Re: [PATCH net-next 0/2] veth: a couple of fixes

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

On Fri, 18 Nov 2022 09:41:05 +0100, Paolo Abeni <pabeni@redhat.com> wrote:
> On Fri, 2022-11-18 at 00:33 +0100, Paolo Abeni wrote:
> > Recent changes in the veth driver caused a few regressions
> > this series addresses a couple of them, causing oops.
> >
> > Paolo Abeni (2):
> >   veth: fix uninitialized napi disable
> >   veth: fix double napi enable
> >
> >  drivers/net/veth.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
>
> @Xuan Zhuo: another option would be reverting 2e0de6366ac1 ("veth:
> Avoid drop packets when xdp_redirect performs") and its follow-up
> 5e5dc33d5dac ("bpf: veth driver panics when xdp prog attached before
> veth_open").
>
> That option would be possibly safer, because I feel there are other
> issues with 2e0de6366ac1, and would offer the opportunity to refactor
> its logic a bit: the napi enable/disable condition is quite complex and
> not used consistently mixing and alternating the gro/xdp/peer xdp check
> with the napi ptr dereference.
>
> Ideally it would be better to have an helper alike
> napi_should_be_enabled(), use it everywhere, and pair the new code with
> some selftests, extending the existing ones.
>
> WDYT?

I take your point.

Thanks.


>
> Side notes:
> - Heng Qi address is bouncing
> - the existing veth self-tests would have caught the bug addressed
> here, if commit afef88e65554 ("selftests/bpf: Store BPF object files
> with .bpf.o extension") would not have broken them meanwhile :(
>
> /P
>