Re: [PATCH v3 2/5] random,x86: Add arch_get_slow_rng_u64

Hannes Frederic Sowa
2014-07-17T18:42:23Z

On Thu, Jul 17, 2014, at 19:34, Andy Lutomirski wrote:
> On Thu, Jul 17, 2014 at 10:32 AM, Theodore Ts'o <tytso@mit.edu> wrote:
> > On Thu, Jul 17, 2014 at 10:12:27AM -0700, Andy Lutomirski wrote:
> >>
> >> Unless I'm reading the code wrong, the prandom_reseed_late call can
> >> happen after userspace is running.
> >
> > But there is also the prandom_reseed() call, which happens early.
> >
>
> Right -- I missed that.

prandom_init is a core_initcall, prandom_reseed is a late_initcall.
During initialization of the network stack we have calls to prandom_u32
before the late_initcall happens. That said, I think it is not that
important to seed prandom with rdseed/rdrand as security relevant
entropy extraction should always use get_random_bytes(), but we should
do it nonetheless.

Bye,
Hannes