[RFC PATCH] OF: fix of_find_node_by_path() assumption that of_allnodes is root

[Frank Rowand <frowand.list@gmail.com>]

From: Frank Rowand <frank.rowand@sonymobile.com>

Pantelis Antoniou reports that of_find_node_by_path() is borked because
of_allnodes is not guaranteed to contain the root of the tree after using
any of the dynamic update functions because some other nodes ends up as
of_allnodes.

Fixes: c22e650e66b8 of: Make of_find_node_by_path() handle /aliases

Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com>
---


Pantelis,

Can you test whether the problem you reported in irc?

This patch has not been tested, not even compile tested.


 drivers/of/base.c |    8 	6 +	2 -	0 !
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: b/drivers/of/base.c
===================================================================
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1948,6 +1948,9 @@ int of_reconfig_notify(unsigned long act
 
 /**
  * of_attach_node - Plug a device node into the tree and global list.
+ *
+ * Put the device node after of_allnodes in the global list so that
+ * of_allnodes remains the root.
  */
 int of_attach_node(struct device_node *np)
 {
@@ -1958,11 +1961,12 @@ int of_attach_node(struct device_node *n
 	if (rc)
 		return rc;
 
+	BUG_ON(!of_allnodes);
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	np->sibling = np->parent->child;
-	np->allnext = of_allnodes;
+	np->allnext = of_allnodes->allnext;
 	np->parent->child = np;
-	of_allnodes = np;
+	of_allnodes->allnext = np;
 	of_node_clear_flag(np, OF_DETACHED);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);