[igt-dev] [PATCH i-g-t] i915/gem_mmap_gtt: Test mmap_gtt extension validity

[Chris Wilson]

Quoting Abdiel Janulgue (2019-11-21 13:09:15)
> If we accidentally modify the mmap_gtt ioctl struct sizes in our headers,
> we might end up feeding garbage into the ioctl and start validating
> that as our flags for the upcoming mmap_offset ioctl. This ensures header
> changes don't mess up with our existing mmap_gtt ioctl.
> 
> Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>

Yes, I have made this mistake before (with DRM_IOCTL_I915_GEM_MMAP).
Once burnt, twice shy.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris