xref: /freebsd/contrib/elftoolchain/libelf/elf_data.c (revision cf781b2e16c26535788abe648f5917f4db09c123)
12de3b87aSKai Wang /*-
22de3b87aSKai Wang  * Copyright (c) 2006,2008,2011 Joseph Koshy
32de3b87aSKai Wang  * All rights reserved.
42de3b87aSKai Wang  *
52de3b87aSKai Wang  * Redistribution and use in source and binary forms, with or without
62de3b87aSKai Wang  * modification, are permitted provided that the following conditions
72de3b87aSKai Wang  * are met:
82de3b87aSKai Wang  * 1. Redistributions of source code must retain the above copyright
92de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer.
102de3b87aSKai Wang  * 2. Redistributions in binary form must reproduce the above copyright
112de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer in the
122de3b87aSKai Wang  *    documentation and/or other materials provided with the distribution.
132de3b87aSKai Wang  *
142de3b87aSKai Wang  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
152de3b87aSKai Wang  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
162de3b87aSKai Wang  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
172de3b87aSKai Wang  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
182de3b87aSKai Wang  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
192de3b87aSKai Wang  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
202de3b87aSKai Wang  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
212de3b87aSKai Wang  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
222de3b87aSKai Wang  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
232de3b87aSKai Wang  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
242de3b87aSKai Wang  * SUCH DAMAGE.
252de3b87aSKai Wang  */
262de3b87aSKai Wang 
272de3b87aSKai Wang #include <assert.h>
282de3b87aSKai Wang #include <errno.h>
292de3b87aSKai Wang #include <libelf.h>
302de3b87aSKai Wang #include <stdlib.h>
312de3b87aSKai Wang 
322de3b87aSKai Wang #include "_libelf.h"
332de3b87aSKai Wang 
34*cf781b2eSEd Maste ELFTC_VCSID("$Id: elf_data.c 3009 2014-03-23 01:49:59Z jkoshy $");
352de3b87aSKai Wang 
362de3b87aSKai Wang Elf_Data *
372de3b87aSKai Wang elf_getdata(Elf_Scn *s, Elf_Data *ed)
382de3b87aSKai Wang {
392de3b87aSKai Wang 	Elf *e;
402de3b87aSKai Wang 	unsigned int sh_type;
412de3b87aSKai Wang 	int elfclass, elftype;
42*cf781b2eSEd Maste 	size_t count, fsz, msz;
432de3b87aSKai Wang 	struct _Libelf_Data *d;
442de3b87aSKai Wang 	uint64_t sh_align, sh_offset, sh_size;
45*cf781b2eSEd Maste 	int (*xlate)(unsigned char *_d, size_t _dsz, unsigned char *_s,
46*cf781b2eSEd Maste 	    size_t _c, int _swap);
472de3b87aSKai Wang 
482de3b87aSKai Wang 	d = (struct _Libelf_Data *) ed;
492de3b87aSKai Wang 
502de3b87aSKai Wang 	if (s == NULL || (e = s->s_elf) == NULL ||
512de3b87aSKai Wang 	    (d != NULL && s != d->d_scn)) {
522de3b87aSKai Wang 		LIBELF_SET_ERROR(ARGUMENT, 0);
532de3b87aSKai Wang 		return (NULL);
542de3b87aSKai Wang 	}
552de3b87aSKai Wang 
562de3b87aSKai Wang 	assert(e->e_kind == ELF_K_ELF);
572de3b87aSKai Wang 
582de3b87aSKai Wang 	if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL)
592de3b87aSKai Wang 		return (&d->d_data);
602de3b87aSKai Wang 
612de3b87aSKai Wang 	if (d != NULL)
622de3b87aSKai Wang 		return (&STAILQ_NEXT(d, d_next)->d_data);
632de3b87aSKai Wang 
642de3b87aSKai Wang 	if (e->e_rawfile == NULL) {
652de3b87aSKai Wang 		/*
662de3b87aSKai Wang 		 * In the ELF_C_WRITE case, there is no source that
672de3b87aSKai Wang 		 * can provide data for the section.
