From: Ingo Molnar <mingo@kernel.org>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Megha Dey <megha.dey@linux.intel.com>,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: SHA1-MB algorithm broken on latest kernel
Date: Fri, 13 May 2016 07:51:03 +0200 [thread overview]
Message-ID: <20160513055103.GB24504@gmail.com> (raw)
In-Reply-To: <20160513031020.GA12467@gondor.apana.org.au>
* Herbert Xu <herbert@gondor.apana.org.au> wrote:
> On Thu, May 12, 2016 at 04:31:06PM -0700, Megha Dey wrote:
> > Hi,
> >
> > When booting latest kernel with the CONFIG_CRYPTO_SHA1_MB enabled, I
> > observe a panic.
> >
> > After having a quick look, on reverting the following patches, I am able
> > to complete the booting process.
> > aec4d0e301f17bb143341c82cc44685b8af0b945
> > 8691ccd764f9ecc69a6812dfe76214c86ac9ba06
> > 68874ac3304ade7ed5ebb12af00d6b9bbbca0a16
> >
> > Of the 3 patches, aec4d0e301f17bb143341c82cc44685b8af0b945 seems wrong.
> > The r10 to r15 registers are used in sha1_x8_avx2.S, which is called
> > from sha1_mb_mgr_flush_avx2.S.
> >
> > I do not think the functionality of the SHA1-MB crypto algorithm has
> > been tested after applying these changes. (I am not sure if any of the
> > other crypto algorithms have been affected by these changes).
>
> Josh, Ingo:
>
> Any ideas on this? Should we revert?
Yeah, I think so - although another option would be to standardize sha1_x8_avx2()
- the problem is that it is a function that clobbers registers without
saving/restoring them, breaking the C function ABI. I realize it's written in
assembly, but unless there are strong performance reasons to deviate from the
regular calling convention it might make sense to fix that.
Do any warnings get generated after the revert, if you enable
CONFIG_STACK_VALIDATION=y?
Thanks,
Ingo
next prev parent reply other threads:[~2016-05-13 5:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-12 23:31 SHA1-MB algorithm broken on latest kernel Megha Dey
2016-05-13 3:10 ` Herbert Xu
2016-05-13 5:51 ` Ingo Molnar [this message]
2016-05-13 17:32 ` Megha Dey
2016-05-16 14:44 ` Josh Poimboeuf
2016-05-16 18:31 ` Megha Dey
2016-05-16 20:16 ` [PATCH] crypto/sha1-mb: make sha1_x8_avx2() conform to C function ABI Josh Poimboeuf
2016-05-16 21:39 ` Megha Dey
2016-05-16 21:46 ` Josh Poimboeuf
2016-05-16 23:07 ` Megha Dey
2016-05-17 6:31 ` Herbert Xu
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=20160513055103.GB24504@gmail.com \
--to=mingo@kernel.org \
--cc=herbert@gondor.apana.org.au \
--cc=jpoimboe@redhat.com \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=megha.dey@linux.intel.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 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.