This has quite a lot of false positives. For example in drivers/firewire/nosy.c at the return 0 just above the label fail_free_irq in the function add_card. Return 0 usually indicates success, and the allocated data is usually saved somwhere before the success exit. In nosy.c, the allocated data is stored in a field of the lynx structure, and the lynx structure is then stored in card_list, via a call to list_add_tail. Maybe it would be sufficient not to mark a return with p2 when the return does return 0. You would thus have: ( if (id == NULL) { ... } | return 0; | *return@p2 ...; ) You might want to limit id to be a "local idexpression" instead of an arbitrary expression. If there is x->y = fn(...), x may be a parameter, or may be a variable that is stored or freed in some other way, hiding the call to pci_free_consistent. Also, you don't need the <... ...> around the rule. There is also a typo in your first keyword. Anyway, you can make those changes and look at the result, and see what the rate of false positives seems to be. It would be good to put a confidence level in your semantic patch as well. You can see examples in the Linux coccinelle directory. julia On Tue, 30 Apr 2013, strnape1@xxxxxxxxxxx wrote: > Created coccinelle script for reporting missing pci_free_consistent() calls. > > Signed-off-by: Petr Strnad <strnape1@xxxxxxxxxxx> > --- > diff --git a/scripts/coccinelle/free/pci_free_consistent.cocci > b/scripts/coccinelle/free/pci_free_consistent.cocci > new file mode 100644 > index 0000000..1196485 > --- /dev/null > +++ b/scripts/coccinelle/free/pci_free_consistent.cocci > @@ -0,0 +1,32 @@ > +/// Find missing pci_free_consistent for every pci_alloc_consistent. > +/// > +// Copyright: (C) 2013 Petr Strnad. GPLv2. > +// URL: http://coccinelle.lip6.fr/ > +// Keywords: pci_free_consisten, pci_alloc_consistent > +// Options: --no-includes --include-headers > + > +virtual report > + > +@search@ > +expression id,x,y,z; > +position p1,p2; > +@@ > + > +<... > +id = pci_alloc_consistent@p1(x,y,z) > +... when != pci_free_consistent(x,y,id,z) > + when forall > +( > +if (id == NULL) { ... } > +| > +*return@p2 ...; > +) > +...> > + > +@script:python depends on report@ > +p1 << search.p1; > +p2 << search.p2; > +@@ > + > +msg = "ERROR: missing pci_free_consistent; pci_alloc_consistent on line %s > and return without freeing on line %s" % (p1[0].line,p2[0].line) > +coccilib.report.print_report(p2[0],msg) > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html