Re: [PATCH] arc: remove #ifndef CONFIG_AS_CFI_SIGNAL_FRAME

From: Masahiro Yamada
Date: Mon Apr 13 2020 - 02:03:02 EST


On Mon, Apr 13, 2020 at 2:38 PM Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx> wrote:
>
> On 4/12/20 7:05 PM, Masahiro Yamada wrote:
> > CONFIG_AS_CFI_SIGNAL_FRAME is never defined for ARC.
> >
> > Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> Where, how ?


I was working on various cleanups of x86 CONFIG_AS_* macros.

https://lore.kernel.org/patchwork/patch/1214512/


I removed CONFIG_AS_CFI_SIGNAL_FRAME from x86.

Nick pointed out the same name macro used in ARC,
which is not defined anywhere.





> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > ---
> >
> > arch/arc/kernel/unwind.c | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
> > index 27ea64b1fa33..f87758a6851b 100644
> > --- a/arch/arc/kernel/unwind.c
> > +++ b/arch/arc/kernel/unwind.c
> > @@ -1178,11 +1178,9 @@ int arc_unwind(struct unwind_frame_info *frame)
> > #endif
> >
> > /* update frame */
> > -#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
> > if (frame->call_frame
> > && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
> > frame->call_frame = 0;
> > -#endif
> > cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
> > startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
> > endLoc = max_t(unsigned long, UNW_SP(frame), cfa);
>
> Actually there's more scope for cleanup here. The while signal frame stuff is not
> relevant here at all as this is only kernel stack frames. So all of
> frame->call_frame stuff is bogus at best.
>
> I once had an branch with ~15 patches to clean this all up. Let me go find it.


I am not familiar with ARC code.

So, I leave this up to you for further cleanups.

>
> Curious though about the CC list, is this patch part of a bigger series or some
> such. So many people from all over suddenly interested in ARC ;-)


Presumably, they touched this file in the past,
and scripts/get_maintainers.pl picked them up.


masahiro@oscar:~/ref/linux$ scripts/get_maintainer.pl -f
arch/arc/kernel/unwind.c
Vineet Gupta <vgupta@xxxxxxxxxxxx> (supporter:SYNOPSYS ARC
ARCHITECTURE,commit_signer:2/5=40%)
Kees Cook <keescook@xxxxxxxxxxxx> (commit_signer:2/5=40%)
"Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
(commit_signer:2/5=40%,authored:2/5=40%,added_lines:3/11=27%,removed_lines:2/14=14%)
Enrico Weigelt <info@xxxxxxxxx> (commit_signer:1/5=20%)
Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> (commit_signer:1/5=20%)
Thomas Gleixner <tglx@xxxxxxxxxxxxx>
(authored:1/5=20%,added_lines:1/11=9%,removed_lines:4/14=29%)
Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@xxxxxxxxx>
(authored:1/5=20%,added_lines:3/11=27%,removed_lines:3/14=21%)
Arnd Bergmann <arnd@xxxxxxxx>
(authored:1/5=20%,added_lines:4/11=36%,removed_lines:5/14=36%)
linux-snps-arc@xxxxxxxxxxxxxxxxxxx (open list:SYNOPSYS ARC ARCHITECTURE)
linux-kernel@xxxxxxxxxxxxxxx (open list)



> -Vineet



--
Best Regards
Masahiro Yamada