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 (struct inferior_list_entry *entry,
  41                                  void *pid_p)
  42 {
  43   struct thread_info *thr = (struct thread_info *) entry;
  44   win32_thread_info *th = (win32_thread_info *) thread_target_data (thr);
  45   int pid = *(int *) pid_p;
  46
  47   /* Only update the threads of this process.  */
  48   if (pid_of (thr) == pid)
  49     {
  50       /* The actual update is done later just before resuming the lwp,
  51          we just mark that the registers need updating.  */
  52       th->debug_registers_changed = 1;
  53     }
  54
  55   return 0;
  56 }
  57
  58 /* Update the inferior's debug register REGNUM from STATE.  */
  59
  60 static void
  61 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  62 {
  63   /* Only update the threads of this process.  */
  64   int pid = pid_of (current_thread);
  65
  66   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  67
  68   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  69 }
  70
  71 /* Update the inferior's DR7 debug control register from STATE.  */
  72
  73 static void
  74 x86_dr_low_set_control (unsigned long control)
  75 {
  76   /* Only update the threads of this process.  */
  77   int pid = pid_of (current_thread);
  78
  79   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  80 }
  81
  82 /* Return the current value of a DR register of the current thread's
  83    context.  */
  84
  85 static DWORD64
  86 win32_get_current_dr (int dr)
  87 {
  88   win32_thread_info *th
  89     = (win32_thread_info *) thread_target_data (current_thread);
  90
  91   win32_require_context (th);
  92
  93 #define RET_DR(DR)                              \
  94   case DR:                                      \
  95     return th->context.Dr ## DR
  96
  97   switch (dr)
  98     {
  99       RET_DR (0);
 100       RET_DR (1);
 101       RET_DR (2);
 102       RET_DR (3);
 103       RET_DR (6);
 104       RET_DR (7);
 105     }
 106
 107 #undef RET_DR
 108
 109   gdb_assert_not_reached ("unhandled dr");
 110 }
 111
 112 static CORE_ADDR
 113 x86_dr_low_get_addr (int regnum)
 114 {
 115   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 116
 117   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 118 }
 119
 120 static unsigned long
 121 x86_dr_low_get_control (void)
 122 {
 123   return win32_get_current_dr (7);
 124 }
 125
 126 /* Get the value of the DR6 debug status register from the inferior
 127    and record it in STATE.  */
 128
 129 static unsigned long
 130 x86_dr_low_get_status (void)
 131 {
 132   return win32_get_current_dr (6);
 133 }
 134
 135 /* Low-level function vector.  */
 136 struct x86_dr_low_type x86_dr_low =
 137   {
 138     x86_dr_low_set_control,
 139     x86_dr_low_set_addr,
 140     x86_dr_low_get_addr,
 141     x86_dr_low_get_status,
 142     x86_dr_low_get_control,
 143     sizeof (void *),
 144   };
 145
 146 /* Breakpoint/watchpoint support.  */
 147
 148 static int
 149 i386_supports_z_point_type (char z_type)
 150 {
 151   switch (z_type)
 152     {
 153     case Z_PACKET_WRITE_WP:
 154     case Z_PACKET_ACCESS_WP:
 155       return 1;
 156     default:
 157       return 0;
 158     }
 159 }
 160
 161 static int
 162 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 163                    int size, struct raw_breakpoint *bp)
 164 {
 165   switch (type)
 166     {
 167     case raw_bkpt_type_write_wp:
 168     case raw_bkpt_type_access_wp:
 169       {
 170         enum target_hw_bp_type hw_type
 171           = raw_bkpt_type_to_target_hw_bp_type (type);
 172
 173         return x86_dr_insert_watchpoint (&debug_reg_state,
 174                                          hw_type, addr, size);
 175       }
 176     default:
 177       /* Unsupported.  */
 178       return 1;
 179     }
 180 }
 181
 182 static int
 183 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 184                    int size, struct raw_breakpoint *bp)
 185 {
 186   switch (type)
 187     {
 188     case raw_bkpt_type_write_wp:
 189     case raw_bkpt_type_access_wp:
 190       {
 191         enum target_hw_bp_type hw_type
 192           = raw_bkpt_type_to_target_hw_bp_type (type);
 193
 194         return x86_dr_remove_watchpoint (&debug_reg_state,
 195                                          hw_type, addr, size);
 196       }
 197     default:
 198       /* Unsupported.  */
 199       return 1;
 200     }
 201 }
 202
 203 static int
 204 x86_stopped_by_watchpoint (void)
 205 {
 206   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 207 }
 208
 209 static CORE_ADDR
 210 x86_stopped_data_address (void)
 211 {
 212   CORE_ADDR addr;
 213   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 214     return addr;
 215   return 0;
 216 }
 217
 218 static void
 219 i386_initial_stuff (void)
 220 {
 221   x86_low_init_dregs (&debug_reg_state);
 222 }
 223
 224 static void
 225 i386_get_thread_context (win32_thread_info *th)
 226 {
 227   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 228      the system doesn't support extended registers.  */
 229   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 230
 231  again:
 232   th->context.ContextFlags = (CONTEXT_FULL
 233                               | CONTEXT_FLOATING_POINT
 234                               | CONTEXT_DEBUG_REGISTERS
 235                               | extended_registers);
 236
 237   if (!GetThreadContext (th->h, &th->context))
 238     {
 239       DWORD e = GetLastError ();
 240
 241       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 242         {
 243           extended_registers = 0;
 244           goto again;
 245         }
 246
 247       error ("GetThreadContext failure %ld\n", (long) e);
 248     }
 249 }
 250
 251 static void
 252 i386_prepare_to_resume (win32_thread_info *th)
 253 {
 254   if (th->debug_registers_changed)
 255     {
 256       struct x86_debug_reg_state *dr = &debug_reg_state;
 257
 258       win32_require_context (th);
 259
 260       th->context.Dr0 = dr->dr_mirror[0];
 261       th->context.Dr1 = dr->dr_mirror[1];
 262       th->context.Dr2 = dr->dr_mirror[2];
 263       th->context.Dr3 = dr->dr_mirror[3];
 264       /* th->context.Dr6 = dr->dr_status_mirror;
 265          FIXME: should we set dr6 also ?? */
 266       th->context.Dr7 = dr->dr_control_mirror;
 267
 268       th->debug_registers_changed = 0;
 269     }
 270 }
 271
 272 static void
 273 i386_thread_added (win32_thread_info *th)
 274 {
 275   th->debug_registers_changed = 1;
 276 }
 277
 278 static void
 279 i386_single_step (win32_thread_info *th)
 280 {
 281   th->context.EFlags |= FLAG_TRACE_BIT;
 282 }
 283
 284 #ifndef __x86_64__
 285
 286 /* An array of offset mappings into a Win32 Context structure.
 287    This is a one-to-one mapping which is indexed by gdb's register
 288    numbers.  It retrieves an offset into the context structure where
 289    the 4 byte register is located.
 290    An offset value of -1 indicates that Win32 does not provide this
 291    register in it's CONTEXT structure.  In this case regptr will return
 292    a pointer into a dummy register.  */
 293 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 294 static const int mappings[] = {
 295   context_offset (Eax),
 296   context_offset (Ecx),
 297   context_offset (Edx),
 298   context_offset (Ebx),
 299   context_offset (Esp),
 300   context_offset (Ebp),
 301   context_offset (Esi),
 302   context_offset (Edi),
 303   context_offset (Eip),
 304   context_offset (EFlags),
 305   context_offset (SegCs),
 306   context_offset (SegSs),
 307   context_offset (SegDs),
 308   context_offset (SegEs),
 309   context_offset (SegFs),
 310   context_offset (SegGs),
 311   context_offset (FloatSave.RegisterArea[0 * 10]),
 312   context_offset (FloatSave.RegisterArea[1 * 10]),
 313   context_offset (FloatSave.RegisterArea[2 * 10]),
 314   context_offset (FloatSave.RegisterArea[3 * 10]),
 315   context_offset (FloatSave.RegisterArea[4 * 10]),
 316   context_offset (FloatSave.RegisterArea[5 * 10]),
 317   context_offset (FloatSave.RegisterArea[6 * 10]),
 318   context_offset (FloatSave.RegisterArea[7 * 10]),
 319   context_offset (FloatSave.ControlWord),
 320   context_offset (FloatSave.StatusWord),
 321   context_offset (FloatSave.TagWord),
 322   context_offset (FloatSave.ErrorSelector),
 323   context_offset (FloatSave.ErrorOffset),
 324   context_offset (FloatSave.DataSelector),
 325   context_offset (FloatSave.DataOffset),
 326   context_offset (FloatSave.ErrorSelector),
 327   /* XMM0-7 */
 328   context_offset (ExtendedRegisters[10 * 16]),
 329   context_offset (ExtendedRegisters[11 * 16]),
 330   context_offset (ExtendedRegisters[12 * 16]),
 331   context_offset (ExtendedRegisters[13 * 16]),
 332   context_offset (ExtendedRegisters[14 * 16]),
 333   context_offset (ExtendedRegisters[15 * 16]),
 334   context_offset (ExtendedRegisters[16 * 16]),
 335   context_offset (ExtendedRegisters[17 * 16]),
 336   /* MXCSR */
