Patch "IB/rxe: Clear queue buffer when modifying QP to reset" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

IB/rxe: Clear queue buffer when modifying QP to reset

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ib-rxe-clear-queue-buffer-when-modifying-qp-to-reset.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Yonatan Cohen <[email protected]>
Date: Wed, 16 Nov 2016 10:39:17 +0200
Subject: IB/rxe: Clear queue buffer when modifying QP to reset

From: Yonatan Cohen <[email protected]>

commit aa75b07b478a774b1432e2df1be5cd8ae834de0f upstream.

RXE resets the send-q only once in rxe_qp_init_req() when QP is created, but when the QP is reused after QP reset, the send-q holds previous garbage data.

This garbage data wrongly fails CQEs that otherwise should have completed successfully.

---
 drivers/infiniband/sw/rxe/rxe_qp.c    |    1 +
 drivers/infiniband/sw/rxe/rxe_queue.c |    9 +++++++++
 drivers/infiniband/sw/rxe/rxe_queue.h |    2 ++
 3 files changed, 12 insertions(+)

@@ -522,6 +522,7 @@ static void rxe_qp_reset(struct rxe_qp *
 	if (qp->sq.queue) {
 		__rxe_do_task(&qp->comp.task);
 		__rxe_do_task(&qp->req.task);
+		rxe_queue_reset(qp->sq.queue);
 	}
 
 	/* cleanup attributes */

@@ -84,6 +84,15 @@ err1:
 	return -EINVAL;
 }
 
+inline void rxe_queue_reset(struct rxe_queue *q)
+{
+	/* queue is comprised from header and the memory
+	 * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
+	 * reset only the queue itself and not the management header
+	 */
+	memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
+}
+
 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
 				 int *num_elem,
 				 unsigned int elem_size)

@@ -84,6 +84,8 @@ int do_mmap_info(struct rxe_dev *rxe,
 		 size_t buf_size,
 		 struct rxe_mmap_info **ip_p);
 
+void rxe_queue_reset(struct rxe_queue *q);
+
 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
 				 int *num_elem,
 				 unsigned int elem_size);

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/ib-rxe-fix-handling-of-erroneous-wr.patch queue-4.8/ib-rxe-update-qp-state-for-user-query.patch queue-4.8/ib-rxe-clear-queue-buffer-when-modifying-qp-to-reset.patch queue-4.8/ib-rxe-fix-kernel-panic-in-udp-tunnel-with-gro-and-rx-checksum.patch