| /* |
| * 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 <util.h> |
| |
| #include <libyasm.h> |
| #define YASM_OBJFMT_ELF_INTERNAL |
| #include "elf.h" |
| #include "elf-machine.h" |
| |
| static elf_machine_ssym elf_x86_x86_ssyms[] = { |
| {"plt", ELF_SSYM_SYM_RELATIVE, R_386_PLT32, 32}, |
| {"gotoff", 0, R_386_GOTOFF, 32}, |
| /* special one for NASM */ |
| {"gotpc", ELF_SSYM_CURPOS_ADJUST, R_386_GOTPC, 32}, |
| {"tlsgd", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_GD, 32}, |
| {"tlsldm", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_LDM, 32}, |
| {"gottpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_IE_32, 32}, |
| {"tpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_LE_32, 32}, |
| {"ntpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_LE, 32}, |
| {"dtpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_LDO_32, 32}, |
| {"gotntpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_GOTIE, 32}, |
| {"indntpoff", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_IE, 32}, |
| {"got", ELF_SSYM_SYM_RELATIVE, R_386_GOT32, 32}, |
| {"tlsdesc", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_GOTDESC, 32}, |
| {"tlscall", ELF_SSYM_SYM_RELATIVE|ELF_SSYM_THREAD_LOCAL, |
| R_386_TLS_DESC_CALL, 32} |
| }; |
| |
| static int |
| elf_x86_x86_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)) != 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, |
| unsigned long offset) |
| { |
| if (!reloc->wrt && reloc->is_GOT_sym && reloc->valsize == 32 && offset != 0) |
| { |
| yasm_intnum *off_intn = yasm_intnum_create_uint(offset); |
| yasm_intnum_calc(intn, YASM_EXPR_ADD, off_intn); |
| yasm_intnum_destroy(off_intn); |
| } |
| return; /* .rel: Leave addend in intn */ |
| } |
| |
| static unsigned int |
| elf_x86_x86_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; |
| } |
| return (unsigned char) ssym->reloc; |
| } else if (reloc->is_GOT_sym && reloc->valsize == 32) { |
| return (unsigned char) R_386_GOTPC; |
| } 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; |
| } |
| |
| 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 |
| }; |
