gdb/gdbserver/linux-low.h

   1 /* Internal interfaces for the GNU/Linux specific target code for gdbserver.
   2    Copyright (C) 2002-2014 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 /* Included for ptrace type definitions.  */
  26 #include "linux-ptrace.h"
  27
  28 #define PTRACE_XFER_TYPE long
  29
  30 #ifdef HAVE_LINUX_REGSETS
  31 typedef void (*regset_fill_func) (struct regcache *, void *);
  32 typedef void (*regset_store_func) (struct regcache *, const void *);
  33 enum regset_type {
  34   GENERAL_REGS,
  35   FP_REGS,
  36   EXTENDED_REGS,
  37 };
  38
  39 struct regset_info
  40 {
  41   int get_request, set_request;
  42   /* If NT_TYPE isn't 0, it will be passed to ptrace as the 3rd
  43      argument and the 4th argument should be "const struct iovec *".  */
  44   int nt_type;
  45   int size;
  46   enum regset_type type;
  47   regset_fill_func fill_function;
  48   regset_store_func store_function;
  49 };
  50
  51 /* Aggregation of all the supported regsets of a given
  52    architecture/mode.  */
  53
  54 struct regsets_info
  55 {
  56   /* The regsets array.  */
  57   struct regset_info *regsets;
  58
  59   /* The number of regsets in the REGSETS array.  */
  60   int num_regsets;
  61
  62   /* If we get EIO on a regset, do not try it again.  Note the set of
  63      supported regsets may depend on processor mode on biarch
  64      machines.  This is a (lazily allocated) array holding one boolean
  65      byte (0/1) per regset, with each element corresponding to the
  66      regset in the REGSETS array above at the same offset.  */
  67   char *disabled_regsets;
  68 };
  69
  70 #endif
  71
  72 /* Mapping between the general-purpose registers in `struct user'
  73    format and GDB's register array layout.  */
  74
  75 struct usrregs_info
  76 {
  77   /* The number of registers accessible.  */
  78   int num_regs;
  79
  80   /* The registers map.  */
  81   int *regmap;
  82 };
  83
  84 /* All info needed to access an architecture/mode's registers.  */
  85
  86 struct regs_info
  87 {
  88   /* Regset support bitmap: 1 for registers that are transferred as a part
  89      of a regset, 0 for ones that need to be handled individually.  This
  90      can be NULL if all registers are transferred with regsets or regsets
  91      are not supported.  */
  92   unsigned char *regset_bitmap;
  93
  94   /* Info used when accessing registers with PTRACE_PEEKUSER /
  95      PTRACE_POKEUSER.  This can be NULL if all registers are
  96      transferred with regsets  .*/
  97   struct usrregs_info *usrregs;
  98
  99 #ifdef HAVE_LINUX_REGSETS
 100   /* Info used when accessing registers with regsets.  */
 101   struct regsets_info *regsets_info;
 102 #endif
 103 };
 104
 105 struct process_info_private
 106 {
 107   /* Arch-specific additions.  */
 108   struct arch_process_info *arch_private;
 109
 110   /* libthread_db-specific additions.  Not NULL if this process has loaded
 111      thread_db, and it is active.  */
 112   struct thread_db *thread_db;
 113
 114   /* &_r_debug.  0 if not yet determined.  -1 if no PT_DYNAMIC in Phdrs.  */
 115   CORE_ADDR r_debug;
 116
 117   /* This flag is true iff we've just created or attached to the first
 118      LWP of this process but it has not stopped yet.  As soon as it
 119      does, we need to call the low target's arch_setup callback.  */
 120   int new_inferior;
 121 };
 122
 123 struct lwp_info;
 124
 125 struct linux_target_ops
 126 {
 127   /* Architecture-specific setup.  */
 128   void (*arch_setup) (void);
 129
 130   const struct regs_info *(*regs_info) (void);
 131   int (*cannot_fetch_register) (int);
 132
 133   /* Returns 0 if we can store the register, 1 if we can not
 134      store the register, and 2 if failure to store the register
 135      is acceptable.  */
 136   int (*cannot_store_register) (int);
 137
 138   /* Hook to fetch a register in some non-standard way.  Used for
 139      example by backends that have read-only registers with hardcoded
 140      values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
 141      REGNO was supplied, false if not, and we should fallback to the
 142      standard ptrace methods.  */
 143   int (*fetch_register) (struct regcache *regcache, int regno);
 144
 145   CORE_ADDR (*get_pc) (struct regcache *regcache);
 146   void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
 147   const unsigned char *breakpoint;
 148   int breakpoint_len;
 149   CORE_ADDR (*breakpoint_reinsert_addr) (void);
 150
 151   int decr_pc_after_break;
 152   int (*breakpoint_at) (CORE_ADDR pc);
 153
 154   /* Breakpoint and watchpoint related functions.  See target.h for
 155      comments.  */
 156   int (*supports_z_point_type) (char z_type);
 157   int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 158                        int size, struct raw_breakpoint *bp);
 159   int (*remove_point) (enum raw_bkpt_type type, CORE_ADDR addr,
 160                        int size, struct raw_breakpoint *bp);
 161
 162   int (*stopped_by_watchpoint) (void);
 163   CORE_ADDR (*stopped_data_address) (void);
 164
 165   /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
 166      for registers smaller than an xfer unit).  */
 167   void (*collect_ptrace_register) (struct regcache *regcache,
 168                                    int regno, char *buf);
 169   void (*supply_ptrace_register) (struct regcache *regcache,
 170                                   int regno, const char *buf);
 171
 172   /* Hook to convert from target format to ptrace format and back.
