[PATCH net-next v4 06/18] net: dsa: mv88e6xxx: refactor mv88e6xxx_port_vlan()

[Florian Fainelli]

On 4/15/2022 5:29 AM, Jakob Koschel wrote:
> From: Vladimir Oltean <vladimir.oltean at nxp.com>
> 
> To avoid bugs and speculative execution exploits due to type-confused
> pointers at the end of a list_for_each_entry() loop, one measure is to
> restrict code to not use the iterator variable outside the loop block.
> 
> In the case of mv88e6xxx_port_vlan(), this isn't a problem, as we never
> let the loops exit through "natural causes" anyway, by using a "found"
> variable and then using the last "dp" iterator prior to the break, which
> is a safe thing to do.
> 
> Nonetheless, with the expected new syntax, this pattern will no longer
> be possible.
> 
> Profit off of the occasion and break the two port finding methods into
> smaller sub-functions. Somehow, returning a copy of the iterator pointer
> is still accepted.
> 
> This change makes it redundant to have a "bool found", since the "dp"
> from mv88e6xxx_port_vlan() now holds NULL if we haven't found what we
> were looking for.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean at nxp.com>
> Signed-off-by: Jakob Koschel <jakobkoschel at gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli at gmail.com>
-- 
Florian