Re: [PATCH v3 0/4] Introduce the latent_entropy gcc plugin

From: Kees Cook <keescook@chromium.org>
To: Emese Revfy <re.emese@gmail.com>, Greg KH <gregkh@linuxfoundation.org>
Cc: "kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	PaX Team <pageexec@freemail.hu>,
	Brad Spengler <spender@grsecurity.net>,
	Michal Marek <mmarek@suse.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	linux-kbuild <linux-kbuild@vger.kernel.org>,
	"Theodore Ts'o" <tytso@mit.edu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux-MM <linux-mm@kvack.org>, Jens Axboe <axboe@kernel.dk>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Paul McKenney <paulmck@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	bart.vanassche@sandisk.com,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v3 0/4] Introduce the latent_entropy gcc plugin
Date: Wed, 15 Jun 2016 16:01:49 -0700	[thread overview]
Message-ID: <CAGXu5jJH2FNenOpAE3Rqh8q=s01sbHmf=QobT98u4h=anjRubw@mail.gmail.com> (raw)
In-Reply-To: <20160615223952.f3a4ece452b15c62babf4629@gmail.com>

On Wed, Jun 15, 2016 at 1:39 PM, Emese Revfy <re.emese@gmail.com> wrote:
> On Wed, 15 Jun 2016 11:55:44 -0700
> Kees Cook <keescook@chromium.org> wrote:
>
>>  The limit on the length of lines is 80 columns and this is a strongly
>>  preferred limit.
>
> I think the code looks worse when it is truncated to 80 columns but
> I'll do it and resend the patches.

Yup, I understand your concerns, but since we're optimizing for
readability by a larger audience that has agreed to the guidelines in
CodingStyle, this is what we get. :)

One area I'm unclear on with kernel coding style, though, is if
splitting all the stuff prior to function name onto a separate line is
"acceptable", since that solves most of the long lines where
__latent_entropy has been added. For example, I don't know which is
better:

All on one line (gmail may split this, but my intention is all one line):

static __latent_entropy void rcu_process_callbacks(struct
softirq_action *unused)

Types and attributes on a separate line:

static __latent_entropy void
rcu_process_callbacks(struct softirq_action *unused)

All arguments on the next line:

static __latent_entropy void rcu_process_callbacks(
                                                          struct
softirq_action *unused)

Greg, do you have a better sense of how to split (or not split) these
kinds of long lines?

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security