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   /* Returns true if the low target supports tracepoints.  */
 135   int (*supports_tracepoints) (void);
 136
 137   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 138      success, -1 on failure.  */
 139   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 140
 141   /* Install a fast tracepoint jump pad.  See target.h for
 142      comments.  */
 143   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 144                                            CORE_ADDR collector,
 145                                            CORE_ADDR lockaddr,
 146                                            ULONGEST orig_size,
 147                                            CORE_ADDR *jump_entry,
 148                                            CORE_ADDR *trampoline,
 149                                            ULONGEST *trampoline_size,
 150                                            unsigned char *jjump_pad_insn,
 151                                            ULONGEST *jjump_pad_insn_size,
 152                                            CORE_ADDR *adjusted_insn_addr,
 153                                            CORE_ADDR *adjusted_insn_addr_end,
 154                                            char *err);
 155
 156   /* Return the bytecode operations vector for the current inferior.
 157      Returns NULL if bytecode compilation is not supported.  */
 158   struct emit_ops *(*emit_ops) (void);
 159
 160   /* Return the minimum length of an instruction that can be safely overwritten
 161      for use as a fast tracepoint.  */
 162   int (*get_min_fast_tracepoint_insn_len) (void);
 163
 164   /* Returns true if the low target supports range stepping.  */
 165   int (*supports_range_stepping) (void);
 166
 167   /* See target.h.  */
 168   int (*supports_hardware_single_step) (void);
 169
 170   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
 171      inferior is stopped due to SYSCALL_SIGTRAP.  */
 172   void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno);
 173
 174   /* See target.h.  */
 175   int (*get_ipa_tdesc_idx) (void);
 176 };
 177
 178 extern struct linux_target_ops the_low_target;
 179
 180 /* Target ops definitions for a Linux target.  */
 181
 182 class linux_process_target : public process_stratum_target
 183 {
 184 public:
 185
 186   int create_inferior (const char *program,
 187                        const std::vector<char *> &program_args) override;
 188
 189   void post_create_inferior () override;
 190
 191   int attach (unsigned long pid) override;
 192
 193   int kill (process_info *proc) override;
 194
 195   int detach (process_info *proc) override;
 196
 197   void mourn (process_info *proc) override;
 198
 199   void join (int pid) override;
 200
 201   bool thread_alive (ptid_t pid) override;
 202
 203   void resume (thread_resume *resume_info, size_t n) override;
 204
 205   ptid_t wait (ptid_t ptid, target_waitstatus *status,
 206                int options) override;
 207
 208   void fetch_registers (regcache *regcache, int regno) override;
 209
 210   void store_registers (regcache *regcache, int regno) override;
 211
 212   int prepare_to_access_memory () override;
 213
 214   void done_accessing_memory () override;
 215
 216   int read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
 217                    int len) override;
 218
 219   int write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 220                     int len) override;
 221
 222   void look_up_symbols () override;
 223
 224   void request_interrupt () override;
 225
 226   bool supports_read_auxv () override;
 227
 228   int read_auxv (CORE_ADDR offset, unsigned char *myaddr,
 229                  unsigned int len) override;
 230
 231   int insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 232                     int size, raw_breakpoint *bp) override;
 233
 234   int remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 235                     int size, raw_breakpoint *bp) override;
 236
 237   bool stopped_by_sw_breakpoint () override;
 238
 239   bool supports_stopped_by_sw_breakpoint () override;
 240
 241   bool stopped_by_hw_breakpoint () override;
 242
 243   bool supports_stopped_by_hw_breakpoint () override;
 244
 245   bool supports_hardware_single_step () override;
 246
 247   bool stopped_by_watchpoint () override;
 248
 249   CORE_ADDR stopped_data_address () override;
 250
 251   bool supports_read_offsets () override;
 252
 253   int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 254
 255   bool supports_get_tls_address () override;
 256
 257   int get_tls_address (thread_info *thread, CORE_ADDR offset,
 258                        CORE_ADDR load_module, CORE_ADDR *address) override;
 259
 260   bool supports_qxfer_osdata () override;
 261
 262   int qxfer_osdata (const char *annex, unsigned char *readbuf,
