path: root/include/net/act_api.h
diff options
authorVlad Buslov <vladbu@mellanox.com>2019-09-13 18:28:40 +0300
committerDavid S. Miller <davem@davemloft.net>2019-09-16 09:18:03 +0200
commit4a5da47d5cb6aba3c26a5cc0dddfb2d577e851e9 (patch)
treec6f58d1ec493b1cd695eb7135af7255f2fc9c20d /include/net/act_api.h
parentnet: sched: extend flow_action_entry with destructor (diff)
net: sched: take reference to psample group in flow_action infra
With recent patch set that removed rtnl lock dependency from cls hardware offload API rtnl lock is only taken when reading action data and can be released after action-specific data is parsed into intermediate representation. However, sample action psample group is passed by pointer without obtaining reference to it first, which makes it possible to concurrently overwrite the action and deallocate object pointed by psample_group pointer after rtnl lock is released but before driver finished using the pointer. To prevent such race condition, obtain reference to psample group while it is used by flow_action infra. Extend psample API with function psample_group_take() that increments psample group reference counter. Extend struct tc_action_ops with new get_psample_group() API. Implement the API for action sample using psample_group_take() and already existing psample_group_put() as a destructor. Use it in tc_setup_flow_action() to take reference to psample group pointed to by entry->sample.psample_group and release it in tc_cleanup_flow_action(). Disable bh when taking psample_groups_lock. The lock is now taken while holding action tcf_lock that is used by data path and requires bh to be disabled, so doing the same for psample_groups_lock is necessary to preserve SOFTIRQ-irq-safety. Fixes: 918190f50eb6 ("net: sched: flower: don't take rtnl lock for cls hw offloads API") Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/act_api.h')
1 files changed, 5 insertions, 0 deletions
diff --git a/include/net/act_api.h b/include/net/act_api.h
index 3a1a72990fce..4be8b0daedf0 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -78,6 +78,8 @@ static inline void tcf_tm_dump(struct tcf_t *dtm, const struct tcf_t *stm)
#define ACT_P_CREATED 1
#define ACT_P_DELETED 1
+typedef void (*tc_action_priv_destructor)(void *priv);
struct tc_action_ops {
struct list_head head;
char kind[IFNAMSIZ];
@@ -101,6 +103,9 @@ struct tc_action_ops {
size_t (*get_fill_size)(const struct tc_action *act);
struct net_device *(*get_dev)(const struct tc_action *a);
void (*put_dev)(struct net_device *dev);
+ struct psample_group *
+ (*get_psample_group)(const struct tc_action *a,
+ tc_action_priv_destructor *destructor);
struct tc_action_net {