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Subject: Re: [PATCH] x86/fpu: move FPU state into separate cache
To: Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirski <luto@amacapital.net>
CC: Kees Cook <keescook@chromium.org>, LKML <linux-kernel@vger.kernel.org>,
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On March 29, 2017 2:41:00 PM PDT, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>On Wed, Mar 29, 2017 at 2:35 PM, Andy Lutomirski <luto@amacapital.net>
>wrote:
>>
>> Randomization also needs to leave thread_info at the beginning.  Can
>it do that?
>
>Good point, and good question. No idea if the gcc extension can do,
>but yes, it clearly needs a "you can't move this entry".
>
>I assume it has some such capability already, because it's fairly
>common to have that kind of "beginning of structure if fixed" due to
>unions of structures anyway.
>
>                 Linus

An alternative is to wrap the randomized structure inside a nonrandomized wrapper structure.
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