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_Rela *
gelf_getrela(Elf_Data * d,int ndx,GElf_Rela * dst)38 gelf_getrela(Elf_Data *d, int ndx, GElf_Rela *dst)
39 {
40 int ec;
41 Elf *e;
42 Elf_Scn *scn;
43 Elf32_Rela *rela32;
44 Elf64_Rela *rela64;
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_RELA) {
64 LIBELF_SET_ERROR(ARGUMENT, 0);
65 return (NULL);
66 }
67
68 msz = _libelf_msize(ELF_T_RELA, 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 rela32 = (Elf32_Rela *) d->d_buf + ndx;
79
80 dst->r_offset = (Elf64_Addr) rela32->r_offset;
81 dst->r_info = ELF64_R_INFO(
82 (Elf64_Xword) ELF32_R_SYM(rela32->r_info),
83 ELF32_R_TYPE(rela32->r_info));
84 dst->r_addend = (Elf64_Sxword) rela32->r_addend;
85
86 } else {
87
88 rela64 = (Elf64_Rela *) d->d_buf + ndx;
89
90 *dst = *rela64;
91 }
92
93 return (dst);
94 }
95
96 int
gelf_update_rela(Elf_Data * d,int ndx,GElf_Rela * dr)97 gelf_update_rela(Elf_Data *d, int ndx, GElf_Rela *dr)
98 {
99 int ec;
100 Elf *e;
101 Elf_Scn *scn;
102 Elf32_Rela *rela32;
103 Elf64_Rela *rela64;
104 size_t msz;
105 uint32_t sh_type;
106
107 if (d == NULL || ndx < 0 || dr == NULL ||
108 (scn = d->d_scn) == NULL ||
109 (e = scn->s_elf) == NULL) {
110 LIBELF_SET_ERROR(ARGUMENT, 0);
111 return (0);
112 }
113
114 ec = e->e_class;
115 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
116
117 if (ec == ELFCLASS32)
118 sh_type = scn->s_shdr.s_shdr32.sh_type;
119 else
120 sh_type = scn->s_shdr.s_shdr64.sh_type;
121
122 if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
123 LIBELF_SET_ERROR(ARGUMENT, 0);
124 return (0);
125 }
126
127 msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
128 assert(msz > 0);
129
130 if (msz * ndx >= d->d_size) {
131 LIBELF_SET_ERROR(ARGUMENT, 0);
132 return (0);
133 }
134
135 if (ec == ELFCLASS32) {
136 rela32 = (Elf32_Rela *) d->d_buf + ndx;
137
138 LIBELF_COPY_U32(rela32, dr, r_offset);
139
140 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
141 ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
142 LIBELF_SET_ERROR(RANGE, 0);
143 return (0);
144 }
145 rela32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
146 ELF64_R_TYPE(dr->r_info));
147
148 LIBELF_COPY_S32(rela32, dr, r_addend);
149 } else {
150 rela64 = (Elf64_Rela *) d->d_buf + ndx;
151
152 *rela64 = *dr;
153 }
154
155 return (1);
156 }
157