Re: [PATCH net-next v8 11/11] onsemi: s2500: Added selftest support to onsemi's S2500 driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] net: s2500: returning 0 for ETH_SS_TEST triggers kernel WARN_ON
--

commit 7e6f8dc25f867f635c1cf55921f54019505bb547
Author: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>

onsemi: s2500: Added selftest support to onsemi's S2500 driver

This commit adds selftest support for the onsemi S2500 MAC-PHY.

> diff --git a/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c b/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c
> index 65bbcc1c7dc8f..08e748d4b10cc 100644
> --- a/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c
> +++ b/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c
[ ... ]
> @@ -193,6 +194,8 @@ static int s2500_get_sset_count(struct net_device *ndev, int sset)
>  	switch (sset) {
>  	case ETH_SS_STATS:
>  		return S2500_MAC_STATS_LEN;
> +	case ETH_SS_TEST:
> +		return net_selftest_get_count();

[Severity: Medium]
Could this trigger a kernel warning in the ethtool core when
CONFIG_NET_SELFTESTS is disabled?

When CONFIG_NET_SELFTESTS is disabled, net_selftest_get_count() statically
returns 0. The core ethtool logic in ethtool_self_test() expects a non-zero
test count and triggers a warning if it is 0:

net/ethtool/ioctl.c:ethtool_self_test() {
    ...
    WARN_ON(test_len == 0);
    ...
}

A user with CAP_NET_ADMIN executing an ethtool test or querying ETH_SS_TEST
strings could trigger this warning, polluting the kernel log and causing a
panic if panic_on_warn is enabled.

Should this explicitly return -EOPNOTSUPP if net_selftest_get_count()
evaluates to 0?

>  	default:
>  		return -EOPNOTSUPP;
>  	}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260928-s2500-mac-phy-support-v8-0-7e011aacc309@onsemi.com?part=11