[lvc-project] [PATCH v2 3/3] net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers

[Andrew Lunn]

On Tue, Nov 29, 2022 at 01:38:01PM +0300, Daniil Tatianin wrote:
> So that it's easier to follow and make sense of the branching and
> various conditions.
> 
> Stats retrieval has been split into two separate functions
> ethtool_get_phy_stats_phydev & ethtool_get_phy_stats_ethtool.
> The former attempts to retrieve the stats using phydev & phy_ops, while
> the latter uses ethtool_ops.
> 
> Actual n_stats validation & array allocation has been moved into a new
> ethtool_vzalloc_stats_array helper.
> 
> This also fixes a potential NULL dereference of
> ops->get_ethtool_phy_stats where it was getting called in an else branch
> unconditionally without making sure it was actually present.
> 
> Found by Linux Verification Center (linuxtesting.org) with the SVACE
> static analysis tool.
> 
> Signed-off-by: Daniil Tatianin <d-tatianin at yandex-team.ru>

Reviewed-by: Andrew Lunn <andrew at lunn.ch>

    Andrew