From: Andi Kleen <ak@suse.de>

There is some assembly code in setup.c which doesn't explicitly set its
section.  It comes after a C function which is marked __init.  The compiler
does not reset the section after such C functions.  The assembly code is
going into .text.init.

That's the wrong section.  We get oopses modprobing sctp and, with Manfred's
unmap-free-pages debug patch we get oopses modprobing e100.ko.  In
apply_alternatives().