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 int
  40 update_debug_registers_callback (thread_info *thr, void *pid_p)
  41 {
  42   win32_thread_info *th = (win32_thread_info *) thread_target_data (thr);
  43   int pid = *(int *) pid_p;
  44
  45   /* Only update the threads of this process.  */
  46   if (pid_of (thr) == pid)
  47     {
  48       /* The actual update is done later just before resuming the lwp,
  49          we just mark that the registers need updating.  */
  50       th->debug_registers_changed = 1;
  51     }
  52
  53   return 0;
  54 }
  55
  56 /* Update the inferior's debug register REGNUM from STATE.  */
  57
  58 static void
  59 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  60 {
  61   /* Only update the threads of this process.  */
  62   int pid = pid_of (current_thread);
  63
  64   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  65
  66   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  67 }
  68
  69 /* Update the inferior's DR7 debug control register from STATE.  */
  70
  71 static void
  72 x86_dr_low_set_control (unsigned long control)
  73 {
  74   /* Only update the threads of this process.  */
  75   int pid = pid_of (current_thread);
  76
  77   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  78 }
  79
  80 /* Return the current value of a DR register of the current thread's
  81    context.  */
  82
  83 static DWORD64
  84 win32_get_current_dr (int dr)
  85 {
  86   win32_thread_info *th
  87     = (win32_thread_info *) thread_target_data (current_thread);
  88
  89   win32_require_context (th);
  90
  91 #define RET_DR(DR)                              \
  92   case DR:                                      \
  93     return th->context.Dr ## DR
  94
  95   switch (dr)
  96     {
  97       RET_DR (0);
  98       RET_DR (1);
  99       RET_DR (2);
 100       RET_DR (3);
 101       RET_DR (6);
 102       RET_DR (7);
 103     }
 104
 105 #undef RET_DR
 106
 107   gdb_assert_not_reached ("unhandled dr");
 108 }
 109
 110 static CORE_ADDR
 111 x86_dr_low_get_addr (int regnum)
 112 {
 113   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 114
 115   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 116 }
 117
 118 static unsigned long
 119 x86_dr_low_get_control (void)
 120 {
 121   return win32_get_current_dr (7);
 122 }
 123
 124 /* Get the value of the DR6 debug status register from the inferior
 125    and record it in STATE.  */
 126
 127 static unsigned long
 128 x86_dr_low_get_status (void)
 129 {
 130   return win32_get_current_dr (6);
 131 }
 132
 133 /* Low-level function vector.  */
 134 struct x86_dr_low_type x86_dr_low =
 135   {
 136     x86_dr_low_set_control,
 137     x86_dr_low_set_addr,
 138     x86_dr_low_get_addr,
 139     x86_dr_low_get_status,
 140     x86_dr_low_get_control,
 141     sizeof (void *),
 142   };
 143
 144 /* Breakpoint/watchpoint support.  */
 145
 146 static int
 147 i386_supports_z_point_type (char z_type)
 148 {
 149   switch (z_type)
 150     {
 151     case Z_PACKET_WRITE_WP:
 152     case Z_PACKET_ACCESS_WP:
 153       return 1;
 154     default:
 155       return 0;
 156     }
 157 }
 158
 159 static int
 160 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 161                    int size, struct raw_breakpoint *bp)
 162 {
 163   switch (type)
 164     {
 165     case raw_bkpt_type_write_wp:
 166     case raw_bkpt_type_access_wp:
 167       {
 168         enum target_hw_bp_type hw_type
 169           = raw_bkpt_type_to_target_hw_bp_type (type);
 170
 171         return x86_dr_insert_watchpoint (&debug_reg_state,
 172                                          hw_type, addr, size);
 173       }
 174     default:
 175       /* Unsupported.  */
 176       return 1;
 177     }
 178 }
 179
 180 static int
 181 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 182                    int size, struct raw_breakpoint *bp)
 183 {
 184   switch (type)
 185     {
 186     case raw_bkpt_type_write_wp:
 187     case raw_bkpt_type_access_wp:
 188       {
 189         enum target_hw_bp_type hw_type
 190           = raw_bkpt_type_to_target_hw_bp_type (type);
 191
 192         return x86_dr_remove_watchpoint (&debug_reg_state,
 193                                          hw_type, addr, size);
 194       }
 195     default:
 196       /* Unsupported.  */
 197       return 1;
 198     }
 199 }
