From: Matthew Wilcox <willy@infradead.org>
To: Miaohe Lin <linmiaohe@huawei.com>
Cc: akpm@linux-foundation.org, naoya.horiguchi@nec.com,
shy828301@gmail.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
Date: Sat, 15 Jul 2023 04:50:27 +0100 [thread overview]
Message-ID: <ZLIXg7BPPAoUYUGV@casper.infradead.org> (raw)
In-Reply-To: <20230715031729.2420338-2-linmiaohe@huawei.com>
On Sat, Jul 15, 2023 at 11:17:26AM +0800, Miaohe Lin wrote:
> Hwpoisoned dirty swap cache page is kept in the swap cache and there's
> simple interception code in do_swap_page() to catch it. But when trying
> to swapoff, unuse_pte() will wrongly install a general sense of "future
> accesses are invalid" swap entry for hwpoisoned swap cache page due to
> unaware of such type of page. The user will receive SIGBUS signal without
> expected BUS_MCEERR_AR payload.
Have you observed this, or do you just think it's true?
> +++ b/mm/swapfile.c
> @@ -1767,7 +1767,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
> swp_entry_t swp_entry;
>
> dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
> - if (hwposioned) {
> + /* Hwpoisoned swapcache page is also !PageUptodate. */
> + if (hwposioned || PageHWPoison(page)) {
This line makes no sense to me. How do we get here with PageHWPoison()
being true and hwposioned being false?
> swp_entry = make_hwpoison_entry(swapcache);
> page = swapcache;
> } else {
> --
> 2.33.0
>
>
next prev parent reply other threads:[~2023-07-15 3:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-15 3:17 [PATCH 0/4] A few fixup and cleanup patches for memory-failure Miaohe Lin
2023-07-15 3:17 ` [PATCH 1/4] mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page Miaohe Lin
2023-07-15 3:50 ` Matthew Wilcox [this message]
2023-07-17 2:33 ` Miaohe Lin
2023-07-17 2:53 ` Matthew Wilcox
2023-07-17 5:55 ` Miaohe Lin
2023-07-23 2:23 ` Miaohe Lin
2023-07-15 3:17 ` [PATCH 2/4] mm: memory-failure: fix potential unexpected return value from unpoison_memory() Miaohe Lin
2023-07-19 23:48 ` Naoya Horiguchi
2023-07-20 8:44 ` Miaohe Lin
2023-07-15 3:17 ` [PATCH 3/4] mm: memory-failure: avoid false hwpoison page mapped error info Miaohe Lin
2023-07-15 3:59 ` Matthew Wilcox
2023-07-19 23:50 ` Naoya Horiguchi
2023-07-15 3:17 ` [PATCH 4/4] mm: memory-failure: add PageOffline() check Miaohe Lin
2023-07-20 1:09 ` Naoya Horiguchi
2023-07-20 8:42 ` Miaohe Lin
2023-07-20 23:55 ` Naoya Horiguchi
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=ZLIXg7BPPAoUYUGV@casper.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=naoya.horiguchi@nec.com \
--cc=shy828301@gmail.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