1 /* Core dump and executable file functions above target vector, for GDB. 2 3 Copyright (C) 1986-2013 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "gdb_string.h" 22 #include <errno.h> 23 #include <signal.h> 24 #include <fcntl.h> 25 #include "inferior.h" 26 #include "symtab.h" 27 #include "command.h" 28 #include "gdbcmd.h" 29 #include "bfd.h" 30 #include "target.h" 31 #include "gdbcore.h" 32 #include "dis-asm.h" 33 #include "gdb_stat.h" 34 #include "completer.h" 35 #include "exceptions.h" 36 #include "observer.h" 37 #include "cli/cli-utils.h" 38 39 /* Local function declarations. */ 40 41 extern void _initialize_core (void); 42 static void call_extra_exec_file_hooks (char *filename); 43 44 /* You can have any number of hooks for `exec_file_command' command to 45 call. If there's only one hook, it is set in exec_file_display 46 hook. If there are two or more hooks, they are set in 47 exec_file_extra_hooks[], and deprecated_exec_file_display_hook is 48 set to a function that calls all of them. This extra complexity is 49 needed to preserve compatibility with old code that assumed that 50 only one hook could be set, and which called 51 deprecated_exec_file_display_hook directly. */ 52 53 typedef void (*hook_type) (char *); 54 55 hook_type deprecated_exec_file_display_hook; /* The original hook. */ 56 static hook_type *exec_file_extra_hooks; /* Array of additional 57 hooks. */ 58 static int exec_file_hook_count = 0; /* Size of array. */ 59 60 /* Binary file diddling handle for the core file. */ 61 62 bfd *core_bfd = NULL; 63 64 /* corelow.c target. It is never NULL after GDB initialization. */ 65 66 struct target_ops *core_target; 67 68 69 /* Backward compatability with old way of specifying core files. */ 70 71 void 72 core_file_command (char *filename, int from_tty) 73 { 74 dont_repeat (); /* Either way, seems bogus. */ 75 76 gdb_assert (core_target != NULL); 77 78 if (!filename) 79 (core_target->to_detach) (core_target, filename, from_tty); 80 else 81 (core_target->to_open) (filename, from_tty); 82 } 83 84 85 /* If there are two or more functions that wish to hook into 86 exec_file_command, this function will call all of the hook 87 functions. */ 88 89 static void 90 call_extra_exec_file_hooks (char *filename) 91 { 92 int i; 93 94 for (i = 0; i < exec_file_hook_count; i++) 95 (*exec_file_extra_hooks[i]) (filename); 96 } 97 98 /* Call this to specify the hook for exec_file_command to call back. 99 This is called from the x-window display code. */ 100 101 void 102 specify_exec_file_hook (void (*hook) (char *)) 103 { 104 hook_type *new_array; 105 106 if (deprecated_exec_file_display_hook != NULL) 107 { 108 /* There's already a hook installed. Arrange to have both it 109 and the subsequent hooks called. */ 110 if (exec_file_hook_count == 0) 111 { 112 /* If this is the first extra hook, initialize the hook 113 array. */ 114 exec_file_extra_hooks = (hook_type *) 115 xmalloc (sizeof (hook_type)); 116 exec_file_extra_hooks[0] = deprecated_exec_file_display_hook; 117 deprecated_exec_file_display_hook = call_extra_exec_file_hooks; 118 exec_file_hook_count = 1; 119 } 120 121 /* Grow the hook array by one and add the new hook to the end. 122 Yes, it's inefficient to grow it by one each time but since 123 this is hardly ever called it's not a big deal. */ 124 exec_file_hook_count++; 125 new_array = (hook_type *) 126 xrealloc (exec_file_extra_hooks, 127 exec_file_hook_count * sizeof (hook_type)); 128 exec_file_extra_hooks = new_array; 129 exec_file_extra_hooks[exec_file_hook_count - 1] = hook; 130 } 131 else 132 deprecated_exec_file_display_hook = hook; 133 } 134 135 void 136 reopen_exec_file (void) 137 { 138 char *filename; 139 int res; 140 struct stat st; 141 struct cleanup *cleanups; 142 143 /* Don't do anything if there isn't an exec file. */ 144 if (exec_bfd == NULL) 145 return; 146 147 /* If the timestamp of the exec file has changed, reopen it. */ 148 filename = xstrdup (bfd_get_filename (exec_bfd)); 149 cleanups = make_cleanup (xfree, filename); 150 res = stat (filename, &st); 151 152 if (exec_bfd_mtime && exec_bfd_mtime != st.st_mtime) 153 exec_file_attach (filename, 0); 154 else 155 /* If we accessed the file since last opening it, close it now; 156 this stops GDB from holding the executable open after it 157 exits. */ 158 bfd_cache_close_all (); 159 160 do_cleanups (cleanups); 161 } 162 163 /* If we have both a core file and an exec file, 164 print a warning if they don't go together. */ 165 166 void 167 validate_files (void) 168 { 169 if (exec_bfd && core_bfd) 170 { 171 if (!core_file_matches_executable_p (core_bfd, exec_bfd)) 172 warning (_("core file may not match specified executable file.")); 173 else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd)) 174 warning (_("exec file is newer than core file.")); 175 } 176 } 177 178 /* Return the name of the executable file as a string. 