1 /* Target-vector operations for controlling Unix child processes, for GDB. 2 3 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 4 2000, 2002, 2003, 2004 Free Software Foundation, Inc. 5 6 Contributed by Cygnus Support. 7 8 ## Contains temporary hacks.. 9 10 This file is part of GDB. 11 12 This program is free software; you can redistribute it and/or modify 13 it under the terms of the GNU General Public License as published by 14 the Free Software Foundation; either version 2 of the License, or 15 (at your option) any later version. 16 17 This program is distributed in the hope that it will be useful, 18 but WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 GNU General Public License for more details. 21 22 You should have received a copy of the GNU General Public License 23 along with this program; if not, write to the Free Software 24 Foundation, Inc., 59 Temple Place - Suite 330, 25 Boston, MA 02111-1307, USA. */ 26 27 #include "defs.h" 28 #include "frame.h" /* required by inferior.h */ 29 #include "inferior.h" 30 #include "target.h" 31 #include "gdbcore.h" 32 #include "command.h" 33 #include "gdb_stat.h" 34 #include <signal.h> 35 #include <sys/types.h> 36 #include <fcntl.h> 37 38 #include "gdb_wait.h" 39 #include "inflow.h" 40 41 extern struct symtab_and_line *child_enable_exception_callback (enum 42 exception_event_kind, 43 int); 44 45 extern struct exception_event_record 46 *child_get_current_exception_event (void); 47 48 extern void _initialize_inftarg (void); 49 50 static void child_prepare_to_store (void); 51 52 #ifndef CHILD_WAIT 53 static ptid_t child_wait (ptid_t, struct target_waitstatus *); 54 #endif /* CHILD_WAIT */ 55 56 #if !defined(CHILD_POST_WAIT) 57 void child_post_wait (ptid_t, int); 58 #endif 59 60 static void child_open (char *, int); 61 62 static void child_files_info (struct target_ops *); 63 64 static void child_detach (char *, int); 65 66 static void child_attach (char *, int); 67 68 #if !defined(CHILD_POST_ATTACH) 69 extern void child_post_attach (int); 70 #endif 71 72 static void ptrace_me (void); 73 74 static void ptrace_him (int); 75 76 static void child_create_inferior (char *, char *, char **); 77 78 static void child_mourn_inferior (void); 79 80 static int child_can_run (void); 81 82 static void child_stop (void); 83 84 #ifndef CHILD_THREAD_ALIVE 85 int child_thread_alive (ptid_t); 86 #endif 87 88 static void init_child_ops (void); 89 90 extern char **environ; 91 92 struct target_ops child_ops; 93 94 int child_suppress_run = 0; /* Non-zero if inftarg should pretend not to 95 be a runnable target. Used by targets 96 that can sit atop inftarg, such as HPUX 97 thread support. */ 98 99 #ifndef CHILD_WAIT 100 101 /* Wait for child to do something. Return pid of child, or -1 in case 102 of error; store status through argument pointer OURSTATUS. */ 103 104 static ptid_t 105 child_wait (ptid_t ptid, struct target_waitstatus *ourstatus) 106 { 107 int save_errno; 108 int status; 109 char *execd_pathname = NULL; 110 int exit_status; 111 int related_pid; 112 int syscall_id; 113 enum target_waitkind kind; 114 int pid; 115 116 do 117 { 118 set_sigint_trap (); /* Causes SIGINT to be passed on to the 119 attached process. */ 120 set_sigio_trap (); 121 122 pid = ptrace_wait (inferior_ptid, &status); 123 124 save_errno = errno; 125 126 clear_sigio_trap (); 127 128 clear_sigint_trap (); 129 130 if (pid == -1) 131 { 132 if (save_errno == EINTR) 133 continue; 134 135 fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n", 136 safe_strerror (save_errno)); 137 138 /* Claim it exited with unknown signal. */ 139 ourstatus->kind = TARGET_WAITKIND_SIGNALLED; 140 ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN; 141 return pid_to_ptid (-1); 142 } 143 144 /* Did it exit? 145 */ 146 if (target_has_exited (pid, status, &exit_status)) 147 { 148 /* ??rehrauer: For now, ignore this. */ 149 continue; 150 } 151 152 if (!target_thread_alive (pid_to_ptid (pid))) 153 { 154 ourstatus->kind = TARGET_WAITKIND_SPURIOUS; 155 return pid_to_ptid (pid); 156 } 157 } while (pid != PIDGET (inferior_ptid)); /* Some other child died or stopped */ 158 159 store_waitstatus (ourstatus, status); 160 return pid_to_ptid (pid); 161 } 162 #endif /* CHILD_WAIT */ 163 164 #if !defined(CHILD_POST_WAIT) 165 void 166 child_post_wait (ptid_t ptid, int wait_status) 167 { 168 /* This version of Unix doesn't require a meaningful "post wait" 169 operation. 