RE: [PATCH] random: cleanup fractional entropy shift constants
From: David Laight
Date: Fri Jan 14 2022 - 10:39:12 EST
From: Jason A. Donenfeld
> Sent: 14 January 2022 15:33
>
> The entropy estimator is calculated in terms of 1/8 bits, which means
> there are various constants where things are shifted by 3. Move these
> into our pool info enum with the other relevant constants, and normalize
> the name a bit, prepending a POOL_ like the rest. While we're at it,
> move an English assertion about sizes into a proper BUILD_BUG_ON so
> that the compiler can ensure this invariant.
>
...
> -#define ENTROPY_SHIFT 3
> -#define ENTROPY_BITS() (input_pool.entropy_count >> ENTROPY_SHIFT)
..
> + POOL_ENTROPY_SHIFT = 3,
> +#define POOL_ENTROPY_BITS() (input_pool.entropy_count >> POOL_ENTROPY_SHIFT)
The rename ought to be a different patch.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)