Re: [PATCH v2 1/1] KVM: s390: pv: fix race when making a page secure

Claudio Imbrenda
2025-02-26T16:58:42Z

On Wed, 26 Feb 2025 16:05:11 +0100
David Hildenbrand <david@redhat.com> wrote:

> > +int make_hva_secure(struct mm_struct *mm, unsigned long hva, struct uv_cb_header *uvcb)
> > +{
> > + struct folio *folio;
> > + spinlock_t *ptelock;
> > + pte_t *ptep;
> > + int rc;
> > +
> > + ptep = get_locked_valid_pte(mm, hva, &ptelock);
> > + if (!ptep)
> > + return -ENXIO;
>
> You very likely need a pte_write() check we had there before, as you
> might effectively modify page content by clearing the page.

it's not really needed, but it doesn't hurt either, I'll add a check