On 2018-12-21 4:10 a.m., Yu Zhao wrote:
> Userspace may request pitch alignment that is not supported by GPU.
> Some requests 32, but GPU ignores it and uses default 64 when cpp is
> 4. If GEM object is allocated based on the smaller alignment, GPU
> DMA will go out of bound.
> 
> For GPU that does frame buffer compression, DMA writing out of bound
> memory will cause memory corruption.
> 
> Signed-off-by: Yu Zhao <yuz...@google.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> index e309d26170db..755daa332f8a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> @@ -527,6 +527,15 @@ amdgpu_display_user_framebuffer_create(struct drm_device 
> *dev,
>       struct drm_gem_object *obj;
>       struct amdgpu_framebuffer *amdgpu_fb;
>       int ret;
> +     struct amdgpu_device *adev = dev->dev_private;
> +     int cpp = drm_format_plane_cpp(mode_cmd->pixel_format, 0);
> +     int pitch = amdgpu_align_pitch(adev, mode_cmd->width, cpp, false);

Also, this needs to use mode_cmd->pitches[0] instead of mode_cmd->width,
otherwise it'll spuriously fail for larger but well-aligned pitches.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to