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 static void
  49 i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
  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 static 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 static void
  72 i386_dr_low_set_control (unsigned long control)
  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 static unsigned long
  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 static unsigned long
  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 /* Low-level function vector.  */
  99 struct i386_dr_low_type i386_dr_low =
 100   {
 101     i386_dr_low_set_control,
 102     i386_dr_low_set_addr,
 103     i386_dr_low_get_addr,
 104     i386_dr_low_get_status,
 105     i386_dr_low_get_control,
 106     sizeof (void *),
 107   };
 108
 109 /* Breakpoint/watchpoint support.  */
 110
 111 static int
 112 i386_supports_z_point_type (char z_type)
 113 {
 114   switch (z_type)
 115     {
 116     case Z_PACKET_WRITE_WP:
 117     case Z_PACKET_ACCESS_WP:
 118       return 1;
 119     default:
 120       return 0;
 121     }
 122 }
 123
 124 static int
 125 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 126                    int size, struct raw_breakpoint *bp)
 127 {
 128   switch (type)
 129     {
 130     case raw_bkpt_type_write_wp:
 131     case raw_bkpt_type_access_wp:
 132       {
 133         enum target_hw_bp_type hw_type
 134           = raw_bkpt_type_to_target_hw_bp_type (type);
 135
 136         return i386_dr_insert_watchpoint (&debug_reg_state,
 137                                           hw_type, addr, size);
 138       }
 139     default:
 140       /* Unsupported.  */
 141       return 1;
 142     }
 143 }
 144
 145 static int
 146 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 147                    int size, struct raw_breakpoint *bp)
 148 {
 149   switch (type)
 150     {
 151     case raw_bkpt_type_write_wp:
 152     case raw_bkpt_type_access_wp:
 153       {
 154         enum target_hw_bp_type hw_type
 155           = raw_bkpt_type_to_target_hw_bp_type (type);
 156
 157         return i386_dr_remove_watchpoint (&debug_reg_state,
 158                                           hw_type, addr, size);
 159       }
 160     default:
 161       /* Unsupported.  */
 162       return 1;
 163     }
 164 }
 165
 166 static int
 167 i386_stopped_by_watchpoint (void)
 168 {
 169   return i386_dr_stopped_by_watchpoint (&debug_reg_state);
 170 }
 171
 172 static CORE_ADDR
 173 i386_stopped_data_address (void)
 174 {
 175   CORE_ADDR addr;
 176   if (i386_dr_stopped_data_address (&debug_reg_state, &addr))
 177     return addr;
 178   return 0;
 179 }
 180
 181 static void
 182 i386_initial_stuff (void)
 183 {
 184   i386_low_init_dregs (&debug_reg_state);
 185   debug_registers_changed = 0;
 186   debug_registers_used = 0;
 187 }
 188
 189 static void
 190 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 191 {
 192   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 193      the system doesn't support extended registers.  */
 194   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 195
 196  again:
 197   th->context.ContextFlags = (CONTEXT_FULL
 198                               | CONTEXT_FLOATING_POINT
 199                               | CONTEXT_DEBUG_REGISTERS
 200                               | extended_registers);
 201
 202   if (!GetThreadContext (th->h, &th->context))
 203     {
 204       DWORD e = GetLastError ();
 205
 206       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 207         {
 208           extended_registers = 0;
 209           goto again;
 210         }
 211
 212       error ("GetThreadContext failure %ld\n", (long) e);
 213     }
 214
 215   debug_registers_changed = 0;
 216
 217   if (th->tid == current_event->dwThreadId)
 218     {
 219       /* Copy dr values from the current thread.  */
 220       struct i386_debug_reg_state *dr = &debug_reg_state;
 221       dr->dr_mirror[0] = th->context.Dr0;
 222       dr->dr_mirror[1] = th->context.Dr1;
 223       dr->dr_mirror[2] = th->context.Dr2;
 224       dr->dr_mirror[3] = th->context.Dr3;
 225       dr->dr_status_mirror = th->context.Dr6;
 226       dr->dr_control_mirror = th->context.Dr7;
 227     }
 228 }
 229
 230 static void
 231 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 232 {
 233   if (debug_registers_changed)
 234     {
 235       struct i386_debug_reg_state *dr = &debug_reg_state;
 236       th->context.Dr0 = dr->dr_mirror[0];
 237       th->context.Dr1 = dr->dr_mirror[1];
 238       th->context.Dr2 = dr->dr_mirror[2];
 239       th->context.Dr3 = dr->dr_mirror[3];
 240       /* th->context.Dr6 = dr->dr_status_mirror;
 241          FIXME: should we set dr6 also ?? */
 242       th->context.Dr7 = dr->dr_control_mirror;
 243     }
 244
 245   SetThreadContext (th->h, &th->context);
 246 }
 247
 248 static void
 249 i386_thread_added (win32_thread_info *th)
 250 {
 251   /* Set the debug registers for the new thread if they are used.  */
 252   if (debug_registers_used)
 253     {
 254       struct i386_debug_reg_state *dr = &debug_reg_state;
 255       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 256       GetThreadContext (th->h, &th->context);
 257
 258       th->context.Dr0 = dr->dr_mirror[0];
 259       th->context.Dr1 = dr->dr_mirror[1];
 260       th->context.Dr2 = dr->dr_mirror[2];
 261       th->context.Dr3 = dr->dr_mirror[3];
 262       /* th->context.Dr6 = dr->dr_status_mirror;
 263          FIXME: should we set dr6 also ?? */
 264       th->context.Dr7 = dr->dr_control_mirror;
 265
 266       SetThreadContext (th->h, &th->context);
 267       th->context.ContextFlags = 0;
 268     }
 269 }
 270
 271 static void
 272 i386_single_step (win32_thread_info *th)
 273 {
 274   th->context.EFlags |= FLAG_TRACE_BIT;
 275 }
 276
 277 #ifndef __x86_64__
 278
 279 /* An array of offset mappings into a Win32 Context structure.
 280    This is a one-to-one mapping which is indexed by gdb's register
 281    numbers.  It retrieves an offset into the context structure where
 282    the 4 byte register is located.
 283    An offset value of -1 indicates that Win32 does not provide this
 284    register in it's CONTEXT structure.  In this case regptr will return
 285    a pointer into a dummy register.  */
 286 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 287 static const int mappings[] = {
 288   context_offset (Eax),
 289   context_offset (Ecx),
 290   context_offset (Edx),
 291   context_offset (Ebx),
 292   context_offset (Esp),
 293   context_offset (Ebp),
 294   context_offset (Esi),
 295   context_offset (Edi),
 296   context_offset (Eip),
 297   context_offset (EFlags),
 298   context_offset (SegCs),
 299   context_offset (SegSs),
 300   context_offset (SegDs),
 301   context_offset (SegEs),
 302   context_offset (SegFs),
 303   context_offset (SegGs),
 304   context_offset (FloatSave.RegisterArea[0 * 10]),
 305   context_offset (FloatSave.RegisterArea[1 * 10]),
 306   context_offset (FloatSave.RegisterArea[2 * 10]),
 307   context_offset (FloatSave.RegisterArea[3 * 10]),
 308   context_offset (FloatSave.RegisterArea[4 * 10]),
 309   context_offset (FloatSave.RegisterArea[5 * 10]),
 310   context_offset (FloatSave.RegisterArea[6 * 10]),
 311   context_offset (FloatSave.RegisterArea[7 * 10]),
 312   context_offset (FloatSave.ControlWord),
 313   context_offset (FloatSave.StatusWord),
 314   context_offset (FloatSave.TagWord),
 315   context_offset (FloatSave.ErrorSelector),
 316   context_offset (FloatSave.ErrorOffset),
 317   context_offset (FloatSave.DataSelector),
 318   context_offset (FloatSave.DataOffset),
 319   context_offset (FloatSave.ErrorSelector),
 320   /* XMM0-7 */
 321   context_offset (ExtendedRegisters[10 * 16]),
 322   context_offset (ExtendedRegisters[11 * 16]),
 323   context_offset (ExtendedRegisters[12 * 16]),
 324   context_offset (ExtendedRegisters[13 * 16]),
 325   context_offset (ExtendedRegisters[14 * 16]),
 326   context_offset (ExtendedRegisters[15 * 16]),
 327   context_offset (ExtendedRegisters[16 * 16]),
 328   context_offset (ExtendedRegisters[17 * 16]),
 329   /* MXCSR */
 330   context_offset (ExtendedRegisters[24])
 331 };
 332 #undef context_offset
 333
 334 #else /* __x86_64__ */
 335
 336 #define context_offset(x) (offsetof (CONTEXT, x))
