/* Native-dependent code for FreeBSD/amd64.

Copyright (C) 2003-2016 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"



/* 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

};



/* 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 */

};



/* 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;

}



/* 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 tdesc_amd64;

else

return tdesc_i386;

}

/* 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

}