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 "x86-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 x86_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 static void
  49 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  50 {
  51   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  52
  53   /* debug_reg_state.dr_mirror is already set.
  54      Just notify i386_set_thread_context, i386_thread_added
  55      that the registers need to be updated.  */
  56   debug_registers_changed = 1;
  57   debug_registers_used = 1;
  58 }
  59
  60 static CORE_ADDR
  61 x86_dr_low_get_addr (int regnum)
  62 {
  63   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  64
  65   return debug_reg_state.dr_mirror[regnum];
  66 }
  67
  68 /* Update the inferior's DR7 debug control register from STATE.  */
  69
  70 static void
  71 x86_dr_low_set_control (unsigned long control)
  72 {
  73   /* debug_reg_state.dr_control_mirror is already set.
  74      Just notify i386_set_thread_context, i386_thread_added
  75      that the registers need to be updated.  */
  76   debug_registers_changed = 1;
  77   debug_registers_used = 1;
  78 }
  79
  80 static unsigned long
  81 x86_dr_low_get_control (void)
  82 {
  83   return debug_reg_state.dr_control_mirror;
  84 }
  85
  86 /* Get the value of the DR6 debug status register from the inferior
  87    and record it in STATE.  */
  88
  89 static unsigned long
  90 x86_dr_low_get_status (void)
  91 {
  92   /* We don't need to do anything here, the last call to thread_rec for
  93      current_event.dwThreadId id has already set it.  */
  94   return debug_reg_state.dr_status_mirror;
  95 }
  96
  97 /* Low-level function vector.  */
  98 struct x86_dr_low_type x86_dr_low =
  99   {
 100     x86_dr_low_set_control,
 101     x86_dr_low_set_addr,
 102     x86_dr_low_get_addr,
 103     x86_dr_low_get_status,
 104     x86_dr_low_get_control,
 105     sizeof (void *),
 106   };
 107
 108 /* Breakpoint/watchpoint support.  */
 109
 110 static int
 111 i386_supports_z_point_type (char z_type)
 112 {
 113   switch (z_type)
 114     {
 115     case Z_PACKET_WRITE_WP:
 116     case Z_PACKET_ACCESS_WP:
 117       return 1;
 118     default:
 119       return 0;
 120     }
 121 }
 122
 123 static int
 124 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 125                    int size, struct raw_breakpoint *bp)
 126 {
 127   switch (type)
 128     {
 129     case raw_bkpt_type_write_wp:
 130     case raw_bkpt_type_access_wp:
 131       {
 132         enum target_hw_bp_type hw_type
 133           = raw_bkpt_type_to_target_hw_bp_type (type);
 134
 135         return x86_dr_insert_watchpoint (&debug_reg_state,
 136                                          hw_type, addr, size);
 137       }
 138     default:
 139       /* Unsupported.  */
 140       return 1;
 141     }
 142 }
 143
 144 static int
 145 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 146                    int size, struct raw_breakpoint *bp)
 147 {
 148   switch (type)
 149     {
 150     case raw_bkpt_type_write_wp:
 151     case raw_bkpt_type_access_wp:
 152       {
 153         enum target_hw_bp_type hw_type
 154           = raw_bkpt_type_to_target_hw_bp_type (type);
 155
 156         return x86_dr_remove_watchpoint (&debug_reg_state,
 157                                          hw_type, addr, size);
 158       }
 159     default:
 160       /* Unsupported.  */
 161       return 1;
 162     }
 163 }
 164
 165 static int
 166 x86_stopped_by_watchpoint (void)
 167 {
 168   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 169 }
 170
 171 static CORE_ADDR
 172 x86_stopped_data_address (void)
 173 {
 174   CORE_ADDR addr;
 175   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 176     return addr;
 177   return 0;
 178 }
 179
 180 static void
 181 i386_initial_stuff (void)
 182 {
 183   x86_low_init_dregs (&debug_reg_state);
 184   debug_registers_changed = 0;
 185   debug_registers_used = 0;
 186 }
 187
 188 static void
 189 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 190 {
 191   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 192      the system doesn't support extended registers.  */
 193   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 194
 195  again:
 196   th->context.ContextFlags = (CONTEXT_FULL
 197                               | CONTEXT_FLOATING_POINT
 198                               | CONTEXT_DEBUG_REGISTERS
 199                               | extended_registers);
 200
 201   if (!GetThreadContext (th->h, &th->context))
