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
  27 #ifndef CONTEXT_EXTENDED_REGISTERS
  28 #define CONTEXT_EXTENDED_REGISTERS 0
  29 #endif
  30
  31 #define FCS_REGNUM 27
  32 #define FOP_REGNUM 31
  33
  34 #define FLAG_TRACE_BIT 0x100
  35
  36 static struct x86_debug_reg_state debug_reg_state;
  37
  38 static int
  39 update_debug_registers_callback (struct inferior_list_entry *entry,
  40                                  void *pid_p)
  41 {
  42   struct thread_info *thr = (struct thread_info *) entry;
  43   win32_thread_info *th = (win32_thread_info *) thread_target_data (thr);
  44   int pid = *(int *) pid_p;
  45
  46   /* Only update the threads of this process.  */
  47   if (pid_of (thr) == pid)
  48     {
  49       /* The actual update is done later just before resuming the lwp,
  50          we just mark that the registers need updating.  */
  51       th->debug_registers_changed = 1;
  52     }
  53
  54   return 0;
  55 }
  56
  57 /* Update the inferior's debug register REGNUM from STATE.  */
  58
  59 static void
  60 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  61 {
  62   /* Only update the threads of this process.  */
  63   int pid = pid_of (current_thread);
  64
  65   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  66
  67   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  68 }
  69
  70 /* Update the inferior's DR7 debug control register from STATE.  */
  71
  72 static void
  73 x86_dr_low_set_control (unsigned long control)
  74 {
  75   /* Only update the threads of this process.  */
  76   int pid = pid_of (current_thread);
  77
  78   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  79 }
  80
  81 /* Return the current value of a DR register of the current thread's
  82    context.  */
  83
  84 static DWORD64
  85 win32_get_current_dr (int dr)
  86 {
  87   win32_thread_info *th
  88     = (win32_thread_info *) thread_target_data (current_thread);
  89
  90   win32_require_context (th);
  91
  92 #define RET_DR(DR)                              \
  93   case DR:                                      \
  94     return th->context.Dr ## DR
  95
  96   switch (dr)
  97     {
  98       RET_DR (0);
  99       RET_DR (1);
 100       RET_DR (2);
 101       RET_DR (3);
 102       RET_DR (6);
 103       RET_DR (7);
 104     }
 105
 106 #undef RET_DR
 107
 108   gdb_assert_not_reached ("unhandled dr");
 109 }
 110
 111 static CORE_ADDR
 112 x86_dr_low_get_addr (int regnum)
 113 {
 114   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 115
 116   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 117 }
 118
 119 static unsigned long
 120 x86_dr_low_get_control (void)
 121 {
 122   return win32_get_current_dr (7);
 123 }
 124
 125 /* Get the value of the DR6 debug status register from the inferior
 126    and record it in STATE.  */
 127
 128 static unsigned long
 129 x86_dr_low_get_status (void)
 130 {
 131   return win32_get_current_dr (6);
 132 }
 133
 134 /* Low-level function vector.  */
 135 struct x86_dr_low_type x86_dr_low =
 136   {
 137     x86_dr_low_set_control,
 138     x86_dr_low_set_addr,
 139     x86_dr_low_get_addr,
 140     x86_dr_low_get_status,
 141     x86_dr_low_get_control,
 142     sizeof (void *),
 143   };
 144
 145 /* Breakpoint/watchpoint support.  */
 146
 147 static int
 148 i386_supports_z_point_type (char z_type)
 149 {
 150   switch (z_type)
 151     {
 152     case Z_PACKET_WRITE_WP:
 153     case Z_PACKET_ACCESS_WP:
 154       return 1;
 155     default:
 156       return 0;
 157     }
 158 }
 159
 160 static int
 161 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 162                    int size, struct raw_breakpoint *bp)
 163 {
 164   switch (type)
 165     {
 166     case raw_bkpt_type_write_wp:
 167     case raw_bkpt_type_access_wp:
 168       {
 169         enum target_hw_bp_type hw_type
 170           = raw_bkpt_type_to_target_hw_bp_type (type);
 171
 172         return x86_dr_insert_watchpoint (&debug_reg_state,
 173                                          hw_type, addr, size);
 174       }
 175     default:
 176       /* Unsupported.  */
 177       return 1;
 178     }
 179 }
 180
 181 static int
 182 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 183                    int size, struct raw_breakpoint *bp)
 184 {
 185   switch (type)
 186     {
 187     case raw_bkpt_type_write_wp:
 188     case raw_bkpt_type_access_wp:
 189       {
 190         enum target_hw_bp_type hw_type
 191           = raw_bkpt_type_to_target_hw_bp_type (type);
 192
 193         return x86_dr_remove_watchpoint (&debug_reg_state,
