gdbserver/linux-low.h

   1 /* Internal interfaces for the GNU/Linux specific target code for gdbserver.
   2    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef GDBSERVER_LINUX_LOW_H
  20 #define GDBSERVER_LINUX_LOW_H
  21
  22 #include "nat/linux-nat.h"
  23 #include "nat/gdb_thread_db.h"
  24 #include <signal.h>
  25
  26 #include "gdbthread.h"
  27 #include "gdb_proc_service.h"
  28
  29 /* Included for ptrace type definitions.  */
  30 #include "nat/linux-ptrace.h"
  31 #include "target/waitstatus.h" /* For enum target_stop_reason.  */
  32 #include "tracepoint.h"
  33
  34 #define PTRACE_XFER_TYPE long
  35
  36 #ifdef HAVE_LINUX_REGSETS
  37 typedef void (*regset_fill_func) (struct regcache *, void *);
  38 typedef void (*regset_store_func) (struct regcache *, const void *);
  39 enum regset_type {
  40   GENERAL_REGS,
  41   FP_REGS,
  42   EXTENDED_REGS,
  43   OPTIONAL_REGS, /* Do not error if the regset cannot be accessed.  */
  44 };
  45
  46 /* The arch's regsets array initializer must be terminated with a NULL
  47    regset.  */
  48 #define NULL_REGSET \
  49   { 0, 0, 0, -1, (enum regset_type) -1, NULL, NULL }
  50
  51 struct regset_info
  52 {
  53   int get_request, set_request;
  54   /* If NT_TYPE isn't 0, it will be passed to ptrace as the 3rd
  55      argument and the 4th argument should be "const struct iovec *".  */
  56   int nt_type;
  57   int size;
  58   enum regset_type type;
  59   regset_fill_func fill_function;
  60   regset_store_func store_function;
  61 };
  62
  63 /* Aggregation of all the supported regsets of a given
  64    architecture/mode.  */
  65
  66 struct regsets_info
  67 {
  68   /* The regsets array.  */
  69   struct regset_info *regsets;
  70
  71   /* The number of regsets in the REGSETS array.  */
  72   int num_regsets;
  73
  74   /* If we get EIO on a regset, do not try it again.  Note the set of
  75      supported regsets may depend on processor mode on biarch
  76      machines.  This is a (lazily allocated) array holding one boolean
  77      byte (0/1) per regset, with each element corresponding to the
  78      regset in the REGSETS array above at the same offset.  */
  79   char *disabled_regsets;
  80 };
  81
  82 #endif
  83
  84 /* Mapping between the general-purpose registers in `struct user'
  85    format and GDB's register array layout.  */
  86
  87 struct usrregs_info
  88 {
  89   /* The number of registers accessible.  */
  90   int num_regs;
  91
  92   /* The registers map.  */
  93   int *regmap;
  94 };
  95
  96 /* All info needed to access an architecture/mode's registers.  */
  97
  98 struct regs_info
  99 {
 100   /* Regset support bitmap: 1 for registers that are transferred as a part
 101      of a regset, 0 for ones that need to be handled individually.  This
 102      can be NULL if all registers are transferred with regsets or regsets
 103      are not supported.  */
 104   unsigned char *regset_bitmap;
 105
 106   /* Info used when accessing registers with PTRACE_PEEKUSER /
 107      PTRACE_POKEUSER.  This can be NULL if all registers are
 108      transferred with regsets  .*/
 109   struct usrregs_info *usrregs;
 110
 111 #ifdef HAVE_LINUX_REGSETS
 112   /* Info used when accessing registers with regsets.  */
 113   struct regsets_info *regsets_info;
 114 #endif
 115 };
 116
 117 struct process_info_private
 118 {
 119   /* Arch-specific additions.  */
 120   struct arch_process_info *arch_private;
 121
 122   /* libthread_db-specific additions.  Not NULL if this process has loaded
 123      thread_db, and it is active.  */
 124   struct thread_db *thread_db;
 125
 126   /* &_r_debug.  0 if not yet determined.  -1 if no PT_DYNAMIC in Phdrs.  */
 127   CORE_ADDR r_debug;
 128 };
 129
 130 struct lwp_info;
 131
 132 struct linux_target_ops
 133 {
 134   /* Architecture-specific setup.  */
 135   void (*arch_setup) (void);
 136
 137   const struct regs_info *(*regs_info) (void);
 138
 139   /* Return 0 if we can fetch/store the register, 1 if we cannot
 140      fetch/store the register.  */
 141   int (*cannot_fetch_register) (int);
 142   int (*cannot_store_register) (int);
 143
 144   /* Hook to fetch a register in some non-standard way.  Used for
 145      example by backends that have read-only registers with hardcoded
 146      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 147      REGNO was supplied, false if not, and we should fallback to the
 148      standard ptrace methods.  */
