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   /* Return 0 if we can fetch/store the register, 1 if we cannot
 135      fetch/store the register.  */
 136   int (*cannot_fetch_register) (int);
 137   int (*cannot_store_register) (int);
 138
 139   /* Hook to fetch a register in some non-standard way.  Used for
 140      example by backends that have read-only registers with hardcoded
 141      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 142      REGNO was supplied, false if not, and we should fallback to the
 143      standard ptrace methods.  */
 144   int (*fetch_register) (struct regcache *regcache, int regno);
 145
 146   CORE_ADDR (*get_pc) (struct regcache *regcache);
 147   void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
 148
 149   /* See target.h for details.  */
 150   int (*breakpoint_kind_from_pc) (CORE_ADDR *pcptr);
 151
 152   /* See target.h for details.  */
 153   const gdb_byte *(*sw_breakpoint_from_kind) (int kind, int *size);
 154
 155   /* Find the next possible PCs after the current instruction executes.  */
 156   std::vector<CORE_ADDR> (*get_next_pcs) (struct regcache *regcache);
 157
 158   int decr_pc_after_break;
 159   int (*breakpoint_at) (CORE_ADDR pc);
 160
 161   /* Breakpoint and watchpoint related functions.  See target.h for
 162      comments.  */
 163   int (*supports_z_point_type) (char z_type);
 164   int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 165                        int size, struct raw_breakpoint *bp);
 166   int (*remove_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 167                        int size, struct raw_breakpoint *bp);
 168
 169   int (*stopped_by_watchpoint) (void);
 170   CORE_ADDR (*stopped_data_address) (void);
 171
 172   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 173      for registers smaller than an xfer unit).  */
 174   void (*collect_ptrace_register) (struct regcache *regcache,
 175                                    int regno, char *buf);
 176   void (*supply_ptrace_register) (struct regcache *regcache,
 177                                   int regno, const char *buf);
 178
 179   /* Hook to convert from target format to ptrace format and back.
 180      Returns true if any conversion was done; false otherwise.
 181      If DIRECTION is 1, then copy from INF to NATIVE.
 182      If DIRECTION is 0, copy from NATIVE to INF.  */
 183   int (*siginfo_fixup) (siginfo_t *native, gdb_byte *inf, int direction);
 184
 185   /* Hook to call when a new process is created or attached to.
 186      If extra per-process architecture-specific data is needed,
 187      allocate it here.  */
 188   struct arch_process_info * (*new_process) (void);
 189
 190   /* Hook to call when a process is being deleted.  If extra per-process
 191      architecture-specific data is needed, delete it here.  */
 192   void (*delete_process) (struct arch_process_info *info);
 193
 194   /* Hook to call when a new thread is detected.
 195      If extra per-thread architecture-specific data is needed,
 196      allocate it here.  */
 197   void (*new_thread) (struct lwp_info *);
 198
 199   /* Hook to call when a thread is being deleted.  If extra per-thread
 200      architecture-specific data is needed, delete it here.  */
 201   void (*delete_thread) (struct arch_lwp_info *);
 202
 203   /* Hook to call, if any, when a new fork is attached.  */
 204   void (*new_fork) (struct process_info *parent, struct process_info *child);
 205
 206   /* Hook to call prior to resuming a thread.  */
 207   void (*prepare_to_resume) (struct lwp_info *);
 208
 209   /* Hook to support target specific qSupported.  */
 210   void (*process_qsupported) (char **, int count);
 211
 212   /* Returns true if the low target supports tracepoints.  */
 213   int (*supports_tracepoints) (void);
 214
 215   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 216      success, -1 on failure.  */
 217   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 218
 219   /* Install a fast tracepoint jump pad.  See target.h for
 220      comments.  */
 221   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 222                                            CORE_ADDR collector,
 223                                            CORE_ADDR lockaddr,
 224                                            ULONGEST orig_size,
 225                                            CORE_ADDR *jump_entry,
 226                                            CORE_ADDR *trampoline,
 227                                            ULONGEST *trampoline_size,
 228                                            unsigned char *jjump_pad_insn,
 229                                            ULONGEST *jjump_pad_insn_size,
 230                                            CORE_ADDR *adjusted_insn_addr,
 231                                            CORE_ADDR *adjusted_insn_addr_end,
 232                                            char *err);
 233
 234   /* Return the bytecode operations vector for the current inferior.
