On 07/02/2013 08:35 PM, NISHIMOTO Hiroki wrote:
on master/next branch,
of_find_matching_node_and_match macro can make infinite loop.
Hiroki,
I confirmed that infinite loop but there are more functions
that suffer from this infinite loop.
This is because, of_tree_for_each_node traverse all nodes each time.
But a callee of of_find_matching_node_and_match,
such as for_each_matching_node, calls it by changing "from" arg.
So if "matches" have two or more nodes, previously matched node can be re-matched.
Below change can fix the issue.
@Sascha: please confirm the below. It is what I understand from your
last comments about OF API improvements.
Actually, root_node is only the list head for the currently active
device tree. There can be other device trees you want to use the
of_for_each_.. on, so we need to find another way to check for the
list head of the tree the "from" node is in.
From what I can see from linux linked lists API, there is no safe
way to determine the start of a linked list without knowing what
has been the first list node in the first place.
Sascha knows barebox struct device_node lists for sure, maybe he
can point us to the best way to solve this?
Sebastian
Or is it better to port node->allnext from linux kernel?
Signed-off-by: NISHIMOTO Hiroki<hiroki.nishimoto.if@xxxxxxxxx>
---
drivers/of/base.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 63ff647..36774de 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -36,6 +36,9 @@
#define of_tree_for_each_node(node, root) \
list_for_each_entry(node,&root->list, list)
+#define of_get_next_node(np) \
+ list_first_entry(&np->list, typeof(*np), list)
+
/**
* struct alias_prop - Alias property in 'aliases' node
* @link: List node to link the structure in aliases_lookup list
@@ -444,17 +447,20 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from,
if (match)
*match = NULL;
- if (!from)
- from = root_node;
+ np = from ? of_get_next_node(from) : root_node;
- of_tree_for_each_node(np, from) {
+ if (from != NULL&& np == root_node)
+ return NULL;
+
+ do {
const struct of_device_id *m = of_match_node(matches, np);
if (m) {
if (match)
*match = m;
return np;
}
- }
+ np = of_get_next_node(np);
+ } while (np != root_node);
return NULL;
}
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