gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007-2014 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include "server.h"
  19 #include "win32-low.h"
  20 #include "i386-low.h"
  21
  22 #ifndef CONTEXT_EXTENDED_REGISTERS
  23 #define CONTEXT_EXTENDED_REGISTERS 0
  24 #endif
  25
  26 #define FCS_REGNUM 27
  27 #define FOP_REGNUM 31
  28
  29 #define FLAG_TRACE_BIT 0x100
  30
  31 #ifdef __x86_64__
  32 /* Defined in auto-generated file reg-amd64.c.  */
  33 void init_registers_amd64 (void);
  34 extern const struct target_desc *tdesc_amd64;
  35 #else
  36 /* Defined in auto-generated file reg-i386.c.  */
  37 void init_registers_i386 (void);
  38 extern const struct target_desc *tdesc_i386;
  39 #endif
  40
  41 static struct i386_debug_reg_state debug_reg_state;
  42
  43 static int debug_registers_changed = 0;
  44 static int debug_registers_used = 0;
  45
  46 /* Update the inferior's debug register REGNUM from STATE.  */
  47
  48 void
  49 i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
  50 {
  51   if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
  52     fatal ("Invalid debug register %d", regnum);
  53
  54   /* debug_reg_state.dr_mirror is already set.
  55      Just notify i386_set_thread_context, i386_thread_added
  56      that the registers need to be updated.  */
  57   debug_registers_changed = 1;
  58   debug_registers_used = 1;
  59 }
  60
  61 CORE_ADDR
  62 i386_dr_low_get_addr (int regnum)
  63 {
  64   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  65
  66   return debug_reg_state.dr_mirror[regnum];
  67 }
  68
  69 /* Update the inferior's DR7 debug control register from STATE.  */
  70
  71 void
  72 i386_dr_low_set_control (const struct i386_debug_reg_state *state)
  73 {
  74   /* debug_reg_state.dr_control_mirror is already set.
  75      Just notify i386_set_thread_context, i386_thread_added
  76      that the registers need to be updated.  */
  77   debug_registers_changed = 1;
  78   debug_registers_used = 1;
  79 }
  80
  81 unsigned
  82 i386_dr_low_get_control (void)
  83 {
  84   return debug_reg_state.dr_control_mirror;
  85 }
  86
  87 /* Get the value of the DR6 debug status register from the inferior
  88    and record it in STATE.  */
  89
  90 unsigned
  91 i386_dr_low_get_status (void)
  92 {
  93   /* We don't need to do anything here, the last call to thread_rec for
  94      current_event.dwThreadId id has already set it.  */
  95   return debug_reg_state.dr_status_mirror;
  96 }
  97
  98 /* Breakpoint/watchpoint support.  */
  99
 100 static int
 101 i386_supports_z_point_type (char z_type)
 102 {
 103   switch (z_type)
 104     {
 105     case Z_PACKET_WRITE_WP:
 106     case Z_PACKET_ACCESS_WP:
 107       return 1;
 108     default:
 109       return 0;
 110     }
 111 }
 112
 113 static int
 114 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 115                    int size, struct raw_breakpoint *bp)
 116 {
 117   switch (type)
 118     {
 119     case raw_bkpt_type_write_wp:
 120     case raw_bkpt_type_access_wp:
 121       {
 122         enum target_hw_bp_type hw_type
 123           = raw_bkpt_type_to_target_hw_bp_type (type);
 124
 125         return i386_low_insert_watchpoint (&debug_reg_state,
 126                                            hw_type, addr, size);
 127       }
 128     default:
 129       /* Unsupported.  */
 130       return 1;
 131     }
 132 }
 133
 134 static int
 135 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 136                    int size, struct raw_breakpoint *bp)
 137 {
 138   switch (type)
 139     {
 140     case raw_bkpt_type_write_wp:
 141     case raw_bkpt_type_access_wp:
 142       {
 143         enum target_hw_bp_type hw_type
 144           = raw_bkpt_type_to_target_hw_bp_type (type);
 145
