/* *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, 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 License for more details. * *  You should have received a copy of the GNU General Public License *  along with this program; if not, write to the Free Software *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * *  Copyright (C) 2001 Rusty Russell. *  Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org) *  Copyright (C) 2005 Thiemo Seufer *  Copyright (C) 2015 Imagination Technologies Ltd. */ #include <linux/elf.h>#include <linux/err.h>#include <linux/errno.h>#include <linux/moduleloader.h> extern int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v); static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v){	*location = v; 	return 0;} static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v){	if (v % 4) {		pr_err("module %s: dangerous R_MIPS_26 RELA relocation\n",		       me->name);		return -ENOEXEC;	} 	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {		pr_err("module %s: relocation overflow\n", me->name);		return -ENOEXEC;	} 	*location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); 	return 0;} static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v){	*location = (*location & 0xffff0000) |		    ((((long long) v + 0x8000LL) >> 16) & 0xffff); 	return 0;} static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v){	*location = (*location & 0xffff0000) | (v & 0xffff); 	return 0;} static int apply_r_mips_pc_rela(struct module *me, u32 *location, Elf_Addr v,				unsigned bits){	unsigned long mask = GENMASK(bits - 1, 0);	unsigned long se_bits;	long offset; 	if (v % 4) {		pr_err("module %s: dangerous R_MIPS_PC%u RELA relocation\n",		       me->name, bits);		return -ENOEXEC;	} 	offset = ((long)v - (long)location) >> 2; 	/* check the sign bit onwards are identical - ie. we didn't overflow */	se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;	if ((offset & ~mask) != (se_bits & ~mask)) {		pr_err("module %s: relocation overflow\n", me->name);		return -ENOEXEC;	} 	*location = (*location & ~mask) | (offset & mask); 	return 0;} static int apply_r_mips_pc16_rela(struct module *me, u32 *location, Elf_Addr v){	return apply_r_mips_pc_rela(me, location, v, 16);} static int apply_r_mips_pc21_rela(struct module *me, u32 *location, Elf_Addr v){	return apply_r_mips_pc_rela(me, location, v, 21);} static int apply_r_mips_pc26_rela(struct module *me, u32 *location, Elf_Addr v){	return apply_r_mips_pc_rela(me, location, v, 26);} static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v){	*(Elf_Addr *)location = v; 	return 0;} static int apply_r_mips_higher_rela(struct module *me, u32 *location,				    Elf_Addr v){	*location = (*location & 0xffff0000) |		    ((((long long) v + 0x80008000LL) >> 32) & 0xffff); 	return 0;} static int apply_r_mips_highest_rela(struct module *me, u32 *location,				     Elf_Addr v){	*location = (*location & 0xffff0000) |		    ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); 	return 0;} static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,				Elf_Addr v) = {	[R_MIPS_NONE]		= apply_r_mips_none,	[R_MIPS_32]		= apply_r_mips_32_rela,	[R_MIPS_26]		= apply_r_mips_26_rela,	[R_MIPS_HI16]		= apply_r_mips_hi16_rela,	[R_MIPS_LO16]		= apply_r_mips_lo16_rela,	[R_MIPS_PC16]		= apply_r_mips_pc16_rela,	[R_MIPS_64]		= apply_r_mips_64_rela,	[R_MIPS_HIGHER]		= apply_r_mips_higher_rela,	[R_MIPS_HIGHEST]	= apply_r_mips_highest_rela,	[R_MIPS_PC21_S2]	= apply_r_mips_pc21_rela,	[R_MIPS_PC26_S2]	= apply_r_mips_pc26_rela,}; int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,		       unsigned int symindex, unsigned int relsec,		       struct module *me){	Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;	int (*handler)(struct module *me, u32 *location, Elf_Addr v);	Elf_Sym *sym;	u32 *location;	unsigned int i, type;	Elf_Addr v;	int res; 	pr_debug("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 it is referring to */		sym = (Elf_Sym *)sechdrs[symindex].sh_addr			+ ELF_MIPS_R_SYM(rel[i]);		if (sym->st_value >= -MAX_ERRNO) {			/* Ignore unresolved weak symbol */			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)				continue;			pr_warn("%s: Unknown symbol %s\n",			       me->name, strtab + sym->st_name);			return -ENOENT;		} 		type = ELF_MIPS_R_TYPE(rel[i]); 		if (type < ARRAY_SIZE(reloc_handlers_rela))			handler = reloc_handlers_rela[type];		else			handler = NULL; 		if (!handler) {			pr_err("%s: Unknown relocation type %u\n",			       me->name, type);			return -EINVAL;		} 		v = sym->st_value + rel[i].r_addend;		res = handler(me, location, v);		if (res)			return res;	} 	return 0;}