gdb/gdbserver/linux-low.h

   1 /* Internal interfaces for the GNU/Linux specific target code for gdbserver.
   2    Copyright (C) 2002-2013 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 #include "gdb_thread_db.h"
  20 #include <signal.h>
  21
  22 #include "gdbthread.h"
  23 #include "gdb_proc_service.h"
  24
  25 #define PTRACE_TYPE_ARG3 void *
  26 #define PTRACE_TYPE_ARG4 void *
  27 #define PTRACE_XFER_TYPE long
  28
  29 #ifdef HAVE_LINUX_REGSETS
  30 typedef void (*regset_fill_func) (struct regcache *, void *);
  31 typedef void (*regset_store_func) (struct regcache *, const void *);
  32 enum regset_type {
  33   GENERAL_REGS,
  34   FP_REGS,
  35   EXTENDED_REGS,
  36 };
  37
  38 struct regset_info
  39 {
  40   int get_request, set_request;
  41   /* If NT_TYPE isn't 0, it will be passed to ptrace as the 3rd
  42      argument and the 4th argument should be "const struct iovec *".  */
  43   int nt_type;
  44   int size;
  45   enum regset_type type;
  46   regset_fill_func fill_function;
  47   regset_store_func store_function;
  48 };
  49
  50 /* Aggregation of all the supported regsets of a given
  51    architecture/mode.  */
  52
  53 struct regsets_info
  54 {
  55   /* The regsets array.  */
  56   struct regset_info *regsets;
  57
  58   /* The number of regsets in the REGSETS array.  */
  59   int num_regsets;
  60
  61   /* If we get EIO on a regset, do not try it again.  Note the set of
  62      supported regsets may depend on processor mode on biarch
  63      machines.  This is a (lazily allocated) array holding one boolean
  64      byte (0/1) per regset, with each element corresponding to the
  65      regset in the REGSETS array above at the same offset.  */
  66   char *disabled_regsets;
  67 };
  68
  69 #endif
  70
  71 /* Mapping between the general-purpose registers in `struct user'
  72    format and GDB's register array layout.  */
  73
  74 struct usrregs_info
  75 {
  76   /* The number of registers accessible.  */
  77   int num_regs;
  78
  79   /* The registers map.  */
  80   int *regmap;
  81 };
  82
  83 /* All info needed to access an architecture/mode's registers.  */
  84
  85 struct regs_info
  86 {
  87   /* Regset support bitmap: 1 for registers that are transferred as a part
  88      of a regset, 0 for ones that need to be handled individually.  This
  89      can be NULL if all registers are transferred with regsets or regsets
  90      are not supported.  */
  91   unsigned char *regset_bitmap;
  92
  93   /* Info used when accessing registers with PTRACE_PEEKUSER /
  94      PTRACE_POKEUSER.  This can be NULL if all registers are
  95      transferred with regsets  .*/
  96   struct usrregs_info *usrregs;
  97
  98 #ifdef HAVE_LINUX_REGSETS
  99   /* Info used when accessing registers with regsets.  */
 100   struct regsets_info *regsets_info;
 101 #endif
 102 };
 103
 104 struct process_info_private
 105 {
 106   /* Arch-specific additions.  */
 107   struct arch_process_info *arch_private;
 108
 109   /* libthread_db-specific additions.  Not NULL if this process has loaded
 110      thread_db, and it is active.  */
 111   struct thread_db *thread_db;
 112
 113   /* &_r_debug.  0 if not yet determined.  -1 if no PT_DYNAMIC in Phdrs.  */
 114   CORE_ADDR r_debug;
 115
 116   /* This flag is true iff we've just created or attached to the first
 117      LWP of this process but it has not stopped yet.  As soon as it
 118      does, we need to call the low target's arch_setup callback.  */
 119   int new_inferior;
 120 };
 121
 122 struct lwp_info;
 123
 124 struct linux_target_ops
 125 {
 126   /* Architecture-specific setup.  */
 127   void (*arch_setup) (void);
 128
 129   const struct regs_info *(*regs_info) (void);
 130   int (*cannot_fetch_register) (int);
 131
 132   /* Returns 0 if we can store the register, 1 if we can not
 133      store the register, and 2 if failure to store the register
 134      is acceptable.  */
 135   int (*cannot_store_register) (int);
 136
 137   /* Hook to fetch a register in some non-standard way.  Used for
 138      example by backends that have read-only registers with hardcoded
 139      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 140      REGNO was supplied, false if not, and we should fallback to the
 141      standard ptrace methods.  */
 142   int (*fetch_register) (struct regcache *regcache, int regno);
 143
 144   CORE_ADDR (*get_pc) (struct regcache *regcache);
 145   void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
 146   const unsigned char *breakpoint;
 147   int breakpoint_len;
 148   CORE_ADDR (*breakpoint_reinsert_addr) (void);
 149
 150   int decr_pc_after_break;
 151   int (*breakpoint_at) (CORE_ADDR pc);
 152
 153   /* Breakpoint and watchpoint related functions.  See target.h for
 154      comments.  */
 155   int (*insert_point) (char type, CORE_ADDR addr, int len);
 156   int (*remove_point) (char type, CORE_ADDR addr, int len);
 157   int (*stopped_by_watchpoint) (void);
 158   CORE_ADDR (*stopped_data_address) (void);
 159
 160   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 161      for registers smaller than an xfer unit).  */
 162   void (*collect_ptrace_register) (struct regcache *regcache,
 163                                    int regno, char *buf);
 164   void (*supply_ptrace_register) (struct regcache *regcache,
 165                                   int regno, const char *buf);
 166
 167   /* Hook to convert from target format to ptrace format and back.