 194                                          hw_type, addr, size);
 195       }
 196     default:
 197       /* Unsupported.  */
 198       return 1;
 199     }
 200 }
 201
 202 static int
 203 x86_stopped_by_watchpoint (void)
 204 {
 205   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 206 }
 207
 208 static CORE_ADDR
 209 x86_stopped_data_address (void)
 210 {
 211   CORE_ADDR addr;
 212   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 213     return addr;
 214   return 0;
 215 }
 216
 217 static void
 218 i386_initial_stuff (void)
 219 {
 220   x86_low_init_dregs (&debug_reg_state);
 221 }
 222
 223 static void
 224 i386_get_thread_context (win32_thread_info *th)
 225 {
 226   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 227      the system doesn't support extended registers.  */
 228   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 229
 230  again:
 231   th->context.ContextFlags = (CONTEXT_FULL
 232                               | CONTEXT_FLOATING_POINT
 233                               | CONTEXT_DEBUG_REGISTERS
 234                               | extended_registers);
 235
 236   if (!GetThreadContext (th->h, &th->context))
 237     {
 238       DWORD e = GetLastError ();
 239
 240       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 241         {
 242           extended_registers = 0;
 243           goto again;
 244         }
 245
 246       error ("GetThreadContext failure %ld\n", (long) e);
 247     }
 248 }
 249
 250 static void
 251 i386_prepare_to_resume (win32_thread_info *th)
 252 {
 253   if (th->debug_registers_changed)
 254     {
 255       struct x86_debug_reg_state *dr = &debug_reg_state;
 256
 257       win32_require_context (th);
 258
 259       th->context.Dr0 = dr->dr_mirror[0];
 260       th->context.Dr1 = dr->dr_mirror[1];
 261       th->context.Dr2 = dr->dr_mirror[2];
 262       th->context.Dr3 = dr->dr_mirror[3];
 263       /* th->context.Dr6 = dr->dr_status_mirror;
 264          FIXME: should we set dr6 also ?? */
 265       th->context.Dr7 = dr->dr_control_mirror;
 266
 267       th->debug_registers_changed = 0;
 268     }
 269 }
 270
 271 static void
 272 i386_thread_added (win32_thread_info *th)
 273 {
 274   th->debug_registers_changed = 1;
 275 }
 276
 277 static void
 278 i386_single_step (win32_thread_info *th)
 279 {
 280   th->context.EFlags |= FLAG_TRACE_BIT;
 281 }
 282
 283 #ifndef __x86_64__
 284
 285 /* An array of offset mappings into a Win32 Context structure.
 286    This is a one-to-one mapping which is indexed by gdb's register
 287    numbers.  It retrieves an offset into the context structure where
 288    the 4 byte register is located.
 289    An offset value of -1 indicates that Win32 does not provide this
 290    register in it's CONTEXT structure.  In this case regptr will return
 291    a pointer into a dummy register.  */
 292 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 293 static const int mappings[] = {
 294   context_offset (Eax),
 295   context_offset (Ecx),
 296   context_offset (Edx),
 297   context_offset (Ebx),
 298   context_offset (Esp),
 299   context_offset (Ebp),
 300   context_offset (Esi),
 301   context_offset (Edi),
 302   context_offset (Eip),
 303   context_offset (EFlags),
 304   context_offset (SegCs),
 305   context_offset (SegSs),
 306   context_offset (SegDs),
 307   context_offset (SegEs),
 308   context_offset (SegFs),
 309   context_offset (SegGs),
 310   context_offset (FloatSave.RegisterArea[0 * 10]),
 311   context_offset (FloatSave.RegisterArea[1 * 10]),
 312   context_offset (FloatSave.RegisterArea[2 * 10]),
 313   context_offset (FloatSave.RegisterArea[3 * 10]),
 314   context_offset (FloatSave.RegisterArea[4 * 10]),
 315   context_offset (FloatSave.RegisterArea[5 * 10]),
 316   context_offset (FloatSave.RegisterArea[6 * 10]),
 317   context_offset (FloatSave.RegisterArea[7 * 10]),
 318   context_offset (FloatSave.ControlWord),
 319   context_offset (FloatSave.StatusWord),
 320   context_offset (FloatSave.TagWord),
 321   context_offset (FloatSave.ErrorSelector),
 322   context_offset (FloatSave.ErrorOffset),
 323   context_offset (FloatSave.DataSelector),
 324   context_offset (FloatSave.DataOffset),
 325   context_offset (FloatSave.ErrorSelector),
 326   /* XMM0-7 */
 327   context_offset (ExtendedRegisters[10 * 16]),
 328   context_offset (ExtendedRegisters[11 * 16]),
 329   context_offset (ExtendedRegisters[12 * 16]),
 330   context_offset (ExtendedRegisters[13 * 16]),
 331   context_offset (ExtendedRegisters[14 * 16]),
