[PATCH] arm64: mm: fix warning in arch_faults_on_old_pte()

[Yu Zhao]

On Tue, Jun 15, 2021 at 7:47 AM Catalin Marinas <catalin.marinas at arm.com> wrote:
>
> On Tue, Jun 15, 2021 at 11:52:30AM +0100, Will Deacon wrote:
> > On Sun, Jun 13, 2021 at 03:47:28PM -0600, Yu Zhao wrote:
> > > cow_user_page() doesn't disable preemption, and it triggers the
> > > warning in arch_faults_on_old_pte() when CONFIG_PREEMPT_COUNT=y.
> >
> > Doesn't kmap_atomic() disable preemption?
>
> Good point, I missed that. I wonder whether there are additional patches
> on top that replace it with kmap_local_page(). I couldn't see any in
> -next.

Duh, I have been using a bad backport which has
arch_faults_on_old_pte() called before kmap_atomic().

Sorry for the false alarm!