Re: [PATCH -tip 1/2] Kconfig: Bump required compiler version of KASAN and UBSAN

[Marco Elver]

On Wed, 3 Jun 2020 at 15:35, 'Andrey Konovalov' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Jun 2, 2020 at 8:44 PM Marco Elver <elver@xxxxxxxxxx> wrote:
> >
> > Adds config variable CC_HAS_WORKING_NOSANITIZE, which will be true if we
> > have a compiler that does not fail builds due to no_sanitize functions.
> > This does not yet mean they work as intended, but for automated
> > build-tests, this is the minimum requirement.
> >
> > For example, we require that __always_inline functions used from
> > no_sanitize functions do not generate instrumentation. On GCC <= 7 this
> > fails to build entirely, therefore we make the minimum version GCC 8.
> >
> > For KCSAN this is a non-functional change, however, we should add it in
> > case this variable changes in future.
> >
> > Link: https://lkml.kernel.org/r/20200602175859.GC2604@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
>
> Acked-by:  Andrey Konovalov <andreyknvl@xxxxxxxxxx>

I've sent a v2 of this, which limits the compiler-bump to KASAN only.
It appears no_sanitize_undefined (for UBSAN) is not broken GCC <= 7,
and in general the no_sanitize attributes seem to behave differently
from sanitizer to sanitizer as we discovered for UBSAN.

https://lkml.kernel.org/r/20200604055811.247298-1-elver@xxxxxxxxxx