tree e2557e7b679eeee6d361b08812f9b10b96a301ec
parent 0136611c62e8650e354b95c76dff6d2ce6030eff
author Eric W. Biederman <ebiederm@xmission.com> 1159260758 +0200
committer Andi Kleen <andi@basil.nowhere.org> 1159260758 +0200

[PATCH] Reload CS when startup_64 is used.

In long mode the %cs is largely a relic.  However there are a few cases
like iret where it matters that we have a valid value.  Without this
patch it is possible to enter the kernel in startup_64 without setting
%cs to a valid value.  With this patch we don't care what %cs value
we enter the kernel with, so long as the cs shadow register indicates
it is a privileged code segment.

Thanks to Magnus Damm for finding this problem and posting the
first workable patch.  I have moved the jump to set %cs down a
few instructions so we don't need to take an extra jump.  Which
keeps the code simpler.

Signed-of-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>