Re: [PATCH net] mptcp: protect listener backlog reads in diagnostics

[gang.yan@linux.dev]

October 26, 2026 at 10:44 PM, "Cen Zhang" <zzzccc427@gmail.com mailto:zzzccc427@gmail.com?to=%22Cen%20Zhang%22%20%3Czzzccc427%40gmail.com%3E > wrote:


> 
> Hi Eric,
> 
> Eric Dumazet <edumazet@kernel.org> 于2026年10月26日周一 20:38写道：
> 
> > 
> > Adding these stack traces without symbols is not really nice.
> > 
> >  Time to use scripts/decode_stacktrace.sh
> > 
> Sorry about that, v2 carries the report decoded with
> scripts/decode_stacktrace.sh and trimmed to the relevant frames.
> 
> > 
> > msk->first is a TCP socket: TCP listeners have SOCK_RCU_FREE, and
> >  tcp_prot / tcpv6_prot use SLAB_TYPESAFE_BY_RCU. Reading two integers
> >  under rcu_read_lock() is safe, and stale values are fine for diag.
> > 
> Thanks for the suggestions.

Hi Cen,

Basically this looks fine to me, I don't see any issue with the overall
approach.

Also, could you send v3 separately to the MPTCP mailing list? It seems the
CI checks were not triggered this time. I guess it might be because the
patch was not based on the export branch of the mptcp repo on GitHub, so
you can generate the patch based on that branch
(multipath-tcp/mptcp_net-next, branch export).

Two notes for next time (Important):
1. For MPTCP-only patches, it is enough to send them to the MPTCP list
   only, no need to CC netdev.
2. If a new version is needed, please wait 24 hours before sending it.



Thanks
Gang


> 
> Best regards,
> Cen Zhang
>