Author: Julia Lawall <julia@diku.dk> The test on map4 should be a test on map6. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @@ expression *x; identifier f; constant char *C; @@ x = \(kmalloc\|kcalloc\|kzalloc\)(…); … when != x == NULL when != x != NULL when != (x || …) ( …