IB/cm: Replace members of sa_path_rec with 'struct sgid_attr *'

While processing a path record entry in CM messages the associated GID
attribute is now also supplied.

Currently for RoCE a netdevice's net namespace pointer and ifindex are
stored in path record entry. Both of these fields of the netdev can change
anytime while processing CM messages. Additionally storing net namespace
without holding reference will lead to use-after-free crash. Therefore it
is removed. Netdevice information for RoCE is instead provided via
referenced gid attribute in ib_cm requests.

Such a design leads to a situation where the kernel can crash when the net
pointer becomes invalid. However today it is always initialized to
init_net, which cannot become invalid. In order to support processing
packets in any arbitrary namespace of the received packet, it is necessary
to avoid such conditions.

This patch removes the dependency on the net pointer and ifindex; instead
it will rely on SGID attribute which contains a pointer to netdev.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

1 files changed, 3 insertions, 46 deletions

diff --git a/include/rdma/ib_sa.h b/include/rdma/ib_sa.h
index bacb144f7780..b6ddf2a1b9d8 100644
--- a/include/rdma/ib_sa.h
+++ b/include/rdma/ib_sa.h
@@ -172,12 +172,7 @@ struct sa_path_rec_ib {
  */
 struct sa_path_rec_roce {
 	bool	route_resolved;
-	u8           dmac[ETH_ALEN];
-	/* ignored in IB */
-	int	     ifindex;
-	/* ignored in IB */
-	struct net  *net;
-
+	u8	dmac[ETH_ALEN];
 };
 
 struct sa_path_rec_opa {
@@ -556,13 +551,10 @@ int ib_init_ah_from_mcmember(struct ib_device *device, u8 port_num,
 			     enum ib_gid_type gid_type,
 			     struct rdma_ah_attr *ah_attr);
 
-/**
- * ib_init_ah_attr_from_path - Initialize address handle attributes based on
- *   an SA path record.
- */
 int ib_init_ah_attr_from_path(struct ib_device *device, u8 port_num,
 			      struct sa_path_rec *rec,
-			      struct rdma_ah_attr *ah_attr);
+			      struct rdma_ah_attr *ah_attr,
+			      const struct ib_gid_attr *sgid_attr);
 
 /**
  * ib_sa_pack_path - Conert a path record from struct ib_sa_path_rec
@@ -667,45 +659,10 @@ static inline void sa_path_set_dmac_zero(struct sa_path_rec *rec)
 		eth_zero_addr(rec->roce.dmac);
 }
 
-static inline void sa_path_set_ifindex(struct sa_path_rec *rec, int ifindex)
-{
-	if (sa_path_is_roce(rec))
-		rec->roce.ifindex = ifindex;
-}
-
-static inline void sa_path_set_ndev(struct sa_path_rec *rec, struct net *net)
-{
-	if (sa_path_is_roce(rec))
-		rec->roce.net = net;
-}
-
 static inline u8 *sa_path_get_dmac(struct sa_path_rec *rec)
 {
 	if (sa_path_is_roce(rec))
 		return rec->roce.dmac;
 	return NULL;
 }
-
-static inline int sa_path_get_ifindex(struct sa_path_rec *rec)
-{
-	if (sa_path_is_roce(rec))
-		return rec->roce.ifindex;
-	return 0;
-}
-
-static inline struct net *sa_path_get_ndev(struct sa_path_rec *rec)
-{
-	if (sa_path_is_roce(rec))
-		return rec->roce.net;
-	return NULL;
-}
-
-static inline struct net_device *ib_get_ndev_from_path(struct sa_path_rec *rec)
-{
-	return sa_path_get_ndev(rec) ?
-		dev_get_by_index(sa_path_get_ndev(rec),
-				 sa_path_get_ifindex(rec))
-		: NULL;
-}
-
 #endif /* IB_SA_H */