5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Pirko jiri@nvidia.com
[ 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@nvidia.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: dd205fcc33d9 ("ipv4: use RCU protection in rt_is_expired()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/net_namespace.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 0d61b452b9082..6ce0ec2dd2032 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -310,21 +310,30 @@ 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