Re: Integer subtype and NaN trick

[Coda Highland <chighland@...>]

I was, but Owen's right -- the part of the system responsible for
doing the address mapping is implemented in hardware.

/s/ Adam

On Sun, Jun 16, 2013 at 4:02 PM, Tim Hill <drtimhill@gmail.com> wrote:
> Thats physical addresses .. I think the poster was talking about virtual addresses (that is, before the virtual address translation).
>
> --Tim
>
> On Jun 16, 2013, at 12:14 AM, Owen Shepherd <owen.shepherd@e43.eu> wrote:
>
>> Coda Highland wrote:
>>>
>>> Unless I'm wrong, ASLR isn't restricted to 48 bits. Virtual memory
>>> allocation can use whatever addresses it wants.
>>
>>
>> The hardware itself is physically limited to 48-bits.  Each page is 4kB, plus there are 4 layers of page tables, bringing the total up to 48 bits.
>>
>> The processors throw an exception on a memory access if bits 63-48 don't match bit 47.
>>
>> This is all baked into silicon
>
>