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

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

[Yihao Han]

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>
---
Change log:
v2:
- Remove temp variable.
---
 samples/bpf/xsk_fwd.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/samples/bpf/xsk_fwd.c b/samples/bpf/xsk_fwd.c
index 1cd97c84c337..db15323728c0 100644
--- a/samples/bpf/xsk_fwd.c
+++ b/samples/bpf/xsk_fwd.c
@@ -651,11 +651,8 @@ static void swap_mac_addresses(void *data)
 	struct ether_header *eth = (struct ether_header *)data;
 	struct ether_addr *src_addr = (struct ether_addr *)&eth->ether_shost;
 	struct ether_addr *dst_addr = (struct ether_addr *)&eth->ether_dhost;
-	struct ether_addr tmp;
 
-	tmp = *src_addr;
-	*src_addr = *dst_addr;
-	*dst_addr = tmp;
+	swap(*src_addr, *dst_addr);
 }
 
 static void *
-- 
2.17.1

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

[John Fastabend]

Yihao Han wrote:
> 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>
> ---

LGTM

Acked-by: John Fastabend <john.fastabend@gmail.com>

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

[Toke Høiland-Jørgensen]

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:

  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? :)

-Toke

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

[Andrii Nakryiko]

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.

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.


>
>   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.

>
> -Toke
>

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

[Toke Høiland-Jørgensen]

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 ?

-Toke

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

[Andrii Nakryiko]

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.

>
> -Toke
>

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

[Toke Høiland-Jørgensen]

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