 337   context_offset (ExtendedRegisters[24])
 338 };
 339 #undef context_offset
 340
 341 #else /* __x86_64__ */
 342
 343 #define context_offset(x) (offsetof (CONTEXT, x))
 344 static const int mappings[] =
 345 {
 346   context_offset (Rax),
 347   context_offset (Rbx),
 348   context_offset (Rcx),
 349   context_offset (Rdx),
 350   context_offset (Rsi),
 351   context_offset (Rdi),
 352   context_offset (Rbp),
 353   context_offset (Rsp),
 354   context_offset (R8),
 355   context_offset (R9),
 356   context_offset (R10),
 357   context_offset (R11),
 358   context_offset (R12),
 359   context_offset (R13),
 360   context_offset (R14),
 361   context_offset (R15),
 362   context_offset (Rip),
 363   context_offset (EFlags),
 364   context_offset (SegCs),
 365   context_offset (SegSs),
 366   context_offset (SegDs),
 367   context_offset (SegEs),
 368   context_offset (SegFs),
 369   context_offset (SegGs),
 370   context_offset (FloatSave.FloatRegisters[0]),
 371   context_offset (FloatSave.FloatRegisters[1]),
 372   context_offset (FloatSave.FloatRegisters[2]),
 373   context_offset (FloatSave.FloatRegisters[3]),
 374   context_offset (FloatSave.FloatRegisters[4]),
 375   context_offset (FloatSave.FloatRegisters[5]),
 376   context_offset (FloatSave.FloatRegisters[6]),
 377   context_offset (FloatSave.FloatRegisters[7]),
 378   context_offset (FloatSave.ControlWord),
 379   context_offset (FloatSave.StatusWord),
 380   context_offset (FloatSave.TagWord),
 381   context_offset (FloatSave.ErrorSelector),
 382   context_offset (FloatSave.ErrorOffset),
 383   context_offset (FloatSave.DataSelector),
 384   context_offset (FloatSave.DataOffset),
 385   context_offset (FloatSave.ErrorSelector)
 386   /* XMM0-7 */ ,
 387   context_offset (Xmm0),
 388   context_offset (Xmm1),
 389   context_offset (Xmm2),
 390   context_offset (Xmm3),
 391   context_offset (Xmm4),
 392   context_offset (Xmm5),
 393   context_offset (Xmm6),
 394   context_offset (Xmm7),
 395   context_offset (Xmm8),
 396   context_offset (Xmm9),
 397   context_offset (Xmm10),
 398   context_offset (Xmm11),
 399   context_offset (Xmm12),
 400   context_offset (Xmm13),
 401   context_offset (Xmm14),
 402   context_offset (Xmm15),
 403   /* MXCSR */
 404   context_offset (FloatSave.MxCsr)
 405 };
 406 #undef context_offset
 407
 408 #endif /* __x86_64__ */
 409
 410 /* Fetch register from gdbserver regcache data.  */
 411 static void
 412 i386_fetch_inferior_register (struct regcache *regcache,
 413                               win32_thread_info *th, int r)
 414 {
 415   char *context_offset = (char *) &th->context + mappings[r];
 416
 417   long l;
 418   if (r == FCS_REGNUM)
 419     {
 420       l = *((long *) context_offset) & 0xffff;
 421       supply_register (regcache, r, (char *) &l);
 422     }
 423   else if (r == FOP_REGNUM)
 424     {
 425       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 426       supply_register (regcache, r, (char *) &l);
 427     }
 428   else
 429     supply_register (regcache, r, context_offset);
 430 }
 431
 432 /* Store a new register value into the thread context of TH.  */
 433 static void
 434 i386_store_inferior_register (struct regcache *regcache,
 435                               win32_thread_info *th, int r)
 436 {
 437   char *context_offset = (char *) &th->context + mappings[r];
 438   collect_register (regcache, r, context_offset);
 439 }
 440
 441 static const unsigned char i386_win32_breakpoint = 0xcc;
 442 #define i386_win32_breakpoint_len 1
 443
 444 static void
 445 i386_arch_setup (void)
 446 {
 447   struct target_desc *tdesc;
 448
 449 #ifdef __x86_64__
 450   tdesc = amd64_create_target_description (X86_XSTATE_SSE_MASK, false,
 451                                                  false);
 452 #else
 453   tdesc = i386_create_target_description (X86_XSTATE_SSE_MASK, false);
 454 #endif
 455
 456   init_target_desc (tdesc);
 457
 458   win32_tdesc = tdesc;
 459 }
 460
 461 struct win32_target_ops the_low_target = {
 462   i386_arch_setup,
 463   sizeof (mappings) / sizeof (mappings[0]),
 464   i386_initial_stuff,
 465   i386_get_thread_context,
 466   i386_prepare_to_resume,
 467   i386_thread_added,
 468   i386_fetch_inferior_register,
 469   i386_store_inferior_register,
 470   i386_single_step,
 471   &i386_win32_breakpoint,
 472   i386_win32_breakpoint_len,
 473   i386_supports_z_point_type,
 474   i386_insert_point,
 475   i386_remove_point,
 476   x86_stopped_by_watchpoint,
 477   x86_stopped_data_address
 478 };