 202     {
 203       DWORD e = GetLastError ();
 204
 205       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 206         {
 207           extended_registers = 0;
 208           goto again;
 209         }
 210
 211       error ("GetThreadContext failure %ld\n", (long) e);
 212     }
 213
 214   debug_registers_changed = 0;
 215
 216   if (th->tid == current_event->dwThreadId)
 217     {
 218       /* Copy dr values from the current thread.  */
 219       struct x86_debug_reg_state *dr = &debug_reg_state;
 220       dr->dr_mirror[0] = th->context.Dr0;
 221       dr->dr_mirror[1] = th->context.Dr1;
 222       dr->dr_mirror[2] = th->context.Dr2;
 223       dr->dr_mirror[3] = th->context.Dr3;
 224       dr->dr_status_mirror = th->context.Dr6;
 225       dr->dr_control_mirror = th->context.Dr7;
 226     }
 227 }
 228
 229 static void
 230 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 231 {
 232   if (debug_registers_changed)
 233     {
 234       struct x86_debug_reg_state *dr = &debug_reg_state;
 235       th->context.Dr0 = dr->dr_mirror[0];
 236       th->context.Dr1 = dr->dr_mirror[1];
 237       th->context.Dr2 = dr->dr_mirror[2];
 238       th->context.Dr3 = dr->dr_mirror[3];
 239       /* th->context.Dr6 = dr->dr_status_mirror;
 240          FIXME: should we set dr6 also ?? */
 241       th->context.Dr7 = dr->dr_control_mirror;
 242     }
 243
 244   SetThreadContext (th->h, &th->context);
 245 }
 246
 247 static void
 248 i386_thread_added (win32_thread_info *th)
 249 {
 250   /* Set the debug registers for the new thread if they are used.  */
 251   if (debug_registers_used)
 252     {
 253       struct x86_debug_reg_state *dr = &debug_reg_state;
 254       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 255       GetThreadContext (th->h, &th->context);
 256
 257       th->context.Dr0 = dr->dr_mirror[0];
 258       th->context.Dr1 = dr->dr_mirror[1];
 259       th->context.Dr2 = dr->dr_mirror[2];
 260       th->context.Dr3 = dr->dr_mirror[3];
 261       /* th->context.Dr6 = dr->dr_status_mirror;
 262          FIXME: should we set dr6 also ?? */
 263       th->context.Dr7 = dr->dr_control_mirror;
 264
 265       SetThreadContext (th->h, &th->context);
 266       th->context.ContextFlags = 0;
 267     }
 268 }
 269
 270 static void
 271 i386_single_step (win32_thread_info *th)
 272 {
 273   th->context.EFlags |= FLAG_TRACE_BIT;
 274 }
 275
 276 #ifndef __x86_64__
 277
 278 /* An array of offset mappings into a Win32 Context structure.
 279    This is a one-to-one mapping which is indexed by gdb's register
 280    numbers.  It retrieves an offset into the context structure where
 281    the 4 byte register is located.
 282    An offset value of -1 indicates that Win32 does not provide this
 283    register in it's CONTEXT structure.  In this case regptr will return
 284    a pointer into a dummy register.  */
 285 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 286 static const int mappings[] = {
 287   context_offset (Eax),
 288   context_offset (Ecx),
 289   context_offset (Edx),
 290   context_offset (Ebx),
 291   context_offset (Esp),
 292   context_offset (Ebp),
 293   context_offset (Esi),
 294   context_offset (Edi),
 295   context_offset (Eip),
 296   context_offset (EFlags),
 297   context_offset (SegCs),
 298   context_offset (SegSs),
 299   context_offset (SegDs),
 300   context_offset (SegEs),
 301   context_offset (SegFs),
 302   context_offset (SegGs),
 303   context_offset (FloatSave.RegisterArea[0 * 10]),
 304   context_offset (FloatSave.RegisterArea[1 * 10]),
 305   context_offset (FloatSave.RegisterArea[2 * 10]),
 306   context_offset (FloatSave.RegisterArea[3 * 10]),
 307   context_offset (FloatSave.RegisterArea[4 * 10]),
 308   context_offset (FloatSave.RegisterArea[5 * 10]),
 309   context_offset (FloatSave.RegisterArea[6 * 10]),
 310   context_offset (FloatSave.RegisterArea[7 * 10]),
 311   context_offset (FloatSave.ControlWord),
 312   context_offset (FloatSave.StatusWord),
 313   context_offset (FloatSave.TagWord),
 314   context_offset (FloatSave.ErrorSelector),
 315   context_offset (FloatSave.ErrorOffset),
 316   context_offset (FloatSave.DataSelector),
 317   context_offset (FloatSave.DataOffset),
 318   context_offset (FloatSave.ErrorSelector),
 319   /* XMM0-7 */
 320   context_offset (ExtendedRegisters[10 * 16]),
 321   context_offset (ExtendedRegisters[11 * 16]),
 322   context_offset (ExtendedRegisters[12 * 16]),
 323   context_offset (ExtendedRegisters[13 * 16]),
