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 : #include <unistd.h>
35 :
36 :
37 : int
38 96 : dwfl_build_id_find_debuginfo (Dwfl_Module *mod,
39 : void **userdata __attribute__ ((unused)),
40 : const char *modname __attribute__ ((unused)),
41 : Dwarf_Addr base __attribute__ ((unused)),
42 : const char *file __attribute__ ((unused)),
43 : const char *debuglink __attribute__ ((unused)),
44 : GElf_Word crc __attribute__ ((unused)),
45 : char **debuginfo_file_name)
46 : {
47 96 : int fd = -1;
48 :
49 : /* Are we looking for a separate debug file for the main file or for
50 : an alternate (dwz multi) debug file? Alternatively we could check
51 : whether the dwbias == -1. */
52 96 : if (mod->dw != NULL)
53 : {
54 : const void *build_id;
55 : const char *altname;
56 5 : ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw,
57 : &altname,
58 : &build_id);
59 5 : if (build_id_len > 0)
60 5 : fd = __libdwfl_open_by_build_id (mod, true, debuginfo_file_name,
61 : build_id_len, build_id);
62 :
63 5 : if (fd >= 0)
64 : {
65 : /* We need to open an Elf handle on the file so we can check its
66 : build ID note for validation. Backdoor the handle into the
67 : module data structure since we had to open it early anyway. */
68 0 : Dwfl_Error error = __libdw_open_file (&fd, &mod->alt_elf,
69 : true, false);
70 0 : if (error != DWFL_E_NOERROR)
71 0 : __libdwfl_seterrno (error);
72 : else
73 : {
74 : const void *alt_build_id;
75 0 : ssize_t alt_len = INTUSE(dwelf_elf_gnu_build_id) (mod->alt_elf,
76 : &alt_build_id);
77 0 : if (alt_len > 0 && alt_len == build_id_len
78 0 : && memcmp (build_id, alt_build_id, alt_len) == 0)
79 0 : return fd;
80 : else
81 : {
82 : /* A mismatch! */
83 0 : elf_end (mod->alt_elf);
84 0 : mod->alt_elf = NULL;
85 0 : close (fd);
86 0 : fd = -1;
87 : }
88 0 : free (*debuginfo_file_name);
89 0 : *debuginfo_file_name = NULL;
90 0 : errno = 0;
91 : }
92 : }
93 5 : return fd;
94 : }
95 :
96 : /* We don't even have the Dwarf yet and it isn't in the main file.
97 : Try to find separate debug file now using the module build id. */
98 : const unsigned char *bits;
99 : GElf_Addr vaddr;
100 :
101 91 : if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
102 91 : fd = __libdwfl_open_mod_by_build_id (mod, true, debuginfo_file_name);
103 91 : if (fd >= 0)
104 : {
105 : /* We need to open an Elf handle on the file so we can check its
106 : build ID note for validation. Backdoor the handle into the
107 : module data structure since we had to open it early anyway. */
108 9 : Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, true, false);
109 9 : if (error != DWFL_E_NOERROR)
110 0 : __libdwfl_seterrno (error);
111 9 : else if (likely (__libdwfl_find_build_id (mod, false,
112 : mod->debug.elf) == 2))
113 : {
114 : /* Also backdoor the gratuitous flag. */
115 9 : mod->debug.valid = true;
116 9 : return fd;
117 : }
118 : else
119 : {
120 : /* A mismatch! */
121 0 : elf_end (mod->debug.elf);
122 0 : mod->debug.elf = NULL;
123 0 : close (fd);
124 0 : fd = -1;
125 : }
126 0 : free (*debuginfo_file_name);
127 0 : *debuginfo_file_name = NULL;
128 0 : errno = 0;
129 : }
130 82 : return fd;
131 : }
132 : INTDEF (dwfl_build_id_find_debuginfo)
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