Re: [PATCH net] net: phy: Warn if phy is attached when removing

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 16 Aug 2022 12:37:01 -0400 Sean Anderson wrote:
> netdevs using phylib can be oopsed from userspace in the following
> manner:
> 
> $ ip link set $iface up
> $ echo $(basename $(readlink /sys/class/net/$iface/phydev)) > \
>       /sys/class/net/$iface/phydev/driver/unbind
> $ ip link set $iface down
> 
> However, the traceback provided is a bit too late, since it does not
> capture the root of the problem (unbinding the driver). It's also
> possible that the memory has been reallocated if sufficient time passes
> between when the phy is detached and when the netdev touches the phy
> (which could result in silent memory corruption). Add a warning at the
> source of the problem. A future patch could make this more robust by
> calling dev_close.

Hm, so we're adding the warning to get more detailed reports "from the
field"? Guess we've all done that, so fair.

Acks? It can still make -rc2 if that matters...