RDMA/ucma: Convert open-coded equivalent to memdup_user()

---
 drivers/infiniband/core/ucma.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)
 
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 893cb87..6bf8504 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1002,23 +1002,18 @@ static ssize_t ucma_set_option(struct ucma_file *file, const char __user *inbuf,
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
-	optval = kmalloc(cmd.optlen, GFP_KERNEL);
-	if (!optval) {
-		ret = -ENOMEM;
-		goto out1;
-	}
-
-	if (copy_from_user(optval, (void __user *) (unsigned long) cmd.optval,
-			   cmd.optlen)) {
-		ret = -EFAULT;
-		goto out2;
+	optval = memdup_user((void __user *) (unsigned long) cmd.optval,
+			     cmd.optlen);
+	if (IS_ERR(optval)) {
+		ret = PTR_ERR(optval);
+		goto out;
 	}
 
 	ret = ucma_set_option_level(ctx, cmd.level, cmd.optname, optval,
 				    cmd.optlen);
-out2:
 	kfree(optval);
-out1:
+
+out:
 	ucma_put_ctx(ctx);
 	return ret;
 }