2020-02-16 15:51:07

by Masahiro Yamada

[permalink] [raw]
Subject: [PATCH] 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 entries 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 is saner 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This file path is no longer valid.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.

Signed-off-by: Masahiro Yamada <[email protected]>
---

arch/sh/Kconfig | 5 -----
arch/sparc/Kconfig | 5 -----
arch/x86/Kconfig | 5 -----
arch/x86/um/Kconfig | 5 -----
init/Kconfig | 3 +--
5 files changed, 1 insertion(+), 22 deletions(-)

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 9ece111b0254..b4f0e37b83eb 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -87,11 +87,6 @@ config SUPERH64
select HAVE_EXIT_THREAD
select KALLSYMS

-config ARCH_DEFCONFIG
- string
- default "arch/sh/configs/shx3_defconfig" if SUPERH32
- default "arch/sh/configs/cayman_defconfig" if SUPERH64
-
config GENERIC_BUG
def_bool y
depends on BUG && SUPERH32
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c1dd6dd642f4..0de15380d1fc 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -95,11 +95,6 @@ config SPARC64
select PCI_DOMAINS if PCI
select ARCH_HAS_GIGANTIC_PAGE

-config ARCH_DEFCONFIG
- string
- default "arch/sparc/configs/sparc32_defconfig" if SPARC32
- default "arch/sparc/configs/sparc64_defconfig" if SPARC64
-
config ARCH_PROC_KCORE_TEXT
def_bool y

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index beea77046f9b..98935f4387f9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -240,11 +240,6 @@ config OUTPUT_FORMAT
default "elf32-i386" if X86_32
default "elf64-x86-64" if X86_64

-config ARCH_DEFCONFIG
- string
- default "arch/x86/configs/i386_defconfig" if X86_32
- default "arch/x86/configs/x86_64_defconfig" if X86_64
-
config LOCKDEP_SUPPORT
def_bool y

diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index a8985e1f7432..95d26a69088b 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig
@@ -27,11 +27,6 @@ config X86_64
def_bool 64BIT
select MODULES_USE_ELF_RELA

-config ARCH_DEFCONFIG
- string
- default "arch/um/configs/i386_defconfig" if X86_32
- default "arch/um/configs/x86_64_defconfig" if X86_64
-
config 3_LEVEL_PGTABLES
bool "Three-level pagetables" if !64BIT
default 64BIT
diff --git a/init/Kconfig b/init/Kconfig
index 452bc1835cd4..6ccdb168dee5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -6,8 +6,7 @@ config DEFCONFIG_LIST
default "/lib/modules/$(shell,uname -r)/.config"
default "/etc/kernel-config"
default "/boot/config-$(shell,uname -r)"
- default ARCH_DEFCONFIG
- default "arch/$(ARCH)/defconfig"
+ default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"

config CC_IS_GCC
def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
--
2.17.1


2020-02-21 08:52:01

by Marek Szyprowski

[permalink] [raw]
Subject: Re: [PATCH] kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST

Dear All,

On 16.02.2020 16:45, Masahiro Yamada wrote:
> 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 entries 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 is saner 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.
>
> Signed-off-by: Masahiro Yamada <[email protected]>

This patch landed in today's linux-next (next-20200221) and broke arm64
builds:

--->8---

$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# configuration written to .config
#
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image.gz
scripts/kconfig/conf  --syncconfig Kconfig
scripts/kconfig/conf  --syncconfig Kconfig
scripts/kconfig/conf  --syncconfig Kconfig
scripts/kconfig/conf  --syncconfig Kconfig
scripts/kconfig/conf  --syncconfig Kconfig
...

(endless loop)

--->8---

Reverting it fixes the issue:

--->8---

$ git revert cdd5d1a207d6a3a06c9e627a0234d9a6af6ad347
[detached HEAD 1080d6a13b6d] Revert "kbuild: use KBUILD_DEFCONFIG as the
fallback for DEFCONFIG_LIST"
 5 files changed, 22 insertions(+), 1 deletion(-)
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# No change to .config
#
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image.gz
scripts/kconfig/conf  --syncconfig Kconfig
  UPD     include/config/kernel.release
  UPD     include/generated/utsrelease.h
  CC      scripts/mod/empty.o
...

$ aarch64-linux-gnu-gcc --version
aarch64-linux-gnu-gcc (Ubuntu/Linaro 7.4.0-1ubuntu1~18.04.1) 7.4.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
--->8---

It looks that the issue is similar to the one described here:

https://patchwork.kernel.org/patch/10453685/

I hope this report helps fixing the issue.

