[deliverable/binutils-gdb.git] / gdb / i386bsd-nat.c

/* Native-dependent code for modern i386 BSD's.

   Copyright 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "regcache.h"

#include "gdb_assert.h"
#include <signal.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <machine/reg.h>
#include <machine/frame.h>

#ifdef HAVE_SYS_PROCFS_H
#include <sys/procfs.h>
#endif

#ifndef HAVE_GREGSET_T
typedef struct reg gregset_t;
#endif

#ifndef HAVE_FPREGSET_T
typedef struct fpreg fpregset_t;
#endif

#include "i386-tdep.h"
#include "i387-tdep.h"
\f

/* In older BSD versions we cannot get at some of the segment
   registers.  FreeBSD for example didn't support the %fs and %gs
   registers until the 3.0 release.  We have autoconf checks for their
   presence, and deal gracefully with their absence.  */

/* Registers we shouldn't try to fetch.  */
#undef CANNOT_FETCH_REGISTER
#define CANNOT_FETCH_REGISTER(regnum) cannot_fetch_register (regnum)

/* Registers we shouldn't try to store.  */
#undef CANNOT_STORE_REGISTER
#define CANNOT_STORE_REGISTER(regnum) cannot_fetch_register (regnum)

/* Offset to the gregset_t location where REG is stored.  */
#define REG_OFFSET(reg) offsetof (gregset_t, reg)

/* At reg_offset[REGNUM] you'll find the offset to the gregset_t
   location where the GDB register REGNUM is stored.  Unsupported
   registers are marked with `-1'.  */
static int reg_offset[] =
{
  REG_OFFSET (r_eax),
  REG_OFFSET (r_ecx),
  REG_OFFSET (r_edx),
  REG_OFFSET (r_ebx),
  REG_OFFSET (r_esp),
  REG_OFFSET (r_ebp),
  REG_OFFSET (r_esi),
  REG_OFFSET (r_edi),
  REG_OFFSET (r_eip),
  REG_OFFSET (r_eflags),
  REG_OFFSET (r_cs),
  REG_OFFSET (r_ss),
  REG_OFFSET (r_ds),
  REG_OFFSET (r_es),
#ifdef HAVE_STRUCT_REG_R_FS
  REG_OFFSET (r_fs),
#else
  -1,
#endif
#ifdef HAVE_STRUCT_REG_R_GS
  REG_OFFSET (r_gs)
#else
  -1
#endif
};

#define REG_ADDR(regset, regnum) ((char *) (regset) + reg_offset[regnum])

/* Macro to determine if a register is fetched with PT_GETREGS.  */
#define GETREGS_SUPPLIES(regnum) \
  ((0 <= (regnum) && (regnum) <= 15))

#ifdef HAVE_PT_GETXMMREGS
/* Set to 1 if the kernel supports PT_GETXMMREGS.  Initialized to -1
   so that we try PT_GETXMMREGS the first time around.  */
static int have_ptrace_xmmregs = -1;
#endif

/* Return nonzero if we shouldn't try to fetch register REGNUM.  */

static int
cannot_fetch_register (int regnum)
{
  return (reg_offset[regnum] == -1);
}
\f

/* Transfering the registers between GDB, inferiors and core files.  */

/* Fill GDB's register array with the general-purpose register values
   in *GREGSETP.  */

static void
supply_gregset (gregset_t *gregsetp)
{
  struct regcache *regcache = current_regcache;
  int regnum;

  for (regnum = 0; regnum < I386_NUM_GREGS; regnum++)
    {
      if (CANNOT_FETCH_REGISTER (regnum))
	regcache_raw_supply (regcache, regnum, NULL);
      else
	regcache_raw_supply (regcache, regnum, REG_ADDR (gregsetp, regnum));
    }
}

/* Fill register REGNUM (if it is a general-purpose register) in
   *GREGSETPS with the value in GDB's register array.  If REGNUM is -1,
   do this for all registers.  */

static void
fill_gregset (gregset_t *gregsetp, int regnum)
{
  struct regcache *regcache = current_regcache;
  int i;

  for (i = 0; i < I386_NUM_GREGS; i++)
    if ((regnum == -1 || regnum == i) && ! CANNOT_STORE_REGISTER (i))
      regcache_raw_collect (regcache, i, REG_ADDR (gregsetp, i));
}


/* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
   for all registers (including the floating point registers).  */

void
fetch_inferior_registers (int regnum)
{
  if (regnum == -1 || GETREGS_SUPPLIES (regnum))
    {
      gregset_t gregs;

      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
		  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	perror_with_name ("Couldn't get registers");

      supply_gregset (&gregs);
      if (regnum != -1)
	return;
    }

  if (regnum == -1 || regnum >= I386_ST0_REGNUM)
    {
      fpregset_t fpregs;
#ifdef HAVE_PT_GETXMMREGS
      char xmmregs[512];

      if (have_ptrace_xmmregs != 0
	  && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
		    (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	{
	  have_ptrace_xmmregs = 1;
	  i387_supply_fxsave (current_regcache, -1, xmmregs);
	}
      else
	{
          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't get floating point status");

	  i387_supply_fsave (current_regcache, -1, &fpregs);
	}
#else
      if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		  (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	perror_with_name ("Couldn't get floating point status");

      i387_supply_fsave (current_regcache, -1, &fpregs);
#endif
    }
}

/* Store register REGNUM back into the inferior.  If REGNUM is -1, do
   this for all registers (including the floating point registers).  */

void
store_inferior_registers (int regnum)
{
  if (regnum == -1 || GETREGS_SUPPLIES (regnum))
    {
      gregset_t gregs;

      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
                  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
        perror_with_name ("Couldn't get registers");

      fill_gregset (&gregs, regnum);

      if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
	          (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
        perror_with_name ("Couldn't write registers");

      if (regnum != -1)
	return;
    }

  if (regnum == -1 || regnum >= I386_ST0_REGNUM)
    {
      fpregset_t fpregs;
#ifdef HAVE_PT_GETXMMREGS
      char xmmregs[512];

      if (have_ptrace_xmmregs != 0
	  && ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
		    (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	{
	  have_ptrace_xmmregs = 1;

	  i387_collect_fxsave (current_regcache, regnum, xmmregs);

	  if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) xmmregs, 0) == -1)
            perror_with_name ("Couldn't write XMM registers");
	}
      else
	{
	  have_ptrace_xmmregs = 0;
#endif
          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't get floating point status");

          i387_collect_fsave (current_regcache, regnum, &fpregs);

          if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't write floating point status");
#ifdef HAVE_PT_GETXMMREGS
        }
#endif
    }
}
\f

/* Support for debug registers.  */

#ifdef HAVE_PT_GETDBREGS

/* Not all versions of FreeBSD/i386 that support the debug registers
   have this macro.  */
#ifndef DBREG_DRX
#define DBREG_DRX(d, x) ((&d->dr0)[x])
#endif

static void
i386bsd_dr_set (int regnum, unsigned int value)
{
  struct dbreg dbregs;

  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
    perror_with_name ("Couldn't get debug registers");

  /* For some mysterious reason, some of the reserved bits in the
     debug control register get set.  Mask these off, otherwise the
     ptrace call below will fail.  */
  DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00);

  DBREG_DRX ((&dbregs), regnum) = value;

  if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid),
              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
    perror_with_name ("Couldn't write debug registers");
}

void
i386bsd_dr_set_control (unsigned long control)
{
  i386bsd_dr_set (7, control);
}

void
i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
{
  gdb_assert (regnum >= 0 && regnum <= 4);

  i386bsd_dr_set (regnum, addr);
}

void
i386bsd_dr_reset_addr (int regnum)
{
  gdb_assert (regnum >= 0 && regnum <= 4);

  i386bsd_dr_set (regnum, 0);
}

unsigned long
i386bsd_dr_get_status (void)
{
  struct dbreg dbregs;

  /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
     ptrace call fails breaks debugging remote targets.  The correct
     way to fix this is to add the hardware breakpoint and watchpoint
     stuff to the target vector.  For now, just return zero if the
     ptrace call fails.  */
  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
	      (PTRACE_ARG3_TYPE) & dbregs, 0) == -1)
#if 0
    perror_with_name ("Couldn't read debug registers");
#else
    return 0;
#endif

  return DBREG_DRX ((&dbregs), 6);
}

#endif /* PT_GETDBREGS */
\f

/* Support for the user struct.  */

/* Return the address register REGNUM.  BLOCKEND is the value of
   u.u_ar0, which should point to the registers.  */

