From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>
Cc: <shy828301@gmail.com>, <willy@infradead.org>,
<zokeefe@google.com>, <songmuchun@bytedance.com>,
<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<linmiaohe@huawei.com>
Subject: [PATCH v3 02/16] mm/huge_memory: access vm_page_prot with READ_ONCE in remove_migration_pmd
Date: Mon, 4 Jul 2022 21:21:47 +0800 [thread overview]
Message-ID: <20220704132201.14611-3-linmiaohe@huawei.com> (raw)
In-Reply-To: <20220704132201.14611-1-linmiaohe@huawei.com>
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 f4e581eefb67..a010f9ba15ce 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3309,7 +3309,7 @@ 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
next prev parent reply other threads:[~2022-07-04 13:22 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-04 13:21 [PATCH v3 00/16] A few cleanup patches for huge_memory Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 01/16] mm/huge_memory: use flush_pmd_tlb_range in move_huge_pmd Miaohe Lin
2022-07-04 13:21 ` Miaohe Lin [this message]
2022-07-04 13:21 ` [PATCH v3 03/16] mm/huge_memory: fix comment of __pud_trans_huge_lock Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 04/16] mm/huge_memory: use helper touch_pud in huge_pud_set_accessed Miaohe Lin
2022-07-04 13:52 ` Muchun Song
2022-07-04 13:21 ` [PATCH v3 05/16] mm/huge_memory: use helper touch_pmd in huge_pmd_set_accessed Miaohe Lin
2022-07-04 13:53 ` Muchun Song
2022-07-04 13:21 ` [PATCH v3 06/16] mm/huge_memory: rename mmun_start to haddr in remove_migration_pmd Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 07/16] mm/huge_memory: use helper function vma_lookup in split_huge_pages_pid Miaohe Lin
2022-07-04 13:54 ` Muchun Song
2022-07-04 13:21 ` [PATCH v3 08/16] mm/huge_memory: use helper macro __ATTR_RW Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 09/16] mm/huge_memory: fix comment in zap_huge_pud Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 10/16] mm/huge_memory: check pmd_present first in is_huge_zero_pmd Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 11/16] mm/huge_memory: try to free subpage in swapcache when possible Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 12/16] mm/huge_memory: minor cleanup for split_huge_pages_all Miaohe Lin
2022-07-04 13:21 ` [PATCH v3 13/16] mm/huge_memory: fix comment of page_deferred_list Miaohe Lin
2022-07-04 13:55 ` Muchun Song
2022-07-04 13:21 ` [PATCH v3 14/16] mm/huge_memory: correct comment of prep_transhuge_page Miaohe Lin
2022-07-04 13:22 ` [PATCH v3 15/16] mm/huge_memory: comment the subtly logic in __split_huge_pmd Miaohe Lin
2022-07-04 13:22 ` [PATCH v3 16/16] mm/huge_memory: use helper macro IS_ERR_OR_NULL in split_huge_pages_pid Miaohe Lin
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