179 ERR nonzero means get error if there is none specified; 180 otherwise return 0 in that case. */ 181 182 char * 183 get_exec_file (int err) 184 { 185 if (exec_filename) 186 return exec_filename; 187 if (!err) 188 return NULL; 189 190 error (_("No executable file specified.\n\ 191 Use the \"file\" or \"exec-file\" command.")); 192 return NULL; 193 } 194 195 196 /* Report a memory error by throwing a MEMORY_ERROR error. */ 197 198 void 199 memory_error (int status, CORE_ADDR memaddr) 200 { 201 if (status == EIO) 202 /* Actually, address between memaddr and memaddr + len was out of 203 bounds. */ 204 throw_error (MEMORY_ERROR, 205 _("Cannot access memory at address %s"), 206 paddress (target_gdbarch (), memaddr)); 207 else 208 throw_error (MEMORY_ERROR, 209 _("Error accessing memory address %s: %s."), 210 paddress (target_gdbarch (), memaddr), 211 safe_strerror (status)); 212 } 213 214 /* Same as target_read_memory, but report an error if can't read. */ 215 216 void 217 read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) 218 { 219 int status; 220 221 status = target_read_memory (memaddr, myaddr, len); 222 if (status != 0) 223 memory_error (status, memaddr); 224 } 225 226 /* Same as target_read_stack, but report an error if can't read. */ 227 228 void 229 read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) 230 { 231 int status; 232 233 status = target_read_stack (memaddr, myaddr, len); 234 if (status != 0) 235 memory_error (status, memaddr); 236 } 237 238 /* Argument / return result struct for use with 239 do_captured_read_memory_integer(). MEMADDR and LEN are filled in 240 by gdb_read_memory_integer(). RESULT is the contents that were 241 successfully read from MEMADDR of length LEN. */ 242 243 struct captured_read_memory_integer_arguments 244 { 245 CORE_ADDR memaddr; 246 int len; 247 enum bfd_endian byte_order; 248 LONGEST result; 249 }; 250 251 /* Helper function for gdb_read_memory_integer(). DATA must be a 252 pointer to a captured_read_memory_integer_arguments struct. 253 Return 1 if successful. Note that the catch_errors() interface 254 will return 0 if an error occurred while reading memory. This 255 choice of return code is so that we can distinguish between 256 success and failure. */ 257 258 static int 259 do_captured_read_memory_integer (void *data) 260 { 261 struct captured_read_memory_integer_arguments *args 262 = (struct captured_read_memory_integer_arguments*) data; 263 CORE_ADDR memaddr = args->memaddr; 264 int len = args->len; 265 enum bfd_endian byte_order = args->byte_order; 266 267 args->result = read_memory_integer (memaddr, len, byte_order); 268 269 return 1; 270 } 271 272 /* Read memory at MEMADDR of length LEN and put the contents in 273 RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero 274 if successful. */ 275 276 int 277 safe_read_memory_integer (CORE_ADDR memaddr, int len, 278 enum bfd_endian byte_order, 279 LONGEST *return_value) 280 { 281 int status; 282 struct captured_read_memory_integer_arguments args; 283 284 args.memaddr = memaddr; 285 args.len = len; 286 args.byte_order = byte_order; 287 288 status = catch_errors (do_captured_read_memory_integer, &args, 289 "", RETURN_MASK_ALL); 290 if (status) 291 *return_value = args.result; 292 293 return status; 294 } 295 296 LONGEST 297 read_memory_integer (CORE_ADDR memaddr, int len, 298 enum bfd_endian byte_order) 299 { 300 gdb_byte buf[sizeof (LONGEST)]; 301 302 read_memory (memaddr, buf, len); 303 return extract_signed_integer (buf, len, byte_order); 304 } 305 306 ULONGEST 307 read_memory_unsigned_integer (CORE_ADDR memaddr, int len, 308 enum bfd_endian byte_order) 309 { 310 gdb_byte buf[sizeof (ULONGEST)]; 311 312 read_memory (memaddr, buf, len); 313 return extract_unsigned_integer (buf, len, byte_order); 314 } 315 316 void 317 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len) 318 { 319 char *cp; 320 int i; 321 int cnt; 322 323 cp = buffer; 324 while (1) 325 { 326 if (cp - buffer >= max_len) 327 { 328 buffer[max_len - 1] = '\0'; 329 break; 330 } 331 cnt = max_len - (cp - buffer); 332 if (cnt > 8) 333 cnt = 8; 334 read_memory (memaddr + (int) (cp - buffer), (gdb_byte *) cp, cnt); 335 for (i = 0; i < cnt && *cp; i++, cp++) 336 ; /* null body */ 337 338 if (i < cnt && !