From f7c9ccaadffd13066353332c13d7e9bf73b8f92d Mon Sep 17 00:00:00 2001
From: Fedor Pchelkin <pchelkin@ispras.ru>
Date: Sat, 4 May 2024 14:47:02 +0300
Subject: [PATCH] dma-mapping: benchmark: avoid needless copy_to_user if
 benchmark fails

If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.

Suggested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/dma/map_benchmark.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
index 2478957cf9f8..a6edb1ef98c8 100644
--- a/kernel/dma/map_benchmark.c
+++ b/kernel/dma/map_benchmark.c
@@ -256,6 +256,9 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 		 * dma_mask changed by benchmark
 		 */
 		dma_set_mask(map->dev, old_dma_mask);
+
+		if (ret)
+			return ret;
 		break;
 	default:
 		return -EINVAL;