[RFC PATCH v3 1/4] base/node.c: initialize the accessor list before registering

[Gregory Price]

The current code registers the node as available in the node array
before initializing the accessor list.  This makes it so that
anything which might access the accessor list as a result of
allocations will cause an undefined memory access.

In one example, an extension to access hmat data during interleave
caused this undefined access as a result of a bulk allocation
that occurs during node initialization but before the accessor
list is initialized.

Initialize the accessor list before making the node generally
available to the global system.

Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx>
---
 drivers/base/node.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 493d533f8375..4d588f4658c8 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -868,11 +868,15 @@ int __register_one_node(int nid)
 {
 	int error;
 	int cpu;
+	struct node *node;
 
-	node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
-	if (!node_devices[nid])
+	node = kzalloc(sizeof(struct node), GFP_KERNEL);
+	if (!node)
 		return -ENOMEM;
 
+	INIT_LIST_HEAD(&node->access_list);
+	node_devices[nid] = node;
+
 	error = register_node(node_devices[nid], nid);
 
 	/* link cpu under this node */
@@ -881,7 +885,6 @@ int __register_one_node(int nid)
 			register_cpu_under_node(cpu, nid);
 	}
 
-	INIT_LIST_HEAD(&node_devices[nid]->access_list);
 	node_init_caches(nid);
 
 	return error;
-- 
2.39.1