From: Daniil Tatianin <d-tatianin@yandex-team.ru>
Date: Mon, 26 Dec 2022 11:48:23 +0000 (+0300)
Subject: net/ethtool/ioctl: return -EOPNOTSUPP if we have no phy stats
X-Git-Tag: baikal/aarch64/sdk5.9~185
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=d619c3f8ea7f7351316333f8a9574ea331edcae8;p=kernel.git

net/ethtool/ioctl: return -EOPNOTSUPP if we have no phy stats

[ Upstream commit 9deb1e9fb88b1120a908676fa33bdf9e2eeaefce ]

It's not very useful to copy back an empty ethtool_stats struct and
return 0 if we didn't actually have any stats. This also allows for
further simplification of this function in the future commits.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index cbd1885f24592..9ae38c3e2bf0a 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1947,7 +1947,8 @@ static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
 		return n_stats;
 	if (n_stats > S32_MAX / sizeof(u64))
 		return -ENOMEM;
-	WARN_ON_ONCE(!n_stats);
+	if (WARN_ON_ONCE(!n_stats))
+		return -EOPNOTSUPP;
 
 	if (copy_from_user(&stats, useraddr, sizeof(stats)))
 		return -EFAULT;