Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

From: Kees Cook
Date: Wed Nov 16 2022 - 17:43:31 EST


On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote:
> - (get_random_u32_below(1024) + 1) * PAGE_SIZE;
> + get_random_u32_between(1, 1024 + 1) * PAGE_SIZE;

I really don't like "between". Can't this be named "inclusive" (and
avoid adding 1 everywhere, which seems ugly), or at least named
something less ambiguous?

> - n = get_random_u32_below(100) + 1;
> + n = get_random_u32_between(1, 101);

Because I find this much less readable. "Below 100" is clear: 0-99
inclusive, plus 1, so 1-100 inclusive. "Between 1 and 101" is not obvious
to me to mean: 1-100 inclusive.

These seem so much nicer:
get_random_u32_inclusive(1, 1024)
get_random_u32_inclusive(1, 100)

--
Kees Cook