CORE_ADDR
register_u_addr (CORE_ADDR blockend, int regnum)
{
  return (CORE_ADDR) REG_ADDR (blockend, regnum);
}

#include <sys/param.h>
#include <sys/user.h>

/* Return the size of the user struct.  */

int
kernel_u_size (void)
{
  return (sizeof (struct user));
}
\f
void
_initialize_i386bsd_nat (void)
{
  int offset;

  /* To support the recognition of signal handlers, i386bsd-tdep.c
     hardcodes some constants.  Inclusion of this file means that we
     are compiling a native debugger, which means that we can use the
     system header files and sysctl(3) to get at the relevant
     information.  */

#if defined (__FreeBSD_version) && __FreeBSD_version >= 400011
#define SC_REG_OFFSET i386fbsd4_sc_reg_offset
#elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005
#define SC_REG_OFFSET i386fbsd_sc_reg_offset
#elif defined (NetBSD) || defined (__NetBSD_Version__)
#define SC_REG_OFFSET i386nbsd_sc_reg_offset
#elif defined (OpenBSD)
#define SC_REG_OFFSET i386obsd_sc_reg_offset
#else
#define SC_REG_OFFSET i386bsd_sc_reg_offset
#endif

  /* We only check the program counter, stack pointer and frame
     pointer since these members of `struct sigcontext' are essential
     for providing backtraces.  More checks could be added, but would
     involve adding configure checks for the appropriate structure
     members, since older BSD's don't provide all of them.  */

#define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM]
#define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM]
#define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM]

  /* Override the default value for the offset of the program counter
     in the sigcontext structure.  */
  offset = offsetof (struct sigcontext, sc_pc);

  if (SC_PC_OFFSET != offset)
    {
      warning ("\
offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\
Please report this to <bug-gdb@gnu.org>.", 
	       offset, SC_PC_OFFSET);
    }

  SC_PC_OFFSET = offset;

  /* Likewise for the stack pointer.  */
  offset = offsetof (struct sigcontext, sc_sp);

  if (SC_SP_OFFSET != offset)
    {
      warning ("\
offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\
Please report this to <bug-gdb@gnu.org>.",
	       offset, SC_SP_OFFSET);
    }

  SC_SP_OFFSET = offset;

  /* And the frame pointer.  */
  offset = offsetof (struct sigcontext, sc_fp);

  if (SC_FP_OFFSET != offset)
    {
      warning ("\
offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\
Please report this to <bug-gdb@gnu.org>.",
	       offset, SC_FP_OFFSET);
    }

