[PATCH 1/9] checkpatch: add checks for in_atomic()

[Andy Whitcroft <apw@shadowen.org>]

in_atomic() is not for driver use so report any such use as an ERROR.
Also in_atomic() is often used to determine if we may sleep, but it is
not reliable in this use model therefore strongly discourage its use.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
---
 scripts/checkpatch.pl |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e30bac1..dbbf96f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2466,6 +2466,15 @@ sub process {
 				last;
 			}
 		}
+
+# whine mightly about in_atomic
+		if ($line =~ /\bin_atomic\s*\(/) {
+			if ($realfile =~ m@^drivers/@) {
+				ERROR("do not use in_atomic in drivers\n" . $herecurr);
+			} else {
+				WARN("use of in_atomic() is incorrect outside core kernel code\n" . $herecurr);
+			}
+		}
 	}
 
 	# If we have no input at all, then there is nothing to report on
-- 
1.6.0.2.711.gf1ba4