Re: [PATCH bpf 1/1] selftests/bpf: Enable BLK_DEV_NBD for raw_tp_writable_reject_nbd_invalid

[Shung-Hsi Yu <shung-hsi.yu@suse.com>]

On Mon, Jul 13, 2026 at 01:47:18PM -0700, Eduard Zingerman wrote:
> On Mon, 2026-07-13 at 14:35 +0800, Shung-Hsi Yu wrote:
> > The raw_tp_writable_reject_nbd_invalid test relies on availability of the
> > nbd_send_request tracepoint, which is only present if the selftest kernel is
> > built with CONFIG_BLK_DEV_NBD=y and the kernel built from current BPF selftests
> > config lacks.
> > 
> > Without it, the bpf_raw_tracepoint_open() call always returns with -2, leaving
> > raw_tp_writable_reject_nbd_invalid test always passing without exercising the
> > checks bpf_probe_register().
> > 
> > Cc: <stable@vger.kernel.org> # 5.2.0
> > Link: https://lore.kernel.org/bpf/alRtilWhKw4zzMkI@u94a
> > Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
> > ---
> > Not sure if fixes tag is the right thing to use here, so use the cc
> > stable tag instead to get this config change propogated to other stable
> > branches to make stable BPF CI's job easier.
> 
> Shung-Hsi,
> 
> Thank you for figuring this out.
> I'd suggest we switch to bpf_testmod_test_writable_bare_tp() [1]
> from the test module to avoid the config dependency and let
> Sun pack all of this as a single patch-set to simplify backports
> (if such are necessary). Wdyt?

Make sense, that's probably for the better.

pw-bot: changes-requested

@Sun can you make sure to include the follow tag for [1] when you send
it? Should give a better guarantee that is will be picked up by AUTOSEL.
Thanks!

  Cc: <stable@vger.kernel.org> # 5.2.0