 146         return i386_low_remove_watchpoint (&debug_reg_state,
 147                                            hw_type, addr, size);
 148       }
 149     default:
 150       /* Unsupported.  */
 151       return 1;
 152     }
 153 }
 154
 155 static int
 156 i386_stopped_by_watchpoint (void)
 157 {
 158   return i386_low_stopped_by_watchpoint (&debug_reg_state);
 159 }
 160
 161 static CORE_ADDR
 162 i386_stopped_data_address (void)
 163 {
 164   CORE_ADDR addr;
 165   if (i386_low_stopped_data_address (&debug_reg_state, &addr))
 166     return addr;
 167   return 0;
 168 }
 169
 170 static void
 171 i386_initial_stuff (void)
 172 {
 173   i386_low_init_dregs (&debug_reg_state);
 174   debug_registers_changed = 0;
 175   debug_registers_used = 0;
 176 }
 177
 178 static void
 179 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 180 {
 181   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 182      the system doesn't support extended registers.  */
 183   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 184
 185  again:
 186   th->context.ContextFlags = (CONTEXT_FULL
 187                               | CONTEXT_FLOATING_POINT
 188                               | CONTEXT_DEBUG_REGISTERS
 189                               | extended_registers);
 190
 191   if (!GetThreadContext (th->h, &th->context))
 192     {
 193       DWORD e = GetLastError ();
 194
 195       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 196         {
 197           extended_registers = 0;
 198           goto again;
 199         }
 200
 201       error ("GetThreadContext failure %ld\n", (long) e);
 202     }
 203
 204   debug_registers_changed = 0;
 205
 206   if (th->tid == current_event->dwThreadId)
 207     {
 208       /* Copy dr values from the current thread.  */
 209       struct i386_debug_reg_state *dr = &debug_reg_state;
 210       dr->dr_mirror[0] = th->context.Dr0;
 211       dr->dr_mirror[1] = th->context.Dr1;
 212       dr->dr_mirror[2] = th->context.Dr2;
 213       dr->dr_mirror[3] = th->context.Dr3;
 214       dr->dr_status_mirror = th->context.Dr6;
 215       dr->dr_control_mirror = th->context.Dr7;
 216     }
 217 }
 218
 219 static void
 220 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 221 {
 222   if (debug_registers_changed)
 223     {
 224       struct i386_debug_reg_state *dr = &debug_reg_state;
 225       th->context.Dr0 = dr->dr_mirror[0];
 226       th->context.Dr1 = dr->dr_mirror[1];
 227       th->context.Dr2 = dr->dr_mirror[2];
 228       th->context.Dr3 = dr->dr_mirror[3];
 229       /* th->context.Dr6 = dr->dr_status_mirror;
 230          FIXME: should we set dr6 also ?? */
 231       th->context.Dr7 = dr->dr_control_mirror;
 232     }
 233
 234   SetThreadContext (th->h, &th->context);
 235 }
 236
 237 static void
 238 i386_thread_added (win32_thread_info *th)
 239 {
 240   /* Set the debug registers for the new thread if they are used.  */
 241   if (debug_registers_used)
 242     {
 243       struct i386_debug_reg_state *dr = &debug_reg_state;
 244       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 245       GetThreadContext (th->h, &th->context);
 246
 247       th->context.Dr0 = dr->dr_mirror[0];
 248       th->context.Dr1 = dr->dr_mirror[1];
 249       th->context.Dr2 = dr->dr_mirror[2];
 250       th->context.Dr3 = dr->dr_mirror[3];
 251       /* th->context.Dr6 = dr->dr_status_mirror;
 252          FIXME: should we set dr6 also ?? */
 253       th->context.Dr7 = dr->dr_control_mirror;
 254
 255       SetThreadContext (th->h, &th->context);
 256       th->context.ContextFlags = 0;
 257     }
 258 }
 259
 260 static void
 261 i386_single_step (win32_thread_info *th)
 262 {
 263   th->context.EFlags |= FLAG_TRACE_BIT;
 264 }
 265
 266 #ifndef __x86_64__
 267
 268 /* An array of offset mappings into a Win32 Context structure.
