From: Peter Xu <peterx@redhat.com>
To: Alistair Popple <alistair@popple.id.au>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Andrew Morton" <akpm@linux-foundation.org>,
"Jérôme Glisse" <jglisse@redhat.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Ralph Campbell" <rcampbell@nvidia.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 1/2] mm/migrate: Fixup setting UFFD_WP flag
Date: Mon, 24 Aug 2020 11:44:52 -0400 [thread overview]
Message-ID: <20200824154452.GB8605@xz-x1> (raw)
In-Reply-To: <20200824083128.12684-1-alistair@popple.id.au>
On Mon, Aug 24, 2020 at 06:31:27PM +1000, Alistair Popple wrote:
> Commit f45ec5ff16a75 ("userfaultfd: wp: support swap and page
> migration") introduced support for tracking the uffd wp bit during page
> migration. However the non-swap PTE variant was used to set the flag for
> zone device private pages which are a type of swap page.
>
> This leads to corruption of the swap offset if the original PTE has the
> uffd_wp flag set.
>
> Fixes: f45ec5ff16a75 ("userfaultfd: wp: support swap and page migration")
> Signed-off-by: Alistair Popple <alistair@popple.id.au>
> Cc: stable@vger.kernel.org
> ---
> mm/migrate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 34a842a8eb6a..ddb64253fe3e 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -251,7 +251,7 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
> entry = make_device_private_entry(new, pte_write(pte));
> pte = swp_entry_to_pte(entry);
> if (pte_swp_uffd_wp(*pvmw.pte))
> - pte = pte_mkuffd_wp(pte);
> + pte = pte_swp_mkuffd_wp(pte);
> }
> }
Looks correct... thanks!
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
prev parent reply other threads:[~2020-08-24 15:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-24 8:31 [PATCH 1/2] mm/migrate: Fixup setting UFFD_WP flag Alistair Popple
2020-08-24 8:31 ` [PATCH 2/2] mm/rmap: Fixup copying of soft dirty and uffd ptes Alistair Popple
2020-08-24 15:43 ` Peter Xu
2020-08-25 5:19 ` Alistair Popple
2020-08-24 15:44 ` Peter Xu [this message]
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=20200824154452.GB8605@xz-x1 \
--to=peterx@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alistair@popple.id.au \
--cc=jglisse@redhat.com \
--cc=jhubbard@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rcampbell@nvidia.com \
--cc=stable@vger.kernel.org \
/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).