[7/9] batman-adv: Use kref_get for batadv_gw_select
Commit Message
batadv_gw_select requires that the caller already has a valid reference for
new_gw_node. It is therefore not possible that it has an reference counter
of 0 and was still given to this function
The kref_get function instead WARNs (with debug information) when the
reference counter would still be 0. This makes a bug in batman-adv better
visible because kref_get_unless_zero would have ignored this problem.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
net/batman-adv/gateway_client.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
On Saturday, March 05, 2016 16:09:22 Sven Eckelmann wrote:
> batadv_gw_select requires that the caller already has a valid reference for
> new_gw_node. It is therefore not possible that it has an reference counter
> of 0 and was still given to this function
>
> The kref_get function instead WARNs (with debug information) when the
> reference counter would still be 0. This makes a bug in batman-adv better
> visible because kref_get_unless_zero would have ignored this problem.
>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> net/batman-adv/gateway_client.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Applied in revision e698321.
Thanks,
Marek
@@ -135,8 +135,8 @@ static void batadv_gw_select(struct batadv_priv *bat_priv,
spin_lock_bh(&bat_priv->gw.list_lock);
- if (new_gw_node && !kref_get_unless_zero(&new_gw_node->refcount))
- new_gw_node = NULL;
+ if (new_gw_node)
+ kref_get(&new_gw_node->refcount);
curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);