One interesting thing I've discovered is the gcc --version may make a
difference.
The kernel panic that occurred from Ingo's config, I was able to replicate
with GCC 4.2.0 (which is on our devel server). But this one complained
about not being able to handle the STACK-PROTECTOR option so I moved
everything to another machine that has 4.2.4, and now it seems that it
works fine. I'm still re-verifying that the source bits and config options are identical (it was a later git-remote update), and that in fact it is
the gcc --version, but that may be the conclusion. (My code also has some
patches submitted but not yet included in the tip/master tree. Curiously
just enabling some debug options changed the footprint of the panic.)
Are we allowed to insist on a specific level of GCC for compiling the
kernel?