gdb/gdbserver/target.h

   1 /* Target operations for the remote server for GDB.
   2    Copyright (C) 2002-2005, 2007-2012 Free Software Foundation, Inc.
   3
   4    Contributed by MontaVista Software.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef TARGET_H
  22 #define TARGET_H
  23
  24 struct emit_ops;
  25
  26 /* Ways to "resume" a thread.  */
  27
  28 enum resume_kind
  29 {
  30   /* Thread should continue.  */
  31   resume_continue,
  32
  33   /* Thread should single-step.  */
  34   resume_step,
  35
  36   /* Thread should be stopped.  */
  37   resume_stop
  38 };
  39
  40 /* This structure describes how to resume a particular thread (or all
  41    threads) based on the client's request.  If thread is -1, then this
  42    entry applies to all threads.  These are passed around as an
  43    array.  */
  44
  45 struct thread_resume
  46 {
  47   ptid_t thread;
  48
  49   /* How to "resume".  */
  50   enum resume_kind kind;
  51
  52   /* If non-zero, send this signal when we resume, or to stop the
  53      thread.  If stopping a thread, and this is 0, the target should
  54      stop the thread however it best decides to (e.g., SIGSTOP on
  55      linux; SuspendThread on win32).  This is a host signal value (not
  56      enum target_signal).  */
  57   int sig;
  58 };
  59
  60 /* Generally, what has the program done?  */
  61 enum target_waitkind
  62   {
  63     /* The program has exited.  The exit status is in
  64        value.integer.  */
  65     TARGET_WAITKIND_EXITED,
  66
  67     /* The program has stopped with a signal.  Which signal is in
  68        value.sig.  */
  69     TARGET_WAITKIND_STOPPED,
  70
  71     /* The program has terminated with a signal.  Which signal is in
  72        value.sig.  */
  73     TARGET_WAITKIND_SIGNALLED,
  74
  75     /* The program is letting us know that it dynamically loaded
  76        something.  */
  77     TARGET_WAITKIND_LOADED,
  78
  79     /* The program has exec'ed a new executable file.  The new file's
  80        pathname is pointed to by value.execd_pathname.  */
  81     TARGET_WAITKIND_EXECD,
  82
  83     /* Nothing of interest to GDB happened, but we stopped anyway.  */
  84     TARGET_WAITKIND_SPURIOUS,
  85
  86     /* An event has occurred, but we should wait again.  In this case,
  87        we want to go back to the event loop and wait there for another
  88        event from the inferior.  */
  89     TARGET_WAITKIND_IGNORE
  90   };
  91
  92 struct target_waitstatus
  93   {
  94     enum target_waitkind kind;
  95
  96     /* Forked child pid, execd pathname, exit status or signal number.  */
  97     union
  98       {
  99         int integer;
 100         enum target_signal sig;
 101         ptid_t related_pid;
 102         char *execd_pathname;
 103       }
 104     value;
 105   };
 106
 107 /* Options that can be passed to target_ops->wait.  */
 108
 109 #define TARGET_WNOHANG 1
 110
 111 struct target_ops
 112 {
 113   /* Start a new process.
 114
 115      PROGRAM is a path to the program to execute.
 116      ARGS is a standard NULL-terminated array of arguments,
 117      to be passed to the inferior as ``argv''.
 118
 119      Returns the new PID on success, -1 on failure.  Registers the new
 120      process with the process list.  */
 121
 122   int (*create_inferior) (char *program, char **args);
 123
 124   /* Attach to a running process.
 125
 126      PID is the process ID to attach to, specified by the user
 127      or a higher layer.
 128
 129      Returns -1 if attaching is unsupported, 0 on success, and calls
 130      error() otherwise.  */
 131
 132   int (*attach) (unsigned long pid);
 133
 134   /* Kill inferior PID.  Return -1 on failure, and 0 on success.  */
 135
 136   int (*kill) (int pid);
 137
 138   /* Detach from inferior PID. Return -1 on failure, and 0 on
 139      success.  */
 140
 141   int (*detach) (int pid);
 142
 143   /* The inferior process has died.  Do what is right.  */
 144
 145   void (*mourn) (struct process_info *proc);
 146
 147   /* Wait for inferior PID to exit.  */
 148   void (*join) (int pid);
 149
 150   /* Return 1 iff the thread with process ID PID is alive.  */
 151
 152   int (*thread_alive) (ptid_t pid);
 153
 154   /* Resume the inferior process.  */
 155
 156   void (*resume) (struct thread_resume *resume_info, size_t n);
 157
 158   /* Wait for the inferior process or thread to change state.  Store
 159      status through argument pointer STATUS.
