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 <errno.h>
  26 #include <string.h>
  27
  28 #include <mach.h>
  29 #include <mach_error.h>
  30 #include <mach/message.h>
  31 #include <mach/exception.h>
  32
  33 #include "i386-tdep.h"
  34
  35 #include "gnu-nat.h"
  36 #include "i387-tdep.h"
  37
  38 #ifdef HAVE_SYS_PROCFS_H
  39 # include <sys/procfs.h>
  40 # include "gregset.h"
  41 #endif
  42
  43 /* Offset to the thread_state_t location where REG is stored.  */
  44 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  45
  46 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  47    the GDB register N is stored.  */
  48 static int reg_offset[] =
  49 {
  50   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  51   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  52   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  53   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  54 };
  55
  56 /* Offset to the greg_t location where REG is stored.  */
  57 #define CREG_OFFSET(reg) (REG_##reg * 4)
  58
  59 /* At CREG_OFFSET[N] is the offset to the greg_t location where
  60    the GDB register N is stored.  */
  61 static int creg_offset[] =
  62 {
  63   CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
  64   CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
  65   CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
  66   CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
  67 };
  68
  69 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  70 #define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
  71
  72 \f
  73 /* Get the whole floating-point state of THREAD and record the values
  74    of the corresponding (pseudo) registers.  */
  75
  76 static void
  77 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  78 {
  79   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  80   struct i386_float_state state;
  81   error_t err;
  82
  83   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  84                           (thread_state_t) &state, &count);
  85   if (err)
  86     {
  87       warning (_("Couldn't fetch floating-point state from %s"),
  88                proc_string (thread));
  89       return;
  90     }
  91
  92   if (!state.initialized)
  93     {
  94       /* The floating-point state isn't initialized.  */
  95       i387_supply_fsave (regcache, -1, NULL);
  96     }
  97   else
  98     {
  99       /* Supply the floating-point registers.  */
 100       i387_supply_fsave (regcache, -1, state.hw_state);
 101     }
 102 }
 103
 104 #ifdef HAVE_SYS_PROCFS_H
 105 /* These two calls are used by the core-regset.c code for
 106    reading ELF core files.  */
 107 void
 108 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
 109 {
 110   int i;
 111   for (i = 0; i < I386_NUM_GREGS; i++)
 112     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 113 }
 114
 115 void
 116 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 117 {
 118   i387_supply_fsave (regcache, -1, fpregs);
 119 }
 120 #endif
 121
 122 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 123 static void
 124 gnu_fetch_registers (struct target_ops *ops,
 125                      struct regcache *regcache, int regno)
 126 {
 127   struct proc *thread;
 128
 129   /* Make sure we know about new threads.  */
 130   inf_update_procs (gnu_current_inf);
 131
 132   thread = inf_tid_to_thread (gnu_current_inf,
 133                               ptid_get_lwp (inferior_ptid));
 134   if (!thread)
 135     error (_("Can't fetch registers from thread %s: No such thread"),
 136            target_pid_to_str (inferior_ptid));
 137
 138   if (regno < I386_NUM_GREGS || regno == -1)
 139     {
 140       thread_state_t state;
 141
 142       /* This does the dirty work for us.  */
 143       state = proc_get_state (thread, 0);
 144       if (!state)
 145         {
 146           warning (_("Couldn't fetch registers from %s"),
 147                    proc_string (thread));
 148           return;
 149         }
 150
 151       if (regno == -1)
 152         {
 153           int i;
 154
 155           proc_debug (thread, "fetching all register");
 156
 157           for (i = 0; i < I386_NUM_GREGS; i++)
 158             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 159           thread->fetched_regs = ~0;
 160         }
 161       else
 162         {
 163           proc_debug (thread, "fetching register %s",
 164                       gdbarch_register_name (get_regcache_arch (regcache),
 165                                              regno));
 166
 167           regcache_raw_supply (regcache, regno,
 168                                REG_ADDR (state, regno));
 169           thread->fetched_regs |= (1 << regno);
 170         }
 171     }
 172
 173   if (regno >= I386_NUM_GREGS || regno == -1)
 174     {
 175       proc_debug (thread, "fetching floating-point registers");
 176
 177       fetch_fpregs (regcache, thread);
 178     }
 179 }
 180 \f
 181
 182 /* Store the whole floating-point state into THREAD using information
 183    from the corresponding (pseudo) registers.  */
 184 static void
 185 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 186 {
