gdb/i386gnu-nat.c

   1 /* Low level interface to i386 running the GNU Hurd.
   2
   3    Copyright (C) 1992, 1995, 1996, 1998, 2000, 2001, 2004, 2007, 2008
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"
  23 #include "floatformat.h"
  24 #include "regcache.h"
  25
  26 #include "gdb_assert.h"
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include "gdb_string.h"
  30
  31 #include <mach.h>
  32 #include <mach_error.h>
  33 #include <mach/message.h>
  34 #include <mach/exception.h>
  35
  36 #include "i386-tdep.h"
  37
  38 #include "gnu-nat.h"
  39 #include "i387-tdep.h"
  40
  41 #ifdef HAVE_SYS_PROCFS_H
  42 # include <sys/procfs.h>
  43 # include "gregset.h"
  44 #endif
  45
  46 /* Offset to the thread_state_t location where REG is stored.  */
  47 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  48
  49 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  50    the GDB register N is stored.  */
  51 static int reg_offset[] =
  52 {
  53   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  54   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  55   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  56   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  57 };
  58
  59 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  60 #define CREG_ADDR(state, regnum) ((const char *)(state) + reg_offset[regnum])
  61
  62 \f
  63 /* Get the whole floating-point state of THREAD and record the values
  64    of the corresponding (pseudo) registers.  */
  65
  66 static void
  67 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  68 {
  69   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  70   struct i386_float_state state;
  71   error_t err;
  72
  73   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  74                           (thread_state_t) &state, &count);
  75   if (err)
  76     {
  77       warning (_("Couldn't fetch floating-point state from %s"),
  78                proc_string (thread));
  79       return;
  80     }
  81
  82   if (!state.initialized)
  83     {
  84       /* The floating-point state isn't initialized.  */
  85       i387_supply_fsave (regcache, -1, NULL);
  86     }
  87   else
  88     {
  89       /* Supply the floating-point registers.  */
  90       i387_supply_fsave (regcache, -1, state.hw_state);
  91     }
  92 }
  93
  94 #ifdef HAVE_SYS_PROCFS_H
  95 /* These two calls are used by the core-regset.c code for
  96    reading ELF core files.  */
  97 void
  98 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
  99 {
 100   int i;
 101   for (i = 0; i < I386_NUM_GREGS; i++)
 102     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 103 }
 104
 105 void
 106 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 107 {
 108   i387_supply_fsave (regcache, -1, fpregs);
 109 }
 110 #endif
 111
 112 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 113 void
 114 gnu_fetch_registers (struct regcache *regcache, int regno)
 115 {
 116   struct proc *thread;
 117
 118   /* Make sure we know about new threads.  */
 119   inf_update_procs (current_inferior);
 120
 121   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
 122   if (!thread)
 123     error (_("Can't fetch registers from thread %d: No such thread"),
 124            PIDGET (inferior_ptid));
 125
 126   if (regno < I386_NUM_GREGS || regno == -1)
 127     {
 128       thread_state_t state;
 129
 130       /* This does the dirty work for us.  */
 131       state = proc_get_state (thread, 0);
 132       if (!state)
 133         {
 134           warning (_("Couldn't fetch registers from %s"),
 135                    proc_string (thread));
 136           return;
 137         }
 138
 139       if (regno == -1)
 140         {
 141           int i;
 142
 143           proc_debug (thread, "fetching all register");
 144
 145           for (i = 0; i < I386_NUM_GREGS; i++)
 146             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 147           thread->fetched_regs = ~0;
 148         }
 149       else
 150         {
 151           proc_debug (thread, "fetching register %s",
 152                       gdbarch_register_name (get_regcache_arch (regcache),
 153                                              regno));
 154
 155           regcache_raw_supply (regcache, regno,
 156                                REG_ADDR (state, regno));
 157           thread->fetched_regs |= (1 << regno);
 158         }
 159     }
 160
 161   if (regno >= I386_NUM_GREGS || regno == -1)
 162     {
 163       proc_debug (thread, "fetching floating-point registers");
 164
 165       fetch_fpregs (regcache, thread);
 166     }
 167 }
 168 \f
 169
