Re: [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Avoid u32 overflow during gateway select

David Miller
2015-06-21T16:37:13Z

From: Antonio Quartulli <antonio@meshcoding.com>
Date: Tue, 16 Jun 2015 21:06:23 +0200

> @@ -133,7 +133,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
> struct batadv_neigh_node *router;
> struct batadv_neigh_ifinfo *router_ifinfo;
> struct batadv_gw_node *gw_node, *curr_gw = NULL;
> - uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
> + uint64_t max_gw_factor = 0, tmp_gw_factor = 0;
> uint32_t gw_divisor;

Divides are performed using these variables, so if you make
them 64-bit the build will fail. You have to use one of the
routines in include/linux/math64.h in this situation, but
realize that this operation is now going to be quite expensive.