On 04/04/2013 01:47 PM, Eric Northup wrote:
>>
>> 1. actually compose the kernel of multiple independently relocatable
>> pieces (maybe chunk it on 2M boundaries or something.)
>
> Without increasing the entropy bits, does this actually increase the #
> of tries necessary for an attacker to guess correctly? It
> dramatically increases the number of possible configurations of kernel
> address space, but for any given piece there are only 256 possible
> locations.
>
The 2M chunk was a red herring; one would of course effectively pack
blocks together, probably packed back to back, in random order.
>> 2. compile the kernel as one of the memory models which can be executed
>> anywhere in the 64-bit address space. The cost of this would have
>> to be quantified, of course.
>
> I attempted to do this, but was limited by my knowledge of the
> toolchain. I would welcome help or suggestions!
Start by looking at the ABI document. I suspect what we need is some
variant of the small PIC model.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
