Re: [PATCH -tip 2/2] compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr

[Marco Elver]

On Tue, 2 Jun 2020 at 20:49, 'Nick Desaulniers' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Jun 2, 2020 at 11:44 AM 'Marco Elver' via Clang Built Linux
> <clang-built-linux@xxxxxxxxxxxxxxxx> wrote:
> >
> > Adds the portable definitions for __no_sanitize_address, and
> > __no_sanitize_undefined, and subsequently changes noinstr to use the
> > attributes to disable instrumentation via KASAN or UBSAN.
> >
> > Link: https://lore.kernel.org/lkml/000000000000d2474c05a6c938fe@xxxxxxxxxx/
> > Reported-by: syzbot+dc1fa714cb070b184db5@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
>
> Currently most of our compiler attribute detection is done in
> include/linux/compiler_attributes.h; I think this should be handled
> there. +Miguel Ojeda

GCC and Clang define these very differently, and the way to query for
them is different too. All we want is a portable __no_sanitize, and
compiler-{gcc,clang}.h is the right place for that. Similar to why we
define the other __no_sanitize above the places they were added.

Thanks,
-- Marco