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 <string.h>
  28
  29 #include <mach.h>
  30 #include <mach_error.h>
  31 #include <mach/message.h>
  32 #include <mach/exception.h>
  33
  34 #include "i386-tdep.h"
  35
  36 #include "gnu-nat.h"
  37 #include "i387-tdep.h"
  38
  39 #ifdef HAVE_SYS_PROCFS_H
  40 # include <sys/procfs.h>
  41 # include "gregset.h"
  42 #endif
  43
  44 /* Offset to the thread_state_t location where REG is stored.  */
  45 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
  46
  47 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
  48    the GDB register N is stored.  */
  49 static int reg_offset[] =
  50 {
  51   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
  52   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
  53   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
  54   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
  55 };
  56
  57 /* Offset to the greg_t location where REG is stored.  */
  58 #define CREG_OFFSET(reg) (REG_##reg * 4)
  59
  60 /* At CREG_OFFSET[N] is the offset to the greg_t location where
  61    the GDB register N is stored.  */
  62 static int creg_offset[] =
  63 {
  64   CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
  65   CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
  66   CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
  67   CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
  68 };
  69
  70 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
  71 #define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
  72
  73 \f
  74 /* Get the whole floating-point state of THREAD and record the values
  75    of the corresponding (pseudo) registers.  */
  76
  77 static void
  78 fetch_fpregs (struct regcache *regcache, struct proc *thread)
  79 {
  80   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
  81   struct i386_float_state state;
  82   error_t err;
  83
  84   err = thread_get_state (thread->port, i386_FLOAT_STATE,
  85                           (thread_state_t) &state, &count);
  86   if (err)
  87     {
  88       warning (_("Couldn't fetch floating-point state from %s"),
  89                proc_string (thread));
  90       return;
  91     }
  92
  93   if (!state.initialized)
  94     {
  95       /* The floating-point state isn't initialized.  */
  96       i387_supply_fsave (regcache, -1, NULL);
  97     }
  98   else
  99     {
 100       /* Supply the floating-point registers.  */
 101       i387_supply_fsave (regcache, -1, state.hw_state);
 102     }
 103 }
 104
 105 #ifdef HAVE_SYS_PROCFS_H
 106 /* These two calls are used by the core-regset.c code for
 107    reading ELF core files.  */
 108 void
 109 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
 110 {
 111   int i;
 112   for (i = 0; i < I386_NUM_GREGS; i++)
 113     regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
 114 }
 115
 116 void
 117 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 118 {
 119   i387_supply_fsave (regcache, -1, fpregs);
 120 }
 121 #endif
 122
 123 /* Fetch register REGNO, or all regs if REGNO is -1.  */
 124 static void
 125 gnu_fetch_registers (struct target_ops *ops,
 126                      struct regcache *regcache, int regno)
 127 {
 128   struct proc *thread;
 129
 130   /* Make sure we know about new threads.  */
 131   inf_update_procs (gnu_current_inf);
 132
 133   thread = inf_tid_to_thread (gnu_current_inf,
 134                               ptid_get_lwp (inferior_ptid));
 135   if (!thread)
 136     error (_("Can't fetch registers from thread %s: No such thread"),
 137            target_pid_to_str (inferior_ptid));
 138
 139   if (regno < I386_NUM_GREGS || regno == -1)
 140     {
 141       thread_state_t state;
 142
 143       /* This does the dirty work for us.  */
 144       state = proc_get_state (thread, 0);
 145       if (!state)
 146         {
 147           warning (_("Couldn't fetch registers from %s"),
 148                    proc_string (thread));
 149           return;
 150         }
 151
 152       if (regno == -1)
 153         {
 154           int i;
 155
 156           proc_debug (thread, "fetching all register");
 157
 158           for (i = 0; i < I386_NUM_GREGS; i++)
 159             regcache_raw_supply (regcache, i, REG_ADDR (state, i));
 160           thread->fetched_regs = ~0;
 161         }
 162       else
 163         {
 164           proc_debug (thread, "fetching register %s",
 165                       gdbarch_register_name (get_regcache_arch (regcache),
 166                                              regno));
 167
 168           regcache_raw_supply (regcache, regno,
 169                                REG_ADDR (state, regno));
 170           thread->fetched_regs |= (1 << regno);
 171         }
 172     }
 173
 174   if (regno >= I386_NUM_GREGS || regno == -1)
 175     {
 176       proc_debug (thread, "fetching floating-point registers");
 177
 178       fetch_fpregs (regcache, thread);
 179     }
 180 }
 181 \f
 182
 183 /* Store the whole floating-point state into THREAD using information
 184    from the corresponding (pseudo) registers.  */
 185 static void
 186 store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
 187 {
