[PATCH v7 0/4] KASAN for powerpc64 radix

Daniel Axtens
2020-02-13T00:48:00Z

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.

v7: Tweaks from Christophe, fix issues detected by snowpatch.

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.