| 1 | /* Core dump and executable file functions above target vector, for GDB. |
| 2 | |
| 3 | Copyright (C) 1986-2018 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 | |
| 36 | /* You can have any number of hooks for `exec_file_command' command to |
| 37 | call. If there's only one hook, it is set in exec_file_display |
| 38 | hook. If there are two or more hooks, they are set in |
| 39 | exec_file_extra_hooks[], and deprecated_exec_file_display_hook is |
| 40 | set to a function that calls all of them. This extra complexity is |
| 41 | needed to preserve compatibility with old code that assumed that |
| 42 | only one hook could be set, and which called |
| 43 | deprecated_exec_file_display_hook directly. */ |
| 44 | |
| 45 | typedef void (*hook_type) (const char *); |
| 46 | |
| 47 | hook_type deprecated_exec_file_display_hook; /* The original hook. */ |
| 48 | static hook_type *exec_file_extra_hooks; /* Array of additional |
| 49 | hooks. */ |
| 50 | static int exec_file_hook_count = 0; /* Size of array. */ |
| 51 | |
| 52 | /* Binary file diddling handle for the core file. */ |
| 53 | |
| 54 | bfd *core_bfd = NULL; |
| 55 | |
| 56 | /* corelow.c target. It is never NULL after GDB initialization. */ |
| 57 | |
| 58 | struct target_ops *core_target; |
| 59 | \f |
| 60 | |
| 61 | /* Backward compatability with old way of specifying core files. */ |
| 62 | |
| 63 | void |
| 64 | core_file_command (const char *filename, int from_tty) |
| 65 | { |
| 66 | dont_repeat (); /* Either way, seems bogus. */ |
| 67 | |
| 68 | gdb_assert (core_target != NULL); |
| 69 | |
| 70 | if (!filename) |
| 71 | (core_target->to_detach) (core_target, current_inferior (), from_tty); |
| 72 | else |
| 73 | (core_target->to_open) (filename, from_tty); |
| 74 | } |
| 75 | \f |
| 76 | |
| 77 | /* If there are two or more functions that wish to hook into |
| 78 | exec_file_command, this function will call all of the hook |
| 79 | functions. */ |
| 80 | |
| 81 | static void |
| 82 | call_extra_exec_file_hooks (const char *filename) |
| 83 | { |
| 84 | int i; |
| 85 | |
| 86 | for (i = 0; i < exec_file_hook_count; i++) |
| 87 | (*exec_file_extra_hooks[i]) (filename); |
| 88 | } |
| 89 | |
| 90 | /* Call this to specify the hook for exec_file_command to call back. |
| 91 | This is called from the x-window display code. */ |
| 92 | |
| 93 | void |
| 94 | specify_exec_file_hook (void (*hook) (const char *)) |
| 95 | { |
| 96 | hook_type *new_array; |
| 97 | |
| 98 | if (deprecated_exec_file_display_hook != NULL) |
| 99 | { |
| 100 | /* There's already a hook installed. Arrange to have both it |
| 101 | and the subsequent hooks called. */ |
| 102 | if (exec_file_hook_count == 0) |
| 103 | { |
| 104 | /* If this is the first extra hook, initialize the hook |
| 105 | array. */ |
| 106 | exec_file_extra_hooks = XNEW (hook_type); |
| 107 | exec_file_extra_hooks[0] = deprecated_exec_file_display_hook; |
| 108 | deprecated_exec_file_display_hook = call_extra_exec_file_hooks; |
| 109 | exec_file_hook_count = 1; |
| 110 | } |
| 111 | |
| 112 | /* Grow the hook array by one and add the new hook to the end. |
| 113 | Yes, it's inefficient to grow it by one each time but since |
| 114 | this is hardly ever called it's not a big deal. */ |
| 115 | exec_file_hook_count++; |
| 116 | new_array = (hook_type *) |
| 117 | xrealloc (exec_file_extra_hooks, |
