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/* Native-dependent code for 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 "gdbarch.h"
#include "regcache.h"
#include "i386-tdep.h"
#include "amd64-tdep.h"
#include "amd64-nat.h"
/* The following bits of code help with implementing debugging 32-bit
code natively on AMD64. The idea is to define two mappings between
the register number as used by GDB and the register set used by the
host to represent the general-purpose registers; one for 32-bit
code and one for 64-bit code. The mappings are specified by the
following variables and consist of an array of offsets within the
register set indexed by register number, and the number of
registers supported by the mapping. We don't need mappings for the
floating-point and SSE registers, since the difference between
64-bit and 32-bit variants are negligible. The difference in the
number of SSE registers is already handled by the target code. */
/* General-purpose register mapping for native 32-bit code. */
int *amd64_native_gregset32_reg_offset;
int amd64_native_gregset32_num_regs = I386_NUM_GREGS;
/* General-purpose register mapping for native 64-bit code. */
int *amd64_native_gregset64_reg_offset;
int amd64_native_gregset64_num_regs = AMD64_NUM_GREGS;
/* Return the offset of REGNUM within the appropriate native
general-purpose register set. */
static int
amd64_native_gregset_reg_offset (struct gdbarch *gdbarch, int regnum)
{
int *reg_offset = amd64_native_gregset64_reg_offset;
int num_regs = amd64_native_gregset64_num_regs;
gdb_assert (regnum >= 0);
if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
{
reg_offset = amd64_native_gregset32_reg_offset;
num_regs = amd64_native_gregset32_num_regs;
}
if (num_regs > gdbarch_num_regs (gdbarch))
num_regs = gdbarch_num_regs (gdbarch);
if (regnum >= num_regs)
return -1;
/* Kernels that predate Linux 2.6.25 don't provide access to
these segment registers in user_regs_struct. */
#ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
if (regnum == AMD64_FSBASE_REGNUM || regnum == AMD64_GSBASE_REGNUM)
return -1;
#endif
return reg_offset[regnum];
}
/* Return whether the native general-purpose register set supplies
register REGNUM. */
int
amd64_native_gregset_supplies_p (struct gdbarch *gdbarch, int regnum)
{
return (amd64_native_gregset_reg_offset (gdbarch, regnum) != -1);
}
/* Supply register REGNUM, whose contents are stored in GREGS, to
REGCACHE. If REGNUM is -1, supply all appropriate registers. */
void
amd64_supply_native_gregset (struct regcache *regcache,
const void *gregs, int regnum)
{
const char *regs = (const char *) gregs;
struct gdbarch *gdbarch = regcache->arch ();
int num_regs = amd64_native_gregset64_num_regs;
int i;
if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
num_regs = amd64_native_gregset32_num_regs;
if (num_regs > gdbarch_num_regs (gdbarch))
num_regs = gdbarch_num_regs (gdbarch);
for (i = 0; i < num_regs; i++)
{
if (regnum == -1 || regnum == i)
{
int offset = amd64_native_gregset_reg_offset (gdbarch, i);
if (offset != -1)
regcache->raw_supply (i, regs + offset);
}
}
}
/* Collect register REGNUM from REGCACHE and store its contents in
GREGS. If REGNUM is -1, collect and store all appropriate
registers. */
void
amd64_collect_native_gregset (const struct regcache *regcache,
void *gregs, int regnum)
{
char *regs = (char *) gregs;
struct gdbarch *gdbarch = regcache->arch ();
int num_regs = amd64_native_gregset64_num_regs;
int i;
if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
{
num_regs = amd64_native_gregset32_num_regs;
/* Make sure %eax, %ebx, %ecx, %edx, %esi, %edi, %ebp, %esp and
%eip get zero-extended to 64 bits. */
for (i = 0; i <= I386_EIP_REGNUM; i++)
{
if (regnum == -1 || regnum == i)
memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8);
}
/* Ditto for %cs, %ss, %ds, %es, %fs, and %gs. */
for (i = I386_CS_REGNUM; i <= I386_GS_REGNUM; i++)
{
if (regnum == -1 || regnum == i)
memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8);
}
}
if (num_regs > gdbarch_num_regs (gdbarch))
num_regs = gdbarch_num_regs (gdbarch);
for (i = 0; i < num_regs; i++)
{
if (regnum == -1 || regnum == i)
{
int offset = amd64_native_gregset_reg_offset (gdbarch, i);
if (offset != -1)
regcache->raw_collect (i, regs + offset);
}
}
}
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