Re: [PATCH][GIT PULL][v3.3] x86: Test saved %rip in NMI todetermine nested NMI

From: Steven Rostedt
Date: Sun Feb 19 2012 - 15:35:15 EST


On Sun, 2012-02-19 at 05:46 -0800, hpanvin@xxxxxxxxx wrote:
> Vsyscall page, not vdso...
>

Peter,

My original patch was to check the %cs register against __KERNEL_CS, but
IIRC, you said that userspace can change that register to anything it
wanted before doing a long jump or something. Is this true for x86_64 as
well? I guess it would be because x86_64 can support 32bit apps.

Anyway, I'll add a check that makes sure that the RIP is less than the
FIXADDR sections as well.

-- Steve


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