[PATCH 0/4] powerpc: KASAN for 64-bit Book3S on Radix

[Daniel Axtens]

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

It builds on top Christophe's work on 32bit. It also builds on my
generic KASAN_VMALLOC series, available at:
https://patchwork.kernel.org/project/linux-mm/list/?series=153209

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

Notable changes from the RFC:

 - I've dropped Book3E 64-bit for now.

 - Now instead of hacking into the KASAN core to disable module
   allocations, we use KASAN_VMALLOC.

 - More testing, including on real hardware. This revealed that
   discontiguous memory is a bit of a headache, at the moment we
   must disable memory not contiguous from 0. 
   
 - Update to deal with kasan bitops instrumentation that landed
   between RFC and now.

 - Documentation!

 - Various cleanups and tweaks.

I am getting occasional problems on boot of real hardware where it
seems vmalloc space mappings don't get installed in time. (We get a
BUG that memory is not accessible, but by the time we hit xmon the
memory then is accessible!) It happens once every few boots. I haven't
yet been able to figure out what is happening and why. I'm going to
look in to it, but I think the patches are in good enough shape to
review while I work on it.

Regards,
Daniel

Daniel Axtens (4):
  kasan: allow arches to provide their own early shadow setup
  kasan: support instrumented bitops with generic non-atomic bitops
  powerpc: support KASAN instrumentation of bitops
  powerpc: Book3S 64-bit "heavyweight" KASAN support

 Documentation/dev-tools/kasan.rst            |   7 +-
 Documentation/powerpc/kasan.txt              | 111 ++++++++++++++
 arch/powerpc/Kconfig                         |   4 +
 arch/powerpc/Kconfig.debug                   |  21 +++
 arch/powerpc/Makefile                        |   7 +
 arch/powerpc/include/asm/bitops.h            |  25 ++--
 arch/powerpc/include/asm/book3s/64/radix.h   |   5 +
 arch/powerpc/include/asm/kasan.h             |  35 ++++-
 arch/powerpc/kernel/process.c                |   8 ++
 arch/powerpc/kernel/prom.c                   |  57 +++++++-
 arch/powerpc/mm/kasan/Makefile               |   1 +
 arch/powerpc/mm/kasan/kasan_init_book3s_64.c |  76 ++++++++++
 include/asm-generic/bitops-instrumented.h    | 144 ++++++++++---------
 include/linux/kasan.h                        |   2 +
 lib/Kconfig.kasan                            |   3 +
 mm/kasan/init.c                              |  10 ++
 16 files changed, 431 insertions(+), 85 deletions(-)
 create mode 100644 Documentation/powerpc/kasan.txt
 create mode 100644 arch/powerpc/mm/kasan/kasan_init_book3s_64.c

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2.20.1