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

[Nicolas Schier <nsc@kernel.org>]

On Thu, Mar 26, 2026 at 11:45:57AM +0100, Janne Grunau wrote:
> 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@vger.kernel.org
> > Reviewed-by: Simon Glass <sjg@chromium.org>
> > Signed-off-by: Janne Grunau <j@jannau.net>
> > ---
> > 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@jannau.net
> > ---
> >  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

Please just remove the comment.  With v2 the change is such simple that
it's obvious what is done here.

-- 
Nicolas