[PATCH V4 0/6] RCU get_user_pages_fast and __get_user_pages_fast

[Mark Rutland]

> > Head's up: these patches are currently implicated in a rare-to-trigger
> > hang that we are seeing on an internal kernel. An extensive effort is
> > underway to confirm whether these are the cause. Will followup.
> 
> I'm currently investigating an intermittent memory corruption issue in
> v4.0-rc1 I'm able to trigger on Seattle with 4K pages and 48-bit VA,
> which may or may not be related. Sometimes it results in a hang (when
> the vectors get corrupted and the CPUs get caught in a recursive
> exception loop).

FWIW my issue appears to be a bug in the old firmware I'm running.
Sorry for the noise!

Mark.