From: Andrew Morton <akpm@linux-foundation.org>
To: Peter Xu <peterx@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Dan Williams <dan.j.williams@intel.com>,
Pasha Tatashin <pasha.tatashin@soleen.com>
Subject: Re: [PATCH] mm/page_table_check: Fix crash on ZONE_DEVICE
Date: Wed, 5 Jun 2024 15:05:43 -0700 [thread overview]
Message-ID: <20240605150543.87c81189fa7cb562e73fa0b8@linux-foundation.org> (raw)
In-Reply-To: <20240605212146.994486-1-peterx@redhat.com>
On Wed, 5 Jun 2024 17:21:46 -0400 Peter Xu <peterx@redhat.com> wrote:
> Not all pages may apply to pgtable check. One example is ZONE_DEVICE
> pages: they map PFNs directly, and they don't allocate page_ext at all even
> if there's struct page around. One may reference devm_memremap_pages().
>
> When both ZONE_DEVICE and page-table-check enabled, then try to map some
> dax memories, one can trigger kernel bug constantly now when the kernel was
> trying to inject some pfn maps on the dax device:
>
> kernel BUG at mm/page_table_check.c:55!
>
> While it's pretty legal to use set_pxx_at() for ZONE_DEVICE pages for page
> fault resolutions, skip all the checks if page_ext doesn't even exist in
> pgtable checker, which applies to ZONE_DEVICE but maybe more.
Do we have a Reported-by: for this one?
And a Fixes? It looks like df4e817b7108?
next prev parent reply other threads:[~2024-06-05 22:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-05 21:21 [PATCH] mm/page_table_check: Fix crash on ZONE_DEVICE Peter Xu
2024-06-05 22:05 ` Andrew Morton [this message]
2024-06-06 13:14 ` Peter Xu
2024-06-05 22:54 ` Dan Williams
2024-06-05 22:58 ` Alistair Popple
2024-06-06 0:01 ` Pasha Tatashin
2024-06-06 0:20 ` Dan Williams
2024-06-06 0:24 ` Pasha Tatashin
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=20240605150543.87c81189fa7cb562e73fa0b8@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=pasha.tatashin@soleen.com \
--cc=peterx@redhat.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