gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007-2015 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 file reg-amd64.c.  */
  33 void init_registers_amd64 (void);
  34 extern const struct target_desc *tdesc_amd64;
  35 #else
  36 /* Defined in auto-generated file reg-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 = 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 = inferior_target_data (current_thread);
  93
  94   win32_require_context (th);
  95
  96 #define RET_DR(DR)                              \
  97   case DR:                                      \
  98     return th->context.Dr ## DR
  99
 100   switch (dr)
 101     {
 102       RET_DR (0);
 103       RET_DR (1);
 104       RET_DR (2);
 105       RET_DR (3);
 106       RET_DR (6);
 107       RET_DR (7);
 108     }
 109
 110 #undef RET_DR
 111
 112   gdb_assert_not_reached ("unhandled dr");
 113 }
 114
 115 static CORE_ADDR
 116 x86_dr_low_get_addr (int regnum)
 117 {
 118   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 119
 120   return win32_get_current_dr (regnum - DR_FIRSTADDR);
 121 }
 122
 123 static unsigned long
 124 x86_dr_low_get_control (void)
 125 {
 126   return win32_get_current_dr (7);
 127 }
 128
 129 /* Get the value of the DR6 debug status register from the inferior
 130    and record it in STATE.  */
 131
 132 static unsigned long
 133 x86_dr_low_get_status (void)
 134 {
 135   return win32_get_current_dr (6);
 136 }
 137
 138 /* Low-level function vector.  */
 139 struct x86_dr_low_type x86_dr_low =
 140   {
 141     x86_dr_low_set_control,
 142     x86_dr_low_set_addr,
 143     x86_dr_low_get_addr,
 144     x86_dr_low_get_status,
 145     x86_dr_low_get_control,
 146     sizeof (void *),
 147   };
 148
 149 /* Breakpoint/watchpoint support.  */
 150
 151 static int
 152 i386_supports_z_point_type (char z_type)
 153 {
 154   switch (z_type)
 155     {
 156     case Z_PACKET_WRITE_WP:
 157     case Z_PACKET_ACCESS_WP:
 158       return 1;
 159     default:
 160       return 0;
 161     }
 162 }
 163
 164 static int
 165 i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
 166                    int size, struct raw_breakpoint *bp)
 167 {
 168   switch (type)
 169     {
 170     case raw_bkpt_type_write_wp:
 171     case raw_bkpt_type_access_wp:
 172       {
 173         enum target_hw_bp_type hw_type
 174           = raw_bkpt_type_to_target_hw_bp_type (type);
 175
 176         return x86_dr_insert_watchpoint (&debug_reg_state,
 177                                          hw_type, addr, size);
 178       }
 179     default:
 180       /* Unsupported.  */
 181       return 1;
 182     }
 183 }
 184
 185 static int
 186 i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
 187                    int size, struct raw_breakpoint *bp)
 188 {
 189   switch (type)
 190     {
 191     case raw_bkpt_type_write_wp:
 192     case raw_bkpt_type_access_wp:
 193       {
 194         enum target_hw_bp_type hw_type
 195           = raw_bkpt_type_to_target_hw_bp_type (type);
 196
 197         return x86_dr_remove_watchpoint (&debug_reg_state,
 198                                          hw_type, addr, size);
 199       }
 200     default:
 201       /* Unsupported.  */
 202       return 1;
 203     }
 204 }
 205
 206 static int
 207 x86_stopped_by_watchpoint (void)
 208 {
 209   return x86_dr_stopped_by_watchpoint (&debug_reg_state);
 210 }
 211
 212 static CORE_ADDR
 213 x86_stopped_data_address (void)
 214 {
 215   CORE_ADDR addr;
 216   if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
 217     return addr;
 218   return 0;
 219 }
 220
 221 static void
 222 i386_initial_stuff (void)
 223 {
 224   x86_low_init_dregs (&debug_reg_state);
 225 }
 226
 227 static void
 228 i386_get_thread_context (win32_thread_info *th)
 229 {
 230   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 231      the system doesn't support extended registers.  */
