Re: [PATCH v6 1/1] x86_64: fix KASan shadow region page tables

From: Ingo Molnar
Date: Fri Jun 19 2015 - 10:01:14 EST



* Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx> wrote:

> On 06/19/2015 03:06 PM, Borislav Petkov wrote:
> > On Fri, Jun 19, 2015 at 02:49:19PM +0300, Andrey Ryabinin wrote:
> >> I guess that AMD cpus is more strict (unlike Intel) about violation
> >> of reserved/unused bits in page table entries. Please, try with this
> >> patch.
> >
> > With that the guest boots.
> >
>
> Great! Thanks.
>
> > How do I check whether KASan actually works? I don't see any note in
> > dmesg or some file named "*kasan*" in sysfs...
> >
>
> kasan will print report in dmesg whant it will find anything.

It should also printk a one line message at bootup, so that people can be sure
they are running a KASan-enabled kernel.

> To make sure that it works you could try to load testing module (CONFIG_TEST_KASAN).
> This module has bugs that kasan should catch.

That's a way too obscure mechanism just to determine whether the right kernel
config was booted. Please add a printk(), ok?

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at http://www.tux.org/lkml/