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From:   Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Date:   Thu, 24 Mar 2022 11:42:01 +0900
Message-ID: <CAMZ6RqJ7B_Yqs0jE0nmkX2Z=xh7Jj6J_ihP=ybLVn5VXY+5kTA@mail.gmail.com>
Subject: Re: [PATCH] x86: bug.h: merge annotate_reachable into _BUG_FLAGS for __WARN_FLAGS
To:     Nick Desaulniers <ndesaulniers@google.com>
Cc:     Charlemagne Lasse <charlemagnelasse@gmail.com>,
        jpoimboe@redhat.com, adobriyan@gmail.com, bp@alien8.de,
        dave.hansen@linux.intel.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org, linux-sparse@vger.kernel.org,
        llvm@lists.linux.dev, luc.vanoostenryck@gmail.com,
        mingo@redhat.com, nathan@kernel.org, peterz@infradead.org,
        tglx@linutronix.de, x86@kernel.org, Sasha Levin <sashal@kernel.org>
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On Thu. 24 Mar 2022 at 04:41, Nick Desaulniers <ndesaulniers@google.com> wrote:
> On Wed, Mar 23, 2022 at 12:30 PM Charlemagne Lasse
> <charlemagnelasse@gmail.com> 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@wanadoo.fr/
> 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@wanadoo.fr/

Yours sincerely,
Vincent Mailhol