gdb/gdbserver/win32-i386-low.c

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