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gelf_rel.c revision 1.1.1.3 
      1 /*	$NetBSD: gelf_rel.c,v 1.1.1.3 2024/03/03 14:41:47 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006,2008 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 #include <sys/cdefs.h>
     30 
     31 #include <assert.h>
     32 #include <gelf.h>
     33 #include <limits.h>
     34 #include <stdint.h>
     35 
     36 #include "_libelf.h"
     37 
     38 ELFTC_VCSID("Id: gelf_rel.c 3977 2022-05-01 06:45:34Z jkoshy");
     39 
     40 __RCSID("$NetBSD: gelf_rel.c,v 1.1.1.3 2024/03/03 14:41:47 christos Exp $");
     41 
     42 GElf_Rel *
     43 gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
     44 {
     45 	int ec;
     46 	Elf *e;
     47 	size_t msz;
     48 	Elf_Scn *scn;
     49 	uint32_t sh_type;
     50 	Elf32_Rel *rel32;
     51 	Elf64_Rel *rel64;
     52 	struct _Libelf_Data *d;
     53 
     54 	d = (struct _Libelf_Data *) ed;
     55 
     56 	if (d == NULL || ndx < 0 || dst == NULL ||
     57 	    (scn = d->d_scn) == NULL ||
     58 	    (e = scn->s_elf) == NULL) {
     59 		LIBELF_SET_ERROR(ARGUMENT, 0);
     60 		return (NULL);
     61 	}
     62 
     63 	ec = e->e_class;
     64 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
     65 
     66 	if (ec == ELFCLASS32)
     67 		sh_type = scn->s_shdr.s_shdr32.sh_type;
     68 	else
     69 		sh_type = scn->s_shdr.s_shdr64.sh_type;
     70 
     71 	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
     72 		LIBELF_SET_ERROR(ARGUMENT, 0);
     73 		return (NULL);
     74 	}
     75 
     76 	if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0)
     77 		return (NULL);
     78 
     79 	assert(ndx >= 0);
     80 
     81 	if (msz * (size_t) ndx >= d->d_data.d_size) {
     82 		LIBELF_SET_ERROR(ARGUMENT, 0);
     83 		return (NULL);
     84 	}
     85 
     86 	if (ec == ELFCLASS32) {
     87 		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
     88 
     89 		dst->r_offset = (Elf64_Addr) rel32->r_offset;
     90 		dst->r_info   = ELF64_R_INFO(
     91 		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
     92 		    ELF32_R_TYPE(rel32->r_info));
     93 
     94 	} else {
     95 
     96 		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
     97 
     98 		*dst = *rel64;
     99 	}
    100 
    101 	return (dst);
    102 }
    103 
    104 int
    105 gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
    106 {
    107 	int ec;
    108 	Elf *e;
    109 	size_t msz;
    110 	Elf_Scn *scn;
    111 	uint32_t sh_type;
    112 	Elf32_Rel *rel32;
    113 	Elf64_Rel *rel64;
    114 	struct _Libelf_Data *d;
    115 
    116 	d = (struct _Libelf_Data *) ed;
    117 
    118 	if (d == NULL || ndx < 0 || dr == NULL ||
    119 	    (scn = d->d_scn) == NULL ||
    120 	    (e = scn->s_elf) == NULL) {
    121 		LIBELF_SET_ERROR(ARGUMENT, 0);
    122 		return (0);
    123 	}
    124 
    125 	ec = e->e_class;
    126 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
    127 
    128 	if (ec == ELFCLASS32)
    129 		sh_type = scn->s_shdr.s_shdr32.sh_type;
    130 	else
    131 		sh_type = scn->s_shdr.s_shdr64.sh_type;
    132 
    133 	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
    134 		LIBELF_SET_ERROR(ARGUMENT, 0);
    135 		return (0);
    136 	}
    137 
    138 	if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0)
    139 		return (0);
    140 
    141 	assert(ndx >= 0);
    142 
    143 	if (msz * (size_t) ndx >= d->d_data.d_size) {
    144 		LIBELF_SET_ERROR(ARGUMENT, 0);
    145 		return (0);
    146 	}
    147 
    148 	if (ec == ELFCLASS32) {
    149 		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
    150 
    151 		LIBELF_COPY_U32(rel32, dr, r_offset);
    152 
    153 		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) ||
    154 		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
    155 			LIBELF_SET_ERROR(RANGE, 0);
    156 			return (0);
    157 		}
    158 		rel32->r_info = ELF32_R_INFO(
    159 			(Elf32_Word) ELF64_R_SYM(dr->r_info),
    160 			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
    161 	} else {
    162 		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
    163 
    164 		*rel64 = *dr;
    165 	}
    166 
    167 	return (1);
    168 }
    169