[lunar:linux][lunar:linux-unstable][PATCH v2 1/3] UBUNTU: [Packaging] Support skipped dkms modules

[Dimitri John Ledkov]

On Tue, 7 Mar 2023 at 09:46, Andrea Righi <andrea.righi at canonical.com> wrote:
>
> On Mon, Feb 27, 2023 at 02:49:51PM +0000, Dimitri John Ledkov wrote:
> > In recent releases we have fixed up most dkms modules to correctly
> > detect, and skip building dkms modules when compiling against
> > incompatible kernels. For example, trying to build a WiFi driver
> > against a kernel without 80221 config enabled, results in dkms
> > returning error code 9 skipped build, due to incompatibility. Our DKMS
> > autopkgtests already honor such cases, and mark test results as
> > passing for skipped {kernel, dkms-module} combinations.
> >
> > Improve kernel's dkms-build script to distinguish failed versus
> > skipped builds, by propagating exact status code. For standalone
> > skipped dkms modules, skip generating an empty deb packages.
> >
> > Also do not fail over missing make.log for the skipped dkms builds,
> > which do not have one.
> >
> > This change will enable us to use a static list of dkms-versions
> > across all kernels, without need to do anything special for cases were
> > a vendored dkms module is declared incompatible in dkms.conf for a
> > given kernel.
> >
> > For example, v4l2loopback incompatible with cloud kernels that do not
> > enable CONFIG_VIDEO, or backports-iwlwifi incompatible with kvm
> > kernel.
> >
> > This patch is tested against working, skipepd, and FTBFS dkms modules,
> > which correctly built the full kernel, skipped some dkms modules, or
> > failed the overall build.
> >
> > Signed-off-by: Dimitri John Ledkov <dimitri.ledkov at canonical.com>
> > ---
> >  debian/rules.d/2-binary-arch.mk | 3 ++-
> >  debian/scripts/dkms-build       | 5 ++---
> >  2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/debian/rules.d/2-binary-arch.mk b/debian/rules.d/2-binary-arch.mk
> > index 4cebe66dfd..4d393e890e 100644
> > --- a/debian/rules.d/2-binary-arch.mk
> > +++ b/debian/rules.d/2-binary-arch.mk
> > @@ -71,7 +71,7 @@ define build_dkms_sign =
> >       )
> >  endef
> >  define build_dkms =
> > -     ARCH=$(build_arch) CROSS_COMPILE=$(CROSS_COMPILE) $(SHELL) $(DROOT)/scripts/dkms-build $(dkms_dir) $(abi_release)-$* '$(call build_dkms_sign,$(builddir)/build-$*)' $(1) $(2) $(3) $(4) $(5)
> > +     rc=0; ARCH=$(build_arch) CROSS_COMPILE=$(CROSS_COMPILE) $(SHELL) $(DROOT)/scripts/dkms-build $(dkms_dir) $(abi_release)-$* '$(call build_dkms_sign,$(builddir)/build-$*)' $(1) $(2) $(3) $(4) $(5) || rc=$$?; if [ "$$rc" = "9" ]; then echo do_$(4)_$*=false >> $(builddir)/skipped-dkms.mk; rc=0; fi; if [ "$$rc" != "0" ]; then exit $$rc; fi
>
> What does rc==9 mean? It seems to be the "skip case, right? Maybe a
> little comment here explaining the meaning of this special value would
> be helpful.
>

In our case it is:

# Error out if build_exclude is set
    [[ $build_exclude ]] && die 9 \
        $"The $base_dir/dkms.conf for module $module includes a
BUILD_EXCLUSIVE directive which does not match this
kernel/arch/config."\
        $"This indicates that it should not be built."

However, exit code 9 can have other meanings too, w.r.t. missing
dkms.conf and permissions when making precompiled tarballs. I think
this is ok for now, but i will contact upstream about making error
codes unique / fixed.


> Everything else looks good to me.
>
> -Andrea



-- 
okurrr,

Dimitri