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   /* Breakpoint and watchpoint related functions.  See target.h for
 135      comments.  */
 136   int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 137                        int size, struct raw_breakpoint *bp);
 138   int (*remove_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 139                        int size, struct raw_breakpoint *bp);
 140
 141   int (*stopped_by_watchpoint) (void);
 142   CORE_ADDR (*stopped_data_address) (void);
 143
 144   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 145      for registers smaller than an xfer unit).  */
 146   void (*collect_ptrace_register) (struct regcache *regcache,
 147                                    int regno, char *buf);
 148   void (*supply_ptrace_register) (struct regcache *regcache,
 149                                   int regno, const char *buf);
 150
 151   /* Hook to convert from target format to ptrace format and back.
 152      Returns true if any conversion was done; false otherwise.
 153      If DIRECTION is 1, then copy from INF to NATIVE.
 154      If DIRECTION is 0, copy from NATIVE to INF.  */
 155   int (*siginfo_fixup) (siginfo_t *native, gdb_byte *inf, int direction);
 156
 157   /* Hook to call when a new process is created or attached to.
 158      If extra per-process architecture-specific data is needed,
 159      allocate it here.  */
 160   struct arch_process_info * (*new_process) (void);
 161
 162   /* Hook to call when a process is being deleted.  If extra per-process
 163      architecture-specific data is needed, delete it here.  */
 164   void (*delete_process) (struct arch_process_info *info);
 165
 166   /* Hook to call when a new thread is detected.
 167      If extra per-thread architecture-specific data is needed,
 168      allocate it here.  */
 169   void (*new_thread) (struct lwp_info *);
 170
 171   /* Hook to call when a thread is being deleted.  If extra per-thread
 172      architecture-specific data is needed, delete it here.  */
 173   void (*delete_thread) (struct arch_lwp_info *);
 174
 175   /* Hook to call, if any, when a new fork is attached.  */
 176   void (*new_fork) (struct process_info *parent, struct process_info *child);
 177
 178   /* Hook to call prior to resuming a thread.  */
 179   void (*prepare_to_resume) (struct lwp_info *);
 180
 181   /* Hook to support target specific qSupported.  */
 182   void (*process_qsupported) (char **, int count);
 183
 184   /* Returns true if the low target supports tracepoints.  */
 185   int (*supports_tracepoints) (void);
 186
 187   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 188      success, -1 on failure.  */
 189   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 190
 191   /* Install a fast tracepoint jump pad.  See target.h for
 192      comments.  */
 193   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 194                                            CORE_ADDR collector,
 195                                            CORE_ADDR lockaddr,
 196                                            ULONGEST orig_size,
 197                                            CORE_ADDR *jump_entry,
 198                                            CORE_ADDR *trampoline,
 199                                            ULONGEST *trampoline_size,
 200                                            unsigned char *jjump_pad_insn,
 201                                            ULONGEST *jjump_pad_insn_size,
 202                                            CORE_ADDR *adjusted_insn_addr,
 203                                            CORE_ADDR *adjusted_insn_addr_end,
 204                                            char *err);
 205
 206   /* Return the bytecode operations vector for the current inferior.
