[openib-general] Re: [PATCH 1/2] (fixed) mthca: max_inline_data support

[Roland Dreier]

    Michael> Another problem is that fls may return 32 and you end up
    Michael> with 1 << 32 which AFAIK has undefined behaviour in C.  I
    Michael> guess kernel clients can be trusted not to, but uverbs
    Michael> better check this.

Good point.  Maybe something like this would be a good idea?

 - R.

--- infiniband/hw/mthca/mthca_qp.c	(revision 2360)
+++ infiniband/hw/mthca/mthca_qp.c	(working copy)
@@ -1210,6 +1210,11 @@ static int mthca_alloc_qp_common(struct 
 static int mthca_set_qp_size(struct mthca_dev *dev, struct ib_qp_cap *cap,
 			     struct mthca_qp *qp)
 {
+	/* Sanity check QP size before proceeding */
+	if (cap->max_send_wr  > 65536 || cap->max_recv_wr  > 65536 ||
+	    cap->max_send_sge > 64    || cap->max_recv_sge > 64)
+		return -EINVAL;
+
 	if (mthca_is_memfree(dev)) {
 		qp->rq.max = cap->max_recv_wr ?
 			roundup_pow_of_two(cap->max_recv_wr) : 0;