gdb/i386gnu-nat.c

   1 /* Low level interface to i386 running the GNU Hurd.
   2
   3    Copyright (C) 1992-2013 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 "inferior.h"
  22 #include "floatformat.h"
  23 #include "regcache.h"
  24
  25 #include "gdb_assert.h"
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include "gdb_string.h"
  29
  30 #include <mach.h>
  31 #include <mach_error.h>
  32 #include <mach/message.h>
  33 #include <mach/exception.h>
  34
  35 #include "i386-tdep.h"
  36
  37 #include "gnu-nat.h"
  38 #include "i387-tdep.h"
  39
  40 #ifdef HAVE_SYS_PROCFS_H
  41 # include <sys/procfs.h>
  42 # include "gregset.h"
  43 #endif
  44
  45 /* Offset to the thread_state_t location where REG is stored.  */
  46 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  47
  48 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  49    the GDB register N is stored.  */
  50 static int reg_offset[] =
  51 {
  52   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  53   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  54   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  55   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  56 };
  57
  58 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  59 #define CREG_ADDR(state, regnum) ((const char *)(state) + reg_offset[regnum])
  60
  61 \f
  62 /* Get the whole floating-point state of THREAD and record the values
  63    of the corresponding (pseudo) registers.  */
  64
  65 static void
  66 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  67 {
  68   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  69   struct i386_float_state state;
  70   error_t err;
  71
  72   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  73                           (thread_state_t) &state, &count);
  74   if (err)
  75     {
  76       warning (_("Couldn't fetch floating-point state from %s"),
  77                proc_string (thread));
  78       return;
  79     }
  80
  81   if (!state.initialized)
  82     {
  83       /* The floating-point state isn't initialized.  */
  84       i387_supply_fsave (regcache, -1, NULL);
  85     }
  86   else
  87     {
  88       /* Supply the floating-point registers.  */
  89       i387_supply_fsave (regcache, -1, state.hw_state);
  90     }
  91 }
  92
  93 #ifdef HAVE_SYS_PROCFS_H
  94 /* These two calls are used by the core-regset.c code for
  95    reading ELF core files.  */
  96 void
  97 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
  98 {
  99   int i;
 100   for (i = 0; i < I386_NUM_GREGS; i++)
 101     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 102 }
 103
 104 void
 105 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 106 {
 107   i387_supply_fsave (regcache, -1, fpregs);
 108 }
 109 #endif
 110
 111 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 112 static void
 113 gnu_fetch_registers (struct target_ops *ops,
 114                      struct regcache *regcache, int regno)
 115 {
 116   struct proc *thread;
 117
 118   /* Make sure we know about new threads.  */
 119   inf_update_procs (gnu_current_inf);
 120
 121   thread = inf_tid_to_thread (gnu_current_inf,
 122                               ptid_get_tid (inferior_ptid));
 123   if (!thread)
 124     error (_("Can't fetch registers from thread %s: No such thread"),
 125            target_pid_to_str (inferior_ptid));
 126
 127   if (regno < I386_NUM_GREGS || regno == -1)
 128     {
 129       thread_state_t state;
 130
 131       /* This does the dirty work for us.  */
 132       state = proc_get_state (thread, 0);
 133       if (!state)
 134         {
 135           warning (_("Couldn't fetch registers from %s"),
 136                    proc_string (thread));
 137           return;
 138         }
 139
 140       if (regno == -1)
 141         {
 142           int i;
 143
 144           proc_debug (thread, "fetching all register");
 145
 146           for (i = 0; i < I386_NUM_GREGS; i++)
 147             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 148           thread->fetched_regs = ~0;
 149         }
 150       else
 151         {
 152           proc_debug (thread, "fetching register %s",
 153                       gdbarch_register_name (get_regcache_arch (regcache),
 154                                              regno));
 155
 156           regcache_raw_supply (regcache, regno,
 157                                REG_ADDR (state, regno));
 158           thread->fetched_regs |= (1 << regno);
 159         }
 160     }
 161
 162   if (regno >= I386_NUM_GREGS || regno == -1)
 163     {
 164       proc_debug (thread, "fetching floating-point registers");
 165
 166       fetch_fpregs (regcache, thread);
 167     }
 168 }
 169 \f
 170
 171 /* Store the whole floating-point state into THREAD using information
 172    from the corresponding (pseudo) registers.  */
 173 static void
 174 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 175 {
 176   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 177   struct i386_float_state state;