 324   context_offset (ExtendedRegisters[14 * 16]),
 325   context_offset (ExtendedRegisters[15 * 16]),
 326   context_offset (ExtendedRegisters[16 * 16]),
 327   context_offset (ExtendedRegisters[17 * 16]),
 328   /* MXCSR */
 329   context_offset (ExtendedRegisters[24])
 330 };
 331 #undef context_offset
 332
 333 #else /* __x86_64__ */
 334
 335 #define context_offset(x) (offsetof (CONTEXT, x))
 336 static const int mappings[] =
 337 {
 338   context_offset (Rax),
 339   context_offset (Rbx),
 340   context_offset (Rcx),
 341   context_offset (Rdx),
 342   context_offset (Rsi),
 343   context_offset (Rdi),
 344   context_offset (Rbp),
 345   context_offset (Rsp),
 346   context_offset (R8),
 347   context_offset (R9),
 348   context_offset (R10),
 349   context_offset (R11),
 350   context_offset (R12),
 351   context_offset (R13),
 352   context_offset (R14),
 353   context_offset (R15),
 354   context_offset (Rip),
 355   context_offset (EFlags),
 356   context_offset (SegCs),
 357   context_offset (SegSs),
 358   context_offset (SegDs),
 359   context_offset (SegEs),
 360   context_offset (SegFs),
 361   context_offset (SegGs),
 362   context_offset (FloatSave.FloatRegisters[0]),
 363   context_offset (FloatSave.FloatRegisters[1]),
 364   context_offset (FloatSave.FloatRegisters[2]),
 365   context_offset (FloatSave.FloatRegisters[3]),
 366   context_offset (FloatSave.FloatRegisters[4]),
 367   context_offset (FloatSave.FloatRegisters[5]),
 368   context_offset (FloatSave.FloatRegisters[6]),
 369   context_offset (FloatSave.FloatRegisters[7]),
 370   context_offset (FloatSave.ControlWord),
 371   context_offset (FloatSave.StatusWord),
 372   context_offset (FloatSave.TagWord),
 373   context_offset (FloatSave.ErrorSelector),
 374   context_offset (FloatSave.ErrorOffset),
 375   context_offset (FloatSave.DataSelector),
 376   context_offset (FloatSave.DataOffset),
 377   context_offset (FloatSave.ErrorSelector)
 378   /* XMM0-7 */ ,
 379   context_offset (Xmm0),
 380   context_offset (Xmm1),
 381   context_offset (Xmm2),
 382   context_offset (Xmm3),
 383   context_offset (Xmm4),
 384   context_offset (Xmm5),
 385   context_offset (Xmm6),
 386   context_offset (Xmm7),
 387   context_offset (Xmm8),
 388   context_offset (Xmm9),
 389   context_offset (Xmm10),
 390   context_offset (Xmm11),
 391   context_offset (Xmm12),
 392   context_offset (Xmm13),
 393   context_offset (Xmm14),
 394   context_offset (Xmm15),
 395   /* MXCSR */
 396   context_offset (FloatSave.MxCsr)
 397 };
 398 #undef context_offset
 399
 400 #endif /* __x86_64__ */
 401
 402 /* Fetch register from gdbserver regcache data.  */
 403 static void
 404 i386_fetch_inferior_register (struct regcache *regcache,
 405                               win32_thread_info *th, int r)
 406 {
 407   char *context_offset = (char *) &th->context + mappings[r];
 408
 409   long l;
 410   if (r == FCS_REGNUM)
 411     {
 412       l = *((long *) context_offset) & 0xffff;
 413       supply_register (regcache, r, (char *) &l);
 414     }
 415   else if (r == FOP_REGNUM)
 416     {
 417       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 418       supply_register (regcache, r, (char *) &l);
 419     }
 420   else
 421     supply_register (regcache, r, context_offset);
 422 }
 423
 424 /* Store a new register value into the thread context of TH.  */
 425 static void
 426 i386_store_inferior_register (struct regcache *regcache,
 427                               win32_thread_info *th, int r)
 428 {
 429   char *context_offset = (char *) &th->context + mappings[r];
 430   collect_register (regcache, r, context_offset);
 431 }
 432
 433 static const unsigned char i386_win32_breakpoint = 0xcc;
 434 #define i386_win32_breakpoint_len 1
 435
 436 static void
 437 i386_arch_setup (void)
 438 {
 439 #ifdef __x86_64__
 440   init_registers_amd64 ();
 441   win32_tdesc = tdesc_amd64;
 442 #else
 443   init_registers_i386 ();
 444   win32_tdesc = tdesc_i386;
 445 #endif
 446 }
 447
 448 struct win32_target_ops the_low_target = {
 449   i386_arch_setup,
 450   sizeof (mappings) / sizeof (mappings[0]),
 451   i386_initial_stuff,
 452   i386_get_thread_context,
 453   i386_set_thread_context,
 454   i386_thread_added,
 455   i386_fetch_inferior_register,
 456   i386_store_inferior_register,
 457   i386_single_step,
 458   &i386_win32_breakpoint,
 459   i386_win32_breakpoint_len,
 460   i386_supports_z_point_type,
 461   i386_insert_point,
 462   i386_remove_point,
 463   x86_stopped_by_watchpoint,
 464   x86_stopped_data_address
 465 };