I came now up with this ...
--
Best, Philip
From: Philip Müller <philm@xxxxxxxxxxx>
Date: Sat, 15 Oct 2021 20:09:13 +0200
Subject: [PATCH] bpf: Add skip_encoding_btf_enum64 option to pahole
New pahole (version 1.24) generates by default new BTF_KIND_ENUM64 BTF tag,
which is not supported by stable kernel.
As a result the kernel with CONFIG_DEBUG_INFO_BTF option will fail to
compile with following error:
BTFIDS vmlinux
FAILED: load BTF from vmlinux: Invalid argument
New pahole provides --skip_encoding_btf_enum64 option to skip BTF_KIND_ENUM64
generation and produce BTF supported by stable kernel.
Adding this option to scripts/link-vmlinux.sh.
This change does not have equivalent commit in linus tree, because linus tree
has support for BTF_KIND_ENUM64 tag, so it does not need to be disabled.
Signed-off-by: Philip Müller <philm@xxxxxxxxxxx>
---
scripts/link-vmlinux.sh | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3b261b0f74f0a7..667aacb9261cf2 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -213,6 +213,7 @@ vmlinux_link()
gen_btf()
{
local pahole_ver
+ local extra_paholeopt=
if ! [ -x "$(command -v ${PAHOLE})" ]; then
echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
@@ -227,8 +228,12 @@ gen_btf()
vmlinux_link ${1}
+ if [ "${pahole_ver}" -ge "124" ]; then
+ extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_enum64"
+ fi
+
info "BTF" ${2}
- LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
+ LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${extra_paholeopt} ${1}
# Create ${2} which contains just .BTF section but no symbols. Add
# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
