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From: Andy Lutomirski <luto@kernel.org>
Date: Wed, 1 Nov 2017 13:33:31 -0700
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Subject: Re: [PATCH 00/23] KAISER: unmap most of the kernel from userspace
 page tables
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>, Kees Cook <keescook@google.com>,
        Hugh Dickins <hughd@google.com>
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On Wed, Nov 1, 2017 at 12:05 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Wed, Nov 1, 2017 at 11:46 AM, Dave Hansen
> <dave.hansen@linux.intel.com> wrote:
>>
>> The vmalloc()'d stacks definitely need the page table walk.
>
> Ugh, yes. Nasty.
>
> Andy at some point mentioned a per-cpu initial stack trampoline thing
> for his exception patches, but I'm not sure he actually ever did that.
>
> Andy?

I'm going to push it to kernel.org very shortly (like twenty minutes
maybe).  Then the 0day bot can chew on it.  With the proposed LDT
rework, we don't need to do any of dynamic mapping stuff, I think.

>
>               Linus