Re: [PATCH net 2/2] netpoll: Use rcu_access_pointer() in netpoll_poll_lock

[Breno Leitao]

On Mon, Nov 18, 2024 at 01:20:30PM +0100, Michal Kubiak wrote:
> On Mon, Nov 18, 2024 at 03:15:18AM -0800, Breno Leitao wrote:
> > The ndev->npinfo pointer in netpoll_poll_lock() is RCU-protected but is
> > being accessed directly for a NULL check. While no RCU read lock is held
> > in this context, we should still use proper RCU primitives for
> > consistency and correctness.
> > 
> > Replace the direct NULL check with rcu_access_pointer(), which is the
> > appropriate primitive when only checking for NULL without dereferencing
> > the pointer. This function provides the necessary ordering guarantees
> > without requiring RCU read-side protection.
> > 
> > Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> > Fixes: bea3348eef27 ("[NET]: Make NAPI polling independent of struct net_device objects.")
> 
> nitpick: As for the first patch - please check the tags order.
> 
> Thanks,
> Reviewed-by: Michal Kubiak <michal.kubiak@xxxxxxxxx>

Thanks for the review.

I am not planning to resend it now, since I think maintainer's tooling will
reorder that.

If that is not true, I am more than happy to resend fixing the order.

Thanks
Breno