE(rela[i].r_info));			return -ENOEXEC; 		default:			printk("%s: unexpected relocation: %u\n",			       mod->name,			       ELF32_R_TYPE(rela[i].r_info));			return -ENOEXEC;		}	}	return 0;}