diff mbox series

[v2,4/6] mm: hugetlb_vmemmap: add missing smp_wmb() before set_pte_at()

Message ID 20220823030209.57434-5-linmiaohe@huawei.com (mailing list archive)
State New
Headers show
Series A few fixup patches for hugetlb | expand

Commit Message

Miaohe Lin Aug. 23, 2022, 3:02 a.m. UTC 
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@huawei.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/hugetlb_vmemmap.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 196159000897..ba2a2596fb4e 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -286,6 +286,11 @@  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));
 }