Re: [PATCH v15 13/25] x86/reboot: Add ljmp instructions to stacktool whitelist

[Josh Poimboeuf]

On Tue, Jan 19, 2016 at 09:50:31PM -0800, H. Peter Anvin wrote:
> 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...

Ah, I completely missed the fact that they're ASCII.  And it spells
"xen" of course :-)

-- 
Josh