[PATCH v5 2/3] kho: add KHOSER_COPY_PTR to allow phys copy of serialized ptr

[tarunsahu at google.com]

+mike

As per you suggestion:


	({								\
		typeof((dest).ptr) __dst;				\
		typeof((src).ptr) __src;				\
		static_assert(						\
			__builtin_types_compatible_p(__dst, __src)) ||	\
			__builtin_types_compatible_p(__dst, void *) ||	\
			__builtin_types_compatible_p(__src, void *),	\
			"pointer type mismatch in KHOSER_COPY_PTR"	\
		); \
		(dest).phys = (src).phys; \
	})

This is incorrect:  as it looks for type instead of var and adding
typedef like below throws warning in checkpatch : no new typedefs.



	({								\
		typedef typeof((dest).ptr) __dst;			\
		typedef typeof((src).ptr) __src;			\
		static_assert(						\
			__builtin_types_compatible_p(__dst, __src)) ||	\
			__builtin_types_compatible_p(__dst, void *) ||	\
			__builtin_types_compatible_p(__src, void *),	\
			"pointer type mismatch in KHOSER_COPY_PTR"	\
		); \
		(dest).phys = (src).phys; \
	})

OR we can add __builtin_...(typeof(__dst), typeof(__src)), But this does
not solve the purpose of improving the readability.

So I am fine with the original, as it is more straight-forward to read.
Typeof(pointer of destination) (typeof(dst.ptr)) and so on.

~Tarun

Tarun Sahu <tarunsahu at google.com> writes:

> Adding KHOSER_COPY_PTR to copy one serializeable pointer to
> another. It basically allows copy of phys val of the
> serializeable pointer.
>
> It ignores the typecheck if any of the argument is of void *
>
> Signed-off-by: Tarun Sahu <tarunsahu at google.com>
> ---
>  include/linux/kho/abi/kexec_handover.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/include/linux/kho/abi/kexec_handover.h b/include/linux/kho/abi/kexec_handover.h
> index 5e2eb8519bda..c1b61d875dcc 100644
> --- a/include/linux/kho/abi/kexec_handover.h
> +++ b/include/linux/kho/abi/kexec_handover.h
> @@ -139,6 +139,17 @@
>  		(typeof((s).ptr))((s).phys ? phys_to_virt((s).phys) : NULL); \
>  	})
>  
> +/* Copies one serializable pointer to another. */
> +#define KHOSER_COPY_PTR(dest, src) \
> +	({ \
> +		static_assert( \
> +			__builtin_types_compatible_p(typeof((dest).ptr), typeof((src).ptr)) || \
> +			__builtin_types_compatible_p(typeof((dest).ptr), void *) || \
> +			__builtin_types_compatible_p(typeof((src).ptr), void *), \
> +			"pointer type mismatch in KHOSER_COPY_PTR" \
> +		); \
> +		(dest).phys = (src).phys; \
> +	})
>  /*
>   * This header is embedded at the beginning of each `kho_vmalloc_chunk`
>   * and contains a pointer to the next chunk in the linked list,
> -- 
> 2.55.0.rc0.786.g65d90a0328-goog