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Commit e3fd112c authored by Kalderon, Michal's avatar Kalderon, Michal Committed by Jason Gunthorpe
Browse files

RDMA/qedr: Fix kernel panic when running fio over NFSoRDMA 



Race in qedr_poll_cq, lastest_cqe wasn't protected by lock,
leading to a case where two context's accessing poll_cq at
the same time lead to one of them having a pointer to an old
latest_cqe and reading an invalid cqe element

Signed-off-by: default avatarAmit Radzi <Amit.Radzi@cavium.com>
Signed-off-by: default avatarMichal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: default avatarAriel Elior <Ariel.Elior@cavium.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent ea0ed478

drivers/infiniband/hw/qedr/verbs.c

+2 −1
Original line number Diff line number Diff line
@@ -3724,7 +3724,7 @@ int qedr_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc) 
{

	struct qedr_dev *dev = get_qedr_dev(ibcq->device);

	struct qedr_cq *cq = get_qedr_cq(ibcq);

	union rdma_cqe *cqe = cq->latest_cqe;

	union rdma_cqe *cqe;

	u32 old_cons, new_cons;

	unsigned long flags;

	int update = 0;
@@ -3741,6 +3741,7 @@ int qedr_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc) 
		return qedr_gsi_poll_cq(ibcq, num_entries, wc);



	spin_lock_irqsave(&cq->cq_lock, flags);

	cqe = cq->latest_cqe;

	old_cons = qed_chain_get_cons_idx_u32(&cq->pbl);

	while (num_entries && is_valid_cqe(cq, cqe)) {

		struct qedr_qp *qp;