gdb/i386gnu-nat.c

   1 /* Low level interface to i386 running the GNU Hurd.
   2
   3    Copyright (C) 1992-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "x86-nat.h"
  22 #include "inferior.h"
  23 #include "floatformat.h"
  24 #include "regcache.h"
  25
  26 #include <mach.h>
  27 #include <mach_error.h>
  28 #include <mach/message.h>
  29 #include <mach/exception.h>
  30
  31 #include "i386-tdep.h"
  32
  33 #include "gnu-nat.h"
  34 #include "inf-child.h"
  35 #include "i387-tdep.h"
  36
  37 #ifdef HAVE_SYS_PROCFS_H
  38 # include <sys/procfs.h>
  39 # include "gregset.h"
  40 #endif
  41
  42 /* Offset to the thread_state_t location where REG is stored.  */
  43 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  44
  45 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  46    the GDB register N is stored.  */
  47 static int reg_offset[] =
  48 {
  49   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  50   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  51   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  52   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  53 };
  54
  55 /* Offset to the greg_t location where REG is stored.  */
  56 #define CREG_OFFSET(reg) (REG_##reg * 4)
  57
  58 /* At CREG_OFFSET[N] is the offset to the greg_t location where
  59    the GDB register N is stored.  */
  60 static int creg_offset[] =
  61 {
  62   CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
  63   CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
  64   CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
  65   CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
  66 };
  67
  68 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  69 #define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
  70
  71 \f
  72 /* Get the whole floating-point state of THREAD and record the values
  73    of the corresponding (pseudo) registers.  */
  74
  75 static void
  76 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  77 {
  78   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  79   struct i386_float_state state;
  80   error_t err;
  81
  82   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  83                           (thread_state_t) &state, &count);
  84   if (err)
  85     {
  86       warning (_("Couldn't fetch floating-point state from %s"),
  87                proc_string (thread));
  88       return;
  89     }
  90
  91   if (!state.initialized)
  92     {
  93       /* The floating-point state isn't initialized.  */
  94       i387_supply_fsave (regcache, -1, NULL);
  95     }
  96   else
  97     {
  98       /* Supply the floating-point registers.  */
  99       i387_supply_fsave (regcache, -1, state.hw_state);
 100     }
 101 }
 102
 103 #ifdef HAVE_SYS_PROCFS_H
 104 /* These two calls are used by the core-regset.c code for
 105    reading ELF core files.  */
 106 void
 107 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
 108 {
 109   int i;
 110   for (i = 0; i < I386_NUM_GREGS; i++)
 111     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 112 }
 113
 114 void
 115 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 116 {
 117   i387_supply_fsave (regcache, -1, fpregs);
 118 }
 119 #endif
 120
 121 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 122 static void
 123 gnu_fetch_registers (struct target_ops *ops,
 124                      struct regcache *regcache, int regno)
 125 {
 126   struct proc *thread;
 127
 128   /* Make sure we know about new threads.  */
 129   inf_update_procs (gnu_current_inf);
 130
 131   thread = inf_tid_to_thread (gnu_current_inf,
 132                               ptid_get_lwp (inferior_ptid));
 133   if (!thread)
 134     error (_("Can't fetch registers from thread %s: No such thread"),
 135            target_pid_to_str (inferior_ptid));
 136
 137   if (regno < I386_NUM_GREGS || regno == -1)
 138     {
 139       thread_state_t state;
 140
 141       /* This does the dirty work for us.  */
 142       state = proc_get_state (thread, 0);
 143       if (!state)
 144         {
 145           warning (_("Couldn't fetch registers from %s"),
 146                    proc_string (thread));
 147           return;
 148         }
 149
 150       if (regno == -1)
 151         {
 152           int i;
 153
 154           proc_debug (thread, "fetching all register");
 155
 156           for (i = 0; i < I386_NUM_GREGS; i++)
 157             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 158           thread->fetched_regs = ~0;
 159         }
 160       else
 161         {
 162           proc_debug (thread, "fetching register %s",
 163                       gdbarch_register_name (get_regcache_arch (regcache),
 164                                              regno));
 165
 166           regcache_raw_supply (regcache, regno,
 167                                REG_ADDR (state, regno));
 168           thread->fetched_regs |= (1 << regno);
 169         }
 170     }
 171
 172   if (regno >= I386_NUM_GREGS || regno == -1)
