| File: | src/lib/libelf/elf_update.c |
| Warning: | line 1048, column 2 Value stored to 'nrc' is never read |
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| 1 | /*- |
| 2 | * Copyright (c) 2006-2011 Joseph Koshy |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 24 | * SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include <sys/stat.h> |
| 28 | |
| 29 | #include <assert.h> |
| 30 | #include <errno(*__errno()).h> |
| 31 | #include <gelf.h> |
| 32 | #include <libelf.h> |
| 33 | #include <stdlib.h> |
| 34 | #include <string.h> |
| 35 | #include <unistd.h> |
| 36 | |
| 37 | #include "_libelf.h" |
| 38 | |
| 39 | #if ELFTC_HAVE_MMAP1 |
| 40 | #include <sys/mman.h> |
| 41 | #endif |
| 42 | |
| 43 | ELFTC_VCSID("$Id: elf_update.c,v 1.4 2021/09/02 21:12:25 deraadt Exp $")__asm__(".ident\t\"" "$Id: elf_update.c,v 1.4 2021/09/02 21:12:25 deraadt Exp $" "\""); |
| 44 | |
| 45 | /* |
| 46 | * Layout strategy: |
| 47 | * |
| 48 | * - Case 1: ELF_F_LAYOUT is asserted |
| 49 | * In this case the application has full control over where the |
| 50 | * section header table, program header table, and section data |
| 51 | * will reside. The library only perform error checks. |
| 52 | * |
| 53 | * - Case 2: ELF_F_LAYOUT is not asserted |
| 54 | * |
| 55 | * The library will do the object layout using the following |
| 56 | * ordering: |
| 57 | * - The executable header is placed first, are required by the |
| 58 | * ELF specification. |
| 59 | * - The program header table is placed immediately following the |
| 60 | * executable header. |
| 61 | * - Section data, if any, is placed after the program header |
| 62 | * table, aligned appropriately. |
| 63 | * - The section header table, if needed, is placed last. |
| 64 | * |
| 65 | * There are two sub-cases to be taken care of: |
| 66 | * |
| 67 | * - Case 2a: e->e_cmd == ELF_C_READ or ELF_C_RDWR |
| 68 | * |
| 69 | * In this sub-case, the underlying ELF object may already have |
| 70 | * content in it, which the application may have modified. The |
| 71 | * library will retrieve content from the existing object as |
| 72 | * needed. |
| 73 | * |
| 74 | * - Case 2b: e->e_cmd == ELF_C_WRITE |
| 75 | * |
| 76 | * The ELF object is being created afresh in this sub-case; |
| 77 | * there is no pre-existing content in the underlying ELF |
| 78 | * object. |
| 79 | */ |
| 80 | |
| 81 | /* |
| 82 | * The types of extents in an ELF object. |
| 83 | */ |
| 84 | enum elf_extent { |
| 85 | ELF_EXTENT_EHDR, |
| 86 | ELF_EXTENT_PHDR, |
| 87 | ELF_EXTENT_SECTION, |
| 88 | ELF_EXTENT_SHDR |
| 89 | }; |
| 90 | |
| 91 | /* |
| 92 | * A extent descriptor, used when laying out an ELF object. |
| 93 | */ |
| 94 | struct _Elf_Extent { |
| 95 | SLIST_ENTRY(_Elf_Extent)struct { struct _Elf_Extent *sle_next; } ex_next; |
| 96 | uint64_t ex_start; /* Start of the region. */ |
| 97 | uint64_t ex_size; /* The size of the region. */ |
| 98 | enum elf_extent ex_type; /* Type of region. */ |
| 99 | void *ex_desc; /* Associated descriptor. */ |
| 100 | }; |
| 101 | |
| 102 | SLIST_HEAD(_Elf_Extent_List, _Elf_Extent)struct _Elf_Extent_List { struct _Elf_Extent *slh_first; }; |
| 103 | |
| 104 | /* |
| 105 | * Compute the extents of a section, by looking at the data |
| 106 | * descriptors associated with it. The function returns 1 |
| 107 | * if successful, or zero if an error was detected. |
| 108 | */ |
| 109 | static int |
| 110 | _libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t rc) |
| 111 | { |
| 112 | Elf_Data *d; |
| 113 | size_t fsz, msz; |
| 114 | int ec, elftype; |
| 115 | uint32_t sh_type; |
| 116 | uint64_t d_align; |
| 117 | Elf32_Shdr *shdr32; |
| 118 | Elf64_Shdr *shdr64; |
| 119 | struct _Libelf_Data *ld; |
| 120 | uint64_t scn_size, scn_alignment; |
| 121 | uint64_t sh_align, sh_entsize, sh_offset, sh_size; |
| 122 | |
| 123 | ec = e->e_class; |
| 124 | |
| 125 | shdr32 = &s->s_shdr.s_shdr32; |
| 126 | shdr64 = &s->s_shdr.s_shdr64; |
| 127 | if (ec == ELFCLASS321) { |
| 128 | sh_type = shdr32->sh_type; |
| 129 | sh_align = (uint64_t) shdr32->sh_addralign; |
| 130 | sh_entsize = (uint64_t) shdr32->sh_entsize; |
| 131 | sh_offset = (uint64_t) shdr32->sh_offset; |
| 132 | sh_size = (uint64_t) shdr32->sh_size; |
| 133 | } else { |
| 134 | sh_type = shdr64->sh_type; |
| 135 | sh_align = shdr64->sh_addralign; |
| 136 | sh_entsize = shdr64->sh_entsize; |
| 137 | sh_offset = shdr64->sh_offset; |
| 138 | sh_size = shdr64->sh_size; |
| 139 | } |
| 140 | |
| 141 | assert(sh_type != SHT_NULL && sh_type != SHT_NOBITS)((sh_type != 0 && sh_type != 8) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 141, __func__, "sh_type != SHT_NULL && sh_type != SHT_NOBITS" )); |
| 142 | |
| 143 | elftype = _libelf_xlate_shtype(sh_type); |
| 144 | if (elftype < ELF_T_FIRSTELF_T_ADDR || elftype > ELF_T_LASTELF_T_GNUHASH) { |
| 145 | LIBELF_SET_ERROR(SECTION, 0)do { (_libelf.libelf_error) = (((ELF_E_SECTION) & 0xFF) | (((0)) << 8)); } while (0); |
| 146 | return (0); |
| 147 | } |
| 148 | |
| 149 | if (sh_align == 0) |
| 150 | sh_align = _libelf_falign(elftype, ec); |
| 151 | |
| 152 | /* |
| 153 | * Compute the section's size and alignment using the data |
| 154 | * descriptors associated with the section. |
| 155 | */ |
| 156 | if (STAILQ_EMPTY(&s->s_data)(((&s->s_data)->stqh_first) == ((void *)0))) { |
| 157 | /* |
| 158 | * The section's content (if any) has not been read in |
| 159 | * yet. If section is not dirty marked dirty, we can |
| 160 | * reuse the values in the 'sh_size' and 'sh_offset' |
| 161 | * fields of the section header. |
| 162 | */ |
| 163 | if ((s->s_flags & ELF_F_DIRTY0x002U) == 0) { |
| 164 | /* |
| 165 | * If the library is doing the layout, then we |
| 166 | * compute the new start offset for the |
| 167 | * section based on the current offset and the |
| 168 | * section's alignment needs. |
| 169 | * |
| 170 | * If the application is doing the layout, we |
| 171 | * can use the value in the 'sh_offset' field |
| 172 | * in the section header directly. |
| 173 | */ |
| 174 | if (e->e_flags & ELF_F_LAYOUT0x001U) |
| 175 | goto updatedescriptor; |
| 176 | else |
| 177 | goto computeoffset; |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * Otherwise, we need to bring in the section's data |
| 182 | * from the underlying ELF object. |
| 183 | */ |