 173      Returns true if any conversion was done; false otherwise.
 174      If DIRECTION is 1, then copy from INF to NATIVE.
 175      If DIRECTION is 0, copy from NATIVE to INF.  */
 176   int (*siginfo_fixup) (siginfo_t *native, void *inf, int direction);
 177
 178   /* Hook to call when a new process is created or attached to.
 179      If extra per-process architecture-specific data is needed,
 180      allocate it here.  */
 181   struct arch_process_info * (*new_process) (void);
 182
 183   /* Hook to call when a new thread is detected.
 184      If extra per-thread architecture-specific data is needed,
 185      allocate it here.  */
 186   struct arch_lwp_info * (*new_thread) (void);
 187
 188   /* Hook to call prior to resuming a thread.  */
 189   void (*prepare_to_resume) (struct lwp_info *);
 190
 191   /* Hook to support target specific qSupported.  */
 192   void (*process_qsupported) (const char *);
 193
 194   /* Returns true if the low target supports tracepoints.  */
 195   int (*supports_tracepoints) (void);
 196
 197   /* Fill ADDRP with the thread area address of LWPID.  Returns 0 on
 198      success, -1 on failure.  */
 199   int (*get_thread_area) (int lwpid, CORE_ADDR *addrp);
 200
 201   /* Install a fast tracepoint jump pad.  See target.h for
 202      comments.  */
 203   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 204                                            CORE_ADDR collector,
 205                                            CORE_ADDR lockaddr,
 206                                            ULONGEST orig_size,
 207                                            CORE_ADDR *jump_entry,
 208                                            CORE_ADDR *trampoline,
 209                                            ULONGEST *trampoline_size,
 210                                            unsigned char *jjump_pad_insn,
 211                                            ULONGEST *jjump_pad_insn_size,
 212                                            CORE_ADDR *adjusted_insn_addr,
 213                                            CORE_ADDR *adjusted_insn_addr_end,
 214                                            char *err);
 215
 216   /* Return the bytecode operations vector for the current inferior.
 217      Returns NULL if bytecode compilation is not supported.  */
 218   struct emit_ops *(*emit_ops) (void);
 219
 220   /* Return the minimum length of an instruction that can be safely overwritten
 221      for use as a fast tracepoint.  */
 222   int (*get_min_fast_tracepoint_insn_len) (void);
 223
 224   /* Returns true if the low target supports range stepping.  */
 225   int (*supports_range_stepping) (void);
 226 };
 227
 228 extern struct linux_target_ops the_low_target;
 229
 230 #define get_thread_lwp(thr) ((struct lwp_info *) (inferior_target_data (thr)))
 231 #define get_lwp_thread(lwp) ((lwp)->thread)
 232
 233 /* This struct is recorded in the target_data field of struct thread_info.