> ---
>
> arch/sh/Kconfig | 5 -----
> arch/sparc/Kconfig | 5 -----
> arch/x86/Kconfig | 5 -----
> arch/x86/um/Kconfig | 5 -----
> init/Kconfig | 3 +--
> 5 files changed, 1 insertion(+), 22 deletions(-)
>
> diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> index 9ece111b0254..b4f0e37b83eb 100644
> --- a/arch/sh/Kconfig
> +++ b/arch/sh/Kconfig
> @@ -87,11 +87,6 @@ config SUPERH64
> select HAVE_EXIT_THREAD
> select KALLSYMS
>
> -config ARCH_DEFCONFIG
> - string
> - default "arch/sh/configs/shx3_defconfig" if SUPERH32
> - default "arch/sh/configs/cayman_defconfig" if SUPERH64
> -
> config GENERIC_BUG
> def_bool y
> depends on BUG && SUPERH32
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index c1dd6dd642f4..0de15380d1fc 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -95,11 +95,6 @@ config SPARC64
> select PCI_DOMAINS if PCI
> select ARCH_HAS_GIGANTIC_PAGE
>
> -config ARCH_DEFCONFIG
> - string
> - default "arch/sparc/configs/sparc32_defconfig" if SPARC32
> - default "arch/sparc/configs/sparc64_defconfig" if SPARC64
> -
> config ARCH_PROC_KCORE_TEXT
> def_bool y
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index beea77046f9b..98935f4387f9 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -240,11 +240,6 @@ config OUTPUT_FORMAT
> default "elf32-i386" if X86_32
> default "elf64-x86-64" if X86_64
>
> -config ARCH_DEFCONFIG
> - string
> - default "arch/x86/configs/i386_defconfig" if X86_32
> - default "arch/x86/configs/x86_64_defconfig" if X86_64
> -
> config LOCKDEP_SUPPORT
> def_bool y
>
> diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
> index a8985e1f7432..95d26a69088b 100644
> --- a/arch/x86/um/Kconfig
> +++ b/arch/x86/um/Kconfig
> @@ -27,11 +27,6 @@ config X86_64
> def_bool 64BIT
> select MODULES_USE_ELF_RELA
>
> -config ARCH_DEFCONFIG
> - string
> - default "arch/um/configs/i386_defconfig" if X86_32
> - default "arch/um/configs/x86_64_defconfig" if X86_64
> -
> config 3_LEVEL_PGTABLES
> bool "Three-level pagetables" if !64BIT
> default 64BIT
> diff --git a/init/Kconfig b/init/Kconfig
> index 452bc1835cd4..6ccdb168dee5 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -6,8 +6,7 @@ config DEFCONFIG_LIST
> default "/lib/modules/$(shell,uname -r)/.config"
> default "/etc/kernel-config"
> default "/boot/config-$(shell,uname -r)"
> - default ARCH_DEFCONFIG
> - default "arch/$(ARCH)/defconfig"
> + default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
>
> config CC_IS_GCC
> def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

2020-02-21 09:20:11

by Masahiro Yamada

[permalink] [raw]
Subject: Re: [PATCH] kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST

On Fri, Feb 21, 2020 at 5:50 PM Marek Szyprowski
<[email protected]> wrote:
>
> Dear All,
>
> On 16.02.2020 16:45, Masahiro Yamada wrote:
> > 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 entries 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 is saner 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.
> >
> > Signed-off-by: Masahiro Yamada <[email protected]>
>
> This patch landed in today's linux-next (next-20200221) and broke arm64
> builds:
>
> --->8---
>
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
> *** Default configuration is based on 'defconfig'
> #
> # configuration written to .config
> #
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image.gz
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> ...
>
> (endless loop)
>
> --->8---
>
> Reverting it fixes the issue:



My bad.

This is because arch/arm64/Makefile does not define
KBUILD_DEFCONFIG.



I will drop it.

Sorry about that.