  SC_FP_OFFSET = offset;
}
Commit	Line	Data
	1	/* Native-dependent code for modern i386 BSD's.
	2
	3	Copyright 2000, 2001, 2002, 2003, 2004 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 2 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, write to the Free Software
	19	Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
	21
	22	#include "defs.h"
	23	#include "inferior.h"
	24	#include "regcache.h"
	25
	26	#include "gdb_assert.h"
	27	#include <signal.h>
	28	#include <stddef.h>
	29	#include <sys/types.h>
	30	#include <sys/ptrace.h>
	31	#include <machine/reg.h>
	32	#include <machine/frame.h>
	33
	34	#ifdef HAVE_SYS_PROCFS_H
	35	#include <sys/procfs.h>
	36	#endif
	37
	38	#ifndef HAVE_GREGSET_T
	39	typedef struct reg gregset_t;
	40	#endif
	41
	42	#ifndef HAVE_FPREGSET_T
	43	typedef struct fpreg fpregset_t;
	44	#endif
	45
	46	#include "i386-tdep.h"
	47	#include "i387-tdep.h"
	48	\f
	49
	50	/* In older BSD versions we cannot get at some of the segment
	51	registers. FreeBSD for example didn't support the %fs and %gs
	52	registers until the 3.0 release. We have autoconf checks for their
	53	presence, and deal gracefully with their absence. */
	54
	55	/* Registers we shouldn't try to fetch. */
	56	#undef CANNOT_FETCH_REGISTER
	57	#define CANNOT_FETCH_REGISTER(regnum) cannot_fetch_register (regnum)
	58
	59	/* Registers we shouldn't try to store. */
	60	#undef CANNOT_STORE_REGISTER
	61	#define CANNOT_STORE_REGISTER(regnum) cannot_fetch_register (regnum)
	62
	63	/* Offset to the gregset_t location where REG is stored. */
	64	#define REG_OFFSET(reg) offsetof (gregset_t, reg)
	65
	66	/* At reg_offset[REGNUM] you'll find the offset to the gregset_t
	67	location where the GDB register REGNUM is stored. Unsupported
	68	registers are marked with `-1'. */
	69	static int reg_offset[] =
	70	{
	71	REG_OFFSET (r_eax),
	72	REG_OFFSET (r_ecx),
	73	REG_OFFSET (r_edx),
	74	REG_OFFSET (r_ebx),
	75	REG_OFFSET (r_esp),
	76	REG_OFFSET (r_ebp),
	77	REG_OFFSET (r_esi),
	78	REG_OFFSET (r_edi),
	79	REG_OFFSET (r_eip),
	80	REG_OFFSET (r_eflags),
	81	REG_OFFSET (r_cs),
	82	REG_OFFSET (r_ss),
	83	REG_OFFSET (r_ds),
	84	REG_OFFSET (r_es),
	85	#ifdef HAVE_STRUCT_REG_R_FS
	86	REG_OFFSET (r_fs),
	87	#else
	88	-1,
	89	#endif
	90	#ifdef HAVE_STRUCT_REG_R_GS
	91	REG_OFFSET (r_gs)
	92	#else
	93	-1
	94	#endif
	95	};
	96
	97	#define REG_ADDR(regset, regnum) ((char *) (regset) + reg_offset[regnum])
	98
	99	/* Macro to determine if a register is fetched with PT_GETREGS. */
	100	#define GETREGS_SUPPLIES(regnum) \
	101	((0 <= (regnum) && (regnum) <= 15))
	102
	103	#ifdef HAVE_PT_GETXMMREGS
	104	/* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1
	105	so that we try PT_GETXMMREGS the first time around. */
	106	static int have_ptrace_xmmregs = -1;
	107	#endif
	108
	109	/* Return nonzero if we shouldn't try to fetch register REGNUM. */
	110
	111	static int
	112	cannot_fetch_register (int regnum)
	113	{
	114	return (reg_offset[regnum] == -1);
	115	}
	116	\f
	117
	118	/* Transfering the registers between GDB, inferiors and core files. */
	119
	120	/* Fill GDB's register array with the general-purpose register values
	121	in GREGSETP. /
	122
	123	static void
	124	supply_gregset (gregset_t *gregsetp)
	125	{
	126	struct regcache *regcache = current_regcache;
	127	int regnum;
	128
	129	for (regnum = 0; regnum < I386_NUM_GREGS; regnum++)
	130	{
	131	if (CANNOT_FETCH_REGISTER (regnum))
	132	regcache_raw_supply (regcache, regnum, NULL);
	133	else
	134	regcache_raw_supply (regcache, regnum, REG_ADDR (gregsetp, regnum));
	135	}
	136	}
	137
	138	/* Fill register REGNUM (if it is a general-purpose register) in
	139	*GREGSETPS with the value in GDB's register array. If REGNUM is -1,
	140	do this for all registers. */
	141
	142	static void
	143	fill_gregset (gregset_t *gregsetp, int regnum)
	144	{
	145	struct regcache *regcache = current_regcache;
	146	int i;
	147
	148	for (i = 0; i < I386_NUM_GREGS; i++)
	149	if ((regnum == -1 \|\| regnum == i) && ! CANNOT_STORE_REGISTER (i))
	150	regcache_raw_collect (regcache, i, REG_ADDR (gregsetp, i));
	151	}
	152
	153
	154
	155	/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
	156	for all registers (including the floating point registers). */
