Line data Source code
1 : /* Return build ID information for a module.
2 : Copyright (C) 2007-2010, 2014 Red Hat, Inc.
3 : This file is part of elfutils.
4 :
5 : This file is free software; you can redistribute it and/or modify
6 : it under the terms of either
7 :
8 : * 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
21 : 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 :
25 : 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/>. */
28 :
29 : #ifdef HAVE_CONFIG_H
30 : # include <config.h>
31 : #endif
32 :
33 : #include "libdwflP.h"
34 :
35 : static int
36 103 : found_build_id (Dwfl_Module *mod, bool set,
37 : const void *bits, int len, GElf_Addr vaddr)
38 : {
39 103 : if (!set)
40 : /* When checking bits, we do not compare VADDR because the
41 : address found in a debuginfo file may not match the main
42 : file as modified by prelink. */
43 70 : return 1 + (mod->build_id_len == len
44 35 : && !memcmp (bits, mod->build_id_bits, len));
45 :
46 68 : void *copy = malloc (len);
47 68 : if (unlikely (copy == NULL))
48 : {
49 0 : __libdwfl_seterrno (DWFL_E_NOMEM);
50 0 : return -1;
51 : }
52 :
53 136 : mod->build_id_bits = memcpy (copy, bits, len);
54 68 : mod->build_id_vaddr = vaddr;
55 68 : mod->build_id_len = len;
56 68 : return len;
57 : }
58 :
59 : int
60 : internal_function
61 114 : __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
62 : {
63 : const void *build_id_bits;
64 : GElf_Addr build_id_elfaddr;
65 : int build_id_len;
66 :
67 : /* For mod == NULL use dwelf_elf_gnu_build_id directly. */
68 114 : assert (mod != NULL);
69 :
70 114 : int result = __libdwfl_find_elf_build_id (mod, elf, &build_id_bits,
71 : &build_id_elfaddr, &build_id_len);
72 114 : if (result <= 0)
73 : return result;
74 :
75 206 : GElf_Addr build_id_vaddr = build_id_elfaddr + (build_id_elfaddr != 0
76 103 : ? mod->main_bias : 0);
77 103 : return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr);
78 : }
79 :
80 : int
81 209 : dwfl_module_build_id (Dwfl_Module *mod,
82 : const unsigned char **bits, GElf_Addr *vaddr)
83 : {
84 209 : if (mod == NULL)
85 : return -1;
86 :
87 209 : if (mod->build_id_len == 0 && mod->main.elf != NULL)
88 : {
89 : /* We have the file, but have not examined it yet. */
90 79 : int result = __libdwfl_find_build_id (mod, true, mod->main.elf);
91 79 : if (result <= 0)
92 : {
93 11 : mod->build_id_len = -1; /* Cache negative result. */
94 11 : return result;
95 : }
96 : }
97 :
98 198 : if (mod->build_id_len <= 0)
99 : return 0;
100 :
101 194 : *bits = mod->build_id_bits;
102 194 : *vaddr = mod->build_id_vaddr;
103 194 : return mod->build_id_len;
104 : }
105 : INTDEF (dwfl_module_build_id)
106 : NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138)
107 :
108 : #ifdef SYMBOL_VERSIONING
109 : COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end)
110 :
111 : int
112 : _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod,
113 : const unsigned char **bits,
114 : GElf_Addr *vaddr)
115 : {
116 : int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr);
117 : if (result > 0)
118 : *vaddr += (result + 3) & -4;
119 : return result;
120 : }
121 : #endif
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