[deliverable/binutils-gdb.git] / gdb / amd64-fbsd-nat.c

/* Native-dependent code for FreeBSD/amd64.

   Copyright (C) 2003-2017 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 "inferior.h"
#include "regcache.h"
#include "target.h"

#include <signal.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <machine/reg.h>

#include "fbsd-nat.h"
#include "amd64-tdep.h"
#include "amd64-nat.h"
#include "x86-bsd-nat.h"
#include "x86-nat.h"
\f

/* Offset in `struct reg' where MEMBER is stored.  */
#define REG_OFFSET(member) offsetof (struct reg, member)

/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
   `struct reg' location where the GDB register REGNUM is stored.
   Unsupported registers are marked with `-1'.  */
static int amd64fbsd64_r_reg_offset[] =
{
  REG_OFFSET (r_rax),
  REG_OFFSET (r_rbx),
  REG_OFFSET (r_rcx),
  REG_OFFSET (r_rdx),
  REG_OFFSET (r_rsi),
  REG_OFFSET (r_rdi),
  REG_OFFSET (r_rbp),
  REG_OFFSET (r_rsp),
  REG_OFFSET (r_r8),
  REG_OFFSET (r_r9),
  REG_OFFSET (r_r10),
  REG_OFFSET (r_r11),
  REG_OFFSET (r_r12),
  REG_OFFSET (r_r13),
  REG_OFFSET (r_r14),
  REG_OFFSET (r_r15),
  REG_OFFSET (r_rip),
  REG_OFFSET (r_rflags),
  REG_OFFSET (r_cs),
  REG_OFFSET (r_ss),
  -1,
  -1,
  -1,
  -1
};
\f

/* Mapping between the general-purpose registers in FreeBSD/amd64
   `struct reg' format and GDB's register cache layout for
   FreeBSD/i386.

   Note that most FreeBSD/amd64 registers are 64-bit, while the
   FreeBSD/i386 registers are all 32-bit, but since we're
   little-endian we get away with that.  */

/* From <machine/reg.h>.  */
static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
{
  14 * 8, 13 * 8,		/* %eax, %ecx */
  12 * 8, 11 * 8,		/* %edx, %ebx */
  20 * 8, 10 * 8,		/* %esp, %ebp */
  9 * 8, 8 * 8,			/* %esi, %edi */
  17 * 8, 19 * 8,		/* %eip, %eflags */
  18 * 8, 21 * 8,		/* %cs, %ss */
  -1, -1, -1, -1		/* %ds, %es, %fs, %gs */
};
\f

/* Support for debugging kernel virtual memory images.  */

#include <machine/pcb.h>
#include <osreldate.h>

#include "bsd-kvm.h"

static int
amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
{
  /* The following is true for FreeBSD 5.2:

     The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
     %ds, %es, %fs and %gs.  This accounts for all callee-saved
     registers specified by the psABI and then some.  Here %esp
     contains the stack pointer at the point just after the call to
     cpu_switch().  From this information we reconstruct the register
     state as it would like when we just returned from cpu_switch().  */

  /* The stack pointer shouldn't be zero.  */
  if (pcb->pcb_rsp == 0)
    return 0;

  pcb->pcb_rsp += 8;
  regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
  regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
  regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
  regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
  regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
  regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
  regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
  regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
  /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
     up until __FreeBSD_version 800074: The removal of these fields
     occurred on 2009-04-01 while the __FreeBSD_version number was
     bumped to 800075 on 2009-04-06.  So 800075 is the closest version
     number where we should not try to access these fields.  */
  regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
  regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
  regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
  regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
#endif

  return 1;
}
\f

/* Implement the to_read_description method.  */

static const struct target_desc *
amd64fbsd_read_description (struct target_ops *ops)
{
#ifdef PT_GETXSTATE_INFO
  static int xsave_probed;
  static uint64_t xcr0;
#endif
  struct reg regs;
  int is64;

  if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid),
	      (PTRACE_TYPE_ARG3) &regs, 0) == -1)
    perror_with_name (_("Couldn't get registers"));
  is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
#ifdef PT_GETXSTATE_INFO
  if (!xsave_probed)
    {
      struct ptrace_xstate_info info;

      if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid),
		  (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
	{
	  x86bsd_xsave_len = info.xsave_len;
	  xcr0 = info.xsave_mask;
	}
      xsave_probed = 1;
    }

  if (x86bsd_xsave_len != 0)
    {
      if (is64)
	return amd64_target_description (xcr0);
      else
	return i386_target_description (xcr0);
    }
#endif
  if (is64)
    return amd64_target_description (X86_XSTATE_SSE_MASK);
  else
    return i386_target_description (X86_XSTATE_SSE_MASK);
}

