Line data Source code
1 : /* Get ELF header.
2 : Copyright (C) 1998, 1999, 2000, 2002, 2015 Red Hat, Inc.
3 : This file is part of elfutils.
4 : Written by Ulrich Drepper <drepper@redhat.com>, 1998.
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 <libelf.h>
35 : #include <stddef.h>
36 :
37 : #include "libelfP.h"
38 :
39 : #ifndef LIBELFBITS
40 : # define LIBELFBITS 32
41 : #endif
42 :
43 :
44 : static ElfW2(LIBELFBITS,Ehdr) *
45 404 : getehdr_impl (Elf *elf, int wrlock)
46 : {
47 404 : if (elf == NULL)
48 : return NULL;
49 :
50 404 : if (unlikely (elf->kind != ELF_K_ELF))
51 : {
52 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE);
53 0 : return NULL;
54 : }
55 :
56 404 : again:
57 404 : if (elf->class == 0)
58 : {
59 0 : if (!wrlock)
60 : {
61 : rwlock_unlock (elf->lock);
62 : rwlock_wrlock (elf->lock);
63 : wrlock = 1;
64 : goto again;
65 : }
66 0 : elf->class = ELFW(ELFCLASS,LIBELFBITS);
67 : }
68 404 : else if (unlikely (elf->class != ELFW(ELFCLASS,LIBELFBITS)))
69 : {
70 0 : __libelf_seterrno (ELF_E_INVALID_CLASS);
71 0 : return NULL;
72 : }
73 :
74 404 : return elf->state.ELFW(elf,LIBELFBITS).ehdr;
75 : }
76 :
77 : ElfW2(LIBELFBITS,Ehdr) *
78 : internal_function
79 398 : __elfw2(LIBELFBITS,getehdr_wrlock) (Elf *elf)
80 : {
81 398 : return getehdr_impl (elf, 1);
82 : }
83 :
84 : ElfW2(LIBELFBITS,Ehdr) *
85 6 : elfw2(LIBELFBITS,getehdr) (Elf *elf)
86 : {
87 : ElfW2(LIBELFBITS,Ehdr) *result;
88 6 : if (elf == NULL)
89 : return NULL;
90 :
91 : rwlock_rdlock (elf->lock);
92 6 : result = getehdr_impl (elf, 0);
93 : rwlock_unlock (elf->lock);
94 :
95 6 : return result;
96 : }
|