gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007, 2008, 2009, 2010, 2011 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 #else
  35 /* Defined in auto-generated file reg-i386.c.  */
  36 void init_registers_i386 (void);
  37 #endif
  38
  39 static struct i386_debug_reg_state debug_reg_state;
  40
  41 static int debug_registers_changed = 0;
  42 static int debug_registers_used = 0;
  43
  44 /* Update the inferior's debug register REGNUM from STATE.  */
  45
  46 void
  47 i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
  48 {
  49   if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
  50     fatal ("Invalid debug register %d", regnum);
  51
  52   /* debug_reg_state.dr_mirror is already set.
  53      Just notify i386_set_thread_context, i386_thread_added
  54      that the registers need to be updated.  */
  55   debug_registers_changed = 1;
  56   debug_registers_used = 1;
  57 }
  58
  59 CORE_ADDR
  60 i386_dr_low_get_addr (int regnum)
  61 {
  62   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  63
  64   return debug_reg_state.dr_mirror[regnum];
  65 }
  66
  67 /* Update the inferior's DR7 debug control register from STATE.  */
  68
  69 void
  70 i386_dr_low_set_control (const struct i386_debug_reg_state *state)
  71 {
  72   /* debug_reg_state.dr_control_mirror is already set.
  73      Just notify i386_set_thread_context, i386_thread_added
  74      that the registers need to be updated.  */
  75   debug_registers_changed = 1;
  76   debug_registers_used = 1;
  77 }
  78
  79 unsigned
  80 i386_dr_low_get_control (void)
  81 {
  82   return debug_reg_state.dr_control_mirror;
  83 }
  84
  85 /* Get the value of the DR6 debug status register from the inferior
  86    and record it in STATE.  */
  87
  88 unsigned
  89 i386_dr_low_get_status (void)
  90 {
  91   /* We don't need to do anything here, the last call to thread_rec for
  92      current_event.dwThreadId id has already set it.  */
  93   return debug_reg_state.dr_status_mirror;
  94 }
  95
  96 /* Watchpoint support.  */
  97
  98 static int
  99 i386_insert_point (char type, CORE_ADDR addr, int len)
 100 {
 101   switch (type)
 102     {
 103     case '2':
 104     case '3':
 105     case '4':
 106       return i386_low_insert_watchpoint (&debug_reg_state,
 107                                          type, addr, len);
 108     default:
 109       /* Unsupported.  */
 110       return 1;
 111     }
 112 }
 113
 114 static int
 115 i386_remove_point (char type, CORE_ADDR addr, int len)
 116 {
 117   switch (type)
 118     {
 119     case '2':
 120     case '3':
 121     case '4':
 122       return i386_low_remove_watchpoint (&debug_reg_state,
 123                                          type, addr, len);
 124     default:
 125       /* Unsupported.  */
 126       return 1;
 127     }
 128 }
 129
 130 static int
 131 i386_stopped_by_watchpoint (void)
 132 {
 133   return i386_low_stopped_by_watchpoint (&debug_reg_state);
 134 }
 135
 136 static CORE_ADDR
 137 i386_stopped_data_address (void)
 138 {
 139   CORE_ADDR addr;
 140   if (i386_low_stopped_data_address (&debug_reg_state, &addr))
 141     return addr;
 142   return 0;
 143 }
 144
 145 static void
 146 i386_initial_stuff (void)
 147 {
 148   i386_low_init_dregs (&debug_reg_state);
 149   debug_registers_changed = 0;
 150   debug_registers_used = 0;
 151 }
 152
 153 static void
 154 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 155 {
 156   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 157      the system doesn't support extended registers.  */
 158   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 159
 160  again:
 161   th->context.ContextFlags = (CONTEXT_FULL
 162                               | CONTEXT_FLOATING_POINT
 163                               | CONTEXT_DEBUG_REGISTERS
 164                               | extended_registers);
 165
 166   if (!GetThreadContext (th->h, &th->context))
 167     {
 168       DWORD e = GetLastError ();
 169
 170       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 171         {
 172           extended_registers = 0;
 173           goto again;
 174         }
 175
 176       error ("GetThreadContext failure %ld\n", (long) e);
 177     }
 178
 179   debug_registers_changed = 0;
 180
