1/*	$NetBSD: gelf_sym.c,v 1.5 2024/03/03 17:37:34 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#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_sym.c,v 1.5 2024/03/03 17:37:34 christos Exp $");
43ELFTC_VCSID("Id: gelf_sym.c 3977 2022-05-01 06:45:34Z jkoshy");
44
45GElf_Sym *
46gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst)
47{
48	int ec;
49	Elf *e;
50	size_t msz;
51	Elf_Scn *scn;
52	uint32_t sh_type;
53	Elf32_Sym *sym32;
54	Elf64_Sym *sym64;
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_SYM) {
75		LIBELF_SET_ERROR(ARGUMENT, 0);
76		return (NULL);
77	}
78
79	if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0)
80		return (NULL);
81
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		sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
91
92		dst->st_name  = sym32->st_name;
93		dst->st_value = (Elf64_Addr) sym32->st_value;
94		dst->st_size  = (Elf64_Xword) sym32->st_size;
95		dst->st_info  = sym32->st_info;
96		dst->st_other = sym32->st_other;
97		dst->st_shndx = sym32->st_shndx;
98	} else {
99		sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
100
101		*dst = *sym64;
102	}
103
104	return (dst);
105}
106
107int
108gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs)
109{
110	int ec;
111	Elf *e;
112	size_t msz;
113	Elf_Scn *scn;
114	uint32_t sh_type;
115	Elf32_Sym *sym32;
116	Elf64_Sym *sym64;
117	struct _Libelf_Data *d;
118
119	d = (struct _Libelf_Data *) ed;
120
121	if (d == NULL || ndx < 0 || gs == 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_SYM) {
137		LIBELF_SET_ERROR(ARGUMENT, 0);
138		return (0);
139	}
140
141	if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0)
142		return (0);
143
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		sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
153
154		sym32->st_name  = gs->st_name;
155		sym32->st_info  = gs->st_info;
156		sym32->st_other = gs->st_other;
157		sym32->st_shndx = gs->st_shndx;
158
159		LIBELF_COPY_U32(sym32, gs, st_value);
160		LIBELF_COPY_U32(sym32, gs, st_size);
161	} else {
162		sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
163
164		*sym64 = *gs;
165	}
166
167	return (1);
168}
169