[deliverable/binutils-gdb.git] / gdb / i386-fbsd-tdep.c

/* Target-dependent code for FreeBSD/i386.

   Copyright (C) 2003-2019 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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "arch-utils.h"
#include "gdbcore.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "i386-fbsd-tdep.h"
#include "common/x86-xstate.h"

#include "i386-tdep.h"
#include "i387-tdep.h"
#include "fbsd-tdep.h"
#include "solib-svr4.h"

/* Support for signal handlers.  */

/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
   routine.  */

/* FreeBSD/i386 supports three different signal trampolines, one for
   versions before 4.0, a second for 4.x, and a third for 5.0 and
   later.  To complicate matters, FreeBSD/i386 binaries running under
   an amd64 kernel use a different set of trampolines.  These
   trampolines differ from the i386 kernel trampolines in that they
   omit a middle section that conditionally restores %gs.  */

static const gdb_byte i386fbsd_sigtramp_start[] =
{
  0x8d, 0x44, 0x24, 0x20,       /* lea     SIGF_UC(%esp),%eax */
  0x50				/* pushl   %eax */
};

static const gdb_byte i386fbsd_sigtramp_middle[] =
{
  0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
				/* testl   $PSL_VM,UC_EFLAGS(%eax) */
  0x75, 0x03,			/* jne	   +3 */
  0x8e, 0x68, 0x14		/* mov	   UC_GS(%eax),%gs */
};

static const gdb_byte i386fbsd_sigtramp_end[] =
{
  0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl   $SYS_sigreturn,%eax */
  0x50,			/* pushl   %eax */
  0xcd, 0x80			/* int	   $0x80 */
};

static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] =
{
  0x8d, 0x44, 0x24, 0x14,	/* lea	   SIGF_UC4(%esp),%eax */
  0x50				/* pushl   %eax */
};

static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] =
{
  0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
				/* testl   $PSL_VM,UC4_EFLAGS(%eax) */
  0x75, 0x03,			/* jne	   +3 */
  0x8e, 0x68, 0x14		/* mov	   UC4_GS(%eax),%gs */
};

static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] =
{
  0xb8, 0x58, 0x01, 0x00, 0x00, /* movl    $344,%eax */
  0x50,			/* pushl   %eax */
  0xcd, 0x80			/* int	   $0x80 */
};

static const gdb_byte i386fbsd_osigtramp_start[] =
{
  0x8d, 0x44, 0x24, 0x14,	/* lea	   SIGF_SC(%esp),%eax */
  0x50				/* pushl   %eax */
};

static const gdb_byte i386fbsd_osigtramp_middle[] =
{
  0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00,
				/* testl   $PSL_VM,SC_PS(%eax) */
  0x75, 0x03,			/* jne	   +3 */
  0x8e, 0x68, 0x44		/* mov	   SC_GS(%eax),%gs */
};

static const gdb_byte i386fbsd_osigtramp_end[] =
{
  0xb8, 0x67, 0x00, 0x00, 0x00, /* movl    $103,%eax */
  0x50,			/* pushl   %eax */
  0xcd, 0x80			/* int	   $0x80 */
};

/* The three different trampolines are all the same size.  */
gdb_static_assert (sizeof i386fbsd_sigtramp_start
		   == sizeof i386fbsd_freebsd4_sigtramp_start);
gdb_static_assert (sizeof i386fbsd_sigtramp_start
		   == sizeof i386fbsd_osigtramp_start);
gdb_static_assert (sizeof i386fbsd_sigtramp_middle
		   == sizeof i386fbsd_freebsd4_sigtramp_middle);
gdb_static_assert (sizeof i386fbsd_sigtramp_middle
		   == sizeof i386fbsd_osigtramp_middle);
gdb_static_assert (sizeof i386fbsd_sigtramp_end
		   == sizeof i386fbsd_freebsd4_sigtramp_end);
gdb_static_assert (sizeof i386fbsd_sigtramp_end
		   == sizeof i386fbsd_osigtramp_end);

/* We assume that the middle is the largest chunk below.  */
gdb_static_assert (sizeof i386fbsd_sigtramp_middle
		   > sizeof i386fbsd_sigtramp_start);
gdb_static_assert (sizeof i386fbsd_sigtramp_middle
		   > sizeof i386fbsd_sigtramp_end);

static int
i386fbsd_sigtramp_p (struct frame_info *this_frame)
{
  CORE_ADDR pc = get_frame_pc (this_frame);
  gdb_byte buf[sizeof i386fbsd_sigtramp_middle];
  const gdb_byte *middle, *end;

