gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007, 2008, 2009 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 #define FCS_REGNUM 27
  23 #define FOP_REGNUM 31
  24
  25 #define FLAG_TRACE_BIT 0x100
  26
  27 /* Defined in auto-generated file reg-i386.c.  */
  28 void init_registers_i386 (void);
  29
  30 static struct i386_debug_reg_state debug_reg_state;
  31
  32 static int debug_registers_changed = 0;
  33 static int debug_registers_used = 0;
  34
  35 /* Update the inferior's debug register REGNUM from STATE.  */
  36
  37 void
  38 i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
  39 {
  40   if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
  41     fatal ("Invalid debug register %d", regnum);
  42
  43   /* debug_reg_state.dr_mirror is already set.
  44      Just notify i386_set_thread_context, i386_thread_added
  45      that the registers need to be updated.  */
  46   debug_registers_changed = 1;
  47   debug_registers_used = 1;
  48 }
  49
  50 /* Update the inferior's DR7 debug control register from STATE.  */
  51
  52 void
  53 i386_dr_low_set_control (const struct i386_debug_reg_state *state)
  54 {
  55   /* debug_reg_state.dr_control_mirror is already set.
  56      Just notify i386_set_thread_context, i386_thread_added
  57      that the registers need to be updated.  */
  58   debug_registers_changed = 1;
  59   debug_registers_used = 1;
  60 }
  61
  62 /* Get the value of the DR6 debug status register from the inferior
  63    and record it in STATE.  */
  64
  65 void
  66 i386_dr_low_get_status (struct i386_debug_reg_state *state)
  67 {
  68   /* We don't need to do anything here, the last call to thread_rec for
  69      current_event.dwThreadId id has already set it.  */
  70 }
  71
  72 /* Watchpoint support.  */
  73
  74 static int
  75 i386_insert_point (char type, CORE_ADDR addr, int len)
  76 {
  77   switch (type)
  78     {
  79     case '2':
  80     case '3':
  81     case '4':
  82       return i386_low_insert_watchpoint (&debug_reg_state,
  83                                          type, addr, len);
  84     default:
  85       /* Unsupported.  */
  86       return 1;
  87     }
  88 }
  89
  90 static int
  91 i386_remove_point (char type, CORE_ADDR addr, int len)
  92 {
  93   switch (type)
  94     {
  95     case '2':
  96     case '3':
  97     case '4':
  98       return i386_low_remove_watchpoint (&debug_reg_state,
  99                                          type, addr, len);
 100     default:
 101       /* Unsupported.  */
 102       return 1;
 103     }
 104 }
 105
 106 static int
 107 i386_stopped_by_watchpoint (void)
 108 {
 109   return i386_low_stopped_by_watchpoint (&debug_reg_state);
 110 }
 111
 112 static CORE_ADDR
 113 i386_stopped_data_address (void)
 114 {
 115   CORE_ADDR addr;
 116   if (i386_low_stopped_data_address (&debug_reg_state, &addr))
 117     return addr;
 118   return 0;
 119 }
 120
 121 static void
 122 i386_initial_stuff (void)
 123 {
 124   i386_low_init_dregs (&debug_reg_state);
 125   debug_registers_changed = 0;
 126   debug_registers_used = 0;
 127 }
 128
 129 static void
 130 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 131 {
 132   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 133      the system doesn't support extended registers.  */
 134   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 135
 136  again:
 137   th->context.ContextFlags = (CONTEXT_FULL
 138                               | CONTEXT_FLOATING_POINT
 139                               | CONTEXT_DEBUG_REGISTERS
 140                               | extended_registers);
 141
 142   if (!GetThreadContext (th->h, &th->context))
 143     {
 144       DWORD e = GetLastError ();
 145
 146       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 147         {
 148           extended_registers = 0;
 149           goto again;
 150         }
 151
 152       error ("GetThreadContext failure %ld\n", (long) e);
 153     }
 154
 155   debug_registers_changed = 0;
 156
 157   if (th->tid == current_event->dwThreadId)
 158     {
 159       /* Copy dr values from the current thread.  */
 160       struct i386_debug_reg_state *dr = &debug_reg_state;
 161       dr->dr_mirror[0] = th->context.Dr0;
 162       dr->dr_mirror[1] = th->context.Dr1;
 163       dr->dr_mirror[2] = th->context.Dr2;
 164       dr->dr_mirror[3] = th->context.Dr3;
 165       dr->dr_status_mirror = th->context.Dr6;
 166       dr->dr_control_mirror = th->context.Dr7;
 167     }
 168 }
 169
 170 static void
 171 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 172 {
 173   if (debug_registers_changed)
 174     {
 175       struct i386_debug_reg_state *dr = &debug_reg_state;
 176       th->context.Dr0 = dr->dr_mirror[0];
 177       th->context.Dr1 = dr->dr_mirror[1];
 178       th->context.Dr2 = dr->dr_mirror[2];
 179       th->context.Dr3 = dr->dr_mirror[3];
 180       /* th->context.Dr6 = dr->dr_status_mirror;
 181          FIXME: should we set dr6 also ?? */
 182       th->context.Dr7 = dr->dr_control_mirror;
 183     }
 184
 185   SetThreadContext (th->h, &th->context);
 186 }
 187
 188 static void
 189 i386_thread_added (win32_thread_info *th)
 190 {
 191   /* Set the debug registers for the new thread if they are used.  */
 192   if (debug_registers_used)
 193     {
 194       struct i386_debug_reg_state *dr = &debug_reg_state;
 195       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 196       GetThreadContext (th->h, &th->context);
 197
 198       th->context.Dr0 = dr->dr_mirror[0];
 199       th->context.Dr1 = dr->dr_mirror[1];
 200       th->context.Dr2 = dr->dr_mirror[2];
 201       th->context.Dr3 = dr->dr_mirror[3];
 202       /* th->context.Dr6 = dr->dr_status_mirror;
 203          FIXME: should we set dr6 also ?? */
 204       th->context.Dr7 = dr->dr_control_mirror;
 205
 206       SetThreadContext (th->h, &th->context);
 207       th->context.ContextFlags = 0;
 208     }
 209 }
 210
 211 static void
 212 i386_single_step (win32_thread_info *th)
 213 {
 214   th->context.EFlags |= FLAG_TRACE_BIT;
 215 }
 216
 217 /* An array of offset mappings into a Win32 Context structure.
