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References: <20200413020538.31322-1-masahiroy@kernel.org>
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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 13 Apr 2020 11:20:02 -0700
Message-ID: <CAKwvOdk3-o2-Zom-Ejt0HP3vn+QWBYkJo+kPNzamofc-eH-FjA@mail.gmail.com>
Subject: Re: [PATCH] arc: remove #ifndef CONFIG_AS_CFI_SIGNAL_FRAME
To:     Masahiro Yamada <masahiroy@kernel.org>
Cc:     Vineet Gupta <vgupta@synopsys.com>,
        linux-snps-arc@lists.infradead.org,
        Allison Randal <allison@lohutok.net>,
        Arnd Bergmann <arnd@arndb.de>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        Kees Cook <keescook@chromium.org>,
        Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
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On Sun, Apr 12, 2020 at 7:06 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> CONFIG_AS_CFI_SIGNAL_FRAME is never defined for ARC.
>
> Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Thanks for the patch.  I worry there may be many preprocessor checks
in the kernel that are always true/false.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>


> ---
>
>  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);
> --
> 2.25.1
>


-- 
Thanks,
~Nick Desaulniers