  /* Look for a matching start.  */
  if (!safe_frame_unwind_memory (this_frame, pc, buf,
				 sizeof i386fbsd_sigtramp_start))
    return 0;
  if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start)
      == 0)
    {
      middle = i386fbsd_sigtramp_middle;
      end = i386fbsd_sigtramp_end;
    }
  else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start,
		   sizeof i386fbsd_freebsd4_sigtramp_start) == 0)
    {
      middle = i386fbsd_freebsd4_sigtramp_middle;
      end = i386fbsd_freebsd4_sigtramp_end;
    }
  else if (memcmp (buf, i386fbsd_osigtramp_start,
		   sizeof i386fbsd_osigtramp_start) == 0)
    {
      middle = i386fbsd_osigtramp_middle;
      end = i386fbsd_osigtramp_end;
    }
  else
    return 0;

  /* Since the end is shorter than the middle, check for a matching end
     next.  */
  pc += sizeof i386fbsd_sigtramp_start;
  if (!safe_frame_unwind_memory (this_frame, pc, buf,
				 sizeof i386fbsd_sigtramp_end))
    return 0;
  if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0)
    return 1;

  /* If the end didn't match, check for a matching middle.  */
  if (!safe_frame_unwind_memory (this_frame, pc, buf,
				 sizeof i386fbsd_sigtramp_middle))
    return 0;
  if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0)
    return 0;

  /* The middle matched, check for a matching end.  */
  pc += sizeof i386fbsd_sigtramp_middle;
  if (!safe_frame_unwind_memory (this_frame, pc, buf,
				 sizeof i386fbsd_sigtramp_end))
    return 0;
  if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0)
    return 0;

  return 1;
}

/* FreeBSD 3.0-RELEASE or later.  */

/* From <machine/reg.h>.  */
static int i386fbsd_r_reg_offset[] =
{
  9 * 4, 8 * 4, 7 * 4, 6 * 4,	/* %eax, %ecx, %edx, %ebx */
  15 * 4, 4 * 4,		/* %esp, %ebp */
  3 * 4, 2 * 4,			/* %esi, %edi */
  12 * 4, 14 * 4,		/* %eip, %eflags */
  13 * 4, 16 * 4,		/* %cs, %ss */
  1 * 4, 0 * 4, -1, -1		/* %ds, %es, %fs, %gs */
};

/* Sigtramp routine location.  */
CORE_ADDR i386fbsd_sigtramp_start_addr;
CORE_ADDR i386fbsd_sigtramp_end_addr;

/* From <machine/signal.h>.  */
int i386fbsd_sc_reg_offset[] =
{
  8 + 14 * 4,			/* %eax */
  8 + 13 * 4,			/* %ecx */
  8 + 12 * 4,			/* %edx */
  8 + 11 * 4,			/* %ebx */
  8 + 0 * 4,                    /* %esp */
  8 + 1 * 4,                    /* %ebp */
  8 + 10 * 4,                   /* %esi */
  8 + 9 * 4,                    /* %edi */
  8 + 3 * 4,                    /* %eip */
  8 + 4 * 4,                    /* %eflags */
  8 + 7 * 4,                    /* %cs */
  8 + 8 * 4,                    /* %ss */
  8 + 6 * 4,                    /* %ds */
  8 + 5 * 4,                    /* %es */
  8 + 15 * 4,			/* %fs */
  8 + 16 * 4			/* %gs */
};

/* Get XSAVE extended state xcr0 from core dump.  */

uint64_t
i386fbsd_core_read_xcr0 (bfd *abfd)
{
  asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate");
  uint64_t xcr0;

  if (xstate)
    {
      size_t size = bfd_section_size (abfd, xstate);

      /* Check extended state size.  */
      if (size < X86_XSTATE_AVX_SIZE)
	xcr0 = X86_XSTATE_SSE_MASK;
      else
	{
	  char contents[8];

	  if (! bfd_get_section_contents (abfd, xstate, contents,
					  I386_FBSD_XSAVE_XCR0_OFFSET,
					  8))
	    {
	      warning (_("Couldn't read `xcr0' bytes from "
			 "`.reg-xstate' section in core file."));
	      return X86_XSTATE_SSE_MASK;
	    }

	  xcr0 = bfd_get_64 (abfd, contents);
	}
    }
  else
    xcr0 = X86_XSTATE_SSE_MASK;

  return xcr0;
}

/* Implement the core_read_description gdbarch method.  */

static const struct target_desc *
i386fbsd_core_read_description (struct gdbarch *gdbarch,
				struct target_ops *target,
				bfd *abfd)
{
  return i386_target_description (i386fbsd_core_read_xcr0 (abfd));
}

