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 "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 <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 /* Offset to the greg_t location where REG is stored.  */
  59 #define CREG_OFFSET(reg) (REG_##reg * 4)
  60
  61 /* At CREG_OFFSET[N] is the offset to the greg_t location where
  62    the GDB register N is stored.  */
  63 static int creg_offset[] =
  64 {
  65   CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
  66   CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
  67   CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
  68   CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
  69 };
  70
  71 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  72 #define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
  73
  74 \f
  75 /* Get the whole floating-point state of THREAD and record the values
  76    of the corresponding (pseudo) registers.  */
  77
  78 static void
  79 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  80 {
  81   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  82   struct i386_float_state state;
  83   error_t err;
  84
  85   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  86                           (thread_state_t) &state, &count);
  87   if (err)
  88     {
  89       warning (_("Couldn't fetch floating-point state from %s"),
  90                proc_string (thread));
  91       return;
  92     }
  93
  94   if (!state.initialized)
  95     {
  96       /* The floating-point state isn't initialized.  */
  97       i387_supply_fsave (regcache, -1, NULL);
  98     }
  99   else
 100     {
 101       /* Supply the floating-point registers.  */
 102       i387_supply_fsave (regcache, -1, state.hw_state);
 103     }
 104 }
 105
 106 #ifdef HAVE_SYS_PROCFS_H
 107 /* These two calls are used by the core-regset.c code for
 108    reading ELF core files.  */
 109 void
 110 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
 111 {
 112   int i;
 113   for (i = 0; i < I386_NUM_GREGS; i++)
 114     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 115 }
 116
 117 void
 118 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 119 {
 120   i387_supply_fsave (regcache, -1, fpregs);
 121 }
 122 #endif
 123
 124 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 125 static void
 126 gnu_fetch_registers (struct target_ops *ops,
 127                      struct regcache *regcache, int regno)
 128 {
 129   struct proc *thread;
 130
 131   /* Make sure we know about new threads.  */
 132   inf_update_procs (gnu_current_inf);
 133
 134   thread = inf_tid_to_thread (gnu_current_inf,
 135                               ptid_get_lwp (inferior_ptid));
 136   if (!thread)
 137     error (_("Can't fetch registers from thread %s: No such thread"),
 138            target_pid_to_str (inferior_ptid));
 139
 140   if (regno < I386_NUM_GREGS || regno == -1)
 141     {
 142       thread_state_t state;
 143
 144       /* This does the dirty work for us.  */
 145       state = proc_get_state (thread, 0);
 146       if (!state)
 147         {
 148           warning (_("Couldn't fetch registers from %s"),
 149                    proc_string (thread));
 150           return;
 151         }
 152
 153       if (regno == -1)
 154         {
 155           int i;
 156
 157           proc_debug (thread, "fetching all register");
 158
 159           for (i = 0; i < I386_NUM_GREGS; i++)
 160             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 161           thread->fetched_regs = ~0;
 162         }
 163       else
 164         {
 165           proc_debug (thread, "fetching register %s",
 166                       gdbarch_register_name (get_regcache_arch (regcache),
 167                                              regno));
 168
 169           regcache_raw_supply (regcache, regno,
 170                                REG_ADDR (state, regno));
 171           thread->fetched_regs |= (1 << regno);
 172         }
 173     }
 174
 175   if (regno >= I386_NUM_GREGS || regno == -1)
 176     {
 177       proc_debug (thread, "fetching floating-point registers");
 178
 179       fetch_fpregs (regcache, thread);
 180     }
 181 }
 182 \f
 183
 184 /* Store the whole floating-point state into THREAD using information
 185    from the corresponding (pseudo) registers.  */
 186 static void
 187 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 188 {
 189   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 190   struct i386_float_state state;
 191   error_t err;
 192
 193   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 194                           (thread_state_t) &state, &count);
 195   if (err)
 196     {
 197       warning (_("Couldn't fetch floating-point state from %s"),
 198                proc_string (thread));
