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 };
 135
 136 extern struct linux_target_ops the_low_target;
 137
 138 /* Target ops definitions for a Linux target.  */
 139
 140 class linux_process_target : public process_stratum_target
 141 {
 142 public:
 143
 144   int create_inferior (const char *program,
 145                        const std::vector<char *> &program_args) override;
 146
 147   void post_create_inferior () override;
 148
 149   int attach (unsigned long pid) override;
 150
 151   int kill (process_info *proc) override;
 152
 153   int detach (process_info *proc) override;
 154
 155   void mourn (process_info *proc) override;
 156
 157   void join (int pid) override;
 158
 159   bool thread_alive (ptid_t pid) override;
 160
 161   void resume (thread_resume *resume_info, size_t n) override;
 162
 163   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 164                int options) override;
 165
 166   void fetch_registers (regcache *regcache, int regno) override;
 167
 168   void store_registers (regcache *regcache, int regno) override;
 169
 170   int prepare_to_access_memory () override;
 171
 172   void done_accessing_memory () override;
 173
 174   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 175                    int len) override;
 176
 177   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 178                     int len) override;
 179
 180   void look_up_symbols () override;
 181
 182   void request_interrupt () override;
 183
 184   bool supports_read_auxv () override;
 185
 186   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 187                  unsigned int len) override;
 188
 189   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 190                     int size, raw_breakpoint *bp) override;
 191
 192   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 193                     int size, raw_breakpoint *bp) override;
 194
 195   bool stopped_by_sw_breakpoint () override;
 196
 197   bool supports_stopped_by_sw_breakpoint () override;
 198
 199   bool stopped_by_hw_breakpoint () override;
 200
 201   bool supports_stopped_by_hw_breakpoint () override;
 202
 203   bool supports_hardware_single_step () override;
 204
 205   bool stopped_by_watchpoint () override;
 206
 207   CORE_ADDR stopped_data_address () override;
 208
 209   bool supports_read_offsets () override;
 210
 211   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 212
 213   bool supports_get_tls_address () override;
 214
 215   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 216                        CORE_ADDR load_module, CORE_ADDR *address) override;
 217
 218   bool supports_qxfer_osdata () override;
 219
 220   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 221                     unsigned const char *writebuf,
 222                     CORE_ADDR offset, int len) override;
 223
 224   bool supports_qxfer_siginfo () override;
 225
 226   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 227                      unsigned const char *writebuf,
 228                      CORE_ADDR offset, int len) override;
 229
 230   bool supports_non_stop () override;
 231
 232   bool async (bool enable) override;
 233
 234   int start_non_stop (bool enable) override;
 235
 236   bool supports_multi_process () override;
 237
 238   bool supports_fork_events () override;
 239
 240   bool supports_vfork_events () override;
 241
 242   bool supports_exec_events () override;
 243
 244   void handle_new_gdb_connection () override;
 245
 246   int handle_monitor_command (char *mon) override;
 247
 248   int core_of_thread (ptid_t ptid) override;
 249
 250 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 251   bool supports_read_loadmap () override;
 252
 253   int read_loadmap (const char *annex, CORE_ADDR offset,
 254                     unsigned char *myaddr, unsigned int len) override;
 255 #endif
 256
 257   CORE_ADDR read_pc (regcache *regcache) override;
 258
 259   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 260
 261   bool supports_thread_stopped () override;
 262
 263   bool thread_stopped (thread_info *thread) override;
 264
 265   void pause_all (bool freeze) override;
 266
 267   void unpause_all (bool unfreeze) override;
 268
 269   void stabilize_threads () override;
 270
 271   bool supports_disable_randomization () override;
 272
 273   bool supports_qxfer_libraries_svr4 () override;
 274
 275   int qxfer_libraries_svr4 (const char *annex,
 276                             unsigned char *readbuf,
 277                             unsigned const char *writebuf,
 278                             CORE_ADDR offset, int len) override;
 279
 280   bool supports_agent () override;
 281
 282 #ifdef HAVE_LINUX_BTRACE
 283   btrace_target_info *enable_btrace (ptid_t ptid,
 284                                      const btrace_config *conf) override;
 285
 286   int disable_btrace (btrace_target_info *tinfo) override;
 287
 288   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 289                    enum btrace_read_type type) override;
 290
 291   int read_btrace_conf (const btrace_target_info *tinfo,
 292                         buffer *buf) override;
 293 #endif
 294
 295   bool supports_range_stepping () override;
 296
 297   bool supports_pid_to_exec_file () override;
 298
 299   char *pid_to_exec_file (int pid) override;
 300
 301   bool supports_multifs () override;
 302
 303   int multifs_open (int pid, const char *filename, int flags,
 304                     mode_t mode) override;
 305
 306   int multifs_unlink (int pid, const char *filename) override;
 307
 308   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 309                             size_t bufsiz) override;
 310
 311   const char *thread_name (ptid_t thread) override;
 312
 313 #if USE_THREAD_DB
 314   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 315                       int *handle_len) override;
 316 #endif
 317
 318   bool supports_catch_syscall () override;
 319
 320   /* Return the information to access registers.  This has public
 321      visibility because proc-service uses it.  */
 322   virtual const regs_info *get_regs_info () = 0;
 323
 324 private:
 325
 326   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 327      fork, or vfork event, we need to add the new LWP to our list
 328      (and return 0 so as not to report the trap to higher layers).
