IB/mlx4: Test return value of calls to ib_get_cached_pkey

In the mlx4_ib_post_send() flow, some functions call ib_get_cached_pkey()
without checking its return value. If ib_get_cached_pkey() returns an
error code, these functions should return failure.

Fixes: 1ffeb2e ("IB/mlx4: SR-IOV IB context objects and proxy/tunnel SQP support")
Fixes: 225c7b1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
Fixes: e622f2f ("IB: split struct ib_send_wr")
Link: https://lore.kernel.org/r/20200426075921.130074-1-leon@kernel.org
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx4/qp.c

@@ -2891,6 +2891,7 @@ static int build_sriov_qp0_header(struct mlx4_ib_sqp *sqp,
 	int send_size;
 	int header_size;
 	int spc;
+	int err;
 	int i;
 
 	if (wr->wr.opcode != IB_WR_SEND)
@@ -2925,7 +2926,9 @@ static int build_sriov_qp0_header(struct mlx4_ib_sqp *sqp,
 
 	sqp->ud_header.lrh.virtual_lane    = 0;
 	sqp->ud_header.bth.solicited_event = !!(wr->wr.send_flags & IB_SEND_SOLICITED);
-	ib_get_cached_pkey(ib_dev, sqp->qp.port, 0, &pkey);
+	err = ib_get_cached_pkey(ib_dev, sqp->qp.port, 0, &pkey);
+	if (err)
+		return err;
 	sqp->ud_header.bth.pkey = cpu_to_be16(pkey);
 	if (sqp->qp.mlx4_ib_qp_type == MLX4_IB_QPT_TUN_SMI_OWNER)
 		sqp->ud_header.bth.destination_qpn = cpu_to_be32(wr->remote_qpn);
@@ -3212,9 +3215,14 @@ static int build_mlx_header(struct mlx4_ib_sqp *sqp, const struct ib_ud_wr *wr,
 	}
 	sqp->ud_header.bth.solicited_event = !!(wr->wr.send_flags & IB_SEND_SOLICITED);
 	if (!sqp->qp.ibqp.qp_num)
-		ib_get_cached_pkey(ib_dev, sqp->qp.port, sqp->pkey_index, &pkey);
+		err = ib_get_cached_pkey(ib_dev, sqp->qp.port, sqp->pkey_index,
+					 &pkey);
 	else
-		ib_get_cached_pkey(ib_dev, sqp->qp.port, wr->pkey_index, &pkey);
+		err = ib_get_cached_pkey(ib_dev, sqp->qp.port, wr->pkey_index,
+					 &pkey);
+	if (err)
+		return err;
+
 	sqp->ud_header.bth.pkey = cpu_to_be16(pkey);
 	sqp->ud_header.bth.destination_qpn = cpu_to_be32(wr->remote_qpn);
 	sqp->ud_header.bth.psn = cpu_to_be32((sqp->send_psn++) & ((1 << 24) - 1));