 160
 161      PTID = -1 to wait for any pid to do something, PTID(pid,0,0) to
 162      wait for any thread of process pid to do something.  Return ptid
 163      of child, or -1 in case of error; store status through argument
 164      pointer STATUS.  OPTIONS is a bit set of options defined as
 165      TARGET_W* above.  If options contains TARGET_WNOHANG and there's
 166      no child stop to report, return is
 167      null_ptid/TARGET_WAITKIND_IGNORE.  */
 168
 169   ptid_t (*wait) (ptid_t ptid, struct target_waitstatus *status, int options);
 170
 171   /* Fetch registers from the inferior process.
 172
 173      If REGNO is -1, fetch all registers; otherwise, fetch at least REGNO.  */
 174
 175   void (*fetch_registers) (struct regcache *regcache, int regno);
 176
 177   /* Store registers to the inferior process.
 178
 179      If REGNO is -1, store all registers; otherwise, store at least REGNO.  */
 180
 181   void (*store_registers) (struct regcache *regcache, int regno);
 182
 183   /* Prepare to read or write memory from the inferior process.
 184      Targets use this to do what is necessary to get the state of the
 185      inferior such that it is possible to access memory.
 186
 187      This should generally only be called from client facing routines,
 188      such as gdb_read_memory/gdb_write_memory, or the insert_point
 189      callbacks.
 190
 191      Like `read_memory' and `write_memory' below, returns 0 on success
 192      and errno on failure.  */
 193
 194   int (*prepare_to_access_memory) (void);
 195
 196   /* Undo the effects of prepare_to_access_memory.  */
 197
 198   void (*done_accessing_memory) (void);
 199
 200   /* Read memory from the inferior process.  This should generally be
 201      called through read_inferior_memory, which handles breakpoint shadowing.
 202
 203      Read LEN bytes at MEMADDR into a buffer at MYADDR.
 204
 205      Returns 0 on success and errno on failure.  */
 206
 207   int (*read_memory) (CORE_ADDR memaddr, unsigned char *myaddr, int len);
 208
 209   /* Write memory to the inferior process.  This should generally be
 210      called through write_inferior_memory, which handles breakpoint shadowing.
 211
 212      Write LEN bytes from the buffer at MYADDR to MEMADDR.
 213
 214      Returns 0 on success and errno on failure.  */
 215
 216   int (*write_memory) (CORE_ADDR memaddr, const unsigned char *myaddr,
 217                        int len);
 218
 219   /* Query GDB for the values of any symbols we're interested in.
 220      This function is called whenever we receive a "qSymbols::"
 221      query, which corresponds to every time more symbols (might)
 222      become available.  NULL if we aren't interested in any
 223      symbols.  */
 224
 225   void (*look_up_symbols) (void);
 226
 227   /* Send an interrupt request to the inferior process,
 228      however is appropriate.  */
 229
 230   void (*request_interrupt) (void);
 231
 232   /* Read auxiliary vector data from the inferior process.
 233
 234      Read LEN bytes at OFFSET into a buffer at MYADDR.  */
 235
 236   int (*read_auxv) (CORE_ADDR offset, unsigned char *myaddr,
 237                     unsigned int len);
 238
 239   /* Insert and remove a break or watchpoint.
 240      Returns 0 on success, -1 on failure and 1 on unsupported.
 241      The type is coded as follows:
 242        '0' - software-breakpoint
 243        '1' - hardware-breakpoint
 244        '2' - write watchpoint
 245        '3' - read watchpoint
 246        '4' - access watchpoint  */
 247
 248   int (*insert_point) (char type, CORE_ADDR addr, int len);
 249   int (*remove_point) (char type, CORE_ADDR addr, int len);
 250
 251   /* Returns 1 if target was stopped due to a watchpoint hit, 0 otherwise.  */
 252
 253   int (*stopped_by_watchpoint) (void);
 254
 255   /* Returns the address associated with the watchpoint that hit, if any;
 256      returns 0 otherwise.  */
 257
 258   CORE_ADDR (*stopped_data_address) (void);
 259
 260   /* Reports the text, data offsets of the executable.  This is
 261      needed for uclinux where the executable is relocated during load
 262      time.  */
 263
 264   int (*read_offsets) (CORE_ADDR *text, CORE_ADDR *data);
 265
 266   /* Fetch the address associated with a specific thread local storage
 267      area, determined by the specified THREAD, OFFSET, and LOAD_MODULE.
 268      Stores it in *ADDRESS and returns zero on success; otherwise returns
 269      an error code.  A return value of -1 means this system does not
 270      support the operation.  */
 271
 272   int (*get_tls_address) (struct thread_info *thread, CORE_ADDR offset,
 273                           CORE_ADDR load_module, CORE_ADDR *address);
 274
 275    /* Read/Write from/to spufs using qXfer packets.  */
 276   int (*qxfer_spu) (const char *annex, unsigned char *readbuf,
 277                     unsigned const char *writebuf, CORE_ADDR offset, int len);
 278
 279   /* Fill BUF with an hostio error packet representing the last hostio
 280      error.  */
 281   void (*hostio_last_error) (char *buf);
 282
 283   /* Read/Write OS data using qXfer packets.  */
 284   int (*qxfer_osdata) (const char *annex, unsigned char *readbuf,
 285                        unsigned const char *writebuf, CORE_ADDR offset,
 286                        int len);
 287
 288   /* Read/Write extra signal info.  */
 289   int (*qxfer_siginfo) (const char *annex, unsigned char *readbuf,
 290                         unsigned const char *writebuf,
 291                         CORE_ADDR offset, int len);
 292
 293   int (*supports_non_stop) (void);
 294
 295   /* Enables async target events.  Returns the previous enable
 296      state.  */
 297   int (*async) (int enable);
 298
 299   /* Switch to non-stop (1) or all-stop (0) mode.  Return 0 on
 300      success, -1 otherwise.  */
 301   int (*start_non_stop) (int);
 302
 303   /* Returns true if the target supports multi-process debugging.  */
 304   int (*supports_multi_process) (void);
 305
 306   /* If not NULL, target-specific routine to process monitor command.
 307      Returns 1 if handled, or 0 to perform default processing.  */
 308   int (*handle_monitor_command) (char *);
 309
 310   /* Returns the core given a thread, or -1 if not known.  */
 311   int (*core_of_thread) (ptid_t);
 312
 313   /* Read loadmaps.  Read LEN bytes at OFFSET into a buffer at MYADDR.  */
 314   int (*read_loadmap) (const char *annex, CORE_ADDR offset,
 315                        unsigned char *myaddr, unsigned int len);
 316
 317   /* Target specific qSupported support.  */
 318   void (*process_qsupported) (const char *);
 319
 320   /* Return 1 if the target supports tracepoints, 0 (or leave the
 321      callback NULL) otherwise.  */
 322   int (*supports_tracepoints) (void);
 323
 324   /* Read PC from REGCACHE.  */
 325   CORE_ADDR (*read_pc) (struct regcache *regcache);
 326
 327   /* Write PC to REGCACHE.  */
 328   void (*write_pc) (struct regcache *regcache, CORE_ADDR pc);
 329
 330   /* Return true if THREAD is known to be stopped now.  */
 331   int (*thread_stopped) (struct thread_info *thread);
 332
 333   /* Read Thread Information Block address.  */
 334   int (*get_tib_address) (ptid_t ptid, CORE_ADDR *address);
 335
 336   /* Pause all threads.  If FREEZE, arrange for any resume attempt to
 337      be ignored until an unpause_all call unfreezes threads again.
