Re: [PATCH v2] kbuild: modules-cpio-pkg: Respect INSTALL_MOD_PATH

[Janne Grunau]

On Wed, Mar 25, 2026 at 03:57:25PM +0100, Janne Grunau wrote:
> The modules-cpio-pkg target added in commit 2a9c8c0b59d3 ("kbuild: add
> target to build a cpio containing modules") is incompatible with
> initramfs with merged /lib and /usr/lib directories [1]. "/lib" cannot
> be a link and directory at the same time.
> Respect a non-empty INSTALL_MOD_PATH in the modules-cpio-pkg target so
> that `make INSTALL_MOD_PATH=/usr modules-cpio-pkg` results in the same
> module install location as `make INSTALL_MOD_PATH=/usr modules_install`.
> 
> Tested with Fedora distribution initramfs produced by dracut.
> 
> Link: https://systemd.io/THE_CASE_FOR_THE_USR_MERGE/ [1]
> Fixes: 2a9c8c0b59d3 ("kbuild: add target to build a cpio containing modules")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Simon Glass <sjg@xxxxxxxxxxxx>
> Signed-off-by: Janne Grunau <j@xxxxxxxxxx>
> ---
> Hej,
> 
> this patch allows to produce modules-cpio initramfs which are compatible
> with initramfs with merged /lib and /usr/lib (/lib as symlink to
> /usr/lib). I expect initramfs of distributions with merged /usr to have
> a merged /usr as well. This is at least true for Fedora initramfs built
> with dracut.
> 
> Janne
> ---
> Changes in v2:
> - drop pointless avoidance of repeated slashes
> - comment the changed Makefile rule
> - break long modles-cpio-pkg help text to 2 lines
> - imported Simon's Rb:
> - add fixes tag for commit 2a9c8c0b59d3 ("kbuild: add target to build a cpio containing modules")
> - Link to v1: https://lore.kernel.org/r/20260320-kbuild-modules-cpio-pkg-usr-merge-v1-1-cee1ad1bb7cb@xxxxxxxxxx
> ---
>  scripts/Makefile.package | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/Makefile.package b/scripts/Makefile.package
> index 0ec946f9b905f74f8698d8d6967d22f5b76f64e0..c19b88b346d0632cc99e74617d79b07d81d48635 100644
> --- a/scripts/Makefile.package
> +++ b/scripts/Makefile.package
> @@ -195,7 +195,8 @@ tar%-pkg: linux-$(KERNELRELEASE)-$(ARCH).tar.% FORCE
>  .tmp_modules_cpio: FORCE
>  	$(Q)$(MAKE) -f $(srctree)/Makefile
>  	$(Q)rm -rf $@
> -	$(Q)$(MAKE) -f $(srctree)/Makefile INSTALL_MOD_PATH=$@ modules_install
> +	# Prepend INSTALL_MOD_PATH inside the staging dir

The comment needs to be indented with spaces. With a tab it gets printed
to the shell.

I'll send a v3 tomorrow

Janne