gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007-2016 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
  22 #ifndef CONTEXT_EXTENDED_REGISTERS
  23 #define CONTEXT_EXTENDED_REGISTERS 0
  24 #endif
  25
  26 #define FCS_REGNUM 27
  27 #define FOP_REGNUM 31
  28
  29 #define FLAG_TRACE_BIT 0x100
  30
  31 #ifdef __x86_64__
  32 /* Defined in auto-generated build-time file gdb/gdbserver/amd64.c.  */
  33 void init_registers_amd64 (void);
  34 extern const struct target_desc *tdesc_amd64;
  35 #else
  36 /* Defined in auto-generated build-time file gdb/gdbserver/i386.c.  */
  37 void init_registers_i386 (void);
  38 extern const struct target_desc *tdesc_i386;
  39 #endif
  40
  41 static struct x86_debug_reg_state debug_reg_state;
  42
  43 static int
  44 update_debug_registers_callback (struct inferior_list_entry *entry,
  45                                  void *pid_p)
  46 {
  47   struct thread_info *thr = (struct thread_info *) entry;
  48   win32_thread_info *th = (win32_thread_info *) inferior_target_data (thr);
  49   int pid = *(int *) pid_p;
  50
  51   /* Only update the threads of this process.  */
  52   if (pid_of (thr) == pid)
  53     {
  54       /* The actual update is done later just before resuming the lwp,
  55          we just mark that the registers need updating.  */
  56       th->debug_registers_changed = 1;
  57     }
  58
  59   return 0;
  60 }
  61
  62 /* Update the inferior's debug register REGNUM from STATE.  */
  63
  64 static void
  65 x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
  66 {
  67   /* Only update the threads of this process.  */
  68   int pid = pid_of (current_thread);
  69
  70   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  71
  72   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  73 }
  74
  75 /* Update the inferior's DR7 debug control register from STATE.  */
  76
  77 static void
  78 x86_dr_low_set_control (unsigned long control)
  79 {
  80   /* Only update the threads of this process.  */
  81   int pid = pid_of (current_thread);
  82
  83   find_inferior (&all_threads, update_debug_registers_callback, &pid);
  84 }
  85
  86 /* Return the current value of a DR register of the current thread's
  87    context.  */
  88
  89 static DWORD64
  90 win32_get_current_dr (int dr)
  91 {
  92   win32_thread_info *th
  93     = (win32_thread_info *) inferior_target_data (current_thread);
  94
  95   win32_require_context (th);
  96
  97 #define RET_DR(DR)                              \
  98   case DR:                                      \
  99     return th->context.Dr ## DR
 100
 101   switch (dr)
 102     {
 103       RET_DR (0);
 104       RET_DR (1);
 105       RET_DR (2);
 106       RET_DR (3);
 107       RET_DR (6);
 108       RET_DR (7);
 109     }
 110
 111 #undef RET_DR
 112
 113   gdb_assert_not_reached ("unhandled dr");
 114 }
 115
 116 static CORE_ADDR
 117 x86_dr_low_get_addr (int regnum)
 118 {
 119   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 120
 121   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 122 }
 123
 124 static unsigned long
 125 x86_dr_low_get_control (void)
 126 {
 127   return win32_get_current_dr (7);
 128 }
 129
 130 /* Get the value of the DR6 debug status register from the inferior
 131    and record it in STATE.  */
 132
 133 static unsigned long
 134 x86_dr_low_get_status (void)
 135 {
 136   return win32_get_current_dr (6);
 137 }
 138
 139 /* Low-level function vector.  */
 140 struct x86_dr_low_type x86_dr_low =
 141   {
 142     x86_dr_low_set_control,
 143     x86_dr_low_set_addr,
 144     x86_dr_low_get_addr,
 145     x86_dr_low_get_status,
 146     x86_dr_low_get_control,
 147     sizeof (void *),
 148   };
 149
 150 /* Breakpoint/watchpoint support.  */
 151
 152 static int
 153 i386_supports_z_point_type (char z_type)
 154 {
 155   switch (z_type)
 156     {
 157     case Z_PACKET_WRITE_WP:
 158     case Z_PACKET_ACCESS_WP:
 159       return 1;
 160     default:
 161       return 0;
 162     }
 163 }
 164
 165 static int
 166 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 167                    int size, struct raw_breakpoint *bp)
 168 {
 169   switch (type)
 170     {
 171     case raw_bkpt_type_write_wp:
 172     case raw_bkpt_type_access_wp:
 173       {
 174         enum target_hw_bp_type hw_type
 175           = raw_bkpt_type_to_target_hw_bp_type (type);
 176
 177         return x86_dr_insert_watchpoint (&debug_reg_state,
 178                                          hw_type, addr, size);
 179       }
 180     default:
 181       /* Unsupported.  */
 182       return 1;
 183     }
 184 }
 185
 186 static int
