Re: [PATCH] x86: bug.h: merge annotate_reachable into _BUG_FLAGS for __WARN_FLAGS

[Vincent MAILHOL]

On Thu. 24 Mar 2022 at 04:41, Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:
> On Wed, Mar 23, 2022 at 12:30 PM Charlemagne Lasse
> <charlemagnelasse@xxxxxxxxx> wrote:
> >
> > > @@ -75,9 +77,9 @@ do {                                \
> > >   */
> > >  #define __WARN_FLAGS(flags)                    \
> > >  do {                                \
> > > +    __auto_type f = BUGFLAG_WARNING|(flags);        \
> > >      instrumentation_begin();                \
> > > -    _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags));        \
> > > -    annotate_reachable();                    \
> > > +    _BUG_FLAGS(ASM_UD2, f, ASM_REACHABLE);            \
> > >      instrumentation_end();                    \
> > >  } while (0)
> >
> > This causes following sparse warning on x86:
> >
> > make allnoconfig && touch init/version.c && make CHECK="sparse
> > -Wshadow"  C=1 init/version.o
> > #
> > # No change to .config
> > #
> >  CALL    scripts/checksyscalls.sh
> >  CALL    scripts/atomic/check-atomics.sh
> >  CHK     include/generated/compile.h
> >  CC      init/version.o
> >  CHECK   init/version.c
> > init/version.c: note: in included file (through
> > include/linux/rculist.h, include/linux/pid.h, include/linux/sched.h,
> > include/linux/utsname.h):
> > ./include/linux/rcupdate.h:1007:9: warning: symbol 'f' shadows an earlier one
> > ./include/linux/rcupdate.h:1001:47: originally declared here
>
> Thanks for the report. There was already a fix sent for this:
> https://lore.kernel.org/lkml/20220317065743.8467-1-mailhol.vincent@xxxxxxxxxx/
> but it doesn't mention that sparse is warning about this, too.
>
> I think if Vincent sent a v3 that mentioned that sparse is warning
> about this, too, and cc'ed you, you could then supply
> signed-off/tested-by tags (or just do so on v2, though it doesn't
> mention sparse), and maybe Josh would be so kind as to pick that up?

Thank Nick, I did as you suggested. Here is the v3:
https://lore.kernel.org/all/20220324023742.106546-1-mailhol.vincent@xxxxxxxxxx/

Yours sincerely,
Vincent Mailhol