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 <sys/cdefs.h>
28
29 #include <assert.h>
30 #include <gelf.h>
31 #include <limits.h>
32
33 #include "_libelf.h"
34
35 ELFTC_VCSID("$Id$");
36
37 GElf_Sym *
gelf_getsym(Elf_Data * ed,int ndx,GElf_Sym * dst)38 gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst)
39 {
40 int ec;
41 Elf *e;
42 size_t msz;
43 Elf_Scn *scn;
44 uint32_t sh_type;
45 Elf32_Sym *sym32;
46 Elf64_Sym *sym64;
47 struct _Libelf_Data *d;
48
49 d = (struct _Libelf_Data *) ed;
50
51 if (d == NULL || ndx < 0 || dst == NULL ||
52 (scn = d->d_scn) == NULL ||
53 (e = scn->s_elf) == NULL) {
54 LIBELF_SET_ERROR(ARGUMENT, 0);
55 return (NULL);
56 }
57
58 ec = e->e_class;
59 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
60
61 if (ec == ELFCLASS32)
62 sh_type = scn->s_shdr.s_shdr32.sh_type;
63 else
64 sh_type = scn->s_shdr.s_shdr64.sh_type;
65
66 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
67 LIBELF_SET_ERROR(ARGUMENT, 0);
68 return (NULL);
69 }
70
71 msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
72
73 assert(msz > 0);
74 assert(ndx >= 0);
75
76 if (msz * (size_t) ndx >= d->d_data.d_size) {
77 LIBELF_SET_ERROR(ARGUMENT, 0);
78 return (NULL);
79 }
80
81 if (ec == ELFCLASS32) {
82 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
83
84 dst->st_name = sym32->st_name;
85 dst->st_value = (Elf64_Addr) sym32->st_value;
86 dst->st_size = (Elf64_Xword) sym32->st_size;
87 dst->st_info = sym32->st_info;
88 dst->st_other = sym32->st_other;
89 dst->st_shndx = sym32->st_shndx;
90 } else {
91 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
92
93 *dst = *sym64;
94 }
95
96 return (dst);
97 }
98
99 int
gelf_update_sym(Elf_Data * ed,int ndx,GElf_Sym * gs)100 gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs)
101 {
102 int ec;
103 Elf *e;
104 size_t msz;
105 Elf_Scn *scn;
106 uint32_t sh_type;
107 Elf32_Sym *sym32;
108 Elf64_Sym *sym64;
109 struct _Libelf_Data *d;
110
111 d = (struct _Libelf_Data *) ed;
112
113 if (d == NULL || ndx < 0 || gs == NULL ||
114 (scn = d->d_scn) == NULL ||
115 (e = scn->s_elf) == NULL) {
116 LIBELF_SET_ERROR(ARGUMENT, 0);
117 return (0);
118 }
119
120 ec = e->e_class;
121 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
122
123 if (ec == ELFCLASS32)
124 sh_type = scn->s_shdr.s_shdr32.sh_type;
125 else
126 sh_type = scn->s_shdr.s_shdr64.sh_type;
127
128 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
129 LIBELF_SET_ERROR(ARGUMENT, 0);
130 return (0);
131 }
132
133 msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
134
135 assert(msz > 0);
136 assert(ndx >= 0);
137
138 if (msz * (size_t) ndx >= d->d_data.d_size) {
139 LIBELF_SET_ERROR(ARGUMENT, 0);
140 return (0);
141 }
142
143 if (ec == ELFCLASS32) {
144 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
145
146 sym32->st_name = gs->st_name;
147 sym32->st_info = gs->st_info;
148 sym32->st_other = gs->st_other;
149 sym32->st_shndx = gs->st_shndx;
150
151 LIBELF_COPY_U32(sym32, gs, st_value);
152 LIBELF_COPY_U32(sym32, gs, st_size);
153 } else {
154 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
155
156 *sym64 = *gs;
157 }
158
159 return (1);
160 }
161