Re: linux/master crashes on boot with KASAN=y

From: Thomas Gleixner
Date: Wed Dec 27 2017 - 13:10:04 EST


On Tue, 26 Dec 2017, Andrey Ryabinin wrote:
> On 12/24/2017 04:48 AM, Andy Lutomirski wrote:
> > Could this be #define MODULES_END KASAN_ROUND_DOWN(__fix_to_virt(...)) instead?
> >
> Actually, we could simply set fixed MODULES_END, as it was before
> f06bdd4001c2 ("x86/mm: Adapt MODULES_END based on fixmap section size").
> AFAICS, the whole point of f06bdd4001c2 was to move MODULES_END down if
> NR_CPUS is big. But since 92a0f81d8957 ("x86/cpu_entry_area: Move it out
> of the fixmap") cpu_entry_area is not in fixmap anymore. So it should be
> fine to set fixed MODULES_END.
>
> The only concern I have is 4.14 stable, where 21506525f ("x86/kasan/64:
> Teach KASAN about the cpu_entry_area") was backported. Is 92a0f81d8957
> ("x86/cpu_entry_area: Move it out of the fixmap") also a candidate for
> stable?
>
> If so, fixed MODULES_END seems like a better choice.

Yes, it's on the way there.

Thanks,

tglx