 170 /* Store the whole floating-point state into THREAD using information
 171    from the corresponding (pseudo) registers.  */
 172 static void
 173 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 174 {
 175   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 176   struct i386_float_state state;
 177   error_t err;
 178
 179   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 180                           (thread_state_t) &state, &count);
 181   if (err)
 182     {
 183       warning (_("Couldn't fetch floating-point state from %s"),
 184                proc_string (thread));
 185       return;
 186     }
 187
 188   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 189      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 190   i387_collect_fsave (regcache, regno, state.hw_state);
 191
 192   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 193                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 194   if (err)
 195     {
 196       warning (_("Couldn't store floating-point state into %s"),
 197                proc_string (thread));
 198       return;
 199     }
 200 }
 201
 202 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 203 void
 204 gnu_store_registers (struct regcache *regcache, int regno)
 205 {
 206   struct proc *thread;
 207   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 208
 209   /* Make sure we know about new threads.  */
 210   inf_update_procs (current_inferior);
 211
 212   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
 213   if (!thread)
 214     error (_("Couldn't store registers into thread %d: No such thread"),
 215            PIDGET (inferior_ptid));
 216
 217   if (regno < I386_NUM_GREGS || regno == -1)
 218     {
 219       thread_state_t state;
 220       thread_state_data_t old_state;
 221       int was_aborted = thread->aborted;
 222       int was_valid = thread->state_valid;
 223       int trace;
 224
 225       if (!was_aborted && was_valid)
 226         memcpy (&old_state, &thread->state, sizeof (old_state));
 227
 228       state = proc_get_state (thread, 1);
 229       if (!state)
 230         {
 231           warning (_("Couldn't store registers into %s"), proc_string (thread));
 232           return;
 233         }
 234
 235       /* Save the T bit.  We might try to restore the %eflags register
 236          below, but changing the T bit would seriously confuse GDB.  */
 237       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 238
 239       if (!was_aborted && was_valid)
 240         /* See which registers have changed after aborting the thread.  */
 241         {
 242           int check_regno;
 243
 244           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 245             if ((thread->fetched_regs & (1 << check_regno))
 246                 && memcpy (REG_ADDR (&old_state, check_regno),
 247                            REG_ADDR (state, check_regno),
 248                            register_size (gdbarch, check_regno)))
 249               /* Register CHECK_REGNO has changed!  Ack!  */
 250               {
 251                 warning (_("Register %s changed after the thread was aborted"),
 252                          gdbarch_register_name (gdbarch, check_regno));
 253                 if (regno >= 0 && regno != check_regno)
 254                   /* Update GDB's copy of the register.  */
 255                   regcache_raw_supply (regcache, check_regno,
 256                                        REG_ADDR (state, check_regno));
 257                 else
 258                   warning (_("... also writing this register!  Suspicious..."));
 259               }
 260         }
 261
 262       if (regno == -1)
 263         {
 264           int i;
 265
 266           proc_debug (thread, "storing all registers");
 267
 268           for (i = 0; i < I386_NUM_GREGS; i++)
 269             if (regcache_valid_p (regcache, i))
 270               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 271         }
 272       else
 273         {
 274           proc_debug (thread, "storing register %s",
 275                       gdbarch_register_name (gdbarch, regno));
 276
 277           gdb_assert (regcache_valid_p (regcache, regno));
 278           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 279         }
 280
 281       /* Restore the T bit.  */
 282       ((struct i386_thread_state *)state)->efl &= ~0x100;
 283       ((struct i386_thread_state *)state)->efl |= trace;
 284     }
 285
 286   if (regno >= I386_NUM_GREGS || regno == -1)
 287     {
 288       proc_debug (thread, "storing floating-point registers");
 289
 290       store_fpregs (regcache, thread, regno);
 291     }
 292 }