Re: [PATCH v2] samples/bpf: xdpsock: fix swap.cocci warning

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:

> On Sat, Dec 11, 2021 at 10:07 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>>
>> Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:
>>
>> > On Fri, Dec 10, 2021 at 6:26 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>> >>
>> >> Yihao Han <hanyihao@vivo.com> writes:
>> >>
>> >> > Fix following swap.cocci warning:
>> >> > ./samples/bpf/xdpsock_user.c:528:22-23:
>> >> > WARNING opportunity for swap()
>> >> >
>> >> > Signed-off-by: Yihao Han <hanyihao@vivo.com>
>> >>
>> >> Erm, did this get applied without anyone actually trying to compile
>> >> samples? I'm getting build errors as:
>> >
>> > Good news: I actually do build samples/bpf nowadays after fixing a
>> > bunch of compilation issues recently.
>>
>> Awesome!
>>
>> > Bad news: seems like I didn't pay too much attention after building
>> > samples/bpf for this particular patch, sorry about that. I've dropped
>> > this patch, samples/bpf builds for me. We should be good now.
>>
>> Yup, looks good, thanks!
>>
>> >>   CC  /home/build/linux/samples/bpf/xsk_fwd.o
>> >> /home/build/linux/samples/bpf/xsk_fwd.c: In function ‘swap_mac_addresses’:
>> >> /home/build/linux/samples/bpf/xsk_fwd.c:658:9: warning: implicit declaration of function ‘swap’; did you mean ‘swab’? [-Wimplicit-function-declaration]
>> >>   658 |         swap(*src_addr, *dst_addr);
>> >>       |         ^~~~
>> >>       |         swab
>> >>
>> >> /usr/bin/ld: /home/build/linux/samples/bpf/xsk_fwd.o: in function `thread_func':
>> >> xsk_fwd.c:(.text+0x440): undefined reference to `swap'
>> >> collect2: error: ld returned 1 exit status
>> >>
>> >>
>> >> Could we maybe get samples/bpf added to the BPF CI builds? :)
>> >
>> > Maybe we could, if someone dedicated their effort towards making this
>> > happen.
>>
>> Is it documented anywhere what that would entail? Is it just a matter of
>> submitting a change to https://github.com/kernel-patches/vmtest ?
>
> I think the right way would be to build samples/bpf from
> selftests/bpf's Makefile. At the very least we should not require make
> headers_install (I never understood that with samples/bpf, all those
> up-to-date UAPI headers are right there in the same repo). Once that
> is done, at the very least we'll build tests samples/bpf during CI
> runs.

Alright, sounds fair. I'll look into that, but probably before the
holidays :)

-Toke