1/* Native-dependent code for modern i386 BSD's.
2   Copyright 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
3
4   This file is part of GDB.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software
18   Foundation, Inc., 59 Temple Place - Suite 330,
19   Boston, MA 02111-1307, USA.  */
20
21#include "defs.h"
22#include "inferior.h"
23#include "regcache.h"
24
25#include "gdb_assert.h"
26#include <signal.h>
27#include <stddef.h>
28#include <sys/types.h>
29#include <sys/ptrace.h>
30#include <machine/reg.h>
31#include <machine/frame.h>
32
33#ifdef HAVE_SYS_PROCFS_H
34#include <sys/procfs.h>
35#endif
36
37#ifndef HAVE_GREGSET_T
38typedef struct reg gregset_t;
39#endif
40
41#ifndef HAVE_FPREGSET_T
42typedef struct fpreg fpregset_t;
43#endif
44
45#include "gregset.h"
46#include "i386-tdep.h"
47
48
49/* In older BSD versions we cannot get at some of the segment
50   registers.  FreeBSD for example didn't support the %fs and %gs
51   registers until the 3.0 release.  We have autoconf checks for their
52   presence, and deal gracefully with their absence.  */
53
54/* Registers we shouldn't try to fetch.  */
55#if !defined (CANNOT_FETCH_REGISTER)
56#define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno)
57#endif
58
59/* Registers we shouldn't try to store.  */
60#if !defined (CANNOT_STORE_REGISTER)
61#define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno)
62#endif
63
64/* Offset to the gregset_t location where REG is stored.  */
65#define REG_OFFSET(reg) offsetof (gregset_t, reg)
66
67/* At reg_offset[REGNO] you'll find the offset to the gregset_t
68   location where the GDB register REGNO is stored.  Unsupported
69   registers are marked with `-1'.  */
70static int reg_offset[] =
71{
72  REG_OFFSET (r_eax),
73  REG_OFFSET (r_ecx),
74  REG_OFFSET (r_edx),
75  REG_OFFSET (r_ebx),
76  REG_OFFSET (r_esp),
77  REG_OFFSET (r_ebp),
78  REG_OFFSET (r_esi),
79  REG_OFFSET (r_edi),
80  REG_OFFSET (r_eip),
81  REG_OFFSET (r_eflags),
82  REG_OFFSET (r_cs),
83  REG_OFFSET (r_ss),
84  REG_OFFSET (r_ds),
85  REG_OFFSET (r_es),
86#ifdef HAVE_STRUCT_REG_R_FS
87  REG_OFFSET (r_fs),
88#else
89  -1,
90#endif
91#ifdef HAVE_STRUCT_REG_R_GS
92  REG_OFFSET (r_gs)
93#else
94  -1
95#endif
96};
97
98#define REG_ADDR(regset, regno) ((char *) (regset) + reg_offset[regno])
99
100/* Macro to determine if a register is fetched with PT_GETREGS.  */
101#define GETREGS_SUPPLIES(regno) \
102  ((0 <= (regno) && (regno) <= 15))
103
104#ifdef HAVE_PT_GETXMMREGS
105/* Set to 1 if the kernel supports PT_GETXMMREGS.  Initialized to -1
106   so that we try PT_GETXMMREGS the first time around.  */
107static int have_ptrace_xmmregs = -1;
108#endif
109
110/* Return nonzero if we shouldn't try to fetch register REGNO.  */
111
112static int
113cannot_fetch_register (int regno)
114{
115  return (reg_offset[regno] == -1);
116}
117
118
119/* Transfering the registers between GDB, inferiors and core files.  */
120
121/* Fill GDB's register array with the general-purpose register values
122   in *GREGSETP.  */
123
124void
125supply_gregset (gregset_t *gregsetp)
126{
127  int i;
128
129  for (i = 0; i < I386_NUM_GREGS; i++)
130    {
131      if (CANNOT_FETCH_REGISTER (i))
132	supply_register (i, NULL);
133      else
134	supply_register (i, REG_ADDR (gregsetp, i));
135    }
136}
137
138/* Fill register REGNO (if it is a general-purpose register) in
139   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
140   do this for all registers.  */
141
142void
143fill_gregset (gregset_t *gregsetp, int regno)
144{
145  int i;
146
147  for (i = 0; i < I386_NUM_GREGS; i++)
148    if ((regno == -1 || regno == i) && ! CANNOT_STORE_REGISTER (i))
149      regcache_collect (i, REG_ADDR (gregsetp, i));
150}
151
152#include "i387-tdep.h"
153
154/* Fill GDB's register array with the floating-point register values
155   in *FPREGSETP.  */
156
157void
158supply_fpregset (fpregset_t *fpregsetp)
159{
160  i387_supply_fsave (current_regcache, -1, fpregsetp);
161}
162
163/* Fill register REGNO (if it is a floating-point register) in
164   *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
165   do this for all registers.  */
166
167void
168fill_fpregset (fpregset_t *fpregsetp, int regno)
169{
170  i387_fill_fsave ((char *) fpregsetp, regno);
171}
172
