1/* Low level interface to i386 running the GNU Hurd.
2
3   Copyright (C) 1992, 1995, 1996, 1998, 2000, 2001, 2004, 2007
4   Free Software Foundation, Inc.
5
6   This file is part of GDB.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 3 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20
21#include "defs.h"
22#include "inferior.h"
23#include "floatformat.h"
24#include "regcache.h"
25
26#include "gdb_assert.h"
27#include <errno.h>
28#include <stdio.h>
29#include "gdb_string.h"
30
31#include <mach.h>
32#include <mach_error.h>
33#include <mach/message.h>
34#include <mach/exception.h>
35
36#include "i386-tdep.h"
37
38#include "gnu-nat.h"
39#include "i387-tdep.h"
40
41#ifdef HAVE_SYS_PROCFS_H
42# include <sys/procfs.h>
43# include "gregset.h"
44#endif
45
46/* Offset to the thread_state_t location where REG is stored.  */
47#define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
48
49/* At REG_OFFSET[N] is the offset to the thread_state_t location where
50   the GDB register N is stored.  */
51static int reg_offset[] =
52{
53  REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
54  REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
55  REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
56  REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
57};
58
59#define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
60#define CREG_ADDR(state, regnum) ((const char *)(state) + reg_offset[regnum])
61
62
63/* Get the whole floating-point state of THREAD and record the values
64   of the corresponding (pseudo) registers.  */
65
66static void
67fetch_fpregs (struct regcache *regcache, struct proc *thread)
68{
69  mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
70  struct i386_float_state state;
71  error_t err;
72
73  err = thread_get_state (thread->port, i386_FLOAT_STATE,
74			  (thread_state_t) &state, &count);
75  if (err)
76    {
77      warning (_("Couldn't fetch floating-point state from %s"),
78	       proc_string (thread));
79      return;
80    }
81
82  if (!state.initialized)
83    {
84      /* The floating-point state isn't initialized.  */
85      i387_supply_fsave (regcache, -1, NULL);
86    }
87  else
88    {
89      /* Supply the floating-point registers.  */
90      i387_supply_fsave (regcache, -1, state.hw_state);
91    }
92}
93
94#ifdef HAVE_SYS_PROCFS_H
95/* These two calls are used by the core-regset.c code for
96   reading ELF core files.  */
97void
98supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs)
99{
100  int i;
101  for (i = 0; i < I386_NUM_GREGS; i++)
102    regcache_raw_supply (regcache, i, CREG_ADDR (gregs, i));
103}
104
105void
106supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
107{
108  i387_supply_fsave (regcache, -1, fpregs);
109}
110#endif
111
112/* Fetch register REGNO, or all regs if REGNO is -1.  */
113void
114gnu_fetch_registers (struct regcache *regcache, int regno)
115{
116  struct proc *thread;
117
118  /* Make sure we know about new threads.  */
119  inf_update_procs (current_inferior);
120
121  thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
122  if (!thread)
123    error (_("Can't fetch registers from thread %d: No such thread"),
124	   PIDGET (inferior_ptid));
125
126  if (regno < I386_NUM_GREGS || regno == -1)
127    {
128      thread_state_t state;
129
130      /* This does the dirty work for us.  */
131      state = proc_get_state (thread, 0);
132      if (!state)
133	{
134	  warning (_("Couldn't fetch registers from %s"),
135		   proc_string (thread));
136	  return;
137	}
138
139      if (regno == -1)
140	{
141	  int i;
142
143	  proc_debug (thread, "fetching all register");
144
145	  for (i = 0; i < I386_NUM_GREGS; i++)
146	    regcache_raw_supply (regcache, i, REG_ADDR (state, i));
147	  thread->fetched_regs = ~0;
148	}
149      else
150	{
151	  proc_debug (thread, "fetching register %s",
152		      gdbarch_register_name (current_gdbarch, regno));
153
154	  regcache_raw_supply (regcache, regno,
155			       REG_ADDR (state, regno));
156	  thread->fetched_regs |= (1 << regno);
157	}
158    }
159
160  if (regno >= I386_NUM_GREGS || regno == -1)
161    {
162      proc_debug (thread, "fetching floating-point registers");