 200
 201 static int
 202 x86_stopped_by_watchpoint (void)
 203 {
 204   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 205 }
 206
 207 static CORE_ADDR
 208 x86_stopped_data_address (void)
 209 {
 210   CORE_ADDR addr;
 211   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 212     return addr;
 213   return 0;
 214 }
 215
 216 static void
 217 i386_initial_stuff (void)
 218 {
 219   x86_low_init_dregs (&debug_reg_state);
 220 }
 221
 222 static void
 223 i386_get_thread_context (win32_thread_info *th)
 224 {
 225   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 226      the system doesn't support extended registers.  */
 227   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 228
 229  again:
 230   th->context.ContextFlags = (CONTEXT_FULL
 231                               | CONTEXT_FLOATING_POINT
 232                               | CONTEXT_DEBUG_REGISTERS
 233                               | extended_registers);
 234
 235   if (!GetThreadContext (th->h, &th->context))
 236     {
 237       DWORD e = GetLastError ();
 238
 239       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 240         {
 241           extended_registers = 0;
 242           goto again;
 243         }
 244
 245       error ("GetThreadContext failure %ld\n", (long) e);
 246     }
 247 }
 248
 249 static void
 250 i386_prepare_to_resume (win32_thread_info *th)
 251 {
 252   if (th->debug_registers_changed)
 253     {
 254       struct x86_debug_reg_state *dr = &debug_reg_state;
 255
 256       win32_require_context (th);
 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       th->debug_registers_changed = 0;
 267     }
 268 }
 269
 270 static void
 271 i386_thread_added (win32_thread_info *th)
 272 {
 273   th->debug_registers_changed = 1;
 274 }
 275
 276 static void
 277 i386_single_step (win32_thread_info *th)
 278 {
 279   th->context.EFlags |= FLAG_TRACE_BIT;
 280 }
 281
 282 #ifndef __x86_64__
 283
 284 /* An array of offset mappings into a Win32 Context structure.
 285    This is a one-to-one mapping which is indexed by gdb's register
 286    numbers.  It retrieves an offset into the context structure where
 287    the 4 byte register is located.
 288    An offset value of -1 indicates that Win32 does not provide this
 289    register in it's CONTEXT structure.  In this case regptr will return
 290    a pointer into a dummy register.  */
 291 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 292 static const int mappings[] = {
 293   context_offset (Eax),
 294   context_offset (Ecx),
 295   context_offset (Edx),
 296   context_offset (Ebx),
 297   context_offset (Esp),
 298   context_offset (Ebp),
 299   context_offset (Esi),
 300   context_offset (Edi),
 301   context_offset (Eip),
 302   context_offset (EFlags),
 303   context_offset (SegCs),
 304   context_offset (SegSs),
 305   context_offset (SegDs),
 306   context_offset (SegEs),
 307   context_offset (SegFs),
 308   context_offset (SegGs),
 309   context_offset (FloatSave.RegisterArea[0 * 10]),
 310   context_offset (FloatSave.RegisterArea[1 * 10]),
 311   context_offset (FloatSave.RegisterArea[2 * 10]),
 312   context_offset (FloatSave.RegisterArea[3 * 10]),
 313   context_offset (FloatSave.RegisterArea[4 * 10]),
 314   context_offset (FloatSave.RegisterArea[5 * 10]),
 315   context_offset (FloatSave.RegisterArea[6 * 10]),
 316   context_offset (FloatSave.RegisterArea[7 * 10]),
 317   context_offset (FloatSave.ControlWord),
 318   context_offset (FloatSave.StatusWord),
 319   context_offset (FloatSave.TagWord),
 320   context_offset (FloatSave.ErrorSelector),
 321   context_offset (FloatSave.ErrorOffset),
 322   context_offset (FloatSave.DataSelector),
 323   context_offset (FloatSave.DataOffset),
 324   context_offset (FloatSave.ErrorSelector),
 325   /* XMM0-7 */
 326   context_offset (ExtendedRegisters[10 * 16]),
 327   context_offset (ExtendedRegisters[11 * 16]),
 328   context_offset (ExtendedRegisters[12 * 16]),
 329   context_offset (ExtendedRegisters[13 * 16]),
 330   context_offset (ExtendedRegisters[14 * 16]),
 331   context_offset (ExtendedRegisters[15 * 16]),
 332   context_offset (ExtendedRegisters[16 * 16]),
 333   context_offset (ExtendedRegisters[17 * 16]),
 334   /* MXCSR */
 335   context_offset (ExtendedRegisters[24])
 336 };
 337 #undef context_offset
 338
 339 #else /* __x86_64__ */
 340
