Re: [tip:x86/kaslr] x86, kaslr: Provide randomness functions

[H. Peter Anvin]

On 11/11/2013 11:58 AM, Ingo Molnar wrote:
>>
>> Use the i8254 if and only if nothing else is available, it isn't safe to
>> touch on some newer systems.
> 
> I concur - the i8254 is probably also a low entry source, given that this 
> all runs early bootup.
> 

Well, it is a 16-bit 1.19318 MHz counter so at least on older systems it
is likely to provide at least a modicum on entropy.  On systems with a
TSC it is likely to be redundant with the TSC.

> In any case there's no excuse for not mixing RDRAND and RDTSC entropy.

	-hpa


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