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_rela.c 3739 2019-05-06 05:18:15Z jkoshy $");
35
36 GElf_Rela *
gelf_getrela(Elf_Data * ed,int ndx,GElf_Rela * dst)37 gelf_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
103 int
gelf_update_rela(Elf_Data * ed,int ndx,GElf_Rela * dr)104 gelf_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