From: David Hildenbrand <david@redhat.com>
To: Aili Yao <yaoaili@kingsoft.com>,
akpm@linux-foundation.org, naoya.horiguchi@nec.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
yangfeng1@kingsoft.com, sunhao2@kingsoft.com,
Oscar Salvador <osalvador@suse.de>,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: [PATCH] mm/gup: check page posion status for coredump.
Date: Wed, 17 Mar 2021 10:12:02 +0100 [thread overview]
Message-ID: <20a0d078-f49d-54d6-9f04-f6b41dd51e5f@redhat.com> (raw)
In-Reply-To: <20210317163714.328a038d@alex-virtual-machine>
On 17.03.21 09:37, Aili Yao wrote:
> When we do coredump for user process signal, this may be an SIGBUS signal
> with BUS_MCEERR_AR or BUS_MCEERR_AO code, which means this signal is
> resulted from ECC memory fail like SRAR or SRAO, we expect the memory
> recovery work is finished correctly, then the get_dump_page() will not
> return the error page as its process pte is set invalid by
> memory_failure().
>
> But memory_failure() may fail, and the process's related pte may not be
> correctly set invalid, for current code, we will return the poison page
> and get it dumped and lead to system panic as its in kernel code.
>
> So check the poison status in get_dump_page(), and if TRUE, return NULL.
>
> Signed-off-by: Aili Yao <yaoaili@kingsoft.com>
> ---
> mm/gup.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index e4c224c..499a496 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1536,6 +1536,14 @@ struct page *get_dump_page(unsigned long addr)
> FOLL_FORCE | FOLL_DUMP | FOLL_GET);
> if (locked)
> mmap_read_unlock(mm);
> +
> + if (IS_ENABLED(CONFIG_MEMORY_FAILURE) && ret == 1) {
> + if (unlikely(PageHuge(page) && PageHWPoison(compound_head(page))))
> + ret = 0;
> + else if (unlikely(PageHWPoison(page)))
> + ret = 0;
> + }
I wonder if a simple
if (PageHWPoison(compound_head(page)))
ret = 0;
won't suffice. But I guess the "issue" is compound pages that are not
huge pages or transparent huge pages.
If not, we certainly want a wrapper for that magic, otherwise we have to
replicate the same logic all over the place.
> +
> return (ret == 1) ? page : NULL;
> }
> #endif /* CONFIG_ELF_CORE */
>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-03-17 9:12 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 8:37 [PATCH] mm/gup: check page posion status for coredump Aili Yao
2021-03-17 9:12 ` David Hildenbrand [this message]
2021-03-18 3:15 ` Aili Yao
2021-03-18 3:18 ` [PATCH v2] " Aili Yao
2021-03-18 4:46 ` [PATCH] " Matthew Wilcox
2021-03-18 5:34 ` Aili Yao
2021-03-19 2:44 ` [PATCH v3] " Aili Yao
2021-03-20 0:35 ` Matthew Wilcox
2021-03-22 3:40 ` Aili Yao
2021-03-22 11:33 ` [PATCH v5] mm/gup: check page hwposion " Aili Yao
2021-03-26 14:09 ` David Hildenbrand
2021-03-26 14:22 ` David Hildenbrand
2021-03-31 1:52 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-31 2:43 ` Aili Yao
2021-03-31 4:32 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-31 6:44 ` David Hildenbrand
2021-03-31 7:07 ` Aili Yao
2021-04-01 2:31 ` Aili Yao
2021-04-06 2:23 ` [PATCH v6] mm/gup: check page hwpoison status for memory recovery failures Aili Yao
2021-04-06 2:41 ` [PATCH v7] " Aili Yao
2021-04-07 1:54 ` HORIGUCHI NAOYA(堀口 直也)
2021-04-07 7:48 ` Aili Yao
2021-05-10 3:13 ` Aili Yao
2021-03-31 6:07 ` [PATCH v5] mm/gup: check page hwposion status for coredump Matthew Wilcox
2021-03-31 6:53 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-31 7:05 ` David Hildenbrand
2021-03-18 8:14 ` [PATCH] mm/gup: check page posion " David Hildenbrand
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