1 /* Error handling in libdwfl.
2 Copyright (C) 2005, 2006 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4
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.
8
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.
13
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.
17
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.
41
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>. */
49
50 #ifdef HAVE_CONFIG_H
51 # include <config.h>
52 #endif
53
54 #include <assert.h>
55 #include <libintl.h>
56 #include <stdbool.h>
57 #include <stdint.h>
58 #include <stdlib.h>
59 #include <errno.h>
60
61 #include "libdwflP.h"
62
63
64 #ifdef USE_TLS
65 /* The error number. */
66 static __thread int global_error;
67 #else
68 /* This is the key for the thread specific memory. */
69 static tls_key_t key;
70
71 /* The error number. Used in non-threaded programs. */
72 static int global_error;
73 static bool threaded;
74 /* We need to initialize the thread-specific data. */
75 once_define (static, once);
76
77 /* The initialization and destruction functions. */
78 static void init (void);
79 static void free_key_mem (void *mem);
80 #endif /* TLS */
81
82
83 int
dwfl_errno(void)84 dwfl_errno (void)
85 {
86 int result;
87
88 #ifndef USE_TLS
89 /* If we have not yet initialized the buffer do it now. */
90 once_execute (once, init);
91
92 if (threaded)
93 {
94 /* We do not allocate memory for the data. It is only a word.
95 We can store it in place of the pointer. */
96 result = (intptr_t) getspecific (key);
97
98 setspecific (key, (void *) (intptr_t) DWFL_E_NOERROR);
99 return result;
100 }
101 #endif /* TLS */
102
103 result = global_error;
104 global_error = DWFL_E_NOERROR;
105 return result;
106 }
107
108
109 static const struct msgtable
110 {
111 #define DWFL_ERROR(name, text) char msg_##name[sizeof text];
112 DWFL_ERRORS
113 #undef DWFL_ERROR
114 } msgtable =
115 {
116 #define DWFL_ERROR(name, text) text,
117 DWFL_ERRORS
118 #undef DWFL_ERROR
119 };
120 #define msgstr (&msgtable.msg_NOERROR[0])
121
122 static const uint_fast16_t msgidx[] =
123 {
124 #define DWFL_ERROR(name, text) \
125 [DWFL_E_##name] = offsetof (struct msgtable, msg_##name),
126 DWFL_ERRORS
127 #undef DWFL_ERROR
128 };
129 #define nmsgidx (sizeof msgidx / sizeof msgidx[0])
130
131
132 static inline int
canonicalize(Dwfl_Error error)133 canonicalize (Dwfl_Error error)
134 {
135 unsigned int value;
136
137 switch (error)
138 {
139 default:
140 value = error;
141 if ((value &~ 0xffff) != 0)
142 break;
143 assert (value < nmsgidx);
144 break;
145 case DWFL_E_ERRNO:
146 value = DWFL_E (ERRNO, errno);
147 break;
148 case DWFL_E_LIBELF:
149 value = DWFL_E (LIBELF, elf_errno ());
150 break;
151 case DWFL_E_LIBDW:
152 value = DWFL_E (LIBDW, INTUSE(dwarf_errno) ());
153 break;
154 #if 0
155 DWFL_E_LIBEBL:
156 value = DWFL_E (LIBEBL, ebl_errno ());
157 break;
158 #endif
159 }
160
161 return value;
162 }
163
164 int
165 internal_function
__libdwfl_canon_error(Dwfl_Error error)166 __libdwfl_canon_error (Dwfl_Error error)
167 {
168 return canonicalize (error);
169 }
170
171 void
172 internal_function
__libdwfl_seterrno(Dwfl_Error error)173 __libdwfl_seterrno (Dwfl_Error error)
174 {
175 int value = canonicalize (error);
176
177 #ifndef USE_TLS
178 /* If we have not yet initialized the buffer do it now. */
179 once_execute (once, init);
180
181 if (threaded)
182 /* We do not allocate memory for the data. It is only a word.
183 We can store it in place of the pointer. */
184 setspecific (key, (void *) (intptr_t) value);
185 #endif /* TLS */
186
187 global_error = value;
188 }
189
190
191 const char *
dwfl_errmsg(error)192 dwfl_errmsg (error)
193 int error;
194 {
195 if (error == 0 || error == -1)
196 {
197 int last_error;
198
199 #ifndef USE_TLS
200 /* If we have not yet initialized the buffer do it now. */
201 once_execute (once, init);
202
203 if (threaded)
204 /* We do not allocate memory for the data. It is only a word.
205 We can store it in place of the pointer. */
206 last_error = (intptr_t) getspecific (key);
207 else
208 #endif /* TLS */
209 last_error = global_error;
210
211 if (error == 0 && last_error == 0)
212 return NULL;
213
214 error = last_error;
215 global_error = DWFL_E_NOERROR;
216 }
217
218 switch (error &~ 0xffff)
219 {
220 case OTHER_ERROR (ERRNO):
221 /* ANDROID_CHANGE_BEGIN */
222 #ifdef __BIONIC__
223 strerror_r (error & 0xffff, "bad", 0);
224 return NULL;
225 #else
226 return strerror_r (error & 0xffff, "bad", 0);
227 #endif
228 /* ANDROID_CHANGE_END */
229 case OTHER_ERROR (LIBELF):
230 return elf_errmsg (error & 0xffff);
231 case OTHER_ERROR (LIBDW):
232 return INTUSE(dwarf_errmsg) (error & 0xffff);
233 #if 0
234 case OTHER_ERROR (LIBEBL):
235 return ebl_errmsg (error & 0xffff);
236 #endif
237 }
238
239 return _(&msgstr[msgidx[(unsigned int) error < nmsgidx
240 ? error : DWFL_E_UNKNOWN_ERROR]]);
241 }
INTDEF(dwfl_errmsg)242 INTDEF (dwfl_errmsg)
243
244
245 #ifndef USE_TLS
246 /* Free the thread specific data, this is done if a thread terminates. */
247 static void
248 free_key_mem (void *mem __attribute__ ((unused)))
249 {
250 setspecific (key, NULL);
251 }
252
253
254 /* Initialize the key for the global variable. */
255 static void
init(void)256 init (void)
257 {
258 // XXX Screw you, gcc4, the unused function attribute does not work.
259 __asm ("" :: "r" (free_key_mem));
260
261 if (key_create (&key, free_key_mem) == 0)
262 /* Creating the key succeeded. */
263 threaded = true;
264 }
265 #endif /* TLS */
266