bpf: Add --skip_encoding_btf_inconsistent_proto, --btf_gen_optimized to pahole flags...

v1.25 of pahole supports filtering out functions with multiple inconsistent
function prototypes or optimized-out parameters from the BTF representation.
These present problems because there is no additional info in BTF saying which
inconsistent prototype matches which function instance to help guide attachment,
and functions with optimized-out parameters can lead to incorrect assumptions
about register contents.

So for now, filter out such functions while adding BTF representations for
functions that have "."-suffixes (foo.isra.0) but not optimized-out parameters.
This patch assumes that below linked changes land in pahole for v1.25.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/1675790102-23037-1-git-send-email-alan.maguire@oracle.com
Link: https://lore.kernel.org/bpf/1675949331-27935-1-git-send-email-alan.maguire@oracle.com

diff --git a/scripts/pahole-flags.sh b/scripts/pahole-flags.sh
index 1f1f1d3..728d551 100755 (executable)
--- a/scripts/pahole-flags.sh
+++ b/scripts/pahole-flags.sh
@@ -23,5 +23,8 @@ if [ "${pahole_ver}" -ge "124" ]; then
        # see PAHOLE_HAS_LANG_EXCLUDE
        extra_paholeopt="${extra_paholeopt} --lang_exclude=rust"
 fi
+if [ "${pahole_ver}" -ge "125" ]; then
+       extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_inconsistent_proto --btf_gen_optimized"
+fi
 
 echo ${extra_paholeopt}