double fault -> PAGE_KERNEL flagged memory

[Roland McGrath]

> But less so for other stuff.  I'll get the translator to switch to
> kmalloc as much as possible.

More or less only for things larger than a page, I think.

> > In the current Linus kernel, the i386 do_page_fault routine is
> > marked with __kprobes.  [...]
> 
> Maybe that decoration was missing from some transitively called function?

Could be, though there aren't any actual calls in the vmalloc_fault path, I
think.  The annotations (and the protections) don't exist at all in RHEL4
kernels, looking at it now.  (I was looking at the current upstream kernel
earlier.)