Re: [PATCH net-next 0/2] Bonding: support new xfrm state offload functions

[Hangbin Liu <liuhangbin@gmail.com>]

On Fri, Aug 16, 2024 at 09:06:12AM +0300, Nikolay Aleksandrov wrote:
> On 16/08/2024 06:55, Hangbin Liu wrote:
> > I planned to add the new XFRM state offload functions after Jianbo's
> > patchset [1], but it seems that may take some time. Therefore, I am
> > posting these two patches to net-next now, as our users are waiting for
> > this functionality. If Jianbo's patch is applied first, I can update these
> > patches accordingly.
> > 
> > [1] https://lore.kernel.org/netdev/20240815142103.2253886-2-tariqt@nvidia.com
> > 
> > Hangbin Liu (2):
> >   bonding: Add ESN support to IPSec HW offload
> >   bonding: support xfrm state update
> > 
> >  drivers/net/bonding/bond_main.c | 76 +++++++++++++++++++++++++++++++++
> >  1 file changed, 76 insertions(+)
> > 
> 
> (not related to this set, but to bond xfrm)
> By the way looking at bond's xfrm code, what prevents bond_ipsec_offload_ok()
> from dereferencing a null ptr?
> I mean it does:
>         curr_active = rcu_dereference(bond->curr_active_slave);
>         real_dev = curr_active->dev;
> 
> If this is running only under RCU as the code suggests then
> curr_active_slave can change to NULL in parallel. Should there be a
> check for curr_active before deref or am I missing something?

Yes, we can do like
real_dev = curr_active ? curr_active->dev : NULL;

Thanks
Hangbin