 341 #define context_offset(x) (offsetof (CONTEXT, x))
 342 static const int mappings[] =
 343 {
 344   context_offset (Rax),
 345   context_offset (Rbx),
 346   context_offset (Rcx),
 347   context_offset (Rdx),
 348   context_offset (Rsi),
 349   context_offset (Rdi),
 350   context_offset (Rbp),
 351   context_offset (Rsp),
 352   context_offset (R8),
 353   context_offset (R9),
 354   context_offset (R10),
 355   context_offset (R11),
 356   context_offset (R12),
 357   context_offset (R13),
 358   context_offset (R14),
 359   context_offset (R15),
 360   context_offset (Rip),
 361   context_offset (EFlags),
 362   context_offset (SegCs),
 363   context_offset (SegSs),
 364   context_offset (SegDs),
 365   context_offset (SegEs),
 366   context_offset (SegFs),
 367   context_offset (SegGs),
 368   context_offset (FloatSave.FloatRegisters[0]),
 369   context_offset (FloatSave.FloatRegisters[1]),
 370   context_offset (FloatSave.FloatRegisters[2]),
 371   context_offset (FloatSave.FloatRegisters[3]),
 372   context_offset (FloatSave.FloatRegisters[4]),
 373   context_offset (FloatSave.FloatRegisters[5]),
 374   context_offset (FloatSave.FloatRegisters[6]),
 375   context_offset (FloatSave.FloatRegisters[7]),
 376   context_offset (FloatSave.ControlWord),
 377   context_offset (FloatSave.StatusWord),
 378   context_offset (FloatSave.TagWord),
 379   context_offset (FloatSave.ErrorSelector),
 380   context_offset (FloatSave.ErrorOffset),
 381   context_offset (FloatSave.DataSelector),
 382   context_offset (FloatSave.DataOffset),
 383   context_offset (FloatSave.ErrorSelector)
 384   /* XMM0-7 */ ,
 385   context_offset (Xmm0),
 386   context_offset (Xmm1),
 387   context_offset (Xmm2),
 388   context_offset (Xmm3),
 389   context_offset (Xmm4),
 390   context_offset (Xmm5),
 391   context_offset (Xmm6),
 392   context_offset (Xmm7),
 393   context_offset (Xmm8),
 394   context_offset (Xmm9),
 395   context_offset (Xmm10),
 396   context_offset (Xmm11),
 397   context_offset (Xmm12),
 398   context_offset (Xmm13),
 399   context_offset (Xmm14),
 400   context_offset (Xmm15),
 401   /* MXCSR */
 402   context_offset (FloatSave.MxCsr)
 403 };
 404 #undef context_offset
 405
 406 #endif /* __x86_64__ */
 407
 408 /* Fetch register from gdbserver regcache data.  */
 409 static void
 410 i386_fetch_inferior_register (struct regcache *regcache,
 411                               win32_thread_info *th, int r)
 412 {
 413   char *context_offset = (char *) &th->context + mappings[r];
 414
 415   long l;
 416   if (r == FCS_REGNUM)
 417     {
 418       l = *((long *) context_offset) & 0xffff;
 419       supply_register (regcache, r, (char *) &l);
 420     }
 421   else if (r == FOP_REGNUM)
 422     {
 423       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 424       supply_register (regcache, r, (char *) &l);
 425     }
 426   else
 427     supply_register (regcache, r, context_offset);
 428 }
 429
 430 /* Store a new register value into the thread context of TH.  */
 431 static void
 432 i386_store_inferior_register (struct regcache *regcache,
 433                               win32_thread_info *th, int r)
 434 {
 435   char *context_offset = (char *) &th->context + mappings[r];
 436   collect_register (regcache, r, context_offset);
 437 }
 438
 439 static const unsigned char i386_win32_breakpoint = 0xcc;
 440 #define i386_win32_breakpoint_len 1
 441
 442 static void
 443 i386_arch_setup (void)
 444 {
 445   struct target_desc *tdesc;
 446
 447 #ifdef __x86_64__
 448   tdesc = amd64_create_target_description (X86_XSTATE_SSE_MASK, false,
 449                                                  false);
 450 #else
 451   tdesc = i386_create_target_description (X86_XSTATE_SSE_MASK, false);
 452 #endif
 453
 454   init_target_desc (tdesc);
 455
 456   win32_tdesc = tdesc;
 457 }
 458
 459 struct win32_target_ops the_low_target = {
 460   i386_arch_setup,
 461   sizeof (mappings) / sizeof (mappings[0]),
 462   i386_initial_stuff,
 463   i386_get_thread_context,
 464   i386_prepare_to_resume,
 465   i386_thread_added,
 466   i386_fetch_inferior_register,
 467   i386_store_inferior_register,
 468   i386_single_step,
 469   &i386_win32_breakpoint,
 470   i386_win32_breakpoint_len,
 471   i386_supports_z_point_type,
 472   i386_insert_point,
 473   i386_remove_point,
 474   x86_stopped_by_watchpoint,
 475   x86_stopped_data_address
 476 };