 338      There can be nested calls to pause_all, so a freeze counter
 339      should be maintained.  */
 340   void (*pause_all) (int freeze);
 341
 342   /* Unpause all threads.  Threads that hadn't been resumed by the
 343      client should be left stopped.  Basically a pause/unpause call
 344      pair should not end up resuming threads that were stopped before
 345      the pause call.  */
 346   void (*unpause_all) (int unfreeze);
 347
 348   /* Cancel all pending breakpoints hits in all threads.  */
 349   void (*cancel_breakpoints) (void);
 350
 351   /* Stabilize all threads.  That is, force them out of jump pads.  */
 352   void (*stabilize_threads) (void);
 353
 354   /* Install a fast tracepoint jump pad.  TPOINT is the address of the
 355      tracepoint internal object as used by the IPA agent.  TPADDR is
 356      the address of tracepoint.  COLLECTOR is address of the function
 357      the jump pad redirects to.  LOCKADDR is the address of the jump
 358      pad lock object.  ORIG_SIZE is the size in bytes of the
 359      instruction at TPADDR.  JUMP_ENTRY points to the address of the
 360      jump pad entry, and on return holds the address past the end of
 361      the created jump pad.  If a trampoline is created by the function,
 362      then TRAMPOLINE and TRAMPOLINE_SIZE return the address and size of
 363      the trampoline, else they remain unchanged.  JJUMP_PAD_INSN is a
 364      buffer containing a copy of the instruction at TPADDR.
 365      ADJUST_INSN_ADDR and ADJUST_INSN_ADDR_END are output parameters that
 366      return the address range where the instruction at TPADDR was relocated
 367      to.  If an error occurs, the ERR may be used to pass on an error
 368      message.  */
 369   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 370                                            CORE_ADDR collector,
 371                                            CORE_ADDR lockaddr,
 372                                            ULONGEST orig_size,
 373                                            CORE_ADDR *jump_entry,
 374                                            CORE_ADDR *trampoline,
 375                                            ULONGEST *trampoline_size,
 376                                            unsigned char *jjump_pad_insn,
 377                                            ULONGEST *jjump_pad_insn_size,
 378                                            CORE_ADDR *adjusted_insn_addr,
 379                                            CORE_ADDR *adjusted_insn_addr_end,
 380                                            char *err);
 381
 382   /* Return the bytecode operations vector for the current inferior.
 383      Returns NULL if bytecode compilation is not supported.  */
 384   struct emit_ops *(*emit_ops) (void);
 385
 386   /* Returns true if the target supports disabling randomization.  */
 387   int (*supports_disable_randomization) (void);
 388
 389   /* Return the minimum length of an instruction that can be safely overwritten
 390      for use as a fast tracepoint.  */
 391   int (*get_min_fast_tracepoint_insn_len) (void);
 392
 393   /* Read solib info on SVR4 platforms.  */
 394   int (*qxfer_libraries_svr4) (const char *annex, unsigned char *readbuf,
 395                                unsigned const char *writebuf,
 396                                CORE_ADDR offset, int len);
 397
 398   /* Return true if target supports debugging agent.  */
 399   int (*supports_agent) (void);
 400 };
 401
 402 extern struct target_ops *the_target;
 403
 404 void set_target_ops (struct target_ops *);
 405
 406 #define create_inferior(program, args) \
 407   (*the_target->create_inferior) (program, args)
 408
 409 #define myattach(pid) \
 410   (*the_target->attach) (pid)
 411
 412 #define kill_inferior(pid) \
 413   (*the_target->kill) (pid)
 414
 415 #define detach_inferior(pid) \
 416   (*the_target->detach) (pid)
 417
 418 #define mourn_inferior(PROC) \
 419   (*the_target->mourn) (PROC)
 420
 421 #define mythread_alive(pid) \
 422   (*the_target->thread_alive) (pid)
 423
 424 #define fetch_inferior_registers(regcache, regno)       \
 425   (*the_target->fetch_registers) (regcache, regno)
 426
 427 #define store_inferior_registers(regcache, regno) \
 428   (*the_target->store_registers) (regcache, regno)
 429
 430 #define join_inferior(pid) \
 431   (*the_target->join) (pid)
 432
 433 #define target_supports_non_stop() \
 434   (the_target->supports_non_stop ? (*the_target->supports_non_stop ) () : 0)
 435
 436 #define target_async(enable) \
 437   (the_target->async ? (*the_target->async) (enable) : 0)
 438
 439 #define target_supports_multi_process() \
 440   (the_target->supports_multi_process ? \
 441    (*the_target->supports_multi_process) () : 0)
 442
 443 #define target_process_qsupported(query)                \
 444   do                                                    \
 445     {                                                   \
 446       if (the_target->process_qsupported)               \
