@@ -325,6 +325,7 @@ static int overlay_get_nodes_info(const void *fdto, char **nodes_full_path)
int node_name_len;
unsigned int target_path_len = strlen(target_path);
unsigned int node_full_name_len;
+ unsigned int extra_len;
node_name = fdt_get_name(fdto, subnode, &node_name_len);
@@ -332,10 +333,13 @@ static int overlay_get_nodes_info(const void *fdto, char **nodes_full_path)
return node_name_len;
/*
- * Magic number 2 is for adding '/' and '\0'. This is done to keep
- * the node_full_path in the correct full node name format.
+ * Extra length is for adding '/' and '\0' unless the target path is
+ * root in which case we don't add the '/' at the beginning. This is
+ * done to keep the node_full_path in the correct full node name
+ * format.
*/
- node_full_name_len = target_path_len + node_name_len + 2;
+ extra_len = (target_path_len > 1) + 1;
+ node_full_name_len = target_path_len + node_name_len + extra_len;
nodes_full_path[node_num] = xmalloc_bytes(node_full_name_len);
@@ -344,9 +348,11 @@ static int overlay_get_nodes_info(const void *fdto, char **nodes_full_path)
memcpy(nodes_full_path[node_num], target_path, target_path_len);
- nodes_full_path[node_num][target_path_len] = '/';
+ /* Target is not root - add separator */
+ if ( target_path_len > 1 )
+ nodes_full_path[node_num][target_path_len++] = '/';
- memcpy(nodes_full_path[node_num] + target_path_len + 1,
+ memcpy(nodes_full_path[node_num] + target_path_len,
node_name, node_name_len);
nodes_full_path[node_num][node_full_name_len - 1] = '\0';
Even though in most cases device nodes are not present directly under the root node, it's a perfectly valid configuration (e.g. Qemu virt machine dtb). At the moment, we don't handle this scenario which leads to unconditional addition of extra leading '/' in the node full path. This makes the attempt to add such device overlay to fail. Signed-off-by: Michal Orzel <michal.orzel@amd.com> --- xen/common/dt-overlay.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)