682de3b87aSKai Wang 		 */
692de3b87aSKai Wang 		LIBELF_SET_ERROR(ARGUMENT, 0);
702de3b87aSKai Wang 		return (NULL);
712de3b87aSKai Wang 	}
722de3b87aSKai Wang 
732de3b87aSKai Wang 	elfclass = e->e_class;
742de3b87aSKai Wang 
752de3b87aSKai Wang 	assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
762de3b87aSKai Wang 
772de3b87aSKai Wang 	if (elfclass == ELFCLASS32) {
782de3b87aSKai Wang 		sh_type   = s->s_shdr.s_shdr32.sh_type;
792de3b87aSKai Wang 		sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
802de3b87aSKai Wang 		sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
812de3b87aSKai Wang 		sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
822de3b87aSKai Wang 	} else {
832de3b87aSKai Wang 		sh_type   = s->s_shdr.s_shdr64.sh_type;
842de3b87aSKai Wang 		sh_offset = s->s_shdr.s_shdr64.sh_offset;
852de3b87aSKai Wang 		sh_size   = s->s_shdr.s_shdr64.sh_size;
862de3b87aSKai Wang 		sh_align  = s->s_shdr.s_shdr64.sh_addralign;
872de3b87aSKai Wang 	}
882de3b87aSKai Wang 
892de3b87aSKai Wang 	if (sh_type == SHT_NULL) {
902de3b87aSKai Wang 		LIBELF_SET_ERROR(SECTION, 0);
912de3b87aSKai Wang 		return (NULL);
922de3b87aSKai Wang 	}
932de3b87aSKai Wang 
942de3b87aSKai Wang 	if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST ||
952de3b87aSKai Wang 	    elftype > ELF_T_LAST || (sh_type != SHT_NOBITS &&
962de3b87aSKai Wang 	    sh_offset + sh_size > (uint64_t) e->e_rawsize)) {
972de3b87aSKai Wang 		LIBELF_SET_ERROR(SECTION, 0);
982de3b87aSKai Wang 		return (NULL);
992de3b87aSKai Wang 	}
1002de3b87aSKai Wang 
1012de3b87aSKai Wang 	if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)
1022de3b87aSKai Wang             (elftype, (size_t) 1, e->e_version)) == 0) {
1032de3b87aSKai Wang 		LIBELF_SET_ERROR(UNIMPL, 0);
1042de3b87aSKai Wang 		return (NULL);
1052de3b87aSKai Wang 	}
1062de3b87aSKai Wang 
1072de3b87aSKai Wang 	if (sh_size % fsz) {
1082de3b87aSKai Wang 		LIBELF_SET_ERROR(SECTION, 0);
1092de3b87aSKai Wang 		return (NULL);
1102de3b87aSKai Wang 	}
1112de3b87aSKai Wang 
112*cf781b2eSEd Maste 	if (sh_size / fsz > SIZE_MAX) {
113*cf781b2eSEd Maste 		LIBELF_SET_ERROR(RANGE, 0);
114*cf781b2eSEd Maste 		return (NULL);
115*cf781b2eSEd Maste 	}
116*cf781b2eSEd Maste 
117*cf781b2eSEd Maste 	count = (size_t) (sh_size / fsz);
1182de3b87aSKai Wang 
1192de3b87aSKai Wang 	msz = _libelf_msize(elftype, elfclass, e->e_version);
1202de3b87aSKai Wang 
121*cf781b2eSEd Maste 	if (count > 0 && msz > SIZE_MAX / count) {
122*cf781b2eSEd Maste 		LIBELF_SET_ERROR(RANGE, 0);
123*cf781b2eSEd Maste 		return (NULL);
124*cf781b2eSEd Maste 	}
125*cf781b2eSEd Maste 
1262de3b87aSKai Wang 	assert(msz > 0);
127*cf781b2eSEd Maste 	assert(count <= SIZE_MAX);
128*cf781b2eSEd Maste 	assert(msz * count <= SIZE_MAX);
1292de3b87aSKai Wang 
1302de3b87aSKai Wang 	if ((d = _libelf_allocate_data(s)) == NULL)
1312de3b87aSKai Wang 		return (NULL);
1322de3b87aSKai Wang 
1332de3b87aSKai Wang 	d->d_data.d_buf     = NULL;
1342de3b87aSKai Wang 	d->d_data.d_off     = 0;
1352de3b87aSKai Wang 	d->d_data.d_align   = sh_align;
1362de3b87aSKai Wang 	d->d_data.d_size    = msz * count;
1372de3b87aSKai Wang 	d->d_data.d_type    = elftype;
