/* * ELF object format helpers - x86:amd64 * * 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 #include #define YASM_OBJFMT_ELF_INTERNAL #include "elf.h" #include "elf-machine.h" static elf_machine_ssym elf_x86_amd64_ssyms[] = { {"pltoff", ELF_SSYM_SYM_RELATIVE, R_X86_64_PLTOFF64, 64}, {"plt", ELF_SSYM_SYM_RELATIVE, R_X86_64_PLT32, 32}, {"gotplt", ELF_SSYM_SYM_RELATIVE, R_X86_64_GOTPLT64, 64}, {"gotoff", ELF_SSYM_SYM_RELATIVE, R_X86_64_GOTOFF64, 64}, {"gotpcrel", ELF_SSYM_SYM_RELATIVE, R_X86_64_GOTPCREL, 32}, {"tlsgd", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_TLSGD, 32}, {"tlsld", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_TLSLD, 32}, {"gottpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_GOTTPOFF, 32}, {"tpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_TPOFF32, 32}, {"dtpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_DTPOFF32, 32}, {"got", ELF_SSYM_SYM_RELATIVE, R_X86_64_GOT32, 32}, {"tlsdesc", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_GOTPC32_TLSDESC, 32}, {"tlscall", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, R_X86_64_TLSDESC_CALL, 32} }; static int elf_x86_amd64_accepts_reloc(size_t val, yasm_symrec *wrt) { if (wrt) { const elf_machine_ssym *ssym = (elf_machine_ssym *) yasm_symrec_get_data(wrt, &elf_ssym_symrec_data); if (!ssym || val != ssym->size) return 0; return 1; } return (val&(val-1)) ? 0 : ((val & (8|16|32|64)) != 0); } static void elf_x86_amd64_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_8(bufp, ELF64_ST_INFO(entry->bind, entry->type)); YASM_WRITE_8(bufp, ELF64_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); } YASM_WRITE_64I_L(bufp, value_intn); YASM_WRITE_64I_L(bufp, size_intn); } static void elf_x86_amd64_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_64Z_L(bufp, shead->flags); YASM_WRITE_64Z_L(bufp, 0); /* vmem address */ YASM_WRITE_64Z_L(bufp, shead->offset); YASM_WRITE_64I_L(bufp, shead->size); YASM_WRITE_32_L(bufp, shead->link); YASM_WRITE_32_L(bufp, shead->info); YASM_WRITE_64Z_L(bufp, shead->align); YASM_WRITE_64Z_L(bufp, shead->entsize); } static void elf_x86_amd64_write_secthead_rel(unsigned char *bufp, elf_secthead *shead, elf_section_index symtab_idx, elf_section_index sindex) { yasm_intnum *nreloc; yasm_intnum *relocsize; YASM_WRITE_32_L(bufp, shead->rel_name ? shead->rel_name->index : 0); YASM_WRITE_32_L(bufp, SHT_RELA); YASM_WRITE_64Z_L(bufp, 0); YASM_WRITE_64Z_L(bufp, 0); YASM_WRITE_64Z_L(bufp, shead->rel_offset); nreloc = yasm_intnum_create_uint(shead->nreloc); relocsize = yasm_intnum_create_uint(RELOC64A_SIZE); yasm_intnum_calc(relocsize, YASM_EXPR_MUL, nreloc); YASM_WRITE_64I_L(bufp, relocsize); /* size */ yasm_intnum_destroy(nreloc); yasm_intnum_destroy(relocsize); YASM_WRITE_32_L(bufp, symtab_idx); /* link: symtab index */ YASM_WRITE_32_L(bufp, shead->index); /* info: relocated's index */ YASM_WRITE_64Z_L(bufp, RELOC64_ALIGN); /* align */ YASM_WRITE_64Z_L(bufp, RELOC64A_SIZE); /* entity size */ } static void elf_x86_amd64_handle_reloc_addend(yasm_intnum *intn, elf_reloc_entry *reloc, unsigned long offset) { /* .rela: copy value out as addend, replace original with 0 */ reloc->addend = yasm_intnum_copy(intn); yasm_intnum_zero(intn); } static unsigned int elf_x86_amd64_map_reloc_info_to_type(elf_reloc_entry *reloc) { if (reloc->wrt) { const elf_machine_ssym *ssym = (elf_machine_ssym *) yasm_symrec_get_data(reloc->wrt, &elf_ssym_symrec_data); if (!ssym || reloc->valsize != ssym->size) yasm_internal_error(N_("Unsupported WRT")); /* Force TLS type; this is required by the linker. */ if (ssym->sym_rel & ELF_SSYM_THREAD_LOCAL) { elf_symtab_entry *esym; esym = yasm_symrec_get_data(reloc->reloc.sym, &elf_symrec_data); if (esym) esym->type = STT_TLS; } /* Map PC-relative GOT to appropriate relocation */ if (reloc->rtype_rel && ssym->reloc == R_X86_64_GOT32) return (unsigned char) R_X86_64_GOTPCREL; return (unsigned char) ssym->reloc; } else if (reloc->is_GOT_sym && reloc->valsize == 32) { return (unsigned char) R_X86_64_GOTPC32; } else if (reloc->is_GOT_sym && reloc->valsize == 64) { return (unsigned char) R_X86_64_GOTPC64; } else if (reloc->rtype_rel) { switch (reloc->valsize) { case 8: return (unsigned char) R_X86_64_PC8; case 16: return (unsigned char) R_X86_64_PC16; case 32: return (unsigned char) R_X86_64_PC32; case 64: return (unsigned char) R_X86_64_PC64; default: yasm_internal_error(N_("Unsupported relocation size")); } } else { switch (reloc->valsize) { case 8: return (unsigned char) R_X86_64_8; case 16: return (unsigned char) R_X86_64_16; case 32: return (unsigned char) R_X86_64_32; case 64: return (unsigned char) R_X86_64_64; default: yasm_internal_error(N_("Unsupported relocation size")); } } return 0; } static void elf_x86_amd64_write_reloc(unsigned char *bufp, elf_reloc_entry *reloc, unsigned int r_type, unsigned int r_sym) { YASM_WRITE_64I_L(bufp, reloc->reloc.addr); /*YASM_WRITE_64_L(bufp, ELF64_R_INFO(r_sym, r_type));*/ YASM_WRITE_64C_L(bufp, r_sym, r_type); if (reloc->addend) YASM_WRITE_64I_L(bufp, reloc->addend); else { YASM_WRITE_32_L(bufp, 0); YASM_WRITE_32_L(bufp, 0); } } static void elf_x86_amd64_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, ELFCLASS64); /* elf class */ YASM_WRITE_8(bufp, ELFDATA2LSB); /* data encoding :: MSB? */ YASM_WRITE_8(bufp, EV_CURRENT); /* elf version */ YASM_WRITE_8(bufp, ELFOSABI_SYSV); /* os/abi */ YASM_WRITE_8(bufp, 0); /* SYSV v3 ABI=0 */ 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_X86_64); /* e_machine - or others */ YASM_WRITE_32_L(bufp, EV_CURRENT); /* elf version */ YASM_WRITE_64Z_L(bufp, 0); /* e_entry */ YASM_WRITE_64Z_L(bufp, 0); /* e_phoff */ YASM_WRITE_64Z_L(bufp, secthead_addr); /* e_shoff secthead off */ YASM_WRITE_32_L(bufp, 0); /* e_flags */ YASM_WRITE_16_L(bufp, EHDR64_SIZE); /* e_ehsize */ YASM_WRITE_16_L(bufp, 0); /* e_phentsize */ YASM_WRITE_16_L(bufp, 0); /* e_phnum */ YASM_WRITE_16_L(bufp, SHDR64_SIZE); /* e_shentsize */ YASM_WRITE_16_L(bufp, secthead_count); /* e_shnum */ YASM_WRITE_16_L(bufp, shstrtab_index); /* e_shstrndx */ *bufpp = bufp; } const elf_machine_handler elf_machine_handler_x86_amd64 = { "x86", "amd64", ".rela", SYMTAB64_SIZE, SYMTAB64_ALIGN, RELOC64A_SIZE, SHDR64_SIZE, EHDR64_SIZE, elf_x86_amd64_accepts_reloc, elf_x86_amd64_write_symtab_entry, elf_x86_amd64_write_secthead, elf_x86_amd64_write_secthead_rel, elf_x86_amd64_handle_reloc_addend, elf_x86_amd64_map_reloc_info_to_type, elf_x86_amd64_write_reloc, elf_x86_amd64_write_proghead, elf_x86_amd64_ssyms, sizeof(elf_x86_amd64_ssyms)/sizeof(elf_x86_amd64_ssyms[0]), 64 };