Re: [PATCH v2 1/8] evtchn: avoid race in get_xen_consumer()

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Oct 20, 2020 at 04:08:13PM +0200, Jan Beulich wrote:
> There's no global lock around the updating of this global piece of data.
> Make use of cmpxchgptr() to avoid two entities racing with their
> updates.
> 
> While touching the functionality, mark xen_consumers[] read-mostly (or
> else the if() condition could use the result of cmpxchgptr(), writing to
> the slot unconditionally).
> 
> The use of cmpxchgptr() here points out (by way of clang warning about
> it) that its original use of const was slightly wrong. Adjust the
> placement, or else undefined behavior of const qualifying a function
> type will result.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks, Roger.