[PATCH] Add null pointer check to of_find_property

[Timur Tabi]

Update function of_find_property() to return NULL if the device_node passed
to it is also NULL.  Otherwise, passing NULL will cause a null pointer
dereference.

Signed-off-by: Timur Tabi <timur at freescale.com>
---

This patch allows callers to do this:

np = of_find_compatible_node(...);
prop = of_get_property(np);
if (!prop)
     goto error;

Today, we need a np==NULL check between the two of_ calls.  Some callers may
not care whether the node is missing or the property is missing.

 drivers/of/base.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 9bd7c4a..23ffb7c 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -65,6 +65,9 @@ struct property *of_find_property(const struct device_node *np,
 {
 	struct property *pp;
 
+	if (!np)
+		return NULL;
+
 	read_lock(&devtree_lock);
 	for (pp = np->properties; pp != 0; pp = pp->next) {
 		if (of_prop_cmp(pp->name, name) == 0) {
-- 
1.5.5