The patch below does not apply to the 5.11-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 899aba891cab1555c9ca16a558769efb177baf44 Mon Sep 17 00:00:00 2001
From: Bob Pearson rpearsonhpe@gmail.com Date: Thu, 28 Jan 2021 17:33:19 -0600 Subject: [PATCH] RDMA/rxe: Fix FIXME in rxe_udp_encap_recv()
rxe_udp_encap_recv() drops the reference to rxe->ib_dev taken by rxe_get_dev_from_net() which should be held until each received skb is freed. This patch moves the calls to ib_device_put() to each place a received skb is freed. It also takes references to the ib_device for each cloned skb created to process received multicast packets.
Fixes: 4c173f596b3f ("RDMA/rxe: Use ib_device_get_by_netdev() instead of open coding") Link: https://lore.kernel.org/r/20210128233318.2591-1-rpearson@hpe.com Signed-off-by: Bob Pearson rpearson@hpe.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com
diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c index 0a1e6393250b..a8ac791a1bb9 100644 --- a/drivers/infiniband/sw/rxe/rxe_comp.c +++ b/drivers/infiniband/sw/rxe/rxe_comp.c @@ -515,6 +515,7 @@ static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) while ((skb = skb_dequeue(&qp->resp_pkts))) { rxe_drop_ref(qp); kfree_skb(skb); + ib_device_put(qp->ibqp.device); }
while ((wqe = queue_head(qp->sq.queue))) { @@ -527,6 +528,17 @@ static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) } }
+static void free_pkt(struct rxe_pkt_info *pkt) +{ + struct sk_buff *skb = PKT_TO_SKB(pkt); + struct rxe_qp *qp = pkt->qp; + struct ib_device *dev = qp->ibqp.device; + + kfree_skb(skb); + rxe_drop_ref(qp); + ib_device_put(dev); +} + int rxe_completer(void *arg) { struct rxe_qp *qp = (struct rxe_qp *)arg; @@ -624,11 +636,8 @@ int rxe_completer(void *arg) break;
case COMPST_DONE: - if (pkt) { - rxe_drop_ref(pkt->qp); - kfree_skb(skb); - skb = NULL; - } + if (pkt) + free_pkt(pkt); goto done;
case COMPST_EXIT: @@ -671,12 +680,8 @@ int rxe_completer(void *arg) */ if (qp->comp.started_retry && !qp->comp.timeout_retry) { - if (pkt) { - rxe_drop_ref(pkt->qp); - kfree_skb(skb); - skb = NULL; - } - + if (pkt) + free_pkt(pkt); goto done; }
@@ -699,13 +704,8 @@ int rxe_completer(void *arg) qp->comp.started_retry = 1; rxe_run_task(&qp->req.task, 0); } - - if (pkt) { - rxe_drop_ref(pkt->qp); - kfree_skb(skb); - skb = NULL; - } - + if (pkt) + free_pkt(pkt); goto done;
} else { @@ -726,9 +726,7 @@ int rxe_completer(void *arg) mod_timer(&qp->rnr_nak_timer, jiffies + rnrnak_jiffies(aeth_syn(pkt) & ~AETH_TYPE_MASK)); - rxe_drop_ref(pkt->qp); - kfree_skb(skb); - skb = NULL; + free_pkt(pkt); goto exit; } else { rxe_counter_inc(rxe, @@ -742,13 +740,8 @@ int rxe_completer(void *arg) WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); do_complete(qp, wqe); rxe_qp_error(qp); - - if (pkt) { - rxe_drop_ref(pkt->qp); - kfree_skb(skb); - skb = NULL; - } - + if (pkt) + free_pkt(pkt); goto exit; } } diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c index 0d4125b867b7..36d56163afac 100644 --- a/drivers/infiniband/sw/rxe/rxe_net.c +++ b/drivers/infiniband/sw/rxe/rxe_net.c @@ -152,10 +152,14 @@ static struct dst_entry *rxe_find_route(struct net_device *ndev, static int rxe_udp_encap_recv(struct sock *sk, struct sk_buff *skb) { struct udphdr *udph; + struct rxe_dev *rxe; struct net_device *ndev = skb->dev; - struct rxe_dev *rxe = rxe_get_dev_from_net(ndev); struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+ /* takes a reference on rxe->ib_dev + * drop when skb is freed + */ + rxe = rxe_get_dev_from_net(ndev); if (!rxe) goto drop;
@@ -174,12 +178,6 @@ static int rxe_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
rxe_rcv(skb);
- /* - * FIXME: this is in the wrong place, it needs to be done when pkt is - * destroyed - */ - ib_device_put(&rxe->ib_dev); - return 0; drop: kfree_skb(skb); diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c index 2bbcea61b780..8a48a33d587b 100644 --- a/drivers/infiniband/sw/rxe/rxe_recv.c +++ b/drivers/infiniband/sw/rxe/rxe_recv.c @@ -274,6 +274,10 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) */ if (mce->qp_list.next != &mcg->qp_list) { per_qp_skb = skb_clone(skb, GFP_ATOMIC); + if (WARN_ON(!ib_device_try_get(&rxe->ib_dev))) { + kfree_skb(per_qp_skb); + continue; + } } else { per_qp_skb = skb; /* show we have consumed the skb */ @@ -296,6 +300,7 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) err1: /* free skb if not consumed */ kfree_skb(skb); + ib_device_put(&rxe->ib_dev); }
/** @@ -405,4 +410,5 @@ void rxe_rcv(struct sk_buff *skb) rxe_drop_ref(pkt->qp);
kfree_skb(skb); + ib_device_put(&rxe->ib_dev); } diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index 5a098083a9d2..5fd26786d79b 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -99,6 +99,7 @@ static inline enum resp_states get_req(struct rxe_qp *qp, while ((skb = skb_dequeue(&qp->req_pkts))) { rxe_drop_ref(qp); kfree_skb(skb); + ib_device_put(qp->ibqp.device); }
/* go drain recv wr queue */ @@ -1012,6 +1013,7 @@ static enum resp_states cleanup(struct rxe_qp *qp, skb = skb_dequeue(&qp->req_pkts); rxe_drop_ref(qp); kfree_skb(skb); + ib_device_put(qp->ibqp.device); }
if (qp->resp.mr) { @@ -1176,6 +1178,7 @@ static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify) while ((skb = skb_dequeue(&qp->req_pkts))) { rxe_drop_ref(qp); kfree_skb(skb); + ib_device_put(qp->ibqp.device); }
if (notify)