Re: [linux-next:master 8173/8441] include/linux/list.h:53:13: warning: '__preserve_most__' calling convention is not supported for this target

[Marco Elver <elver@google.com>]

On Wed, 9 Aug 2023 at 17:53, Nick Desaulniers <ndesaulniers@google.com> wrote:
>
> On Wed, Aug 9, 2023 at 4:15 AM Marco Elver <elver@google.com> wrote:
> >
> > On Wed, Aug 09, 2023 at 06:27PM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   21ef7b1e17d039053edaeaf41142423810572741
> > > commit: fee8feb67f0b2954eb7a2a259122e43a15cf3a52 [8173/8441] list_debug: introduce CONFIG_DEBUG_LIST_MINIMAL
> > > config: hexagon-randconfig-r041-20230808 (https://download.01.org/0day-ci/archive/20230809/202308091820.0dPY7D6f-lkp@intel.com/config)
> > > compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
> > > reproduce: (https://download.01.org/0day-ci/archive/20230809/202308091820.0dPY7D6f-lkp@intel.com/reproduce)
> > >
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202308091820.0dPY7D6f-lkp@intel.com/
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > >    In file included from arch/hexagon/kernel/asm-offsets.c:12:
> > >    In file included from include/linux/compat.h:14:
> > >    In file included from include/linux/sem.h:5:
> > >    In file included from include/uapi/linux/sem.h:5:
> > >    In file included from include/linux/ipc.h:5:
> > >    In file included from include/linux/spinlock.h:56:
> > >    In file included from include/linux/preempt.h:12:
> > > >> include/linux/list.h:53:13: warning: '__preserve_most__' calling convention is not supported for this target [-Wignored-attributes]
> > >    extern bool __list_valid_slowpath __list_add_valid_or_report(struct list_head *new,
> > >                ^
> > >    include/linux/list.h:44:39: note: expanded from macro '__list_valid_slowpath'
> > >    # define __list_valid_slowpath __cold __preserve_most
> > >                                          ^
> > >    include/linux/compiler_types.h:132:49: note: expanded from macro '__preserve_most'
> > >    # define __preserve_most notrace __attribute__((__preserve_most__))
> >
> > To silence this warning, we can just guard it based on known-supported architectures:
>
> As a band-aid, sure.
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Long term, perhaps we can fix in clang what __has_attribute evaluates
> to for this attribute depending on the target.  Filed:
> https://github.com/ClangBuiltLinux/linux/issues/1908
> ^ Consider adding a comment linking to that in the sources.

I will fold it into patch 1/3 of the original series. May I apply your
Reviewed-by there?
I think there needs to be a v4, also because of some other change requests, too.

Andrew, please shout if you'd rather have them as fix patches.

Thanks!