 207      Returns NULL if bytecode compilation is not supported.  */
 208   struct emit_ops *(*emit_ops) (void);
 209
 210   /* Return the minimum length of an instruction that can be safely overwritten
 211      for use as a fast tracepoint.  */
 212   int (*get_min_fast_tracepoint_insn_len) (void);
 213
 214   /* Returns true if the low target supports range stepping.  */
 215   int (*supports_range_stepping) (void);
 216
 217   /* See target.h.  */
 218   int (*supports_hardware_single_step) (void);
 219
 220   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 221      inferior is stopped due to SYSCALL_SIGTRAP.  */
 222   void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno);
 223
 224   /* See target.h.  */
 225   int (*get_ipa_tdesc_idx) (void);
 226 };
 227
 228 extern struct linux_target_ops the_low_target;
 229
 230 /* Target ops definitions for a Linux target.  */
 231
 232 class linux_process_target : public process_stratum_target
 233 {
 234 public:
 235
 236   int create_inferior (const char *program,
 237                        const std::vector<char *> &program_args) override;
 238
 239   void post_create_inferior () override;
 240
 241   int attach (unsigned long pid) override;
 242
 243   int kill (process_info *proc) override;
 244
 245   int detach (process_info *proc) override;
 246
 247   void mourn (process_info *proc) override;
 248
 249   void join (int pid) override;
 250
 251   bool thread_alive (ptid_t pid) override;
 252
 253   void resume (thread_resume *resume_info, size_t n) override;
 254
 255   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 256                int options) override;
 257
 258   void fetch_registers (regcache *regcache, int regno) override;
 259
 260   void store_registers (regcache *regcache, int regno) override;
 261
 262   int prepare_to_access_memory () override;
 263
 264   void done_accessing_memory () override;
 265
 266   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 267                    int len) override;
 268
 269   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 270                     int len) override;
 271
 272   void look_up_symbols () override;
 273
 274   void request_interrupt () override;
 275
 276   bool supports_read_auxv () override;
 277
 278   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 279                  unsigned int len) override;
 280
 281   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 282                     int size, raw_breakpoint *bp) override;
 283
 284   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 285                     int size, raw_breakpoint *bp) override;
 286
 287   bool stopped_by_sw_breakpoint () override;
 288
 289   bool supports_stopped_by_sw_breakpoint () override;
 290
 291   bool stopped_by_hw_breakpoint () override;
 292
 293   bool supports_stopped_by_hw_breakpoint () override;
 294
 295   bool supports_hardware_single_step () override;
 296
 297   bool stopped_by_watchpoint () override;
 298
 299   CORE_ADDR stopped_data_address () override;
 300
 301   bool supports_read_offsets () override;
 302
 303   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 304
 305   bool supports_get_tls_address () override;
 306
 307   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 308                        CORE_ADDR load_module, CORE_ADDR *address) override;
 309
 310   bool supports_qxfer_osdata () override;
 311
 312   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 313                     unsigned const char *writebuf,
 314                     CORE_ADDR offset, int len) override;
 315
 316   bool supports_qxfer_siginfo () override;
 317
 318   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 319                      unsigned const char *writebuf,
 320                      CORE_ADDR offset, int len) override;
 321
 322   bool supports_non_stop () override;
 323
 324   bool async (bool enable) override;
 325
 326   int start_non_stop (bool enable) override;
 327
 328   bool supports_multi_process () override;
 329
 330   bool supports_fork_events () override;
 331
 332   bool supports_vfork_events () override;
 333
 334   bool supports_exec_events () override;
 335
 336   void handle_new_gdb_connection () override;
 337
 338   int handle_monitor_command (char *mon) override;
 339
 340   int core_of_thread (ptid_t ptid) override;
 341
 342 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 343   bool supports_read_loadmap () override;
 344
 345   int read_loadmap (const char *annex, CORE_ADDR offset,
 346                     unsigned char *myaddr, unsigned int len) override;
 347 #endif
 348
 349   void process_qsupported (char **features, int count) override;
 350
 351   bool supports_tracepoints () override;
 352
 353   CORE_ADDR read_pc (regcache *regcache) override;
 354
 355   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 356
 357   bool supports_thread_stopped () override;
 358
 359   bool thread_stopped (thread_info *thread) override;
 360
 361   void pause_all (bool freeze) override;
 362
 363   void unpause_all (bool unfreeze) override;
