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