BUG: crash in __tlb_remove_page_size with STRICT_KERNEL_RWX on BOOK3S_32

[Serge Belyshev]

Hi! Commit 63b2bc61956 aka "powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX"
caused my old powerbook to crash under I/O.  After "dd if=/dev/hda of=/null"
the crash happens in seconds.  Reverting the commit helps, as well as
disabling STRICT_KERNEL_RWX.  Unfortunately, I was unable to capture the oops
via the usb serial console, as it stuck right after the first "BUG: Unable to
handle kernel data access at 0xe0c29000" message. Oops screenshot:
http://aargh.no-ip.org/oops.jpg