From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: arm64: virt_to_page() does not return right page for a kernel image address
Date: Thu, 5 Jan 2017 10:57:58 +0000 [thread overview]
Message-ID: <20170105105757.GA29765@e104818-lin.cambridge.arm.com> (raw)
In-Reply-To: <322d61f1-0b72-6125-f5cd-153e0baad733@redhat.com>
On Wed, Jan 04, 2017 at 10:39:05AM -0800, Laura Abbott wrote:
> On 01/04/2017 04:13 AM, Catalin Marinas wrote:
> > On Wed, Jan 04, 2017 at 11:19:38AM +0530, Pratyush Anand wrote:
> >> I noticed that on arm64 kmap_atomic() does not return correct address
> >> corresponding to a page located in data section. It causes crash in
> >> kdump kernel with v29 kdump patches. crash happens in a newly
> >> implemented crypto test [1], and the same test fails(even though it
> >> does not crash) in 1st kernel as well.
> >>
> >> Further debugging showed that the physical address returned by
> >> virt_to_phys(kaddr) and virt_to_phys(kmap_atomic(virt_to_page(kaddr))
> >> + offset_in_page(kaddr)) are not same.
>
> I think the underlying issue has been resolved but in general, relying
> on virt_to_phys(kmap_atomic(page)) to work at all doesn't seem
> correct. On arm64 and other !CONFIG_HIGHMEM systems this currently
> returns the page_address but if it's actually remapped this isn't
> going to work.
Good point, kmap_atomic() does not always return an address in the
linear map, so virt_to_phys() on such address is not generally expected
to work (unrelated to arm64).
--
Catalin
prev parent reply other threads:[~2017-01-05 10:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-04 5:49 arm64: virt_to_page() does not return right page for a kernel image address Pratyush Anand
2017-01-04 11:11 ` Mark Rutland
2017-01-04 11:58 ` Pratyush Anand
2017-01-04 12:06 ` Mark Rutland
2017-01-04 12:23 ` Pratyush Anand
2017-01-04 13:24 ` Ard Biesheuvel
2017-01-04 14:03 ` Pratyush Anand
2017-01-04 12:13 ` Catalin Marinas
2017-01-04 18:39 ` Laura Abbott
2017-01-05 10:57 ` Catalin Marinas [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=20170105105757.GA29765@e104818-lin.cambridge.arm.com \
--to=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.