163
164      fetch_fpregs (regcache, thread);
165    }
166}
167
168
169/* Store the whole floating-point state into THREAD using information
170   from the corresponding (pseudo) registers.  */
171static void
172store_fpregs (const struct regcache *regcache, struct proc *thread, int regno)
173{
174  mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
175  struct i386_float_state state;
176  error_t err;
177
178  err = thread_get_state (thread->port, i386_FLOAT_STATE,
179			  (thread_state_t) &state, &count);
180  if (err)
181    {
182      warning (_("Couldn't fetch floating-point state from %s"),
183	       proc_string (thread));
184      return;
185    }
186
187  /* FIXME: kettenis/2001-07-15: Is this right?  Should we somehow
188     take into account DEPRECATED_REGISTER_VALID like the old code did?  */
189  i387_collect_fsave (regcache, regno, state.hw_state);
190
191  err = thread_set_state (thread->port, i386_FLOAT_STATE,
192			  (thread_state_t) &state, i386_FLOAT_STATE_COUNT);
193  if (err)
194    {
195      warning (_("Couldn't store floating-point state into %s"),
196	       proc_string (thread));
197      return;
198    }
199}
200
201/* Store at least register REGNO, or all regs if REGNO == -1.  */
202void
203gnu_store_registers (struct regcache *regcache, int regno)
204{
205  struct proc *thread;
206
207  /* Make sure we know about new threads.  */
208  inf_update_procs (current_inferior);
209
210  thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
211  if (!thread)
212    error (_("Couldn't store registers into thread %d: No such thread"),
213	   PIDGET (inferior_ptid));
214
215  if (regno < I386_NUM_GREGS || regno == -1)
216    {
217      thread_state_t state;
218      thread_state_data_t old_state;
219      int was_aborted = thread->aborted;
220      int was_valid = thread->state_valid;
221      int trace;
222
223      if (!was_aborted && was_valid)
224	memcpy (&old_state, &thread->state, sizeof (old_state));
225
226      state = proc_get_state (thread, 1);
227      if (!state)
228	{
229	  warning (_("Couldn't store registers into %s"), proc_string (thread));
230	  return;
231	}
232
233      /* Save the T bit.  We might try to restore the %eflags register
234         below, but changing the T bit would seriously confuse GDB.  */
235      trace = ((struct i386_thread_state *)state)->efl & 0x100;
236
237      if (!was_aborted && was_valid)
238	/* See which registers have changed after aborting the thread.  */
239	{
240	  int check_regno;
241
242	  for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
243	    if ((thread->fetched_regs & (1 << check_regno))
244		&& memcpy (REG_ADDR (&old_state, check_regno),
245			   REG_ADDR (state, check_regno),
246			   register_size (current_gdbarch, check_regno)))
247	      /* Register CHECK_REGNO has changed!  Ack!  */
248	      {
249		warning (_("Register %s changed after the thread was aborted"),
250			 gdbarch_register_name (current_gdbarch, check_regno));
251		if (regno >= 0 && regno != check_regno)
252		  /* Update GDB's copy of the register.  */
253		  regcache_raw_supply (regcache, check_regno,
254				       REG_ADDR (state, check_regno));
255		else
256		  warning (_("... also writing this register!  Suspicious..."));
257	      }
258	}
259
260      if (regno == -1)
261	{
262	  int i;
263
264	  proc_debug (thread, "storing all registers");
265
266	  for (i = 0; i < I386_NUM_GREGS; i++)
267	    if (regcache_valid_p (regcache, i))
268	      regcache_raw_collect (regcache, i, REG_ADDR (state, i));
269	}
270      else
271	{
272	  proc_debug (thread, "storing register %s",
273		      gdbarch_register_name (current_gdbarch, regno));
274
275	  gdb_assert (regcache_valid_p (regcache, regno));
276	  regcache_raw_collect (regcache, regno, REG_ADDR (state, regno));
277	}
278
279      /* Restore the T bit.  */
280      ((struct i386_thread_state *)state)->efl &= ~0x100;
281      ((struct i386_thread_state *)state)->efl |= trace;
282    }
283
284  if (regno >= I386_NUM_GREGS || regno == -1)
285    {
286      proc_debug (thread, "storing floating-point registers");
287
288      store_fpregs (regcache, thread, regno);
289    }
290}
291