1 files changed, 92 insertions, 0 deletions
diff --git a/scripts/coccinelle/locks/double_lock.cocci b/scripts/coccinelle/locks/double_lock.cocci
new file mode 100644
index 000000000..002752f97
--- /dev/null
+++ b/scripts/coccinelle/locks/double_lock.cocci
@@ -0,0 +1,92 @@
+/// Find double locks.  False positives may occur when some paths cannot
+/// occur at execution, due to the values of variables, and when there is
+/// an intervening function call that releases the lock.
+///
+// Confidence: Moderate
+// Copyright: (C) 2010 Nicolas Palix, DIKU.  GPLv2.
+// Copyright: (C) 2010 Julia Lawall, DIKU.  GPLv2.
+// Copyright: (C) 2010 Gilles Muller, INRIA/LiP6.  GPLv2.
+// URL: http://coccinelle.lip6.fr/
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual org
+virtual report
+
+@locked@
+position p1;
+expression E1;
+position p;
+@@
+
+(
+mutex_lock@p1
+|
+mutex_trylock@p1
+|
+spin_lock@p1
+|
+spin_trylock@p1
+|
+read_lock@p1
+|
+read_trylock@p1
+|
+write_lock@p1
+|
+write_trylock@p1
+) (E1@p,...);
+
+@balanced@
+position p1 != locked.p1;
+position locked.p;
+identifier lock,unlock;
+expression x <= locked.E1;
+expression E,locked.E1;
+expression E2;
+@@
+
+if (E) {
+ <+... when != E1
+ lock(E1@p,...)
+ ...+>
+}
+... when != E1
+    when != \(x = E2\|&x\)
+    when forall
+if (E) {
+ <+... when != E1
+ unlock@p1(E1,...)
+ ...+>
+}
+
+@r depends on !balanced exists@
+expression x <= locked.E1;
+expression locked.E1;
+expression E2;
+identifier lock;
+position locked.p,p1,p2;
+@@
+
+lock@p1 (E1@p,...);
+... when != E1
+    when != \(x = E2\|&x\)
+lock@p2 (E1,...);
+
+@script:python depends on org@
+p1 << r.p1;
+p2 << r.p2;
+lock << r.lock;
+@@
+
+cocci.print_main(lock,p1)
+cocci.print_secs("second lock",p2)
+
+@script:python depends on report@
+p1 << r.p1;
+p2 << r.p2;
+lock << r.lock;
+@@
+
+msg = "second lock on line %s" % (p2[0].line)
+coccilib.report.print_report(p1[0],msg)