*cp) 339 break; 340 } 341 } 342 343 CORE_ADDR 344 read_memory_typed_address (CORE_ADDR addr, struct type *type) 345 { 346 gdb_byte *buf = alloca (TYPE_LENGTH (type)); 347 348 read_memory (addr, buf, TYPE_LENGTH (type)); 349 return extract_typed_address (buf, type); 350 } 351 352 /* Same as target_write_memory, but report an error if can't 353 write. */ 354 void 355 write_memory (CORE_ADDR memaddr, 356 const bfd_byte *myaddr, ssize_t len) 357 { 358 int status; 359 360 status = target_write_memory (memaddr, myaddr, len); 361 if (status != 0) 362 memory_error (status, memaddr); 363 } 364 365 /* Same as write_memory, but notify 'memory_changed' observers. */ 366 367 void 368 write_memory_with_notification (CORE_ADDR memaddr, const bfd_byte *myaddr, 369 ssize_t len) 370 { 371 write_memory (memaddr, myaddr, len); 372 observer_notify_memory_changed (current_inferior (), memaddr, len, myaddr); 373 } 374 375 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned 376 integer. */ 377 void 378 write_memory_unsigned_integer (CORE_ADDR addr, int len, 379 enum bfd_endian byte_order, 380 ULONGEST value) 381 { 382 gdb_byte *buf = alloca (len); 383 384 store_unsigned_integer (buf, len, byte_order, value); 385 write_memory (addr, buf, len); 386 } 387 388 /* Store VALUE at ADDR in the inferior as a LEN-byte signed 389 integer. */ 390 void 391 write_memory_signed_integer (CORE_ADDR addr, int len, 392 enum bfd_endian byte_order, 393 LONGEST value) 394 { 395 gdb_byte *buf = alloca (len); 396 397 store_signed_integer (buf, len, byte_order, value); 398 write_memory (addr, buf, len); 399 } 400 401 /* The current default bfd target. Points to storage allocated for 402 gnutarget_string. */ 403 char *gnutarget; 404 405 /* Same thing, except it is "auto" not NULL for the default case. */ 406 static char *gnutarget_string; 407 static void 408 show_gnutarget_string (struct ui_file *file, int from_tty, 409 struct cmd_list_element *c, 410 const char *value) 411 { 412 fprintf_filtered (file, 413 _("The current BFD target is \"%s\".\n"), value); 414 } 415 416 static void set_gnutarget_command (char *, int, 417 struct cmd_list_element *); 418 419 static void 420 set_gnutarget_command (char *ignore, int from_tty, 421 struct cmd_list_element *c) 422 { 423 char *gend = gnutarget_string + strlen (gnutarget_string); 424 425 gend = remove_trailing_whitespace (gnutarget_string, gend); 426 *gend = '\0'; 427 428 if (strcmp (gnutarget_string, "auto") == 0) 429 gnutarget = NULL; 430 else 431 gnutarget = gnutarget_string; 432 } 433 434 /* A completion function for "set gnutarget". */ 435 436 static VEC (char_ptr) * 437 complete_set_gnutarget (struct cmd_list_element *cmd, char *text, char *word) 438 { 439 static const char **bfd_targets; 440 441 if (bfd_targets == NULL) 442 { 443 int last; 444 445 bfd_targets = bfd_target_list (); 446 for (last = 0; bfd_targets[last] != NULL; ++last) 447 ; 448 449 bfd_targets = xrealloc (bfd_targets, (last + 2) * sizeof (const char **)); 450 bfd_targets[last] = "auto"; 451 bfd_targets[last + 1] = NULL; 452 } 453 454 return complete_on_enum (bfd_targets, text, word); 455 } 456 457 /* Set the gnutarget. */ 458 void 459 set_gnutarget (char *newtarget) 460 { 461 if (gnutarget_string != NULL) 462 xfree (gnutarget_string); 463 gnutarget_string = xstrdup (newtarget); 464 set_gnutarget_command (NULL, 0, NULL); 465 } 466 467 void 468 _initialize_core (void) 469 { 470 struct cmd_list_element *c; 471 472 c = add_cmd ("core-file", class_files, core_file_command, _("\ 473 Use FILE as core dump for examining memory and registers.\n\ 474 No arg means have no core file. This command has been superseded by the\n\ 475 `target core' and `detach' commands."), &cmdlist); 476 set_cmd_completer (c, filename_completer); 477 478 479 c = add_setshow_string_noescape_cmd ("gnutarget", class_files, 480 &gnutarget_string, _("\ 481 Set the current BFD target."), _("\ 482 Show the current BFD target."), _("\ 483 Use `set gnutarget auto' to specify automatic detection."), 484 set_gnutarget_command, 485 show_gnutarget_string, 486 &setlist, &showlist); 487 set_cmd_completer (c, complete_set_gnutarget); 488 489 add_alias_cmd ("g", "gnutarget", class_files, 1, &setlist); 490 491 if (getenv ("GNUTARGET")) 492 set_gnutarget (getenv ("GNUTARGET")); 493 else 494 set_gnutarget ("auto"); 495 } 496