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 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 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 166 __libdwfl_canon_error (Dwfl_Error error) 167 { 168 return canonicalize (error); 169 } 170 171 void 172 internal_function 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 * 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 } 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 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
