1 /* $NetBSD: elf_data.c,v 1.2 2014/03/09 16:58:04 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2006,2008,2011 Joseph Koshy 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #if HAVE_NBTOOL_CONFIG_H 30 # include "nbtool_config.h" 31 #endif 32 33 #include <assert.h> 34 #include <errno.h> 35 #include <libelf.h> 36 #include <stdlib.h> 37 38 #include "_libelf.h" 39 40 __RCSID("$NetBSD: elf_data.c,v 1.2 2014/03/09 16:58:04 christos Exp $"); 41 ELFTC_VCSID("Id: elf_data.c 2921 2013-03-04 16:19:22Z jkoshy "); 42 43 Elf_Data * 44 elf_getdata(Elf_Scn *s, Elf_Data *ed) 45 { 46 Elf *e; 47 unsigned int sh_type; 48 int elfclass, elftype; 49 size_t fsz, msz, count; 50 struct _Libelf_Data *d; 51 uint64_t sh_align, sh_offset, sh_size; 52 int (*xlate)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); 53 54 d = (struct _Libelf_Data *) ed; 55 56 if (s == NULL || (e = s->s_elf) == NULL || 57 (d != NULL && s != d->d_scn)) { 58 LIBELF_SET_ERROR(ARGUMENT, 0); 59 return (NULL); 60 } 61 62 assert(e->e_kind == ELF_K_ELF); 63 64 if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL) 65 return (&d->d_data); 66 67 if (d != NULL) 68 return (&STAILQ_NEXT(d, d_next)->d_data); 69 70 if (e->e_rawfile == NULL) { 71 /* 72 * In the ELF_C_WRITE case, there is no source that 73 * can provide data for the section. 74 */ 75 LIBELF_SET_ERROR(ARGUMENT, 0); 76 return (NULL); 77 } 78 79 elfclass = e->e_class; 80 81 assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); 82 83 if (elfclass == ELFCLASS32) { 84 sh_type = s->s_shdr.s_shdr32.sh_type; 85 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 86 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 87 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 88 } else { 89 sh_type = s->s_shdr.s_shdr64.sh_type; 90 sh_offset = s->s_shdr.s_shdr64.sh_offset; 91 sh_size = s->s_shdr.s_shdr64.sh_size; 92 sh_align = s->s_shdr.s_shdr64.sh_addralign; 93 } 94 95 if (sh_type == SHT_NULL) { 96 LIBELF_SET_ERROR(SECTION, 0); 97 return (NULL); 98 } 99 100 if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST || 101 elftype > ELF_T_LAST || (sh_type != SHT_NOBITS && 102 sh_offset + sh_size > (uint64_t) e->e_rawsize)) { 103 LIBELF_SET_ERROR(SECTION, 0); 104 return (NULL); 105 } 106 107 if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize) 108 (elftype, (size_t) 1, e->e_version)) == 0) { 109 LIBELF_SET_ERROR(UNIMPL, 0); 110 return (NULL); 111 } 112 113 if (sh_size % fsz) { 114 LIBELF_SET_ERROR(SECTION, 0); 115 return (NULL); 116 } 117 118 count = sh_size / fsz; 119 120 msz = _libelf_msize(elftype, elfclass, e->e_version); 121 122 assert(msz > 0); 123 124 if ((d = _libelf_allocate_data(s)) == NULL) 125 return (NULL); 126 127 d->d_data.d_buf = NULL; 128 d->d_data.d_off = 0; 129 d->d_data.d_align = sh_align; 130 d->d_data.d_size = msz * count; 131 d->d_data.d_type = elftype; 132 d->d_data.d_version = e->e_version; 133 134 if (sh_type == SHT_NOBITS || sh_size == 0) { 135 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 136 return (&d->d_data); 137 } 138 139 if ((d->d_data.d_buf = malloc(msz*count)) == NULL) { 140 (void) _libelf_release_data(d); 141 LIBELF_SET_ERROR(RESOURCE, 0); 142 return (NULL); 143 } 144 145 d->d_flags |= LIBELF_F_DATA_MALLOCED; 146 147 xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass); 148 if (!(*xlate)(d->d_data.d_buf, d->d_data.d_size, 149 e->e_rawfile + sh_offset, count, 150 e->e_byteorder != _libelf_host_byteorder())) { 151 _libelf_release_data(d); 152 LIBELF_SET_ERROR(DATA, 0); 153 return (NULL); 154 } 155 156 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 157 158 return (&d->d_data); 159 } 160 161 Elf_Data * 162 elf_newdata(Elf_Scn *s) 163 { 164 Elf *e; 165 struct _Libelf_Data *d; 166 167 if (s == NULL || (e = s->s_elf) == NULL) { 168 LIBELF_SET_ERROR(ARGUMENT, 0); 169 return (NULL); 170 } 171 172 assert(e->e_kind == ELF_K_ELF); 173 174 /* 175 * elf_newdata() has to append a data descriptor, so 176 * bring in existing section data if not already present. 177 */ 178 if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data)) 179 if (elf_getdata(s, NULL) == NULL) 180 return (NULL); 181 182 if ((d = _libelf_allocate_data(s)) == NULL) 183 return (NULL); 184 185 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 186 187 d->d_data.d_align = 1; 188 d->d_data.d_buf = NULL; 189 d->d_data.d_off = (uint64_t) ~0; 190 d->d_data.d_size = 0; 191 d->d_data.d_type = ELF_T_BYTE; 192 d->d_data.d_version = LIBELF_PRIVATE(version); 193 194 (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY); 195 196 return (&d->d_data); 197 } 198 199 /* 200 * Retrieve a data descriptor for raw (untranslated) data for section 201 * `s'. 202 */ 203 204 Elf_Data * 205 elf_rawdata(Elf_Scn *s, Elf_Data *ed) 206 { 207 Elf *e; 208 int elf_class; 209 uint32_t sh_type; 210 struct _Libelf_Data *d; 211 uint64_t sh_align, sh_offset, sh_size; 212 213 if (s == NULL || (e = s->s_elf) == NULL || e->e_rawfile == NULL) { 214 LIBELF_SET_ERROR(ARGUMENT, 0); 215 return (NULL); 216 } 217 218 assert(e->e_kind == ELF_K_ELF); 219 220 d = (struct _Libelf_Data *) ed; 221 222 if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL) 223 return (&d->d_data); 224 225 if (d != NULL) 226 return (&STAILQ_NEXT(d, d_next)->d_data); 227 228 elf_class = e->e_class; 229 230 assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64); 231 232 if (elf_class == ELFCLASS32) { 233 sh_type = s->s_shdr.s_shdr32.sh_type; 234 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 235 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 236 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 237 } else { 238 sh_type = s->s_shdr.s_shdr64.sh_type; 239 sh_offset = s->s_shdr.s_shdr64.sh_offset; 240 sh_size = s->s_shdr.s_shdr64.sh_size; 241 sh_align = s->s_shdr.s_shdr64.sh_addralign; 242 } 243 244 if (sh_type == SHT_NULL) { 245 LIBELF_SET_ERROR(SECTION, 0); 246 return (NULL); 247 } 248 249 if ((d = _libelf_allocate_data(s)) == NULL) 250 return (NULL); 251 252 d->d_data.d_buf = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL : 253 e->e_rawfile + sh_offset; 254 d->d_data.d_off = 0; 255 d->d_data.d_align = sh_align; 256 d->d_data.d_size = sh_size; 257 d->d_data.d_type = ELF_T_BYTE; 258 d->d_data.d_version = e->e_version; 259 260 STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next); 261 262 return (&d->d_data); 263 } 264