 149   int (*fetch_register) (struct regcache *regcache, int regno);
 150
 151   CORE_ADDR (*get_pc) (struct regcache *regcache);
 152   void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
 153
 154   /* See target.h for details.  */
 155   int (*breakpoint_kind_from_pc) (CORE_ADDR *pcptr);
 156
 157   /* See target.h for details.  */
 158   const gdb_byte *(*sw_breakpoint_from_kind) (int kind, int *size);
 159
 160   /* Find the next possible PCs after the current instruction executes.  */
 161   std::vector<CORE_ADDR> (*get_next_pcs) (struct regcache *regcache);
 162
 163   int decr_pc_after_break;
 164   int (*breakpoint_at) (CORE_ADDR pc);
 165
 166   /* Breakpoint and watchpoint related functions.  See target.h for
 167      comments.  */
 168   int (*supports_z_point_type) (char z_type);
 169   int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 170                        int size, struct raw_breakpoint *bp);
 171   int (*remove_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 172                        int size, struct raw_breakpoint *bp);
 173
 174   int (*stopped_by_watchpoint) (void);
 175   CORE_ADDR (*stopped_data_address) (void);
 176
 177   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 178      for registers smaller than an xfer unit).  */
 179   void (*collect_ptrace_register) (struct regcache *regcache,
 180                                    int regno, char *buf);
 181   void (*supply_ptrace_register) (struct regcache *regcache,
 182                                   int regno, const char *buf);
 183
 184   /* Hook to convert from target format to ptrace format and back.
 185      Returns true if any conversion was done; false otherwise.
 186      If DIRECTION is 1, then copy from INF to NATIVE.
 187      If DIRECTION is 0, copy from NATIVE to INF.  */
 188   int (*siginfo_fixup) (siginfo_t *native, gdb_byte *inf, int direction);
 189
 190   /* Hook to call when a new process is created or attached to.
 191      If extra per-process architecture-specific data is needed,
 192      allocate it here.  */
 193   struct arch_process_info * (*new_process) (void);
 194
 195   /* Hook to call when a process is being deleted.  If extra per-process
 196      architecture-specific data is needed, delete it here.  */
 197   void (*delete_process) (struct arch_process_info *info);
 198
 199   /* Hook to call when a new thread is detected.
 200      If extra per-thread architecture-specific data is needed,
 201      allocate it here.  */
 202   void (*new_thread) (struct lwp_info *);
 203
 204   /* Hook to call when a thread is being deleted.  If extra per-thread
 205      architecture-specific data is needed, delete it here.  */
 206   void (*delete_thread) (struct arch_lwp_info *);
 207
 208   /* Hook to call, if any, when a new fork is attached.  */
 209   void (*new_fork) (struct process_info *parent, struct process_info *child);
 210
 211   /* Hook to call prior to resuming a thread.  */
 212   void (*prepare_to_resume) (struct lwp_info *);
 213
 214   /* Hook to support target specific qSupported.  */
 215   void (*process_qsupported) (char **, int count);
 216
 217   /* Returns true if the low target supports tracepoints.  */
 218   int (*supports_tracepoints) (void);
 219
 220   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 221      success, -1 on failure.  */
 222   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 223
 224   /* Install a fast tracepoint jump pad.  See target.h for
 225      comments.  */
 226   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 227                                            CORE_ADDR collector,
 228                                            CORE_ADDR lockaddr,
 229                                            ULONGEST orig_size,
 230                                            CORE_ADDR *jump_entry,
 231                                            CORE_ADDR *trampoline,
 232                                            ULONGEST *trampoline_size,
 233                                            unsigned char *jjump_pad_insn,
 234                                            ULONGEST *jjump_pad_insn_size,
 235                                            CORE_ADDR *adjusted_insn_addr,
 236                                            CORE_ADDR *adjusted_insn_addr_end,
 237                                            char *err);
 238
 239   /* Return the bytecode operations vector for the current inferior.