 364
 365   void stabilize_threads () override;
 366
 367   bool supports_fast_tracepoints () override;
 368
 369   int install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
 370                                         CORE_ADDR tpaddr,
 371                                         CORE_ADDR collector,
 372                                         CORE_ADDR lockaddr,
 373                                         ULONGEST orig_size,
 374                                         CORE_ADDR *jump_entry,
 375                                         CORE_ADDR *trampoline,
 376                                         ULONGEST *trampoline_size,
 377                                         unsigned char *jjump_pad_insn,
 378                                         ULONGEST *jjump_pad_insn_size,
 379                                         CORE_ADDR *adjusted_insn_addr,
 380                                         CORE_ADDR *adjusted_insn_addr_end,
 381                                         char *err) override;
 382
 383   int get_min_fast_tracepoint_insn_len () override;
 384
 385   struct emit_ops *emit_ops () override;
 386
 387   bool supports_disable_randomization () override;
 388
 389   bool supports_qxfer_libraries_svr4 () override;
 390
 391   int qxfer_libraries_svr4 (const char *annex,
 392                             unsigned char *readbuf,
 393                             unsigned const char *writebuf,
 394                             CORE_ADDR offset, int len) override;
 395
 396   bool supports_agent () override;
 397
 398 #ifdef HAVE_LINUX_BTRACE
 399   btrace_target_info *enable_btrace (ptid_t ptid,
 400                                      const btrace_config *conf) override;
 401
 402   int disable_btrace (btrace_target_info *tinfo) override;
 403
 404   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 405                    enum btrace_read_type type) override;
 406
 407   int read_btrace_conf (const btrace_target_info *tinfo,
 408                         buffer *buf) override;
 409 #endif
 410
 411   bool supports_range_stepping () override;
 412
 413   bool supports_pid_to_exec_file () override;
 414
 415   char *pid_to_exec_file (int pid) override;
 416
 417   bool supports_multifs () override;
 418
 419   int multifs_open (int pid, const char *filename, int flags,
 420                     mode_t mode) override;
 421
 422   int multifs_unlink (int pid, const char *filename) override;
 423
 424   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 425                             size_t bufsiz) override;
 426
 427   const char *thread_name (ptid_t thread) override;
 428
 429 #if USE_THREAD_DB
 430   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 431                       int *handle_len) override;
 432 #endif
 433
 434   bool supports_catch_syscall () override;
 435
 436   int get_ipa_tdesc_idx () override;
 437
 438   /* Return the information to access registers.  This has public
 439      visibility because proc-service uses it.  */
 440   virtual const regs_info *get_regs_info () = 0;
 441
 442 private:
 443
 444   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 445      fork, or vfork event, we need to add the new LWP to our list
 446      (and return 0 so as not to report the trap to higher layers).
 447      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 448      to a new LWP representing the new program.  */
 449   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 450
 451   /* Do low-level handling of the event, and check if we should go on
 452      and pass it to caller code.  Return the affected lwp if we are, or
 453      NULL otherwise.  */
 454   lwp_info *filter_event (int lwpid, int wstat);
 455
 456   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 457      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 458      minus_one_ptid, to specify any child; a pid PTID, specifying all
 459      lwps of a thread group; or a PTID representing a single lwp.  Store
 460      the stop status through the status pointer WSTAT.  OPTIONS is
 461      passed to the waitpid call.  Return 0 if no event was found and
 462      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 463      was found.  Return the PID of the stopped child otherwise.  */
 464   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 465                                int *wstatp, int options);
 466
 467   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 468      minus_one_ptid, to specify any child; a pid PTID, specifying all
 469      lwps of a thread group; or a PTID representing a single lwp.  Store
 470      the stop status through the status pointer WSTAT.  OPTIONS is
 471      passed to the waitpid call.  Return 0 if no event was found and
 472      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 473      was found.  Return the PID of the stopped child otherwise.  */
 474   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 475
 476   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 477   void wait_for_sigstop ();
 478
 479   /* Wait for process, returns status.  */
