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

[Daniel Axtens]

Christophe Leroy <christophe.leroy at c-s.fr> writes:

> Le 07/08/2019 à 01:38, Daniel Axtens a écrit :
>> 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
>
> Would be good to send that one to the powerpc list as well.
>

Done for v4.

>> 
>> 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.
>
> This is rather independant and also applies to PPC32. Could it be a 
> separate series that Michael could apply earlier ?
>

Will do this and address your feedback on the rest of the series later.

Regards,
Daniel

> Christophe
>
>> 
>>   - 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
>>