net: ethernet: mtk_eth_soc: fix error check return value of debugfs_create_dir()

Commit Message

CGEL April 19, 2022, 1:58 a.m. UTC

From: Lv Ruyi <[e-mail]>

If an error occurs, debugfs_create_file() will return ERR_PTR(-ERROR),
so use IS_ERR() to check it.

Fixes: 804775dfc288 ("net: ethernet: mtk_eth_soc: add support for Wireless Ethernet Dispatch (WED)")
Reported-by: Zeal Robot <[e-mail]>
Signed-off-by: Lv Ruyi <[e-mail]>
---
 drivers/net/ethernet/mediatek/mtk_wed_debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Andrew Lunn April 19, 2022, 9:55 p.m. UTC | #1

On Tue, Apr 19, 2022 at 01:58:32AM +0000, [e-mail] wrote:
> From: Lv Ruyi <[e-mail]>
> 
> If an error occurs, debugfs_create_file() will return ERR_PTR(-ERROR),
> so use IS_ERR() to check it.

Please take a look at for example:

https://lkml.iu.edu/hypermail/linux/kernel/1901.2/06005.html
https://lkml.iu.edu/hypermail/linux/kernel/1901.2/06006.html
https://lkml.iu.edu/hypermail/linux/kernel/1901.2/05993.html

This is the author of debugfs remove exactly the sort of code you are
adding.

Please teach the Zeal Bot that such code is wrong, and you should be
submitting patches to actually remove testing the return values for
anything which starts with debugfs_

	Andrew

Patch

diff --git a/drivers/net/ethernet/mediatek/mtk_wed_debugfs.c b/drivers/net/ethernet/mediatek/mtk_wed_debugfs.c
index a81d3fd1a439..0c284c18a8d7 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed_debugfs.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed_debugfs.c
@@ -165,7 +165,7 @@  void mtk_wed_hw_add_debugfs(struct mtk_wed_hw *hw)
 
 	snprintf(hw->dirname, sizeof(hw->dirname), "wed%d", hw->index);
 	dir = debugfs_create_dir(hw->dirname, NULL);
-	if (!dir)
+	if (IS_ERR(dir))
 		return;
 
 	hw->debugfs_dir = dir;