1382de3b87aSKai Wang 	d->d_data.d_version = e->e_version;
1392de3b87aSKai Wang 
1402de3b87aSKai Wang 	if (sh_type == SHT_NOBITS || sh_size == 0) {
1412de3b87aSKai Wang 	        STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
1422de3b87aSKai Wang 		return (&d->d_data);
1432de3b87aSKai Wang         }
1442de3b87aSKai Wang 
1452de3b87aSKai Wang 	if ((d->d_data.d_buf = malloc(msz * count)) == NULL) {
1462de3b87aSKai Wang 		(void) _libelf_release_data(d);
1472de3b87aSKai Wang 		LIBELF_SET_ERROR(RESOURCE, 0);
1482de3b87aSKai Wang 		return (NULL);
1492de3b87aSKai Wang 	}
1502de3b87aSKai Wang 
1512de3b87aSKai Wang 	d->d_flags  |= LIBELF_F_DATA_MALLOCED;
1522de3b87aSKai Wang 
1532de3b87aSKai Wang 	xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass);
154*cf781b2eSEd Maste 	if (!(*xlate)(d->d_data.d_buf, (size_t) d->d_data.d_size,
1552de3b87aSKai Wang 	    e->e_rawfile + sh_offset, count,
1562de3b87aSKai Wang 	    e->e_byteorder != LIBELF_PRIVATE(byteorder))) {
1572de3b87aSKai Wang 		_libelf_release_data(d);
1582de3b87aSKai Wang 		LIBELF_SET_ERROR(DATA, 0);
1592de3b87aSKai Wang 		return (NULL);
1602de3b87aSKai Wang 	}
1612de3b87aSKai Wang 
1622de3b87aSKai Wang 	STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
1632de3b87aSKai Wang 
1642de3b87aSKai Wang 	return (&d->d_data);
1652de3b87aSKai Wang }
1662de3b87aSKai Wang 
1672de3b87aSKai Wang Elf_Data *
1682de3b87aSKai Wang elf_newdata(Elf_Scn *s)
1692de3b87aSKai Wang {
1702de3b87aSKai Wang 	Elf *e;
1712de3b87aSKai Wang 	struct _Libelf_Data *d;
1722de3b87aSKai Wang 
1732de3b87aSKai Wang 	if (s == NULL || (e = s->s_elf) == NULL) {
1742de3b87aSKai Wang 		LIBELF_SET_ERROR(ARGUMENT, 0);
1752de3b87aSKai Wang 		return (NULL);
1762de3b87aSKai Wang 	}
1772de3b87aSKai Wang 
1782de3b87aSKai Wang 	assert(e->e_kind == ELF_K_ELF);
1792de3b87aSKai Wang 
1802de3b87aSKai Wang 	/*
1812de3b87aSKai Wang 	 * elf_newdata() has to append a data descriptor, so
1822de3b87aSKai Wang 	 * bring in existing section data if not already present.
1832de3b87aSKai Wang 	 */
1842de3b87aSKai Wang 	if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data))
1852de3b87aSKai Wang 		if (elf_getdata(s, NULL) == NULL)
1862de3b87aSKai Wang 			return (NULL);
1872de3b87aSKai Wang 
1882de3b87aSKai Wang 	if ((d = _libelf_allocate_data(s)) == NULL)
1892de3b87aSKai Wang 		return (NULL);
1902de3b87aSKai Wang 
1912de3b87aSKai Wang 	STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
1922de3b87aSKai Wang 
1932de3b87aSKai Wang 	d->d_data.d_align = 1;
1942de3b87aSKai Wang 	d->d_data.d_buf = NULL;
1952de3b87aSKai Wang 	d->d_data.d_off = (uint64_t) ~0;
1962de3b87aSKai Wang 	d->d_data.d_size = 0;
1972de3b87aSKai Wang 	d->d_data.d_type = ELF_T_BYTE;
1982de3b87aSKai Wang 	d->d_data.d_version = LIBELF_PRIVATE(version);
1992de3b87aSKai Wang 
2002de3b87aSKai Wang 	(void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY);
2012de3b87aSKai Wang 
2022de3b87aSKai Wang 	return (&d->d_data);
2032de3b87aSKai Wang }
2042de3b87aSKai Wang 
2052de3b87aSKai Wang /*
2062de3b87aSKai Wang  * Retrieve a data descriptor for raw (untranslated) data for section
2072de3b87aSKai Wang  * `s'.
