1 /*-
2 * Copyright (c) 2006 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 __FBSDID("$FreeBSD$");
29
30 #include <sys/limits.h>
31
32 #include <assert.h>
33 #include <gelf.h>
34
35 #include "_libelf.h"
36
37 GElf_Rel *
gelf_getrel(Elf_Data * d,int ndx,GElf_Rel * dst)38 gelf_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
95 int
gelf_update_rel(Elf_Data * d,int ndx,GElf_Rel * dr)96 gelf_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