>
> --->8---
>
> $ git revert cdd5d1a207d6a3a06c9e627a0234d9a6af6ad347
> [detached HEAD 1080d6a13b6d] Revert "kbuild: use KBUILD_DEFCONFIG as the
> fallback for DEFCONFIG_LIST"
> 5 files changed, 22 insertions(+), 1 deletion(-)
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
> *** Default configuration is based on 'defconfig'
> #
> # No change to .config
> #
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image.gz
> scripts/kconfig/conf --syncconfig Kconfig
> UPD include/config/kernel.release
> UPD include/generated/utsrelease.h
> CC scripts/mod/empty.o
> ...
>
> $ aarch64-linux-gnu-gcc --version
> aarch64-linux-gnu-gcc (Ubuntu/Linaro 7.4.0-1ubuntu1~18.04.1) 7.4.0
> Copyright (C) 2017 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions. There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> --->8---
>
> It looks that the issue is similar to the one described here:
>
> https://patchwork.kernel.org/patch/10453685/
>
> I hope this report helps fixing the issue.
>
> > ---
> >
> > arch/sh/Kconfig | 5 -----
> > arch/sparc/Kconfig | 5 -----
> > arch/x86/Kconfig | 5 -----
> > arch/x86/um/Kconfig | 5 -----
> > init/Kconfig | 3 +--
> > 5 files changed, 1 insertion(+), 22 deletions(-)
> >
> > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> > index 9ece111b0254..b4f0e37b83eb 100644
> > --- a/arch/sh/Kconfig
> > +++ b/arch/sh/Kconfig
> > @@ -87,11 +87,6 @@ config SUPERH64
> > select HAVE_EXIT_THREAD
> > select KALLSYMS
> >
> > -config ARCH_DEFCONFIG
> > - string
> > - default "arch/sh/configs/shx3_defconfig" if SUPERH32
> > - default "arch/sh/configs/cayman_defconfig" if SUPERH64
> > -
> > config GENERIC_BUG
> > def_bool y
> > depends on BUG && SUPERH32
> > diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> > index c1dd6dd642f4..0de15380d1fc 100644
> > --- a/arch/sparc/Kconfig
> > +++ b/arch/sparc/Kconfig
> > @@ -95,11 +95,6 @@ config SPARC64
> > select PCI_DOMAINS if PCI
> > select ARCH_HAS_GIGANTIC_PAGE
> >
> > -config ARCH_DEFCONFIG
> > - string
> > - default "arch/sparc/configs/sparc32_defconfig" if SPARC32
> > - default "arch/sparc/configs/sparc64_defconfig" if SPARC64
> > -
> > config ARCH_PROC_KCORE_TEXT
> > def_bool y
> >
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index beea77046f9b..98935f4387f9 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -240,11 +240,6 @@ config OUTPUT_FORMAT
> > default "elf32-i386" if X86_32
> > default "elf64-x86-64" if X86_64
> >
> > -config ARCH_DEFCONFIG
> > - string
> > - default "arch/x86/configs/i386_defconfig" if X86_32
> > - default "arch/x86/configs/x86_64_defconfig" if X86_64
> > -
> > config LOCKDEP_SUPPORT
> > def_bool y
> >
> > diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
> > index a8985e1f7432..95d26a69088b 100644
> > --- a/arch/x86/um/Kconfig
> > +++ b/arch/x86/um/Kconfig
> > @@ -27,11 +27,6 @@ config X86_64
> > def_bool 64BIT
> > select MODULES_USE_ELF_RELA
> >
> > -config ARCH_DEFCONFIG
> > - string
> > - default "arch/um/configs/i386_defconfig" if X86_32
> > - default "arch/um/configs/x86_64_defconfig" if X86_64
> > -
> > config 3_LEVEL_PGTABLES
> > bool "Three-level pagetables" if !64BIT
> > default 64BIT
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 452bc1835cd4..6ccdb168dee5 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -6,8 +6,7 @@ config DEFCONFIG_LIST
> > default "/lib/modules/$(shell,uname -r)/.config"
> > default "/etc/kernel-config"
> > default "/boot/config-$(shell,uname -r)"
> > - default ARCH_DEFCONFIG
> > - default "arch/$(ARCH)/defconfig"
> > + default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
> >
> > config CC_IS_GCC
> > def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>


--
Best Regards
Masahiro Yamada

2020-02-21 09:23:24

by Will Deacon

[permalink] [raw]
Subject: Re: [PATCH] kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST

On Fri, Feb 21, 2020 at 06:18:50PM +0900, Masahiro Yamada wrote:
> On Fri, Feb 21, 2020 at 5:50 PM Marek Szyprowski
> <[email protected]> wrote:
> > This patch landed in today's linux-next (next-20200221) and broke arm64
> > builds:
> >
> > --->8---
> >
> > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
> > *** Default configuration is based on 'defconfig'
> > #
> > # configuration written to .config
> > #
> > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image.gz
> > scripts/kconfig/conf --syncconfig Kconfig
> > scripts/kconfig/conf --syncconfig Kconfig
> > scripts/kconfig/conf --syncconfig Kconfig
> > scripts/kconfig/conf --syncconfig Kconfig
> > scripts/kconfig/conf --syncconfig Kconfig
> > ...
> >
> > (endless loop)
> >
> > --->8---
> >
> > Reverting it fixes the issue:
>
>
>
> My bad.
>
> This is because arch/arm64/Makefile does not define
> KBUILD_DEFCONFIG.
>
>
>
> I will drop it.
>
> Sorry about that.

Thanks, Masahiro.

Will