Re: [PATCH 0/3] allow DRM drivers to limit creation of blobs

[cohens@codeaurora.org]

On 2019-11-08 03:34, Daniel Vetter wrote:
> On Thu, Nov 07, 2019 at 02:39:11PM -0500, Steve Cohen wrote:
>> Fuzzers used in Android compliance testing repeatedly call the
>> create blob IOCTL which eventually exhausts the system memory.
>> This series adds a hook which allows drivers to impose their own
>> limitations on the size and/or number of blobs created.
> 
> Pretty sure this isn't just a problem for msm/dpu alone, why this very
> limited approach?
> 
I'm not familiar enough with the blob requirements for other
vendor's drivers to impose any restrictions on them. The idea
was to provide the hook for vendors to implement their own
checks. Support for msm/mdp* drivers will be added in v2 if this
approach is acceptable.

> Also, why are your fuzzers not also allocating enormous amounts of gem
> buffers, which will also exhaust memory eventually?

Excellent question... This will likely come in a follow-up series.

> -Daniel
> 
>> 
>> Steve Cohen (3):
>>   drm: add driver hook for create blob limitations
>>   drm/msm: add support for createblob_check driver hook
>>   drm/msm/dpu: check blob limitations during create blob ioctl
>> 
>>  drivers/gpu/drm/drm_property.c          |  7 +++++++
>>  drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 14 ++++++++++++++
>>  drivers/gpu/drm/msm/msm_drv.c           | 25 
>> +++++++++++++++++++++++++
>>  drivers/gpu/drm/msm/msm_kms.h           |  1 +
>>  include/drm/drm_drv.h                   |  9 +++++++++
>>  5 files changed, 56 insertions(+)
>> 
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project
>> 
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