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

/* Native-dependent code for FreeBSD/amd64.

   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 "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 "amd64-bsd-nat.h"
#include "x86-nat.h"
#include "gdbsupport/x86-xstate.h"
\f

class amd64_fbsd_nat_target final
  : public amd64_bsd_nat_target<fbsd_nat_target>
{
public:
  /* Add some extra features to the common *BSD/amd64 target.  */
  const struct target_desc *read_description () override;

#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
  bool supports_stopped_by_hw_breakpoint () override;
#endif
};

static amd64_fbsd_nat_target the_amd64_fbsd_nat_target;

/* 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 (AMD64_RIP_REGNUM, &pcb->pcb_rip);
  regcache->raw_supply (AMD64_RBX_REGNUM, &pcb->pcb_rbx);
  regcache->raw_supply (AMD64_RSP_REGNUM, &pcb->pcb_rsp);
  regcache->raw_supply (AMD64_RBP_REGNUM, &pcb->pcb_rbp);
  regcache->raw_supply (12, &pcb->pcb_r12);
  regcache->raw_supply (13, &pcb->pcb_r13);
  regcache->raw_supply (14, &pcb->pcb_r14);
  regcache->raw_supply (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 (AMD64_DS_REGNUM, &pcb->pcb_ds);
  regcache->raw_supply (AMD64_ES_REGNUM, &pcb->pcb_es);
  regcache->raw_supply (AMD64_FS_REGNUM, &pcb->pcb_fs);
  regcache->raw_supply (AMD64_GS_REGNUM, &pcb->pcb_gs);
#endif

  return 1;
}
\f

/* Implement the read_description method.  */

const struct target_desc *
amd64_fbsd_nat_target::read_description ()
{
#ifdef PT_GETXSTATE_INFO
  static int xsave_probed;
  static uint64_t xcr0;
#endif
  struct reg regs;
  int is64;

  if (ptrace (PT_GETREGS, inferior_ptid.pid (),
	      (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, inferior_ptid.pid (),
		  (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, true);
      else
	return i386_target_description (xcr0, true);
    }
#endif
  if (is64)
    return amd64_target_description (X86_XSTATE_SSE_MASK, true);
  else
    return i386_target_description (X86_XSTATE_SSE_MASK, true);
}

#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
/* Implement the supports_stopped_by_hw_breakpoints method.  */

bool
amd64_fbsd_nat_target::supports_stopped_by_hw_breakpoint ()
{
  return true;
}
#endif

void
_initialize_amd64fbsd_nat (void)
{
  int offset;

  amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
  amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;

  add_inf_child_target (&the_amd64_fbsd_nat_target);

