Re: [PATCH v7] scripts/config: honor $KBUILD_OUTPUT by default

[Nicolas Schier <nsc@kernel.org>]

On Thu, Nov 12, 2026 at 09:59:06PM -0700, Nathan Chancellor wrote:
> Hi Dmitry,
> 
> On 2026-10-06 18:11 +0200, Dmitry Voytik wrote:
> > If $KBUILD_OUTPUT is set, use it by default if --file is not passed.
> > 
> > Fix the issue when the script silently updates a stale .config in
> > the root directory, while the user expects ${KBUILD_OUTPUT}/.config
> > to be updated.
> > Handle properly if the config file is a relative path.
> > 
> > The problem can be worked around with --file, but this is easy to miss,
> > and is inconsistent with how the Makefile and other tools work
> > (e.g., scripts/diffconfig).
> 
> I was finally able to sit down and look at this a little bit more. I
> think we can avoid the use of realpath altogether, which would avoid
> most of what Sashiko is complaining about. I tested the following diff
> with your examples and they appear to pass without any issues. Please
> give it a shot.

Thanks, somehow the sashiko mail missed my inbox.

realpath on Linux uses '-E' behaviour by default, which is what we want:
check existence of all directory path components of the given path.
Adding the POSIX '-E' option explicitly should solve the non-Linux
issues.

As a follow-up, I would like to add support for $KCONFIG_CONFIG as well.

> I think we can drop most of the reproduction and
> examples in the commit message. If you want to include them for others,
> please put it below the '---' where you have the changelog, as I don't
> think it needs to end up in git history.

+1

But still thanks for providing the test examples, it was and is indeed
helpful for my follow-up tests.

> 
> diff --git a/scripts/config b/scripts/config
> index 32428ea909c2..497551538433 100755
> --- a/scripts/config
> +++ b/scripts/config
> @@ -144,6 +144,22 @@ while [[ $# -gt 0 ]]; do
>  	fi
>  done
>  
> +# If no '--file' was specified, use KBUILD_OUTPUT as the base if it exists
> +if [[ "$FN" = ".config" && -n "$KBUILD_OUTPUT" ]]; then
> +	if [[ ! -d "$KBUILD_OUTPUT" ]]; then
> +		echo "KBUILD_OUTPUT is set ('$KBUILD_OUTPUT') but does not exist or is not a directory." >&2
> +		echo "Create it before running $myname or use '--file' to specify configuration file." >&2
> +		exit 1
> +	fi
> +	FN="$KBUILD_OUTPUT/$FN"
> +fi
> +# Turn FN into an absolute path if it is relative so that '--refresh' works on
> +# the correct file. This does not use realpath, as $FN may not exist yet.
> +case "$FN" in
> +	/*) ;;
> +	*) FN="$PWD/$FN" ;;
> +esac
> +
>  set -- "${CMDS[@]}"
>  if [ "$1" = "" ] ; then
>  	usage
> @@ -200,10 +216,10 @@ while [ "$1" != "" ] ; do
>  		;;
>  
>  	--state|-s)
> -		if grep -q "# ${CONFIG_}$ARG is not set" $FN ; then
> +		if grep -q "# ${CONFIG_}$ARG is not set" "$FN" ; then
>  			echo n
>  		else
> -			V="$(grep "^${CONFIG_}$ARG=" $FN)"
> +			V="$(grep "^${CONFIG_}$ARG=" "$FN")"
>  			if [ $? != 0 ] ; then
>  				echo undef
>  			else
> @@ -229,7 +245,7 @@ while [ "$1" != "" ] ; do
>  		;;
>  
>  	--refresh)
> -		yes "" | make oldconfig KCONFIG_CONFIG=$FN
> +		yes "" | make oldconfig KCONFIG_CONFIG="$FN"
>  		;;
>  
>  	*)
> 
> -- 
> Cheers,
> Nathan
> 

Looks good to me, thanks.

Reviewed-by: Nicolas Schier <nsc@fjasle.eu>


-- 
Nicolas