| /* |
| * 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); |
| } |
| |
| /* |
| * This gets called before relocation loop in generic loader |
| * Make a note of the section index of unwinding section |
| */ |
| 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, ".eh_frame") == 0) { |
| 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)) /* ME ( S + A ) */ |
| arc_write_me((unsigned short *)location, relocation); |
| else if (R_ARC_32 == relo_type) /* ( S + A ) */ |
| *((Elf32_Addr *) location) = relocation; |
| else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */ |
| *((Elf32_Addr *) location) = relocation - location; |
| 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; |
| } |