kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST

PATCH In review Masahiro Yamada 3 participants 4 messages Feb 16, 2020 – Feb 21, 2020

Subsystems (6)

x86 Kbuild RISC-V SuperH +2 more subsystems

lore

Share & tools

lore

Masahiro Yamada

author

2020-02-16 15:45 UTC #0 lore raw

PATCH 1/1 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This file path is no longer valid.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(-)

arch/sh/Kconfig +0 -5

index 9ece111b0254..b4f0e37b83eb 100644
@@ -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

arch/sparc/Kconfig +0 -5

index c1dd6dd642f4..0de15380d1fc 100644
@@ -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

arch/x86/Kconfig +0 -5

index beea77046f9b..98935f4387f9 100644
@@ -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

arch/x86/um/Kconfig +0 -5

index a8985e1f7432..95d26a69088b 100644
@@ -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

init/Kconfig +1 -2

index 452bc1835cd4..6ccdb168dee5 100644
@@ -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)

Signature · 1 line

2.17.1

Marek Szyprowski

2020-02-21 08:50 UTC #1 lore raw

Dear All,

Quoted 37 lines · Masahiro Yamada

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

Quoted 5 lines

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_COMPILEªrch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# configuration written to .config
#
$ make ARCH=arm64 CROSS_COMPILEªrch64-linux-gnu- Image.gz
scripts/kconfig/confÂ  --syncconfig Kconfig
scripts/kconfig/confÂ  --syncconfig Kconfig
scripts/kconfig/confÂ  --syncconfig Kconfig
scripts/kconfig/confÂ  --syncconfig Kconfig
scripts/kconfig/confÂ  --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"
 Â 5 files changed, 22 insertions(+), 1 deletion(-)
$ make ARCH=arm64 CROSS_COMPILEªrch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# No change to .config
#
$ make ARCH=arm64 CROSS_COMPILEªrch64-linux-gnu- Image.gz
scripts/kconfig/confÂ  --syncconfig Kconfig
 Â  UPDÂ Â Â Â  include/config/kernel.release
 Â  UPDÂ Â Â Â  include/generated/utsrelease.h
 Â  CCÂ Â Â Â Â  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.

Quoted 78 lines

---

  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(-)

arch/sh/Kconfig +0 -5

index 9ece111b0254..b4f0e37b83eb 100644
@@ -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

arch/sparc/Kconfig +0 -5

index c1dd6dd642f4..0de15380d1fc 100644
@@ -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

arch/x86/Kconfig +0 -5

index beea77046f9b..98935f4387f9 100644
@@ -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

arch/x86/um/Kconfig +0 -5

index a8985e1f7432..95d26a69088b 100644
@@ -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

init/Kconfig +0 -0

index 452bc1835cd4..6ccdb168dee5 100644

init/Kconfig config DEFCONFIG_LIST · line 12

Quoted 9 lines

init/Kconfig +1 -2

@@ -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

Signature · 2 lines

Marek Szyprowski, PhD
Samsung R&D Institute Poland

Masahiro Yamada

author

2020-02-21 09:18 UTC #2 lore raw

Quoted 65 lines · Marek Szyprowski

Dear All,
Quoted 37 lines · Masahiro Yamada
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
Quoted 5 lines
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_COMPILEªrch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# configuration written to .config
#
$ make ARCH=arm64 CROSS_COMPILEªrch64-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
...

Quoted 5 lines

(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.

Quoted 125 lines

--->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_COMPILEªrch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# No change to .config
#
$ make ARCH=arm64 CROSS_COMPILEªrch64-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.

Quoted 78 lines

---

  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(-)

arch/sh/Kconfig +0 -5

index 9ece111b0254..b4f0e37b83eb 100644
@@ -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

arch/sparc/Kconfig +0 -5

index c1dd6dd642f4..0de15380d1fc 100644
@@ -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

arch/x86/Kconfig +0 -5

index beea77046f9b..98935f4387f9 100644
@@ -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

arch/x86/um/Kconfig +0 -5

index a8985e1f7432..95d26a69088b 100644
@@ -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

init/Kconfig +0 -0

index 452bc1835cd4..6ccdb168dee5 100644

init/Kconfig config DEFCONFIG_LIST · line 12

Quoted 9 lines

init/Kconfig +1 -2

@@ -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

Signature · 2 lines

Best Regards
Masahiro Yamada

Will Deacon

2020-02-21 09:22 UTC #3 lore raw

Quoted 30 lines · Masahiro Yamada

Quoted 18 lines · Marek Szyprowski
This patch landed in today's linux-next (next-20200221) and broke arm64 builds:
--->8---
$ make ARCH=arm64 CROSS_COMPILEªrch64-linux-gnu- defconfig
*** Default configuration is based on 'defconfig'
#
# configuration written to .config
#
$ make ARCH=arm64 CROSS_COMPILEªrch64-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
...
Quoted 5 lines
(endless loop)
--->8---
Reverting it fixes the issue:
My bad.

Quoted 8 lines

This is because arch/arm64/Makefile does not define KBUILD_DEFCONFIG.
I will drop it.
Sorry about that.

Thanks, Masahiro.

Will