 168      Returns true if any conversion was done; false otherwise.
 169      If DIRECTION is 1, then copy from INF to NATIVE.
 170      If DIRECTION is 0, copy from NATIVE to INF.  */
 171   int (*siginfo_fixup) (siginfo_t *native, void *inf, int direction);
 172
 173   /* Hook to call when a new process is created or attached to.
 174      If extra per-process architecture-specific data is needed,
 175      allocate it here.  */
 176   struct arch_process_info * (*new_process) (void);
 177
 178   /* Hook to call when a new thread is detected.
 179      If extra per-thread architecture-specific data is needed,
 180      allocate it here.  */
 181   struct arch_lwp_info * (*new_thread) (void);
 182
 183   /* Hook to call prior to resuming a thread.  */
 184   void (*prepare_to_resume) (struct lwp_info *);
 185
 186   /* Hook to support target specific qSupported.  */
 187   void (*process_qsupported) (const char *);
 188
 189   /* Returns true if the low target supports tracepoints.  */
 190   int (*supports_tracepoints) (void);
 191
 192   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 193      success, -1 on failure.  */
 194   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 195
 196   /* Install a fast tracepoint jump pad.  See target.h for
 197      comments.  */
 198   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 199                                            CORE_ADDR collector,
 200                                            CORE_ADDR lockaddr,
 201                                            ULONGEST orig_size,
 202                                            CORE_ADDR *jump_entry,
 203                                            CORE_ADDR *trampoline,
 204                                            ULONGEST *trampoline_size,
 205                                            unsigned char *jjump_pad_insn,
 206                                            ULONGEST *jjump_pad_insn_size,
 207                                            CORE_ADDR *adjusted_insn_addr,
 208                                            CORE_ADDR *adjusted_insn_addr_end,
 209                                            char *err);
 210
 211   /* Return the bytecode operations vector for the current inferior.