 181   if (th->tid == current_event->dwThreadId)
 182     {
 183       /* Copy dr values from the current thread.  */
 184       struct i386_debug_reg_state *dr = &debug_reg_state;
 185       dr->dr_mirror[0] = th->context.Dr0;
 186       dr->dr_mirror[1] = th->context.Dr1;
 187       dr->dr_mirror[2] = th->context.Dr2;
 188       dr->dr_mirror[3] = th->context.Dr3;
 189       dr->dr_status_mirror = th->context.Dr6;
 190       dr->dr_control_mirror = th->context.Dr7;
 191     }
 192 }
 193
 194 static void
 195 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 196 {
 197   if (debug_registers_changed)
 198     {
 199       struct i386_debug_reg_state *dr = &debug_reg_state;
 200       th->context.Dr0 = dr->dr_mirror[0];
 201       th->context.Dr1 = dr->dr_mirror[1];
 202       th->context.Dr2 = dr->dr_mirror[2];
 203       th->context.Dr3 = dr->dr_mirror[3];
 204       /* th->context.Dr6 = dr->dr_status_mirror;
 205          FIXME: should we set dr6 also ?? */
 206       th->context.Dr7 = dr->dr_control_mirror;
 207     }
 208
 209   SetThreadContext (th->h, &th->context);
 210 }
 211
 212 static void
 213 i386_thread_added (win32_thread_info *th)
 214 {
 215   /* Set the debug registers for the new thread if they are used.  */
 216   if (debug_registers_used)
 217     {
 218       struct i386_debug_reg_state *dr = &debug_reg_state;
 219       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 220       GetThreadContext (th->h, &th->context);
 221
 222       th->context.Dr0 = dr->dr_mirror[0];
 223       th->context.Dr1 = dr->dr_mirror[1];
 224       th->context.Dr2 = dr->dr_mirror[2];
 225       th->context.Dr3 = dr->dr_mirror[3];
 226       /* th->context.Dr6 = dr->dr_status_mirror;
 227          FIXME: should we set dr6 also ?? */
 228       th->context.Dr7 = dr->dr_control_mirror;
 229
 230       SetThreadContext (th->h, &th->context);
 231       th->context.ContextFlags = 0;
 232     }
 233 }
 234
 235 static void
 236 i386_single_step (win32_thread_info *th)
 237 {
 238   th->context.EFlags |= FLAG_TRACE_BIT;
 239 }
 240
 241 #ifndef __x86_64__
 242
 243 /* An array of offset mappings into a Win32 Context structure.
 244    This is a one-to-one mapping which is indexed by gdb's register
 245    numbers.  It retrieves an offset into the context structure where
 246    the 4 byte register is located.
 247    An offset value of -1 indicates that Win32 does not provide this
 248    register in it's CONTEXT structure.  In this case regptr will return
 249    a pointer into a dummy register.  */
 250 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 251 static const int mappings[] = {
 252   context_offset (Eax),
 253   context_offset (Ecx),
 254   context_offset (Edx),
 255   context_offset (Ebx),
 256   context_offset (Esp),
 257   context_offset (Ebp),
 258   context_offset (Esi),
 259   context_offset (Edi),
 260   context_offset (Eip),
 261   context_offset (EFlags),
 262   context_offset (SegCs),
 263   context_offset (SegSs),
 264   context_offset (SegDs),
 265   context_offset (SegEs),
 266   context_offset (SegFs),
 267   context_offset (SegGs),
 268   context_offset (FloatSave.RegisterArea[0 * 10]),
 269   context_offset (FloatSave.RegisterArea[1 * 10]),
 270   context_offset (FloatSave.RegisterArea[2 * 10]),
 271   context_offset (FloatSave.RegisterArea[3 * 10]),
 272   context_offset (FloatSave.RegisterArea[4 * 10]),
 273   context_offset (FloatSave.RegisterArea[5 * 10]),
 274   context_offset (FloatSave.RegisterArea[6 * 10]),
 275   context_offset (FloatSave.RegisterArea[7 * 10]),
 276   context_offset (FloatSave.ControlWord),
 277   context_offset (FloatSave.StatusWord),
 278   context_offset (FloatSave.TagWord),
 279   context_offset (FloatSave.ErrorSelector),
 280   context_offset (FloatSave.ErrorOffset),
 281   context_offset (FloatSave.DataSelector),
 282   context_offset (FloatSave.DataOffset),
 283   context_offset (FloatSave.ErrorSelector),
 284   /* XMM0-7 */
 285   context_offset (ExtendedRegisters[10 * 16]),
 286   context_offset (ExtendedRegisters[11 * 16]),
 287   context_offset (ExtendedRegisters[12 * 16]),
 288   context_offset (ExtendedRegisters[13 * 16]),
 289   context_offset (ExtendedRegisters[14 * 16]),
 290   context_offset (ExtendedRegisters[15 * 16]),
 291   context_offset (ExtendedRegisters[16 * 16]),
