Re: [PATCH v4 11/35] kmsan: Allow disabling KMSAN checks for the current task

[Alexander Potapenko]

On Thu, Jun 13, 2024 at 5:39 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
>
> Like for KASAN, it's useful to temporarily disable KMSAN checks around,
> e.g., redzone accesses. Introduce kmsan_disable_current() and
> kmsan_enable_current(), which are similar to their KASAN counterparts.
>
> Make them reentrant in order to handle memory allocations in interrupt
> context. Repurpose the allow_reporting field for this.

I am still a bit reluctant, because these nested counters always end
up being inconsistent.
But your patch series fixes support for SLUB_DEBUG, and I don't have
better ideas how to do this.

Could you please extend "Disabling the instrumentation" in kmsan.rst
so that it explains the new enable/disable API?
I think we should mention that the users need to be careful with it,
keeping the regions short and preferring other ways to disable
instrumentation, where possible.

> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>