 234
 235    On linux ``all_threads'' is keyed by the LWP ID, which we use as the
 236    GDB protocol representation of the thread ID.  Threads also have
 237    a "process ID" (poorly named) which is (presently) the same as the
 238    LWP ID.
 239
 240    There is also ``all_processes'' is keyed by the "overall process ID",
 241    which GNU/Linux calls tgid, "thread group ID".  */
 242
 243 struct lwp_info
 244 {
 245   /* Backlink to the parent object.  */
 246   struct thread_info *thread;
 247
 248   /* If this flag is set, the next SIGSTOP will be ignored (the
 249      process will be immediately resumed).  This means that either we
 250      sent the SIGSTOP to it ourselves and got some other pending event
 251      (so the SIGSTOP is still pending), or that we stopped the
 252      inferior implicitly via PTRACE_ATTACH and have not waited for it
 253      yet.  */
 254   int stop_expected;
 255
 256   /* When this is true, we shall not try to resume this thread, even
 257      if last_resume_kind isn't resume_stop.  */
 258   int suspended;
 259
 260   /* If this flag is set, the lwp is known to be stopped right now (stop
 261      event already received in a wait()).  */
 262   int stopped;
 263
 264   /* If this flag is set, the lwp is known to be dead already (exit
 265      event already received in a wait(), and is cached in
 266      status_pending).  */
 267   int dead;
 268
 269   /* When stopped is set, the last wait status recorded for this lwp.  */
 270   int last_status;
 271
 272   /* When stopped is set, this is where the lwp stopped, with
 273      decr_pc_after_break already accounted for.  */
 274   CORE_ADDR stop_pc;
 275
 276   /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
 277      been reported.  */
 278   int status_pending_p;
 279   int status_pending;
 280
 281   /* STOPPED_BY_WATCHPOINT is non-zero if this LWP stopped with a data
 282      watchpoint trap.  */
 283   int stopped_by_watchpoint;
 284
 285   /* On architectures where it is possible to know the data address of
 286      a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and
 287      contains such data address.  Only valid if STOPPED_BY_WATCHPOINT
 288      is true.  */
 289   CORE_ADDR stopped_data_address;
 290
 291   /* If this is non-zero, it is a breakpoint to be reinserted at our next
 292      stop (SIGTRAP stops only).  */
 293   CORE_ADDR bp_reinsert;
 294
 295   /* If this flag is set, the last continue operation at the ptrace
 296      level on this process was a single-step.  */
 297   int stepping;
 298
 299   /* Range to single step within.  This is a copy of the step range
 300      passed along the last resume request.  See 'struct
 301      thread_resume'.  */
 302   CORE_ADDR step_range_start;   /* Inclusive */
 303   CORE_ADDR step_range_end;     /* Exclusive */
 304
 305   /* If this flag is set, we need to set the event request flags the
 306      next time we see this LWP stop.  */
 307   int must_set_ptrace_flags;
 308
 309   /* If this is non-zero, it points to a chain of signals which need to
 310      be delivered to this process.  */
 311   struct pending_signals *pending_signals;
 312
 313   /* A link used when resuming.  It is initialized from the resume request,
 314      and then processed and cleared in linux_resume_one_lwp.  */
 315   struct thread_resume *resume;
 316
 317   /* True if it is known that this lwp is presently collecting a fast
 318      tracepoint (it is in the jump pad or in some code that will
 319      return to the jump pad.  Normally, we won't care about this, but
 320      we will if a signal arrives to this lwp while it is
 321      collecting.  */
 322   int collecting_fast_tracepoint;
 323
 324   /* If this is non-zero, it points to a chain of signals which need
 325      to be reported to GDB.  These were deferred because the thread
 326      was doing a fast tracepoint collect when they arrived.  */
 327   struct pending_signals *pending_signals_to_report;
 328
 329   /* When collecting_fast_tracepoint is first found to be 1, we insert
 330      a exit-jump-pad-quickly breakpoint.  This is it.  */
 331   struct breakpoint *exit_jump_pad_bkpt;
 332
 333   /* True if the LWP was seen stop at an internal breakpoint and needs
 334      stepping over later when it is resumed.  */
 335   int need_step_over;
 336
 337 #ifdef USE_THREAD_DB
 338   int thread_known;
 339   /* The thread handle, used for e.g. TLS access.  Only valid if
 340      THREAD_KNOWN is set.  */
 341   td_thrhandle_t th;
 342 #endif
 343
 344   /* Arch-specific additions.  */
 345   struct arch_lwp_info *arch_private;
 346 };
 347
 348 int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine);
 349
 350 /* Attach to PTID.  Returns 0 on success, non-zero otherwise (an
 351    errno).  */
 352 int linux_attach_lwp (ptid_t ptid);
 353
 354 /* Return the reason an attach failed, in string form.  ERR is the
 355    error returned by linux_attach_lwp (an errno).  This string should
 356    be copied into a buffer by the client if the string will not be
 357    immediately used, or if it must persist.  */
 358 char *linux_attach_fail_reason_string (ptid_t ptid, int err);
 359
 360 struct lwp_info *find_lwp_pid (ptid_t ptid);
 361 void linux_stop_lwp (struct lwp_info *lwp);
 362
 363 #ifdef HAVE_LINUX_REGSETS
 364 void initialize_regsets_info (struct regsets_info *regsets_info);
 365 #endif
 366
 367 void initialize_low_arch (void);
 368
 369 /* From thread-db.c  */
 370 int thread_db_init (int use_events);
 371 void thread_db_detach (struct process_info *);
 372 void thread_db_mourn (struct process_info *);
 373 int thread_db_handle_monitor_command (char *);
 374 int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
 375                                CORE_ADDR load_module, CORE_ADDR *address);
 376 int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp);