gdbserver/target.cc

   1 /* Target operations for the remote server for GDB.
   2    Copyright (C) 2002-2023 Free Software Foundation, Inc.
   3
   4    Contributed by MontaVista Software.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "server.h"
  22 #include "tracepoint.h"
  23 #include "gdbsupport/byte-vector.h"
  24 #include "hostio.h"
  25 #include <fcntl.h>
  26 #include <unistd.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29
  30 process_stratum_target *the_target;
  31
  32 /* See target.h.  */
  33
  34 bool
  35 set_desired_thread ()
  36 {
  37   client_state &cs = get_client_state ();
  38   thread_info *found = find_thread_ptid (cs.general_thread);
  39
  40   if (found == nullptr)
  41     {
  42       process_info *proc = find_process_pid (cs.general_thread.pid ());
  43       if (proc == nullptr)
  44         {
  45           threads_debug_printf
  46             ("did not find thread nor process for general_thread %s",
  47              cs.general_thread.to_string ().c_str ());
  48         }
  49       else
  50         {
  51           threads_debug_printf
  52             ("did not find thread for general_thread %s, but found process",
  53              cs.general_thread.to_string ().c_str ());
  54         }
  55       switch_to_process (proc);
  56     }
  57   else
  58     switch_to_thread (found);
  59
  60   return (current_thread != NULL);
  61 }
  62
  63 /* See target.h.  */
  64
  65 bool
  66 set_desired_process ()
  67 {
  68   client_state &cs = get_client_state ();
  69
  70   process_info *proc = find_process_pid (cs.general_thread.pid ());
  71   if (proc == nullptr)
  72     {
  73       threads_debug_printf
  74         ("did not find process for general_thread %s",
  75          cs.general_thread.to_string ().c_str ());
  76     }
  77   switch_to_process (proc);
  78
  79   return proc != nullptr;
  80 }
  81
  82 /* See target.h.  */
  83
  84 int
  85 read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
  86 {
  87   /* At the time of writing, GDB only sends write packets with LEN==0,
  88      not read packets (see comment in target_write_memory), but it
  89      doesn't hurt to prevent problems if it ever does, or we're
  90      connected to some client other than GDB that does.  */
  91   if (len == 0)
  92     return 0;
  93
  94   int res = the_target->read_memory (memaddr, myaddr, len);
  95   check_mem_read (memaddr, myaddr, len);
  96   return res;
  97 }
  98
  99 /* See target/target.h.  */
 100
 101 int
 102 target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 103 {
 104   return read_inferior_memory (memaddr, myaddr, len);
 105 }
 106
 107 /* See target/target.h.  */
 108
 109 int
 110 target_read_uint32 (CORE_ADDR memaddr, uint32_t *result)
 111 {
 112   return read_inferior_memory (memaddr, (gdb_byte *) result, sizeof (*result));
 113 }
 114
 115 /* See target/target.h.  */
 116
 117 int
 118 target_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 119                      ssize_t len)
 120 {
 121   /* GDB may send X packets with LEN==0, for probing packet support.
 122      If we let such a request go through, then buffer.data() below may
 123      return NULL, which may confuse target implementations.  Handle it
 124      here to avoid lower levels having to care about this case.  */
 125   if (len == 0)
 126     return 0;
 127
 128   /* Make a copy of the data because check_mem_write may need to
 129      update it.  */
 130   gdb::byte_vector buffer (myaddr, myaddr + len);
 131   check_mem_write (memaddr, buffer.data (), myaddr, len);
 132   return the_target->write_memory (memaddr, buffer.data (), len);
 133 }
 134
 135 ptid_t
 136 mywait (ptid_t ptid, struct target_waitstatus *ourstatus,
 137         target_wait_flags options, int connected_wait)
 138 {
 139   ptid_t ret;
 140
 141   if (connected_wait)
 142     server_waiting = 1;
 143
 144   ret = target_wait (ptid, ourstatus, options);
 145
 146   /* We don't expose _LOADED events to gdbserver core.  See the
 147      `dlls_changed' global.  */
 148   if (ourstatus->kind () == TARGET_WAITKIND_LOADED)
 149     ourstatus->set_stopped (GDB_SIGNAL_0);
 150
 151   /* If GDB is connected through TCP/serial, then GDBserver will most
 152      probably be running on its own terminal/console, so it's nice to
 153      print there why is GDBserver exiting.  If however, GDB is
 154      connected through stdio, then there's no need to spam the GDB
