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