 240      Returns NULL if bytecode compilation is not supported.  */
 241   struct emit_ops *(*emit_ops) (void);
 242
 243   /* Return the minimum length of an instruction that can be safely overwritten
 244      for use as a fast tracepoint.  */
 245   int (*get_min_fast_tracepoint_insn_len) (void);
 246
 247   /* Returns true if the low target supports range stepping.  */
 248   int (*supports_range_stepping) (void);
 249
 250   /* See target.h.  */
 251   int (*breakpoint_kind_from_current_state) (CORE_ADDR *pcptr);
 252
 253   /* See target.h.  */
 254   int (*supports_hardware_single_step) (void);
 255
 256   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 257      inferior is stopped due to SYSCALL_SIGTRAP.  */
 258   void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno);
 259
 260   /* See target.h.  */
 261   int (*get_ipa_tdesc_idx) (void);
 262 };
 263
 264 extern struct linux_target_ops the_low_target;
 265
 266 /* Target ops definitions for a Linux target.  */
 267
 268 class linux_process_target : public process_stratum_target
 269 {
 270 public:
 271
 272   int create_inferior (const char *program,
 273                        const std::vector<char *> &program_args) override;
 274
 275   void post_create_inferior () override;
 276
 277   int attach (unsigned long pid) override;
 278
 279   int kill (process_info *proc) override;
 280
 281   int detach (process_info *proc) override;
 282
 283   void mourn (process_info *proc) override;
 284
 285   void join (int pid) override;
 286
 287   bool thread_alive (ptid_t pid) override;
 288
 289   void resume (thread_resume *resume_info, size_t n) override;
 290
 291   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 292                int options) override;
 293
 294   void fetch_registers (regcache *regcache, int regno) override;
 295
 296   void store_registers (regcache *regcache, int regno) override;
 297
 298   int prepare_to_access_memory () override;
 299
 300   void done_accessing_memory () override;
 301
 302   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 303                    int len) override;
 304
 305   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 306                     int len) override;
 307
 308   void look_up_symbols () override;
 309
 310   void request_interrupt () override;
 311
 312   bool supports_read_auxv () override;
 313
 314   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 315                  unsigned int len) override;
 316
 317   bool supports_z_point_type (char z_type) override;
 318
 319   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 320                     int size, raw_breakpoint *bp) override;
 321
 322   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 323                     int size, raw_breakpoint *bp) override;
 324
 325   bool stopped_by_sw_breakpoint () override;
 326
 327   bool supports_stopped_by_sw_breakpoint () override;
 328
 329   bool stopped_by_hw_breakpoint () override;
 330
 331   bool supports_stopped_by_hw_breakpoint () override;
 332
 333   bool supports_hardware_single_step () override;
 334
 335   bool stopped_by_watchpoint () override;
 336
 337   CORE_ADDR stopped_data_address () override;
 338
 339   bool supports_read_offsets () override;
 340
 341   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 342
 343   bool supports_get_tls_address () override;
 344
 345   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 346                        CORE_ADDR load_module, CORE_ADDR *address) override;
 347
 348   bool supports_qxfer_osdata () override;
 349
 350   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 351                     unsigned const char *writebuf,
 352                     CORE_ADDR offset, int len) override;
 353
 354   bool supports_qxfer_siginfo () override;
 355
 356   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 357                      unsigned const char *writebuf,
 358                      CORE_ADDR offset, int len) override;
 359
 360   bool supports_non_stop () override;
 361
 362   bool async (bool enable) override;
 363
 364   int start_non_stop (bool enable) override;
 365
 366   bool supports_multi_process () override;
 367
 368   bool supports_fork_events () override;
 369
 370   bool supports_vfork_events () override;
 371
 372   bool supports_exec_events () override;
 373
 374   void handle_new_gdb_connection () override;
 375
 376   int handle_monitor_command (char *mon) override;
 377
 378   int core_of_thread (ptid_t ptid) override;
 379
 380 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 381   bool supports_read_loadmap () override;
 382
 383   int read_loadmap (const char *annex, CORE_ADDR offset,
 384                     unsigned char *myaddr, unsigned int len) override;
