gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007-2017 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 #include "x86-xstate.h"
  22 #ifdef __x86_64__
  23 #include "arch/amd64.h"
  24 #endif
  25 #include "arch/i386.h"
  26 #include "tdesc.h"
  27
  28 #ifndef CONTEXT_EXTENDED_REGISTERS
  29 #define CONTEXT_EXTENDED_REGISTERS 0
  30 #endif
  31
  32 #define FCS_REGNUM 27
  33 #define FOP_REGNUM 31
  34
  35 #define FLAG_TRACE_BIT 0x100
  36
  37 static struct x86_debug_reg_state debug_reg_state;
  38
  39 static void
  40 update_debug_registers (thread_info *thread)
  41 {
  42   win32_thread_info *th = (win32_thread_info *) thread_target_data (thread);
  43
  44   /* The actual update is done later just before resuming the lwp,
  45      we just mark that the registers need updating.  */
  46   th->debug_registers_changed = 1;
  47 }
  48
  49 /* Update the inferior's debug register REGNUM from STATE.  */
  50
  51 static void
  52 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  53 {
  54   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  55
  56   /* Only update the threads of this process.  */
  57   for_each_thread (current_thread->id.pid (), update_debug_registers);
  58 }
  59
  60 /* Update the inferior's DR7 debug control register from STATE.  */
  61
  62 static void
  63 x86_dr_low_set_control (unsigned long control)
  64 {
  65   /* Only update the threads of this process.  */
  66   for_each_thread (current_thread->id.pid (), update_debug_registers);
  67 }
  68
  69 /* Return the current value of a DR register of the current thread's
  70    context.  */
  71
  72 static DWORD64
  73 win32_get_current_dr (int dr)
  74 {
  75   win32_thread_info *th
  76     = (win32_thread_info *) thread_target_data (current_thread);
  77
  78   win32_require_context (th);
  79
  80 #define RET_DR(DR)                              \
  81   case DR:                                      \
  82     return th->context.Dr ## DR
  83
  84   switch (dr)
  85     {
  86       RET_DR (0);
  87       RET_DR (1);
  88       RET_DR (2);
  89       RET_DR (3);
  90       RET_DR (6);
  91       RET_DR (7);
  92     }
  93
  94 #undef RET_DR
  95
  96   gdb_assert_not_reached ("unhandled dr");
  97 }
  98
  99 static CORE_ADDR
 100 x86_dr_low_get_addr (int regnum)
 101 {
 102   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 103
 104   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 105 }
 106
 107 static unsigned long
 108 x86_dr_low_get_control (void)
 109 {
 110   return win32_get_current_dr (7);
 111 }
 112
 113 /* Get the value of the DR6 debug status register from the inferior
 114    and record it in STATE.  */
 115
 116 static unsigned long
 117 x86_dr_low_get_status (void)
 118 {
 119   return win32_get_current_dr (6);
 120 }
 121
 122 /* Low-level function vector.  */
 123 struct x86_dr_low_type x86_dr_low =
 124   {
 125     x86_dr_low_set_control,
 126     x86_dr_low_set_addr,
 127     x86_dr_low_get_addr,
 128     x86_dr_low_get_status,
 129     x86_dr_low_get_control,
 130     sizeof (void *),
 131   };
 132
 133 /* Breakpoint/watchpoint support.  */
 134
 135 static int
 136 i386_supports_z_point_type (char z_type)
 137 {
 138   switch (z_type)
 139     {
 140     case Z_PACKET_WRITE_WP:
 141     case Z_PACKET_ACCESS_WP:
 142       return 1;
 143     default:
 144       return 0;
 145     }
 146 }
 147
 148 static int
 149 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 150                    int size, struct raw_breakpoint *bp)
 151 {
 152   switch (type)
 153     {
 154     case raw_bkpt_type_write_wp:
 155     case raw_bkpt_type_access_wp:
 156       {
 157         enum target_hw_bp_type hw_type
 158           = raw_bkpt_type_to_target_hw_bp_type (type);
 159
 160         return x86_dr_insert_watchpoint (&debug_reg_state,
 161                                          hw_type, addr, size);
 162       }
 163     default:
 164       /* Unsupported.  */
 165       return 1;
 166     }
 167 }
 168
 169 static int
 170 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 171                    int size, struct raw_breakpoint *bp)
 172 {
 173   switch (type)
 174     {
 175     case raw_bkpt_type_write_wp:
 176     case raw_bkpt_type_access_wp:
 177       {
 178         enum target_hw_bp_type hw_type
 179           = raw_bkpt_type_to_target_hw_bp_type (type);
 180
 181         return x86_dr_remove_watchpoint (&debug_reg_state,