 187 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 188                    int size, struct raw_breakpoint *bp)
 189 {
 190   switch (type)
 191     {
 192     case raw_bkpt_type_write_wp:
 193     case raw_bkpt_type_access_wp:
 194       {
 195         enum target_hw_bp_type hw_type
 196           = raw_bkpt_type_to_target_hw_bp_type (type);
 197
 198         return x86_dr_remove_watchpoint (&debug_reg_state,
 199                                          hw_type, addr, size);
 200       }
 201     default:
 202       /* Unsupported.  */
 203       return 1;
 204     }
 205 }
 206
 207 static int
 208 x86_stopped_by_watchpoint (void)
 209 {
 210   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 211 }
 212
 213 static CORE_ADDR
 214 x86_stopped_data_address (void)
 215 {
 216   CORE_ADDR addr;
 217   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 218     return addr;
 219   return 0;
 220 }
 221
 222 static void
 223 i386_initial_stuff (void)
 224 {
 225   x86_low_init_dregs (&debug_reg_state);
 226 }
 227
 228 static void
 229 i386_get_thread_context (win32_thread_info *th)
 230 {
 231   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 232      the system doesn't support extended registers.  */
 233   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 234
 235  again:
 236   th->context.ContextFlags = (CONTEXT_FULL
 237                               | CONTEXT_FLOATING_POINT
 238                               | CONTEXT_DEBUG_REGISTERS
 239                               | extended_registers);
 240
 241   if (!GetThreadContext (th->h, &th->context))
 242     {
 243       DWORD e = GetLastError ();
 244
 245       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 246         {
 247           extended_registers = 0;
 248           goto again;
 249         }
 250
 251       error ("GetThreadContext failure %ld\n", (long) e);
 252     }
 253 }
 254
 255 static void
 256 i386_prepare_to_resume (win32_thread_info *th)
 257 {
 258   if (th->debug_registers_changed)
 259     {
 260       struct x86_debug_reg_state *dr = &debug_reg_state;
 261
 262       win32_require_context (th);
 263
 264       th->context.Dr0 = dr->dr_mirror[0];
 265       th->context.Dr1 = dr->dr_mirror[1];
 266       th->context.Dr2 = dr->dr_mirror[2];
 267       th->context.Dr3 = dr->dr_mirror[3];
 268       /* th->context.Dr6 = dr->dr_status_mirror;
 269          FIXME: should we set dr6 also ?? */
 270       th->context.Dr7 = dr->dr_control_mirror;
 271
 272       th->debug_registers_changed = 0;
 273     }
 274 }
 275
 276 static void
 277 i386_thread_added (win32_thread_info *th)
 278 {
 279   th->debug_registers_changed = 1;
 280 }
 281
 282 static void
 283 i386_single_step (win32_thread_info *th)
 284 {
 285   th->context.EFlags |= FLAG_TRACE_BIT;
 286 }
 287
 288 #ifndef __x86_64__
 289
 290 /* An array of offset mappings into a Win32 Context structure.
 291    This is a one-to-one mapping which is indexed by gdb's register
 292    numbers.  It retrieves an offset into the context structure where
 293    the 4 byte register is located.
 294    An offset value of -1 indicates that Win32 does not provide this
 295    register in it's CONTEXT structure.  In this case regptr will return
 296    a pointer into a dummy register.  */
 297 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 298 static const int mappings[] = {
 299   context_offset (Eax),
 300   context_offset (Ecx),
 301   context_offset (Edx),
 302   context_offset (Ebx),
 303   context_offset (Esp),
 304   context_offset (Ebp),
 305   context_offset (Esi),
 306   context_offset (Edi),
 307   context_offset (Eip),
 308   context_offset (EFlags),
 309   context_offset (SegCs),
 310   context_offset (SegSs),
 311   context_offset (SegDs),
 312   context_offset (SegEs),
 313   context_offset (SegFs),
 314   context_offset (SegGs),
 315   context_offset (FloatSave.RegisterArea[0 * 10]),
 316   context_offset (FloatSave.RegisterArea[1 * 10]),
 317   context_offset (FloatSave.RegisterArea[2 * 10]),
 318   context_offset (FloatSave.RegisterArea[3 * 10]),
 319   context_offset (FloatSave.RegisterArea[4 * 10]),
 320   context_offset (FloatSave.RegisterArea[5 * 10]),
 321   context_offset (FloatSave.RegisterArea[6 * 10]),
 322   context_offset (FloatSave.RegisterArea[7 * 10]),
 323   context_offset (FloatSave.ControlWord),
 324   context_offset (FloatSave.StatusWord),
 325   context_offset (FloatSave.TagWord),
 326   context_offset (FloatSave.ErrorSelector),
 327   context_offset (FloatSave.ErrorOffset),
 328   context_offset (FloatSave.DataSelector),
 329   context_offset (FloatSave.DataOffset),
 330   context_offset (FloatSave.ErrorSelector),
 331   /* XMM0-7 */
 332   context_offset (ExtendedRegisters[10 * 16]),