/* Similar to i386_supply_fpregset, but use XSAVE extended state.  */

static void
i386fbsd_supply_xstateregset (const struct regset *regset,
			      struct regcache *regcache, int regnum,
			      const void *xstateregs, size_t len)
{
  i387_supply_xsave (regcache, regnum, xstateregs);
}

/* Similar to i386_collect_fpregset, but use XSAVE extended state.  */

static void
i386fbsd_collect_xstateregset (const struct regset *regset,
			       const struct regcache *regcache,
			       int regnum, void *xstateregs, size_t len)
{
  i387_collect_xsave (regcache, regnum, xstateregs, 1);
}

/* Register set definitions.  */

static const struct regset i386fbsd_xstateregset =
  {
    NULL,
    i386fbsd_supply_xstateregset,
    i386fbsd_collect_xstateregset
  };

/* Iterate over core file register note sections.  */

static void
i386fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
				       iterate_over_regset_sections_cb *cb,
				       void *cb_data,
				       const struct regcache *regcache)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  cb (".reg", tdep->sizeof_gregset, tdep->sizeof_gregset, &i386_gregset, NULL,
      cb_data);
  cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &i386_fpregset,
      NULL, cb_data);

  if (tdep->xcr0 & X86_XSTATE_AVX)
    cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
	X86_XSTATE_SIZE (tdep->xcr0), &i386fbsd_xstateregset,
	"XSAVE extended state", cb_data);
}

static void
i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  /* Obviously FreeBSD is BSD-based.  */
  i386bsd_init_abi (info, gdbarch);

  /* FreeBSD has a different `struct reg', and reserves some space for
     its FPU emulator in `struct fpreg'.  */
  tdep->gregset_reg_offset = i386fbsd_r_reg_offset;
  tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd_r_reg_offset);
  tdep->sizeof_gregset = 18 * 4;
  tdep->sizeof_fpregset = 176;

  /* FreeBSD uses -freg-struct-return by default.  */
  tdep->struct_return = reg_struct_return;

  tdep->sigtramp_p = i386fbsd_sigtramp_p;

  /* FreeBSD uses a different memory layout.  */
  tdep->sigtramp_start = i386fbsd_sigtramp_start_addr;
  tdep->sigtramp_end = i386fbsd_sigtramp_end_addr;

  /* FreeBSD has a more complete `struct sigcontext'.  */
  tdep->sc_reg_offset = i386fbsd_sc_reg_offset;
  tdep->sc_num_regs = ARRAY_SIZE (i386fbsd_sc_reg_offset);

  i386_elf_init_abi (info, gdbarch);

  /* FreeBSD uses SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
}

/* FreeBSD 4.0-RELEASE or later.  */

/* From <machine/reg.h>.  */
static int i386fbsd4_r_reg_offset[] =
{
  10 * 4, 9 * 4, 8 * 4, 7 * 4,	/* %eax, %ecx, %edx, %ebx */
  16 * 4, 5 * 4,		/* %esp, %ebp */
  4 * 4, 3 * 4,			/* %esi, %edi */
  13 * 4, 15 * 4,		/* %eip, %eflags */
  14 * 4, 17 * 4,		/* %cs, %ss */
  2 * 4, 1 * 4, 0 * 4, 18 * 4	/* %ds, %es, %fs, %gs */
};

/* From <machine/signal.h>.  */
int i386fbsd4_sc_reg_offset[] =
{
  20 + 11 * 4,			/* %eax */
  20 + 10 * 4,			/* %ecx */
  20 + 9 * 4,			/* %edx */
  20 + 8 * 4,			/* %ebx */
  20 + 17 * 4,			/* %esp */
  20 + 6 * 4,			/* %ebp */
  20 + 5 * 4,			/* %esi */
  20 + 4 * 4,			/* %edi */
  20 + 14 * 4,			/* %eip */
  20 + 16 * 4,			/* %eflags */
  20 + 15 * 4,			/* %cs */
  20 + 18 * 4,			/* %ss */
  20 + 3 * 4,			/* %ds */
  20 + 2 * 4,			/* %es */
  20 + 1 * 4,			/* %fs */
  20 + 0 * 4			/* %gs */
};

static void
i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  /* Generic FreeBSD support. */
  fbsd_init_abi (info, gdbarch);

