On Wed 08 Aug 2018 at 08:03, Jiri Pirko <j...@resnulli.us> wrote:
> Wed, Aug 08, 2018 at 09:40:35AM CEST, vla...@mellanox.com wrote:
>>
>>On Tue 07 Aug 2018 at 16:36, Jiri Pirko <j...@resnulli.us> wrote:
>>> Mon, Aug 06, 2018 at 08:54:23AM CEST, vla...@mellanox.com wrote:
>>>
>>> [...]
>>>
>>>>diff --git a/include/net/tc_act/tc_tunnel_key.h
>>>>b/include/net/tc_act/tc_tunnel_key.h
>>>>index 46b8c7f1c8d5..e6e475d788c6 100644
>>>>--- a/include/net/tc_act/tc_tunnel_key.h
>>>>+++ b/include/net/tc_act/tc_tunnel_key.h
>>>>@@ -30,26 +30,47 @@ struct tcf_tunnel_key {
>>>>
>>>> static inline bool is_tcf_tunnel_set(const struct tc_action *a)
>>>> {
>>>>+ bool ret = false;
>>>> #ifdef CONFIG_NET_CLS_ACT
>>>> struct tcf_tunnel_key *t = to_tunnel_key(a);
>>>>- struct tcf_tunnel_key_params *params = rtnl_dereference(t->params);
>>>>+ struct tcf_tunnel_key_params *params;
>>>>
>>>>+ rcu_read_lock();
>>>>+ params = rcu_dereference(t->params);
>>>> if (a->ops && a->ops->type == TCA_ACT_TUNNEL_KEY)
>>>>- return params->tcft_action == TCA_TUNNEL_KEY_ACT_SET;
>>>>+ ret = params->tcft_action == TCA_TUNNEL_KEY_ACT_SET;
>>>>+ rcu_read_unlock();
>>>> #endif
>>>>- return false;
>>>>+ return ret;
>>>> }
>>>>
>>>> static inline bool is_tcf_tunnel_release(const struct tc_action *a)
>>>
>>> Why are these tunnel things in a mirred patch?
>>
>>Mistake during re-slit. Will move those to tunnel_key patch.
>
> Are you sure that the changes are safe? I just quickly looked over it
> and it smells:
> drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:
> if (is_tcf_tunnel_set(a)) {
> info = tcf_tunnel_info(a);
>
> Why the "t->params" can't be nulled in the middle?
First of all, no API is actually "unlocked" with this patch. It is a
preparation, rtnl mutex is still in use.
Callers of these functions will have to be updated, for example, to use
their _rcu version while holding rcu_read_lock.