/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_amd64fbsd_nat (void);

void
_initialize_amd64fbsd_nat (void)
{
  struct target_ops *t;
  int offset;

  amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
  amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;

  /* Add some extra features to the common *BSD/i386 target.  */
  t = amd64bsd_target ();
  t->to_read_description = amd64fbsd_read_description;

  fbsd_nat_add_target (t);

  /* Support debugging kernel virtual memory images.  */
  bsd_kvm_add_target (amd64fbsd_supply_pcb);

  /* To support the recognition of signal handlers, i386-bsd-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.  */

#define SC_REG_OFFSET amd64fbsd_sc_reg_offset

  /* We only check the program counter, stack pointer and frame
     pointer since these members of `struct sigcontext' are essential
     for providing backtraces.  */

#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]

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

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

  SC_RIP_OFFSET = offset;

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

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

  SC_RSP_OFFSET = offset;

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

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

  SC_RBP_OFFSET = offset;

#ifdef KERN_PROC_SIGTRAMP
  /* Normally signal frames are detected via amd64fbsd_sigtramp_p.
     However, FreeBSD 9.2 through 10.1 do not include the page holding
     the signal code in core dumps.  These releases do provide a
     kern.proc.sigtramp.<pid> sysctl that returns the location of the
     signal trampoline for a running process.  We fetch the location
     of the current (gdb) process and use this to identify signal
     frames in core dumps from these releases.  Note that this only
     works for core dumps of 64-bit (FreeBSD/amd64) processes and does
     not handle core dumps of 32-bit (FreeBSD/i386) processes.  */
  {
    int mib[4];
    struct kinfo_sigtramp kst;
    size_t len;

