Subject: Re: [PATCH v4 bpf-next 3/9] bpf, xdp: extract common XDP program attachment logic

From: [email-masked]
Date: Tue, 11 Aug 2020 11:14:03 -0700

On 07/21, Andrii Nakryiko wrote:
> Further refactor XDP attachment code. dev_change_xdp_fd() is split into  
> two
> parts: getting bpf_progs from FDs and attachment logic, working with
> bpf_progs. This makes attachment  logic a bit more straightforward and
> prepares code for bpf_xdp_link inclusion, which will share the common  
> logic.
It looks like this patch breaks xdp tests for me:
* test_xdping.sh
* test_xdp_vlan.sh

Can you please verify on your side?

Looking at tools/testing/selftests/bpf/xdping.c I see it has:
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;

And it attaches program two times in the same net namespace,
so I don't see how it could've worked before the change :-/
(unless, of coarse, the previous code was buggy).