[deliverable/binutils-gdb.git] / gdb / i386nbsd-tdep.c

/* Target-dependent code for NetBSD/i386.

   Copyright 1988, 1989, 1991, 1992, 1994, 1996, 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 "gdbtypes.h"
#include "gdbcore.h"
#include "regcache.h"
#include "arch-utils.h"
#include "osabi.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 (current_regcache, -1, 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 (current_regcache, -1, 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 (current_regcache, -1, 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_reg_offset[I386_NUM_GREGS] =
{
  10 * 4,			/* %eax */
  9 * 4,			/* %ecx */
  8 * 4,			/* %edx */
  7 * 4,			/* %ebx */
  14 * 4,			/* %esp */
  6 * 4,			/* %ebp */
  5 * 4,			/* %esi */
  4 * 4,			/* %edi */
  11 * 4,			/* %eip */
  13 * 4,			/* %eflags */
  12 * 4,			/* %cs */
  15 * 4,			/* %ss */
  3 * 4,			/* %ds */
  2 * 4,			/* %es */
  1 * 4,			/* %fs */
  0 * 4				/* %gs */
};

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_reg_offset = i386nbsd_sc_reg_offset;
  tdep->sc_num_regs = I386_NUM_GREGS;
}

/* 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, 0, GDB_OSABI_NETBSD_AOUT,
			  i386nbsd_init_abi);
  gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
			  i386nbsdelf_init_abi);
}
Commit	Line	Data
ed504bdf MK	1	/* Target-dependent code for NetBSD/i386.
ed504bdf MK	2
4be87837	3	Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003
0fc93e6b C	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 "gdbtypes.h"
dfe6eb1f JT	25	#include "gdbcore.h"
dfe6eb1f JT	26	#include "regcache.h"
3cac699e	27	#include "arch-utils.h"
4be87837	28	#include "osabi.h"
0fc93e6b	29
3cac699e	30	#include "i386-tdep.h"
dfe6eb1f	31	#include "i387-tdep.h"
3cac699e	32	#include "nbsd-tdep.h"
dfe6eb1f	33
7d400e77 JT	34	#include "solib-svr4.h"
7d400e77 JT	35
dfe6eb1f JT	36	/* Map a GDB register number to an offset in the reg structure. */
	37	static int regmap[] =
	38	{
	39	( 0 * 4), /* %eax */
	40	( 1 * 4), /* %ecx */
	41	( 2 * 4), /* %edx */
	42	( 3 * 4), /* %ebx */
	43	( 4 * 4), /* %esp */
	44	( 5 * 4), /* %epb */
	45	( 6 * 4), /* %esi */
	46	( 7 * 4), /* %edi */
	47	( 8 * 4), /* %eip */
	48	( 9 * 4), /* %eflags */
	49	(10 * 4), /* %cs */
	50	(11 * 4), /* %ss */
	51	(12 * 4), /* %ds */
	52	(13 * 4), /* %es */
	53	(14 * 4), /* %fs */
	54	(15 * 4), /* %gs */
	55	};
	56
	57	#define SIZEOF_STRUCT_REG (16 * 4)
	58
	59	static void
	60	i386nbsd_supply_reg (char *regs, int regno)
	61	{
	62	int i;
	63
	64	for (i = 0; i <= 15; i++)
	65	if (regno == i \|\| regno == -1)
	66	supply_register (i, regs + regmap[i]);
	67	}
	68
	69	static void
	70	fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
	71	CORE_ADDR ignore)
	72	{
	73	char regs, fsave;
	74
	75	/* We get everything from one section. */
	76	if (which != 0)
	77	return;
	78
	79	if (core_reg_size < (SIZEOF_STRUCT_REG + 108))
	80	{
	81	warning ("Wrong size register set in core file.");
	82	return;
	83	}
	84
	85	regs = core_reg_sect;
	86	fsave = core_reg_sect + SIZEOF_STRUCT_REG;
	87
	88	/* Integer registers. */
	89	i386nbsd_supply_reg (regs, -1);
	90
	91	/* Floating point registers. */
41d041d6	92	i387_supply_fsave (current_regcache, -1, fsave);
dfe6eb1f JT	93	}
	94
	95	static void
6f558d74 MK	96	fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size,
6f558d74 MK	97	int which, CORE_ADDR ignore)
dfe6eb1f JT	98	{
	99	switch (which)
	100	{
	101	case 0: /* Integer registers. */
	102	if (core_reg_size != SIZEOF_STRUCT_REG)