    mib[0] = CTL_KERN;
    mib[1] = KERN_PROC;
    mib[2] = KERN_PROC_SIGTRAMP;
    mib[3] = getpid ();
    len = sizeof (kst);
    if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
      {
	amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
	amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
      }
  }
#endif
}
Commit	Line	Data
68cc0bfb	1	/* Native-dependent code for FreeBSD/amd64.
2a6d284d	2
61baf725	3	Copyright (C) 2003-2017 Free Software Foundation, Inc.
68cc0bfb MK	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
a9762ec7	9	the Free Software Foundation; either version 3 of the License, or
68cc0bfb MK	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
a9762ec7	18	along with this program. If not, see <http://www.gnu.org/licenses/>. */
68cc0bfb MK	19
	20	#include "defs.h"
	21	#include "inferior.h"
	22	#include "regcache.h"
6a5c78a3	23	#include "target.h"
68cc0bfb	24
68cc0bfb	25	#include <signal.h>
68cc0bfb MK	26	#include <sys/types.h>
	27	#include <sys/ptrace.h>
	28	#include <sys/sysctl.h>
cf424aef	29	#include <sys/user.h>
68cc0bfb MK	30	#include <machine/reg.h>
68cc0bfb MK	31
6a5c78a3	32	#include "fbsd-nat.h"
85be1ca6	33	#include "amd64-tdep.h"
2a6d284d	34	#include "amd64-nat.h"
03b62bbb	35	#include "x86-bsd-nat.h"
df7e5265	36	#include "x86-nat.h"
68cc0bfb MK	37	\f
68cc0bfb MK	38
cb461069 MK	39	/* Offset in `struct reg' where MEMBER is stored. */
cb461069 MK	40	#define REG_OFFSET(member) offsetof (struct reg, member)
68cc0bfb	41
cb461069 MK	42	/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
	43	`struct reg' location where the GDB register REGNUM is stored.
	44	Unsupported registers are marked with `-1'. */
	45	static int amd64fbsd64_r_reg_offset[] =
68cc0bfb MK	46	{
	47	REG_OFFSET (r_rax),
	48	REG_OFFSET (r_rbx),
	49	REG_OFFSET (r_rcx),
	50	REG_OFFSET (r_rdx),
	51	REG_OFFSET (r_rsi),
	52	REG_OFFSET (r_rdi),
	53	REG_OFFSET (r_rbp),
	54	REG_OFFSET (r_rsp),
	55	REG_OFFSET (r_r8),
	56	REG_OFFSET (r_r9),
	57	REG_OFFSET (r_r10),
	58	REG_OFFSET (r_r11),
	59	REG_OFFSET (r_r12),
	60	REG_OFFSET (r_r13),
	61	REG_OFFSET (r_r14),
	62	REG_OFFSET (r_r15),
	63	REG_OFFSET (r_rip),
	64	REG_OFFSET (r_rflags),
af233647 MK	65	REG_OFFSET (r_cs),
af233647 MK	66	REG_OFFSET (r_ss),
68cc0bfb MK	67	-1,
	68	-1,
	69	-1,
	70	-1
	71	};
2a6d284d MK	72	\f
	73
	74	/* Mapping between the general-purpose registers in FreeBSD/amd64
	75	`struct reg' format and GDB's register cache layout for
	76	FreeBSD/i386.
68cc0bfb	77
2a6d284d MK	78	Note that most FreeBSD/amd64 registers are 64-bit, while the
	79	FreeBSD/i386 registers are all 32-bit, but since we're
	80	little-endian we get away with that. */
68cc0bfb	81
2a6d284d MK	82	/* From <machine/reg.h>. */
	83	static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
	84	{
	85	14 * 8, 13 * 8, /* %eax, %ecx */
	86	12 * 8, 11 * 8, /* %edx, %ebx */
	87	20 * 8, 10 * 8, /* %esp, %ebp */
	88	9 * 8, 8 * 8, /* %esi, %edi */
	89	17 * 8, 19 * 8, /* %eip, %eflags */
	90	18 * 8, 21 * 8, /* %cs, %ss */
	91	-1, -1, -1, -1 /* %ds, %es, %fs, %gs */
	92	};
68cc0bfb MK	93	\f
68cc0bfb MK	94
315c4276 MK	95	/* Support for debugging kernel virtual memory images. */
315c4276 MK	96
315c4276	97	#include <machine/pcb.h>
1f596238	98	#include <osreldate.h>
315c4276 MK	99
	100	#include "bsd-kvm.h"
	101
	102	static int
	103	amd64fbsd_supply_pcb (struct regcache regcache, struct pcb pcb)
	104	{
	105	/* The following is true for FreeBSD 5.2:
	106
	107	The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
	108	%ds, %es, %fs and %gs. This accounts for all callee-saved
	109	registers specified by the psABI and then some. Here %esp
	110	contains the stack pointer at the point just after the call to
	111	cpu_switch(). From this information we reconstruct the register
	112	state as it would like when we just returned from cpu_switch(). */
	113
	114	/* The stack pointer shouldn't be zero. */
	115	if (pcb->pcb_rsp == 0)
	116	return 0;
	117
	118	pcb->pcb_rsp += 8;
	119	regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
	120	regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
	121	regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
	122	regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
	123	regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
	124	regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
	125	regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
	126	regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
c1dec97b	127	#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
ffeecffa JB	128	/* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
	129	up until __FreeBSD_version 800074: The removal of these fields
	130	occurred on 2009-04-01 while the __FreeBSD_version number was
	131	bumped to 800075 on 2009-04-06. So 800075 is the closest version
	132	number where we should not try to access these fields. */
315c4276 MK	133	regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
	134	regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
	135	regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
	136	regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
1f596238	137	#endif
315c4276 MK	138
	139	return 1;
	140	}
	141	\f
	142
97de3545 JB	143	/* Implement the to_read_description method. */