 173     {
 174       proc_debug (thread, "fetching floating-point registers");
 175
 176       fetch_fpregs (regcache, thread);
 177     }
 178 }
 179 \f
 180
 181 /* Store the whole floating-point state into THREAD using information
 182    from the corresponding (pseudo) registers.  */
 183 static void
 184 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 185 {
 186   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 187   struct i386_float_state state;
 188   error_t err;
 189
 190   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 191                           (thread_state_t) &state, &count);
 192   if (err)
 193     {
 194       warning (_("Couldn't fetch floating-point state from %s"),
 195                proc_string (thread));
 196       return;
 197     }
 198
 199   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 200      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 201   i387_collect_fsave (regcache, regno, state.hw_state);
 202
 203   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 204                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 205   if (err)
 206     {
 207       warning (_("Couldn't store floating-point state into %s"),
 208                proc_string (thread));
 209       return;
 210     }
 211 }
 212
 213 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 214 static void
 215 gnu_store_registers (struct target_ops *ops,
 216                      struct regcache *regcache, int regno)
 217 {
 218   struct proc *thread;
 219   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 220
 221   /* Make sure we know about new threads.  */
 222   inf_update_procs (gnu_current_inf);
 223
 224   thread = inf_tid_to_thread (gnu_current_inf,
 225                               ptid_get_lwp (inferior_ptid));
 226   if (!thread)
 227     error (_("Couldn't store registers into thread %s: No such thread"),
 228            target_pid_to_str (inferior_ptid));
 229
 230   if (regno < I386_NUM_GREGS || regno == -1)
 231     {
 232       thread_state_t state;
 233       thread_state_data_t old_state;
 234       int was_aborted = thread->aborted;
 235       int was_valid = thread->state_valid;
 236       int trace;
 237
 238       if (!was_aborted && was_valid)
 239         memcpy (&old_state, &thread->state, sizeof (old_state));
 240
 241       state = proc_get_state (thread, 1);
 242       if (!state)
 243         {
 244           warning (_("Couldn't store registers into %s"),
 245                    proc_string (thread));
 246           return;
 247         }
 248
 249       /* Save the T bit.  We might try to restore the %eflags register
 250          below, but changing the T bit would seriously confuse GDB.  */
 251       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 252
 253       if (!was_aborted && was_valid)
 254         /* See which registers have changed after aborting the thread.  */
 255         {
 256           int check_regno;
 257
 258           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 259             if ((thread->fetched_regs & (1 << check_regno))
 260                 && memcpy (REG_ADDR (&old_state, check_regno),
 261                            REG_ADDR (state, check_regno),
 262                            register_size (gdbarch, check_regno)))
 263               /* Register CHECK_REGNO has changed!  Ack!  */
 264               {
 265                 warning (_("Register %s changed after the thread was aborted"),
 266                          gdbarch_register_name (gdbarch, check_regno));
 267                 if (regno >= 0 && regno != check_regno)
 268                   /* Update GDB's copy of the register.  */
 269                   regcache_raw_supply (regcache, check_regno,
 270                                        REG_ADDR (state, check_regno));
 271                 else
 272                   warning (_("... also writing this register!  "
 273                              "Suspicious..."));
 274               }
 275         }
 276
 277       if (regno == -1)
 278         {
 279           int i;
 280
 281           proc_debug (thread, "storing all registers");
 282
 283           for (i = 0; i < I386_NUM_GREGS; i++)
 284             if (REG_VALID == regcache_register_status (regcache, i))
 285               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 286         }
 287       else
 288         {
 289           proc_debug (thread, "storing register %s",
 290                       gdbarch_register_name (gdbarch, regno));
 291
 292           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 293           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 294         }
 295
 296       /* Restore the T bit.  */
 297       ((struct i386_thread_state *)state)->efl &= ~0x100;
 298       ((struct i386_thread_state *)state)->efl |= trace;
 299     }
 300
 301   if (regno >= I386_NUM_GREGS || regno == -1)
 302     {
 303       proc_debug (thread, "storing floating-point registers");
