netdev - Re: [PATCH bpf-next 4/4] selftests/bpf: Remove tests for prologue/epilogue with kfuncs

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Message-ID: <87o6mnthwf.fsf@cloudflare.com>
Date: Wed, 21 Jan 2026 10:49:20 +0100
From: Jakub Sitnicki <jakub@...udflare.com>
To: Martin KaFai Lau <martin.lau@...ux.dev>
Cc: Alexei Starovoitov <ast@...nel.org>,  Daniel Borkmann
 <daniel@...earbox.net>,  John Fastabend <john.fastabend@...il.com>,
  Andrii Nakryiko <andrii@...nel.org>,  Eduard Zingerman
 <eddyz87@...il.com>,  Song Liu <song@...nel.org>,  Yonghong Song
 <yonghong.song@...ux.dev>,  KP Singh <kpsingh@...nel.org>,  Stanislav
 Fomichev <sdf@...ichev.me>,  Hao Luo <haoluo@...gle.com>,  Jiri Olsa
 <jolsa@...nel.org>,  Amery Hung <ameryhung@...il.com>,
  netdev@...r.kernel.org,  kernel-team@...udflare.com,  bpf@...r.kernel.org
Subject: Re: [PATCH bpf-next 4/4] selftests/bpf: Remove tests for
 prologue/epilogue with kfuncs

On Tue, Jan 20, 2026 at 03:48 PM -08, Martin KaFai Lau wrote:
> On 1/19/26 11:53 AM, Jakub Sitnicki wrote:
>> Remove pro_epilogue_with_kfunc test program and its supporting code in
>> bpf_testmod. This test exercised calling kfuncs from prologue and epilogue,
>> which is no longer supported after the switch to direct helper calls.
>
> Is it easy to change it to test calling helper in pro/epilogue?

I gave it a shot and the obstacle is that bpf_cgroup_from_id and
bpf_cgroup_release are not exported symbols, so they can't be referred
to from bpf_testmod. We'd have to move the whole thing to lib/test_bpf
so it's a built-in.