gelf_rela.c revision 367466 
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 <assert.h>
28#include <gelf.h>
29#include <limits.h>
30#include <stdint.h>
31
32#include "_libelf.h"
33
34ELFTC_VCSID("$Id: gelf_rela.c 3739 2019-05-06 05:18:15Z jkoshy $");
35
36GElf_Rela *
37gelf_getrela(Elf_Data *ed, int ndx, GElf_Rela *dst)
38{
39	int ec;
40	Elf *e;
41	size_t msz;
42	Elf_Scn *scn;
43	uint32_t sh_type;
44	Elf32_Rela *rela32;
45	Elf64_Rela *rela64;
46	struct _Libelf_Data *d;
47
48	d = (struct _Libelf_Data *) ed;
49
50	if (d == NULL || ndx < 0 || dst == NULL ||
51	    (scn = d->d_scn) == NULL ||
52	    (e = scn->s_elf) == NULL) {
53		LIBELF_SET_ERROR(ARGUMENT, 0);
54		return (NULL);
55	}
56
57	ec = e->e_class;
58	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
59
60	if (ec == ELFCLASS32)
61		sh_type = scn->s_shdr.s_shdr32.sh_type;
62	else
63		sh_type = scn->s_shdr.s_shdr64.sh_type;
64
65	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
66		LIBELF_SET_ERROR(ARGUMENT, 0);
67		return (NULL);
68	}
69
70	if ((msz = _libelf_msize(ELF_T_RELA, ec, e->e_version)) == 0)
71		return (NULL);
72
73	assert(ndx >= 0);
74
75	if (msz * (size_t) ndx >= d->d_data.d_size) {
76		LIBELF_SET_ERROR(ARGUMENT, 0);
77		return (NULL);
78	}
79
80	if (ec == ELFCLASS32) {
81		rela32 = (Elf32_Rela *) d->d_data.d_buf + ndx;
82
83		dst->r_offset = (Elf64_Addr) rela32->r_offset;
84		dst->r_info   = ELF64_R_INFO(
85		    (Elf64_Xword) ELF32_R_SYM(rela32->r_info),
86		    ELF32_R_TYPE(rela32->r_info));
87		dst->r_addend = (Elf64_Sxword) rela32->r_addend;
88
89	} else {
90
91		rela64 = (Elf64_Rela *) d->d_data.d_buf + ndx;
92
93		*dst = *rela64;
94
95		if (_libelf_is_mips64el(e))
96			dst->r_info =
97			    _libelf_mips64el_r_info_tom(rela64->r_info);
98	}
99
100	return (dst);
101}
102
103int
104gelf_update_rela(Elf_Data *ed, int ndx, GElf_Rela *dr)
105{
106	int ec;
107	Elf *e;
108	size_t msz;
109	Elf_Scn *scn;
110	uint32_t sh_type;
111	Elf32_Rela *rela32;
112	Elf64_Rela *rela64;
113	struct _Libelf_Data *d;
114
115	d = (struct _Libelf_Data *) ed;
116
117	if (d == NULL || ndx < 0 || dr == NULL ||
118	    (scn = d->d_scn) == NULL ||
119	    (e = scn->s_elf) == NULL) {
120		LIBELF_SET_ERROR(ARGUMENT, 0);
121		return (0);
122	}
123
124	ec = e->e_class;
125	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
126
127	if (ec == ELFCLASS32)
128		sh_type = scn->s_shdr.s_shdr32.sh_type;
129	else
130		sh_type = scn->s_shdr.s_shdr64.sh_type;
131
132	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
133		LIBELF_SET_ERROR(ARGUMENT, 0);
134		return (0);
135	}
136
137	if ((msz = _libelf_msize(ELF_T_RELA, ec, e->e_version)) == 0)
138		return (0);
139
140	assert(ndx >= 0);
141
142	if (msz * (size_t) ndx >= d->d_data.d_size) {
143		LIBELF_SET_ERROR(ARGUMENT, 0);
144		return (0);
145	}
146
147	if (ec == ELFCLASS32) {
148		rela32 = (Elf32_Rela *) d->d_data.d_buf + ndx;
149
150		LIBELF_COPY_U32(rela32, dr, r_offset);
151
152		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) ||
153		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
154			LIBELF_SET_ERROR(RANGE, 0);
155			return (0);
156		}
157		rela32->r_info = ELF32_R_INFO(
158			(Elf32_Word) ELF64_R_SYM(dr->r_info),
159			(Elf32_Word) ELF64_R_TYPE(dr->r_info));
160
161		LIBELF_COPY_S32(rela32, dr, r_addend);
162	} else {
163		rela64 = (Elf64_Rela *) d->d_data.d_buf + ndx;
164
165		*rela64 = *dr;
166
167		if (_libelf_is_mips64el(e))
168			rela64->r_info = _libelf_mips64el_r_info_tof(dr->r_info);
169	}
170
171	return (1);
172}
173