[PATCH v2 08/16] IB/rdmavt: Don't abuse udata and ib_respond_udata()

[Jason Gunthorpe <jgg@nvidia.com>]

Use copy_to_user() directly since the data is not being placed in the
udata response memory.

It is unclear why this is trying to do two copies, but leave it alone.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/infiniband/sw/rdmavt/srq.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/sw/rdmavt/srq.c b/drivers/infiniband/sw/rdmavt/srq.c
index fe125bf85b2726..d022aa56c5bfd5 100644
--- a/drivers/infiniband/sw/rdmavt/srq.c
+++ b/drivers/infiniband/sw/rdmavt/srq.c
@@ -128,6 +128,7 @@ int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
 	struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
 	struct rvt_rq tmp_rq = {};
+	__u64 offset_addr;
 	int ret = 0;
 
 	if (attr_mask & IB_SRQ_MAX_WR) {
@@ -149,19 +150,17 @@ int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 			return -ENOMEM;
 		/* Check that we can write the offset to mmap. */
 		if (udata && udata->inlen >= sizeof(__u64)) {
-			__u64 offset_addr;
 			__u64 offset = 0;
 
 			ret = ib_copy_from_udata(&offset_addr, udata,
 						 sizeof(offset_addr));
 			if (ret)
 				goto bail_free;
-			udata->outbuf = (void __user *)
-					(unsigned long)offset_addr;
-			ret = ib_copy_to_udata(udata, &offset,
-					       sizeof(offset));
-			if (ret)
+			if (copy_to_user(u64_to_user_ptr(offset_addr), &offset,
+					 sizeof(offset))) {
+				ret = -EFAULT;
 				goto bail_free;
+			}
 		}
 
 		spin_lock_irq(&srq->rq.kwq->c_lock);
@@ -236,10 +235,10 @@ int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 			 * See rvt_mmap() for details.
 			 */
 			if (udata && udata->inlen >= sizeof(__u64)) {
-				ret = ib_copy_to_udata(udata, &ip->offset,
-						       sizeof(ip->offset));
-				if (ret)
-					return ret;
+				if (copy_to_user(u64_to_user_ptr(offset_addr),
+						 &ip->offset,
+						 sizeof(ip->offset)))
+					return -EFAULT;
 			}
 
 			/*
-- 
2.43.0