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 /* Target ops definitions for a Linux target.  */
 133
 134 class linux_process_target : public process_stratum_target
 135 {
 136 public:
 137
 138   int create_inferior (const char *program,
 139                        const std::vector<char *> &program_args) override;
 140
 141   void post_create_inferior () override;
 142
 143   int attach (unsigned long pid) override;
 144
 145   int kill (process_info *proc) override;
 146
 147   int detach (process_info *proc) override;
 148
 149   void mourn (process_info *proc) override;
 150
 151   void join (int pid) override;
 152
 153   bool thread_alive (ptid_t pid) override;
 154
 155   void resume (thread_resume *resume_info, size_t n) override;
 156
 157   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 158                int options) override;
 159
 160   void fetch_registers (regcache *regcache, int regno) override;
 161
 162   void store_registers (regcache *regcache, int regno) override;
 163
 164   int prepare_to_access_memory () override;
 165
 166   void done_accessing_memory () override;
 167
 168   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 169                    int len) override;
 170
 171   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 172                     int len) override;
 173
 174   void look_up_symbols () override;
 175
 176   void request_interrupt () override;
 177
 178   bool supports_read_auxv () override;
 179
 180   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 181                  unsigned int len) override;
 182
 183   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 184                     int size, raw_breakpoint *bp) override;
 185
 186   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 187                     int size, raw_breakpoint *bp) override;
 188
 189   bool stopped_by_sw_breakpoint () override;
 190
 191   bool supports_stopped_by_sw_breakpoint () override;
 192
 193   bool stopped_by_hw_breakpoint () override;
 194
 195   bool supports_stopped_by_hw_breakpoint () override;
 196
 197   bool supports_hardware_single_step () override;
 198
 199   bool stopped_by_watchpoint () override;
 200
 201   CORE_ADDR stopped_data_address () override;
 202
 203   bool supports_read_offsets () override;
 204
 205   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 206
 207   bool supports_get_tls_address () override;
 208
 209   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 210                        CORE_ADDR load_module, CORE_ADDR *address) override;
 211
 212   bool supports_qxfer_osdata () override;
 213
 214   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 215                     unsigned const char *writebuf,
 216                     CORE_ADDR offset, int len) override;
 217
 218   bool supports_qxfer_siginfo () override;
 219
 220   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 221                      unsigned const char *writebuf,
 222                      CORE_ADDR offset, int len) override;
 223
 224   bool supports_non_stop () override;
 225
 226   bool async (bool enable) override;
 227
 228   int start_non_stop (bool enable) override;
 229
 230   bool supports_multi_process () override;
 231
 232   bool supports_fork_events () override;
 233
 234   bool supports_vfork_events () override;
 235
 236   bool supports_exec_events () override;
 237
 238   void handle_new_gdb_connection () override;
 239
 240   int handle_monitor_command (char *mon) override;
 241
 242   int core_of_thread (ptid_t ptid) override;
 243
 244 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 245   bool supports_read_loadmap () override;
 246
 247   int read_loadmap (const char *annex, CORE_ADDR offset,
 248                     unsigned char *myaddr, unsigned int len) override;
 249 #endif
 250
 251   CORE_ADDR read_pc (regcache *regcache) override;
 252
 253   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 254
 255   bool supports_thread_stopped () override;
 256
 257   bool thread_stopped (thread_info *thread) override;
 258
 259   void pause_all (bool freeze) override;
 260
 261   void unpause_all (bool unfreeze) override;
 262
 263   void stabilize_threads () override;
 264
 265   bool supports_disable_randomization () override;
 266
 267   bool supports_qxfer_libraries_svr4 () override;
 268
 269   int qxfer_libraries_svr4 (const char *annex,
 270                             unsigned char *readbuf,
 271                             unsigned const char *writebuf,
 272                             CORE_ADDR offset, int len) override;
 273
 274   bool supports_agent () override;
 275
 276 #ifdef HAVE_LINUX_BTRACE
 277   btrace_target_info *enable_btrace (ptid_t ptid,
 278                                      const btrace_config *conf) override;
 279
 280   int disable_btrace (btrace_target_info *tinfo) override;
 281
 282   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 283                    enum btrace_read_type type) override;
 284
 285   int read_btrace_conf (const btrace_target_info *tinfo,
 286                         buffer *buf) override;
 287 #endif
 288
 289   bool supports_range_stepping () override;
 290
 291   bool supports_pid_to_exec_file () override;
 292
 293   char *pid_to_exec_file (int pid) override;
 294
 295   bool supports_multifs () override;
 296
 297   int multifs_open (int pid, const char *filename, int flags,
 298                     mode_t mode) override;
 299
 300   int multifs_unlink (int pid, const char *filename) override;
 301
 302   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 303                             size_t bufsiz) override;
 304
 305   const char *thread_name (ptid_t thread) override;
 306
 307 #if USE_THREAD_DB
 308   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 309                       int *handle_len) override;
 310 #endif
 311
 312   bool supports_catch_syscall () override;
 313
 314   /* Return the information to access registers.  This has public
 315      visibility because proc-service uses it.  */
 316   virtual const regs_info *get_regs_info () = 0;
 317
 318 private:
 319
 320   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 321      fork, or vfork event, we need to add the new LWP to our list
 322      (and return 0 so as not to report the trap to higher layers).
