xref: /netbsd-src/external/bsd/elftoolchain/dist/libelf/gelf_rel.c (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /*	$NetBSD: gelf_rel.c,v 1.4 2022/05/01 19:41:35 jkoshy 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 #if HAVE_NBTOOL_CONFIG_H
30 # include "nbtool_config.h"
31 #endif
32 
33 #include <sys/cdefs.h>
34 
35 #include <assert.h>
36 #include <gelf.h>
37 #include <limits.h>
38 #include <stdint.h>
39 
40 #include "_libelf.h"
41 
42 __RCSID("$NetBSD: gelf_rel.c,v 1.4 2022/05/01 19:41:35 jkoshy Exp $");
43 ELFTC_VCSID("Id: gelf_rel.c 3177 2015-03-30 18:19:41Z emaste");
44 
45 GElf_Rel *
46 gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
47 {
48 	int ec;
49 	Elf *e;
50 	size_t msz;
51 	Elf_Scn *scn;
52 	uint32_t sh_type;
53 	Elf32_Rel *rel32;
54 	Elf64_Rel *rel64;
55 	struct _Libelf_Data *d;
56 
57 	d = (struct _Libelf_Data *) ed;
58 
59 	if (d == NULL || ndx < 0 || dst == NULL ||
60 	    (scn = d->d_scn) == NULL ||
61 	    (e = scn->s_elf) == NULL) {
62 		LIBELF_SET_ERROR(ARGUMENT, 0);
63 		return (NULL);
64 	}
65 
66 	ec = e->e_class;
67 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
68 
69 	if (ec == ELFCLASS32)
70 		sh_type = scn->s_shdr.s_shdr32.sh_type;
71 	else
72 		sh_type = scn->s_shdr.s_shdr64.sh_type;
73 
74 	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
75 		LIBELF_SET_ERROR(ARGUMENT, 0);
76 		return (NULL);
77 	}
78 
79 	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
80 
81 	assert(msz > 0);
82 	assert(ndx >= 0);
83 
84 	if (msz * (size_t) ndx >= d->d_data.d_size) {
85 		LIBELF_SET_ERROR(ARGUMENT, 0);
86 		return (NULL);
87 	}
88 
89 	if (ec == ELFCLASS32) {
90 		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
91 
92 		dst->r_offset = (Elf64_Addr) rel32->r_offset;
93 		dst->r_info   = ELF64_R_INFO(
94 		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
95 		    ELF32_R_TYPE(rel32->r_info));
96 
97 	} else {
98 
99 		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
100 
101 		*dst = *rel64;
102 	}
103 
104 	return (dst);
105 }
106 
107 int
108 gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
109 {
110 	int ec;
111 	Elf *e;
112 	size_t msz;
113 	Elf_Scn *scn;
114 	uint32_t sh_type;
115 	Elf32_Rel *rel32;
116 	Elf64_Rel *rel64;
117 	struct _Libelf_Data *d;
118 
119 	d = (struct _Libelf_Data *) ed;
120 
121 	if (d == NULL || ndx < 0 || dr == NULL ||
122 	    (scn = d->d_scn) == NULL ||
123 	    (e = scn->s_elf) == NULL) {
124 		LIBELF_SET_ERROR(ARGUMENT, 0);
125 		return (0);
126 	}
127 
128 	ec = e->e_class;
129 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
130 
131 	if (ec == ELFCLASS32)
132 		sh_type = scn->s_shdr.s_shdr32.sh_type;
133 	else
134 		sh_type = scn->s_shdr.s_shdr64.sh_type;
135 
136 	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
137 		LIBELF_SET_ERROR(ARGUMENT, 0);
138 		return (0);
139 	}
140 
141 	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
142 
143 	assert(msz > 0);
144 	assert(ndx >= 0);
145 
146 	if (msz * (size_t) ndx >= d->d_data.d_size) {
147 		LIBELF_SET_ERROR(ARGUMENT, 0);
148 		return (0);
149 	}
150 
151 	if (ec == ELFCLASS32) {
152 		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
153 
154 		LIBELF_COPY_U32(rel32, dr, r_offset);
155 
156 		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
157 		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
158 			LIBELF_SET_ERROR(RANGE, 0);
159 			return (0);
160 		}
161 		rel32->r_info = ELF32_R_INFO(
162 			(Elf32_Word) ELF64_R_SYM(dr->r_info),
163 			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
164 	} else {
165 		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
166 
167 		*rel64 = *dr;
168 	}
169 
170 	return (1);
171 }
172