 155      console with this -- the user will already see the exit through
 156      regular GDB output, in that same terminal.  */
 157   if (!remote_connection_is_stdio ())
 158     {
 159       if (ourstatus->kind () == TARGET_WAITKIND_EXITED)
 160         fprintf (stderr,
 161                  "\nChild exited with status %d\n", ourstatus->exit_status ());
 162       else if (ourstatus->kind () == TARGET_WAITKIND_SIGNALLED)
 163         fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
 164                  gdb_signal_to_host (ourstatus->sig ()),
 165                  gdb_signal_to_name (ourstatus->sig ()));
 166     }
 167
 168   if (connected_wait)
 169     server_waiting = 0;
 170
 171   return ret;
 172 }
 173
 174 /* See target/target.h.  */
 175
 176 void
 177 target_stop_and_wait (ptid_t ptid)
 178 {
 179   struct target_waitstatus status;
 180   bool was_non_stop = non_stop;
 181   struct thread_resume resume_info;
 182
 183   resume_info.thread = ptid;
 184   resume_info.kind = resume_stop;
 185   resume_info.sig = GDB_SIGNAL_0;
 186   the_target->resume (&resume_info, 1);
 187
 188   non_stop = true;
 189   mywait (ptid, &status, 0, 0);
 190   non_stop = was_non_stop;
 191 }
 192
 193 /* See target/target.h.  */
 194
 195 ptid_t
 196 target_wait (ptid_t ptid, struct target_waitstatus *status,
 197              target_wait_flags options)
 198 {
 199   return the_target->wait (ptid, status, options);
 200 }
 201
 202 /* See target/target.h.  */
 203
 204 void
 205 target_mourn_inferior (ptid_t ptid)
 206 {
 207   the_target->mourn (find_process_pid (ptid.pid ()));
 208 }
 209
 210 /* See target/target.h.  */
 211
 212 void
 213 target_continue_no_signal (ptid_t ptid)
 214 {
 215   struct thread_resume resume_info;
 216
 217   resume_info.thread = ptid;
 218   resume_info.kind = resume_continue;
 219   resume_info.sig = GDB_SIGNAL_0;
 220   the_target->resume (&resume_info, 1);
 221 }
 222
 223 /* See target/target.h.  */
 224
 225 void
 226 target_continue (ptid_t ptid, enum gdb_signal signal)
 227 {
 228   struct thread_resume resume_info;
 229
 230   resume_info.thread = ptid;
 231   resume_info.kind = resume_continue;
 232   resume_info.sig = gdb_signal_to_host (signal);
 233   the_target->resume (&resume_info, 1);
 234 }
 235
 236 /* See target/target.h.  */
 237
 238 int
 239 target_supports_multi_process (void)
 240 {
 241   return the_target->supports_multi_process ();
 242 }
 243
 244 void
 245 set_target_ops (process_stratum_target *target)
 246 {
 247   the_target = target;
 248 }
 249
 250 /* Convert pid to printable format.  */
 251
 252 std::string
 253 target_pid_to_str (ptid_t ptid)
 254 {
 255   if (ptid == minus_one_ptid)
 256     return string_printf("<all threads>");
 257   else if (ptid == null_ptid)
 258     return string_printf("<null thread>");
 259   else if (ptid.tid () != 0)
 260     return string_printf("Thread %d.0x%s",
 261                          ptid.pid (),
 262                          phex_nz (ptid.tid (), sizeof (ULONGEST)));
 263   else if (ptid.lwp () != 0)
 264     return string_printf("LWP %d.%ld",
 265                          ptid.pid (), ptid.lwp ());
 266   else
 267     return string_printf("Process %d",
 268                          ptid.pid ());
 269 }
 270
 271 int
 272 kill_inferior (process_info *proc)
 273 {
 274   gdb_agent_about_to_close (proc->pid);
 275
 276   return the_target->kill (proc);
 277 }
 278
 279 /* Define it.  */
 280
 281 target_terminal_state target_terminal::m_terminal_state
 282   = target_terminal_state::is_ours;
 283
 284 /* See target/target.h.  */
 285
 286 void
 287 target_terminal::init ()
 288 {
 289   /* Placeholder needed because of fork_inferior.  Not necessary on
 290      GDBserver.  */
 291 }
 292
 293 /* See target/target.h.  */
 294
 295 void
 296 target_terminal::inferior ()
 297 {
 298   /* Placeholder needed because of fork_inferior.  Not necessary on
 299      GDBserver.  */
 300 }
 301
 302 /* See target/target.h.  */
 303
 304 void
 305 target_terminal::ours ()
 306 {
 307   /* Placeholder needed because of fork_inferior.  Not necessary on
 308      GDBserver.  */
 309 }
 310
 311 /* See target/target.h.  */
 312
 313 void
 314 target_terminal::ours_for_output (void)
 315 {
 316   /* Placeholder.  */
 317 }
 318
 319 /* See target/target.h.  */
 320
 321 void
 322 target_terminal::info (const char *arg, int from_tty)
 323 {
 324   /* Placeholder.  */
 325 }
 326
 327 /* Default implementations of target ops.