 235      Returns NULL if bytecode compilation is not supported.  */
 236   struct emit_ops *(*emit_ops) (void);
 237
 238   /* Return the minimum length of an instruction that can be safely overwritten
 239      for use as a fast tracepoint.  */
 240   int (*get_min_fast_tracepoint_insn_len) (void);
 241
 242   /* Returns true if the low target supports range stepping.  */
 243   int (*supports_range_stepping) (void);
 244
 245   /* See target.h.  */
 246   int (*breakpoint_kind_from_current_state) (CORE_ADDR *pcptr);
 247
 248   /* See target.h.  */
 249   int (*supports_hardware_single_step) (void);
 250
 251   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 252      inferior is stopped due to SYSCALL_SIGTRAP.  */
 253   void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno);
 254
 255   /* See target.h.  */
 256   int (*get_ipa_tdesc_idx) (void);
 257 };
 258
 259 extern struct linux_target_ops the_low_target;
 260
 261 /* Target ops definitions for a Linux target.  */
 262
 263 class linux_process_target : public process_stratum_target
 264 {
 265 public:
 266
 267   int create_inferior (const char *program,
 268                        const std::vector<char *> &program_args) override;
 269
 270   void post_create_inferior () override;
 271
 272   int attach (unsigned long pid) override;
 273
 274   int kill (process_info *proc) override;
 275
 276   int detach (process_info *proc) override;
 277
 278   void mourn (process_info *proc) override;
 279
 280   void join (int pid) override;
 281
 282   bool thread_alive (ptid_t pid) override;
 283
 284   void resume (thread_resume *resume_info, size_t n) override;
 285
 286   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 287                int options) override;
 288
 289   void fetch_registers (regcache *regcache, int regno) override;
 290
 291   void store_registers (regcache *regcache, int regno) override;
 292
 293   int prepare_to_access_memory () override;
 294
 295   void done_accessing_memory () override;
 296
 297   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 298                    int len) override;
 299
 300   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 301                     int len) override;
 302
 303   void look_up_symbols () override;
 304
 305   void request_interrupt () override;
 306
 307   bool supports_read_auxv () override;
 308
 309   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 310                  unsigned int len) override;
 311
 312   bool supports_z_point_type (char z_type) override;
 313
 314   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 315                     int size, raw_breakpoint *bp) override;
 316
 317   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 318                     int size, raw_breakpoint *bp) override;
 319
 320   bool stopped_by_sw_breakpoint () override;
 321
 322   bool supports_stopped_by_sw_breakpoint () override;
 323
 324   bool stopped_by_hw_breakpoint () override;
 325
 326   bool supports_stopped_by_hw_breakpoint () override;
 327
 328   bool supports_hardware_single_step () override;
 329
 330   bool stopped_by_watchpoint () override;
 331
 332   CORE_ADDR stopped_data_address () override;
 333
 334   bool supports_read_offsets () override;
 335
 336   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 337
 338   bool supports_get_tls_address () override;
 339
 340   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 341                        CORE_ADDR load_module, CORE_ADDR *address) override;
 342
 343   bool supports_qxfer_osdata () override;
 344
 345   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 346                     unsigned const char *writebuf,
 347                     CORE_ADDR offset, int len) override;
 348
 349   bool supports_qxfer_siginfo () override;
 350
 351   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 352                      unsigned const char *writebuf,
 353                      CORE_ADDR offset, int len) override;
 354
 355   bool supports_non_stop () override;
 356
 357   bool async (bool enable) override;
 358
 359   int start_non_stop (bool enable) override;
 360
 361   bool supports_multi_process () override;
 362
 363   bool supports_fork_events () override;
 364
 365   bool supports_vfork_events () override;
 366
 367   bool supports_exec_events () override;
 368
 369   void handle_new_gdb_connection () override;
 370
 371   int handle_monitor_command (char *mon) override;
 372
 373   int core_of_thread (ptid_t ptid) override;
 374
 375 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 376   bool supports_read_loadmap () override;
 377
 378   int read_loadmap (const char *annex, CORE_ADDR offset,
 379                     unsigned char *myaddr, unsigned int len) override;
 380 #endif
 381
 382   void process_qsupported (char **features, int count) override;
 383
 384   bool supports_tracepoints () override;
 385
 386   CORE_ADDR read_pc (regcache *regcache) override;
