From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751750AbcGUSFS (ORCPT <rfc822;w@1wt.eu>);
	Thu, 21 Jul 2016 14:05:18 -0400
Received: from mail.windriver.com ([147.11.1.11]:51034 "EHLO
	mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750884AbcGUSFP (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 21 Jul 2016 14:05:15 -0400
Date: Thu, 21 Jul 2016 14:04:37 -0400
From: Paul Gortmaker <paul.gortmaker@windriver.com>
To: Joel Stanley <joel@jms.id.au>
CC: <linux-kernel@vger.kernel.org>, Russell King <linux@armlinux.org.uk>,
        Florian Fainelli <f.fainelli@gmail.com>, Ray Jui <rjui@broadcom.com>,
        Scott Branden <sbranden@broadcom.com>,
        Stephen Warren <swarren@wwwdotorg.org>, Lee Jones <lee@kernel.org>,
        Eric Anholt <eric@anholt.net>, <linux-arm-kernel@lists.infradead.org>,
        <bcm-kernel-feedback-list@broadcom.com>
Subject: Re: [PATCH] ARM: dont specify STACKPROTECTOR in defconfigs
Message-ID: <20160721180437.GE21225@windriver.com>
References: <20160721151134.5803-1-paul.gortmaker@windriver.com>
 <CACPK8XfRFPxr6NbaMBztNCrOnGUkFaAiE+op+Mxyqk7de4_2ng@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CACPK8XfRFPxr6NbaMBztNCrOnGUkFaAiE+op+Mxyqk7de4_2ng@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

[Re: [PATCH] ARM: dont specify STACKPROTECTOR in defconfigs] On 22/07/2016 (Fri 01:40) Joel Stanley wrote:

> Hi Paul,
> 
> On Fri, Jul 22, 2016 at 12:41 AM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > Note the output from the following:
> >
> >    $ git grep STACKPROTECTOR arch/arm/configs/
> >    arch/arm/configs/aspeed_g4_defconfig:CONFIG_CC_STACKPROTECTOR_STRONG=y
> >    arch/arm/configs/aspeed_g5_defconfig:CONFIG_CC_STACKPROTECTOR_STRONG=y
> >    arch/arm/configs/bcm2835_defconfig:CONFIG_CC_STACKPROTECTOR_REGULAR=y
> >    $
> >
> > Only three defconfigs specify a value.  And two of the three ask for
> > the strong variant, which isn't supported by older toolchains.
> >
> > Due to the nature of ARM having more platform specific code than say
> > x86, the allyesconfig and allmodconfig aren't as effective for build
> > coverage.  So, in addition, I like to use a trivial script to walk all
> > the defconfigs and build each one.
> >
> > However I will get false positives on unsupported stackprotector values
> > with an older toolchain like gcc-4.6.3.  As in this instance I am just
> > using the compiler as a glorified syntax checker on a machine where I
> > build a bunch of other arch for the same reason, there is no real
> > motivation to get a newer toolchain for improved optimization etc.
> 
> I'm happy to remove it from the Aspeed configurations as I'm not sure
> why it was enabled in the first place.
> 
> However, I do not agree with the reasoning here. If you're building to
> check syntax a modern GCC will certainly pick up on more than one from
> four years ago.

Just to clarify, syntax in this case is just for fat fingered typos and
ensuring functions resolve with the appropriate header includes.  If I
was coding new stuff specifically for ARM, then that would be different.

> 
> > Since there are only three of them, and there is nothing about these
> > settings that are board/platform specific, I propose we just eliminate
> > the three existing instances and take the default.
> 
> This makes sense to me.
> 
> Acked-by: Joel Stanley <joel@jms.id.au>

Thanks,
Paul.
--