Re: [PATCH RFC] random: Account for entropy loss due to overwrites

From: Theodore Ts'o
Date: Tue Oct 16 2012 - 00:09:32 EST

On Sat, Sep 29, 2012 at 12:47:04PM -0700, H. Peter Anvin wrote:
> >-static struct poolinfo {
> >+static const struct poolinfo {
> >+ int poolshift; /* log2(POOLBITS) */
> > int poolwords;
> > int tap1, tap2, tap3, tap4, tap5;

Poolshift is duplicated information; it's just log2(poolwords) + 5
(since POOLBITS is poolwords*32).

Granted you don't want to recalculate it every single time you need to
use it, but perhaps it would be better to add poolshift to struct
entropy_store, and set it in init_std_data()?

- Ted
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