| Message ID | 1500989968-30889-2-git-send-email-andrew.boyer@dell.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Tue, Jul 25, 2017 at 4:39 PM, Andrew Boyer <andrew.boyer@dell.com> wrote: > The network stack will call nskb's destructor, rxe_skb_tx_dtor(), if the > packet gets dropped by ip_local_out()/ip6_local_out(). Thus we need to add > the QP ref before output to avoid extra dereferences during network > congestion. This could lead to unwanted destruction of the QP. > > Fix up the skb_out accounting, too. > > Fixes: fda85ce91240 ("IB/rxe: Fix kernel panic from skb destructor") > Signed-off-by: Andrew Boyer <andrew.boyer@dell.com> > --- Acked-by: Moni Shoua <monis@mellanox.com> -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c index 08f3f90..0810f38 100644 --- a/drivers/infiniband/sw/rxe/rxe_net.c +++ b/drivers/infiniband/sw/rxe/rxe_net.c @@ -460,12 +460,17 @@ int rxe_send(struct rxe_dev *rxe, struct rxe_pkt_info *pkt, struct sk_buff *skb) nskb->destructor = rxe_skb_tx_dtor; nskb->sk = pkt->qp->sk->sk; + rxe_add_ref(pkt->qp); + atomic_inc(&pkt->qp->skb_out); + if (av->network_type == RDMA_NETWORK_IPV4) { err = ip_local_out(dev_net(skb_dst(skb)->dev), nskb->sk, nskb); } else if (av->network_type == RDMA_NETWORK_IPV6) { err = ip6_local_out(dev_net(skb_dst(skb)->dev), nskb->sk, nskb); } else { pr_err("Unknown layer 3 protocol: %d\n", av->network_type); + atomic_dec(&pkt->qp->skb_out); + rxe_drop_ref(pkt->qp); kfree_skb(nskb); return -EINVAL; } @@ -475,10 +480,7 @@ int rxe_send(struct rxe_dev *rxe, struct rxe_pkt_info *pkt, struct sk_buff *skb) return -EAGAIN; } - rxe_add_ref(pkt->qp); - atomic_inc(&pkt->qp->skb_out); kfree_skb(skb); - return 0; }
The network stack will call nskb's destructor, rxe_skb_tx_dtor(), if the packet gets dropped by ip_local_out()/ip6_local_out(). Thus we need to add the QP ref before output to avoid extra dereferences during network congestion. This could lead to unwanted destruction of the QP. Fix up the skb_out accounting, too. Fixes: fda85ce91240 ("IB/rxe: Fix kernel panic from skb destructor") Signed-off-by: Andrew Boyer <andrew.boyer@dell.com> --- drivers/infiniband/sw/rxe/rxe_net.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)