linux-kernel - Re: [PATCH] lib/lz4: remove the exporting of LZ4HC

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Message-ID: <CAK7LNAQkQBM1cbcCtYDPtcVrXmvd4j8C5c5Va4qwnJ_KXrAZ0g@mail.gmail.com>
Date:   Tue, 10 Sep 2019 21:16:22 +0900
From:   Masahiro Yamada <yamada.masahiro@...ionext.com>
To:     Denis Efremov <efremov@...ux.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Sven Schmidt <4sschmid@...ormatik.uni-hamburg.de>,
        Arnd Bergmann <arnd@...db.de>,
        Bongkyu Kim <bongkyu.kim@....com>,
        Rui Salvaterra <rsalvaterra@...il.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S . Miller" <davem@...emloft.net>,
        Anton Vorontsov <anton@...msg.org>,
        Colin Cross <ccross@...roid.com>,
        Kees Cook <keescook@...omium.org>,
        Tony Luck <tony.luck@...el.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] lib/lz4: remove the exporting of LZ4HC_setExternalDict

On Tue, Sep 10, 2019 at 9:13 PM Denis Efremov <efremov@...ux.com> wrote:
>
> +Cc: Andrew Morton <akpm@...ux-foundation.org>,
>      Masahiro Yamada <yamada.masahiro@...ionext.com>
>
> Hi,
>
> On 7/8/19 6:15 PM, Denis Efremov wrote:
> > The function LZ4HC_setExternalDict is declared static and marked
> > EXPORT_SYMBOL, which is at best an odd combination. Because the function
> > is not used outside of the lib/lz4/lz4hc_compress.c file it is defined in,
> > this commit removes the EXPORT_SYMBOL() marking.
> >
> > Signed-off-by: Denis Efremov <efremov@...ux.com>

Reviewed-by: Masahiro Yamada <yamada.masahiro@...ionext.com>


> > ---
> >  lib/lz4/lz4hc_compress.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/lib/lz4/lz4hc_compress.c b/lib/lz4/lz4hc_compress.c
> > index 176f03b83e56..1b61d874e337 100644
> > --- a/lib/lz4/lz4hc_compress.c
> > +++ b/lib/lz4/lz4hc_compress.c
> > @@ -663,7 +663,6 @@ static void LZ4HC_setExternalDict(
> >       /* match referencing will resume from there */
> >       ctxPtr->nextToUpdate = ctxPtr->dictLimit;
> >  }
> > -EXPORT_SYMBOL(LZ4HC_setExternalDict);
> >
> >  static int LZ4_compressHC_continue_generic(
> >       LZ4_streamHC_t *LZ4_streamHCPtr,
> >
>
> Andrew, could you please look at this patch and accept it if everybody agrees?
> static LZ4HC_setExternalDict will trigger a warning after this check
> will be in tree https://lkml.org/lkml/2019/7/14/118
>
> There is also a different fix by Arnd Bergmann with making this function non-static:
> https://lkml.org/lkml/2019/9/6/669
>
> But since there is no uses of this EXPORT_SYMBOL in kernel and LZ4HC_setExternalDict
> is indeed static in the original library https://github.com/lz4/lz4/blob/dev/lib/lz4hc.c#L1054
> we came to the conclusion that it will be better to simply unexport the symbol.
>
> Thanks,
> Denis



-- 
Best Regards
Masahiro Yamada