Hello Adit Ranadive,
The patch 29c8d9eba550: "IB: Add vmw_pvrdma driver" from Oct 2, 2016,
leads to the following Smatch static checker warning:
drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c:712 pvrdma_post_send()
warn: unsigned 'wr->opcode' is never less than zero.
drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c
671 int pvrdma_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
672 const struct ib_send_wr **bad_wr)
673 {
674 struct pvrdma_qp *qp = to_vqp(ibqp);
675 struct pvrdma_dev *dev = to_vdev(ibqp->device);
676 unsigned long flags;
677 struct pvrdma_sq_wqe_hdr *wqe_hdr;
678 struct pvrdma_sge *sge;
679 int i, ret;
680
681 /*
682 * In states lower than RTS, we can fail immediately. In other states,
683 * just post and let the device figure it out.
684 */
685 if (qp->state < IB_QPS_RTS) {
686 *bad_wr = wr;
687 return -EINVAL;
688 }
689
690 spin_lock_irqsave(&qp->sq.lock, flags);
691
692 while (wr) {
693 unsigned int tail = 0;
694
695 if (unlikely(!pvrdma_idx_ring_has_space(
696 qp->sq.ring, qp->sq.wqe_cnt, &tail))) {
697 dev_warn_ratelimited(&dev->pdev->dev,
698 "send queue is full\n");
699 *bad_wr = wr;
700 ret = -ENOMEM;
701 goto out;
702 }
703
704 if (unlikely(wr->num_sge > qp->sq.max_sg || wr->num_sge < 0)) {
705 dev_warn_ratelimited(&dev->pdev->dev,
706 "send SGE overflow\n");
707 *bad_wr = wr;
708 ret = -EINVAL;
709 goto out;
710 }
711
--> 712 if (unlikely(wr->opcode < 0)) {
^^^^^^^^^^
wr->opcode is an enum and enum signedness is undefined in C but in this
context it's unsigned. Just checking for negatives seems insufficient
here anyway. Perhaps the check can be deleted?
713 dev_warn_ratelimited(&dev->pdev->dev,
714 "invalid send opcode\n");
715 *bad_wr = wr;
716 ret = -EINVAL;
717 goto out;
718 }
719
720 /*
721 * Only support UD, RC.
722 * Need to check opcode table for thorough checking.
723 * opcode _UD _UC _RC
724 * _SEND x x x
725 * _SEND_WITH_IMM x x x
726 * _RDMA_WRITE x x
727 * _RDMA_WRITE_WITH_IMM x x
728 * _LOCAL_INV x x
729 * _SEND_WITH_INV x x
730 * _RDMA_READ x
731 * _ATOMIC_CMP_AND_SWP x
732 * _ATOMIC_FETCH_AND_ADD x
733 * _MASK_ATOMIC_CMP_AND_SWP x
734 * _MASK_ATOMIC_FETCH_AND_ADD x
735 * _REG_MR x
736 *
737 */
738 if (qp->ibqp.qp_type != IB_QPT_UD &&
739 qp->ibqp.qp_type != IB_QPT_RC &&
740 wr->opcode != IB_WR_SEND) {
regards,
dan carpenter