 447         the_target->process_qsupported (query);         \
 448     } while (0)
 449
 450 #define target_supports_tracepoints()                   \
 451   (the_target->supports_tracepoints                     \
 452    ? (*the_target->supports_tracepoints) () : 0)
 453
 454 #define target_supports_fast_tracepoints()              \
 455   (the_target->install_fast_tracepoint_jump_pad != NULL)
 456
 457 #define target_get_min_fast_tracepoint_insn_len()       \
 458   (the_target->get_min_fast_tracepoint_insn_len         \
 459    ? (*the_target->get_min_fast_tracepoint_insn_len) () : 0)
 460
 461 #define thread_stopped(thread) \
 462   (*the_target->thread_stopped) (thread)
 463
 464 #define pause_all(freeze)                       \
 465   do                                            \
 466     {                                           \
 467       if (the_target->pause_all)                \
 468         (*the_target->pause_all) (freeze);      \
 469     } while (0)
 470
 471 #define unpause_all(unfreeze)                   \
 472   do                                            \
 473     {                                           \
 474       if (the_target->unpause_all)              \
 475         (*the_target->unpause_all) (unfreeze);  \
 476     } while (0)
 477
 478 #define cancel_breakpoints()                    \
 479   do                                            \
 480     {                                           \
 481       if (the_target->cancel_breakpoints)       \
 482         (*the_target->cancel_breakpoints) ();   \
 483     } while (0)
 484
 485 #define stabilize_threads()                     \
 486   do                                            \
 487     {                                           \
 488       if (the_target->stabilize_threads)        \
 489         (*the_target->stabilize_threads) ();    \
 490     } while (0)
 491
 492 #define install_fast_tracepoint_jump_pad(tpoint, tpaddr,                \
 493                                          collector, lockaddr,           \
 494                                          orig_size,                     \
 495                                          jump_entry,                    \
 496                                          trampoline, trampoline_size,   \
 497                                          jjump_pad_insn,                \
 498                                          jjump_pad_insn_size,           \
 499                                          adjusted_insn_addr,            \
 500                                          adjusted_insn_addr_end,        \
 501                                          err)                           \
 502   (*the_target->install_fast_tracepoint_jump_pad) (tpoint, tpaddr,      \
 503                                                    collector,lockaddr,  \
 504                                                    orig_size, jump_entry, \
 505                                                    trampoline,          \
 506                                                    trampoline_size,     \
 507                                                    jjump_pad_insn,      \
 508                                                    jjump_pad_insn_size, \
 509                                                    adjusted_insn_addr,  \
 510                                                    adjusted_insn_addr_end, \
 511                                                    err)
 512
 513 #define target_emit_ops() \
 514   (the_target->emit_ops ? (*the_target->emit_ops) () : NULL)
 515
 516 #define target_supports_disable_randomization() \
 517   (the_target->supports_disable_randomization ? \
 518    (*the_target->supports_disable_randomization) () : 0)
 519
 520 #define target_supports_agent() \
 521   (the_target->supports_agent ? \
 522    (*the_target->supports_agent) () : 0)
 523
 524 /* Start non-stop mode, returns 0 on success, -1 on failure.   */
 525
 526 int start_non_stop (int nonstop);
 527
 528 ptid_t mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
 529                int connected_wait);
 530
 531 #define prepare_to_access_memory()              \
 532   (the_target->prepare_to_access_memory         \
 533    ? (*the_target->prepare_to_access_memory) () \
 534    : 0)
 535
 536 #define done_accessing_memory()                         \
 537   do                                                    \
 538     {                                                   \
 539       if (the_target->done_accessing_memory)            \
 540         (*the_target->done_accessing_memory) ();        \
 541     } while (0)
 542
 543 int read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len);
 544
 545 int write_inferior_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 546                            int len);
 547
 548 void set_desired_inferior (int id);
 549
 550 const char *target_pid_to_str (ptid_t);
 551
 552 const char *target_waitstatus_to_string (const struct target_waitstatus *);
 553
 554 #endif /* TARGET_H */