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Subject: Re: [PATCH] drm: Use kvzalloc for allocating blob property memory
To:     =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>
Cc:     David Airlie <airlied@linux.ie>, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org
References: <20180629142710.2069-1-michel@daenzer.net>
 <20180629161205.GE5565@intel.com>
From:   =?UTF-8?Q?Michel_D=c3=a4nzer?= <michel@daenzer.net>
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Message-ID: <32deece3-b583-ca58-cd41-ba11846240c8@daenzer.net>
Date:   Fri, 29 Jun 2018 18:27:28 +0200
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On 2018-06-29 06:12 PM, Ville Syrjälä wrote:
> On Fri, Jun 29, 2018 at 04:27:10PM +0200, Michel Dänzer wrote:
>> From: Michel Dänzer <michel.daenzer@amd.com>
>>
>> The property size may be controlled by userspace, can be large (I've
>> seen failure with order 4, i.e. 16 pages / 64 KB) and doesn't need to be
>> physically contiguous.
> 
> I wonder if we should enforce some kind of reasonable limit
> on the blob size. Looks like we allow anything up to
> ULONG_MAX currently. We can't tell at createblob time how
> the thing is going to be used, so can't have any kind
> of property specific limit unfortunately.

The failure I was seeing was for a gamma LUT, so a size limit alone
cannot solve the issue.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer