/* * ELF object format helpers - x86:x86 * * Copyright (C) 2004-2007 Michael Urman * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include /*@unused@*/ RCSID("$Id: elf-x86-x86.c 1976 2007-09-21 16:48:25Z peter $"); #include #define YASM_OBJFMT_ELF_INTERNAL #include "elf.h" #include "elf-machine.h" enum ssym_index { SSYM_GOTPC = 0, SSYM_GOTOFF, SSYM_GOT, SSYM_PLT }; static int elf_x86_x86_accepts_reloc(size_t val, yasm_symrec *wrt, yasm_symrec **ssyms) { if (wrt) { if ((wrt == ssyms[SSYM_GOTPC] && val == 32) || (wrt == ssyms[SSYM_GOTOFF] && val == 32) || (wrt == ssyms[SSYM_GOT] && val == 32) || (wrt == ssyms[SSYM_PLT] && val == 32)) return 1; else return 0; } return (val&(val-1)) ? 0 : ((val & (8|16|32)) != 0); } static void elf_x86_x86_write_symtab_entry(unsigned char *bufp, elf_symtab_entry *entry, yasm_intnum *value_intn, yasm_intnum *size_intn) { YASM_WRITE_32_L(bufp, entry->name ? entry->name->index : 0); YASM_WRITE_32I_L(bufp, value_intn); YASM_WRITE_32I_L(bufp, size_intn); YASM_WRITE_8(bufp, ELF32_ST_INFO(entry->bind, entry->type)); YASM_WRITE_8(bufp, ELF32_ST_OTHER(entry->vis)); if (entry->sect) { elf_secthead *shead = yasm_section_get_data(entry->sect, &elf_section_data); if (!shead) yasm_internal_error(N_("symbol references section without data")); YASM_WRITE_16_L(bufp, shead->index); } else { YASM_WRITE_16_L(bufp, entry->index); } } static void elf_x86_x86_write_secthead(unsigned char *bufp, elf_secthead *shead) { YASM_WRITE_32_L(bufp, shead->name ? shead->name->index : 0); YASM_WRITE_32_L(bufp, shead->type); YASM_WRITE_32_L(bufp, shead->flags); YASM_WRITE_32_L(bufp, 0); /* vmem address */ YASM_WRITE_32_L(bufp, shead->offset); YASM_WRITE_32I_L(bufp, shead->size); YASM_WRITE_32_L(bufp, shead->link); YASM_WRITE_32_L(bufp, shead->info); YASM_WRITE_32_L(bufp, shead->align); YASM_WRITE_32_L(bufp, shead->entsize); } static void elf_x86_x86_write_secthead_rel(unsigned char *bufp, elf_secthead *shead, elf_section_index symtab_idx, elf_section_index sindex) { YASM_WRITE_32_L(bufp, shead->rel_name ? shead->rel_name->index : 0); YASM_WRITE_32_L(bufp, SHT_REL); YASM_WRITE_32_L(bufp, 0); YASM_WRITE_32_L(bufp, 0); YASM_WRITE_32_L(bufp, shead->rel_offset); YASM_WRITE_32_L(bufp, RELOC32_SIZE * shead->nreloc);/* size */ YASM_WRITE_32_L(bufp, symtab_idx); /* link: symtab index */ YASM_WRITE_32_L(bufp, shead->index); /* info: relocated's index */ YASM_WRITE_32_L(bufp, RELOC32_ALIGN); /* align */ YASM_WRITE_32_L(bufp, RELOC32_SIZE); /* entity size */ } static void elf_x86_x86_handle_reloc_addend(yasm_intnum *intn, elf_reloc_entry *reloc) { return; /* .rel: Leave addend in intn */ } static unsigned int elf_x86_x86_map_reloc_info_to_type(elf_reloc_entry *reloc, yasm_symrec **ssyms) { if (reloc->wrt) { if (reloc->wrt == ssyms[SSYM_GOTPC] && reloc->valsize == 32) return (unsigned char) R_386_GOTPC; else if (reloc->wrt == ssyms[SSYM_GOTOFF] && reloc->valsize == 32) return (unsigned char) R_386_GOTOFF; else if (reloc->wrt == ssyms[SSYM_GOT] && reloc->valsize == 32) return (unsigned char) R_386_GOT32; else if (reloc->wrt == ssyms[SSYM_PLT] && reloc->valsize == 32) return (unsigned char) R_386_PLT32; else yasm_internal_error(N_("Unsupported WRT")); } else if (reloc->rtype_rel) { switch (reloc->valsize) { case 8: return (unsigned char) R_386_PC8; case 16: return (unsigned char) R_386_PC16; case 32: return (unsigned char) R_386_PC32; default: yasm_internal_error(N_("Unsupported relocation size")); } } else { switch (reloc->valsize) { case 8: return (unsigned char) R_386_8; case 16: return (unsigned char) R_386_16; case 32: return (unsigned char) R_386_32; default: yasm_internal_error(N_("Unsupported relocation size")); } } return 0; } static void elf_x86_x86_write_reloc(unsigned char *bufp, elf_reloc_entry *reloc, unsigned int r_type, unsigned int r_sym) { YASM_WRITE_32I_L(bufp, reloc->reloc.addr); YASM_WRITE_32_L(bufp, ELF32_R_INFO((unsigned long)r_sym, (unsigned char)r_type)); } static void elf_x86_x86_write_proghead(unsigned char **bufpp, elf_offset secthead_addr, unsigned long secthead_count, elf_section_index shstrtab_index) { unsigned char *bufp = *bufpp; unsigned char *buf = bufp-4; YASM_WRITE_8(bufp, ELFCLASS32); /* elf class */ YASM_WRITE_8(bufp, ELFDATA2LSB); /* data encoding :: MSB? */ YASM_WRITE_8(bufp, EV_CURRENT); /* elf version */ while (bufp-buf < EI_NIDENT) /* e_ident padding */ YASM_WRITE_8(bufp, 0); YASM_WRITE_16_L(bufp, ET_REL); /* e_type - object file */ YASM_WRITE_16_L(bufp, EM_386); /* e_machine - or others */ YASM_WRITE_32_L(bufp, EV_CURRENT); /* elf version */ YASM_WRITE_32_L(bufp, 0); /* e_entry exection startaddr */ YASM_WRITE_32_L(bufp, 0); /* e_phoff program header off */ YASM_WRITE_32_L(bufp, secthead_addr); /* e_shoff section header off */ YASM_WRITE_32_L(bufp, 0); /* e_flags also by arch */ YASM_WRITE_16_L(bufp, EHDR32_SIZE); /* e_ehsize */ YASM_WRITE_16_L(bufp, 0); /* e_phentsize */ YASM_WRITE_16_L(bufp, 0); /* e_phnum */ YASM_WRITE_16_L(bufp, SHDR32_SIZE); /* e_shentsize */ YASM_WRITE_16_L(bufp, secthead_count); /* e_shnum */ YASM_WRITE_16_L(bufp, shstrtab_index); /* e_shstrndx */ *bufpp = bufp; } static elf_machine_ssym elf_x86_x86_ssyms[] = { {"..gotpc", ELF_SSYM_CURPOS_ADJUST}, {"..gotoff", 0}, {"..got", ELF_SSYM_SYM_RELATIVE}, {"..plt", 0} }; const elf_machine_handler elf_machine_handler_x86_x86 = { "x86", "x86", ".rel", SYMTAB32_SIZE, SYMTAB32_ALIGN, RELOC32_SIZE, SHDR32_SIZE, EHDR32_SIZE, elf_x86_x86_accepts_reloc, elf_x86_x86_write_symtab_entry, elf_x86_x86_write_secthead, elf_x86_x86_write_secthead_rel, elf_x86_x86_handle_reloc_addend, elf_x86_x86_map_reloc_info_to_type, elf_x86_x86_write_reloc, elf_x86_x86_write_proghead, elf_x86_x86_ssyms, sizeof(elf_x86_x86_ssyms)/sizeof(elf_x86_x86_ssyms[0]), 32 };