elf_data.c revision 164190
1164190Sjkoshy/*- 2164190Sjkoshy * Copyright (c) 2006 Joseph Koshy 3164190Sjkoshy * All rights reserved. 4164190Sjkoshy * 5164190Sjkoshy * Redistribution and use in source and binary forms, with or without 6164190Sjkoshy * modification, are permitted provided that the following conditions 7164190Sjkoshy * are met: 8164190Sjkoshy * 1. Redistributions of source code must retain the above copyright 9164190Sjkoshy * notice, this list of conditions and the following disclaimer. 10164190Sjkoshy * 2. Redistributions in binary form must reproduce the above copyright 11164190Sjkoshy * notice, this list of conditions and the following disclaimer in the 12164190Sjkoshy * documentation and/or other materials provided with the distribution. 13164190Sjkoshy * 14164190Sjkoshy * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15164190Sjkoshy * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16164190Sjkoshy * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17164190Sjkoshy * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18164190Sjkoshy * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19164190Sjkoshy * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20164190Sjkoshy * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21164190Sjkoshy * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22164190Sjkoshy * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23164190Sjkoshy * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24164190Sjkoshy * SUCH DAMAGE. 25164190Sjkoshy */ 26164190Sjkoshy 27164190Sjkoshy#include <sys/cdefs.h> 28164190Sjkoshy__FBSDID("$FreeBSD: head/lib/libelf/elf_data.c 164190 2006-11-11 17:16:35Z jkoshy $"); 29164190Sjkoshy 30164190Sjkoshy#include <assert.h> 31164190Sjkoshy#include <errno.h> 32164190Sjkoshy#include <libelf.h> 33164190Sjkoshy#include <stdlib.h> 34164190Sjkoshy 35164190Sjkoshy#include "_libelf.h" 36164190Sjkoshy 37164190Sjkoshy 38164190SjkoshyElf_Data * 39164190Sjkoshyelf_getdata(Elf_Scn *s, Elf_Data *d) 40164190Sjkoshy{ 41164190Sjkoshy Elf *e; 42164190Sjkoshy char *dst; 43164190Sjkoshy size_t fsz, msz, count; 44164190Sjkoshy int elfclass, elftype; 45164190Sjkoshy unsigned int sh_type; 46164190Sjkoshy uint64_t sh_align, sh_offset, sh_size; 47164190Sjkoshy void (*xlate)(char *_d, char *_s, size_t _c, int _swap); 48164190Sjkoshy 49164190Sjkoshy if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF || 50164190Sjkoshy (d != NULL && s != d->d_scn)) { 51164190Sjkoshy LIBELF_SET_ERROR(ARGUMENT, 0); 52164190Sjkoshy return (NULL); 53164190Sjkoshy } 54164190Sjkoshy 55164190Sjkoshy if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL) 56164190Sjkoshy return (d); 57164190Sjkoshy 58164190Sjkoshy if (d != NULL) 59164190Sjkoshy return (STAILQ_NEXT(d, d_next)); 60164190Sjkoshy 61164190Sjkoshy if (e->e_rawfile == NULL) { 62164190Sjkoshy LIBELF_SET_ERROR(SEQUENCE, 0); 63164190Sjkoshy return (NULL); 64164190Sjkoshy } 65164190Sjkoshy 66164190Sjkoshy elfclass = e->e_class; 67164190Sjkoshy 68164190Sjkoshy assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); 69164190Sjkoshy 70164190Sjkoshy if (elfclass == ELFCLASS32) { 71164190Sjkoshy sh_type = s->s_shdr.s_shdr32.sh_type; 72164190Sjkoshy sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 73164190Sjkoshy sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 74164190Sjkoshy sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 75164190Sjkoshy } else { 76164190Sjkoshy sh_type = s->s_shdr.s_shdr64.sh_type; 77164190Sjkoshy sh_offset = s->s_shdr.s_shdr64.sh_offset; 78164190Sjkoshy sh_size = s->s_shdr.s_shdr64.sh_size; 79164190Sjkoshy sh_align = s->s_shdr.s_shdr64.sh_addralign; 80164190Sjkoshy } 81164190Sjkoshy 82164190Sjkoshy if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST || 83164190Sjkoshy elftype > ELF_T_LAST || 84164190Sjkoshy sh_offset + sh_size > (uint64_t) e->e_rawsize) { 85164190Sjkoshy LIBELF_SET_ERROR(SECTION, 0); 86164190Sjkoshy return (NULL); 87164190Sjkoshy } 88164190Sjkoshy 89164190Sjkoshy if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)(elftype, 90164190Sjkoshy (size_t) 1, e->e_version)) == 0) { 91164190Sjkoshy LIBELF_SET_ERROR(UNIMPL, 0); 92164190Sjkoshy return (NULL); 93164190Sjkoshy } 94164190Sjkoshy 95164190Sjkoshy 96164190Sjkoshy if (sh_size % fsz) { 97164190Sjkoshy LIBELF_SET_ERROR(SECTION, 0); 98164190Sjkoshy return (NULL); 99164190Sjkoshy } 100164190Sjkoshy 101164190Sjkoshy count = sh_size / fsz; 102164190Sjkoshy 103164190Sjkoshy msz = _libelf_msize(elftype, elfclass, e->e_version); 104164190Sjkoshy 