Re: Changes to make /dev/*random better sooner

On Apr 8, 2014, at 21:33, Thor Lancelot Simon <[email protected]> wrote:

> On Wed, Apr 09, 2014 at 02:43:23AM +0100, Mindaugas Rasiukevicius wrote:
>> Few fragments which caught my eye while skimming through the diff..
>> 
>>> #if defined(__HAVE_CPU_COUNTER)
>>> -	if (cpu_hascounter())
>>> -		return (cpu_counter32());
>>> +	if (cpu_hascounter() && sizeof(cpu_counter() == sizeof(uint64_t))) {
>>> +		return (cpu_counter());
>>> +	}
>>> #endif
>> 
>> ??
> 
> We provide no MI API for obtaining a counter value of any known size except
> 32 bits, unfortunately.  The instrumentation I added while developing these
> changes revealed that the delta entropy estimator was terribly broken due
> to wraparound; changing it to 64 bits is the fix.

I don't have any knowledge or opinion about that, but maybe the "??" 
has to do with the sizeof? I think the parens are wrong; they're around 
the entire equality comparison.
-- 
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