RDMA/rxe: Fix a race condition in rxe_requester() (65567e41) · Commits · 戴 / test

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>

drivers/infiniband/sw/rxe/rxe_loc.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -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);

drivers/infiniband/sw/rxe/rxe_req.c

+1 −8

Original line number	Diff line number	Diff line
		@@ -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);

drivers/infiniband/sw/rxe/rxe_resp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

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