Re: [PATCH 5/6] selftests/nolibc: extraconfig support

[Willy Tarreau]

On Sun, Nov 05, 2023 at 11:09:59AM +0100, Thomas Weißschuh wrote:
> Allow some postprocessing of defconfig files.
> 
> Suggested-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
> Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> ---
>  tools/testing/selftests/nolibc/Makefile | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
> index f8fea9fa0263..02c074e73a28 100644
> --- a/tools/testing/selftests/nolibc/Makefile
> +++ b/tools/testing/selftests/nolibc/Makefile
> @@ -81,6 +81,8 @@ DEFCONFIG_s390       = defconfig
>  DEFCONFIG_loongarch  = defconfig
>  DEFCONFIG            = $(DEFCONFIG_$(XARCH))
>  
> +EXTRACONFIG           = $(EXTRACONFIG_$(XARCH))
> +
>  # optional tests to run (default = all)
>  TEST =
>  
> @@ -227,6 +229,10 @@ initramfs: nolibc-test
>  
>  defconfig:
>  	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare
> +	$(Q)if [ -n "$(EXTRACONFIG)" ]; then \
> +		$(srctree)/scripts/config --file $(objtree)/.config $(EXTRACONFIG); \
> +		$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) oldconfig < /dev/null; \

You should instead use "olddefconfig" for this. It reuses defconfig but
uses defaults for new questions. I've already experienced issues from
time to time using /dev/null with oldconfig as you did above, with a
process looping forever (probably on a non acceptable choice I guess),
and never met such issues anymore since I switched to olddefconfig
instead.

Willy