Messages in this thread Patch in this message | | | From | Miaohe Lin <> | Subject | [PATCH 02/16] mm/huge_memory: access vm_page_prot with READ_ONCE in remove_migration_pmd | Date | Thu, 23 Jun 2022 01:06:13 +0800 |
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vma->vm_page_prot is read lockless from the rmap_walk, it may be updated concurrently. Using READ_ONCE to prevent the risk of reading intermediate values.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index fd6da053a13e..83fb6c3442ff 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3202,7 +3202,7 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) entry = pmd_to_swp_entry(*pvmw->pmd); get_page(new); - pmde = pmd_mkold(mk_huge_pmd(new, vma->vm_page_prot)); + pmde = pmd_mkold(mk_huge_pmd(new, READ_ONCE(vma->vm_page_prot))); if (pmd_swp_soft_dirty(*pvmw->pmd)) pmde = pmd_mksoft_dirty(pmde); if (is_writable_migration_entry(entry)) -- 2.23.0
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