	157
	158	void
	159	fetch_inferior_registers (int regnum)
	160	{
	161	if (regnum == -1 \|\| GETREGS_SUPPLIES (regnum))
	162	{
	163	gregset_t gregs;
	164
	165	if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
	166	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	167	perror_with_name ("Couldn't get registers");
	168
	169	supply_gregset (&gregs);
	170	if (regnum != -1)
	171	return;
	172	}
	173
	174	if (regnum == -1 \|\| regnum >= I386_ST0_REGNUM)
	175	{
	176	fpregset_t fpregs;
	177	#ifdef HAVE_PT_GETXMMREGS
	178	char xmmregs[512];
	179
	180	if (have_ptrace_xmmregs != 0
	181	&& ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
	182	(PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	183	{
	184	have_ptrace_xmmregs = 1;
	185	i387_supply_fxsave (current_regcache, -1, xmmregs);
	186	}
	187	else
	188	{
	189	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
	190	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	191	perror_with_name ("Couldn't get floating point status");
	192
	193	i387_supply_fsave (current_regcache, -1, &fpregs);
	194	}
	195	#else
	196	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
	197	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	198	perror_with_name ("Couldn't get floating point status");
	199
	200	i387_supply_fsave (current_regcache, -1, &fpregs);
	201	#endif
	202	}
	203	}
	204
	205	/* Store register REGNUM back into the inferior. If REGNUM is -1, do
	206	this for all registers (including the floating point registers). */
	207
	208	void
	209	store_inferior_registers (int regnum)
	210	{
	211	if (regnum == -1 \|\| GETREGS_SUPPLIES (regnum))
	212	{
	213	gregset_t gregs;
	214
	215	if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
	216	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	217	perror_with_name ("Couldn't get registers");
	218
	219	fill_gregset (&gregs, regnum);
	220
	221	if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
	222	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	223	perror_with_name ("Couldn't write registers");
	224
	225	if (regnum != -1)
	226	return;
	227	}
	228
	229	if (regnum == -1 \|\| regnum >= I386_ST0_REGNUM)
	230	{
	231	fpregset_t fpregs;
	232	#ifdef HAVE_PT_GETXMMREGS
	233	char xmmregs[512];
	234
	235	if (have_ptrace_xmmregs != 0
	236	&& ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
	237	(PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	238	{
	239	have_ptrace_xmmregs = 1;
	240
	241	i387_collect_fxsave (current_regcache, regnum, xmmregs);
	242
	243	if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid),
	244	(PTRACE_ARG3_TYPE) xmmregs, 0) == -1)
	245	perror_with_name ("Couldn't write XMM registers");
	246	}
	247	else
	248	{
	249	have_ptrace_xmmregs = 0;
	250	#endif
	251	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
	252	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	253	perror_with_name ("Couldn't get floating point status");
	254
	255	i387_collect_fsave (current_regcache, regnum, &fpregs);
	256
	257	if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
	258	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	259	perror_with_name ("Couldn't write floating point status");
	260	#ifdef HAVE_PT_GETXMMREGS
	261	}
	262	#endif
	263	}
	264	}
	265	\f
	266
	267	/* Support for debug registers. */
	268
	269	#ifdef HAVE_PT_GETDBREGS
	270
	271	/* Not all versions of FreeBSD/i386 that support the debug registers
	272	have this macro. */
	273	#ifndef DBREG_DRX
	274	#define DBREG_DRX(d, x) ((&d->dr0)[x])
	275	#endif
	276
	277	static void
	278	i386bsd_dr_set (int regnum, unsigned int value)
	279	{
	280	struct dbreg dbregs;
	281
	282	if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
	283	(PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
	284	perror_with_name ("Couldn't get debug registers");
	285
	286	/* For some mysterious reason, some of the reserved bits in the
	287	debug control register get set. Mask these off, otherwise the
	288	ptrace call below will fail. */
	289	DBREG_DRX ((&dbregs), 7) &= ~(0x0000fc00);
	290
	291	DBREG_DRX ((&dbregs), regnum) = value;
	292
	293	if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid),
	294	(PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
