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authorBart Van Assche <bart.vanassche@wdc.com>2018-01-12 15:11:58 -0800
committerDoug Ledford <dledford@redhat.com>2018-01-18 14:49:19 -0500
commit65567e41219888feec72fee1de98ccf1efbbc16d (patch)
tree5d1c39d42c4c0d89f461fc7159e8a49dcab8f7d6 /drivers/infiniband/sw
parent37cb11acf1f72a007a85894a6dd2ec93932bde46 (diff)
RDMA/rxe: Fix a race condition in rxe_requester()
The rxe driver works as follows: * The send queue, receive queue and completion queues are implemented as circular buffers. * ib_post_send() and ib_post_recv() calls are serialized through a spinlock. * Removing elements from various queues happens from tasklet context. Tasklets are guaranteed to run on at most one CPU. This serializes access to these queues. See also rxe_completer(), rxe_requester() and rxe_responder(). * rxe_completer() processes the skbs queued onto qp->resp_pkts. * rxe_requester() handles the send queue (qp->sq.queue). * rxe_responder() processes the skbs queued onto qp->req_pkts. Since rxe_drain_req_pkts() processes qp->req_pkts, calling rxe_drain_req_pkts() from rxe_requester() is racy. Hence this patch. Reported-by: Moni Shoua <monis@mellanox.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: stable@vger.kernel.org Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/sw')
-rw-r--r--drivers/infiniband/sw/rxe/rxe_loc.h1
-rw-r--r--drivers/infiniband/sw/rxe/rxe_req.c9
-rw-r--r--drivers/infiniband/sw/rxe/rxe_resp.c2
3 files changed, 2 insertions, 10 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
index d7472a442a2c..96c3a6c5c4b5 100644
--- a/drivers/infiniband/sw/rxe/rxe_loc.h
+++ b/drivers/infiniband/sw/rxe/rxe_loc.h
@@ -237,7 +237,6 @@ int rxe_srq_from_attr(struct rxe_dev *rxe, struct rxe_srq *srq,
void rxe_release(struct kref *kref);
-void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify);
int rxe_completer(void *arg);
int rxe_requester(void *arg);
int rxe_responder(void *arg);
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 26a7f923045b..7bdaf71b8221 100644
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -594,15 +594,8 @@ int rxe_requester(void *arg)
rxe_add_ref(qp);
next_wqe:
- if (unlikely(!qp->valid)) {
- rxe_drain_req_pkts(qp, true);
+ if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
goto exit;
- }
-
- if (unlikely(qp->req.state == QP_STATE_ERROR)) {
- rxe_drain_req_pkts(qp, true);
- goto exit;
- }
if (unlikely(qp->req.state == QP_STATE_RESET)) {
qp->req.wqe_index = consumer_index(qp->sq.queue);
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index f07324f2cde2..d37bb9b97569 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -1209,7 +1209,7 @@ static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
}
}
-void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
+static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
{
struct sk_buff *skb;