From: Pintu Agarwal <pintu.ping@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ardb@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Arnd Bergmann <arnd@arndb.de>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Marc Zyngier <marc.zyngier@arm.com>,
Dave Martin <dave.martin@arm.com>,
Kernelnewbies <kernelnewbies@kernelnewbies.org>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
open list <linux-kernel@vger.kernel.org>,
Tony Lindgren <tony@atomide.com>,
matt@codeblueprint.co.uk, nico@linaro.org,
Thomas Garnier <thgarnie@google.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: KASLR support on ARM with Kernel 4.9 and 4.14
Date: Wed, 30 Sep 2020 19:28:02 +0530 [thread overview]
Message-ID: <CAOuPNLijjua222eV-6bnLyidsuY49-KuQSERUSXLpc+u+qeqLg@mail.gmail.com> (raw)
In-Reply-To: <202009281248.6F601005CA@keescook>
On Tue, 29 Sep 2020 at 01:20, Kees Cook <keescook@chromium.org> wrote:
> Note that I still can't explain what you're seeing. /proc/kallsyms
> shouldn't be affected by these patches -- I would expect it to either
> report the true value or 00s.
>
> > I will disable kptr_restrict and check or, I will enable
> > CONFIG_DEBUG_CONSOLE_UNHASHED_POINTERS and check.
>
> I would start with kptr_restrict=0 and see if that changes the contents
> of /proc/kallsyms. If it does, then it is the hashing. If it doesn't,
> well, we're back to square one. :)
Actually in that board, the kptr_restrict=0 already in both case: 4.9
and 4.14 Kernel boards.
In another board with 4.14 and kptr_restrict=2, I see that the
addresses are 00 always.
I further checked that when I enable this config:
CONFIG_DEBUG_CONSOLE_UNHASHED_POINTERS,
then the addresses are remaining the same in every boot.
But this particular config is not present in 4.9 Kernel.
So, I think it is controlled using this config.
--
Pintu
prev parent reply other threads:[~2020-09-30 13:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 15:03 KASLR support on ARM with Kernel 4.9 and 4.14 Pintu Agarwal
2020-09-25 20:26 ` Kees Cook
2020-09-25 20:37 ` Ard Biesheuvel
2020-09-25 20:47 ` Kees Cook
2020-09-25 21:09 ` Ard Biesheuvel
2020-09-25 23:47 ` Kees Cook
2020-09-26 7:58 ` Pintu Agarwal
2020-09-26 16:40 ` Kees Cook
2020-09-28 13:45 ` Pintu Agarwal
2020-09-28 14:11 ` Pintu Agarwal
2020-09-28 19:50 ` Kees Cook
2020-09-30 13:58 ` Pintu Agarwal [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=CAOuPNLijjua222eV-6bnLyidsuY49-KuQSERUSXLpc+u+qeqLg@mail.gmail.com \
--to=pintu.ping@gmail.com \
--cc=ard.biesheuvel@linaro.org \
--cc=ardb@kernel.org \
--cc=arnd@arndb.de \
--cc=dave.martin@arm.com \
--cc=keescook@chromium.org \
--cc=kernelnewbies@kernelnewbies.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=marc.zyngier@arm.com \
--cc=mark.rutland@arm.com \
--cc=matt@codeblueprint.co.uk \
--cc=nico@linaro.org \
--cc=thgarnie@google.com \
--cc=tony@atomide.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).