netdev - Re: [PATCH v2 net] net: bridge: annotate data-races around fdb->{updated,used}

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Message-ID: <CANn89iLaMpL1Kz=t13b0eGZ+m5dBxUpXx8oPKD1V-VwBAkzbJA@mail.gmail.com>
Date: Wed, 7 Jan 2026 11:46:51 +0100
From: Eric Dumazet <edumazet@...gle.com>
To: Nikolay Aleksandrov <razor@...ckwall.org>
Cc: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>, netdev@...r.kernel.org, 
	eric.dumazet@...il.com, Ido Schimmel <idosch@...dia.com>
Subject: Re: [PATCH v2 net] net: bridge: annotate data-races around fdb->{updated,used}

On Wed, Jan 7, 2026 at 11:43 AM Nikolay Aleksandrov <razor@...ckwall.org> wrote:
>
> On 07/01/2026 11:00, Nikolay Aleksandrov wrote:
> > On 07/01/2026 10:32, Eric Dumazet wrote:
> >> fdb->updated and fdb->used are read and written locklessly.
> >>
> >> Add READ_ONCE()/WRITE_ONCE() annotations.
> >>
> >> Fixes: 31cbc39b6344 ("net: bridge: add option to allow activity
> >> notifications for any fdb entries")
> >> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> >> Cc: Nikolay Aleksandrov <razor@...ckwall.org>
> >> ---
> >> v2: annotate all problematic fdb->updated and fdb->used reads/writes.
> >> v1: https://lore.kernel.org/netdev/CANn89iL8-e_jphcg49eX=zdWrOeuA-
> >> AJDL0qhsTrApA4YnOFEg@...l.gmail.com/T/
> >> #mf99b76469697813939abe745f42ace3e201ef6f4
> >>
> >>   net/bridge/br_fdb.c | 28 ++++++++++++++++------------
> >>   1 file changed, 16 insertions(+), 12 deletions(-)
> >>
> >
> > +CC Ido
> >
> > Oh you took care of ->used as well, even better. Thanks!
> > Acked-by: Nikolay Aleksandrov <razor@...ckwall.org>
> >
>
> Sorry, I forgot about br_input.c: br_handle_frame_finish()
> use of ->used:
> ...
>                  if (now != dst->used)
>                          dst->used = now;
> ...
>
> That will need annotations as well.

No worries, I will add this in V3 tomorrow.