gelf_rel.c revision 276371 
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#include <stdint.h>
33
34#include "_libelf.h"
35
36ELFTC_VCSID("$Id: gelf_rel.c 2998 2014-03-18 17:19:00Z jkoshy $");
37
38GElf_Rel *
39gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
40{
41	int ec;
42	Elf *e;
43	size_t msz;
44	Elf_Scn *scn;
45	uint32_t sh_type;
46	Elf32_Rel *rel32;
47	Elf64_Rel *rel64;
48	struct _Libelf_Data *d;
49
50	d = (struct _Libelf_Data *) ed;
51
52	if (d == NULL || ndx < 0 || dst == NULL ||
53	    (scn = d->d_scn) == NULL ||
54	    (e = scn->s_elf) == NULL) {
55		LIBELF_SET_ERROR(ARGUMENT, 0);
56		return (NULL);
57	}
58
59	ec = e->e_class;
60	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
61
62	if (ec == ELFCLASS32)
63		sh_type = scn->s_shdr.s_shdr32.sh_type;
64	else
65		sh_type = scn->s_shdr.s_shdr64.sh_type;
66
67	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
68		LIBELF_SET_ERROR(ARGUMENT, 0);
69		return (NULL);
70	}
71
72	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
73
74	assert(msz > 0);
75	assert(ndx >= 0);
76
77	if (msz * (size_t) ndx >= d->d_data.d_size) {
78		LIBELF_SET_ERROR(ARGUMENT, 0);
79		return (NULL);
80	}
81
82	if (ec == ELFCLASS32) {
83		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
84
85		dst->r_offset = (Elf64_Addr) rel32->r_offset;
86		dst->r_info   = ELF64_R_INFO(
87		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
88		    ELF32_R_TYPE(rel32->r_info));
89
90	} else {
91
92		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
93
94		*dst = *rel64;
95	}
96
97	return (dst);
98}
99
100int
101gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
102{
103	int ec;
104	Elf *e;
105	size_t msz;
106	Elf_Scn *scn;
107	uint32_t sh_type;
108	Elf32_Rel *rel32;
109	Elf64_Rel *rel64;
110	struct _Libelf_Data *d;
111
112	d = (struct _Libelf_Data *) ed;
113
114	if (d == NULL || ndx < 0 || dr == NULL ||
115	    (scn = d->d_scn) == NULL ||
116	    (e = scn->s_elf) == NULL) {
117		LIBELF_SET_ERROR(ARGUMENT, 0);
118		return (0);
119	}
120
121	ec = e->e_class;
122	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
123
124	if (ec == ELFCLASS32)
125		sh_type = scn->s_shdr.s_shdr32.sh_type;
126	else
127		sh_type = scn->s_shdr.s_shdr64.sh_type;
128
129	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
130		LIBELF_SET_ERROR(ARGUMENT, 0);
131		return (0);
132	}
133
134	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
135
136	assert(msz > 0);
137	assert(ndx >= 0);
138
139	if (msz * (size_t) ndx >= d->d_data.d_size) {
140		LIBELF_SET_ERROR(ARGUMENT, 0);
141		return (0);
142	}
143
144	if (ec == ELFCLASS32) {
145		rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
146
147		LIBELF_COPY_U32(rel32, dr, r_offset);
148
149		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
150		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
151			LIBELF_SET_ERROR(RANGE, 0);
152			return (0);
153		}
154		rel32->r_info = ELF32_R_INFO(
155			(Elf32_Word) ELF64_R_SYM(dr->r_info),
156			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
157	} else {
158		rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
159
160		*rel64 = *dr;
161	}
162
163	return (1);
164}
165