 263                     unsigned const char *writebuf,
 264                     CORE_ADDR offset, int len) override;
 265
 266   bool supports_qxfer_siginfo () override;
 267
 268   int qxfer_siginfo (const char *annex, unsigned char *readbuf,
 269                      unsigned const char *writebuf,
 270                      CORE_ADDR offset, int len) override;
 271
 272   bool supports_non_stop () override;
 273
 274   bool async (bool enable) override;
 275
 276   int start_non_stop (bool enable) override;
 277
 278   bool supports_multi_process () override;
 279
 280   bool supports_fork_events () override;
 281
 282   bool supports_vfork_events () override;
 283
 284   bool supports_exec_events () override;
 285
 286   void handle_new_gdb_connection () override;
 287
 288   int handle_monitor_command (char *mon) override;
 289
 290   int core_of_thread (ptid_t ptid) override;
 291
 292 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
 293   bool supports_read_loadmap () override;
 294
 295   int read_loadmap (const char *annex, CORE_ADDR offset,
 296                     unsigned char *myaddr, unsigned int len) override;
 297 #endif
 298
 299   bool supports_tracepoints () override;
 300
 301   CORE_ADDR read_pc (regcache *regcache) override;
 302
 303   void write_pc (regcache *regcache, CORE_ADDR pc) override;
 304
 305   bool supports_thread_stopped () override;
 306
 307   bool thread_stopped (thread_info *thread) override;
 308
 309   void pause_all (bool freeze) override;
 310
 311   void unpause_all (bool unfreeze) override;
 312
 313   void stabilize_threads () override;
 314
 315   bool supports_fast_tracepoints () override;
 316
 317   int install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
 318                                         CORE_ADDR tpaddr,
 319                                         CORE_ADDR collector,
 320                                         CORE_ADDR lockaddr,
 321                                         ULONGEST orig_size,
 322                                         CORE_ADDR *jump_entry,
 323                                         CORE_ADDR *trampoline,
 324                                         ULONGEST *trampoline_size,
 325                                         unsigned char *jjump_pad_insn,
 326                                         ULONGEST *jjump_pad_insn_size,
 327                                         CORE_ADDR *adjusted_insn_addr,
 328                                         CORE_ADDR *adjusted_insn_addr_end,
 329                                         char *err) override;
 330
 331   int get_min_fast_tracepoint_insn_len () override;
 332
 333   struct emit_ops *emit_ops () override;
 334
 335   bool supports_disable_randomization () override;
 336
 337   bool supports_qxfer_libraries_svr4 () override;
 338
 339   int qxfer_libraries_svr4 (const char *annex,
 340                             unsigned char *readbuf,
 341                             unsigned const char *writebuf,
 342                             CORE_ADDR offset, int len) override;
 343
 344   bool supports_agent () override;
 345
 346 #ifdef HAVE_LINUX_BTRACE
 347   btrace_target_info *enable_btrace (ptid_t ptid,
 348                                      const btrace_config *conf) override;
 349
 350   int disable_btrace (btrace_target_info *tinfo) override;
 351
 352   int read_btrace (btrace_target_info *tinfo, buffer *buf,
 353                    enum btrace_read_type type) override;
 354
 355   int read_btrace_conf (const btrace_target_info *tinfo,
 356                         buffer *buf) override;
 357 #endif
 358
 359   bool supports_range_stepping () override;
 360
 361   bool supports_pid_to_exec_file () override;
 362
 363   char *pid_to_exec_file (int pid) override;
 364
 365   bool supports_multifs () override;
 366
 367   int multifs_open (int pid, const char *filename, int flags,
 368                     mode_t mode) override;
 369
 370   int multifs_unlink (int pid, const char *filename) override;
 371
 372   ssize_t multifs_readlink (int pid, const char *filename, char *buf,
 373                             size_t bufsiz) override;
 374
 375   const char *thread_name (ptid_t thread) override;
 376
 377 #if USE_THREAD_DB
 378   bool thread_handle (ptid_t ptid, gdb_byte **handle,
 379                       int *handle_len) override;
 380 #endif
 381
 382   bool supports_catch_syscall () override;
 383
 384   int get_ipa_tdesc_idx () override;
 385
 386   /* Return the information to access registers.  This has public
 387      visibility because proc-service uses it.  */
 388   virtual const regs_info *get_regs_info () = 0;
 389
 390 private:
 391
 392   /* Handle a GNU/Linux extended wait response.  If we see a clone,
 393      fork, or vfork event, we need to add the new LWP to our list
 394      (and return 0 so as not to report the trap to higher layers).