  /* 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
42a4f53d	3	Copyright (C) 2003-2019 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
68cc0bfb MK	20	#include "defs.h"
4de283e4 TT	21	#include "inferior.h"
	22	#include "regcache.h"
	23	#include "target.h"
68cc0bfb	24
68cc0bfb	25	#include <signal.h>
4de283e4	26	#include <sys/types.h>
68cc0bfb MK	27	#include <sys/ptrace.h>
68cc0bfb MK	28	#include <sys/sysctl.h>
cf424aef	29	#include <sys/user.h>
4de283e4	30	#include <machine/reg.h>
68cc0bfb	31
d55e5aa6	32	#include "fbsd-nat.h"
4de283e4 TT	33	#include "amd64-tdep.h"
	34	#include "amd64-nat.h"
	35	#include "amd64-bsd-nat.h"
d55e5aa6	36	#include "x86-nat.h"
268a13a5	37	#include "gdbsupport/x86-xstate.h"
68cc0bfb MK	38	\f
68cc0bfb MK	39
f6ac5f3d PA	40	class amd64_fbsd_nat_target final
	41	: public amd64_bsd_nat_target<fbsd_nat_target>
	42	{
	43	public:
	44	/* Add some extra features to the common BSD/amd64 target. /
	45	const struct target_desc *read_description () override;
	46
	47	#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
57810aa7	48	bool supports_stopped_by_hw_breakpoint () override;
f6ac5f3d PA	49	#endif
	50	};
	51
	52	static amd64_fbsd_nat_target the_amd64_fbsd_nat_target;
	53
cb461069 MK	54	/* Offset in `struct reg' where MEMBER is stored. */
cb461069 MK	55	#define REG_OFFSET(member) offsetof (struct reg, member)
68cc0bfb	56
cb461069 MK	57	/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
	58	`struct reg' location where the GDB register REGNUM is stored.
	59	Unsupported registers are marked with `-1'. */
	60	static int amd64fbsd64_r_reg_offset[] =
68cc0bfb MK	61	{
	62	REG_OFFSET (r_rax),
	63	REG_OFFSET (r_rbx),
	64	REG_OFFSET (r_rcx),
	65	REG_OFFSET (r_rdx),
	66	REG_OFFSET (r_rsi),
	67	REG_OFFSET (r_rdi),
	68	REG_OFFSET (r_rbp),
	69	REG_OFFSET (r_rsp),
	70	REG_OFFSET (r_r8),
	71	REG_OFFSET (r_r9),
	72	REG_OFFSET (r_r10),
	73	REG_OFFSET (r_r11),
	74	REG_OFFSET (r_r12),
	75	REG_OFFSET (r_r13),
	76	REG_OFFSET (r_r14),
	77	REG_OFFSET (r_r15),
	78	REG_OFFSET (r_rip),
	79	REG_OFFSET (r_rflags),
af233647 MK	80	REG_OFFSET (r_cs),
af233647 MK	81	REG_OFFSET (r_ss),
68cc0bfb MK	82	-1,
	83	-1,
	84	-1,
	85	-1
	86	};
2a6d284d MK	87	\f
	88
	89	/* Mapping between the general-purpose registers in FreeBSD/amd64
	90	`struct reg' format and GDB's register cache layout for
	91	FreeBSD/i386.
68cc0bfb	92
2a6d284d MK	93	Note that most FreeBSD/amd64 registers are 64-bit, while the
	94	FreeBSD/i386 registers are all 32-bit, but since we're
	95	little-endian we get away with that. */
68cc0bfb	96
2a6d284d MK	97	/* From <machine/reg.h>. */
	98	static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
	99	{
	100	14 * 8, 13 * 8, /* %eax, %ecx */
	101	12 * 8, 11 * 8, /* %edx, %ebx */
	102	20 * 8, 10 * 8, /* %esp, %ebp */
	103	9 * 8, 8 * 8, /* %esi, %edi */
	104	17 * 8, 19 * 8, /* %eip, %eflags */
	105	18 * 8, 21 * 8, /* %cs, %ss */
	106	-1, -1, -1, -1 /* %ds, %es, %fs, %gs */
	107	};
68cc0bfb MK	108	\f
68cc0bfb MK	109
315c4276 MK	110	/* Support for debugging kernel virtual memory images. */
315c4276 MK	111
315c4276	112	#include <machine/pcb.h>
1f596238	113	#include <osreldate.h>
315c4276 MK	114
	115	#include "bsd-kvm.h"
	116
	117	static int
	118	amd64fbsd_supply_pcb (struct regcache regcache, struct pcb pcb)
	119	{
	120	/* The following is true for FreeBSD 5.2:
	121
	122	The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
	123	%ds, %es, %fs and %gs. This accounts for all callee-saved
