From: "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
To: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
Cc: David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Matt Fleming
<matt-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org>,
linux-efi <linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Matthew Garrett <mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org>
Subject: Re: EFI runtime and kexec
Date: Fri, 01 Mar 2013 15:50:03 -0800 [thread overview]
Message-ID: <51313EAB.7010707@zytor.com> (raw)
In-Reply-To: <20130301230733.GL30938-fF5Pk5pvG8Y@public.gmane.org>
On 03/01/2013 03:07 PM, Borislav Petkov wrote:
>
> Hmm, yeah, that's nasty. This also means option #2 can go too because
> of the fixed addresses. Option #1 is also kinda polluting user address
> space so maybe the most elegant one would be #4, AFAICT.
>
No, it doesn't pollute the user address space, because the EFI BIOS is
effectively a process. We *have* to switch cr3 anyway around EFI calls,
because BIOSes in the field are known to use physical addresses instead
of virtual.
If Windows really does map EFI BIOS 1:1 then that explains why, and is
probably going to be the stable thing going forward.
-hpa
prev parent reply other threads:[~2013-03-01 23:50 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130301213903.GI30938@pd.tnic>
[not found] ` <20130301213903.GI30938-fF5Pk5pvG8Y@public.gmane.org>
2013-03-01 22:32 ` EFI runtime and kexec H. Peter Anvin
[not found] ` <51312C8F.8000503-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-03-01 22:53 ` Borislav Petkov
[not found] ` <20130301225303.GK30938-fF5Pk5pvG8Y@public.gmane.org>
2013-03-01 22:58 ` H. Peter Anvin
[not found] ` <513132B0.3050308-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-03-01 23:07 ` Borislav Petkov
[not found] ` <20130301230733.GL30938-fF5Pk5pvG8Y@public.gmane.org>
2013-03-01 23:30 ` David Woodhouse
[not found] ` <1362180625.29011.4.camel-Fexsq3y4057IgHVZqg5X0TlWvGAXklZc@public.gmane.org>
2013-03-01 23:34 ` David Woodhouse
[not found] ` <1362180853.29011.6.camel-Fexsq3y4057IgHVZqg5X0TlWvGAXklZc@public.gmane.org>
2013-03-01 23:36 ` Matthew Garrett
2013-03-01 23:39 ` Borislav Petkov
[not found] ` <20130301233924.GM30938-fF5Pk5pvG8Y@public.gmane.org>
2013-03-01 23:48 ` H. Peter Anvin
2013-03-02 1:11 ` H. Peter Anvin
[not found] ` <513151C2.60907-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-03-02 1:51 ` David Woodhouse
[not found] ` <1362189072.32131.6.camel-Fexsq3y4057IgHVZqg5X0TlWvGAXklZc@public.gmane.org>
2013-03-02 2:04 ` H. Peter Anvin
[not found] ` <94a3c086-b0b2-4820-8f4c-66d1496b89dc-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2013-03-02 11:47 ` Borislav Petkov
2013-03-01 23:50 ` H. Peter Anvin [this message]
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