On Wed, Jan 29, 2025 at 10:29:24AM +0300, Dan Carpenter wrote:
> drivers/iommu/iommufd/iommufd_private.h
> 243 static inline struct iommufd_ioas *iommufd_get_ioas(struct
> iommufd_ctx *ictx,
> 244 u32 id)
> 245 {
> 246 return container_of(iommufd_get_object(ictx, id,
> 247 IOMMUFD_OBJ_IOAS),
> 248 struct iommufd_ioas, obj);
> 249 }
>
> It's just a cast like you say, but it looks like pointer math. It would
> be more readable as container_of_first().
I left out the important bit... iommufd_get_object() returns error pointers.
It doesn't make sense to pass error pointers to container_of() unless the
offset is zero.
Smatch could check that the offset is zero, but Coccinelle can't. There are
a bunch of advantages to Coccinelle at times so this will improve the
readability and make it easier for static checkers as well.
regards,
dan carpenter
