Re: [PATCH] [PATCH v2] AARCH64: Add gcc Shadow Call Stack support

[Dan Li]

On 2/28/22 14:35, Nick Desaulniers wrote:
> On Sun, Feb 27, 2022 at 11:37 PM Dan Li <ashimida@xxxxxxxxxxxxxxxxx> wrote:
> > > > +#ifdef CONFIG_SHADOW_CALL_STACK
> > > > +#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
> > > > +#endif
> > >
> > > Since both compilers have it, and I guess the `#ifdef` condition would
> > > work for both, could this be moved into `compiler_types.h` where the
> > > empty `__noscs` definition is, and remove the one from
> > > `compiler-clang.h`?
> > In the clang documentation I see __has_feature(shadow_call_stack) is
> > used to check if -fsanitize=shadow-call-stack is enabled, so I think
> > maybe it's fine to use "#ifdef CONFIG_SHADOW_CALL_STACK"
> > instead of "#if __has_attribute(__no_sanitize_address__)" here, then
> > move it to `compiler_types.h`.
>
> Or simply add a #define for __noscs to include/linux/compiler-gcc.h
> with appropriate guard and leave the existing #ifndef in
> include/linux/compiler_types.h as is.  I'd prefer that when the
> compilers differ in terms of feature detection since it's as explicit
> as possible.

To make sure I understand correctly, that means I should keep
the current patch unchanged right?

Thanks,
Dan.