 218    This is a one-to-one mapping which is indexed by gdb's register
 219    numbers.  It retrieves an offset into the context structure where
 220    the 4 byte register is located.
 221    An offset value of -1 indicates that Win32 does not provide this
 222    register in it's CONTEXT structure.  In this case regptr will return
 223    a pointer into a dummy register.  */
 224 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 225 static const int mappings[] = {
 226   context_offset (Eax),
 227   context_offset (Ecx),
 228   context_offset (Edx),
 229   context_offset (Ebx),
 230   context_offset (Esp),
 231   context_offset (Ebp),
 232   context_offset (Esi),
 233   context_offset (Edi),
 234   context_offset (Eip),
 235   context_offset (EFlags),
 236   context_offset (SegCs),
 237   context_offset (SegSs),
 238   context_offset (SegDs),
 239   context_offset (SegEs),
 240   context_offset (SegFs),
 241   context_offset (SegGs),
 242   context_offset (FloatSave.RegisterArea[0 * 10]),
 243   context_offset (FloatSave.RegisterArea[1 * 10]),
 244   context_offset (FloatSave.RegisterArea[2 * 10]),
 245   context_offset (FloatSave.RegisterArea[3 * 10]),
 246   context_offset (FloatSave.RegisterArea[4 * 10]),
 247   context_offset (FloatSave.RegisterArea[5 * 10]),
 248   context_offset (FloatSave.RegisterArea[6 * 10]),
 249   context_offset (FloatSave.RegisterArea[7 * 10]),
 250   context_offset (FloatSave.ControlWord),
 251   context_offset (FloatSave.StatusWord),
 252   context_offset (FloatSave.TagWord),
 253   context_offset (FloatSave.ErrorSelector),
 254   context_offset (FloatSave.ErrorOffset),
 255   context_offset (FloatSave.DataSelector),
 256   context_offset (FloatSave.DataOffset),
 257   context_offset (FloatSave.ErrorSelector),
 258   /* XMM0-7 */
 259   context_offset (ExtendedRegisters[10 * 16]),
 260   context_offset (ExtendedRegisters[11 * 16]),
 261   context_offset (ExtendedRegisters[12 * 16]),
 262   context_offset (ExtendedRegisters[13 * 16]),
 263   context_offset (ExtendedRegisters[14 * 16]),
 264   context_offset (ExtendedRegisters[15 * 16]),
 265   context_offset (ExtendedRegisters[16 * 16]),
 266   context_offset (ExtendedRegisters[17 * 16]),
 267   /* MXCSR */
 268   context_offset (ExtendedRegisters[24])
 269 };
 270 #undef context_offset
 271
 272 /* Fetch register from gdbserver regcache data.  */
 273 static void
 274 i386_fetch_inferior_register (win32_thread_info *th, int r)
 275 {
 276   char *context_offset = (char *) &th->context + mappings[r];
 277
 278   long l;
 279   if (r == FCS_REGNUM)
 280     {
 281       l = *((long *) context_offset) & 0xffff;
 282       supply_register (r, (char *) &l);
 283     }
 284   else if (r == FOP_REGNUM)
 285     {
 286       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 287       supply_register (r, (char *) &l);
 288     }
 289   else
 290     supply_register (r, context_offset);
 291 }
 292
 293 /* Store a new register value into the thread context of TH.  */
 294 static void
 295 i386_store_inferior_register (win32_thread_info *th, int r)
 296 {
 297   char *context_offset = (char *) &th->context + mappings[r];
 298   collect_register (r, context_offset);
 299 }
 300
 301 static const unsigned char i386_win32_breakpoint = 0xcc;
 302 #define i386_win32_breakpoint_len 1
 303
 304 struct win32_target_ops the_low_target = {
 305   init_registers_i386,
 306   sizeof (mappings) / sizeof (mappings[0]),
 307   i386_initial_stuff,
 308   i386_get_thread_context,
 309   i386_set_thread_context,
 310   i386_thread_added,
 311   i386_fetch_inferior_register,
 312   i386_store_inferior_register,
 313   i386_single_step,
 314   &i386_win32_breakpoint,
 315   i386_win32_breakpoint_len,
 316   i386_insert_point,
 317   i386_remove_point,
 318   i386_stopped_by_watchpoint,
 319   i386_stopped_data_address
 320 };