 329      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 330      to a new LWP representing the new program.  */
 331   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 332
 333   /* Do low-level handling of the event, and check if we should go on
 334      and pass it to caller code.  Return the affected lwp if we are, or
 335      NULL otherwise.  */
 336   lwp_info *filter_event (int lwpid, int wstat);
 337
 338   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 339      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 340      minus_one_ptid, to specify any child; a pid PTID, specifying all
 341      lwps of a thread group; or a PTID representing a single lwp.  Store
 342      the stop status through the status pointer WSTAT.  OPTIONS is
 343      passed to the waitpid call.  Return 0 if no event was found and
 344      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 345      was found.  Return the PID of the stopped child otherwise.  */
 346   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 347                                int *wstatp, int options);
 348
 349   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 350      minus_one_ptid, to specify any child; a pid PTID, specifying all
 351      lwps of a thread group; or a PTID representing a single lwp.  Store
 352      the stop status through the status pointer WSTAT.  OPTIONS is
 353      passed to the waitpid call.  Return 0 if no event was found and
 354      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 355      was found.  Return the PID of the stopped child otherwise.  */
 356   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 357
 358   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 359   void wait_for_sigstop ();
 360
 361   /* Wait for process, returns status.  */
 362   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 363                  int target_options);
 364
 365   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 366      If SUSPEND, then also increase the suspend count of every LWP,
 367      except EXCEPT.  */
 368   void stop_all_lwps (int suspend, lwp_info *except);
 369
 370   /* Stopped LWPs that the client wanted to be running, that don't have
 371      pending statuses, are set to run again, except for EXCEPT, if not
 372      NULL.  This undoes a stop_all_lwps call.  */
 373   void unstop_all_lwps (int unsuspend, lwp_info *except);
 374
 375   /* Start a step-over operation on LWP.  When LWP stopped at a
 376      breakpoint, to make progress, we need to remove the breakpoint out
 377      of the way.  If we let other threads run while we do that, they may
 378      pass by the breakpoint location and miss hitting it.  To avoid
 379      that, a step-over momentarily stops all threads while LWP is
 380      single-stepped by either hardware or software while the breakpoint
 381      is temporarily uninserted from the inferior.  When the single-step
 382      finishes, we reinsert the breakpoint, and let all threads that are
 383      supposed to be running, run again.  */
 384   void start_step_over (lwp_info *lwp);
 385
 386   /* If there's a step over in progress, wait until all threads stop
 387      (that is, until the stepping thread finishes its step), and
 388      unsuspend all lwps.  The stepping thread ends with its status
 389      pending, which is processed later when we get back to processing
 390      events.  */
 391   void complete_ongoing_step_over ();
 392
 393   /* Finish a step-over.  Reinsert the breakpoint we had uninserted in
 394      start_step_over, if still there, and delete any single-step
 395      breakpoints we've set, on non hardware single-step targets.
