checkpatch: validate MODULE_LICENSE content

There is a well defined list of expected values for MODULE_LICENSE so warn
the user upon usage of unknown values.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: Joe Perches <joe@perches.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 dfeb553..4cf4473 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5626,6 +5626,24 @@ sub process {
                                }
                        }
                }
+
+# validate content of MODULE_LICENSE against list from include/linux/module.h
+               if ($line =~ /\bMODULE_LICENSE\s*\(\s*($String)\s*\)/) {
+                       my $extracted_string = get_quoted_string($line, $rawline);
+                       my $valid_licenses = qr{
+                                               GPL|
+                                               GPL\ v2|
+                                               GPL\ and\ additional\ rights|
+                                               Dual\ BSD/GPL|
+                                               Dual\ MIT/GPL|
+                                               Dual\ MPL/GPL|
+                                               Proprietary
+                                       }x;
+                       if ($extracted_string !~ /^"(?:$valid_licenses)"$/x) {
+                               WARN("MODULE_LICENSE",
+                                    "unknown module license " . $extracted_string . "\n" . $herecurr);
+                       }
+               }
        }
 
        # If we have no input at all, then there is nothing to report on