 212      Returns NULL if bytecode compilation is not supported.  */
 213   struct emit_ops *(*emit_ops) (void);
 214
 215   /* Return the minimum length of an instruction that can be safely overwritten
 216      for use as a fast tracepoint.  */
 217   int (*get_min_fast_tracepoint_insn_len) (void);
 218
 219   /* Returns true if the low target supports range stepping.  */
 220   int (*supports_range_stepping) (void);
 221 };
 222
 223 extern struct linux_target_ops the_low_target;
 224
 225 #define ptid_of(proc) ((proc)->head.id)
 226 #define pid_of(proc) ptid_get_pid ((proc)->head.id)
 227 #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
 228
 229 #define get_lwp(inf) ((struct lwp_info *)(inf))
 230 #define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
 231 #define get_lwp_thread(proc) ((struct thread_info *)                    \
 232                               find_inferior_id (&all_threads,           \
 233                                                 get_lwp (proc)->head.id))
 234
 235 struct lwp_info
 236 {
 237   struct inferior_list_entry head;
 238
 239   /* If this flag is set, the next SIGSTOP will be ignored (the
 240      process will be immediately resumed).  This means that either we
 241      sent the SIGSTOP to it ourselves and got some other pending event
 242      (so the SIGSTOP is still pending), or that we stopped the
 243      inferior implicitly via PTRACE_ATTACH and have not waited for it
 244      yet.  */
 245   int stop_expected;
 246
 247   /* When this is true, we shall not try to resume this thread, even
 248      if last_resume_kind isn't resume_stop.  */
 249   int suspended;
 250
 251   /* If this flag is set, the lwp is known to be stopped right now (stop
 252      event already received in a wait()).  */
 253   int stopped;
 254
 255   /* If this flag is set, the lwp is known to be dead already (exit
 256      event already received in a wait(), and is cached in
 257      status_pending).  */
 258   int dead;
 259
 260   /* When stopped is set, the last wait status recorded for this lwp.  */
 261   int last_status;
 262
 263   /* When stopped is set, this is where the lwp stopped, with
 264      decr_pc_after_break already accounted for.  */
 265   CORE_ADDR stop_pc;
 266
 267   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 268      been reported.  */
 269   int status_pending_p;
 270   int status_pending;
 271
 272   /* STOPPED_BY_WATCHPOINT is non-zero if this LWP stopped with a data
 273      watchpoint trap.  */
 274   int stopped_by_watchpoint;
 275
 276   /* On architectures where it is possible to know the data address of
 277      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 278      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 279      is true.  */
 280   CORE_ADDR stopped_data_address;
 281
 282   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 283      stop (SIGTRAP stops only).  */
 284   CORE_ADDR bp_reinsert;
 285
 286   /* If this flag is set, the last continue operation at the ptrace
 287      level on this process was a single-step.  */
 288   int stepping;
 289
 290   /* Range to single step within.  This is a copy of the step range
 291      passed along the last resume request.  See 'struct
 292      thread_resume'.  */
 293   CORE_ADDR step_range_start;   /* Inclusive */
 294   CORE_ADDR step_range_end;     /* Exclusive */
 295
 296   /* If this flag is set, we need to set the event request flags the
 297      next time we see this LWP stop.  */
 298   int must_set_ptrace_flags;
 299
 300   /* If this is non-zero, it points to a chain of signals which need to
 301      be delivered to this process.  */
 302   struct pending_signals *pending_signals;
 303
 304   /* A link used when resuming.  It is initialized from the resume request,
 305      and then processed and cleared in linux_resume_one_lwp.  */
 306   struct thread_resume *resume;
 307
 308   /* True if it is known that this lwp is presently collecting a fast
 309      tracepoint (it is in the jump pad or in some code that will
 310      return to the jump pad.  Normally, we won't care about this, but
 311      we will if a signal arrives to this lwp while it is
 312      collecting.  */
 313   int collecting_fast_tracepoint;
 314
 315   /* If this is non-zero, it points to a chain of signals which need
 316      to be reported to GDB.  These were deferred because the thread
 317      was doing a fast tracepoint collect when they arrived.  */
 318   struct pending_signals *pending_signals_to_report;
 319
 320   /* When collecting_fast_tracepoint is first found to be 1, we insert
 321      a exit-jump-pad-quickly breakpoint.  This is it.  */
 322   struct breakpoint *exit_jump_pad_bkpt;
 323
 324   /* True if the LWP was seen stop at an internal breakpoint and needs
 325      stepping over later when it is resumed.  */
 326   int need_step_over;
 327
 328 #ifdef USE_THREAD_DB
 329   int thread_known;
 330   /* The thread handle, used for e.g. TLS access.  Only valid if
 331      THREAD_KNOWN is set.  */
 332   td_thrhandle_t th;
 333 #endif
 334
 335   /* Arch-specific additions.  */
 336   struct arch_lwp_info *arch_private;
 337 };
 338
 339 extern struct inferior_list all_lwps;
 340
 341 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 342
 343 void linux_attach_lwp (unsigned long pid);
 344 struct lwp_info *find_lwp_pid (ptid_t ptid);
 345 void linux_stop_lwp (struct lwp_info *lwp);
 346
 347 #ifdef HAVE_LINUX_REGSETS
 348 void initialize_regsets_info (struct regsets_info *regsets_info);
 349 #endif
 350
 351 void initialize_low_arch (void);
 352
 353 /* From thread-db.c  */
 354 int thread_db_init (int use_events);
 355 void thread_db_detach (struct process_info *);
 356 void thread_db_mourn (struct process_info *);
 357 int thread_db_handle_monitor_command (char *);
 358 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 359                                CORE_ADDR load_module, CORE_ADDR *address);
 360 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);