Subject: Re: [PATCH] drm/panfrost: Avoid user size passed to kvmalloc()
To:     Alyssa Rosenzweig <alyssa@collabora.com>,
        Steven Price <steven.price@arm.com>
Cc:     Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
        Rob Herring <robh@kernel.org>,
        Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
        Boris Brezillon <boris.brezillon@collabora.com>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Dan Carpenter <dan.carpenter@oracle.com>
References: <20211216161603.983711-1-steven.price@arm.com>
 <Ybt8QWEAooP++R7a@maud>
From:   Tomeu Vizoso <tomeu.vizoso@collabora.com>
Message-ID: <aa7be5e4-591f-b7df-12e3-1eff77e53741@collabora.com>
Date:   Fri, 17 Dec 2021 08:38:34 +0100
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On 12/16/21 6:49 PM, Alyssa Rosenzweig wrote:
>> This provides an easy method for user
>> space to trigger the OOM killer (by temporarily allocating large amounts
>> of kernel memory)
> 
> panfrost user space has a lot of easy ways to trigger to the OOM killer
> unfortunately .... if this is something we want to fix there are a lot
> more patches coming :(

What are you thinking of, Alyssa?

My understanding is that the problem are kernel allocations that aren't 
accounted per userspace process. I would expect shmem-backed BOs to be 
taken into account by the OOM killer, so the offending process would be 
terminated without affecting the other processes in the system.

Cheers,

Tomeu