linux-kernel - Re: [Intel-gfx] [PATCH 2/3] drm/i915: split out check for noncontiguous pfn range

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20170321102339.GD11338@nuc-i3427.alporthouse.com>
Date:   Tue, 21 Mar 2017 10:23:39 +0000
From:   Chris Wilson <chris@...is-wilson.co.uk>
To:     Arnd Bergmann <arnd@...db.de>,
        Daniel Vetter <daniel.vetter@...el.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        David Airlie <airlied@...ux.ie>,
        Tvrtko Ursulin <tvrtko.ursulin@...el.com>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: Re: [Intel-gfx] [PATCH 2/3] drm/i915: split out check for
 noncontiguous pfn range

On Tue, Mar 21, 2017 at 09:56:52AM +0000, Chris Wilson wrote:
> On Mon, Mar 20, 2017 at 10:40:28AM +0100, Arnd Bergmann wrote:
> > We get a warning with gcc-7 about a pointless comparison when
> > using a linear memmap:
> > 
> > drivers/gpu/drm/i915/selftests/scatterlist.c: In function 'alloc_table':
> > drivers/gpu/drm/i915/selftests/scatterlist.c:219:66: error: self-comparison always evaluates to false [-Werror=tautological-compare]
> > 
> > Splitting out the comparison into a separate function avoids the warning
> > and makes it slightly more obvious what happens.
> 
> I worried whether gcc will simply get smarter and apply its warning more
> consistently, but I agree the helper is good documentation.
>  
> > Fixes: 935a2f776aa5 ("drm/i915: Add some selftests for sg_table manipulation")
> > Signed-off-by: Arnd Bergmann <arnd@...db.de>
> Reviewed-by: Chris Wilson <chris@...is-wilson.co.uk>

And applied.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre