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Subject: Re: [PATCH v15 13/25] x86/reboot: Add ljmp instructions to stacktool
 whitelist
To: Josh Poimboeuf <jpoimboe@redhat.com>, Ingo Molnar <mingo@kernel.org>
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Cc: Borislav Petkov <bp@alien8.de>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, x86@kernel.org,
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        Namhyung Kim <namhyung@gmail.com>,
        Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
        Chris J Arges <chris.j.arges@canonical.com>,
        Andrew Morton <akpm@linux-foundation.org>, Jiri Slaby <jslaby@suse.cz>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
From: "H. Peter Anvin" <hpa@zytor.com>
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Date: Tue, 19 Jan 2016 21:50:31 -0800
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On 01/19/16 21:42, Josh Poimboeuf wrote:
>>>>
>>>>   Apparently(?) xen treats the ud2 special when it's followed by "78 65
>>>>   6e".  This is confusing for stacktool because ud2 is normally a dead
>>>>   end, and it thinks the instructions after it will never run.
>>>>   

Cute.  UD2 followed by three ASCII characters.  I guess that becomes
really fun when using UD2 + a string for error reporting.  Of course, no
software does that...

	-hpa