Arm + KASAN + syzbot

[Dmitry Vyukov]

On Tue, Jan 19, 2021 at 11:28 AM Linus Walleij <linus.walleij at linaro.org> wrote:
>
> On Tue, Jan 19, 2021 at 11:23 AM Dmitry Vyukov <dvyukov at google.com> wrote:
> > On Tue, Jan 19, 2021 at 11:17 AM Linus Walleij <linus.walleij at linaro.org> wrote:
> > > > > You could also try other QEMU machine (I don't know many of them, some
> > > > > time ago I was using exynos defconfig on smdkc210, but without KASAN).
> > > >
> > > > vexpress-a15 seems to be the most widely used and more maintained. It
> > > > works without KASAN. Is there a reason to switch to something else?
> > >
> > > Vexpress A15 is as good as any.
> > >
> > > It can however be compiled in two different ways depending on whether
> > > you use LPAE or not, and the defconfig does not use LPAE.
> > > By setting CONFIG_ARM_LPAE you more or less activate a totally
> > > different MMU on the same machine, and those are the two
> > > MMUs used by ARM32 systems, so I would test these two.
> > >
> > > The other interesting Qemu target that is and was used a lot is
> > > Versatile, versatile_defconfig. This is an older ARMv5 (ARM926EJ-S)
> > > CPU core with less memory, but the MMU should be behaving the same
> > > as vanilla Vexpress.
> >
> > That's interesting. If we have more than 1 instance in future we could
> > vary different aspects between them to get more combined coverage.
> > E.g. one could use ARM_LPAE=y while another ARM_LPAE=n.
> >
> > But let's start with 1 instance running first :)
>
> Hm I noticed that I was running in LPAE mode by default on Vexpress
> so I try non-LPAE now. Let's see what happens...

Good point. I've tried to enable CONFIG_ARM_LPAE=y in my config with
KASAN, and it did not help. No output after 8 minutes.