From dab2175800ef0b45d5e70a7337bd6cb311292ebe Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Thu, 2 May 2019 10:48:05 +0300 Subject: [PATCH] RDMA/rxe: Use rdma_read_gid_attr_ndev_rcu to access netdev Use rdma_read_gid_attr_ndev_rcu() to access netdevice attached to GID entry under rcu lock. This ensures that while working on the netdevice of the GID, it doesn't get freed. Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/sw/rxe/rxe_net.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c index c441397..5a3474f 100644 --- a/drivers/infiniband/sw/rxe/rxe_net.c +++ b/drivers/infiniband/sw/rxe/rxe_net.c @@ -458,7 +458,7 @@ struct sk_buff *rxe_init_packet(struct rxe_dev *rxe, struct rxe_av *av, int paylen, struct rxe_pkt_info *pkt) { unsigned int hdr_len; - struct sk_buff *skb; + struct sk_buff *skb = NULL; struct net_device *ndev; const struct ib_gid_attr *attr; const int port_num = 1; @@ -466,7 +466,6 @@ struct sk_buff *rxe_init_packet(struct rxe_dev *rxe, struct rxe_av *av, attr = rdma_get_gid_attr(&rxe->ib_dev, port_num, av->grh.sgid_index); if (IS_ERR(attr)) return NULL; - ndev = attr->ndev; if (av->network_type == RDMA_NETWORK_IPV4) hdr_len = ETH_HLEN + sizeof(struct udphdr) + @@ -475,16 +474,26 @@ struct sk_buff *rxe_init_packet(struct rxe_dev *rxe, struct rxe_av *av, hdr_len = ETH_HLEN + sizeof(struct udphdr) + sizeof(struct ipv6hdr); + rcu_read_lock(); + ndev = rdma_read_gid_attr_ndev_rcu(attr); + if (IS_ERR(ndev)) { + rcu_read_unlock(); + goto out; + } skb = alloc_skb(paylen + hdr_len + LL_RESERVED_SPACE(ndev), GFP_ATOMIC); - if (unlikely(!skb)) + if (unlikely(!skb)) { + rcu_read_unlock(); goto out; + } skb_reserve(skb, hdr_len + LL_RESERVED_SPACE(ndev)); /* FIXME: hold reference to this netdev until life of this skb. */ skb->dev = ndev; + rcu_read_unlock(); + if (av->network_type == RDMA_NETWORK_IPV4) skb->protocol = htons(ETH_P_IP); else -- 2.7.4