checkpatch: check for __smp outside barrier.h

Introduction of __smp barriers cleans up a bunch of duplicate code, but it gives people an additional handle onto a "new" set of barriers - just because they're prefixed with __* unfortunately doesn't stop anyone from using it (as happened with other arch stuff before.) Add a checkpatch test so it will trigger a warning. Reported-by: Russell King <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Acked-by: Julian Calaby <[email protected]> Acked-by: Joe Perches <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]>
anatol · Jan 12, 2016 · f4073b0 · f4073b0
1 parent 402c255
commit f4073b0
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
@@ -5143,6 +5143,16 @@ sub process {
 			}
 		}
 
+		my $underscore_smp_barriers = qr{__smp_(?:$barrier_stems)}x;
+
+		if ($realfile !~ m@^include/asm-generic/@ &&
+		    $realfile !~ m@/barrier\.h$@ &&
+		    $line =~ m/\b(?:$underscore_smp_barriers)\s*\(/ &&
+		    $line !~ m/^.\s*\#\s*define\s+(?:$underscore_smp_barriers)\s*\(/) {
+			WARN("MEMORY_BARRIER",
+			     "__smp memory barriers shouldn't be used outside barrier.h and asm-generic\n" . $herecurr);
+		}
+
 # check for waitqueue_active without a comment.
 		if ($line =~ /\bwaitqueue_active\s*\(/) {
 			if (!ctx_has_comment($first_line, $linenr)) {