 480   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 481                  int target_options);
 482
 483   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 484      If SUSPEND, then also increase the suspend count of every LWP,
 485      except EXCEPT.  */
 486   void stop_all_lwps (int suspend, lwp_info *except);
 487
 488   /* Stopped LWPs that the client wanted to be running, that don't have
 489      pending statuses, are set to run again, except for EXCEPT, if not
 490      NULL.  This undoes a stop_all_lwps call.  */
 491   void unstop_all_lwps (int unsuspend, lwp_info *except);
 492
 493   /* Start a step-over operation on LWP.  When LWP stopped at a
 494      breakpoint, to make progress, we need to remove the breakpoint out
 495      of the way.  If we let other threads run while we do that, they may
 496      pass by the breakpoint location and miss hitting it.  To avoid
 497      that, a step-over momentarily stops all threads while LWP is
 498      single-stepped by either hardware or software while the breakpoint
 499      is temporarily uninserted from the inferior.  When the single-step
 500      finishes, we reinsert the breakpoint, and let all threads that are
 501      supposed to be running, run again.  */
 502   void start_step_over (lwp_info *lwp);
 503
 504   /* If there's a step over in progress, wait until all threads stop
 505      (that is, until the stepping thread finishes its step), and
 506      unsuspend all lwps.  The stepping thread ends with its status
 507      pending, which is processed later when we get back to processing
 508      events.  */
 509   void complete_ongoing_step_over ();
 510
 511   /* When we finish a step-over, set threads running again.  If there's
 512      another thread that may need a step-over, now's the time to start
 513      it.  Eventually, we'll move all threads past their breakpoints.  */
 514   void proceed_all_lwps ();
 515
 516   /* The reason we resume in the caller, is because we want to be able
 517      to pass lwp->status_pending as WSTAT, and we need to clear
 518      status_pending_p before resuming, otherwise, resume_one_lwp
 519      refuses to resume.  */
 520   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 521
 522   /* Move THREAD out of the jump pad.  */
 523   void move_out_of_jump_pad (thread_info *thread);
 524
 525   /* Call low_arch_setup on THREAD.  */
 526   void arch_setup_thread (thread_info *thread);
 527
 528 #ifdef HAVE_LINUX_USRREGS
 529   /* Fetch one register.  */
 530   void fetch_register (const usrregs_info *usrregs, regcache *regcache,
 531                        int regno);
 532
 533   /* Store one register.  */
 534   void store_register (const usrregs_info *usrregs, regcache *regcache,
 535                        int regno);
 536 #endif
 537
 538   /* Fetch all registers, or just one, from the child process.
 539      If REGNO is -1, do this for all registers, skipping any that are
 540      assumed to have been retrieved by regsets_fetch_inferior_registers,
 541      unless ALL is non-zero.
 542      Otherwise, REGNO specifies which register (so we can save time).  */
 543   void usr_fetch_inferior_registers (const regs_info *regs_info,
 544                                      regcache *regcache, int regno, int all);
 545
 546   /* Store our register values back into the inferior.
 547      If REGNO is -1, do this for all registers, skipping any that are
 548      assumed to have been saved by regsets_store_inferior_registers,
 549      unless ALL is non-zero.
 550      Otherwise, REGNO specifies which register (so we can save time).  */
 551   void usr_store_inferior_registers (const regs_info *regs_info,
 552                                      regcache *regcache, int regno, int all);
 553
 554   /* Return the PC as read from the regcache of LWP, without any
 555      adjustment.  */
 556   CORE_ADDR get_pc (lwp_info *lwp);
 557
 558   /* Called when the LWP stopped for a signal/trap.  If it stopped for a
 559      trap check what caused it (breakpoint, watchpoint, trace, etc.),
 560      and save the result in the LWP's stop_reason field.  If it stopped
 561      for a breakpoint, decrement the PC if necessary on the lwp's
 562      architecture.  Returns true if we now have the LWP's stop PC.  */
 563   bool save_stop_reason (lwp_info *lwp);
 564
 565   /* Resume execution of LWP.  If STEP is nonzero, single-step it.  If
 566      SIGNAL is nonzero, give it that signal.  */
 567   void resume_one_lwp_throw (lwp_info *lwp, int step, int signal,
 568                              siginfo_t *info);
 569
 570   /* Like resume_one_lwp_throw, but no error is thrown if the LWP
 571      disappears while we try to resume it.  */
 572   void resume_one_lwp (lwp_info *lwp, int step, int signal, siginfo_t *info);
 573
 574   /* This function is called once per thread.  We check the thread's
 575      last resume request, which will tell us whether to resume, step, or
 576      leave the thread stopped.  Any signal the client requested to be
 577      delivered has already been enqueued at this point.
 578
 579      If any thread that GDB wants running is stopped at an internal
 580      breakpoint that needs stepping over, we start a step-over operation
 581      on that particular thread, and leave all others stopped.  */
 582   void proceed_one_lwp (thread_info *thread, lwp_info *except);
 583
 584   /* This function is called once per thread.  We check the thread's
 585      resume request, which will tell us whether to resume, step, or
 586      leave the thread stopped; and what signal, if any, it should be
 587      sent.
 588
 589      For threads which we aren't explicitly told otherwise, we preserve
 590      the stepping flag; this is used for stepping over gdbserver-placed
 591      breakpoints.
 592
 593      If pending_flags was set in any thread, we queue any needed
 594      signals, since we won't actually resume.  We already have a pending
 595      event to report, so we don't need to preserve any step requests;
 596      they should be re-issued if necessary.  */
 597   void resume_one_thread (thread_info *thread, bool leave_all_stopped);
 598
 599   /* Return true if this lwp has an interesting status pending.  */
 600   bool status_pending_p_callback (thread_info *thread, ptid_t ptid);
 601
 602   /* Resume LWPs that are currently stopped without any pending status
 603      to report, but are resumed from the core's perspective.  */
 604   void resume_stopped_resumed_lwps (thread_info *thread);
 605
 606   /* Unsuspend THREAD, except EXCEPT, and proceed.  */
 607   void unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except);
 608
 609   /* Return true if this lwp still has an interesting status pending.
 610      If not (e.g., it had stopped for a breakpoint that is gone), return
 611      false.  */
 612   bool thread_still_has_status_pending (thread_info *thread);
 613
 614   /* Return true if this lwp is to-be-resumed and has an interesting
 615      status pending.  */
 616   bool resume_status_pending (thread_info *thread);
 617
 618   /* Return true if this lwp that GDB wants running is stopped at an
 619      internal breakpoint that we need to step over.  It assumes that
 620      any required STOP_PC adjustment has already been propagated to
 621      the inferior's regcache.  */
 622   bool thread_needs_step_over (thread_info *thread);
 623
 624   /* Single step via hardware or software single step.
 625      Return 1 if hardware single stepping, 0 if software single stepping
 626      or can't single step.  */
 627   int single_step (lwp_info* lwp);
 628
 629   /* Install breakpoints for software single stepping.  */
 630   void install_software_single_step_breakpoints (lwp_info *lwp);
 631
 632 protected:
 633   /* The architecture-specific "low" methods are listed below.  */
 634
 635   /* Architecture-specific setup for the current thread.  */
 636   virtual void low_arch_setup () = 0;
 637
 638   /* Return false if we can fetch/store the register, true if we cannot
 639      fetch/store the register.  */
 640   virtual bool low_cannot_fetch_register (int regno) = 0;
 641
 642   virtual bool low_cannot_store_register (int regno) = 0;
 643
 644   /* Hook to fetch a register in some non-standard way.  Used for
 645      example by backends that have read-only registers with hardcoded
 646      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 647      REGNO was supplied, false if not, and we should fallback to the
 648      standard ptrace methods.  */
 649   virtual bool low_fetch_register (regcache *regcache, int regno);
 650
 651   /* Return true if breakpoints are supported.  Such targets must
 652      implement the GET_PC and SET_PC methods.  */
 653   virtual bool low_supports_breakpoints ();
 654
 655   virtual CORE_ADDR low_get_pc (regcache *regcache);
 656
 657   virtual void low_set_pc (regcache *regcache, CORE_ADDR newpc);
 658
 659   /* Find the next possible PCs after the current instruction executes.