 395      If we see an exec event, we will modify ORIG_EVENT_LWP to point
 396      to a new LWP representing the new program.  */
 397   int handle_extended_wait (lwp_info **orig_event_lwp, int wstat);
 398
 399   /* Do low-level handling of the event, and check if we should go on
 400      and pass it to caller code.  Return the affected lwp if we are, or
 401      NULL otherwise.  */
 402   lwp_info *filter_event (int lwpid, int wstat);
 403
 404   /* Wait for an event from child(ren) WAIT_PTID, and return any that
 405      match FILTER_PTID (leaving others pending).  The PTIDs can be:
 406      minus_one_ptid, to specify any child; a pid PTID, specifying all
 407      lwps of a thread group; or a PTID representing a single lwp.  Store
 408      the stop status through the status pointer WSTAT.  OPTIONS is
 409      passed to the waitpid call.  Return 0 if no event was found and
 410      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 411      was found.  Return the PID of the stopped child otherwise.  */
 412   int wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 413                                int *wstatp, int options);
 414
 415   /* Wait for an event from child(ren) PTID.  PTIDs can be:
 416      minus_one_ptid, to specify any child; a pid PTID, specifying all
 417      lwps of a thread group; or a PTID representing a single lwp.  Store
 418      the stop status through the status pointer WSTAT.  OPTIONS is
 419      passed to the waitpid call.  Return 0 if no event was found and
 420      OPTIONS contains WNOHANG.  Return -1 if no unwaited-for children
 421      was found.  Return the PID of the stopped child otherwise.  */
 422   int wait_for_event (ptid_t ptid, int *wstatp, int options);
 423
 424   /* Wait for all children to stop for the SIGSTOPs we just queued.  */
 425   void wait_for_sigstop ();
 426
 427   /* Wait for process, returns status.  */
 428   ptid_t wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
 429                  int target_options);
 430
 431   /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
 432      If SUSPEND, then also increase the suspend count of every LWP,
 433      except EXCEPT.  */
 434   void stop_all_lwps (int suspend, lwp_info *except);
 435
 436   /* Stopped LWPs that the client wanted to be running, that don't have
 437      pending statuses, are set to run again, except for EXCEPT, if not
 438      NULL.  This undoes a stop_all_lwps call.  */
 439   void unstop_all_lwps (int unsuspend, lwp_info *except);
 440
 441   /* Start a step-over operation on LWP.  When LWP stopped at a
 442      breakpoint, to make progress, we need to remove the breakpoint out
 443      of the way.  If we let other threads run while we do that, they may
 444      pass by the breakpoint location and miss hitting it.  To avoid
 445      that, a step-over momentarily stops all threads while LWP is
 446      single-stepped by either hardware or software while the breakpoint
 447      is temporarily uninserted from the inferior.  When the single-step
 448      finishes, we reinsert the breakpoint, and let all threads that are
 449      supposed to be running, run again.  */
 450   void start_step_over (lwp_info *lwp);
 451
 452   /* If there's a step over in progress, wait until all threads stop
 453      (that is, until the stepping thread finishes its step), and
 454      unsuspend all lwps.  The stepping thread ends with its status
 455      pending, which is processed later when we get back to processing
 456      events.  */
 457   void complete_ongoing_step_over ();
 458
 459   /* When we finish a step-over, set threads running again.  If there's
 460      another thread that may need a step-over, now's the time to start
 461      it.  Eventually, we'll move all threads past their breakpoints.  */
