Re: [PATCH bpf-next] selftests/bpf: Tolerate libarena skeleton failures under BPF_STRICT_BUILD=0

[HyeongJun An]

On Fri Sep 11, 2026 at 03:02:35PM -0300, Ricardo B. Marlière (SUSE) wrote:

> Under which circumstances does this happen to you? I missed this because I
> was using defconfig + DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT + DEBUG_INFO_BTF +
> BPF_SYSCALL + BPF_JIT

Building against the distro kernel's BTF rather than one from the tree.
On Ubuntu 6.17, /sys/kernel/btf/vmlinux carries no bpf_kfunc DECL_TAGs,
so the vmlinux.h generated from it has 5 __ksym declarations where a
tree-built kernel gives 269, and all six libarena BPF sources fail on
undeclared bpf_preempt_disable, bpf_preempt_enable and
bpf_stream_vprintk. It seems that is why you did not run into it with a
kernel you built yourself.

Thanks for the ack. I checked what the two bots raised and they are both
right, including the Fixes: tag, so the patch needs more work than this.

HyeongJun