Re: [GIT PULL] x86/kaslr for v3.14

[Kees Cook]

On Fri, Feb 7, 2014 at 11:07 AM, H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> wrote:
> On 02/07/2014 06:49 AM, Vivek Goyal wrote:
>>
>> As a workaround, Dave is currently using "nokaslr" command line parameter
>> for second kernel. He is still facing issues where makedumpfile segment
>> faults. He is looking into it further.
>>
>
> Now, let's state this: kaslr for kdump is almost certainly useless (the
> amount of reserved memory is not enough to provide any meaningful
> randomization, so any randomization needs to happen during the memory
> reservation phase.)  So disabling kaslr in the kdump kernel is entirely
> appropriate.

Peter covered everything already, but yeah, kaslr and kdump may not
make a lot of sense together, but regardless, yes, it only examines
e820 for memory space. It has to do all this work before the kernel
decompresses, so it's very early.

-Kees

-- 
Kees Cook
Chrome OS Security
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