 387
 388   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 389
 390   bool supports_thread_stopped () override;
 391
 392   bool thread_stopped (thread_info *thread) override;
 393
 394   void pause_all (bool freeze) override;
 395
 396   void unpause_all (bool unfreeze) override;
 397
 398   void stabilize_threads () override;
 399
 400   bool supports_fast_tracepoints () override;
 401
 402   int install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
 403                                         CORE_ADDR tpaddr,
 404                                         CORE_ADDR collector,
 405                                         CORE_ADDR lockaddr,
 406                                         ULONGEST orig_size,
 407                                         CORE_ADDR *jump_entry,
 408                                         CORE_ADDR *trampoline,
 409                                         ULONGEST *trampoline_size,
 410                                         unsigned char *jjump_pad_insn,
 411                                         ULONGEST *jjump_pad_insn_size,
 412                                         CORE_ADDR *adjusted_insn_addr,
 413                                         CORE_ADDR *adjusted_insn_addr_end,
 414                                         char *err) override;
 415
 416   int get_min_fast_tracepoint_insn_len () override;
 417
 418   struct emit_ops *emit_ops () override;
 419
 420   bool supports_disable_randomization () override;
 421
 422   bool supports_qxfer_libraries_svr4 () override;
 423
 424   int qxfer_libraries_svr4 (const char *annex,
 425                             unsigned char *readbuf,
 426                             unsigned const char *writebuf,
 427                             CORE_ADDR offset, int len) override;
 428
 429   bool supports_agent () override;
 430
 431 #ifdef HAVE_LINUX_BTRACE
 432   btrace_target_info *enable_btrace (ptid_t ptid,
 433                                      const btrace_config *conf) override;
 434
 435   int disable_btrace (btrace_target_info *tinfo) override;
 436
 437   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 438                    enum btrace_read_type type) override;
 439
 440   int read_btrace_conf (const btrace_target_info *tinfo,
 441                         buffer *buf) override;
 442 #endif
 443
 444   bool supports_range_stepping () override;
 445
 446   bool supports_pid_to_exec_file () override;
 447
 448   char *pid_to_exec_file (int pid) override;
 449
 450   bool supports_multifs () override;
 451
 452   int multifs_open (int pid, const char *filename, int flags,
 453                     mode_t mode) override;
 454
 455   int multifs_unlink (int pid, const char *filename) override;
 456
 457   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 458                             size_t bufsiz) override;
 459
 460   int breakpoint_kind_from_pc (CORE_ADDR *pcptr) override;
 461
 462   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
 463
 464   int breakpoint_kind_from_current_state (CORE_ADDR *pcptr) override;
 465
 466   const char *thread_name (ptid_t thread) override;
 467
 468 #if USE_THREAD_DB
 469   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 470                       int *handle_len) override;
 471 #endif
 472
 473   bool supports_software_single_step () override;
 474
 475   bool supports_catch_syscall () override;
 476
 477   int get_ipa_tdesc_idx () override;
 478
 479   /* Return the information to access registers.  This has public
 480      visibility because proc-service uses it.  */
 481   virtual const regs_info *get_regs_info () = 0;
 482
 483 private:
 484
 485   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 486      fork, or vfork event, we need to add the new LWP to our list
 487      (and return 0 so as not to report the trap to higher layers).
 488      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 489      to a new LWP representing the new program.  */
 490   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 491
 492   /* Do low-level handling of the event, and check if we should go on
 493      and pass it to caller code.  Return the affected lwp if we are, or
 494      NULL otherwise.  */
 495   lwp_info *filter_event (int lwpid, int wstat);
 496
 497   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 498      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 499      minus_one_ptid, to specify any child; a pid PTID, specifying all
 500      lwps of a thread group; or a PTID representing a single lwp.  Store
 501      the stop status through the status pointer WSTAT.  OPTIONS is
 502      passed to the waitpid call.  Return 0 if no event was found and
 503      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 504      was found.  Return the PID of the stopped child otherwise.  */
 505   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 506                                int *wstatp, int options);
