[PATCH 0/2] fix sysenter for 32-on-64 processes

[Jeremy Fitzhardinge <jeremy@goop.org>]

Hi Ingo,

Here's a little two-part patch series which fixes 32-on-64 syscalls 
using sysenter.

The first is a difference in ordering in arch_setup(); the 64-bit code 
was calling early_init_cpu() way too late.  Moving it earlier, to the 
same place as the 32-bit code, works for me, but I wonder if it might 
cause problems with other configurations.  Certainly it makes logical 
sense that both architectures do the same cpu setup at the same place.

The other fix is an outright Xen-specific bug, which resulted in 
usermode registers being trashed as a result of an over-enthusiastic use 
of sysret.

Both patches are .27 material, but I expect the arch_setup() change 
needs to cooking before being comfortable with it.

Thanks,
    J