 385 #endif
 386
 387   void process_qsupported (char **features, int count) override;
 388
 389   bool supports_tracepoints () override;
 390
 391   CORE_ADDR read_pc (regcache *regcache) override;
 392
 393   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 394
 395   bool supports_thread_stopped () override;
 396
 397   bool thread_stopped (thread_info *thread) override;
 398
 399   void pause_all (bool freeze) override;
 400
 401   void unpause_all (bool unfreeze) override;
 402
 403   void stabilize_threads () override;
 404
 405   bool supports_fast_tracepoints () override;
 406
 407   int install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
 408                                         CORE_ADDR tpaddr,
 409                                         CORE_ADDR collector,
 410                                         CORE_ADDR lockaddr,
 411                                         ULONGEST orig_size,
 412                                         CORE_ADDR *jump_entry,
 413                                         CORE_ADDR *trampoline,
 414                                         ULONGEST *trampoline_size,
 415                                         unsigned char *jjump_pad_insn,
 416                                         ULONGEST *jjump_pad_insn_size,
 417                                         CORE_ADDR *adjusted_insn_addr,
 418                                         CORE_ADDR *adjusted_insn_addr_end,
 419                                         char *err) override;
 420
 421   int get_min_fast_tracepoint_insn_len () override;
 422
 423   struct emit_ops *emit_ops () override;
 424
 425   bool supports_disable_randomization () override;
 426
 427   bool supports_qxfer_libraries_svr4 () override;
 428
 429   int qxfer_libraries_svr4 (const char *annex,
 430                             unsigned char *readbuf,
 431                             unsigned const char *writebuf,
 432                             CORE_ADDR offset, int len) override;
 433
 434   bool supports_agent () override;
 435
 436 #ifdef HAVE_LINUX_BTRACE
 437   btrace_target_info *enable_btrace (ptid_t ptid,
 438                                      const btrace_config *conf) override;
 439
 440   int disable_btrace (btrace_target_info *tinfo) override;
 441
 442   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 443                    enum btrace_read_type type) override;
 444
 445   int read_btrace_conf (const btrace_target_info *tinfo,
 446                         buffer *buf) override;
 447 #endif
 448
 449   bool supports_range_stepping () override;
 450
 451   bool supports_pid_to_exec_file () override;
 452
 453   char *pid_to_exec_file (int pid) override;
 454
 455   bool supports_multifs () override;
 456
 457   int multifs_open (int pid, const char *filename, int flags,
 458                     mode_t mode) override;
 459
 460   int multifs_unlink (int pid, const char *filename) override;
 461
 462   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 463                             size_t bufsiz) override;
 464
 465   int breakpoint_kind_from_pc (CORE_ADDR *pcptr) override;
 466
 467   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
 468
 469   int breakpoint_kind_from_current_state (CORE_ADDR *pcptr) override;
 470
 471   const char *thread_name (ptid_t thread) override;
 472
 473 #if USE_THREAD_DB
 474   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 475                       int *handle_len) override;
 476 #endif
 477
 478   bool supports_software_single_step () override;
 479
 480   bool supports_catch_syscall () override;
 481
 482   int get_ipa_tdesc_idx () override;
 483
 484 private:
 485
 486   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 487      fork, or vfork event, we need to add the new LWP to our list
 488      (and return 0 so as not to report the trap to higher layers).
 489      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 490      to a new LWP representing the new program.  */
 491   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 492
 493   /* Do low-level handling of the event, and check if we should go on
 494      and pass it to caller code.  Return the affected lwp if we are, or
 495      NULL otherwise.  */
 496   lwp_info *filter_event (int lwpid, int wstat);
 497
 498   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 499      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 500      minus_one_ptid, to specify any child; a pid PTID, specifying all
 501      lwps of a thread group; or a PTID representing a single lwp.  Store
 502      the stop status through the status pointer WSTAT.  OPTIONS is
 503      passed to the waitpid call.  Return 0 if no event was found and
 504      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 505      was found.  Return the PID of the stopped child otherwise.  */
 506   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 507                                int *wstatp, int options);
 508
 509   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 510      minus_one_ptid, to specify any child; a pid PTID, specifying all
 511      lwps of a thread group; or a PTID representing a single lwp.  Store
 512      the stop status through the status pointer WSTAT.  OPTIONS is
 513      passed to the waitpid call.  Return 0 if no event was found and
 514      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 515      was found.  Return the PID of the stopped child otherwise.  */
 516   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 517
 518   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 519   void wait_for_sigstop ();
 520
 521   /* Wait for process, returns status.  */
 522   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 523                  int target_options);
 524
 525   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 526      If SUSPEND, then also increase the suspend count of every LWP,
 527      except EXCEPT.  */
 528   void stop_all_lwps (int suspend, lwp_info *except);
 529
 530   /* Stopped LWPs that the client wanted to be running, that don't have
 531      pending statuses, are set to run again, except for EXCEPT, if not
 532      NULL.  This undoes a stop_all_lwps call.  */
 533   void unstop_all_lwps (int unsuspend, lwp_info *except);
 534
 535   /* Start a step-over operation on LWP.  When LWP stopped at a
 536      breakpoint, to make progress, we need to remove the breakpoint out
 537      of the way.  If we let other threads run while we do that, they may
 538      pass by the breakpoint location and miss hitting it.  To avoid
 539      that, a step-over momentarily stops all threads while LWP is
 540      single-stepped by either hardware or software while the breakpoint
 541      is temporarily uninserted from the inferior.  When the single-step
 542      finishes, we reinsert the breakpoint, and let all threads that are
 543      supposed to be running, run again.  */
 544   void start_step_over (lwp_info *lwp);
 545
 546   /* If there's a step over in progress, wait until all threads stop
 547      (that is, until the stepping thread finishes its step), and
 548      unsuspend all lwps.  The stepping thread ends with its status
 549      pending, which is processed later when we get back to processing
 550      events.  */
 551   void complete_ongoing_step_over ();
 552
 553   /* When we finish a step-over, set threads running again.  If there's
 554      another thread that may need a step-over, now's the time to start
 555      it.  Eventually, we'll move all threads past their breakpoints.  */
 556   void proceed_all_lwps ();
 557
 558   /* The reason we resume in the caller, is because we want to be able
 559      to pass lwp->status_pending as WSTAT, and we need to clear
 560      status_pending_p before resuming, otherwise, resume_one_lwp
 561      refuses to resume.  */
 562   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 563
 564   /* Move THREAD out of the jump pad.  */
 565   void move_out_of_jump_pad (thread_info *thread);
 566 };
 567
 568 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 569 #define get_lwp_thread(lwp) ((lwp)->thread)
 570
 571 /* This struct is recorded in the target_data field of struct thread_info.
 572
 573    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 574    GDB protocol representation of the thread ID.  Threads also have
 575    a "process ID" (poorly named) which is (presently) the same as the
 576    LWP ID.
 577
 578    There is also ``all_processes'' is keyed by the "overall process ID",
 579    which GNU/Linux calls tgid, "thread group ID".  */
 580
 581 struct lwp_info
 582 {
 583   /* Backlink to the parent object.  */
 584   struct thread_info *thread;
 585
 586   /* If this flag is set, the next SIGSTOP will be ignored (the
 587      process will be immediately resumed).  This means that either we
 588      sent the SIGSTOP to it ourselves and got some other pending event
 589      (so the SIGSTOP is still pending), or that we stopped the
 590      inferior implicitly via PTRACE_ATTACH and have not waited for it
 591      yet.  */
 592   int stop_expected;
 593
 594   /* When this is true, we shall not try to resume this thread, even
 595      if last_resume_kind isn't resume_stop.  */
 596   int suspended;
 597
 598   /* If this flag is set, the lwp is known to be stopped right now (stop
 599      event already received in a wait()).  */
 600   int stopped;
 601
 602   /* Signal whether we are in a SYSCALL_ENTRY or
 603      in a SYSCALL_RETURN event.