	124	registers specified by the psABI and then some. Here %esp
	125	contains the stack pointer at the point just after the call to
	126	cpu_switch(). From this information we reconstruct the register
	127	state as it would like when we just returned from cpu_switch(). */
	128
	129	/* The stack pointer shouldn't be zero. */
	130	if (pcb->pcb_rsp == 0)
	131	return 0;
	132
	133	pcb->pcb_rsp += 8;
73e1c03f SM	134	regcache->raw_supply (AMD64_RIP_REGNUM, &pcb->pcb_rip);
	135	regcache->raw_supply (AMD64_RBX_REGNUM, &pcb->pcb_rbx);
	136	regcache->raw_supply (AMD64_RSP_REGNUM, &pcb->pcb_rsp);
	137	regcache->raw_supply (AMD64_RBP_REGNUM, &pcb->pcb_rbp);
	138	regcache->raw_supply (12, &pcb->pcb_r12);
	139	regcache->raw_supply (13, &pcb->pcb_r13);
	140	regcache->raw_supply (14, &pcb->pcb_r14);
	141	regcache->raw_supply (15, &pcb->pcb_r15);
c1dec97b	142	#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
ffeecffa JB	143	/* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
	144	up until __FreeBSD_version 800074: The removal of these fields
	145	occurred on 2009-04-01 while the __FreeBSD_version number was
	146	bumped to 800075 on 2009-04-06. So 800075 is the closest version
	147	number where we should not try to access these fields. */
73e1c03f SM	148	regcache->raw_supply (AMD64_DS_REGNUM, &pcb->pcb_ds);
	149	regcache->raw_supply (AMD64_ES_REGNUM, &pcb->pcb_es);
	150	regcache->raw_supply (AMD64_FS_REGNUM, &pcb->pcb_fs);
	151	regcache->raw_supply (AMD64_GS_REGNUM, &pcb->pcb_gs);
1f596238	152	#endif
315c4276 MK	153
	154	return 1;
	155	}
	156	\f
	157
f6ac5f3d	158	/* Implement the read_description method. */
97de3545	159
f6ac5f3d PA	160	const struct target_desc *
f6ac5f3d PA	161	amd64_fbsd_nat_target::read_description ()
97de3545 JB	162	{
	163	#ifdef PT_GETXSTATE_INFO
	164	static int xsave_probed;
	165	static uint64_t xcr0;
	166	#endif
	167	struct reg regs;
	168	int is64;
	169
e99b03dc	170	if (ptrace (PT_GETREGS, inferior_ptid.pid (),
97de3545 JB	171	(PTRACE_TYPE_ARG3) &regs, 0) == -1)
	172	perror_with_name (_("Couldn't get registers"));
	173	is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
	174	#ifdef PT_GETXSTATE_INFO
	175	if (!xsave_probed)
	176	{
	177	struct ptrace_xstate_info info;
	178
e99b03dc	179	if (ptrace (PT_GETXSTATE_INFO, inferior_ptid.pid (),
97de3545 JB	180	(PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
97de3545 JB	181	{
a3405d12	182	x86bsd_xsave_len = info.xsave_len;
97de3545 JB	183	xcr0 = info.xsave_mask;
	184	}
	185	xsave_probed = 1;
	186	}
	187
a3405d12	188	if (x86bsd_xsave_len != 0)
97de3545 JB	189	{
97de3545 JB	190	if (is64)
41206e32	191	return amd64_target_description (xcr0, true);
97de3545	192	else
dd6876c9	193	return i386_target_description (xcr0, true);
97de3545 JB	194	}
	195	#endif
	196	if (is64)
41206e32	197	return amd64_target_description (X86_XSTATE_SSE_MASK, true);
97de3545	198	else
dd6876c9	199	return i386_target_description (X86_XSTATE_SSE_MASK, true);
97de3545 JB	200	}
97de3545 JB	201
f6ac5f3d PA	202	#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
	203	/* Implement the supports_stopped_by_hw_breakpoints method. */
	204
57810aa7	205	bool
f6ac5f3d PA	206	amd64_fbsd_nat_target::supports_stopped_by_hw_breakpoint ()
f6ac5f3d PA	207	{
57810aa7	208	return true;
f6ac5f3d PA	209	}
	210	#endif
	211
68cc0bfb	212	void
1c671366	213	_initialize_amd64fbsd_nat (void)
68cc0bfb MK	214	{
	215	int offset;
	216
2a6d284d	217	amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