 323      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 324      to a new LWP representing the new program.  */
 325   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 326
 327   /* Do low-level handling of the event, and check if we should go on
 328      and pass it to caller code.  Return the affected lwp if we are, or
 329      NULL otherwise.  */
 330   lwp_info *filter_event (int lwpid, int wstat);
 331
 332   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 333      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 334      minus_one_ptid, to specify any child; a pid PTID, specifying all
 335      lwps of a thread group; or a PTID representing a single lwp.  Store
 336      the stop status through the status pointer WSTAT.  OPTIONS is
 337      passed to the waitpid call.  Return 0 if no event was found and
 338      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 339      was found.  Return the PID of the stopped child otherwise.  */
 340   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 341                                int *wstatp, int options);
 342
 343   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 344      minus_one_ptid, to specify any child; a pid PTID, specifying all
 345      lwps of a thread group; or a PTID representing a single lwp.  Store
 346      the stop status through the status pointer WSTAT.  OPTIONS is
 347      passed to the waitpid call.  Return 0 if no event was found and
 348      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 349      was found.  Return the PID of the stopped child otherwise.  */
 350   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 351
 352   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 353   void wait_for_sigstop ();
 354
 355   /* Wait for process, returns status.  */
 356   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 357                  int target_options);
 358
 359   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 360      If SUSPEND, then also increase the suspend count of every LWP,
 361      except EXCEPT.  */
 362   void stop_all_lwps (int suspend, lwp_info *except);
 363
 364   /* Stopped LWPs that the client wanted to be running, that don't have
 365      pending statuses, are set to run again, except for EXCEPT, if not
 366      NULL.  This undoes a stop_all_lwps call.  */
 367   void unstop_all_lwps (int unsuspend, lwp_info *except);
 368
 369   /* Start a step-over operation on LWP.  When LWP stopped at a
 370      breakpoint, to make progress, we need to remove the breakpoint out
 371      of the way.  If we let other threads run while we do that, they may
 372      pass by the breakpoint location and miss hitting it.  To avoid
 373      that, a step-over momentarily stops all threads while LWP is
 374      single-stepped by either hardware or software while the breakpoint
 375      is temporarily uninserted from the inferior.  When the single-step
 376      finishes, we reinsert the breakpoint, and let all threads that are
 377      supposed to be running, run again.  */
 378   void start_step_over (lwp_info *lwp);
 379
 380   /* If there's a step over in progress, wait until all threads stop
 381      (that is, until the stepping thread finishes its step), and
 382      unsuspend all lwps.  The stepping thread ends with its status
 383      pending, which is processed later when we get back to processing
 384      events.  */
 385   void complete_ongoing_step_over ();
 386
 387   /* Finish a step-over.  Reinsert the breakpoint we had uninserted in
 388      start_step_over, if still there, and delete any single-step
 389      breakpoints we've set, on non hardware single-step targets.