  /* Inherit stuff from older releases.  We assume that FreeBSD
     4.0-RELEASE always uses ELF.  */
  i386fbsd_init_abi (info, gdbarch);

  /* FreeBSD 4.0 introduced a new `struct reg'.  */
  tdep->gregset_reg_offset = i386fbsd4_r_reg_offset;
  tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd4_r_reg_offset);
  tdep->sizeof_gregset = 19 * 4;

  /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
  tdep->sc_reg_offset = i386fbsd4_sc_reg_offset;
  tdep->sc_num_regs = ARRAY_SIZE (i386fbsd4_sc_reg_offset);

  tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;

  /* Iterate over core file register note sections.  */
  set_gdbarch_iterate_over_regset_sections
    (gdbarch, i386fbsd_iterate_over_regset_sections);

  set_gdbarch_core_read_description (gdbarch,
				     i386fbsd_core_read_description);
}

void
_initialize_i386fbsd_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD,
			  i386fbsd4_init_abi);
}
Commit	Line	Data
	1	/* Target-dependent code for FreeBSD/i386.
	2
	3	Copyright (C) 2003-2019 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 3 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, see <http://www.gnu.org/licenses/>. */
	19
	20	#include "defs.h"
	21	#include "arch-utils.h"
	22	#include "gdbcore.h"
	23	#include "osabi.h"
	24	#include "regcache.h"
	25	#include "regset.h"
	26	#include "i386-fbsd-tdep.h"
	27	#include "common/x86-xstate.h"
	28
	29	#include "i386-tdep.h"
	30	#include "i387-tdep.h"
	31	#include "fbsd-tdep.h"
	32	#include "solib-svr4.h"
	33
	34	/* Support for signal handlers. */
	35
	36	/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
	37	routine. */
	38
	39	/* FreeBSD/i386 supports three different signal trampolines, one for
	40	versions before 4.0, a second for 4.x, and a third for 5.0 and
	41	later. To complicate matters, FreeBSD/i386 binaries running under
	42	an amd64 kernel use a different set of trampolines. These
	43	trampolines differ from the i386 kernel trampolines in that they
	44	omit a middle section that conditionally restores %gs. */
	45
	46	static const gdb_byte i386fbsd_sigtramp_start[] =
	47	{
	48	0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */
	49	0x50 /* pushl %eax */
	50	};
	51
	52	static const gdb_byte i386fbsd_sigtramp_middle[] =
	53	{
	54	0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
	55	/* testl $PSL_VM,UC_EFLAGS(%eax) */
	56	0x75, 0x03, /* jne +3 */
	57	0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */
	58	};
	59
	60	static const gdb_byte i386fbsd_sigtramp_end[] =
	61	{
	62	0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */
	63	0x50, /* pushl %eax */
	64	0xcd, 0x80 /* int $0x80 */
	65	};
	66
	67	static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] =
	68	{
	69	0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */
	70	0x50 /* pushl %eax */
	71	};
	72
	73	static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] =
	74	{
	75	0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
	76	/* testl $PSL_VM,UC4_EFLAGS(%eax) */
	77	0x75, 0x03, /* jne +3 */
	78	0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */
	79	};
	80
	81	static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] =
	82	{
	83	0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */
	84	0x50, /* pushl %eax */
	85	0xcd, 0x80 /* int $0x80 */
	86	};
	87
	88	static const gdb_byte i386fbsd_osigtramp_start[] =
	89	{
	90	0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */
	91	0x50 /* pushl %eax */
	92	};
	93
	94	static const gdb_byte i386fbsd_osigtramp_middle[] =
