gelf_rel.c revision 176727 
1240116Smarcel/*-
2240116Smarcel * Copyright (c) 2006 Joseph Koshy
3240116Smarcel * All rights reserved.
4240116Smarcel *
5240116Smarcel * Redistribution and use in source and binary forms, with or without
6240116Smarcel * modification, are permitted provided that the following conditions
7240116Smarcel * are met:
8262855Sjmmv * 1. Redistributions of source code must retain the above copyright
9262855Sjmmv *    notice, this list of conditions and the following disclaimer.
10262855Sjmmv * 2. Redistributions in binary form must reproduce the above copyright
11262855Sjmmv *    notice, this list of conditions and the following disclaimer in the
12262855Sjmmv *    documentation and/or other materials provided with the distribution.
13240116Smarcel *
14262855Sjmmv * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15262855Sjmmv * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16262855Sjmmv * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17262855Sjmmv * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18262855Sjmmv * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19262855Sjmmv * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20240116Smarcel * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21240116Smarcel * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22240116Smarcel * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23240116Smarcel * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24240116Smarcel * SUCH DAMAGE.
25240116Smarcel */
26240116Smarcel
27240116Smarcel#include <sys/cdefs.h>
28240116Smarcel__FBSDID("$FreeBSD: head/lib/libelf/gelf_rel.c 176727 2008-03-02 06:33:10Z jkoshy $");
29240116Smarcel
30240116Smarcel#include <sys/limits.h>
31240116Smarcel
32240116Smarcel#include <assert.h>
33240116Smarcel#include <gelf.h>
34240116Smarcel
35240116Smarcel#include "_libelf.h"
36240116Smarcel
37240116SmarcelGElf_Rel *
38gelf_getrel(Elf_Data *d, int ndx, GElf_Rel *dst)
39{
40	int ec;
41	Elf *e;
42	Elf_Scn *scn;
43	Elf32_Rel *rel32;
44	Elf64_Rel *rel64;
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_REL) {
64		LIBELF_SET_ERROR(ARGUMENT, 0);
65		return (NULL);
66	}
67
68	msz = _libelf_msize(ELF_T_REL, 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		rel32 = (Elf32_Rel *) d->d_buf + ndx;
79
80		dst->r_offset = (Elf64_Addr) rel32->r_offset;
81		dst->r_info   = ELF64_R_INFO(
82		    (Elf64_Xword) ELF32_R_SYM(rel32->r_info),
83		    ELF32_R_TYPE(rel32->r_info));
84
85	} else {
86
87		rel64 = (Elf64_Rel *) d->d_buf + ndx;
88
89		*dst = *rel64;
90	}
91
92	return (dst);
93}
94
95int
96gelf_update_rel(Elf_Data *d, int ndx, GElf_Rel *dr)
97{
98	int ec;
99	Elf *e;
100	Elf_Scn *scn;
101	Elf32_Rel *rel32;
102	Elf64_Rel *rel64;
103	size_t msz;
104	uint32_t sh_type;
105
106	if (d == NULL || ndx < 0 || dr == NULL ||
107	    (scn = d->d_scn) == NULL ||
108	    (e = scn->s_elf) == NULL) {
109		LIBELF_SET_ERROR(ARGUMENT, 0);
110		return (0);
111	}
112
113	ec = e->e_class;
114	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
115
116	if (ec == ELFCLASS32)
117		sh_type = scn->s_shdr.s_shdr32.sh_type;
118	else
119		sh_type = scn->s_shdr.s_shdr64.sh_type;
120
121	if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
122		LIBELF_SET_ERROR(ARGUMENT, 0);
123		return (0);
124	}
125
126	msz = _libelf_msize(ELF_T_REL, ec, e->e_version);
127	assert(msz > 0);
128
129	if (msz * ndx >= d->d_size) {
130		LIBELF_SET_ERROR(ARGUMENT, 0);
131		return (0);
132	}
133
134	if (ec == ELFCLASS32) {
135		rel32 = (Elf32_Rel *) d->d_buf + ndx;
136
137		LIBELF_COPY_U32(rel32, dr, r_offset);
138
139		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
140		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
141			LIBELF_SET_ERROR(RANGE, 0);
142			return (0);
143		}
144		rel32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
145		    ELF64_R_TYPE(dr->r_info));
146	} else {
147		rel64 = (Elf64_Rel *) d->d_buf + ndx;
148
149		*rel64 = *dr;
150	}
151
152	return (1);
153}
154