Re: [PATCH net 1/1] batman-adv: stop caching unowned originator pointers in BAT IV

[Sven Eckelmann <sven@narfation.org>]

On Sun, 03 May 2026 12:28:58 +0800, Ren Wei <n05ec@lzu.edu.cn> wrote:
> [...]
> Reported-by: Yuan Tan <yuantan098@gmail.com>
> Reported-by: Yifan Wu <yifanwucs@gmail.com>
> Reported-by: Juefei Pu <tomapufckgml@gmail.com>
> Reported-by: Xin Liu <bird@lzu.edu.cn>
> Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>

This looks half finished from the types perspective: 

net/batman-adv/bat_v_ogm.c:
713 |         if (router && router->orig_node != orig_node && !orig_neigh_router) {

net/batman-adv/originator.c:
697 |         neigh_node->orig_node = orig_node;

net/batman-adv/types.h:

631 |         struct batadv_orig_node *orig_node;


Not sure if __private and ACCESS_PRIVATE() would be an option - just to handle
this non-deref comparison while still allowing a fast comparison of the pointer
value.

I don't want to make this a show-stopper - just a possibility to think about
this for a moment. Especially because I am waiting for some info about the
sashiko.dev "Embargoed" state

>
>
> diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
> index f28e9cbf..168b413d 100644
> --- a/net/batman-adv/bat_iv_ogm.c
> +++ b/net/batman-adv/bat_iv_ogm.c
> @@ -906,6 +899,31 @@ static u8 batadv_iv_orig_ifinfo_sum(struct batadv_orig_node *orig_node,
> [ ... skip 22 lines ... ]
> +	sum = batadv_iv_orig_ifinfo_sum(orig_neigh, neigh_node->if_incoming);
> +	batadv_orig_node_put(orig_neigh);
> +
> +	return sum;
> +}
> +

@Marek, @Simon, Maybe you can also get a good cup of tea and think (besides
performance implications) think about other side effects.

-- 
Sven Eckelmann <sven@narfation.org>