Coccinelle: Find nested lock+irqsave functions that use the same flags variables.

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Nicolas Palix <npalix.work@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/coccinelle/locks/flags.cocci

+/// Find nested lock+irqsave functions that use the same flags variables
+///
+// Confidence: High
+// 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 context
+virtual org
+virtual report
+
+@r@
+expression lock1,lock2,flags;
+position p1,p2;
+@@
+
+(
+spin_lock_irqsave@p1(lock1,flags)
+|
+read_lock_irqsave@p1(lock1,flags)
+|
+write_lock_irqsave@p1(lock1,flags)
+)
+... when != flags
+(
+spin_lock_irqsave(lock1,flags)
+|
+read_lock_irqsave(lock1,flags)
+|
+write_lock_irqsave(lock1,flags)
+|
+spin_lock_irqsave@p2(lock2,flags)
+|
+read_lock_irqsave@p2(lock2,flags)
+|
+write_lock_irqsave@p2(lock2,flags)
+)
+
+@d@
+expression f <= r.flags;
+expression lock1,lock2,flags;
+position r.p1, r.p2;
+@@
+
+(
+*spin_lock_irqsave@p1(lock1,flags)
+|
+*read_lock_irqsave@p1(lock1,flags)
+|
+*write_lock_irqsave@p1(lock1,flags)
+)
+... when != f
+(
+*spin_lock_irqsave@p2(lock2,flags)
+|
+*read_lock_irqsave@p2(lock2,flags)
+|
+*write_lock_irqsave@p2(lock2,flags)
+)
+
+// ----------------------------------------------------------------------
+
+@script:python depends on d && org@
+p1 << r.p1;
+p2 << r.p2;
+@@
+
+cocci.print_main("original lock",p1)
+cocci.print_secs("nested lock+irqsave that reuses flags",p2)
+
+@script:python depends on d && report@
+p1 << r.p1;
+p2 << r.p2;
+@@
+
+msg="ERROR: nested lock+irqsave that reuses flags from %s." % (p1[0].line)
+coccilib.report.print_report(p2[0], msg)