1 /* Core dump and executable file functions above target vector, for GDB. 2 3 Copyright (C) 1986-2020 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 <signal.h> 22 #include <fcntl.h> 23 #include "inferior.h" 24 #include "symtab.h" 25 #include "command.h" 26 #include "gdbcmd.h" 27 #include "bfd.h" 28 #include "target.h" 29 #include "gdbcore.h" 30 #include "dis-asm.h" 31 #include <sys/stat.h> 32 #include "completer.h" 33 #include "observable.h" 34 #include "cli/cli-utils.h" 35 #include "gdbarch.h" 36 37 /* You can have any number of hooks for `exec_file_command' command to 38 call. If there's only one hook, it is set in exec_file_display 39 hook. If there are two or more hooks, they are set in 40 exec_file_extra_hooks[], and deprecated_exec_file_display_hook is 41 set to a function that calls all of them. This extra complexity is 42 needed to preserve compatibility with old code that assumed that 43 only one hook could be set, and which called 44 deprecated_exec_file_display_hook directly. */ 45 46 typedef void (*hook_type) (const char *); 47 48 hook_type deprecated_exec_file_display_hook; /* The original hook. */ 49 static hook_type *exec_file_extra_hooks; /* Array of additional 50 hooks. */ 51 static int exec_file_hook_count = 0; /* Size of array. */ 52 53 54 55 /* If there are two or more functions that wish to hook into 56 exec_file_command, this function will call all of the hook 57 functions. */ 58 59 static void 60 call_extra_exec_file_hooks (const char *filename) 61 { 62 int i; 63 64 for (i = 0; i < exec_file_hook_count; i++) 65 (*exec_file_extra_hooks[i]) (filename); 66 } 67 68 /* Call this to specify the hook for exec_file_command to call back. 69 This is called from the x-window display code. */ 70 71 void 72 specify_exec_file_hook (void (*hook) (const char *)) 73 { 74 hook_type *new_array; 75 76 if (deprecated_exec_file_display_hook != NULL) 77 { 78 /* There's already a hook installed. Arrange to have both it 79 and the subsequent hooks called. */ 80 if (exec_file_hook_count == 0) 81 { 82 /* If this is the first extra hook, initialize the hook 83 array. */ 84 exec_file_extra_hooks = XNEW (hook_type); 85 exec_file_extra_hooks[0] = deprecated_exec_file_display_hook; 86 deprecated_exec_file_display_hook = call_extra_exec_file_hooks; 87 exec_file_hook_count = 1; 88 } 89 90 /* Grow the hook array by one and add the new hook to the end. 91 Yes, it's inefficient to grow it by one each time but since 92 this is hardly ever called it's not a big deal. */ 93 exec_file_hook_count++; 94 new_array = (hook_type *) 95 xrealloc (exec_file_extra_hooks, 96 exec_file_hook_count * sizeof (hook_type)); 97 exec_file_extra_hooks = new_array; 98 exec_file_extra_hooks[exec_file_hook_count - 1] = hook; 99 } 100 else 101 deprecated_exec_file_display_hook = hook; 102 } 103 104 void 105 reopen_exec_file (void) 106 { 107 int res; 108 struct stat st; 109 110 /* Don't do anything if there isn't an exec file. */ 111 if (exec_bfd == NULL) 112 return; 113 114 /* If the timestamp of the exec file has changed, reopen it. */ 115 std::string filename = bfd_get_filename (exec_bfd); 116 res = stat (filename.c_str (), &st); 117 118 if (res == 0 && exec_bfd_mtime && exec_bfd_mtime != st.st_mtime) 119 exec_file_attach (filename.c_str (), 0); 120 else 121 /* If we accessed the file since last opening it, close it now; 122 this stops GDB from holding the executable open after it 123 exits. */ 124 bfd_cache_close_all (); 125 } 126 127 /* If we have both a core file and an exec file, 128 print a warning if they don't go together. */ 129 130 void 131 validate_files (void) 132 { 133 if (exec_bfd && core_bfd) 134 { 135 if (!core_file_matches_executable_p (core_bfd, exec_bfd)) 136 warning (_("core file may not match specified executable file.")); 137 else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd)) 138 warning (_("exec file is newer than core file.")); 139 } 140 } 141 142 /* See gdbsupport/common-inferior.h. */ 143 144 const char * 145 get_exec_file (int err) 146 { 147 if (exec_filename) 148 return exec_filename; 149 if (!err) 150 return NULL; 151 152 error (_("No executable file specified.