xref: /openbsd/gnu/usr.bin/binutils/gdb/i386gnu-nat.c (revision 4cfece93)
1 /* Low level interface to i386 running the GNU Hurd.
2 
3    Copyright 1992, 1995, 1996, 1998, 2000, 2001, 2004
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 2 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, write to the Free Software
20    Foundation, Inc., 59 Temple Place - Suite 330,
21    Boston, MA 02111-1307, USA.  */
22 
23 #include "defs.h"
24 #include "inferior.h"
25 #include "floatformat.h"
26 #include "regcache.h"
27 
28 #include "gdb_assert.h"
29 #include <errno.h>
30 #include <stdio.h>
31 #include "gdb_string.h"
32 
33 #include <mach.h>
34 #include <mach_error.h>
35 #include <mach/message.h>
36 #include <mach/exception.h>
37 
38 #include "i386-tdep.h"
39 
40 #include "gnu-nat.h"
41 #include "i387-tdep.h"
42 
43 #ifdef HAVE_SYS_PROCFS_H
44 # include <sys/procfs.h>
45 # include "gregset.h"
46 #endif
47 
48 /* Offset to the thread_state_t location where REG is stored.  */
49 #define REG_OFFSET(reg) offsetof (struct i386_thread_state, reg)
50 
51 /* At REG_OFFSET[N] is the offset to the thread_state_t location where
52    the GDB register N is stored.  */
53 static int reg_offset[] =
54 {
55   REG_OFFSET (eax), REG_OFFSET (ecx), REG_OFFSET (edx), REG_OFFSET (ebx),
56   REG_OFFSET (uesp), REG_OFFSET (ebp), REG_OFFSET (esi), REG_OFFSET (edi),
57   REG_OFFSET (eip), REG_OFFSET (efl), REG_OFFSET (cs), REG_OFFSET (ss),
58   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
59 };
60 
61 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
62 
63 
64 /* Get the whole floating-point state of THREAD and record the values
65    of the corresponding (pseudo) registers.  */
66 
67 static void
68 fetch_fpregs (struct proc *thread)
69 {
70   mach_msg_type_number_t count = i386_FLOAT_STATE_COUNT;
71   struct i386_float_state state;
72   error_t err;
73 
74   err = thread_get_state (thread->port, i386_FLOAT_STATE,
75 			  (thread_state_t) &state, &count);
76   if (err)
77     {
78       warning ("Couldn't fetch floating-point state from %s",
79 	       proc_string (thread));
80       return;
81     }
82 
83   if (!state.initialized)
84     {
85       /* The floating-point state isn't initialized.  */
86       i387_supply_fsave (current_regcache, -1, NULL);
87     }
88   else
89     {
90       /* Supply the floating-point registers.  */
91       i387_supply_fsave (current_regcache, -1, state.hw_state);
92     }
93 }
94 
95 #ifdef HAVE_SYS_PROCFS_H
96 /* These two calls are used by the core-regset.c code for
97    reading ELF core files.  */
98 void
99 supply_gregset (gdb_gregset_t *gregs)
100 {
101   int i;
102   for (i = 0; i < I386_NUM_GREGS; i++)
103     regcache_raw_supply (current_regcache, i, REG_ADDR (gregs, i));
104 }
105 
106 void
107 supply_fpregset (gdb_fpregset_t *fpregs)
108 {
109   i387_supply_fsave (current_regcache, -1, fpregs);
110 }
111 #endif
112 
113 /* Fetch register REGNO, or all regs if REGNO is -1.  */
114 void
115 gnu_fetch_registers (int regno)
116 {
117   struct proc *thread;
118 
119   /* Make sure we know about new threads.  */
120   inf_update_procs (current_inferior);
121 
122   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
123   if (!thread)
124     error ("Can't fetch registers from thread %d: No such thread",
125 	   PIDGET (inferior_ptid));
126 
127   if (regno < I386_NUM_GREGS || regno == -1)
128     {
129       thread_state_t state;
130 
131       /* This does the dirty work for us.  */
132       state = proc_get_state (thread, 0);
