On Thu, 4 Apr 2024 at 16:31, Stephen Hemminger <step...@networkplumber.org> wrote: > > On Wed, 3 Apr 2024 22:19:20 +0100 > Luca Boccassi <bl...@debian.org> wrote: > > > On Wed, 3 Apr 2024 at 16:55, Stephen Hemminger > > <step...@networkplumber.org> wrote: > > > > > > On Wed, 03 Apr 2024 12:50:35 +0100 > > > Luca Boccassi <bl...@debian.org> wrote: > > > > > > > Using bpftool to generate the header at build time is a bit icky, > > > > because it will look at sysfs on the build system, which is from the > > > > running kernel. But a build system's kernel might be some ancient LTS, > > > > and even be a completely different kconfig/build/distro from the actual > > > > runtime one. > > > > > > One other option would be to ship a pre-built skeleton file. > > > Which is what the method the old code did. > > > But that creates an implied dependency on the developers machine build > > > environment. > > > > That's what the distro-provided vmlinux.h should help with - by > > #include'ing that, it should be possible to build a co-re bpf program, > > no other artifacts needed. You can try it out locally by generating it > > from the local running kernel on your dev machine: > > > > bpftool btf dump file /sys/kernel/btf/vmlinux format c > vmlinux.h > > What about Ubuntu with borked installation of bpftool?
Yeah that's a bit confusing, the way to do it is to install linux-tools-generic and then here's logic to find the right one: https://git.launchpad.net/ubuntu/+source/xdp-tools/tree/debian/rules#n34 But I wouldn't bother with it in upstream projects, let the integrators deal with it
