[Linux-kernel-mentees] [PATCH] checkpatch: add new warnings to author signoff checks.

[Dwaipayan Ray]

On Mon, Oct 5, 2020 at 3:27 PM Dwaipayan Ray <dwaipayanray1 at gmail.com> wrote:
>
> The author signed-off-by checks are currently very vague.
> Cases like same name or same address are not handled separately.
>
> For example, running checkpatch on commit be6577af0cef
> ("parisc: Add atomic64_set_release() define to avoid CPU soft lockups"),
> gives:
>
> WARNING: Missing Signed-off-by: line by nominal patch author
> 'John David Anglin <dave.anglin at bell.net>'
>
> The signoff line was:
> "Signed-off-by: Dave Anglin <dave.anglin at bell.net>"
>
> Clearly the author has signed off but with a slightly different version
> of his name. A more appropriate warning would have been to point out
> at the name mismatch instead.
>
> Introduced three new types of warnings:
>
> 1) Address matches, but names are different.
>    "James Watson <james at gmail.com>", "James <james at gmail.com>"
>
> 2) Name matches, but addresses are different.
>    "James Watson <james at watson.com>", "James Watson <james at gmail.com>"
>
> 3) Name matches, but addresses without mail extensions are same.
>    "James Watson <james at gmail.com>", "James Watson <james+a at gmail.com>"
>
> For the 3rd class, a --strict check message is generated, and for the
> other two, warnings are generated.
>
> Link: https://lore.kernel.org/lkml/7958ded756c895ca614ba900aae7b830a992475e.camel@perches.com/
> Signed-off-by: Dwaipayan Ray <dwaipayanray1 at gmail.com>
> ---
>  scripts/checkpatch.pl | 54 +++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 50 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 31624bbb342e..1380212f1a9d 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2347,6 +2347,7 @@ sub process {
>         my $signoff = 0;
>         my $author = '';
>         my $authorsignoff = 0;
> +       my $author_sob = '';
>         my $is_patch = 0;
>         my $is_binding_patch = -1;
>         my $in_header_lines = $file ? 0 : 1;
> @@ -2674,9 +2675,34 @@ sub process {
>                 if ($line =~ /^\s*signed-off-by:\s*(.*)/i) {
>                         $signoff++;
>                         $in_commit_log = 0;
> -                       if ($author ne '') {
> +                       if ($author ne ''  && $authorsignoff != 1) {
>                                 if (same_email_addresses($1, $author)) {
>                                         $authorsignoff = 1;
> +                               } else {
> +                                       my $ctx = $1;
> +                                       my ($email_name, $email_comment, $email_address, $comment1) = parse_email($ctx);
> +                                       my ($author_name, $author_comment, $author_address, $comment2) = parse_email($author);
> +
> +                                       if ($email_address eq $author_address) {
> +                                               $author_sob = $ctx;
> +                                               $authorsignoff = 2;
> +                                       } elsif ($email_name eq $author_name) {
> +                                               $author_sob = $ctx;
> +                                               $authorsignoff = 3;
> +
> +                                               my $address1 = $email_address;
> +                                               my $address2 = $author_address;
> +
> +                                               if ($address1 =~ /(\S+)\+\S+(\@.*)/) {
> +                                                       $address1 = $1.$2;
> +                                               }
> +                                               if ($address2 =~ /(\S+)\+\S+(\@.*)/) {
> +                                                       $address2 = $1.$2;
> +                                               }
> +                                               if ($address1 eq $address2) {
> +                                                       $authorsignoff = 4;
> +                                               }
> +                                       }
>                                 }
>                         }
>                 }
> @@ -6891,9 +6917,29 @@ sub process {
>                 if ($signoff == 0) {
>                         ERROR("MISSING_SIGN_OFF",
>                               "Missing Signed-off-by: line(s)\n");
> -               } elsif (!$authorsignoff) {
> -                       WARN("NO_AUTHOR_SIGN_OFF",
> -                            "Missing Signed-off-by: line by nominal patch author '$author'\n");
> +               } elsif ($authorsignoff != 1) {
> +                       # authorsignoff values:
> +                       # 0 -> missing sign off
> +                       # 1 -> sign off identical
> +                       # 2 -> addresses match, names different
> +                       # 3 -> names match, addresses different
> +                       # 4 -> names match, addresses excuding mail extensions (subaddresses) match
> +
> +                       my $sob_msg = "'From: $author' != 'Signed-off-by: $author_sob'";
> +
> +                       if ($authorsignoff == 0) {
> +                               WARN("NO_AUTHOR_SIGN_OFF",
> +                                        "Missing Signed-off-by: line by nominal patch author '$author'\n");
> +                       } elsif ($authorsignoff == 2) {
> +                               WARN("NO_AUTHOR_SIGN_OFF",
> +                                        "From:/Signed-off-by: email name mismatch:\n$sob_msg\n");
> +                       } elsif ($authorsignoff == 3) {
> +                               WARN("NO_AUTHOR_SIGN_OFF",
> +                                        "From:/Signed-off-by: email address mismatch:\n$sob_msg\n");
> +                       } elsif ($authorsignoff == 4) {
> +                               CHK("NO_AUTHOR_SIGN_OFF",
> +                                       "From:/Signed-off-by: email extension mismatch:\n$sob_msg\n");
> +                       }
>                 }
>         }
>
> --
> 2.27.0
>

Hi Lukas,
This is the updated patch with some style changes, and
Joe's suggestions.

Please let me know if I am missing something or if it is
ready to be sent back again to Joe and LKML.

Thanks,
Dwaipayan.