 182                                          hw_type, addr, size);
 183       }
 184     default:
 185       /* Unsupported.  */
 186       return 1;
 187     }
 188 }
 189
 190 static int
 191 x86_stopped_by_watchpoint (void)
 192 {
 193   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 194 }
 195
 196 static CORE_ADDR
 197 x86_stopped_data_address (void)
 198 {
 199   CORE_ADDR addr;
 200   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 201     return addr;
 202   return 0;
 203 }
 204
 205 static void
 206 i386_initial_stuff (void)
 207 {
 208   x86_low_init_dregs (&debug_reg_state);
 209 }
 210
 211 static void
 212 i386_get_thread_context (win32_thread_info *th)
 213 {
 214   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 215      the system doesn't support extended registers.  */
 216   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 217
 218  again:
 219   th->context.ContextFlags = (CONTEXT_FULL
 220                               | CONTEXT_FLOATING_POINT
 221                               | CONTEXT_DEBUG_REGISTERS
 222                               | extended_registers);
 223
 224   if (!GetThreadContext (th->h, &th->context))
 225     {
 226       DWORD e = GetLastError ();
 227
 228       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 229         {
 230           extended_registers = 0;
 231           goto again;
 232         }
 233
 234       error ("GetThreadContext failure %ld\n", (long) e);
 235     }
 236 }
 237
 238 static void
 239 i386_prepare_to_resume (win32_thread_info *th)
 240 {
 241   if (th->debug_registers_changed)
 242     {
 243       struct x86_debug_reg_state *dr = &debug_reg_state;
 244
 245       win32_require_context (th);
 246
 247       th->context.Dr0 = dr->dr_mirror[0];
 248       th->context.Dr1 = dr->dr_mirror[1];
 249       th->context.Dr2 = dr->dr_mirror[2];
 250       th->context.Dr3 = dr->dr_mirror[3];
 251       /* th->context.Dr6 = dr->dr_status_mirror;
 252          FIXME: should we set dr6 also ?? */
 253       th->context.Dr7 = dr->dr_control_mirror;
 254
 255       th->debug_registers_changed = 0;
 256     }
 257 }
 258
 259 static void
 260 i386_thread_added (win32_thread_info *th)
 261 {
 262   th->debug_registers_changed = 1;
 263 }
 264
 265 static void
 266 i386_single_step (win32_thread_info *th)
 267 {
 268   th->context.EFlags |= FLAG_TRACE_BIT;
 269 }
 270
 271 #ifndef __x86_64__
 272
 273 /* An array of offset mappings into a Win32 Context structure.
 274    This is a one-to-one mapping which is indexed by gdb's register
 275    numbers.  It retrieves an offset into the context structure where
 276    the 4 byte register is located.
 277    An offset value of -1 indicates that Win32 does not provide this
 278    register in it's CONTEXT structure.  In this case regptr will return
 279    a pointer into a dummy register.  */
 280 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 281 static const int mappings[] = {
 282   context_offset (Eax),
 283   context_offset (Ecx),
 284   context_offset (Edx),
 285   context_offset (Ebx),
 286   context_offset (Esp),
 287   context_offset (Ebp),
 288   context_offset (Esi),
 289   context_offset (Edi),
 290   context_offset (Eip),
 291   context_offset (EFlags),
 292   context_offset (SegCs),
 293   context_offset (SegSs),
 294   context_offset (SegDs),
 295   context_offset (SegEs),
 296   context_offset (SegFs),
 297   context_offset (SegGs),
 298   context_offset (FloatSave.RegisterArea[0 * 10]),
 299   context_offset (FloatSave.RegisterArea[1 * 10]),
 300   context_offset (FloatSave.RegisterArea[2 * 10]),
 301   context_offset (FloatSave.RegisterArea[3 * 10]),
 302   context_offset (FloatSave.RegisterArea[4 * 10]),
 303   context_offset (FloatSave.RegisterArea[5 * 10]),
 304   context_offset (FloatSave.RegisterArea[6 * 10]),
 305   context_offset (FloatSave.RegisterArea[7 * 10]),
 306   context_offset (FloatSave.ControlWord),
 307   context_offset (FloatSave.StatusWord),
 308   context_offset (FloatSave.TagWord),
 309   context_offset (FloatSave.ErrorSelector),
 310   context_offset (FloatSave.ErrorOffset),
 311   context_offset (FloatSave.DataSelector),
 312   context_offset (FloatSave.DataOffset),
 313   context_offset (FloatSave.ErrorSelector),
 314   /* XMM0-7 */
 315   context_offset (ExtendedRegisters[10 * 16]),
 316   context_offset (ExtendedRegisters[11 * 16]),
 317   context_offset (ExtendedRegisters[12 * 16]),
 318   context_offset (ExtendedRegisters[13 * 16]),
 319   context_offset (ExtendedRegisters[14 * 16]),
 320   context_offset (ExtendedRegisters[15 * 16]),
 321   context_offset (ExtendedRegisters[16 * 16]),
 322   context_offset (ExtendedRegisters[17 * 16]),
 323   /* MXCSR */
 324   context_offset (ExtendedRegisters[24])
 325 };
 326 #undef context_offset
 327
 328 #else /* __x86_64__ */
 329
 330 #define context_offset(x) (offsetof (CONTEXT, x))
 331 static const int mappings[] =
 332 {
 333   context_offset (Rax),
 334   context_offset (Rbx),
 335   context_offset (Rcx),
 336   context_offset (Rdx),
 337   context_offset (Rsi),
 338   context_offset (Rdi),
 339   context_offset (Rbp),
 340   context_offset (Rsp),
 341   context_offset (R8),
 342   context_offset (R9),
 343   context_offset (R10),
 344   context_offset (R11),
 345   context_offset (R12),
 346   context_offset (R13),
 347   context_offset (R14),
 348   context_offset (R15),
 349   context_offset (Rip),
 350   context_offset (EFlags),
 351   context_offset (SegCs),
 352   context_offset (SegSs),
 353   context_offset (SegDs),
 354   context_offset (SegEs),
 355   context_offset (SegFs),
 356   context_offset (SegGs),
 357   context_offset (FloatSave.FloatRegisters[0]),
 358   context_offset (FloatSave.FloatRegisters[1]),
 359   context_offset (FloatSave.FloatRegisters[2]),
 360   context_offset (FloatSave.FloatRegisters[3]),
 361   context_offset (FloatSave.FloatRegisters[4]),
 362   context_offset (FloatSave.FloatRegisters[5]),
 363   context_offset (FloatSave.FloatRegisters[6]),
 364   context_offset (FloatSave.FloatRegisters[7]),
 365   context_offset (FloatSave.ControlWord),
 366   context_offset (FloatSave.StatusWord),
 367   context_offset (FloatSave.TagWord),
 368   context_offset (FloatSave.ErrorSelector),
 369   context_offset (FloatSave.ErrorOffset),
 370   context_offset (FloatSave.DataSelector),
 371   context_offset (FloatSave.DataOffset),
 372   context_offset (FloatSave.ErrorSelector)
 373   /* XMM0-7 */ ,
 374   context_offset (Xmm0),
 375   context_offset (Xmm1),
 376   context_offset (Xmm2),
 377   context_offset (Xmm3),
 378   context_offset (Xmm4),
 379   context_offset (Xmm5),
 380   context_offset (Xmm6),
 381   context_offset (Xmm7),
 382   context_offset (Xmm8),
 383   context_offset (Xmm9),
 384   context_offset (Xmm10),
 385   context_offset (Xmm11),
 386   context_offset (Xmm12),
 387   context_offset (Xmm13),
 388   context_offset (Xmm14),
 389   context_offset (Xmm15),
 390   /* MXCSR */
 391   context_offset (FloatSave.MxCsr)
 392 };
 393 #undef context_offset
 394
 395 #endif /* __x86_64__ */
 396
 397 /* Fetch register from gdbserver regcache data.  */
 398 static void
 399 i386_fetch_inferior_register (struct regcache *regcache,
 400                               win32_thread_info *th, int r)
 401 {
 402   char *context_offset = (char *) &th->context + mappings[r];
 403
 404   long l;
 405   if (r == FCS_REGNUM)
 406     {
 407       l = *((long *) context_offset) & 0xffff;
 408       supply_register (regcache, r, (char *) &l);
 409     }
 410   else if (r == FOP_REGNUM)
 411     {
 412       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 413       supply_register (regcache, r, (char *) &l);
 414     }
 415   else
 416     supply_register (regcache, r, context_offset);
 417 }
 418
 419 /* Store a new register value into the thread context of TH.  */
 420 static void
 421 i386_store_inferior_register (struct regcache *regcache,
 422                               win32_thread_info *th, int r)
 423 {
 424   char *context_offset = (char *) &th->context + mappings[r];
 425   collect_register (regcache, r, context_offset);
 426 }
 427
 428 static const unsigned char i386_win32_breakpoint = 0xcc;
 429 #define i386_win32_breakpoint_len 1
 430
 431 static void
 432 i386_arch_setup (void)
 433 {
 434   struct target_desc *tdesc;
 435
 436 #ifdef __x86_64__
 437   tdesc = amd64_create_target_description (X86_XSTATE_SSE_MASK, false,
 438                                                  false);
 439 #else
 440   tdesc = i386_create_target_description (X86_XSTATE_SSE_MASK, false);
 441 #endif
 442
 443   init_target_desc (tdesc);
 444
 445   win32_tdesc = tdesc;
 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_prepare_to_resume,
 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 };