 269    This is a one-to-one mapping which is indexed by gdb's register
 270    numbers.  It retrieves an offset into the context structure where
 271    the 4 byte register is located.
 272    An offset value of -1 indicates that Win32 does not provide this
 273    register in it's CONTEXT structure.  In this case regptr will return
 274    a pointer into a dummy register.  */
 275 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 276 static const int mappings[] = {
 277   context_offset (Eax),
 278   context_offset (Ecx),
 279   context_offset (Edx),
 280   context_offset (Ebx),
 281   context_offset (Esp),
 282   context_offset (Ebp),
 283   context_offset (Esi),
 284   context_offset (Edi),
 285   context_offset (Eip),
 286   context_offset (EFlags),
 287   context_offset (SegCs),
 288   context_offset (SegSs),
 289   context_offset (SegDs),
 290   context_offset (SegEs),
 291   context_offset (SegFs),
 292   context_offset (SegGs),
 293   context_offset (FloatSave.RegisterArea[0 * 10]),
 294   context_offset (FloatSave.RegisterArea[1 * 10]),
 295   context_offset (FloatSave.RegisterArea[2 * 10]),
 296   context_offset (FloatSave.RegisterArea[3 * 10]),
 297   context_offset (FloatSave.RegisterArea[4 * 10]),
 298   context_offset (FloatSave.RegisterArea[5 * 10]),
 299   context_offset (FloatSave.RegisterArea[6 * 10]),
 300   context_offset (FloatSave.RegisterArea[7 * 10]),
 301   context_offset (FloatSave.ControlWord),
 302   context_offset (FloatSave.StatusWord),
 303   context_offset (FloatSave.TagWord),
 304   context_offset (FloatSave.ErrorSelector),
 305   context_offset (FloatSave.ErrorOffset),
 306   context_offset (FloatSave.DataSelector),
 307   context_offset (FloatSave.DataOffset),
 308   context_offset (FloatSave.ErrorSelector),
 309   /* XMM0-7 */
 310   context_offset (ExtendedRegisters[10 * 16]),
 311   context_offset (ExtendedRegisters[11 * 16]),
 312   context_offset (ExtendedRegisters[12 * 16]),
 313   context_offset (ExtendedRegisters[13 * 16]),
 314   context_offset (ExtendedRegisters[14 * 16]),
 315   context_offset (ExtendedRegisters[15 * 16]),
 316   context_offset (ExtendedRegisters[16 * 16]),
 317   context_offset (ExtendedRegisters[17 * 16]),
 318   /* MXCSR */
 319   context_offset (ExtendedRegisters[24])
 320 };
 321 #undef context_offset
 322
 323 #else /* __x86_64__ */
 324
 325 #define context_offset(x) (offsetof (CONTEXT, x))
 326 static const int mappings[] =
 327 {
 328   context_offset (Rax),
 329   context_offset (Rbx),
 330   context_offset (Rcx),
 331   context_offset (Rdx),
 332   context_offset (Rsi),
 333   context_offset (Rdi),
 334   context_offset (Rbp),
 335   context_offset (Rsp),
 336   context_offset (R8),
 337   context_offset (R9),
 338   context_offset (R10),
 339   context_offset (R11),
 340   context_offset (R12),
 341   context_offset (R13),
 342   context_offset (R14),
 343   context_offset (R15),
 344   context_offset (Rip),
 345   context_offset (EFlags),
 346   context_offset (SegCs),
 347   context_offset (SegSs),
 348   context_offset (SegDs),
 349   context_offset (SegEs),
 350   context_offset (SegFs),
 351   context_offset (SegGs),
 352   context_offset (FloatSave.FloatRegisters[0]),
 353   context_offset (FloatSave.FloatRegisters[1]),