 396      Return true if step over finished.  */
 397   bool finish_step_over (lwp_info *lwp);
 398
 399   /* When we finish a step-over, set threads running again.  If there's
 400      another thread that may need a step-over, now's the time to start
 401      it.  Eventually, we'll move all threads past their breakpoints.  */
 402   void proceed_all_lwps ();
 403
 404   /* The reason we resume in the caller, is because we want to be able
 405      to pass lwp->status_pending as WSTAT, and we need to clear
 406      status_pending_p before resuming, otherwise, resume_one_lwp
 407      refuses to resume.  */
 408   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 409
 410   /* Move THREAD out of the jump pad.  */
 411   void move_out_of_jump_pad (thread_info *thread);
 412
 413   /* Call low_arch_setup on THREAD.  */
 414   void arch_setup_thread (thread_info *thread);
 415
 416 #ifdef HAVE_LINUX_USRREGS
 417   /* Fetch one register.  */
 418   void fetch_register (const usrregs_info *usrregs, regcache *regcache,
 419                        int regno);
 420
 421   /* Store one register.  */
 422   void store_register (const usrregs_info *usrregs, regcache *regcache,
 423                        int regno);
 424 #endif
 425
 426   /* Fetch all registers, or just one, from the child process.
 427      If REGNO is -1, do this for all registers, skipping any that are
 428      assumed to have been retrieved by regsets_fetch_inferior_registers,
 429      unless ALL is non-zero.
 430      Otherwise, REGNO specifies which register (so we can save time).  */
 431   void usr_fetch_inferior_registers (const regs_info *regs_info,
 432                                      regcache *regcache, int regno, int all);
 433
 434   /* Store our register values back into the inferior.
 435      If REGNO is -1, do this for all registers, skipping any that are
 436      assumed to have been saved by regsets_store_inferior_registers,
 437      unless ALL is non-zero.
 438      Otherwise, REGNO specifies which register (so we can save time).  */
 439   void usr_store_inferior_registers (const regs_info *regs_info,
 440                                      regcache *regcache, int regno, int all);
 441
 442   /* Return the PC as read from the regcache of LWP, without any
 443      adjustment.  */
 444   CORE_ADDR get_pc (lwp_info *lwp);
 445
 446   /* Called when the LWP stopped for a signal/trap.  If it stopped for a
 447      trap check what caused it (breakpoint, watchpoint, trace, etc.),
 448      and save the result in the LWP's stop_reason field.  If it stopped
 449      for a breakpoint, decrement the PC if necessary on the lwp's
 450      architecture.  Returns true if we now have the LWP's stop PC.  */
 451   bool save_stop_reason (lwp_info *lwp);
 452
 453   /* Resume execution of LWP.  If STEP is nonzero, single-step it.  If
 454      SIGNAL is nonzero, give it that signal.  */
 455   void resume_one_lwp_throw (lwp_info *lwp, int step, int signal,
 456                              siginfo_t *info);
 457
 458   /* Like resume_one_lwp_throw, but no error is thrown if the LWP
 459      disappears while we try to resume it.  */
 460   void resume_one_lwp (lwp_info *lwp, int step, int signal, siginfo_t *info);
 461
 462   /* This function is called once per thread.  We check the thread's
 463      last resume request, which will tell us whether to resume, step, or
 464      leave the thread stopped.  Any signal the client requested to be
 465      delivered has already been enqueued at this point.
 466
 467      If any thread that GDB wants running is stopped at an internal
 468      breakpoint that needs stepping over, we start a step-over operation
 469      on that particular thread, and leave all others stopped.  */
 470   void proceed_one_lwp (thread_info *thread, lwp_info *except);
 471
 472   /* This function is called once per thread.  We check the thread's
 473      resume request, which will tell us whether to resume, step, or
 474      leave the thread stopped; and what signal, if any, it should be
 475      sent.
 476
 477      For threads which we aren't explicitly told otherwise, we preserve
 478      the stepping flag; this is used for stepping over gdbserver-placed
 479      breakpoints.
 480
 481      If pending_flags was set in any thread, we queue any needed
 482      signals, since we won't actually resume.  We already have a pending
 483      event to report, so we don't need to preserve any step requests;
 484      they should be re-issued if necessary.  */
 485   void resume_one_thread (thread_info *thread, bool leave_all_stopped);
 486
 487   /* Return true if this lwp has an interesting status pending.  */
 488   bool status_pending_p_callback (thread_info *thread, ptid_t ptid);
 489
 490   /* Resume LWPs that are currently stopped without any pending status
 491      to report, but are resumed from the core's perspective.  */
 492   void resume_stopped_resumed_lwps (thread_info *thread);
 493
 494   /* Unsuspend THREAD, except EXCEPT, and proceed.  */
 495   void unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except);
 496
 497   /* Return true if this lwp still has an interesting status pending.
 498      If not (e.g., it had stopped for a breakpoint that is gone), return
 499      false.  */
 500   bool thread_still_has_status_pending (thread_info *thread);
 501
 502   /* Return true if this lwp is to-be-resumed and has an interesting
 503      status pending.  */
 504   bool resume_status_pending (thread_info *thread);
 505
 506   /* Return true if this lwp that GDB wants running is stopped at an
 507      internal breakpoint that we need to step over.  It assumes that
 508      any required STOP_PC adjustment has already been propagated to
 509      the inferior's regcache.  */
 510   bool thread_needs_step_over (thread_info *thread);
 511
 512   /* Single step via hardware or software single step.
 513      Return 1 if hardware single stepping, 0 if software single stepping
 514      or can't single step.  */
 515   int single_step (lwp_info* lwp);
 516
 517   /* Return true if THREAD is doing hardware single step.  */
 518   bool maybe_hw_step (thread_info *thread);
 519
 520   /* Install breakpoints for software single stepping.  */
 521   void install_software_single_step_breakpoints (lwp_info *lwp);
 522
 523   /* Fetch the possibly triggered data watchpoint info and store it in
 524      CHILD.
 525
 526      On some archs, like x86, that use debug registers to set
 527      watchpoints, it's possible that the way to know which watched
 528      address trapped, is to check the register that is used to select
 529      which address to watch.  Problem is, between setting the watchpoint
 530      and reading back which data address trapped, the user may change
 531      the set of watchpoints, and, as a consequence, GDB changes the
 532      debug registers in the inferior.  To avoid reading back a stale
 533      stopped-data-address when that happens, we cache in LP the fact
 534      that a watchpoint trapped, and the corresponding data address, as
 535      soon as we see CHILD stop with a SIGTRAP.  If GDB changes the debug
 536      registers meanwhile, we have the cached data we can rely on.  */
 537   bool check_stopped_by_watchpoint (lwp_info *child);
 538
 539   /* Convert a native/host siginfo object, into/from the siginfo in the
 540      layout of the inferiors' architecture.  */
 541   void siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo,
 542                       int direction);
 543
 544   /* Add a process to the common process list, and set its private
 545      data.  */
 546   process_info *add_linux_process (int pid, int attached);
 547
 548   /* Add a new thread.  */
 549   lwp_info *add_lwp (ptid_t ptid);
 550
 551   /* Delete a thread.  */
 552   void delete_lwp (lwp_info *lwp);
 553
 554 public: /* Make this public because it's used from outside.  */
 555   /* Attach to an inferior process.  Returns 0 on success, ERRNO on
 556      error.  */
 557   int attach_lwp (ptid_t ptid);
 558
 559 private: /* Back to private.  */
 560   /* Detach from LWP.  */
 561   void detach_one_lwp (lwp_info *lwp);
 562
 563   /* Detect zombie thread group leaders, and "exit" them.  We can't
 564      reap their exits until all other threads in the group have
 565      exited.  */
 566   void check_zombie_leaders ();
 567
 568   /* Convenience function that is called when the kernel reports an exit
 569      event.  This decides whether to report the event to GDB as a
 570      process exit event, a thread exit event, or to suppress the
 571      event.  */
 572   ptid_t filter_exit_event (lwp_info *event_child,
 573                             target_waitstatus *ourstatus);
 574
 575   /* Returns true if THREAD is stopped in a jump pad, and we can't
 576      move it out, because we need to report the stop event to GDB.  For
 577      example, if the user puts a breakpoint in the jump pad, it's
 578      because she wants to debug it.  */
 579   bool stuck_in_jump_pad (thread_info *thread);
 580
 581   /* Convenience wrapper.  Returns information about LWP's fast tracepoint
 582      collection status.  */
 583   fast_tpoint_collect_result linux_fast_tracepoint_collecting
 584     (lwp_info *lwp, fast_tpoint_collect_status *status);
 585
 586   /* This function should only be called if LWP got a SYSCALL_SIGTRAP.
