gelf_rel.c revision 261246 
1/*-
2 * Copyright (c) 2006,2008 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
29#include <assert.h>
30#include <gelf.h>
31#include <limits.h>
32
33#include "_libelf.h"
34
35ELFTC_VCSID("$Id: gelf_rel.c 2272 2011-12-03 17:07:31Z jkoshy $");
36
37GElf_Rel *
38gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
39{
40	int ec;
41	Elf *e;
42	size_t msz;
43	Elf_Scn *scn;
44	uint32_t sh_type;
45	Elf32_Rel *rel32;
46	Elf64_Rel *rel64;
47	struct _Libelf_Data *d;
48
49	d = (struct _Libelf_Data *) ed;
50
51	if (d == NULL || ndx < 0 || dst == NULL ||
52	    (scn = d->d_scn) == NULL ||
53	    (e = scn->s_elf) == NULL) {
54		LIBELF_SET_ERROR(ARGUMENT, 0);
55		return (NULL);
56	}
57
58	ec = e->e_class;
59	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
60
61	if (ec == ELFCLASS32)
62		sh_type = scn->s_shdr.s_shdr32.sh_type;
63	else
64		sh_type = scn->s_shdr.s_shdr64.sh_type;
65
66	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
67		LIBELF_SET_ERROR(ARGUMENT, 0);
68		return (NULL);
69	}
70
71	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
72
73	assert(msz > 0);
74
75	if (msz * ndx >= d->d_data.d_size) {
76		LIBELF_SET_ERROR(ARGUMENT, 0);
77		return (NULL);
78	}
79
80	if (ec == ELFCLASS32) {
81		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
82
83		dst->r_offset = (Elf64_Addr) rel32->r_offset;
84		dst->r_info   = ELF64_R_INFO(
85		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
86		    ELF32_R_TYPE(rel32->r_info));
87
88	} else {
89
90		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
91
92		*dst = *rel64;
93	}
94
95	return (dst);
96}
97
98int
99gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
100{
101	int ec;
102	Elf *e;
103	size_t msz;
104	Elf_Scn *scn;
105	uint32_t sh_type;
106	Elf32_Rel *rel32;
107	Elf64_Rel *rel64;
108	struct _Libelf_Data *d;
109
110	d = (struct _Libelf_Data *) ed;
111
112	if (d == NULL || ndx < 0 || dr == NULL ||
113	    (scn = d->d_scn) == NULL ||
114	    (e = scn->s_elf) == NULL) {
115		LIBELF_SET_ERROR(ARGUMENT, 0);
116		return (0);
117	}
118
119	ec = e->e_class;
120	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
121
122	if (ec == ELFCLASS32)
123		sh_type = scn->s_shdr.s_shdr32.sh_type;
124	else
125		sh_type = scn->s_shdr.s_shdr64.sh_type;
126
127	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
128		LIBELF_SET_ERROR(ARGUMENT, 0);
129		return (0);
130	}
131
132	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
133	assert(msz > 0);
134
135	if (msz * ndx >= d->d_data.d_size) {
136		LIBELF_SET_ERROR(ARGUMENT, 0);
137		return (0);
138	}
139
140	if (ec == ELFCLASS32) {
141		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
142
143		LIBELF_COPY_U32(rel32, dr, r_offset);
144
145		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
146		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
147			LIBELF_SET_ERROR(RANGE, 0);
148			return (0);
149		}
150		rel32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
151		    ELF64_R_TYPE(dr->r_info));
152	} else {
153		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
154
155		*rel64 = *dr;
156	}
157
158	return (1);
159}
160