 354   context_offset (FloatSave.FloatRegisters[2]),
 355   context_offset (FloatSave.FloatRegisters[3]),
 356   context_offset (FloatSave.FloatRegisters[4]),
 357   context_offset (FloatSave.FloatRegisters[5]),
 358   context_offset (FloatSave.FloatRegisters[6]),
 359   context_offset (FloatSave.FloatRegisters[7]),
 360   context_offset (FloatSave.ControlWord),
 361   context_offset (FloatSave.StatusWord),
 362   context_offset (FloatSave.TagWord),
 363   context_offset (FloatSave.ErrorSelector),
 364   context_offset (FloatSave.ErrorOffset),
 365   context_offset (FloatSave.DataSelector),
 366   context_offset (FloatSave.DataOffset),
 367   context_offset (FloatSave.ErrorSelector)
 368   /* XMM0-7 */ ,
 369   context_offset (Xmm0),
 370   context_offset (Xmm1),
 371   context_offset (Xmm2),
 372   context_offset (Xmm3),
 373   context_offset (Xmm4),
 374   context_offset (Xmm5),
 375   context_offset (Xmm6),
 376   context_offset (Xmm7),
 377   context_offset (Xmm8),
 378   context_offset (Xmm9),
 379   context_offset (Xmm10),
 380   context_offset (Xmm11),
 381   context_offset (Xmm12),
 382   context_offset (Xmm13),
 383   context_offset (Xmm14),
 384   context_offset (Xmm15),
 385   /* MXCSR */
 386   context_offset (FloatSave.MxCsr)
 387 };
 388 #undef context_offset
 389
 390 #endif /* __x86_64__ */
 391
 392 /* Fetch register from gdbserver regcache data.  */
 393 static void
 394 i386_fetch_inferior_register (struct regcache *regcache,
 395                               win32_thread_info *th, int r)
 396 {
 397   char *context_offset = (char *) &th->context + mappings[r];
 398
 399   long l;
 400   if (r == FCS_REGNUM)
 401     {
 402       l = *((long *) context_offset) & 0xffff;
 403       supply_register (regcache, r, (char *) &l);
 404     }
 405   else if (r == FOP_REGNUM)
 406     {
 407       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 408       supply_register (regcache, r, (char *) &l);
 409     }
 410   else
 411     supply_register (regcache, r, context_offset);
 412 }
 413
 414 /* Store a new register value into the thread context of TH.  */
 415 static void
 416 i386_store_inferior_register (struct regcache *regcache,
 417                               win32_thread_info *th, int r)
 418 {
 419   char *context_offset = (char *) &th->context + mappings[r];
 420   collect_register (regcache, r, context_offset);
 421 }
 422
 423 static const unsigned char i386_win32_breakpoint = 0xcc;
 424 #define i386_win32_breakpoint_len 1
 425
 426 static void
 427 i386_arch_setup (void)
 428 {
 429 #ifdef __x86_64__
 430   init_registers_amd64 ();
 431   win32_tdesc = tdesc_amd64;
 432 #else
 433   init_registers_i386 ();
 434   win32_tdesc = tdesc_i386;
 435 #endif
 436 }
 437
 438 struct win32_target_ops the_low_target = {
 439   i386_arch_setup,
 440   sizeof (mappings) / sizeof (mappings[0]),
 441   i386_initial_stuff,
 442   i386_get_thread_context,
 443   i386_set_thread_context,
 444   i386_thread_added,
 445   i386_fetch_inferior_register,
 446   i386_store_inferior_register,
 447   i386_single_step,
 448   &i386_win32_breakpoint,
 449   i386_win32_breakpoint_len,
 450   i386_supports_z_point_type,
 451   i386_insert_point,
 452   i386_remove_point,
 453   i386_stopped_by_watchpoint,
 454   i386_stopped_data_address
 455 };