On 8/16/2022 9:05 PM, Miaohe Lin wrote: > The memory barrier smp_wmb() is needed to make sure that preceding stores > to the page contents become visible before the below set_pte_at() write. > > Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Yin Fengwei <fengwei.yin@xxxxxxxxx> Regards Yin, Fengwei > --- > mm/hugetlb_vmemmap.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index 20f414c0379f..76b2d03a0d8d 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -287,6 +287,11 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, > copy_page(to, (void *)walk->reuse_addr); > reset_struct_pages(to); > > + /* > + * Makes sure that preceding stores to the page contents become visible > + * before the set_pte_at() write. > + */ > + smp_wmb(); > set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot)); > } >