| 184 | if (e->e_cmd != ELF_C_WRITE && elf_getdata(s, NULL((void *)0)) == NULL((void *)0)) |
| 185 | return (0); |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * Loop through the section's data descriptors. |
| 190 | */ |
| 191 | scn_size = 0L; |
| 192 | scn_alignment = 0; |
| 193 | STAILQ_FOREACH(ld, &s->s_data, d_next)for ((ld) = ((&s->s_data)->stqh_first); (ld) != ((void *)0); (ld) = ((ld)->d_next.stqe_next)) { |
| 194 | |
| 195 | d = &ld->d_data; |
| 196 | |
| 197 | /* |
| 198 | * The data buffer's type is known. |
| 199 | */ |
| 200 | if (d->d_type >= ELF_T_NUM) { |
| 201 | LIBELF_SET_ERROR(DATA, 0)do { (_libelf.libelf_error) = (((ELF_E_DATA) & 0xFF) | (( (0)) << 8)); } while (0); |
| 202 | return (0); |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * The data buffer's version is supported. |
| 207 | */ |
| 208 | if (d->d_version != e->e_version) { |
| 209 | LIBELF_SET_ERROR(VERSION, 0)do { (_libelf.libelf_error) = (((ELF_E_VERSION) & 0xFF) | (((0)) << 8)); } while (0); |
| 210 | return (0); |
| 211 | } |
| 212 | |
| 213 | /* |
| 214 | * The buffer's alignment is non-zero and a power of |
| 215 | * two. |
| 216 | */ |
| 217 | if ((d_align = d->d_align) == 0 || |
| 218 | (d_align & (d_align - 1))) { |
| 219 | LIBELF_SET_ERROR(DATA, 0)do { (_libelf.libelf_error) = (((ELF_E_DATA) & 0xFF) | (( (0)) << 8)); } while (0); |
| 220 | return (0); |
| 221 | } |
| 222 | |
| 223 | /* |
| 224 | * The data buffer's ELF type, ELF class and ELF version |
| 225 | * should be supported. |
| 226 | */ |
| 227 | if ((msz = _libelf_msize(d->d_type, ec, e->e_version)) == 0) |
| 228 | return (0); |
| 229 | |
| 230 | /* |
| 231 | * The buffer's size should be a multiple of the |
| 232 | * memory size of the underlying type. |
| 233 | */ |
| 234 | if (d->d_size % msz) { |
| 235 | LIBELF_SET_ERROR(DATA, 0)do { (_libelf.libelf_error) = (((ELF_E_DATA) & 0xFF) | (( (0)) << 8)); } while (0); |
| 236 | return (0); |
| 237 | } |
| 238 | |
| 239 | /* |
| 240 | * If the application is controlling layout, then the |
| 241 | * d_offset field should be compatible with the |
| 242 | * buffer's specified alignment. |
| 243 | */ |
| 244 | if ((e->e_flags & ELF_F_LAYOUT0x001U) && |
| 245 | (d->d_off & (d_align - 1))) { |
| 246 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 247 | return (0); |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * Compute the section's size. |
| 252 | */ |
| 253 | if (e->e_flags & ELF_F_LAYOUT0x001U) { |
| 254 | if ((uint64_t) d->d_off + d->d_size > scn_size) |
| 255 | scn_size = d->d_off + d->d_size; |
| 256 | } else { |
| 257 | scn_size = roundup2(scn_size, d->d_align)((((scn_size)+((d->d_align)-1))/(d->d_align))*(d->d_align )); |
| 258 | d->d_off = scn_size; |
| 259 | fsz = _libelf_fsize(d->d_type, ec, d->d_version, |
| 260 | (size_t) d->d_size / msz); |
| 261 | scn_size += fsz; |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * The section's alignment is the maximum alignment |
| 266 | * needed for its data buffers. |
| 267 | */ |
| 268 | if (d_align > scn_alignment) |
| 269 | scn_alignment = d_align; |
| 270 | } |
| 271 | |
| 272 | |
| 273 | /* |
| 274 | * If the application is requesting full control over the |
| 275 | * layout of the section, check the section's specified size, |
| 276 | * offsets and alignment for sanity. |
| 277 | */ |
| 278 | if (e->e_flags & ELF_F_LAYOUT0x001U) { |
| 279 | if (scn_alignment > sh_align || |
| 280 | sh_offset % sh_align || |
| 281 | sh_size < scn_size || |
| 282 | sh_offset % _libelf_falign(elftype, ec)) { |
| 283 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 284 | return (0); |
| 285 | } |
| 286 | goto updatedescriptor; |
| 287 | } |
| 288 | |
| 289 | /* |
| 290 | * Otherwise, compute the values in the section header. |
| 291 | * |
| 292 | * The section alignment is the maximum alignment for any of |
| 293 | * its contained data descriptors. |
| 294 | */ |
| 295 | if (scn_alignment > sh_align) |
| 296 | sh_align = scn_alignment; |
| 297 | |
| 298 | /* |
| 299 | * If the section entry size is zero, try and fill in an |
| 300 | * appropriate entry size. Per the elf(5) manual page |
| 301 | * sections without fixed-size entries should have their |
| 302 | * 'sh_entsize' field set to zero. |
| 303 | */ |
| 304 | if (sh_entsize == 0 && |
| 305 | (sh_entsize = _libelf_fsize(elftype, ec, e->e_version, |
| 306 | (size_t) 1)) == 1) |
| 307 | sh_entsize = 0; |
| 308 | |
| 309 | sh_size = scn_size; |
| 310 | |
| 311 | computeoffset: |
| 312 | /* |
| 313 | * Compute the new offset for the section based on |
| 314 | * the section's alignment needs. |
| 315 | */ |
| 316 | sh_offset = roundup((uint64_t) rc, sh_align)(((((uint64_t) rc)+((sh_align)-1))/(sh_align))*(sh_align)); |
| 317 | |
| 318 | /* |
| 319 | * Update the section header. |
| 320 | */ |
| 321 | if (ec == ELFCLASS321) { |
| 322 | shdr32->sh_addralign = (uint32_t) sh_align; |
| 323 | shdr32->sh_entsize = (uint32_t) sh_entsize; |
| 324 | shdr32->sh_offset = (uint32_t) sh_offset; |
| 325 | shdr32->sh_size = (uint32_t) sh_size; |
| 326 | } else { |
| 327 | shdr64->sh_addralign = sh_align; |
| 328 | shdr64->sh_entsize = sh_entsize; |
| 329 | shdr64->sh_offset = sh_offset; |
| 330 | shdr64->sh_size = sh_size; |
| 331 | } |
| 332 | |
| 333 | updatedescriptor: |
| 334 | /* |
| 335 | * Update the section descriptor. |
| 336 | */ |
| 337 | s->s_size = sh_size; |
| 338 | s->s_offset = sh_offset; |
| 339 | |
| 340 | return (1); |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * Free a list of extent descriptors. |
| 345 | */ |
| 346 | |
| 347 | static void |
| 348 | _libelf_release_extents(struct _Elf_Extent_List *extents) |
| 349 | { |
| 350 | struct _Elf_Extent *ex; |
| 351 | |
| 352 | while ((ex = SLIST_FIRST(extents)((extents)->slh_first)) != NULL((void *)0)) { |
| 353 | SLIST_REMOVE_HEAD(extents, ex_next)do { (extents)->slh_first = (extents)->slh_first->ex_next .sle_next; } while (0); |
| 354 | free(ex); |
| 355 | } |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * Check if an extent 's' defined by [start..start+size) is free. |
| 360 | * This routine assumes that the given extent list is sorted in order |
| 361 | * of ascending extent offsets. |
| 362 | */ |
| 363 | |
| 364 | static int |
| 365 | _libelf_extent_is_unused(struct _Elf_Extent_List *extents, |
| 366 | const uint64_t start, const uint64_t size, struct _Elf_Extent **prevt) |
| 367 | { |
| 368 | uint64_t tmax, tmin; |
| 369 | struct _Elf_Extent *t, *pt; |
| 370 | const uint64_t smax = start + size; |
| 371 | |
| 372 | /* First, look for overlaps with existing extents. */ |
| 373 | pt = NULL((void *)0); |
| 374 | SLIST_FOREACH(t, extents, ex_next)for((t) = ((extents)->slh_first); (t) != ((void *)0); (t) = ((t)->ex_next.sle_next)) { |
| 375 | tmin = t->ex_start; |
| 376 | tmax = tmin + t->ex_size; |
| 377 | |
| 378 | if (tmax <= start) { |
| 379 | /* |
| 380 | * 't' lies entirely before 's': ...| t |...| s |... |
| 381 | */ |
| 382 | pt = t; |
| 383 | continue; |
| 384 | } else if (smax <= tmin) { |
| 385 | /* |
| 386 | * 's' lies entirely before 't', and after 'pt': |
| 387 | * ...| pt |...| s |...| t |... |
| 388 | */ |
| 389 | assert(pt == NULL ||((pt == ((void *)0) || pt->ex_start + pt->ex_size <= start) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 390, __func__, "pt == NULL || pt->ex_start + pt->ex_size <= start" )) |
| 390 | pt->ex_start + pt->ex_size <= start)((pt == ((void *)0) || pt->ex_start + pt->ex_size <= start) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 390, __func__, "pt == NULL || pt->ex_start + pt->ex_size <= start" )); |
| 391 | break; |
| 392 | } else |
| 393 | /* 's' and 't' overlap. */ |
| 394 | return (0); |
| 395 | } |
| 396 | |
| 397 | if (prevt) |
| 398 | *prevt = pt; |
| 399 | return (1); |
| 400 | } |
| 401 | |
| 402 | /* |
| 403 | * Insert an extent into the list of extents. |
| 404 | */ |
| 405 | |
| 406 | static int |
| 407 | _libelf_insert_extent(struct _Elf_Extent_List *extents, int type, |
| 408 | uint64_t start, uint64_t size, void *desc) |
| 409 | { |
| 410 | struct _Elf_Extent *ex, *prevt; |
| 411 | |
| 412 | assert(type >= ELF_EXTENT_EHDR && type <= ELF_EXTENT_SHDR)((type >= ELF_EXTENT_EHDR && type <= ELF_EXTENT_SHDR ) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 412 , __func__, "type >= ELF_EXTENT_EHDR && type <= ELF_EXTENT_SHDR" )); |
| 413 | |
| 414 | prevt = NULL((void *)0); |
| 415 | |
| 416 | /* |
| 417 | * If the requested range overlaps with an existing extent, |
| 418 | * signal an error. |
| 419 | */ |
| 420 | if (!_libelf_extent_is_unused(extents, start, size, &prevt)) { |
| 421 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 422 | return (0); |
| 423 | } |
| 424 | |
| 425 | /* Allocate and fill in a new extent descriptor. */ |
| 426 | if ((ex = malloc(sizeof(struct _Elf_Extent))) == NULL((void *)0)) { |
| 427 | LIBELF_SET_ERROR(RESOURCE, errno)do { (_libelf.libelf_error) = (((ELF_E_RESOURCE) & 0xFF) | ((((*__errno()))) << 8)); } while (0); |
| 428 | return (0); |
| 429 | } |
| 430 | ex->ex_start = start; |
| 431 | ex->ex_size = size; |
| 432 | ex->ex_desc = desc; |
| 433 | ex->ex_type = type; |
| 434 | |
| 435 | /* Insert the region descriptor into the list. */ |
| 436 | if (prevt) |
| 437 | SLIST_INSERT_AFTER(prevt, ex, ex_next)do { (ex)->ex_next.sle_next = (prevt)->ex_next.sle_next ; (prevt)->ex_next.sle_next = (ex); } while (0); |
| 438 | else |
| 439 | SLIST_INSERT_HEAD(extents, ex, ex_next)do { (ex)->ex_next.sle_next = (extents)->slh_first; (extents )->slh_first = (ex); } while (0); |
| 440 | return (1); |
| 441 | } |
| 442 | |
| 443 | /* |
| 444 | * Recompute section layout. |
| 445 | */ |
| 446 | |
| 447 | static off_t |
| 448 | _libelf_resync_sections(Elf *e, off_t rc, struct _Elf_Extent_List *extents) |
| 449 | { |
| 450 | int ec; |
| 451 | Elf_Scn *s; |
| 452 | size_t sh_type; |
| 453 | |
| 454 | ec = e->e_class; |
| 455 | |
| 456 | /* |
| 457 | * Make a pass through sections, computing the extent of each |
| 458 | * section. |
| 459 | */ |
| 460 | STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next)for ((s) = ((&e->e_u.e_elf.e_scn)->stqh_first); (s) != ((void *)0); (s) = ((s)->s_next.stqe_next)) { |
| 461 | if (ec == ELFCLASS321) |
| 462 | sh_type = s->s_shdr.s_shdr32.sh_type; |
| 463 | else |
| 464 | sh_type = s->s_shdr.s_shdr64.sh_type; |
| 465 | |
| 466 | if (sh_type == SHT_NOBITS8 || sh_type == SHT_NULL0) |
| 467 | continue; |
| 468 | |
| 469 | if (_libelf_compute_section_extents(e, s, rc) == 0) |
| 470 | return ((off_t) -1); |
| 471 | |
| 472 | if (s->s_size == 0) |
| 473 | continue; |
| 474 | |
| 475 | if (!_libelf_insert_extent(extents, ELF_EXTENT_SECTION, |
| 476 | s->s_offset, s->s_size, s)) |
| 477 | return ((off_t) -1); |
| 478 | |
| 479 | if ((size_t) rc < s->s_offset + s->s_size) |
| 480 | rc = (off_t) (s->s_offset + s->s_size); |
| 481 | } |
| 482 | |
| 483 | return (rc); |
| 484 | } |
| 485 | |
| 486 | /* |
| 487 | * Recompute the layout of the ELF object and update the internal data |
| 488 | * structures associated with the ELF descriptor. |
| 489 | * |
| 490 | * Returns the size in bytes the ELF object would occupy in its file |
| 491 | * representation. |
| 492 | * |
| 493 | * After a successful call to this function, the following structures |
| 494 | * are updated: |
| 495 | * |
| 496 | * - The ELF header is updated. |
| 497 | * - All extents in the ELF object are sorted in order of ascending |
| 498 | * addresses. Sections have their section header table entries |
| 499 | * updated. An error is signalled if an overlap was detected among |
| 500 | * extents. |
| 501 | * - Data descriptors associated with sections are checked for valid |
| 502 | * types, offsets and alignment. |
| 503 | * |
| 504 | * After a resync_elf() successfully returns, the ELF descriptor is |
| 505 | * ready for being handed over to _libelf_write_elf(). |
| 506 | */ |
| 507 | |
| 508 | static off_t |
| 509 | _libelf_resync_elf(Elf *e, struct _Elf_Extent_List *extents) |
| 510 | { |
| 511 | int ec, eh_class; |
| 512 | unsigned int eh_byteorder, eh_version; |
| 513 | size_t align, fsz; |
| 514 | size_t phnum, shnum; |
| 515 | off_t rc, phoff, shoff; |
| 516 | void *ehdr, *phdr; |
| 517 | Elf32_Ehdr *eh32; |
| 518 | Elf64_Ehdr *eh64; |
| 519 | |
| 520 | rc = 0; |
| 521 | |
| 522 | ec = e->e_class; |
| 523 | |
| 524 | assert(ec == ELFCLASS32 || ec == ELFCLASS64)((ec == 1 || ec == 2) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 524, __func__, "ec == ELFCLASS32 || ec == ELFCLASS64")); |
| 525 | |
| 526 | /* |
| 527 | * Prepare the EHDR. |
| 528 | */ |
| 529 | if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL((void *)0)) |
| 530 | return ((off_t) -1); |
| 531 | |
