On Tue, Sep 01, 2026 at 05:57:52PM +0100, Alan Maguire wrote:
> Add CONFIG_DEBUG_INFO_BTF_INLINE to generate BTF inline-location
> information with pahole v1.31 and later.
>
> Enable pahole's inline feature and pass --inline to resolve_btfids.
> This extracts LOC_PARAM, LOC_PROTO, and LOCSEC types into a split BTF
> blob named <output>.BTF.inline while the ordinary BTF remains in .BTF.
>
> Embed the resulting blob in a .BTF.inline ELF section for vmlinux and
> modules. Add the vmlinux linker-script output section to avoid it
> being treated as an orphan.
>
> Use the inline pahole feature unconditionally for both in-tree and
> external modules; the generated split BTF has the same format in both
> cases.
>
> Signed-off-by: Alan Maguire <[email protected]>
> ---
> include/asm-generic/vmlinux.lds.h | 11 +++++++++++
> lib/Kconfig.debug | 17 +++++++++++++++++
> scripts/Makefile.btf | 7 +++++++
> scripts/gen-btf.sh | 17 +++++++++++++++--
> 4 files changed, 50 insertions(+), 2 deletions(-)
>
[...]
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 1244dcac2294..dd1b2d9ebe99 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -425,6 +425,12 @@ config PAHOLE_HAS_LANG_EXCLUDE
> otherwise it would emit malformed kernel and module binaries when
> using DEBUG_INFO_BTF_MODULES.
>
> +config PAHOLE_HAS_INLINE
> + def_bool PAHOLE_VERSION >= 131
[...]
> +config DEBUG_INFO_BTF_INLINE
> + bool "Provide information about inline sites in BTF"
> + default n
> + depends on DEBUG_INFO_BTF && PAHOLE_HAS_INLINE && SYSFS
[...]
> diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf
> index a1812985a61a..d42dbc8d7199 100644
> --- a/scripts/Makefile.btf
> +++ b/scripts/Makefile.btf
> @@ -22,7 +22,14 @@ endif
>
> pahole-flags-$(CONFIG_PAHOLE_HAS_LANG_EXCLUDE) +=
> --lang_exclude=rust
>
> +btf-inline := $(CONFIG_DEBUG_INFO_BTF_INLINE)
> +ifneq ($(btf-inline),)
> +btf-inline-feat := inline
> +pahole-flags-$(call test-ge, $(pahole-ver), 131) +=
> --btf_features=$(btf-inline-feat)
> +endif
> +
> export PAHOLE_FLAGS := $(pahole-flags-y)
> +export BTF_INLINE := $(btf-inline)
As btf-inline and btf-inline-feat are not used anywhere else, and
CONFIG_DEBUG_INFO_BTF_INLINE can only be set for PAHOLE_VERSION >= 131,
this looks a bit noisy to me. I think it would be good to keep that
change in scripts/Makefile.btf as short as possible, e.g.:
pahole-flags-$(CONFIG_DEBUG_INFO_BTF_INLINE) += --btf_features=inline
and for scripts/gen-btf.sh something like:
if is_enabled CONFIG_DEBUG_INFO_BTF_INLINE; then
BTF_INLINE=inline
fi
Kind regards,
Nicolas