170 */ 171 } 172 #endif 173 174 175 #ifndef CHILD_THREAD_ALIVE 176 177 /* Check to see if the given thread is alive. 178 179 FIXME: Is kill() ever the right way to do this? I doubt it, but 180 for now we're going to try and be compatable with the old thread 181 code. */ 182 int 183 child_thread_alive (ptid_t ptid) 184 { 185 pid_t pid = PIDGET (ptid); 186 187 return (kill (pid, 0) != -1); 188 } 189 190 #endif 191 192 /* Attach to process PID, then initialize for debugging it. */ 193 194 static void 195 child_attach (char *args, int from_tty) 196 { 197 if (!args) 198 error_no_arg ("process-id to attach"); 199 200 #ifndef ATTACH_DETACH 201 error ("Can't attach to a process on this machine."); 202 #else 203 { 204 char *exec_file; 205 int pid; 206 char *dummy; 207 208 dummy = args; 209 pid = strtol (args, &dummy, 0); 210 /* Some targets don't set errno on errors, grrr! */ 211 if ((pid == 0) && (args == dummy)) 212 error ("Illegal process-id: %s\n", args); 213 214 if (pid == getpid ()) /* Trying to masturbate? */ 215 error ("I refuse to debug myself!"); 216 217 if (from_tty) 218 { 219 exec_file = (char *) get_exec_file (0); 220 221 if (exec_file) 222 printf_unfiltered ("Attaching to program: %s, %s\n", exec_file, 223 target_pid_to_str (pid_to_ptid (pid))); 224 else 225 printf_unfiltered ("Attaching to %s\n", 226 target_pid_to_str (pid_to_ptid (pid))); 227 228 gdb_flush (gdb_stdout); 229 } 230 231 attach (pid); 232 233 inferior_ptid = pid_to_ptid (pid); 234 push_target (&child_ops); 235 } 236 #endif /* ATTACH_DETACH */ 237 } 238 239 #if !defined(CHILD_POST_ATTACH) 240 void 241 child_post_attach (int pid) 242 { 243 /* This version of Unix doesn't require a meaningful "post attach" 244 operation by a debugger. */ 245 } 246 #endif 247 248 /* Take a program previously attached to and detaches it. 249 The program resumes execution and will no longer stop 250 on signals, etc. We'd better not have left any breakpoints 251 in the program or it'll die when it hits one. For this 252 to work, it may be necessary for the process to have been 253 previously attached. It *might* work if the program was 254 started via the normal ptrace (PTRACE_TRACEME). */ 255 256 static void 257 child_detach (char *args, int from_tty) 258 { 259 #ifdef ATTACH_DETACH 260 { 261 int siggnal = 0; 262 int pid = PIDGET (inferior_ptid); 263 264 if (from_tty) 265 { 266 char *exec_file = get_exec_file (0); 267 if (exec_file == 0) 268 exec_file = ""; 269 printf_unfiltered ("Detaching from program: %s, %s\n", exec_file, 270 target_pid_to_str (pid_to_ptid (pid))); 271 gdb_flush (gdb_stdout); 272 } 273 if (args) 274 siggnal = atoi (args); 275 276 detach (siggnal); 277 278 inferior_ptid = null_ptid; 279 unpush_target (&child_ops); 280 } 281 #else 282 error ("This version of Unix does not support detaching a process."); 283 #endif 284 } 285 286 /* Get ready to modify the registers array. On machines which store 287 individual registers, this doesn't need to do anything. On machines 288 which store all the registers in one fell swoop, this makes sure 289 that registers contains all the registers from the program being 290 debugged. */ 291 292 static void 293 child_prepare_to_store (void) 294 { 295 #ifdef CHILD_PREPARE_TO_STORE 296 CHILD_PREPARE_TO_STORE (); 297 #endif 298 } 299 300 /* Print status information about what we're accessing. */ 301 302 static void 303 child_files_info (struct target_ops *ignore) 304 { 305 printf_unfiltered ("\tUsing the running image of %s %s.