1/*-
2 * Copyright (c) 2006 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/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/limits.h>
31
32#include <assert.h>
33#include <gelf.h>
34
35#include "_libelf.h"
36
37GElf_Sym *
38gelf_getsym(Elf_Data *d, int ndx, GElf_Sym *dst)
39{
40	int ec;
41	Elf *e;
42	Elf_Scn *scn;
43	Elf32_Sym *sym32;
44	Elf64_Sym *sym64;
45	size_t msz;
46	uint32_t sh_type;
47
48	if (d == NULL || ndx < 0 || dst == NULL ||
49	    (scn = d->d_scn) == NULL ||
50	    (e = scn->s_elf) == NULL) {
51		LIBELF_SET_ERROR(ARGUMENT, 0);
52		return (NULL);
53	}
54
55	ec = e->e_class;
56	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
57
58	if (ec == ELFCLASS32)
59		sh_type = scn->s_shdr.s_shdr32.sh_type;
60	else
61		sh_type = scn->s_shdr.s_shdr64.sh_type;
62
63	if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
64		LIBELF_SET_ERROR(ARGUMENT, 0);
65		return (NULL);
66	}
67
68	msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
69
70	assert(msz > 0);
71
72	if (msz * ndx >= d->d_size) {
73		LIBELF_SET_ERROR(ARGUMENT, 0);
74		return (NULL);
75	}
76
77	if (ec == ELFCLASS32) {
78
79		sym32 = (Elf32_Sym *) d->d_buf + ndx;
80
81		dst->st_name  = sym32->st_name;
82		dst->st_value = (Elf64_Addr) sym32->st_value;
83		dst->st_size  = (Elf64_Xword) sym32->st_size;
84		dst->st_info  = ELF64_ST_INFO(ELF32_ST_BIND(sym32->st_info),
85		    ELF32_ST_TYPE(sym32->st_info));
86		dst->st_other = sym32->st_other;
87		dst->st_shndx = sym32->st_shndx;
88	} else {
89
90		sym64 = (Elf64_Sym *) d->d_buf + ndx;
91
92		*dst = *sym64;
93	}
94
95	return (dst);
96}
97
98int
99gelf_update_sym(Elf_Data *d, int ndx, GElf_Sym *gs)
100{
101	int ec;
102	Elf *e;
103	Elf_Scn *scn;
104	Elf32_Sym *sym32;
105	Elf64_Sym *sym64;
106	size_t msz;
107	uint32_t sh_type;
108
109	if (d == NULL || ndx < 0 || gs == NULL ||
110	    (scn = d->d_scn) == NULL ||
111	    (e = scn->s_elf) == NULL) {
112		LIBELF_SET_ERROR(ARGUMENT, 0);
113		return (0);
114	}
115
116	ec = e->e_class;
117	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
118
119	if (ec == ELFCLASS32)
120		sh_type = scn->s_shdr.s_shdr32.sh_type;
121	else
122		sh_type = scn->s_shdr.s_shdr64.sh_type;
123
124	if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
125		LIBELF_SET_ERROR(ARGUMENT, 0);
126		return (0);
127	}
128
129	msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
130	assert(msz > 0);
131
132	if (msz * ndx >= d->d_size) {
133		LIBELF_SET_ERROR(ARGUMENT, 0);
134		return (0);
135	}
136
137	if (ec == ELFCLASS32) {
138		sym32 = (Elf32_Sym *) d->d_buf + ndx;
139
140		sym32->st_name  = gs->st_name;
141		sym32->st_info  = gs->st_info;
142		sym32->st_other = gs->st_other;
143		sym32->st_shndx = gs->st_shndx;
144
145		LIBELF_COPY_U32(sym32, gs, st_value);
146		LIBELF_COPY_U32(sym32, gs, st_size);
147	} else {
148		sym64 = (Elf64_Sym *) d->d_buf + ndx;
149
150		*sym64 = *gs;
151	}
152
153	return (1);
154}
155