linux-kernel - Re: [PATCH] drm: powerplay: use div64_s64 instead of do

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

Date:	Mon, 4 Jan 2016 09:17:50 +0100
From:	Thierry Reding <thierry.reding@...il.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Jammy Zhou <Jammy.Zhou@....com>, David Airlie <airlied@...ux.ie>,
	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
	Alex Deucher <alexander.deucher@....com>,
	David Zhang <david1.zhang@....com>,
	Eric Huang <JinHuiEric.Huang@....com>,
	Christian König <christian.koenig@....com>
Subject: Re: [PATCH] drm: powerplay: use div64_s64 instead of do_div

On Fri, Jan 01, 2016 at 02:07:41PM +0100, Arnd Bergmann wrote:
> The newly added code for Fiji creates a correct compiler warning
> about invalid use of the do_div macro:
> 
> In file included from powerplay/hwmgr/ppatomctrl.c:31:0:
> drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/ppevvmath.h: In function 'fDivide':
> drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/ppevvmath.h:382:89: warning: comparison of distinct pointer types lacks a cast
>      do_div(longlongX, longlongY); /*Q(32,32) divided by Q(16,16) = Q(16,16) Back to original format */
> 
> do_div() divides an unsigned 64-bit number by an unsigned 32-bit number.
> The code instead wants to divide two signed 64-bit numbers, which is done
> using the div64_s64 function.
> 
> Signed-off-by: Arnd Bergmann <arnd@...db.de>
> Fixes: 770911a3cfbb ("drm/amd/powerplay: add/update headers for Fiji SMU and DPM")
> ---
> Found on ARM allmodconfig on yesterday's linux-next 

Reviewed-by: Thierry Reding <treding@...dia.com>

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)