Re: [PATCH] s390: disable -Warray-bounds

From: Philipp Zabel <p.zabel@pengutronix.de>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Kees Cook <keescook@chromium.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	David Howells <dhowells@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] s390: disable -Warray-bounds
Date: Thu, 09 Jun 2022 11:56:14 +0200	[thread overview]
Message-ID: <236b39507da31d80a948fe308f515587e96c28de.camel@pengutronix.de> (raw)
In-Reply-To: <CAHk-=wiFn-_OaWKY=nXt3YSiy=obrNoQW_u7zKO7qoArez=GUw@mail.gmail.com>

Hi Linus,

On Mi, 2022-06-08 at 16:59 -0700, Linus Torvalds wrote:
> On Wed, Jun 8, 2022 at 2:33 PM Kees Cook <keescook@chromium.org> wrote:
> > 
> > I and others have been working through a bunch of them, though yes,
> > they're not all fixed yet. I've been trying to track it here[1], but
> > many of those fixes are only in -next.
> 
> Hmm. Even with that disabled, I get a few warnings I *really* would
> want to get rid of.
> 
> The one in ipuv3-crtc.c seems valid about "address used as boolean is
> always true".
> 
> The 'dangling-pointer' warning does seem interesting, but not when the
> compiler does as bad a job as gcc seems to do.
> 
> See the attached patch for
> 
>  (a) make the s390 "use -Wno-array-bounds for gcc-12" be generic
> 
>  (b) fix the ipuv3-crtc.c one. IMX people?

Thank you, this fix clearly matches the original intention.

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>

The mistake had no adverse effect since the following condition doesn't
actually dereference the NULL pointer, but given the compiler warning
this

Fixes: eb8c88808c83 ("drm/imx: add deferred plane disabling")

regards
Philipp