 328    See target.h for definitions.  */
 329
 330 void
 331 process_stratum_target::post_create_inferior ()
 332 {
 333   /* Nop.  */
 334 }
 335
 336 void
 337 process_stratum_target::look_up_symbols ()
 338 {
 339   /* Nop.  */
 340 }
 341
 342 bool
 343 process_stratum_target::supports_read_auxv ()
 344 {
 345   return false;
 346 }
 347
 348 int
 349 process_stratum_target::read_auxv (int pid, CORE_ADDR offset,
 350                                    unsigned char *myaddr, unsigned int len)
 351 {
 352   gdb_assert_not_reached ("target op read_auxv not supported");
 353 }
 354
 355 bool
 356 process_stratum_target::supports_z_point_type (char z_type)
 357 {
 358   return false;
 359 }
 360
 361 int
 362 process_stratum_target::insert_point (enum raw_bkpt_type type,
 363                                       CORE_ADDR addr,
 364                                       int size, raw_breakpoint *bp)
 365 {
 366   return 1;
 367 }
 368
 369 int
 370 process_stratum_target::remove_point (enum raw_bkpt_type type,
 371                                       CORE_ADDR addr,
 372                                       int size, raw_breakpoint *bp)
 373 {
 374   return 1;
 375 }
 376
 377 bool
 378 process_stratum_target::stopped_by_sw_breakpoint ()
 379 {
 380   return false;
 381 }
 382
 383 bool
 384 process_stratum_target::supports_stopped_by_sw_breakpoint ()
 385 {
 386   return false;
 387 }
 388
 389 bool
 390 process_stratum_target::stopped_by_hw_breakpoint ()
 391 {
 392   return false;
 393 }
 394
 395 bool
 396 process_stratum_target::supports_stopped_by_hw_breakpoint ()
 397 {
 398   return false;
 399 }
 400
 401 bool
 402 process_stratum_target::supports_hardware_single_step ()
 403 {
 404   return false;
 405 }
 406
 407 bool
 408 process_stratum_target::stopped_by_watchpoint ()
 409 {
 410   return false;
 411 }
 412
 413 CORE_ADDR
 414 process_stratum_target::stopped_data_address ()
 415 {
 416   return 0;
 417 }
 418
 419 bool
 420 process_stratum_target::supports_read_offsets ()
 421 {
 422   return false;
 423 }
 424
 425 bool
 426 process_stratum_target::supports_memory_tagging ()
 427 {
 428   return false;
 429 }
 430
 431 bool
 432 process_stratum_target::fetch_memtags (CORE_ADDR address, size_t len,
 433                                        gdb::byte_vector &tags, int type)
 434 {
 435   gdb_assert_not_reached ("target op fetch_memtags not supported");
 436 }
 437
 438 bool
 439 process_stratum_target::store_memtags (CORE_ADDR address, size_t len,
 440                                        const gdb::byte_vector &tags, int type)
 441 {
 442   gdb_assert_not_reached ("target op store_memtags not supported");
 443 }
 444
 445 int
 446 process_stratum_target::read_offsets (CORE_ADDR *text, CORE_ADDR *data)
 447 {
 448   gdb_assert_not_reached ("target op read_offsets not supported");
 449 }
 450
 451 bool
 452 process_stratum_target::supports_get_tls_address ()
 453 {
 454   return false;
 455 }
 456
 457 int
 458 process_stratum_target::get_tls_address (thread_info *thread,
 459                                          CORE_ADDR offset,
 460                                          CORE_ADDR load_module,
 461                                          CORE_ADDR *address)
 462 {
 463   gdb_assert_not_reached ("target op get_tls_address not supported");
 464 }
 465
 466 bool
 467 process_stratum_target::supports_qxfer_osdata ()
 468 {
 469   return false;
 470 }
 471
 472 int
 473 process_stratum_target::qxfer_osdata (const char *annex,
 474                                       unsigned char *readbuf,
 475                                       unsigned const char *writebuf,
 476                                       CORE_ADDR offset, int len)
 477 {
 478   gdb_assert_not_reached ("target op qxfer_osdata not supported");
 479 }
 480
 481 bool
 482 process_stratum_target::supports_qxfer_siginfo ()
 483 {
 484   return false;
 485 }
 486
 487 int
 488 process_stratum_target::qxfer_siginfo (const char *annex,
 489                                        unsigned char *readbuf,
 490                                        unsigned const char *writebuf,
 491                                        CORE_ADDR offset, int len)
