Re: [PATCH v6 03/24] mm: Dont assume page-table invariance during faults
From: Andi Kleen
Date: Tue Jan 16 2018 - 22:04:26 EST
Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> writes:
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> One of the side effects of speculating on faults (without holding
> mmap_sem) is that we can race with free_pgtables() and therefore we
> cannot assume the page-tables will stick around.
>
> Remove the reliance on the pte pointer.
This needs a lot more explanation. So why is this code not needed with
SPF only?
-Andi