[RFC][PATCH] x86: don't destroy %rbp on kernel-mode faults

[Vegard Nossum]

Hi,

The RFC part of this patch is: Does anybody see why touching %rcx would
be bad? It certainly looks like %ecx is free. This fixes the stacktrace
problem I was seeing, and Pekka tested a bootup to userspace. (Pekka also
did half of the debugging. When will git allow multiple authors for a
patch? :-))


Vegard