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

Andy Lutomirski
2014-07-17T19:16:03Z

On Thu, Jul 17, 2014 at 11:42 AM, Hannes Frederic Sowa
<hannes@stressinduktion.org> wrote:
>
>
> 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.
>

Regardless, I don't want to do this as part of this patch series. One
thing at a time...

--Andy