From: Matthew Wilcox <willy@infradead.org>
To: Aili Yao <yaoaili@kingsoft.com>
Cc: David Hildenbrand <david@redhat.com>,
akpm@linux-foundation.org, naoya.horiguchi@nec.com,
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 v3] mm/gup: check page posion status for coredump.
Date: Sat, 20 Mar 2021 00:35:16 +0000 [thread overview]
Message-ID: <20210320003516.GC3420@casper.infradead.org> (raw)
In-Reply-To: <20210319104437.6f30e80d@alex-virtual-machine>
On Fri, Mar 19, 2021 at 10:44:37AM +0800, Aili Yao wrote:
> +++ b/mm/gup.c
> @@ -1536,6 +1536,10 @@ struct page *get_dump_page(unsigned long addr)
> FOLL_FORCE | FOLL_DUMP | FOLL_GET);
> if (locked)
> mmap_read_unlock(mm);
> +
> + if (ret == 1 && is_page_poisoned(page))
> + return NULL;
> +
> return (ret == 1) ? page : NULL;
> }
> #endif /* CONFIG_ELF_CORE */
> diff --git a/mm/internal.h b/mm/internal.h
> index 25d2b2439..902d993 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -97,6 +97,27 @@ static inline void set_page_refcounted(struct page *page)
> set_page_count(page, 1);
> }
>
> +/*
> + * When kernel touch the user page, the user page may be have been marked
> + * poison but still mapped in user space, if without this page, the kernel
> + * can guarantee the data integrity and operation success, the kernel is
> + * better to check the posion status and avoid touching it, be good not to
> + * panic, coredump for process fatal signal is a sample case matching this
> + * scenario. Or if kernel can't guarantee the data integrity, it's better
> + * not to call this function, let kernel touch the poison page and get to
> + * panic.
> + */
> +static inline bool is_page_poisoned(struct page *page)
> +{
> + if (page != NULL) {
Why are you checking page for NULL here? How can it possibly be NULL?
> + if (PageHWPoison(page))
> + return true;
> + else if (PageHuge(page) && PageHWPoison(compound_head(page)))
> + return true;
> + }
> + return 0;
> +}
> +
> extern unsigned long highest_memmap_pfn;
>
> /*
> --
> 1.8.3.1
>
>
next prev parent reply other threads:[~2021-03-20 0:35 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210320003516.GC3420@casper.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=naoya.horiguchi@nec.com \
--cc=osalvador@suse.de \
--cc=sunhao2@kingsoft.com \
--cc=yangfeng1@kingsoft.com \
--cc=yaoaili@kingsoft.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).