Re: [bug report] selftests/bpf: Verify that the cgroup_skb filters receive expected packets.

[Kui-Feng Lee <sinquersw@gmail.com>]

On 8/3/23 22:13, Dan Carpenter wrote:
> On Thu, Aug 03, 2023 at 01:43:33PM -0700, Kui-Feng Lee wrote:
>>>>       113         int err;
>>>>       114
>>>>       115         addr.sin6_port = htons(get_sock_port_v6(listen_fd));
>>>> --> 116         if (addr.sin6_port < 0)
>>>>                       ^^^^^^^^^^^^^^^^^^
>>>> Impossible and also it doesn't make sense to compare network endian data
>>>> with < 0.
>>>
>>> Hi Dan,
>>>
>>> Thank you for pointing it out. It should check the returned value
>>> of get_sock_port_v6() before calling htons(). I will send a patch
>>> to fix it asap.
>>
>> Could you show me how to run Smatch againt bpf selftests?
>>
> 
> Oh wow...  You don't want to know.  So sometimes I'll go through and
> do a `find -name \*.c` and if there isn't a matching .o file I'll just
> run:
> 
> 	~/path/to/smatch tools/testing/selftests/bpf/prog_tests/cgroup_tcp_skb.c
> 
> Smatch has a thing where if the .h file is missing it will just include
> the nearest .h file with a similar name.  This doesn't work well and
> generates a ton of errors.  But I grep the output for specific types
> of errors like "is never less than zero".

Got it! Thanks!

> 
> regards,
> dan carpenter
>