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path: root/drivers/of/overlay.c
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-rw-r--r--drivers/of/overlay.c58
1 files changed, 49 insertions, 9 deletions
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index c8f88b0836a3..8af8115bd36e 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -392,14 +392,6 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
* a live devicetree created from Open Firmware.
*
* NOTE_2: Multiple mods of created nodes not supported.
- * If more than one fragment contains a node that does not already exist
- * in the live tree, then for each fragment of_changeset_attach_node()
- * will add a changeset entry to add the node. When the changeset is
- * applied, __of_attach_node() will attach the node twice (once for
- * each fragment). At this point the device tree will be corrupted.
- *
- * TODO: add integrity check to ensure that multiple fragments do not
- * create the same node.
*
* Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
* invalid @overlay.
@@ -517,6 +509,54 @@ static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
}
/**
+ * check_changeset_dup_add_node() - changeset validation: duplicate add node
+ * @ovcs: Overlay changeset
+ *
+ * Check changeset @ovcs->cset for multiple add node entries for the same
+ * node.
+ *
+ * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid overlay in @ovcs->fragments[].
+ */
+static int check_changeset_dup_add_node(struct overlay_changeset *ovcs)
+{
+ struct of_changeset_entry *ce_1, *ce_2;
+ char *fn_1, *fn_2;
+ int name_match;
+
+ list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
+
+ if (ce_1->action == OF_RECONFIG_ATTACH_NODE ||
+ ce_1->action == OF_RECONFIG_DETACH_NODE) {
+
+ ce_2 = ce_1;
+ list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+ if (ce_2->action == OF_RECONFIG_ATTACH_NODE ||
+ ce_2->action == OF_RECONFIG_DETACH_NODE) {
+ /* inexpensive name compare */
+ if (!of_node_cmp(ce_1->np->full_name,
+ ce_2->np->full_name)) {
+ /* expensive full path name compare */
+ fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+ fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+ name_match = !strcmp(fn_1, fn_2);
+ kfree(fn_1);
+ kfree(fn_2);
+ if (name_match) {
+ pr_err("ERROR: multiple overlay fragments add and/or delete node %pOF\n",
+ ce_1->np);
+ return -EINVAL;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
* build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
* @ovcs: Overlay changeset
*
@@ -571,7 +611,7 @@ static int build_changeset(struct overlay_changeset *ovcs)
}
}
- return 0;
+ return check_changeset_dup_add_node(ovcs);
}
/*