105164190Sjkoshy assert(msz > 0); 106164190Sjkoshy 107164190Sjkoshy if ((dst = malloc(msz*count)) == NULL) { 108164190Sjkoshy LIBELF_SET_ERROR(RESOURCE, 0); 109164190Sjkoshy return (NULL); 110164190Sjkoshy } 111164190Sjkoshy 112164190Sjkoshy if ((d = _libelf_allocate_data(s)) == NULL) 113164190Sjkoshy return (NULL); 114164190Sjkoshy 115164190Sjkoshy d->d_buf = dst; 116164190Sjkoshy d->d_off = 0; 117164190Sjkoshy d->d_align = sh_align; 118164190Sjkoshy d->d_size = msz * count; 119164190Sjkoshy d->d_type = elftype; 120164190Sjkoshy d->d_version = e->e_version; 121164190Sjkoshy 122164190Sjkoshy d->d_flags |= LIBELF_F_MALLOCED; 123164190Sjkoshy STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 124164190Sjkoshy 125164190Sjkoshy xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass); 126164190Sjkoshy (*xlate)(d->d_buf, e->e_rawfile + sh_offset, count, e->e_byteorder != 127164190Sjkoshy LIBELF_PRIVATE(byteorder)); 128164190Sjkoshy 129164190Sjkoshy return (d); 130164190Sjkoshy} 131164190Sjkoshy 132164190SjkoshyElf_Data * 133164190Sjkoshyelf_newdata(Elf_Scn *s) 134164190Sjkoshy{ 135164190Sjkoshy Elf *e; 136164190Sjkoshy Elf_Data *d; 137164190Sjkoshy 138164190Sjkoshy if (s == NULL || (e = s->s_elf) == NULL || 139164190Sjkoshy e->e_kind != ELF_K_ELF) { 140164190Sjkoshy LIBELF_SET_ERROR(ARGUMENT, 0); 141164190Sjkoshy return (NULL); 142164190Sjkoshy } 143164190Sjkoshy 144164190Sjkoshy /* 145164190Sjkoshy * elf_newdata() has to append a data descriptor, so 146164190Sjkoshy * bring in existing section data if not already present. 147164190Sjkoshy */ 148164190Sjkoshy if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data)) 149164190Sjkoshy if (elf_getdata(s, NULL) == NULL) 150164190Sjkoshy return (NULL); 151164190Sjkoshy 152164190Sjkoshy if ((d = malloc(sizeof(Elf_Data))) == NULL) { 153164190Sjkoshy LIBELF_SET_ERROR(RESOURCE, errno); 154164190Sjkoshy return (NULL); 155164190Sjkoshy } 156164190Sjkoshy 157164190Sjkoshy STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 158164190Sjkoshy d->d_flags = 0; 159164190Sjkoshy d->d_scn = s; 160164190Sjkoshy 161164190Sjkoshy d->d_align = 1; 162164190Sjkoshy d->d_buf = NULL; 163164190Sjkoshy d->d_off = (uint64_t) ~0; 164164190Sjkoshy d->d_size = 0; 165164190Sjkoshy d->d_type = ELF_T_BYTE; 166164190Sjkoshy d->d_version = LIBELF_PRIVATE(version); 167164190Sjkoshy 168164190Sjkoshy (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY); 169164190Sjkoshy 170164190Sjkoshy return (d); 171164190Sjkoshy} 172164190Sjkoshy 173164190Sjkoshy/* 174164190Sjkoshy * Retrieve a data descriptor for raw (untranslated) data for section 175164190Sjkoshy * `s'. 176164190Sjkoshy */ 177164190Sjkoshy 178164190SjkoshyElf_Data * 179164190Sjkoshyelf_rawdata(Elf_Scn *s, Elf_Data *d) 180164190Sjkoshy{ 181164190Sjkoshy Elf *e; 182164190Sjkoshy int elf_class; 183164190Sjkoshy uint64_t sh_align, sh_offset, sh_size; 184164190Sjkoshy 185164190Sjkoshy if (s == NULL || (e = s->s_elf) == NULL || 186164190Sjkoshy e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) { 187164190Sjkoshy LIBELF_SET_ERROR(ARGUMENT, 0); 188164190Sjkoshy return (NULL); 189164190Sjkoshy } 190164190Sjkoshy 191164190Sjkoshy if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL) 192164190Sjkoshy return (d); 193164190Sjkoshy 194164190Sjkoshy if (d != NULL) 195164190Sjkoshy return (STAILQ_NEXT(d, d_next)); 196164190Sjkoshy 197164190Sjkoshy elf_class = e->e_class; 198164190Sjkoshy 199164190Sjkoshy assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64); 200164190Sjkoshy 201164190Sjkoshy if (elf_class == ELFCLASS32) { 202164190Sjkoshy sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 203164190Sjkoshy sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 204164190Sjkoshy sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 205164190Sjkoshy } else { 206164190Sjkoshy sh_offset = s->s_shdr.s_shdr32.sh_offset; 207164190Sjkoshy sh_size = s->s_shdr.s_shdr32.sh_size; 208164190Sjkoshy sh_align = s->s_shdr.s_shdr32.sh_addralign; 209164190Sjkoshy } 210164190Sjkoshy 211164190Sjkoshy if ((d = _libelf_allocate_data(s)) == NULL) 212164190Sjkoshy return (NULL); 213164190Sjkoshy 214164190Sjkoshy d->d_buf = e->e_rawfile + sh_offset; 215164190Sjkoshy d->d_off = 0; 216164190Sjkoshy d->d_align = sh_align; 217164190Sjkoshy d->d_size = sh_size; 218164190Sjkoshy d->d_type = ELF_T_BYTE; 219164190Sjkoshy d->d_version = e->e_version; 220164190Sjkoshy 221164190Sjkoshy STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next); 222164190Sjkoshy 223164190Sjkoshy return (d); 224164190Sjkoshy} 225