Re: [PATCH] lib/lz4: remove the exporting of LZ4HC_setExternalDict

[Denis Efremov]

+Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>,
     Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

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@xxxxxxxxx>
> ---
>  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