 188   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
 189   struct i386_float_state state;
 190   error_t err;
 191
 192   err = thread_get_state (thread->port, i386_FLOAT_STATE,
 193                           (thread_state_t) &state, &count);
 194   if (err)
 195     {
 196       warning (_("Couldn't fetch floating-point state from %s"),
 197                proc_string (thread));
 198       return;
 199     }
 200
 201   /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
 202      take into account DEPRECATED_REGISTER_VALID like the old code did?  */
 203   i387_collect_fsave (regcache, regno, state.hw_state);
 204
 205   err = thread_set_state (thread->port, i386_FLOAT_STATE,
 206                           (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
 207   if (err)
 208     {
 209       warning (_("Couldn't store floating-point state into %s"),
 210                proc_string (thread));
 211       return;
 212     }
 213 }
 214
 215 /* Store at least register REGNO, or all regs if REGNO == -1.  */
 216 static void
 217 gnu_store_registers (struct target_ops *ops,
 218                      struct regcache *regcache, int regno)
 219 {
 220   struct proc *thread;
 221   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 222
 223   /* Make sure we know about new threads.  */
 224   inf_update_procs (gnu_current_inf);
 225
 226   thread = inf_tid_to_thread (gnu_current_inf,
 227                               ptid_get_lwp (inferior_ptid));
 228   if (!thread)
 229     error (_("Couldn't store registers into thread %s: No such thread"),
 230            target_pid_to_str (inferior_ptid));
 231
 232   if (regno < I386_NUM_GREGS || regno == -1)
 233     {
 234       thread_state_t state;
 235       thread_state_data_t old_state;
 236       int was_aborted = thread->aborted;
 237       int was_valid = thread->state_valid;
 238       int trace;
 239
 240       if (!was_aborted && was_valid)
 241         memcpy (&old_state, &thread->state, sizeof (old_state));
 242
 243       state = proc_get_state (thread, 1);
 244       if (!state)
 245         {
 246           warning (_("Couldn't store registers into %s"),
 247                    proc_string (thread));
 248           return;
 249         }
 250
 251       /* Save the T bit.  We might try to restore the %eflags register
 252          below, but changing the T bit would seriously confuse GDB.  */
 253       trace = ((struct i386_thread_state *)state)->efl & 0x100;
 254
 255       if (!was_aborted && was_valid)
 256         /* See which registers have changed after aborting the thread.  */
 257         {
 258           int check_regno;
 259
 260           for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
 261             if ((thread->fetched_regs & (1 << check_regno))
 262                 && memcpy (REG_ADDR (&old_state, check_regno),
 263                            REG_ADDR (state, check_regno),
 264                            register_size (gdbarch, check_regno)))
 265               /* Register CHECK_REGNO has changed!  Ack!  */
 266               {
 267                 warning (_("Register %s changed after the thread was aborted"),
 268                          gdbarch_register_name (gdbarch, check_regno));
 269                 if (regno >= 0 && regno != check_regno)
 270                   /* Update GDB's copy of the register.  */
 271                   regcache_raw_supply (regcache, check_regno,
 272                                        REG_ADDR (state, check_regno));
 273                 else
 274                   warning (_("... also writing this register!  "
 275                              "Suspicious..."));
 276               }
 277         }
 278
 279       if (regno == -1)
 280         {
 281           int i;
 282
 283           proc_debug (thread, "storing all registers");
 284
 285           for (i = 0; i < I386_NUM_GREGS; i++)
 286             if (REG_VALID == regcache_register_status (regcache, i))
 287               regcache_raw_collect (regcache, i, REG_ADDR (state, i));
 288         }
 289       else
 290         {
 291           proc_debug (thread, "storing register %s",
 292                       gdbarch_register_name (gdbarch, regno));
 293
 294           gdb_assert (REG_VALID == regcache_register_status (regcache, regno));
 295           regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
 296         }
 297
 298       /* Restore the T bit.  */
 299       ((struct i386_thread_state *)state)->efl &= ~0x100;
 300       ((struct i386_thread_state *)state)->efl |= trace;
 301     }
 302
 303   if (regno >= I386_NUM_GREGS || regno == -1)
 304     {
 305       proc_debug (thread, "storing floating-point registers");
 306
 307       store_fpregs (regcache, thread, regno);
 308     }
 309 }
 310
 311 /* Provide a prototype to silence -Wmissing-prototypes.  */
 312 extern initialize_file_ftype _initialize_i386gnu_nat;
 313
 314 void
 315 _initialize_i386gnu_nat (void)
 316 {
 317   struct target_ops *t;
 318
 319   /* Fill in the generic GNU/Hurd methods.  */
 320   t = gnu_target ();
 321
 322   t->to_fetch_registers = gnu_fetch_registers;
 323   t->to_store_registers = gnu_store_registers;
 324
 325   /* Register the target.  */
 326   add_target (t);
 327 }