Re: [PATCH net-next v1 0/7] net: extend ethtool link mode bitmaps to 48 bits

[Ben Hutchings <ben@decadent.org.uk>]

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On Mon, 2015-01-05 at 01:34 +0100, Maciej Żenczykowski wrote:
> >> I can send updates to other drivers, even though it's rather pointless
> >> to update 1G drivers at this point for example. Please let me know,
> >> but I'd prefer to do this in follow-up patches outside this first
> >> patch series.
> > [...]
> >
> > They should be changed to ensure they reject setting any of the high
> > advertising flags, but it's not urgent.
> 
> if old drivers advertised a get/set_bits function while new drivers
> advertised a get/set_new_bits function,
> you could not updated any old drivers, and simply take care of
> rejecting invalid bits in core, by calling set_new_bits if provided,
> if not, rejecting bad bits and calling set_bits if no bad bits were
> set.

We've never checked that the reserved fields are zero before, and I
think there are still drivers that don't fully validate the existing 32
bits.  So while I think drivers should fully validate the advertising
flags, userland generally can't assume they do.  And therefore I don't
think it's worth adding complexity to the ethtool core that only partly
fixes this.

Ben.

-- 
Ben Hutchings
This sentence contradicts itself - no actually it doesn't.

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