Re: [PATCH bpf-next v3 03/14] selftests/bpf: test_xsk: Fix memory leaks

Bastien Curutchet
2025-09-17T15:33:02Z

Hi Maciej

On 9/16/25 7:58 PM, Maciej Fijalkowski wrote:
> On Thu, Sep 04, 2025 at 12:10:18PM +0200, Bastien Curutchet (eBPF Foundation) wrote:
>> Some tests introduce memory leaks by not freeing all the pkt_stream
>> objects they're creating.
>>
>> Fix these memory leaks.
>
> I would appreciate being more explicit here as I've been scratching my
> head here.
>

Indeed it lacks details sorry. IIRC I spotted these with valgrind, maybe
I can add valgrind's output to the commit log in next iteration.

> From what I see the problem is with testapp_stats_rx_dropped() as it's the
> one case that uses replace and receive half of pkt streams, both of which
> overwrite the default pkt stream. So we lose a pointer to one of pkt
> streams and leak it eventually.
>

Exactly, we lose pointers in some cases when xsk->pkt_stream gets
replaced by a new stream. testapp_stats_rx_dropped() is the most
convoluted of these cases.

Best regards,
--
Bastien Curutchet, Bootlin
Embedded Linux and Kernel engineering