Re: [PATCH net-next v5 07/20] zinc: Poly1305 generic C implementations and selftest

From: Andy Lutomirski <luto@amacapital.net>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Eric Biggers <ebiggers@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Netdev <netdev@vger.kernel.org>,
	Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
	David Miller <davem@davemloft.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Samuel Neves <sneves@dei.uc.pt>,
	Andrew Lutomirski <luto@kernel.org>,
	Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Subject: Re: [PATCH net-next v5 07/20] zinc: Poly1305 generic C implementations and selftest
Date: Tue, 18 Sep 2018 21:13:04 -0700	[thread overview]
Message-ID: <BF781C43-52C2-410A-A6D0-AAD0AC998C2D@amacapital.net> (raw)
In-Reply-To: <CAHmME9oL98adRp6xXqaXxA0E4Oa4ecPW+JHChCS3hTgH7RLPjA@mail.gmail.com>

> On Sep 18, 2018, at 6:35 PM, Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> 
>> On Wed, Sep 19, 2018 at 2:50 AM Eric Biggers <ebiggers@kernel.org> wrote:
>> Hardcoding the 'input' array to 600 bytes forces the full amount of space to be
>> reserved in the kernel image for every test vector.  Also, if anyone adds a
>> longer test vector they will need to remember to increase the value.
>> 
>> It should be a const pointer instead, like the test vectors in crypto/testmgr.h.
> 
> I know. The agony. This has been really annoying me. I originally did
> it the right way, but removed it last week, when I noticed that gcc
> failed to put it in the initconst section:
> 
> https://git.zx2c4.com/WireGuard/commit/?id=f4698d20f13946afc6ce99e98685ba3f9adc4474
> 
> Even changing the (u8[]){ ... } into a (const u8[]){ ... } or even
> into a const string literal does not do the trick. It makes it into
> the constant data section with const, but it does not make it into the
> initconst section. What a bummer.
> 
> I went asking about this on the gcc mailing list, to see if there was
> just some aspect of C that I had overlooked:
> https://gcc.gnu.org/ml/gcc/2018-09/msg00043.html

Can you not uglify the code a bit by using normal (non-compound) liberals as described in the response to that email?