Arm + KASAN + syzbot

[Linus Walleij]

On Tue, Jan 19, 2021 at 9:37 AM Krzysztof Kozlowski <krzk at kernel.org> wrote:

> No clue but I just tried KASAN on my ARMv7 Exynos5422 board (real
> hardware) and it works (although kernel log appeared with a bigger
> delay):
>
> [    0.000000] Booting Linux on physical CPU 0x100
> [    0.000000] Linux version
> 5.11.0-rc3-next-20210115-00001-g77140600eeec (kozik at kozik-lap)
> (arm-linux-gnueabi-gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, GNU ld
> (GNU Binutils for Ubuntu) 2.34) #144 SMP PREEMPT Tue Jan 19 09:23:24
> CET 2021
> [    0.000000] CPU: ARMv7 Processor [410fc073] revision 3 (ARMv7), cr=10c5387d
> ...
> [    0.000000] kasan: Truncating shadow for memory block at
> 0x40000000-0xbea00000 to lowmem region at 0x70000000
> [    0.000000] kasan: Mapping kernel virtual memory block:
> c0000000-f0000000 at shadow: b7000000-bd000000
> [    0.000000] kasan: Mapping kernel virtual memory block:
> bf000000-c0000000 at shadow: b6e00000-b7000000
> [    0.000000] kasan: Kernel address sanitizer initialized

This looks right, I'm happy that it works on Exynos! :)

I recently summarized the stuff we had to fix up for getting
KASAN to work on ARM in a talkative blog post:
https://people.kernel.org/linusw/kasan-for-arm32-decompression-stop

Yours,
Linus Walleij