On Fri, Nov 1, 2024 at 1:29 AM Viktor Malik <vmalik@xxxxxxxxxx> wrote: > > In order to specify extra compilation or linking flags to BPF selftests, > it is possible to set EXTRA_CFLAGS and EXTRA_LDFLAGS from the command > line. The problem is that they are not propagated to sub-make calls > (runqslower, bpftool, libbpf) and in the better case are not applied, in > the worse case cause the entire build fail. > > Propagate EXTRA_CFLAGS and EXTRA_LDFLAGS to the sub-makes. > > This, for instance, allows to build selftests as PIE with > > $ make EXTRA_CFLAGS='-fPIE' EXTRA_LDFLAGS='-pie' > > Without this change, the command would fail because libbpf.a would not > be built with -fPIE and other PIE binaries would not link against it. > > The only problem is that we have to explicitly provide empty > EXTRA_CFLAGS='' and EXTRA_LDFLAGS='' to the builds of kernel modules as > we don't want to build modules with flags used for userspace (the above > example would fail as kernel doesn't support PIE). > > Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx> > --- > tools/testing/selftests/bpf/Makefile | 34 +++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 11 deletions(-) > Ok, so this will conflict with Toke's [0]. Who should go first? :) And given you guys touch these more obscure parts of BPF selftests Makefile, I'd really appreciate it if you can help reviewing them for each other :) [0] https://patchwork.kernel.org/project/netdevbpf/patch/20241031-bpf-selftests-mod-compile-v1-1-1a63af2385f1@xxxxxxxxxx/ [...]