 337 static const int mappings[] =
 338 {
 339   context_offset (Rax),
 340   context_offset (Rbx),
 341   context_offset (Rcx),
 342   context_offset (Rdx),
 343   context_offset (Rsi),
 344   context_offset (Rdi),
 345   context_offset (Rbp),
 346   context_offset (Rsp),
 347   context_offset (R8),
 348   context_offset (R9),
 349   context_offset (R10),
 350   context_offset (R11),
 351   context_offset (R12),
 352   context_offset (R13),
 353   context_offset (R14),
 354   context_offset (R15),
 355   context_offset (Rip),
 356   context_offset (EFlags),
 357   context_offset (SegCs),
 358   context_offset (SegSs),
 359   context_offset (SegDs),
 360   context_offset (SegEs),
 361   context_offset (SegFs),
 362   context_offset (SegGs),
 363   context_offset (FloatSave.FloatRegisters[0]),
 364   context_offset (FloatSave.FloatRegisters[1]),
 365   context_offset (FloatSave.FloatRegisters[2]),
 366   context_offset (FloatSave.FloatRegisters[3]),
 367   context_offset (FloatSave.FloatRegisters[4]),
 368   context_offset (FloatSave.FloatRegisters[5]),
 369   context_offset (FloatSave.FloatRegisters[6]),
 370   context_offset (FloatSave.FloatRegisters[7]),
 371   context_offset (FloatSave.ControlWord),
 372   context_offset (FloatSave.StatusWord),
 373   context_offset (FloatSave.TagWord),
 374   context_offset (FloatSave.ErrorSelector),
 375   context_offset (FloatSave.ErrorOffset),
 376   context_offset (FloatSave.DataSelector),
 377   context_offset (FloatSave.DataOffset),
 378   context_offset (FloatSave.ErrorSelector)
 379   /* XMM0-7 */ ,
 380   context_offset (Xmm0),
 381   context_offset (Xmm1),
 382   context_offset (Xmm2),
 383   context_offset (Xmm3),
 384   context_offset (Xmm4),
 385   context_offset (Xmm5),
 386   context_offset (Xmm6),
 387   context_offset (Xmm7),
 388   context_offset (Xmm8),
 389   context_offset (Xmm9),
 390   context_offset (Xmm10),
 391   context_offset (Xmm11),
 392   context_offset (Xmm12),
 393   context_offset (Xmm13),
 394   context_offset (Xmm14),
 395   context_offset (Xmm15),
 396   /* MXCSR */
 397   context_offset (FloatSave.MxCsr)
 398 };
 399 #undef context_offset
 400
 401 #endif /* __x86_64__ */
 402
 403 /* Fetch register from gdbserver regcache data.  */
 404 static void
 405 i386_fetch_inferior_register (struct regcache *regcache,
 406                               win32_thread_info *th, int r)
 407 {
 408   char *context_offset = (char *) &th->context + mappings[r];
 409
 410   long l;
 411   if (r == FCS_REGNUM)
 412     {
 413       l = *((long *) context_offset) & 0xffff;
 414       supply_register (regcache, r, (char *) &l);
 415     }
 416   else if (r == FOP_REGNUM)
 417     {
 418       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 419       supply_register (regcache, r, (char *) &l);
 420     }
 421   else
 422     supply_register (regcache, r, context_offset);
 423 }
 424
 425 /* Store a new register value into the thread context of TH.  */
 426 static void
 427 i386_store_inferior_register (struct regcache *regcache,
 428                               win32_thread_info *th, int r)
 429 {
 430   char *context_offset = (char *) &th->context + mappings[r];
 431   collect_register (regcache, r, context_offset);
 432 }
 433
 434 static const unsigned char i386_win32_breakpoint = 0xcc;
 435 #define i386_win32_breakpoint_len 1
 436
 437 static void
 438 i386_arch_setup (void)
 439 {
 440 #ifdef __x86_64__
 441   init_registers_amd64 ();
 442   win32_tdesc = tdesc_amd64;
 443 #else
 444   init_registers_i386 ();
 445   win32_tdesc = tdesc_i386;
 446 #endif
 447 }
 448
 449 struct win32_target_ops the_low_target = {
 450   i386_arch_setup,
 451   sizeof (mappings) / sizeof (mappings[0]),
 452   i386_initial_stuff,
 453   i386_get_thread_context,
 454   i386_set_thread_context,
 455   i386_thread_added,
 456   i386_fetch_inferior_register,
 457   i386_store_inferior_register,
 458   i386_single_step,
 459   &i386_win32_breakpoint,
 460   i386_win32_breakpoint_len,
 461   i386_supports_z_point_type,
 462   i386_insert_point,
 463   i386_remove_point,
 464   i386_stopped_by_watchpoint,
 465   i386_stopped_data_address
 466 };