1 /* Get REL relocation information at given index.
2 Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
3 Written by Ulrich Drepper <drepper@redhat.com>, 2000.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, version 2.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
17
18 #ifdef HAVE_CONFIG_H
19 # include <config.h>
20 #endif
21
22 #include <gelf.h>
23 #include <string.h>
24
25 #include "libelfP.h"
26
27
28 GElf_Rel *
gelf_getrel(data,ndx,dst)29 gelf_getrel (data, ndx, dst)
30 Elf_Data *data;
31 int ndx;
32 GElf_Rel *dst;
33 {
34 Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
35 Elf_Scn *scn;
36 GElf_Rel *result;
37
38 if (data_scn == NULL)
39 return NULL;
40
41 if (unlikely (ndx < 0))
42 {
43 __libelf_seterrno (ELF_E_INVALID_INDEX);
44 return NULL;
45 }
46
47 if (unlikely (data_scn->d.d_type != ELF_T_REL))
48 {
49 __libelf_seterrno (ELF_E_INVALID_HANDLE);
50 return NULL;
51 }
52
53 /* This is the one place where we have to take advantage of the fact
54 that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
55 The interface is broken so that it requires this hack. */
56 scn = data_scn->s;
57
58 rwlock_rdlock (scn->elf->lock);
59
60 if (scn->elf->class == ELFCLASS32)
61 {
62 /* We have to convert the data. */
63 if (unlikely ((ndx + 1) * sizeof (Elf32_Rel) > data_scn->d.d_size))
64 {
65 __libelf_seterrno (ELF_E_INVALID_INDEX);
66 result = NULL;
67 }
68 else
69 {
70 Elf32_Rel *src = &((Elf32_Rel *) data_scn->d.d_buf)[ndx];
71
72 dst->r_offset = src->r_offset;
73 dst->r_info = GELF_R_INFO (ELF32_R_SYM (src->r_info),
74 ELF32_R_TYPE (src->r_info));
75
76 result = dst;
77 }
78 }
79 else
80 {
81 /* Simply copy the data after we made sure we are actually getting
82 correct data. */
83 if (unlikely ((ndx + 1) * sizeof (Elf64_Rel) > data_scn->d.d_size))
84 {
85 __libelf_seterrno (ELF_E_INVALID_INDEX);
86 result = NULL;
87 }
88 else
89 result = memcpy (dst, &((Elf64_Rel *) data_scn->d.d_buf)[ndx],
90 sizeof (Elf64_Rel));
91 }
92
93 rwlock_unlock (scn->elf->lock);
94
95 return result;
96 }
97