 390      Return true if step over finished.  */
 391   bool finish_step_over (lwp_info *lwp);
 392
 393   /* When we finish a step-over, set threads running again.  If there's
 394      another thread that may need a step-over, now's the time to start
 395      it.  Eventually, we'll move all threads past their breakpoints.  */
 396   void proceed_all_lwps ();
 397
 398   /* The reason we resume in the caller, is because we want to be able
 399      to pass lwp->status_pending as WSTAT, and we need to clear
 400      status_pending_p before resuming, otherwise, resume_one_lwp
 401      refuses to resume.  */
 402   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 403
 404   /* Move THREAD out of the jump pad.  */
 405   void move_out_of_jump_pad (thread_info *thread);
 406
 407   /* Call low_arch_setup on THREAD.  */
 408   void arch_setup_thread (thread_info *thread);
 409
 410 #ifdef HAVE_LINUX_USRREGS
 411   /* Fetch one register.  */
 412   void fetch_register (const usrregs_info *usrregs, regcache *regcache,
 413                        int regno);
 414
 415   /* Store one register.  */
 416   void store_register (const usrregs_info *usrregs, regcache *regcache,
 417                        int regno);
 418 #endif
 419
 420   /* Fetch all registers, or just one, from the child process.
 421      If REGNO is -1, do this for all registers, skipping any that are
 422      assumed to have been retrieved by regsets_fetch_inferior_registers,
 423      unless ALL is non-zero.
 424      Otherwise, REGNO specifies which register (so we can save time).  */
 425   void usr_fetch_inferior_registers (const regs_info *regs_info,
 426                                      regcache *regcache, int regno, int all);
 427
 428   /* Store our register values back into the inferior.
 429      If REGNO is -1, do this for all registers, skipping any that are
 430      assumed to have been saved by regsets_store_inferior_registers,
 431      unless ALL is non-zero.
 432      Otherwise, REGNO specifies which register (so we can save time).  */
 433   void usr_store_inferior_registers (const regs_info *regs_info,
 434                                      regcache *regcache, int regno, int all);
 435
 436   /* Return the PC as read from the regcache of LWP, without any
 437      adjustment.  */
 438   CORE_ADDR get_pc (lwp_info *lwp);
 439
 440   /* Called when the LWP stopped for a signal/trap.  If it stopped for a
 441      trap check what caused it (breakpoint, watchpoint, trace, etc.),
 442      and save the result in the LWP's stop_reason field.  If it stopped
 443      for a breakpoint, decrement the PC if necessary on the lwp's
 444      architecture.  Returns true if we now have the LWP's stop PC.  */
 445   bool save_stop_reason (lwp_info *lwp);
 446
 447   /* Resume execution of LWP.  If STEP is nonzero, single-step it.  If
 448      SIGNAL is nonzero, give it that signal.  */
 449   void resume_one_lwp_throw (lwp_info *lwp, int step, int signal,
 450                              siginfo_t *info);
 451
 452   /* Like resume_one_lwp_throw, but no error is thrown if the LWP
 453      disappears while we try to resume it.  */
 454   void resume_one_lwp (lwp_info *lwp, int step, int signal, siginfo_t *info);
 455
 456   /* This function is called once per thread.  We check the thread's
 457      last resume request, which will tell us whether to resume, step, or
 458      leave the thread stopped.  Any signal the client requested to be
 459      delivered has already been enqueued at this point.
 460
 461      If any thread that GDB wants running is stopped at an internal
 462      breakpoint that needs stepping over, we start a step-over operation
 463      on that particular thread, and leave all others stopped.  */
 464   void proceed_one_lwp (thread_info *thread, lwp_info *except);
 465
 466   /* This function is called once per thread.  We check the thread's
 467      resume request, which will tell us whether to resume, step, or
 468      leave the thread stopped; and what signal, if any, it should be
 469      sent.
 470
 471      For threads which we aren't explicitly told otherwise, we preserve
 472      the stepping flag; this is used for stepping over gdbserver-placed
 473      breakpoints.
