Re: [PATCH bpf-next] bpf: Add --skip_encoding_btf_inconsistent_proto, --btf_gen_optimized to pahole flags for v1.25

[Jiri Olsa <olsajiri@gmail.com>]

On Wed, May 10, 2023 at 02:02:41PM +0100, Alan Maguire wrote:
> 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.
> 
> Issues with pahole filtering being too aggressive in removing functions
> appear to be resolved now, but CI and further testing will confirm.
> 
> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

jirka

> ---
>  scripts/pahole-flags.sh | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/scripts/pahole-flags.sh b/scripts/pahole-flags.sh
> index 1f1f1d397c39..728d55190d97 100755
> --- 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}
> -- 
> 2.31.1
>