[Linux-kernel-mentees] [PATCH] checkpatch: Fix SPDX license check for scripts

[Lukas Bulwahn]

On Mon, 13 Jul 2020, Mrinal Pandey wrote:

> In all the scripts, the SPDX license should be on the second line,
> the first line being the "sh-bang", but checkpatch issues a warning
> "Misplaced SPDX-License-Identifier tag - use line 1 instead" for the
> scripts that have SPDX license in the second line.
> 
> However, this warning is not issued when checkpatch is run on a file using
> `-f` option. The case for files has been handled gracefully by changing
> `$checklicenseline` to `2` but a corresponding check when running checkpatch
> on a commit hash is missing.
> 
> I noticed this false positive while running checkpatch on the set of
> commits from v5.7 to v5.8-rc1 of the kernel on the commits which modified
> a script file.
> 
> This check is missing in checkpatch since commit a8da38a9cf0e
> ("checkpatch: add test for SPDX-License-Identifier on wrong line #")
> when the corresponding rule was first commited.
> 
> Fix this by setting `$checklicenseline` to `2` when the diff content that
> is being checked originates from a script, thus, informing checkpatch that
> the SPDX license should be on the second line.
> 
> Signed-off-by: Mrinal Pandey <mrinalmni at gmail.com>
> ---
>  scripts/checkpatch.pl | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 4c820607540b..bbffd0c4449d 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3218,6 +3218,9 @@ sub process {
>  		next if ($realfile !~ /\.(h|c|s|S|sh|dtsi|dts)$/);
>  
>  # check for using SPDX-License-Identifier on the wrong line number
> +		if ($realfile =~ /^scripts/) {
> +                    $checklicenseline = 2;
> +	        }

I think this is somehow wrong here. The check for checklicenseline = 2 
looks very different above.

Why does -f work and using a patch file not work?

Lukas


>  		if ($realline != $checklicenseline &&
>  		    $rawline =~ /\bSPDX-License-Identifier:/ &&
>  		    substr($line, @-, @+ - @-) eq "$;" x (@+ - @-)) {
> -- 
> 2.25.1
> 
>