From: Andi Kleen <ak@linux.intel.com>
Date: Thu, 3 May 2012 05:44:11 +0000 (+1000)
Subject: checkpatch: check for spin_is_locked()
X-Git-Tag: next-20120503~2^2~136
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b88cda3ecb0897035dcbcb3833c4a41f74522a28;p=karo-tx-linux.git

checkpatch: check for spin_is_locked()

spin_is_locked() is usually misued. In checkpatch.pl:

- warn when it is used at all

- error out when it is asserted on free, because that's usually broken
  (e.g.  doesn't work on on uni processor builds).  Recommend
  lockdep_assert_held() instead.

[joe@perches.com: some improvements]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index faea0ec612bf..b8ed516b34ec 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3452,6 +3452,20 @@ sub process {
 			}
 		}
 
+# spin_is_locked is usually misused. warn about it.
+		if ($line =~ /\bspin_is_locked\s*\(/) {
+			# BUG_ON/WARN_ON(!spin_is_locked() is generally a bug
+			if ($line =~ /(BUG_ON|WARN_ON|ASSERT)\s*\(!spin_is_locked/) {
+				ERROR("SPIN_IS_LOCKED",
+				     "Use lockdep_assert_held() instead of asserts on !spin_is_locked\n"
+				      . $herecurr);
+			} else {
+				WARN("SPIN_IS_LOCKED",
+			     "spin_is_locked is usually misused. See Documentation/spinlocks.txt\n"
+					. $herecurr)
+			}
+		}
+
 # check for lockdep_set_novalidate_class
 		if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||
 		    $line =~ /__lockdep_no_validate__\s*\)/ ) {