| 532 | eh32 = ehdr; |
| 533 | eh64 = ehdr; |
| 534 | |
| 535 | if (ec == ELFCLASS321) { |
| 536 | eh_byteorder = eh32->e_ident[EI_DATA5]; |
| 537 | eh_class = eh32->e_ident[EI_CLASS4]; |
| 538 | phoff = (off_t) eh32->e_phoff; |
| 539 | shoff = (off_t) eh32->e_shoff; |
| 540 | eh_version = eh32->e_version; |
| 541 | } else { |
| 542 | eh_byteorder = eh64->e_ident[EI_DATA5]; |
| 543 | eh_class = eh64->e_ident[EI_CLASS4]; |
| 544 | phoff = (off_t) eh64->e_phoff; |
| 545 | shoff = (off_t) eh64->e_shoff; |
| 546 | eh_version = eh64->e_version; |
| 547 | } |
| 548 | |
| 549 | if (phoff < 0 || shoff < 0) { |
| 550 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 551 | return ((off_t) -1); |
| 552 | } |
| 553 | |
| 554 | if (eh_version == EV_NONE0) |
| 555 | eh_version = EV_CURRENT1; |
| 556 | |
| 557 | if (eh_version != e->e_version) { /* always EV_CURRENT */ |
| 558 | LIBELF_SET_ERROR(VERSION, 0)do { (_libelf.libelf_error) = (((ELF_E_VERSION) & 0xFF) | (((0)) << 8)); } while (0); |
| 559 | return ((off_t) -1); |
| 560 | } |
| 561 | |
| 562 | if (eh_class != e->e_class) { |
| 563 | LIBELF_SET_ERROR(CLASS, 0)do { (_libelf.libelf_error) = (((ELF_E_CLASS) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 564 | return ((off_t) -1); |
| 565 | } |
| 566 | |
| 567 | if (e->e_cmd != ELF_C_WRITE && eh_byteorder != e->e_byteorder) { |
| 568 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 569 | return ((off_t) -1); |
| 570 | } |
| 571 | |
| 572 | shnum = e->e_u.e_elf.e_nscn; |
| 573 | phnum = e->e_u.e_elf.e_nphdr; |
| 574 | |
| 575 | e->e_byteorder = eh_byteorder; |
| 576 | |
| 577 | #define INITIALIZE_EHDR(E,EC,V)do { unsigned int _version = (unsigned int) (V); (E)->e_ident [0] = 0x7f; (E)->e_ident[1] = 'E'; (E)->e_ident[2] = 'L' ; (E)->e_ident[3] = 'F'; (E)->e_ident[4] = (unsigned char ) (EC); (E)->e_ident[6] = (_version & 0xFFU); (E)-> e_ehsize = (uint16_t) _libelf_fsize(ELF_T_EHDR, (EC), _version , (size_t) 1); (E)->e_phentsize = (uint16_t) ((phnum == 0) ? 0 : _libelf_fsize(ELF_T_PHDR, (EC), _version, (size_t) 1)) ; (E)->e_shentsize = (uint16_t) _libelf_fsize(ELF_T_SHDR, ( EC), _version, (size_t) 1); } while (0) do { \ |
| 578 | unsigned int _version = (unsigned int) (V); \ |
| 579 | (E)->e_ident[EI_MAG00] = ELFMAG00x7f; \ |
| 580 | (E)->e_ident[EI_MAG11] = ELFMAG1'E'; \ |
| 581 | (E)->e_ident[EI_MAG22] = ELFMAG2'L'; \ |
| 582 | (E)->e_ident[EI_MAG33] = ELFMAG3'F'; \ |
| 583 | (E)->e_ident[EI_CLASS4] = (unsigned char) (EC); \ |
| 584 | (E)->e_ident[EI_VERSION6] = (_version & 0xFFU); \ |
| 585 | (E)->e_ehsize = (uint16_t) _libelf_fsize(ELF_T_EHDR, \ |
| 586 | (EC), _version, (size_t) 1); \ |
| 587 | (E)->e_phentsize = (uint16_t) ((phnum == 0) ? 0 : \ |
| 588 | _libelf_fsize(ELF_T_PHDR, (EC), _version, \ |
| 589 | (size_t) 1)); \ |
| 590 | (E)->e_shentsize = (uint16_t) _libelf_fsize(ELF_T_SHDR, \ |
| 591 | (EC), _version, (size_t) 1); \ |
| 592 | } while (0) |
| 593 | |
| 594 | if (ec == ELFCLASS321) |
| 595 | INITIALIZE_EHDR(eh32, ec, eh_version)do { unsigned int _version = (unsigned int) (eh_version); (eh32 )->e_ident[0] = 0x7f; (eh32)->e_ident[1] = 'E'; (eh32)-> e_ident[2] = 'L'; (eh32)->e_ident[3] = 'F'; (eh32)->e_ident [4] = (unsigned char) (ec); (eh32)->e_ident[6] = (_version & 0xFFU); (eh32)->e_ehsize = (uint16_t) _libelf_fsize (ELF_T_EHDR, (ec), _version, (size_t) 1); (eh32)->e_phentsize = (uint16_t) ((phnum == 0) ? 0 : _libelf_fsize(ELF_T_PHDR, ( ec), _version, (size_t) 1)); (eh32)->e_shentsize = (uint16_t ) _libelf_fsize(ELF_T_SHDR, (ec), _version, (size_t) 1); } while (0); |
| 596 | else |
| 597 | INITIALIZE_EHDR(eh64, ec, eh_version)do { unsigned int _version = (unsigned int) (eh_version); (eh64 )->e_ident[0] = 0x7f; (eh64)->e_ident[1] = 'E'; (eh64)-> e_ident[2] = 'L'; (eh64)->e_ident[3] = 'F'; (eh64)->e_ident [4] = (unsigned char) (ec); (eh64)->e_ident[6] = (_version & 0xFFU); (eh64)->e_ehsize = (uint16_t) _libelf_fsize (ELF_T_EHDR, (ec), _version, (size_t) 1); (eh64)->e_phentsize = (uint16_t) ((phnum == 0) ? 0 : _libelf_fsize(ELF_T_PHDR, ( ec), _version, (size_t) 1)); (eh64)->e_shentsize = (uint16_t ) _libelf_fsize(ELF_T_SHDR, (ec), _version, (size_t) 1); } while (0); |
| 598 | |
| 599 | (void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY0x002U); |
| 600 | |
| 601 | rc += (off_t) _libelf_fsize(ELF_T_EHDR, ec, eh_version, (size_t) 1); |
| 602 | |
| 603 | if (!_libelf_insert_extent(extents, ELF_EXTENT_EHDR, 0, (uint64_t) rc, |
| 604 | ehdr)) |
| 605 | return ((off_t) -1); |
| 606 | |
| 607 | /* |
| 608 | * Compute the layout the program header table, if one is |
| 609 | * present. The program header table needs to be aligned to a |
| 610 | * `natural' boundary. |
| 611 | */ |
| 612 | if (phnum) { |
| 613 | fsz = _libelf_fsize(ELF_T_PHDR, ec, eh_version, phnum); |
| 614 | align = _libelf_falign(ELF_T_PHDR, ec); |
| 615 | |
| 616 | if (e->e_flags & ELF_F_LAYOUT0x001U) { |
| 617 | /* |
| 618 | * Check offsets for sanity. |
| 619 | */ |
| 620 | if (rc > phoff) { |
| 621 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 622 | return ((off_t) -1); |
| 623 | } |
| 624 | |
| 625 | if (phoff % (off_t) align) { |
| 626 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 627 | return ((off_t) -1); |
| 628 | } |
| 629 | |
| 630 | } else |
| 631 | phoff = roundup(rc, (off_t) align)((((rc)+(((off_t) align)-1))/((off_t) align))*((off_t) align) ); |
| 632 | |
| 633 | rc = phoff + (off_t) fsz; |
| 634 | |
| 635 | phdr = _libelf_getphdr(e, ec); |
| 636 | |
| 637 | if (!_libelf_insert_extent(extents, ELF_EXTENT_PHDR, |
| 638 | (uint64_t) phoff, fsz, phdr)) |
| 639 | return ((off_t) -1); |
| 640 | } else |
| 641 | phoff = 0; |
| 642 | |
| 643 | /* |
| 644 | * Compute the layout of the sections associated with the |
| 645 | * file. |
| 646 | */ |
| 647 | |
| 648 | if (e->e_cmd != ELF_C_WRITE && |
| 649 | (e->e_flags & LIBELF_F_SHDRS_LOADED0x200000U) == 0 && |
| 650 | _libelf_load_section_headers(e, ehdr) == 0) |
| 651 | return ((off_t) -1); |
| 652 | |
| 653 | if ((rc = _libelf_resync_sections(e, rc, extents)) < 0) |
| 654 | return ((off_t) -1); |
| 655 | |
| 656 | /* |
| 657 | * Compute the space taken up by the section header table, if |
| 658 | * one is needed. |
| 659 | * |
| 660 | * If ELF_F_LAYOUT has been asserted, the application may have |
| 661 | * placed the section header table in between existing |