 187   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 188   struct i386_float_state state;
 189   error_t err;
 190
 191   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 192                           (thread_state_t) &state, &count);
 193   if (err)
 194     {
 195       warning (_("Couldn't fetch floating-point state from %s"),
 196                proc_string (thread));
 197       return;
 198     }
 199
 200   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 201      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 202   i387_collect_fsave (regcache, regno, state.hw_state);
 203
 204   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 205                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 206   if (err)
 207     {
 208       warning (_("Couldn't store floating-point state into %s"),
 209                proc_string (thread));
 210       return;
 211     }
 212 }
 213
 214 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 215 static void
 216 gnu_store_registers (struct target_ops *ops,
 217                      struct regcache *regcache, int regno)
 218 {
 219   struct proc *thread;
 220   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 221
 222   /* Make sure we know about new threads.  */
 223   inf_update_procs (gnu_current_inf);
 224
 225   thread = inf_tid_to_thread (gnu_current_inf,
 226                               ptid_get_lwp (inferior_ptid));
 227   if (!thread)
 228     error (_("Couldn't store registers into thread %s: No such thread"),
 229            target_pid_to_str (inferior_ptid));
 230
 231   if (regno < I386_NUM_GREGS || regno == -1)
 232     {
 233       thread_state_t state;
 234       thread_state_data_t old_state;
 235       int was_aborted = thread->aborted;
 236       int was_valid = thread->state_valid;
 237       int trace;
 238
 239       if (!was_aborted && was_valid)
 240         memcpy (&old_state, &thread->state, sizeof (old_state));
 241
 242       state = proc_get_state (thread, 1);
 243       if (!state)
 244         {
 245           warning (_("Couldn't store registers into %s"),
 246                    proc_string (thread));
 247           return;
 248         }
 249
 250       /* Save the T bit.  We might try to restore the %eflags register
 251          below, but changing the T bit would seriously confuse GDB.  */
 252       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 253
 254       if (!was_aborted && was_valid)
 255         /* See which registers have changed after aborting the thread.  */
 256         {
 257           int check_regno;
 258
 259           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 260             if ((thread->fetched_regs & (1 << check_regno))
 261                 && memcpy (REG_ADDR (&old_state, check_regno),
 262                            REG_ADDR (state, check_regno),
 263                            register_size (gdbarch, check_regno)))
 264               /* Register CHECK_REGNO has changed!  Ack!  */
 265               {
 266                 warning (_("Register %s changed after the thread was aborted"),
 267                          gdbarch_register_name (gdbarch, check_regno));
 268                 if (regno >= 0 && regno != check_regno)
 269                   /* Update GDB's copy of the register.  */
 270                   regcache_raw_supply (regcache, check_regno,
 271                                        REG_ADDR (state, check_regno));
 272                 else
 273                   warning (_("... also writing this register!  "
 274                              "Suspicious..."));
 275               }
 276         }
 277
 278       if (regno == -1)
 279         {
 280           int i;
 281
 282           proc_debug (thread, "storing all registers");
 283
 284           for (i = 0; i < I386_NUM_GREGS; i++)
 285             if (REG_VALID == regcache_register_status (regcache, i))
 286               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 287         }
 288       else
 289         {
 290           proc_debug (thread, "storing register %s",
 291                       gdbarch_register_name (gdbarch, regno));
 292
 293           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 294           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 295         }
 296
 297       /* Restore the T bit.  */
 298       ((struct i386_thread_state *)state)->efl &= ~0x100;
 299       ((struct i386_thread_state *)state)->efl |= trace;
 300     }
 301
 302   if (regno >= I386_NUM_GREGS || regno == -1)
 303     {
 304       proc_debug (thread, "storing floating-point registers");
 305
 306       store_fpregs (regcache, thread, regno);
 307     }
 308 }
 309
 310 /* Provide a prototype to silence -Wmissing-prototypes.  */
 311 extern initialize_file_ftype _initialize_i386gnu_nat;
 312
 313 void
 314 _initialize_i386gnu_nat (void)
 315 {
 316   struct target_ops *t;
 317
 318   /* Fill in the generic GNU/Hurd methods.  */
 319   t = gnu_target ();
 320
 321   t->to_fetch_registers = gnu_fetch_registers;
 322   t->to_store_registers = gnu_store_registers;
 323
 324   /* Register the target.  */
 325   add_target (t);
 326 }