> diff --git a/include/asm-generic/vmlinux.lds.h
> b/include/asm-generic/vmlinux.lds.h
> index b2988aa12f66..a2e192854c47 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -675,12 +675,23 @@
> /*
> * .BTF
> */
[ ... ]
> 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
[ ... ]
> @@ -432,6 +438,17 @@ config DEBUG_INFO_BTF_MODULES
> help
> Generate compact split BTF type information for kernel modules.
>
> +config DEBUG_INFO_BTF_INLINE
> + bool "Provide information about inline sites in BTF"
> + default n
> + depends on DEBUG_INFO_BTF && PAHOLE_HAS_INLINE && SYSFS
> + help
> + Generate information about inline sites in .BTF.inline sections.
> + These sections contain split BTF relative to the kernel or module BTF
> + and are made available in /sys/kernel/btf with a ".inline" suffix.
> + The information describes inline locations and how to retrieve their
> + associated parameters.
> +
This isn't a bug, but could the changelog lead with why inline location
info is wanted and what a consumer does with it, rather than one sentence
per hunk?
In particular, is the in-tree/external-module paragraph still describing
something in this patch, and would it help to note that the SYSFS
dependency and the /sys/kernel/btf exposure mentioned in the help text
arrive in a later patch?
> 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 := $(btf-inline)
This isn't a bug, but could this collapse to something closer to the
surrounding one-liners, e.g. `pahole-flags-$(CONFIG_DEBUG_INFO_BTF_INLINE)
+= --btf_features=inline` plus `export BTF_INLINE :=
$(CONFIG_DEBUG_INFO_BTF_INLINE)`?
Since DEBUG_INFO_BTF_INLINE already depends on PAHOLE_HAS_INLINE
(PAHOLE_VERSION >= 131), is the extra test-ge 131 check inside the block
doing anything, and is the `btf-inline-feat` indirection needed?
> diff --git a/scripts/gen-btf.sh b/scripts/gen-btf.sh
> index 8ca96eb10a69..a75f41878c32 100755
> --- a/scripts/gen-btf.sh
> +++ b/scripts/gen-btf.sh
> @@ -76,6 +76,7 @@ gen_btf_data()
>
> ${RESOLVE_BTFIDS} ${RESOLVE_BTFIDS_FLAGS} \
> ${BTF_BASE:+--btf_base ${BTF_BASE}} \
> + ${BTF_INLINE:+--inline} \
> --btf ${btf1} "${ELF_FILE}"
> }
>
> @@ -83,14 +84,21 @@ gen_btf_o()
> {
> btf_data=${ELF_FILE}.btf.o
>
> - # Create ${btf_data} which contains just .BTF section but no symbols.
> Add
> + # Create ${btf_data} which contains just BTF sections but no symbols.
> Add
> # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
> # deletes all symbols including __start_BTF and __stop_BTF, which will
> # be redefined in the linker script.
> echo "" | ${CC} ${CLANG_FLAGS} ${KBUILD_CPPFLAGS} ${KBUILD_CFLAGS}
> -fno-lto -c -x c -o ${btf_data} -
> ${OBJCOPY} --add-section .BTF=${ELF_FILE}.BTF \
> --set-section-flags .BTF=alloc,readonly ${btf_data}
> - ${OBJCOPY} --only-section=.BTF --strip-all ${btf_data}
> + ONLY_SEC="--only-section=.BTF"
> + btf_inline=${ELF_FILE}.BTF.inline
> + if [ -n "${BTF_INLINE}" ] && [ -f "${btf_inline}" ]; then
> + ${OBJCOPY} --add-section .BTF.inline=${btf_inline} \
> + --set-section-flags .BTF.inline=alloc,readonly
> ${btf_data}
> + ONLY_SEC="${ONLY_SEC} --only-section=.BTF.inline"
> + fi
> + ${OBJCOPY} ${ONLY_SEC} --strip-all ${btf_data}
This isn't a bug, but would a lower-case name like `only_sec` fit better
here, given `btf_inline` right below it and the rest of the locals in this
script?
> @@ -111,6 +119,10 @@ embed_btf_data()
> if [ -f "${btf_base}" ]; then
> ${OBJCOPY} --add-section .BTF.base=${btf_base} ${ELF_FILE}
> fi
> + btf_inline=${ELF_FILE}.BTF.inline
> + if [ -n "${BTF_INLINE}" ] && [ -f "${btf_inline}" ]; then
> + ${OBJCOPY} --add-section .BTF.inline=${btf_inline} ${ELF_FILE}
> + fi
[ ... ]
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/33537080133