| 662 | * sections, so the net size of the file need not increase due |
| 663 | * to the presence of the section header table. |
| 664 | * |
| 665 | * If the library is responsible for laying out the object, |
| 666 | * the section header table is placed after section data. |
| 667 | */ |
| 668 | if (shnum) { |
| 669 | fsz = _libelf_fsize(ELF_T_SHDR, ec, eh_version, shnum); |
| 670 | align = _libelf_falign(ELF_T_SHDR, ec); |
| 671 | |
| 672 | if (e->e_flags & ELF_F_LAYOUT0x001U) { |
| 673 | if (shoff % (off_t) align) { |
| 674 | LIBELF_SET_ERROR(LAYOUT, 0)do { (_libelf.libelf_error) = (((ELF_E_LAYOUT) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 675 | return ((off_t) -1); |
| 676 | } |
| 677 | } else |
| 678 | shoff = roundup(rc, (off_t) align)((((rc)+(((off_t) align)-1))/((off_t) align))*((off_t) align) ); |
| 679 | |
| 680 | if (shoff + (off_t) fsz > rc) |
| 681 | rc = shoff + (off_t) fsz; |
| 682 | |
| 683 | if (!_libelf_insert_extent(extents, ELF_EXTENT_SHDR, |
| 684 | (uint64_t) shoff, fsz, NULL((void *)0))) |
| 685 | return ((off_t) -1); |
| 686 | } else |
| 687 | shoff = 0; |
| 688 | |
| 689 | /* |
| 690 | * Set the fields of the Executable Header that could potentially use |
| 691 | * extended numbering. |
| 692 | */ |
| 693 | _libelf_setphnum(e, ehdr, ec, phnum); |
| 694 | _libelf_setshnum(e, ehdr, ec, shnum); |
| 695 | |
| 696 | /* |
| 697 | * Update the `e_phoff' and `e_shoff' fields if the library is |
| 698 | * doing the layout. |
| 699 | */ |
| 700 | if ((e->e_flags & ELF_F_LAYOUT0x001U) == 0) { |
| 701 | if (ec == ELFCLASS321) { |
| 702 | eh32->e_phoff = (uint32_t) phoff; |
| 703 | eh32->e_shoff = (uint32_t) shoff; |
| 704 | } else { |
| 705 | eh64->e_phoff = (uint64_t) phoff; |
| 706 | eh64->e_shoff = (uint64_t) shoff; |
| 707 | } |
| 708 | } |
| 709 | |
| 710 | return (rc); |
| 711 | } |
| 712 | |
| 713 | /* |
| 714 | * Write out the contents of an ELF section. |
| 715 | */ |
| 716 | |
| 717 | static off_t |
| 718 | _libelf_write_scn(Elf *e, unsigned char *nf, struct _Elf_Extent *ex) |
| 719 | { |
| 720 | off_t rc; |
| 721 | int ec, em; |
| 722 | Elf_Scn *s; |
| 723 | int elftype; |
| 724 | Elf_Data *d, dst; |
| 725 | uint32_t sh_type; |
| 726 | struct _Libelf_Data *ld; |
| 727 | uint64_t sh_off, sh_size; |
| 728 | size_t fsz, msz, nobjects; |
| 729 | |
| 730 | assert(ex->ex_type == ELF_EXTENT_SECTION)((ex->ex_type == ELF_EXTENT_SECTION) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 730, __func__, "ex->ex_type == ELF_EXTENT_SECTION" )); |
| 731 | |
| 732 | s = ex->ex_desc; |
| 733 | rc = (off_t) ex->ex_start; |
| 734 | |
| 735 | if ((ec = e->e_class) == ELFCLASS321) { |
| 736 | sh_type = s->s_shdr.s_shdr32.sh_type; |
| 737 | sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; |
| 738 | } else { |
| 739 | sh_type = s->s_shdr.s_shdr64.sh_type; |
| 740 | sh_size = s->s_shdr.s_shdr64.sh_size; |
| 741 | } |
| 742 | |
| 743 | /* |
| 744 | * Ignore sections that do not allocate space in the file. |
| 745 | */ |
| 746 | if (sh_type == SHT_NOBITS8 || sh_type == SHT_NULL0 || sh_size == 0) |
| 747 | return (rc); |
| 748 | |
| 749 | elftype = _libelf_xlate_shtype(sh_type); |
| 750 | assert(elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST)((elftype >= ELF_T_ADDR && elftype <= ELF_T_GNUHASH ) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 750 , __func__, "elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST" )); |
| 751 | |
| 752 | sh_off = s->s_offset; |
| 753 | assert(sh_off % _libelf_falign(elftype, ec) == 0)((sh_off % _libelf_falign(elftype, ec) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 753, __func__, "sh_off % _libelf_falign(elftype, ec) == 0" )); |
| 754 | |
| 755 | em = _libelf_elfmachine(e); |
| 756 | assert(em >= EM_NONE && em < EM__LAST__)((em >= 0 && em < (0x9026 + 1)) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 756, __func__, "em >= EM_NONE && em < EM__LAST__" )); |
| 757 | |
| 758 | /* |
| 759 | * If the section has a `rawdata' descriptor, and the section |
| 760 | * contents have not been modified, use its contents directly. |
| 761 | * The `s_rawoff' member contains the offset into the original |
| 762 | * file, while `s_offset' contains its new location in the |
| 763 | * destination. |
| 764 | */ |
| 765 | |
| 766 | if (STAILQ_EMPTY(&s->s_data)(((&s->s_data)->stqh_first) == ((void *)0))) { |
| 767 | |
| 768 | if ((d = elf_rawdata(s, NULL((void *)0))) == NULL((void *)0)) |
| 769 | return ((off_t) -1); |
| 770 | |
| 771 | STAILQ_FOREACH(ld, &s->s_rawdata, d_next)for ((ld) = ((&s->s_rawdata)->stqh_first); (ld) != ( (void *)0); (ld) = ((ld)->d_next.stqe_next)) { |
| 772 | |
| 773 | d = &ld->d_data; |
| 774 | |
| 775 | if ((uint64_t) rc < sh_off + d->d_off) |
| 776 | (void) memset(nf + rc, |
| 777 | LIBELF_PRIVATE(fillchar)(_libelf.libelf_fillchar), |
| 778 | (size_t) (sh_off + d->d_off - |
| 779 | (uint64_t) rc)); |
| 780 | rc = (off_t) (sh_off + d->d_off); |
| 781 | |
| 782 | assert(d->d_buf != NULL)((d->d_buf != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 782, __func__, "d->d_buf != NULL")); |
| 783 | assert(d->d_type == ELF_T_BYTE)((d->d_type == ELF_T_BYTE) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 783, __func__, "d->d_type == ELF_T_BYTE")); |
| 784 | assert(d->d_version == e->e_version)((d->d_version == e->e_version) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 784, __func__, "d->d_version == e->e_version")); |
| 785 | |
| 786 | (void) memcpy(nf + rc, |
| 787 | e->e_rawfile + s->s_rawoff + d->d_off, |
| 788 | (size_t) d->d_size); |
| 789 | |
| 790 | rc += (off_t) d->d_size; |
| 791 | } |
| 792 | |
| 793 | return (rc); |
| 794 | } |
| 795 | |
| 796 | /* |
| 797 | * Iterate over the set of data descriptors for this section. |
| 798 | * The prior call to _libelf_resync_elf() would have setup the |
| 799 | * descriptors for this step. |
| 800 | */ |
| 801 | |
| 802 | dst.d_version = e->e_version; |
| 803 | |
| 804 | STAILQ_FOREACH(ld, &s->s_data, d_next)for ((ld) = ((&s->s_data)->stqh_first); (ld) != ((void *)0); (ld) = ((ld)->d_next.stqe_next)) { |
| 805 | |
| 806 | d = &ld->d_data; |
| 807 | |
| 808 | if ((msz = _libelf_msize(d->d_type, ec, e->e_version)) == 0) |
| 809 | return ((off_t) -1); |
| 810 | |
| 811 | if ((uint64_t) rc < sh_off + d->d_off) |
| 812 | (void) memset(nf + rc, |
| 813 | LIBELF_PRIVATE(fillchar)(_libelf.libelf_fillchar), |