	95	{
	96	0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00,
	97	/* testl $PSL_VM,SC_PS(%eax) */
	98	0x75, 0x03, /* jne +3 */
	99	0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */
	100	};
	101
	102	static const gdb_byte i386fbsd_osigtramp_end[] =
	103	{
	104	0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */
	105	0x50, /* pushl %eax */
	106	0xcd, 0x80 /* int $0x80 */
	107	};
	108
	109	/* The three different trampolines are all the same size. */
	110	gdb_static_assert (sizeof i386fbsd_sigtramp_start
	111	== sizeof i386fbsd_freebsd4_sigtramp_start);
	112	gdb_static_assert (sizeof i386fbsd_sigtramp_start
	113	== sizeof i386fbsd_osigtramp_start);
	114	gdb_static_assert (sizeof i386fbsd_sigtramp_middle
	115	== sizeof i386fbsd_freebsd4_sigtramp_middle);
	116	gdb_static_assert (sizeof i386fbsd_sigtramp_middle
	117	== sizeof i386fbsd_osigtramp_middle);
	118	gdb_static_assert (sizeof i386fbsd_sigtramp_end
	119	== sizeof i386fbsd_freebsd4_sigtramp_end);
	120	gdb_static_assert (sizeof i386fbsd_sigtramp_end
	121	== sizeof i386fbsd_osigtramp_end);
	122
	123	/* We assume that the middle is the largest chunk below. */
	124	gdb_static_assert (sizeof i386fbsd_sigtramp_middle
	125	> sizeof i386fbsd_sigtramp_start);
	126	gdb_static_assert (sizeof i386fbsd_sigtramp_middle
	127	> sizeof i386fbsd_sigtramp_end);
	128
	129	static int
	130	i386fbsd_sigtramp_p (struct frame_info *this_frame)
	131	{
	132	CORE_ADDR pc = get_frame_pc (this_frame);
	133	gdb_byte buf[sizeof i386fbsd_sigtramp_middle];
	134	const gdb_byte middle, end;
	135
	136	/* Look for a matching start. */
	137	if (!safe_frame_unwind_memory (this_frame, pc, buf,
	138	sizeof i386fbsd_sigtramp_start))
	139	return 0;
	140	if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start)
	141	== 0)
	142	{
	143	middle = i386fbsd_sigtramp_middle;
	144	end = i386fbsd_sigtramp_end;
	145	}
	146	else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start,
	147	sizeof i386fbsd_freebsd4_sigtramp_start) == 0)
	148	{
	149	middle = i386fbsd_freebsd4_sigtramp_middle;
	150	end = i386fbsd_freebsd4_sigtramp_end;
	151	}
	152	else if (memcmp (buf, i386fbsd_osigtramp_start,
	153	sizeof i386fbsd_osigtramp_start) == 0)
	154	{
	155	middle = i386fbsd_osigtramp_middle;
	156	end = i386fbsd_osigtramp_end;
	157	}
	158	else
	159	return 0;
	160
	161	/* Since the end is shorter than the middle, check for a matching end
	162	next. */
	163	pc += sizeof i386fbsd_sigtramp_start;
	164	if (!safe_frame_unwind_memory (this_frame, pc, buf,
	165	sizeof i386fbsd_sigtramp_end))
	166	return 0;
	167	if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0)
	168	return 1;
	169
	170	/* If the end didn't match, check for a matching middle. */
	171	if (!safe_frame_unwind_memory (this_frame, pc, buf,
	172	sizeof i386fbsd_sigtramp_middle))
	173	return 0;
	174	if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0)
	175	return 0;
	176
	177	/* The middle matched, check for a matching end. */
	178	pc += sizeof i386fbsd_sigtramp_middle;
	179	if (!safe_frame_unwind_memory (this_frame, pc, buf,
	180	sizeof i386fbsd_sigtramp_end))
	181	return 0;
	182	if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0)
	183	return 0;
	184
	185	return 1;
	186	}
	187
	188	/* FreeBSD 3.0-RELEASE or later. */
	189
	190	/* From <machine/reg.h>. */
	191	static int i386fbsd_r_reg_offset[] =
	192	{
	193	9 * 4, 8 * 4, 7 * 4, 6 * 4, /* %eax, %ecx, %edx, %ebx */
	194	15 * 4, 4 * 4, /* %esp, %ebp */
	195	3 * 4, 2 * 4, /* %esi, %edi */
