/* * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * * 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/module.h>#include <linux/moduleloader.h>#include <linux/kernel.h>#include <linux/elf.h>#include <linux/vmalloc.h>#include <linux/slab.h>#include <linux/fs.h>#include <linux/string.h>#include <asm/unwind.h> static inline void arc_write_me(unsigned short *addr, unsigned long value){	*addr = (value & 0xffff0000) >> 16;	*(addr + 1) = (value & 0xffff);} /* ARC specific section quirks - before relocation loop in generic loader * * For dwarf unwinding out of modules, this needs to * 1. Ensure the .debug_frame is allocatable (ARC Linker bug: despite *    -fasynchronous-unwind-tables it doesn't). * 2. Since we are iterating thru sec hdr tbl anyways, make a note of *    the exact section index, for later use. */int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,			      char *secstr, struct module *mod){#ifdef CONFIG_ARC_DW2_UNWIND	int i; 	mod->arch.unw_sec_idx = 0;	mod->arch.unw_info = NULL; 	for (i = 1; i < hdr->e_shnum; i++) {		if (strcmp(secstr+sechdrs[i].sh_name, ".debug_frame") == 0) {			sechdrs[i].sh_flags |= SHF_ALLOC;			mod->arch.unw_sec_idx = i;			break;		}	}#endif    return 0;} void module_arch_cleanup(struct module *mod){#ifdef CONFIG_ARC_DW2_UNWIND	if (mod->arch.unw_info)		unwind_remove_table(mod->arch.unw_info, 0);#endif} int apply_relocate_add(Elf32_Shdr *sechdrs,		       const char *strtab,		       unsigned int symindex,	/* sec index for sym tbl */		       unsigned int relsec,	/* sec index for relo sec */		       struct module *module){	int i, n;	Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;	Elf32_Sym *sym_entry, *sym_sec;	Elf32_Addr relocation;	Elf32_Addr location;	Elf32_Addr sec_to_patch;	int relo_type; 	sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr;	sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;	n = sechdrs[relsec].sh_size / sizeof(*rel_entry); 	pr_debug("\n========== Module Sym reloc ===========================\n");	pr_debug("Section to fixup %x\n", sec_to_patch);	pr_debug("=========================================================\n");	pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n");	pr_debug("=========================================================\n"); 	/* Loop thru entries in relocation section */	for (i = 0; i < n; i++) { 		/* This is where to make the change */		location = sec_to_patch + rel_entry[i].r_offset; 		/* This is the symbol it is referring to.  Note that all		   undefined symbols have been resolved.  */		sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info); 		relocation = sym_entry->st_value + rel_entry[i].r_addend; 		pr_debug("\t%x\t\t%x\t\t%x  %x %x [%s]\n",			rel_entry[i].r_offset, rel_entry[i].r_addend,			sym_entry->st_value, location, relocation,			strtab + sym_entry->st_name); 		/* This assumes modules are built with -mlong-calls		 * so any branches/jumps are absolute 32 bit jmps		 * global data access again is abs 32 bit.		 * Both of these are handled by same relocation type		 */		relo_type = ELF32_R_TYPE(rel_entry[i].r_info); 		if (likely(R_ARC_32_ME == relo_type))			arc_write_me((unsigned short *)location, relocation);		else if (R_ARC_32 == relo_type)			*((Elf32_Addr *) location) = relocation;		else			goto relo_err; 	}	return 0; relo_err:	pr_err("%s: unknown relocation: %u\n",		module->name, ELF32_R_TYPE(rel_entry[i].r_info));	return -ENOEXEC; } /* Just before lift off: After sections have been relocated, we add the * dwarf section to unwinder table pool * This couldn't be done in module_frob_arch_sections() because * relocations had not been applied by then */int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,		    struct module *mod){#ifdef CONFIG_ARC_DW2_UNWIND	void *unw;	int unwsec = mod->arch.unw_sec_idx; 	if (unwsec) {		unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,				       sechdrs[unwsec].sh_size);		mod->arch.unw_info = unw;	}#endif    return 0;}