diff options
| author | Miaohe Lin <linmiaohe@huawei.com> | 2022-07-04 21:21:47 +0800 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-07-17 17:14:44 -0700 |
| commit | 4286f14748c13de42c1c4ab77a92fdfb37e6e5ef (patch) | |
| tree | 56130c5b8745e809b1ed26ebb697b58f3614f803 /mm/huge_memory.c | |
| parent | 7c38f1812d5bc118e29cb898e7104387a6cc0b76 (diff) | |
mm/huge_memory: access vm_page_prot with READ_ONCE in remove_migration_pmd
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.
Link: https://lkml.kernel.org/r/20220704132201.14611-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 627b98dfd51e..fb0011fe9128 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3205,7 +3205,7 @@ 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)) |