\n", 306 attach_flag ? "attached" : "child", target_pid_to_str (inferior_ptid)); 307 } 308 309 static void 310 child_open (char *arg, int from_tty) 311 { 312 error ("Use the \"run\" command to start a Unix child process."); 313 } 314 315 /* Stub function which causes the inferior that runs it, to be ptrace-able 316 by its parent process. */ 317 318 static void 319 ptrace_me (void) 320 { 321 /* "Trace me, Dr. Memory!" */ 322 call_ptrace (0, 0, (PTRACE_ARG3_TYPE) 0, 0); 323 } 324 325 /* Stub function which causes the GDB that runs it, to start ptrace-ing 326 the child process. */ 327 328 static void 329 ptrace_him (int pid) 330 { 331 push_target (&child_ops); 332 333 /* On some targets, there must be some explicit synchronization 334 between the parent and child processes after the debugger 335 forks, and before the child execs the debuggee program. This 336 call basically gives permission for the child to exec. 337 */ 338 339 target_acknowledge_created_inferior (pid); 340 341 /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h, 342 * and will be 1 or 2 depending on whether we're starting 343 * without or with a shell. 344 */ 345 startup_inferior (START_INFERIOR_TRAPS_EXPECTED); 346 347 /* On some targets, there must be some explicit actions taken after 348 the inferior has been started up. 349 */ 350 target_post_startup_inferior (pid_to_ptid (pid)); 351 } 352 353 /* Start an inferior Unix child process and sets inferior_ptid to its pid. 354 EXEC_FILE is the file to run. 355 ALLARGS is a string containing the arguments to the program. 356 ENV is the environment vector to pass. Errors reported with error(). */ 357 358 static void 359 child_create_inferior (char *exec_file, char *allargs, char **env) 360 { 361 #ifdef HPUXHPPA 362 fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, pre_fork_inferior, NULL); 363 #else 364 fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, NULL, NULL); 365 #endif 366 /* We are at the first instruction we care about. */ 367 /* Pedal to the metal... */ 368 proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0); 369 } 370 371 #if !defined(CHILD_POST_STARTUP_INFERIOR) 372 void 373 child_post_startup_inferior (ptid_t ptid) 374 { 375 /* This version of Unix doesn't require a meaningful "post startup inferior" 376 operation by a debugger. 377 */ 378 } 379 #endif 380 381 #if !defined(CHILD_ACKNOWLEDGE_CREATED_INFERIOR) 382 void 383 child_acknowledge_created_inferior (int pid) 384 { 385 /* This version of Unix doesn't require a meaningful "acknowledge created inferior" 386 operation by a debugger. 387 */ 388 } 389 #endif 390 391 392 #if !defined(CHILD_INSERT_FORK_CATCHPOINT) 393 int 394 child_insert_fork_catchpoint (int pid) 395 { 396 /* This version of Unix doesn't support notification of fork events. */ 397 return 0; 398 } 399 #endif 400 401 #if !defined(CHILD_REMOVE_FORK_CATCHPOINT) 402 int 403 child_remove_fork_catchpoint (int pid) 404 { 405 /* This version of Unix doesn't support notification of fork events. */ 406 return 0; 407 } 408 #endif 409 410 #if !defined(CHILD_INSERT_VFORK_CATCHPOINT) 411 int 412 child_insert_vfork_catchpoint (int pid) 413 { 414 /* This version of Unix doesn't support notification of vfork events. */ 415 return 0; 416 } 417 #endif 418 419 #if !defined(CHILD_REMOVE_VFORK_CATCHPOINT) 420 int 421 child_remove_vfork_catchpoint (int pid) 422 { 423 /* This version of Unix doesn't support notification of vfork events. */ 424 return 0; 425 } 426 #endif 427 428 #if !defined(CHILD_FOLLOW_FORK) 429 int 430 child_follow_fork (int follow_child) 431 { 432 /* This version of Unix doesn't support following fork or vfork events. */ 433 return 0; 434 } 435 #endif 436 437 #if !defined(CHILD_INSERT_EXEC_CATCHPOINT) 438 int 439 child_insert_exec_catchpoint (int pid) 440 { 441 /* This version of Unix doesn't support notification of exec events. */ 442 return 0; 443 } 444 #endif 445 446 #if !defined(CHILD_REMOVE_EXEC_CATCHPOINT) 447 int 448 child_remove_exec_catchpoint (int pid) 449 { 450 /* This version of Unix doesn't support notification of exec events. */ 451 return 0; 452 } 453 #endif 454 455 #if !defined(CHILD_REPORTED_EXEC_EVENTS_PER_EXEC_CALL) 456 int 457 child_reported_exec_events_per_exec_call (void) 458 { 459 /* This version of Unix doesn't support notification of exec events. 460 */ 461 return 1; 462 } 463 #endif 464 465 #if !defined(CHILD_HAS_EXITED) 466 int 467 child_has_exited (int pid, int wait_status, int *exit_status) 468 { 469 if (WIFEXITED (wait_status)) 470 { 471 *exit_status = WEXITSTATUS (wait_status); 472 return 1; 473 } 474 475 if (WIFSIGNALED (wait_status)) 476 { 477 *exit_status = 0; /* ?? Don't know what else to say here. */ 478 return 1; 479 } 480 481 /* ?? Do we really need to consult the event state, too? Assume the 482 wait_state alone suffices. 483 */ 484 return 0; 485 } 486 #endif 487 488 489 static void 490 child_mourn_inferior (void) 491 { 492 unpush_target (&child_ops); 493 generic_mourn_inferior (); 494 } 495 496 static int 497 child_can_run (void) 498 { 499 /* This variable is controlled by modules that sit atop inftarg that may layer 500 their own process structure atop that provided here. hpux-thread.c does 501 this because of the Hpux user-mode level thread model. */ 502 503 return !child_suppress_run; 504 } 505 506 /* Send a SIGINT to the process group. This acts just like the user typed a 507 ^C on the controlling terminal. 508 509 XXX - This may not be correct for all systems. Some may want to use 510 killpg() instead of kill (-pgrp). */ 511 512 static void 513 child_stop (void) 514 { 515 kill (-inferior_process_group, SIGINT); 516 } 517 518 #if !defined(CHILD_ENABLE_EXCEPTION_CALLBACK) 519 struct symtab_and_line * 520 child_enable_exception_callback (enum exception_event_kind kind, int enable) 521 { 522 return (struct symtab_and_line *) NULL; 523 } 524 #endif 525 526 #if !defined(CHILD_GET_CURRENT_EXCEPTION_EVENT) 527 struct exception_event_record * 528 child_get_current_exception_event (void) 529 { 530 return (struct exception_event_record *) NULL; 531 } 532 #endif 533 534 535 #if !defined(CHILD_PID_TO_EXEC_FILE) 536 char * 537 child_pid_to_exec_file (int pid) 538 { 539 /* This version of Unix doesn't support translation of a process ID 540 to the filename of the executable file. 541 */ 542 return NULL; 543 } 544 #endif 545 546 char * 547 child_core_file_to_sym_file (char *core) 548 { 549 /* The target stratum for a running executable need not support 550 this operation. 551 */ 552 return NULL; 553 } 554 555 /* Perform a partial transfer to/from the specified object. For 556 memory transfers, fall back to the old memory xfer functions. */ 557 558 static LONGEST 559 child_xfer_partial (struct target_ops *ops, enum target_object object, 560 const char *annex, void *readbuf, 561 const void *writebuf, ULONGEST offset, LONGEST len) 562 { 563 switch (object) 564 { 565 case TARGET_OBJECT_MEMORY: 566 if (readbuf) 567 return child_xfer_memory (offset, readbuf, len, 0/*write*/, 568 NULL, ops); 569 if (writebuf) 570 return child_xfer_memory (offset, readbuf, len, 1/*write*/, 571 NULL, ops); 572 return -1; 573 574 case TARGET_OBJECT_UNWIND_TABLE: 575 #ifndef NATIVE_XFER_UNWIND_TABLE 576 #define NATIVE_XFER_UNWIND_TABLE(OPS,OBJECT,ANNEX,WRITEBUF,READBUF,OFFSET,LEN) (-1) 577 #endif 578 return NATIVE_XFER_UNWIND_TABLE (ops, object, annex, readbuf, writebuf, 579 offset, len); 580 581 case TARGET_OBJECT_AUXV: 582 #ifndef NATIVE_XFER_AUXV 583 #define NATIVE_XFER_AUXV(OPS,OBJECT,ANNEX,WRITEBUF,READBUF,OFFSET,LEN) (-1) 584 #endif 585 return NATIVE_XFER_AUXV (ops, object, annex, readbuf, writebuf, 586 offset, len); 587 588 case TARGET_OBJECT_WCOOKIE: 589 #ifndef NATIVE_XFER_WCOOKIE 590 #define NATIVE_XFER_WCOOKIE(OPS,OBJECT,ANNEX,WRITEBUF,READBUF,OFFSET,LEN) (-1) 591 #endif 592 return NATIVE_XFER_WCOOKIE (ops, object, annex, readbuf, writebuf, 593 offset, len); 594 595 default: 596 return -1; 597 } 598 } 599 600 #if !defined(CHILD_PID_TO_STR) 601 char * 602 child_pid_to_str (ptid_t ptid) 603 { 604 return normal_pid_to_str (ptid); 605 } 606 #endif 607 608 static void 609 init_child_ops (void) 610 { 611 child_ops.to_shortname = "child"; 612 child_ops.to_longname = "Unix child process"; 613 child_ops.to_doc = "Unix child process (started by the \"run\" command)."; 614 child_ops.to_open = child_open; 615 child_ops.to_attach = child_attach; 616 child_ops.to_post_attach = child_post_attach; 617 child_ops.to_detach = child_detach; 618 child_ops.to_resume = child_resume; 619 child_ops.to_wait = child_wait; 620 child_ops.to_post_wait = child_post_wait; 621 child_ops.to_fetch_registers = fetch_inferior_registers; 622 child_ops.to_store_registers = store_inferior_registers; 623 child_ops.to_prepare_to_store = child_prepare_to_store; 624 child_ops.to_xfer_memory = child_xfer_memory; 625 child_ops.to_xfer_partial = child_xfer_partial; 626 child_ops.to_files_info = child_files_info; 627 child_ops.to_insert_breakpoint = memory_insert_breakpoint; 628 child_ops.to_remove_breakpoint = memory_remove_breakpoint; 629 child_ops.to_terminal_init = terminal_init_inferior; 630 child_ops.to_terminal_inferior = terminal_inferior; 631 child_ops.to_terminal_ours_for_output = terminal_ours_for_output; 632 child_ops.to_terminal_save_ours = terminal_save_ours; 633 child_ops.to_terminal_ours = terminal_ours; 634 child_ops.to_terminal_info = child_terminal_info; 635 child_ops.to_kill = kill_inferior; 636 child_ops.to_create_inferior = child_create_inferior; 637 child_ops.to_post_startup_inferior = child_post_startup_inferior; 638 child_ops.to_acknowledge_created_inferior = child_acknowledge_created_inferior; 639 child_ops.to_insert_fork_catchpoint = child_insert_fork_catchpoint; 640 child_ops.to_remove_fork_catchpoint = child_remove_fork_catchpoint; 641 child_ops.to_insert_vfork_catchpoint = child_insert_vfork_catchpoint; 642 child_ops.to_remove_vfork_catchpoint = child_remove_vfork_catchpoint; 643 child_ops.to_follow_fork = child_follow_fork; 644 child_ops.to_insert_exec_catchpoint = child_insert_exec_catchpoint; 645 child_ops.to_remove_exec_catchpoint = child_remove_exec_catchpoint; 646 child_ops.to_reported_exec_events_per_exec_call = child_reported_exec_events_per_exec_call; 647 child_ops.to_has_exited = child_has_exited; 648 child_ops.to_mourn_inferior = child_mourn_inferior; 649 child_ops.to_can_run = child_can_run; 650 child_ops.to_thread_alive = child_thread_alive; 651 child_ops.to_pid_to_str = child_pid_to_str; 652 child_ops.to_stop = child_stop; 653 child_ops.to_enable_exception_callback = child_enable_exception_callback; 654 child_ops.to_get_current_exception_event = child_get_current_exception_event; 655 child_ops.to_pid_to_exec_file = child_pid_to_exec_file; 656 child_ops.to_stratum = process_stratum; 657 child_ops.to_has_all_memory = 1; 658 child_ops.to_has_memory = 1; 659 child_ops.to_has_stack = 1; 660 child_ops.to_has_registers = 1; 661 child_ops.to_has_execution = 1; 662 child_ops.to_magic = OPS_MAGIC; 663 } 664 665 /* Take over the 'find_mapped_memory' vector from inftarg.c. */ 666 extern void 667 inftarg_set_find_memory_regions (int (*func) (int (*) (CORE_ADDR, 668 unsigned long, 669 int, int, int, 670 void *), 671 void *)) 672 { 673 child_ops.to_find_memory_regions = func; 674 } 675 676 /* Take over the 'make_corefile_notes' vector from inftarg.c. */ 677 extern void 678 inftarg_set_make_corefile_notes (char * (*func) (bfd *, int *)) 679 { 680 child_ops.to_make_corefile_notes = func; 681 } 682 683 void 684 _initialize_inftarg (void) 685 { 686 #ifdef HAVE_OPTIONAL_PROC_FS 687 char procname[32]; 688 int fd; 689 690 /* If we have an optional /proc filesystem (e.g. under OSF/1), 691 don't add ptrace support if we can access the running GDB via /proc. */ 692 #ifndef PROC_NAME_FMT 693 #define PROC_NAME_FMT "/proc/%05d" 694 #endif 695 sprintf (procname, PROC_NAME_FMT, getpid ()); 696 fd = open (procname, O_RDONLY); 697 if (fd >= 0) 698 { 699 close (fd); 700 return; 701 } 702 #endif 703 704 init_child_ops (); 705 add_target (&child_ops); 706 } 707