Line data Source code
1 : /* Get symbol information from symbol table at the given index.
2 : Copyright (C) 1999, 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc.
3 : This file is part of elfutils.
4 : Written by Ulrich Drepper <drepper@redhat.com>, 1999.
5 :
6 : This file is free software; you can redistribute it and/or modify
7 : it under the terms of either
8 :
9 : * the GNU Lesser General Public License as published by the Free
10 : Software Foundation; either version 3 of the License, or (at
11 : your option) any later version
12 :
13 : or
14 :
15 : * the GNU General Public License as published by the Free
16 : Software Foundation; either version 2 of the License, or (at
17 : your option) any later version
18 :
19 : or both in parallel, as here.
20 :
21 : elfutils is distributed in the hope that it will be useful, but
22 : WITHOUT ANY WARRANTY; without even the implied warranty of
23 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 : General Public License for more details.
25 :
26 : You should have received copies of the GNU General Public License and
27 : the GNU Lesser General Public License along with this program. If
28 : not, see <http://www.gnu.org/licenses/>. */
29 :
30 : #ifdef HAVE_CONFIG_H
31 : # include <config.h>
32 : #endif
33 :
34 : #include <assert.h>
35 : #include <gelf.h>
36 : #include <string.h>
37 :
38 : #include "libelfP.h"
39 :
40 :
41 : GElf_Sym *
42 99990 : gelf_getsym (Elf_Data *data, int ndx, GElf_Sym *dst)
43 : {
44 99990 : Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
45 99990 : GElf_Sym *result = NULL;
46 :
47 99990 : if (data == NULL)
48 : return NULL;
49 :
50 99990 : if (unlikely (data->d_type != ELF_T_SYM))
51 : {
52 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE);
53 0 : return NULL;
54 : }
55 :
56 99990 : rwlock_rdlock (data_scn->s->elf->lock);
57 :
58 : /* This is the one place where we have to take advantage of the fact
59 : that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
60 : The interface is broken so that it requires this hack. */
61 99990 : if (data_scn->s->elf->class == ELFCLASS32)
62 : {
63 : Elf32_Sym *src;
64 :
65 : /* Here it gets a bit more complicated. The format of the symbol
66 : table entries has to be adopted. The user better has provided
67 : a buffer where we can store the information. While copying the
68 : data we are converting the format. */
69 31748 : if (INVALID_NDX (ndx, Elf32_Sym, data))
70 : {
71 0 : __libelf_seterrno (ELF_E_INVALID_INDEX);
72 0 : goto out;
73 : }
74 :
75 31748 : src = &((Elf32_Sym *) data->d_buf)[ndx];
76 :
77 : /* This might look like a simple copy operation but it's
78 : not. There are zero- and sign-extensions going on. */
79 : #define COPY(name) \
80 : dst->name = src->name
81 31748 : COPY (st_name);
82 : /* Please note that we can simply copy the `st_info' element since
83 : the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
84 : for the 64 bit variant. */
85 31748 : COPY (st_info);
86 31748 : COPY (st_other);
87 31748 : COPY (st_shndx);
88 31748 : COPY (st_value);
89 31748 : COPY (st_size);
90 : }
91 : else
92 : {
93 : /* If this is a 64 bit object it's easy. */
94 : assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym));
95 :
96 : /* The data is already in the correct form. Just make sure the
97 : index is OK. */
98 68242 : if (INVALID_NDX (ndx, GElf_Sym, data))
99 : {
100 0 : __libelf_seterrno (ELF_E_INVALID_INDEX);
101 0 : goto out;
102 : }
103 :
104 68242 : *dst = ((GElf_Sym *) data->d_buf)[ndx];
105 : }
106 :
107 : result = dst;
108 :
109 99990 : out:
110 : rwlock_unlock (data_scn->s->elf->lock);
111 :
112 99990 : return result;
113 : }
114 : INTDEF(gelf_getsym)
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