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: <202108141331.fMjjWaW2-lkp@intel.com> <CAMuHMdXUpk_dLhvcdgs1H6yLPrwXFJz_86dfXpm8PYxNq+DXrQ@mail.gmail.com>
In-Reply-To: <CAMuHMdXUpk_dLhvcdgs1H6yLPrwXFJz_86dfXpm8PYxNq+DXrQ@mail.gmail.com>
From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Wed, 25 Aug 2021 10:41:03 -0700
Message-ID: <CAKwvOd=HkZPN-0k=QYGx6y4q1ig7=8dQY3d_OU10Qp0N__tZcA@mail.gmail.com>
Subject: Re: arch/arm/boot/compressed/fdt_check_mem_start.c:62:10: warning: no
 previous prototype for function 'fdt_check_mem_start'
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     kernel test robot <lkp@intel.com>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        kbuild-all@lists.01.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Ard Biesheuvel <ardb@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Sat, Aug 21, 2021 at 1:46 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Dear Robot,
>
> On Sat, Aug 14, 2021 at 7:43 AM kernel test robot <lkp@intel.com> wrote:
> > FYI, the error/warning still remains.
>
> Yes, and that's fine, as this function is never called from C code,
> only from assembler.

That's fine, then you can add a prototype to the .c source file.  See
what we do for stpcpy: 1e1b6d63d6340.

>
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   dfa377c35d70c31139b1274ec49f87d380996c42
> > commit: 0673cb38951215060d7993b43ad3c45cd413c2c3 ARM: 9045/1: uncompress: Validate start of physical memory against passed DTB
> > date:   6 months ago
> > config: arm-randconfig-r003-20210814 (attached as .config)
> > compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 62df4df41c939205b2dc0a2a3bfb75b8c1ed74fa)
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0673cb38951215060d7993b43ad3c45cd413c2c3
> >         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout 0673cb38951215060d7993b43ad3c45cd413c2c3
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> arch/arm/boot/compressed/fdt_check_mem_start.c:62:10: warning: no previous prototype for function 'fdt_check_mem_start' [-Wmissing-prototypes]
> >    uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
> >             ^
> >    arch/arm/boot/compressed/fdt_check_mem_start.c:62:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> >    uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
> >    ^
> >    static
> >    1 warning generated.
> >
> >
> > vim +/fdt_check_mem_start +62 arch/arm/boot/compressed/fdt_check_mem_start.c
> >
> >     46
> >     47  /*
> >     48   * Check the start of physical memory
> >     49   *
> >     50   * Traditionally, the start address of physical memory is obtained by masking
> >     51   * the program counter.  However, this does require that this address is a
> >     52   * multiple of 128 MiB, precluding booting Linux on platforms where this
> >     53   * requirement is not fulfilled.
> >     54   * Hence validate the calculated address against the memory information in the
> >     55   * DTB, and, if out-of-range, replace it by the real start address.
> >     56   * To preserve backwards compatibility (systems reserving a block of memory
> >     57   * at the start of physical memory, kdump, ...), the traditional method is
> >     58   * always used if it yields a valid address.
> >     59   *
> >     60   * Return value: start address of physical memory to use
> >     61   */
> >   > 62  uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
> >
> > ---
> > 0-DAY CI Kernel Test Service, Intel Corporation
> > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.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
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/CAMuHMdXUpk_dLhvcdgs1H6yLPrwXFJz_86dfXpm8PYxNq%2BDXrQ%40mail.gmail.com.


-- 
Thanks,
~Nick Desaulniers