 507
 508   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 509      minus_one_ptid, to specify any child; a pid PTID, specifying all
 510      lwps of a thread group; or a PTID representing a single lwp.  Store
 511      the stop status through the status pointer WSTAT.  OPTIONS is
 512      passed to the waitpid call.  Return 0 if no event was found and
 513      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 514      was found.  Return the PID of the stopped child otherwise.  */
 515   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 516
 517   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 518   void wait_for_sigstop ();
 519
 520   /* Wait for process, returns status.  */
 521   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 522                  int target_options);
 523
 524   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 525      If SUSPEND, then also increase the suspend count of every LWP,
 526      except EXCEPT.  */
 527   void stop_all_lwps (int suspend, lwp_info *except);
 528
 529   /* Stopped LWPs that the client wanted to be running, that don't have
 530      pending statuses, are set to run again, except for EXCEPT, if not
 531      NULL.  This undoes a stop_all_lwps call.  */
 532   void unstop_all_lwps (int unsuspend, lwp_info *except);
 533
 534   /* Start a step-over operation on LWP.  When LWP stopped at a
 535      breakpoint, to make progress, we need to remove the breakpoint out
 536      of the way.  If we let other threads run while we do that, they may
 537      pass by the breakpoint location and miss hitting it.  To avoid
 538      that, a step-over momentarily stops all threads while LWP is
 539      single-stepped by either hardware or software while the breakpoint
 540      is temporarily uninserted from the inferior.  When the single-step
 541      finishes, we reinsert the breakpoint, and let all threads that are
 542      supposed to be running, run again.  */
 543   void start_step_over (lwp_info *lwp);
 544
 545   /* If there's a step over in progress, wait until all threads stop
 546      (that is, until the stepping thread finishes its step), and
 547      unsuspend all lwps.  The stepping thread ends with its status
 548      pending, which is processed later when we get back to processing
 549      events.  */
 550   void complete_ongoing_step_over ();
 551
 552   /* When we finish a step-over, set threads running again.  If there's
 553      another thread that may need a step-over, now's the time to start
 554      it.  Eventually, we'll move all threads past their breakpoints.  */
 555   void proceed_all_lwps ();
 556
 557   /* The reason we resume in the caller, is because we want to be able
 558      to pass lwp->status_pending as WSTAT, and we need to clear
 559      status_pending_p before resuming, otherwise, resume_one_lwp
 560      refuses to resume.  */
 561   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 562
 563   /* Move THREAD out of the jump pad.  */
 564   void move_out_of_jump_pad (thread_info *thread);
 565
 566   /* Call low_arch_setup on THREAD.  */
 567   void arch_setup_thread (thread_info *thread);
 568
 569 protected:
 570   /* The architecture-specific "low" methods are listed below.  */
 571
 572   /* Architecture-specific setup for the current thread.  */
 573   virtual void low_arch_setup () = 0;
 574 };
 575
 576 extern linux_process_target *the_linux_target;
 577
 578 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 579 #define get_lwp_thread(lwp) ((lwp)->thread)
 580
 581 /* This struct is recorded in the target_data field of struct thread_info.
 582
 583    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 584    GDB protocol representation of the thread ID.  Threads also have
 585    a "process ID" (poorly named) which is (presently) the same as the
 586    LWP ID.
 587
 588    There is also ``all_processes'' is keyed by the "overall process ID",
 589    which GNU/Linux calls tgid, "thread group ID".  */
 590
 591 struct lwp_info
 592 {
 593   /* Backlink to the parent object.  */
 594   struct thread_info *thread;
 595
 596   /* If this flag is set, the next SIGSTOP will be ignored (the
 597      process will be immediately resumed).  This means that either we
 598      sent the SIGSTOP to it ourselves and got some other pending event
 599      (so the SIGSTOP is still pending), or that we stopped the
 600      inferior implicitly via PTRACE_ATTACH and have not waited for it
 601      yet.  */
 602   int stop_expected;
 603
 604   /* When this is true, we shall not try to resume this thread, even
 605      if last_resume_kind isn't resume_stop.  */
 606   int suspended;
 607
 608   /* If this flag is set, the lwp is known to be stopped right now (stop
 609      event already received in a wait()).  */
 610   int stopped;
 611
 612   /* Signal whether we are in a SYSCALL_ENTRY or
 613      in a SYSCALL_RETURN event.
