mm: hugetlb_vmemmap: add missing smp_wmb() before set_pte_at()
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.
Link: https://lkml.kernel.org/r/20220816130553.31406-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 20f414c..76b2d03 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));
}