 462   void proceed_all_lwps ();
 463
 464   /* The reason we resume in the caller, is because we want to be able
 465      to pass lwp->status_pending as WSTAT, and we need to clear
 466      status_pending_p before resuming, otherwise, resume_one_lwp
 467      refuses to resume.  */
 468   bool maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat);
 469
 470   /* Move THREAD out of the jump pad.  */
 471   void move_out_of_jump_pad (thread_info *thread);
 472
 473   /* Call low_arch_setup on THREAD.  */
 474   void arch_setup_thread (thread_info *thread);
 475
 476 #ifdef HAVE_LINUX_USRREGS
 477   /* Fetch one register.  */
 478   void fetch_register (const usrregs_info *usrregs, regcache *regcache,
 479                        int regno);
 480
 481   /* Store one register.  */
 482   void store_register (const usrregs_info *usrregs, regcache *regcache,
 483                        int regno);
 484 #endif
 485
 486   /* Fetch all registers, or just one, from the child process.
 487      If REGNO is -1, do this for all registers, skipping any that are
 488      assumed to have been retrieved by regsets_fetch_inferior_registers,
 489      unless ALL is non-zero.
 490      Otherwise, REGNO specifies which register (so we can save time).  */
 491   void usr_fetch_inferior_registers (const regs_info *regs_info,
 492                                      regcache *regcache, int regno, int all);
 493
 494   /* Store our register values back into the inferior.
 495      If REGNO is -1, do this for all registers, skipping any that are
 496      assumed to have been saved by regsets_store_inferior_registers,
 497      unless ALL is non-zero.
 498      Otherwise, REGNO specifies which register (so we can save time).  */
 499   void usr_store_inferior_registers (const regs_info *regs_info,
 500                                      regcache *regcache, int regno, int all);
 501
 502   /* Return the PC as read from the regcache of LWP, without any
 503      adjustment.  */
 504   CORE_ADDR get_pc (lwp_info *lwp);
 505
 506   /* Called when the LWP stopped for a signal/trap.  If it stopped for a
 507      trap check what caused it (breakpoint, watchpoint, trace, etc.),
 508      and save the result in the LWP's stop_reason field.  If it stopped
 509      for a breakpoint, decrement the PC if necessary on the lwp's
 510      architecture.  Returns true if we now have the LWP's stop PC.  */
 511   bool save_stop_reason (lwp_info *lwp);
 512
 513   /* Resume execution of LWP.  If STEP is nonzero, single-step it.  If
 514      SIGNAL is nonzero, give it that signal.  */
 515   void resume_one_lwp_throw (lwp_info *lwp, int step, int signal,
 516                              siginfo_t *info);
 517
 518   /* Like resume_one_lwp_throw, but no error is thrown if the LWP
 519      disappears while we try to resume it.  */
 520   void resume_one_lwp (lwp_info *lwp, int step, int signal, siginfo_t *info);
 521
 522   /* This function is called once per thread.  We check the thread's
 523      last resume request, which will tell us whether to resume, step, or
 524      leave the thread stopped.  Any signal the client requested to be
 525      delivered has already been enqueued at this point.
 526
 527      If any thread that GDB wants running is stopped at an internal
 528      breakpoint that needs stepping over, we start a step-over operation
 529      on that particular thread, and leave all others stopped.  */
 530   void proceed_one_lwp (thread_info *thread, lwp_info *except);
 531
 532   /* This function is called once per thread.  We check the thread's
 533      resume request, which will tell us whether to resume, step, or
 534      leave the thread stopped; and what signal, if any, it should be
 535      sent.
