list_entry, which is an alias for container_of, cannot return NULL, as
there is no way to add a NULL value to a doubly linked list.
A simplified version of the semantic match that findds this problem is as
follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r@
expression x,E;
statement S1,S2;
position p,p1;
@@
*x = list_entry@p(...)
... when != x = E
*if@p1 (x == NULL) S1 else S2
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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