cb461069	218	amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
2a6d284d	219
d9f719f1	220	add_inf_child_target (&the_amd64_fbsd_nat_target);
6a5c78a3 MK	221
	222	/* Support debugging kernel virtual memory images. */
	223	bsd_kvm_add_target (amd64fbsd_supply_pcb);
	224
03b62bbb	225	/* To support the recognition of signal handlers, i386-bsd-tdep.c
68cc0bfb MK	226	hardcodes some constants. Inclusion of this file means that we
	227	are compiling a native debugger, which means that we can use the
	228	system header files and sysctl(3) to get at the relevant
	229	information. */
	230
68cc0bfb MK	231	#define SC_REG_OFFSET amd64fbsd_sc_reg_offset
	232
	233	/* We only check the program counter, stack pointer and frame
	234	pointer since these members of `struct sigcontext' are essential
	235	for providing backtraces. */
	236
90f90721 MK	237	#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
	238	#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
	239	#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
68cc0bfb MK	240
	241	/* Override the default value for the offset of the program counter
	242	in the sigcontext structure. */
	243	offset = offsetof (struct sigcontext, sc_rip);
	244
	245	if (SC_RIP_OFFSET != offset)
	246	{
edefbb7c	247	warning (_("\
68cc0bfb	248	offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
edefbb7c	249	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	250	offset, SC_RIP_OFFSET);
	251	}
	252
	253	SC_RIP_OFFSET = offset;
	254
	255	/* Likewise for the stack pointer. */
	256	offset = offsetof (struct sigcontext, sc_rsp);
	257
	258	if (SC_RSP_OFFSET != offset)
	259	{
edefbb7c	260	warning (_("\
68cc0bfb	261	offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
edefbb7c	262	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	263	offset, SC_RSP_OFFSET);
	264	}
	265
	266	SC_RSP_OFFSET = offset;
	267
	268	/* And the frame pointer. */
	269	offset = offsetof (struct sigcontext, sc_rbp);
	270
	271	if (SC_RBP_OFFSET != offset)
	272	{
edefbb7c	273	warning (_("\
68cc0bfb	274	offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
edefbb7c	275	Please report this to <bug-gdb@gnu.org>."),
68cc0bfb MK	276	offset, SC_RBP_OFFSET);
	277	}
	278
	279	SC_RBP_OFFSET = offset;
	280
cf424aef JB	281	#ifdef KERN_PROC_SIGTRAMP
	282	/* Normally signal frames are detected via amd64fbsd_sigtramp_p.
	283	However, FreeBSD 9.2 through 10.1 do not include the page holding
	284	the signal code in core dumps. These releases do provide a
	285	kern.proc.sigtramp.<pid> sysctl that returns the location of the
	286	signal trampoline for a running process. We fetch the location
	287	of the current (gdb) process and use this to identify signal
	288	frames in core dumps from these releases. Note that this only
	289	works for core dumps of 64-bit (FreeBSD/amd64) processes and does
	290	not handle core dumps of 32-bit (FreeBSD/i386) processes. */
68cc0bfb	291	{
cf424aef JB	292	int mib[4];
cf424aef JB	293	struct kinfo_sigtramp kst;
68cc0bfb MK	294	size_t len;
68cc0bfb MK	295
68cc0bfb	296	mib[0] = CTL_KERN;
cf424aef JB	297	mib[1] = KERN_PROC;
	298	mib[2] = KERN_PROC_SIGTRAMP;
	299	mib[3] = getpid ();
	300	len = sizeof (kst);
	301	if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
68cc0bfb	302	{
cf424aef JB	303	amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
cf424aef JB	304	amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
68cc0bfb MK	305	}
68cc0bfb MK	306	}
cf424aef	307	#endif
68cc0bfb	308	}