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8d25ccebef
This allows the argument to be a const.
The other option was to keep it an inline function and make the argument
a const:
static inline struct drm_gem_cma_object *
to_drm_gem_cma_obj(const struct drm_gem_object *gem_obj)
{
return container_of(gem_obj, struct drm_gem_cma_object, base);
}
This will happily return a non-const pointer to the drm_gem_cma_object
based on a const pointer to the contained drm_gem_object, thus creating
const-safety problems.
There was an attempt to fix the problem in the container_of() macro
itself (see https://lkml.org/lkml/2017/5/19/381) but the patch seems to
have fallen through the cracks. It would require turning this inline
function into a macro.
By making this a macro now, we will benefit from a possible future
enhancement of container_of(). We don't loose type checking by doing
this, container_of() takes care of that.
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107191348.17555-7-noralf@tronnes.org
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.