On Sun, Apr 24, 2022 at 03:45:02PM +0800, Muchun Song wrote:
> On Sun, Apr 24, 2022 at 02:33:19PM +0800, Baolin Wang wrote:
> > Missed calling flush_cache_range() before removing the sharing PMD entrires,
> > otherwise data consistence issue may be occurred on some architectures whose
> > caches are strict and require a virtual–>physical translation to exist for
> > a virtual address. Thus add it.
> >
> > Fixes: 6dfeaff93be1 ("hugetlb/userfaultfd: unshare all pmds for hugetlbfs when register wp")
> > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
>
> CONFIG_ARCH_WANT_HUGE_PMD_SHARE is only definded on riscv, arm64 and
> x86. All of them do not have a VIVT cache. In others words,
> flush_cache_range() is null on those architectures. So I suspect
> in practice this does not cause any issue. It is better to
> clarify this in commit log.
Looks correct.
>
> Anyway:
>
> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Thanks,
--
Peter Xu
