of_node_put is needed before discarding a value received from
of_find_node_by_name, eg in error handling code or when the device
node is no longer used.
The semantic match that catches the bug is as follows:
(http://www.emn.fr/x-info/coccinelle/)
n@p1 = of_find_node_by_name(...)
...
if (!n) S
... when != of_node_put(n)
when != n1 = f(n,...)
when != E = n
when any
when strict
(
return \(0\|<+...n...+>\|ptr\);
|
return@p2 ...;
|
of_node_put(n);
|
n1 = f(n,...)
|
E = n
)