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 <mach.h>
  26 #include <mach_error.h>
  27 #include <mach/message.h>
  28 #include <mach/exception.h>
  29
  30 #include "i386-tdep.h"
  31
  32 #include "gnu-nat.h"
  33 #include "i387-tdep.h"
  34
  35 #ifdef HAVE_SYS_PROCFS_H
  36 # include <sys/procfs.h>
  37 # include "gregset.h"
  38 #endif
  39
  40 /* Offset to the thread_state_t location where REG is stored.  */
  41 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  42
  43 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  44    the GDB register N is stored.  */
  45 static int reg_offset[] =
  46 {
  47   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  48   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  49   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  50   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  51 };
  52
  53 /* Offset to the greg_t location where REG is stored.  */
  54 #define CREG_OFFSET(reg) (REG_##reg * 4)
  55
  56 /* At CREG_OFFSET[N] is the offset to the greg_t location where
  57    the GDB register N is stored.  */
  58 static int creg_offset[] =
  59 {
  60   CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
  61   CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
  62   CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
  63   CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
  64 };
  65
  66 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  67 #define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
  68
  69 \f
  70 /* Get the whole floating-point state of THREAD and record the values
  71    of the corresponding (pseudo) registers.  */
  72
  73 static void
  74 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  75 {
  76   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  77   struct i386_float_state state;
  78   error_t err;
  79
  80   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  81                           (thread_state_t) &state, &count);
  82   if (err)
  83     {
  84       warning (_("Couldn't fetch floating-point state from %s"),
  85                proc_string (thread));
  86       return;
  87     }
  88
  89   if (!state.initialized)
  90     {
  91       /* The floating-point state isn't initialized.  */
  92       i387_supply_fsave (regcache, -1, NULL);
  93     }
  94   else
  95     {
  96       /* Supply the floating-point registers.  */
  97       i387_supply_fsave (regcache, -1, state.hw_state);
  98     }
  99 }
 100
 101 #ifdef HAVE_SYS_PROCFS_H
 102 /* These two calls are used by the core-regset.c code for
 103    reading ELF core files.  */
 104 void
 105 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
 106 {
 107   int i;
 108   for (i = 0; i < I386_NUM_GREGS; i++)
 109     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 110 }
 111
 112 void
 113 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 114 {
 115   i387_supply_fsave (regcache, -1, fpregs);
 116 }
 117 #endif
 118
 119 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 120 static void
 121 gnu_fetch_registers (struct target_ops *ops,
 122                      struct regcache *regcache, int regno)
 123 {
 124   struct proc *thread;
 125
 126   /* Make sure we know about new threads.  */
 127   inf_update_procs (gnu_current_inf);
 128
 129   thread = inf_tid_to_thread (gnu_current_inf,
 130                               ptid_get_lwp (inferior_ptid));
 131   if (!thread)
 132     error (_("Can't fetch registers from thread %s: No such thread"),
 133            target_pid_to_str (inferior_ptid));
 134
 135   if (regno < I386_NUM_GREGS || regno == -1)
 136     {
 137       thread_state_t state;
 138
 139       /* This does the dirty work for us.  */
 140       state = proc_get_state (thread, 0);
 141       if (!state)
 142         {
 143           warning (_("Couldn't fetch registers from %s"),
 144                    proc_string (thread));
 145           return;
 146         }
 147
 148       if (regno == -1)
 149         {
 150           int i;
 151
 152           proc_debug (thread, "fetching all register");
 153
 154           for (i = 0; i < I386_NUM_GREGS; i++)
 155             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 156           thread->fetched_regs = ~0;
 157         }
 158       else
 159         {
 160           proc_debug (thread, "fetching register %s",
 161                       gdbarch_register_name (get_regcache_arch (regcache),
 162                                              regno));
 163
 164           regcache_raw_supply (regcache, regno,
 165                                REG_ADDR (state, regno));
 166           thread->fetched_regs |= (1 << regno);
 167         }
 168     }
 169
 170   if (regno >= I386_NUM_GREGS || regno == -1)
 171     {
 172       proc_debug (thread, "fetching floating-point registers");
 173
 174       fetch_fpregs (regcache, thread);
 175     }
 176 }
 177 \f
 178
 179 /* Store the whole floating-point state into THREAD using information
 180    from the corresponding (pseudo) registers.  */
 181 static void
 182 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 183 {
