From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: David Laight <David.Laight@aculab.com>
Cc: Netdev <netdev@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
LKML <linux-kernel@vger.kernel.org>,
"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
Ted Tso <tytso@mit.edu>,
Hannes Frederic Sowa <hannes@stressinduktion.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Eric Biggers <ebiggers3@gmail.com>,
Tom Herbert <tom@herbertland.com>,
George Spelvin <linux@sciencehorizons.net>,
Vegard Nossum <vegard.nossum@gmail.com>,
"ak@linux.intel.com" <ak@linux.intel.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"luto@amacapital.net" <luto@amacapital.net>
Subject: Re: [PATCH v5 3/4] secure_seq: use SipHash in place of MD5
Date: Fri, 16 Dec 2016 16:57:38 +0100 [thread overview]
Message-ID: <CAHmME9quRDe2FZgV4oAnJ_Cj_GDJo5pUAmQkdpeJe+7_TNMuiA@mail.gmail.com> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6DB0240E66@AcuExch.aculab.com>
Hi David,
On Fri, Dec 16, 2016 at 10:59 AM, David Laight <David.Laight@aculab.com> wrote:
> You are still putting over-aligned data on stack.
> You only need to align it to the alignment of u64 (not the size of u64).
> If an on-stack item has a stronger alignment requirement than the stack
> the gcc has to generate two stack frames for the function.
Yesterday, folks were saying that sometimes 32-bit platforms need
8-byte alignment for certain 64-bit operations, so I shouldn't fall
back to 4-byte alignment there. But actually, looking at this more
closely, I can just make SIPHASH_ALIGNMENT == __alignof__(u64), which
will take care of all possible concerns, since gcc knows best which
platforms need what alignment. Thanks for making this clear to me with
"the alignment of u64 (not the size of u64)".
> Oh - and wait a bit longer between revisions.
Okay. We can be turtles.
Jason
next prev parent reply other threads:[~2016-12-16 15:57 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-15 20:29 [PATCH v5 0/4] The SipHash Patchset Jason A. Donenfeld
2016-12-15 20:30 ` [PATCH v5 1/4] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-15 22:42 ` George Spelvin
2016-12-16 2:14 ` kbuild test robot
2016-12-17 14:55 ` Jeffrey Walton
2016-12-19 17:08 ` Jason A. Donenfeld
2016-12-15 20:30 ` [PATCH v5 2/4] siphash: add Nu{32,64} helpers Jason A. Donenfeld
2016-12-16 10:39 ` David Laight
2016-12-16 15:44 ` George Spelvin
2016-12-15 20:30 ` [PATCH v5 3/4] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-16 9:59 ` David Laight
2016-12-16 15:57 ` Jason A. Donenfeld [this message]
2016-12-15 20:30 ` [PATCH v5 4/4] random: " Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 0/5] The SipHash Patchset Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 1/5] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 2/5] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 3/5] random: " Jason A. Donenfeld
2016-12-16 21:31 ` Andy Lutomirski
2016-12-16 3:03 ` [PATCH v6 4/5] md5: remove from lib and only live in crypto Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 5/5] syncookies: use SipHash in place of SHA1 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 0/6] The SipHash Patchset Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 1/6] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-22 1:40 ` Stephen Hemminger
2016-12-21 23:02 ` [PATCH v7 2/6] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 3/6] random: " Jason A. Donenfeld
2016-12-21 23:13 ` Jason A. Donenfeld
2016-12-21 23:42 ` Andy Lutomirski
2016-12-22 2:07 ` Hannes Frederic Sowa
2016-12-22 2:09 ` Andy Lutomirski
2016-12-22 2:49 ` Jason A. Donenfeld
2016-12-22 3:12 ` Jason A. Donenfeld
2016-12-22 5:41 ` [kernel-hardening] " Theodore Ts'o
2016-12-22 6:03 ` Jason A. Donenfeld
2016-12-22 15:58 ` Theodore Ts'o
2016-12-22 16:16 ` Jason A. Donenfeld
2016-12-22 16:30 ` Theodore Ts'o
2016-12-22 16:36 ` Jason A. Donenfeld
2016-12-22 12:47 ` Hannes Frederic Sowa
2016-12-22 13:10 ` Jason A. Donenfeld
2016-12-22 15:05 ` Hannes Frederic Sowa
2016-12-22 15:12 ` Jason A. Donenfeld
2016-12-22 15:29 ` Jason A. Donenfeld
2016-12-22 15:33 ` Hannes Frederic Sowa
2016-12-22 15:41 ` Jason A. Donenfeld
2016-12-22 15:51 ` Hannes Frederic Sowa
2016-12-22 15:53 ` Jason A. Donenfeld
2016-12-22 15:54 ` Theodore Ts'o
2016-12-22 18:08 ` Hannes Frederic Sowa
2016-12-22 18:13 ` Jason A. Donenfeld
2016-12-22 19:50 ` Theodore Ts'o
2016-12-22 2:31 ` Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 4/6] md5: remove from lib and only live in crypto Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 5/6] syncookies: use SipHash in place of SHA1 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 6/6] siphash: implement HalfSipHash1-3 for hash tables Jason A. Donenfeld
2016-12-22 0:46 ` Andi Kleen
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