IB/ipath: Fix RDMA reads of length zero and error handling

Fix RDMA read response length checking for RDMA_READ_RESPONSE_ONLY to
allow a zero length response.  RDMA read responses which don't match
the expected length or occur in response to some other operation
should generate a completion queue error (see table 56, ch. 9.9.2.3 in
the IB spec).

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 44 insertions, 19 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_rc.c b/drivers/infiniband/hw/ipath/ipath_rc.c
index d6aa14afa26..b4b88d0b53f 100644
--- a/drivers/infiniband/hw/ipath/ipath_rc.c
+++ b/drivers/infiniband/hw/ipath/ipath_rc.c
@@ -1136,7 +1136,7 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
                         goto ack_done;
                 hdrsize += 4;
                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
-                        goto ack_done;
+                        goto ack_op_err;
                 /*
                  * If this is a response to a resent RDMA read, we
                  * have to be careful to copy the data to the right
@@ -1154,12 +1154,12 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
                         goto ack_done;
                 }
                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
-                        goto ack_done;
+                        goto ack_op_err;
         read_middle:
                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
-                        goto ack_done;
+                        goto ack_len_err;
                 if (unlikely(pmtu >= qp->s_rdma_read_len))
-                        goto ack_done;
+                        goto ack_len_err;
 
                 /* We got a response so update the timeout. */
                 spin_lock(&dev->pending_lock);
@@ -1184,12 +1184,20 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
                         goto ack_done;
                 }
                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
-                        goto ack_done;
+                        goto ack_op_err;
+                /* Get the number of bytes the message was padded by. */
+                pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
+                /*
+                 * Check that the data size is >= 0 && <= pmtu.
+                 * Remember to account for the AETH header (4) and
+                 * ICRC (4).
+                 */
+                if (unlikely(tlen < (hdrsize + pad + 8)))
+                        goto ack_len_err;
                 /*
                  * If this is a response to a resent RDMA read, we
                  * have to be careful to copy the data to the right
                  * location.
-                 * XXX should check PSN and wqe opcode first.
                  */
                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
                                                   wqe, psn, pmtu);
@@ -1203,26 +1211,20 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
                         goto ack_done;
                 }
                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
-                        goto ack_done;
-        read_last:
-                /*
-                 * Get the number of bytes the message was padded by.
-                 */
+                        goto ack_op_err;
+                /* Get the number of bytes the message was padded by. */
                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
                 /*
                  * Check that the data size is >= 1 && <= pmtu.
                  * Remember to account for the AETH header (4) and
                  * ICRC (4).
                  */
-                if (unlikely(tlen <= (hdrsize + pad + 8))) {
-                        /* XXX Need to generate an error CQ entry. */
-                        goto ack_done;
-                }
+                if (unlikely(tlen <= (hdrsize + pad + 8)))
+                        goto ack_len_err;
+        read_last:
                 tlen -= hdrsize + pad + 8;
-                if (unlikely(tlen != qp->s_rdma_read_len)) {
-                        /* XXX Need to generate an error CQ entry. */
-                        goto ack_done;
-                }
+                if (unlikely(tlen != qp->s_rdma_read_len))
+                        goto ack_len_err;
                 if (!header_in_data)
                         aeth = be32_to_cpu(ohdr->u.aeth);
                 else {
@@ -1236,6 +1238,29 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
 
 ack_done:
         spin_unlock_irqrestore(&qp->s_lock, flags);
+        goto bail;
+
+ack_op_err:
+        wc.status = IB_WC_LOC_QP_OP_ERR;
+        goto ack_err;
+
+ack_len_err:
+        wc.status = IB_WC_LOC_LEN_ERR;
+ack_err:
+        wc.wr_id = wqe->wr.wr_id;
+        wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
+        wc.vendor_err = 0;
+        wc.byte_len = 0;
+        wc.imm_data = 0;
+        wc.qp = &qp->ibqp;
+        wc.src_qp = qp->remote_qpn;
+        wc.wc_flags = 0;
+        wc.pkey_index = 0;
+        wc.slid = qp->remote_ah_attr.dlid;
+        wc.sl = qp->remote_ah_attr.sl;
+        wc.dlid_path_bits = 0;
+        wc.port_num = 0;
+        ipath_sqerror_qp(qp, &wc);
 bail:
         return;
 }