 536
 537      For threads which we aren't explicitly told otherwise, we preserve
 538      the stepping flag; this is used for stepping over gdbserver-placed
 539      breakpoints.
 540
 541      If pending_flags was set in any thread, we queue any needed
 542      signals, since we won't actually resume.  We already have a pending
 543      event to report, so we don't need to preserve any step requests;
 544      they should be re-issued if necessary.  */
 545   void resume_one_thread (thread_info *thread, bool leave_all_stopped);
 546
 547   /* Return true if this lwp has an interesting status pending.  */
 548   bool status_pending_p_callback (thread_info *thread, ptid_t ptid);
 549
 550   /* Resume LWPs that are currently stopped without any pending status
 551      to report, but are resumed from the core's perspective.  */
 552   void resume_stopped_resumed_lwps (thread_info *thread);
 553
 554   /* Unsuspend THREAD, except EXCEPT, and proceed.  */
 555   void unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except);
 556
 557   /* Return true if this lwp still has an interesting status pending.
 558      If not (e.g., it had stopped for a breakpoint that is gone), return
 559      false.  */
 560   bool thread_still_has_status_pending (thread_info *thread);
 561
 562   /* Return true if this lwp is to-be-resumed and has an interesting
 563      status pending.  */
 564   bool resume_status_pending (thread_info *thread);
 565
 566   /* Return true if this lwp that GDB wants running is stopped at an
 567      internal breakpoint that we need to step over.  It assumes that
 568      any required STOP_PC adjustment has already been propagated to
 569      the inferior's regcache.  */
 570   bool thread_needs_step_over (thread_info *thread);
 571
 572   /* Single step via hardware or software single step.
 573      Return 1 if hardware single stepping, 0 if software single stepping
 574      or can't single step.  */
 575   int single_step (lwp_info* lwp);
 576
 577   /* Install breakpoints for software single stepping.  */
 578   void install_software_single_step_breakpoints (lwp_info *lwp);
 579
 580   /* Fetch the possibly triggered data watchpoint info and store it in
 581      CHILD.
 582
 583      On some archs, like x86, that use debug registers to set
 584      watchpoints, it's possible that the way to know which watched
 585      address trapped, is to check the register that is used to select
 586      which address to watch.  Problem is, between setting the watchpoint
 587      and reading back which data address trapped, the user may change
 588      the set of watchpoints, and, as a consequence, GDB changes the
 589      debug registers in the inferior.  To avoid reading back a stale
 590      stopped-data-address when that happens, we cache in LP the fact
 591      that a watchpoint trapped, and the corresponding data address, as
 592      soon as we see CHILD stop with a SIGTRAP.  If GDB changes the debug
 593      registers meanwhile, we have the cached data we can rely on.  */
 594   bool check_stopped_by_watchpoint (lwp_info *child);
 595
 596   /* Convert a native/host siginfo object, into/from the siginfo in the
 597      layout of the inferiors' architecture.  */
 598   void siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo,
 599                       int direction);
 600
 601   /* Add a process to the common process list, and set its private
 602      data.  */
 603   process_info *add_linux_process (int pid, int attached);
 604
 605   /* Add a new thread.  */
 606   lwp_info *add_lwp (ptid_t ptid);
 607
 608   /* Delete a thread.  */
 609   void delete_lwp (lwp_info *lwp);
 610
 611 public: /* Make this public because it's used from outside.  */
 612   /* Attach to an inferior process.  Returns 0 on success, ERRNO on
 613      error.  */
 614   int attach_lwp (ptid_t ptid);
 615
 616 private: /* Back to private.  */
 617   /* Detach from LWP.  */
 618   void detach_one_lwp (lwp_info *lwp);
