From: Geert Uytterhoeven <geert@linux-m68k.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
wireguard@lists.zx2c4.com,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
bpf <bpf@vger.kernel.org>, Theodore Tso <tytso@mit.edu>,
Greg KH <gregkh@linuxfoundation.org>,
jeanphilippe.aumasson@gmail.com,
Ard Biesheuvel <ardb@kernel.org>
Subject: Re: [PATCH crypto v3 0/2] reduce code size from blake2s on m68k and other small platforms
Date: Wed, 12 Jan 2022 11:59:48 +0100 [thread overview]
Message-ID: <CAMuHMdUcJN_ZZLnx8TuhoXYV1DAKK9NsXjH2M0xAdn9JTS16wA@mail.gmail.com> (raw)
In-Reply-To: <20220111220506.742067-1-Jason@zx2c4.com>
Hi Jason,
On Tue, Jan 11, 2022 at 11:05 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> Geert emailed me this afternoon concerned about blake2s codesize on m68k
> and other small systems. We identified two effective ways of chopping
> down the size. One of them moves some wireguard-specific things into
> wireguard proper. The other one adds a slower codepath for small
> machines to blake2s. This worked, and was v1 of this patchset, but I
> wasn't so much of a fan. Then someone pointed out that the generic C
> SHA-1 implementation is still unrolled, which is a *lot* of extra code.
> Simply rerolling that saves about as much as v1 did. So, we instead do
> that in this patchset. SHA-1 is being phased out, and soon it won't
> be included at all (hopefully). And nothing performance-oriented has
> anything to do with it anyway.
>
> The result of these two patches mitigates Geert's feared code size
> increase for 5.17.
>
> v3 improves on v2 by making the re-rolling of SHA-1 much simpler,
> resulting in even larger code size reduction and much better
> performance. The reason I'm sending yet a third version in such a short
> amount of time is because the trick here feels obvious and substantial
> enough that I'd hate for Geert to waste time measuring the impact of the
> previous commit.
>
> Thanks,
> Jason
>
> Jason A. Donenfeld (2):
> lib/crypto: blake2s: move hmac construction into wireguard
> lib/crypto: sha1: re-roll loops to reduce code size
Thanks for the series!
On m68k:
add/remove: 1/4 grow/shrink: 0/1 up/down: 4/-4232 (-4228)
Function old new delta
__ksymtab_blake2s256_hmac 12 - -12
blake2s_init.constprop 94 - -94
blake2s256_hmac 302 - -302
sha1_transform 4402 582 -3820
Total: Before=4230537, After=4226309, chg -0.10%
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2022-01-16 21:10 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHmME9qbnYmhvsuarButi6s=58=FPiti0Z-QnGMJ=OsMzy1eOg@mail.gmail.com>
2022-01-11 13:49 ` [PATCH crypto 0/2] smaller blake2s code size " Jason A. Donenfeld
2022-01-11 13:49 ` [PATCH crypto 1/2] lib/crypto: blake2s-generic: reduce code size on small systems Jason A. Donenfeld
2022-01-12 10:57 ` Geert Uytterhoeven
2022-01-12 13:16 ` Jason A. Donenfeld
2022-01-12 18:31 ` Eric Biggers
2022-01-12 18:50 ` Jason A. Donenfeld
2022-01-12 21:27 ` David Laight
2022-01-12 22:00 ` Jason A. Donenfeld
2022-01-11 13:49 ` [PATCH crypto 2/2] lib/crypto: blake2s: move hmac construction into wireguard Jason A. Donenfeld
2022-01-11 14:43 ` Ard Biesheuvel
2022-01-12 18:35 ` Eric Biggers
2022-01-11 18:10 ` [PATCH crypto v2 0/2] reduce code size from blake2s on m68k and other small platforms Jason A. Donenfeld
2022-01-11 18:10 ` [PATCH crypto v2 1/2] lib/crypto: blake2s: move hmac construction into wireguard Jason A. Donenfeld
2022-01-11 18:10 ` [PATCH crypto v2 2/2] lib/crypto: sha1: re-roll loops to reduce code size Jason A. Donenfeld
2022-01-11 22:05 ` [PATCH crypto v3 0/2] reduce code size from blake2s on m68k and other small platforms Jason A. Donenfeld
2022-01-11 22:05 ` [PATCH crypto v3 1/2] lib/crypto: blake2s: move hmac construction into wireguard Jason A. Donenfeld
2022-01-11 22:05 ` [PATCH crypto v3 2/2] lib/crypto: sha1: re-roll loops to reduce code size Jason A. Donenfeld
2022-01-12 10:59 ` Geert Uytterhoeven [this message]
2022-01-12 13:18 ` [PATCH crypto v3 0/2] reduce code size from blake2s on m68k and other small platforms Jason A. Donenfeld
2022-01-18 6:42 ` Herbert Xu
2022-01-18 11:43 ` Jason A. Donenfeld
2022-01-18 12:44 ` David Laight
2022-01-18 12:50 ` Jason A. Donenfeld
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