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, 2009,
   4    2010 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 static void
 114 gnu_fetch_registers (struct target_ops *ops,
 115                      struct regcache *regcache, int regno)
 116 {
 117   struct proc *thread;
 118
 119   /* Make sure we know about new threads.  */
 120   inf_update_procs (gnu_current_inf);
 121
 122   thread = inf_tid_to_thread (gnu_current_inf,
 123                               ptid_get_tid (inferior_ptid));
 124   if (!thread)
 125     error (_("Can't fetch registers from thread %s: No such thread"),
 126            target_pid_to_str (inferior_ptid));
 127
 128   if (regno < I386_NUM_GREGS || regno == -1)
 129     {
 130       thread_state_t state;
 131
 132       /* This does the dirty work for us.  */
 133       state = proc_get_state (thread, 0);
 134       if (!state)
 135         {
 136           warning (_("Couldn't fetch registers from %s"),
 137                    proc_string (thread));
 138           return;
 139         }
 140
 141       if (regno == -1)
 142         {
 143           int i;
 144
 145           proc_debug (thread, "fetching all register");
 146
 147           for (i = 0; i < I386_NUM_GREGS; i++)
 148             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 149           thread->fetched_regs = ~0;
 150         }
 151       else
 152         {
 153           proc_debug (thread, "fetching register %s",
 154                       gdbarch_register_name (get_regcache_arch (regcache),
 155                                              regno));
 156
 157           regcache_raw_supply (regcache, regno,
 158                                REG_ADDR (state, regno));
 159           thread->fetched_regs |= (1 << regno);
 160         }
 161     }
 162
 163   if (regno >= I386_NUM_GREGS || regno == -1)
 164     {
 165       proc_debug (thread, "fetching floating-point registers");
 166
 167       fetch_fpregs (regcache, thread);
 168     }
 169 }
 170 \f
 171
 172 /* Store the whole floating-point state into THREAD using information
 173    from the corresponding (pseudo) registers.  */
 174 static void
 175 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 176 {
 177   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 178   struct i386_float_state state;
 179   error_t err;
 180
 181   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 182                           (thread_state_t) &state, &count);
 183   if (err)
 184     {
 185       warning (_("Couldn't fetch floating-point state from %s"),
 186                proc_string (thread));
 187       return;
 188     }
 189
 190   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 191      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 192   i387_collect_fsave (regcache, regno, state.hw_state);
 193
 194   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 195                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 196   if (err)
 197     {
 198       warning (_("Couldn't store floating-point state into %s"),
 199                proc_string (thread));
 200       return;
 201     }
 202 }
 203
 204 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 205 static void
 206 gnu_store_registers (struct target_ops *ops,
 207                      struct regcache *regcache, int regno)
 208 {
 209   struct proc *thread;
 210   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 211
 212   /* Make sure we know about new threads.  */
 213   inf_update_procs (gnu_current_inf);
 214
 215   thread = inf_tid_to_thread (gnu_current_inf,
 216                               ptid_get_tid (inferior_ptid));
 217   if (!thread)
 218     error (_("Couldn't store registers into thread %s: No such thread"),
 219            target_pid_to_str (inferior_ptid));
 220
 221   if (regno < I386_NUM_GREGS || regno == -1)
 222     {
 223       thread_state_t state;
 224       thread_state_data_t old_state;
 225       int was_aborted = thread->aborted;
 226       int was_valid = thread->state_valid;
 227       int trace;
 228
 229       if (!was_aborted && was_valid)
 230         memcpy (&old_state, &thread->state, sizeof (old_state));
 231
 232       state = proc_get_state (thread, 1);
 233       if (!state)
 234         {
 235           warning (_("Couldn't store registers into %s"), 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!  Suspicious..."));
 263               }
 264         }
 265
 266       if (regno == -1)
 267         {
 268           int i;
 269
 270           proc_debug (thread, "storing all registers");
 271
 272           for (i = 0; i < I386_NUM_GREGS; i++)
 273             if (regcache_valid_p (regcache, i))
 274               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 275         }
 276       else
 277         {
 278           proc_debug (thread, "storing register %s",
 279                       gdbarch_register_name (gdbarch, regno));
 280
 281           gdb_assert (regcache_valid_p (regcache, regno));
 282           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 283         }
 284
 285       /* Restore the T bit.  */
 286       ((struct i386_thread_state *)state)->efl &= ~0x100;
 287       ((struct i386_thread_state *)state)->efl |= trace;
 288     }
 289
 290   if (regno >= I386_NUM_GREGS || regno == -1)
 291     {
 292       proc_debug (thread, "storing floating-point registers");
 293
 294       store_fpregs (regcache, thread, regno);
 295     }
 296 }
 297
 298 /* Provide a prototype to silence -Wmissing-prototypes.  */
 299 extern initialize_file_ftype _initialize_i386gnu_nat;
 300
 301 void
 302 _initialize_i386gnu_nat (void)
 303 {
 304   struct target_ops *t;
 305
 306   /* Fill in the generic GNU/Hurd methods.  */
 307   t = gnu_target ();
 308
 309   t->to_fetch_registers = gnu_fetch_registers;
 310   t->to_store_registers = gnu_store_registers;
 311
 312   /* Register the target.  */
 313   add_target (t);
 314 }