2082de3b87aSKai Wang  */
2092de3b87aSKai Wang 
2102de3b87aSKai Wang Elf_Data *
2112de3b87aSKai Wang elf_rawdata(Elf_Scn *s, Elf_Data *ed)
2122de3b87aSKai Wang {
2132de3b87aSKai Wang 	Elf *e;
2142de3b87aSKai Wang 	int elf_class;
2152de3b87aSKai Wang 	uint32_t sh_type;
2162de3b87aSKai Wang 	struct _Libelf_Data *d;
2172de3b87aSKai Wang 	uint64_t sh_align, sh_offset, sh_size;
2182de3b87aSKai Wang 
2192de3b87aSKai Wang 	if (s == NULL || (e = s->s_elf) == NULL || e->e_rawfile == NULL) {
2202de3b87aSKai Wang 		LIBELF_SET_ERROR(ARGUMENT, 0);
2212de3b87aSKai Wang 		return (NULL);
2222de3b87aSKai Wang 	}
2232de3b87aSKai Wang 
2242de3b87aSKai Wang 	assert(e->e_kind == ELF_K_ELF);
2252de3b87aSKai Wang 
2262de3b87aSKai Wang 	d = (struct _Libelf_Data *) ed;
2272de3b87aSKai Wang 
2282de3b87aSKai Wang 	if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL)
2292de3b87aSKai Wang 		return (&d->d_data);
2302de3b87aSKai Wang 
2312de3b87aSKai Wang 	if (d != NULL)
2322de3b87aSKai Wang 		return (&STAILQ_NEXT(d, d_next)->d_data);
2332de3b87aSKai Wang 
2342de3b87aSKai Wang 	elf_class = e->e_class;
2352de3b87aSKai Wang 
2362de3b87aSKai Wang 	assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64);
2372de3b87aSKai Wang 
2382de3b87aSKai Wang 	if (elf_class == ELFCLASS32) {
2392de3b87aSKai Wang 		sh_type   = s->s_shdr.s_shdr32.sh_type;
2402de3b87aSKai Wang 		sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
2412de3b87aSKai Wang 		sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
2422de3b87aSKai Wang 		sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
2432de3b87aSKai Wang 	} else {
2442de3b87aSKai Wang 		sh_type   = s->s_shdr.s_shdr64.sh_type;
2452de3b87aSKai Wang 		sh_offset = s->s_shdr.s_shdr64.sh_offset;
2462de3b87aSKai Wang 		sh_size   = s->s_shdr.s_shdr64.sh_size;
2472de3b87aSKai Wang 		sh_align  = s->s_shdr.s_shdr64.sh_addralign;
2482de3b87aSKai Wang 	}
2492de3b87aSKai Wang 
2502de3b87aSKai Wang 	if (sh_type == SHT_NULL) {
2512de3b87aSKai Wang 		LIBELF_SET_ERROR(SECTION, 0);
2522de3b87aSKai Wang 		return (NULL);
2532de3b87aSKai Wang 	}
2542de3b87aSKai Wang 
2552de3b87aSKai Wang 	if ((d = _libelf_allocate_data(s)) == NULL)
2562de3b87aSKai Wang 		return (NULL);
2572de3b87aSKai Wang 
2582de3b87aSKai Wang 	d->d_data.d_buf = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL :
2592de3b87aSKai Wang 	    e->e_rawfile + sh_offset;
2602de3b87aSKai Wang 	d->d_data.d_off     = 0;
2612de3b87aSKai Wang 	d->d_data.d_align   = sh_align;
2622de3b87aSKai Wang 	d->d_data.d_size    = sh_size;
2632de3b87aSKai Wang 	d->d_data.d_type    = ELF_T_BYTE;
2642de3b87aSKai Wang 	d->d_data.d_version = e->e_version;
2652de3b87aSKai Wang 
2662de3b87aSKai Wang 	STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next);
2672de3b87aSKai Wang 
2682de3b87aSKai Wang 	return (&d->d_data);
2692de3b87aSKai Wang }
270