 614      Values:
 615      - TARGET_WAITKIND_SYSCALL_ENTRY
 616      - TARGET_WAITKIND_SYSCALL_RETURN */
 617   enum target_waitkind syscall_state;
 618
 619   /* When stopped is set, the last wait status recorded for this lwp.  */
 620   int last_status;
 621
 622   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 623      this LWP's last event, to pass to GDB without any further
 624      processing.  This is used to store extended ptrace event
 625      information or exit status until it can be reported to GDB.  */
 626   struct target_waitstatus waitstatus;
 627
 628   /* A pointer to the fork child/parent relative.  Valid only while
 629      the parent fork event is not reported to higher layers.  Used to
 630      avoid wildcard vCont actions resuming a fork child before GDB is
 631      notified about the parent's fork event.  */
 632   struct lwp_info *fork_relative;
 633
 634   /* When stopped is set, this is where the lwp last stopped, with
 635      decr_pc_after_break already accounted for.  If the LWP is
 636      running, this is the address at which the lwp was resumed.  */
 637   CORE_ADDR stop_pc;
 638
 639   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 640      been reported.  */
 641   int status_pending_p;
 642   int status_pending;
 643
 644   /* The reason the LWP last stopped, if we need to track it
 645      (breakpoint, watchpoint, etc.)  */
 646   enum target_stop_reason stop_reason;
 647
 648   /* On architectures where it is possible to know the data address of
 649      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 650      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 651      is true.  */
 652   CORE_ADDR stopped_data_address;
 653
 654   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 655      stop (SIGTRAP stops only).  */
 656   CORE_ADDR bp_reinsert;
 657
 658   /* If this flag is set, the last continue operation at the ptrace
 659      level on this process was a single-step.  */
 660   int stepping;
 661
 662   /* Range to single step within.  This is a copy of the step range
 663      passed along the last resume request.  See 'struct
 664      thread_resume'.  */
 665   CORE_ADDR step_range_start;   /* Inclusive */
 666   CORE_ADDR step_range_end;     /* Exclusive */
 667
 668   /* If this flag is set, we need to set the event request flags the
 669      next time we see this LWP stop.  */
 670   int must_set_ptrace_flags;
 671
 672   /* If this is non-zero, it points to a chain of signals which need to
 673      be delivered to this process.  */
 674   struct pending_signals *pending_signals;
 675
 676   /* A link used when resuming.  It is initialized from the resume request,
 677      and then processed and cleared in linux_resume_one_lwp.  */
 678   struct thread_resume *resume;
 679
 680   /* Information bout this lwp's fast tracepoint collection status (is it
 681      currently stopped in the jump pad, and if so, before or at/after the
 682      relocated instruction).  Normally, we won't care about this, but we will
 683      if a signal arrives to this lwp while it is collecting.  */
 684   fast_tpoint_collect_result collecting_fast_tracepoint;
 685
 686   /* If this is non-zero, it points to a chain of signals which need
 687      to be reported to GDB.  These were deferred because the thread
 688      was doing a fast tracepoint collect when they arrived.  */
 689   struct pending_signals *pending_signals_to_report;
 690
 691   /* When collecting_fast_tracepoint is first found to be 1, we insert
 692      a exit-jump-pad-quickly breakpoint.  This is it.  */
 693   struct breakpoint *exit_jump_pad_bkpt;
 694
 695 #ifdef USE_THREAD_DB
 696   int thread_known;
 697   /* The thread handle, used for e.g. TLS access.  Only valid if
 698      THREAD_KNOWN is set.  */
 699   td_thrhandle_t th;
 700
 701   /* The pthread_t handle.  */
 702   thread_t thread_handle;
 703 #endif
 704
 705   /* Arch-specific additions.  */
 706   struct arch_lwp_info *arch_private;
 707 };
 708
 709 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 710
 711 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 712    errno).  */
 713 int linux_attach_lwp (ptid_t ptid);
 714
 715 struct lwp_info *find_lwp_pid (ptid_t ptid);
 716 /* For linux_stop_lwp see nat/linux-nat.h.  */
 717
 718 #ifdef HAVE_LINUX_REGSETS
 719 void initialize_regsets_info (struct regsets_info *regsets_info);
 720 #endif
 721
 722 void initialize_low_arch (void);
 723
 724 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 725 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 726
 727 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 728 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 729
 730 /* From thread-db.c  */
 731 int thread_db_init (void);
 732 void thread_db_detach (struct process_info *);
 733 void thread_db_mourn (struct process_info *);
 734 int thread_db_handle_monitor_command (char *);
 735 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 736                                CORE_ADDR load_module, CORE_ADDR *address);
 737 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 738
 739 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 740    both the clone and the parent should be stopped.  This function does
 741    whatever is required have the clone under thread_db's control.  */
 742
 743 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 744
 745 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 746
 747 extern int have_ptrace_getregset;
 748
 749 /* Search for the value with type MATCH in the auxv vector with
 750    entries of length WORDSIZE bytes.  If found, store the value in
 751    *VALP and return 1.  If not found or if there is an error, return
 752    0.  */
 753
 754 int linux_get_auxv (int wordsize, CORE_ADDR match,
 755                     CORE_ADDR *valp);
 756
 757 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 758    WORDSIZE.  If no entry was found, return zero.  */
 759
 760 CORE_ADDR linux_get_hwcap (int wordsize);
 761
 762 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 763    WORDSIZE.  If no entry was found, return zero.  */
 764
 765 CORE_ADDR linux_get_hwcap2 (int wordsize);
 766
 767 #endif /* GDBSERVER_LINUX_LOW_H */