| 118 | exec_file_hook_count * sizeof (hook_type)); |
| 119 | exec_file_extra_hooks = new_array; |
| 120 | exec_file_extra_hooks[exec_file_hook_count - 1] = hook; |
| 121 | } |
| 122 | else |
| 123 | deprecated_exec_file_display_hook = hook; |
| 124 | } |
| 125 | |
| 126 | void |
| 127 | reopen_exec_file (void) |
| 128 | { |
| 129 | int res; |
| 130 | struct stat st; |
| 131 | |
| 132 | /* Don't do anything if there isn't an exec file. */ |
| 133 | if (exec_bfd == NULL) |
| 134 | return; |
| 135 | |
| 136 | /* If the timestamp of the exec file has changed, reopen it. */ |
| 137 | std::string filename = bfd_get_filename (exec_bfd); |
| 138 | res = stat (filename.c_str (), &st); |
| 139 | |
| 140 | if (res == 0 && exec_bfd_mtime && exec_bfd_mtime != st.st_mtime) |
| 141 | exec_file_attach (filename.c_str (), 0); |
| 142 | else |
| 143 | /* If we accessed the file since last opening it, close it now; |
| 144 | this stops GDB from holding the executable open after it |
| 145 | exits. */ |
| 146 | bfd_cache_close_all (); |
| 147 | } |
| 148 | \f |
| 149 | /* If we have both a core file and an exec file, |
| 150 | print a warning if they don't go together. */ |
| 151 | |
| 152 | void |
| 153 | validate_files (void) |
| 154 | { |
| 155 | if (exec_bfd && core_bfd) |
| 156 | { |
| 157 | if (!core_file_matches_executable_p (core_bfd, exec_bfd)) |
| 158 | warning (_("core file may not match specified executable file.")); |
| 159 | else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd)) |
| 160 | warning (_("exec file is newer than core file.")); |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | /* See common/common-inferior.h. */ |
| 165 | |
| 166 | char * |
| 167 | get_exec_file (int err) |
| 168 | { |
| 169 | if (exec_filename) |
| 170 | return exec_filename; |
| 171 | if (!err) |
| 172 | return NULL; |
| 173 | |
| 174 | error (_("No executable file specified.\n\ |
| 175 | Use the \"file\" or \"exec-file\" command.")); |
| 176 | return NULL; |
| 177 | } |
| 178 | \f |
| 179 | |
| 180 | std::string |
| 181 | memory_error_message (enum target_xfer_status err, |
| 182 | struct gdbarch *gdbarch, CORE_ADDR memaddr) |
| 183 | { |
| 184 | switch (err) |
| 185 | { |
| 186 | case TARGET_XFER_E_IO: |
| 187 | /* Actually, address between memaddr and memaddr + len was out of |
| 188 | bounds. */ |
| 189 | return string_printf (_("Cannot access memory at address %s"), |
| 190 | paddress (gdbarch, memaddr)); |
| 191 | case TARGET_XFER_UNAVAILABLE: |
| 192 | return string_printf (_("Memory at address %s unavailable."), |
| 193 | paddress (gdbarch, memaddr)); |
| 194 | default: |
| 195 | internal_error (__FILE__, __LINE__, |
| 196 | "unhandled target_xfer_status: %s (%s)", |
| 197 | target_xfer_status_to_string (err), |
| 198 | plongest (err)); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | /* Report a memory error by throwing a suitable exception. */ |
| 203 | |
| 204 | void |
| 205 | memory_error (enum target_xfer_status err, CORE_ADDR memaddr) |
| 206 | { |
| 207 | enum errors exception = GDB_NO_ERROR; |
| 208 | |
| 209 | /* Build error string. */ |
| 210 | std::string str = memory_error_message (err, target_gdbarch (), memaddr); |
| 211 | |
| 212 | /* Choose the right error to throw. */ |
| 213 | switch (err) |
| 214 | { |
| 215 | case TARGET_XFER_E_IO: |
| 216 | exception = MEMORY_ERROR; |
| 217 | break; |
| 218 | case TARGET_XFER_UNAVAILABLE: |