 184   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 185   struct i386_float_state state;
 186   error_t err;
 187
 188   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 189                           (thread_state_t) &state, &count);
 190   if (err)
 191     {
 192       warning (_("Couldn't fetch floating-point state from %s"),
 193                proc_string (thread));
 194       return;
 195     }
 196
 197   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 198      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 199   i387_collect_fsave (regcache, regno, state.hw_state);
 200
 201   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 202                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 203   if (err)
 204     {
 205       warning (_("Couldn't store floating-point state into %s"),
 206                proc_string (thread));
 207       return;
 208     }
 209 }
 210
 211 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 212 static void
 213 gnu_store_registers (struct target_ops *ops,
 214                      struct regcache *regcache, int regno)
 215 {
 216   struct proc *thread;
 217   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 218
 219   /* Make sure we know about new threads.  */
 220   inf_update_procs (gnu_current_inf);
 221
 222   thread = inf_tid_to_thread (gnu_current_inf,
 223                               ptid_get_lwp (inferior_ptid));
 224   if (!thread)
 225     error (_("Couldn't store registers into thread %s: No such thread"),
 226            target_pid_to_str (inferior_ptid));
 227
 228   if (regno < I386_NUM_GREGS || regno == -1)
 229     {
 230       thread_state_t state;
 231       thread_state_data_t old_state;
 232       int was_aborted = thread->aborted;
 233       int was_valid = thread->state_valid;
 234       int trace;
 235
 236       if (!was_aborted && was_valid)
 237         memcpy (&old_state, &thread->state, sizeof (old_state));
 238
 239       state = proc_get_state (thread, 1);
 240       if (!state)
 241         {
 242           warning (_("Couldn't store registers into %s"),
 243                    proc_string (thread));
 244           return;
 245         }
 246
 247       /* Save the T bit.  We might try to restore the %eflags register
 248          below, but changing the T bit would seriously confuse GDB.  */
 249       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 250
 251       if (!was_aborted && was_valid)
 252         /* See which registers have changed after aborting the thread.  */
 253         {
 254           int check_regno;
 255
 256           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 257             if ((thread->fetched_regs & (1 << check_regno))
 258                 && memcpy (REG_ADDR (&old_state, check_regno),
 259                            REG_ADDR (state, check_regno),
 260                            register_size (gdbarch, check_regno)))
 261               /* Register CHECK_REGNO has changed!  Ack!  */
 262               {
 263                 warning (_("Register %s changed after the thread was aborted"),
 264                          gdbarch_register_name (gdbarch, check_regno));
 265                 if (regno >= 0 && regno != check_regno)
 266                   /* Update GDB's copy of the register.  */
 267                   regcache_raw_supply (regcache, check_regno,
 268                                        REG_ADDR (state, check_regno));
 269                 else
 270                   warning (_("... also writing this register!  "
 271                              "Suspicious..."));
 272               }
 273         }
 274
 275       if (regno == -1)
 276         {
 277           int i;
 278
 279           proc_debug (thread, "storing all registers");
 280
 281           for (i = 0; i < I386_NUM_GREGS; i++)
 282             if (REG_VALID == regcache_register_status (regcache, i))
 283               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 284         }
 285       else
 286         {
 287           proc_debug (thread, "storing register %s",
 288                       gdbarch_register_name (gdbarch, regno));
 289
 290           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 291           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 292         }
 293
 294       /* Restore the T bit.  */
 295       ((struct i386_thread_state *)state)->efl &= ~0x100;
 296       ((struct i386_thread_state *)state)->efl |= trace;
 297     }
 298
 299   if (regno >= I386_NUM_GREGS || regno == -1)
 300     {
 301       proc_debug (thread, "storing floating-point registers");
 302
 303       store_fpregs (regcache, thread, regno);
 304     }
 305 }
 306
 307 /* Provide a prototype to silence -Wmissing-prototypes.  */
 308 extern initialize_file_ftype _initialize_i386gnu_nat;
 309
 310 void
 311 _initialize_i386gnu_nat (void)
 312 {
 313   struct target_ops *t;
 314
 315   /* Fill in the generic GNU/Hurd methods.  */
 316   t = gnu_target ();
 317
 318   t->to_fetch_registers = gnu_fetch_registers;
 319   t->to_store_registers = gnu_store_registers;
 320
 321   /* Register the target.  */
 322   add_target (t);
 323 }