 660      Targets that override this method should also override
 661      'supports_software_single_step' to return true.  */
 662   virtual std::vector<CORE_ADDR> low_get_next_pcs (regcache *regcache);
 663
 664   /* Return true if there is a breakpoint at PC.  */
 665   virtual bool low_breakpoint_at (CORE_ADDR pc) = 0;
 666
 667   /* How many bytes the PC should be decremented after a break.  */
 668   virtual int low_decr_pc_after_break ();
 669 };
 670
 671 extern linux_process_target *the_linux_target;
 672
 673 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 674 #define get_lwp_thread(lwp) ((lwp)->thread)
 675
 676 /* This struct is recorded in the target_data field of struct thread_info.
 677
 678    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 679    GDB protocol representation of the thread ID.  Threads also have
 680    a "process ID" (poorly named) which is (presently) the same as the
 681    LWP ID.
 682
 683    There is also ``all_processes'' is keyed by the "overall process ID",
 684    which GNU/Linux calls tgid, "thread group ID".  */
 685
 686 struct lwp_info
 687 {
 688   /* Backlink to the parent object.  */
 689   struct thread_info *thread;
 690
 691   /* If this flag is set, the next SIGSTOP will be ignored (the
 692      process will be immediately resumed).  This means that either we
 693      sent the SIGSTOP to it ourselves and got some other pending event
 694      (so the SIGSTOP is still pending), or that we stopped the
 695      inferior implicitly via PTRACE_ATTACH and have not waited for it
 696      yet.  */
 697   int stop_expected;
 698
 699   /* When this is true, we shall not try to resume this thread, even
 700      if last_resume_kind isn't resume_stop.  */
 701   int suspended;
 702
 703   /* If this flag is set, the lwp is known to be stopped right now (stop
 704      event already received in a wait()).  */
 705   int stopped;
 706
 707   /* Signal whether we are in a SYSCALL_ENTRY or
 708      in a SYSCALL_RETURN event.
 709      Values:
 710      - TARGET_WAITKIND_SYSCALL_ENTRY
 711      - TARGET_WAITKIND_SYSCALL_RETURN */
 712   enum target_waitkind syscall_state;
 713
 714   /* When stopped is set, the last wait status recorded for this lwp.  */
 715   int last_status;
 716
 717   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 718      this LWP's last event, to pass to GDB without any further
 719      processing.  This is used to store extended ptrace event
 720      information or exit status until it can be reported to GDB.  */
 721   struct target_waitstatus waitstatus;
 722
 723   /* A pointer to the fork child/parent relative.  Valid only while
 724      the parent fork event is not reported to higher layers.  Used to
 725      avoid wildcard vCont actions resuming a fork child before GDB is
 726      notified about the parent's fork event.  */
 727   struct lwp_info *fork_relative;
 728
 729   /* When stopped is set, this is where the lwp last stopped, with
 730      decr_pc_after_break already accounted for.  If the LWP is
 731      running, this is the address at which the lwp was resumed.  */
 732   CORE_ADDR stop_pc;
 733
 734   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 735      been reported.  */
 736   int status_pending_p;
 737   int status_pending;
 738
 739   /* The reason the LWP last stopped, if we need to track it
 740      (breakpoint, watchpoint, etc.)  */
 741   enum target_stop_reason stop_reason;
 742
 743   /* On architectures where it is possible to know the data address of
 744      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 745      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 746      is true.  */
 747   CORE_ADDR stopped_data_address;
 748
 749   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 750      stop (SIGTRAP stops only).  */
 751   CORE_ADDR bp_reinsert;
 752
 753   /* If this flag is set, the last continue operation at the ptrace
 754      level on this process was a single-step.  */
 755   int stepping;
 756
 757   /* Range to single step within.  This is a copy of the step range
 758      passed along the last resume request.  See 'struct
