On 10/1/2020 8:22 AM, Linus Walleij wrote:
> This is the 14th iteration of KASan for ARM/Aarch32.
> 
> I have added one patch in the beginning of the series to
> fix the issue when the DTB (often attached DTB) ends up
> in lowmem. It also amends ARM to copy the device tree
> instead of just unflattening it and using it from where
> it is.
> 
> This fixes my particular issue on the Qualcomm APQ8060
> and I hope it may also solve Florian's issue and what
> Ard has been seeing. If you inspect patch 1/6 you can
> see what has been going on for me. My hypothesis about
> what was going on was mostly right.
> 
> You are encouraged to test this patch set to find memory out
> of bounds bugs with ARM32 platforms and drivers.
> 
> There is a git branch you can pull in:
> https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=kasan

It does appear to be slight better, although all platforms that I have 
where memory starts at physical address 0 cannot boot, attached logs 
which are all more or less the same.

The physical memory map looks like this:

0..3GB -> DRAM
3GB..4GB -> Registers, Boot ROM, Boot SRAM
4GB..12GB -> DRAM extension

Do any of the platforms you use for testing have a similar memory map? 
Could you try to contrive a QEMU machine to have something similar in 
case that helps reproducing these failures?

Thanks

> 
> Abbott Liu (1):
>    ARM: Define the virtual space of KASan's shadow region
> 
> Andrey Ryabinin (3):
>    ARM: Disable KASan instrumentation for some code
>    ARM: Replace string mem* functions for KASan
>    ARM: Enable KASan for ARM
> 
> Linus Walleij (2):
>    ARM: Handle a device tree in lowmem
>    ARM: Initialize the mapping of KASan shadow memory
> 
>   Documentation/arm/memory.rst                  |   5 +
>   Documentation/dev-tools/kasan.rst             |   4 +-
>   .../features/debug/KASAN/arch-support.txt     |   2 +-
>   arch/arm/Kconfig                              |  10 +
>   arch/arm/boot/compressed/Makefile             |   1 +
>   arch/arm/boot/compressed/string.c             |  19 ++
>   arch/arm/include/asm/kasan.h                  |  32 ++
>   arch/arm/include/asm/kasan_def.h              |  81 +++++
>   arch/arm/include/asm/memory.h                 |   5 +
>   arch/arm/include/asm/pgalloc.h                |   8 +-
>   arch/arm/include/asm/prom.h                   |   5 +
>   arch/arm/include/asm/string.h                 |  21 ++
>   arch/arm/include/asm/thread_info.h            |   8 +
>   arch/arm/include/asm/uaccess-asm.h            |   2 +-
>   arch/arm/kernel/devtree.c                     |  14 +-
>   arch/arm/kernel/entry-armv.S                  |   3 +-
>   arch/arm/kernel/entry-common.S                |   9 +-
>   arch/arm/kernel/head-common.S                 |   7 +-
>   arch/arm/kernel/setup.c                       |  10 +-
>   arch/arm/kernel/unwind.c                      |   6 +-
>   arch/arm/lib/memcpy.S                         |   3 +
>   arch/arm/lib/memmove.S                        |   5 +-
>   arch/arm/lib/memset.S                         |   3 +
>   arch/arm/mm/Makefile                          |   5 +
>   arch/arm/mm/kasan_init.c                      | 286 ++++++++++++++++++
>   arch/arm/mm/mmu.c                             |  55 +++-
>   arch/arm/mm/pgd.c                             |  16 +-
>   arch/arm/vdso/Makefile                        |   2 +
>   28 files changed, 608 insertions(+), 19 deletions(-)
>   create mode 100644 arch/arm/include/asm/kasan.h
>   create mode 100644 arch/arm/include/asm/kasan_def.h
>   create mode 100644 arch/arm/mm/kasan_init.c
> 

-- 
Florian