 232   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 233
 234  again:
 235   th->context.ContextFlags = (CONTEXT_FULL
 236                               | CONTEXT_FLOATING_POINT
 237                               | CONTEXT_DEBUG_REGISTERS
 238                               | extended_registers);
 239
 240   if (!GetThreadContext (th->h, &th->context))
 241     {
 242       DWORD e = GetLastError ();
 243
 244       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 245         {
 246           extended_registers = 0;
 247           goto again;
 248         }
 249
 250       error ("GetThreadContext failure %ld\n", (long) e);
 251     }
 252 }
 253
 254 static void
 255 i386_prepare_to_resume (win32_thread_info *th)
 256 {
 257   if (th->debug_registers_changed)
 258     {
 259       struct x86_debug_reg_state *dr = &debug_reg_state;
 260
 261       win32_require_context (th);
 262
 263       th->context.Dr0 = dr->dr_mirror[0];
 264       th->context.Dr1 = dr->dr_mirror[1];
 265       th->context.Dr2 = dr->dr_mirror[2];
 266       th->context.Dr3 = dr->dr_mirror[3];
 267       /* th->context.Dr6 = dr->dr_status_mirror;
 268          FIXME: should we set dr6 also ?? */
 269       th->context.Dr7 = dr->dr_control_mirror;
 270
 271       th->debug_registers_changed = 0;
 272     }
 273 }
 274
 275 static void
 276 i386_thread_added (win32_thread_info *th)
 277 {
 278   th->debug_registers_changed = 1;
 279 }
 280
 281 static void
 282 i386_single_step (win32_thread_info *th)
 283 {
 284   th->context.EFlags |= FLAG_TRACE_BIT;
 285 }
 286
 287 #ifndef __x86_64__
 288
 289 /* An array of offset mappings into a Win32 Context structure.
 290    This is a one-to-one mapping which is indexed by gdb's register
 291    numbers.  It retrieves an offset into the context structure where
 292    the 4 byte register is located.
 293    An offset value of -1 indicates that Win32 does not provide this
 294    register in it's CONTEXT structure.  In this case regptr will return
 295    a pointer into a dummy register.  */
 296 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 297 static const int mappings[] = {
 298   context_offset (Eax),
 299   context_offset (Ecx),
 300   context_offset (Edx),
 301   context_offset (Ebx),
 302   context_offset (Esp),
 303   context_offset (Ebp),
 304   context_offset (Esi),
 305   context_offset (Edi),
 306   context_offset (Eip),
 307   context_offset (EFlags),
 308   context_offset (SegCs),
 309   context_offset (SegSs),
 310   context_offset (SegDs),
 311   context_offset (SegEs),
 312   context_offset (SegFs),
 313   context_offset (SegGs),
 314   context_offset (FloatSave.RegisterArea[0 * 10]),
 315   context_offset (FloatSave.RegisterArea[1 * 10]),
 316   context_offset (FloatSave.RegisterArea[2 * 10]),
 317   context_offset (FloatSave.RegisterArea[3 * 10]),
 318   context_offset (FloatSave.RegisterArea[4 * 10]),
 319   context_offset (FloatSave.RegisterArea[5 * 10]),
 320   context_offset (FloatSave.RegisterArea[6 * 10]),
 321   context_offset (FloatSave.RegisterArea[7 * 10]),
 322   context_offset (FloatSave.ControlWord),
 323   context_offset (FloatSave.StatusWord),
 324   context_offset (FloatSave.TagWord),
 325   context_offset (FloatSave.ErrorSelector),
 326   context_offset (FloatSave.ErrorOffset),
 327   context_offset (FloatSave.DataSelector),
 328   context_offset (FloatSave.DataOffset),
 329   context_offset (FloatSave.ErrorSelector),
 330   /* XMM0-7 */
 331   context_offset (ExtendedRegisters[10 * 16]),
 332   context_offset (ExtendedRegisters[11 * 16]),
 333   context_offset (ExtendedRegisters[12 * 16]),
 334   context_offset (ExtendedRegisters[13 * 16]),
 335   context_offset (ExtendedRegisters[14 * 16]),
 336   context_offset (ExtendedRegisters[15 * 16]),
 337   context_offset (ExtendedRegisters[16 * 16]),
