[PATCH v6 0/4] KASAN for powerpc64 radix

[Daniel Axtens <dja@axtens.net>]

Building on the work of Christophe, Aneesh and Balbir, I've ported
KASAN to 64-bit Book3S kernels running on the Radix MMU.

This provides full inline instrumentation on radix, but does require
that you be able to specify the amount of physically contiguous memory
on the system at compile time. More details in patch 4.

v6: Rebase on the latest changes in powerpc/merge. Minor tweaks
      to the documentation. Small tweaks to the header to work
      with the kasan_late_init() function that Christophe added
      for 32-bit kasan-vmalloc support.
    No functional change.

v5: ptdump support. More cleanups, tweaks and fixes, thanks
    Christophe. Details in patch 4.

    I have seen another stack walk splat, but I don't think it's
    related to the patch set, I think there's a bug somewhere else,
    probably in stack frame manipulation in the kernel or (more
    unlikely) in the compiler.

v4: More cleanups, split renaming out, clarify bits and bobs.
    Drop the stack walk disablement, that isn't needed. No other
    functional change.

v3: Reduce the overly ambitious scope of the MAX_PTRS change.
    Document more things, including around why some of the
    restrictions apply.
    Clean up the code more, thanks Christophe.

v2: The big change is the introduction of tree-wide(ish)
    MAX_PTRS_PER_{PTE,PMD,PUD} macros in preference to the previous
    approach, which was for the arch to override the page table array
    definitions with their own. (And I squashed the annoying
    intermittent crash!)

    Apart from that there's just a lot of cleanup. Christophe, I've
    addressed most of what you asked for and I will reply to your v1
    emails to clarify what remains unchanged.