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
   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 2 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, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "defs.h"
  24 #include "inferior.h"
  25 #include "floatformat.h"
  26 #include "regcache.h"
  27
  28 #include "gdb_assert.h"
  29 #include <errno.h>
  30 #include <stdio.h>
  31 #include "gdb_string.h"
  32
  33 #include <mach.h>
  34 #include <mach_error.h>
  35 #include <mach/message.h>
  36 #include <mach/exception.h>
  37
  38 #include "i386-tdep.h"
  39
  40 #include "gnu-nat.h"
  41 #include "i387-tdep.h"
  42
  43 #ifdef HAVE_SYS_PROCFS_H
  44 # include <sys/procfs.h>
  45 # include "gregset.h"
  46 #endif
  47
  48 /* Offset to the thread_state_t location where REG is stored.  */
  49 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  50
  51 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  52    the GDB register N is stored.  */
  53 static int reg_offset[] =
  54 {
  55   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  56   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  57   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  58   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  59 };
  60
  61 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  62
  63 \f
  64 /* Get the whole floating-point state of THREAD and record the values
  65    of the corresponding (pseudo) registers.  */
  66
  67 static void
  68 fetch_fpregs (struct proc *thread)
  69 {
  70   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  71   struct i386_float_state state;
  72   error_t err;
  73
  74   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  75                           (thread_state_t) &state, &count);
  76   if (err)
  77     {
  78       warning (_("Couldn't fetch floating-point state from %s"),
  79                proc_string (thread));
  80       return;
  81     }
  82
  83   if (!state.initialized)
  84     {
  85       /* The floating-point state isn't initialized.  */
  86       i387_supply_fsave (current_regcache, -1, NULL);
  87     }
  88   else
  89     {
  90       /* Supply the floating-point registers.  */
  91       i387_supply_fsave (current_regcache, -1, state.hw_state);
  92     }
  93 }
  94
  95 #ifdef HAVE_SYS_PROCFS_H
  96 /* These two calls are used by the core-regset.c code for
  97    reading ELF core files.  */
  98 void
  99 supply_gregset (gdb_gregset_t *gregs)
 100 {
 101   int i;
 102   for (i = 0; i < I386_NUM_GREGS; i++)
 103     regcache_raw_supply (current_regcache, i, REG_ADDR (gregs, i));
 104 }
 105
 106 void
 107 supply_fpregset (gdb_fpregset_t *fpregs)
 108 {
 109   i387_supply_fsave (current_regcache, -1, fpregs);
 110 }
 111 #endif
 112
 113 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 114 void
 115 gnu_fetch_registers (int regno)
 116 {
 117   struct proc *thread;
 118
 119   /* Make sure we know about new threads.  */
 120   inf_update_procs (current_inferior);
 121
 122   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
 123   if (!thread)
 124     error (_("Can't fetch registers from thread %d: No such thread"),
 125            PIDGET (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 (current_regcache, i, REG_ADDR (state, i));
 148           thread->fetched_regs = ~0;
 149         }
 150       else
 151         {
 152           proc_debug (thread, "fetching register %s", REGISTER_NAME (regno));
 153
 154           regcache_raw_supply (current_regcache, regno,
 155                                REG_ADDR (state, regno));
 156           thread->fetched_regs |= (1 << regno);
 157         }
 158     }
 159
 160   if (regno >= I386_NUM_GREGS || regno == -1)
 161     {
 162       proc_debug (thread, "fetching floating-point registers");
 163
 164       fetch_fpregs (thread);
 165     }
 166 }
 167 \f
 168
 169 /* Store the whole floating-point state into THREAD using information
 170    from the corresponding (pseudo) registers.  */
 171 static void
 172 store_fpregs (struct proc *thread, int regno)
 173 {
 174   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 175   struct i386_float_state state;
 176   error_t err;
 177
 178   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 179                           (thread_state_t) &state, &count);
 180   if (err)
 181     {
 182       warning (_("Couldn't fetch floating-point state from %s"),
 183                proc_string (thread));
 184       return;
 185     }
 186
 187   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 188      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 189   i387_fill_fsave (state.hw_state, regno);
 190
 191   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 192                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 193   if (err)
 194     {
 195       warning (_("Couldn't store floating-point state into %s"),
 196                proc_string (thread));
 197       return;
 198     }
 199 }
 200
 201 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 202 void
 203 gnu_store_registers (int regno)
 204 {
 205   struct regcache *regcache = current_regcache;
 206   struct proc *thread;
 207
 208   /* Make sure we know about new threads.  */
 209   inf_update_procs (current_inferior);
 210
 211   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
 212   if (!thread)
 213     error (_("Couldn't store registers into thread %d: No such thread"),
 214            PIDGET (inferior_ptid));
 215
 216   if (regno < I386_NUM_GREGS || regno == -1)
 217     {
 218       thread_state_t state;
 219       thread_state_data_t old_state;
 220       int was_aborted = thread->aborted;
 221       int was_valid = thread->state_valid;
 222       int trace;
 223
 224       if (!was_aborted && was_valid)
 225         memcpy (&old_state, &thread->state, sizeof (old_state));
 226
 227       state = proc_get_state (thread, 1);
 228       if (!state)
 229         {
 230           warning (_("Couldn't store registers into %s"), proc_string (thread));
 231           return;
 232         }
 233
 234       /* Save the T bit.  We might try to restore the %eflags register
 235          below, but changing the T bit would seriously confuse GDB.  */
 236       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 237
 238       if (!was_aborted && was_valid)
 239         /* See which registers have changed after aborting the thread.  */
 240         {
 241           int check_regno;
 242
 243           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 244             if ((thread->fetched_regs & (1 << check_regno))
 245                 && memcpy (REG_ADDR (&old_state, check_regno),
 246                            REG_ADDR (state, check_regno),
 247                            register_size (current_gdbarch, check_regno)))
 248               /* Register CHECK_REGNO has changed!  Ack!  */
 249               {
 250                 warning (_("Register %s changed after the thread was aborted"),
 251                          REGISTER_NAME (check_regno));
 252                 if (regno >= 0 && regno != check_regno)
 253                   /* Update GDB's copy of the register.  */
 254                   regcache_raw_supply (regcache, check_regno,
 255                                        REG_ADDR (state, check_regno));
 256                 else
 257                   warning (_("... also writing this register!  Suspicious..."));
 258               }
 259         }
 260
 261       if (regno == -1)
 262         {
 263           int i;
 264
 265           proc_debug (thread, "storing all registers");
 266
 267           for (i = 0; i < I386_NUM_GREGS; i++)
 268             if (regcache_valid_p (regcache, i))
 269               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 270         }
 271       else
 272         {
 273           proc_debug (thread, "storing register %s", REGISTER_NAME (regno));
 274
 275           gdb_assert (regcache_valid_p (regcache, regno));
 276           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 277         }
 278
 279       /* Restore the T bit.  */
 280       ((struct i386_thread_state *)state)->efl &= ~0x100;
 281       ((struct i386_thread_state *)state)->efl |= trace;
 282     }
 283
 284   if (regno >= I386_NUM_GREGS || regno == -1)
 285     {
 286       proc_debug (thread, "storing floating-point registers");
 287
 288       store_fpregs (thread, regno);
 289     }
 290 }