 292   context_offset (ExtendedRegisters[17 * 16]),
 293   /* MXCSR */
 294   context_offset (ExtendedRegisters[24])
 295 };
 296 #undef context_offset
 297
 298 #else /* __x86_64__ */
 299
 300 #define context_offset(x) (offsetof (CONTEXT, x))
 301 static const int mappings[] =
 302 {
 303   context_offset (Rax),
 304   context_offset (Rbx),
 305   context_offset (Rcx),
 306   context_offset (Rdx),
 307   context_offset (Rsi),
 308   context_offset (Rdi),
 309   context_offset (Rbp),
 310   context_offset (Rsp),
 311   context_offset (R8),
 312   context_offset (R9),
 313   context_offset (R10),
 314   context_offset (R11),
 315   context_offset (R12),
 316   context_offset (R13),
 317   context_offset (R14),
 318   context_offset (R15),
 319   context_offset (Rip),
 320   context_offset (EFlags),
 321   context_offset (SegCs),
 322   context_offset (SegSs),
 323   context_offset (SegDs),
 324   context_offset (SegEs),
 325   context_offset (SegFs),
 326   context_offset (SegGs),
 327   context_offset (FloatSave.FloatRegisters[0]),
 328   context_offset (FloatSave.FloatRegisters[1]),
 329   context_offset (FloatSave.FloatRegisters[2]),
 330   context_offset (FloatSave.FloatRegisters[3]),
 331   context_offset (FloatSave.FloatRegisters[4]),
 332   context_offset (FloatSave.FloatRegisters[5]),
 333   context_offset (FloatSave.FloatRegisters[6]),
 334   context_offset (FloatSave.FloatRegisters[7]),
 335   context_offset (FloatSave.ControlWord),
 336   context_offset (FloatSave.StatusWord),
 337   context_offset (FloatSave.TagWord),
 338   context_offset (FloatSave.ErrorSelector),
 339   context_offset (FloatSave.ErrorOffset),
 340   context_offset (FloatSave.DataSelector),
 341   context_offset (FloatSave.DataOffset),
 342   context_offset (FloatSave.ErrorSelector)
 343   /* XMM0-7 */ ,
 344   context_offset (Xmm0),
 345   context_offset (Xmm1),
 346   context_offset (Xmm2),
 347   context_offset (Xmm3),
 348   context_offset (Xmm4),
 349   context_offset (Xmm5),
 350   context_offset (Xmm6),
 351   context_offset (Xmm7),
 352   context_offset (Xmm8),
 353   context_offset (Xmm9),
 354   context_offset (Xmm10),
 355   context_offset (Xmm11),
 356   context_offset (Xmm12),
 357   context_offset (Xmm13),
 358   context_offset (Xmm14),
 359   context_offset (Xmm15),
 360   /* MXCSR */
 361   context_offset (FloatSave.MxCsr)
 362 };
 363 #undef context_offset
 364
 365 #endif /* __x86_64__ */
 366
 367 /* Fetch register from gdbserver regcache data.  */
 368 static void
 369 i386_fetch_inferior_register (struct regcache *regcache,
 370                               win32_thread_info *th, int r)
 371 {
 372   char *context_offset = (char *) &th->context + mappings[r];
 373
 374   long l;
 375   if (r == FCS_REGNUM)
 376     {
 377       l = *((long *) context_offset) & 0xffff;
 378       supply_register (regcache, r, (char *) &l);
 379     }
 380   else if (r == FOP_REGNUM)
 381     {
 382       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 383       supply_register (regcache, r, (char *) &l);
 384     }
 385   else
 386     supply_register (regcache, r, context_offset);
 387 }
 388
 389 /* Store a new register value into the thread context of TH.  */
 390 static void
 391 i386_store_inferior_register (struct regcache *regcache,
 392                               win32_thread_info *th, int r)
 393 {
 394   char *context_offset = (char *) &th->context + mappings[r];
 395   collect_register (regcache, r, context_offset);
 396 }
 397
 398 static const unsigned char i386_win32_breakpoint = 0xcc;
 399 #define i386_win32_breakpoint_len 1
 400
 401 static void
 402 init_windows_x86 (void)
 403 {
 404 #ifdef __x86_64__
 405   init_registers_amd64 ();
 406 #else
 407   init_registers_i386 ();
 408 #endif
 409 }
 410
 411 struct win32_target_ops the_low_target = {
 412   init_windows_x86,
 413   sizeof (mappings) / sizeof (mappings[0]),
 414   i386_initial_stuff,
 415   i386_get_thread_context,
 416   i386_set_thread_context,
 417   i386_thread_added,
 418   i386_fetch_inferior_register,
 419   i386_store_inferior_register,
 420   i386_single_step,
 421   &i386_win32_breakpoint,
 422   i386_win32_breakpoint_len,
 423   i386_insert_point,
 424   i386_remove_point,
 425   i386_stopped_by_watchpoint,
 426   i386_stopped_data_address
 427 };