| 219 | exception = NOT_AVAILABLE_ERROR; |
| 220 | break; |
| 221 | } |
| 222 | |
| 223 | /* Throw it. */ |
| 224 | throw_error (exception, ("%s"), str.c_str ()); |
| 225 | } |
| 226 | |
| 227 | /* Helper function. */ |
| 228 | |
| 229 | static void |
| 230 | read_memory_object (enum target_object object, CORE_ADDR memaddr, |
| 231 | gdb_byte *myaddr, ssize_t len) |
| 232 | { |
| 233 | ULONGEST xfered = 0; |
| 234 | |
| 235 | while (xfered < len) |
| 236 | { |
| 237 | enum target_xfer_status status; |
| 238 | ULONGEST xfered_len; |
| 239 | |
| 240 | status = target_xfer_partial (current_target.beneath, |
| 241 | object, NULL, |
| 242 | myaddr + xfered, NULL, |
| 243 | memaddr + xfered, len - xfered, |
| 244 | &xfered_len); |
| 245 | |
| 246 | if (status != TARGET_XFER_OK) |
| 247 | memory_error (status == TARGET_XFER_EOF ? TARGET_XFER_E_IO : status, |
| 248 | memaddr + xfered); |
| 249 | |
| 250 | xfered += xfered_len; |
| 251 | QUIT; |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | /* Same as target_read_memory, but report an error if can't read. */ |
| 256 | |
| 257 | void |
| 258 | read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) |
| 259 | { |
| 260 | read_memory_object (TARGET_OBJECT_MEMORY, memaddr, myaddr, len); |
| 261 | } |
| 262 | |
| 263 | /* Same as target_read_stack, but report an error if can't read. */ |
| 264 | |
| 265 | void |
| 266 | read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) |
| 267 | { |
| 268 | read_memory_object (TARGET_OBJECT_STACK_MEMORY, memaddr, myaddr, len); |
| 269 | } |
| 270 | |
| 271 | /* Same as target_read_code, but report an error if can't read. */ |
| 272 | |
| 273 | void |
| 274 | read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) |
| 275 | { |
| 276 | read_memory_object (TARGET_OBJECT_CODE_MEMORY, memaddr, myaddr, len); |
| 277 | } |
| 278 | |
| 279 | /* Read memory at MEMADDR of length LEN and put the contents in |
| 280 | RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero |
| 281 | if successful. */ |
| 282 | |
| 283 | int |
| 284 | safe_read_memory_integer (CORE_ADDR memaddr, int len, |
| 285 | enum bfd_endian byte_order, |
| 286 | LONGEST *return_value) |
| 287 | { |
| 288 | gdb_byte buf[sizeof (LONGEST)]; |
| 289 | |
| 290 | if (target_read_memory (memaddr, buf, len)) |
| 291 | return 0; |
| 292 | |
| 293 | *return_value = extract_signed_integer (buf, len, byte_order); |
| 294 | return 1; |
| 295 | } |
| 296 | |
| 297 | /* Read memory at MEMADDR of length LEN and put the contents in |
| 298 | RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero |
| 299 | if successful. */ |
| 300 | |
| 301 | int |
| 302 | safe_read_memory_unsigned_integer (CORE_ADDR memaddr, int len, |
| 303 | enum bfd_endian byte_order, |
| 304 | ULONGEST *return_value) |
| 305 | { |
| 306 | gdb_byte buf[sizeof (ULONGEST)]; |
| 307 | |
| 308 | if (target_read_memory (memaddr, buf, len)) |
| 309 | return 0; |
| 310 | |
| 311 | *return_value = extract_unsigned_integer (buf, len, byte_order); |
| 312 | return 1; |
| 313 | } |
| 314 | |
| 315 | LONGEST |
| 316 | read_memory_integer (CORE_ADDR memaddr, int len, |
| 317 | enum bfd_endian byte_order) |
| 318 | { |
| 319 | gdb_byte buf[sizeof (LONGEST)]; |
| 320 | |
| 321 | read_memory (memaddr, buf, len); |
| 322 | return extract_signed_integer (buf, len, byte_order); |
| 323 | } |
| 324 | |
| 325 | ULONGEST |
