Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210915035227.630204-1-linux@roeck-us.net> <20210915035227.630204-2-linux@roeck-us.net>
In-Reply-To: <20210915035227.630204-2-linux@roeck-us.net>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 15 Sep 2021 09:07:47 +0200
Message-ID: <CAMuHMdWiAc_8Z5wK07c5Fi3Zf72RpPzqv32QHC=iYtBQpi=3dg@mail.gmail.com>
Subject: Re: [PATCH v2 1/4] compiler.h: Introduce absolute_pointer macro
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Richard Henderson <rth@twiddle.net>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        Matt Turner <mattst88@gmail.com>,
        "James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
        Helge Deller <deller@gmx.de>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        alpha <linux-alpha@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Parisc List <linux-parisc@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>, linux-sparse@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Sep 15, 2021 at 5:52 AM Guenter Roeck <linux@roeck-us.net> wrote:
> absolute_pointer() disassociates a pointer from its originating symbol
> type and context. Use it to prevent compiler warnings/errors such as
>
> drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
> ./arch/m68k/include/asm/string.h:72:25: error:
>         '__builtin_memcpy' reading 6 bytes from a region of size 0
>                 [-Werror=stringop-overread]
>
> Such warnings may be reported by gcc 11.x for string and memory operations
> on fixed addresses.
>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds