Messages in this thread | | | Subject | Re: [PATCH 4/6] mm: hugetlb_vmemmap: add missing smp_wmb() before set_pte_at() | From | Miaohe Lin <> | Date | Mon, 22 Aug 2022 16:45:16 +0800 |
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On 2022/8/20 16:12, Muchun Song wrote: > > >> On Aug 16, 2022, at 21:05, Miaohe Lin <linmiaohe@huawei.com> wrote: >> >> 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. > > I found another place where is a similar case. See kasan_populate_vmalloc_pte() in > mm/kasan/shadow.c.
Thanks for your report.
> > Should we fix it as well?
I'm not familiar with kasan yet, but I think memory barrier is needed here or memory corrupt can't be detected until the contents are visible. smp_mb__after_atomic before set_pte_at should be enough? What's your opinion?
Thanks, Miaohe Lin
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