 492 {
 493   gdb_assert_not_reached ("target op qxfer_siginfo not supported");
 494 }
 495
 496 bool
 497 process_stratum_target::supports_non_stop ()
 498 {
 499   return false;
 500 }
 501
 502 bool
 503 process_stratum_target::async (bool enable)
 504 {
 505   return false;
 506 }
 507
 508 int
 509 process_stratum_target::start_non_stop (bool enable)
 510 {
 511   if (enable)
 512     return -1;
 513   else
 514     return 0;
 515 }
 516
 517 bool
 518 process_stratum_target::supports_multi_process ()
 519 {
 520   return false;
 521 }
 522
 523 bool
 524 process_stratum_target::supports_fork_events ()
 525 {
 526   return false;
 527 }
 528
 529 bool
 530 process_stratum_target::supports_vfork_events ()
 531 {
 532   return false;
 533 }
 534
 535 gdb_thread_options
 536 process_stratum_target::supported_thread_options ()
 537 {
 538   return 0;
 539 }
 540
 541 bool
 542 process_stratum_target::supports_exec_events ()
 543 {
 544   return false;
 545 }
 546
 547 void
 548 process_stratum_target::handle_new_gdb_connection ()
 549 {
 550   /* Nop.  */
 551 }
 552
 553 int
 554 process_stratum_target::handle_monitor_command (char *mon)
 555 {
 556   return 0;
 557 }
 558
 559 int
 560 process_stratum_target::core_of_thread (ptid_t ptid)
 561 {
 562   return -1;
 563 }
 564
 565 bool
 566 process_stratum_target::supports_read_loadmap ()
 567 {
 568   return false;
 569 }
 570
 571 int
 572 process_stratum_target::read_loadmap (const char *annex,
 573                                       CORE_ADDR offset,
 574                                       unsigned char *myaddr,
 575                                       unsigned int len)
 576 {
 577   gdb_assert_not_reached ("target op read_loadmap not supported");
 578 }
 579
 580 void
 581 process_stratum_target::process_qsupported
 582   (gdb::array_view<const char * const> features)
 583 {
 584   /* Nop.  */
 585 }
 586
 587 bool
 588 process_stratum_target::supports_tracepoints ()
 589 {
 590   return false;
 591 }
 592
 593 CORE_ADDR
 594 process_stratum_target::read_pc (regcache *regcache)
 595 {
 596   gdb_assert_not_reached ("process_target::read_pc: Unable to find PC");
 597 }
 598
 599 void
 600 process_stratum_target::write_pc (regcache *regcache, CORE_ADDR pc)
 601 {
 602   gdb_assert_not_reached ("process_target::write_pc: Unable to update PC");
 603 }
 604
 605 bool
 606 process_stratum_target::supports_thread_stopped ()
 607 {
 608   return false;
 609 }
 610
 611 bool
 612 process_stratum_target::thread_stopped (thread_info *thread)
 613 {
 614   gdb_assert_not_reached ("target op thread_stopped not supported");
 615 }
 616
 617 bool
 618 process_stratum_target::any_resumed ()
 619 {
 620   return true;
 621 }
 622
 623 bool
 624 process_stratum_target::supports_get_tib_address ()
 625 {
 626   return false;
 627 }
 628
 629 int
 630 process_stratum_target::get_tib_address (ptid_t ptid, CORE_ADDR *address)
 631 {
 632   gdb_assert_not_reached ("target op get_tib_address not supported");
 633 }
 634
 635 void
 636 process_stratum_target::pause_all (bool freeze)
 637 {
 638   /* Nop.  */
 639 }
 640
 641 void
 642 process_stratum_target::unpause_all (bool unfreeze)
 643 {
 644   /* Nop.  */
 645 }
 646
 647 void
 648 process_stratum_target::stabilize_threads ()
 649 {
 650   /* Nop.  */
 651 }
 652
 653 bool
 654 process_stratum_target::supports_fast_tracepoints ()
 655 {
 656   return false;
 657 }
 658
 659 int
 660 process_stratum_target::install_fast_tracepoint_jump_pad
 661   (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
 662    CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
 663    CORE_ADDR *trampoline, ULONGEST *trampoline_size,
 664    unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
 665    CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
 666    char *err)
 667 {
 668   gdb_assert_not_reached ("target op install_fast_tracepoint_jump_pad "
 669                           "not supported");
 670 }
 671
 672 int
 673 process_stratum_target::get_min_fast_tracepoint_insn_len ()
 674 {
 675   return 0;
 676 }
 677
 678 struct emit_ops *
 679 process_stratum_target::emit_ops ()
 680 {
 681   return nullptr;
 682 }
 683
 684 bool
