On Sat, Dec 14, 2019 at 06:57:30PM +0100, Ard Biesheuvel wrote:
> +
> +#define efi_table_attr(table, attr, instance) ({ \
> + __typeof__(((table##_t *)0)->attr) __ret; \
> + if (efi_is_native()) { \
> + __ret = ((table##_t *)instance)->attr; \
> + } else { \
> + __typeof__(((table##_32_t *)0)->attr) at; \
> + at = (((table##_32_t *)(unsigned long)instance)->attr); \
> + __ret = (__typeof__(__ret))(unsigned long)at; \
> + } \
> + __ret; \
> +})
The casting of `at' is appropriate if the attr is a pointer type which
needs to be zero-extended to 64-bit, but for other fields it is
unnecessary at best and possibly dangerous. There are probably no
instances currently where it is called for a non-pointer field, but is
it possible to detect if the type is pointer and avoid the cast if not?