 304
 305       store_fpregs (regcache, thread, regno);
 306     }
 307 }
 308
 309 \f
 310 /* Support for debug registers.  */
 311
 312 #ifdef i386_DEBUG_STATE
 313 /* Get debug registers for thread THREAD.  */
 314
 315 static void
 316 i386_gnu_dr_get (struct i386_debug_state *regs, struct proc *thread)
 317 {
 318   mach_msg_type_number_t count = i386_DEBUG_STATE_COUNT;
 319   error_t err;
 320
 321   err = thread_get_state (thread->port, i386_DEBUG_STATE,
 322                           (thread_state_t) regs, &count);
 323   if (err != 0 || count != i386_DEBUG_STATE_COUNT)
 324     warning (_("Couldn't fetch debug state from %s"),
 325              proc_string (thread));
 326 }
 327
 328 /* Set debug registers for thread THREAD.  */
 329
 330 static void
 331 i386_gnu_dr_set (const struct i386_debug_state *regs, struct proc *thread)
 332 {
 333   error_t err;
 334
 335   err = thread_set_state (thread->port, i386_DEBUG_STATE,
 336                           (thread_state_t) regs, i386_DEBUG_STATE_COUNT);
 337   if (err != 0)
 338     warning (_("Couldn't store debug state into %s"),
 339              proc_string (thread));
 340 }
 341
 342 /* Set DR_CONTROL in THREAD.  */
 343
 344 static void
 345 i386_gnu_dr_set_control_one (struct proc *thread, void *arg)
 346 {
 347   unsigned long *control = arg;
 348   struct i386_debug_state regs;
 349
 350   i386_gnu_dr_get (&regs, thread);
 351   regs.dr[DR_CONTROL] = *control;
 352   i386_gnu_dr_set (&regs, thread);
 353 }
 354
 355 /* Set DR_CONTROL to CONTROL in all threads.  */
 356
 357 static void
 358 i386_gnu_dr_set_control (unsigned long control)
 359 {
 360   inf_update_procs (gnu_current_inf);
 361   inf_threads (gnu_current_inf, i386_gnu_dr_set_control_one, &control);
 362 }
 363
 364 /* Parameters to set a debugging address.  */
 365
 366 struct reg_addr
 367 {
 368   int regnum;           /* Register number (zero based).  */
 369   CORE_ADDR addr;       /* Address.  */
 370 };
 371
 372 /* Set address REGNUM (zero based) to ADDR in THREAD.  */
 373
 374 static void
 375 i386_gnu_dr_set_addr_one (struct proc *thread, void *arg)
 376 {
 377   struct reg_addr *reg_addr = arg;
 378   struct i386_debug_state regs;
 379
 380   i386_gnu_dr_get (&regs, thread);
 381   regs.dr[reg_addr->regnum] = reg_addr->addr;
 382   i386_gnu_dr_set (&regs, thread);
 383 }
 384
 385 /* Set address REGNUM (zero based) to ADDR in all threads.  */
 386
 387 static void
 388 i386_gnu_dr_set_addr (int regnum, CORE_ADDR addr)
 389 {
 390   struct reg_addr reg_addr;
 391
 392   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 393
 394   reg_addr.regnum = regnum;
 395   reg_addr.addr = addr;
 396
 397   inf_update_procs (gnu_current_inf);
 398   inf_threads (gnu_current_inf, i386_gnu_dr_set_addr_one, &reg_addr);
 399 }
 400
 401 /* Get debug register REGNUM value from only the one LWP of PTID.  */
 402
 403 static unsigned long
 404 i386_gnu_dr_get_reg (ptid_t ptid, int regnum)
 405 {
 406   struct i386_debug_state regs;
 407   struct proc *thread;
 408
 409   /* Make sure we know about new threads.  */
 410   inf_update_procs (gnu_current_inf);
 411
 412   thread = inf_tid_to_thread (gnu_current_inf, ptid_get_lwp (ptid));
 413   i386_gnu_dr_get (&regs, thread);
 414
 415   return regs.dr[regnum];
 416 }
 417
 418 /* Return the inferior's debug register REGNUM.  */
 419
 420 static CORE_ADDR
 421 i386_gnu_dr_get_addr (int regnum)
 422 {
 423   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
 424
 425   return i386_gnu_dr_get_reg (inferior_ptid, regnum);
 426 }
 427
 428 /* Get DR_STATUS from only the one thread of INFERIOR_PTID.  */
 429
 430 static unsigned long
 431 i386_gnu_dr_get_status (void)
 432 {
 433   return i386_gnu_dr_get_reg (inferior_ptid, DR_STATUS);
 434 }
 435
 436 /* Return the inferior's DR7 debug control register.  */
 437
 438 static unsigned long
 439 i386_gnu_dr_get_control (void)
 440 {
 441   return i386_gnu_dr_get_reg (inferior_ptid, DR_CONTROL);
 442 }
 443 #endif /* i386_DEBUG_STATE */
 444
 445 /* Provide a prototype to silence -Wmissing-prototypes.  */
 446 extern initialize_file_ftype _initialize_i386gnu_nat;
 447
 448 void
 449 _initialize_i386gnu_nat (void)
 450 {
 451   struct target_ops *t;
 452
 453   /* Fill in the generic GNU/Hurd methods.  */
 454   t = gnu_target ();
 455
 456 #ifdef i386_DEBUG_STATE
 457   x86_use_watchpoints (t);
 458
 459   x86_dr_low.set_control = i386_gnu_dr_set_control;
 460   gdb_assert (DR_FIRSTADDR == 0 && DR_LASTADDR < i386_DEBUG_STATE_COUNT);
 461   x86_dr_low.set_addr = i386_gnu_dr_set_addr;
 462   x86_dr_low.get_addr = i386_gnu_dr_get_addr;
 463   x86_dr_low.get_status = i386_gnu_dr_get_status;
 464   x86_dr_low.get_control = i386_gnu_dr_get_control;
 465   x86_set_debug_register_length (4);
 466 #endif /* i386_DEBUG_STATE */
 467
 468   t->to_fetch_registers = gnu_fetch_registers;
 469   t->to_store_registers = gnu_store_registers;
 470
 471   /* Register the target.  */
 472   add_target (t);
 473 }