	196	12 * 4, 14 * 4, /* %eip, %eflags */
	197	13 * 4, 16 * 4, /* %cs, %ss */
	198	1 * 4, 0 * 4, -1, -1 /* %ds, %es, %fs, %gs */
	199	};
	200
	201	/* Sigtramp routine location. */
	202	CORE_ADDR i386fbsd_sigtramp_start_addr;
	203	CORE_ADDR i386fbsd_sigtramp_end_addr;
	204
	205	/* From <machine/signal.h>. */
	206	int i386fbsd_sc_reg_offset[] =
	207	{
	208	8 + 14 * 4, /* %eax */
	209	8 + 13 * 4, /* %ecx */
	210	8 + 12 * 4, /* %edx */
	211	8 + 11 * 4, /* %ebx */
	212	8 + 0 * 4, /* %esp */
	213	8 + 1 * 4, /* %ebp */
	214	8 + 10 * 4, /* %esi */
	215	8 + 9 * 4, /* %edi */
	216	8 + 3 * 4, /* %eip */
	217	8 + 4 * 4, /* %eflags */
	218	8 + 7 * 4, /* %cs */
	219	8 + 8 * 4, /* %ss */
	220	8 + 6 * 4, /* %ds */
	221	8 + 5 * 4, /* %es */
	222	8 + 15 * 4, /* %fs */
	223	8 + 16 * 4 /* %gs */
	224	};
	225
	226	/* Get XSAVE extended state xcr0 from core dump. */
	227
	228	uint64_t
	229	i386fbsd_core_read_xcr0 (bfd *abfd)
	230	{
	231	asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate");
	232	uint64_t xcr0;
	233
	234	if (xstate)
	235	{
	236	size_t size = bfd_section_size (abfd, xstate);
	237
	238	/* Check extended state size. */
	239	if (size < X86_XSTATE_AVX_SIZE)
	240	xcr0 = X86_XSTATE_SSE_MASK;
	241	else
	242	{
	243	char contents[8];
	244
	245	if (! bfd_get_section_contents (abfd, xstate, contents,
	246	I386_FBSD_XSAVE_XCR0_OFFSET,
	247	8))
	248	{
	249	warning (_("Couldn't read `xcr0' bytes from "
	250	"`.reg-xstate' section in core file."));
	251	return X86_XSTATE_SSE_MASK;
	252	}
	253
	254	xcr0 = bfd_get_64 (abfd, contents);
	255	}
	256	}
	257	else
	258	xcr0 = X86_XSTATE_SSE_MASK;
	259
	260	return xcr0;
	261	}
	262
	263	/* Implement the core_read_description gdbarch method. */
	264
	265	static const struct target_desc *
	266	i386fbsd_core_read_description (struct gdbarch *gdbarch,
	267	struct target_ops *target,
	268	bfd *abfd)
	269	{
	270	return i386_target_description (i386fbsd_core_read_xcr0 (abfd));
	271	}
	272
	273	/* Similar to i386_supply_fpregset, but use XSAVE extended state. */
	274
	275	static void
	276	i386fbsd_supply_xstateregset (const struct regset *regset,
	277	struct regcache *regcache, int regnum,
	278	const void *xstateregs, size_t len)
	279	{
	280	i387_supply_xsave (regcache, regnum, xstateregs);
	281	}
	282
	283	/* Similar to i386_collect_fpregset, but use XSAVE extended state. */
	284
	285	static void
	286	i386fbsd_collect_xstateregset (const struct regset *regset,
	287	const struct regcache *regcache,
	288	int regnum, void *xstateregs, size_t len)
	289	{
	290	i387_collect_xsave (regcache, regnum, xstateregs, 1);
	291	}
	292
	293	/* Register set definitions. */
	294
	295	static const struct regset i386fbsd_xstateregset =
	296	{
	297	NULL,
	298	i386fbsd_supply_xstateregset,
	299	i386fbsd_collect_xstateregset
	300	};
	301
	302	/* Iterate over core file register note sections. */
	303
	304	static void
	305	i386fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
	306	iterate_over_regset_sections_cb *cb,
	307	void *cb_data,
	308	const struct regcache *regcache)
	309	{
	310	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	311
	312	cb (".reg", tdep->sizeof_gregset, tdep->sizeof_gregset, &i386_gregset, NULL,
	313	cb_data);
	314	cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &i386_fpregset,
	315	NULL, cb_data);
	316
	317	if (tdep->xcr0 & X86_XSTATE_AVX)
	318	cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
	319	X86_XSTATE_SIZE (tdep->xcr0), &i386fbsd_xstateregset,
	320	"XSAVE extended state", cb_data);
	321	}
