binutils-gdb/gdb/i386bsd-nat.c

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/* Native-dependent code for modern i386 BSD's.
Copyright 2000, 2001, 2002, 2003 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 "gregset.h"
#include "i386-tdep.h"
/* 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. */
#if !defined (CANNOT_FETCH_REGISTER)
#define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno)
#endif
/* Registers we shouldn't try to store. */
#if !defined (CANNOT_STORE_REGISTER)
#define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno)
#endif
/* Offset to the gregset_t location where REG is stored. */
#define REG_OFFSET(reg) offsetof (gregset_t, reg)
/* At reg_offset[REGNO] you'll find the offset to the gregset_t
location where the GDB register REGNO 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, regno) ((char *) (regset) + reg_offset[regno])
/* Macro to determine if a register is fetched with PT_GETREGS. */
#define GETREGS_SUPPLIES(regno) \
((0 <= (regno) && (regno) <= 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 REGNO. */
static int
cannot_fetch_register (int regno)
{
return (reg_offset[regno] == -1);
}
/* Transfering the registers between GDB, inferiors and core files. */
/* Fill GDB's register array with the general-purpose register values
in *GREGSETP. */
void
supply_gregset (gregset_t *gregsetp)
{
int i;
for (i = 0; i < I386_NUM_GREGS; i++)
{
if (CANNOT_FETCH_REGISTER (i))
supply_register (i, NULL);
else
supply_register (i, REG_ADDR (gregsetp, i));
}
}
/* Fill register REGNO (if it is a general-purpose register) in
*GREGSETPS with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_gregset (gregset_t *gregsetp, int regno)
{
int i;
for (i = 0; i < I386_NUM_GREGS; i++)
if ((regno == -1 || regno == i) && ! CANNOT_STORE_REGISTER (i))
regcache_collect (i, REG_ADDR (gregsetp, i));
}
#include "i387-tdep.h"
/* Fill GDB's register array with the floating-point register values
in *FPREGSETP. */
void
supply_fpregset (fpregset_t *fpregsetp)
{
i387_supply_fsave ((const char *) fpregsetp, -1);
}
/* Fill register REGNO (if it is a floating-point register) in
*FPREGSETP with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_fpregset (fpregset_t *fpregsetp, int regno)
{
i387_fill_fsave ((char *) fpregsetp, regno);
}
/* Fetch register REGNO from the inferior. If REGNO is -1, do this
for all registers (including the floating point registers). */
void
fetch_inferior_registers (int regno)
{
if (regno == -1 || GETREGS_SUPPLIES (regno))
{
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 (regno != -1)
return;
}
if (regno == -1 || regno >= FP0_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 (xmmregs, -1);
}
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 ((const char *) &fpregs, -1);
}
#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 ((const char *) &fpregs, -1);
#endif
}
}
/* Store register REGNO back into the inferior. If REGNO is -1, do
this for all registers (including the floating point registers). */
void
store_inferior_registers (int regno)
{
if (regno == -1 || GETREGS_SUPPLIES (regno))
{
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, regno);
if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
perror_with_name ("Couldn't write registers");
if (regno != -1)
return;
}
if (regno == -1 || regno >= FP0_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_fill_fxsave (xmmregs, regno);
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_fill_fsave ((char *) &fpregs, regno);
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
}
}
/* 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 */
/* Support for the user struct. */
/* Return the address register REGNO. BLOCKEND is the value of
u.u_ar0, which should point to the registers. */
CORE_ADDR
register_u_addr (CORE_ADDR blockend, int regno)
{
return (CORE_ADDR) REG_ADDR (blockend, regno);
}
#include <sys/param.h>
#include <sys/user.h>
/* Return the size of the user struct. */
int
kernel_u_size (void)
{
return (sizeof (struct user));
}
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;
}