	103	warning ("Wrong size register set in core file.");
	104	else
	105	i386nbsd_supply_reg (core_reg_sect, -1);
	106	break;
	107
	108	case 2: /* Floating point registers. */
	109	if (core_reg_size != 108)
ed504bdf	110	warning ("Wrong size FP register set in core file.");
dfe6eb1f	111	else
41d041d6	112	i387_supply_fsave (current_regcache, -1, core_reg_sect);
dfe6eb1f JT	113	break;
	114
	115	case 3: /* "Extended" floating point registers. This is gdb-speak
	116	for SSE/SSE2. */
	117	if (core_reg_size != 512)
	118	warning ("Wrong size XMM register set in core file.");
	119	else
41d041d6	120	i387_supply_fxsave (current_regcache, -1, core_reg_sect);
dfe6eb1f JT	121	break;
	122
	123	default:
	124	/* Don't know what kind of register request this is; just ignore it. */
	125	break;
	126	}
	127	}
	128
	129	static struct core_fns i386nbsd_core_fns =
	130	{
	131	bfd_target_unknown_flavour, /* core_flavour */
	132	default_check_format, /* check_format */
	133	default_core_sniffer, /* core_sniffer */
	134	fetch_core_registers, /* core_read_registers */
	135	NULL /* next */
	136	};
	137
	138	static struct core_fns i386nbsd_elfcore_fns =
	139	{
	140	bfd_target_elf_flavour, /* core_flavour */
	141	default_check_format, /* check_format */
	142	default_core_sniffer, /* core_sniffer */
	143	fetch_elfcore_registers, /* core_read_registers */
	144	NULL /* next */
	145	};
	146
d66198e1 JT	147	/* Under NetBSD/i386, signal handler invocations can be identified by the
	148	designated code sequence that is used to return from a signal handler.
	149	In particular, the return address of a signal handler points to the
	150	following code sequence:
	151
	152	leal 0x10(%esp), %eax
	153	pushl %eax
	154	pushl %eax
	155	movl $0x127, %eax # __sigreturn14
	156	int $0x80
	157
	158	Each instruction has a unique encoding, so we simply attempt to match
	159	the instruction the PC is pointing to with any of the above instructions.
	160	If there is a hit, we know the offset to the start of the designated
	161	sequence and can then check whether we really are executing in the
	162	signal trampoline. If not, -1 is returned, otherwise the offset from the
	163	start of the return sequence is returned. */
	164	#define RETCODE_INSN1 0x8d
	165	#define RETCODE_INSN2 0x50
	166	#define RETCODE_INSN3 0x50
	167	#define RETCODE_INSN4 0xb8
	168	#define RETCODE_INSN5 0xcd
	169
	170	#define RETCODE_INSN2_OFF 4
	171	#define RETCODE_INSN3_OFF 5
	172	#define RETCODE_INSN4_OFF 6
	173	#define RETCODE_INSN5_OFF 11
	174
	175	static const unsigned char sigtramp_retcode[] =
3cac699e	176	{
d66198e1 JT	177	RETCODE_INSN1, 0x44, 0x24, 0x10,
	178	RETCODE_INSN2,
	179	RETCODE_INSN3,
	180	RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
	181	RETCODE_INSN5, 0x80,
	182	};
	183
	184	static LONGEST
	185	i386nbsd_sigtramp_offset (CORE_ADDR pc)
	186	{
	187	unsigned char ret[sizeof(sigtramp_retcode)], insn;
	188	LONGEST off;
	189	int i;
	190
	191	if (read_memory_nobpt (pc, &insn, 1) != 0)
	192	return -1;
	193
	194	switch (insn)
	195	{
	196	case RETCODE_INSN1:
	197	off = 0;
	198	break;
	199
	200	case RETCODE_INSN2:
	201	/* INSN2 and INSN3 are the same. Read at the location of PC+1
	202	to determine if we're actually looking at INSN2 or INSN3. */
	203	if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
	204	return -1;
	205
	206	if (insn == RETCODE_INSN3)
	207	off = RETCODE_INSN2_OFF;
	208	else
	209	off = RETCODE_INSN3_OFF;
	210	break;
3cac699e	211
d66198e1 JT	212	case RETCODE_INSN4:
	213	off = RETCODE_INSN4_OFF;
