1 /* Standard find_debuginfo callback for libdwfl.
2 Copyright (C) 2005, 2006, 2007, 2008, 2009 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
5 Red Hat elfutils is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by the
7 Free Software Foundation; version 2 of the License.
9 Red Hat elfutils is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
14 You should have received a copy of the GNU General Public License along
15 with Red Hat elfutils; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18 In addition, as a special exception, Red Hat, Inc. gives You the
19 additional right to link the code of Red Hat elfutils with code licensed
20 under any Open Source Initiative certified open source license
21 (http://www.opensource.org/licenses/index.php) which requires the
22 distribution of source code with any binary distribution and to
23 distribute linked combinations of the two. Non-GPL Code permitted under
24 this exception must only link to the code of Red Hat elfutils through
25 those well defined interfaces identified in the file named EXCEPTION
26 found in the source code files (the "Approved Interfaces"). The files
27 of Non-GPL Code may instantiate templates or use macros or inline
28 functions from the Approved Interfaces without causing the resulting
29 work to be covered by the GNU General Public License. Only Red Hat,
30 Inc. may make changes or additions to the list of Approved Interfaces.
31 Red Hat's grant of this exception is conditioned upon your not adding
32 any new exceptions. If you wish to add a new Approved Interface or
33 exception, please contact Red Hat. You must obey the GNU General Public
34 License in all respects for all of the Red Hat elfutils code and other
35 code used in conjunction with Red Hat elfutils except the Non-GPL Code
36 covered by this exception. If you modify this file, you may extend this
37 exception to your version of the file, but you are not obligated to do
38 so. If you do not wish to provide this exception without modification,
39 you must delete this exception statement from your version and license
40 this file solely under the GPL without exception.
42 Red Hat elfutils is an included package of the Open Invention Network.
43 An included package of the Open Invention Network is a package for which
44 Open Invention Network licensees cross-license their patents. No patent
45 license is granted, either expressly or impliedly, by designation as an
46 included package. Should you wish to participate in the Open Invention
47 Network licensing program, please visit www.openinventionnetwork.com
48 <http://www.openinventionnetwork.com>. */
57 /* Try to open64 [DIR/][SUBDIR/]DEBUGLINK, return file descriptor or -1.
58 On success, *DEBUGINFO_FILE_NAME has the malloc'd name of the open file. */
60 try_open (const char *dir, const char *subdir, const char *debuglink,
61 char **debuginfo_file_name)
64 if (dir == NULL && subdir == NULL)
66 fname = strdup (debuglink);
70 else if ((subdir == NULL ? asprintf (&fname, "%s/%s", dir, debuglink)
71 : dir == NULL ? asprintf (&fname, "%s/%s", subdir, debuglink)
72 : asprintf (&fname, "%s/%s/%s", dir, subdir, debuglink)) < 0)
75 int fd = TEMP_FAILURE_RETRY (open64 (fname, O_RDONLY));
79 *debuginfo_file_name = fname;
84 /* Return true iff the FD's contents CRC matches DEBUGLINK_CRC. */
86 check_crc (int fd, GElf_Word debuglink_crc)
89 return (__libdwfl_crc32_file (fd, &file_crc) == 0
90 && file_crc == debuglink_crc);
94 validate (Dwfl_Module *mod, int fd, bool check, GElf_Word debuglink_crc)
96 /* If we have a build ID, check only that. */
97 if (mod->build_id_len > 0)
99 /* We need to open an Elf handle on the file so we can check its
100 build ID note for validation. Backdoor the handle into the
101 module data structure since we had to open it early anyway. */
103 mod->debug.valid = false;
104 Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, false, false);
105 if (error != DWFL_E_NOERROR)
106 __libdwfl_seterrno (error);
107 else if (likely (__libdwfl_find_build_id (mod, false,
108 mod->debug.elf) == 2))
109 /* Also backdoor the gratuitous flag. */
110 mod->debug.valid = true;
114 elf_end (mod->debug.elf);
115 mod->debug.elf = NULL;
120 return mod->debug.valid;
123 return !check || check_crc (fd, debuglink_crc);
127 find_debuginfo_in_path (Dwfl_Module *mod, const char *file_name,
128 const char *debuglink_file, GElf_Word debuglink_crc,
129 char **debuginfo_file_name)
131 bool cancheck = debuglink_crc != (GElf_Word) 0;
133 const char *file_basename = file_name == NULL ? NULL : basename (file_name);
134 if (debuglink_file == NULL)
136 if (file_basename == NULL)
142 size_t len = strlen (file_basename);
143 char *localname = alloca (len + sizeof ".debug");
144 memcpy (localname, file_basename, len);
145 memcpy (&localname[len], ".debug", sizeof ".debug");
146 debuglink_file = localname;
150 /* Look for a file named DEBUGLINK_FILE in the directories
151 indicated by the debug directory path setting. */
153 const Dwfl_Callbacks *const cb = mod->dwfl->callbacks;
154 char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL)
155 ?: DEFAULT_DEBUGINFO_PATH);
157 /* A leading - or + in the whole path sets whether to check file CRCs. */
158 bool defcheck = true;
159 if (path[0] == '-' || path[0] == '+')
161 defcheck = path[0] == '+';
165 char *file_dirname = (file_basename == file_name ? NULL
166 : strndupa (file_name, file_basename - 1 - file_name));
168 while ((p = strsep (&path, ":")) != NULL)
170 /* A leading - or + says whether to check file CRCs for this element. */
171 bool check = defcheck;
172 if (*p == '+' || *p == '-')
174 check = check && cancheck;
176 const char *dir, *subdir;
180 /* An empty entry says to try the main file's directory. */
185 /* An absolute path says to look there for a subdirectory
186 named by the main file's absolute directory.
187 This cannot be applied to a relative file name. */
188 if (file_dirname == NULL || file_dirname[0] != '/')
191 subdir = file_dirname + 1;
194 /* A relative path says to try a subdirectory of that name
195 in the main file's directory. */
202 int fd = try_open (dir, subdir, debuglink_file, &fname);
212 if (validate (mod, fd, check, debuglink_crc))
214 *debuginfo_file_name = fname;
227 dwfl_standard_find_debuginfo (Dwfl_Module *mod,
228 void **userdata __attribute__ ((unused)),
229 const char *modname __attribute__ ((unused)),
230 GElf_Addr base __attribute__ ((unused)),
231 const char *file_name,
232 const char *debuglink_file,
233 GElf_Word debuglink_crc,
234 char **debuginfo_file_name)
236 /* First try by build ID if we have one. If that succeeds or fails
237 other than just by finding nothing, that's all we do. */
238 const unsigned char *bits;
240 if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
242 int fd = INTUSE(dwfl_build_id_find_debuginfo) (mod,
245 debuginfo_file_name);
246 if (fd >= 0 || errno != 0)
250 /* Failing that, search the path by name. */
251 int fd = find_debuginfo_in_path (mod, file_name,
252 debuglink_file, debuglink_crc,
253 debuginfo_file_name);
255 if (fd < 0 && errno == 0)
257 /* If FILE_NAME is a symlink, the debug file might be associated
258 with the symlink target name instead. */
260 char *canon = canonicalize_file_name (file_name);
261 if (canon != NULL && strcmp (file_name, canon))
262 fd = find_debuginfo_in_path (mod, canon,
263 debuglink_file, debuglink_crc,
264 debuginfo_file_name);
270 INTDEF (dwfl_standard_find_debuginfo)