Branch data Line data Source code
1 : : /* Find the debuginfo file for a module from its build ID.
2 : : Copyright (C) 2007, 2009, 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 : : int
36 : 282 : dwfl_build_id_find_debuginfo (Dwfl_Module *mod,
37 : : void **userdata __attribute__ ((unused)),
38 : : const char *modname __attribute__ ((unused)),
39 : : Dwarf_Addr base __attribute__ ((unused)),
40 : : const char *file __attribute__ ((unused)),
41 : : const char *debuglink __attribute__ ((unused)),
42 : : GElf_Word crc __attribute__ ((unused)),
43 : : char **debuginfo_file_name)
44 : : {
45 : 282 : int fd = -1;
46 : :
47 : : /* Are we looking for a separate debug file for the main file or for
48 : : an alternate (dwz multi) debug file? Alternatively we could check
49 : : whether the dwbias == -1. */
50 [ + + ]: 282 : if (mod->dw != NULL)
51 : : {
52 : 70 : const void *build_id;
53 : 70 : const char *altname;
54 : 70 : ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw,
55 : : &altname,
56 : : &build_id);
57 [ + - ]: 70 : if (build_id_len > 0)
58 : 70 : fd = __libdwfl_open_by_build_id (mod, true, debuginfo_file_name,
59 : : build_id_len, build_id);
60 : :
61 [ - + ]: 70 : if (fd >= 0)
62 : : {
63 : : /* We need to open an Elf handle on the file so we can check its
64 : : build ID note for validation. Backdoor the handle into the
65 : : module data structure since we had to open it early anyway. */
66 : 0 : Dwfl_Error error = __libdw_open_file (&fd, &mod->alt_elf,
67 : : true, false);
68 [ # # ]: 0 : if (error != DWFL_E_NOERROR)
69 : 0 : __libdwfl_seterrno (error);
70 : : else
71 : : {
72 : 0 : const void *alt_build_id;
73 : 0 : ssize_t alt_len = INTUSE(dwelf_elf_gnu_build_id) (mod->alt_elf,
74 : : &alt_build_id);
75 [ # # ]: 0 : if (alt_len > 0 && alt_len == build_id_len
76 [ # # ]: 0 : && memcmp (build_id, alt_build_id, alt_len) == 0)
77 : 0 : return fd;
78 : : else
79 : : {
80 : : /* A mismatch! */
81 : 0 : elf_end (mod->alt_elf);
82 : 0 : mod->alt_elf = NULL;
83 : 0 : close (fd);
84 : 0 : fd = -1;
85 : : }
86 : 0 : free (*debuginfo_file_name);
87 : 0 : *debuginfo_file_name = NULL;
88 : 0 : errno = 0;
89 : : }
90 : : }
91 : 70 : return fd;
92 : : }
93 : :
94 : : /* We don't even have the Dwarf yet and it isn't in the main file.
95 : : Try to find separate debug file now using the module build id. */
96 : 212 : const unsigned char *bits;
97 : 212 : GElf_Addr vaddr;
98 : :
99 [ + - ]: 212 : if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
100 : 212 : fd = __libdwfl_open_mod_by_build_id (mod, true, debuginfo_file_name);
101 [ - + ]: 212 : if (fd >= 0)
102 : : {
103 : : /* We need to open an Elf handle on the file so we can check its
104 : : build ID note for validation. Backdoor the handle into the
105 : : module data structure since we had to open it early anyway. */
106 : 0 : Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, true, false);
107 [ # # ]: 0 : if (error != DWFL_E_NOERROR)
108 : 0 : __libdwfl_seterrno (error);
109 [ # # ]: 0 : else if (likely (__libdwfl_find_build_id (mod, false,
110 : : mod->debug.elf) == 2))
111 : : {
112 : : /* Also backdoor the gratuitous flag. */
113 : 0 : mod->debug.valid = true;
114 : 0 : return fd;
115 : : }
116 : : else
117 : : {
118 : : /* A mismatch! */
119 : 0 : elf_end (mod->debug.elf);
120 : 0 : mod->debug.elf = NULL;
121 : 0 : close (fd);
122 : 0 : fd = -1;
123 : : }
124 : 0 : free (*debuginfo_file_name);
125 : 0 : *debuginfo_file_name = NULL;
126 : 0 : errno = 0;
127 : : }
128 : 212 : return fd;
129 : : }
130 : : INTDEF (dwfl_build_id_find_debuginfo)
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