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_sym.c 3732 2019-04-22 11:08:38Z jkoshy $");
35
36 GElf_Sym *
gelf_getsym(Elf_Data * ed,int ndx,GElf_Sym * dst)37 gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst)
38 {
39 int ec;
40 Elf *e;
41 size_t msz;
42 Elf_Scn *scn;
43 uint32_t sh_type;
44 Elf32_Sym *sym32;
45 Elf64_Sym *sym64;
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_SYM) {
66 LIBELF_SET_ERROR(ARGUMENT, 0);
67 return (NULL);
68 }
69
70 if ((msz = _libelf_msize(ELF_T_SYM, 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 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
82
83 dst->st_name = sym32->st_name;
84 dst->st_value = (Elf64_Addr) sym32->st_value;
85 dst->st_size = (Elf64_Xword) sym32->st_size;
86 dst->st_info = sym32->st_info;
87 dst->st_other = sym32->st_other;
88 dst->st_shndx = sym32->st_shndx;
89 } else {
90 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
91
92 *dst = *sym64;
93 }
94
95 return (dst);
96 }
97
98 int
gelf_update_sym(Elf_Data * ed,int ndx,GElf_Sym * gs)99 gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs)
100 {
101 int ec;
102 Elf *e;
103 size_t msz;
104 Elf_Scn *scn;
105 uint32_t sh_type;
106 Elf32_Sym *sym32;
107 Elf64_Sym *sym64;
108 struct _Libelf_Data *d;
109
110 d = (struct _Libelf_Data *) ed;
111
112 if (d == NULL || ndx < 0 || gs == NULL ||
113 (scn = d->d_scn) == NULL ||
114 (e = scn->s_elf) == NULL) {
115 LIBELF_SET_ERROR(ARGUMENT, 0);
116 return (0);
117 }
118
119 ec = e->e_class;
120 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
121
122 if (ec == ELFCLASS32)
123 sh_type = scn->s_shdr.s_shdr32.sh_type;
124 else
125 sh_type = scn->s_shdr.s_shdr64.sh_type;
126
127 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
128 LIBELF_SET_ERROR(ARGUMENT, 0);
129 return (0);
130 }
131
132 if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0)
133 return (0);
134
135 assert(ndx >= 0);
136
137 if (msz * (size_t) ndx >= d->d_data.d_size) {
138 LIBELF_SET_ERROR(ARGUMENT, 0);
139 return (0);
140 }
141
142 if (ec == ELFCLASS32) {
143 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx;
144
145 sym32->st_name = gs->st_name;
146 sym32->st_info = gs->st_info;
147 sym32->st_other = gs->st_other;
148 sym32->st_shndx = gs->st_shndx;
149
150 LIBELF_COPY_U32(sym32, gs, st_value);
151 LIBELF_COPY_U32(sym32, gs, st_size);
152 } else {
153 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx;
154
155 *sym64 = *gs;
156 }
157
158 return (1);
159 }
160