Branch data Line data Source code
1 : : /* Get information from dynamic table at the given index.
2 : : Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
3 : : This file is part of elfutils.
4 : : Written by Ulrich Drepper <drepper@redhat.com>, 2000.
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_Dyn *
42 : 4321 : gelf_getdyn (data, ndx, dst)
43 : : Elf_Data *data;
44 : : int ndx;
45 : : GElf_Dyn *dst;
46 : : {
47 : 4321 : Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
48 : 4321 : GElf_Dyn *result = NULL;
49 : : Elf *elf;
50 : :
51 [ + - ]: 4321 : if (data_scn == NULL)
52 : : return NULL;
53 : :
54 [ - + ]: 4321 : if (unlikely (data_scn->d.d_type != ELF_T_DYN))
55 : : {
56 : 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE);
57 : 0 : return NULL;
58 : : }
59 : :
60 : 4321 : elf = data_scn->s->elf;
61 : :
62 : : rwlock_rdlock (elf->lock);
63 : :
64 : : /* This is the one place where we have to take advantage of the fact
65 : : that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
66 : : The interface is broken so that it requires this hack. */
67 [ + + ]: 4321 : if (elf->class == ELFCLASS32)
68 : : {
69 : : Elf32_Dyn *src;
70 : :
71 : : /* Here it gets a bit more complicated. The format of the symbol
72 : : table entries has to be adopted. The user better has provided
73 : : a buffer where we can store the information. While copying the
74 : : data we are converting the format. */
75 [ - + ]: 346 : if (unlikely ((ndx + 1) * sizeof (Elf32_Dyn) > data_scn->d.d_size))
76 : : {
77 : 0 : __libelf_seterrno (ELF_E_INVALID_INDEX);
78 : 0 : goto out;
79 : : }
80 : :
81 : 346 : src = &((Elf32_Dyn *) data_scn->d.d_buf)[ndx];
82 : :
83 : : /* This might look like a simple copy operation but it's
84 : : not. There are zero- and sign-extensions going on. */
85 : 346 : dst->d_tag = src->d_tag;
86 : : /* It OK to copy `d_val' since `d_ptr' has the same size. */
87 : 346 : dst->d_un.d_val = src->d_un.d_val;
88 : : }
89 : : else
90 : : {
91 : : /* If this is a 64 bit object it's easy. */
92 : : assert (sizeof (GElf_Dyn) == sizeof (Elf64_Dyn));
93 : :
94 : : /* The data is already in the correct form. Just make sure the
95 : : index is OK. */
96 [ - + ]: 3975 : if (unlikely ((ndx + 1) * sizeof (GElf_Dyn) > data_scn->d.d_size))
97 : : {
98 : 0 : __libelf_seterrno (ELF_E_INVALID_INDEX);
99 : 0 : goto out;
100 : : }
101 : :
102 : 3975 : *dst = ((GElf_Dyn *) data_scn->d.d_buf)[ndx];
103 : : }
104 : :
105 : 4321 : result = dst;
106 : :
107 : : out:
108 : : rwlock_unlock (elf->lock);
109 : :
110 : 4321 : return result;
111 : : }
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