	295	perror_with_name ("Couldn't write debug registers");
	296	}
	297
	298	void
	299	i386bsd_dr_set_control (unsigned long control)
	300	{
	301	i386bsd_dr_set (7, control);
	302	}
	303
	304	void
	305	i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
	306	{
	307	gdb_assert (regnum >= 0 && regnum <= 4);
	308
	309	i386bsd_dr_set (regnum, addr);
	310	}
	311
	312	void
	313	i386bsd_dr_reset_addr (int regnum)
	314	{
	315	gdb_assert (regnum >= 0 && regnum <= 4);
	316
	317	i386bsd_dr_set (regnum, 0);
	318	}
	319
	320	unsigned long
	321	i386bsd_dr_get_status (void)
	322	{
	323	struct dbreg dbregs;
	324
	325	/* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
	326	ptrace call fails breaks debugging remote targets. The correct
	327	way to fix this is to add the hardware breakpoint and watchpoint
	328	stuff to the target vector. For now, just return zero if the
	329	ptrace call fails. */
	330	if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
	331	(PTRACE_ARG3_TYPE) & dbregs, 0) == -1)
	332	#if 0
	333	perror_with_name ("Couldn't read debug registers");
	334	#else
	335	return 0;
	336	#endif
	337
	338	return DBREG_DRX ((&dbregs), 6);
	339	}
	340
	341	#endif /* PT_GETDBREGS */
	342	\f
	343
	344	/* Support for the user struct. */
	345
	346	/* Return the address register REGNUM. BLOCKEND is the value of
	347	u.u_ar0, which should point to the registers. */
	348
	349	CORE_ADDR
	350	register_u_addr (CORE_ADDR blockend, int regnum)
	351	{
	352	return (CORE_ADDR) REG_ADDR (blockend, regnum);
	353	}
	354
	355	#include <sys/param.h>
	356	#include <sys/user.h>
	357
	358	/* Return the size of the user struct. */
	359
	360	int
	361	kernel_u_size (void)
	362	{
	363	return (sizeof (struct user));
	364	}
	365	\f
	366	void
	367	_initialize_i386bsd_nat (void)
	368	{
	369	int offset;
	370
	371	/* To support the recognition of signal handlers, i386bsd-tdep.c
	372	hardcodes some constants. Inclusion of this file means that we
	373	are compiling a native debugger, which means that we can use the
	374	system header files and sysctl(3) to get at the relevant
	375	information. */
	376
	377	#if defined (__FreeBSD_version) && __FreeBSD_version >= 400011
	378	#define SC_REG_OFFSET i386fbsd4_sc_reg_offset
	379	#elif defined (__FreeBSD_version) && __FreeBSD_version >= 300005
	380	#define SC_REG_OFFSET i386fbsd_sc_reg_offset
	381	#elif defined (NetBSD) \|\| defined (__NetBSD_Version__)
	382	#define SC_REG_OFFSET i386nbsd_sc_reg_offset
	383	#elif defined (OpenBSD)
	384	#define SC_REG_OFFSET i386obsd_sc_reg_offset
	385	#else
	386	#define SC_REG_OFFSET i386bsd_sc_reg_offset
	387	#endif
	388
	389	/* We only check the program counter, stack pointer and frame
	390	pointer since these members of `struct sigcontext' are essential
	391	for providing backtraces. More checks could be added, but would
	392	involve adding configure checks for the appropriate structure
	393	members, since older BSD's don't provide all of them. */
	394
	395	#define SC_PC_OFFSET SC_REG_OFFSET[I386_EIP_REGNUM]
	396	#define SC_SP_OFFSET SC_REG_OFFSET[I386_ESP_REGNUM]
	397	#define SC_FP_OFFSET SC_REG_OFFSET[I386_EBP_REGNUM]
	398
	399	/* Override the default value for the offset of the program counter
	400	in the sigcontext structure. */
	401	offset = offsetof (struct sigcontext, sc_pc);
	402
	403	if (SC_PC_OFFSET != offset)
	404	{
	405	warning ("\
	406	offsetof (struct sigcontext, sc_pc) yields %d instead of %d.\n\
	407	Please report this to <bug-gdb@gnu.org>.",
	408	offset, SC_PC_OFFSET);
	409	}
	410
	411	SC_PC_OFFSET = offset;
	412
	413	/* Likewise for the stack pointer. */
	414	offset = offsetof (struct sigcontext, sc_sp);
	415
	416	if (SC_SP_OFFSET != offset)
	417	{
	418	warning ("\
	419	offsetof (struct sigcontext, sc_sp) yields %d instead of %d.\n\
	420	Please report this to <bug-gdb@gnu.org>.",
	421	offset, SC_SP_OFFSET);
	422	}
	423
	424	SC_SP_OFFSET = offset;
	425
	426	/* And the frame pointer. */
	427	offset = offsetof (struct sigcontext, sc_fp);
	428
	429	if (SC_FP_OFFSET != offset)
	430	{
	431	warning ("\
	432	offsetof (struct sigcontext, sc_fp) yields %d instead of %d.\n\
	433	Please report this to <bug-gdb@gnu.org>.",
	434	offset, SC_FP_OFFSET);
	435	}
	436
	437	SC_FP_OFFSET = offset;
	438	}