 332   context_offset (ExtendedRegisters[15 * 16]),
 333   context_offset (ExtendedRegisters[16 * 16]),
 334   context_offset (ExtendedRegisters[17 * 16]),
 335   /* MXCSR */
 336   context_offset (ExtendedRegisters[24])
 337 };
 338 #undef context_offset
 339
 340 #else /* __x86_64__ */
 341
 342 #define context_offset(x) (offsetof (CONTEXT, x))
 343 static const int mappings[] =
 344 {
 345   context_offset (Rax),
 346   context_offset (Rbx),
 347   context_offset (Rcx),
 348   context_offset (Rdx),
 349   context_offset (Rsi),
 350   context_offset (Rdi),
 351   context_offset (Rbp),
 352   context_offset (Rsp),
 353   context_offset (R8),
 354   context_offset (R9),
 355   context_offset (R10),
 356   context_offset (R11),
 357   context_offset (R12),
 358   context_offset (R13),
 359   context_offset (R14),
 360   context_offset (R15),
 361   context_offset (Rip),
 362   context_offset (EFlags),
 363   context_offset (SegCs),
 364   context_offset (SegSs),
 365   context_offset (SegDs),
 366   context_offset (SegEs),
 367   context_offset (SegFs),
 368   context_offset (SegGs),
 369   context_offset (FloatSave.FloatRegisters[0]),
 370   context_offset (FloatSave.FloatRegisters[1]),
 371   context_offset (FloatSave.FloatRegisters[2]),
 372   context_offset (FloatSave.FloatRegisters[3]),
 373   context_offset (FloatSave.FloatRegisters[4]),
 374   context_offset (FloatSave.FloatRegisters[5]),
 375   context_offset (FloatSave.FloatRegisters[6]),
 376   context_offset (FloatSave.FloatRegisters[7]),
 377   context_offset (FloatSave.ControlWord),
 378   context_offset (FloatSave.StatusWord),
 379   context_offset (FloatSave.TagWord),
 380   context_offset (FloatSave.ErrorSelector),
 381   context_offset (FloatSave.ErrorOffset),
 382   context_offset (FloatSave.DataSelector),
 383   context_offset (FloatSave.DataOffset),
 384   context_offset (FloatSave.ErrorSelector)
 385   /* XMM0-7 */ ,
 386   context_offset (Xmm0),
 387   context_offset (Xmm1),
 388   context_offset (Xmm2),
 389   context_offset (Xmm3),
 390   context_offset (Xmm4),
 391   context_offset (Xmm5),
 392   context_offset (Xmm6),
 393   context_offset (Xmm7),
 394   context_offset (Xmm8),
 395   context_offset (Xmm9),
 396   context_offset (Xmm10),
 397   context_offset (Xmm11),
 398   context_offset (Xmm12),
 399   context_offset (Xmm13),
 400   context_offset (Xmm14),
 401   context_offset (Xmm15),
 402   /* MXCSR */
 403   context_offset (FloatSave.MxCsr)
 404 };
 405 #undef context_offset
 406
 407 #endif /* __x86_64__ */
 408
 409 /* Fetch register from gdbserver regcache data.  */
 410 static void
 411 i386_fetch_inferior_register (struct regcache *regcache,
 412                               win32_thread_info *th, int r)
 413 {
 414   char *context_offset = (char *) &th->context + mappings[r];
 415
 416   long l;
 417   if (r == FCS_REGNUM)
 418     {
 419       l = *((long *) context_offset) & 0xffff;
 420       supply_register (regcache, r, (char *) &l);
 421     }
 422   else if (r == FOP_REGNUM)
 423     {
 424       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 425       supply_register (regcache, r, (char *) &l);
 426     }
 427   else
 428     supply_register (regcache, r, context_offset);
 429 }
 430
 431 /* Store a new register value into the thread context of TH.  */
 432 static void
 433 i386_store_inferior_register (struct regcache *regcache,
 434                               win32_thread_info *th, int r)
 435 {
 436   char *context_offset = (char *) &th->context + mappings[r];
 437   collect_register (regcache, r, context_offset);
 438 }
 439
 440 static const unsigned char i386_win32_breakpoint = 0xcc;
 441 #define i386_win32_breakpoint_len 1
 442
 443 static void
 444 i386_arch_setup (void)
 445 {
 446 #ifdef __x86_64__
 447   win32_tdesc = amd64_create_target_description (X86_XSTATE_SSE_MASK, false,
 448                                                  false);
 449 #else
 450   win32_tdesc = i386_create_target_description (X86_XSTATE_SSE_MASK, false);
 451 #endif
 452 }
 453
 454 struct win32_target_ops the_low_target = {
 455   i386_arch_setup,
 456   sizeof (mappings) / sizeof (mappings[0]),
 457   i386_initial_stuff,
 458   i386_get_thread_context,
 459   i386_prepare_to_resume,
 460   i386_thread_added,
 461   i386_fetch_inferior_register,
 462   i386_store_inferior_register,
 463   i386_single_step,
 464   &i386_win32_breakpoint,
 465   i386_win32_breakpoint_len,
 466   i386_supports_z_point_type,
 467   i386_insert_point,
 468   i386_remove_point,
 469   x86_stopped_by_watchpoint,
 470   x86_stopped_data_address
 471 };