 759      thread_resume'.  */
 760   CORE_ADDR step_range_start;   /* Inclusive */
 761   CORE_ADDR step_range_end;     /* Exclusive */
 762
 763   /* If this flag is set, we need to set the event request flags the
 764      next time we see this LWP stop.  */
 765   int must_set_ptrace_flags;
 766
 767   /* If this is non-zero, it points to a chain of signals which need to
 768      be delivered to this process.  */
 769   struct pending_signals *pending_signals;
 770
 771   /* A link used when resuming.  It is initialized from the resume request,
 772      and then processed and cleared in linux_resume_one_lwp.  */
 773   struct thread_resume *resume;
 774
 775   /* Information bout this lwp's fast tracepoint collection status (is it
 776      currently stopped in the jump pad, and if so, before or at/after the
 777      relocated instruction).  Normally, we won't care about this, but we will
 778      if a signal arrives to this lwp while it is collecting.  */
 779   fast_tpoint_collect_result collecting_fast_tracepoint;
 780
 781   /* If this is non-zero, it points to a chain of signals which need
 782      to be reported to GDB.  These were deferred because the thread
 783      was doing a fast tracepoint collect when they arrived.  */
 784   struct pending_signals *pending_signals_to_report;
 785
 786   /* When collecting_fast_tracepoint is first found to be 1, we insert
 787      a exit-jump-pad-quickly breakpoint.  This is it.  */
 788   struct breakpoint *exit_jump_pad_bkpt;
 789
 790 #ifdef USE_THREAD_DB
 791   int thread_known;
 792   /* The thread handle, used for e.g. TLS access.  Only valid if
 793      THREAD_KNOWN is set.  */
 794   td_thrhandle_t th;
 795
 796   /* The pthread_t handle.  */
 797   thread_t thread_handle;
 798 #endif
 799
 800   /* Arch-specific additions.  */
 801   struct arch_lwp_info *arch_private;
 802 };
 803
 804 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 805
 806 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 807    errno).  */
 808 int linux_attach_lwp (ptid_t ptid);
 809
 810 struct lwp_info *find_lwp_pid (ptid_t ptid);
 811 /* For linux_stop_lwp see nat/linux-nat.h.  */
 812
 813 #ifdef HAVE_LINUX_REGSETS
 814 void initialize_regsets_info (struct regsets_info *regsets_info);
 815 #endif
 816
 817 void initialize_low_arch (void);
 818
 819 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 820 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 821
 822 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 823 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 824
 825 /* From thread-db.c  */
 826 int thread_db_init (void);
 827 void thread_db_detach (struct process_info *);
 828 void thread_db_mourn (struct process_info *);
 829 int thread_db_handle_monitor_command (char *);
 830 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 831                                CORE_ADDR load_module, CORE_ADDR *address);
 832 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 833
 834 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 835    both the clone and the parent should be stopped.  This function does
 836    whatever is required have the clone under thread_db's control.  */
 837
 838 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 839
 840 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 841
 842 extern int have_ptrace_getregset;
 843
 844 /* Search for the value with type MATCH in the auxv vector with
 845    entries of length WORDSIZE bytes.  If found, store the value in
 846    *VALP and return 1.  If not found or if there is an error, return
 847    0.  */
 848
 849 int linux_get_auxv (int wordsize, CORE_ADDR match,
 850                     CORE_ADDR *valp);
 851
 852 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 853    WORDSIZE.  If no entry was found, return zero.  */
 854
 855 CORE_ADDR linux_get_hwcap (int wordsize);
 856
 857 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 858    WORDSIZE.  If no entry was found, return zero.  */
 859
 860 CORE_ADDR linux_get_hwcap2 (int wordsize);
 861
 862 #endif /* GDBSERVER_LINUX_LOW_H */