 604      Values:
 605      - TARGET_WAITKIND_SYSCALL_ENTRY
 606      - TARGET_WAITKIND_SYSCALL_RETURN */
 607   enum target_waitkind syscall_state;
 608
 609   /* When stopped is set, the last wait status recorded for this lwp.  */
 610   int last_status;
 611
 612   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 613      this LWP's last event, to pass to GDB without any further
 614      processing.  This is used to store extended ptrace event
 615      information or exit status until it can be reported to GDB.  */
 616   struct target_waitstatus waitstatus;
 617
 618   /* A pointer to the fork child/parent relative.  Valid only while
 619      the parent fork event is not reported to higher layers.  Used to
 620      avoid wildcard vCont actions resuming a fork child before GDB is
 621      notified about the parent's fork event.  */
 622   struct lwp_info *fork_relative;
 623
 624   /* When stopped is set, this is where the lwp last stopped, with
 625      decr_pc_after_break already accounted for.  If the LWP is
 626      running, this is the address at which the lwp was resumed.  */
 627   CORE_ADDR stop_pc;
 628
 629   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 630      been reported.  */
 631   int status_pending_p;
 632   int status_pending;
 633
 634   /* The reason the LWP last stopped, if we need to track it
 635      (breakpoint, watchpoint, etc.)  */
 636   enum target_stop_reason stop_reason;
 637
 638   /* On architectures where it is possible to know the data address of
 639      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 640      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 641      is true.  */
 642   CORE_ADDR stopped_data_address;
 643
 644   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 645      stop (SIGTRAP stops only).  */
 646   CORE_ADDR bp_reinsert;
 647
 648   /* If this flag is set, the last continue operation at the ptrace
 649      level on this process was a single-step.  */
 650   int stepping;
 651
 652   /* Range to single step within.  This is a copy of the step range
 653      passed along the last resume request.  See 'struct
 654      thread_resume'.  */
 655   CORE_ADDR step_range_start;   /* Inclusive */
 656   CORE_ADDR step_range_end;     /* Exclusive */
 657
 658   /* If this flag is set, we need to set the event request flags the
 659      next time we see this LWP stop.  */
 660   int must_set_ptrace_flags;
 661
 662   /* If this is non-zero, it points to a chain of signals which need to
 663      be delivered to this process.  */
 664   struct pending_signals *pending_signals;
 665
 666   /* A link used when resuming.  It is initialized from the resume request,
 667      and then processed and cleared in linux_resume_one_lwp.  */
 668   struct thread_resume *resume;
 669
 670   /* Information bout this lwp's fast tracepoint collection status (is it
 671      currently stopped in the jump pad, and if so, before or at/after the
 672      relocated instruction).  Normally, we won't care about this, but we will
 673      if a signal arrives to this lwp while it is collecting.  */
 674   fast_tpoint_collect_result collecting_fast_tracepoint;
 675
 676   /* If this is non-zero, it points to a chain of signals which need
 677      to be reported to GDB.  These were deferred because the thread
 678      was doing a fast tracepoint collect when they arrived.  */
 679   struct pending_signals *pending_signals_to_report;
 680
 681   /* When collecting_fast_tracepoint is first found to be 1, we insert
 682      a exit-jump-pad-quickly breakpoint.  This is it.  */
 683   struct breakpoint *exit_jump_pad_bkpt;
 684
 685 #ifdef USE_THREAD_DB
 686   int thread_known;
 687   /* The thread handle, used for e.g. TLS access.  Only valid if
 688      THREAD_KNOWN is set.  */
 689   td_thrhandle_t th;
 690
 691   /* The pthread_t handle.  */
 692   thread_t thread_handle;
 693 #endif
 694
 695   /* Arch-specific additions.  */
 696   struct arch_lwp_info *arch_private;
 697 };
 698
 699 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 700
 701 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 702    errno).  */
 703 int linux_attach_lwp (ptid_t ptid);
 704
 705 struct lwp_info *find_lwp_pid (ptid_t ptid);
 706 /* For linux_stop_lwp see nat/linux-nat.h.  */
 707
 708 #ifdef HAVE_LINUX_REGSETS
 709 void initialize_regsets_info (struct regsets_info *regsets_info);
 710 #endif
 711
 712 void initialize_low_arch (void);
 713
 714 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 715 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 716
 717 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 718 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 719
 720 /* From thread-db.c  */
 721 int thread_db_init (void);
 722 void thread_db_detach (struct process_info *);
 723 void thread_db_mourn (struct process_info *);
 724 int thread_db_handle_monitor_command (char *);
 725 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 726                                CORE_ADDR load_module, CORE_ADDR *address);
 727 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 728
 729 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 730    both the clone and the parent should be stopped.  This function does
 731    whatever is required have the clone under thread_db's control.  */
 732
 733 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 734
 735 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 736
 737 extern int have_ptrace_getregset;
 738
 739 /* Search for the value with type MATCH in the auxv vector with
 740    entries of length WORDSIZE bytes.  If found, store the value in
 741    *VALP and return 1.  If not found or if there is an error, return
 742    0.  */
 743
 744 int linux_get_auxv (int wordsize, CORE_ADDR match,
 745                     CORE_ADDR *valp);
 746
 747 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 748    WORDSIZE.  If no entry was found, return zero.  */
 749
 750 CORE_ADDR linux_get_hwcap (int wordsize);
 751
 752 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 753    WORDSIZE.  If no entry was found, return zero.  */
 754
 755 CORE_ADDR linux_get_hwcap2 (int wordsize);
 756
 757 #endif /* GDBSERVER_LINUX_LOW_H */