 587      Fill *SYSNO with the syscall nr trapped.  */
 588   void get_syscall_trapinfo (lwp_info *lwp, int *sysno);
 589
 590   /* Returns true if GDB is interested in the event_child syscall.
 591      Only to be called when stopped reason is SYSCALL_SIGTRAP.  */
 592   bool gdb_catch_this_syscall (lwp_info *event_child);
 593
 594 protected:
 595   /* The architecture-specific "low" methods are listed below.  */
 596
 597   /* Architecture-specific setup for the current thread.  */
 598   virtual void low_arch_setup () = 0;
 599
 600   /* Return false if we can fetch/store the register, true if we cannot
 601      fetch/store the register.  */
 602   virtual bool low_cannot_fetch_register (int regno) = 0;
 603
 604   virtual bool low_cannot_store_register (int regno) = 0;
 605
 606   /* Hook to fetch a register in some non-standard way.  Used for
 607      example by backends that have read-only registers with hardcoded
 608      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 609      REGNO was supplied, false if not, and we should fallback to the
 610      standard ptrace methods.  */
 611   virtual bool low_fetch_register (regcache *regcache, int regno);
 612
 613   /* Return true if breakpoints are supported.  Such targets must
 614      implement the GET_PC and SET_PC methods.  */
 615   virtual bool low_supports_breakpoints ();
 616
 617   virtual CORE_ADDR low_get_pc (regcache *regcache);
 618
 619   virtual void low_set_pc (regcache *regcache, CORE_ADDR newpc);
 620
 621   /* Find the next possible PCs after the current instruction executes.
 622      Targets that override this method should also override
 623      'supports_software_single_step' to return true.  */
 624   virtual std::vector<CORE_ADDR> low_get_next_pcs (regcache *regcache);
 625
 626   /* Return true if there is a breakpoint at PC.  */
 627   virtual bool low_breakpoint_at (CORE_ADDR pc) = 0;
 628
 629   /* Breakpoint and watchpoint related functions.  See target.h for
 630      comments.  */
 631   virtual int low_insert_point (raw_bkpt_type type, CORE_ADDR addr,
 632                                 int size, raw_breakpoint *bp);
 633
 634   virtual int low_remove_point (raw_bkpt_type type, CORE_ADDR addr,
 635                                 int size, raw_breakpoint *bp);
 636
 637   virtual bool low_stopped_by_watchpoint ();
 638
 639   virtual CORE_ADDR low_stopped_data_address ();
 640
 641   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 642      for registers smaller than an xfer unit).  */
 643   virtual void low_collect_ptrace_register (regcache *regcache, int regno,
 644                                             char *buf);
 645
 646   virtual void low_supply_ptrace_register (regcache *regcache, int regno,
 647                                            const char *buf);
 648
 649   /* Hook to convert from target format to ptrace format and back.
 650      Returns true if any conversion was done; false otherwise.
 651      If DIRECTION is 1, then copy from INF to NATIVE.
 652      If DIRECTION is 0, copy from NATIVE to INF.  */
 653   virtual bool low_siginfo_fixup (siginfo_t *native, gdb_byte *inf,
 654                                   int direction);
 655
 656   /* Hook to call when a new process is created or attached to.
 657      If extra per-process architecture-specific data is needed,
 658      allocate it here.  */
 659   virtual arch_process_info *low_new_process ();
 660
 661   /* Hook to call when a process is being deleted.  If extra per-process
 662      architecture-specific data is needed, delete it here.  */
 663   virtual void low_delete_process (arch_process_info *info);
 664
 665   /* Hook to call when a new thread is detected.
