Re: [PATCH 01/62] highmem: mark k[un]map_atomic() with two argumentsas deprecated

[Cesar Eduardo Barros]

Em 27-11-2011 03:26, Cong Wang escreveu:
>   /*
>    * Prevent people trying to call kunmap_atomic() as if it were kunmap()
>    * kunmap_atomic() should get the return value of kmap_atomic, not the page.
>    */
> -#define kunmap_atomic(addr, args...)				\
> -do {								\
> -	BUILD_BUG_ON(__same_type((addr), struct page *));	\
> -	__kunmap_atomic(addr);					\
> -} while (0)
> +static inline void kunmap_atomic(void *addr)
> +{
> +	BUILD_BUG_ON(__same_type((addr), struct page *));
> +	__kunmap_atomic(addr);
> +}
> +
> +static inline void __deprecated kunmap_atomic_deprecated(void *addr,
> +							enum km_type km)
> +{
> +	BUILD_BUG_ON(__same_type((addr), struct page *));
> +	__kunmap_atomic(addr);
> +}

This will break the misuse detection of kunmap_atomic (see commit 
597781f3e51f48ef8e67be772196d9e9673752c4).

kunmap_atomic() _must_ be a macro, so the __same_type can see the type 
the caller used. If you use an inline function, all it will see is a 
void *, even if the caller confused it with kunmap() and passed a struct 
page *.

--
Cesar Eduardo Barros
cesarb@xxxxxxxxxx
cesar.barros@xxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/