binutils-gdb/gdb/i386nbsd-tdep.c

307 lines
8.1 KiB
C

/* Target-dependent code for NetBSD/i386, for GDB.
Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002
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 "gdbtypes.h"
#include "gdbcore.h"
#include "regcache.h"
#include "arch-utils.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "nbsd-tdep.h"
#include "solib-svr4.h"
/* Map a GDB register number to an offset in the reg structure. */
static int regmap[] =
{
( 0 * 4), /* %eax */
( 1 * 4), /* %ecx */
( 2 * 4), /* %edx */
( 3 * 4), /* %ebx */
( 4 * 4), /* %esp */
( 5 * 4), /* %epb */
( 6 * 4), /* %esi */
( 7 * 4), /* %edi */
( 8 * 4), /* %eip */
( 9 * 4), /* %eflags */
(10 * 4), /* %cs */
(11 * 4), /* %ss */
(12 * 4), /* %ds */
(13 * 4), /* %es */
(14 * 4), /* %fs */
(15 * 4), /* %gs */
};
#define SIZEOF_STRUCT_REG (16 * 4)
static void
i386nbsd_supply_reg (char *regs, int regno)
{
int i;
for (i = 0; i <= 15; i++)
if (regno == i || regno == -1)
supply_register (i, regs + regmap[i]);
}
static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
CORE_ADDR ignore)
{
char *regs, *fsave;
/* We get everything from one section. */
if (which != 0)
return;
if (core_reg_size < (SIZEOF_STRUCT_REG + 108))
{
warning ("Wrong size register set in core file.");
return;
}
regs = core_reg_sect;
fsave = core_reg_sect + SIZEOF_STRUCT_REG;
/* Integer registers. */
i386nbsd_supply_reg (regs, -1);
/* Floating point registers. */
i387_supply_fsave (fsave);
}
static void
fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size,
int which, CORE_ADDR ignore)
{
switch (which)
{
case 0: /* Integer registers. */
if (core_reg_size != SIZEOF_STRUCT_REG)
warning ("Wrong size register set in core file.");
else
i386nbsd_supply_reg (core_reg_sect, -1);
break;
case 2: /* Floating point registers. */
if (core_reg_size != 108)
warning ("Wrong size FP register set in core file.");
else
i387_supply_fsave (core_reg_sect);
break;
case 3: /* "Extended" floating point registers. This is gdb-speak
for SSE/SSE2. */
if (core_reg_size != 512)
warning ("Wrong size XMM register set in core file.");
else
i387_supply_fxsave (core_reg_sect);
break;
default:
/* Don't know what kind of register request this is; just ignore it. */
break;
}
}
static struct core_fns i386nbsd_core_fns =
{
bfd_target_unknown_flavour, /* core_flavour */
default_check_format, /* check_format */
default_core_sniffer, /* core_sniffer */
fetch_core_registers, /* core_read_registers */
NULL /* next */
};
static struct core_fns i386nbsd_elfcore_fns =
{
bfd_target_elf_flavour, /* core_flavour */
default_check_format, /* check_format */
default_core_sniffer, /* core_sniffer */
fetch_elfcore_registers, /* core_read_registers */
NULL /* next */
};
/* Under NetBSD/i386, signal handler invocations can be identified by the
designated code sequence that is used to return from a signal handler.
In particular, the return address of a signal handler points to the
following code sequence:
leal 0x10(%esp), %eax
pushl %eax
pushl %eax
movl $0x127, %eax # __sigreturn14
int $0x80
Each instruction has a unique encoding, so we simply attempt to match
the instruction the PC is pointing to with any of the above instructions.
If there is a hit, we know the offset to the start of the designated
sequence and can then check whether we really are executing in the
signal trampoline. If not, -1 is returned, otherwise the offset from the
start of the return sequence is returned. */
#define RETCODE_INSN1 0x8d
#define RETCODE_INSN2 0x50
#define RETCODE_INSN3 0x50
#define RETCODE_INSN4 0xb8
#define RETCODE_INSN5 0xcd
#define RETCODE_INSN2_OFF 4
#define RETCODE_INSN3_OFF 5
#define RETCODE_INSN4_OFF 6
#define RETCODE_INSN5_OFF 11
static const unsigned char sigtramp_retcode[] =
{
RETCODE_INSN1, 0x44, 0x24, 0x10,
RETCODE_INSN2,
RETCODE_INSN3,
RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
RETCODE_INSN5, 0x80,
};
static LONGEST
i386nbsd_sigtramp_offset (CORE_ADDR pc)
{
unsigned char ret[sizeof(sigtramp_retcode)], insn;
LONGEST off;
int i;
if (read_memory_nobpt (pc, &insn, 1) != 0)
return -1;
switch (insn)
{
case RETCODE_INSN1:
off = 0;
break;
case RETCODE_INSN2:
/* INSN2 and INSN3 are the same. Read at the location of PC+1
to determine if we're actually looking at INSN2 or INSN3. */
if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
return -1;
if (insn == RETCODE_INSN3)
off = RETCODE_INSN2_OFF;
else
off = RETCODE_INSN3_OFF;
break;
case RETCODE_INSN4:
off = RETCODE_INSN4_OFF;
break;
case RETCODE_INSN5:
off = RETCODE_INSN5_OFF;
break;
default:
return -1;
}
pc -= off;
if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
return -1;
if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
return off;
return -1;
}
static int
i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
return (nbsd_pc_in_sigtramp (pc, name)
|| i386nbsd_sigtramp_offset (pc) >= 0);
}
/* From <machine/signal.h>. */
int i386nbsd_sc_pc_offset = 44;
int i386nbsd_sc_sp_offset = 56;
static void
i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Obviously NetBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
/* NetBSD has different signal trampoline conventions. */
set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp);
/* FIXME: kettenis/20020906: We should probably provide
NetBSD-specific versions of these functions if we want to
recognize signal trampolines that live on the stack. */
set_gdbarch_sigtramp_start (gdbarch, NULL);
set_gdbarch_sigtramp_end (gdbarch, NULL);
/* NetBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* NetBSD has a `struct sigcontext' that's different from the
origional 4.3 BSD. */
tdep->sc_pc_offset = i386nbsd_sc_pc_offset;
tdep->sc_sp_offset = i386nbsd_sc_sp_offset;
}
/* NetBSD ELF. */
static void
i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* It's still NetBSD. */
i386nbsd_init_abi (info, gdbarch);
/* But ELF-based. */
i386_elf_init_abi (info, gdbarch);
/* NetBSD ELF uses SVR4-style shared libraries. */
set_gdbarch_in_solib_call_trampoline (gdbarch,
generic_in_solib_call_trampoline);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
/* NetBSD ELF uses -fpcc-struct-return by default. */
tdep->struct_return = pcc_struct_return;
/* We support the SSE registers on NetBSD ELF. */
tdep->num_xmm_regs = I386_NUM_XREGS - 1;
set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS
+ I386_NUM_XREGS);
}
void
_initialize_i386nbsd_tdep (void)
{
add_core_fns (&i386nbsd_core_fns);
add_core_fns (&i386nbsd_elfcore_fns);
gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT,
i386nbsd_init_abi);
gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF,
i386nbsdelf_init_abi);
}