[PATCH v2 5/7] drm/i915: Check if the size is too big while creating shmem file

[Mauro Carvalho Chehab]

On Tue,  5 Jul 2022 15:24:53 +0300
Gwan-gyeong Mun <gwan-gyeong.mun at intel.com> wrote:

> The __shmem_file_setup() function returns -EINVAL if size is greater than
> MAX_LFS_FILESIZE. To handle the same error as other code that returns
> -E2BIG when the size is too large, it add a code that returns -E2BIG when
> the size is larger than the size that can be handled.
> 
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Matthew Auld <matthew.auld at intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Reviewed-by: Nirmoy Das <nirmoy.das at intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab at kernel.org>

> ---
>  drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index 604e8829e8ea..8495e87432f6 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -541,6 +541,15 @@ static int __create_shmem(struct drm_i915_private *i915,
>  
>  	drm_gem_private_object_init(&i915->drm, obj, size);
>  
> +	/* XXX: The __shmem_file_setup() function returns -EINVAL if size is
> +	 * greater than MAX_LFS_FILESIZE.
> +	 * To handle the same error as other code that returns -E2BIG when
> +	 * the size is too large, we add a code that returns -E2BIG when the
> +	 * size is larger than the size that can be handled.
> +	 */
> +	if (size > MAX_LFS_FILESIZE)
> +		return -E2BIG;
> +
>  	if (i915->mm.gemfs)
>  		filp = shmem_file_setup_with_mnt(i915->mm.gemfs, "i915", size,
>  						 flags);