| 814 | (size_t) (sh_off + d->d_off - (uint64_t) rc)); |
| 815 | |
| 816 | rc = (off_t) (sh_off + d->d_off); |
| 817 | |
| 818 | assert(d->d_buf != NULL)((d->d_buf != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 818, __func__, "d->d_buf != NULL")); |
| 819 | assert(d->d_version == e->e_version)((d->d_version == e->e_version) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 819, __func__, "d->d_version == e->e_version")); |
| 820 | assert(d->d_size % msz == 0)((d->d_size % msz == 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 820, __func__, "d->d_size % msz == 0")); |
| 821 | assert(msz != 0)((msz != 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 821, __func__, "msz != 0")); |
| 822 | |
| 823 | nobjects = (size_t) (d->d_size / msz); |
| 824 | |
| 825 | fsz = _libelf_fsize(d->d_type, ec, e->e_version, nobjects); |
| 826 | |
| 827 | dst.d_buf = nf + rc; |
| 828 | dst.d_size = fsz; |
| 829 | |
| 830 | if (_libelf_xlate(&dst, d, e->e_byteorder, ec, em, ELF_TOFILE) |
| 831 | == NULL((void *)0)) |
| 832 | return ((off_t) -1); |
| 833 | |
| 834 | rc += (off_t) fsz; |
| 835 | } |
| 836 | |
| 837 | return (rc); |
| 838 | } |
| 839 | |
| 840 | /* |
| 841 | * Write out an ELF Executable Header. |
| 842 | */ |
| 843 | |
| 844 | static off_t |
| 845 | _libelf_write_ehdr(Elf *e, unsigned char *nf, struct _Elf_Extent *ex) |
| 846 | { |
| 847 | int ec, em; |
| 848 | void *ehdr; |
| 849 | size_t fsz, msz; |
| 850 | Elf_Data dst, src; |
| 851 | |
| 852 | assert(ex->ex_type == ELF_EXTENT_EHDR)((ex->ex_type == ELF_EXTENT_EHDR) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 852, __func__, "ex->ex_type == ELF_EXTENT_EHDR")); |
| 853 | assert(ex->ex_start == 0)((ex->ex_start == 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 853, __func__, "ex->ex_start == 0")); /* Ehdr always comes first. */ |
| 854 | |
| 855 | ec = e->e_class; |
| 856 | |
| 857 | ehdr = _libelf_ehdr(e, ec, 0); |
| 858 | assert(ehdr != NULL)((ehdr != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 858, __func__, "ehdr != NULL")); |
| 859 | |
| 860 | fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1); |
| 861 | if ((msz = _libelf_msize(ELF_T_EHDR, ec, e->e_version)) == 0) |
| 862 | return ((off_t) -1); |
| 863 | |
| 864 | em = _libelf_elfmachine(e); |
| 865 | |
| 866 | (void) memset(&dst, 0, sizeof(dst)); |
| 867 | (void) memset(&src, 0, sizeof(src)); |
| 868 | |
| 869 | src.d_buf = ehdr; |
| 870 | src.d_size = msz; |
| 871 | src.d_type = ELF_T_EHDR; |
| 872 | src.d_version = dst.d_version = e->e_version; |
| 873 | |
| 874 | dst.d_buf = nf; |
| 875 | dst.d_size = fsz; |
| 876 | |
| 877 | if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, em, ELF_TOFILE) == |
| 878 | NULL((void *)0)) |
| 879 | return ((off_t) -1); |
| 880 | |
| 881 | return ((off_t) fsz); |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Write out an ELF program header table. |
| 886 | */ |
| 887 | |
| 888 | static off_t |
| 889 | _libelf_write_phdr(Elf *e, unsigned char *nf, struct _Elf_Extent *ex) |
| 890 | { |
| 891 | int ec, em; |
| 892 | void *ehdr; |
| 893 | Elf32_Ehdr *eh32; |
| 894 | Elf64_Ehdr *eh64; |
| 895 | Elf_Data dst, src; |
| 896 | size_t fsz, msz, phnum; |
| 897 | uint64_t phoff; |
| 898 | |
| 899 | assert(ex->ex_type == ELF_EXTENT_PHDR)((ex->ex_type == ELF_EXTENT_PHDR) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 899, __func__, "ex->ex_type == ELF_EXTENT_PHDR")); |
| 900 | |
| 901 | ec = e->e_class; |
| 902 | |
| 903 | ehdr = _libelf_ehdr(e, ec, 0); |
| 904 | assert(ehdr != NULL)((ehdr != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 904, __func__, "ehdr != NULL")); |
| 905 | |
| 906 | phnum = e->e_u.e_elf.e_nphdr; |
| 907 | assert(phnum > 0)((phnum > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 907, __func__, "phnum > 0")); |
| 908 | |
| 909 | if (ec == ELFCLASS321) { |
| 910 | eh32 = (Elf32_Ehdr *) ehdr; |
| 911 | phoff = (uint64_t) eh32->e_phoff; |
| 912 | } else { |
| 913 | eh64 = (Elf64_Ehdr *) ehdr; |
| 914 | phoff = eh64->e_phoff; |
| 915 | } |
| 916 | |
| 917 | em = _libelf_elfmachine(e); |
| 918 | |
| 919 | assert(phoff > 0)((phoff > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 919, __func__, "phoff > 0")); |
| 920 | assert(ex->ex_start == phoff)((ex->ex_start == phoff) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 920, __func__, "ex->ex_start == phoff")); |
| 921 | assert(phoff % _libelf_falign(ELF_T_PHDR, ec) == 0)((phoff % _libelf_falign(ELF_T_PHDR, ec) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 921, __func__, "phoff % _libelf_falign(ELF_T_PHDR, ec) == 0" )); |
| 922 | |
| 923 | (void) memset(&dst, 0, sizeof(dst)); |
| 924 | (void) memset(&src, 0, sizeof(src)); |
| 925 | |
| 926 | if ((msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version)) == 0) |
| 927 | return ((off_t) -1); |
| 928 | fsz = _libelf_fsize(ELF_T_PHDR, ec, e->e_version, phnum); |
| 929 | assert(fsz > 0)((fsz > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 929, __func__, "fsz > 0")); |
| 930 | |
| 931 | src.d_buf = _libelf_getphdr(e, ec); |
| 932 | src.d_version = dst.d_version = e->e_version; |
| 933 | src.d_type = ELF_T_PHDR; |
| 934 | src.d_size = phnum * msz; |
| 935 | |
| 936 | dst.d_size = fsz; |
| 937 | dst.d_buf = nf + ex->ex_start; |
| 938 | |
| 939 | if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, em, ELF_TOFILE) == |
| 940 | NULL((void *)0)) |
| 941 | return ((off_t) -1); |
| 942 | |
| 943 | return ((off_t) (phoff + fsz)); |
| 944 | } |
| 945 | |
| 946 | /* |
| 947 | * Write out an ELF section header table. |
| 948 | */ |
| 949 | |
| 950 | static off_t |
| 951 | _libelf_write_shdr(Elf *e, unsigned char *nf, struct _Elf_Extent *ex) |
| 952 | { |
| 953 | int ec, em; |
| 954 | void *ehdr; |
| 955 | Elf_Scn *scn; |
| 956 | uint64_t shoff; |
| 957 | Elf32_Ehdr *eh32; |
| 958 | Elf64_Ehdr *eh64; |
| 959 | size_t fsz, msz, nscn; |
| 960 | Elf_Data dst, src; |
| 961 | |
| 962 | assert(ex->ex_type == ELF_EXTENT_SHDR)((ex->ex_type == ELF_EXTENT_SHDR) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 962, __func__, "ex->ex_type == ELF_EXTENT_SHDR")); |
| 963 | |
| 964 | ec = e->e_class; |
| 965 | |
| 966 | ehdr = _libelf_ehdr(e, ec, 0); |
| 967 | assert(ehdr != NULL)((ehdr != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 967, __func__, "ehdr != NULL")); |
| 968 | |
| 969 | nscn = e->e_u.e_elf.e_nscn; |
| 970 | |
| 971 | if (ec == ELFCLASS321) { |
| 972 | eh32 = (Elf32_Ehdr *) ehdr; |
| 973 | shoff = (uint64_t) eh32->e_shoff; |
| 974 | } else { |
| 975 | eh64 = (Elf64_Ehdr *) ehdr; |
| 976 | shoff = eh64->e_shoff; |
| 977 | } |
| 978 | |
| 979 | em = _libelf_elfmachine(e); |
| 980 | |
| 981 | assert(nscn > 0)((nscn > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 981, __func__, "nscn > 0")); |
| 982 | assert(shoff % _libelf_falign(ELF_T_SHDR, ec) == 0)((shoff % _libelf_falign(ELF_T_SHDR, ec) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 982, __func__, "shoff % _libelf_falign(ELF_T_SHDR, ec) == 0" )); |
| 983 | assert(ex->ex_start == shoff)((ex->ex_start == shoff) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 983, __func__, "ex->ex_start == shoff")); |
| 984 | |
| 985 | (void) memset(&dst, 0, sizeof(dst)); |
| 986 | (void) memset(&src, 0, sizeof(src)); |
| 987 | |
| 988 | if ((msz = _libelf_msize(ELF_T_SHDR, ec, e->e_version)) == 0) |
| 989 | return ((off_t) -1); |
| 990 | |
| 991 | src.d_type = ELF_T_SHDR; |
| 992 | src.d_size = msz; |
| 993 | src.d_version = dst.d_version = e->e_version; |
| 994 | |
| 995 | fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1); |
| 996 | |
| 997 | STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next)for ((scn) = ((&e->e_u.e_elf.e_scn)->stqh_first); ( scn) != ((void *)0); (scn) = ((scn)->s_next.stqe_next)) { |
| 998 | if (ec == ELFCLASS321) |
| 999 | src.d_buf = &scn->s_shdr.s_shdr32; |
| 1000 | else |
| 1001 | src.d_buf = &scn->s_shdr.s_shdr64; |
| 1002 | |
| 1003 | dst.d_size = fsz; |
| 1004 | dst.d_buf = nf + ex->ex_start + scn->s_ndx * fsz; |
| 1005 | |
| 1006 | if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, em, |
| 1007 | ELF_TOFILE) == NULL((void *)0)) |
| 1008 | return ((off_t) -1); |
| 1009 | } |
| 1010 | |
| 1011 | return ((off_t) (ex->ex_start + nscn * fsz)); |
| 1012 | } |
| 1013 | |
| 1014 | /* |
| 1015 | * Write out the file image. |
| 1016 | * |
| 1017 | * The original file could have been mapped in with an ELF_C_RDWR |
| 1018 | * command and the application could have added new content or |
| 1019 | * re-arranged its sections before calling elf_update(). Consequently |
| 1020 | * its not safe to work `in place' on the original file. So we |
| 1021 | * malloc() the required space for the updated ELF object and build |
| 1022 | * the object there and write it out to the underlying file at the |
| 1023 | * end. Note that the application may have opened the underlying file |
| 1024 | * in ELF_C_RDWR and only retrieved/modified a few sections. We take |
| 1025 | * care to avoid translating file sections unnecessarily. |
| 1026 | * |
| 1027 | * Gaps in the coverage of the file by the file's sections will be |
| 1028 | * filled with the fill character set by elf_fill(3). |
| 1029 | */ |
| 1030 | |
| 1031 | static off_t |
| 1032 | _libelf_write_elf(Elf *e, off_t newsize, struct _Elf_Extent_List *extents) |
| 1033 | { |
| 1034 | off_t nrc, rc; |
| 1035 | Elf_Scn *scn, *tscn; |
| 1036 | struct _Elf_Extent *ex; |
| 1037 | unsigned char *newfile; |
| 1038 | |
| 1039 | assert(e->e_kind == ELF_K_ELF)((e->e_kind == ELF_K_ELF) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1039, __func__, "e->e_kind == ELF_K_ELF")); |
| 1040 | assert(e->e_cmd == ELF_C_RDWR || e->e_cmd == ELF_C_WRITE)((e->e_cmd == ELF_C_RDWR || e->e_cmd == ELF_C_WRITE) ? ( void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 1040, __func__ , "e->e_cmd == ELF_C_RDWR || e->e_cmd == ELF_C_WRITE")); |
| 1041 | assert(e->e_fd >= 0)((e->e_fd >= 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1041, __func__, "e->e_fd >= 0")); |
| 1042 | |
| 1043 | if ((newfile = malloc((size_t) newsize)) == NULL((void *)0)) { |
| 1044 | LIBELF_SET_ERROR(RESOURCE, errno)do { (_libelf.libelf_error) = (((ELF_E_RESOURCE) & 0xFF) | ((((*__errno()))) << 8)); } while (0); |
| 1045 | return ((off_t) -1); |
| 1046 | } |
| 1047 | |
| 1048 | nrc = rc = 0; |
Value stored to 'nrc' is never read | |
| 1049 | SLIST_FOREACH(ex, extents, ex_next)for((ex) = ((extents)->slh_first); (ex) != ((void *)0); (ex ) = ((ex)->ex_next.sle_next)) { |
| 1050 | |
| 1051 | /* Fill inter-extent gaps. */ |
| 1052 | if (ex->ex_start > (size_t) rc) |
| 1053 | (void) memset(newfile + rc, LIBELF_PRIVATE(fillchar)(_libelf.libelf_fillchar), |
| 1054 | (size_t) (ex->ex_start - (uint64_t) rc)); |
| 1055 | |
| 1056 | switch (ex->ex_type) { |
| 1057 | case ELF_EXTENT_EHDR: |
| 1058 | if ((nrc = _libelf_write_ehdr(e, newfile, ex)) < 0) |
| 1059 | goto error; |
| 1060 | break; |
| 1061 | |
| 1062 | case ELF_EXTENT_PHDR: |
| 1063 | if ((nrc = _libelf_write_phdr(e, newfile, ex)) < 0) |
| 1064 | goto error; |
| 1065 | break; |
| 1066 | |
| 1067 | case ELF_EXTENT_SECTION: |
| 1068 | if ((nrc = _libelf_write_scn(e, newfile, ex)) < 0) |
| 1069 | goto error; |
| 1070 | break; |
| 1071 | |
| 1072 | case ELF_EXTENT_SHDR: |
| 1073 | if ((nrc = _libelf_write_shdr(e, newfile, ex)) < 0) |
| 1074 | goto error; |
| 1075 | break; |
| 1076 | |
| 1077 | default: |
| 1078 | assert(0)((0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1078, __func__, "0")); |
| 1079 | break; |
| 1080 | } |
| 1081 | |
| 1082 | assert(ex->ex_start + ex->ex_size == (size_t) nrc)((ex->ex_start + ex->ex_size == (size_t) nrc) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 1082, __func__ , "ex->ex_start + ex->ex_size == (size_t) nrc")); |
| 1083 | assert(rc < nrc)((rc < nrc) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1083, __func__, "rc < nrc")); |
| 1084 | |
| 1085 | rc = nrc; |
| 1086 | } |
| 1087 | |
| 1088 | assert(rc == newsize)((rc == newsize) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1088, __func__, "rc == newsize")); |
| 1089 | |
| 1090 | /* |
| 1091 | * For regular files, throw away existing file content and |
| 1092 | * unmap any existing mappings. |
| 1093 | */ |
| 1094 | if ((e->e_flags & LIBELF_F_SPECIAL_FILE0x400000U) == 0) { |
| 1095 | if (ftruncate(e->e_fd, (off_t) 0) < 0 || |
| 1096 | lseek(e->e_fd, (off_t) 0, SEEK_SET0)) { |
| 1097 | LIBELF_SET_ERROR(IO, errno)do { (_libelf.libelf_error) = (((ELF_E_IO) & 0xFF) | (((( *__errno()))) << 8)); } while (0); |
| 1098 | goto error; |
| 1099 | } |
| 1100 | #if ELFTC_HAVE_MMAP1 |
| 1101 | if (e->e_flags & LIBELF_F_RAWFILE_MMAP0x100000U) { |
