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_Sym *
gelf_getsym(Elf_Data * d,int ndx,GElf_Sym * dst)38 gelf_getsym(Elf_Data *d, int ndx, GElf_Sym *dst)
39 {
40 int ec;
41 Elf *e;
42 Elf_Scn *scn;
43 Elf32_Sym *sym32;
44 Elf64_Sym *sym64;
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_SYM) {
64 LIBELF_SET_ERROR(ARGUMENT, 0);
65 return (NULL);
66 }
67
68 msz = _libelf_msize(ELF_T_SYM, 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
79 sym32 = (Elf32_Sym *) d->d_buf + ndx;
80
81 dst->st_name = sym32->st_name;
82 dst->st_value = (Elf64_Addr) sym32->st_value;
83 dst->st_size = (Elf64_Xword) sym32->st_size;
84 dst->st_info = ELF64_ST_INFO(ELF32_ST_BIND(sym32->st_info),
85 ELF32_ST_TYPE(sym32->st_info));
86 dst->st_other = sym32->st_other;
87 dst->st_shndx = sym32->st_shndx;
88 } else {
89
90 sym64 = (Elf64_Sym *) d->d_buf + ndx;
91
92 *dst = *sym64;
93 }
94
95 return (dst);
96 }
97
98 int
gelf_update_sym(Elf_Data * d,int ndx,GElf_Sym * gs)99 gelf_update_sym(Elf_Data *d, int ndx, GElf_Sym *gs)
100 {
101 int ec;
102 Elf *e;
103 Elf_Scn *scn;
104 Elf32_Sym *sym32;
105 Elf64_Sym *sym64;
106 size_t msz;
107 uint32_t sh_type;
108
109 if (d == NULL || ndx < 0 || gs == NULL ||
110 (scn = d->d_scn) == NULL ||
111 (e = scn->s_elf) == NULL) {
112 LIBELF_SET_ERROR(ARGUMENT, 0);
113 return (0);
114 }
115
116 ec = e->e_class;
117 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
118
119 if (ec == ELFCLASS32)
120 sh_type = scn->s_shdr.s_shdr32.sh_type;
121 else
122 sh_type = scn->s_shdr.s_shdr64.sh_type;
123
124 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
125 LIBELF_SET_ERROR(ARGUMENT, 0);
126 return (0);
127 }
128
129 msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
130 assert(msz > 0);
131
132 if (msz * ndx >= d->d_size) {
133 LIBELF_SET_ERROR(ARGUMENT, 0);
134 return (0);
135 }
136
137 if (ec == ELFCLASS32) {
138 sym32 = (Elf32_Sym *) d->d_buf + ndx;
139
140 sym32->st_name = gs->st_name;
141 sym32->st_info = gs->st_info;
142 sym32->st_other = gs->st_other;
143 sym32->st_shndx = gs->st_shndx;
144
145 LIBELF_COPY_U32(sym32, gs, st_value);
146 LIBELF_COPY_U32(sym32, gs, st_size);
147 } else {
148 sym64 = (Elf64_Sym *) d->d_buf + ndx;
149
150 *sym64 = *gs;
151 }
152
153 return (1);
154 }
155