	144
	145	static const struct target_desc *
	146	amd64fbsd_read_description (struct target_ops *ops)
	147	{
	148	#ifdef PT_GETXSTATE_INFO
	149	static int xsave_probed;
	150	static uint64_t xcr0;
	151	#endif
	152	struct reg regs;
	153	int is64;
	154
	155	if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid),
	156	(PTRACE_TYPE_ARG3) &regs, 0) == -1)
	157	perror_with_name (_("Couldn't get registers"));
	158	is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
	159	#ifdef PT_GETXSTATE_INFO
	160	if (!xsave_probed)
	161	{
	162	struct ptrace_xstate_info info;
	163
	164	if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid),
	165	(PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
	166	{
a3405d12	167	x86bsd_xsave_len = info.xsave_len;
97de3545 JB	168	xcr0 = info.xsave_mask;
	169	}
	170	xsave_probed = 1;
	171	}
	172
a3405d12	173	if (x86bsd_xsave_len != 0)
97de3545 JB	174	{
	175	if (is64)
	176	return amd64_target_description (xcr0);
	177	else
	178	return i386_target_description (xcr0);
	179	}
	180	#endif
	181	if (is64)
2434b019	182	return amd64_target_description (X86_XSTATE_SSE_MASK);
97de3545	183	else
ca1fa5ee	184	return i386_target_description (X86_XSTATE_SSE_MASK);
97de3545 JB	185	}
97de3545 JB	186
68cc0bfb MK	187	/* Provide a prototype to silence -Wmissing-prototypes. */
	188	void _initialize_amd64fbsd_nat (void);
	189
	190	void
1c671366	191	_initialize_amd64fbsd_nat (void)
68cc0bfb	192	{
6a5c78a3	193	struct target_ops *t;
68cc0bfb MK	194	int offset;
68cc0bfb MK	195
2a6d284d	196	amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
cb461069	197	amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
2a6d284d	198
6a5c78a3 MK	199	/* Add some extra features to the common BSD/i386 target. /
6a5c78a3 MK	200	t = amd64bsd_target ();
97de3545	201	t->to_read_description = amd64fbsd_read_description;
26cb8b7c	202
8f60fe01	203	fbsd_nat_add_target (t);
6a5c78a3 MK	204
	205	/* Support debugging kernel virtual memory images. */
	206	bsd_kvm_add_target (amd64fbsd_supply_pcb);
	207
03b62bbb	208	/* To support the recognition of signal handlers, i386-bsd-tdep.c
68cc0bfb MK	209	hardcodes some constants. Inclusion of this file means that we
	210	are compiling a native debugger, which means that we can use the
	211	system header files and sysctl(3) to get at the relevant
	212	information. */
	213
68cc0bfb MK	214	#define SC_REG_OFFSET amd64fbsd_sc_reg_offset
	215
	216	/* We only check the program counter, stack pointer and frame
	217	pointer since these members of `struct sigcontext' are essential
	218	for providing backtraces. */
	219
90f90721 MK	220	#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
	221	#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
	222	#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
68cc0bfb MK	223
	224	/* Override the default value for the offset of the program counter
	225	in the sigcontext structure. */
	226	offset = offsetof (struct sigcontext, sc_rip);
	227
	228	if (SC_RIP_OFFSET != offset)
	229	{
edefbb7c	230	warning (_("\
68cc0bfb	231	offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
edefbb7c	232	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	233	offset, SC_RIP_OFFSET);
	234	}
	235
	236	SC_RIP_OFFSET = offset;
	237
	238	/* Likewise for the stack pointer. */
	239	offset = offsetof (struct sigcontext, sc_rsp);
	240
	241	if (SC_RSP_OFFSET != offset)
	242	{
edefbb7c	243	warning (_("\
68cc0bfb	244	offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
edefbb7c	245	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	246	offset, SC_RSP_OFFSET);
	247	}
	248
	249	SC_RSP_OFFSET = offset;
	250
	251	/* And the frame pointer. */
	252	offset = offsetof (struct sigcontext, sc_rbp);
	253
	254	if (SC_RBP_OFFSET != offset)
	255	{
edefbb7c	256	warning (_("\
68cc0bfb	257	offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
edefbb7c	258	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	259	offset, SC_RBP_OFFSET);
	260	}
	261
	262	SC_RBP_OFFSET = offset;
	263
cf424aef JB	264	#ifdef KERN_PROC_SIGTRAMP
	265	/* Normally signal frames are detected via amd64fbsd_sigtramp_p.
	266	However, FreeBSD 9.2 through 10.1 do not include the page holding
	267	the signal code in core dumps. These releases do provide a
	268	kern.proc.sigtramp.<pid> sysctl that returns the location of the
	269	signal trampoline for a running process. We fetch the location
	270	of the current (gdb) process and use this to identify signal
	271	frames in core dumps from these releases. Note that this only
	272	works for core dumps of 64-bit (FreeBSD/amd64) processes and does
	273	not handle core dumps of 32-bit (FreeBSD/i386) processes. */
68cc0bfb	274	{
cf424aef JB	275	int mib[4];
cf424aef JB	276	struct kinfo_sigtramp kst;
68cc0bfb MK	277	size_t len;
68cc0bfb MK	278
68cc0bfb	279	mib[0] = CTL_KERN;
cf424aef JB	280	mib[1] = KERN_PROC;
	281	mib[2] = KERN_PROC_SIGTRAMP;
	282	mib[3] = getpid ();
	283	len = sizeof (kst);
	284	if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
68cc0bfb	285	{
cf424aef JB	286	amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
cf424aef JB	287	amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
68cc0bfb MK	288	}
68cc0bfb MK	289	}
cf424aef	290	#endif
68cc0bfb	291	}