On Sun, Aug 28, 2022 at 01:51:24PM -0300, Martin Reboredo wrote:
> From: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>
>
> After the release of pahole 1.24 some people in the dwarves mailing list
> notified issues related to building the kernel with the BTF_DEBUG_INFO
> option toggled. They seem to be happenning due to the kernel and
> resolve_btfids interpreting btf types erroneously. In the dwarves list
> I've proposed a change to the scripts that I've written while testing
> the Rust kernel, it simply passes the --skip_encoding_btf_enum64 to
> pahole if it has version 1.24, but it might be desirable to have the
> option to pass said flag.
as I wrote in the original thread, I think we need to do this just for
stable kernels that don't have enum64 support and use pahole 1.24
I think we should switch it off there by default without config option
jirka
>
> Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>
> ---
> lib/Kconfig.debug | 14 ++++++++++++++
> scripts/pahole-flags.sh | 7 +++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 072e4b289c13..638a33cf9e57 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -356,6 +356,20 @@ config PAHOLE_HAS_BTF_TAG
> btf_decl_tag) or not. Currently only clang compiler implements
> these attributes, so make the config depend on CC_IS_CLANG.
>
> +config PAHOLE_HAS_SKIP_ENCODING_BTF_ENUM64
> + def_bool PAHOLE_VERSION >= 124
> + help
> + Encoding BTF enum64s can be skipped with the
> + --skip_encoding_btf_enum64 pahole option.
> +
> +config DEBUG_INFO_BTF_SKIP_ENCODING_ENUM64
> + def_bool n
> + depends on DEBUG_INFO_BTF && PAHOLE_HAS_SKIP_ENCODING_BTF_ENUM64
> + help
> + Omit the encoding of 64 bits enum values with pahole. With certain
> + kernel configurations having ENUM64s enabled may result in malformed
> + output binaries.
> +
> config DEBUG_INFO_BTF_MODULES
> def_bool y
> depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
> diff --git a/scripts/pahole-flags.sh b/scripts/pahole-flags.sh
> index 0d99ef17e4a5..e44bc2a947ce 100755
> --- a/scripts/pahole-flags.sh
> +++ b/scripts/pahole-flags.sh
> @@ -9,6 +9,10 @@ fi
>
> pahole_ver=$($(dirname $0)/pahole-version.sh ${PAHOLE})
>
> +is_enabled() {
> + grep -q "^$1=y" include/config/auto.conf
> +}
> +
> if [ "${pahole_ver}" -ge "118" ] && [ "${pahole_ver}" -le "121" ]; then
> # pahole 1.18 through 1.21 can't handle zero-sized per-CPU vars
> extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_vars"
> @@ -19,5 +23,8 @@ fi
> if [ "${pahole_ver}" -ge "122" ]; then
> extra_paholeopt="${extra_paholeopt} -j"
> fi
> +if is_enabled DEBUG_INFO_BTF_SKIP_ENCODING_ENUM64; then
> + extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_enum64"
> +fi
>
> echo ${extra_paholeopt}
> --
> 2.37.2
>
