checkpatch: warn on logging continuations

pr_cont(...) and printk(KERN_CONT ...) uses should be discouraged
as their output can be interleaved by multiple logging processes.

Link: http://lkml.kernel.org/r/7100ba00098694ec81471a299583ed068975fd05.1483465888.git.joe@perches.com
Signed-off-by: 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 4f53093..3df2cec 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5287,6 +5287,12 @@ sub process {
                        }
                }
 
+# check for logging continuations
+               if ($line =~ /\bprintk\s*\(\s*KERN_CONT\b|\bpr_cont\s*\(/) {
+                       WARN("LOGGING_CONTINUATION",
+                            "Avoid logging continuation uses where feasible\n" . $herecurr);
+               }
+
 # check for mask then right shift without a parentheses
                if ($^V && $^V ge 5.10.0 &&
                    $line =~ /$LvalOrFunc\s*\&\s*($LvalOrFunc)\s*>>/ &&