| 1102 | assert(e->e_rawfile != NULL)((e->e_rawfile != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1102, __func__, "e->e_rawfile != NULL")); |
| 1103 | assert(e->e_cmd == ELF_C_RDWR)((e->e_cmd == ELF_C_RDWR) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1103, __func__, "e->e_cmd == ELF_C_RDWR")); |
| 1104 | if (munmap(e->e_rawfile, (size_t) e->e_rawsize) < 0) { |
| 1105 | LIBELF_SET_ERROR(IO, errno)do { (_libelf.libelf_error) = (((ELF_E_IO) & 0xFF) | (((( *__errno()))) << 8)); } while (0); |
| 1106 | goto error; |
| 1107 | } |
| 1108 | } |
| 1109 | #endif |
| 1110 | } |
| 1111 | |
| 1112 | /* |
| 1113 | * Write out the new contents. |
| 1114 | */ |
| 1115 | if (write(e->e_fd, newfile, (size_t) newsize) != newsize) { |
| 1116 | LIBELF_SET_ERROR(IO, errno)do { (_libelf.libelf_error) = (((ELF_E_IO) & 0xFF) | (((( *__errno()))) << 8)); } while (0); |
| 1117 | goto error; |
| 1118 | } |
| 1119 | |
| 1120 | /* |
| 1121 | * For files opened in ELF_C_RDWR mode, set up the new 'raw' |
| 1122 | * contents. |
| 1123 | */ |
| 1124 | if (e->e_cmd == ELF_C_RDWR) { |
| 1125 | assert(e->e_rawfile != NULL)((e->e_rawfile != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1125, __func__, "e->e_rawfile != NULL")); |
| 1126 | assert((e->e_flags & LIBELF_F_RAWFILE_MALLOC) ||(((e->e_flags & 0x080000U) || (e->e_flags & 0x100000U )) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 1127 , __func__, "(e->e_flags & LIBELF_F_RAWFILE_MALLOC) || (e->e_flags & LIBELF_F_RAWFILE_MMAP)" )) |
| 1127 | (e->e_flags & LIBELF_F_RAWFILE_MMAP))(((e->e_flags & 0x080000U) || (e->e_flags & 0x100000U )) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c", 1127 , __func__, "(e->e_flags & LIBELF_F_RAWFILE_MALLOC) || (e->e_flags & LIBELF_F_RAWFILE_MMAP)" )); |
| 1128 | if (e->e_flags & LIBELF_F_RAWFILE_MALLOC0x080000U) { |
| 1129 | assert((e->e_flags & LIBELF_F_RAWFILE_MMAP) == 0)(((e->e_flags & 0x100000U) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 1129, __func__, "(e->e_flags & LIBELF_F_RAWFILE_MMAP) == 0" )); |
| 1130 | free(e->e_rawfile); |
| 1131 | e->e_rawfile = newfile; |
| 1132 | newfile = NULL((void *)0); |
| 1133 | } |
| 1134 | #if ELFTC_HAVE_MMAP1 |
| 1135 | else if (e->e_flags & LIBELF_F_RAWFILE_MMAP0x100000U) { |
| 1136 | assert((e->e_flags & LIBELF_F_RAWFILE_MALLOC) == 0)(((e->e_flags & 0x080000U) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_update.c", 1136, __func__, "(e->e_flags & LIBELF_F_RAWFILE_MALLOC) == 0" )); |
| 1137 | if ((e->e_rawfile = mmap(NULL((void *)0), (size_t) newsize, |
| 1138 | PROT_READ0x01, MAP_PRIVATE0x0002, e->e_fd, (off_t) 0)) == |
| 1139 | MAP_FAILED((void *)-1)) { |
| 1140 | LIBELF_SET_ERROR(IO, errno)do { (_libelf.libelf_error) = (((ELF_E_IO) & 0xFF) | (((( *__errno()))) << 8)); } while (0); |
| 1141 | goto error; |
| 1142 | } |
| 1143 | } |
| 1144 | #endif /* ELFTC_HAVE_MMAP */ |
| 1145 | |
| 1146 | /* Record the new size of the file. */ |
| 1147 | e->e_rawsize = newsize; |
| 1148 | } else { |
| 1149 | /* File opened in ELF_C_WRITE mode. */ |
| 1150 | assert(e->e_rawfile == NULL)((e->e_rawfile == ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_update.c" , 1150, __func__, "e->e_rawfile == NULL")); |
| 1151 | } |
| 1152 | |
| 1153 | /* |
| 1154 | * Reset flags, remove existing section descriptors and |
| 1155 | * {E,P}HDR pointers so that a subsequent elf_get{e,p}hdr() |
| 1156 | * and elf_getscn() will function correctly. |
| 1157 | */ |
| 1158 | |
| 1159 | e->e_flags &= ~ELF_F_DIRTY0x002U; |
| 1160 | |
| 1161 | STAILQ_FOREACH_SAFE(scn, &e->e_u.e_elf.e_scn, s_next, tscn)for ((scn) = ((&e->e_u.e_elf.e_scn)->stqh_first); ( scn) && ((tscn) = ((scn)->s_next.stqe_next), 1); ( scn) = (tscn)) |
| 1162 | _libelf_release_scn(scn); |
| 1163 | |
| 1164 | if (e->e_class == ELFCLASS321) { |
| 1165 | free(e->e_u.e_elf.e_ehdr.e_ehdr32); |
| 1166 | if (e->e_u.e_elf.e_phdr.e_phdr32) |
| 1167 | free(e->e_u.e_elf.e_phdr.e_phdr32); |
| 1168 | |
| 1169 | e->e_u.e_elf.e_ehdr.e_ehdr32 = NULL((void *)0); |
| 1170 | e->e_u.e_elf.e_phdr.e_phdr32 = NULL((void *)0); |
| 1171 | } else { |
| 1172 | free(e->e_u.e_elf.e_ehdr.e_ehdr64); |
| 1173 | if (e->e_u.e_elf.e_phdr.e_phdr64) |
| 1174 | free(e->e_u.e_elf.e_phdr.e_phdr64); |
| 1175 | |
| 1176 | e->e_u.e_elf.e_ehdr.e_ehdr64 = NULL((void *)0); |
| 1177 | e->e_u.e_elf.e_phdr.e_phdr64 = NULL((void *)0); |
| 1178 | } |
| 1179 | |
| 1180 | /* Free the temporary buffer. */ |
| 1181 | if (newfile) |
| 1182 | free(newfile); |
| 1183 | |
| 1184 | return (rc); |
| 1185 | |
| 1186 | error: |
| 1187 | free(newfile); |
| 1188 | |
| 1189 | return ((off_t) -1); |
| 1190 | } |
| 1191 | |
| 1192 | /* |
| 1193 | * Update an ELF object. |
| 1194 | */ |
| 1195 | |
| 1196 | off_t |
| 1197 | elf_update(Elf *e, Elf_Cmd c) |
| 1198 | { |
| 1199 | int ec; |
| 1200 | off_t rc; |
| 1201 | struct _Elf_Extent_List extents; |
| 1202 | |
| 1203 | rc = (off_t) -1; |
| 1204 | |
| 1205 | if (e == NULL((void *)0) || e->e_kind != ELF_K_ELF || |
| 1206 | (c != ELF_C_NULL && c != ELF_C_WRITE)) { |
| 1207 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
| 1208 | return (rc); |
| 1209 | } |
| 1210 | |
| 1211 | if ((ec = e->e_class) != ELFCLASS321 && ec != ELFCLASS642) { |
| 1212 | LIBELF_SET_ERROR(CLASS, 0)do { (_libelf.libelf_error) = (((ELF_E_CLASS) & 0xFF) | ( ((0)) << 8)); } while (0); |
| 1213 | return (rc); |
| 1214 | } |
| 1215 | |
| 1216 | if (e->e_version == EV_NONE0) |
| 1217 | e->e_version = EV_CURRENT1; |
| 1218 | |
| 1219 | if (c == ELF_C_WRITE && e->e_cmd == ELF_C_READ) { |
| 1220 | LIBELF_SET_ERROR(MODE, 0)do { (_libelf.libelf_error) = (((ELF_E_MODE) & 0xFF) | (( (0)) << 8)); } while (0); |
| 1221 | return (rc); |
| 1222 | } |
| 1223 | |
| 1224 | SLIST_INIT(&extents){ ((&extents)->slh_first) = ((void *)0); }; |
| 1225 | |
| 1226 | if ((rc = _libelf_resync_elf(e, &extents)) < 0) |
| 1227 | goto done; |
| 1228 | |
| 1229 | if (c == ELF_C_NULL) |
| 1230 | goto done; |
| 1231 | |
| 1232 | if (e->e_fd < 0) { |
| 1233 | rc = (off_t) -1; |
| 1234 | LIBELF_SET_ERROR(SEQUENCE, 0)do { (_libelf.libelf_error) = (((ELF_E_SEQUENCE) & 0xFF) | (((0)) << 8)); } while (0); |
| 1235 | goto done; |
| 1236 | } |
| 1237 | |
| 1238 | rc = _libelf_write_elf(e, rc, &extents); |
| 1239 | |
| 1240 | done: |
| 1241 | _libelf_release_extents(&extents); |
| 1242 | return (rc); |
| 1243 | } |