 338   context_offset (ExtendedRegisters[17 * 16]),
 339   /* MXCSR */
 340   context_offset (ExtendedRegisters[24])
 341 };
 342 #undef context_offset
 343
 344 #else /* __x86_64__ */
 345
 346 #define context_offset(x) (offsetof (CONTEXT, x))
 347 static const int mappings[] =
 348 {
 349   context_offset (Rax),
 350   context_offset (Rbx),
 351   context_offset (Rcx),
 352   context_offset (Rdx),
 353   context_offset (Rsi),
 354   context_offset (Rdi),
 355   context_offset (Rbp),
 356   context_offset (Rsp),
 357   context_offset (R8),
 358   context_offset (R9),
 359   context_offset (R10),
 360   context_offset (R11),
 361   context_offset (R12),
 362   context_offset (R13),
 363   context_offset (R14),
 364   context_offset (R15),
 365   context_offset (Rip),
 366   context_offset (EFlags),
 367   context_offset (SegCs),
 368   context_offset (SegSs),
 369   context_offset (SegDs),
 370   context_offset (SegEs),
 371   context_offset (SegFs),
 372   context_offset (SegGs),
 373   context_offset (FloatSave.FloatRegisters[0]),
 374   context_offset (FloatSave.FloatRegisters[1]),
 375   context_offset (FloatSave.FloatRegisters[2]),
 376   context_offset (FloatSave.FloatRegisters[3]),
 377   context_offset (FloatSave.FloatRegisters[4]),
 378   context_offset (FloatSave.FloatRegisters[5]),
 379   context_offset (FloatSave.FloatRegisters[6]),
 380   context_offset (FloatSave.FloatRegisters[7]),
 381   context_offset (FloatSave.ControlWord),
 382   context_offset (FloatSave.StatusWord),
 383   context_offset (FloatSave.TagWord),
 384   context_offset (FloatSave.ErrorSelector),
 385   context_offset (FloatSave.ErrorOffset),
 386   context_offset (FloatSave.DataSelector),
 387   context_offset (FloatSave.DataOffset),
 388   context_offset (FloatSave.ErrorSelector)
 389   /* XMM0-7 */ ,
 390   context_offset (Xmm0),
 391   context_offset (Xmm1),
 392   context_offset (Xmm2),
 393   context_offset (Xmm3),
 394   context_offset (Xmm4),
 395   context_offset (Xmm5),
 396   context_offset (Xmm6),
 397   context_offset (Xmm7),
 398   context_offset (Xmm8),
 399   context_offset (Xmm9),
 400   context_offset (Xmm10),
 401   context_offset (Xmm11),
 402   context_offset (Xmm12),
 403   context_offset (Xmm13),
 404   context_offset (Xmm14),
 405   context_offset (Xmm15),
 406   /* MXCSR */
 407   context_offset (FloatSave.MxCsr)
 408 };
 409 #undef context_offset
 410
 411 #endif /* __x86_64__ */
 412
 413 /* Fetch register from gdbserver regcache data.  */
 414 static void
 415 i386_fetch_inferior_register (struct regcache *regcache,
 416                               win32_thread_info *th, int r)
 417 {
 418   char *context_offset = (char *) &th->context + mappings[r];
 419
 420   long l;
 421   if (r == FCS_REGNUM)
 422     {
 423       l = *((long *) context_offset) & 0xffff;
 424       supply_register (regcache, r, (char *) &l);
 425     }
 426   else if (r == FOP_REGNUM)
 427     {
 428       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 429       supply_register (regcache, r, (char *) &l);
 430     }
 431   else
 432     supply_register (regcache, r, context_offset);
 433 }
 434
 435 /* Store a new register value into the thread context of TH.  */
 436 static void
 437 i386_store_inferior_register (struct regcache *regcache,
 438                               win32_thread_info *th, int r)
 439 {
 440   char *context_offset = (char *) &th->context + mappings[r];
 441   collect_register (regcache, r, context_offset);
 442 }
 443
 444 static const unsigned char i386_win32_breakpoint = 0xcc;
 445 #define i386_win32_breakpoint_len 1
 446
 447 static void
 448 i386_arch_setup (void)
 449 {
 450 #ifdef __x86_64__
 451   init_registers_amd64 ();
 452   win32_tdesc = tdesc_amd64;
 453 #else
 454   init_registers_i386 ();
 455   win32_tdesc = tdesc_i386;
 456 #endif
 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 };