 685 process_stratum_target::supports_disable_randomization ()
 686 {
 687   return false;
 688 }
 689
 690 bool
 691 process_stratum_target::supports_qxfer_libraries_svr4 ()
 692 {
 693   return false;
 694 }
 695
 696 int
 697 process_stratum_target::qxfer_libraries_svr4 (const char *annex,
 698                                               unsigned char *readbuf,
 699                                               unsigned const char *writebuf,
 700                                               CORE_ADDR offset, int len)
 701 {
 702   gdb_assert_not_reached ("target op qxfer_libraries_svr4 not supported");
 703 }
 704
 705 bool
 706 process_stratum_target::supports_agent ()
 707 {
 708   return false;
 709 }
 710
 711 bool
 712 process_stratum_target::supports_btrace ()
 713 {
 714   return false;
 715 }
 716
 717 btrace_target_info *
 718 process_stratum_target::enable_btrace (thread_info *tp,
 719                                        const btrace_config *conf)
 720 {
 721   error (_("Target does not support branch tracing."));
 722 }
 723
 724 int
 725 process_stratum_target::disable_btrace (btrace_target_info *tinfo)
 726 {
 727   error (_("Target does not support branch tracing."));
 728 }
 729
 730 int
 731 process_stratum_target::read_btrace (btrace_target_info *tinfo,
 732                                      std::string *buffer,
 733                                      enum btrace_read_type type)
 734 {
 735   error (_("Target does not support branch tracing."));
 736 }
 737
 738 int
 739 process_stratum_target::read_btrace_conf (const btrace_target_info *tinfo,
 740                                           std::string *buffer)
 741 {
 742   error (_("Target does not support branch tracing."));
 743 }
 744
 745 bool
 746 process_stratum_target::supports_range_stepping ()
 747 {
 748   return false;
 749 }
 750
 751 bool
 752 process_stratum_target::supports_pid_to_exec_file ()
 753 {
 754   return false;
 755 }
 756
 757 const char *
 758 process_stratum_target::pid_to_exec_file (int pid)
 759 {
 760   gdb_assert_not_reached ("target op pid_to_exec_file not supported");
 761 }
 762
 763 bool
 764 process_stratum_target::supports_multifs ()
 765 {
 766   return false;
 767 }
 768
 769 int
 770 process_stratum_target::multifs_open (int pid, const char *filename,
 771                                       int flags, mode_t mode)
 772 {
 773   return open (filename, flags, mode);
 774 }
 775
 776 int
 777 process_stratum_target::multifs_unlink (int pid, const char *filename)
 778 {
 779   return unlink (filename);
 780 }
 781
 782 ssize_t
 783 process_stratum_target::multifs_readlink (int pid, const char *filename,
 784                                           char *buf, size_t bufsiz)
 785 {
 786   return readlink (filename, buf, bufsiz);
 787 }
 788
 789 int
 790 process_stratum_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
 791 {
 792   /* The default behavior is to use the size of a breakpoint as the
 793      kind.  */
 794   int size = 0;
 795   sw_breakpoint_from_kind (0, &size);
 796   return size;
 797 }
 798
 799 int
 800 process_stratum_target::breakpoint_kind_from_current_state (CORE_ADDR *pcptr)
 801 {
 802   return breakpoint_kind_from_pc (pcptr);
 803 }
 804
 805 const char *
 806 process_stratum_target::thread_name (ptid_t thread)
 807 {
 808   return nullptr;
 809 }
 810
 811 bool
 812 process_stratum_target::thread_handle (ptid_t ptid, gdb_byte **handle,
 813                                        int *handle_len)
 814 {
 815   return false;
 816 }
 817
 818 thread_info *
 819 process_stratum_target::thread_pending_parent (thread_info *thread)
 820 {
 821   return nullptr;
 822 }
 823
 824 thread_info *
 825 process_stratum_target::thread_pending_child (thread_info *thread,
 826                                               target_waitkind *kind)
 827 {
 828   return nullptr;
 829 }
 830
 831 bool
 832 process_stratum_target::supports_software_single_step ()
 833 {
 834   return false;
 835 }
 836
 837 bool
 838 process_stratum_target::supports_catch_syscall ()
 839 {
 840   return false;
 841 }
 842
 843 int
 844 process_stratum_target::get_ipa_tdesc_idx ()
 845 {
 846   return 0;
 847 }