Re: [PATCH 3/7] x86, kaslr: find minimum safe relocation position

From: H. Peter Anvin
Date: Thu Oct 03 2013 - 18:47:25 EST


On 10/03/2013 03:43 PM, Kees Cook wrote:
>> This is highly problematic. The standard protocol is to hoist the
>> initramfs as high as possible in memory, so this may really unacceptably
>> restrict the available range.
>
> Doesn't this depend on the boot loader's behavior?

It does, but the recommended (and *required* for compatibility with
older kernels) behavior is to hoist as high as possible.

>> It would be better to treat these the same as reserved regions in the
>> e820 map as far as the address space picking algorithm is concerned.
>
> Could this be considered a future optimization, or do you feel this is
> required even for this first patch series landing?

Yes, I consider it required because of the above.

-hpa


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