 619
 620   /* Detect zombie thread group leaders, and "exit" them.  We can't
 621      reap their exits until all other threads in the group have
 622      exited.  */
 623   void check_zombie_leaders ();
 624
 625   /* Convenience function that is called when the kernel reports an exit
 626      event.  This decides whether to report the event to GDB as a
 627      process exit event, a thread exit event, or to suppress the
 628      event.  */
 629   ptid_t filter_exit_event (lwp_info *event_child,
 630                             target_waitstatus *ourstatus);
 631
 632 protected:
 633   /* The architecture-specific "low" methods are listed below.  */
 634
 635   /* Architecture-specific setup for the current thread.  */
 636   virtual void low_arch_setup () = 0;
 637
 638   /* Return false if we can fetch/store the register, true if we cannot
 639      fetch/store the register.  */
 640   virtual bool low_cannot_fetch_register (int regno) = 0;
 641
 642   virtual bool low_cannot_store_register (int regno) = 0;
 643
 644   /* Hook to fetch a register in some non-standard way.  Used for
 645      example by backends that have read-only registers with hardcoded
 646      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 647      REGNO was supplied, false if not, and we should fallback to the
 648      standard ptrace methods.  */
 649   virtual bool low_fetch_register (regcache *regcache, int regno);
 650
 651   /* Return true if breakpoints are supported.  Such targets must
 652      implement the GET_PC and SET_PC methods.  */
 653   virtual bool low_supports_breakpoints ();
 654
 655   virtual CORE_ADDR low_get_pc (regcache *regcache);
 656
 657   virtual void low_set_pc (regcache *regcache, CORE_ADDR newpc);
 658
 659   /* Find the next possible PCs after the current instruction executes.
 660      Targets that override this method should also override
 661      'supports_software_single_step' to return true.  */
 662   virtual std::vector<CORE_ADDR> low_get_next_pcs (regcache *regcache);
 663
 664   /* Return true if there is a breakpoint at PC.  */
 665   virtual bool low_breakpoint_at (CORE_ADDR pc) = 0;
 666
 667   /* Breakpoint and watchpoint related functions.  See target.h for
 668      comments.  */
 669   virtual int low_insert_point (raw_bkpt_type type, CORE_ADDR addr,
 670                                 int size, raw_breakpoint *bp);
 671
 672   virtual int low_remove_point (raw_bkpt_type type, CORE_ADDR addr,
 673                                 int size, raw_breakpoint *bp);
 674
 675   virtual bool low_stopped_by_watchpoint ();
 676
 677   virtual CORE_ADDR low_stopped_data_address ();
 678
 679   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 680      for registers smaller than an xfer unit).  */
 681   virtual void low_collect_ptrace_register (regcache *regcache, int regno,
 682                                             char *buf);
 683
 684   virtual void low_supply_ptrace_register (regcache *regcache, int regno,
 685                                            const char *buf);
 686
 687   /* Hook to convert from target format to ptrace format and back.
 688      Returns true if any conversion was done; false otherwise.
 689      If DIRECTION is 1, then copy from INF to NATIVE.
 690      If DIRECTION is 0, copy from NATIVE to INF.  */
 691   virtual bool low_siginfo_fixup (siginfo_t *native, gdb_byte *inf,
 692                                   int direction);
 693
 694   /* Hook to call when a new process is created or attached to.
 695      If extra per-process architecture-specific data is needed,
 696      allocate it here.  */
 697   virtual arch_process_info *low_new_process ();
 698
 699   /* Hook to call when a process is being deleted.  If extra per-process
 700      architecture-specific data is needed, delete it here.  */
 701   virtual void low_delete_process (arch_process_info *info);
 702
 703   /* Hook to call when a new thread is detected.
