Re: [PATCH] mm, kmsan: fix infinite recursion due to RCU critical section

From: Alexander Potapenko
Date: Thu Jan 18 2024 - 07:47:15 EST


On Thu, Jan 18, 2024 at 12:28 PM Charan Teja Kalla
<quic_charante@xxxxxxxxxxx> wrote:
>
> May I ask if KMSAN also instruments the access to the memory managed as
> ZONE_DEVICE. You know this is not the RAM and also these pages will
> never be onlined thus also not be available in buddy.

Is there a way to tell whether a memory chunk belongs to ZONE_DEVICE
by its address?
Won't such check involve calling pfn_valid() or a similar function
that would also require synchronization?

In general, if e.g. one can call memset() on ZONE_DEVICE memory, it is
already going to be instrumented by KMSAN.