 474
 475      If pending_flags was set in any thread, we queue any needed
 476      signals, since we won't actually resume.  We already have a pending
 477      event to report, so we don't need to preserve any step requests;
 478      they should be re-issued if necessary.  */
 479   void resume_one_thread (thread_info *thread, bool leave_all_stopped);
 480
 481   /* Return true if this lwp has an interesting status pending.  */
 482   bool status_pending_p_callback (thread_info *thread, ptid_t ptid);
 483
 484   /* Resume LWPs that are currently stopped without any pending status
 485      to report, but are resumed from the core's perspective.  */
 486   void resume_stopped_resumed_lwps (thread_info *thread);
 487
 488   /* Unsuspend THREAD, except EXCEPT, and proceed.  */
 489   void unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except);
 490
 491   /* Return true if this lwp still has an interesting status pending.
 492      If not (e.g., it had stopped for a breakpoint that is gone), return
 493      false.  */
 494   bool thread_still_has_status_pending (thread_info *thread);
 495
 496   /* Return true if this lwp is to-be-resumed and has an interesting
 497      status pending.  */
 498   bool resume_status_pending (thread_info *thread);
 499
 500   /* Return true if this lwp that GDB wants running is stopped at an
 501      internal breakpoint that we need to step over.  It assumes that
 502      any required STOP_PC adjustment has already been propagated to
 503      the inferior's regcache.  */
 504   bool thread_needs_step_over (thread_info *thread);
 505
 506   /* Single step via hardware or software single step.
 507      Return 1 if hardware single stepping, 0 if software single stepping
 508      or can't single step.  */
 509   int single_step (lwp_info* lwp);
 510
 511   /* Return true if THREAD is doing hardware single step.  */
 512   bool maybe_hw_step (thread_info *thread);
 513
 514   /* Install breakpoints for software single stepping.  */
 515   void install_software_single_step_breakpoints (lwp_info *lwp);
 516
 517   /* Fetch the possibly triggered data watchpoint info and store it in
 518      CHILD.
 519
 520      On some archs, like x86, that use debug registers to set
 521      watchpoints, it's possible that the way to know which watched
 522      address trapped, is to check the register that is used to select
 523      which address to watch.  Problem is, between setting the watchpoint
 524      and reading back which data address trapped, the user may change
 525      the set of watchpoints, and, as a consequence, GDB changes the
 526      debug registers in the inferior.  To avoid reading back a stale
 527      stopped-data-address when that happens, we cache in LP the fact
 528      that a watchpoint trapped, and the corresponding data address, as
 529      soon as we see CHILD stop with a SIGTRAP.  If GDB changes the debug
 530      registers meanwhile, we have the cached data we can rely on.  */
 531   bool check_stopped_by_watchpoint (lwp_info *child);
 532
 533   /* Convert a native/host siginfo object, into/from the siginfo in the
 534      layout of the inferiors' architecture.  */
 535   void siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo,
 536                       int direction);
 537
 538   /* Add a process to the common process list, and set its private
 539      data.  */
 540   process_info *add_linux_process (int pid, int attached);
 541
 542   /* Add a new thread.  */
 543   lwp_info *add_lwp (ptid_t ptid);
 544
 545   /* Delete a thread.  */
 546   void delete_lwp (lwp_info *lwp);
 547
 548 public: /* Make this public because it's used from outside.  */
 549   /* Attach to an inferior process.  Returns 0 on success, ERRNO on
 550      error.  */
 551   int attach_lwp (ptid_t ptid);
 552
 553 private: /* Back to private.  */
 554   /* Detach from LWP.  */
 555   void detach_one_lwp (lwp_info *lwp);
 556
 557   /* Detect zombie thread group leaders, and "exit" them.  We can't
 558      reap their exits until all other threads in the group have
 559      exited.  */
 560   void check_zombie_leaders ();
 561
 562   /* Convenience function that is called when the kernel reports an exit
 563      event.  This decides whether to report the event to GDB as a
 564      process exit event, a thread exit event, or to suppress the
 565      event.  */
 566   ptid_t filter_exit_event (lwp_info *event_child,
 567                             target_waitstatus *ourstatus);
 568
 569   /* Returns true if THREAD is stopped in a jump pad, and we can't
 570      move it out, because we need to report the stop event to GDB.  For
 571      example, if the user puts a breakpoint in the jump pad, it's
 572      because she wants to debug it.  */
 573   bool stuck_in_jump_pad (thread_info *thread);
 574
 575   /* Convenience wrapper.  Returns information about LWP's fast tracepoint
 576      collection status.  */
 577   fast_tpoint_collect_result linux_fast_tracepoint_collecting
 578     (lwp_info *lwp, fast_tpoint_collect_status *status);
 579
 580   /* This function should only be called if LWP got a SYSCALL_SIGTRAP.
