NACK: [SRU][M][PATCH 1/1] UBUNTU: [Packaging] define Rust flags only with Rust-enabled kernels
Dimitri John Ledkov
dimitri.ledkov at canonical.com
Tue Sep 26 17:09:28 UTC 2023
On Tue, 26 Sept 2023 at 13:14, Juerg Haefliger
<juerg.haefliger at canonical.com> wrote:
>
> On Tue, 26 Sep 2023 11:27:43 +0100
> Dimitri John Ledkov <dimitri.ledkov at canonical.com> wrote:
>
> > On Tue, 26 Sept 2023 at 09:32, Andrea Righi <andrea.righi at canonical.com> wrote:
> > >
> > > To enable Rust support in the kernel we need to pass special build
> > > flags, that are used to select the proper Rust toolchain version and
> > > dependent components.
> > >
> > > These flags are passed also to the scripts called during the
> > > updateconfigs step and the build, such as 'kernelconfig', using the
> > > $(kmake) variable.
> > >
> > > However, $(kmake) can also contain cross-compiler variables that may
> > > potentially affect the config or the build in certain architectures.
> >
> > Not potentially, but intentionally.
> >
> > Because sometimes we use different gcc for different arch (i.e. gcc-11
> > for armhf, and gcc-12 for arm64 build), and we must use full kmake for
> > generating the configs that should be the same as the one that will be
> > used for build.
> >
> > I don't see how this will produce correct results. Excluding rust
> > variables is good, but the gcc and crosscompile should remain in place
> > imho.
>
> gcc is set separately in the kernelconfig script (also ugly) and so are ARCH
> and CROSS_COMPILE. We used to use 'plain' make in kernelconfig until Andrea
> switched to kmake for Rust. We do not need kmake in kernelconfig. But yes,
> best to use kmake everywhere but that's a bigger change.
>
I do agree here that ideally we don't need all of those tools
installed, and we should be able to produce correct config always.
Thus I guess the next cycle goal is to fake upstream fake tools to
actually produce valid configs by default as needed by us. Meaning
adding fake tools for rust, llvm, and anything else not already
covered there.
Because a chroot without GCC should be able to still produce valid
config for us for all arches.
> ...Juerg
>
>
> >
> > >
> > > For this reason, avoid using kmake during 'updateconfigs' and explicitly
> > > pass the Rust flags using a separate environment variable that will be
> > > defined only for Rust-enabled kernels (do_lib_rust=true).
> > >
> > > Signed-off-by: Andrea Righi <andrea.righi at canonical.com>
> > > ---
> > > debian/rules.d/0-common-vars.mk | 2 --
> > > debian/rules.d/1-maintainer.mk | 2 +-
> > > debian/rules.d/2-binary-arch.mk | 16 ++++++++++++++++
> > > debian/scripts/misc/kernelconfig | 2 +-
> > > 4 files changed, 18 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/debian/rules.d/0-common-vars.mk b/debian/rules.d/0-common-vars.mk
> > > index 410de315afba..d62a9b063241 100644
> > > --- a/debian/rules.d/0-common-vars.mk
> > > +++ b/debian/rules.d/0-common-vars.mk
> > > @@ -238,8 +238,6 @@ kmake = make ARCH=$(build_arch) \
> > > CROSS_COMPILE=$(CROSS_COMPILE) \
> > > HOSTCC=$(HOSTCC) \
> > > CC=$(CROSS_COMPILE)$(gcc) \
> > > - RUSTC=rustc-1.68 HOSTRUSTC=rustc-1.68 BINDGEN=bindgen-0.56 RUSTFMT=/usr/lib/rust-1.68/bin/rustfmt RUST_LIB_SRC=/usr/src/rustc-1.68.2/library \
> > > - CLANG_PATH=clang-15 LIBCLANG_PATH=/usr/lib/llvm-15/lib \
> > > KERNELVERSION=$(abi_release)-$(target_flavour) \
> > > CONFIG_DEBUG_SECTION_MISMATCH=y \
> > > KBUILD_BUILD_VERSION="$(uploadnum)" \
> > > diff --git a/debian/rules.d/1-maintainer.mk b/debian/rules.d/1-maintainer.mk
> > > index 839e93a15371..a72e5fe93784 100644
> > > --- a/debian/rules.d/1-maintainer.mk
> > > +++ b/debian/rules.d/1-maintainer.mk
> > > @@ -29,7 +29,7 @@ configs-targets := updateconfigs defaultconfigs genconfigs editconfigs
> > > .PHONY: $(configs-targets)
> > > $(configs-targets):
> > > dh_testdir
> > > - kmake='$(kmake)' skip_checks=$(do_skip_checks) conc_level=$(conc_level) \
> > > + RUST_FLAGS='$(RUST_FLAGS)' skip_checks=$(do_skip_checks) conc_level=$(conc_level) \
> > > $(SHELL) $(DROOT)/scripts/misc/kernelconfig $@
> > >
> > > .PHONY: printenv
> > > diff --git a/debian/rules.d/2-binary-arch.mk b/debian/rules.d/2-binary-arch.mk
> > > index 53fbb55c198a..6e9c78aadb45 100644
> > > --- a/debian/rules.d/2-binary-arch.mk
> > > +++ b/debian/rules.d/2-binary-arch.mk
> > > @@ -10,6 +10,22 @@ build_cd =
> > > build_O = O=$(builddir)/build-$*
> > > endif
> > >
> > > +# Define Rust build flags only for Rust-enabled kernels
> > > +ifeq ($(do_lib_rust),true)
> > > +RUST_FLAGS = \
> > > + RUSTC=rustc-1.68 \
> > > + HOSTRUSTC=rustc-1.68 \
> > > + BINDGEN=bindgen-0.56 \
> > > + RUSTFMT=/usr/lib/rust-1.68/bin/rustfmt \
> > > + RUST_LIB_SRC=/usr/src/rustc-1.68.2/library \
> > > + CLANG_PATH=clang-15 \
> > > + LIBCLANG_PATH=/usr/lib/llvm-15/lib
> > > +else
> > > +RUST_FLAGS=
> > > +endif
> > > +
> > > +kmake += $(RUST_FLAGS)
> > > +
> > > # TODO this is probably wrong, and should be using $(DEB_HOST_MULTIARCH)
> > > shlibdeps_opts = $(if $(CROSS_COMPILE),-- -l$(CROSS_COMPILE:%-=/usr/%)/lib)
> > >
> > > diff --git a/debian/scripts/misc/kernelconfig b/debian/scripts/misc/kernelconfig
> > > index 035426762f8a..741650340b65 100755
> > > --- a/debian/scripts/misc/kernelconfig
> > > +++ b/debian/scripts/misc/kernelconfig
> > > @@ -118,7 +118,7 @@ EOF
> > > # Call config target
> > > echo
> > > echo "* Run ${target} on ${arch}/${flavour} ..."
> > > - ${kmake} O=build "${env[@]}" "${target}"
> > > + make ${RUST_FLAGS} O=build "${env[@]}" "${target}"
> > >
> > > # Move config for further processing
> > > mv build/.config "${tmp_conf_file}"
> > > --
> > > 2.40.1
> > >
> > >
> > > --
> > > kernel-team mailing list
> > > kernel-team at lists.ubuntu.com
> > > https://lists.ubuntu.com/mailman/listinfo/kernel-team
> >
> >
> >
>
--
okurrr,
Dimitri
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