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 #include "libdwflP.h"
30
31 static int
found_build_id(Dwfl_Module * mod,bool set,const void * bits,int len,GElf_Addr vaddr)32 found_build_id (Dwfl_Module *mod, bool set,
33 const void *bits, int len, GElf_Addr vaddr)
34 {
35 if (!set)
36 /* When checking bits, we do not compare VADDR because the
37 address found in a debuginfo file may not match the main
38 file as modified by prelink. */
39 return 1 + (mod->build_id_len == len
40 && !memcmp (bits, mod->build_id_bits, len));
41
42 void *copy = malloc (len);
43 if (unlikely (copy == NULL))
44 {
45 __libdwfl_seterrno (DWFL_E_NOMEM);
46 return -1;
47 }
48
49 mod->build_id_bits = memcpy (copy, bits, len);
50 mod->build_id_vaddr = vaddr;
51 mod->build_id_len = len;
52 return len;
53 }
54
55 int
56 internal_function
__libdwfl_find_build_id(Dwfl_Module * mod,bool set,Elf * elf)57 __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
58 {
59 const void *build_id_bits;
60 GElf_Addr build_id_elfaddr;
61 int build_id_len;
62
63 /* For mod == NULL use dwelf_elf_gnu_build_id directly. */
64 assert (mod != NULL);
65
66 int result = __libdwfl_find_elf_build_id (mod, elf, &build_id_bits,
67 &build_id_elfaddr, &build_id_len);
68 if (result <= 0)
69 return result;
70
71 GElf_Addr build_id_vaddr = build_id_elfaddr + (build_id_elfaddr != 0
72 ? mod->main_bias : 0);
73 return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr);
74 }
75
76 int
dwfl_module_build_id(Dwfl_Module * mod,const unsigned char ** bits,GElf_Addr * vaddr)77 dwfl_module_build_id (Dwfl_Module *mod,
78 const unsigned char **bits, GElf_Addr *vaddr)
79 {
80 if (mod == NULL)
81 return -1;
82
83 if (mod->build_id_len == 0 && mod->main.elf != NULL)
84 {
85 /* We have the file, but have not examined it yet. */
86 int result = __libdwfl_find_build_id (mod, true, mod->main.elf);
87 if (result <= 0)
88 {
89 mod->build_id_len = -1; /* Cache negative result. */
90 return result;
91 }
92 }
93
94 if (mod->build_id_len <= 0)
95 return 0;
96
97 *bits = mod->build_id_bits;
98 *vaddr = mod->build_id_vaddr;
99 return mod->build_id_len;
100 }
101 INTDEF (dwfl_module_build_id)
102 NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138)
103
104 #ifdef SYMBOL_VERSIONING
105 COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end)
106
107 int
_compat_vaddr_at_end_dwfl_module_build_id(Dwfl_Module * mod,const unsigned char ** bits,GElf_Addr * vaddr)108 _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod,
109 const unsigned char **bits,
110 GElf_Addr *vaddr)
111 {
112 int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr);
113 if (result > 0)
114 *vaddr += (result + 3) & -4;
115 return result;
116 }
117 #endif
118