[PATCH 1/3] timers: Add rb_init_node() to allow for stack allocated rb nodes

[John Stultz]

In cases where a timerqueue_node or some structure that utilizes
a timerqueue_node is allocated on the stack, gcc would give warnings
caused by the timerqueue_init()'s calling RB_CLEAR_NODE, which
self-references the nodes uninitialized data.

The solution is to create an rb_init_node() function that zeros
the rb_node structure out and then calls RB_CLEAR_NODE(), and
then call the new init function from timerqueue_init().

CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: patches@xxxxxxxxxx
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
 include/linux/rbtree.h     |    8 ++++++++
 include/linux/timerqueue.h |    2 +-
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 7066acb..033b507 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -136,6 +136,14 @@ static inline void rb_set_color(struct rb_node *rb, int color)
 #define RB_EMPTY_NODE(node)	(rb_parent(node) == node)
 #define RB_CLEAR_NODE(node)	(rb_set_parent(node, node))
 
+static inline void rb_init_node(struct rb_node *rb)
+{
+	rb->rb_parent_color = 0;
+	rb->rb_right = NULL;
+	rb->rb_left = NULL;
+	RB_CLEAR_NODE(rb);
+}
+
 extern void rb_insert_color(struct rb_node *, struct rb_root *);
 extern void rb_erase(struct rb_node *, struct rb_root *);
 
diff --git a/include/linux/timerqueue.h b/include/linux/timerqueue.h
index d24aaba..98b0a6c 100644
--- a/include/linux/timerqueue.h
+++ b/include/linux/timerqueue.h
@@ -39,7 +39,7 @@ struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
 
 static inline void timerqueue_init(struct timerqueue_node *node)
 {
-	RB_CLEAR_NODE(&node->node);
+	rb_init_node(&node->node);
 }
 
 static inline void timerqueue_init_head(struct timerqueue_head *head)
-- 
1.7.3.2.146.gca209

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