[PATCH 4/4] of/irq: add missing of_node_put

From: Julia Lawall
Date: Thu Oct 22 2015 - 05:14:48 EST


for_each_matching_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression n;
expression e;
identifier l;
@@

for_each_matching_node(n,...) {
...
(
of_node_put(n);
|
e = n
|
+ of_node_put(n);
? goto l;
)
...
}
...
l: ... when != n
// </smpl>

Besides the issue found by the semantic patch, this code also stores the
device_node value in a list, which requires an of_node_get, and then cleans
up the list on exit from the function, which requires an of_node_put.

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
drivers/of/irq.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 171798d..902b89b 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -501,10 +501,12 @@ void __init of_irq_init(const struct of_device_id *matches)
* pointer, interrupt-parent device_node etc.
*/
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
- if (WARN_ON(!desc))
+ if (WARN_ON(!desc)) {
+ of_node_put(np);
goto err;
+ }

- desc->dev = np;
+ desc->dev = of_node_get(np);
desc->interrupt_parent = of_irq_find_parent(np);
if (desc->interrupt_parent == np)
desc->interrupt_parent = NULL;
@@ -575,6 +577,7 @@ void __init of_irq_init(const struct of_device_id *matches)
err:
list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
list_del(&desc->list);
+ of_node_put(desc->dev);
kfree(desc);
}
}

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