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authorJohan Hovold <johan@kernel.org>2018-08-27 10:21:45 +0200
committerRob Herring <robh@kernel.org>2018-08-29 08:06:46 -0500
commit36156f9241cb0f9e37d998052873ca7501ad4b36 (patch)
tree203d1e52a9e5a942a2b99ae0ecb984fa87453df8 /include/linux
parent5b394b2ddf0347bef56e50c69a58773c94343ff3 (diff)
downloadlinux-rt-36156f9241cb0f9e37d998052873ca7501ad4b36.tar.gz
of: add helper to lookup compatible child node
Add of_get_compatible_child() helper that can be used to lookup compatible child nodes. Several drivers currently use of_find_compatible_node() to lookup child nodes while failing to notice that the of_find_ functions search the entire tree depth-first (from a given start node) and therefore can match unrelated nodes. The fact that these functions also drop a reference to the node they start searching from (e.g. the parent node) is typically also overlooked, something which can lead to use-after-free bugs. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/of.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/of.h b/include/linux/of.h
index 4d25e4f952d9..b99a1a8c2952 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -290,6 +290,8 @@ extern struct device_node *of_get_next_child(const struct device_node *node,
extern struct device_node *of_get_next_available_child(
const struct device_node *node, struct device_node *prev);
+extern struct device_node *of_get_compatible_child(const struct device_node *parent,
+ const char *compatible);
extern struct device_node *of_get_child_by_name(const struct device_node *node,
const char *name);
@@ -632,6 +634,12 @@ static inline bool of_have_populated_dt(void)
return false;
}
+static inline struct device_node *of_get_compatible_child(const struct device_node *parent,
+ const char *compatible)
+{
+ return NULL;
+}
+
static inline struct device_node *of_get_child_by_name(
const struct device_node *node,
const char *name)