173/* Fetch register REGNO from the inferior.  If REGNO is -1, do this
174   for all registers (including the floating point registers).  */
175
176void
177fetch_inferior_registers (int regno)
178{
179  if (regno == -1 || GETREGS_SUPPLIES (regno))
180    {
181      gregset_t gregs;
182
183      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
184		  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
185	perror_with_name ("Couldn't get registers");
186
187      supply_gregset (&gregs);
188      if (regno != -1)
189	return;
190    }
191
192  if (regno == -1 || regno >= FP0_REGNUM)
193    {
194      fpregset_t fpregs;
195#ifdef HAVE_PT_GETXMMREGS
196      char xmmregs[512];
197
198      if (have_ptrace_xmmregs != 0
199	  && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
200		    (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
201	{
202	  have_ptrace_xmmregs = 1;
203	  i387_supply_fxsave (current_regcache, -1, xmmregs);
204	}
205      else
206	{
207          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
208		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
209	    perror_with_name ("Couldn't get floating point status");
210
211	  i387_supply_fsave (current_regcache, -1, &fpregs);
212	}
213#else
214      if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
215		  (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
216	perror_with_name ("Couldn't get floating point status");
217
218      i387_supply_fsave (current_regcache, -1, &fpregs);
219#endif
220    }
221}
222
223/* Store register REGNO back into the inferior.  If REGNO is -1, do
224   this for all registers (including the floating point registers).  */
225
226void
227store_inferior_registers (int regno)
228{
229  if (regno == -1 || GETREGS_SUPPLIES (regno))
230    {
231      gregset_t gregs;
232
233      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
234                  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
235        perror_with_name ("Couldn't get registers");
236
237      fill_gregset (&gregs, regno);
238
239      if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
240	          (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
241        perror_with_name ("Couldn't write registers");
242
243      if (regno != -1)
244	return;
245    }
246
247  if (regno == -1 || regno >= FP0_REGNUM)
248    {
249      fpregset_t fpregs;
250#ifdef HAVE_PT_GETXMMREGS
251      char xmmregs[512];
252
253      if (have_ptrace_xmmregs != 0
254	  && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
255		    (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
256	{
257	  have_ptrace_xmmregs = 1;
258
259	  i387_fill_fxsave (xmmregs, regno);
260
261	  if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid),
262		      (PTRACE_ARG3_TYPE) xmmregs, 0) == -1)
263            perror_with_name ("Couldn't write XMM registers");
264	}
265      else
266	{
267	  have_ptrace_xmmregs = 0;
268#endif
269          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
270		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
271	    perror_with_name ("Couldn't get floating point status");
272
273          i387_fill_fsave ((char *) &fpregs, regno);
274
275          if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
276		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
277	    perror_with_name ("Couldn't write floating point status");
278#ifdef HAVE_PT_GETXMMREGS
279        }
280#endif
281    }
282}
283
284
285/* Support for debug registers.  */
286
287#ifdef HAVE_PT_GETDBREGS
288
289/* Not all versions of FreeBSD/i386 that support the debug registers
290   have this macro.  */
291#ifndef DBREG_DRX
292#define DBREG_DRX(d, x) ((&d->dr0)[x])
293#endif
294
295static void
296i386bsd_dr_set (int regnum, unsigned int value)
297{
298  struct dbreg dbregs;
299
300  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
301              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
302    perror_with_name ("Couldn't get debug registers");
303
304  /* For some mysterious reason, some of the reserved bits in the
305     debug control register get set.  Mask these off, otherwise the
306     ptrace call below will fail.  */
307  DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00);
308
309  DBREG_DRX ((&dbregs), regnum) = value;
310
