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SubjectRe: [PATCH 01/62] highmem: mark k[un]map_atomic() with two arguments as deprecated
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@cesarb.net
cesar.barros@gmail.com


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