 333   context_offset (ExtendedRegisters[11 * 16]),
 334   context_offset (ExtendedRegisters[12 * 16]),
 335   context_offset (ExtendedRegisters[13 * 16]),
 336   context_offset (ExtendedRegisters[14 * 16]),
 337   context_offset (ExtendedRegisters[15 * 16]),
 338   context_offset (ExtendedRegisters[16 * 16]),
 339   context_offset (ExtendedRegisters[17 * 16]),
 340   /* MXCSR */
 341   context_offset (ExtendedRegisters[24])
 342 };
 343 #undef context_offset
 344
 345 #else /* __x86_64__ */
 346
 347 #define context_offset(x) (offsetof (CONTEXT, x))
 348 static const int mappings[] =
 349 {
 350   context_offset (Rax),
 351   context_offset (Rbx),
 352   context_offset (Rcx),
 353   context_offset (Rdx),
 354   context_offset (Rsi),
 355   context_offset (Rdi),
 356   context_offset (Rbp),
 357   context_offset (Rsp),
 358   context_offset (R8),
 359   context_offset (R9),
 360   context_offset (R10),
 361   context_offset (R11),
 362   context_offset (R12),
 363   context_offset (R13),
 364   context_offset (R14),
 365   context_offset (R15),
 366   context_offset (Rip),
 367   context_offset (EFlags),
 368   context_offset (SegCs),
 369   context_offset (SegSs),
 370   context_offset (SegDs),
 371   context_offset (SegEs),
 372   context_offset (SegFs),
 373   context_offset (SegGs),
 374   context_offset (FloatSave.FloatRegisters[0]),
 375   context_offset (FloatSave.FloatRegisters[1]),
 376   context_offset (FloatSave.FloatRegisters[2]),
 377   context_offset (FloatSave.FloatRegisters[3]),
 378   context_offset (FloatSave.FloatRegisters[4]),
 379   context_offset (FloatSave.FloatRegisters[5]),
 380   context_offset (FloatSave.FloatRegisters[6]),
 381   context_offset (FloatSave.FloatRegisters[7]),
 382   context_offset (FloatSave.ControlWord),
 383   context_offset (FloatSave.StatusWord),
 384   context_offset (FloatSave.TagWord),
 385   context_offset (FloatSave.ErrorSelector),
 386   context_offset (FloatSave.ErrorOffset),
 387   context_offset (FloatSave.DataSelector),
 388   context_offset (FloatSave.DataOffset),
 389   context_offset (FloatSave.ErrorSelector)
 390   /* XMM0-7 */ ,
 391   context_offset (Xmm0),
 392   context_offset (Xmm1),
 393   context_offset (Xmm2),
 394   context_offset (Xmm3),
 395   context_offset (Xmm4),
 396   context_offset (Xmm5),
 397   context_offset (Xmm6),
 398   context_offset (Xmm7),
 399   context_offset (Xmm8),
 400   context_offset (Xmm9),
 401   context_offset (Xmm10),
 402   context_offset (Xmm11),
 403   context_offset (Xmm12),
 404   context_offset (Xmm13),
 405   context_offset (Xmm14),
 406   context_offset (Xmm15),
 407   /* MXCSR */
 408   context_offset (FloatSave.MxCsr)
 409 };
 410 #undef context_offset
 411
 412 #endif /* __x86_64__ */
 413
 414 /* Fetch register from gdbserver regcache data.  */
 415 static void
 416 i386_fetch_inferior_register (struct regcache *regcache,
 417                               win32_thread_info *th, int r)
 418 {
 419   char *context_offset = (char *) &th->context + mappings[r];
 420
 421   long l;
 422   if (r == FCS_REGNUM)
 423     {
 424       l = *((long *) context_offset) & 0xffff;
 425       supply_register (regcache, r, (char *) &l);
 426     }
 427   else if (r == FOP_REGNUM)
 428     {
 429       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 430       supply_register (regcache, r, (char *) &l);
 431     }
 432   else
 433     supply_register (regcache, r, context_offset);
 434 }
 435
 436 /* Store a new register value into the thread context of TH.  */
 437 static void
 438 i386_store_inferior_register (struct regcache *regcache,
 439                               win32_thread_info *th, int r)
 440 {
 441   char *context_offset = (char *) &th->context + mappings[r];
 442   collect_register (regcache, r, context_offset);
 443 }
 444
 445 static const unsigned char i386_win32_breakpoint = 0xcc;
 446 #define i386_win32_breakpoint_len 1
 447
 448 static void
 449 i386_arch_setup (void)
 450 {
 451 #ifdef __x86_64__
 452   init_registers_amd64 ();
 453   win32_tdesc = tdesc_amd64;
 454 #else
 455   init_registers_i386 ();
 456   win32_tdesc = tdesc_i386;
 457 #endif
 458 }
 459
 460 struct win32_target_ops the_low_target = {
 461   i386_arch_setup,
 462   sizeof (mappings) / sizeof (mappings[0]),
 463   i386_initial_stuff,
 464   i386_get_thread_context,
 465   i386_prepare_to_resume,
 466   i386_thread_added,
 467   i386_fetch_inferior_register,
 468   i386_store_inferior_register,
 469   i386_single_step,
 470   &i386_win32_breakpoint,
 471   i386_win32_breakpoint_len,
 472   i386_supports_z_point_type,
 473   i386_insert_point,
 474   i386_remove_point,
 475   x86_stopped_by_watchpoint,
 476   x86_stopped_data_address
 477 };