 199       return;
 200     }
 201
 202   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 203      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 204   i387_collect_fsave (regcache, regno, state.hw_state);
 205
 206   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 207                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 208   if (err)
 209     {
 210       warning (_("Couldn't store floating-point state into %s"),
 211                proc_string (thread));
 212       return;
 213     }
 214 }
 215
 216 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 217 static void
 218 gnu_store_registers (struct target_ops *ops,
 219                      struct regcache *regcache, int regno)
 220 {
 221   struct proc *thread;
 222   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 223
 224   /* Make sure we know about new threads.  */
 225   inf_update_procs (gnu_current_inf);
 226
 227   thread = inf_tid_to_thread (gnu_current_inf,
 228                               ptid_get_lwp (inferior_ptid));
 229   if (!thread)
 230     error (_("Couldn't store registers into thread %s: No such thread"),
 231            target_pid_to_str (inferior_ptid));
 232
 233   if (regno < I386_NUM_GREGS || regno == -1)
 234     {
 235       thread_state_t state;
 236       thread_state_data_t old_state;
 237       int was_aborted = thread->aborted;
 238       int was_valid = thread->state_valid;
 239       int trace;
 240
 241       if (!was_aborted && was_valid)
 242         memcpy (&old_state, &thread->state, sizeof (old_state));
 243
 244       state = proc_get_state (thread, 1);
 245       if (!state)
 246         {
 247           warning (_("Couldn't store registers into %s"),
 248                    proc_string (thread));
 249           return;
 250         }
 251
 252       /* Save the T bit.  We might try to restore the %eflags register
 253          below, but changing the T bit would seriously confuse GDB.  */
 254       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 255
 256       if (!was_aborted && was_valid)
 257         /* See which registers have changed after aborting the thread.  */
 258         {
 259           int check_regno;
 260
 261           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 262             if ((thread->fetched_regs & (1 << check_regno))
 263                 && memcpy (REG_ADDR (&old_state, check_regno),
 264                            REG_ADDR (state, check_regno),
 265                            register_size (gdbarch, check_regno)))
 266               /* Register CHECK_REGNO has changed!  Ack!  */
 267               {
 268                 warning (_("Register %s changed after the thread was aborted"),
 269                          gdbarch_register_name (gdbarch, check_regno));
 270                 if (regno >= 0 && regno != check_regno)
 271                   /* Update GDB's copy of the register.  */
 272                   regcache_raw_supply (regcache, check_regno,
 273                                        REG_ADDR (state, check_regno));
 274                 else
 275                   warning (_("... also writing this register!  "
 276                              "Suspicious..."));
 277               }
 278         }
 279
 280       if (regno == -1)
 281         {
 282           int i;
 283
 284           proc_debug (thread, "storing all registers");
 285
 286           for (i = 0; i < I386_NUM_GREGS; i++)
 287             if (REG_VALID == regcache_register_status (regcache, i))
 288               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 289         }
 290       else
 291         {
 292           proc_debug (thread, "storing register %s",
 293                       gdbarch_register_name (gdbarch, regno));
 294
 295           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 296           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 297         }
 298
 299       /* Restore the T bit.  */
 300       ((struct i386_thread_state *)state)->efl &= ~0x100;
 301       ((struct i386_thread_state *)state)->efl |= trace;
 302     }
 303
 304   if (regno >= I386_NUM_GREGS || regno == -1)
 305     {
 306       proc_debug (thread, "storing floating-point registers");
 307
 308       store_fpregs (regcache, thread, regno);
 309     }
 310 }
 311
 312 /* Provide a prototype to silence -Wmissing-prototypes.  */
 313 extern initialize_file_ftype _initialize_i386gnu_nat;
 314
 315 void
 316 _initialize_i386gnu_nat (void)
 317 {
 318   struct target_ops *t;
 319
 320   /* Fill in the generic GNU/Hurd methods.  */
 321   t = gnu_target ();
 322
 323   t->to_fetch_registers = gnu_fetch_registers;
 324   t->to_store_registers = gnu_store_registers;
 325
 326   /* Register the target.  */
 327   add_target (t);
 328 }