1fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta/* 2fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * 4fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * This program is free software; you can redistribute it and/or modify 5fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * it under the terms of the GNU General Public License version 2 as 6fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * published by the Free Software Foundation. 7fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta */ 8fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 9fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/module.h> 10fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/moduleloader.h> 11fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/kernel.h> 12fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/elf.h> 13fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/vmalloc.h> 14fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/slab.h> 15fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/fs.h> 16fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta#include <linux/string.h> 17854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#include <asm/unwind.h> 18fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 19fa1c3ff935179453801d763940c38c3ac2d581ebVineet Guptastatic inline void arc_write_me(unsigned short *addr, unsigned long value) 20fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta{ 21fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta *addr = (value & 0xffff0000) >> 16; 22fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta *(addr + 1) = (value & 0xffff); 23fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta} 24fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 25854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta/* ARC specific section quirks - before relocation loop in generic loader 26854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * 27854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * For dwarf unwinding out of modules, this needs to 28854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * 1. Ensure the .debug_frame is allocatable (ARC Linker bug: despite 29854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * -fasynchronous-unwind-tables it doesn't). 30854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * 2. Since we are iterating thru sec hdr tbl anyways, make a note of 31854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * the exact section index, for later use. 32854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta */ 33854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Guptaint module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, 34854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta char *secstr, struct module *mod) 35854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta{ 36854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#ifdef CONFIG_ARC_DW2_UNWIND 37854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta int i; 38854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 39854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta mod->arch.unw_sec_idx = 0; 40854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta mod->arch.unw_info = NULL; 41854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 42854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta for (i = 1; i < hdr->e_shnum; i++) { 43854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta if (strcmp(secstr+sechdrs[i].sh_name, ".debug_frame") == 0) { 44854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta sechdrs[i].sh_flags |= SHF_ALLOC; 45854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta mod->arch.unw_sec_idx = i; 46854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta break; 47854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta } 48854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta } 49854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#endif 50955ad5959f913bd340ecb8d5e78d03ef7d1b0392Sachin Kamat return 0; 51854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta} 52854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 53854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Guptavoid module_arch_cleanup(struct module *mod) 54854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta{ 55854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#ifdef CONFIG_ARC_DW2_UNWIND 56854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta if (mod->arch.unw_info) 57854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta unwind_remove_table(mod->arch.unw_info, 0); 58854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#endif 59854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta} 60854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 61fa1c3ff935179453801d763940c38c3ac2d581ebVineet Guptaint apply_relocate_add(Elf32_Shdr *sechdrs, 62fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta const char *strtab, 63fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta unsigned int symindex, /* sec index for sym tbl */ 64fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta unsigned int relsec, /* sec index for relo sec */ 65fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta struct module *module) 66fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta{ 67fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta int i, n; 68fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr; 69fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta Elf32_Sym *sym_entry, *sym_sec; 70fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta Elf32_Addr relocation; 71fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta Elf32_Addr location; 72fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta Elf32_Addr sec_to_patch; 73fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta int relo_type; 74fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 75fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr; 76fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr; 77fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta n = sechdrs[relsec].sh_size / sizeof(*rel_entry); 78fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 79fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("\n========== Module Sym reloc ===========================\n"); 80fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("Section to fixup %x\n", sec_to_patch); 81fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("=========================================================\n"); 82fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n"); 83fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("=========================================================\n"); 84fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 85fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta /* Loop thru entries in relocation section */ 86fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta for (i = 0; i < n; i++) { 87fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 88fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta /* This is where to make the change */ 89fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta location = sec_to_patch + rel_entry[i].r_offset; 90fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 91fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta /* This is the symbol it is referring to. Note that all 92fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta undefined symbols have been resolved. */ 93fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info); 94fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 95fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta relocation = sym_entry->st_value + rel_entry[i].r_addend; 96fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 97fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n", 98fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta rel_entry[i].r_offset, rel_entry[i].r_addend, 99fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta sym_entry->st_value, location, relocation, 100fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta strtab + sym_entry->st_name); 101fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 102fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta /* This assumes modules are built with -mlong-calls 103fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * so any branches/jumps are absolute 32 bit jmps 104fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * global data access again is abs 32 bit. 105fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta * Both of these are handled by same relocation type 106fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta */ 107fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta relo_type = ELF32_R_TYPE(rel_entry[i].r_info); 108fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 109fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta if (likely(R_ARC_32_ME == relo_type)) 110fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta arc_write_me((unsigned short *)location, relocation); 111fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta else if (R_ARC_32 == relo_type) 112fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta *((Elf32_Addr *) location) = relocation; 113fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta else 114fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta goto relo_err; 115fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 116fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta } 117fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta return 0; 118fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 119fa1c3ff935179453801d763940c38c3ac2d581ebVineet Guptarelo_err: 120fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta pr_err("%s: unknown relocation: %u\n", 121fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta module->name, ELF32_R_TYPE(rel_entry[i].r_info)); 122fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta return -ENOEXEC; 123fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta 124fa1c3ff935179453801d763940c38c3ac2d581ebVineet Gupta} 125854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 126854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta/* Just before lift off: After sections have been relocated, we add the 127854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * dwarf section to unwinder table pool 128854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * This couldn't be done in module_frob_arch_sections() because 129854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta * relocations had not been applied by then 130854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta */ 131854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Guptaint module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 132854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta struct module *mod) 133854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta{ 134854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#ifdef CONFIG_ARC_DW2_UNWIND 135854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta void *unw; 136854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta int unwsec = mod->arch.unw_sec_idx; 137854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta 138854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta if (unwsec) { 139854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr, 140854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta sechdrs[unwsec].sh_size); 141854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta mod->arch.unw_info = unw; 142854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta } 143854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta#endif 144955ad5959f913bd340ecb8d5e78d03ef7d1b0392Sachin Kamat return 0; 145854a0d95056c265d96cb449bc97bc5ef9bbed835Vineet Gupta} 146