	214	break;
	215
	216	case RETCODE_INSN5:
	217	off = RETCODE_INSN5_OFF;
	218	break;
	219
	220	default:
	221	return -1;
	222	}
	223
	224	pc -= off;
3cac699e	225
d66198e1 JT	226	if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
d66198e1 JT	227	return -1;
3cac699e	228
d66198e1 JT	229	if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
	230	return off;
	231
	232	return -1;
3cac699e JT	233	}
3cac699e JT	234
d66198e1 JT	235	static int
	236	i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
	237	{
d66198e1 JT	238	return (nbsd_pc_in_sigtramp (pc, name)
	239	\|\| i386nbsd_sigtramp_offset (pc) >= 0);
	240	}
3cac699e JT	241
3cac699e JT	242	/* From <machine/signal.h>. */
a3386186 MK	243	int i386nbsd_sc_reg_offset[I386_NUM_GREGS] =
	244	{
	245	10 * 4, /* %eax */
	246	9 * 4, /* %ecx */
	247	8 * 4, /* %edx */
	248	7 * 4, /* %ebx */
	249	14 * 4, /* %esp */
	250	6 * 4, /* %ebp */
	251	5 * 4, /* %esi */
	252	4 * 4, /* %edi */
	253	11 * 4, /* %eip */
	254	13 * 4, /* %eflags */
	255	12 * 4, /* %cs */
	256	15 * 4, /* %ss */
	257	3 * 4, /* %ds */
	258	2 * 4, /* %es */
	259	1 * 4, /* %fs */
	260	0 * 4 /* %gs */
	261	};
3cac699e JT	262
	263	static void
	264	i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	265	{
	266	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	267
	268	/* Obviously NetBSD is BSD-based. */
	269	i386bsd_init_abi (info, gdbarch);
	270
	271	/* NetBSD has different signal trampoline conventions. */
	272	set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp);
4b218c18 MK	273	/* FIXME: kettenis/20020906: We should probably provide
	274	NetBSD-specific versions of these functions if we want to
	275	recognize signal trampolines that live on the stack. */
	276	set_gdbarch_sigtramp_start (gdbarch, NULL);
	277	set_gdbarch_sigtramp_end (gdbarch, NULL);
3cac699e JT	278
	279	/* NetBSD uses -freg-struct-return by default. */
	280	tdep->struct_return = reg_struct_return;
	281
3cac699e JT	282	/* NetBSD has a `struct sigcontext' that's different from the
3cac699e JT	283	origional 4.3 BSD. */
a3386186 MK	284	tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
a3386186 MK	285	tdep->sc_num_regs = I386_NUM_GREGS;
3cac699e JT	286	}
	287
	288	/* NetBSD ELF. */
	289	static void
	290	i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	291	{
	292	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	293
	294	/* It's still NetBSD. */
	295	i386nbsd_init_abi (info, gdbarch);
	296
	297	/* But ELF-based. */
	298	i386_elf_init_abi (info, gdbarch);
	299
	300	/* NetBSD ELF uses SVR4-style shared libraries. */
	301	set_gdbarch_in_solib_call_trampoline (gdbarch,
	302	generic_in_solib_call_trampoline);
7d400e77 JT	303	set_solib_svr4_fetch_link_map_offsets (gdbarch,
7d400e77 JT	304	nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
3cac699e JT	305
	306	/* NetBSD ELF uses -fpcc-struct-return by default. */
	307	tdep->struct_return = pcc_struct_return;
	308
	309	/* We support the SSE registers on NetBSD ELF. */
	310	tdep->num_xmm_regs = I386_NUM_XREGS - 1;
	311	set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS
	312	+ I386_NUM_XREGS);
	313	}
	314
dfe6eb1f JT	315	void
	316	_initialize_i386nbsd_tdep (void)
	317	{
	318	add_core_fns (&i386nbsd_core_fns);
	319	add_core_fns (&i386nbsd_elfcore_fns);
3cac699e	320
05816f70	321	gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
3cac699e	322	i386nbsd_init_abi);
05816f70	323	gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
3cac699e	324	i386nbsdelf_init_abi);
dfe6eb1f	325	}