| 326 | read_memory_unsigned_integer (CORE_ADDR memaddr, int len, |
| 327 | enum bfd_endian byte_order) |
| 328 | { |
| 329 | gdb_byte buf[sizeof (ULONGEST)]; |
| 330 | |
| 331 | read_memory (memaddr, buf, len); |
| 332 | return extract_unsigned_integer (buf, len, byte_order); |
| 333 | } |
| 334 | |
| 335 | LONGEST |
| 336 | read_code_integer (CORE_ADDR memaddr, int len, |
| 337 | enum bfd_endian byte_order) |
| 338 | { |
| 339 | gdb_byte buf[sizeof (LONGEST)]; |
| 340 | |
| 341 | read_code (memaddr, buf, len); |
| 342 | return extract_signed_integer (buf, len, byte_order); |
| 343 | } |
| 344 | |
| 345 | ULONGEST |
| 346 | read_code_unsigned_integer (CORE_ADDR memaddr, int len, |
| 347 | enum bfd_endian byte_order) |
| 348 | { |
| 349 | gdb_byte buf[sizeof (ULONGEST)]; |
| 350 | |
| 351 | read_code (memaddr, buf, len); |
| 352 | return extract_unsigned_integer (buf, len, byte_order); |
| 353 | } |
| 354 | |
| 355 | void |
| 356 | read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len) |
| 357 | { |
| 358 | char *cp; |
| 359 | int i; |
| 360 | int cnt; |
| 361 | |
| 362 | cp = buffer; |
| 363 | while (1) |
| 364 | { |
| 365 | if (cp - buffer >= max_len) |
| 366 | { |
| 367 | buffer[max_len - 1] = '\0'; |
| 368 | break; |
| 369 | } |
| 370 | cnt = max_len - (cp - buffer); |
| 371 | if (cnt > 8) |
| 372 | cnt = 8; |
| 373 | read_memory (memaddr + (int) (cp - buffer), (gdb_byte *) cp, cnt); |
| 374 | for (i = 0; i < cnt && *cp; i++, cp++) |
| 375 | ; /* null body */ |
| 376 | |
| 377 | if (i < cnt && !*cp) |
| 378 | break; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | CORE_ADDR |
| 383 | read_memory_typed_address (CORE_ADDR addr, struct type *type) |
| 384 | { |
| 385 | gdb_byte *buf = (gdb_byte *) alloca (TYPE_LENGTH (type)); |
| 386 | |
| 387 | read_memory (addr, buf, TYPE_LENGTH (type)); |
| 388 | return extract_typed_address (buf, type); |
| 389 | } |
| 390 | |
| 391 | /* See gdbcore.h. */ |
| 392 | |
| 393 | void |
| 394 | write_memory (CORE_ADDR memaddr, |
| 395 | const bfd_byte *myaddr, ssize_t len) |
| 396 | { |
| 397 | int status; |
| 398 | |
| 399 | status = target_write_memory (memaddr, myaddr, len); |
| 400 | if (status != 0) |
| 401 | memory_error (TARGET_XFER_E_IO, memaddr); |
| 402 | } |
| 403 | |
| 404 | /* Same as write_memory, but notify 'memory_changed' observers. */ |
| 405 | |
| 406 | void |
| 407 | write_memory_with_notification (CORE_ADDR memaddr, const bfd_byte *myaddr, |
| 408 | ssize_t len) |
| 409 | { |
| 410 | write_memory (memaddr, myaddr, len); |
| 411 | gdb::observers::memory_changed.notify (current_inferior (), memaddr, len, myaddr); |
| 412 | } |
| 413 | |
| 414 | /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned |
| 415 | integer. */ |
| 416 | void |
| 417 | write_memory_unsigned_integer (CORE_ADDR addr, int len, |
| 418 | enum bfd_endian byte_order, |
| 419 | ULONGEST value) |
| 420 | { |
| 421 | gdb_byte *buf = (gdb_byte *) alloca (len); |
| 422 | |
| 423 | store_unsigned_integer (buf, len, byte_order, value); |
| 424 | write_memory (addr, buf, len); |
| 425 | } |
| 426 | |
| 427 | /* Store VALUE at ADDR in the inferior as a LEN-byte signed |
| 428 | integer. */ |
| 429 | void |
| 430 | write_memory_signed_integer (CORE_ADDR addr, int len, |
| 431 | enum bfd_endian byte_order, |
| 432 | LONGEST value) |
| 433 | { |
| 434 | gdb_byte *buf = (gdb_byte *) alloca (len); |
