On Mon, Apr 17, 2017 at 04:31:24PM -0700, Eric Anholt wrote:
> The stub get_unmapped_area() function was actually getting called, so
> all of our mmap()s failed.
> 
> Cc: Yannick Fertre <yannick.fer...@st.com>
> Fixes: 97bf3a9aa60f ("drm/cma: Update DEFINE_DRM_GEM_CMA_FOPS to add 
> get_unmapped_area")
> Signed-off-by: Eric Anholt <e...@anholt.net>

Oh drat, I assumed the core would only call this when needed, but things
don't work like that.

Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>

The strange thing is that in some cases ->mm->get_unmapped_area overwrites
fops->get_unmapped_area, but not for do_mmap in the mmu case. Seems not
entirely thought out to me ...
-Daniel

> ---
>  include/drm/drm_gem_cma_helper.h | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/include/drm/drm_gem_cma_helper.h 
> b/include/drm/drm_gem_cma_helper.h
> index 7320b140545a..b42529e0fae0 100644
> --- a/include/drm/drm_gem_cma_helper.h
> +++ b/include/drm/drm_gem_cma_helper.h
> @@ -26,6 +26,13 @@ to_drm_gem_cma_obj(struct drm_gem_object *gem_obj)
>       return container_of(gem_obj, struct drm_gem_cma_object, base);
>  }
>  
> +#ifndef CONFIG_MMU
> +#define DRM_GEM_CMA_UNMAPPED_AREA_FOPS \
> +     .get_unmapped_area      = drm_gem_cma_get_unmapped_area,
> +#else
> +#define DRM_GEM_CMA_UNMAPPED_AREA_FOPS
> +#endif
> +
>  /**
>   * DEFINE_DRM_GEM_CMA_FOPS() - macro to generate file operations for CMA 
> drivers
>   * @name: name for the generated structure
> @@ -50,7 +57,7 @@ to_drm_gem_cma_obj(struct drm_gem_object *gem_obj)
>               .read           = drm_read,\
>               .llseek         = noop_llseek,\
>               .mmap           = drm_gem_cma_mmap,\
> -             .get_unmapped_area      = drm_gem_cma_get_unmapped_area,\
> +             DRM_GEM_CMA_UNMAPPED_AREA_FOPS \
>       }
>  
>  /* free GEM object */
> @@ -86,15 +93,6 @@ unsigned long drm_gem_cma_get_unmapped_area(struct file 
> *filp,
>                                           unsigned long len,
>                                           unsigned long pgoff,
>                                           unsigned long flags);
> -#else
> -static inline unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,
> -                                                       unsigned long addr,
> -                                                       unsigned long len,
> -                                                       unsigned long pgoff,
> -                                                       unsigned long flags)
> -{
> -     return -EINVAL;
> -}
>  #endif
>  
>  #ifdef CONFIG_DEBUG_FS
> -- 
> 2.11.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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