blob: 1a36855331b8f9a764444e8b06ced6bfb0bf6567 [file] [log] [blame]
Roland McGrathc76f0b02007-09-27 07:31:33 +00001/* Get note information at the supplied offset.
2 Copyright (C) 2007 Red Hat, Inc.
Mark Wielaardde2ed972012-06-05 17:15:16 +02003 This file is part of elfutils.
Roland McGrathc76f0b02007-09-27 07:31:33 +00004
Mark Wielaardde2ed972012-06-05 17:15:16 +02005 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
Roland McGrathc76f0b02007-09-27 07:31:33 +00007
Mark Wielaardde2ed972012-06-05 17:15:16 +02008 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
11
12 or
13
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
17
18 or both in parallel, as here.
19
20 elfutils is distributed in the hope that it will be useful, but
Roland McGrathc76f0b02007-09-27 07:31:33 +000021 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
24
Mark Wielaardde2ed972012-06-05 17:15:16 +020025 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
Roland McGrathc76f0b02007-09-27 07:31:33 +000028
29#ifdef HAVE_CONFIG_H
30# include <config.h>
31#endif
32
33#include <assert.h>
34#include <gelf.h>
35#include <string.h>
36
37#include "libelfP.h"
38
39size_t
40gelf_getnote (data, offset, result, name_offset, desc_offset)
41 Elf_Data *data;
42 size_t offset;
43 GElf_Nhdr *result;
44 size_t *name_offset;
45 size_t *desc_offset;
46{
47 if (data == NULL)
48 return 0;
49
50 if (unlikely (data->d_type != ELF_T_NHDR))
51 {
52 __libelf_seterrno (ELF_E_INVALID_HANDLE);
53 return 0;
54 }
55
56 /* It's easy to handle this type. It has the same size for 32 and
57 64 bit objects. */
58 assert (sizeof (GElf_Nhdr) == sizeof (Elf32_Nhdr));
59 assert (sizeof (GElf_Nhdr) == sizeof (Elf64_Nhdr));
60
Roland McGrathb4d6f0f2008-08-25 22:55:17 +000061 rwlock_rdlock (((Elf_Data_Scn *) data)->s->elf->lock);
Roland McGrathc76f0b02007-09-27 07:31:33 +000062
63 /* The data is already in the correct form. Just make sure the
64 offset is OK. */
65 if (unlikely (offset + sizeof (GElf_Nhdr) > data->d_size))
66 {
67 __libelf_seterrno (ELF_E_OFFSET_RANGE);
68 offset = 0;
69 }
70 else
71 {
72 const GElf_Nhdr *n = data->d_buf + offset;
73 offset += sizeof *n;
74
75 GElf_Word namesz = NOTE_ALIGN (n->n_namesz);
76 GElf_Word descsz = NOTE_ALIGN (n->n_descsz);
77
78 if (unlikely (data->d_size - offset < namesz))
79 offset = 0;
80 else
81 {
82 *name_offset = offset;
83 offset += namesz;
84 if (unlikely (data->d_size - offset < descsz))
85 offset = 0;
86 else
87 {
88 *desc_offset = offset;
89 offset += descsz;
90 *result = *n;
91 }
92 }
93 }
94
Roland McGrathb4d6f0f2008-08-25 22:55:17 +000095 rwlock_unlock (((Elf_Data_Scn *) data)->s->elf->lock);
Roland McGrathc76f0b02007-09-27 07:31:33 +000096
97 return offset;
98}