133       if (!state)
134 	{
135 	  warning ("Couldn't fetch registers from %s",
136 		   proc_string (thread));
137 	  return;
138 	}
139 
140       if (regno == -1)
141 	{
142 	  int i;
143 
144 	  proc_debug (thread, "fetching all register");
145 
146 	  for (i = 0; i < I386_NUM_GREGS; i++)
147 	    regcache_raw_supply (current_regcache, i, REG_ADDR (state, i));
148 	  thread->fetched_regs = ~0;
149 	}
150       else
151 	{
152 	  proc_debug (thread, "fetching register %s", REGISTER_NAME (regno));
153 
154 	  regcache_raw_supply (current_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 (thread);
165     }
166 }
167 
168 
169 /* Store the whole floating-point state into THREAD using information
170    from the corresponding (pseudo) registers.  */
171 static void
172 store_fpregs (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_fill_fsave (state.hw_state, regno);
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.  */
202 void
203 gnu_store_registers (int regno)
204 {
205   struct regcache *regcache = current_regcache;
206   struct proc *thread;
207 
208   /* Make sure we know about new threads.  */
209   inf_update_procs (current_inferior);
210 
211   thread = inf_tid_to_thread (current_inferior, PIDGET (inferior_ptid));
212   if (!thread)
213     error ("Couldn't store registers into thread %d: No such thread",
214 	   PIDGET (inferior_ptid));
215 
216   if (regno < I386_NUM_GREGS || regno == -1)
217     {
218       thread_state_t state;
219       thread_state_data_t old_state;
220       int was_aborted = thread->aborted;
221       int was_valid = thread->state_valid;
222       int trace;
223 
224       if (!was_aborted && was_valid)
225 	memcpy (&old_state, &thread->state, sizeof (old_state));
226 
227       state = proc_get_state (thread, 1);
228       if (!state)
229 	{
230 	  warning ("Couldn't store registers into %s", proc_string (thread));
231 	  return;
232 	}
233 
234       /* Save the T bit.  We might try to restore the %eflags register
235          below, but changing the T bit would seriously confuse GDB.  */
236       trace = ((struct i386_thread_state *)state)->efl & 0x100;
237 
238       if (!was_aborted && was_valid)
239 	/* See which registers have changed after aborting the thread.  */
240 	{
241 	  int check_regno;
242 
243 	  for (check_regno = 0; check_regno < I386_NUM_GREGS; check_regno++)
244 	    if ((thread->fetched_regs & (1 << check_regno))
245 		&& memcpy (REG_ADDR (&old_state, check_regno),
246 			   REG_ADDR (state, check_regno),
247 			   register_size (current_gdbarch, check_regno)))
248 	      /* Register CHECK_REGNO has changed!  Ack!  */
249 	      {
250 		warning ("Register %s changed after the thread was aborted",
251 			 REGISTER_NAME (check_regno));
252 		if (regno >= 0 && regno != check_regno)
253 		  /* Update GDB's copy of the register.  */
254 		  regcache_raw_supply (regcache, check_regno,
255 				       REG_ADDR (state, check_regno));
256 		else
257 		  warning ("... also writing this register!  Suspicious...");
258 	      }
259 	}
260 
261       if (regno == -1)
262 	{
263 	  int i;
264 
265 	  proc_debug (thread, "storing all registers");
266 
267 	  for (i = 0; i < I386_NUM_GREGS; i++)
268 	    if (regcache_valid_p (regcache, i))
269 	      regcache_raw_collect (regcache, i, REG_ADDR (state, i));
270 	}
271       else
272 	{
273 	  proc_debug (thread, "storing register %s", REGISTER_NAME (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 (thread, regno);
289     }
290 }
291