311  if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid),
312              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
313    perror_with_name ("Couldn't write debug registers");
314}
315
316void
317i386bsd_dr_set_control (unsigned long control)
318{
319  i386bsd_dr_set (7, control);
320}
321
322void
323i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
324{
325  gdb_assert (regnum >= 0 && regnum <= 4);
326
327  i386bsd_dr_set (regnum, addr);
328}
329
330void
331i386bsd_dr_reset_addr (int regnum)
332{
333  gdb_assert (regnum >= 0 && regnum <= 4);
334
335  i386bsd_dr_set (regnum, 0);
336}
337
338unsigned long
339i386bsd_dr_get_status (void)
340{
341  struct dbreg dbregs;
342
343  /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
344     ptrace call fails breaks debugging remote targets.  The correct
345     way to fix this is to add the hardware breakpoint and watchpoint
346     stuff to the target vector.  For now, just return zero if the
347     ptrace call fails.  */
348  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
349	      (PTRACE_ARG3_TYPE) & dbregs, 0) == -1)
350#if 0
351    perror_with_name ("Couldn't read debug registers");
352#else
353    return 0;
354#endif
355
356  return DBREG_DRX ((&dbregs), 6);
357}
358
359#endif /* PT_GETDBREGS */
360
361
362/* Support for the user struct.  */
363
364/* Return the address register REGNO.  BLOCKEND is the value of
365   u.u_ar0, which should point to the registers.  */
366
367CORE_ADDR
368register_u_addr (CORE_ADDR blockend, int regno)
369{
370  return (CORE_ADDR) REG_ADDR (blockend, regno);
371}
372
373#include <sys/param.h>
374#include <sys/user.h>
375
376/* Return the size of the user struct.  */
377
378int
379kernel_u_size (void)
380{
381  return (sizeof (struct user));
382}
383
384void
385_initialize_i386bsd_nat (void)
386{
387  int offset;
388
389  /* To support the recognition of signal handlers, i386bsd-tdep.c
390     hardcodes some constants.  Inclusion of this file means that we
391     are compiling a native debugger, which means that we can use the
392     system header files and sysctl(3) to get at the relevant
393     information.  */
394
395#if defined (__FreeBSD_version) && __FreeBSD_version >= 400011
396#define SC_REG_OFFSET i386fbsd4_sc_reg_offset
397#elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005
398#define SC_REG_OFFSET i386fbsd_sc_reg_offset
399#elif defined (NetBSD) || defined (__NetBSD_Version__)
400#define SC_REG_OFFSET i386nbsd_sc_reg_offset
401#elif defined (OpenBSD)
402#define SC_REG_OFFSET i386obsd_sc_reg_offset
403#else
404#define SC_REG_OFFSET i386bsd_sc_reg_offset
405#endif
406
407  /* We only check the program counter, stack pointer and frame
408     pointer since these members of `struct sigcontext' are essential
409     for providing backtraces.  More checks could be added, but would
410     involve adding configure checks for the appropriate structure
411     members, since older BSD's don't provide all of them.  */
412
413#define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM]
414#define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM]
415#define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM]
416
417  /* Override the default value for the offset of the program counter
418     in the sigcontext structure.  */
419  offset = offsetof (struct sigcontext, sc_pc);
420
421  if (SC_PC_OFFSET != offset)
422    {
423      warning ("\
424offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\
425Please report this to <bug-gdb@gnu.org>.",
426	       offset, SC_PC_OFFSET);
427    }
428
429  SC_PC_OFFSET = offset;
430
431  /* Likewise for the stack pointer.  */
432  offset = offsetof (struct sigcontext, sc_sp);
433
434  if (SC_SP_OFFSET != offset)
435    {
436      warning ("\
437offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\
438Please report this to <bug-gdb@gnu.org>.",
439	       offset, SC_SP_OFFSET);
440    }
441
442  SC_SP_OFFSET = offset;
443
444  /* And the frame pointer.  */
445  offset = offsetof (struct sigcontext, sc_fp);
446
447  if (SC_FP_OFFSET != offset)
448    {
449      warning ("\
450offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\
451Please report this to <bug-gdb@gnu.org>.",
452	       offset, SC_FP_OFFSET);
453    }
454
455  SC_FP_OFFSET = offset;
456}
457