Re: [PATCH 1/4] container_of: add container_of_const() that preserves const-ness of the pointer

From: Sakari Ailus
Date: Thu Dec 01 2022 - 18:22:03 EST


Hi Greg,

On Thu, Dec 01, 2022 at 08:30:54PM +0100, Greg Kroah-Hartman wrote:
> container_of does not preserve the const-ness of a pointer that is
> passed into it, which can cause C code that passes in a const pointer to
> get a pointer back that is not const and then scribble all over the data
> in it. To prevent this, container_of_const() will preserve the const
> status of the pointer passed into it using the newly available _Generic()
> method.

"_const" in the name suggests that the macro would always take a const
argument. Could this be called e.g. container_of_safe() (for type-safe, but
full type_safe would be a bit long)?

--
Kind regards,

Sakari Ailus