 704      If extra per-thread architecture-specific data is needed,
 705      allocate it here.  */
 706   virtual void low_new_thread (lwp_info *);
 707
 708   /* Hook to call when a thread is being deleted.  If extra per-thread
 709      architecture-specific data is needed, delete it here.  */
 710   virtual void low_delete_thread (arch_lwp_info *);
 711
 712   /* Hook to call, if any, when a new fork is attached.  */
 713   virtual void low_new_fork (process_info *parent, process_info *child);
 714
 715   /* Hook to call prior to resuming a thread.  */
 716   virtual void low_prepare_to_resume (lwp_info *lwp);
 717
 718   /* How many bytes the PC should be decremented after a break.  */
 719   virtual int low_decr_pc_after_break ();
 720 };
 721
 722 extern linux_process_target *the_linux_target;
 723
 724 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
 725 #define get_lwp_thread(lwp) ((lwp)->thread)
 726
 727 /* This struct is recorded in the target_data field of struct thread_info.
 728
 729    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 730    GDB protocol representation of the thread ID.  Threads also have
 731    a "process ID" (poorly named) which is (presently) the same as the
 732    LWP ID.
 733
 734    There is also ``all_processes'' is keyed by the "overall process ID",
 735    which GNU/Linux calls tgid, "thread group ID".  */
 736
 737 struct lwp_info
 738 {
 739   /* Backlink to the parent object.  */
 740   struct thread_info *thread;
 741
 742   /* If this flag is set, the next SIGSTOP will be ignored (the
 743      process will be immediately resumed).  This means that either we
 744      sent the SIGSTOP to it ourselves and got some other pending event
 745      (so the SIGSTOP is still pending), or that we stopped the
 746      inferior implicitly via PTRACE_ATTACH and have not waited for it
 747      yet.  */
 748   int stop_expected;
 749
 750   /* When this is true, we shall not try to resume this thread, even
 751      if last_resume_kind isn't resume_stop.  */
 752   int suspended;
 753
 754   /* If this flag is set, the lwp is known to be stopped right now (stop
 755      event already received in a wait()).  */
 756   int stopped;
 757
 758   /* Signal whether we are in a SYSCALL_ENTRY or
 759      in a SYSCALL_RETURN event.
 760      Values:
 761      - TARGET_WAITKIND_SYSCALL_ENTRY
 762      - TARGET_WAITKIND_SYSCALL_RETURN */
 763   enum target_waitkind syscall_state;
 764
 765   /* When stopped is set, the last wait status recorded for this lwp.  */
 766   int last_status;
 767
 768   /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for
 769      this LWP's last event, to pass to GDB without any further
 770      processing.  This is used to store extended ptrace event
 771      information or exit status until it can be reported to GDB.  */
 772   struct target_waitstatus waitstatus;
 773
 774   /* A pointer to the fork child/parent relative.  Valid only while
 775      the parent fork event is not reported to higher layers.  Used to
 776      avoid wildcard vCont actions resuming a fork child before GDB is
 777      notified about the parent's fork event.  */
 778   struct lwp_info *fork_relative;
 779
 780   /* When stopped is set, this is where the lwp last stopped, with
 781      decr_pc_after_break already accounted for.  If the LWP is
 782      running, this is the address at which the lwp was resumed.  */
 783   CORE_ADDR stop_pc;
 784
 785   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 786      been reported.  */
 787   int status_pending_p;
 788   int status_pending;
 789
 790   /* The reason the LWP last stopped, if we need to track it
 791      (breakpoint, watchpoint, etc.)  */
 792   enum target_stop_reason stop_reason;
 793
 794   /* On architectures where it is possible to know the data address of
 795      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 796      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 797      is true.  */
 798   CORE_ADDR stopped_data_address;
 799
 800   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 801      stop (SIGTRAP stops only).  */
 802   CORE_ADDR bp_reinsert;
 803
 804   /* If this flag is set, the last continue operation at the ptrace
 805      level on this process was a single-step.  */
 806   int stepping;
 807
