Date: Fri, 6 Nov 2015 14:24:47 +0100
From: Borislav Petkov <bp@alien8.de>
To: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@amacapital.net>, Ingo Molnar <mingo@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Stephen Smalley <sds@tycho.nsa.gov>,
        Dave Jones <davej@codemonkey.org.uk>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>,
        Denys Vlasenko <dvlasenk@redhat.com>,
        Kees Cook <keescook@chromium.org>, linux-efi@vger.kernel.org
Subject: Re: [GIT PULL] x86/mm changes for v4.4
Message-ID: <20151106132447.GB19522@pd.tnic>
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 <20151105021710.GA22941@codemonkey.org.uk>
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On Fri, Nov 06, 2015 at 01:09:48PM +0000, Matt Fleming wrote:
> On Thu, 05 Nov, at 11:05:35PM, Andy Lutomirski wrote:
> > 
> > Admittedly, we might need to use a certain amount of care to avoid
> > interesting conflicts with the vmap mechanism.  We might need to vmap
> > all of the EFI stuff, and possibly even all the top-level entries that
> > contain EFI stuff (i.e. exactly one of them unless EFI ends up *huge*)
> > as a blank not-present region to avoid overlaps, but that's not a big
> > deal.
> 
> There shouldn't be any room for conflicting with vmap() because the VA
> region where we map EFI regions is still carved out especially for us.
> 
> Right Boris?

Yap:

ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)

vs

ffffffef00000000 - ffffffff00000000 EFI region in trampoline_pgd

the new pagetable will make that issue moot too.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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