This is a note to let you know that I've just added the patch titled
net: treat possible_net_t net pointer as an RCU one and add read_pnet_rcu()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-treat-possible_net_t-net-pointer-as-an-rcu-one-a.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d19a98544f6b1e7b0f15f6520870fb0fa7fb14b6
Author: Jiri Pirko <jiri@xxxxxxxxxxx>
Date: Fri Oct 13 14:10:23 2023 +0200
net: treat possible_net_t net pointer as an RCU one and add read_pnet_rcu()
[ Upstream commit 2034d90ae41ae93e30d492ebcf1f06f97a9cfba6 ]
Make the net pointer stored in possible_net_t structure annotated as
an RCU pointer. Change the access helpers to treat it as such.
Introduce read_pnet_rcu() helper to allow caller to dereference
the net pointer under RCU read lock.
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: dd205fcc33d9 ("ipv4: use RCU protection in rt_is_expired()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index c41e922fdd97e..0dfcf2f0ef62a 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -320,21 +320,30 @@ static inline int check_net(const struct net *net)
typedef struct {
#ifdef CONFIG_NET_NS
- struct net *net;
+ struct net __rcu *net;
#endif
} possible_net_t;
static inline void write_pnet(possible_net_t *pnet, struct net *net)
{
#ifdef CONFIG_NET_NS
- pnet->net = net;
+ rcu_assign_pointer(pnet->net, net);
#endif
}
static inline struct net *read_pnet(const possible_net_t *pnet)
{
#ifdef CONFIG_NET_NS
- return pnet->net;
+ return rcu_dereference_protected(pnet->net, true);
+#else
+ return &init_net;
+#endif
+}
+
+static inline struct net *read_pnet_rcu(possible_net_t *pnet)
+{
+#ifdef CONFIG_NET_NS
+ return rcu_dereference(pnet->net);
#else
return &init_net;
#endif