 666      If extra per-thread architecture-specific data is needed,
 667      allocate it here.  */
 668   virtual void low_new_thread (lwp_info *);
 669
 670   /* Hook to call when a thread is being deleted.  If extra per-thread
 671      architecture-specific data is needed, delete it here.  */
 672   virtual void low_delete_thread (arch_lwp_info *);
 673
 674   /* Hook to call, if any, when a new fork is attached.  */
 675   virtual void low_new_fork (process_info *parent, process_info *child);
 676
 677   /* Hook to call prior to resuming a thread.  */
 678   virtual void low_prepare_to_resume (lwp_info *lwp);
 679
 680   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 681      success, -1 on failure.  */
 682   virtual int low_get_thread_area (int lwpid, CORE_ADDR *addrp);
 683
 684   /* Returns true if the low target supports range stepping.  */
 685   virtual bool low_supports_range_stepping ();
 686
 687   /* Return true if the target supports catch syscall.  Such targets
 688      override the low_get_syscall_trapinfo method below.  */
 689   virtual bool low_supports_catch_syscall ();
 690
 691   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 692      inferior is stopped due to SYSCALL_SIGTRAP.  */
 693   virtual void low_get_syscall_trapinfo (regcache *regcache, int *sysno);
 694
 695   /* How many bytes the PC should be decremented after a break.  */
 696   virtual int low_decr_pc_after_break ();
 697 };
 698
 699 extern linux_process_target *the_linux_target;
 700
 701 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 702 #define get_lwp_thread(lwp) ((lwp)->thread)
 703
 704 /* This struct is recorded in the target_data field of struct thread_info.
 705
 706    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 707    GDB protocol representation of the thread ID.  Threads also have
 708    a "process ID" (poorly named) which is (presently) the same as the
 709    LWP ID.
 710
 711    There is also ``all_processes'' is keyed by the "overall process ID",
 712    which GNU/Linux calls tgid, "thread group ID".  */
 713
 714 struct lwp_info
 715 {
 716   /* Backlink to the parent object.  */
 717   struct thread_info *thread;
 718
 719   /* If this flag is set, the next SIGSTOP will be ignored (the
 720      process will be immediately resumed).  This means that either we
 721      sent the SIGSTOP to it ourselves and got some other pending event
 722      (so the SIGSTOP is still pending), or that we stopped the
 723      inferior implicitly via PTRACE_ATTACH and have not waited for it
 724      yet.  */
 725   int stop_expected;
 726
 727   /* When this is true, we shall not try to resume this thread, even
 728      if last_resume_kind isn't resume_stop.  */
 729   int suspended;
 730
 731   /* If this flag is set, the lwp is known to be stopped right now (stop
 732      event already received in a wait()).  */
 733   int stopped;
 734
 735   /* Signal whether we are in a SYSCALL_ENTRY or
 736      in a SYSCALL_RETURN event.
 737      Values:
 738      - TARGET_WAITKIND_SYSCALL_ENTRY
 739      - TARGET_WAITKIND_SYSCALL_RETURN */
 740   enum target_waitkind syscall_state;
 741
 742   /* When stopped is set, the last wait status recorded for this lwp.  */
 743   int last_status;
 744
 745   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 746      this LWP's last event, to pass to GDB without any further
 747      processing.  This is used to store extended ptrace event
 748      information or exit status until it can be reported to GDB.  */
 749   struct target_waitstatus waitstatus;
 750
 751   /* A pointer to the fork child/parent relative.  Valid only while
 752      the parent fork event is not reported to higher layers.  Used to
 753      avoid wildcard vCont actions resuming a fork child before GDB is
 754      notified about the parent's fork event.  */
 755   struct lwp_info *fork_relative;
 756
 757   /* When stopped is set, this is where the lwp last stopped, with
 758      decr_pc_after_break already accounted for.  If the LWP is
 759      running, this is the address at which the lwp was resumed.  */
 760   CORE_ADDR stop_pc;
 761
 762   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 763      been reported.  */
 764   int status_pending_p;
 765   int status_pending;
 766
 767   /* The reason the LWP last stopped, if we need to track it
 768      (breakpoint, watchpoint, etc.)  */
 769   enum target_stop_reason stop_reason;
 770
 771   /* On architectures where it is possible to know the data address of
 772      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 773      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 774      is true.  */
