Re: [PATCH] lib/Kconfig.debug: disable FRAME_WARN for kasan and kcsan

[Hamza Mahfooz]

On 10/18/23 14:29, Geert Uytterhoeven wrote:
> Hi Hamza,
>
> On Wed, Oct 18, 2023 at 8:24 PM Hamza Mahfooz <hamza.mahfooz@xxxxxxx> wrote:
> > With every release of LLVM, both of these sanitizers eat up more and
> > more of the stack. So, set FRAME_WARN to 0 if either of them is enabled
> > for a given build.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
>
> Thanks for your patch!
>
> > --- a/lib/Kconfig.debug
> > +++ b/lib/Kconfig.debug
> > @@ -429,11 +429,10 @@ endif # DEBUG_INFO
> >   config FRAME_WARN
> >          int "Warn for stack frames larger than"
> >          range 0 8192
> > -       default 0 if KMSAN
> > +       default 0 if KASAN || KCSAN || KMSAN
>
> Are kernels with KASAN || KCSAN || KMSAN enabled supposed to be bootable?

They are all intended to be used for runtime debugging, so I'd imagine so.

> Stack overflows do cause crashes.

It is worth noting that FRAME_WARN has been disabled for KMSAN for quite
a while and as far as I can tell no one has complained.

> >          default 2048 if GCC_PLUGIN_LATENT_ENTROPY
> >          default 2048 if PARISC
> >          default 1536 if (!64BIT && XTENSA)
> > -       default 1280 if KASAN && !64BIT
> >          default 1024 if !64BIT
> >          default 2048 if 64BIT
> >          help
>
> Gr{oetje,eeting}s,
>
>                          Geert
--
Hamza