 581      Fill *SYSNO with the syscall nr trapped.  */
 582   void get_syscall_trapinfo (lwp_info *lwp, int *sysno);
 583
 584   /* Returns true if GDB is interested in the event_child syscall.
 585      Only to be called when stopped reason is SYSCALL_SIGTRAP.  */
 586   bool gdb_catch_this_syscall (lwp_info *event_child);
 587
 588 protected:
 589   /* The architecture-specific "low" methods are listed below.  */
 590
 591   /* Architecture-specific setup for the current thread.  */
 592   virtual void low_arch_setup () = 0;
 593
 594   /* Return false if we can fetch/store the register, true if we cannot
 595      fetch/store the register.  */
 596   virtual bool low_cannot_fetch_register (int regno) = 0;
 597
 598   virtual bool low_cannot_store_register (int regno) = 0;
 599
 600   /* Hook to fetch a register in some non-standard way.  Used for
 601      example by backends that have read-only registers with hardcoded
 602      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 603      REGNO was supplied, false if not, and we should fallback to the
 604      standard ptrace methods.  */
 605   virtual bool low_fetch_register (regcache *regcache, int regno);
 606
 607   /* Return true if breakpoints are supported.  Such targets must
 608      implement the GET_PC and SET_PC methods.  */
 609   virtual bool low_supports_breakpoints ();
 610
 611   virtual CORE_ADDR low_get_pc (regcache *regcache);
 612
 613   virtual void low_set_pc (regcache *regcache, CORE_ADDR newpc);
 614
 615   /* Find the next possible PCs after the current instruction executes.
 616      Targets that override this method should also override
 617      'supports_software_single_step' to return true.  */
 618   virtual std::vector<CORE_ADDR> low_get_next_pcs (regcache *regcache);
 619
 620   /* Return true if there is a breakpoint at PC.  */
 621   virtual bool low_breakpoint_at (CORE_ADDR pc) = 0;
 622
 623   /* Breakpoint and watchpoint related functions.  See target.h for
 624      comments.  */
 625   virtual int low_insert_point (raw_bkpt_type type, CORE_ADDR addr,
 626                                 int size, raw_breakpoint *bp);
 627
 628   virtual int low_remove_point (raw_bkpt_type type, CORE_ADDR addr,
 629                                 int size, raw_breakpoint *bp);
 630
 631   virtual bool low_stopped_by_watchpoint ();
 632
 633   virtual CORE_ADDR low_stopped_data_address ();
 634
 635   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 636      for registers smaller than an xfer unit).  */
 637   virtual void low_collect_ptrace_register (regcache *regcache, int regno,
 638                                             char *buf);
 639
 640   virtual void low_supply_ptrace_register (regcache *regcache, int regno,
 641                                            const char *buf);
 642
 643   /* Hook to convert from target format to ptrace format and back.
 644      Returns true if any conversion was done; false otherwise.
 645      If DIRECTION is 1, then copy from INF to NATIVE.
 646      If DIRECTION is 0, copy from NATIVE to INF.  */
 647   virtual bool low_siginfo_fixup (siginfo_t *native, gdb_byte *inf,
 648                                   int direction);
 649
 650   /* Hook to call when a new process is created or attached to.
 651      If extra per-process architecture-specific data is needed,
 652      allocate it here.  */
 653   virtual arch_process_info *low_new_process ();
 654
 655   /* Hook to call when a process is being deleted.  If extra per-process
 656      architecture-specific data is needed, delete it here.  */
 657   virtual void low_delete_process (arch_process_info *info);
 658
 659   /* Hook to call when a new thread is detected.
 660      If extra per-thread architecture-specific data is needed,
 661      allocate it here.  */
 662   virtual void low_new_thread (lwp_info *);
 663
 664   /* Hook to call when a thread is being deleted.  If extra per-thread
 665      architecture-specific data is needed, delete it here.  */
 666   virtual void low_delete_thread (arch_lwp_info *);
 667
 668   /* Hook to call, if any, when a new fork is attached.  */
 669   virtual void low_new_fork (process_info *parent, process_info *child);
 670
 671   /* Hook to call prior to resuming a thread.  */
 672   virtual void low_prepare_to_resume (lwp_info *lwp);
 673
 674   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 675      success, -1 on failure.  */
 676   virtual int low_get_thread_area (int lwpid, CORE_ADDR *addrp);
 677
 678   /* Returns true if the low target supports range stepping.  */
 679   virtual bool low_supports_range_stepping ();
 680
 681   /* Return true if the target supports catch syscall.  Such targets
 682      override the low_get_syscall_trapinfo method below.  */
 683   virtual bool low_supports_catch_syscall ();
 684
 685   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 686      inferior is stopped due to SYSCALL_SIGTRAP.  */
 687   virtual void low_get_syscall_trapinfo (regcache *regcache, int *sysno);
 688
 689   /* How many bytes the PC should be decremented after a break.  */
 690   virtual int low_decr_pc_after_break ();
 691 };
 692
 693 extern linux_process_target *the_linux_target;
 694
 695 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 696 #define get_lwp_thread(lwp) ((lwp)->thread)
 697
 698 /* This struct is recorded in the target_data field of struct thread_info.
 699
 700    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 701    GDB protocol representation of the thread ID.  Threads also have
 702    a "process ID" (poorly named) which is (presently) the same as the
 703    LWP ID.
 704
 705    There is also ``all_processes'' is keyed by the "overall process ID",
 706    which GNU/Linux calls tgid, "thread group ID".  */
 707
 708 struct lwp_info
 709 {
 710   /* Backlink to the parent object.  */
 711   struct thread_info *thread;
 712
 713   /* If this flag is set, the next SIGSTOP will be ignored (the
 714      process will be immediately resumed).  This means that either we
 715      sent the SIGSTOP to it ourselves and got some other pending event
 716      (so the SIGSTOP is still pending), or that we stopped the
 717      inferior implicitly via PTRACE_ATTACH and have not waited for it
 718      yet.  */
 719   int stop_expected;
 720
 721   /* When this is true, we shall not try to resume this thread, even
 722      if last_resume_kind isn't resume_stop.  */
 723   int suspended;
 724
 725   /* If this flag is set, the lwp is known to be stopped right now (stop
 726      event already received in a wait()).  */
 727   int stopped;
 728
 729   /* Signal whether we are in a SYSCALL_ENTRY or
 730      in a SYSCALL_RETURN event.
 731      Values:
 732      - TARGET_WAITKIND_SYSCALL_ENTRY
 733      - TARGET_WAITKIND_SYSCALL_RETURN */
 734   enum target_waitkind syscall_state;
 735
 736   /* When stopped is set, the last wait status recorded for this lwp.  */
 737   int last_status;
 738
 739   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 740      this LWP's last event, to pass to GDB without any further
 741      processing.  This is used to store extended ptrace event
 742      information or exit status until it can be reported to GDB.  */
 743   struct target_waitstatus waitstatus;
 744
 745   /* A pointer to the fork child/parent relative.  Valid only while
 746      the parent fork event is not reported to higher layers.  Used to
 747      avoid wildcard vCont actions resuming a fork child before GDB is
 748      notified about the parent's fork event.  */
 749   struct lwp_info *fork_relative;
 750
 751   /* When stopped is set, this is where the lwp last stopped, with
 752      decr_pc_after_break already accounted for.  If the LWP is
 753      running, this is the address at which the lwp was resumed.  */
 754   CORE_ADDR stop_pc;
 755
 756   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 757      been reported.  */
 758   int status_pending_p;
 759   int status_pending;
 760
 761   /* The reason the LWP last stopped, if we need to track it
 762      (breakpoint, watchpoint, etc.)  */
 763   enum target_stop_reason stop_reason;
 764
 765   /* On architectures where it is possible to know the data address of
 766      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 767      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 768      is true.  */