 178   error_t err;
 179
 180   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 181                           (thread_state_t) &state, &count);
 182   if (err)
 183     {
 184       warning (_("Couldn't fetch floating-point state from %s"),
 185                proc_string (thread));
 186       return;
 187     }
 188
 189   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 190      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 191   i387_collect_fsave (regcache, regno, state.hw_state);
 192
 193   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 194                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 195   if (err)
 196     {
 197       warning (_("Couldn't store floating-point state into %s"),
 198                proc_string (thread));
 199       return;
 200     }
 201 }
 202
 203 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 204 static void
 205 gnu_store_registers (struct target_ops *ops,
 206                      struct regcache *regcache, int regno)
 207 {
 208   struct proc *thread;
 209   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 210
 211   /* Make sure we know about new threads.  */
 212   inf_update_procs (gnu_current_inf);
 213
 214   thread = inf_tid_to_thread (gnu_current_inf,
 215                               ptid_get_tid (inferior_ptid));
 216   if (!thread)
 217     error (_("Couldn't store registers into thread %s: No such thread"),
 218            target_pid_to_str (inferior_ptid));
 219
 220   if (regno < I386_NUM_GREGS || regno == -1)
 221     {
 222       thread_state_t state;
 223       thread_state_data_t old_state;
 224       int was_aborted = thread->aborted;
 225       int was_valid = thread->state_valid;
 226       int trace;
 227
 228       if (!was_aborted && was_valid)
 229         memcpy (&old_state, &thread->state, sizeof (old_state));
 230
 231       state = proc_get_state (thread, 1);
 232       if (!state)
 233         {
 234           warning (_("Couldn't store registers into %s"),
 235                    proc_string (thread));
 236           return;
 237         }
 238
 239       /* Save the T bit.  We might try to restore the %eflags register
 240          below, but changing the T bit would seriously confuse GDB.  */
 241       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 242
 243       if (!was_aborted && was_valid)
 244         /* See which registers have changed after aborting the thread.  */
 245         {
 246           int check_regno;
 247
 248           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 249             if ((thread->fetched_regs & (1 << check_regno))
 250                 && memcpy (REG_ADDR (&old_state, check_regno),
 251                            REG_ADDR (state, check_regno),
 252                            register_size (gdbarch, check_regno)))
 253               /* Register CHECK_REGNO has changed!  Ack!  */
 254               {
 255                 warning (_("Register %s changed after the thread was aborted"),
 256                          gdbarch_register_name (gdbarch, check_regno));
 257                 if (regno >= 0 && regno != check_regno)
 258                   /* Update GDB's copy of the register.  */
 259                   regcache_raw_supply (regcache, check_regno,
 260                                        REG_ADDR (state, check_regno));
 261                 else
 262                   warning (_("... also writing this register!  "
 263                              "Suspicious..."));
 264               }
 265         }
 266
 267       if (regno == -1)
 268         {
 269           int i;
 270
 271           proc_debug (thread, "storing all registers");
 272
 273           for (i = 0; i < I386_NUM_GREGS; i++)
 274             if (REG_VALID == regcache_register_status (regcache, i))
 275               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 276         }
 277       else
 278         {
 279           proc_debug (thread, "storing register %s",
 280                       gdbarch_register_name (gdbarch, regno));
 281
 282           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 283           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 284         }
 285
 286       /* Restore the T bit.  */
 287       ((struct i386_thread_state *)state)->efl &= ~0x100;
 288       ((struct i386_thread_state *)state)->efl |= trace;
 289     }
 290
 291   if (regno >= I386_NUM_GREGS || regno == -1)
 292     {
 293       proc_debug (thread, "storing floating-point registers");
 294
 295       store_fpregs (regcache, thread, regno);
 296     }
 297 }
 298
 299 /* Provide a prototype to silence -Wmissing-prototypes.  */
 300 extern initialize_file_ftype _initialize_i386gnu_nat;
 301
 302 void
 303 _initialize_i386gnu_nat (void)
 304 {
 305   struct target_ops *t;
 306
 307   /* Fill in the generic GNU/Hurd methods.  */
 308   t = gnu_target ();
 309
 310   t->to_fetch_registers = gnu_fetch_registers;
 311   t->to_store_registers = gnu_store_registers;
 312
 313   /* Register the target.  */
 314   add_target (t);
 315 }