linux-stable/arch/x86/um/Kconfig
Masahiro Yamada 2a86f66121 kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST
Most of the Kconfig commands (except defconfig and all*config) read
the .config file as a base set of CONFIG options.

When it does not exist, the files in DEFCONFIG_LIST are searched in
this order and loaded if found.

I do not see much sense in the last two lines in DEFCONFIG_LIST.

[1] ARCH_DEFCONFIG

The entry for DEFCONFIG_LIST is guarded by 'depends on !UML'. So, the
ARCH_DEFCONFIG definition in arch/x86/um/Kconfig is meaningless.

arch/{sh,sparc,x86}/Kconfig define ARCH_DEFCONFIG depending on 32 or
64 bit variant symbols. This is a little bit strange; ARCH_DEFCONFIG
should be a fixed string because the base config file is loaded before
the symbol evaluation stage.

Using KBUILD_DEFCONFIG makes more sense because it is fixed before
Kconfig is invoked. Fortunately, arch/{sh,sparc,x86}/Makefile define it
in the same way, and it works as expected. Hence, replace ARCH_DEFCONFIG
with "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)".

[2] arch/$(ARCH)/defconfig

This file path is no longer valid. The defconfig files are always located
in the arch configs/ directories.

  $ find arch -name defconfig | sort
  arch/alpha/configs/defconfig
  arch/arm64/configs/defconfig
  arch/csky/configs/defconfig
  arch/nds32/configs/defconfig
  arch/riscv/configs/defconfig
  arch/s390/configs/defconfig
  arch/unicore32/configs/defconfig

The path arch/*/configs/defconfig is already covered by
"arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". So, this file path is
not necessary.

I moved the default KBUILD_DEFCONFIG to the top Makefile. Otherwise,
the 7 architectures listed above would end up with endless loop of
syncconfig.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-03 20:49:21 +09:00

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# SPDX-License-Identifier: GPL-2.0
menu "Host processor type and features"
source "arch/x86/Kconfig.cpu"
endmenu
config UML_X86
def_bool y
select GENERIC_FIND_FIRST_BIT
config 64BIT
bool "64-bit kernel" if "$(SUBARCH)" = "x86"
default "$(SUBARCH)" != "i386"
config X86_32
def_bool !64BIT
select ARCH_32BIT_OFF_T
select ARCH_WANT_IPC_PARSE_VERSION
select MODULES_USE_ELF_REL
select CLONE_BACKWARDS
select OLD_SIGSUSPEND3
select OLD_SIGACTION
config X86_64
def_bool 64BIT
select MODULES_USE_ELF_RELA
config 3_LEVEL_PGTABLES
bool "Three-level pagetables" if !64BIT
default 64BIT
help
Three-level pagetables will let UML have more than 4G of physical
memory. All the memory that can't be mapped directly will be treated
as high memory.
However, this it experimental on 32-bit architectures, so if unsure say
N (on x86-64 it's automatically enabled, instead, as it's safe there).
config ARCH_HAS_SC_SIGNALS
def_bool !64BIT
config ARCH_REUSE_HOST_VSYSCALL_AREA
def_bool !64BIT
config GENERIC_HWEIGHT
def_bool y