On Mon, 2015-08-17 at 12:06 +0530, Aneesh Kumar K.V wrote:

Hi,

This patchset implements kernel address sanitizer for ppc64.
Since ppc64 virtual address range is divided into different regions,
we can't have one contigous area for the kasan shadow range. Hence
we don't support the INLINE kasan instrumentation. With Outline
instrumentation, we override the shadow_to_mem and mem_to_shadow
callbacks, so that we map only the kernel linear range (ie,
region with ID 0xc). For region with ID 0xd and 0xf (vmalloc
and vmemmap ) we return the address of the zero page. This
works because kasan doesn't track both vmemmap and vmalloc address.

So bear with me, I don't know anything about KASAN, but if you want a
shadow, can't you just add a fixed offset to the address and thus
effectively shadow each region independently while keeping the inline
helpers ?

Cheers,
Ben.

Aneesh Kumar K.V (8):
  powerpc/mm: Add virt_to_pfn and use this instead of opencoding
  kasan: MODULE_VADDR is not available on all archs
  kasan: Rename kasan_enabled to kasan_report_enabled
  kasan: Don't use kasan shadow pointer in generic functions
  kasan: Enable arch to hook into kasan callbacks.
  kasan: Allow arch to overrride kasan shadow offsets
  powerpc/mm: kasan: Add kasan support for ppc64
  powerpc: Disable kasan for kernel/ and mm/ directory

-aneesh

 arch/powerpc/include/asm/kasan.h         | 74 
++++++++++++++++++++++++++++++++
 arch/powerpc/include/asm/page.h          |  5 ++-
 arch/powerpc/include/asm/pgtable-ppc64.h |  1 +
 arch/powerpc/include/asm/ppc_asm.h       | 10 +++++
 arch/powerpc/include/asm/string.h        | 13 ++++++
 arch/powerpc/kernel/Makefile             |  2 +
 arch/powerpc/kernel/prom_init_check.sh   |  2 +-
 arch/powerpc/kernel/setup_64.c           |  3 ++
 arch/powerpc/lib/mem_64.S                |  6 ++-
 arch/powerpc/lib/memcpy_64.S             |  3 +-
 arch/powerpc/lib/ppc_ksyms.c             | 10 +++++
 arch/powerpc/mm/Makefile                 |  4 ++
 arch/powerpc/mm/kasan_init.c             | 44 +++++++++++++++++++
 arch/powerpc/mm/slb_low.S                |  4 ++
 arch/powerpc/platforms/Kconfig.cputype   |  1 +
 include/linux/kasan.h                    |  3 ++
 mm/kasan/kasan.c                         |  9 ++++
 mm/kasan/kasan.h                         | 20 ++++++++-
 mm/kasan/report.c                        | 19 ++++----
 19 files changed, 216 insertions(+), 17 deletions(-)
 create mode 100644 arch/powerpc/include/asm/kasan.h
 create mode 100644 arch/powerpc/mm/kasan_init.c