Re: [PATCH 1/2] mm: kmsan: fix iounmap metadata teardown

[Dmytro Koziuk]

Hi Andrew,

Just a gentle ping on this. Is there anything else I should address?

Thanks,
Dima

ср, 16 сент. 2026 г. в 10:22, Dmytro Koziuk <dmytrokoziuk68@xxxxxxxxx>:
>
> >  AI review might have a found a couple of issues - please check?
>
> I don't think the patch needs to be changed for these issues. For
> normal iounmap(), the
> caller must ensure that the mapping is no longer in use. Also,
> the x86 implementation keeps the virtual range reserved until after
> kmsan_iounmap_page_range() returns and its TLB flush completes.
>
> For the kmsan_ioremap_page_range() error path, the mapping has not yet
> been returned to the caller. Cleanup and the TLB flush complete before
> the reserved virtual range is released.
>
>
> ср, 16 сент. 2026 г. в 01:35, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>:
> >
> > On Tue, 15 Sep 2026 19:02:06 +0300 Dima Koziuk <dmytrokoziuk68@xxxxxxxxx> wrote:
> >
> > > While studying the code, I noticed that kmsan_iounmap_page_range() calls
> > > __vunmap_range_noflush(v_shadow, vmalloc_shadow(end)) inside its per-page
> > > loop, and does the same for origin. The first iteration therefore unmaps
> > > the entire metadata range, removing the PTEs for later pages before the
> > > loop can recover their backing pages.
> >
> > Thanks.
> >
> > AI review might have a found a couple of issues - please check?
> >
> > https://sashiko.dev/#/patchset/20260915160207.2952-1-dmytrokoziuk68@xxxxxxxxx