1*fa1c3ff9SVineet Gupta /* 2*fa1c3ff9SVineet Gupta * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3*fa1c3ff9SVineet Gupta * 4*fa1c3ff9SVineet Gupta * This program is free software; you can redistribute it and/or modify 5*fa1c3ff9SVineet Gupta * it under the terms of the GNU General Public License version 2 as 6*fa1c3ff9SVineet Gupta * published by the Free Software Foundation. 7*fa1c3ff9SVineet Gupta */ 8*fa1c3ff9SVineet Gupta 9*fa1c3ff9SVineet Gupta #include <linux/module.h> 10*fa1c3ff9SVineet Gupta #include <linux/moduleloader.h> 11*fa1c3ff9SVineet Gupta #include <linux/kernel.h> 12*fa1c3ff9SVineet Gupta #include <linux/elf.h> 13*fa1c3ff9SVineet Gupta #include <linux/vmalloc.h> 14*fa1c3ff9SVineet Gupta #include <linux/slab.h> 15*fa1c3ff9SVineet Gupta #include <linux/fs.h> 16*fa1c3ff9SVineet Gupta #include <linux/string.h> 17*fa1c3ff9SVineet Gupta 18*fa1c3ff9SVineet Gupta static inline void arc_write_me(unsigned short *addr, unsigned long value) 19*fa1c3ff9SVineet Gupta { 20*fa1c3ff9SVineet Gupta *addr = (value & 0xffff0000) >> 16; 21*fa1c3ff9SVineet Gupta *(addr + 1) = (value & 0xffff); 22*fa1c3ff9SVineet Gupta } 23*fa1c3ff9SVineet Gupta 24*fa1c3ff9SVineet Gupta int apply_relocate_add(Elf32_Shdr *sechdrs, 25*fa1c3ff9SVineet Gupta const char *strtab, 26*fa1c3ff9SVineet Gupta unsigned int symindex, /* sec index for sym tbl */ 27*fa1c3ff9SVineet Gupta unsigned int relsec, /* sec index for relo sec */ 28*fa1c3ff9SVineet Gupta struct module *module) 29*fa1c3ff9SVineet Gupta { 30*fa1c3ff9SVineet Gupta int i, n; 31*fa1c3ff9SVineet Gupta Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr; 32*fa1c3ff9SVineet Gupta Elf32_Sym *sym_entry, *sym_sec; 33*fa1c3ff9SVineet Gupta Elf32_Addr relocation; 34*fa1c3ff9SVineet Gupta Elf32_Addr location; 35*fa1c3ff9SVineet Gupta Elf32_Addr sec_to_patch; 36*fa1c3ff9SVineet Gupta int relo_type; 37*fa1c3ff9SVineet Gupta 38*fa1c3ff9SVineet Gupta sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr; 39*fa1c3ff9SVineet Gupta sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr; 40*fa1c3ff9SVineet Gupta n = sechdrs[relsec].sh_size / sizeof(*rel_entry); 41*fa1c3ff9SVineet Gupta 42*fa1c3ff9SVineet Gupta pr_debug("\n========== Module Sym reloc ===========================\n"); 43*fa1c3ff9SVineet Gupta pr_debug("Section to fixup %x\n", sec_to_patch); 44*fa1c3ff9SVineet Gupta pr_debug("=========================================================\n"); 45*fa1c3ff9SVineet Gupta pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n"); 46*fa1c3ff9SVineet Gupta pr_debug("=========================================================\n"); 47*fa1c3ff9SVineet Gupta 48*fa1c3ff9SVineet Gupta /* Loop thru entries in relocation section */ 49*fa1c3ff9SVineet Gupta for (i = 0; i < n; i++) { 50*fa1c3ff9SVineet Gupta 51*fa1c3ff9SVineet Gupta /* This is where to make the change */ 52*fa1c3ff9SVineet Gupta location = sec_to_patch + rel_entry[i].r_offset; 53*fa1c3ff9SVineet Gupta 54*fa1c3ff9SVineet Gupta /* This is the symbol it is referring to. Note that all 55*fa1c3ff9SVineet Gupta undefined symbols have been resolved. */ 56*fa1c3ff9SVineet Gupta sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info); 57*fa1c3ff9SVineet Gupta 58*fa1c3ff9SVineet Gupta relocation = sym_entry->st_value + rel_entry[i].r_addend; 59*fa1c3ff9SVineet Gupta 60*fa1c3ff9SVineet Gupta pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n", 61*fa1c3ff9SVineet Gupta rel_entry[i].r_offset, rel_entry[i].r_addend, 62*fa1c3ff9SVineet Gupta sym_entry->st_value, location, relocation, 63*fa1c3ff9SVineet Gupta strtab + sym_entry->st_name); 64*fa1c3ff9SVineet Gupta 65*fa1c3ff9SVineet Gupta /* This assumes modules are built with -mlong-calls 66*fa1c3ff9SVineet Gupta * so any branches/jumps are absolute 32 bit jmps 67*fa1c3ff9SVineet Gupta * global data access again is abs 32 bit. 68*fa1c3ff9SVineet Gupta * Both of these are handled by same relocation type 69*fa1c3ff9SVineet Gupta */ 70*fa1c3ff9SVineet Gupta relo_type = ELF32_R_TYPE(rel_entry[i].r_info); 71*fa1c3ff9SVineet Gupta 72*fa1c3ff9SVineet Gupta if (likely(R_ARC_32_ME == relo_type)) 73*fa1c3ff9SVineet Gupta arc_write_me((unsigned short *)location, relocation); 74*fa1c3ff9SVineet Gupta else if (R_ARC_32 == relo_type) 75*fa1c3ff9SVineet Gupta *((Elf32_Addr *) location) = relocation; 76*fa1c3ff9SVineet Gupta else 77*fa1c3ff9SVineet Gupta goto relo_err; 78*fa1c3ff9SVineet Gupta 79*fa1c3ff9SVineet Gupta } 80*fa1c3ff9SVineet Gupta return 0; 81*fa1c3ff9SVineet Gupta 82*fa1c3ff9SVineet Gupta relo_err: 83*fa1c3ff9SVineet Gupta pr_err("%s: unknown relocation: %u\n", 84*fa1c3ff9SVineet Gupta module->name, ELF32_R_TYPE(rel_entry[i].r_info)); 85*fa1c3ff9SVineet Gupta return -ENOEXEC; 86*fa1c3ff9SVineet Gupta 87*fa1c3ff9SVineet Gupta } 88