\n\ 153 Use the \"file\" or \"exec-file\" command.")); 154 } 155 156 157 std::string 158 memory_error_message (enum target_xfer_status err, 159 struct gdbarch *gdbarch, CORE_ADDR memaddr) 160 { 161 switch (err) 162 { 163 case TARGET_XFER_E_IO: 164 /* Actually, address between memaddr and memaddr + len was out of 165 bounds. */ 166 return string_printf (_("Cannot access memory at address %s"), 167 paddress (gdbarch, memaddr)); 168 case TARGET_XFER_UNAVAILABLE: 169 return string_printf (_("Memory at address %s unavailable."), 170 paddress (gdbarch, memaddr)); 171 default: 172 internal_error (__FILE__, __LINE__, 173 "unhandled target_xfer_status: %s (%s)", 174 target_xfer_status_to_string (err), 175 plongest (err)); 176 } 177 } 178 179 /* Report a memory error by throwing a suitable exception. */ 180 181 void 182 memory_error (enum target_xfer_status err, CORE_ADDR memaddr) 183 { 184 enum errors exception = GDB_NO_ERROR; 185 186 /* Build error string. */ 187 std::string str = memory_error_message (err, target_gdbarch (), memaddr); 188 189 /* Choose the right error to throw. */ 190 switch (err) 191 { 192 case TARGET_XFER_E_IO: 193 exception = MEMORY_ERROR; 194 break; 195 case TARGET_XFER_UNAVAILABLE: 196 exception = NOT_AVAILABLE_ERROR; 197 break; 198 } 199 200 /* Throw it. */ 201 throw_error (exception, ("%s"), str.c_str ()); 202 } 203 204 /* Helper function. */ 205 206 static void 207 read_memory_object (enum target_object object, CORE_ADDR memaddr, 208 gdb_byte *myaddr, ssize_t len) 209 { 210 ULONGEST xfered = 0; 211 212 while (xfered < len) 213 { 214 enum target_xfer_status status; 215 ULONGEST xfered_len; 216 217 status = target_xfer_partial (current_top_target (), object, NULL, 218 myaddr + xfered, NULL, 219 memaddr + xfered, len - xfered, 220 &xfered_len); 221 222 if (status != TARGET_XFER_OK) 223 memory_error (status == TARGET_XFER_EOF ? TARGET_XFER_E_IO : status, 224 memaddr + xfered); 225 226 xfered += xfered_len; 227 QUIT; 228 } 229 } 230 231 /* Same as target_read_memory, but report an error if can't read. */ 232 233 void 234 read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) 235 { 236 read_memory_object (TARGET_OBJECT_MEMORY, memaddr, myaddr, len); 237 } 238 239 /* Same as target_read_stack, but report an error if can't read. */ 240 241 void 242 read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) 243 { 244 read_memory_object (TARGET_OBJECT_STACK_MEMORY, memaddr, myaddr, len); 245 } 246 247 /* Same as target_read_code, but report an error if can't read. */ 248 249 void 250 read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) 251 { 252 read_memory_object (TARGET_OBJECT_CODE_MEMORY, memaddr, myaddr, len); 253 } 254 255 /* Read memory at MEMADDR of length LEN and put the contents in 256 RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero 257 if successful. */ 258 259 int 260 safe_read_memory_integer (CORE_ADDR memaddr, int len, 261 enum bfd_endian byte_order, 262 LONGEST *return_value) 263 { 264 gdb_byte buf[sizeof (LONGEST)]; 265 266 if (target_read_memory (memaddr, buf, len)) 267 return 0; 268 269 *return_value = extract_signed_integer (buf, len, byte_order); 270 return 1; 271 } 272 273 /* Read memory at MEMADDR of length LEN and put the contents in 274 RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero 275 if successful. */ 276 277 int 278 safe_read_memory_unsigned_integer (CORE_ADDR memaddr, int len, 279 enum bfd_endian byte_order, 280 ULONGEST *return_value) 281 { 282 gdb_byte buf[sizeof (ULONGEST)]; 283 284 if (target_read_memory (memaddr, buf, len)) 285 return 0; 286 287 *return_value = extract_unsigned_integer (buf, len, byte_order); 288 return 1; 289 } 290 291 LONGEST 292 read_memory_integer (CORE_ADDR memaddr, int len, 293 enum bfd_endian byte_order) 294 { 295 gdb_byte buf[sizeof (LONGEST)]; 296 297 read_memory (memaddr, buf, len); 298 return extract_signed_integer (buf, len, byte_order); 299 } 300 301 ULONGEST 302 read_memory_unsigned_integer (CORE_ADDR memaddr, int len, 303 enum bfd_endian byte_order) 304 { 305 gdb_byte buf[sizeof (ULONGEST)]; 306 307 read_memory (memaddr, buf, len); 308 return extract_unsigned_integer (buf, len, byte_order); 309 } 310 311 LONGEST 312 read_code_integer (CORE_ADDR memaddr, int len, 313 enum bfd_endian byte_order) 314 { 315 gdb_byte buf[sizeof (LONGEST)]; 316 317 read_code (memaddr, buf, len); 318 return extract_signed_integer (buf, len, byte_order); 319 } 320 321 ULONGEST 322 read_code_unsigned_integer (CORE_ADDR memaddr, int len, 323 enum bfd_endian byte_order) 324 { 325 gdb_byte buf[sizeof (ULONGEST)]; 326 327 read_code (memaddr, buf, len); 328 return extract_unsigned_integer (buf, len, byte_order); 329 } 330 331 CORE_ADDR 332 read_memory_typed_address (CORE_ADDR addr, struct type *type) 333 { 334 gdb_byte *buf = (gdb_byte *) alloca (TYPE_LENGTH (type)); 335 336 read_memory (addr, buf, TYPE_LENGTH (type)); 337 return extract_typed_address (buf, type); 338 } 339 340 /* See gdbcore.h. */ 341 342 void 343 write_memory (CORE_ADDR memaddr, 344 const bfd_byte *myaddr, ssize_t len) 345 { 346 int status; 347 348 status = target_write_memory (memaddr, myaddr, len); 349 if (status != 0) 350 memory_error (TARGET_XFER_E_IO, memaddr); 351 } 352 353 /* Same as write_memory, but notify 'memory_changed' observers. */ 354 355 void 356 write_memory_with_notification (CORE_ADDR memaddr, const bfd_byte *myaddr, 357 ssize_t len) 358 { 359 write_memory (memaddr, myaddr, len); 360 gdb::observers::memory_changed.notify (current_inferior (), memaddr, len, myaddr); 361 } 362 363 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned 364 integer. */ 365 void 366 write_memory_unsigned_integer (CORE_ADDR addr, int len, 367 enum bfd_endian byte_order, 368 ULONGEST value) 369 { 370 gdb_byte *buf = (gdb_byte *) alloca (len); 371 372 store_unsigned_integer (buf, len, byte_order, value); 373 write_memory (addr, buf, len); 374 } 375 376 /* Store VALUE at ADDR in the inferior as a LEN-byte signed 377 integer. */ 378 void 379 write_memory_signed_integer (CORE_ADDR addr, int len, 380 enum bfd_endian byte_order, 381 LONGEST value) 382 { 383 gdb_byte *buf = (gdb_byte *) alloca (len); 384 385 store_signed_integer (buf, len, byte_order, value); 386 write_memory (addr, buf, len); 387 } 388 389 /* The current default bfd target. Points to storage allocated for 390 gnutarget_string. */ 391 const char *gnutarget; 392 393 /* Same thing, except it is "auto" not NULL for the default case. */ 394 static char *gnutarget_string; 395 static void 396 show_gnutarget_string (struct ui_file *file, int from_tty, 397 struct cmd_list_element *c, 398 const char *value) 399 { 400 fprintf_filtered (file, 401 _("The current BFD target is \"%s\".\n"), value); 402 } 403 404 static void 405 set_gnutarget_command (const char *ignore, int from_tty, 406 struct cmd_list_element *c) 407 { 408 char *gend = gnutarget_string + strlen (gnutarget_string); 409 410 gend = remove_trailing_whitespace (gnutarget_string, gend); 411 *gend = '\0'; 412 413 if (strcmp (gnutarget_string, "auto") == 0) 414 gnutarget = NULL; 415 else 416 gnutarget = gnutarget_string; 417 } 418 419 /* A completion function for "set gnutarget". */ 420 421 static void 422 complete_set_gnutarget (struct cmd_list_element *cmd, 423 completion_tracker &tracker, 424 const char *text, const char *word) 425 { 426 static const char **bfd_targets; 427 428 if (bfd_targets == NULL) 429 { 430 int last; 431 432 bfd_targets = bfd_target_list (); 433 for (last = 0; bfd_targets[last] != NULL; ++last) 434 ; 435 436 bfd_targets = XRESIZEVEC (const char *, bfd_targets, last + 2); 437 bfd_targets[last] = "auto"; 438 bfd_targets[last + 1] = NULL; 439 } 440 441 complete_on_enum (tracker, bfd_targets, text, word); 442 } 443 444 /* Set the gnutarget. */ 445 void 446 set_gnutarget (const char *newtarget) 447 { 448 xfree (gnutarget_string); 449 gnutarget_string = xstrdup (newtarget); 450 set_gnutarget_command (NULL, 0, NULL); 451 } 452 453 void _initialize_core (); 454 void 455 _initialize_core () 456 { 457 struct cmd_list_element *c; 458 459 c = add_cmd ("core-file", class_files, core_file_command, _("\ 460 Use FILE as core dump for examining memory and registers.\n\ 461 Usage: core-file FILE\n\ 462 No arg means have no core file. This command has been superseded by the\n\ 463 `target core' and `detach' commands."), &cmdlist); 464 set_cmd_completer (c, filename_completer); 465 466 467 c = add_setshow_string_noescape_cmd ("gnutarget", class_files, 468 &gnutarget_string, _("\ 469 Set the current BFD target."), _("\ 470 Show the current BFD target."), _("\ 471 Use `set gnutarget auto' to specify automatic detection."), 472 set_gnutarget_command, 473 show_gnutarget_string, 474 &setlist, &showlist); 475 set_cmd_completer (c, complete_set_gnutarget); 476 477 add_alias_cmd ("g", "gnutarget", class_files, 1, &setlist); 478 479 if (getenv ("GNUTARGET")) 480 set_gnutarget (getenv ("GNUTARGET")); 481 else 482 set_gnutarget ("auto"); 483 } 484