 769   CORE_ADDR stopped_data_address;
 770
 771   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 772      stop (SIGTRAP stops only).  */
 773   CORE_ADDR bp_reinsert;
 774
 775   /* If this flag is set, the last continue operation at the ptrace
 776      level on this process was a single-step.  */
 777   int stepping;
 778
 779   /* Range to single step within.  This is a copy of the step range
 780      passed along the last resume request.  See 'struct
 781      thread_resume'.  */
 782   CORE_ADDR step_range_start;   /* Inclusive */
 783   CORE_ADDR step_range_end;     /* Exclusive */
 784
 785   /* If this flag is set, we need to set the event request flags the
 786      next time we see this LWP stop.  */
 787   int must_set_ptrace_flags;
 788
 789   /* If this is non-zero, it points to a chain of signals which need to
 790      be delivered to this process.  */
 791   struct pending_signals *pending_signals;
 792
 793   /* A link used when resuming.  It is initialized from the resume request,
 794      and then processed and cleared in linux_resume_one_lwp.  */
 795   struct thread_resume *resume;
 796
 797   /* Information bout this lwp's fast tracepoint collection status (is it
 798      currently stopped in the jump pad, and if so, before or at/after the
 799      relocated instruction).  Normally, we won't care about this, but we will
 800      if a signal arrives to this lwp while it is collecting.  */
 801   fast_tpoint_collect_result collecting_fast_tracepoint;
 802
 803   /* If this is non-zero, it points to a chain of signals which need
 804      to be reported to GDB.  These were deferred because the thread
 805      was doing a fast tracepoint collect when they arrived.  */
 806   struct pending_signals *pending_signals_to_report;
 807
 808   /* When collecting_fast_tracepoint is first found to be 1, we insert
 809      a exit-jump-pad-quickly breakpoint.  This is it.  */
 810   struct breakpoint *exit_jump_pad_bkpt;
 811
 812 #ifdef USE_THREAD_DB
 813   int thread_known;
 814   /* The thread handle, used for e.g. TLS access.  Only valid if
 815      THREAD_KNOWN is set.  */
 816   td_thrhandle_t th;
 817
 818   /* The pthread_t handle.  */
 819   thread_t thread_handle;
 820 #endif
 821
 822   /* Arch-specific additions.  */
 823   struct arch_lwp_info *arch_private;
 824 };
 825
 826 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 827
 828 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 829    errno).  */
 830 int linux_attach_lwp (ptid_t ptid);
 831
 832 struct lwp_info *find_lwp_pid (ptid_t ptid);
 833 /* For linux_stop_lwp see nat/linux-nat.h.  */
 834
 835 #ifdef HAVE_LINUX_REGSETS
 836 void initialize_regsets_info (struct regsets_info *regsets_info);
 837 #endif
 838
 839 void initialize_low_arch (void);
 840
 841 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 842 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 843
 844 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 845 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 846
 847 /* From thread-db.c  */
 848 int thread_db_init (void);
 849 void thread_db_detach (struct process_info *);
 850 void thread_db_mourn (struct process_info *);
 851 int thread_db_handle_monitor_command (char *);
 852 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 853                                CORE_ADDR load_module, CORE_ADDR *address);
 854 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 855
 856 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 857    both the clone and the parent should be stopped.  This function does
 858    whatever is required have the clone under thread_db's control.  */
 859
 860 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 861
 862 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 863
 864 extern int have_ptrace_getregset;
 865
 866 /* Search for the value with type MATCH in the auxv vector with
 867    entries of length WORDSIZE bytes.  If found, store the value in
 868    *VALP and return 1.  If not found or if there is an error, return
 869    0.  */
 870
 871 int linux_get_auxv (int wordsize, CORE_ADDR match,
 872                     CORE_ADDR *valp);
 873
 874 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 875    WORDSIZE.  If no entry was found, return zero.  */
 876
 877 CORE_ADDR linux_get_hwcap (int wordsize);
 878
 879 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 880    WORDSIZE.  If no entry was found, return zero.  */
 881
 882 CORE_ADDR linux_get_hwcap2 (int wordsize);
 883
 884 #endif /* GDBSERVER_LINUX_LOW_H */