| 435 | |
| 436 | store_signed_integer (buf, len, byte_order, value); |
| 437 | write_memory (addr, buf, len); |
| 438 | } |
| 439 | \f |
| 440 | /* The current default bfd target. Points to storage allocated for |
| 441 | gnutarget_string. */ |
| 442 | char *gnutarget; |
| 443 | |
| 444 | /* Same thing, except it is "auto" not NULL for the default case. */ |
| 445 | static char *gnutarget_string; |
| 446 | static void |
| 447 | show_gnutarget_string (struct ui_file *file, int from_tty, |
| 448 | struct cmd_list_element *c, |
| 449 | const char *value) |
| 450 | { |
| 451 | fprintf_filtered (file, |
| 452 | _("The current BFD target is \"%s\".\n"), value); |
| 453 | } |
| 454 | |
| 455 | static void |
| 456 | set_gnutarget_command (const char *ignore, int from_tty, |
| 457 | struct cmd_list_element *c) |
| 458 | { |
| 459 | char *gend = gnutarget_string + strlen (gnutarget_string); |
| 460 | |
| 461 | gend = remove_trailing_whitespace (gnutarget_string, gend); |
| 462 | *gend = '\0'; |
| 463 | |
| 464 | if (strcmp (gnutarget_string, "auto") == 0) |
| 465 | gnutarget = NULL; |
| 466 | else |
| 467 | gnutarget = gnutarget_string; |
| 468 | } |
| 469 | |
| 470 | /* A completion function for "set gnutarget". */ |
| 471 | |
| 472 | static void |
| 473 | complete_set_gnutarget (struct cmd_list_element *cmd, |
| 474 | completion_tracker &tracker, |
| 475 | const char *text, const char *word) |
| 476 | { |
| 477 | static const char **bfd_targets; |
| 478 | |
| 479 | if (bfd_targets == NULL) |
| 480 | { |
| 481 | int last; |
| 482 | |
| 483 | bfd_targets = bfd_target_list (); |
| 484 | for (last = 0; bfd_targets[last] != NULL; ++last) |
| 485 | ; |
| 486 | |
| 487 | bfd_targets = XRESIZEVEC (const char *, bfd_targets, last + 2); |
| 488 | bfd_targets[last] = "auto"; |
| 489 | bfd_targets[last + 1] = NULL; |
| 490 | } |
| 491 | |
| 492 | complete_on_enum (tracker, bfd_targets, text, word); |
| 493 | } |
| 494 | |
| 495 | /* Set the gnutarget. */ |
| 496 | void |
| 497 | set_gnutarget (const char *newtarget) |
| 498 | { |
| 499 | if (gnutarget_string != NULL) |
| 500 | xfree (gnutarget_string); |
| 501 | gnutarget_string = xstrdup (newtarget); |
| 502 | set_gnutarget_command (NULL, 0, NULL); |
| 503 | } |
| 504 | |
| 505 | void |
| 506 | _initialize_core (void) |
| 507 | { |
| 508 | struct cmd_list_element *c; |
| 509 | |
| 510 | c = add_cmd ("core-file", class_files, core_file_command, _("\ |
| 511 | Use FILE as core dump for examining memory and registers.\n\ |
| 512 | No arg means have no core file. This command has been superseded by the\n\ |
| 513 | `target core' and `detach' commands."), &cmdlist); |
| 514 | set_cmd_completer (c, filename_completer); |
| 515 | |
| 516 | |
| 517 | c = add_setshow_string_noescape_cmd ("gnutarget", class_files, |
| 518 | &gnutarget_string, _("\ |
| 519 | Set the current BFD target."), _("\ |
| 520 | Show the current BFD target."), _("\ |
| 521 | Use `set gnutarget auto' to specify automatic detection."), |
| 522 | set_gnutarget_command, |
| 523 | show_gnutarget_string, |
| 524 | &setlist, &showlist); |
| 525 | set_cmd_completer (c, complete_set_gnutarget); |
| 526 | |
| 527 | add_alias_cmd ("g", "gnutarget", class_files, 1, &setlist); |
| 528 | |
| 529 | if (getenv ("GNUTARGET")) |
| 530 | set_gnutarget (getenv ("GNUTARGET")); |
| 531 | else |
| 532 | set_gnutarget ("auto"); |
| 533 | } |