checkpatch: avoid COMMIT_LOG_LONG_LINE warning for signature tags

Currently checkpatch warns us for long lines in commits even for signature
tag lines.

Generally these lines exceed the 75-character limit because of:

 1) long names and long email address

 2) some comments on scoped review and acknowledgement, i.e., for a
    dedicated pointer on what was reported by the identity in
    'Reported-by'

 3) some additional comments on CC: stable@vger.org tags

Exclude signature tag lines from this class of warning.

There were 1896 COMMIT_LOG_LONG_LINE warnings in v5.6..v5.8 before this
patch application and 1879 afterwards.

A quick manual check found all the dropped warnings related to signature
tags.

Link: https://lkml.kernel.org/r/20201116083754.10629-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 041b82f..176ea2c 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2952,8 +2952,8 @@ sub process {
                                        # file delta changes
                      $line =~ /^\s*(?:[\w\.\-]+\/)++[\w\.\-]+:/ ||
                                        # filename then :
-                     $line =~ /^\s*(?:Fixes:|Link:)/i ||
-                                       # A Fixes: or Link: line
+                     $line =~ /^\s*(?:Fixes:|Link:|$signature_tags)/i ||
+                                       # A Fixes: or Link: line or signature tag line
                      $commit_log_possible_stack_dump)) {
                        WARN("COMMIT_LOG_LONG_LINE",
                             "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);