[PATCH][oracular] UBUNTU: [Packaging] add linux-bpf-dev package

[luca.boccassi at gmail.com]

From: Luca Boccassi <bluca at debian.org>

BugLink: https://bugs.launchpad.net/bugs/2050083

Add a new binary linux-bpf-dev package that ships a generated vmlinux.h
header. This can be used by packages building CO-RE BPF programs instead
of generating it at build time based on the kernel running on the package
build system, which might or might not match the kernel that is actually
shipped. It ensures that a matching header can always be used.

Matches changes in Debian, including the package name and header installation
location, so that we do not have to ifdef:

https://salsa.debian.org/kernel-team/linux/-/commit/f52d006f3915ac4358dc8c98aa417477ebee026e

This is already used by systemd to build various CO-RE programs, and
right now on Ubuntu due to the lack of this package the header is
generated from sysfs in the build system where the systemd packages are
built.

Signed-off-by: Luca Boccassi <bluca at debian.org>
---
Based on the master-next branch of:
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/oracular

 debian/control.d/linux-bpf-dev.stub | 7 +++++++
 debian/rules                        | 1 +
 debian/rules.d/2-binary-arch.mk     | 8 ++++----
 3 files changed, 12 insertions(+), 4 deletions(-)
 create mode 100644 debian/control.d/linux-bpf-dev.stub

diff --git a/debian/control.d/linux-bpf-dev.stub b/debian/control.d/linux-bpf-dev.stub
new file mode 100644
index 000000000000..2967299aec18
--- /dev/null
+++ b/debian/control.d/linux-bpf-dev.stub
@@ -0,0 +1,7 @@
+Package: linux-bpf-dev
+Architecture: amd64 armhf arm64 i386 ppc64el riscv64 s390x
+Depends: ${misc:Depends}
+Multi-Arch: same
+Description: Headers for BPF development
+ The vmlinux.h header is provided to allow userspace to build BPF CO-RE
+ programs targeting the packaged kernel.
diff --git a/debian/rules b/debian/rules
index 43eae8d5aaa8..5fd39b2b0bcc 100755
--- a/debian/rules
+++ b/debian/rules
@@ -175,6 +175,7 @@ ifeq ($(src_pkg_name),linux)
 	control_files += debian/control.d/linux-tools-host.stub
 	control_files += debian/control.d/linux-source.stub
 	control_files += debian/control.d/linux-doc.stub
+	control_files += debian/control.d/linux-bpf-dev.stub
 endif
 
 # Calculate Ubuntu Compatible Signing levels
diff --git a/debian/rules.d/2-binary-arch.mk b/debian/rules.d/2-binary-arch.mk
index cda3522d7b5b..792276bf8458 100644
--- a/debian/rules.d/2-binary-arch.mk
+++ b/debian/rules.d/2-binary-arch.mk
@@ -256,9 +256,7 @@ ifeq ($(do_dbgsym_package),true)
 	rm -f $(dbgpkgdir)/usr/lib/debug/lib/modules/$(abi_release)-$*/modules.*
 	rm -fr $(dbgpkgdir)/usr/lib/debug/lib/firmware
 endif
-ifeq ($(do_tools_bpftool),true)
 	cp $(builddir)/build-$*/vmlinux tools/bpf/bpftool/
-endif
 
 	# The flavour specific headers image
 	# TODO: Would be nice if we didn't have to dupe the original builddir
@@ -616,6 +614,7 @@ endif
 ifeq ($(do_cloud_tools),true)
 	$(call dh_all,$(pkgcloud))
 endif
+	$(call dh_all,linux-bpf-dev)
 
 #
 # per-architecture packages
@@ -658,11 +657,10 @@ ifeq ($(do_tools_perf),true)
 	cd $(builddirpa)/tools/perf && \
 		$(kmake) prefix=/usr NO_LIBTRACEEVENT=1 HAVE_CPLUS_DEMANGLE_SUPPORT=1 CROSS_COMPILE=$(CROSS_COMPILE) NO_LIBPERL=1 WERROR=0
 endif
-ifeq ($(do_tools_bpftool),true)
 	mv $(builddirpa)/tools/bpf/bpftool/vmlinux $(builddirpa)/vmlinux
 	$(kmake) NO_LIBTRACEEVENT=1 CROSS_COMPILE=$(CROSS_COMPILE) -C $(builddirpa)/tools/bpf/bpftool
+	$(builddirpa)/tools/bpf/bpftool/bpftool btf dump file $(builddirpa)/vmlinux format c > $(builddirpa)/vmlinux.h
 	rm -f $(builddirpa)/vmlinux
-endif
 ifeq ($(do_tools_x86),true)
 	cd $(builddirpa)/tools/power/x86/x86_energy_perf_policy && make CROSS_COMPILE=$(CROSS_COMPILE)
 	cd $(builddirpa)/tools/power/x86/turbostat && make CROSS_COMPILE=$(CROSS_COMPILE)
@@ -713,6 +711,8 @@ endif
 ifeq ($(do_tools_bpftool),true)
 	install -m755 $(builddirpa)/tools/bpf/bpftool/bpftool $(toolspkgdir)/usr/lib/$(src_pkg_name)-tools-$(abi_release)
 endif
+	install -d -m755 $(CURDIR)/debian/linux-bpf-dev/usr/include/$(DEB_HOST_MULTIARCH)/linux/
+	install -m644 $(builddirpa)/vmlinux.h $(CURDIR)/debian/linux-bpf-dev/usr/include/$(DEB_HOST_MULTIARCH)/linux/vmlinux.h
 ifeq ($(do_tools_x86),true)
 	install -m755 \
 		$(addprefix $(builddirpa)/tools/power/x86/, x86_energy_perf_policy/x86_energy_perf_policy turbostat/turbostat) \
-- 
2.39.2