 808   /* Range to single step within.  This is a copy of the step range
 809      passed along the last resume request.  See 'struct
 810      thread_resume'.  */
 811   CORE_ADDR step_range_start;   /* Inclusive */
 812   CORE_ADDR step_range_end;     /* Exclusive */
 813
 814   /* If this flag is set, we need to set the event request flags the
 815      next time we see this LWP stop.  */
 816   int must_set_ptrace_flags;
 817
 818   /* If this is non-zero, it points to a chain of signals which need to
 819      be delivered to this process.  */
 820   struct pending_signals *pending_signals;
 821
 822   /* A link used when resuming.  It is initialized from the resume request,
 823      and then processed and cleared in linux_resume_one_lwp.  */
 824   struct thread_resume *resume;
 825
 826   /* Information bout this lwp's fast tracepoint collection status (is it
 827      currently stopped in the jump pad, and if so, before or at/after the
 828      relocated instruction).  Normally, we won't care about this, but we will
 829      if a signal arrives to this lwp while it is collecting.  */
 830   fast_tpoint_collect_result collecting_fast_tracepoint;
 831
 832   /* If this is non-zero, it points to a chain of signals which need
 833      to be reported to GDB.  These were deferred because the thread
 834      was doing a fast tracepoint collect when they arrived.  */
 835   struct pending_signals *pending_signals_to_report;
 836
 837   /* When collecting_fast_tracepoint is first found to be 1, we insert
 838      a exit-jump-pad-quickly breakpoint.  This is it.  */
 839   struct breakpoint *exit_jump_pad_bkpt;
 840
 841 #ifdef USE_THREAD_DB
 842   int thread_known;
 843   /* The thread handle, used for e.g. TLS access.  Only valid if
 844      THREAD_KNOWN is set.  */
 845   td_thrhandle_t th;
 846
 847   /* The pthread_t handle.  */
 848   thread_t thread_handle;
 849 #endif
 850
 851   /* Arch-specific additions.  */
 852   struct arch_lwp_info *arch_private;
 853 };
 854
 855 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 856
 857 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 858    errno).  */
 859 int linux_attach_lwp (ptid_t ptid);
 860
 861 struct lwp_info *find_lwp_pid (ptid_t ptid);
 862 /* For linux_stop_lwp see nat/linux-nat.h.  */
 863
 864 #ifdef HAVE_LINUX_REGSETS
 865 void initialize_regsets_info (struct regsets_info *regsets_info);
 866 #endif
 867
 868 void initialize_low_arch (void);
 869
 870 void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc);
 871 CORE_ADDR linux_get_pc_32bit (struct regcache *regcache);
 872
 873 void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc);
 874 CORE_ADDR linux_get_pc_64bit (struct regcache *regcache);
 875
 876 /* From thread-db.c  */
 877 int thread_db_init (void);
 878 void thread_db_detach (struct process_info *);
 879 void thread_db_mourn (struct process_info *);
 880 int thread_db_handle_monitor_command (char *);
 881 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 882                                CORE_ADDR load_module, CORE_ADDR *address);
 883 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);
 884
 885 /* Called from linux-low.c when a clone event is detected.  Upon entry,
 886    both the clone and the parent should be stopped.  This function does
 887    whatever is required have the clone under thread_db's control.  */
 888
 889 void thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid);
 890
 891 bool thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len);
 892
 893 extern int have_ptrace_getregset;
 894
 895 /* Search for the value with type MATCH in the auxv vector with
 896    entries of length WORDSIZE bytes.  If found, store the value in
 897    *VALP and return 1.  If not found or if there is an error, return
 898    0.  */
 899
 900 int linux_get_auxv (int wordsize, CORE_ADDR match,
 901                     CORE_ADDR *valp);
 902
 903 /* Fetch the AT_HWCAP entry from the auxv vector, where entries are length
 904    WORDSIZE.  If no entry was found, return zero.  */
 905
 906 CORE_ADDR linux_get_hwcap (int wordsize);
 907
 908 /* Fetch the AT_HWCAP2 entry from the auxv vector, where entries are length
 909    WORDSIZE.  If no entry was found, return zero.  */
 910
 911 CORE_ADDR linux_get_hwcap2 (int wordsize);
 912
 913 #endif /* GDBSERVER_LINUX_LOW_H */