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
34 ELFTC_VCSID("$Id: gelf_rel.c 3739 2019-05-06 05:18:15Z jkoshy $");
35
36 GElf_Rel *
gelf_getrel(Elf_Data * ed,int ndx,GElf_Rel * dst)37 gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst)
38 {
39 int ec;
40 Elf *e;
41 size_t msz;
42 Elf_Scn *scn;
43 uint32_t sh_type;
44 Elf32_Rel *rel32;
45 Elf64_Rel *rel64;
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_REL) {
66 LIBELF_SET_ERROR(ARGUMENT, 0);
67 return (NULL);
68 }
69
70 if ((msz = _libelf_msize(ELF_T_REL, 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 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 if (_libelf_is_mips64el(e))
95 dst->r_info = _libelf_mips64el_r_info_tom(rel64->r_info);
96 }
97
98 return (dst);
99 }
100
101 int
gelf_update_rel(Elf_Data * ed,int ndx,GElf_Rel * dr)102 gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr)
103 {
104 int ec;
105 Elf *e;
106 size_t msz;
107 Elf_Scn *scn;
108 uint32_t sh_type;
109 Elf32_Rel *rel32;
110 Elf64_Rel *rel64;
111 struct _Libelf_Data *d;
112
113 d = (struct _Libelf_Data *) ed;
114
115 if (d == NULL || ndx < 0 || dr == NULL ||
116 (scn = d->d_scn) == NULL ||
117 (e = scn->s_elf) == NULL) {
118 LIBELF_SET_ERROR(ARGUMENT, 0);
119 return (0);
120 }
121
122 ec = e->e_class;
123 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
124
125 if (ec == ELFCLASS32)
126 sh_type = scn->s_shdr.s_shdr32.sh_type;
127 else
128 sh_type = scn->s_shdr.s_shdr64.sh_type;
129
130 if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) {
131 LIBELF_SET_ERROR(ARGUMENT, 0);
132 return (0);
133 }
134
135 if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0)
136 return (0);
137
138 assert(ndx >= 0);
139
140 if (msz * (size_t) ndx >= d->d_data.d_size) {
141 LIBELF_SET_ERROR(ARGUMENT, 0);
142 return (0);
143 }
144
145 if (ec == ELFCLASS32) {
146 rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx;
147
148 LIBELF_COPY_U32(rel32, dr, r_offset);
149
150 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) ||
151 ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
152 LIBELF_SET_ERROR(RANGE, 0);
153 return (0);
154 }
155 rel32->r_info = ELF32_R_INFO(
156 (Elf32_Word) ELF64_R_SYM(dr->r_info),
157 (Elf32_Word) ELF64_R_TYPE(dr->r_info));
158 } else {
159 rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx;
160
161 *rel64 = *dr;
162
163 if (_libelf_is_mips64el(e))
164 rel64->r_info = _libelf_mips64el_r_info_tof(dr->r_info);
165 }
166
167 return (1);
168 }
169