 775   CORE_ADDR stopped_data_address;
 776
 777   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 778      stop (SIGTRAP stops only).  */
 779   CORE_ADDR bp_reinsert;
 780
 781   /* If this flag is set, the last continue operation at the ptrace
 782      level on this process was a single-step.  */
 783   int stepping;
 784
 785   /* Range to single step within.  This is a copy of the step range
 786      passed along the last resume request.  See 'struct
 787      thread_resume'.  */
 788   CORE_ADDR step_range_start;   /* Inclusive */
 789   CORE_ADDR step_range_end;     /* Exclusive */
 790
 791   /* If this flag is set, we need to set the event request flags the
 792      next time we see this LWP stop.  */
 793   int must_set_ptrace_flags;
 794
 795   /* If this is non-zero, it points to a chain of signals which need to
 796      be delivered to this process.  */
 797   struct pending_signals *pending_signals;
 798
 799   /* A link used when resuming.  It is initialized from the resume request,
 800      and then processed and cleared in linux_resume_one_lwp.  */
 801   struct thread_resume *resume;
 802
 803   /* Information bout this lwp's fast tracepoint collection status (is it
 804      currently stopped in the jump pad, and if so, before or at/after the
 805      relocated instruction).  Normally, we won't care about this, but we will
 806      if a signal arrives to this lwp while it is collecting.  */
 807   fast_tpoint_collect_result collecting_fast_tracepoint;
 808
 809   /* If this is non-zero, it points to a chain of signals which need
 810      to be reported to GDB.  These were deferred because the thread
 811      was doing a fast tracepoint collect when they arrived.  */
 812   struct pending_signals *pending_signals_to_report;
 813
 814   /* When collecting_fast_tracepoint is first found to be 1, we insert
 815      a exit-jump-pad-quickly breakpoint.  This is it.  */
 816   struct breakpoint *exit_jump_pad_bkpt;
 817
 818 #ifdef USE_THREAD_DB
 819   int thread_known;
 820   /* The thread handle, used for e.g. TLS access.  Only valid if
 821      THREAD_KNOWN is set.  */
 822   td_thrhandle_t th;
 823
 824   /* The pthread_t handle.  */
 825   thread_t thread_handle;
 826 #endif
 827
 828   /* Arch-specific additions.  */
 829   struct arch_lwp_info *arch_private;
 830 };
 831
 832 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 833
 834 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 835    errno).  */
 836 int linux_attach_lwp (ptid_t ptid);
 837
 838 struct lwp_info *find_lwp_pid (ptid_t ptid);
 839 /* For linux_stop_lwp see nat/linux-nat.h.  */
 840
 841 #ifdef HAVE_LINUX_REGSETS
 842 void initialize_regsets_info (struct regsets_info *regsets_info);
 843 #endif
 844
 845 void initialize_low_arch (void);
 846
 847 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 848 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 849
 850 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 851 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 852
 853 /* From thread-db.c  */
 854 int thread_db_init (void);
 855 void thread_db_detach (struct process_info *);
 856 void thread_db_mourn (struct process_info *);
 857 int thread_db_handle_monitor_command (char *);
 858 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 859                                CORE_ADDR load_module, CORE_ADDR *address);
 860 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 861
 862 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 863    both the clone and the parent should be stopped.  This function does
 864    whatever is required have the clone under thread_db's control.  */
 865
 866 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 867
 868 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 869
 870 extern int have_ptrace_getregset;
 871
 872 /* Search for the value with type MATCH in the auxv vector with
 873    entries of length WORDSIZE bytes.  If found, store the value in
 874    *VALP and return 1.  If not found or if there is an error, return
 875    0.  */
 876
 877 int linux_get_auxv (int wordsize, CORE_ADDR match,
 878                     CORE_ADDR *valp);
 879
 880 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 881    WORDSIZE.  If no entry was found, return zero.  */
 882
 883 CORE_ADDR linux_get_hwcap (int wordsize);
 884
 885 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 886    WORDSIZE.  If no entry was found, return zero.  */
 887
 888 CORE_ADDR linux_get_hwcap2 (int wordsize);
 889
 890 #endif /* GDBSERVER_LINUX_LOW_H */