	322
	323	static void
	324	i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	325	{
	326	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	327
	328	/* Obviously FreeBSD is BSD-based. */
	329	i386bsd_init_abi (info, gdbarch);
	330
	331	/* FreeBSD has a different `struct reg', and reserves some space for
	332	its FPU emulator in `struct fpreg'. */
	333	tdep->gregset_reg_offset = i386fbsd_r_reg_offset;
	334	tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd_r_reg_offset);
	335	tdep->sizeof_gregset = 18 * 4;
	336	tdep->sizeof_fpregset = 176;
	337
	338	/* FreeBSD uses -freg-struct-return by default. */
	339	tdep->struct_return = reg_struct_return;
	340
	341	tdep->sigtramp_p = i386fbsd_sigtramp_p;
	342
	343	/* FreeBSD uses a different memory layout. */
	344	tdep->sigtramp_start = i386fbsd_sigtramp_start_addr;
	345	tdep->sigtramp_end = i386fbsd_sigtramp_end_addr;
	346
	347	/* FreeBSD has a more complete `struct sigcontext'. */
	348	tdep->sc_reg_offset = i386fbsd_sc_reg_offset;
	349	tdep->sc_num_regs = ARRAY_SIZE (i386fbsd_sc_reg_offset);
	350
	351	i386_elf_init_abi (info, gdbarch);
	352
	353	/* FreeBSD uses SVR4-style shared libraries. */
	354	set_solib_svr4_fetch_link_map_offsets
	355	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
	356	}
	357
	358	/* FreeBSD 4.0-RELEASE or later. */
	359
	360	/* From <machine/reg.h>. */
	361	static int i386fbsd4_r_reg_offset[] =
	362	{
	363	10 * 4, 9 * 4, 8 * 4, 7 * 4, /* %eax, %ecx, %edx, %ebx */
	364	16 * 4, 5 * 4, /* %esp, %ebp */
	365	4 * 4, 3 * 4, /* %esi, %edi */
	366	13 * 4, 15 * 4, /* %eip, %eflags */
	367	14 * 4, 17 * 4, /* %cs, %ss */
	368	2 * 4, 1 * 4, 0 * 4, 18 * 4 /* %ds, %es, %fs, %gs */
	369	};
	370
	371	/* From <machine/signal.h>. */
	372	int i386fbsd4_sc_reg_offset[] =
	373	{
	374	20 + 11 * 4, /* %eax */
	375	20 + 10 * 4, /* %ecx */
	376	20 + 9 * 4, /* %edx */
	377	20 + 8 * 4, /* %ebx */
	378	20 + 17 * 4, /* %esp */
	379	20 + 6 * 4, /* %ebp */
	380	20 + 5 * 4, /* %esi */
	381	20 + 4 * 4, /* %edi */
	382	20 + 14 * 4, /* %eip */
	383	20 + 16 * 4, /* %eflags */
	384	20 + 15 * 4, /* %cs */
	385	20 + 18 * 4, /* %ss */
	386	20 + 3 * 4, /* %ds */
	387	20 + 2 * 4, /* %es */
	388	20 + 1 * 4, /* %fs */
	389	20 + 0 * 4 /* %gs */
	390	};
	391
	392	static void
	393	i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	394	{
	395	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	396
	397	/* Generic FreeBSD support. */
	398	fbsd_init_abi (info, gdbarch);
	399
	400	/* Inherit stuff from older releases. We assume that FreeBSD
	401	4.0-RELEASE always uses ELF. */
	402	i386fbsd_init_abi (info, gdbarch);
	403
	404	/* FreeBSD 4.0 introduced a new `struct reg'. */
	405	tdep->gregset_reg_offset = i386fbsd4_r_reg_offset;
	406	tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd4_r_reg_offset);
	407	tdep->sizeof_gregset = 19 * 4;
	408
	409	/* FreeBSD 4.0 introduced a new `struct sigcontext'. */
	410	tdep->sc_reg_offset = i386fbsd4_sc_reg_offset;
	411	tdep->sc_num_regs = ARRAY_SIZE (i386fbsd4_sc_reg_offset);
	412
	413	tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
	414
	415	/* Iterate over core file register note sections. */
	416	set_gdbarch_iterate_over_regset_sections
	417	(gdbarch, i386fbsd_iterate_over_regset_sections);
	418
	419	set_gdbarch_core_read_description (gdbarch,
	420	i386fbsd_core_read_description);
	421	}
	422
	423	void
	424	_initialize_i386fbsd_tdep (void)
	425	{
	426	gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD,
	427	i386fbsd4_init_abi);
	428	}